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International audience; The energy loss of protons, in the range between 1.6 MeV and 6 MeV, in a 3.5 μm thick single-crystal diamond membrane was determined by the transmission method. The thickness and surface uniformity of the target were checked by two independent techniques before ion beam irradiation. The stopping power of diamond was evaluated from these data and compared with SRIM Monte Carlo simulations of ion transport, showing a slight overestimate of the simulated values over the experimental stopping powers. In addition, a comparison was made with theoretical calculations based on the Bethe formula to extract the mean ionization potential, I, of carbon atoms in diamond. The obtained I-value was 81 ± 4 eV. A discussion and comparison with results of other authors is given.

The Sodium-iodide with Active Background REjection (SABRE) experiment is planned to consist of 50 kg of ultrapure thallium doped sodium iodide (NaI(Tl)) scintillator contained within a liquid scintillation (LS) veto detector of approximately 10,500 kg (2.6 m in diameter and height), and will search for dark matter interactions in the inner NaI(Tl) detectors. Linear alkylbenzene (LAB) has been chosen as the LS solvent for the SABRE South experiment and the LS veto detector design includes numerous materials that will be in contact with the liquid scintillator over the uninterrupted multi-year (3 to 5 years) operation. The SABRE specifications require LAB of high chemical purity and low radioactive background to maximise the light yield and optical attenuation length, thus giving optimum energy resolution and detection efficiency of the LS veto detector. In this study, the service lifetime of Viton O-rings, required as seals in the detector, were examined under different ageing temperatures while exposed to LAB scintillator and to air. Compression set experiments, solvent swelling, Young’s modulus measurements, scanning electron microscopy (SEM) and attenuated total reflection- Fourier transform infrared spectroscopy (ATR-FTIR) all being used. LAB was purified with a custom-made vacuum distillation process to reduce chemical and radioactive impurities. The effects of tentatively identified impurities on the LAB scintillation light yield were investigated with a custom-made scintillation light yield setup. In addition, the optimal LAB LS preparation techniques with higher scintillation light yield were explored. The chemical and physical suitability of selected materials used in detector components (~ 28 types) when in contact with the LAB liquid scintillator (~ 2 types) under normal operation were also investigated based on relative light yield and optical absorbance over the time period of ~ 560 days. In conclusion, the study provides much useful information in regard to LAB purification, scintillation light yield maximization by 13%, optical light attenuation length improvements (~ 4 m), impurity identification and compatibility tests of components with optimization of energy resolution and detection sensitivity for a large-scale veto liquid scintillation detector. This work could aid design and fabrication of other types of scintillation detector for nuclear science, medical and particle physics applications.

A novel approach for rapid 89, 90Sr determination in seawater samples is developed. For the first time in the radioanalytical application, the features of the synthetic zeolite Z4A and a highly selective material for Sr separation were synergically employed. Seawater composition significantly reduces Sr yield on highly selective solid-phase extraction materials, making the preconcentration step essentially important but laborious and timeconsuming. To address this issue, the ability of zeolite 4A to concentrate the Sr from the seawater matrix was employed. With the proposed method, two important goals were achieved: (i) simple preconcentration of Sr that can be conducted directly at the sampling site, enabling a rapid procedure for 89, 90Sr determination in emergencies, and (ii) high and stable Sr recoveries (89 ± 4%) necessary for lowering detection limits. Strontium is effectively separated from 1 L of seawater in less than 1.5 h, which is especially important in emergency situations, such as the Fukushima Daiichi Nuclear Power Plant accident. Minimum detectable activities achieved for 89Sr:90Sr activity ratio ~10:1 were 0.74 Bq/L for 89Sr, and 1.47 Bq/L for 90Sr, detected by Cherenkov counting, 36–38 h after separation, and 30 min counting time.

In this study we analyzed the dose response of natLiF:Mg,Cu,P (MCP-N) detectors in two different TLD readers (Harshaw 5500 and Toledo 654 Vinten) at 7 dose levels, ranging from 0.5 mGy to 5 Gy, for different heating rates (2 °C/s, 5 °C/s, 10 °C/s and 15 °C/s) and using 2 protocols: one without pre-heating and a maximum reading temperature of 255 °C and one including external pre-heating before the readout for 20 min at 100 °C and maximum temperature of 230 °C. The results show a supralinear behavior for Harshaw 5500 reader at high doses which is more pronounced for the fast heating rates. For the 15 °C/s heating rate, the supralinearity starts at 2 Gy for the protocol without pre-heating and at 0.5 Gy for the protocol with pre-heating reaching up to linearity indices of respectively 1.42 ± 0.05 and 1.67 ± 0.05 at 5 Gy. The 2 °C/s heating rate does not show supralinearity up till 5 Gy. The Toledo 654 Vinten reader shows no supralinear behavior. The shape of the glow curves is different between readers and reading protocols while the glow curve peaks shift towards higher temperatures for increasing heating rates due to thermal lag effects. This study demonstrates the different behaviors of TLD readers, for different heating rates and two types of protocols with an important concern for a Harshaw reader.

When a radiological and nuclear (R/N) emergency occurs, the categorization of individuals into those who are unaffected and those requiring medical intervention is a high priority. At times, a professional dosimeter is not available and therefore some common belongings may be used as fortuitous dosimeters. The preparation of these objects for the measurement should be such as to give the most accurate and precise results. This paper focused on the Photo-Stimulated Luminescence (PSL) response of salty crackers confronts the problem of sample preparation (mass, grain size), dose response and signal stability. The dose response was determined for doses up to 5 Gy, which allowed the calculation of the limit of detection. Additionally, the signal stability was investigated for samples irradiated with 0.3 and 3 Gy. The observed decrease of the signal does not prevent the detection in the dose range typical for R/N emergency. The main dosimetric characteristics were investigated by using two different models of PSL readers equipped with single (infrared) or double (infrared, blue light) stimulation. The results indicated that the limit of detection can be improved by applying blue light stimulation. Moreover, strong correlation of the measurements performed in the two different instruments, as well as the rapidity of the analysis and the simplicity of the operations, suggest that this method can be suitable for a rapid radiation triage of a large number of civilians in a mass casualty event. The study was simultaneously conducted by two laboratories (Ruder Bošković Institute, RBI, Croatia and Istituto Superiore di Sanità, ISS, Italy) involved in the BioPhyMeTRE project (grant No. G5684) supported by NATO Science for Peace and Security Programme.

The 14C method can be successfully applied for determination of biogenic component in any type of samples and different measurement techniques can be applied. For a special case of liquid fuels, direct method by measurement 14C activity of liquid fuel samples in liquid scintillation counter (the „direct LSC method“) has been recognized as a powerful and reliable method of determination of biogenic component (fbio). In the Ruđer Bošković Institute (RBI) Radiocarbon Laboratory we have been implemented our own data evaluation method based on the quench properties of fuels (SQP(E) – Standard Quench Parameter in LSC Quantulus 1220) [1]. We participated in the international intercomparison study ILC/2018 Content of biocomponent in liquid fuel samples, which was organized in 2018 by the Institute of Ceramics and Building Materials (Opole, Poland). Here we compare our fbio results with the fbio-ILC official results and report optimization of the direct LSC method. Laboratories obtained seven samples of diesel type of fuel having different colors. Consequently, the samples resulted in different SQP(E) values when the direct LSC methods was applied. Three samples were analyzed by the AMS (Accelerator Mass Spectrometry) method. The LSC results were quantitatively acceptable for four samples with SQP(E) values above 700 (Figure 1), which was taken as the lowest limit of quantitative fbio determination. Qualitatively acceptable, but quantitatively unacceptable results, were obtained for two samples with the SQP(E) values between 600 and 700, that was defined as the region of limited applicability. For one of the samples the quenching was high, SQP(E) < 600, and the direct LSC method did not give any result. However, all AMS results were acceptable (Figure 1) since AMS does not depend on the sample color. The obtained results have been used for further validation and optimization of the direct LSC method. We defined the limits of applicability of the direct-LSC method for both quantitative (SQP(E) > 700) and qualitative results (600 < SQP(E) < 700). A sample of used edible oil (UEO, laboratory code Z-7226) was used to test these limits. The UEO was a dark sample giving the SQP(E) value of 546 (below the limit of qualitative applicability), while the AMS revealed fbio = 97.9 ± 0.3 % (and δ13C = -29.6 ‰). We mixed the UEO with the (fossil) petrol (benzene) sample (laboratory code Z-6266), which we used as the background sample (fbio = 0 %) with good quenching properties (SQP(E) = 864). We monitored changes in the SQP(E) and fbio values in UEO-petrol mixtures in the concentration range 0 – 100 %. The total mixture volume was 10 mL and 10 mL of Ultima Gold F scintillation cocktail was added, i.e., the measurement was performed in the same manner as all other organic liquid samples [1]. Mixtures of 10 % and 20 % of UEO gave SQP(E) values of 773 and 759, and the fbio was calculated to be 104.0 ± 1.2 % and 101.1 ± 1.3 %, respectively, confirming the quantitative region of SQP(E) values above 700. Mixtures containing 30 – 50 % of UEO resulted in SQP(E) values between 671 and 609, while the fbio values were about 150 %, confirming qualitatively acceptable results. Mixtures containing more than 60 % of UEO had SQP values below 600 and fbio values had a large spread. The presented results showed that the direct LSC method with an evaluation method developed in our laboratory was suitable for determination of the fbio in liquid fuels, providing the correctly defined limits of applicability for highly quenched samples. The RBI Laboratory has a possibility of applying also AMS 14C measurement technique that can satisfactorily determine fbio also in highly quenched samples, but the AMS technique is more complicated and more expensive.

