ML17333A828

Application for Amends to Licenses DPR-58 & DPR-74, Modifying TS 4.7.5.1.e.2 Which Describes Control Room Ventilation Sys Autostart Functions

ML17333A828
Person / Time
Site:	Cook
Issue date:	03/26/1997
From:	Fitzpatrick E AMERICAN ELECTRIC POWER CO., INC., INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17333A829	List: ML17333A828 ML17333A830
References
AEP:NRC:0398AS, AEP:NRC:398AS, NUDOCS 9704010316
Download: ML17333A828 (8)

Text

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ACCESSION NBR:9704010316 DOC.DATE: 97/03/26 NOTARIZED: YES DOCKET TACIT>..50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana M 05000315

,'0-316 Donald C. Cook Nuclear Power Plant, Unit 2, Indiana M 05000316 AU i'H. NAME AUTHOR AFFILIATION FITZPATRICK,E. American Electric Power Co., Inc.

FITZPATRICK,E. Indiana Michigan Power Co. (formerly Indiana a Michigan Ele RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Application for amends to licenses DPR-58 a DPR-74, modifying 'TS 4.7.5.l.e.2 which describes control room ventilation sys autostart functions.

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TITLE: OR Submittal:.General Distribution NOTES:

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U E

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FM" Indiana Michigan Power Company

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500 Circle Drive Buchanan, Ml 49107 1395 INQMNSl MICNIayAN POMfM March 26, 1997 AEP:NRC:0398AS Docket Nos.: 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

Donald C. Cook Nuclear Plant Units 1 and 2 TECHNICAL SPECIFICATION CHANGE REQUEST CONTROL ROOM VENTILATION SYSTEM REVISE AUTOSTART DESCRIPTION Thi's letter and its attachments constitute an application for amendment to the technical specifications (T/Ss) for Donald C. Cook Nuclear Plant units 1 and 2. Specifically, we propose to modify T/S 4.7.5.1.e.2 which describes the control room ventilation system autostart functions.

Attachment 1 provides a detailed description of the proposed changes, the justification for the changes, and our determination of no significant hazards consideration performed pursuant to 10 CFR 50.92. Attachment 2 contains the existing T/S pages marked to reflect the proposed changes. Attachment 3 contains the proposed revised T/S pages.

We believe the proposed changes will not result in: (1) a significant change in the types of any effluent that may be released offsite; or (2) a significant increase in individual or cumulative occupational radiation exposure.

These proposed changes have been reviewed and approved by the Plant Nuclear Safety Review Committee and the Nuclear Safety and Design Review Committee.

In compliance with the requirements of 10 CFR 50.91(b) (1), copies of this letter and its attachments have been transmitted to the Michigan Public Service Commission and to the Michigan Department of Public Health.

This letter is submitted pursuant to 10 CFR 50.30(b), and, as such, an oath statement is attached.

Sincerely, EC~

E. E.

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Fitzpatrick Vice President S WORN TO AND T cP~

My Commission DAY OF SUBSCRIBED BEFORE ME Notary Public Expires: ~+ /

1997 PHOO I 1

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U. S. Nuclear Regulatory Commission AEP:NRC:0398AS Page 2 cc: A. A. Blind A. B. Beach MDEQ - DW & RPD NRC Resident inspector J. R. Padgett

ATTACHMENT 1 TO AEP:NRC:0398AS DESCRIPTION AND JUSTIFICATION OF CHANGES 10 CFR 50.92 ANALYSIS FOR CHANGES TO DONALD C. COOK NUCLEAR PLANT UNITS 1 AND 2 TECHNICAL SPECIFICATIONS to AEP:NRC:0398AS Page 1 Introduction The purpose of these changes is to clarify the description of control room ventilation system operation that is included in the present T/Ss.

These changes were originally proposed to the NRC in our letter AEP:NRC:08560, dated July 10, 1986, as part of a larger group of proposed changes related to NUREG 0737 Ztem ZIZ.d.3.4, "Control Room Habitability." These changes were subsequently withdrawn, and submitted in revised>> form in our letter AEP:NRC:0398R, dated June 29, 1989.

For reasons unrelated to the specific changes proposed in this letter, the changes were again withdrawn (ref. AEP:NRC:0398T, dated June 15, 1990), per agreement with the NRC, with an understanding that they would be resubmitted following NRC approval of our 10 CFR 50 Appendix B control room dose analyses that were submitted separately in our letter AEP:NRC:0398AA, dated April 7, 1995.

In order to ensure that our T/Ss accurately describe the design of the control room ventilation system, and following discussions with our NRC resident inspector, we now are proposing to resubmit the specific changes described below, apart from those last proposed in AEP:NRC:0398R. The changes submitted here do not depend on the control room dose calculations currently under NRC review.

Control Room Ventilation S stem Various rooms are served by the control room ventilation system, including the control room itself, the HVAC machine room (which houses the various ventilation equipment), and the computer room.

During normal operation, outdoor air is drawn into the system through the normal air conditioning units and supplied to the computer room and the control room. The computer room and the machine room are connected by an open grating. Return flow is drawn directly from the control room and the machine room.

