ML19354E675
| ML19354E675 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 01/24/1990 |
| From: | Chandu Patel Office of Nuclear Reactor Regulation |
| To: | Kovach T COMMONWEALTH EDISON CO. |
| References | |
| GL-88-05, GL-88-5, TAC-68968, TAC-68969, NUDOCS 9002010073 | |
| Download: ML19354E675 (11) | |
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January 24, 1990 Docket llos. 50-295 and 50-304 Thomas J. Kovach Nuclear Licensing Manager comonwealth Edison Company OPUS West 111 1400 OPUS Place, Suite 300 Downers Grove, Illinois 60515
Dear Pr. Kovach:
SUBJECT:
PP.EVENTION OF BORIC ACID CORROSION AT ZION GENERATING STATION l' NITS 1 AND 2 (GENERIC LETTER 88-05) (TAC NOS. 68968 AND 68969)
The purpose of this letter is to advise you that our audit of your boric acid corrosion prevention program has resulted in an acceptable finding and we now consider this issue to be closed.
On May 30 through June 1,1989, the HP.C staff and our consultant visited the Zion Generating Station Units 1 and 2 to audit the program to prevent boric acid-related corrosion.
The audit team included K. Parcrewski (NRC), M.
Schuster (consultant, Brookhaven Nation Laboratory), and V. L. Rooney'(NRC).
Boric acid corrosion prevention requirements were described in Generic Letter 88-05 which was issued on March 17, 1988, and requested the implementation of such a progran by all licensees of operating PWRs and holders of construction permits for PWRs.
In your letter dated May 31, 1988, you provided a description of, and a commitment to, a boric acid leakage monitoring and a corrosion preventive program for Zion.
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 through carbon steel components caused by boric acid corrosion as described in your submittal dated May 31, 1988 for the Zion Facility. However, we direct your attention to certain weak areas in your program for boric acid corrosion prevention which are discussed in the conclusions section of the enclosed trip report.
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o' Thoras J. Kovach January 24, 1990 i
Our revies of this issue for the Zion Generating Station Unit Nos. I and 2 l
is closed, l
Sincerely, 1
Clamh R W Chandu P. Patel, Project Manager l
Project Directorate III-2 i
Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation l
Enclosure:
As stated cc w/ enclosure:
See next page t
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a, Thomas'J. Kovach January 24, 1990 u -
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Our review of this issue for the Zion Generating Station Unit Nos.(1 and 2-1 is closed.
4 Sincerely,
@tb k Chandu P. Patel, Project Manager Project Directorate III-2 Division of Reactor Projects - 111, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/ enclosure:
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j Mr. Thomas J. Kovach Zion Nuclear Power Station Comonwealth Edison Company Units 1 and 2 i
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Robert J. Vollen, Esquire 109 North Dearborn Street Chicago, Illinois 60602 j
Dr. Cecil Lue-Hing i
Director of Research and Development Metropolitan Sanitary District i
of Greater Chicago 100 East Erie Street Chicago, Illinois 60611 Phillip Steptoe, Esq.
Sidley and Austin One First National Plaza Chicago, Illinois 60603 Mayor of Zion Zion, Illinois 60099 1111nois Department of Nuclear Safety Office of Nuclear Facility Safety 1035 Outer Park Drive Springfield, Illinois 62704 U.S. Nuclear Regulatory Comission Resident Inspectors Office t
105 Shiloh Blvd.
Zion, Illir.ois 60099 Regional Administrator, Region 111 U.S. Nuclear Regulatory Comission 799 Roosevelt Road, Bldg. #4 Glen Ellyn, Illinois 60137 l
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ENCLOSURE BORIC ACID PREVENTION TRIP REPORT A.
INTRODUCTION On May 30 - June 1,1989, a USNRC audit team visited the Zion Nuclear Power Station Units 1, 2.
The team was comprised of Messrs. Kris Parczewski and Vern Rooney of the U.S. NRC and Mr. M. Schuster 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 plants.
