Activation and safety analyses for the D-3He fueled tokamak reactor Apollo

An activation analysis was performed for the Apollo D-³He-fueled reactor. Three different steel alloys (PCA, 316 SS, and the manganese steel Tenelon) were considered for use in the first wall, shield, and vacuum vessel. The activity, decay heat, and biological hazard potential (BHP) following shutdown were compared for the three alloys. PCA and 316 SS yield similar results. The total integrated decay heat generated from the Tenelon over a period of one day after shutdown is about a factor of two larger than that generated from PCA and 316 SS. This is still more than an order of magnitude lower than that obtained in a D-T-fueled reactor. The results showed that after the full reactor lifetime, both PCA and Type 316 SS do not quality as class-C low-level waste (LLW), while Tenelon can be disposed of as class-C LLW. The thermal response of the shield following a loss-of-coolant accident (LOCA) was determined using the different structural materials. Using the magnet as a heat sink, it has been shown that the maximum first-wall temperature two weeks after LOCA levels off close to 200°C even with Tenelon used as a structural material. The biological dose rate after shutdown at the back of the shield is excessive, implying that full remote maintenance is needed. However, the dose rate at the back of the magnet allows for limited access for magnet maintenance