核医疗船反应堆屏蔽初步设计及优化

摘要

The program of nuclear medical ship,funded by the cancer healing program of IAEA,was proposed according to the existing Miniature Neutron Source Reactor (MNSR)technology.The nuclear medical ship equipped with Boron Neutron Cap-ture Therapy(BNCT)device was developed,which opened a new scope of nuclear science application.The reactor of nuclear med-ical ship was designed in accordance with In-hospital Neutron Irradiator mark I (IHNI-1).In IHNI-1,heavy concrete was used as shielding material,and the reactor pool was cylindrical.Whereas,the volume and total weight of the reactor were too large to meet the ship’s requirement.After the design and optimization of the reactor’s shielding system by M-C method,stainless steel and B-polyethylene were chosen as shielding materials,and square pool was substituted by compact cylindrical pool.The result shows that on the premise of guaranteeing safety,shielding system’s mass and volume were cut down greatly,i.e.,this design can meet the requirement of nuclear medical ship.%核医疗船的概念是在现有微堆(MNSR)技术的基础上提出的，它基于 IAEA 的癌症关怀项目，开发配备硼中子俘获治疗技术(BNCT)的远洋核医疗船，该项目开辟核科技应用的新领域。核医疗船的反应堆设计参考了已建成的医院中子照射器-1型(IHNI-1)反应堆，该堆采用重混凝土作为主要屏蔽材料，水池为方形，其体积和质量都很大，不能满足船用要求。为了使反应堆能够满足船用要求，使用蒙特卡罗方法对医院中子照射器的反应堆屏蔽系统进行重新设计和优化，通过对多个方案的综合对比，最终确定采用不锈钢、含硼聚乙烯为屏蔽材料，并将水池设计成结构紧凑的圆柱形结构，该屏蔽方案在保证安全的基础上，使屏蔽系统的质量和体积大大降低，满足了船用要求。