ML20094D898
| ML20094D898 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 07/16/1984 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8408090025 | |
| Download: ML20094D898 (2) | |
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TENNESSEE VALLEY AUTHORITY-.
' CHATTANOOGA. TENNESSEE 37401,
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400 Chestnut Street Tower II July 16,1984
.BLRD-50-438/83 BLRD-50-439/83-06 n.
U.S. Nuclear. Regulatory Commission Region II.
- Attn
- - Mr. James P. O'Reilly, Regional. Administrator.
101 Marietta Street, NW, Suite 2900 Atlanta, Gergia 30323
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT: UNITS 1 AND 2 - BACKFLOW NOT. CONSIDERED FOR ERCW' BOOSTER PUMP SHUTOFF - PLRD-50-438/83-09, BLRD-50-439/83 THIRD INTERIM REPORT The subject deficiency was' initially repwted to NRC-0IE Inspector l
L. Watson on December 30, 1982 in accordance with 10 CFR 50.55(e) as NCR'BLN BLP 8233 This was followed by our interim reports dated January 28 and May 6,1983 Enclosed is our third interim report. We expect to submit our next report by February 15, 1985.
If you have any questions, please get in touch with R. H. Shell at-FTS 858-2688.
[
Very truly yours, l
TENNESSEE VALLEY AUTHORITY i
L. M. Mills, Manager Nuclear Licensing Enclosure oc:
Mr. Richard C. D9 Young, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure) l Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 l
'B408090025 840716
'983-TVA 50TH ANNIVERSARY
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f DR ADOCK 05000438
.S PDR An Equal Opportunity Employer i
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ENCLOSURE A
.s BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 BACKFLOW NOT CONSIDERED FOR ERCW BOOSTER PUMP SHUTOFF BLRD-50-438/83-09, BLRD-50-439/83-06 10 CFR 50.55(e)
NCR BLN BLP 8233 THIRD INTERIM REPORT Description of Deficiency
. During design of the Essential Raw Cooling Water (ERCW) System, consideration was not given to booster pump shutdosn and the prevention of backflow.
Designers had considered that these pumps would cperate continuously and would not require backflow prevention. During loss of offsite power or during routine maintenance the pumps would shut down thereby resulting in backflow. This deficiency was discovered during the design review process.
A check valve should have been placed in the discharge line of the booster pumps to prevent backflow when the pump shuts down.
Interim Progress 1
TVA has issued engineering change notice 1718. The ERCW design criteria diagram has been nodified to include check valves in the discharge of the booster pumps. Check valve procurement documents have been issued. Piping drawings have been -revised to include the check valves. Seismic analysis drawings will be revised to include the check valves. Seismic support will be dhanged as necessary.
To prevent recurrence of this deficiency, TVA will reinstruct designers to consider pump shutdown as an operating mode in preparation of design criteria diagrams,
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