ML20033E783
| ML20033E783 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/28/1990 |
| From: | Swenson W Office of Nuclear Reactor Regulation |
| To: | Fay C WISCONSIN ELECTRIC POWER CO. |
| References | |
| GL-88-05, GL-88-5, TAC-68297, TAC-68298, NUDOCS 9003140156 | |
| Download: ML20033E783 (10) | |
Text
~
i February 28,1990 i
Docket Nos. 50-266 DISTRIBUTION:
and 50-301 195HETITW NRC & Local FDRs l
PD111-3 r/f JZwolinski JHannon WSwenson PKreutzer EJordan Mr. C. W.. Fay, Vice President OGC-WF1 ACRS(10)
Nuclear Power Department PDIll-3 Gray DDilanni Wisconsin Electric Power Company j
231 W. Michigan Street, Room 308 Milwaukee, Wisconsin 53201
Dear Mr. Fay:
SUBJECT:
POINT BEACH NUCLEAR PLANT, UNIT NOS. 1 AND 2 -- BORIC ACID CORROS10N PREVENTION PROGRAM AUDIT (TAC NOS. 68297 AND 68298)
+
This letter is to advise you that the audit of your boric acid corrosion pre-
[
vention program at the Point Beach Nuclear Piant (PBNP) has resulted in en' acceptable finding and the NRC staff considers'this issue to be closed.
On July 10-12, 1989, the NRC staff and our consultant visited the Point Beach Nuclear Plant to audit your program to prevent boric acid-related corrosion.
The audit team included Messrs. K. Parczewski (NRC) and C. Czajkowski (Brook-havenNationalLaboratory). Boric acid corrosion prevention requirements were described in Generic Letter 88-05 which was issued on March 17, 1988.- The generic letter further requested the implementation of such a-program by all licensees operating PWRs and licensees holding PWR construction permits.
In your letter dated May 24, 1988 you provided a description of, and a commitment to, a boric ucid leakage monitoring and corrosion preventive program for PBNP.
A copy of the trip report, prepared by our consultant, covering the results >
of the audit is enclosed. The staff has reviewed this report and agrees with its findings and conclusions. Based on the observations made during the audit, we conclude that you have adequately implemented a program for monitoring small i
primary coolant lea bqe through carbon steel components caused by boric acid corrosion, as described in your submittal dated May 24, 1988. The results of the PBNP audit will be used along with eudit results from other plants in our overall determination of future action to be taken regarding final NRC resolution of this industry-wide generic issue.
Our review of this issue for PBNP is closed.
Sincerely, p
$u Warren H. Swenson, Project Manager
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Project Directorate 111-3 N
N Division of Reactor Projects - 111, 88 IV, V and Special Projects O' O Office of Nuclear Reactor Regulation
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Enclosure:
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PD/ 111-3 Surname: PKreltrer wen n/tg JHannon Date:
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UNITED STATES NUCLEAR REGULATORY COMMISSION i
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k..... /l wAswiwovow. o. c. rosss February 28, 1990
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Docket Nos. 50-266 and 50-301 Mr. C. W. Fay, Vice President Nuclear Power Department Wisconsin Electric Power Company 1
231 W. Michigan Street, Room 308 Milwaukee, Wisconsin 53201 i
Dear Mr. Fay:
SUBJECT:
POINT BEACH NUCLEAR PLANT, UNIT N05. 1 AMD 2 -- BORIC ACID CORROSION PREVENTION PROGRAM AUDIT (TAC N05. 68297 AND 68298)
This letter is to advise you that the audit of your boric acid corrosion pre-ventionprogramatthePointBeachNuclearPlant(PBNP)hasresultedinan acceptable finding and the NRC staff considers this issue to be closed.
On July 10-12, 1989, the NRC staff and our consultant visited the Point Beach Nuclear Plant to audit your program to prevent boric acid-related corrosion.
The audit team included Messrs. K. Parerewski (NRC) and C. Crajkowski (Brook-havenNationalLaboratory). Eoric acid corrosion prevention requirements were described in Generic Letter 88-05 which was issued on March 17, 1988. The generic letter further requested the implementation of such a program by all licensees operating PWRs and licensees holding PWR construction permits.
In your letter dated May 24, 1988, you provided a description of, and a commitment to, a boric acid leakage monitoring and corrosion preventive program for PBNP.
i A copy of the trip report, prepared by our consultant, covering the results of the audit is enclosed. The staff has reviewed this report and agrees with its findings and conclusions.
