ML20140F416
| ML20140F416 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/28/1986 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| FVY-86-27, IEIN-86-013, IEIN-86-13, NUDOCS 8604010043 | |
| Download: ML20140F416 (1) | |
Text
-
O-D VERMONT YANKEE NUCLEAR PO'wER CORPORATION FVY 86-27 RD 5. Box 169. Ferry Road, Brattleboro, VT 05301
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ENGINEERING OFFICE 1671 WORCESTER ROAD FRAMINGHAM, MASSACHUSETTS 01701 March 28, 1986 TEL E PHONE 617-8 72-8100 W
,r United States Nuclear Regulatory Commission g
Edward L. Jordan, Director Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement Washington, D.C.
20555
References:
a) License DPR 28 Docket 50-271 b) NRC Information Notice 86-13, dated February 21, 1986
Dear Sir:
Subject:
IE Information Notice 86-13 This letter is to inform you that the event description contained in the subject Information Notice may be misleading to other utilities.
Your Information Notice stated that the cause of this occurrence was a combination of a wiring error on Vermont Yankee's part and the incorrect pin to bridgewire wiring of the connector that was supplied with the squib valve primer charge. Our investigation has concluded that the as-found wiring was in accordance with the wiring illustrated in General Electric Service Information Letter (SIL) 186. Accordingly, Standby Liquid Control System inoperability is attributed solely to the incorrect pin to bridgewire wiring associated with the squib valve primer charge.
We believe it is signigicant to emphasize to utilities that an installation fully in accordance with General Electric SIL 186 does not give assurance that a squib valve will fire if it was manufactured with the wiring configuration found at Vermont Yankee.
At the request of Eric Weiss, we are submitting a marked-up copy of what we feel should be included in the I&E Information Notice.
If we can be of any further assistance, please contact David K. McElwee at (802) 257-5271.
Very truly yours, W
Vice President an Manager of Operations cc: Eric Weiss Glen Myers
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Bill Raymond 0604010043 860329 ADOCK 0 % 2 1
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[ VERMONT YANKdE h RECF.IVED SSINS No..
6835 UCENSING IN 86-13 UNITED STATES NUCLEAR REGULATORY C09911SSION j
OFFICE OF INSPECTION AND ENFORCEMENT I
WASHINGTON, D.C.
20555 February 21, 1986 NVY 86-32
'.!E INFORMATION NOTICE h0. 86-13: STANDBY LIQUID CONTROL SYSTEM SQUIB VA FAILURE TO FIRE Addressees:
All boiling water reactor facilities holding an operating license (OL) or a construction permit (CP).
Purpose:
This notice is to alert addressees to a potentially generic problem with explosive squib valves used in the standby liquid control system. Recipients are expected to review the information for applicability to their facilities and consider actions, if appropriate, to preclude similar problems occurring at their facilities. However, suggestions contained in-this information notice do not constitute NRC requirements; therefore, no specific action or written response is required.
Description of Circumstances:
During a recent routine surveillance, Vermont Yankee found that squib valves used ig both pathways of the standby liquid control system (SLCS) failed to fire. IThe f ailure of the squibs to fire was caused by 4w; ;;reblem;.
C=
-probic: :: t ha t-t he-pl an t-had-c ha nged-t he-w i r i ng -i n-t he-te rm i na l-bo x-to-the-t wib valve: #ir-ing-circuit
-the-ether-problem-was incorrec wiring of the connector that is supplied ith the squib valve primer charge.
F.n To bndsevm-c The explosive primer charge assembly for the SLCS at Vermont Yankee was supplied The explosive primer charge assembly has two sets of by Conax Corporation.
resistance wires, i.e., bridgewires, internal to the charge either of which However, some of the charges were manufactured with will fire the explosive.
incorrect pin-to-bridgewire groupings so that when connected at Vermont Yankee, two high-side leads were connected to one bridgewire set and two neutral leads were connected to the other bridgewire set internal to the explosive primer.
Examination of spare squibs at Vermont Yankee identified four others with incorrect pin-to-brigdewire groupings.
1 -> The-squids-are-connected-to-the-plant!s-wiring-via-four--pin-connectors.
Lsed Incorrect Viring at the Vermont Yankee local terminal box resulted in the If the sequence around the connector being high, high, neutral, neutral.
l wiring in the terminal box had 4::r according-to-the-design-drawing-and-had-been high, neutral, high, neutral, the squib charge would have fired even l
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Insert 1 to I&E Notice 86-13 The squibs are connected to the plants wiring via four pin connectors.