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 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 The licensee provided the following in its response to Generic Letter 88-05 dated May 31,1988:
At Zion Station, the principal locations where leaks that are smaller than the allowable Technical Specification limits can cause degradation of the reactor coolant pressure boundary by boric acid attack are the Steam Generator primary side manway bolting, reactor pressure vessel head closure bolting, pressurizer manway bolting, and the reactor coolant pump flange bolting.
Valve packing glands, gaskets in bolted flange connections, and reactor head canopy seal welds, are locations which have the potential for conditions that could cause high j
concentrations of boric acid on carbon steel pressure boundary components.
The primary method of inspection for leakage is' visual with all piping in an assigned area inspected as a walk down requirement. ASME, Piping, components and valves inspection /results are the responsibility of the ASME Section XI.
Program and group using Section XI requirements and VT-2 procedure requirements.
Non ASME/ Code component inspections /results are the responsibility of the Plant Staff Operations Personnel with inspection guidelines provided in the Reactor Coolant System Operations program in accordance with Plant Technical Specifi-cation requirements.
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Leakage is also monitored in accordance with Reactor Coolant Pressurization System Integrity Technical Specification Section:
l 4.3 3.
Leakage (per unit) i A.
When Reactor Coolant System pressure is greater than 500 ssig, one of the following monitoring requirements shall Mt performed (4.3.3. A.1 or 4.3.3. A.2):
i 1.
Containment activity shall be continuously monitored by radiation detector: 9 0bilA or RE 0012A.
2.
Manual sampling of the containment atmosphere shall be performed once a shift.
B.
When Reactor Coolant System pressure is greater than 500 psig, at least three of the following monitoring requirements shall be performed (4.3.3.B.1,2,3,4, and 5):
4.3.3.B 1.
The amount of Reactor Coolant System makeup water required to maintain pressurizer level and volume control tank level shall be recorded.
2.
Containment sump and reactor cavit sump water accumulation shall be monitored daily. y 3.
Containment pressure, temperature and humidity shall be monitored.
4.
The high temperature alarm (TE-401) in the reactor head flange leakoff piping shall be operable.
5.
The Reactor Vessel Leak Detection system (RE-PR12A, RE-PR12B, RY-PR12A, and associated alarms) shall be
- operable, r
C.
If the monitoring performed in sections 4.3.3.A and 4.3.3.B indicates significant leakage, a detailed investigation shall be performed to identify the sources and quantity of leakage, The licensee meets the intent of Generic Letter 88.05.
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C.
PROCEDURES FOR LOCATING $NALL COOLANT LEAKS The principal procedure utilized by the utility for inspections is titled,
'VT 2 Visual Examinations Performed for Section XI,' the objective, scope, conditions to be examined, etc., for this procedure is as follows:
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n Obiective VT-2 1.1 To perform visual examinations of pressure retainin9 components during the conduct of Section XI system pressure tests: to locate evidence of leakage from such pressure retaining components, or abnormal leakage from components with or without leakage collection systems. Exam' nations shall be in compliance with the requirements of paragraph IWA 2212, ASME Section XI; the 1977 Edition (Summer 1978 and Summer 1979 Addenda), the 1980 Edition (Winter 1980 and Winter 1981 Addenda)ly applicable to those items specified for VT-
, and the 1983 Edition (Summer 1983 Addenda).
This procedure is on 2 exacination in the Inservice Inspection PrograWPlan or per the Repair / Replacement Procedure for each Nuclear Unit, k.0at VT 2 2.lThe instructions contained herein established the minimum requirements necessary to accomplish VT 2 visual examinations designated in ASME Section XI for Class 1. Class 2 Class 3 pressure retaining components.
2.2 Only certified Level 11 or Level 111 VT r personnel shall be considered capable of performing, interpreting and reporting the results of VT 2 examinations.
Conditions To Be Eramined For VT 2 4.3.1 Water or steam leakage from any pressure retaining boundary or insulation surrounding that boundary.
4.3.2 Evidence of water or steam leakage such as water or moisture collected or flowing on walls, structures, etc., and especially puddled on the floor.
Such evidence is to be traced to the point of origin.
