ML20081M365
| ML20081M365 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 11/03/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-83 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8311170234 | |
| Download: ML20081M365 (3) | |
Text
TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ol 400 Chestnut Street Tower II N
November 3,1983 BLRD-50-438/82-30 BLRD-50-439/82-27 U.S. Nuclear Regulatory Consnission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900
. Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - DEFECTS IN RPS AND ESFAS MODULES SUPPLIED BY BAILEY METER COMPANY - BLRD-50-438/82-30, BLRD-50-439/82 FINAL REPORT The subject deficiency was ini+.ially reported to NRC-0IE Inspector J. Bryant on April 14, 1982 in accordance with 10 CFR 50.55(e) as NCR 1795. This was followed by our first interim report dated May 11, 1982.
Related NCR 1860 was also determined to' be reportable in accordance with 10 CFR 50.55(e). This was followed by our interim reports dated August 10 and October 26, 1982 and January 3 and May 26, 1983 Enclosed is our final report. We consider 10 CFR Part 21 applicable to this deficiency.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours,
' TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Licensing Enclosure cc (Enclosure):
Mr. Richard C. DeYoung, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Conunission Washington, D.C.
20555 Babcock & Wilcox Company F.O. Box 1260 Lynchburg, Virginia 24505 Attention:
H. B. Barkley g-
- f. h<'[OTI cc: Continued on page 2 8311170234 831103 t
- 1MV PDR ADOCK 05000438
.k / ]f S
PDR g
1983-TVA SOTH ANNIVERSARY An Equal Opportunity Employer
\\
- U.S.. Nuclear Regulatory Coimmission November 3,1983
= Records Center Institute of Nuclear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339
/
ENCLOSUi'E 4
1 BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 DEFECTS IN RPS AND ESFAS MODULES SUPPLIED BY BAILEY METER COMPANY NCR'S 1795 AND 1860 BLRD-50-438/82-30, BLRD-50-439/82-27 10 CFR 50.55(e)
FINAL REPORT Description of Deficienov Nonconformance report (NCR) 1795 deals with connector and support brackets for the printed subcircuit boards in the plug-in modules of the Reactor Protection System (RPS) and the Engineered Safety Features Actuation System (ESFAS). These brackets have stress fractures and show evidence of having been glued. This deficiency was discovered during routine surveillance inspection of the modules. Approximately 500 connector and support bracket assemblies are involved. The same problem has also been found in the non-Class IE Protection System Auxiliary Cabinets.
Subsequent inspection has identified additional problems (NCR 1860) with approximately 150 modules in the RPS and ESFAS that have built-in indicators, both flow cad temperature type.
In these ufpe modules, there is a general distribution of built-in indicators which have cracked housings, loose terminals, damaged terminal studs, improper size terminals used on 24AW6 wire, and general]y poor quality crimps.
The apparent cause of the deficiencies detailed in both NCRs is poor assembly by the module manufacturer, Bailey Meter Company of Kendrick, Ohio, a subcontractor of Babcock and Wilcox.
Safety Implications The defects described in NCR 1795 could result in the failure of two types of four support devices used for each board. Loss of the two support types could compromise the structural soundness of the assembly and could result in a failure of the module (s). For the problems described in NCR 1860 it was determined that loose terminals and terminal studs were the only conditions that could significantly affect safe ' operation of the modules. These loose connections could cause an open condition in various circuits on the modules.
Loss of the modules through deficient structural support or improper l
operation of individual circuits due to faulty connections could prevent the RPS or ESFAS from tripping the reactor or from mitigating the consequences of a LOCA or secondary system rupture.
Corrective Action In June 1983, a representative of Bailey Meter Company insnected the j
faulted equipment and determined:
1.
Twenty-nine of the unit 1 modules had at least one unacceptable connector / retaining clip each which required replacement.
T
2.
Indicator housings contained hairline cracks only, and these cracks did not impair the functioning of the housings. These housings could be used as is.
3.
Loose indicator terminals and terminal studs were found which required retightening.
4.
Damaged terminal studs were apparently held by pliers when tightening the connection, but the damage was not sufficient to affect terminal function and did not require replacement.
5.
A missing dust plug would need to be replaced.
6.
A crimp type lug had been soldered, but this provided an acceptable connection which could be used as is.
Bailey Meter Company will be providing replacement parts where necessary, as well as instructions on replacement of the unit 1 connectors / retaining clips. They will also inspect the first few corrections, and then will inspect the unit 2 modules and determine which clips will have to be replaced by TVA. All corrective actions on these boards will be completed by April 15, 1984.
TVA's Quality Engineering Branch (QEB) normally monitors cabinet assembly at Bailey Meter Company to a limited extent and concentrates on the final inspection where functicnal checkout and testing is performed. However, to prevent a recurrence of this ty7e-nonconforming condition at TVA, QEB has alerted their regional office of these nonconforming conditions and has instructed them to increase their surveillance activities in the areas of assembly and installation on printed circuit boards. Also, Bailey Meter Company has increased their audits of this component from their subvendor and has revised the design specification issued for procurement of the polycarbonate overhead retaining clips.
h