The use of patient contact-shielding has become a topic of intensive scientific debate. While it has been common practice during the last decades, some studies have questioned the efficiency of using such shielding while others have highlighted the inconsistencies in its application. The objective of this work is to review current recommendations and legislative documents on the use of out-of-field shielding in X-ray imaging, including those from national authorities and from international and national organisations and professional bodies. The review, performed within the framework of the activities of EURADOS Working Group 12, covers available recommendations on use of contact shielding in adult, pregnant and paediatric patients in general radiography, fluoroscopy, computed tomography, mammography and dental radiology. It includes a comprehensive search of 83 documents from 32 countries and 6 international organisations over the last 39 years. In general, using shielding is recommended only under two conditions: if it does not compromise the diagnostic task and the performance of the procedure and/or if it reassures the patient and comforters that they are appropriately protected against potentially harmful effects of radiation. There are very few specific regulatory requirements to use shielding in a particular imaging modality, although they may consider use of shielding either as part of good radiological practice or as requirements for availability of protective or ancillary tools, without further specification of their use. There is a wide variety of positions among documents that recommend out-of-field shielding, those that do not recommend it and those that are not specific. Therefore, evidence-based consensus is still needed to ensure best and consistent practice.

The lowest possible energy of proton scanning beam in cyclotron proton therapy facilities is typically between 60 and 100 MeV. Treatment of superficial lesions requires a pre-absorber to deliver doses to shallower volumes. In most of the cases a range shifter (RS) is used, but as an alternative solution, a patient-specific 3D printed proton beam compensator (BC) can be applied. A BC enables further reduction of the air gap and consequently reduction of beam scattering. Such pre-absorbers are additional sources of secondary radiation. The aim of this work was the comparison of RS and BC with respect to out-of-field doses for a simulated treatment of superficial paediatric brain tumours. EURADOS WG9 performed comparative measurements of scattered radiation in the Proteus C-235 IBA facility (Cyclotron Centre Bronowice at the Institute of Nuclear Physics, CCB IFJ PAN, Kraków, Poland) using two anthropomorphic phantoms—5 and 10 yr old—for a superficial target in the brain. Both active detectors located inside the therapy room, and passive detectors placed inside the phantoms were used. Measurements were supplemented by Monte Carlo simulation of the radiation transport. For the applied 3D printed pre-absorbers, out-of-field doses from both secondary photons and neutrons were lower than for RS. Measurements with active environmental dosimeters at five positions inside the therapy room indicated that the RS/BC ratio of the out-of-field dose was also higher than one, with a maximum of 1.7. Photon dose inside phantoms leads to higher out-of-field doses for RS than BC to almost all organs with the highest RS/BC ratio 12.5 and 13.2 for breasts for 5 and 10 yr old phantoms, respectively. For organs closest to the isocentre such as the thyroid, neutron doses were lower for BC than RS due to neutrons moderation in the target volume, but for more distant organs like bladder—conversely—lower doses for RS than BC were observed. The use of 3D printed BC as the pre-absorber placed in the near vicinity of patient in the treatment of superficial tumours does not result in the increase of secondary radiation compared to the treatment with RS, placed far from the patient.

Hrvatsko društvo za zaštitu od zračenja (HDZZ) bira vodstvo Društva svake 4 godine. Izborna skupština Zbora članova HDZZ-a se tradicionalno održava tijekom simpozija. Međutim, simpozij koji je trebao biti organiziran tijekom 2021. godine, odgođen je predvidivo za 2023. godinu zbog pandemije COVID-19. Dosadašnjem vodstvu mandat je produljen za šest mjeseci do listopada 2021., te je Izborna skupština Zbora članova HDZZ-a organizirana 6. listopada 2021. na Institutu Ruđer Bošković u Zagrebu. Sudjelovala su 33 člana Društva, što je bilo dovoljno da prema Statutu HDZZ-a izborna skupština bude pravovaljana. Predsjedavajući Zbora Željko Grahek podnio je izvještaj o radu Zbora u proteklom mandatu (2017. – 2021.) naglasivši da tijekom 2020. i 2021. i nije bilo posebne aktivnosti Zbora upravo zbog pandemijskih uvjeta. Predsjednica Društva Ines Krajcar Bronić podnijela je izvještaj o radu Upravnog odbora u proteklom mandatu. Znatno više aktivnosti, uključujući i organizaciju 12. simpozija, provedeno je u prvoj polovini mandata. Sekcija mladih organizirala je Prvi i Drugi skup sekcije mladih HDZZ-a, 2018. i 2020. godine, a tijekom 12. simpozija organizirano je neformalno druženje mladih HDZZ-a sa sudionicima simpozija. Raspisani su natječaji za najbolji rad mladih znanstvenika i stručnjaka iz područja zaštite od zračenja ili znanosti o zračenju. Na natječaje raspisane 2017. i 2021. nije bilo prijavljenih kandidata, tako da HDZZ nije imao predstavnika u natjecanju mladih na europskim kongresima IRPA 2018. i 2022. godine. Na natječaju iz 2019. godine nagradu je osvojio Marko Gerić te je predstavljao HDZZ na 15. Kongresu IRPA koji se održao online u siječnju 2021. Društvo je redovno sudjelovalo sa svojim predstavnikom na sastancima europskih društava za zaštitu od zračenja. U listopadu 2019. godine organiziran je skup u Zagrebu, na kojem je sudjelovalo 25 predstavnika 15 europskih društava. Napomenimo da je to bio posljednji takav skup uživo, a nakon toga su skupovi 2020. i 2021. održani online. U proteklom razdoblju provedena je revizija članstva te je smanjen broj članova na trenutnih 121. Društvo je imalo i plodnu suradnju s društvima u regiji, a posebno treba naglasiti suradnju sa Društvom za zaštitu od zračenja Srbije i Crne Gore (DZZSCG) i Slovenskim društvom za zaštitu od zračenja. Predstavnici tih društava redovno su sudjelovali na simpozijima HDZZ-a, a predstavnici HDZZ-a na simpozijima koje je organiziralo DZZSCG. Rizničarka Jasminka Senčar je u svom financijskom izvještaju naglasila da je Društvo i dalje likvidno i da redovno ispunjava svoje financijske obveze. U ime Nadzornog odbora izvještaj je podnijela Gorana Karanović naglasivši da je Nadzorni odbor imao uvid u rad Upravnog odbora tijekom cijelog mandata i da nisu bile uočene nepravilnosti u radu. Nakon što su svi izvještaji prihvaćeni, članovi vodstva Društva u razdoblju 2017. – 2021. dobili su razrješnice i pristupilo se utvrđivanju kandidata za funkcije u Društvu i članstvo u Upravnom i Nadzornom odboru. Nakon potvrđivanja izborne liste pristupilo se glasovanju i Izborno povjerenstvo je nakon prebrojavanja glasova izvijestilo o rezultatima. Za predsjednicu HDZZ-a izabrana je Ivana Coha, a za dopredsjednika Branko Petrinec. Za tajnicu je izabrana Renata Ban te za rizničarku Iva Franulović. Za predsjedavajućeg Zbora ponovno je izabran Željko Grahek. Izabrani članovi Upravnog odbora su: Tomislav Bituh, Hrvoje Hršak, Željka Knežević Medija, Marija Majer, Luka Pavelić, Marina Poje Sovilj i Jelena Popić. Za članove Nadzornog odbora izabrani su: Marko Gerić, Gorana Karanović i Ines Krajcar Bronić. Prije završetka Zbora, bivša predsjednica dala je nekoliko prijedloga za rad Upravnog odbora u novom mandatu, a novoizabrana predsjednica pismom je zahvalila na povjerenju.

Due to the need for harmonization of passive dosimetry and the requirements of the international standards in the area of environmental monitoring in radiation protection, multiple types of various passive dosimetry systems based on different ionizing radiation detection mechanisms were subjected to extensive performance testing. In the scope of the EMPIR project 16ENV04 Preparedness, the performance of 12 passive dosimetry systems was examined in radiation fields of different photon energies, angles of incidence and ambient dose equivalent rates in order to estimate their performance in the almost omni-directionally and energetically broad radiation field of the natural environment. The use of different detectors, holders, calibrations, measurement procedures and uncertainties, leads to differences in the measured data. Prior investigations and harmonization of passive dosimetry systems are necessary to achieve reliable and comparable dose measurements in Europe.

A rapid, automated separation procedure was developed for radioactive strontium and lead isotope determination. This system includes a portable automated system for the preconcentration and sequential elution of targeting isotopes with an Na2H2EDTA solution from solid phase extraction materials, AnaLig®Sr-01 and SuperLig®620, provided by IBC Technologies. Strontium and lead were separated from the majority of matrix constituents to obtain pure fractions of Pb and Sr prior to radiometric detection. In case of barium presence, it can also be fully isolated and completely separated from Sr. The automated procedure can be successfully used for preconcentration and separation from high as well as low radioactivity samples. With only a 1 mL column filled with SuperLig®620, it is possible to isolate Sr and Pb with 100% recovery from 1 L to 2 L of sample at a flow rate of up to 10 mL min−1 within several hours. 89,90Sr isotopes can be further determined by Cherenkov counting, while 210Pb isotopes can be determined by either gamma spectrometry or liquid scintillation counter. The method was tested and validated using certified standard materials and proficiency test samples. The synergy of automated separation and detection procedures enables the determination of the low level activity of 90Sr and 210Pb in a short time with detection limits of 20 mBq L−1 for both isotopes. The proposed method enables lower labour costs, minimal size of apparatuses and columns, low separation time, and reduced secondary waste production. The automated procedure may be easily implemented in laboratories worldwide and can also be used at sampling sites.

