ML17326B130

Informs of Temporary Procedural Change to Ensure That Plant Operations Consistent W/Fsar Analysis Assumptions for Interim Period,Until Proposed Tech Spec Change Re Reactor Coolant Pump Operability at Hot Zero Power Approved

ML17326B130
Person / Time
Site:	Cook
Issue date:	07/30/1984
From:	Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	Harold Denton Office of Nuclear Reactor Regulation
References
AEP:NRC:0895, AEP:NRC:895, NUDOCS 8408060076
Download: ML17326B130 (7)

Text

REGULATORY INFORMATION DISTRIBUTION S'i l'EM (RIDS)

ACCESSION NBRo8408060076 DOC+DATE: 84/07/30 NOTARIZED:

NO DOCKET

,FACIL:50-315 Donald C,

Cook Nuclear Power Plant~

Unit l~ Indiana 8

05000315 50-316 Donald C ~,Cook Nuclear Power Plant~

Unit 2~ Indiana 8

05000316 AUTH,NAME AUTHOR AF FILI )TION ALEXICH,M,P, Indiana 8 Michigan Electric Co, REC IP ~ NAIVE RECIPIENT AFF ILIATION DENTONgHqR~

Office of Nuclear Reactor Regulationi Director

SUBJECT:

Informs of temporary procedural change to ensure that plant operations consistent w/FSAR analysis assumptions for interim period until proposed Tech Spec change re reactor coolant pump operability at hot zero power approved, DISTRIBUTION CODE:

A001S COPIES RECEIVED:LTR ENCL SIZE:

TITLE:

OR Submittal:

General Distr ibution NOTES:

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L 00 COPIES LTTR ENCL 1

0 1

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1 EXTFRNAL: ACRS NRC PDR NTIS 09 02 6

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TOTAL NUMBER OF COPIES REQUIRED:

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INDIANA8 MICHIGAN ELECTRIC COMPANY P.O. BOX 16631 COLUMBUS, OHIO 43216 July 30, 1984 AEP:NRC:0895 Donald C. Cook Nuclear Plant Unit Nos.

1 and 2

Docket Nos. 50-315 and 50-316 License Nos.

DPR-58 and DPR-74 NUMBER OF REACTOR COOLANT PUMPS OPERATIONAL IN MODE 3 Mr. Harold R. Denton, Director Of ice of Nuclear Reactor Rcgulaticn U. S. Nuclear Regulatory Commission Washington, D. C.

20555

Dear Mr. Denton:

By letter dated June 6,

1984, Indiana 4 Michigan Electrio Company (IMECo) was notified by Westinghouse Electric Corporation (g) that several Final Safety Analysis Report (FSAR) analyses performed at Hot Zero Power (HZP) assumed the operation of two (2) Reactor Coolant Pumps (RCPs).

The limiting analyses at HZP, i.e., steam line break, rod eJection, and bank withdrawal from subcritical conditions, are assumed to bound postulated Operational Mode 3 acoidents and transients.

The Donald C.

Cook Nuclear Plant Unit Nos.

1 and 2

Appendix "A"

Technical Specification (T/S) 3.4.1.2, however, requires that only one (1) 'RCP be operating during Operational Mode 3, and that at least one (1) additional RCP be available to meet single failure criteria.

The attaohment to this letter contains a copy of the notification which 'we received from g.

As noted in this

letter, g

has determined that the inconsistency between the FSAR and the T/S will not impact the FSAR conclusions for the steam line break accident and the rod egection transient.

For the bank withdrawal from subcritical conditions transient, g calculations indicate that the departure from nucleate boiling (DNB) design basis may not be met when only one (1)

RCP is running.

On a best estimate basis, however, g believes that

. the DNB design basis can be met.

The FSAR licensing basis analysis includes conservatisms (such as high reactivity insertions rates) which when

removed, show that [departure from nucleate boiling ratio] DNBR is above the limit value.

Thus, no significant safety hazard exists.

We are currently preparing a proposed amendment to the T/S to deal with this situation.

In the interim period until the modified T/S is approved by your staff, we have instituted a temporary procedural change to ensure that plant operations are consistent with the FSAR analysis assumptions.

That instruction requires that we operate with at least two (2) reactor coolant pumps while in Mode 3 unless the reactor trip breakers are disconnected.

840806007h 8407$ Q,

,PDR ADOCK 050003i5 I'i P

PDR pc@l4

Mr. Harold R. Denton AEP:NRC:0895 We are notifying you consistent with 10CFR50.36.

