Information Notice 2006-02, Use of Galvanized Supports and Cable Trays with Meggitt Si 2400 Stainless Steel Jacketed Electrical Cables
| ML053200005 | |
| Person / Time | |
|---|---|
| Issue date: | 01/19/2006 |
| From: | Charemagne Grimes, Pierson R NRC/NMSS/FCSS, NRC/NRR/ADRA/DPR |
| To: | |
| References | |
| +sunsimjr=200611 IN-06-002 | |
| Download: ML053200005 (3) | |
UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D.C. 20555-0001January 19, 2006NRC INFORMATION NOTICE 2006-02: USE OF GALVANIZED SUPPORTS AND CABLETRAYS WITH MEGGITT Si 2400 STAINLESS-
STEEL-JACKETED ELECTRICAL CABLES
ADDRESSEES
All holders of operating licenses for nuclear reactors except those who have permanentlyceased operations and have certified that fuel has been permanently removed from the reactor
vessel; and fuel cycle licensees and certificate holders.
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to informaddressees of the potential generic issue of using galvanized supports or galvanized cable
trays with Meggitt Si 2400 stainless-steel-jacketed electrical cables. Recipients are expected to
review the information for applicability to their facilities and consider actions to avoid similarproblems. However, suggestions contained in this IN are not
NRC requirements; therefore, nospecific action or written response is required.
DESCRIPTION OF CIRCUMSTANCES
In March 2004, Omega Point Laboratories, Inc. did a fire test of Meggitt Safety Systems, Inc.'sSi 2400 stainless-steel-jacketed electrical cables on behalf of Progress Energy Carolinas, Inc.,
as described in its license amendment request for the Harris Nuclear Plant dated
August 18, 2005 (Accession No. ML052640144). The test did not successfully demonstrate
continued electrical functionality of the cables for the complete duration of the fire test. The
cable samples were installed on galvanized supports for the fire test. Wherever the cables
came in contact with a galvanized support, the cable jacket was degraded. The degradation
was attributed to liquid metal embrittlement of the stainless steel cable jacket directly contacting
the galvanized support material at high temperatures. The cable jacket failure was not
discovered until a hose stream test at the end of the fire test.A second fire test was done later using stainless steel supports so that no cable samples werein direct contact with galvanized material. No cable jacket degradation was observed during the
second test.
DISCUSSION
Meggitt Si 2400 stainless-steel-jacketed cable is designed to function during a fire. Thestainless steel jacket acts as a fire barrier. This cable is used in some nuclear facilities to
provide power to equipment required for safe shutdown of the facility. If galvanized supports are in contact with the stainless steel jacket of the cable, the stainlesssteel jacket could degrade during a fire event. Degradation of the cable jacket would expose
the cable to the fire and possibly result in damage to the cable. Consequently, the equipment
being powered by the cable might malfunction during shutdown of the plant. According to
Section 4.0 j of Meggitt document ER 05-179 (Revision A, dated October 7, 2005), "Unpacking, Inspection, Installation and Standard Practices of Si 2400 Fire Rated Cable,"
"Si 2400 Fire Cable may be routed in cable trays; Stainless steel trays are recommended.
Cable should not be installed in galvanized trays and should NOT be in direct contact with
galvanized or aluminum trays or structures." This statement was added to the document as a
result of the unsuccessful March 2004 fire test.
Addressees
should be aware that fuel cycle licensees and certificate holders are not held to thesame fire protection requirements specified in Title 10 of the Code of Federal Regulations, Part 50, with regard to electrical circuits, but there are a limited number of safety events that
could be triggered by damage to electrical cables during a fire at a fuel cycle facility (e.g., lossof power for maintaining a vacuum in gloveboxes). Fuel cycle licensees and certificate holdersalso may be interested in knowing about this generic issue because there may be potential for
loss of some safeguards capabilities during a fire, if power to safeguards equipment were lost.GENERIC IMPLICATIONSGalvanized supports and cable trays with Meggitt Si 2400 stainless-steel-jacketed electricalcables can impact the safe shutdown functions of the equipment powered by the cables.
CONTACT
This IN requires no specific action or written response. Please direct any questions about thismatter to the technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.Robert C. Pierson, Director/RA/ Christopher I. Grimes, Director /RA/Division of Fuel Cycle Safety & SafeguardsDivision of Policy and Rulemaking
Office of Nuclear Material Safety and SafeguardsOffice of Nuclear Reactor RegulationTechnical Contacts: Robert Wolfgang, NRR Rex Wescott, NMSS301-415-1624 301-415-6727 E-mail: rjw1@nrc.govE-mail: rgw@nrc.govNote: NRC generic communications may be found on the
NRC public Web site,http://www.nrc.gov, under Electronic Reading Room/Document Collections.
ML053200005OFFICEIOEB:DIRSTECH EDITORNRRBC:AFPBD:DRANAMECRoquecruzPKleeneRWolfgangSWeerakkodyJELyonsDATE11/29/200511/15/200511/18/200511/18/200511/28/2005OFFICEBC:IOEB:DIRSBC:PGCBD:DPRNMSSD:FCSSNAMEMJRoss-LeeCJacksonCIGrimesRWescottRPiersonDATE11/30/200512/16/2005 01/19/200601/11/200601/12/2006