Radiocarbon (14C) is both the cosmogenic and anthropogenic isotope. Anthropogenic sources of 14C are atmospheric nuclear bomb tests, various nuclear facilities and fossil fuel combustion. The bomb-produced 14C has been globally distributed across the planet and can be considered as a new- natural level (clean-air sites). Combustion of fossil fuels that do not contain 14C causes increase of atmospheric CO2 concentration and depletion of local 14C levels, while nuclear sources increase local or regional atmospheric 14C level. Naturally produced CO2 and that formed by fossil fuel combustion are characterized by different content of the stable isotope13C (delta13C values) in addition to their different 14C content. Therefore, the carbon isotope composition (13C and 14C) of the atmospheric CO2 can indicate sources of CO2 at each location, if it is far from nuclear facilities. 14C activity in the atmospheric CO2 in Zagreb, Croatia, has been monitored since 1985. Recently we have been monitoring carbon isotope composition at several other locations in Croatia (city of Rijeka and rural areas around Zagreb and Rijeka) with the aim of determining influence of fossil fuel combustion on atmospheric 14C activity and 13C values at different locations with the hypothesis that the urban sites are affected by fossil fuel uses. Rural locations show higher 14C activities (by about 2 pMC – percent Modern Carbon) and higher delta13C values than the urban sites in accordance with the hypothesis. The difference is larger during winter (about 2.4 pMC) due to more intense fossil fuel combustion in the cities.

The European Radiation Dosimetry Group (EURADOS) is a network of organizations and scientists promoting research and development in the dosimetry of ionizing radiation, contributing to harmonization in dosimetry practice across Europe, and offering education and training in areas relevant for dosimetry. As a registered non-profit association under German law, EURADOS is currently running eight active working groups (WGs): WG2 on “Harmonization of Individual Monitoring”, WG3 on “Environmental Dosimetry”, WG6 on “Computational Dosimetry”, WG7 on “Internal Dosimetry”, WG9 on “Dosimetry in Radiotherapy”, WG10 on “Retrospective Dosimetry”, WG11 on “Dosimetry in High-Energy Radiation Fields”, and WG12 on “Dosimetry in Medical Imaging”. This paper presents recent scientific results obtained within these working groups, and additionally highlights the role of EURADOS as an organization which contributes to the development of a systematic strategy of radiation protection research in Europe.

International audience; In order to address the recent concerns over a possible increasing in brain tumour mortality among interventional radiologists and cardiologist, this work evaluated the exposure conditions of the operator’s brain during interventional procedures using Monte Carlo simulations with anthropomorphic phantoms. The absorbed doses in several predefined segments of the operator’s brain were estimated in a typical interventional radiology irradiation scenario. The doses were normalized to the KAP values simulated for ten X-ray beam qualities and four projections (PA, RAO 25°, LAO 25° and CRA 25°). For the interventional radiology scenario, because of the position of the operator, no difference was found in the exposure between the left and right regions of the brain for the first operator, while for the second operator standing at a farer distance from the tube, the exposure of the left part of the brain is up to two times higher than that of the right part. The results are in agreement with dose measurements reported in the literature. The conversion factors, obtained as the absorbed dose per KAP, can be used to obtain a first estimate of the exposure of the brain of the operators during interventional procedures

Medical staff in interventional procedures are among the professionals with the highest occupational doses. Appropriate dosimetric follow up is very important, so that the doses can be kept as low as possible. Active personal dosemeters (APDs) can help in optimizing the exposure during the interventional procedures. However, there can be problems when using APDs during interventional procedures, due to the specific energy and angular distribution of the radiation field, and because of the pulsed nature of the radiation. Many parameters influence the occupational exposure and the scattered radiation around the patient. These include, among others, the type of interventional procedure, personal habits and working technques, protection tools used and X-ray field characteristics. In this paper, we describe the results of an experiment of EURADOS WG12. We compare the results from 3 types of APDs with a passive personal dosimetry system while being used in real clinical environment by the interventional staff. The results show that there is a large spread in the ratios of the passive and active devices. Not all results can be explained by laboratory experiments, showing that there are many parameters that influence the response of these devices.

Our current understanding of the importance of surface-active substances (SAS) on atmospheric aerosol cloud-forming efficiency is limited, as explicit data on the content of size-resolved ambient aerosol SAS, which are responsible for lowering the surface tension (σ) of activating droplets, are not available. We report on the first data comprising seasonal variability of size-segregated SAS concentrations in ambient aerosol particulate matter (PM). To assess the impact of SAS distribution within PM on cloud droplet activation and growth, a concept of surfactant activity was adopted and a parametrization developed ; i.e., surfactant activity factor (SAF) was defined, which allowed translation of experimental data for use in cloud parcel modeling. The results show that SAS-induced σ depression during cloud activation may affect droplet number ( Nd) as much as a 2-fold increase in particle number, whereas by considering also the size distribution of particulate SAS, Nd may increase for another 10%. This study underscores the importance of size-resolved SAS perspective on cloud activation, as data typically obtained from aqueous extracts of PM2.5 and PM10 may result in misleading conclusions about droplet growth due to large mass fractions of supermicron particles with SAS deficit and little or no influence on CCN and Nd.

The purpose of this study was to measure out-of-field organ doses in two anthropomorphic child phantoms for the treatment of large brain arteriovenous malformations (AVMs) using hypofractionated gamma knife (GK) radiosurgery and to compare these with an alternative treatment using intensity-modulated radiation therapy (IMRT). Target volume was identical in size and shape in all cases. Radiophotoluminescent (RPL), thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters were used for out-of-field dosimetry during GK treatment and a good agreement within 1-2% between results was shown. In addition, the use of multiple dosimetry systems strengthens the reliability of the findings. The number of GK isocentres was confirmed to be important for the magnitude of out-of-field doses. Measured GK doses for the same distance from the target, when expressed per target dose and isocentre, were comparable in both phantoms. GK out-of-field doses averaged for both phantoms were evaluated to be 120 mGy/Gy for eyes then sharply reduced to 20 mGy/Gy for mandible and slowly reduced up to 0.8 mGy/Gy for testes. Taking into account the fractionation regimen used to treat AVM patients, the total treatment organ doses to the out-of-field organs were calculated and compared with IMRT. The eyes were better spared with GK whilst for more distant organs doses were up to a factor of 2.8 and 4 times larger for GK compared to IMRT in 5-year and 10-year old phantoms, respectively. Presented out-of-field dose values are specific for the investigated AVM case, phantoms and treatment plans used for GK and IMRT, but provide useful information about out-of-field dose levels and emphasise their importance.

The purpose of this study was to measure out-of-field organ doses in clinical conditions in anthropomorphic paediatric phantoms which received a simulated treatment of a brain tumour with intensity modulated radiotherapy (IMRT) and 3D conformal radiotherapy (3D CRT). Organ doses measured with radiophotoluminescent and thermoluminescent dosemeters were on average 1.6 and 3.0 times higher for the 5 year-old than for the 10 year-old phantom for IMRT and 3D CRT, respectively. A larger 5-year to 10-year organ dose ratio for 3D CRT can be explained because the use of a mechanical wedge for the 5 year-old 3D CRT phantom treatment increased out-of-field doses. Due to different configurations of the radiation fields, for both phantoms, the IMRT technique resulted in a higher non-target brain dose and higher eye doses but lower thyroid doses compared to 3D CRT. For 3D CRT (which used a noncoplanar field configuration), eye doses were 3-6% and for IMRT (which used a coplanar field configuration) 27-30% of the treatment dose, respectively. For thyroid and more distant organs, doses were less than 1% of the treatment dose. Comparison of measured doses and doses calculated by the treatment planning system (TPS) showed that the TPS underestimated out-of-field doses both for IMRT and 3D CRT.

Zbornik radova Dvanaestog simpozija Hrvatskog društva za zaštitu od zračenja (12HDZZ) sadrži 64 rada predstavljena na 12. simpoziju u Varaždinu, 10. - 12. travnja 2019. Radovi su podijeljeni u sekcije: Opće teme u zaštiti od zračenja, Izazovi u zaštiti od zračenja (ujedno glavna tema simpozija), Dozimetrija zračenja, Biološki učinci zračenja, Izloženost stanovništva zračenju, Zaštita od zračenja u medicini, Radioekologija, Radon, Instrumentacija i mjerne tehnike, Neionizirajuća zračenja.

