ML20198Q968
| ML20198Q968 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 05/21/1986 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-86, REF-PT21-86-196-000 ANPP-36651-EEVB, DER-86-19, PT21-86-196, PT21-86-196-000, NUDOCS 8606090428 | |
| Download: ML20198Q968 (5) | |
Text
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Arizona Nuclear Power Project 7
P O Box 52034 '
- PHOENIX. ARIZONA 85072-2034
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May 21, 1986 ANPP-36651-EEVB/LAS/DRL-92.1L
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zw U. S. Nuclear Regulatory Commission lf
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Region V r;
1450 Maria Lane - Suite 210 Walnut Creek, California 94596-5368 so Attention:
Mr. D. F. Kirsch, Acting Director Division of Reactor Safety and Projects Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2 and 3 Docket Nos.
50/528, 50/529, 50/530
Subject:
Interim Report - DER 86-19 A 50.55(e) Potentially Reportable Deficiency Relating To BOP ESFAS Cabinets File:
86-006-216; D.4.33.2
Reference:
(A) Telephone Conversation Between A. Hon and D. R. Larkin i
on April 24, 1986 (Initial Reportability - DER 86-19)
(B) Telephone Conversation Between R. C. Sorenson and j
D. R. Larkin on April 30, 1986 (Initial Notification
)
10CFR Part 21, BOP ESFAS Pin Connectors)
)
(C) ANPP-36467, dated May 2, 1986 (Notification of 10CFR Part 21, BOP ESFAS Pin Connectors) i i
Dear Sir:
The NRC was notified of a potentially reportable deficiency by Reference (A) and initial reportability of a 10CFR Part 21 by References (B) and (C). At that time, it was er,timated that a determination of reportability would be made within thirty (30) days (May 23, 1986).
Due to extensive investigation and evaluation required, an Interim Report is attached.
It is now expected that this information will be finalized by June 30, 1986, at which time a complete report will be submitted.
Very truly ur,
8606090428 860521 O
{DR ADOCK0500g8 E. E. Van Brunt, Jr.
Executive Vice President Project Director EEVBJr/DRL/ldf Idf/008/IR86-19 Attachment cc:
See Page Two j
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LD n21
DER 86 Interim Report Mr. D. F. Kirsch Acting Director ANPP-36651-EEVB/LAS/DRL-92.11 thy 21,1986 Page 2 cc:
J. M. Taylor, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 A. C. Gehr (4141)
R. P. Zimmerman (6295)
Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway - Suite 1500 Atlanta, Georgia 30339 1MfAdF4/TETME-T
4 INTERIM REPORT - DER 86-19 POTENTIAL REPORTABLE DEFICIENCY ARIZONA NUCLEAR POWER PROJECT PVNGS UNITS 1, 2 AND 3 I.
Potential Problem Several deficient conditions have been reported for the B0P ESFAS digital logic modules:
A.
Per Reference A, GA Sorrento Electronics informed ANPP that several BOP ESFAS digital logic modules repaired at their facility and returned to ANPP during the later part of 1985 and early 1986 were missing a #6 lock washer that should have been installed between the screw head and the To-3 insulating cover.
The cover is designed such that the lock washer provides the electrical connection between the mounting screws and the voltage regulator. Omission of the lock washer may result in the regulated output voltage approaching the unregulated input. In the case of the BOP ESFAS modules, 28 Vdc would be applied to the input of the integrated circuits (IC's) in the modules resulting in IC and module failure.
B.
While reworking a loose wire found during testing of the Unit 2 B0P ESFAS system, it was determined that the individual module "multimate" ( AMP) pin connectors in cabinet "A" might not meet the required contact length (Reference B).
Further investigation determined that the problem also existed in cabinet "B".
Units 1 and l
3 have similar AMP pin connectors and will also require inspection.
As a result of this finding, a review determined that several broken I
wires have been found in the internal wiring of the BOP ESFAS cabinets over the past year (Reference C).
In each case the wires broke at the crimped socket contacts of the AMP connectors that the modules plug into.
C.
While the modules were being inspected for missing lock washers, a problem was found with regard to the physical size of the voltage regulator heat sink on two of the spare modules and two of the Unit 1 modules (Reference D).
The size of these heat sinks prevents the chip from fully inserting into the socket.
Also the shoulders on the socket for the voltage regulators do not-properly mate with (a) the holes in the module case, and (b) the socket that the voltage regulator plugs into. Neither of these items affect operability.
Q II.
Approach To and Status of Proposed Resolution A.
Missing Lock Washers All modules (Units 1, 2 and 3, and spares) have been returned to GA Sorrento Electronics. The Voltage Regulators covers and Lockwashers have been removed by GA Sorrento via Reference F, which determined l
_ that the lockwashers are not necessary for ground path when
- insulating covers are removed. Unita 1 and 2 modules, plus spares have been received from GA Sorrento and have been retested.
DER 86 Interim Report Page Two B.
Short Connector Pins and Broken Wires Investigation by ANPP Operations Engineering revealed that the broken wires resulted from frequent manual movement by personnel in trying to get a good electrical connection with short pins.
The pins on the male end (module side) of the multi-mate connectors have been replaced with those of correct length while the modules were at Sorrento. Again, these are all modules (Units 1, 2 and 3, and spares).
The female end (cabinet side) of the connectors will be resocketed at the jobsite. Unit i resocketting has been done by Sorrento. Unit 2 rework has been done by ANPP.
Unit 3 rework will be done per SFR/NCR.
To alleviate any wire strain that may be occurring on these connections, a strain relief bracket has been installed to support the field wiring harnesses.
As a result of finding short pins in the BOP ESFAS connectors, EER 86-XI-005 was generated to determine if similar AMP connectors (series M) used elsewhere throughout Units 1, 2 and 3 also have short pins and/or broken wires. The other problems i.e., missing lock washers, heat sink size and misfitting sockets, are unique to BOP ESFAS modules.
The interim and final responses to this EER have been received from Bechtel. No similar problems with AMP connectors were discovered during an intensive search and inspection thru all project procurement documents and related documentation.
The BOP-ESFAS system is the only system supplied to ANPP by General Atomics -
Sorrento Electronics.
C.
Heat Sinks and Voltage Regulator Sockets Installation of heat sinks of correct size and replacement of misfitting voltage regulator sockets have also been done on the applicable modules while they were at G.A. Sorrento.
III. Projected Completion of Corrective Action and Submittal of the Final Report Root cause is currently being investigated by G.A. Sorrento and Engineering.
The rework for Units 1 and 2 has been completed, and the components have been tested and declared operational.
U it 3 modules and some spares are n
still at G.A. Sorrento for the rework and when complete they will be retested. The completed evaluation and final report are forecast for-June 30,1986.
l..
s l
DER 86 Interim Report Page Ihree REFERENCE A.
Sorrento (S. Coppock) Letter to ANPP (D. Iagg). No date, received 4-7-86.
B.
SFR 3SA-009 C.
EER 86-SA-010 D.
Communication Record between Sorrento Electronics and ANPP Operations i
Fagineering, dated April 24, 1986.
E.
EER 86-XI-005 F.
G.A. Sorrento Field Change Order (FCO-201) dated 4/28/86.
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