Proposed pressure vessel concept and design for tritium gas for operation to pressures of 68.95 MPa (680.5 atm) and temperatures to 10000C

A proposed design for a pressure vessel to contain thermally hot tritium is described. It is a lined cylinder (4 in. id by 7.5 in. od by 171/8 in. working depth) designed for operation to pressures of 68.95 MPa (680.5 atm) and to temperatures of 10000C. Since these conditions do not allow for external heating, due to reduced strength of alloys and high gas-permeation rates at high pressures and temperatures, it is necessary to use internal heaters. In order to keep the amount of T2 to a minimum for any particular experiment, it was decided to design a system where the T2 would be contained in a small pressure vessel situated within a larger pressure vessel, with the internal pressure balanced externally with a nonradioactive gas. An additional advantage of such a system is that the specimen under T2 does not ''see'' the heater environment and so contamination of the specimen is reduced. However, the converse is not true. The heater will ''see'' some T2 due to diffusion through the inner container wall, the amount depending on pressure, temperature, and duration of the particular experiment. (U.S.)