This matter was discussed with your staff upon notification from Jf, This document has been prepared following Corporate procedures which incorporate a

reasonable set of controls to ensure its accuracy and completeness pr ior to signature by the undersigned.

MPA/dam Attachment M. P.

A xich Vice President

<)npg<

oc:

John E. Dolan W.

G. Smith, Jr. - Bridgman R.

C. Callen G. Charnoff E.

R. Swanson - NRC Resident Inspector, Bridgman

I' 1

I N

Westinghouse Water Reactor Bectrlc Corporation Olv)slons

-'Ui'>>~ ~i- 'i; I

Mr. W.

G. Smith, Plant Manage'r-,...,

0.

C.

Cook Nuclear Plant Indiana and Michigan Power Company P,

O.

Box 458 Bridgman, Michigan 49106 Oear Mr. Smith:

NN;ear Seduces integahon Ombre 8ox 2728 Pmsnuy Pcimsyivaea

)5230 2t28 June 6,

1984 AEP"84"612 American Electric Power Service Corporation 0.

C.

Cook Unit 1

CONSISTENCY BETWEEN SAFETY ANALYSIS AND TECHNICAL SPECIFICATIONS CONCERNING NUMBER OF REACTOR COOLANT PUMPS IN OPERATION Thfs letter fs to notify you of a potential unrevfewed safety question concerning the consistency between the safety analysis and the Technical Specifications.

According to 10CFR50.36, the assumptions fn the safety analysis and the plant Tech Specs must be consistent.

This ensures that the plant fs operated in a manner such that ft fs bounded by the FSAR accident analysis.

As part of an informal review of a utility's Tech Specs fn the NRC Reactor Systems

Branch, the staff asked what the safety analysis assumptions were concerning the number of operating reactor coolant pumps, particularly at or near zero power.

This information fs stated in the FSAR for the zero power accidents.

Although the question was never formally asked, Westinghouse reviewed the analysis assumption with respect to the Tech Specs.

The issue in question concerns the number of operating reactor coolant pumps when fn Mode 3, which is defined in the Tech Specs as between 350 F and the no-load temperature (either 547 or 557'F).

The reactor fs also subcritical as required by the Shutdown Margin Spec, Standard Tech Spec 3.l.l.l.

The STS Spec number (which should co~respond to your Spec number which contains the requirement for the number of operating loops fs Spec

~.l.

This Tech Spec r states that in Mode 3, there must be two loops ooerab le (wh'ich means that the reactor coolant pump must be operable),

but only 'one loop must be actually in

~ooeratin

However, the safety analysis fn the FSAR assumes that either two or all of the reactor coolant pumps are actually operating, not just one.

In the

FSAR, analyses performed at Hot Zero Power (HZP) are assumed to bound Mode 3 opera-tion.

The accidents which are limiting at HZP are steamline

break, rod

0 June 6, 1984 Page 2

ejection and bank withdrawal from subcritical.

Westinghouse has reviewed these accidents under the reduced flow conditions of one pump.

For the rod ejection and steamline break events, Westinghouse has determined that the inconsistency between the safety analysis and the Tech Spec will not impact the conclusions presented in the FSAR.

However, for the bank withdrawal from subcritical accident, Westinghouse has performed calculations which show that the ONB design basis for this Condition II event may not be met when only one pump is in operation.

Thus, the margin for safety as defined in the basis for the Tech Specs fs reduced and this may be an unreviewed safety question according to 10CFR50.59.

Note that on a best estimate basis, the ONB design basis can be met.

The FSAR licensing basis analysis includes conservatisms (such as high reactivity insertions rates) which when

removed, show that the ONBR is above the limit value.

Thus, no significant safety hazard exists.

Westinghouse recommends that you review your FSAR analysis for the bank withdrawal from subcritical event for consistency with your Tech Specs.

Furthermore, Westinghouse recommends that you require the number of operating pumps in Mode 3 to be consistent with the analysis.

Alternatively, you should ensure that rod withdrawal will not occur when in Mode 3 ff the requirement for pump operation cannot be met in Mode 3.

This will ensure that the safety analysis fs consistent with plant operation.

If you have any questions, please contact me.

HT/387L Very truly yours, l4

nson, Manager Projects Oepar tment Central Area cc:,

M, P. Alexich W.

G. Smith J.

Waleko W