ML20011E549
| ML20011E549 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/08/1990 |
| From: | Wambach T Office of Nuclear Reactor Regulation |
| To: | Shelton D TOLEDO EDISON CO. |
| References | |
| GL-88-05, GL-88-5, TAC-68915, NUDOCS 9002160071 | |
| Download: ML20011E549 (11) | |
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UNITED STATES I
8-NUCLEAR RECULATORY COMMISSION
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WASHINGTON, D. C,30H6
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Tebruary 8,1990 Docket No: 50-346 i
Mr. Donald C. Shelton a
Vice President, Nuclear i
Toledo Edison Company Edison Plaza-Stop 712 300 Madison Avenue Toledo, Ohio 43652
Dear Mr. Shelton:
SUBJECT:
PREVENTION OF BORIC ACID CORROSION AT DAVIS-BESSE NUCLEAR POWERPLANT(GENERICLETTER88-05),(TACNO.68915) t The purpose of this letter is to advise you that our audit of your i
boric acid corrosion prevention program has resulted in an acceptable finding and we now consider this issue to be closed.
On September 11-13, 1989, the NRC staff and our consultant visited the Davis-Besse Nuclear Power Plant to audit the program to prevent boric acid related corrosion. The audit team included K. Parcrewski (NRC),
C. Czajkowski (consultant, Brookhaven National Laboratory), and T. V.
Wambach(NRC).
Boric acid corrosion prevention requirerents were described in Generic Letter 88-05 which was issued on March-17, 1988, and requested the implementation of such a operating pressurized water reactors (PWRs) program by all licensees of and holders of construction permits for ?WRs.
In your "05000346/LER-1988-011, :on 880408,following Maint on Fire Door 422, Shift Supervisor Incorrectly Declared Fire Door Operable & Terminated Continous Fire Watch for Fire Barrier.Caused by Personnel Error.[[Topic" contains a listed "[" character as part of the property label and has therefore been classified as invalid. Reestablished|letter dated May 27, 1988]], you provided a description of, and a commitment to, a boric acid leakage monitoring program and a corrosion preventive program for Davis-Besse. On June 26, t
1989, you informed us that you were preparing a new procedure to combine the programs described in your May 27, 1988 response.
7 A copy of the trip report covering the results of the audit which was prepared by our consultant is enclosed. The staff has reviewed this report and agrees with its findings and the conclusion. On this basis and the observations made during the audit, we conclude that you have adequately implemented a program for monitoring small primary coolant leakage to prevent boric acid corrosion of carbon steel components.
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Mr. Donald C. Shelton February 8, 1990 t
The results of the Davis-Besse audit will be used along with audit results from other plants in our overall determination of future actions to be taken regarding NRC's final resolution of this industry-wide generic issue.
Our review of this issue for Davis-Besse Nuclear Power Plant is closed.
Sincerely,
/s/
i Thomas V. Wambach, Sr., Project Manager Project Directorate 111-3 Division of Reactor Projects - Ill, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
Audit Report cc w/ enclosure:-
See next page DISTRIBUTION:
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1.4 Mr. Donald C. Shelton Davis-Besse Nuclear Power Station 1
Toledo Edison Company Unit No. 1 cc:
David E. Burke. Esq.
t The Cleveland Electric Radiological Health Program Illuminating Company Ohio Department of Health P. O. Box 5000 1224 Kinnear Road Cleveland, Ohio 44101
-Columbus, Ohio 43212 Mr. Robert W. Schrauder
'orney General l
Manager, Nuclear t.icensing Department of Attorney Toledo Edison Company General Edison Plaza 30 East Broad Street 300 Madison Avenue Columbus, Ohio 43215 Toledo, Ohio 43652 Mr. James W. Harris, Director Gerald Charnoff, Esq.
(Addressee Only)
Shaw, Pittman, Potts Division of Power Generation and Trowbridge Ohio Department of Industrial Relations 2300 N Street N.W.
