ML082470253

Ltr from Hauser to Printz, Exelon Nuclear Byron and Braidwood Nuclear Stations Exelon Frequency Spectrum Analysis Records

ML082470253
Person / Time
Site:	Byron
Issue date:	12/08/2003
From:	Hauser C Westinghouse
To:	Printz T Exelon Nuclear, Office of Nuclear Reactor Regulation
References
CAE-03-107, CCE-03-121, FOIA/PA-2008-0046
Download: ML082470253 (4)

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O Westinghouse Westinghouse Electric Company Nuclear Services P.O. Box 355 Pittsburgh, Pennsylvania 15230-0355 USA Mr. Terry Printz Direct tel: 412-374-4901 Exelon Nuclear Direct fax: 412-374-3257 4300 Winfield Road e-mail: hausercs@westinghouse.com Warrenville, IL 60555 CAE-03-107 CCE-03-121 December 8, 2003 EXELON NUCLEAR BYRON AND BRAIDWOOD NUCLEAR STATIONS EXELON Frequency Spectrum Analysis Records

References:

1) TB-03-6, "CROSSFLOW Ultrasonic Flow Measurement System Signal Issues", September 5, 2003.

2) CAE-03-100, CCE-03-1 10, "CROSSFLOW Feedwater Flow Measurement Recommendations",

November 11, 2003.

3) AMAG-INS-FS-013-01, "Frequency Spectrum Using DIAGNOSE Software", December 5, 2003.

Dear Mr. Printz:

Westinghouse Electric Company recently released the referenced Technical Bulletin, which included several future actions and commitments as well as recommendations for CROSSFLOW users; Since that time, Westinghouse and the Advanced Measurement and Analysis Group, Inc. (AMAG) have completed several of the referenced actions and would like to share the results below.

Following the discovery of signal contamination at Byron Unit 1, Westinghouse and AMAG launched a review of CROSSFLOW test activities and permanent installations performed to date. The following key criteria were used to determine the Extent of Condition and status of CROSSFLOW measurements for each utility customer.

1. Stability and variability of the correction factor during power changes.

-Unexplained changes in Cfbeyond established or alarmed limits need to be investigated.

2. Stability of CROSSFLOW performance (e.g., data rejection rate, standard deviation)

-An unexplained increase in data rejection rate or standard deviation could be a precursor to the effects of signal contamination or to other physical changes to the system. This will ultimately result in an increase in Cf variability.

Official Record Electronically Approved in EDMS 2000 A BNFL Group

Page 2 of 3 CCE-03-121 December 8, 2003

3. Continuous monitoring or an interface with the plant computer.

-Utilities that utilize continuous monitoring or interface with the plant computer have continuous trending data available to capture potential changing conditions as an early warning.

4. Frequency Spectrum Analysis Records.

-Original records that document the absence of contamination were available for many Crossflow installations. Through an interview process, it was verified that several units were tested although the frequency spectrum records were not retained. Several units, with no retained baseline records, were able to be promptly tested. As of this date, Westinghouse/AMAG have records for all Utilities currently using CROSSFLOW to adjust plant power.

Based on the above criteria, as applicable to the EXELON installations, the installations at Clinton, Dresden Units 2 and 3, LaSalle Units 1 and 2 and the common header locations at Braidwood 1 and 2 and Byron 1 and 2 are confirmed to be free from signal interference/contamination and can be used to provide future CROSSFLOW measurements. The baseline scans which were collected in accordance with Reference 3 are provided in the attachment to this letter for your records.

Additional recommendations regarding the CROSSFLOW equipment configuration for future measurements were provided in Reference 2.

Westinghouse will be issuing a Nuclear Safety Advisory Letter in early December that will include further guidance to the industry for monitoring for future potential signal contamination. AMAG is also developing new software to allow utilities to independently perform frequency spectrum analyses on demand. The additional guidance and new software will be presented and discussed at the upcoming CROSSFLOW Owners Meeting January 26-28, 2004 in San Antonio.

If you have any questions or would like further information, please call me at 412-374-4901.

Very truly yours, WESTINGHOUSE ELECTRIC COMPANY C. S. Hauser Nuclear Services Project Manager Exelon Nuclear Official Record Electronically Approved in EDMS 2000 A BNFL Group company

Page 3 of 3 CCE-03-121 December 8, 2003 Cc: T. Eaton - Exelon R. Doney - Westinghouse / Windsor C. S. Hauser - Westinghouse / ECE 5-7 J. M. Bunecicky - Westinghouse / ECE 5-7 Project Letter File Official Record Electronically Approved in EDMS 2000 A BNFL Group company

Pages 4 through 13 redacted for the following reasons:

EXEMPTION 4