Preliminary occupational radiation exposure evaluation related to NET II/ITER

The Occupational Radiation Exposure (ORE) evaluation is part of the safety analysis process that has the purpose to permit the optimisation of protection, according to the basic recommendations of ICRP. This paper presents the criteria adopted in order to evaluate the ORE during normal operation and maintenance of NET II/ITER and some results concerning system components located in tokamak and tritium buildings. Prompt radiation, activity concentration and intake situations as well as number of workers, number of events and exposure time are considered. Many systems and components, whose location in the plant can affect radiological protection during maintenance and/or surveillance, are identified together with the operations needed for each activity. Accidental conditions and equipment failures have been considered in the special maintenance activity when they are due to events with high probability of occurrence so that such events might be expected during the life of the plant. Some results are reported showing the ORE figures with reference to the main activities.