Dose Assessment and ALARA Analysis for the ITER Facility Design

Candesco staff performed the dose assessment for normal and accident conditions for the proposed International Thermonuclear Experimental Reactor (ITER) facility at the Clarington site in Canada and optimized aspects of the design to ensure that all exposures were maintained As Low As Reasonably Achievable, social and economic factors taken into consideration.

Candesco staff calculated the dose rates that would be expected during operations and maintenance of ITER. Radiological hazards associated with activities in areas with dose rates of over 1 Sv/h and high levels of contamination were assessed and appropriate shielding and other protective measures were recommended. This work involved integrating experience with hands-on radiation protection work at active nuclear facilities with an understanding of the ITER facility design and maintenance needs to provide an assessment of the acceptability of the proposed maintenance programs. Assessments of radiation exposure were performed for the maintenance and operation activities and compared against (1) Acceptability with respect to national regulations and international recommendations; (2) Acceptability with respect to good radiation protection practices; and, (3) ALARA. Candesco staff also managed the assessment of conventional occupational hazards at ITER, including potential exposure to Beryllium, vacuums, and RF/microwave radiation.

Candesco team members performed ALARA assessments of the design, operation and maintenance of ITER. This included individual ALARA assessments for specific systems and for specific maintenance activities involving high-hazard components as well as assessment of the over-all anticipated exposure for normal operations and for possible off-normal events. The assessments and the application of mitigating recommendations saw collective dose reductions on the order of 1-2 magnitudes and over-all improvements in maintenance efficiency.

ITER RADIATION PROTECTION:

Candesco staff developed and implemented a process that was used during the design of the ITER facility to ensure that design decisions met the expectations of the regulatory bodies in the nations that were interested in possibly hosting ITER. This work involved developing a process for a first of a kind facility being designed on three continents and without a known regulatory framework.

Challenge

Solution

Outcome