In the event of a radiological accident, the system would automatically be realigned in the "pressurization/cleanup" mode.

This would occur on a safety injection (SI) signal from either unit. In this mode, the pressurization fans start, drawing air through the cleanup system's roughing, high efficiency particulate air (HEPA), and charcoal filters. Dampers automatically realign to prevent unfiltered air from being drawn into the system and to provide recirculation capability within the three room complex.

The pressurization unit fans maintain the control room at positive pressure to limit the potential infiltration of unfiltered radioactive air.

Descri tion of and Justification for Chan es As presently written, T/S 4.7.5.1.e.2 instructs us to verify every 18 months that:

"On a safety injection signal from either Unit 1 or Unit 2, or on a containment phase A isolation signal, the system automatically diverts its inlet flow through the HEPA filters and charcoal adsorber bank and that either fan can then be manually started in the recirculation mode. "

to AEP:NRC:0398AS Page 2 This does not adequately describe the Cook Nuclear Plant control room ventilation system for the foilowing reasons:

(1) Automatic system actuation occurs on an SI signal from either unit. The SI signal will also initiate the respective unit's phase A containment isolation signal. However, the containment phase A isolation signal will not itself initiate ventilation system actuation.

(2) In the event of an SI signal from either unit, both pressurization fans would automatically start. One fan would then be turned off by the operators so that proper iodine residence time is obtained. The T/S as currently written implies that the fans must be turned on manually.

(3) Our control room ventilation units do not have HEPA or charcoal bypasses. Air is drawn through the HEPAs and charcoal whenever the pressurization fans are running.

Therefore, air is not "diverted" through the HEPA and charcoal, as stated in the present T/ST To correct these items, we propose to revise T/S 4.7.5.1.e.2 to require verification that:

a) On a safety injection signal from unit 1, the system automatically operates in the pressurization/cleanup mode.

b) On a safety injection signal from unit 2, the system automatically operates in the pressurization/cleanup mode.

We have separated the testing requirements for the unit 1 and unit 2 signals to emphasize that the signal from both units must be tested, i.e., that either/or is not sufficient.

These changes are administrative in nature, intended to ensure that the description of the control room ventilation system operation in T/S 4.7.5.1.e.2 accurately reflects the system design.

Regardir; (1) above, it is noted that an SI signal is the only signal which will cause the phas" A isolation signal to be initiated automatically.

An independent phase A isolation signal can be generated manually from the control room. This switch would be used by the operators it if was determined or suspected that a required automatic phase A signal did not occur as a result of a safety injection signal.

The emergency operating procedures require verification that the control room ventilation system has responded appropriately to an SI signal. Automatic starting of the pressurization fans and alignment of each of the system dampers is specifically verified.

Regarding (2) above, Cook Nuclear Plant design is conservative with regard to the T/S description because no bypass dampers must function in order to provide flow through the charcoal and HEPA filters.

Regarding (3) above, Cook Nuclear Plant design is conservative with regard to the T/S description because manual action is not, necessary to provide a fan start. Rather, both fans start automatically, and then, as required by the emergency operating to AEP:NRC:0398AS Page 3 procedure, one fan would be shut down by the operator to ensure adequate iodine residence time.

The bases in the Cook Nuclear Plant T/Ss do not specifically discuss the surveillance requirement addressed in this amendment request. However, it was determined to be prudent to add one piece of clarifying information. The following is proposed to be added to the unit 1 (unit 2) specification bases:

"The unit 1 (2) control room emergency ventilation system operates automatically on a safety injection signal from either unit 1 or unit 2. The automatic start from unit 2 (1) is only available when the unit 2 (1) ESF actuation system is active in modes 1 through 4 in unit 2 (1)."

The purpose of adding this paragraph is to clearly address any operability question for the control room emergency ventilation system with respect to the opposite unit status and the availability of the SI initiating signal.

10 CFR 50.92 Anal sis Per 10 CFR 50.92, a proposed amendment will involve a no significant hazards consideration if the proposed amendment does not:

(1) involve a significant increase in the probability or consequences of an accident previously evaluated; (2) create the possibility of a new or different kind of accident from any previously analyzed or evaluated; or (3) involve a significant reduction in a margin of safety.

Criterion 1 These changes are administrative in nature, intended to correct and clarify the T/S description of control room ventilation system operation. '3ecause no changes to plant operations or physical changes to the plant will occur due to these changes, they do not involve a significant increase in the probability or consequences of a previously evaluated accident.

Criterion 2 Because no changes to plant operations or the physical plant will occur due to these changes, the changes will not create the possibility of a new or different kind of accident from any previously evaluated.

Criterion 3 These changes are administrative in nature, intended to correct and clarify the present T/Ss with regard to system operation descriptions. Thus, the changes involve no reduction in margins of safety.

ATTACHMENT 2 TO AEP:NRC:0398AS CURRENT TECHNICAL SPECIFICATION PAGES MARKED WITH PROPOSED CHANGES