Za određivanje koncentracije aktivnosti 3H u vodama metodom tekućinske scintilacijske spektrometrije korištenjem tekućinskog scintilacijskog brojača (LSC, engl. Liquid scintillation counter) koriste se scintilacijski kokteli koji često sadržavaju spojeve štetne za okoliš (npr., NPE - nonylphenolethoxylates). Njihova upotreba će uskoro biti zabranjena (2021. godine) u Europskoj Uniji [1], a zamijenit će ih biorazgradivi scintilacijski kokteli. Poželjno je da novi kokteli imaju barem jednaka svojstva kao trenutno najbolji kokteli u upotrebi. U ovom radu prikazuje se usporedbu mjernih karakteristika koktela Ultima Gold LLT, GoldStar LT2 te ProSafe LT+ iz dvije vrsta ambalaže. Sa svakim koktelom je pripremljeno nekoliko uzoraka različitih koncentracije aktivnosti 3H u rasponu od 0 Bq/L do 600 Bq/L. Usporedili smo i nekoliko vrsta kiveta raznih proizvođača. Scintilacijski koktel UltimaGold LLT (PerkinElmer) pokazao je u svim ispitivanjima najbolje karakteristike. Scintilacijski koktel GoldStar LT2 (Meridian Technologies) iz prve pošiljke pokazao je slične karakteristike kao i UGLLT, ali koktel iz druge pošiljke (GS/2) pokazuje lošija svojstva, najvjerojatnije zbog promjene sastava koktela. Koktel GS sadrži štetne spojeve NPE, koji će uskoro biti zabranjeni za upotrebu, te će se sastav ovog koktela sigurno mijenjati. ProSafe LT+ (Meridian Technologies) koktel je također dobar scintilacijski koktel, iako daje nešto višu granicu detekcije DL i nižu efikasnost nego UGLLT. Pri tome treba paziti da je koktel dostavljen u staklenoj ambalaži. ProSafe LT+ iz aluminijske ambalaže nije pogodan za primjenu jer ima znatno slabije karakteristike, koje se s vremenom pogoršavaju. Sve tri vrste ispitivanih PE kiveta (PerkinElmer, Zinsser Analytic i Meridian Technologies) pokazuju jednaka svojstva ako se koristi isti scintilacijski koktel, pa pri odabiru kiveta treba voditi računa i o cijeni proizvoda. For determination of tritium (3H) activity concentration by liquid scintillation spectrometry method, various scintillation cocktails are mixed with water samples to enable counting tritium decays in liquid scintillation counter. Some scintillation cocktails contain dangerous chemicals, such as NPE (nonylphenolethoxylates) that is harmful for biota in aqueous systems. Use of NPE will be soon forbidden and scintillation cocktails should be biodegradable. At the same time, it is required that the new biodegradable scintillation cocktails retain at least the same counting properties as the best cocktails today. We performed several tests with different scintillation cocktails: Ultima Gold LLT, (UGLLT, by PerkinElmer, “Safer” coctails that contains DIPN - Diisopropyl naphthalene isomers that may be harmful for aquatic biota, suitable for measurement of 3H activity concentration in various types of water, having low background and efficiency of 30 %), Gold Star LT2 (GS, by Meridian Biotechnologies, contains NPE and is considered as a Substances of Very High Concern, harmful for biota in water systems), and ProSafe LT+ (PS, by Meridian Biotechnologies, biodegradable) from two different containers (aluminium and glass). For each test we prepared several samples having 3H activity concentration from 0 Bq/L (tritium-free water, i.e., background) to 600 Bq/L. The ratio sample:cocktail was always 8 mL:12 mL, measurements were performed by LSC Quantulus 1220 for 300 minutes (6 cycles of 50 minutes), and for evaluation of measured spectra the optimized tritium window, channelin the range 25 – 253, was used. The following parameters were compared: background count rate B, calibration factor CF, Standard Quench Parameter SQP(E), detection limit DL, figure of merit FOM and measurement efficiency E. Scintillation cocktail UltimaGold LLT showed in all test best characteristics. Scintillation cocktail GoldStar LT2 (Meridian Technologies) from the first batch showed similarly good performances, while the second batch (GS/2) showed worse performances, most probably due to some changes in the chemical composition. ProSafe LT+ (Meridian Technologies) is also a good scintillation cocktail, although having slightly higher detection limit and lower efficiency. However, this cocktail should be packed in glass bottles. An attempt to use aluminium container was not successful and PS from the aluminium container showed the worst performances among the tested scintillation cocktails. Three types of high density polyethylene vials were also tested (PerkinElmer, Zinsser Analytic and Meridian Technologies) and all showed the same performances if the same scintillation cocktail was used. Therefore, the choice of vials for routine application would depend also on their cost.

U 2018. godini provedena je međunarodna usporedna studija ILC/2018 „Content of biocomponent in liquid fuel samples“ u organizaciji Institute of Ceramics and Building Materials (Opole, Poljska). Laboratoriji IRB i IJS su službeno poslali svoje rezultate, a laboratorij UNS-a je svoju metodu provjerio neslužbenim sudjelovanjem. U ovom radu usporedit ćemo rezultate laboratorija IRB, IJS i UNS s očekivanim vrijednostima te procijeniti prednosti i nedostatke metoda razvijenih u ovim laboratorijima. Organizator interkomparacije nije dostavio konačne službene rezultate studije do trenutka pisanja ovog rada, tako da ova preliminarna usporedba ne uključuje uobičajene statističke parametre. Iako se u nekim detaljima metode određivanja udjela biogene komponente u tekućim gorivima direktnim mjerenjem u LSC primijenjene na tri institucije međusobno razlikuju, preliminarni rezultati ove interkomparacije pokazuju da su sve tri metode pogodne za tu svrhu, uz poštivanje granica primjenjivosti koje su određene gašenjem zbog obojanih uzoraka. Kod uzorka s najvećim gašenjem, koji je uzrokovao probleme u sva tri laboratorija, pokazala se potreba primjene drugih tehnika u kojima se uzorak kemijski obrađuje, tj. spaljuje (AMS, apsorpcija CO2). Međutim, takvi uzorci su rijetki na tržištu pa se ne treba pribojavati neprimjenjivosti direktnih LSC metoda koje su implementirane u ova tri laboratorija. Laboratoriji koji imaju razvijene neke druge tehnike mjerenja aktivnosti 14C mogu odrediti biogenu komponentu i primjenom tih tehnika, koje su znatno složenije i skuplje. Direct method by measurement 14C activity of liquid fuel samples in liquid scintillation counter (the „direct LSC method“) has been recognized as a powerful and reliable method of determination of biogenic component in liquid fuels (fbio). Laboratories of the Ruđer Bošković Institute (RBI) in Zagreb, Croatia, the Jožef Stefan Institute (JSI) in Ljubljana, Slovenia, and at the Faculty of Science of the University of Novi Sad (UNS), in Novi Sad, Serbia, have been implemented and optimized slightly different methods. The 3 laboratories participated in the international intercomparison study ILC/2018 „Content of biocomponent in liquid fuel samples“, which was organized in 2018 by the Institute of Ceramics and Building Materials (Opole, Poland). Here we present the fbio results obtained by these 3 laboratories and compare the results with the expected fbio-exp values since at the moment of preparing this work the official results of the study have not been available. Laboratories obtained 7 samples of different colours and only the basic composition (diesel type of fuel) was known. The results for samples with the SQP(E) values well above the limits of applicability of the direct LSC method were satisfying in all three laboratories. Qualitatively acceptable, but quantitatively unacceptable results, were obtained for a sample in the SQP(E) region of limited applicability. For one of the samples the quenching was high, and the quenching parameter SQP(E) was below the limits of applicability of the direct LSC method in all 3 laboratories. The obtained results will be used for further validation and optimization of the developed direct LSC methods, especially for reconsidering the uncertainty budget and the background level. Although there are some differences in details of the applied direct LSC methods in the laboratories of RBI, JSI and UNS, the presented intercomparison results show that all the methods are suitable for determination of the fbio in liquid fuels, providing the correctly defined limits of applicability for highly quenched samples. Laboratories that have possibility of applying a different 14C measurement technique can satisfactorily determine fbio also in highly quenched samples, but these techniques are more complicated and more expensive.

Zbog međudjelovanja primarnog radioterapijskog snopa s materijom, nastanak sekundarnog zračenja te ozračivanje tkiva izvan ciljnog volumena je neizbježno. Iako se radi o malim dozama, nekoliko redova veličine manjim nego u ciljnom volumenu, one mogu povećati vjerojatnost za nastanak sekundarnih karcinoma. Da bi se moglo procijeniti rizik te usporediti različite radioterapijske tehnike, potrebni su pouzdani dozimetrijski podaci. U okviru radne grupe 9 (Radiation dosimetry in radiotherapy) EURADOS-a (European Radiation Dosimetry Group, http://www.eurados.org/ ) napravljen je niz eksperimenata, počevši od jednostavnih laboratorijskih uvjeta i vodenih fantoma do realnih kliničkih simulacija tretmana antropomorfnih fantoma s ciljem: 1. testiranja postojećih dozimetrijskih sustava za dozimetriju sekundarnog zračenja u fotonskoj radioterapiji, 2. usporedbe izmjerenih doza s vrijednostima koje predviđaju sustavi za planiranje i analitički modeli te 3. usporedbe različitih radioterapijskih tehnika koje se mogu primijeniti za isti klinički slučaj. U radu je biti prikazan pregled dozimetrijskih istraživanja i glavnih rezultata radne grupe 9 vezanih sekundarno zračenje u fotonskoj radioterapiji.

Izneseni su rezultati arheoloških istraživanja provedenih uz utvrdu Sokol u Konavlima 2012. i 2013. godine, te rezultati antropološke analize i analize radioaktivnim ugljikom 14C. Lokalitet Sokol ima dugi kontinuitet u naseljavanju počevši od prapovijesti do ranog novog vijeka. Istraživanje prostora uz utvrdu podijeljeno je na četiri velike sonde od kojih je najkompleksnija ona uz njezinu južnu stranu. Višefazno groblje smješteno je uz južnu i istočnu stranu utvrde s manjim brojem grobova uz njezinu sjevernu stranu. U svim sondama pronađeni su duboki slojevi formirani potresima koji su bili česti na dubrovačkom području. Ti slojevi su osim grobova i ostataka arhitekture sadržavali i kamene gromade koje su se urušile s utvrde tijekom potresa te mnoštvo raznovrsnih nalaza širokog vremenskog raspona, od prapovijesti do novog vijeka. Utvrda je napuštena 1672. godine. Antropološkom analizom obuhvaćeni su svi pronađeni kosturni ostaci iz bolje i slabije sačuvanih grobnih cjelina, čime su definirani ostaci 92 osobe, od čega 57 odraslih i 35 djece. Pregledom osteološkog materijala također su dokumentirane patološke promjene nastale za života osoba. Određivanje starosti kosturnih ostataka provedeno je metodom 14C. Određena je starost kostura u rasponu od 5. do 19. stoljeća. Istom metodom provedeno je i mjerenje starosti karboniziranih badema koji su datirani u starije željezno doba (750. – 400. cal BC)., This paper presents the results of the archaeological excavations conducted next to Fort Sokol in Konavle in 2012 and 2013, as well as the results of the anthropological analysis and radiocarbon (14C) dating. The site of Sokol has a long occupation continuity starting from prehistory until the Early Modern Period. The excavation of the area adjoining the fort was divided into four big probes, the one next to its southern side being the most complex. Multiphase cemetery is located along the southern and eastern side of the fort, with a smaller number of graves along its northern side. All probes revealed deep layers formed in earthquakes that were common in the Dubrovnik region. In addition to graves and architecture remains, these layers contained stone boulders that fell off the fort in earthquakes and an abundance of diverse finds dating to a broad time span, from prehistory to the Modern Period. The fort was deserted in 1672. Anthropological analysis encompassed all recovered skeletal remains from preserved grave units regardless of the state of preservation, whereby the remains of 92 individuals were identified, of which 57 adults and 35 children. Analysis of osteological material also documented pathological changes developed antemortem. Radiocarbon (14C) dating was applied on skeletal remains resulting in chronological range from the 5th to the 19th century. The same method was used for dating carbonized almonds that were dated to the Early Iron Age (750 – 400 cal BC).

