Structural Analysis of Gas Capsules for the Production of ~125I

摘要

Various safety tests and structural analyses have been performed on the sealed capsules of a xenon gas target for the production of ~125I. Since the target is a gas, the structural integrity and the leak tightness of the capsules are thoroughly examined. The capsule of the Xe gas target is designed as a double encapsulation so that no gases could escape during the irradiation in the reactor. The capsule is fabricated with high purity aluminum (A 1050) to minimize radioactive wastes and undesired radionuclide formation. The heat generation during the neutron irradiation is computed by using the MCNP code. The results from this computational analysis are applied to predict the temperature distributions throughout the capsules. By using the FEM code, ABAQUS, the mechanical strength of the capsules is evaluated at the irradiation condition. After computational analysis, vacuum bubble leakage tests are also performed after heating the capsules at 400 °C for 8 hours to demonstrate the safety of the target irradiation. From these analysis and test results, the safety and integrity of the gas target capsule for the production of ~125I could be ensured.