NLS9100058, Application for Amend to License DPR-46,consisting of Proposed Change 93 to Tech Specs Clarifying Terms Sys & Subsystems

Application for Amend to License DPR-46,consisting of Proposed Change 93 to Tech Specs Clarifying Terms Sys & Subsystems

ML20079J212
Person / Time
Site:	Cooper
Issue date:	09/30/1991
From:	Horn G NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20079J213	List: ML20079J215 NLS9100058, Application for Amend to License DPR-46,consisting of Proposed Change 93 to Tech Specs Clarifying Terms Sys & Subsystems
References
NLS9100058, NUDOCS 9110150344
Download: ML20079J212 (9)

Text

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PLS9100058 September 30, 1991 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Vashington, D.C. 20555 Centlemen:

Subject:

Proposed Change No. 93 to Technical Specifications Clarification of System / Subsystem Terms Cooper Nuclear Station NRC Docket No. 50-298, DPR-46 In accordance with the applicable provisions specified in 10 CFR 50, the Nebraska Public Power District (District) requests that the Cooper Nuclear Station Technical Specifications be revised as specified in the attachment.

Currently, the CNS Technical Specifications contain many areas where the terms

" system" and " subsystem" are used interchangeably. This proposed change provides corrections and/or clarifications where necessary to provide continuing assurance of proper and correct interpretation of the CNS Technical Specifications.

Accordingly, the attached contains a description of the proposed change, the attendant 10 CFR 50.92 evaluation, and the CNS Technical Specification pages revised by the institution of this change. This proposed change has been reviewed by the necessary Safety Review Committees and incorporates all amendments to the CNS Facility Operating License through Amendment 146 issued August 20, 1991.

By copy of this letter and attachment the appropriate State of Nebraska official is being notified in accordance with 10 CFR 50.91(b)(1). Copies to the NRC Region IV Office and the CNS Resident Inspector are also being sent in accordance with 10 CFR 50.4(b)(2). , ,

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., ~I U. S. Nuclear Regulatory Commission Page 2.of 3 Gepternber 30, 1991 Should you have any questions or require any additional' information, please contact me.

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.( . lorn NuMear Power. Group Manager CRH/mjb Attachment cc:- H.R. Borchert Department c.f llealth State of Nebraska NRC Regional Office Region IV:

Arlington, TX' NRC Resident Inspector Cooper Nuclear Station

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U. S. Nuclear Regulatory Connission Page_3 of 3 September 30, 1991 STATE OF NEBRASKA)

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PLATTE COUNTY )

C. R. llorn, being first duly sworn, deposes and says that he is an authorized representative of the Nebraska Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly atthorized to submit this request on behalf of Nebraska Public Power Distr.ict; and that the statement,s conta!ned herein are true to the best of his knowledge and belief.

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~ C C. R. Porn Subscribed in my prosence.and sworn to before me this 30 D day of

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-NOTARY PUBLIC ENRK Mastent sitemh ALoss J.HumL Mr eman.Ese. Aug 2L 1M6

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Attachment to-

- NLS9100058 Page 1 of 6_ t REVISED TECHNICAL SPECIFICATIONS

' SYSTEM / SUBSYSTEM CLARIFICATION Revised Pages11-111 131 21 165-166 l 52 52e 180 83 182-183 ,

107 108 205a 110 209a 209b 114-122 215b-215e 124-128 216b2' I. INTRODUCTION The Nebraska Public Power District (District) requests that the NRC

_ approve the proposed changes to the CNS Technical Specifications-

!_ described below. The proposed change primarily entails clarification of the terms " system".versus " subsystem" to ensure terminology consistency throughout the CNS Technical Specifications. In addition, this proposed l change clarifies the operability requirements for the Core Spray System.

f and Low Pressure Coolant Injection (LPCI) System. of the Residual Heat'

. Removal (RHR) System during refueling operatir b ~These7 changes were identified during an NRC inspection as documented by NRC Inspection Report 86-27, dated December 30, 1986. As a result of discussions held during that inspecti n, the District committed to review the CNS Technical _ Specifications to identify, by January 30, 1987, what changes, if any, would be appropriate. Although a preliminary review was completed by that time,-it was determined that it would'be prudent to defer such changes, as it was expected that the

clarifications would be encompassed within the ongoing Technical

-Specification Improvement Program. -However, in light of the' uncertain

, scheoule'of this induetry effort, the District,-during recent

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Ediscussions withLthe CNS Senior Resident Inspector, committed to-reevaluate the CNS Technical Specifications with respect to this issue.

and' submit to the NRC a proposed Technical Specification change.