Cilj istraživanja je značajno smanjiti dozu zračenja na dojku prilikom CT snimanja abdomena (kad dojka nije u primarnom području snimanja) korištenjem posebno skrojenog zaštitnog pokrivala. Materijali i metode: Koristili smo posebno skrojenu zaštitnu pregaču na način da obuhvaća cijelo prsište cirkumferentno. Doze zračenja mjerene su direktnom dozimetrijom sa TL dozimetrima na ukupno 28 pacijenata. Doze zračenja izračunate su mjerenjem u kontrolnim grupama (bez pokrivala i sa samo anteriornom zaštitom). Mjerenje je učinjeno kod redovno naručenih pacijenata za abdominalne CT preglede, uz informirani pristanak za uključenje u istraživanje. Uključili smo sve pacijente ženskog spola bez anatomskih anomalija dojki. Očekivani rezultati: U skladu sa literaturnim podacima očekujemo da će izmjerena apsorbirana doza na dojkama i izračunata efektivna glandularna doza na dojkama biti značajna iako dojke nisu u primarnom snopu zračenja. Izmjerena prosječna redukcija doze sa prednjom zaštitom u našoj studiji je 42%, a uz primjenu cirkumferentne zaštite 57% u odnosu na dozu izmjerenu u pacijenata bez primjene zaštite.

Background and Objectives Out-of-field doses, caused by stray radiation, may increase secondary cancer risk for radiotherapy patients. Children are of particular concern due to high radiosensitivity and long-life expectancy. Therefore out-of-field dose measurement of different radiotherapy techniques is extremely important for risk assessment and radiation protection. Craniospinal (CS) irradiation increased tremendously survival rate for the patients with medulloblastoma which is the most common malignant brain tumour in children. This study, carried out within EURADOS Working Group 9 (Radiation Dosimetry in Radiotherapy), evaluates and compares out-of-field doses for paediatric medulloblastoma treatment using photon and proton CS irradiation. Materials and Methods Photon and proton irradiations were performed on Siemens Artiste linac at UCHCSM UHT (Zagreb) using 3D conformal radiotherapy (3D-CRT) and at CCB (IFJ, Krakow) using pencil beam scanning (PBS) technique (IBA Proteus 235 gantry) respectively. CS treatments of the same target volume (whole brain and spinal cord irradiation + 0.5 cm margin) in CIRS anthropomorphic phantoms representing 5-year and 10-year old children were performed. For 3D-CRT, 6 MV photon beams were used for brain and 6 MV + 18 MV for spinal cord irradiation. The stray doses were measured with three types of thermoluminescent detectors (MTS-7: 7LiF (Mg, Ti) and MTS-6: 6LiF (Mg, Ti) for 10-year ; MCP-n: LiF(Mg, Cu, P) for 5-year) and radiophotoluminescent (RPL) detector type GD-352M. The neutron contribution during PBS was determined with poly-allyl-diglycol-carbonate (PADC) nuclear track detector in 10-year phantom. For 3D-CRT dosimeters were placed in all out-of-field organs, while for PBS dosimeters were put in the selected radiosensitive organs close to spinal cord. Results and Discussion For out-of-field doses during 3D-CRT CS radiotherapy excellent agreement between RPL and MCP-n detectors was confirmed: the RPL/MCP ratio for the same point in 5-year phantom was on average 1.02  0.15. Due to the use of 18 MV photon beams, higher doses were measured with MTS-6 than with MTS-7: the highest gamma-equivalent neutron dose per target dose in 10-year phantom were 293 and 181 mGy/Gy for esophagus and TL/spine respectively. Mean organ doses for both phantoms were comparable with exception of pancreas, stomach and four organs (uterus, adrenals, mandible, testes) with a factor 3.5, 2 and 1.5 higher values for 5-year phantom. This finding is expected due to the closer proximity of organs to the central spine axis in the 5-year phantom. Comparison of stray radiation doses for proton and photon radiotherapy for 10-year phantom is shown in Figure 1. For points in the selected organs shown in Figure 1, gamma doses (RPL) are 2-3 orders of magnitude lower for PBS in comparison to 3D-CRT (MTS-7). For PBS, measured neutron dose equivalents (PADC) are a factor of 5 higher than gamma doses (RPL). In other points (closer to the central spinal axis) of the selected organs (including lungs, thyroid, esophagus), PADC were over-irradiated while measured gamma doses showed a factor 2 to 2000 lower values in comparison to 3D-CRT. Conclusion For measured points CS treatment with protons showed lower out-of-field doses for paediatric patients in comparison to photons.

Some challenges in radiation protection from the point of view of a small radiation protection society are presented, although some of them are not specific for the small societies. Future cooperation among regional radiation protection societies should be improved by organizing a joint conference. Participation in IRPA activities improves the visibility of small societies, but is associated with high financial costs. Challenges in radiation protection in medicine, in radioecology, as well as in method and instrumentation development are also discussed. Special focus is put on young generation in the field of radiation protection and radiation science. The challenges discussed here are certainly far from forming a complete list, however, they indicate that the radiation protection is a vivid area where young generation can find its professional accomplishment.

U radu je razvijena metoda brzog, pouzdanog i jednostavnog istovremenog određivanja 89, 90Sr na koloni u kompleksnim uzorcima iz okoliša, s granicom detekcije koja zadovoljava najstrože propise. U cilju smanjenja udjela ljudskog rada, trajanja analize i proizvodnje otpada razvijen je automatizirani sustav vezanja 89, 90Sr na stroncij specifičnoj koloni volumena do 1 mL i odjeljivanja od svih interferirajućih elementa sa off line detekcijom Čerenkovljevog zračenja direktno na koloni. Istraživanja usmjerena na karakterizaciju visoko specifičnih smola za izolaciju stroncija iz kompleksnih matica (utemeljenih na principima molekularnog prepoznavanja) pokazala su kako SuperLig 620 ima visok afinitet prema stronciju iz širokog raspona koncentracija dušične kiseline, ali i klorovodične kiseline, visoko je selektivan te ne mijenja svojstva pri različitim ispitanim brzinama protoka od 1 do 10 mL/min. Stoga je korištenjem SuperLig 620 pronađen optimalan postupak koncentriranja i izolacije 89, 90Sr i 90Y iz tekućih i krutih uzoraka te njihovog odjeljivanja od interferirajućih elementa uz visoku učinkovitost izolacije stroncija iz uzoraka različitih sastava (voda, tlo, vegetacija). Primjenom ravnotežno disperzijskog modela kromatografije studirana je osjetljivost kolona punjenih različitim visoko specifičnim smolama na varijacije koncentracije stroncija i prisutnost drugih elementa s ciljem predviđanja maksimalne učinkovitosti izolacije. Rezultati dobiveni razvojem i optimiranjem metode Čerenkovljeve sukcesivne detekcije na koloni pokazali su kako se smanjenjem anizotropnosti Čerenkovljevog zračenja može povećati učinkovitost detekcije. Kolona na kojoj je vezan stroncij prije detekcije stavlja se u scintilacijsku bočicu napunjenu vodom kako bi se povećalo raspršenje proizvedenih fotona i povećala učinkovitost detekcije Čerenkovljevog zračenja. Dodatno, prisutnost nitratnih iona u uzorku odnosno na koloni povećava učinkovitost detekcije brojanjem uzoraka na Tri-Carb instrumentu, korištenjem opcije za niskoaktivne uzorke. Tijekom istraživanja osmišljen je upravljački program pomoću kojeg se vodi automatizirani sustav koji se sastoji od sekvencijskih ventila, peristaltičke pumpe i kolona. Radi proširenja omjera aktivnosti 89Sr/90Sr u kojem je moguće brzo i pouzdano odrediti oba izotopa, razvijena metoda usmjerena je na detekciju izotopa na koloni odmah nakon izolacije i naknadnog eluiranja 90Y pomoću 0, 01 mol/L HNO3 samo nekoliko sati nakon prirasta, a radi dodatnog skraćivanja vremena analize, DGA kolona spojena je u seriju sa SuperLig kolonom, gdje se odmah nakon odjeljivanja, 89Sr odredi na SuperLig koloni, a 90Sr preko 90Y vezanog na DGA kolonu. Na temelju provedenih istraživanja kreiran je automatizirani postupak izolacije koji je u kombinaciji s razvijenom tehnikom detekcije na koloni rezultirao razvojem pouzdane i brze metode određivanja 89, 90Sr koja zahtijeva minimalan ljudski angažman, te bitno skraćuje vrijeme analize (trajanje analize sada najviše ovisi o tehničkim karakteristikama instrumenta). Razvijena metoda testirana je određivanjem oba izotopa u interkomparacijskim uzorcima dobivenih od međunarodnih organizacija (Analytics, ERA, IAEA) te je dokazano kako je primjenjiva za različite vrste uzoraka od niskoaktivnog otpada pa sve do morske vode gdje je moguće odrediti i koncentraciju aktivnosti 90Sr manju od 0, 3 Bq/L. Dodatno, dokazano je da je metodologija primjenjiva i za izolaciju 210Pb, te njegovo gama-spektrometrijsko određivanje u uzorcima vode. Primjenom novorazvijenog minijaturiziranog eksperimentalnog postava i automatiziranog postupka izolacije 89, 90Sr te off line Čerenkovljeve detekcije direktno na koloni bitno je skraćeno vrijeme trajanja analize, uz smanjenje udjela ljudskog rada, potrošnje reagenasa i posljedično proizvedenog otpada.