2323 West 5th Avenue Washington, D.C. 20037 P. O. Box 825 Columbus, Ohio 43216 Regional Administrator, Region 111 U.S. Nuclear Regulatory Comission Ohio Environmental Protection Agency 799 Roosevelt Road 361 East Broad Street Glen Ellyn, Illinois 60137 Columbus, Ohio 43266-0558 l
President Board of Mr. Robert B. Borsum founty Comissioners of Babcock & Wilcox Ottawa County Nuclear Power Generation Division Port Clinton, Ohio 43452 Suite 525, 1700 Rockville Pike Rockville, Maryland 20852 State of Ohio Public Utilities Comission Resident inspector 180 East Broad Street U.S. Nuclear Regulatory Comission Columbus, Ohio 43266-0573 5503 N. State Route 2 Oak Harbor, Ohio 43449 O
BORIC ACID PREVENTION Trip Report A.
Introduction On September 11-13, 1989, a USNRC audit team visited the Davis-Besse Nuclear Power Ctation. The team was comprised of Messrs. K. Parcrewski and T. Winbach of the USNRC and Mr. C. Czajkowski of Brookhaven National Laboratory (BNL).
3 The purpose of the plant visit was to audit the licensee's implemented i
program for prevention of carbon steel corrosion by boric acid in the reactor pressure boundary of the plant.
The verification of the program implementation took the form of an audit of the Unit's written procedures, interviews with plant staff personnel and verifyin9 that the techniques used by the utility were proper and performed by adequately trained / certified personnel.
The guidelines 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 limits could cause degradation of the reactor pressure boundary components.
On June 26, 1989, Toledo Edison submitted a revised response to Generic Letter 88-05 to the USNRC. Theutility(intheresponse)statedthat
"...the process for identifying boric acid corrosion needs additional enhancements. This determination has been documented in Toledo Edison Potential Conditions Adverse to Quality Report (PCAQR) 89-0058, initiated on January 27, 1989. Toledo Edison has appointed a task force specifically chartered to improve the boric acid corrosion control process. The outcome of this task force is expected to combine all applicable aspects of the various programs described in Toledo Edison's Mcy 27, 1988, response into a specFic Boric Acid Corrosion Program. A draft procedure for implementation of the Boric Acid Corrosion Program has been developed. The overall program is planned to be implemented by September 1989. This program will satisfactorily l
implement the requirements of Generic Letter Nuclear Group Procedure NG-EN-00324, " Boric Acid Corrosion Control,"
dated September 8, 1989, Revision 0, was written to additionally enhance the Davis-Besse Boric Acid Corrosion Control Program. This procedure's stated purpose:
l "1.0 PURPOSE 1.1 This procedure provides a program which implements systematic measures to ensure that boric acid corrosion at Davis-Besse Nuclear Power Station does not degrade the assurance that the reactor coolant pressure boundary (as defined in 10 CFR 50.2) will have an extremely l
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i low probability of abnormal leakage, rapidly propagating failure, or gross rupture. These measures include:
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1.1.1 identification of principal locations where leaks can cause degradation of the primary pressure boundary by boric acid corrosion.
1.1.2 Procedures for locating small coolant leaks.
]
1.1.3 Methods for conducting examinations and performing engineer-ing evaluations to establish the impact on the reactor i
coolant pressure boundary when leakage is located.
1.1.4 Corrective actions to prevent recurrences of detected boric acid leaks."
This procedure applies whenever a coolant leak is detected anywhere within the primary pressure boundary.
Section 6.1 of this procedure discusses principal leak locations at the Davis-Besse plant:
6.1.1 All areas and components within the primary pressure boundary are capable of developing coolant leaks.
However, when checking for coolant lea ks, it is important to know the principal locations where they are most likely to cause degradation of the primary pressure boundary by boric acid corrosion. The following locations in systems containing boric acid solutions have been identified as the most probable locations of leakage:
a.
Steam Generator manways and handholes b.
Pressurizer manways and handholes c.
