NRC Generic Letter 1980-71
| ML031350427 | |
| Person / Time | |
|---|---|
| Issue date: | 07/31/1980 |
| From: | Grier B H NRC Region 1 |
| To: | |
| References | |
| BL-80-020 GL-80-071, NUDOCS 8008140558 | |
| Download: ML031350427 (5) | |
c RE& UNITED STATESNUCLEAR REGULATORY COMMISSION* REGION I631 PARK AVENUEKING OF PRUSSIA, PENNSYLVANIA 19406July 31, 1980Docket Nos. 50-0350-247Consolidated Edison Company ofNew York, Inc.ATTN: Mr. Peter ZarakasVice President.4 Irving PlaceNew York, New York 10003Gentlemen:Enclosed is IE Bulletin No. 80-20 which requires action by you with respect toyour nuclear power facility(ies).In order to assist the NRC in evaluating the value/impact of each Bulletin onlicensees, it would be helpful if you would provide an estimate of the manpowerexpended in conduct of the review and preparation of the report(s) required bythe Bulletin. Please estimate separately the manpower associated with correctiveactions necessary following identification of problems through the Bulletin.Should you have any questions regarding the Bulletin or actions required byyou, please contact this office.
Sincerely,eH. GrierDirector
Enclosures:
1. IE Bulletin No. 80-20 with Enclosure2. List of Recently Issued IE Bulletins
CONTACT
- E. G. Greenman(215-337-5267)cc w/encls:L. 0. Brooks, Project Manager, IP NuclearW. Monti, Manager -Nuclear Power Generation DepartmentM. Shatkouski, Plant ManagerJ. M. Makepeace, Director, Technical EngineeringW. D. Hamlin, Assistant to Resident ManagerJ. D. Block, Esquire, Executive Vice President -AdministrationJoyce P. Davis, Esquiree 0481 40559 ENCLOSURE 1SSINS No.: 6820UNITED STATES Accession No.:NUCLEAR REGULATORY COMMISSION 8006190023OFFICE OF INSPECTION AND ENFORCEMENTWASHINGTON, D.C. 20555July 31, 1980IE Bulletin No. 80-20 FAILURES OF WESTINGHOUSE TYPE W-2 SPRING RETURN TO NEUTRAL CONTROL SWITCHESBy letter dated June 18, 1980, Commonwealth Edison Company submitted LicenseeEvent Report No. LER 50-295/80-24 to the NRC describing a malfunction of aWestinghouse Type W-2 control switch at the Zion Generating Station, Unit 1.The malfunctioning switch is a three position spring return to neutral switch.Although the switch was in its proper neutral position when it malfunctioned,its neutral contacts failed to close properly thereby preventing the automaticstart of 1A Service Water Pump.Subsequent tests conducted on the malfunctioning switch revealed that contactclosure was intermittent with the switch in the neutral (or "Auto Start")position. Other tests conducted on identical switches from spares and fromUnit 2 equipment disclosed two additional switches with a tendency for inter-mittent contact closure.A review of this matter by Westinghouse led to the issuance of NSD TechnicalBulletin No. NSD-TB-80-9 to the utility owners of all Westinghouse operatingplants. The recommendations contained in the Westinghouse technical bulletininclude: (i) testing the neutral position contacts of the subject W-2 switchesfor continuity, and (ii) rewiring of the indicating light circuit to permitthe early detection of a neutral contact failure as shown in Figure 1.Depending on how the indicating light circuit is wired, loss of continuitythru the neutral position contact of a W-2 switch could remain undetecteduntil the equipment associated with the switch were called upon to operate.Since such a failure would be equivalent to by-passing the system associatedwith the switch, consideration should be given to rewiring the switches usedin safety-related applications as shown in Figure 1. Such rewiring wouldprovide an acceptable means for detecting contact failure, provided theindicating light is in the control room and readily visible by the operator.If the indicating light is not so located, consideration should be given toannunciating the neutral position contact failures at the control room toalert the operator of the inoperable status of a safety-related system. Inaddition, consideration should be given to adding redundant contacts to theW-2 switches or to replacing the W-2 switches with others having