During a shutdown of the Kuosheng 1 plant, Taiwan, operation of the LPCI system for normal shutdown caused failure of an LPRM.
Testing by G.E. in their (HF)2 facility duplicated the failure, which has been attributed to flow-induced vibration of the LPRM. G.E. devised a flow-deflector to prevent cross-flow from the LPCI across core components. This deflector had to be installed in Grand Gulf very quickly to avoid delay in fuel loading.
In order to increase assurance that the design, construction, and installation of the deflector plate were proper, Mississippi Power & Light Company asked O’Donnell to review the problem and the proposed solution. We analytically determined that the fatigue usage factor, pump-induced vibration, low-pressure injection system head loss, fluence at welds, and the diaphragm connection of the LPCI line to the shroud were adequate. Subsequent testing confirmed the adequacy.