ML20215G244
| ML20215G244 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs, Salem, Palisades, Fermi, Hope Creek, Grand Gulf, Summer, San Onofre, Comanche Peak, Big Rock Point, Midland, 05000000, Zimmer |
| Issue date: | 06/16/1987 |
| From: | Jay Dougherty VITRO ENGINEERING CO. |
| To: | NRC |
| References | |
| REF-PT21-87, REF-PT21-87-114-000 PT21-87-114, PT21-87-114-000, NUDOCS 8706230179 | |
| Download: ML20215G244 (3) | |
Text
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June 16,1987 CO R PO R ATION 14000 GEORGIA AVE.
SILVER SPRING, MARYLAND 20910 (301)231 1000 Director i
Office of Inspection and Enforcement Nuclear Regulatory Commission Washington, D.C. 20555
Dear Sir:
Vitro Corporation has been notified by South Carolina Electric and Gas Company (SC E S G),
V.C.
Summer Nuclear Station, that Load Sequencing equipment supplied by Vitro in August 1977 experienced a failure during scheduled testing due to an open electrical connection on one crimp lug. As
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this matter has been reported to the NRC by SCESG in compliance with the provisions of 10 CFR 21, duplicate reporting by Vitro is understood to not be required. However, we wish to inform the NRC of the results of our internal i
review of this issue, and, by copy of this letter, recommend further action by other selected utilities to whom Vitro has previously supplied equipment.
The Load Sequencers supplied to SCESG utilize solderless ring tongue l
terminal lugs for terminating internal wiring to the output terminal blocks.
The procurement specification for this equipment required the use of uninsulated lugs (Amp # 35590) as opposed to insulated lugs which have been the standard used by Vitro on other class IE systems. Recent testing and failure analysis of the sequencers by SCESG disclosed an open electrical connection apparently due to oxidation developing in the crimp area during the ten years since delivery of the equipment to SCE60. Inspection of all crimp connections by SCESG, and subsequently a sample quantity by Vitro, revealed no other open circuits l
but many instances of marginal workmanship. The evidence indicates that wire insulation was permitted to extend into the lug barrel and the crimping operation was performed with a tool not specified by the manufacturer for this particular lug.
Our investigation makes it clear that in mid-1977, when the SCESG equipments were being manufactured, adequate shop and inspection controls were not in place at Vitro. This situation was remedied in September 1978 with the establishment of an internal Manufacturing Process Standard (MPS 136) dealing specifically with crimp connections. Training and certification of manufacturing and inspection personnel to this standard was completed as of April 1979.
Since insulated lugs were utilized on all equipments other than the SCESG order, we believe that workmanship on other class IE equipments supplied by Vitro is entirely satisfactory. For those equipments manufactured prior to April 1979 and full application of MPS 136, the utilities involved may wish to inspect the Vitro equipment to further verify proper workmanship.
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Appropriate inspection criteria will be provided upon request. Listed below are those utilities with pre-1979 Vitro equipment installed.
8706230179 B70616 (l
PDR ADOCK 05000R56 8
PDR L
Utility Emainment.
Shloment Date
' Baltimore Gas and 2](
Engineered Safety Unit 1 11/24/71 Electric Company Features Actuation Unit 2 5/26/72
W Public Service d
Safeguard Equipment Unit 14/4/74 Electric and Gas d
Control' System (SEC)
Unit 2 5/21/74 Company
. The Detroit Edison 34f Automatic Digital Load 5/6/76 Company Sequencing System
( ADLSS)
Consumers Power y5 eac r Depressurizing 12/12/75 Company 1
System (RDS)
Yko Taiwan Power Engineered Safety 11/16/77 Company Features Load Sequencer (ESFLS)
Cincinnati Gas and 3N Essential Relay (IC 8/23/76)
Electric Company Panel (ERP)
(1B) 9/16/76 (1 A) 9/17/76 Central Nuclear Safeguard Sequencer Unit 1 8/17/76 De Almaraz Cabinets (SSC)
Unit 2 9/13/76 (Energy, S. A. )
Texas Utilities 4db&
Solid State Safeguards Unit 1 12/31/77 Generating Company System (SSS)
Unit 2 7/18/79 (TU Electric Co.)
Fuerzas Electricas Engineering Safeguards Unit 1 12/22/77 De Cataluna, S.A.
Loading Sequencer Unit 210/27/77
( Asociacion duelear Asco' A.N. A. )
South Carolina 39 5 Engineered Safety 8/8/77 Electric and Gas Features Loading i
Company Sequencer (ESFLS)
Mississippi Power 3
Load Shedding and Unit 14/21/78 and Light Company Sequencing Panels (LSSP)
Unit 2 9/9/79 i
Southern Californig Emergency Evacuation Partial 9/15/78
- Edison to Alarm System (EEAS)
Final 12/4/78 i n; 4 1
p.
June 16,1987.
With respect to Vitro equipments other than those listed above, no further l
action is believed necessary as they were manufactured under control of our I
process standard for crimp connections.- We will be pleased to assist the NRC-or utility addressees by providing additional information if needed. You may
- contact the undersigned at (301) 231-3030.
1 Sincerely yours,
(,
9,.
James G. Dougherty, Jr. -
Quality Assurance Officer JGD/n Distribution Baltimore Gas and Electric Company Pub!!c Service Electric and Gas Company
- The Detroit Edison Company Consumers' Power Company
- Taiwan Power Company Cincinnati Gas and Electric Company Central Nuclear De Almaraz (Energy, S A.)
- Texas Utilities Generating Company (TU Electric Co.)
Fuerzas Electricas De Cataluna, S.A. (Asociacion Nucler Asco' A.N.A.)
South Carolina Electric and Gas Company Mississippi Power and Light Company Southern California Edison f