Primary design and optimization of shielding for nuclear medical ship reactor

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 Capture Therapy(BNCT) device was developed, which opened a new scope of nuclear science application. The reactor of nuclear medical 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 ships requirement. After the design and optimization of the reactors 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 systems mass and volume were cut down greatly, i. e., this design can meet the requirement of nuclear medical ship.