Results of the activation analysis of the stellarator power plant study

Detailed activation analysis is performed as a part of the Stellarator Power Plant Study (SPPS). The reactor is assumed to operate for 30 full power years (FPY). The activity induced in the blanket at the end of its lifetime is lower than the activity induced in the shield after 30 FPY. At shutdown, the blanket and shield activities are 683 MCi and 3908 MCi, respectively. One year after shutdown the blanket activity drops to 22.3 MCi compared to 505 MCi for the shield. The total decay heat generated in the blanket at shutdown is 7.9 MW and drops to only 0.2 MW within one week. At shutdown, 46.6 MW of decay heat are generated in the shield. The shield´s decay heat drops to only 1.71 MW within a day and 0.77 MW within the first year. One week after shutdown, the values of the integrated decay heat are 333 GJ for the blanket and 1605 GJ for the shield. The total Biological Hazard Potential (BHP) produced in the blanket and shield at shutdown are 469×10⁹ and 492×10⁹ m³ air, respectively. The rad-waste classification of the reactor structure is evaluated according to both the NRC 10CFR61 and Fetter waste disposal concentration limits. The first wall and blanket will only qualify for Class C low level waste according to both limits. The high-temperature shield can only qualify as Class C waste if the 10CFR61 limits are used. The low-temperature shield will have no difficulty qualifying for a Class A or Class C rating according to both limits. Assuming a 25 μSv/h limit for hands-on maintenance, only remote maintenance may be allowed at any location inside the containment building