Cultural heritage objects that are radiation treated in order to stop their biodegradation often contain ornamenting materials that cannot be removed. Radiation may produce unwanted changes to such materials. Nacre is a common ornamenting material so this is an attempt to assess the impact of gamma-radiation on its optical properties. Two types of nacre (yellow and white) were obtained from a museum and subjected to different absorbed doses of Co-60 gamma irradiation under the same conditions. The radiation induced changes of nacres color were investigated with fiber optic reflectance spectroscopy (FORS). Colorimetry in CIE Lab space revealed that in both nacres the lightness shifted to darker grey hues at high doses while the color component's (red, green, yellow and blue) behavior depended on the nacre type. Observable changes occurred at doses much above the dose range needed for radiation treatment of cultural heritage objects that are often ornamented with nacre. In UV–vis reflectance spectra of samples irradiated to high doses carbonate radical anion absorption appeared.

Interventional cardiac procedures may be associated with high patient doses and therefore require special attention to protect the patients from radiation injuries such as skin erythema, cardiovascular tissue reactions or radiation-induced cancer. In this study, patient exposure data is collected from 13 countries (37 clinics and nearly 50 interventional rooms) and for 10 different procedures. Dose data was collected from a total of 14,922 interventional cardiology procedures. Based on these data European diagnostic reference levels (DRL) for air kerma-area product are suggested for coronary angiography (CA, DRL = 35 Gy cm2), percutaneous coronary intervention (PCI, 85 Gy cm2), transcatheter aortic valve implantation (TAVI, 130 Gy cm2), electrophysiological procedures (12 Gy cm2) and pacemaker implantations. Pacemaker implantations were further divided into single-chamber (2.5 Gy cm2) and dual chamber (3.5 Gy cm2) procedures and implantations of cardiac resynchronization therapy pacemaker (18 Gy cm2). Results show that relatively new techniques such as TAVI and treatment of chronic total occlusion (CTO) often produce relatively high doses, and thus emphasises the need for use of an optimization tool such as DRL to assist in reducing patient exposure. The generic DRL presented here facilitate comparison of patient exposure in interventional cardiology. © 2018 Associazione Italiana di Fisica Medica

EURADOS (European Radiation Dosimetry Group) Working Group 12 (dosimetry in medical imaging) established a subtask devoted to the dosimetry of the medical staff employed in interventional radiology practices. As it is widely known, such practices are characterized by high doses, with respect the other medical procedures, both for the patient and the radiologist. For interventional cardiology there are several publications concerning medical staff dosimetry, on the contrary, for interventional radiology, data are more limited. For that reason WG-12 decided to study the irradiation scenario, employing simplified anthropomorphic models (MIRD type) with Monte Carlo simulations, reconstructing some specific interventional radiology practices (PTC and TIPS). In these procedures, where the X-ray C-arm is mainly fixed in PA projection and the beam directed to the patient abdomen, the radiologist is next to the patient right side, in correspondence to the liver region. The usage of the ceiling shielding is not very frequent, due to the difficulties in positioning it between the radiation source (the X-ray and the patient as the scattering source) and the operator. The aim of the simulations program is: to evaluate the dose received by the radiologist, in a region simulating the presence of the dosemeter fixed on the lead apron at the breast level ; to estimate the corresponding effective dose ; to make a sensitivity analysis on different parameters affecting the calculated results (as the reciprocal position between the two operators, the beam quality and the X-ray field dimension). Indeed a particular attention is devoted to the eye lens dosimetry, that has become a “critical issue” for personnel dosimetry, after ICRP has reconsidered the radiation sensitivity of the lens of the eye. In the present work the general scheme, the assumptions and the followed methodology are presented with some very preliminary results of the simulations and the measurements.

Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams (e.g. sharp distal fall off, adjustable range and modulation). In proton therapy, there is the possibility of sparing healthy tissue close to the target volume. This is especially important when tumours are located next to critical organs and while treating cancer in paediatric patients. On the other hand, the interactions of protons with matter result in the production of secondary radiation, mostly neutrons and gamma radiation, which deposit their energy at a distance from the target. The aim of this study was to compare the response of different passive dosimetry systems in mixed radiation field induced by proton pencil beam inside anthropomorphic phantoms representing 5 and 10 years old children. Doses were measured in different organs with thermoluminescent (MTS-7, MTS-6 and MCP-N), radiophotoluminescent (GD-352 M and GD-302M), bubble and poly-allyl-diglycol carbonate (PADC) track detectors. Results show that RPL detectors are the less sensitive for neutrons than LiF TLDs and can be applied for in-phantom dosimetry of gamma component. Neutron doses determined using track detectors, bubble detectors and pairs of MTS-7/MTS-6 are consistent within the uncertainty range. This is the first study dealing with measurements on child anthropomorphic phantoms irradiated by a pencil scanning beam technique.

This paper explores the possibility of a direct measurement of 14C activity concentration in water samples without chemical pretreatment of samples. A method via Liquid Scintillation Counting (LSC) technique has been implemented and optimized. The method assumes mixing of water sample with a scintillation cocktail. Permafluor E+ and Ultima Gold AB cocktails were tested. Polyethylene vials were selected since they induce lower background count rate than glass vials. Measurements were performed on Ultra Low Level LSC Quantulus 1220. Optimization of the method included optimar water:cocktail volume ratio and optimal coounting window selection as well as PAC parameter adjustment, based on the highest FOM value achieved. Quench level parameter has been monitored for all samples while counting. Detection efficiency and detection limit were determined as the main parameters for method's evaluation. The presented method is ultrafast, simple and inexpensive test for the efficient screening of water samples that could be used for 14C monitoring purposes in the case of nuclear emergency. Its application is limited to samples with much higher 14C activities than those of the environmental surface and ground waters.

The feasibility of setting-up generic, hospital-independent dose alert levels to initiate vigilance on possible skin injuries in interventional procedures was studied for three high-dose procedures (chemoembolization (TACE) of the liver, neuro-embolization (NE) and percutaneous coronary intervention (PCI)) in 9 European countries. Gafchromic® films and thermoluminescent dosimeters (TLD) were used to determine the Maximum Skin Dose (MSD). Correlation of the online dose indicators (fluoroscopy time, kerma- or dose-area product (KAP or DAP) and cumulative air kerma at interventional reference point (Ka,r)) with MSD was evaluated and used to establish the alert levels corresponding to a MSD of 2 Gy and 5 Gy. The uncertainties of alert levels in terms of DAP and Ka,r, and uncertainty of MSD were calculated. About 20-30% of all MSD values exceeded 2 Gy while only 2-6% exceeded 5 Gy. The correlations suggest that both DAP and Ka,r can be used as a dose indicator for alert levels (Pearson correlation coefficient p mostly >0.8), while fluoroscopy time is not suitable (p mostly

European Union’s promotion of the use of sustainable and renewable resources requires use of at least 10 % of synthesized biodiesel in liquid fuels by the year 2020. This legislation has stimulated various types of petrodiesel and bio-based component blends production, and development of methods for exact, effective and reliable quantification of biodiesel content. The method for determination of the biogenic fraction in liquid fuels by direct measurement of the 14C activity concentration via liquid scintillation counting (LSC) technique was developed in few laboratories worldwide. It is based on different 14C signatures of the two components: the biogenic component reflects the modern atmospheric 14C activity, and no 14C is present in fossil fuels. The quantity of 14C in the fuel is the criterion for bio-fuel presence. This method is regarded as fast, simple, accurate and sensitive determination procedure for the mass assessment of biogenic fraction in biofuels. Laboratory for low radioactivity at the Department of Physics, University of Novi Sad (UNS), Serbia, and Laboratory for low-level radioactivities of the Ruđer Bošković Institute (RBI) in Zagreb, Croatia have developed two different methods for biogenic fraction determination in liquid fuels [1, 2]. Both laboratories tested the stability of prepared samples by measuring the same samples after some period of time and used the same set of mixtures with the known fractions of the biogenic component, i.e. FAME produced from either sunflower oil or lard fat. The comparison revealed in general good agreement of the results and also indicated some constraints of the methods used, The RBI evaluation technique is limited by the SQP(E) values lower than 600 where the count rates of the biogenic and the fossil samples become indistinguishable. The lower the SQP(E), the larger the relative differences between the measured and the expected biogenic fraction for 600 < SQP(E) < 700. The biogenic fraction can be successfully determined at SQP(E) > 700. The two-step calibration procedure that UNS used implements quench correction and therefore offers more reliable 14C determination in fuels in comparison to one-step calibration method. The application of these calibration curves is limited to samples with chemically identical bio and fossil components. It can be used for precise biogenic fraction determination in examined fuel samples if the components of the fuel mixture are well known in advance. The obtained results showed very important limitation of used methods as the samples have to be analyzed as soon as possible after preparation in order to obtain reliable results.

Self-assembled molecules (SAMs) form layers on copper that have an advantage compared to traditional corrosion inhibitors because of the significant decrease of chemical application. The protective properties of such films can be improved by different procedures of application of the SAM layer. In this work, a SAM layer of elaidic acid, a monounsaturated long-chain fatty acid with trans geometrical configuration, was applied on copper surface. Gamma irradiation was used to improve the protective properties of the SAM layer toward corrosion in 3% NaCl. Influence of gamma irradiation on such layer’s properties was studied by different electrochemical techniques (polarization measurements, EIS), contact angle measurements and FTIR analysis. The results have shown that gamma irradiation at doses 0.5–5 kGy improves the protective properties of the SAM. The surface film became thinner due to stronger adsorption and resulted in better ordering of molecules on the surface of the oxide film although the polymerization involving the participation of oxygen molecules has been initiated by irradiation.

