ＰＷＲ・ＬＯＣＡ条件下における４ｉｎ．口径パイプホイップ試験 オーバーハングの効果

Abstract

This paper presents the results of 4-inch pipe whipping tests under PWR LOCA conditions and the discussion of the effects of the overhang length on the pipe whipping behaviors. The dynamic behaviors of the test pipe and the restaints, which were installed to prevent the pipe from whipping, were studied in the tests. The pipe whipping tests were performed under the pressure and temperature of PWR operating condition. In the tests, the gap between the test pipe and the restraints was kept at the constant value of 8.85mm, and the overhang lengths were 250, 400 and 650mm.The dynamic behaviors of the test pipe and restraints were made clear by measuring the outputs of strain gages and residual deformations. The data of water hammer in subcooled water were also obtained with use of pressure transducers mounted on the piping.The main conclusions obtained from the tests are as follows: (1) The restraints can prevent the pipe more effectively from whipping as the overhang length decreases. (2) The load acting on the restraint-support structure increases as the overhang length decreases.