Development of a Technique for the Leak Testing of Elastomeric Seal Materials at High Temperature·

Performance requirements for radioactive material (RAM) packages are specified in Title 10, Code of Federal Regulations, Part 71 (NRC 1993). Package components that form the containment boundary must function in both high and low temperature environments which are characteristic of the hypothetical fire accident and the -40°F (-40°C) normal transport condition, respectively. Seals that provide the containment system interface between the packaging body and closure(s) are a source of special consideration when designing, testing, and licensing a RAM package. These seals are usually elastomeric 0-rings or gaskets and are tested frequently during development and operational use. Typically, a helium mass spectrometer leak detector (MSLD) or pressure change type of system is used to test the leaktightness of package seals. The type of system used is determined primarily by required test sensitivity. In the MSLD system, helium is used as the tracer gas due to its small molecular size and high activity, which results in higher sensitivity. Such tests are conducted for fabrication or preshipment assembly verification and are conducted at or near ambient temperature conditions.