ML20065Q887

Application for Amend to License NPF-86,permitting Safety Injection Pump to Be Made Operable in Modes 5 & 6 to Support Operation in Reduced Inventory Condition,Per Generic Ltr 88-17

ML20065Q887
Person / Time
Site:	Seabrook
Issue date:	12/14/1990
From:	Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20065Q890	List: ML20065Q887 ML20065Q899
References
GL-88-17, NYN-90211, NUDOCS 9012180108
Download: ML20065Q887 (3)

Text

. y :. _

e New H6mpshire .

Ted C. Folgenbaum i Yh hh' President and -

' Chief Executive Officer NYN 90211 December 14, 1990 United ' States Nuclear Regulatory Commission Washington, D.C. ~20555 Attention: Document Control Desk

References:

(a) Facility Operating License NPF 86, Docket No. 50 443

-(b) USNRC Generic Letter 8817 dated October 17,1988,j' Loss of Decay.

Heat Removal"

Subject:

Request for License Amendment: Safety. Injection Pump - Operability (in : a '

Reduced Inventory Condition Gentlemen:

Pursuant to 10 CFR 50.90, New Hampshire . Yankee (NHY) proposes to amend the Seabrook Station Operating License (Facility Operating License NPF 86) by incorpnating -

the proposed changes, provided herein as Enclosure 1, into-the Seabrook Station Technical Specifications. These proposed changes will allow a Safety injection (SI) pump to be made OPERABLE in Modes 5 and 6 to support oper- 'on in a' reduced inventory, condition in accordance with the recommendations of Oeneric Letter 8817 [ Reference' (b)]. Revised BASES are provided as Enclosure 2:to this letter. In accordance with the provisions of 10.

CFR 50.36, these BASES are not considered to be part of the' Technical Specifications.

The -basis for these proposed changes is providedJin Enclosure 3, which includes a safety evaluation of the proposed changes. Based upon the. information contained in Enclosure 3, NHY has concluded that the proposed changes 'do not involve an Unreviewed '

Safety Question - - ' to 10 CFR 50.59, nor do they involve a .Significant' Hazards Consideration pt 'O CFR 50.92.

New Har ace has reviewed the proposed changes in accordance.with the criteria specifies R 50.92 and has determined that the' proposed changes would,not:

I 9012180108 901214 I PDR- ADOCK 05000443 p .PDR New Hampshire Yankee Division of Public Service Company of New Harrpshire l' P.OiBox 300 ? Seabrook, NH 03874.* Telephone (603) 474 952' - Ol-

t United States Nuclear Regulatory Commission Decembr.r 14, 1990 Attention: Document Control Desk Page two

1. Involve a significant increase in the probability or consequences of any accident previously evaluated. The vly accident adversely affected by the proposed change is the low temperature overpressurization mass addition transient. The probability of this event is not affected since the operable Safety Injection (SI) pump would only start in r:sponse to initiators such as an inadvertent 'S' signal which would start or realign the flow path of the operable Centrifugal Charging pump. The maximum possible flow rate into the Reactor Coolant System (RCS) during the mass addition transient will be increased, however this does not increase the consequences of this type of accident. The consequences of such an event would be mitigated by casuring that a suitable vent path in the RCS pressure boundary exists prior to making an Si pump operable. This vent will prevent any transient induced pressure increase from exceeding the 10CPR50 Appendix G pressure limit. Additionally, by providing an additional source of reactor vessel inventory, the proposed change reduces the consequences of a malfunction of the Residual Heat Removal (RHR) system.

2. Create the possibility of a new or different kind of accident from any previously evaluated. Allowing a Si pump to be operable in these modes creates the possibility of a more severe mass addition transient than those within the capability of the Cold Overpressure Mitigation System (COMS). The proposed requirement to provide a vent path prior to making the SI pump operable provides overpressure protection for the Appendix G limit similar to the existing requirement in Technical Specification 3.4.9.3c to provide an RCS vent of at least 1.58 square inches in the event that neither of the COMS alternate relief valve configurations is available. The opening of a small vent in the RCS pressure boundary to provide overpressure protection is not a new or different approach than that currently used for low temperature overpressure protection and therefore does not create the possibility of a new or different type of accident than any previously evaluated.

3. Involve a significant reduction in a margin of safety. The proposed changes would allow one SI pump to be made operable in Modes 5 and 6 to support operation in a reduced inventory condition, creating the possibility of a mass 5

addition transient more severe than those considered in the COMS design basis.

The requirement to provide a suitably sized RCS vent prior to making the SI pump operable will ensure that no violation of Appendix 0 limits will occur for such an event. This provides protection of the reactor vessel Appendix G limit independent of the COMS system. Therefore the proposed changes do not result in a reduction in the margin of safety.

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1 United Stated Nuclear Regulatory Commission December 14, 1990 Attention: Document Control Desk Page three

! New Hampshire Yankee requests approval of these proposed changes by April 30, l

1991, if you have any questions, please contact Mr. Terry L. Harpster, NHY Director of Licensing Services, at (603) 474 9521, extension 2765.

Very truly yours, W

f)

Ted C. Feigenbaum TCF:RRB/dma/ssl cc: Mr. Thomas T. Martin Regional Administrator United States Nuclear Regulatory Commission Region I 475 Allendale Road rCing of Prussia, PA 19406 Mr. Ocorge L. Iverson, Director.

Office of Emergency Management State Office Park South 107 Pleasant Street Concord, NH 03301 Mr. Victor Nerses, Sr. Project Mgr.

Project Directorate 1-3 Division of Reactor Projects U. S. Nuclear Regulatory Commission Washington, DC 20555 Mr. Noel Dudley NRC Senior Resident Inspector P.O. Box 1149 Seabrook, NH 03874 1

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