Based on the observations made during the audit, we conclude that you have adequately implemented a program for monitoring small primary coolant leakage through carbon steel components caused by boric acid i
corrosion, as described in your submittal dated May 24, 1988. The results of the PBNP audit will be used along with audit results from other plants in our overall determination of future action to be taken reqarding final NRC resolution of this industry-wide generic issue.
Our review of this issue for PBNP is closed.
&B Warren H. Swenson, roject Manager Project Directorate III-3 Division of Reactor Projects - Ill, IV, Y and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc: See next page
l s
tir. C. W. Fay Point Beach Nuclear Plant Wisconsin Electric Power Company Units 1 and 2 e
cc:
Ernest L. Blake Jr.
Shaw, Pittman, Potts and Trowbridge 2300 N Street, N.W.
Washington, DC 20037 Mr. James J. Zach, Manager Point Beach Nuclear Plant Wisconsin Electric Power Company r
6610 Nuclear Road Two Rivers, Wisconsin 54241 Town Chairman Town of Two Creeks Route 3 Two Rivers, Wisconsin 54241 Chairman Public Service Commission of Wisconsin Hills Farms State Office Building Madison, Wisconsin 53702 Regional Administrator, Region III U.S. Nuclear. Regulatory Commission Office of Executive Director for Operations 799 Roosevelt Road Glen Ellyn, Illinois 60137 Resident inspector's Office U.S. Nuclear Regulatory Commission 6612 Nuclear Road Two Rivers, Wisconsin 54241 i
o J
BORIC ACID CORROSION PREVENTION t
Trip Report A.
Introduction On July 10-12, 1989, a USNRC audit team visited the Point Beach Nuclear Power Station Units 1, 2.
The team was comprised of Hessrs. K. Parcrewski of the USNRC and Mr. C. Czajkowski of Brookhaven National Laboratory (BNL).
The purpose of the plant visit was to audit the licensee-implemented program for prevention of carbon steel corrosion by boric acid in the reactor pressure boundary of the plant.
This verification of program implementation took the form of an audit of the Units' written procedures, interviews with plant staff personnel and verifying that the techniques used by the utility were proper and performed by adequately trained / certified personnel.
The cuidelines for the audit fell into four broad areas of concern which should encompass the utilities' elicited responses to NRC Generic Letter 88-05.
B.
Determination of the principal locations where leaks of Primary coolant below the specification linits could cause degradation of the reactor pressure boundary components.
Since the primary pressure boundary is primarily constructed of corrosion rtsistant material, tbt utility has determined that the principal leak locations ere located in:
"A.
Mechanicaljoints(i.e.,manholecovers,manways,andflanged connectiers) to the pressurizer, steam generator and reactor vessel; B.
Other mechanical joints in the primary pressure boundary which use carbon steel bolting; and C.
Valve body to bonnet joints and valve packing bolting..
The allowable leakage rates of reactor coolant is determined by Technical Specification 15.3.1 7 ThisspecifIca/12/76, Unit 1-AmendmentNo.10andUnit2-Amendment No. 12.
tion requires:
"1.
If leakage of reactor coolant from the reactor coolant system is indicated to exceed 1 qpm by the means available such as water inventory balances, monitoring equipment or direct observation a follow-up evaluation of the safety implications shallbeinItiatedassoonaspracticablebutnolaterthan within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Any indicated leak shall be considered to be i
{
1 i '
a real leak until it is determined that either (1) a safety l
problemdoesnotexistor(2)thattheindicatedleakcannot i
be substantiated by direct observation or other indication.
"2.
If the indicated reactor coolant leakage is substantiated and is not evaluated as safe or is determined to exceed 10 gpm, t
reactor shutdown shall be initiated as soon as practicable, but no later than within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the leak was first i
detected."
In containment, physical inspections are performed approximately every two weeks using PC-24 NNSR, Revision 24, 6/29/BB, " Containment inspection Checklist." The checklist lists the various areas to be inspected for various attributes including boric acid leakage and abnormal pump buildup.
C.
Procedures for locating small coolant leaks Various procedures are in use for locating small coolant leaks et the Point Beach Units.
The " Checklist for RCS Leak Test," CL-230. Rev. O, 05/05/89 (Unit 1), CL-235 (11/17/88 - Unit 2) was developed to:
... locate small coolant leaks in Class 1 components (i.e., leakage i
ratesatlessthanTechnicalSpecificationlimits),establishthe path of the leaking coolant, and evaluate any leaks to determine if repair is necessary."
