GO2-83-761, Final & Interim Deficiency Repts Re Conditions 223 & 260 Concerning Standby Liquid Control Sys & Standby Svc Water Flow Problems.Initially Reported on 830127 & 0721.Sys Will Be Modified Per Separation Criteria.Next Rept by 831101

Final & Interim Deficiency Repts Re Conditions 223 & 260 Concerning Standby Liquid Control Sys & Standby Svc Water Flow Problems.Initially Reported on 830127 & 0721.Sys Will Be Modified Per Separation Criteria.Next Rept by 831101

ML20080D615
Person / Time
Site:	Columbia
Issue date:	08/11/1983
From:	Carlisle C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, GLTRO2-83-761, GO2-83-761, NUDOCS 8308300519
Download: ML20080D615 (6)

Text

l Washington Public Power Supply System

.ff5 P.O. Box 968 3000 GeorgeWashingtonWay R ichland, Washington 99352.' d500)372-5000 Docket No. 50-397 'II fgl jy August 11, 1983 NEc g. ,

G02-83-761 Q Mr. J. B. Martin Regional Administrator U.S. Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596

Subject:

NUCLEAR PROJECT NO. 2 10CFR50.55(e) REPORTABLE CONDITIONS: #223, STANDBY LIQUID CONTROL SYSTEM (SLCS); AND #260, STANDBY SERVICE WATER FLOW PROBLEMS

References:

1) Telecon QA2-83-029, dated January 27, 1983, L.C. Floyd to R. Dodds.

2) Telecon QA2-83-178, dated July 21, 1983, L.C. Floyd to R. Dodds.

In accordance with provisions of 10CFR50.55(e), your office was informed, by telephone, of the above subject conditions. Attachment 1 provides the Project's final report on Condition #223. Attachment II provides our interim report on Condition #260 and we will continue to provide your office with quarterly updates until resolved. The next report will be submitted by November 1, 1983.

If you have any questions, please contact Roger Johnson, WNP-2 Project QA Manager, at (509) 377-3501, extension 2712.

Program Director, WNP-2 LCF/kd

Attachment:

AS stated cc: W.S. Chin, BPA N.D. Lewis, ESFEC A. Toth, NRC Resident Inspector Document Control Desk, NRC F308300519 830811 PDR ADOCK 05000397 S PDR

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT N0. 2 l DOCKET NO. 50-397 i LICENSE NO. CPPR-93 10CFR50.55(e) CONDITION #223 STANDBY LIQUID CONTROL SYSTEM (SLCS)

FINAL REPORT Description of Deficiency The Standby Liquid Control System (SLCS), which receives supoly power from AC and DC safety-related buses, is a backup to the control rods for safe shutdown. General Electric electrical elementary diagrams require reliable power sources for the SLCS equipment. The SLCS system is installed with one loop powered ano controlled from safety-related (Class lE) electrical buses, while the other loop of equipment is not. Power supplies which are not safety-related are connected to safety-related buses without isolators, and control circuits within various panels are not separated; both of which are requirements of the WNP-2 Electrical Separation Criteria.

Safety Implication Electrical Separation Criteria has been violated, which degrades the reliabil-ity of safety-related electrical power sources. Electrical failure of safety-related power sources could occur through interaction with the non safety-related SLCS circuits. These conditions may preclude the SLCS from perform-ing its intended function.

Cause of the Deficiency The deficiency exists due to the description of the SLC system power supply requirement within GE documents. GE indicated the power supplies must be highly reliable and must function even with the loss of off-site power.

The safety-related electrical power supplies meet these requirements and were considered by BRI to be the most appropriate power source. However, GE had not intended the SBLC system to be classified or treated as safety-re-lated and therefore, GE had not designed into the various components electri-col .seperation which would ineet the final '.iNP-2 Electrical Separution Criteria for Class lE equipment.

Corrective Action General Electric has clarified the design requirements of the SLCS and submit-ted recommended document changes to preclude misinterpretation of the system's function and the licensing commitments. Corrective action is proceeding in accordance with the clarification, as follows; e The SLCS, by design, is not required to perform a " safety function," nor is it required as a safety backup system to the Reactor Protection System (RPS) or Control Rod Drive System (CRDS). The system, by design, is not required or intended to meet single failure criteria. The SLCS is a backup to the CRDS for plant shutdown for a non-transient event. All SLCS compo-nents required for boron injection shall be Seismic Category I.

