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A concept of the remote handling (RH) tools to maintain the components of the ITER Vacuum Vessel Pressure Suppression System (VVPSS) is developing. These RH tools are designed to remove and replace the rupture disk assembly and the bleed line valve assembly, to clean the relief lines, and to perform any associated operations to maintain them. The RH tools work together with the Neutral Beam Remote Handling System (NBRHS). The main functions of the RH tools are disconnection and connection of the bolted flanges, keeping the static confinement during the RH operations, limiting the spread of contamination, and vacuum or water jet cleaning of the contamination inside the relief line. The RH interfaces in the components are defined during the design process of the RH tools in collaboration with the VVPSS component designers. An RH sequence study is being carried out to demonstrate the feasibility of the maintenance operations within the constrained NB cell environment, and the capability of the NBRHS.

This paper describes the preliminary design result of the Monorail Crane System (MCS), which is a subsystem of the ITER Neutral Beam Remote Handling System. Since the concept design of the MCS, the design is elaborated further detail considering new maintenance requirements, updated interfaces with the components to be maintained, and the latest configurations in the NB cell. The main design updates are described as follows. First, the railway is changed from the one monorail with two side reaction rails to a dual rail system, which has better load distribution within the crane trolley and the building mountings. Second, additional railway and a switching mechanism are added between the HNB#1 and #2 to access to the VVPSS components, which are newly added in the NB cell. Third, the mounting of the transversal beams supporting the dual rails onto the embedded plates are updated and further elaborated. Forth, the crane trolley is designed to have independent redundant kinematic chains so that it is recoverable from a single point failure. Fifth, series of braking systems such as a service brake, an auxiliary brake, and an emergency brake are integrated in each kinematic chain to cope with normal and accidental loads. Sixth, seismic uncoupling devices are integrated to protect the mechanical components of the crane itself and the building structure. Lastly, detailed cabling design is implemented from the control cubicle to the locations where the subcomponents are located.

In the ITER or the future DEMO reactor systems, due to the neutron activation, the remote handling tasks such as inspection, repair and/or maintenance of in-vessel and ex-vessel components must be carried out using a wide variety of special tailored automatic manipulators. These manipulators can be designed as a pure serial articulated arm or a pure parallel mechanism, but for the sophisticated remote handling tasks requiring large workspace and high payload/weight ratio, it would be designed as a hybrid structure combined by these two mechanisms. The complex structure to obtain special remote operation makes the maintenance very time-consuming. To obtain the forward and/or the inverse kinematics of these manipulators, a global optimization method combined by differential evolution (DE) and modified particle swarm optimization (MPSO), here we call it as DEMPSO, is developed to save solution time. The general case studies focus on serial, parallel manipulators and the 10-DOF hybrid redundant serial-parallel robot designed for ITER vacuum vessel remote maintenance. The results would be extrapolated to solve the kinematic problems of the ITER or the future DEMO remote handling manipulators. The proposed optimization algorithm can also be used for the static and/or dynamic parameter identification in robot calibration systems.

The remote inspection and maintenance of the small pieces in vacuum vessel requires certain accuracy to the serial long-reach robot applied in EAST tokamak. The elastic deformations due to gravity and dynamical forces, however, will cause a big trajectory tracking error to the robot end. Therefore, the error prediction and compensation strategy should always be studied in advance to achieve a high required accuracy. This paper presents a mathematical method to estimate the static stiffness of EAST articulated maintenance arm (EAMA) robot. Firstly, the stiffness matrix of the modular parallelogram mechanism of robot is obtained based on the Matrix Structural Analysis (MSA) method. Considering the real constraint conditions of robot arms, the matrix is further simplified to a final version with minimum dimension to improve the computational efficiency. Secondly, the simulation examples have been given to evaluate the accuracy and reliability of the stiffness equations. And finally, the results show that the presented approach has an acceptable prediction error (less than 5%), which can be applied to other similar robotic systems with long-reach complex links.

EAST multi-purpose maintenance deployer (EMMD) system, being collaboratively developed by ASIPP and CEA-IRFM, is built as upgrades for EAMA. Updated kinematics parameters such as DOF distribution and joint angle for EMMD robot are performed and verified in a simulation platform. A new modular joint has been developed to optimize the yaw joint actuator for easy assembly and flexibility reduction. A 3-DOF gripper with cameras and torque sensor has been designed to provide inspection and dexterous handling of small fragments inside the EAST chamber. A conceptual upgrade for EAMA-CASK has been developed for the purpose of protecting the end-effector's sensors which do not have temperature-resistant qualification. The high temperature and vacuum compatible solutions and validation experiments have been presented in this paper.

