ML20247H039
| ML20247H039 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 05/13/1998 |
| From: | Graesser K COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BYRON-98-0153, BYRON-98-153, NUDOCS 9805210050 | |
| Download: ML20247H039 (2) | |
Text
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Commonu ralth 14hwn Company H)ron Generating Station 4 650 North Gernun Church 1(nad thron,11. 61010 979 4 TelHli.Mi-Stil May 13,1993 LTR:
BYRON-98-0153 File:
1.02.1052.2.8
' U. S. Nuclear Regulatory Commission Washington, D. C. 20555 ATTN: Document Control Desk
Subject:
Comed Use of Westinghouse Dynamic Rod Worth Measurement Byron Nuclear Power Station Units 1 and 2 NRC Docket Numbers: 50 - 454 and 50 - 455 Braidwood Nuclear Power Station Units I and 2 NRC Docket Numbers: 50 - 456 and 50 - 457
References:
1.
Letter from R. Jones (NRC) to N. Liparulo (Westinghouse), dated January 5,1996, transmitting NRC approval of WCAP-13360,
" Westinghouse Dynamic Rod Worth Measurement Technique."
2.
Byron Units 1 and 2 Safety Evaluation Report Supplement No. 7, Docket Nos. STN 50-454 and STN 50-455, dated November 1986.
3.
Braidwood Units I and 2 Safety Evaluation Report Supplement No. 2,
()
Docket Nos. STN 50-456 and STN 50-457, dated October 1986.
The purpose of this letter is to advise you that Commonwealth Edison (Comed) intends to use the Westinghouse Dynamic Rod Worth Measurement Technique, as described in g
WCAP-13360-P-A, " Westinghouse Dynamic Rod Worth Measurement Technique," to measure control rod worths (control and shutdown banks) during Low Power Physics Testing.
Comed will use this technique in future octages beginning with the restart from the current l
Byron Unit 2 refueling outage. Comed has previously measured control rod worths using the Westinghouse Rod Swap technique as outlined in WCAP-9863-P-A and discussed in the Byron and Braidwood Safety Evaluation Reports (Ref. 2 and 3).
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PDR ADOCK 05000454; P
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' May 13,1998 L
' Page 2.
U. S. Nuclear Regulatory Commission -
The Westinghouse Dynamic Rod Worth Measurement Technique as outlined in :
WCAP-13360-P-A was previously reviewed and approved bythe NRC (Ref.1). Reference I states that, "The staff does not intend to repeat the review of the matters that are described in
- the report and that were found acceptable when the report appears as a reference in licensing applications, except to ensure that the material is applicable to the specific plant involved." In
. addition, Reference I concludes that, ".the dynamic rod worth measurement technique is
.l acceptable for measurement of rod worth at the beginning of reload cycles for two, three, and j
four loop Westinghouse cores." Byron and Braidwood Units I and 2 are four loop i
I Westinghouse cores. Reference 1 also concludes that the technique is limited to rod patterns and rod worths bounded by the sensitivity studies contained in WCAP-13360-P-A Comed has confirmed that the rod patterns and rod worths are bounded by these sensitivity stu' dies.
Comed will adhere to the NRC reviewed and approved testing program and remedial actions N
.as specified in WCAP-13360-P-A. Consistent with the Reference 1, the Dynamic Rod Worth Measurement review criterion will be restricted to +/- 8 percent of the total measured rod l
worths. The option to use the previously approved Rod Swap technique, with its associated review and acceptance criteria, will be retained, should conditions warrant its use.-
Comed intends to update the Byron and Braidwood UFSAR to reflect that measured control rod worth (control and shutdown banks) is detennined during low power physics testing by use' of Dynamic Rod Worth Measurement or Rod Swap methodology.
If there are any questions regarding this letter, please contact Marcia Lesniak, Byron Nuclear
. Licensing Administrator, at (630) 663-6484.
Sincerely,.
I
~
i.
4
[ K, L. G ae r
Site Vice President Byron Nuclear Power Station KLG/KNK/ld cc:
Byron Project Manager-NRR
- Braidwood Project Manager - NRR Regional Administrator - RIII Senior Resident inspector-Byron Senior Resident inspector - Braidwood Office of Nuclear Facility Safety - IDNS i