ML18037A079

Lists Results of Secondary Containment Leak Rate Test Performed on Reactor Bldg.Test Demonstrated That Unit 3 Matl Interlock Outer Door Has Adequate Sealing to Maintain Secondary Containment Integrity

ML18037A079
Person / Time
Site:	Dresden
Issue date:	11/12/1991
From:	Eenigenburg E COMMONWEALTH EDISON CO.
To:	Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
EDE-LTR-91-700, NUDOCS 9112260334
Download: ML18037A079 (6)

Text

ACCELERATED DISTIUBUTION DEMONST$Q TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

'ACCESSION NBR:9112260334 DOC.DATE: 91/11/12 NOTARIZED: NO DOCKET FACIL:50-237 Dresden Nuclear Power Station, Unit 2, Commonwealth E 05000237 50-249 Dresden Nuclear Power Station, Unit 3, Commonwealth E 05000249 AUTH. NAME , AUTHOR AFFILIATION EENIGENBURG,E. Commonwealth Edison Co.

RECIP.NAME RECIPIENT AFFILIATION DAVIS,A.B. =

Region 3 (Post 820201)

SUBJECT:

Lists results of secondary containment leak rate test performed on reactor bldg. Test demonstrated that Unit 3 matl interlock outer door has adequate sealing to maintain secondary containment-integrity.

DISTRIBUTION CODE: IEOID COPIES RECEIVED:LTR ( ENCL 8 SIZE:

TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response NOTES:License Exp date in accordance with 10CFR2,2.109(12/22/72). 05000237 RECIPIENT COPIES RECIPIENT COPIES 1D CODE/NAME LTTR E CL ID CODE/NAME LTTR ENCL PD3-2 PD 1 SIEGEL,B.

INTERNAL: ACRS AEOD AEOD/DEIIB AEOD/DSP/TPAB DEDRO NRR HARBUCK~ C ~

NRR MORISSEAU,D NRR/DLPQ/LHFBPT I'I!'? ii/DLPQ/LPEB10 NRR/DOEA/OEAB NRR/DREP/PEPB9H NRR/DST/DIR SE2 NPR/PMAS/ILRB12 NUDOCS-ABSTRACT OGC/HDS2 PG FI 02 RGN3 FILE 01 EXTERNAL: EGFrG/BRYCE,J. H. NRC PDR N&IC NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUI!!'.".R OF COPIES REQUIRED: LTTR 24 ENCL

Commo~alth Edison Dresden N~r Power Station R.R. g1 Morris, Illinois 60450 Telephone 815/942-2920 November 12, 1991 PRIPltIyy P0>

e EDE LTR: 091-700 Mr. A. Bert Davis Regional Administrator Directorate of Regulatory Operations Region III F Jl f~+

U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Secondary Containment Leak Rate Testing Dresden Nuclear Power Station Commonwealth Edison Company Docket Nos. 50-237 and 50-249 Dear Mr. Davis As part of the Dresden Unit 3 pre-outage work a Secondary Containment Leak Rate Test (SCLRT) was performed on the Unit 2/3 Reactor Building.

The SCLRT was performed in accordance with Dresden Unit 3 Technical Specification 4.7.C.l.a., which requires that prior to refueling, Secondary Containment integrity must be demonstrated by maintaining )/=

0.25 inches of water vacuum in the Reactor Building with one train of the Standby Gas Treatment system operating at a flow of </= 4000 cubic feet per minute (CFM) under calm wind conditions (</= 5 miles per hour). On September 07, 1991, the SCLRT was performed in accordance with Dresden Technical Staff Surveillance (DTS) Procedure 1600-22. The results of the test are listed below.'2 U3 RX BLDG U3 RX BLDG SCLRT RX BLDG U2 RX BLDG MAT'L INTER- MAT'L INTER- RESULT, TRACKWAY INNER TRACKWAY OUTER LOCK INNER LOCK OUTER INCHES OF QQQKLQMXXQH MhXEMK .

CLOSED CLOSED CLOSED CLOSED -0.273 CLOSED CLOSED OPEN CLOSED -0.191 OPEN CLOSED CLOSED CLOSED -0.268 ZEDE91/447

/For

As shown in the above table, the result with all interlock doors closed was 0.273 inches of water negative pressure in secondary containment with respect to atmosphere, which satisfied the Technical Specification 4.7.C.l.a. requirement. This SCLRT also demonstrated that the Unit 2 Reactor Building trackway interlock outer door has adequate sealing to maintain secondary containment integrity. Additionally, this test demonstrated that the Unit 3 material interlock outer door does not have adequate sealing to maintain secondary containment integrity. Dresden Administrative Procedure (DAP) 13-14, Unit 3 Reactor Building Material Interlock Access Control, is a posted procedure and provides adequate control of this interlock.

This report is being submitted in accordance with Section 6.6.C.3.h. of the Unit 2 and Unit 3 Technical Specifications. Please direct any requests for further information regarding this topic to M. Blakemore, Technical Staff Systems Engineer, at extension 2421.

Sincerely E. D. Eenigenburg Station Manager Dresden Nuclear Power Station cc~ M. Strait S. Lawson G. Smith J. Kotowski L. Gerner M. Blakemore File/NRC File/Numerical ZEDE91/447