ML20248A145
| ML20248A145 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/02/1989 |
| From: | Michael Ray TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-004, IEB-88-4, TAC-69889, NUDOCS 8908080207 | |
| Download: ML20248A145 (3) | |
Text
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'd k TENNESSEE VALLEY AUTHORITY j
CHATTANOOGA. TENNESSEE 37401 -
~
5N 157B Lookout Place I
AUS 021989 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.
20555 i
Gentlemen:
In the Matter of
)
Docket No. 50-260 Tennesseo Valley Authority
)
BROWNS FERRY NUCLEAR PLANT (BFN) - COMPLETION OF'LONG-TERM ACTIONS FOR THE RESOLUTION OF NRC BULLETIN (NRCB) 88-04 FOR UNIT 2 (TAC 69889)
Reference:
TVA letter to NRC dated September 30, 1988, " Browns Ferry (BFN),
i Watts Bar (WBN), and Bellefonte (BLN) Nuclear Plants - NRC Bulletin (NRCB) 88-04, Potential Safety-Related Pump Loss
The purpose of this letter is to provide NRC with the'results of BFN's long term actions to resolve questions regarding the adequacy of safety-related pumps in miniflow conditions. As a result of the Design Calculation Review Program the onclosed deficiencies were identified and corrected (item 4.C of the reference).
This letter completes the actions required in NRCB 88-04 (for unit 2) and i
requests that NRC close the item for unit 2 restart.
If you have any questions, please telephone Patrick P. Carter, BFN, (205) 729-3570.
j Very truly yours, TENNESSEE VALLEY AUTHORITY 1
% % Q g ensing Managery Nucle L
and Regulatory Affairs Enclosure ec: See page 2 4
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l An Equal opportunity Employer o______________________
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U.S. Nuclear Regulatory Commission
/100021964) cc (Enclosure):
l Ms. S. C. Black, Assistant Director for Projects TVA Projects Division
(
U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Assistant Director for Inspection Programs TVA Projects Division i
U.S. Nuclear Regulatory Commission
- Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35609-2000
ENCLOSURE COMPLETION OF LONG-TERM ACTIONS FOR THE RESOLUTION OF NRC BULLE11N (NRCB) 88-04 L
As a result of the Design Calculation Review Program, item 4.C of TVA's original. response to NRCB 88-04, the following deficiencies were identified concerning the adequacy of safety-related pump miniflow:
1.
Core Spray Miniflow Bypess Orifice Size It was determined that for the Core Spray minifliiw bypass a 15/16 inch diameter orifice was required, as shown on the physical piping drawings.
This was in conflict with the orifice size shown on the flow diagram which indicated a 11/16 inch orifice. This condition was documented in TVA's Condition Adverse to Quality (CAQ) process and the following actions were' taken to resolve the deficiency:
A. The affected orifices were removed and inspected to verify that they were 15/16 inch. Orifices that did not meet-the acceptance criteria were bored to the proper size and stamped properly.
B. After the inspection of the orifices the appropriate drawings were l
revised.
l C. The same actions listed above were performed in regards to the Core l
Spray 10 inch full flow test line.
It was found that the subject orifice plates had been incorrectly stamped. The orifice plates were
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then measured to verify the correct size and the orifice plate handles were re-stiimped.
1 2.
Residual Heat Removal Service Water (RHRSW) Discharge Valve j
RHRSW system operating instructions required that the operator start the j
RHRSW pump prior to opening the discharge flow control valves. A previous I
calculation showed that if the valves were not opened within 1.39 minutes that pump damage could occur. A review determined that the operating j
instruction for RHRSW system had r4 time requirement for opening the valves on pump start-up to insure that pump degradation would be i
prevented. This condition was documented according to TVA's CAQ process and the following action was taken to resolve the deficiency:
A. The calculation that determined that pump damage could occur if the pump were dead-headed for 1.39 minutes was reviewed.
It was determined, after removing excess conservatism, that it could take 43 minutes before pump damage could occur.
- 8. The operating instruction for the RHRSW system has been revised to include a warning that pump damage may occur if RHRSW outlet valves are not opened.
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