ML18139A650
| ML18139A650 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 07/31/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Ferguson J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8008150136 | |
| Download: ML18139A650 (5) | |
Text
I In Reply Refer To:
R.u._;:..J+/-tl----lJ~
5 e
e UNITED STATES NUCLEAR REGULATORY COMMISSION REGION II 101 MARIETTA ST., N.W.,SUITE 3100 ATLANTA, GEORGIA 30303 JUL 3 l 1980 Virginia Electric and Power Company ATTN: J. H. Ferguson Executive Vice President-Power P. 0. Box 26666 Richmond, VA 23261 Gentlemen:
Enclosed is IE Bulletin No. 80-20 which requires action by you with regard to your nuclear power facility(ies).
In order to assist the NRC in evaluating the value/impact of each Bulletin on licensees, it would be helpful if you would provide an estimate of the manpower expended in conduct of the review and preparation of the report(s) required by the Bulletin. Please estimate separately the manpower associated with corrective actions necessary following identification of problems through the Bulletin.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely,
..* ---***-*-*-*---~
~~~
James P. O'Reill~
Director
Enclosures:
- 1.
- 2.
List of Recently Is~ued IE Bulletins cc w/encl:
W.R. Cartwright, Station Manager P. G. Perry, Senior Resident Engineer J. L. Wilson, Manager so os 1 so/'}r/p Q
)
e UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 July 31,.1980 e
SSINS No. : 6820 Accession No.:
8006190023 IE Bulletin No. 80-20 FAILURES OF WESTINGHOUSE TYPE W-2 SPRING RETURN TO NEUTRAL CONTROL SWITCHES By letter dated June 18, 1980, Commonwealth Edison Company submitted Licensee Event Report No. LER 50-295/80-24 to the NRC describing a malfunction of a Westinghouse Type W-2 control switch at the Zion Generating Station, Unit 1.
The malfunctioning switch is a three position spring return to neu.tral switch.
Although the switch was in its proper neutral position when it malfunctioned, its neutral contacts failed to close properly thereby preventing the automatic start of IA Service Water Pump.
Subsequent tests conducted on the malfunctioning switch revealed that contact closure was intermittent with the switch in the neutral (or "Auto Start")
position.
Other tests conducted on identical switches from spares and from Unit 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 Technical Bulletin No. NSD-TB-80-9 to the utility owners of all Westinghouse operating plants.
The recommendations contained in the Westinghouse technical bulletin include: (i) testing the neutral position contacts of the subject W-2 switches for continuity, and (ii) rewiring of the indicating light circuit to permit the early detection of a neutral contact failure as shown in Figure 1.
Depending on how the indicating light circuit is wired, loss of continuity thru the neutral position contact of a W-2 switch could remain undetected until the equipment associated with the switch were called upon to operate.
Since such a failure would be equivalent to by-passing the system associated with the switch, consideration should be given to rewiring the switches used in safety-related applications as shown in Figure 1.
Such rewiring would provide an acceptable means for detecting contact failure, provided the indicating light is in the control room and readily visible by the operator.
If the indicating light is not so located, consideration should be given to annunciating the neutral position contact failures at the control room to alert the operator of the inoperable status of a safety-related system.
In addition, consideration should be given to adding redundant contacts to the W-2 switches or to replacing the W-2 switches with others having a more posi-tive contact wiping action.
ACTIONS TO BE TAKEN BY LICENSEES AND HOLDERS OF CONSTRUCTION PERMITS:
- 1.
Determine whether Westinghouse Type W-2 control switches with spring return to neutral position are used in safety-related applications at your facility.
If so, identify the safety-related systems using these
e IE Bulletin No. 80-20 switches and the total number of switches so used.
are used in your facility, you should indicate that ignore the remaining questions.
e July 31, 1980 Page 2 of 2 if no such switches this is the case and
- 2.
Licensees of operating plants using Type W-2 spring return to neutral control switches in safety-related applications shall perform continuity tests on all such switches.
These tests shall be performed with the switch operator in the neutral position and completed within ten (10) days of the date of this bulletin.