4.3.3 Water soaked fibrous insulation shall be investigated to determine the source of water.
4.3.4 Areas of general corrosion and depth of corrosion on pressure retaining components.
4.3.5 Discoloration or accumulations of boric acid residue on or near a borated system.is to be investigated to determine the source of leakage.
4.3.6 Proper operation of leakage collection systems, such as pump leak off instrumentation and valve packing leak off sight gauges.
4.3.7 Pump seal, valve packing and flanged connection external leakage.
4.3.8 Evidence of pressure loss, flow loss or flow impairment when examining buried systems.
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4.3.9 Leakage or evidence of leakage from reassembled connections (such as flanges, pumps, valves, or instrument lines.)
VT 2 5.3.5 Areas of general corrosion resulting in the degradation of the pressure retaining boundary.
5.3.6 Uncollected leakage from valve packing, pump seals and flanged connections shall be recorded for 'information only."
Note: Apparent leakage is not to be confused with moisture from maintenance activities or condensation (sweating) on cooling systems. This type of moisture is not recordable.
Conditions To Be Recorded:
VT 2(22)
(A)
Evidence of through wall leakage.
(B)
Evidence of pressure loss, flow loss, or other leakage exceeding technical specifications.
(C Improper leakage collection system function.
Degradation of pressure retaining boundary due to corrosion.
Leakage from reassembled connections.
All evidence of borated water, discoloration, or boric acid residue, Procedures reviewed meet the intent of Generic Letter 88 05.
e D.
PROCEDURES FOR EVALUATING BORIC ACID INDUCED CORROSION OF CARBON STEEL COMPONENTS IN THE REACTOR PRESSURE BOUNDARY.
The VT 2 procedure provides that when degradation of the pressure boundary has occurred due to borated water or boric acid leakage, a Deviation Report is written.
The normal method of report and repairing inactive leaks and leak were no degradation of the pressure boundary has occurred is by the use of a maintenance work order. Computer tracking of system work orders with subsequent evaluation of components is complete under the utilities Nuclear Plant Reliability Data System and Problem Analysis Data Sheet Program.
In general, these programs require evaluation of components when a repair / rework is required twice within a 12 morth period.
Evaluation is at both site and corporate level.
The Tech Staff Surveillance TSS15.6.21 maintenance order and VT 2 boric acid walkdown procedures discuss the methods of performing walkdown inspections of the RCPB.
Also in accordance with Technical Specification Requirement moisture and radiation activity levels are monitored during operation.
The reviewed procedures and the corrective action program meets the intent of Generic Letter 88 05.
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E.
CORRECTIVE ACT10NS TAKEN BY THE LICENSEE TO PREVENT RECURRENCE OF SIM TYPES OF CORROSION.
Corrketive actions to prevent recurrence of boric acid corrosion include the use of Deviation Reports as provided in the VT 2 procedure for cases when degradation of the pressure boundary has occurred.
The Deviation Report includes corrective actions, and actions to prevent recurrences. The Deviation Re to Engineering evaluations as applicable. port may be subject A deviation report would only be required when degradation of the pressure boundary has occurred.
The primary method to date utilized by the licensee for boric acid leak repair has been the maintenance work order.
In addition to the Deviation Report, the previously mentioned Nuclear Plant Reliability Data System, total job management system and problem analysis data sheet programs also provide engineering evaluations with appropriate corrective actions.
The team completed a plant tour with system inspections for boric acid leaks.
The results of the inspections were as follows:
1)
Volume control system - MOV2VC Il2B - packing leak observed - no work request had been generated.
2)
Boric acid system 2B - BA PUMP - flange seal leak observed - no work request had been generated.
3)
Boric acid system - 2V Pump seal root isolation valve-leak observed work request #282123 dated 5/29/89 had been generated.
4)
Volume control system - 1A charging pump - flange and OB seal leaks were observed - work request Z 64482 dated 11/7/87 and work request Z 70878 dated 5/17/88 had been generated.
5)
OC tank - boric acid residues from a Jan.1989 valve repair were observed.