Vermont Yankee wired the connectors into the firing circuit as shown in the details of General Electric SIL 186. The SIL did not 'specify oc give any guidance as to the orders in which the wires should be connected, only that each charging coil must have a hot and a neutral across its terminals. Vermont Yankee had it wired as described and such that the firing circuit as well as the continuity cir.
cuit would function properly given the correctly wired squib valve.
IN 86-13 February _21,1986 Page 2 M 3\\ i &]}
though the pin-to-bridgewire connection was incorrect. (See Attachment 1.)
In addition, at Vermont Yankee the control room indication of 4LCS: circuit status indicated circuit continuity due to the presence of a sneak curcuit.
At this time, it is not clear whether other primer assemblies, i.e., those
- manufactured at a facility in Florida rather than New York, have the incorrect
- pin-to-bridgewire groupings. However, some potentially suspect primer
- assemblies are:
Number Primer Part Assembly Plant of Pieces Serial Numbers 1617-139-01 Vt. Yankee 6 (defective) 552-557 1617-139-01 Dresden 6
546-551 1621-240-01 Shoreham 7
635-640, 668
- 1621-240-01 Ouane Arnold 6
669-674 1621-240-01 Susquehanna 19 675-681, 686-697 1621-240-01 Limerick 10 699-708 1621-240-01 Pilgrim 3
659-661 NRC Regional representatives have contacted the above facilities by telephone.
In addition, some of the explosive primer charge assemblies were provided to the NORCA Machinery Company, Great Neck, New York for distribution outside of the United States.
The explosive primer charge assembly may be tested for correct pin-to-bridgewire grouping with an ohmmeter that is current limited to no more than 10 millamperes.
Larger currents will cause the charge to explode.
Inquiries concerning this problem may be addressed to:
Conax Corporation 2300 Walden Avenue Buffalo, New York 14225 Mr. Art Haefner phone: (716) 684-4500 extension 233 a.
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IN 86-13 February 21, 1986 Page 3 of 3 No specific action or written response is required by this information notice.
If you have questions about this matter, please contact the Regional Adminis-trator of the appropriate NRC regional office or this office.
l A
dwar Jordan, Director Divisi of Emergency Preparedness and ineering Response Office of Inspection and Enforcement Technical
Contact:
Eric Weiss, IE (301) 492-9005 Attachments:
1.
Squib Schematic 2.
List of Recently Issued IE Information Notices
Attachnent 1 IN 86-13 February 21. 1986 J.4 2 5 "
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END view WIRING DIAGRAMS BRIDGEWIRES
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INCORRECT PIN-TO-BRIDGEWIRE
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y ATTACH 14ENT 1 - SQUlB SCHEMATIC
4 IN 86-13 February 21, 1986 LIST OF RECEMTLY ISSUED IE INFORMATION NOTICES Informatice Date of Notice No.
Subject Issue Issued to 86-12 Target Rock Two-Stage SRV 2/25/86 All power reactor Setpoint Drift facilities holding an OL or CP 86-11 Inadequate Service Water 2/25/86 All power reactor Protection Against Core Melt facilities holding Frequency an OL or CP 84-69 Operation Of Emergency Diesel 2/24/86 All power reactor Sup. 1 Generators facilities holding an OL or CP 86-10 Safety Parameter Display 2/13/86 All power reactor System Malfunctions facilities holding an OL or CP 86-09 Failure Of Check And Stop 2/3/86 All power reactor Check Valves Subjected To facilities holding Low Flow Conditions an OL or CP 86-08 Licensee Event Report (LEoi 2/3/86 All power reactor Format Modification facilities holding an OL or CP 86-07 Lack Of Oetailed Instruction 2/3/86 All power reactor And Inadequate Observance Of facilities holding Precautions During Maintenance an OL or CP And Testing Of Diesel Generator Woodward Governors 86-06 Failure Of Lifting Rig 2/3/86 All power reactor j
Attachment While Lifting The facilities holding Upper Guide Structure At an OL or CP St. Lucie Unit 1 86-05 Main Steam Safety Valve Test 1/31/86 All PWR facilities Failures And Ring Setting holding an OL or i
Adjustments CP l
I OL = Operating License CP = Construction Permit l
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