Occupational doses and impact on fusion economics

As part of the SEAFP-99 programme, water cooled and helium cooled fusion power plant design concepts were assessed with regard to occupational doses and related availability and operating costs. Different design and management measures to reduce occupational doses were considered. This task assessed the existing designs and proposed extensions or changes, where required. For each significant contributor, possible methods were specified which could reduce the operator dose and outage time. Where this was the case expected; costs or savings incurred by the improvement were estimated. Overall, the use of a system to remove particulate corrosion product activity from the primary coolant was considered essential for the water-cooled variant. In addition, application of the most up-to-date ALARA techniques could make the estimated dose for the water-cooled conceptual design appreciably lower than earlier estimated. It was concluded that the water cooled conceptual design could meet the project design target for occupational dose of 0.7 p-Sv per GW(e). A survey of occupational doses from the UK AGR plants was also carried out. From this, it is judged that the helium cooled fusion plant conceptual design could meet the project design target for occupational dose of 0.7 p-Sv per GW(e) without the need for additional plant to reduce primary coolant activity levels.