Intenzivna upotreba fosilnih goriva (ugljen, nafta) za proizvodnju energije i za pokretanje prometnih vozila tijekom 20. stoljeća uzrokovala je porast koncentracije CO2 u atmosferi. Upotreba biogenih materijala kao zamjene za fosilna goriva može usporiti porast atmosferske koncentracije CO2. Europska unija poreznom politikom stimulira korištenje biogenih goriva te se javlja potreba razvoja neovisne i pouzdane metode za određivanje udjela biogene komponente u različitim vrstama materijala koji se mogu koristiti kao izvori energije. Jedna od takvih metoda je metoda radioaktivnog ugljika (14C) koja se zasniva na različitoj koncentraciji 14C u biogenim i fosilnim materijalima: biogeni materijali odražavaju koncentraciju aktivnosti 14C u suvremenoj atmosferi i biosferi, dok fosilni materijali ne sadrže 14C. Metoda se može primijeniti na različite materijale (mješoviti komunalni otpad, iskorištene auto-gume, drvena građa, tekuća goriva, proizvodi široke potrošnje, CO2 nastao spaljivanjem otpada, i slično). Ovisno o vrsti materijala, mogu se primijeniti različite tehnike mjerenja. Posebna pozornost posvetit će se tehnici određivanja biogene komponente u tekućim gorivima mjerenjem koncentracije aktivnosti 14C u gorivima pomoću tekućinskog scintilacijskog brojača.

Systematic and continuous monitoring 14C activity in atmospheric CO2 and biological samples in the vicinity of the Krško Nuclear Power Plant (NEK) in Slovenia has been performed since 2006. The aim of the monitoring was to determine 14C distribution in a close vicinity of the power plant and to estimate a possible contribution of NEK to the effective dose to the local population through food chain. This paper describes a model of food origins developed for the purpose of estimating the effective dose from ingestion of 14C via local food. Some other approaches of diet estimation are also discussed. The slightly increased 14C specific activity in plants very close to NEK could not change significantly the effective dose to the local population due to ingestion of 14C when compared to the effective dose from the ingestion of natural 14C. Sustavni monitoring specifične aktivnosti 14C u atmosferskom CO2 i u biološkim uzorcima iz neposredne okolice Nuklearne elektrane Krško (NEK) u Sloveniji provodi se od 2006. godine. Cilj monitoringa je odrediti prostornu raspodjelu specifične aktivnosti 14C u neposrednoj okolici NEK-a, te njenu ovisnost o razdobljima promjene goriva koja se obavlja svakih 18 mjeseci. Na osnovu izmjerenih specifičnih aktivnosti 14C može se procijeniti doprinos NEK-a efektivnoj dozi koju lokalno stanovništvo primi zbog konzumacije (ingestije) hrane porijeklom iz okolice NEK-a. Budući da je ugljik, pa time i 14C, sastavni dio sve hrane, nije potrebno poznavati detaljne prehrambene navike lokalnog stanovništva. Međutim, potrebno je poznavati ili procijeniti udio hrane iz okolice NEK-a u ukupnoj prehrani. U ovom radu opisano je nekoliko scenarija za porijeklo hrane, počevši od vrlo konzervativnog i malo vjerojatnog scenarija konzumacije samo hrane iz neposredne okolice NEK-a do realističnijeg (iako još uvijek konzervativnog) scenarija od 17 % hrane iz okolice NEK-a, a ostalih 83 % s kontrolne točke na kojoj nije opažen utjecaj 14C iz NEK-a. Malo povišenje specifične aktivnosti 14C u biljkama iz neposredne okolice NEK-a, koje je opaženo tijekom monitoringa, ne utječe značajno na procjenu efektivne doze zbog ingestije 14C, jer je razlika u odnosu na efektivnu dozu zbog ingestije "prirodnog" 14C usporediva ili manja od prirodnih varijacija.

European Union’s promotion of the use of sustainable and renewable resources requires use of at least 10 % of synthesized biodiesel in liquid fuels by the year 2020. This legislation has stimulated various types of petrodiesel and bio-based component blends production, and development of methods for exact, effective and reliable quantification of biodiesel content. The method for determination of the biogenic fraction in liquid fuels by direct measurement of the 14C activity concentration via liquid scintillation counting (LSC) technique was developed in few laboratories worldwide. It is based on different 14C signatures of the two components: the biogenic component reflects the modern atmospheric 14C activity, while no 14C is present in fossil fuels. The quantity of 14C in the fuel is the criterion for bio-fuel presence. A great variety of biogenic matrices in fuels results in a wide range of quenching properties of different fuel mixtures. The laboratories participating in this intercomparison study developed two different calibration techniques. The Ruđer Bošković Institute data evaluation method is based on calibration curves for purely biogenic and purely fossil liquids, and does not depend on the exact chemical composition of the organic liquid. The limits of the method are defined by the SQP of app. 690 below which the count rate of biogenic and fossil liquids become indistinguishable from one another. The University of Novi Sad data evaluation method is very dependent on the composition of the examined fuels, so the obtained results in this case were relatively good. Future investigation should also test whether this calibration method is suitable for some other fuel matrices, for example for various types of domestic oil used in everyday life. Testing advantages and limitations of the two methods will continue in the future.

Sustavno praćenje aktivnosti 14C atmosferskog CO2 i bioloških uzoraka (voće – uglavnom jabuke, povrće, žitarice, kukuruz) u neposrednoj okolici Nuklearne elektrane Krško (NEK) provodi se od 2006. godine s ciljem procjene mogućeg utjecaja NEK-a na razinu aktivnosti 14C u okolišu te na efektivnu dozu koju primi lokalno stanovništvo putem prehrane. Posebna je pozornost posvećena praćenju utjecaja remonta elektrane, koji se provodi svakih 18 mjeseci, na aktivnost 14C u okolišu. U radu će se pokazati značajke aktivnosti 14C u okolišu elektrane i neki zaključci zasnovani na dugogodišnjem iskustvu monitoringa. Atmosferski CO2 sakuplja se na dvije lokacije unutar kruga NEK-a, obično u dvomjesečnim intervalima te u kraćim intervalima tijekom i neposredno nakon remonta. Biološki materijal koji integrira 14C iz atmosfere tijekom relativno kratkog vegetacijskog razdoblja (plodovi jabuke, kukuruz, žitarice i slično) skuplja se na početku vegetacijskog razdoblja (lipanj ili srpanj) te ujesen (prije berbe, rujan ili listopad) na više lokacija u unutarnjem i vanjskom krugu. Referentni uzorci bilja sakupljaju se na kontrolnoj točki kraj Dobove, 11, 2 km (zračna udaljenost) jugoistočno od NEK-a, na kojoj se ne očekuje utjecaj zračnih ispusta iz NEK-a. Praćenje aktivnosti 14C u okolici NEK u razdoblju od 2006. do kraja 2016. godine pokazuje da je utjecaj 14C ispuštenog u okoliš zračnim putem mjerljiv i u atmosferskom CO2 i u biljkama koje koriste CO2 za fotosintezu. Taj je utjecaj kratkoročan i prostorno ograničen na najbližu okolinu. Uočena je korelacija između ukupno ispuštene aktivnosti A14C i izmjerenih vrijednosti a14C u CO2 i u bilju. Systematic and continuous monitoring 14C activity in atmospheric CO2 and biological samples (mostly apples, vegetable, cereals, corn) in the vicinity of the Nuclear Power Plant Krško (NEK) in Slovenia has been performed since 2006. The aim of the monitoring is to determine 14C distribution in a close vicinity of the power plant and to estimate possible contribution of NEK to the effective dose of the local population through food chain. In this paper we describe some characteristics of the 14C distribution in the environment of NEK. The 14C activity of atmospheric CO2 at two locations inside the NEK area is on the average slightly higher than that in Zagreb. It depends on the 14C activity (A14C) released in air-born effluent. The influence of the 14C releases has been observed also in plants. Higher 14C activity in plants is most pronounced shortly after spring refuelling, when plants use atmospheric CO2 that contains 14C released from NEK. The influence of the released air-born 14C activity is measurable in both atmospheric CO2 and in plants; the higher the activity of gaseous effluent, the higher the atmospheric and plant 14C activity. However, the influence is temporally and spatially limited. Average 14C activity in plants at the control location Dobova does not differ from the average atmospheric 14C activity in Zagreb. It was shown earlier that the slightly increased 14C activity in plants does not contribute significantly to the effective dose of the local population due to ingestion of 14C. According to the experience of the whole monitoring, 14C is the only released radionuclide detected in the environment of NEK (Report IJS-DP-12059).

Zbornik sadrži 61 rad na hrvatskom ili engleskom jeziku s obveznim engleskim sažetkom. Radovi su organizirani u sekcije: Etika i kultura u zaštiti od zračenja, Opće teme, Zaštita od zračenja i dozimetrija u medicini, Biološki učinci zračenja. Instrumentacija i mjerne tehnike, Radioekologija, Radon, Izloženost stanovništva zračenju, Neionizirajuća zračenja The Proceedings contains 61 papers in Croatian or English with an obligatory English 1-page abstract. Papers are organized in the following sections: Ethics and culture in radiation protection, General topics, Radiation protection and dosimetry in medicine, Biological effects of radiation, Instrumentation and measuring techniques, Radioecology, Radon, Public exposure and Nonionising radiation

