Slattery, G F
Principal Scientific Officer, Reactor Fuel Element Laboratories, United Kingdom Atomic Energy Authority, Springfields Works, Salwick, Nr. Preston, Lancashire
Pages: 16 Published: Jan 1969
The effects of circumferentially aligned hydride on the transverse mechanical properties of Zircaloy-2 tubing have been determined. Test variables included the method of hydriding, electrolytic versus autoclaving in LiOH solution and the method of the test, ring tension versus closed-end tube burst. The investigation showed that the strength of the Zircaloy-2 decreased by 50 percent between room temperature and 400 C. To maintain adequate ductility above 200 C in hydrided Zircaloy-2 tubing tested under biaxial stress, it is necessary to specify an upper limit in the region of 400 ppm for hydrogen content. The least ductile condition cold is with an external hydride layer present and the ductility can be significantly improved if this layer is absorbed entirely into the tube wall. Under these conditions, the critical threshold for hydrogen embrittlement can be raised from 70 to 450 ppm H2 in the tube wall. Ring tension tests are not as sensitive to hydride embrittlement as the biaxially stressed tube-burst test.
zirconium, zirconium alloys, mechanical properties, cladding, nuclear fuel elements, nuclear reactors, corrosion, tests, evaluation
Paper ID: STP43822S