ML20092A255
| ML20092A255 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 08/12/1983 |
| From: | Patti F BURNS & ROE CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-PT21-83, REF-QA-99900503 83-14, NUDOCS 8406190117 | |
| Download: ML20092A255 (4) | |
Text
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g Burns and Roe,Inc.
185 Crossways Park Drive a Woodbury, New York 11797 m Tel. (516)677-4000 TWX 510 221-2195 l
Main Office 550 Kinderkamack Road
Subject:
W. O. 3900/4000 or o ii. new aersey o7649 Washington Public Power Supply System (201)265-2000 WNP-2 Defect and Noncompliance Evaluation Report No. 83-14 Standby Service Water System Flow August 12, 1983 BRGO-83-004, Rev. 1 U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 Attention:
Mr. J. P. Collins, Regional Administrator Gentlemen:
In accordance with Burns and Roe Project Proce-dure WNP-2-ED-003, Report of Defects and Non-Compliance (Nuclear Projects), Burns and Roe has determined that the subject deficiency is reportable under 10CFR21 and notified your Mr. D. Fox on August 4, 1983.
A copy of Defect and Noncompliance Evaluation Report No. 83-14 is being provided with this letter as required by 10CFR21.
Very truly yours, FJP/pn F.J. Patti Attachment Chief Nuclear Engineer c.c.:
Mr. R. T. Johnson - WPPSS - 1 w/l Director, Office of Inspection & Enforcement - 1 w/3 U.S. Nuclear Regulatory Commission Washington, D. C.
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EVALUATION REPORT h
83-14
\\J STANDBY SERVICE WATER SYSTEM FLOW I.
Description of Deficiency Insufficient flow to several heat excha'ngers in Standby Service Water (SW) loops A and B as. indicated on the table below:
COOLER REQUIRED' FLOW, gpm MEASURED
- FLOW, gem CAC-EV-1A 50 30 CAC-EV-1B 50 10 RHR-P-2A 10 6
RHR-P-2B 10 4.5 RHR-P-2C 10 2.5 WMA-CC-53Al 60 49 WMA-CC-51B1 120 98 WMA-CC-53B1
-60 30
- as of 7/14/83, per SPR-M-2807 II.
Time and Method of Discovery
(/
Date of discovery was July 28,~1983.
Burns and Roe,
~
(BRI) became aware of the low flow conditions in the Standby Service Water System (SW) loops when Start-up Problem Report SPR-M-2400 was transmitted to BRI for evaluation on May 18,1983.
At that time, BRI could not determine if the low flow conditions were caused by design error or by fouling because the SW flow calculations were not based on as-built small bore piping design.
There was an Unmediate effort to update the calculation.
By July 28, there was sufficient information to conclude that some of the low flow conditions were caused by excessive pressure drop in the small bore piping.
III.
Safety Implication Insufficle'nt flow to SW heat exchangers could cause failure of safety-related equipment due to overheating.
' Failure of this equipm'nt could preclude safe shutdown e
of the reactor.
IV.
Cause of' Deficiency The primary cause of this deficiency is due to corrosion
~
product buildup on.the inside surface'of the pipe.
The material buildup reduces the pipe flow area and increases
(-)
resistance.resulting in a low flow condition..
In addition, errors in the original system p,re s sure 'd'rch' ons
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e '
IV.
Cause of Deficiency-(Continued) 2-have.been identified.
The calculations should have.been considered preliminary until all system design information was available' In revising the calculation to the latest design /as-built configuration several cases have been identified where the calculated available pressure head will not provide the required design flow rate.
In these cases, eithar the assumed system resistance was-i less than the as-constructed configuration or the wrong l
parallel flow path wa's as~sumed to be the limiting case.
t V.
Action'to Prevent Recurrence t
A chem'ical treatment program is required to control water quality so as to prevent future material buildup in the pipe.
f There is no' action that can be taxen to completely eliminate errors.
However, two factors should reduce the possibility-of errors in pressure drop / flow calculations in the future..
1)
We are now.using a computer ~ program for such calculations.
This allows.modelling of all loops l
of'large parallel systems which eliminates the
(
need to assume'that a certain loop is limiting..
2)
The plant is built.
There is no need to assume piping configurations.
VI. -
Corrective Action The Standby Service Water System'was chemically cleaned to remove the deposited material.
Subsequent i
testing and inspection has identified that excessive i
fouling still exists and that additional cleanup is i
required.
The deposited material-has been analyzed and chemical
[
t treatment to inhibit future deposits has been identified.
i These topics are discussed in detail in Burns and Roe Technical' Memorandum Number 1300, dated June 9, 1983.
The system pressure drop calculations are being revised to reflect the latest design configuration.
The calculations that have been revised to date indicate that the - required pressure head can be achieved by-
~
thro.ttling the RHR heat exchanger discharge valves (RHR-V-68A, B) and enlarging the removable orifices (SW-FE-1A, B) in the return lines located in the SW pump houses (Figure 1).
.If system design changes are l
identified as,necessary to correct the deficiency, they will be implemented as required.
l
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O SI M PLI FIE D STANDBY-SERVICE WATER FLO W DIAGR AM R W P.- H X-1 A,8 i
R H R-V-6 8 A,6 move..
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-S W-FE-GA,6 SW-FE-I A, B -
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SW-Ro 2A,6 I
I
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TY PICA L HEAT E XCH AhlG E R l
.y SW PUMPHoVSE 1
1
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FIGURE i
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