INDUSTRY EXPERIENCE WITH THERMAL PROTECTORS ON 48 INCH UF6 CYLINDERS

The International Atomic Energy Agency (IAEA) Transport Safety Regulations (TS-R-1) require packages filled with non-fissile and fissile excepted uranium hexafluoride (further indicated as natural and depleted UF6) to pass the thermal test. The thermal behaviour of cylinders filled with UF6 has been studied extensively and also an IAEA Co-ordinated Research Programme was allocated to this subject The studies show that the standard 48-inch UF6 cylinders have a large thermal mass and some conclude that they would meet the thermal test requirement. A continued unilateral approval, however, was not supported by all parties involved. In order to be able to continue international operations under H(U) approval, an industry consortium developed thermal protection units (BTP’s and CTP’s) to be added to the standard cylinders. Actual use of the newly developed thermal protectors started in January 2005. This paper reviews the UF6 specific regulatory developments, research and analysis activities to assist the regulatory development and to verify compliance with the new requirements and describes the industry experience with these. The paper describes experience with the use of thermal protectors. Also, the paper looks forward to new activities with regard to demonstration of compliance with the thermal test.