ML20216E280
| ML20216E280 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 04/07/1998 |
| From: | Dacimo F COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9804160163 | |
| Download: ML20216E280 (2) | |
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April.7 1998 4
United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555
Subject:
Additional Information regarding Containment Leak Chase Channels LaSalle County Station, Units 1 and 2
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Facility Operating License NPF-11 and NPF-18 NRC Docket Nos. 50 373 and 50-374
Reference:
(1)
W. T. Subalusky (Comed) letter to NRC Document Control Desk, " Containment Leak Chase Channels," dated November 26,1997 (2)
Fred Dacimo (Comed) letter to NRC Document Control Desk, " Supplemental information regarding Containment Leak Chase Channels,"
dated February 20,1998 in Reference (1), Commonwealth Edison Company (Comed), LaSalle County Nuclear Power Station, Units 1 and 2 (LaSalle), provided the Uni;ad States Nuclear Regulatory Commission (NRC) with justification to demonstrate that the performance of containment integrated leak rate tests (CILRTs) with the leak chase channel plugs installed satisfied the requirements of Title 10, Code of Federal Regulations, Part 50 (10 CFR 50),
Appendix J. This justification showed that (a) tiie leak chase channel welds are qualitatively equivalent to or better than those for the primary containment liner welds and (b) the leak chase channels will maintain their integrity when subjected to the loading conditions of a postulated design basis accident (DBA) as well as during normal operation. In Reference (2),
LaSalle provided justification for two additional leak chase channel configurations used in the pressure suppression pool (PSP) that were not bounded by the justification in Reference (1).
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There were, however, eighteen (18) specific leak chase channels in this population for each unit that could not be demonstrated to maintain their integrity during a postulated DBA due to their location with respect to the dynamic effects of the PSP water inventory during the postulated event. For those 18 leak chase channels on each unit, the leak chase channel plugs will be permanently removed. Initially, a local leak rate test (LLRT) will be performed on each channel to demonstrate the integrity of the underlying containment liner weld. During future CILRTs, the underlying containment liner welds will be exposed to the containment test pressure.
1 For Unit 1, the 18 leak chase channel plugs have been permanently removed and a successful LLRT of each leak chase channel has been performed. For Unit 2, the 18 leak chase channel plugs will be removed and LLRTs of the leak chase channels will be performed prior to startup from the current refuel outage, L2R07.
If there are any questions or comments conceming this letter, please refer them to Harry Pontious, Regulatory Assurance Manager, at (815) 357-6761, extension 2383.
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V Fred Dacimo Site Vice President LaSalle County Station cc:
A. B. Beach, NRC Region 111 Administrator M. P. Huber, NRC Senior Resident inspector - LaSalle D. M. Skay, Project Manager - NRR - LaSalle F. Niziolek, Office of Nuclear Facility Safety - IDNS 1