a more posi-tive contact wiping actio IE Bulletin No. 80-20 July 31, 1980 ACTIONS TO BE TAKEN BY LICENSEES AND HOLDERS OF CONSTRUCTION PERMITS:1. Determine whether Westinghouse Type W-2 control switches with springreturn to neutral position are used in safety-related applications atyour facility. If so, identify the safety-related systems using theseswitches and the total number of switches so used. If no such switchesare used in your facility, you should indicate that this is the case andignore the remaining questions.2. Licensees of operating plants using Type W-2 spring return to neutralcontrol switches in safety-related applications shall perform continuitytests on all such switches. These tests shall be performed with theswitch operator in the neutral position and completed within ten (10)days of the date of this bulletin. In addition, this continuity testshall be repeated at least every thirty-one (31) days after the initialtest and after each manipulation of the switch from its neutral position.These continuity tests may be discontinued subsequent to implementing thelonger term corrective measures described below.3. Licensees of operating plants and holders of construction permits shalldescribe the longer term corrective measures planned and the date bywhich such measures will be implemented by actual installation or bydesign change, as appropriate. As a minimum, the longer term correctivemeasures should include rewiring the indicating light as shown in Figure1 provided the light is readily visible to the control room operator. Ifnot, failures of the neutral position contacts should be annunicated inthe control room.A report addressing the above matters, including the number of failuresdetected during the first series of tests and the safety-related systemsinvolved, shall be submitted to the director of the appropriate NRC regionaloffice within forty-five (45) days of the date of this bulletin. A copy ofthe report shall be forwarded to the Director, Division of Reactor OperationsInspection, Office of Inspection and Enforcement, Nuclear Regulatory Commission,Washington, D. C. 20555.Approved by GAO, B180225 (R0072); clearance expires 7/31/80. Approval wasgiven under a blanket clearance specifically for identified generic problems.
Enclosure:
Figure 1 Enclosure to IE Bull-tin No. 80-20EXZS~ING INDICATING LIGHT CIRCUIT (TYPICAL)NEUTRALSWITCH
CONTACT
INDICATINGLIGHTSAFETYC-)SIGNIA _C -.I )PROPOSED EC-WIRING OF INDICATING LIGHT CIRCUIT (TYPICAL)NEUTRAL ISWITCH -
CONTACT
mINDICATINGLIGHTIl SAFETYS I VALIIC+)(-)FIGURE 1REWIRING OF INDICATIVIG LIGHT CIRCUIT OF IJ-2 SWITCHESAS RECO.-ENDSD BY WES TI INGY'JSE TECHNICAL 8UL'.ETI1; NSDB-8O-9
.-0 !-s -vIE Bulletin No. 80-20July 31, 1980Enclosure 2RECENTLY ISSUEDIE BULLETINSBulletinNo.80-19SubjectDate Issued7/31/80Issued ToAll nuclear powerfacilities havingeither an OL or a CPFailures of Mercury-Wetted Matrix Relays inReactor Protective Systemsof Operating Nuclear PowerPlants Designed by Combus-tion Engineering80-18Maintenance of AdequateMinimum Flow Thru CentrifugalCharging Pumps FollowingSecondary Side High EnergyLine Rupture7/24/80All PWR power reactorfacilities holding OLsand to those PWRsnearing licensingSupplement 2to 80-17Supplement 1to 80-17Failures. Revealed byTesting Subsequent toFailure of Control Rodsto Insert During a Scramat a BWRFailure of Control Rodsto Insert During a Scramat a BWR7/22/807/18/80All BWR power reactorfacilities holding OLsAll BWR power reactorfacilities holding OLs80-1780-16Failure of Control Rodsto Insert During a Scramat a BWR7/3/80All BWR power reactorfacilities holding OLsAll Power ReactorFacilities with anOL or a CPPotential Misapplication of 6/27/80Rosemount Inc., Models 1151and 1152 Pressure Transmitterswith Either "A" or "D" OutputCodes80-15Possible Loss Of HotlineWith Loss Of Off-Site Power6/18/80All nuclearholding OLsfacilities80-1480-1380-12Degradation of ScramDischarge Volume CapabilityCracking In Core SpraySpargersDecay Heat Removal SystemOperability6/12/805/12/805/9/80All BWR's with anOLAll BWR's with anOLEach PWR with an OL