OCCUPATIONAL DOSE FOR THE WATER COOLING SYSTEM OF THE SEAFP PROJECT

The Occupational Radiation Exposure (ORE) for the water primary coolin g system (PCS) of the SEAFP (Safety and Environmental Assessment of Fu sion Power) alternative plant model (APM) was assessed taking into acc ount the first wall/blanket section only. All the potential radiologic al sources were considered and the analysis was restricted to the most important source at the PCS, the activated corrosion products (ACP). The neutrons have the capability to activate the materials under their flux and therefore also the Inner surface of the in-vessel portion of the PCS undergo to such a process. Production, erosion/corrosion, tra nsport and deposition of the ACP are the subject of a parallel work pr esented al the same meeting. The ACP deposited on the inner surface of the PCS components are responsible for the personnel external irradia tion. The relevant dose rate was evaluated by using the computer code MCNP and comparing the results with the respective values measured at the fission PWR plants. The comparison with the FWR made it possible t o transfer the parameters relevant to the working activities to the SE AFP PCS. Maintenance and inspection were found to be the only working tasks applicable to the SEAFP circuit and the worker access was consid ered to be allowed 24 h after the plant shut down only. The ORE figure s are shown in the work for each working activity and are compared wit h those measured at the PWR similar circuit. The comparison showed a m ore acceptable result from the radiological safety point of view for t he SEAFP staff.