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Final Report - 0223 1 . Page 2 of 2

, e A safety-related Class lE power source is not required for boron injection; however, the redundant pumps, explosive valves and motor operated storage tank outlet valves shall be powered from two separate buses so that a

! single electrical failure will not prevent the systems operation. The SLCS buses shall be connectable to a standby power source to ensure boron injection in the event of a station power failure.

i Based on the above clarification from GE, the SLCS interfaces (electrical 1

and mechanical) have been revised via BRI Project Engineering Directive (PED) 218-E-B100 and GE FDDR-KKI-ll69 to bring the system into compliance with the WNP-2 Electrical Separation Criteria. This change entails that all isola-tion interfaces with safety related systems shall be Class lE, the remainder of the SLCS (non-safety related interface) shall be non-safety related.

Please note, that this is a change from our previous reports, in which we stated that Loop A would be totally Class lE.

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! Actions to Prevent Recurrence i

l The Supply System Equipment Qualification Program identifies and classifies plant safety-related equipment (including equipment to prevent failures of safety related power supplies resulting from failures in non-safety related connected loads) on the safety-related electrical list (Class lE List).

This assures proper classification of equipment by function. Site Engineering personnel were provided training in the application of Electrical Separation Criteria as encompassed in Engineering Criteria Document Appendix 3, WNP-2

Electrical Separation Practice.

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT N0. 2 DOCKET N0. 50-397 LICENSE N0. CPPR-93 EVALUATION OF POTENTIAL 10CFR50.55(e) CONDITION #260 STANDBY SERVICE WATER FLOW PROBLEMS INTERIM REPORT Description of Deficiency Startup testing identified insufficient flow to several heat exchangers in Standby Service Water (SW) loops A and B.

S-fety Implication Insufficient service water flow through heat exchangers could cause failure of safety-related equipment due to overheating. Failure of this equipment could preclude safe shutdown of the reactor. The reportability of the condi-tion is under consideration in accordance with normal project procedures.

Due to the circumstances described in the following sections of this report.

Cause of Deficiency The primary cause of this deficiency is due to corrosion product buildup on the inside surface of the pipe. The material buildup reduces the pipe flow area and increases resistance resulting in a low flow condition. In addition, errors in the original system pressure drop calculations have been identified. The calculations should have been considered preliminary until all system design information was available. In revising the calcula-tion to the latest design /as-built configuration several cases have been identified where the calculated available pressure head will not provide the required design flow rate.

The design aspects of these cases are limited to circuits with low available head across small bore piped heat exchangers for which critical "as-built" information (e.g., small bore isometrics) was not available when the calcu-lations were performed. The standby service water system is the only safety related system where this condition is applicaole.

Action to Prevent Recurrence A chemical treatment program is required to control water quality so as to prevent future material buildup in the pipe.

Two factors should reduce the possibility of design errors in pressure drop /

flow calculations in the future.

1) We are now using a computer program for such calculations. This allows modelling of all loops of large parallel systems.

! 2) We now have available the as-built configuration of the piping within the plant upon which to base calculations.

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.. l Interim Report - #260

.Page 2 of 3 1

I Corrective Action The Standby Service Water System (58.0) was chemically cleaned to remove the deposited material. Subsequent testing and inspection has identified that excessive fouling still exists and that additional cleanup is required.

The deposited material has been analyzed and chemical treatment to inhibit future deposits has been identified. These topics are discussed in detail in Burns and Roe Technical memorandum Number 1300, dated June 9, 1983.

The system pressure drop calculations are being revised to reflect the lat-est design configuration. The calculations that have been revised to date indicate the existing system components can be adjusted to provide the re-quired pressure head. This can be achieved by throttling the RHR heat ex-changer discharge valves (RHR-V-68A, 8) and enlarging the r2 movable orifices (SW-FE-1A, B) in the return lines located in the SW pump houses (Figure 1). If system design changes are identified as necessary to correct the deficiency, they will be implemented as required.

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