Professor, University of Tokyo, Tokyo,
Pages: 19 Published: Jan 1977
In past few years interlaboratory tests were performed among three working groups in Japan. The groups consisted of representatives from various organizations including national laboratories, fuel manufacturers, and cladding tube manufacturers.
Test methods for longitudinal and circumferential strength of Zircaloy cladding tube were discussed. In the tension test, the shape of the plug or mandrel was found to be highly effective for the longitudinal elongation value obtained, as it restrains the deformation of the tube toward decreasing diameter. Tapered plug, therefore, will give larger elongation, and the degree of taper has a notable effect on the elongation value. The improvement in the present manual, therefore, is to be recommended.
In the internal-pressure burst test, the closed-end method showed a larger burst pressure and smaller circumferential elongation than the open-end method. The restraint of the longitudinal deformation of the tube is an important factor in this burst test as the reduction in thickness is quite difficult in such a featured tube. A testing method, therefore, should be chosen as to what sort of information is necessary, corresponding to the actual condition in the reactor concerned.
Measurements of grain size and hydride orientation factor also were discussed, and the results obtained were compared.
zirconium, zirconium alloys, tests
Paper ID: STP35597S