6)
Safety injection system - IB safety injection pump -
flange and OB seal leaks observed - no work request had been generated.
The corrective action programs meet the intent of Generic Letter 88 05.
Component repair and boric acid residue clean up and completion of work is not being completed in a timely This is evidenced by outstanding work order requests manner.
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dated from November 7,1987 and boric acid residues left from a January 1989 valve repair. The licensee indicated they were aware of the work order request backlog and are working to correct the problem.
F.
CONCLUSIONS i
1)
The licensee's program for boric acid corrosion preventions in general meets the intent of generic letter 88 05.
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2)
Positive observations at Zion, NPS are:
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A Excellent training and personnel certification requirements.
8 Extensive component /resair tracking programs.
C Program commitments w11ch encompass safety and non safety related systems.
3)
Weak areas in the program are:
A)
Component repair and boric acid residue clean up scheduling and completion of work is not being completed in a timely manner.
Reducing the work request backlog and a more i
aggressive scheduling of repairs for boric acid leaks is recommended.
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1 B)
A central collecting / evaluation group for boric acid leak data is recommended.
Inspections, work requests, and evaluation for the boric acid program is currently the responsibility of both the Section XI engineering group and plant staff operations personnel.
Both group functions are independent of each other with no formal requirement to exchange / share the data and experience gained from their respective programs.
The team findings were discussed with the utility at the exit meeting.
1 G.
DOCUMENTS REVIEWED 1)
Training / Qualification Records R. Wulf, G. Suendsen, B. Soares, R.
Summers, C. Gosch and J. Tredway.
2)
VT-2 visual examinations performed for section XI procedure.
3)
VT 2 visual examination study guide.
4)
Zion history work request SAS reporting computer Boric Acid Repo
5)
Generating station maintenance - maintenance' history - work request profile tracking report.
6)
Technical Specification Section 4.3 (Reactor coolant system pressurization systemintegrity).
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e 7)
Visual Leak Examination of Class I Components. TSS 15.6.21. (Reactor Cool.
ant System Leak Test), pre exam Technical Staff Surveillance Document.
8)
Visual Leak Examination of Class ! Components. TSS,.15.6.21. (Reactor Coolant System Leak Test), post-exam, Technical Staff Surveillance Document.
9)
Zion Administrative procedure ASME Section XI repairs and replacements.
ZAP 10 51 2, Rev. 2.
10) inservice Ins TSS 15.6.21F,pection, Mechanical Closure / Visual Inspection Surveillance, Technical Staff Surveillance Document.
11)
Total job management (TJM) Boric Acid Master Tracking Report.
12)
Problem Analysis Data System (PADS) Maintenance Dept. Memo No. 07, Rev.
4.
13)
Special Process Procedures Manual.,
14)
Response to NRC Generic Letter 88 05 dated May 31, 1988.
H.
PERSONNEL INTERVIEWED 1)
The following personnel were interviewed during the site visit:
D. Chrzanowski ISI Group Engineer J. Zecca Technical Staff Engineer R. Wilson NPRDS Coordinator D. Chawick Maintenance Staff W. Grundmann Quality Assurance Engineer 2)
The following personnel were present at the entrance presentation:
Kris Parczewski NRC Ron Summers CEC 0 Zion ISI Adam Bless CECO Zion Regulatory Assurance Dave Chrzanowski CECO, Nuc. Eng. (Corp. ISI)
Tom Joyce CECO - Station Manager Terry Rieck CECO - Tech. Supt.
Milford H. Schuster BNL Vernon Rooney NRC AnnMarie Bongiovanni NRC Resident Inspector 3)
The following personnel were present at the exit critique:
Kris Parczewski NRC Vern Rooney NRC Milford N. Schuster BNL 1
Ron Sumners CEC 0 Zion Bob Cascarano CECO Zion Technical Staff Supervisor l
Terry Rieck CEC 0 Adam Bless CECO - Regulatory Assurance i
Dave Chrzanowski CECO Nuc. Eng. (ISI)
Patricia L. Eng NRC - Resident ~ Zion Roy J. Leemon NRC RI Zion 7
.