ML20080Q340

Advises That Util Has Incorporated Three LRG-II Position Papers Into OL Application.Position Paper 3-CSB, Periodic Low Pressure Leakage Testing of Drywell, Constituting Response to Confirmatory Issue 66 of SER (NUREG-0853)

ML20080Q340
Person / Time
Site:	Clinton
Issue date:	09/30/1983
From:	Nelson R ILLINOIS POWER CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
RTR-NUREG-0853, RTR-NUREG-853 L30-83(09-30)-L, L30-83(9-30)-L, U-0071, U-71, NUDOCS 8310120359
Download: ML20080Q340 (3)

Text

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Illinois Power Company U-0671 t30_83(09-30)-L 500 SOUTH 27TH STREET, P. O. BOX 511 DECATUR, ILLINOIS 62525-1805 Docket No. 50-461 September 30, 1983 Director of Nuclear Reactor Regulation Attention: Mr. A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Subj ect : Clinton Power Station Unit 1 Incorporation of Licensing Review Group (LRG)-II Position Papers into the Operating License Application

Dear Mr. Schwencer:

By the letter dated September 19, 1983, Mr. Dale Holtzscher, Chairman of the LRG-II Working Group, provided you with position papers on two of the fifty-eight presently identified LRG-II issues plus a position paper on a new issue which the group has identified and chosen to address generically. As you know, Illinois Power Company is a member of the LRG-II. We would like to advise you, in accordance with the practices developed by NRR and the LRG-II, that Illinois Power Company hereby incorporates those three position papers provided in Mr. Holtzscher's September 19, 1983 letter into the Clinton Power Station OL application.

For specificity, the September 19, 1983 letter provides information on the LRG-II issues identified in the following manner:

9-RSB, Rev. 1 Long Term Operability of Deep Draft Pumps 4-MEB, Rev. 1 Kuosheng Incore Instrument Tube Break 3-CSB, Periodic Low Pressure Leakage Testing of the Drywell It is noted on Page 5 of Position Paper 3-CSB that the drywell HVAC exhaust line could be used to provide drywell pressure control and that this subject may be addressed on a plant-specific basis. The attachment to this letter addresses such use for the Clinton Power Station. The combination of this plant-specific discussion and the generic 3-CSB position paper constitute Illinois Power Company's response to Confirmatory Issue No. 66 as described in the Clinton Power Station Safety Evaluation Report (NUREG-0853).

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-L30-83(09-30)-L September 30, 1983 Page 2 When subsequent LRG-II position papers are developed and provided to NRR, we intend to incorporate them in similar fashion.

Sincerely yours, R. . Nelson Director-Nuclear Licensing and Configuration Nuclear Station Engineering DLH/lt Attachment cc : - G. A. Harrison, NRC Clinton Project Manager NRC' Resident. Office J. J. Stefano , NRC LRG-II Project Manager Illinois Department of Nuclear Safety L. Ruth, Containment Systems --Branch, NRR l

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" Attachment'to

~" , U-0671 dated September 30, 1983 Clinton Power Station Unit 1 Use of Drywell. Purge System for Pressure Control In the Clinton Power Station Safety Evaluation Report (CPS-

'SER), NUREG-0853, Confirmatory Issue #66 addresses NRC concerns relative to " Steam Bypass of the Sup?ression Pool". .This issue addresses NRC concerns relative to the frequency of periodic low pressure leakage testing of the drywell. Illinois Power Company has endorsed the LRG-II generic position paaer, 3-CSB, entitled-

" Periodic Low Pressure Leakage Testing of the Drywell". In this position paper, a drywell leak rate testing frequency consistent with the. containment leak rate testing program is proposed.

Since the drywell purge system' includes potential pathways for. steam bypass'of the suppression pool under post-accident conditions,. resolution of CPS-SER Confirmatory Issue #66 requires addressing the uses proposed for. the drywell purge system during plant operating modes ~1, 2, and 3. -Drywell purging for airborne activity control is not required during these modes since personnel access to the drywell is not-necessary during normal power opera-tion, startup, or hot shutdown conditions.

A_ slight differential pressure, between the drywell and the

-containment, is anticipated to occur,during temperature transients in the drywell-(e.g. during reactor startup). Control of drywell pressure during these times is needed'to prevent an unwarranted

-reactor scram and containment isolation. Therefore, to accommodate the need for drywell pressure. control during such transients, it is Illinois Power Company's position that the exhaust line of the drywell purge. system may_be opened during operating modes 1, 2, and 3 with the following restrictions:

1. While venting the drywell, the containment shall not be vented or purged.

2. The drywell 7 urge supply line shall be sealed closed (as defined iy the Standard Review Plan, Section 6.2.4, Item II.6.f).

3. The. total time of venting the drywell when the reactor operating temperature is above 200*F shall be limited to'five hours (cumulative) [per fuel cycle] pending NRC evaluation of the operability of the drywell purge valves.

Illinois Power Company's' position on drywell " burping" (drywell l venting for pressure control) is identical to that previously approved.by the NRC for Mississippi Power and Light's Grand Gulf

-Nuclear Station, (GGNS). This position is stated in the GGNS 5% Operating License as License Condition #19.

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