Among the eighteen upper ports of the ITER Tokamak, the upper ports #4, #5, #6 and #7 are located in the Neutral Beam (NB) cell. A roughing filter and an upper port plug are located inside each upper port. Vacuum Vessel (VV) in-service inspection and neutron flux monitor ports are located on the balcony area near the third Heating Neutral Beam (HNB). This paper describes the concept design of the Upper Port Remote Handling Equipment (UPRHE) that provides means to maintain the components at the upper ports and the balcony area within the NB cell. The UPRHE can move along the toroidal direction to access the upper ports and can deploy various remote handling (RH) tools into the upper ports to access the components that require maintenance. The UPRHE consists of permanent installations in the NB cell and removable equipment that is transferred from the Hot Cell Facility to the NB cell only when carrying out the maintenance activities. The permanent equipment is the cabling device mounted on wall. The removable equipments are the upper port trolley, manipulator transporter, end-effectors, manipulators, and other RH tools. The concept design and the RH compatibility assessment demonstrate that the proposed UPRHE can perform the identified tasks and is ready to move on to the next design phase.

Fusion Tokamaks are complex machines which require special conditions for their operation, in particular, high vacuum inside the vessel and high temperature of the vessel walls. During plasma phases, the first wall components are highly stressed and a control is necessary in case of doubt about their condition. To be able to make safely such an inspection in a short period of time is a great advantage. The Articulated Inspection Arm (AIA) developed by the CEA provides the capability for fast inspections of the first wall overall surface keeping the vacuum and temperature conditions of the vessel. The robot prototype was validated in Tore Supra in 2008. In the frame of a joint laboratory, CEA/IRFM and ASIPP have decided to upgrade the existing AIA prototype to use it routinely in the EAST and WEST tokamaks. The robot has followed an important upgrade program in 2013 and 2014. The document presents the various upgrades made on the mechanics, the sensors, the electronics, the control station and the integration adaptation for the operation on EAST. From the AIA experience, thoughts for future inspection robots are given.

In this study, a single-pump closed-loop hydraulic system with multiple actuators and load sensitivity is designed for a circular transfer platform, which remotely handles the divertor of the China Fusion Engineering Test Reactor by rotating the divertor module in the non-maintenance window to the designated position along the circular track. The proposed system controls the position and force of the pushing and locking cylinders. The designed closed-loop system synchronizes the movements of the internal and external cylinders. It also controls the displacement and force of the locking cylinder, ensuring the stability of the clamping force and the controllable position of the cylinder. Furthermore, the dynamic performance of the hydraulic control system is verified via the Adams–AMESim software co-simulation.

EAST articulated maintenance arm (EAMA) system is being collaboratively developed by ASIPP and CEA-IRFM for the purpose of remote inspection and simple maintenance operations in EAST vacuum vessel during physical experiments without breaking the ultra-high vacuum condition. The EAMA system design is based on a similar articulated inspection arm robot successfully demonstrated in Tore Supra in 2008. In order to better meet EAST configurations and maintenance requirements, optimized mechanisms and dimensions are considered for EAMA robot as upgrades. Besides, the segmented arm is equipped with a 3-DOF wrist end effector and gripper for gripping operation as well as inspection. Some calculations and simulations on statics, kinematics and workspace of EAMA have been presented to validate the feasibility. This paper introduces the overall design of the EAMA robot and presents implementation progress.

KTX is a new reversed field pinch (RFP) magnetic confinement device which is under design in ASIPP and USTC. Major disruption (MD) events may occur in future operating process, which is simulated with the finite element (FE) method. The results present that the peaks of eddy currents on vessel and conductor shell are respectively 11.791 kA and 68.637 kA with maximum stress 67.1 MPa due to high transient electromagnetic (EM) force. It is confirmed that the structure is still strong enough to bear the electromagnetic loads even if the worst case. Besides, as KTX vacuum vessel will take the method of natural cooling for heat dissipation during plasma discharge (0.5–1.0 MA), a preliminary thermal calculation was implemented in normal condition to decide suitable time parameters such as duration and interval. It is suggested that the discharge interval should be no less than 5 min for the complete 1 MA plasma with 100 ms duration, which can guarantee the temperature of vacuum vessel below 200 °C.