ML20054K607

Application for Amend to License DPR-53,changing Tech Specs for MSIV Closure Time

ML20054K607
Person / Time
Site:	Calvert Cliffs
Issue date:	06/30/1982
From:	Lundvall A BALTIMORE GAS & ELECTRIC CO.
To:	Clark R Office of Nuclear Reactor Regulation
References
NUDOCS 8207020371
Download: ML20054K607 (3)

Text

--

. 4 BALTIMO RE GAS AND ELECTRIC CHARLES CENTER P.O. BOX 1475 BALTIMORE, MARYLAND 21203 ARTHUR E. LUNOVALL. J R.

V CC PRESsOENT SvPPLv June 30,1982 Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Mr. R. A. Clark, Chief Operating Reactors Branch #3 Division of Licensing

Subject:

Calvert Cliffs Nuclear Power Plant Unit No.1, DPR-53 Docket No. 50-317 MSIV Closure Time Reference ( A): A. E. Lundvall to R. A. Clark letter Dated 2-17-82, Unit 1, Cycle 6 Reload License Application Gentlemen:

Baltimore Gas & Electric Company hereby requests an Amendment for Operating License DPR-53 for Calvert Cliffs Unit 1, with the submittal of the enclosed changes to the Technical Specifications.

Technical Specification Change

,~ A proposed change to Unit 1 Technical Specifications for MSIV Closure Time was submitted in Reference (A). Subsequent to that proposal work proceded to justify a similar change for Unit 2. During an internal safety review of Unit 2 work an oversight in the scope of the analysis was revealed. Since a longer MSIV Closure Time (12.9 seconds versus 6.9 seconds) would increase the mass / energy dumped into the containment from the unaffected steam generator during a Steam Line Break Event, the effect on containment pressure should have been investigated.

[

That investigation began immediately for Unit 1 as well as Unit 2 since the Unit 1, Cycle 6 reload license application (Reference (A)) was then being reviewed by NRC. The expectetion was that a containment pressure reanalysis would yield acceptable results. Unfortunately, just completed analyses have revealed that a peak containment pressure of 47.6 psig (the current FSAR value; the design value is 50 psig) can only be realized by operating with a reduced steam / water mass in the steam generators. That reduced mass results in a normal water level somewhat closer to the Steam Generator Low Level trip setpoint and is judged to be too close to accommodate normal operating transients 'nithout unnecessary reactor trips. Consequently, we wish to withdraw our request in Reference (A) to h f

8207020371 820630 ()0f ri PDR ADOCK 05000317 p PDR I

Office of Nuclear Reactor Regulation June 30, 1982 Page 2 increase the MSIV Closure Time to 12.9 seconds. We intend to operate Unit 1 to the following original and more conservative Specification Limits:

T. S. Table 3.3-5, Item 6a - 16.9 seconds T. S. 4.7.1.5 - 13.6 seconds Safety Analysis The effect of this action on the Safety Analysis for Unit 1, Cycle 6 is in the conservative direction. A review of the design basis events (DBEs) for Unit 1, Cycle 6 indicates that only the cooldown events such as steam line breaks and excess load will initiate a SGIS. The analyses assumed that the Main Steam Isolation Valves completely closed in 12.9 seconds (including signal processing delay time) after SGIS was initiated.

Of the two DBEs which initiated SGIS, the Steam Line Break Event is the most limiting event. A closure time of 12.9 seconds (including signal processing delay time) is more conservative than 6.9 seconds because the mass / energy blowdown from the unaffected steam generator is greater. This increases the rate and extent of RCS cooldown and results in a more limiting transient minimum DNBR.

IIence, the results and conclusions reached in the Safety Analysis for a closure time of 12.9 seconds remain valid for a closure time of 6.9 seconds.

Safety Committee Review The Plant Operations and Safety Review Committee and the Offsite Safety Review Committee have reviewed the proposed action and have concluded that it does not constitute an unreviewed safety question nor will it result in an undue j risk to the health and safety of the public.

E Fee Determination l We have determined, pursuant to paragraph 170.22 of 10 CFR 170, that this is a j Class III amendment. Enclosed is BG&E Check No. A042755 in the amount of

$4,000.00 to cover the fee.

Very truly yours, l BALTIMORE GAS AND ELECTRIC COMPANY f

i

- M m , , , Mv// _

A. E. Lundvall, Jr.

i Vice President, Supply [

I i

Office of Nuclear Reactor Regulation June 30, 1982 Page 3 STATE OF MARYLAND, CITY OF BALTIMORE, TO WIT:

Arthur E. Lundvall, Jr., being duly sworn, states that he is Vice President of the Baltimore Gas and Electric Company, a Corporation of the State of Maryland; that he executed the foregoing Amendment for the purposes therein set forth; that the statements made in said Amendment are true and correct to the best of his knowledge, information, and belief; and that he was authorized to execute the Amendment on behalf of said Corporation.

WITNESS My Hand and Notarial Seal this /4l day of 1982.

$bidid7 otary Pubil'c oL, My Commission Expires: 7///76;

//

Enclosure:

(Check A042755)

AEL:WJL:fid cc: J. A. Biddison, Esquire G. F. Trowbridge, Esquire D. II. Jaffe,NRC P. W. Kruse, CE R. E. Architzel, NRC

.. _ , , m _ , . - , .