The proposed changes are' detailed below in Section II. The Significant Hazards determination is provided in Section III. The District's analysis has' determine /. that approval of this proposed change involves no significant hazards consideration.

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Attachment to-NLS9100058 4

Page 2-of 6 II. _ DESCRIPTION OF CHANCEE A. Clarification of " System" Versus " Subsystem" The majority of the proposed revisions consist of a clarification of the terms " system" versus " subsystem." Due to the large number of individual clarifying changes proposed, a description of each will not be presented here; rather, the convention used for the

-basis of_these changes will be discussed. For further

-clarification of the many changes proposed Appendix A of this-discussion provides a markup of the existing CNS Technical Specification pages affected. Appendix B of this discussion provides the clean, revised CNS Technical Specification pages which incorpcrate the proposed changes. -The Technical Specification pages have been revised in accordance:vith the following convention.

Etandby'Liould Control System - The Standby Liquid-Control System is considered a "systen," consisting of two distinct subsystems.-

Core Standbv-Cooling Systems - The Core Stand' y Cooling Systems (CSCS) co.4sist of four distinct systems. These include 1) the High Pressure Coolant Injection (HPCI)= System _ (a single " system"),

.2) the Core Spray'(CS) System (which consists of two distinct j

" subsystems"), 3) the Automatic Depressurization System (ADS) (a single . " system"),' and 4) the Low Pressure Coolant . Injection (LPCI)-

System: consisting-of two distinct' subsystems, and which is also an operating mode of the Residual ~ Heat Removal (RHR) System 1

, . Containment Cooline'- Containment cooling is a function

. accomplished-by means of the RHR Service Water System'(which-consists-of two distinct " subsystems") serving one sida of-the.RHR heat exchangers', and the RHR (LPCI) pumps serving the other side -

of the RHR heat exchangers. The containmeat cooling function is accomplished by cooling the Torus water via the FilR heat exchangers and either returning the flow to the' Torus, or by injecting the water into the Torus and/or drywell spray headers.

Standbv Cas Treatment System - The Standby Cas Treatment System is considered a " system " consisting of two distinct subsystems.

l Reactor Eculoment-Cooling (REC) System.- The REC System is considered a " system,"Leonsisting of two distinct subsystems, each 1

Although LPCI-Is actually an operating mode of the RHR System, the District proposes to refer to it as a " system," which facilitates definition of appropriate limiting conditions and action statements, and which is consistent with Standard Technical Specifications convention.

i

5 Attachment to NLS9100058 Page 3 of 6 capable of serving both critical and non-critical cooling water loops.

Service Water System " ae Service Water System is considered a

" system," consisting of two, distinct subsystems which normally are aligned to dischart,e into a common water supply header, but which are capabic of discharging cooling water into independent cooling water paths.

Shutdown Cooling - Shutdown Cooling is considered a mode of operation of the RllR system. During this mode of operation, the RilR System takes suction from Reactor Recirculation Loop "A,"

directs the flow to the Ri!R heat exchangers where it is cooled by the RllR Service Water System, and returned to the Reactor Recirculation System via the LPCI injection path. This mode of RliR operation is used during normal reactor shutdown and cooldown conditions to remove decay heat from the core.

All changer proposed are clarifications based on the conventions listed above, are editorial, or are as discussed below.

B. Core Standby Coolinc System Operability Reauirements Durinn Refuelinn Operations.

Currently, Section 3.10 F of the CNS Technical Specifications states on page 205a " refueling operation may continue with one core spray system or the LPCI mode of RilR inoperable for a period of 30 days." As discussed in NRC Inspection Report No. 86 27, the District had planned to clarify Specification 3.10.F to enable continuing refueling operations with any two of the four low pressure cooling systems inoperable.

