ML053070378

Generic Letter 88-05: Prevention of Boric Acid Corrosion at Davis-Besse Nuclear Power Plant

ML053070378
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
3166, EXT-90-01022, GL-88-005, TAC 68915
Download: ML053070378 (11)

Text

Q i l O O t 7 0 4 7 7 1 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 EX J-90-01022 February 8, 1990 Docket No: 50-346 Mr. Donald C. Shelton Vice President, Nuclear Toledo Edison Company Edison Plaza-Stop 712 300 Madison Avenue Toledo, Ohio 43652

SUBJECT:

PREVENTION OF BORIC ACID CORROSION AT DAVIS-BESSE NUCLEAR POWER PLANT (GENERIC LETTER 88-05), (TAC NO. 68915)

The purpose of this letter is to advise you that our audit o f your 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. Parczewski (NRC),

C. Czajkowski (consultant, Brookhaven National Laboratory), and T. V.

Wambach (NRC).

described in Generic Letter 88-05 which was issued on March 17, 1988, and requested the implementation of such a program by all licensees of operating pressurized water reactors (PWRs) and holders of construction permits for PWRs.

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.

1989, you informed us that you were preparing a new procedure to combine the programs described in your May 27, 1988 response.

0 Boric acid corrosion prevention requirements were On June 26, A copy of the trip report covering the results o f the audit which was prepared by our consultant is enclosed.

report and agrees with its findings and the conclusion.

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.

The staff has reviewed this On this basis

e i) f) 0 0, I 7 0 4. 7 7 2 '

I Mr. Donald February 8, 1990 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, Thomas V. Wambach, Sr., Project Manager Project Directorate 111-3 Division of Reactor Projects - 111, IV, V and Special Projects Office of Nuclear Reactor Regulation

Enclosure:

Audit Report cc w/enclosure:

See next page

Mr. Donald C. Shelton Toledo Edi son Company e

cc:

David E. Burke, Esq.

The Cleveland Electric Illuminating Company P. 0. Box 5000 Cleveland, Ohio 44101 Mr. Robert W. Schrauder Manager, Nuclear Licensing Toledo Edison Company Edison Plaza 300 Madison Avenue Toledo, Ohio 43652 Gerald Charnoff, Esq.

Shaw, Pittman, Potts and Trowbridge 2300 N Street N.W.

Washington, D.C. 20037 Regional Administrator, Region 111 U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 a

Mr. Robert B. Borsum Babcock & Wi lcox Nuclear Power Generation Division Suite 525, 1700 Rockville Pike Rockville, Maryland 20852 Resident Inspector U.S.

Nuclear Regulatory Commission 5503 N. State Route 2 Oak Harbor, Ohio 43449 Davi s-Besse Nuclear Power Station Unit No. 1 Radiological Health Program Ohio Department o f Health 1224 Ki nnear Road Columbus, Ohio 43212 Attorney General Department of Attorney 30 East Broad Street Columbus, Ohio 43215 Mr. James W. Harris, Director (Addressee Only)

Division o f Power Generation Ohio Department of Industrial Relations 2323 West 5th Avenue P. 0. Box 825 Columbus, Ohio 43216 General Ohio Environmental Protection Agency 361 East Broad Street Columbus, Ohio 43266-0558 President, Board County Commi ss Ottawa County Port Clinton, Oh State o f Ohio Public Utilities 180 East Broad S o f oners of 0 43452 Commi ss i on reet Columbus, Ohio 43266-0573

BORIC ACID PREVENTION Trip Report A.

Introduction On September 11-13, 1989, a USNRC audit team visited the Davis-Besse Nuclear Power Station. The team was comprised of Messrs. K. Parczewski and T. Wambach of the USNRC and Mr. C. Czajkowski of Brookhaven National Laboratory (BNL).

The purpose of the plant visit was to audit the licensee's implemented 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 verifying that the techniques used by the utility were proper and performed by adequately trained/certif ied 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 primarv 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 a

Letter 88-05 to-the USNRC. The utility (in the response) stated that

"...the process for identifying boric acid corrosion needs additional enhancements. This determination has been documented i n 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 May 27, 1988, response into a specific 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 implement the requirements of Generic Letter Nuclear GrOUD Procedure NG-EN-00324. "Boric Acid Corrosion Control,"

dated September 8; 1989, Revi Davis-Besse Boric Acid Corros purpose:

"1.0 PURPOSE 1.1 This procedure prov ion 0, was-written to additionally enhance the on Control Program. This procedure's stated des a program which mp 1 emen t s sy stema t i c measures to ensure that bori c-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 low probability of abnormal leakage, rapidly propagating failure, or gross rupture. These measures include:

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 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 i s detected anywhere within Section 6.1 of this procedure discusses principal leak locations at the the primary pressure boundary.

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 leaks, 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.

b.

d.

e.

f.

C.

9.

h.

i.

