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 STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555-0001 January 19, 2006 NRC INFORMATION NOTICE 2006-02: USE OF GALVANIZED SUPPORTS AND CABLE
TRAYS WITH MEGGITT Si 2400 STAINLESS-
STEEL-JACKETED ELECTRICAL CABLES
ADDRESSEES
All holders of operating licenses for nuclear reactors except those who have permanently
ceased 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 inform
addressees 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 similar
problems. However, suggestions contained in this IN are not NRC requirements; therefore, no
specific 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.s
Si 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 were
in 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. The
stainless 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 stainless
steel 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 the
same 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., loss
of power for maintaining a vacuum in gloveboxes). Fuel cycle licensees and certificate holders
also 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 IMPLICATIONS
Galvanized supports and cable trays with Meggitt Si 2400 stainless-steel-jacketed electrical
cables 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 this
matter 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 & Safeguards Division of Policy and Rulemaking
Office of Nuclear Material Safety and Safeguards Office of Nuclear Reactor Regulation
Technical Contacts: Robert Wolfgang, NRR Rex Wescott, NMSS
301-415-1624 301-415-6727 E-mail: rjw1@nrc.gov E-mail: rgw@nrc.gov
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections.
ML053200005 OFFICE IOEB:DIRS TECH EDITOR NRR BC:AFPB D:DRA
NAME CRoquecruz PKleene RWolfgang SWeerakkody JELyons
DATE 11/29/2005 11/15/2005 11/18/2005 11/18/2005 11/28/2005 OFFICE BC:IOEB:DIRS BC:PGCB D:DPR NMSS D:FCSS
NAME MJRoss-Lee CJackson CIGrimes RWescott RPierson
DATE 11/30/2005 12/16/2005 01/19/2006 01/11/2006 01/12/2006