GE Hitachi (GEH) issued a preliminary report to the NRC today, saying that some of the reactor components it has provided to U.S. nuclear power plants have not been designed to withstand damage from an earthquake.
GEH reported: “GE Hitachi Nuclear Energy (GEH) has identified that engineering evaluations that support the guidance provided in SC 08-05, Revision 1, do not address the potential impact of a seismic event on the ability to scram as it relates to the channel-control blade interference issue.”
The Event Report made clear that the problem is in shutting down a reactor after an earthquake:
“Note that the seismic loads are not a consideration in the scram timing, but rather the ability to insert the control blades. In other words, the control blades must be capable of inserting during the seismic event….”
GEH clarified which U.S. nuclear power plants this design problem could affect:
“Affected US plants … include: Nine Mile Point, Units 1 and 2; Fermi 2; Columbia; FitzPatrick; Pilgrim; Vermont Yankee; Grand Gulf; River Bend; Clinton; Oyster Creek; Dresden, Units 2 and 3; LaSalle, Units 1 and 2; Limerick, Units 1 and 2; Peach Bottom, Units 2 and 3; Quad Cities, Units 1 and 2; Perry, Unit 1; Duane Arnold; Cooper; Monticello; Brunswick, Units 1 and 2; Hope Creek; Hatch, Units 1 and 2; and Browns Ferry, Units 1 and 2.” An addition to the report listed: Susquehanna, Units 1 and 2 and Browns Ferry, Unit 3.
Another late addition to the report drops another potential shoe:
“A statement was added regarding the applicability of this issue to the ABWR and ESBWR design certification documentation.”
The Event Report does not include any further statement on applicability to the two new reactor designs.
Sorry for the technical nature of this note. I’ll try to get clarification and pass it on.