Steam Generator manways and handholes Pressurizer manways and handholes Thermowells Reactor Coolant Pump seals and flanges Control Rod Drive flanges Piping flanges Valves seats and packing glands The Reactor Vessel head gasket Pressurizer Relief Valve rupture discs.

Although the administrative (overall) procedure was in place, various implementing procedures had not been written at the time of the audit.

utility has a requirement (NG-IM-O0155,R5) to have these implementing procedures approved within 90 days of the approval of the overall procedure.

meets the intent of the generic letter.

The NG-EN-00324 C.

Procedures for location small coolant leaks reactor coolant leaks. They include:

The utility has various procedures which provide for routine inspections for 0

OB-PF-03065, ASME Section XI Inservice Pressure Tests DB-OP-06901, Plant Startup DB-OP-06903, Plant Shutdown and Cooldown DB-MN-00002, Preventive Maintenance Additionally, coolant leak inspections may be required by the following:

OB-SP-03357, RCS Water Inventory Balance DB-OP-02522, Small RCS Leaks Personnel performing inspections forleakage (ASME Section XI) are qualified During the audit, VT-2 qualifications were verified for the to a VT-2 criteria.

following personnel:

R. Cockrell Level I 1 P. Vandyne Level I1 M. Hurley Level I1 The ASME Section XI procedure (DB-PF-03065) provides for a step to remove 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 exami ned. ' I Paragraphs 5.6 and 5.7 of the procedure also requires that:

"5.6 Ensure the visual examiner( s) have completed their examinations and documented each line, component, b o u n d a r y 7 area examined on the VT-2 Examination Report.

5.7 Ensure the visual exarniner(s) have documented all identified leakages on the VT-2 Examination Report. ' I These procedures coupled with the training/certif ications of inspectors comply with the intent of the generic letter.

7 0 4 7 7 7 D.

Procedures for evaluation boric acid induced corrosion of carbon steel components in the reactro pressure boundary.

The utility has detailed the following steps to be followed after boric acid leakage i s discovered (Procedure NG-EN-00324).

"6.3.1 Upon notification of boric acid leakage in the Plant, Systems Engineering shall perform an initial inspection of the affected area 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.

b.

C.

d.

e.

f.

9.

h.

i.

Size of the leak or the amount of boric acid residue present or both Component( s) affected Extent of visible damage to the affected area Evaluation of any immediate safety concerns Identification of leak path(s)

Identification of insulation or any other type of interference which must be removed to gain access to the leak Any preliminary preparations necessary for perform-ing subsequent inspections 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)

The boric acid concentration in the reactor coolant.

"6.3.2 System Engineering shall notify the Shift Supervisor of any immediate safety concerns raised by the initial inspection.

"6.3.3 Based on the magnitude of the leak and extent of damage to the affected area, Systems Engineering shall document the inspections by one of the following:

a.

Writing a Potential Condition Adverse to Quality (PCAQ) Report per NG-QA-00702, Potential Condition Adverse to Quality Reporting Writing a Work Request per OB-PN-00007, Control of Work.

b.

0 I 7 0 4 7 "6.3.4 "6.3.5 Systems Engineering shall determine whether additional inspections of If boric acid residue is present, Systems Engineering shall contact Radiological Controls for cleanup of the affected area.

the leak are necessary to fully assess the component damage and determine possible corrective action...I1 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 o f 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 consideration 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.

Redesign insulation layout that would permit draining or shunting o f coolant leaks away from critical areas."

c.

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.

Observations of Boron Accumulation due to Leaking Code Safety Valve, NES.87-00236, 6/15/87.

c.

Potential Condition Adverse to Quality (PCAQ) No.

89-0058, 1/27/89.

For all three items the utility appeared to do a thorough and professional investigation and corrective action follow-up.

3.

A plant tour was provided of accessible areas. Work Order/Requests were randomly recorded during the tour:

• MU58BA

• MU58A

• MU3 MU62

• PO37-01

• MU19 MU804

• OH1518

• MU232 MU803

• DH1517

• MU6420 MU507

• MU6422

0 0 0 0 7 Q 4 7 '9 e

If item is asterisked (*), Maintenance Work Order also reviewed.

No discrepancies were noted.

F.

Conclusions Procedurally the licensee meets the intent o f Generic Letter 88-05 (all four points of the Generic Letter are addressed). The general administrative procedure needs to have the appropriate implementing procedures written in order to fully implement the utility's program requirements.

boric acid corrosion prevention could be enhanced at the Davis-Besse plant:

The following areas of 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.

Letter Response (Revised) to USNRC Generic Letter 88-05, June 26, 1989, Serial No. 1-885.

3.

Administrative Procedure, 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, TSE-87-10049.

5.

6.

7.

Memorandum from J. Wood to P. Hildebrandt, "Observation of Boron Accumulation Due to Leaking Code Safety Valve," 6/15/87, SUS-064-04.