In addition, this continuity test shall be repeated at least every thirty-one (31) days after the initial test and after each manipulation of the switch from its neutral position.
These continuity tests may be discontinued subsequent to implementing the longer term corrective measures described below.
- 3.
Licensees of operating plants and holders of construction permits shall describe the longer term corrective measures planned and the date by which such measures will be implemented by actual installation or by design change, as appropriate.
As a minimum, the longer term corrective measures should include rewiring the indicating light as shown in Figure 1 provided the light is readily visible to the control room operator.
If not, failures of the neutral position contacts should be annunicated in the control room.
A report addressing the above matters, including the number of failures detected during the first series of tests and the safety-related systems involved, shall be submitted to the director of the appropriate NRC regional office within forty-five (45) days of the date of this bulletin.
A copy of the report shall be forwarded to the Director, Division of Reactor Operations Inspection, Office of Inspection and Enforcement, Nuclear Regulatory Commission, Washington, D. C. 20555.
Approved by GAO, B180225 (R0072); clearance expires 7/31/80.
Approval was given under a blanket clearance specifically for identified generic problems.
Enclosure:
Figure 1
..... **:...,~.
e EXISTING INDICAT!~G LIGHT CIRCUIT (TYPICALY T
(+)
NEUTRt.L SWITCH CON7ACT IN:H!:AT.::.NG LIG'iT
... _v** * *:....,u.-r**
- w* i **,_.;,..,w..,*.~.... ;!(~.-, *. (:~-~~... *~--~*:-_;;;:.r.: i~-1~:
- I *;it\\if~~, '"t-f.'~--1~~*.... ;,;;;-,,.__,,,. *..
SAFETY *1
- (-)
SIGNAL T PROPOSED REWIRING..~OF,. J.t'lP.l c~r;r;t~~-.b-.+.~tl1,S.~~£~;J,.£:;\\P.; ~N-:r.;,,,i,:;,,;;'~ ~-~i.;;.;,;~-
- T
(+)
NEUTRAL S~:TCH CONTACT T
FIGI.JRE 1
--)
REWIRING OF INDICATING LIGHT CIQCJIT o~ W-2 ~~!~C~ES AS 'RECOMMENDED BY WESTINGHOUSE TECHNICAL B:.:... LETlN :~SO-TB-80-9 7
.i.
IE Bulletin No. 80-20 July 31, 1980 Bulletin No.
80-19 80-18 Supplement to 80-17 Supplement to 80-17 80-17 80-16 80-15 80-14 80-13 80-12 2
1 RECENTLY ISSUED IE BULLETINS Subject Date Issued Failures of Mercury-7/31/80 Wetted Matrix Relays in Reactor Protective Systems of Operating Nuclear Power Plants Designed by Combus-tion Engineering Maintenance of Adequate 7/24/80 Minimum Flow Thru Centrifugal Charging Pumps Following Secondary Side High Energy Line Rupture Failures Revealed by Testing Subsequent to Failure of Control Rods to Insert During a Scram at a BWR Failure of Control Rods to Insert During a Scram at a BWR Failure of Control Rods to Insert D_uring a Scram at a BWR Potential Misapplication of Rosemount Inc., Models 1151 and 1152 Pressure Transmitters with Either "A" or "D" Output Codes Possible Loss Of Hotline With Loss Of Off-Site Power Degradation of Scram Discharge Volume Capability Cracking In Core Spray Spargers Decay Heat Removal System Operability 7/22/80 7/18/80 7/3/80 6/27/80 6/18/80 6/12/80 5/12/80 5/9/80 Enclosure Issued To All nuclear power facilities having either an OL or a CP All PWR power reactor facilities holding OLs and to those PWRs nearing licensing All BWR power reactor facilities holding OLs All BWR power reactor facilities holding OLs All BWR power reactor facilities holding OLs All Power Reactor Facilities with an OL or a CP All nuclear facilities holding OLs All BWR's with an OL All BWR's with an OL Each PWR with an 01
~-- __ " ________ --------- *---.---- --~... *-** - -..
,, _* -------'------------~