ML20012D968

Discusses Steam Generator Overfill Protection,Per Generic Ltr 89-19 & USI A-47, Safety Implications of Control Sys in LWR Nuclear Power Plants. Steam Generator Overfill Protection at Plant Meets Recommendations of Generic Ltr

ML20012D968
Person / Time
Site:	Seabrook
Issue date:	03/20/1990
From:	Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR GL-89-19, GL-89-21, NYN-90075, NUDOCS 9003290169
Download: ML20012D968 (3)

Text

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N Mompshire Tad C. FO lx-Senior Vice President and

e. . i Chief Operating Ofiker j i: 1 II l L .

l NYN-90075  !

i March 20, 1990

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h United States Nuclear Regulatt,ry Comission Washington, DC 20$55 i Attention: Document Control Desk i

References (a) Facility Operating' License No. NPF-86, Pocket No. 50-443 (b) USNRC Generic Letter 89-19, dated September 20, 1989, Request for Action Related to Resolution of Unresolved Safety Issue A-47 ' Safety Implication of Control Systems l in LWR Nuclear Power Plants' l I

(c) NHY Letter NYN-89162 dated December 11, 1989, ' Response to  !

Generic Letter 89-21,' T.C. Feigenbaun to USNRC. .

Subject:

Response to Generic Letter 89-19

• Gentlemen:

Generic Letter 89-19 requested licensees to verify that steam  !

generator overfill protection meets stated reconsnendations for their i specific plant design. The recommendations of Generic Letter 89-19 applicable to Seabrook Station ares appropriate technical specifica-tions and operability / surveillance procedures, as well as circuitry with the control and protection portions having appropriate physical and electrical separation. .

In the response to Generic Letter 89-21 [ Reference (c)) New Hampshire  ;

Yankee (NHY) addressed the completion status of NRC-recommended actions pertaining to Unresolved Safety Issue (USI) A-47 and concluded that the ,

design of steam generator overfill protection at Seabrook Station met the recommendations of Generic Letter 89-19. In accordance with the reporting requirements of the Generic Letter 89-19, NHY provides the following information regarding steam generator overfill protection at Seabrook Station in support of the above conclusion, pf I

New Hampshire Yankee Division of Public Service Company of New Hampshire i .

P.O. Box 300

• Seabrook, NH 03874

• Telephone (603) 474 9521

r r y

• United States Nuclear Regulatory Commission March 20, 1990 Attention: Document Control Desk Page two The designed steam generator overfill protection at Seabrook Station is the 'P-14' interlock. This interlock generates a signal to trip the turbine and terminate main feedwater flow if steam generator water level exceeds the 'HI.HI' setpoint. P-14 is a protection interlock in the Engineered Safety Features Actuation System described in FSAR Section 7.3.

The P-14 interlock is generated by two-out-of-four coincidence of HI-HI level in any steam generator by redundant, safety-grade instrumentation as shown in FSAR Figure 7.2.1, Sheet 7. The protective actions initiated by v this interlock are listed in FSAR Table 7.3-3 and include:

• Turbine trip.

• Main feedwater pump trip.

• Closure of amin feedwater isolation, control and bypass control valves.

• Inhibit automatic start of the Startup Feedwater Pump.

These protective actions are shown as a logic diagram in FSAR Figure 7.2-1. Sheet 13. This logic diagram indicates that the main feedwater pump trip is a redundant signal, when in fact, it is not. Westinghouse functional design requirements applicable to Seabrook Station do not require redundant main feedwater pump trip signals since the main feedwater isolation valve closure signal is redundant. The correction to Figure 7.2-1 Sheet 13 will be included as part of the initial revision of the updated FSAR per 10CFR50.71(e).

The main feedwater control system circuitry and the P-14 interlock circuitry are electrically isolated and physically located in different cabinets. The P-14 interlock is designed to meet functional requirements stated in FSAR Sections 7.1.2 and 7.7.2.1. FSAR Section 7.1.2 defines the safety criteria applicable to safety-related systems, including the Engineered Safety Features Actuation System. FSAR Section 7.7.2.1 addresses separation of control and protection systems.

Seabrook Station Technical Specifications require that the P-14 interlock be operable during power operation. Technical Specificationo also require calibration and periodic testing of the P-14 interlock instrumenta-tion and associated circuitry. Approved procedures are in place to implement the Technical Specifications requirements.

Based upon the above information and the detailed information pre-sented in the PSAR, Section 7 NHY concludes that steam generator overfill protection at Seabrook Station meets the recommendations of Generic Letter 89-19 because: (1) the steam generator overfill protection system is suf-ficiently separate from the control portion of the main feedwater control system so that it is not powered from the same power source, not located in the same cabinet, and not routed so that a fire is likely to affect both systems (2) the plant procedures and Technical Specifications include requirements to periodically verify operability of this protective feature. l Therefore, no further action in response to Generic Letter 89-19 is planned.

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'* ' Yn. .ited States Nuclear Regulatory Consnission March 20, 1990 f L Attention: Document Control Desk Page three L

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If you have any questions on this matter, please contact Mr. Geoffrey -

Kingston at (603) 474-9521, extension 3371. .

Very truly yours, i 4

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f)h 44' Ted C. Feigenbaum 1

I cci Mr. William T. Russell L = Regional Administrator I I United States Nuclear Regulatory Conunission i Region I  ;

475 Allendale Road King of Prussia, PA 19406 ,

Mr. Victor Neroes, Project Manager Project Directorate I-3 United States Nuclear Regulatory Commission Division of Reactor Projects i Washington, DC 20555 Mr. Noel Dudley NRC Senior Resident Inspector P.O. Box 1149 Seabrook, NH 03874 STATE OF NEW HAMPSHIRE Rockingham, ss. March 20, 1990 Then personally appeared before me, the above-named Ted C. Feigenbaum, being duly sworn, did state that he is Senior Vice President & Chief Operating Officer of the New Hampshire Yankee Division of Public Service Company of New Hampshire, that he is duly authorized to execute and file the foregoing information in the name and on the behalf of New Hampshire Yankee Division of the Public Service Company and that the statements therein are true to the best of his knowledge and belief, bmhb ev30tu Beverly E.1111oway, NotaryJbblic.

My Commission Expires: February 28, 1995 k

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