Standing Order - SO87-015, "RCS Leakage Management," 12/16/87.

Potential Condition Adverse to Quality Report (PCAQR), No. 89-0058, 1/27/89 and the following associated documents:

a.

B&W letter to utility:

Subject:

"Davis-Besse Nuclear Power Station - Unit 8 Leaks at RTD Element Connections," OB-80-147, 4/24/80.

b.

Maintenance Procedure MP 1401.13, "Reactor Coolant System Temperature Detector Removal and Replacement,I' Rev.

11 /19/85.

2,

c.

Maintenance Work Order (MWO) 7-89-0058-01, 3/11/89.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

0 I 7 Q 4 7 a t!

d.

PCAQR Extension Request, 2/10/89.

e.

f.

g.

Memorandum from T. Anderson to Distribution:

Subject:

"Forced Outage Memo,I' 4/28/89.

Plant Procedure, DB-OP-06903 (Supersedes PP 1102. lo), "Plant Shutdown and Cooldown," Rev. 0, 11/18/88.

Maintenance Work Orders:

Nuclear Group Procedure, NG-QA-00702, "Potential Condition Adverse to quality Reporting," Rev. R1 (C-1), 6/7/89.

Abnormal Procedure, DB-OP-02522, "Small RCS Leaks," Rev. 0, 11/16/88.

QA-"General Visual Testing Qualification Card 2E," 8/2/88.

QA-"Visual Testing (VT-2) Qualification Card 21,I' 8/2/85.

Nuclear Group Procedure, NG-IM-00115, "Preparation and Control of Nuclear Group Department and Section Procedures," Rev. 5, 11/4/88.

Survei 1 lance Test Procedure, DB-SP-03357, "RCS Water Inventory Balance," Rev. 0 (C-1), 7/26/89.

Surveillance Test Procedure, OB-PF-03065, "ASME Section XI Pressure Tests," Rev. 0 (C-1), 8/24/89.

Procedure Change Request (PCR), 89-3149, Rev. 0, 4/24/89.

Safety Review and Evaluation, 4/5/89.

1588-2658 (1-87-3004-00) and 1588-7409 (1-88-0065-01).

Plant Procedure, OB-OP-06901, "Plant Startup," Rev. 0, 7/11/89.

Tour Inspection Forms for: August 11, 1989 and August 25, 1989.

Work Requests for the following equipment:

• MU58BA

• MU58A

• MU3 MU62

• PO37-01

• MU19 MUB04

• DH1518

• MU232 MU803

• DH1517

• MU6420 MU507

• MU6422 If item i s asterisked (*), Maintenance Work Order also reviewed.

H.

Personnel Interviewed

1.

The following personnel were present at the entrance meeting:

P. Byron NRC/SRT K. Parctews ki NRC / NRR T. Wambach NRC/NRR Proj. Mgr. 0-B C. Cza j kows k i BNL

Q; 0 a:. I. 7 0 4 7, :i I 0

Toledo Edison Personnel:

R. Holliday E. Mantranga L. Hughes

3. Moyers

3. Sturdavant M. Shepherd D. Wuokko M. Parker R. Brandt K. Dieterich C. Protherd M. Hoffman Licensing Engr.

Systems Engr.

Primary Sys. Engr. Supr.

Mgr:, Quality Verif.

Acting Lic. Comp. Supr.

Sr. Perf. Engr. Advisor Reg. Affairs Supr.

Supr. Ops. Engr.

Mgr. Ops. (Admin)

Mech. Coord.

Design Engr.

Nucl. Training

2.

The following personnel were interviewees during the audit:

E. C. Mantranga M. Hoffman R. Holliday R. Collings M. Shepherd R. Donnaellon J. Schultz W. Beradi M. Parker J. Nevshemal Systems Engineer Training Licensing QA Audit Supr.

Performance Engr.

Mgr. QC QC Supr.

Maintenance 81 Foreman Operations Design Engr.

3.

The following personnel were present at the Exit Critique:

P. Byron NRC/SRI K. Parczews ki NRC/NRR T. Wambach NRC/NRR C. Cza j kows ki BNL Toledo Edison Personnel:

R. Holliday J. Lash L. Worley D. Wuokko E. Salowitz R. Collings J. Moyers M. Parker M. Shepherd L. Hughes M. Hoffman C. Hengge E. Potherd

3. Nevshemal R. Brandt L. Storz J. Gates

0. Timns E. Mantranga Licens. Engr.

ISE Mgr.

QS Mgr.

Nucl. Lic. Supr.

Dir. P&S Supr. QA Audits Mgr. Quality Verif.

Supr. OPS Engr.

Sr. Perf. Engr. Advisor Pri. Sys. Engr. Supr.

Nucl. Training Fire Prot. Supr.

Design Engr.

DED Mgr. OPS (Admin)

PT Mgr DB SED Mgr.

SED E/C Systems Engr.