ML20101T138
| ML20101T138 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 07/10/1992 |
| From: | Mcmeekin T DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9207200296 | |
| Download: ML20101T138 (3) | |
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9 Duke Iburr Comps.'s T C Ma:mn McGmre Nuclear Geneation Departenent lice nrsident
= 12700 Hagen Terry Rud(LIGGIA).
(704)875-4800 Huntersville. NC28018-8985 -
(704)STS4h09fu DUKEPOWER July 10,1932 h
U.S. Nuclea,- Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
McGuire Nuclear Station Docket Nos. 50-369,--370 Inspwtion Report No. 50-369, -370/92-13 Genk men:
Pursuant to 10CFR 2.201, please find attached Duke Power Company's response to Violation 369,370/92-13-02 for McGuire Nuclear St'uion. T his violation was alco disctssed in an Enforcement Conference held on June B,1992.
Should there be any questions cencerning tilis matter, contact Larry Kunka at (734)875-4032.
Very truly yours, T.(d 6DN C. McMeekin LJK
. Attachment xc:
Mr. S, D. Ebneter Administrator, Region ll U.S. Nuclear Regulatory Commission 101 Marietta St., NW, Suite 2900 Atlanta, GA 30323 Mr. Tim Reed U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C. 20555.
Mr. P. K Van Doorn NRC Resident inspector McGuiro Nuclear Staiion 9P072002f6I920710
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PDR ADOCK 05000369 G
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0, McGUIRE NUCLEAR STATION RESPONSE TO NOTICE OF VIOLATION Violation 369. 370/92-13-02 10 CFR 50 Appendix B Criterion lit and the licensee's accepted Quality Assurance Program (Duke Power Company Topical Report Quality Assurance Program, DUKE-1-A) require that measures be established to assure that applicable regulatory requirements and the design basis for structures, systems and components are correctly translated into specifications, drawings, procedures and instructions.
Contrary to the above, measures were not effective to assure that applicable regulatory and the design basis for structures, systems and components were correctly translated into specifications, drawings, procedures and instructions. This is evidenced by the fact that on March 27,1992, air was discovered in the Nuclear Service Wate System and the design control process failed to recognize this possibility. This
- directly impacted the abilay of the Auxiliary Feedwater System to perform its intended safety function.
1.
Reason for violatiqn On March 27,1992, McGuire Engineering (ME) personnel discovered air present at inspection port valve 1RN-1058 in the Nuclear Service Water System (RN) assured makeup flow piping to the Auxiliary Feedwater (CA) System. Valve 1RN-1058 is upstream of the valves which allow the assured makeup flow from the RN system to the CA system. Recognizing that the air could b3 a potential problem, ME personnel reported this discovery to the Operations (OPS) manager and the McGuire Engineering supervisor. OPS and ME personnel began checking for possible sources of air inleakage. These sources included the RN system discharge vacuum breakers from the Control Area Ventilation and Chilled Water (VC/YC) system condensers, On April 1,1992, Train 1B RN vacuum breakers for the VC/YC system were inspected with no sign of air inleakage found. On April 3, air was again discovered to be present at 1 RN-1058. On April 6,1992, Train 1 A RN vacuum breakers for the VC/YC system were inspected with no sign of air inleakage found. Other possible sources of air inleakage were inspected with no problems found On April 7, air was discovered to be present at valves 1CA-163 (CA suction header RN supply tell tale) and 1RN-840 (RN crossover high point vent).
Extensive review and evaluation of the RN system piping layout and vents was conducted by ME and OPS personnel to determine potential air sources. During this time, air continued to show up at locations identified for venting, leading personnel involved to believe they were not dealing with a finite amount of air introduced by maintenance activities. The possibility of oxygen / nitrogen off-gassing (dissolved gases coming out of solution) from Lake Norman became more probable as the possible sources of air inleakage were eliminated.
- Off-gassing was determined to be the source of the air found in the RN piping. The process of off-gassint % the RN piping was not recognized during the design phase. Additionally, the RN assured makeup connections tie in at the top and side of the RN piping, allowing air (dissolved
. gases) to accumulate in this piping.
Investigation has not determined the cause as to why off-gassing on the discharge side of the RN system was not considered in the original design process. It is not a usual design practice to take suction sources, such as was done for the CA system, from the discharge side of another system.
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A detailed piping review of the RN system has confirmed this to be a unique configuration, Therefore, this is considered to be an isolated design oversight.
2.
- Correctivj actions taker. Land results achieveo initial Actions-1.
Periodic venting was established at affected locations 2.
1CA-161C was conservatively closed to assure Unit 1 CA operability 3.
The A train of the RN system supply to Unit 1 and 2 CA was temporarily isolated Subs (quent Actions -
1.
An extensive piping configuration review was conducted by ME and OPS personnel to identify pot,sible sources of inleakage and additional venting locations 2.
Temporary continuous venting system was installed at 1RN-835 and 2RN-815 to assure CA operability
- 3..
Procedure changes were made to assure RN supply during realignment to the Nuclear Service Water Pond.
4.
Performed venting review of CA and ECCS pumps 5.
OPS and ME developed procedures for the venting of the RN system for both units to assure establishment of water solid conditions in the RN system
, 6.
OPS and ME developed procedures for the venting of the CA system for both units to assure establishment of water solid conditions in the CA system 7.
- Permanent continuous venting system was installed at 1RN-1060
- 3.
Corrective actions to be taken to avol(! further violations 1.
ME personnel will coordinate the installation of additional vents to provide flexibility for establishing water solid conditions in the RN system--
2.
Temporary venting system at 1RN-835 and 2RN-815 will be upgraded to permanent 3.
. ME w!!! develop a lessons learned package on this event which will be covered with all -
sppropriate personnel. This 'will be completed and the package covered with all appropriate personnel by October 1,1992.
4.
A synopsis of the lessons learned package will be incorporated into the design input / criteria guidance of McGuire Nuclear Station NSM manual. This manual will be revised by October 1,1992.
4.
D3te when full comoliance will be achieved Full compliance for items 1 and 2 above will be achieved prior to the start of the Unit 2 EOC 8 refueling outage; full compliance for items 3 and 4 will be achieved by October 1,1992
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