Thermowells d.
Reactor Coolant Pump seals and flanges e.
Control Rod Drive flanges f.
Piping flanges g.
Valves seats and packing glands h.
The Reactor Vessel head gasket i.
Pressurizer Relief Valve rupture discs, l'
Althoughtheadministrative(overall)procedurewasinplace,various implementing procedures had not been written at the time of tia audit. The utility has a requirement (NG-TM-00155,RS) to have these implementing procedures approved within 90 days of the approval of the overall procedure. NG-EN-00324 10eets the intent of the generic letter.
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C.
Procedures for location small coolant leaks
)
The utility has various procedures which provide for routine inspections for reactor coolant leaks. They include:
DB-PF-03065, ASME Section XI Inservice Pressure Tests DB-0P-06901, Plant Startup DB-0P-06903, Plant Shutdown and Cooldown i
DB MN-00002, Preventive Maintenance Additionally, coolant leak inspections may be required by the following:
DB-SP-03357, RCS Water Inventory Balance DB-0P-02522, Small RCS Leals Personnel performing inspections forleakage (ASME Section XI) are qualified to a VT 2 criteria.
During the audit, VT-2 qualifications were verified for the following personnel:
R. Cockrell Level II P. Vandyne Level _11 M. Hurley Level 11 TheASMESectionXIprocedure(DB-PF-03065)providesforasteptoremove I
insulation:
paragraph "4.1.15 Identify on Attachment 2 any insulation which must be removed for visual examination of borated system bolted joints..."
Additionally, paragraph 4.2.4 states:
" Ensure the VT-2 visual examination personnel are familiar with the test boundaries to be visually examined."
Paragraphs 5.6 and 5.7 of the procedure also requires that:
"5.6Ensurethevisualexaminer(s)havecompleted their examinations and documented each line, component, boundary or area examined on the VT-2 Examination Report.
5.7Ensurethevisualexaminer(s)havedocumented all identified leakages on the VT-2 Examination Report."
These procedures coupled with the training / certifications of inspectors comply with the intent of the generic letter.
4 D.
Procedures for evaluation boric acid induced corrosion of carbon steel
_ components in the reactro pressure boun6ery.
The utility has detailed the following steps to be followed after boric acid leakage is discovered (Procedure NG-EN-00324).
"6.3.1 Upon notification of boric acid leakage in the Plant Systems Engineeringshallperformaninitialinspectionoftheaffectedarea to determine the as-found conditions, using drawings, photographs, or other aids as appropriate. The following information should be gathered and documented during this inspection:
a.
Size of the leak or the amount of boric acid residue present or both b.
Component (s)affected c.
Extent of visible damage to the affected area d.
Evaluation of any immediate safety concerns e.
Identificationofleakpath(s) f.
Identification of insulation or any other type of interference which must be removed to gain access to the leak g.
Any preliminary preparations necessary for perform-ing subsequent inspections h.
The temperature of affected components (for use in calculating the corrosion rate)
(NOTE:
Component temperature may be measured using a contact pyrometer from the M&TE Issue Room) 1.
The boric acid concentration in the reactor I
coolant.
"6.3.2 System Engineering shall notify the Shift Supervisor of any immediate saf ety concerns raised by the initial inspection.
"6.3.3 Based on the ma nitude of the leak and extent of damage to the affected area stems Engineering shall document the inspections by oneofthefoll ing:
a.
Writing a Potential Condition Adverse to Quality (PCAQ)ReportperNG-QA-00702,PotentialCondition Adverse to Quality Reporting j
b.
Writing a Work Request per DB-PN-00007, Control of Work.
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,g "6.3.4 If boric acid residue is present, Systems Engineering shall contact-Radiological Controls for cleanup of the affected area.
" 6. 3. 5 '-
Systems Engineering shall determine whether additional inspections of the leak are necessary to fully assess the component damage and
. determine possible corrective action..."
Two evaluations of significant boric acid leakage performed by the utility were reviewed during the audit; no discrepancies were noted.