Ilowever, upon further review, the District has determined that one LPCI subsystem should be operable at all times during refuelin6 operations while fuel is in the reactor vessel to ensure that the Shutdown Cooling mode of the Residual llent Removal System is also available. Therefore, the District proposes to change Section 3.10.F of the CNS Technien1 Specifications to allow refueling operations to continue with the following conditions:

With one Core Spray and one LPCI subsystem inoperable, or With both Core Spray subsystems inoperable Either of these combinations would allow for two of the four low pressure CSCS subsystems to be available to mitigate an unlikely loss of coolant event during refueling operations, and ensure that the Shutdown Cooling mode of the Residual llent Removal System is also available, o

Attachment to NLS9100058 Page 4 of 6 III, SIGNIFICANT HAZARDS DETERMINATIOR 10 CFR 50.91(a)(1) requires that licensee requests for operating license amendments be accompanied by an evaluation of significant hazards posed by the issuance of the amendment. This evaluation is to be perf)rmed with respect to the criteria given in 10 CPR 50.92(c). The fol;owing analysis meets these requirements.

Evaluation of this Amendment with Respect to 10 CFR 50.92 The enclosed Technical Specifications change is judged to involve no significant hazards based on the following:

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Evaluatiotl During refueling outages, systems may be taken out of service for maintenance and/or upgrades. The proposed change to Section 3,10,F will ensure that in these instances,-two redundant means remain available to flood and/or spray the core in the unlikely event that a loss of coolant inventory is experienced during refueling operations, and ensure that the Shutdown Cooling mode of the RilR System is also available. With two Core Spray subsystems inoperable. two LPCI subsystems exist to mitigate a coolant inventory loss event. In addition, with only one of two LPCI subsystems operable, and with only one of two Core Spray subsystems operabic, two redundant means exist to mitigate the event, In both of these cases, at least one LPCI subsystem is required to be operable; therefore Shutdown Cooling is assured.

Accordingly, the above combinations of inoperable subsystems ensure that means exist to mitigate a loss of coolant inventory event with consideration of a single failure, as well as provide Shutdown Cooling. On this basis, the proposed change to Section 3.10.F of the CNS Technical Specifications does not involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed changes clarifying the usa. of the terms " system" and " subsystem" and the additional misceilaneous editorial changes do not involve a significant increase in the probability or consequences of an accident previously evaluated. These changes are administrative in nature, do not reflect any changes to the plant configuration or the plant safety analysis, and are proposed to provide clarification to station operators.

Attachment to NLS9100058 Page 5 of 6

2. Does the proposed change create the possibility for a new or different kind of accident from any accident previously evaluated?

Evaluation The changes proposed to Section 3.10.F will not create the possibility for a new or different kind of accident. The changes proposed are consistent with the basis for the existing Technical Specifications r'Sarding this requirement. The proposed changes provide only clarification of appropriate requirements in providing the desired protection against a loss of coolant inventory event while ensuring that the Shutdown Cooling mode of the RHR System is-available during refueling operations while fuel is in the reactor vessel.

In addition, since the. changes proposed to clarify use of the terms " system" and " subsystem" and the remaining editorial changes involve no hardware changes or new mode of plant operation, no possibility for a new or different kind of accident is created.

-3. Does the proposed change create a significant reduction in the margin of safety?

Evaluation.

The proposed changes to the low pressure Core Standby Coolin6 '

System operability requirements during refueling operations do not .

constitute a.significant reduction in the margin of safety. As stated above, the proposed changes provide only clarification of appropriate requirements in providing the desired protection against a loss of coolant inventory event during refueling operations, and will now ensure that the' Shutdown Cooling mode of

. the RHR System is availabic during refueling operations while fuel is in the reactor vessel. -This proposed change provides no less redundancy in backup low pressure injection systems in comparison to that currently specified in the Technical Specifications.

-For the reasons stated above, the changes proposed to provide

]. clarification of the terms " system" and " subsystem" and make the minor editorial changes do not affect the margin of safety. These changes merely clarify the description of the various systems, and do not change-the CNS safety analysis.

IV. CONCLUSION The District has evaluated the proposed changes described above against the criteria given in 10 CFR 50.92(c) in accordance with the b requirements of 10 CFR 50.91(a)(1). This evaluation has determined that i this proposed change will n21 1) involve a significant increase in the probability or consequences of an accident previously evaluated, 2) p

w a Attachment to NLS9100058 Page 6 of 6 create the possibility for a new or different kind of accittent from any accident previously evaluated, or 3) create a significant reduction in the margin of safety. Therefore, for the reasons detailed above, the District requests NRC approval of this Proposed Change 93.

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