Condon Caitlin A, Ivanusa Pavlo, Bunn Amoret L, Jensen Philip J
Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSIN K7-68, Richland, WA 99352.
Health Phys. 2021 Mar 1;120(3):271-277. doi: 10.1097/HP.0000000000001310.
There are unique benefits from advanced/micro-reactor designs and fuel types that offer safety features in the case of an accident that may reduce environmental consequences compared to conventional reactors and fuels. Tristructural isotropic (TRISO) fuel particles are a robust advanced nuclear fuel type that leads to the unique question of how unruptured, activated TRISO particles will interact with humans. TRISO particles are 900 μm in size, and that particle size restricts internal dose assessment to the ingestion pathway. Activity of the TRISO particle was established by High Temperature Engineering Test Reactor simulations. The TRISO particle encapsulation was assumed to be perfect; exploration of internal dose contribution from radionuclides released from encapsulation was not included. The TRISO particle was assumed to be mixed actively within each alimentary tract compartment such that homogenous distribution could be assumed according to the International Commission on Radiological Protection publication 133. The dose assessment results indicate that the rectosigmoid colon had the highest internal organ dose for both reference male (2.1 Sv) and female (2.3 Sv). The internal dose from ingestion of the scenario-specific TRISO particle was 0.25 Sv for the reference male and 0.29 Sv for the reference female, which exceeds the annual occupational effective dose limit of 0.05 Sv in the Code of Federal Regulations, 10 CFR Part 20 Subpart C. Similarly, the annual occupational limit of 0.5 Sv to any one organ would be exceeded for the left colon, right colon, and rectosigmoid colon for both the reference male and female.
先进/微反应堆设计及燃料类型具有独特优势，在发生事故时能提供安全特性，与传统反应堆和燃料相比，这可能会减少环境影响。全陶瓷微球粒（TRISO）燃料颗粒是一种坚固的先进核燃料类型，这引发了一个独特问题：未破裂的、具有放射性的TRISO颗粒会如何与人体相互作用。TRISO颗粒尺寸为900微米，该颗粒尺寸将内部剂量评估限制在摄入途径。TRISO颗粒的放射性通过高温工程试验反应堆模拟确定。假设TRISO颗粒的封装是完美的；未考虑封装释放的放射性核素对内部剂量贡献的探究。假设TRISO颗粒在每个消化道隔室内积极混合，这样根据国际放射防护委员会第133号出版物可假定为均匀分布。剂量评估结果表明，对于参考男性（2.1 Sv）和女性（2.3 Sv），直肠乙状结肠的内部器官剂量最高。摄入特定场景的TRISO颗粒后，参考男性的内部剂量为0.25 Sv，参考女性为0.29 Sv，这超过了联邦法规代码10 CFR Part 20 Subpart C中规定的每年0.05 Sv的职业有效剂量限值。同样，对于参考男性和女性，左结肠、右结肠和直肠乙状结肠对任一器官的每年0.5 Sv职业限值都会被超过。