E..
Corrective actions taken by the licensee to prevent recurrence of similar types of corrosion.
1.
Procedure NG-EN-00324, " Boric Acid Corrosion Control," paragraph 6.3.6.5 requires:
" Determine the corrective actions to be taken to prevent recurrence of boric acid corrosion. These corrective actions should include considerotion of plant design modifications and operating procedure modifications which would:
a.
Reduce the probability of primary coolant leaks at locations where they may cause corrosion damage.
b.
Entail the use of corrosion-resistant materials or the application of protective coatings or claddings, c.
Redesign insulation layout that would permit draining or shunting of coolant leaks away from critical areas."
2.
Three instances of boric acid leakage / evaluation were provided to the inspection team by the utility, they included:
a.
ISE Inspection of Pressurizer for Possible Boric Acid Corrosion, ISE-87-10049,5/28/87.
b.
6bservations of Boron Accumulation due to Leaking Code Safety W1ve,NES.87-00236,6/15/87.
c.
Pctential Condition Adverse to Quality (PCAQ) No. 89-0058, 1/27/89.
i For all three items the utility appeared to do a thorough and professional l
. investigation and corrective action follow-up.
L 3.
A plant tour was provided of accessible areas. Work Order / Requests were j
randomly, recorded during the tour:
- MU58BA
- MU58A
- MU3 MU62
- P037-01
- MU19 MU804
- DH1518
- MU232 MU803
- DH1517
- MU6420 l
MD507
- MU6422 l
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6-If item.is asterisked (*), Maintenance Work Order also reviewed.
No discrepancies were noted.
F.
Conclusions Procedurally the licensee meets the intent of Generic Letter 88-05 (all fourpoints'oftheGenericLetterareaddressed). The general administrative procedure needs to have the appropriate implementing procedures written in order to fully implement the utility's program requirements. The following areas of boric acid corrosion prevention could be enhanced at the Davis-Besse plant:
a)
System and operations engineers who perform boric acid leak inspections should have some formal training prior to performing the inspections.
b)
Inspections performed by the system and operations staff should be documented formally.
These conclusions were discussed with the utility personnel at the Exit Critique.
G.
Documents Reviewed Letter Response to USNRC Generic Letter 88-05, May 27, 1988, Serial No. 1527, 2.
LetterResponse(Revised)toUSNRCG0nericLetter88-05, June 26, 1989, Serial No. 1-885.
3.
Administretive D*ocedure, NG-EN-00324, " Boric Acid Corrosion Control,"
9/8/89,Rev.-0.
4.
Memorandum from S. Jain to L. Storz, "ISE Inspection of Pressurizer for Possible Boric Acid Corrosion," 5/28/87, ISE-87-10049, 5.
Memorandum from J. Wood to P. Hildebrandt, " Observation of Boron Accumulation Due to Leaking Code Safety Valve," 6/15/87, SUS-064-04.
6.
Standing Order - S087-015, "RCS Leakage Management," 12/16/87.
l' 7.
Potential Condition Adverse to Quality Report (PCAQR), No. 89-0058, L
1/27/89 and the following associated documents:
l a.
B&W 1etter to utility:
Subject:
" Davis-Besse Nuclear Power L
Station - Unit 9 Leaks at RTD Element Connections," DB-80-147, l
4/24/80.
L b.
Maintenance Procedure HP 1401.13, " Reactor Coolant System Temperature Detector Removal and Replacement," Rev.
2, 1
11/19/85.
c.
MaintenanceWorkOrder(itWO) 7-89-0058-01, 3/11/89.
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, 1 d.
PCAQR Extension Request, 2/10/89, e.
ProcedureChangeRequest(PCR)', 89-3149, Rev. O, 4/24/89.
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f.
Safety Review and Evaluation, 4/5/89.
g.-
Memorandum from T. Anderson to Distribution:
Subject:
" Forced Outage P ro," 4/28/89.
8.