Etika je filozofska disciplina koja se bavi istraživanjem vrijednosti dobro, tj. onim što je dobro ili loše, što je moralna dužnost i obaveza, koja traga za ispravnom odlukom i za ispravnim djelovanjem, a ispravna odluka je odluka koja se može opravdati i iza koje odgovorno stojimo. To je skup ili sustav moralnih vrijednosti i načela koja određuju ponašanje pojedinca ili grupe. Često se govori o profesionalnoj etici, liječničkoj etici ili znanstvenoj etici. U ovom radu prikazat ćemo etičke osnove sustava zaštite od zračenja koje su razvijene u suradnji međunarodnih organizacija IRPA (International Radiation Protection Association) i ICRP (International Commission on Radiological Protection). Ovaj se zasniva na dokumentu ICRP-a o etičkim temeljima sustava zaštite od zračenja. IRPA i ICRP sve češće organiziraju posebne skupove ili radionice posvećene etičkim vrijednostima u sustavu zaštite od zračenja. Na posljednjem kongresu IRPA-e, koji je održan 2016. godine u Cape Townu, održana je posebna sekcija Policy, Standards and Culture koja je uključivala izlaganja i plenarnu sekciju o etici, sigurnosnim aspektima, obrazovanju i kulturi zaštite od zračenja. Međutim, i kroz sve druge sekcije i panel diskusije kongresa provlačila se tema etike i kulture zaštite od zračenja. Nove tehnologije zasnovane na radijaciji omogućavaju različite nove mogućnosti primjene, ali predstavljaju i velik izazov svima koji ih koriste. Nužna je dobra i široka edukacija i stalno usavršavanje i razmjena znanja i iskustava. Bolje razumijevanje etičkih načela i principa zaštite od zračenja može pomoći pojedincima i društvu da uspješno rješavaju probleme ili konflikte u procesu odlučivanja. Etika može pomoći u usklađivanju dobrobiti pojedinca, održivog razvoja društva i zaštite okoliša. Kultura i etika zaštite od zračenja moraju biti integralni dio svih sustava upravljanja zaštitom od zračenja. Ethics or moral philosophy is a branch of philosophy that deals with concepts of right and wrong conduct. It is also a set of principles of conduct governing and individual or a group (professional ethics). This paper presents ethical values underpinning the radiation protection systems. The paper that is based on the ICRP (International Commission on Radiological Protection) publication Annals of the ICRP. Ethical Foundations of the System of Radiological Protection published 2016 on-line as a Draft for consultation. The modern system of radiation protection is based on three pillars (according to ICRP): scientific knowledge that help us understand how radiation effects people and the environment, ethical values that guide decisions about protection, and experience that teaches us what is practical in implementation. The simple principle do not harm from early days of radiation application developed to ethical theories that include not only humans but also the whole ecosystem. Over past two decades both ICRP and IRPA have dedicated a significant effort to define ethical values (beneficence/non-maleficence, prudence, justice, dignity) underpinning the basic principles of the system of radiological protection (justification, optimization and dose limitation). IRPA Code of Ethics was adopted in 2004. It contains principles that should be regarded as guidelines to the members of IRPA and its associated societies in maintaining a professional level of ethical conduct related to radiation protection. ICRP Code of Ethics (approved in 2014) comprises expectations from its members in the development of recommendations and guidance: commitment to public benefit, by acting to protect humans and the environment from the harmful effects of radiation, independence in actions while being impartial, transparent and accountable. A clear understanding of ethical values and related radiation protection principles can help individuals and societies to address issues emerging in decision-making.

Na Izbornoj sjednici Zbora članova Hrvatskog društva za zaštitu od zračenja (HDZZ) predsjednica je prikazala izvješće o radu Upravnog odbora u proteklom mandatu, tj. između izbornih sjednica 2013. i 2017. Izvješće prikazuje sustav upravljanja društvom, broj članova, način obavještavanja, organiziaciju skupova i predavanja, novosti "mladih", prisustvo u medijima, davanje mišljenja, suradnju sa srodnim društvima u Hrvatskoj, kao i bopgatu međunarodnu suranju - s IRPA-om, s europskim društvima za zaštitu od zračenja i s društvima iz susjednih država.

In this presentation we will summarize the 10-year-long experience in monitoring 14C activity in the close vicinity of the Krško Nuclear Power Plant (NPP) in Slovenia. Atmospheric CO2 samples have been taken in 2-month periods during the regular operation of the power plant, or in shorter periods during refuelling periods. Biological samples (apples, corn, wheat, grass, vegetables) have been samples twice a year (in summer and autumn) in two circles around the NPP, inner and outer, and at the control point 12 km from the plant. The aim of the monitoring was to estimating a possible influence of the NPP on environmental 14C levels and on the effective dose of local population through food chain. Increase of 14C activity in atmospheric CO2 was observed during and immediately after the refuelling of the power plant, performed every 18 months. Good correlation between the total 14C activity released in gaseous effluents and the 14C activity of the atmospheric CO2 has been observed. 14C activity in plants collected close to the Krško NPP is always higher than the activities on the control point, and depends both on the distance from the exhaust of the plant ventilation system and on wind direction: it is higher on the location in the SW-NE direction that coincided with the most pronounced wind directions. Higher 14C activities have been determined in plants collected in summer after the spring refuelling than in those collected during the following vegetation period after the autumn refuelling. This can be explained by the uptake of the CO2 of higher 14C activity for the process of photosynthesis after spring refuelling. To estimate the realistic effective dose due to ingestion to the population in the vicinity, a model of food consumption has been proposed. The calculated dose for the population at the NPP vicinity is not significantly different from the dose for the population at the control point.

For the preparation of Gamma Knife (GK) treatments of brain tumours, a head CT examination is necessary when using a new CT-based convolution dose calculation algorithm included in Leksell Gamma Plan software (version 10.1.1). The purpose of this study was to measure the organ doses in paediatric anthropomorphic phantoms during a head CT scan and compare them with the measured GK treatment doses. CT doses were measured with radiophotoluminescence (RPL) dosimeters and compared with results of MC simulations. Measured doses for organs within the CT scan volume were comparable for both phantoms. The highest organ CT dose was evaluated for eyes: 27.6 ± 0.2 mGy and 27.3 ± 0.6 mGy for 5 and 10 year old phantom respectively. Doses for organs not included in the scan volume decreased with distance from the scan volume and were on average 3.5 times higher for the 5 year old phantom compared with the 10 year old phantom. Comparison of measured and MC dose values showed good agreement. For the 10 year old phantom, CT doses were 22%, 6%, 5% and 3% of the GK dose for thyroid, lungs, eyes and breasts respectively. Enhancement of the total organ doses for the whole GK treatment due to CT scanning is not negligible but nevertheless, the use of the new convolution algorithm seems reasonable.

A method of direct measurement of 14C activity concentration via liquid scintillation counting (LSC) is recognized as good and fast method for determination of biogenic component in liquid fuels. Two laboratories that used this14C technique participated in this survey: Laboratory from University of Novi Sad (UNS), Serbia and Laboratory from Ruđer Bošković Institute (RBI), Croatia. Each laboratory used its own calibration methods on the same set of samples (produced diesel-based bio-fuels and commercially available domestic oils). From the obtained results it can be concluded that each method which uses 14C technique for determination of biogenic component in liquid fuels has its advantages and disadvantages. RBI data evaluation method is based on two calibration curves, for purely biogenic and purely fossil liquids, and the calibration does not depend on the exact chemical composition of the organic liquid. The limits of the method are defined by the SQP(E) of approximately 690. Below this value the count rates of biogenic and fossil liquids become close to each other or even indistinguishable from one another and the obtained results for biogenic fractions are not reliable. In this intercomparison UNS used two different methods, one for produced bio-diesels and the other one for domestic oils. UNS data evaluation method is very dependent on the composition of the examined fuels, so the obtained results with the "two-step" method were relatively good in the case of diesel mixtures with biogenic component. In the case of biogenic oil samples (bought on market), UNS "two-step" method did not give realistic results, and with the "one-step" method the limitation is large quenching in the samples, so for the samples with SQP(E) less than 700 this method could not give expected results. Samples prepared with liquid fuels are usually colored and the main challenge for determination of biogenic component in both laboratories is handling of highly quenched liquids. Prema preporukama Evropske Unije sa ciljem da se koriste obnovljivi i održivi izvori, do 2020. godine zahteva se da se u svim tečnim gorivima koja se koriste nalazi bar 10% sintetisanog biodizela. Da bi se koncentracija biodizela mogla proveriti, nekoliko laboratorija u svetu je razvilo metode za tačnu, efikasnu i pouzdanu kvantifikaciju sadržaja biogene komponente. Direktno merenje koncentracije aktivnosti 14C tečnim scintilacionim detektorom (LSC), koje podrazumeva određivanje količine 14C u uzorku kao meru prisutnosti biogene komponente u testiranom gorivu, pokazalo se kao dobra i brza metoda. U ovoj interkomparaciji učestvovale su dve laboratorije: Laboratorija sa Univerziteta u Novom Sadu (UNS), Srbija i Laboratorija sa Instituta Ruđer Bošković (RBI), Hrvatska. Svaka laboratorija je koristila sopstveni kalibracioni metod i isti set uzoraka za interkomparaciju (proizvedena bio-goriva bazirana na dizelu i komercijalno dostupna domaća ulja). Iz dobijenih rezultata može se zaključiti da svaki od prikazanih metoda ima svoje prednosti i mane, što zavisi od samog sastava uzorka. RBI metod se zasniva na upotrebi dve kalibracione krive, za čisto biogena i čisto fosilna goriva, i kalibracija nije zavisna od hemijskog sastava analiziranog uzorka. Ograničenje ove metode je SQP(E) vrednost niža od 690. Ispod ove vrednosti odbroji biogene i fosilne komponente postaju veoma bliski jedan drugom i samim tim rezultati koji se dobijaju nisu pouzdani. U ovoj interkomparaciji, UNS je koristila dve različite metode kalibracije, jednu za proizvedene bio-dizele, a drugu za domaća ulja. UNS metod evaluacije izmerenih podataka u mnogome zavisi od sastava ispitivanog goriva, pa su rezultati dobijeni sa "two-step" metodom relativno dobri za smeše dizela sa biogenom komponentom. U slučaju biogenih ulja, UNS "two-step" metod nije dao realistične rezultate, zbog toga je korišćen "one-step" metoda za koji je utvrđeno ograničenje za SQP(E) parametar na 700. Uzorci koji se pripremaju sa tečnim gorivima su najčešće obojeni i najveći problem koji se javlja je korekcija na prigušenje u samom uzorku, koja mora biti detaljno sprovedena kako bi se dobio pouzdan rezultat, pa najveći izazov daljnjeg razvoja ovih metoda postaje postupak merenja biogene komponente u jako prigušenim uzorcima. Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. године