ML20196D721

Responds to 980720 Memo from Sj Collins to Lj Callan Re When & How Mesac Approved.Licensee Installed Mirco Electronic Surveillance & Calibration (Mesac) Sys Measurement & Test Equipment as Backup Sys to Normal M&TE

ML20196D721
Person / Time
Site:	Braidwood
Issue date:	08/04/1998
From:	Sheron B NRC (Affiliation Not Assigned)
To:	Burrows F NRC (Affiliation Not Assigned)
Shared Package
ML20196D727	List: ML20196D721 ML20196D771
References
TAC-M65714, NUDOCS 9812020317
Download: ML20196D721 (2)

Text

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[ j UNITED STATES NUCLEAR REGULATORY COMMISSION

. o, f WASHINGTON. D.C. 20666 4 001 s,*****/ August 4, 1998 MEMORANDUM TO: Frederick H. Burrows Electrical Engineering Branch Division of Engineering FROM: i rian W. Sheron, Acting Associate Director or Technical Review Office of Nuclear Reactor Regulation

SUBJECT:

APPROVAL OF MESAC SYSTEM AT BRAIDWOOD

Reference:

Memorandum from Samuel J. Collins, Director, NRR, to L. Joseph Callan, EDO, I dated July 20,1998, " Revised Schedule for Resolution of Differing Professional View Regarding Dynamic Testing of instrument Channels at Braidwood and Dynamic Component Time Constant Uncertainties" In response to the above referenced memorandum, in an e mail dated July 22,1998, to ,

. S. J. Collins, Director, NRR (attached), you inquired ". . . .When and how did we approve '

MESAC7 When and how did we tell Comed that response to staff (member of the staff?)

concerns was voluntary?"

' I have been asked to respond to your questions, and the following is my understanding of the history of your concern. The licensee installed the Micro Electronic Surveillance and

' Calibration (MESAC) system measurement and test equipment (M&TE) as a backup system to the normal M&TE used to perform surveillances and calibrations of the Braidwood Station, Units 1 & 2 reactor protection system channels. in 1987, Dr. Tom Murley, then Director of NRR, was invited by Commonwealth Edison Company (the licensee) to attend a demonstration of the MESAC system. Following Dr. Murley's visit, you and the Project /

Manager, Stephan Sands, visited Braidwood November 9 through November 13,1987, to obtain a better understanding of the MESAC system. Since no licensing action had been /

proposed by the licensee regarding this system, and it was not part of the plant licensing basis, this visit was not considered an inspection. TAC No. 65714 was issued for this visit. This TAC was subsequently closed without further action being taken by the staff '7 .

because the site visit was completed and there was no open licensing action. You a prepared a request for additional information (RAI); however, this RAI was not forwarded to the licensee as no licensing basis issues regarding MESAC existed.

In November 1990, Westinghouse issued _a revision of the Braidwood/ Byron Setpoint Error

. Analysis. Upon review of this document, the licensee noted some discrepancies regarding assumptions about as-built conditions in the plants and the M&TE used in the plants. The licensee determined that some of the discrepancies could affect TS values for total allowance (TA), sensor error (SE), trip setpoint, allowable value (AV) and Z, which is the statistical summation of errors excluding those associated with the sensor and rack drift 9812020317 990904 PDR ADOCK 05000456 P PDR p

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I i l Frederick H. Burrows reconciliation program, and, in April 1992, proposed removing from the TS the relationship l between TA and Z, SE, and RE (the as-measured value of rack error). The values for TA, Z, l and SE were to be maintained under administrative controls through the 10 CFR 50.59 process. The licensee stated that changes to these values could be required due to i different test equipment, plant modifications, and similar activities. The licensee also l stated that the methodology for determining se points and associated parameters had not ,

been changed, and the Westinghouse methodology would continue to be used, thereby ensuring that the values assumed in the safety analysis would remain valid. The resulting TS amendment was granted on April 13,1993. The licensee did not exclude the use of

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the MESAC system from this amendment. Consequently, because the MESAC system was installed at the time of the setpoint reconciliation program, and the resulting TS amendment moved considerations of TA into an administrative process for change under 10CFR50.59, the staff granted tacit approval of the MESAC system testing methodology.

Since the staff has not challenged the 10 CFR50.59 implementation of MESAC, the tacit approval provided in the above TS amendment remains in effect. The staff has not initiated a review of the licensee's 10 CFR 50.59 evaluation on MESAC. Hence, any licensee response to questions from the staff regarding the MESAC system would be voluntary. A review of the MESAC system methodology and its affect on the licensing I basis of the plant is in progress now as part of our effort to address the DPV. l The DPV resolution completion is currently scheduled for mid-September,1998.

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Attachment:

As stated DISTRIBUTION:

SCollins/FMiraglia SPeterson HICB/RF PFoust SEE PREVIOUS CONCURRENCE DOCUMENT NAME: MESAC. MEMO (98-83)

Ta veceive a capu of this document, buscate b the box: 'C' = Copy without ettschmentionetosure *E' = Copy with attachment / enclosure *N' = No cooy OFFICE HICB:DRCH SC:HICB BC:HICB D:DRCH ADT: RR (act' )

NAME MWaterman' JMauck' JWermiel* RLSpessard ' BSh M DATE 07/20/98 07/20/98 07/29/98 07/29/98 08/Y/98 OFFICIAL RECORD COPY i

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