Plant Procedure, DB-0P-06903 (Supersedes PP 1102.10),"PlantShutdown and Cooldown," Rev. O, 11/18/88.
9.
Maintenance Work Orders:
IJ88-2658(1-87-3004-00)andIJ88-7409(1-88-0065-01).
- 10. Nuclear Group Procedun. NG-QA-00702, " Potential Condition Adverse to Quality Reporting," Rev. R1 (C-1), 6/7/89.
- 11. Abnormal Procedure, DB-0P-02522, "Small RCS Leaks," Rev. O, 11/16/88.
- 12. QA " General Visual Testing Qualification Card 2E," 8/2/88, 13.. QA " Visual Testing (VT-2) Qualification Card 21," 8/2/85.
- 14. Nuclear Group Procedure, NG-IM-00115. " Preparation and Control of Nuclear Group Department and Section Procedures," Rev. 5 11/4/88.
15.-
Surveillance Test Procedure, DB-SP-03357, "RCS Water Inventory Balance," Rev. 0-(C-1), 7/26/89.
- 16. Surveillance Test Procedure, DB-PF-03065, "ASME Section XI Pressure Tests,"Rev.0(C-1),8/24/89.
- 17. Plant Procedure, DB-0P-06901, " Plant Startup," Rev. O,~7/11/89.
- 18. Tour Inspection Forms for:- August 11, 1989 and August 25, 1989.
- 19. Work Requests for the following equipment:
- MU58BA
- MU58A
- MU3 MU62
- P037-01
- MU19 MUB04
- DH1518
- MU232 MU803
- DH1517
- MU6420 MU507
- MU6422 Ifitemisasterisked(*),MaintenanceWorkOrderalsoreviewed.
H.
Personnel Interviewed 1.
The following personnel were present at the entrance meeting:
P. Byron NRC/ SRI
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K. Parczewski NRC/NRR
-T.
Wambach NRC/NRR Proj. Mgr. 0-B C. Czajkowski BNL m
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- Toledo Edison-Personnel
R. Holliday Licensing Engr.
3 -
E. Mantranga Systems' Engr.
L. Hughes Primary Sys. Engr. Su J. Moyers Mgr., Quality Verif. pr.
J.-Sturdavant Acting Lic. Comp. Supr.
M. Shepherd Sr. Ferf. Engr. Advisor D. Wuokko Reg. Affairs Supr.
M. Parker Supr. Ops. Engr.
R.-Brandt Mgr. Ops.(Admin)
K. Dieterich Mech. Coord.
C. Protherd Design Engr.
M. Hoffman Nucl. Training 2.
The following personnel were interviewees during the audit:
E. C. Mantranga Systems Engineer M. Hoffman Training R. Holliday Licensing R. Col. lings QA Audit Supr.
1 M. Shepherd Performance Engr.
R. Donnaellon Ngr. QC J. Schultz QC Supr.
W. Beradi Maintenance & Foreman M. Parker Operations
=
J. Nevshemal Design Engr.
3.
The following personnel were present at the Exit Critique:
P. Byron NRC/ SRI K. Parczewski NRC/NRR T. Wambach NRC/NRR C. Czajkowski BNL Toledo Edison Personnel:
R. Holliday Licens. Engr.
J. Lash ISE Mgr.
L. Worley QS Mgr.
D. Wuokko Nucl. Lic. Supr.
E. Salowi u Dir. P&S i-R. Collir Supr. QA Audits J. Moyers Mgr. Quality Verif.
M. Parker Supr. OPS Engr.
M. Shepherd Sr. Perf. Engr. Advisor L. Hughes Pri. Sys. Engr. Supr.
M. Hoffman Nucl. Training C. Hengge Fire Prot. Supr.
E. Potherd Design Engr.
J. Nevshemal DED R. Brandt Mgr. OPS (Admin)
L. Storz PT Mgr DB J. Gates SED Mgr.
l.
D. Timms SED E/C l-E. Mantranga Systems Engr.
l
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