This procedure was also developed to meet the requirements of WEPCO's "Respense to Generic Letter 88-05." [ Attachment A is a list of these components which ere covered by this procedure (Unit 1). - NOT REPRODUCED HERE)
Although used for various components, the previously mentioned (Section B) procedure PC-24 does specifically require inspections of the primary and process systers for leakage.
During the audit, completed checklists (PC-24) were reviewed for Unit 1 -
12/21/88 and 6/22/89; Unit 2 - 6/28/89. These were found to be complete.
Another procedure in use by the utility is CL-40, Rev. 8, 6/21/89, " Outage Valve Inspection Checklist." This checklist includes over 250 individual valves whichareinspected(atthebeginningofeachoutage)forpackingleaksorbody-to-bonnet leaks.
At the end of each outage, a leak test is performed on all safety-related Class i components to assure primary system integrity. These leak tests are performed by qualified operators and inspectors.
P
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- 3=
o Oualifications for three inspectors were checked during the audit ar.d found to be acceptable:
J. Michaelson Level III - V.T.
R. J. VerYooren Level III - V.T.
Z. L. Pianka Level II - V.T.
t The utility also has a procedure for " Reactor Coolant System i.eakage Determination," PBNP 4.11, Rev. 4, 1/2/87, which details the method for trend analysis of reactor coolant leakage and determination of their quantity.
i Leakage is determined by evaluation of six methods of sampling:
1 air particle monitor 2
radiogas monitor 3
relative humidity 4
Sump A drainage 5 Computer and/or marual water balance 6 in-containment physical inspection Primary leak rate calculations are done en a daily basis by the utility and are performed in accordance with 01-55. Rev. 4,10/10/88, " Primary Leak Rate Calculations."
The reviewed procedures meet the intent of Generic Letter 88-05 in scope and det611.
D.
Procedures for evaluating boric acid induced corrosion of carbon steel Components in the reactor pressure boundary.
The licensee primarily uses two methods of evaluating boric acid leakace.
The Maintenance Work Request (PBNP 3.1.3, Rev. 16, 12/07/87) provides a vehicle for:
".. 1.4 To provide a means for all plant personnel to report deficiencies which require corrective action, and to be informed of the completion of such work..."
The majority of minor leakages experienced at Point Beach have been documented using this system. Durinq a plant tour, a number of defect tag i
numbers were recorded and traced through the system. Thest taq numbers were taken off valves / components that were actively leaking or had boric acid crystals in evidence. The following is a list of the defect tag numbers and their associated Maintenance Work Requests (PWR):
i
F i
e o
f b
-4 Date of Issue Defect Tag MWR 10/03/87 08668 873798 1
01/07/88 07900 880076 03/01/88 02586 880851 05/09/89 14311 891916 05/09/89 16438 891898 07/05/89 19044 Not in system yet j
07/05/89 19045 Mot in system yet 04/03/89 18983 891376 i
The fact that some of the lenkers had been "known" lenkers since late 1987 and early 1988 lead to the conclusion that, although procedures are in effect to evaluate boric acid leakage, the implementation of the program does not have a high priority with the utility and in this area the program falls short of the requirements of GL 88-05.
For significant leakage, the utility uses " Control of Nonconformances," QP 15-1, Rev. 1, 05/05/89, which provides for an engineering evaluation of any extensive leakage incidents. This procedure also requires that a copy of the Nonconformance Report be sent to the NPERS root cause engineer.
E.
Corrective actions taken by the licensee to prevent recurrence of similar types of corrosion.
1)
In 1979 an amendment to the Point Beach operatinq license i
reduced the primary system pressure at the Units to 2000 psi.
Although not originally intended to reduce leaks, the utility feels that an effect of the pressure change is a reduction in primary system leaks.
l
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Modification Package 84-281 involved the removal of all isolation valves and vent and drain valves from the R10 loops of the RCS.
In addition, the utility installed welded orifices in lieu of flanged orifices. This was a positive 4
step in reducinq system leakage.
3)
The utility also has an ongoing program in effect to replace carbon steel nuts and bolts on valves with corrosion resistant ASTM A453 GR660 "at convenient opportunity.' This is also a positive step in minimizing boric acid corrosion damage.
4)
A plant tour was provided which included the following equipment (Unit 1,2):
2T-3B Spray Additive Tank SafetyInjectionPumps(Units 1,2)
Containment Spray Pumps Containment Spray Pump Suction /01scharge Charginq pumps l
i i
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, ~,
9 I
5 RCP Root & Throttle Valves Heat Exchanger Charging Lines RHR Heat Exchangers RHR Outlet Control Valve Safety Injection Test Line l
Boric Acid Evaporators and inlet Pressure Control Valves RHR Pumps Spent Fuel Fool Heat Exchangers During the tour, leakage was noted on a vent pipe 0*om SF.7948 P-33
)
Refuelina Water Circulation Pump Discharge Header Relief Valve. There was no defect tag on the valve nor any tray nor bucket to prevent leakage directly 7 nto 1
the floor.
)
A similar vent line was also seen on valve SF794A with no tray under the line. This line was not leaking boric acid solution (no crystals in evidence either). Both of these conditions were brought to the licensee's attentinn t
during the audit. Before leaving the site, the audit team was shown Defect Tao 17097 which was written for the leaking vent line and was assured that the utility would evaluate the non-leakinq line.
4)
Maintenance Wnrk Request 891376 was written for Defect Tag 18983(oneofdefecttagnumberspickedfromplanttour)but the l'WR did not reflect the Defect Tag flumber. This condition was also noticed on MWR 891375 which should reflect Defect Tag 18982 but did not. The utility is investigating this also.
F.
Cenclusions 1)
Procedurally the licensee, in general, meets the intent of Generic Letter 88-05.
^
2)
The cbservations from the plant and the subsequent follow up of random defect tags irdicate that the implementation of tie boric acid corrosion prevention program could be more forceful at the Point Beach Units and should be upgraded in the future.
These conclusions were discussed with the utility personnel at the Exit Critique.
G.
Documents Reviewed 1.
Docket No. 50-266 " Order Modifying Confirmatory Order of November 30, 1979,* Transmittal Letter dated January 3,1980.
2.
Technical Specification 15.3.1.0, " Leakage of Reactor Coolant," Unit 1 - Amendment No. 10. Unit 2 - Amendment No. 12 dated July 17, 1976.
F l
l l.t 6
3.
Wisconsin Electric Response to Generic Letter 88-05. Transmittal Letter dated May 24, 1988.
4.
PBNP 4.11 Revision 4, 1/2/87, " Reactor Coolant System Leakaoe Determination."
5.
01-55 Revision 4,10/10/88, ' Primary leak Rate Calculation."
6.
PC-24, NNSR Revision 26,1/12/89,"ContainmentInspection Checklist,", Unit 2.
i 7.
CL-40, Revision 8, 6/21/89, " Outage Valve Inspection Checklist."
8.
PC-24, NNSR, Revision 25, 2/9/89, " Containment inspection Checklist," Unit 1.
9.
PBNP 3.1.3, Revision 16, 12/7/87, " Maintenance Work Request."
- 10. CL-230 Revision 0, 5/5/89. " Checklist for RCS Leak Test " Unit 1.
- 11. CL-235, Revision 0,11/17/88, " Checklist for RCS Leak Test " Unit 2.
- 12. Completed
- Containment inspection Checklists," Unit 1,12/21/88, while unit at 100% power; Unit 1 - 6/22/89, Unit 2 - 6/28/89.
- 13. Maintenance Work Requests: MWR 890609, MWR 860413, and MWR 892249.
j 14 QP 15-1, Revision 1, 5/5/89, " Control of Nonconformance."
- 15. Modification Package 84-281, (Unit 2) *RTD Bypass Valve Vent Drain and flanced Orifice Removal," and associated documentation.
- 16. Visual Examination Leak Test Records dated:
5/9/89; 5/13/89; and 5/24/89.
- 17. NDE 3, Revision 7, 2/8/88, " Nondestructive Examination Procedures Marual "
s 18.
NDE 750, Revision 7,7/27/88.
H.
Personnel Interviewed 1.
The following personnel were contacted during the site visit:
J. Kohlwey WEPCO Engr. - ISI J. Knorr_
WEPC0 Regulatory Engr.
J. Michaelson WEPC0 QA Engr.
rc
,s
- 2.
The following personnel were present at the entrance meeting:
K. Parcrewski NRC/NRR C. Crajkowski BNL J. Zach Manager - PBNP J. Knorr Regulatory Engr.
G. Sherwood 151 Engr.
J. Kohlwey ISI Engr.
F. Flentje Admin. Spcit.
J. Cadzala NRC - Resident 3.
The following personnel were present at the Exit Critique:
K. Parcrewski NRC/NRR C. Czajkowski BNL J. Gadrala NRC - Resident J. Zack Manager - PBNP J. Kohlwey 151 Engr.
F. Flentje Admin. Spcit.
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