ML20205G282
| ML20205G282 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 03/31/1999 |
| From: | Ewing E ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| W3F1-99-0053, W3F1-99-53, NUDOCS 9904070192 | |
| Download: ML20205G282 (3) | |
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Ent gy Oper tlins,Inc.
Killona. LA 700f4 Tel 504 739 6242 Early C. Ewing, til Director Nu ea afety & Regulatory Affarfs W3F1-99-0053 A4.05 PR March 31,1999 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
Subject:
Waterford 3 SES Docket No. 50-382 License No. NPF-38 Entergy Commitments on instrument Uncertainty Gentlemen:
The purpose of this Letter is for Entergy Operations, Inc. (EOI) to provide an update to the NRC Staff on implementatlcq of our commitments to address instrument uncertainties at Waterford 3. In the following documents EOl committed to ensure that the basis for the Watarford 3 Technical Specification Limiting Conditions for Operation and Surveillance Requirements values include appropriate consideration for instrument uncertainty:
Letter W3F1-97-0025 dated February 6,1997, " Response to NRC Request Under 10CFR50.54(f) Regarding Adequacy and AvailabMity of Design Basis D.
information"
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Letter W3F1-97-0071 dated April 21,1SH, " Licensee Event Report 97-011" Letter W3F1-97-0114 dated May 8,1997, "Waterford 3 Performance
\\,
g Improvement Plan" O
NRC inspection Report 50-382/97-08 and Notice of Violation, dated January 19,1997 Letter W3F1-98-0051 dated April 16,1998, " Licensee Event Report 98-007" Performance Improvement Plan (PIP) Presentation in February 1998 9904070192 990331 s
PDR ADOCK 05000382 d
l P
r Entergy Commitments on Instrument Uncertainty l
W3F1-99-0053 Page 2 ~
March 31,1999 Summary t
EOl has determined that appropriate consideration of instrument uncertainty was l
applied to the Waterford 3 Technical Specification Limiting Conditions for Operation and Surveillance Requi.ement limits. On that basis, EOl considers our commitments to be met. Instrument uncertainty has been considered for TS parameter limits that
- 1) are monitored by instrumentation and 2) have design margins and functions determined to be significant to safety. Although the commitment is complete, Project efforts are continuing to formally document and verify the Expert Panel decisions.
Background
EOl's efforts in response to the October 9,199610CFR50.54(f) letter determined that additional review was needed to assure that the basis for the Technical Specification (TS) S.'r/eillance Requirements (SRs) and Limiting Condition for Operation (LCO) values included appropriate consideration for instrument uncertainty. The TS-LCO Instrument Uncertainty Project was initiated to ensure instrument uncertainty was properly applied to the TS limits. The TS-LCO Instrument Uncertainty Project was an improvement item in the PIP and the status and objectives of the project have been specifically presented to the NRC Staff in PIP Status Updates.
EOl committed to review the Waterford 3 TS-LCO limits against Combustion Engineering Owner's Group (CEOG) published guidelines for application of instrument uncertainty. EOl completed this review in January 1998. This review determined that design documentation specifying the treatment of instrument uncertainty for some of the operating limits was not readily available.
In January 1998, EOl issued a Design Engineering Administmtive Manual guideline, IC-G-001-01 "I&C Uncertainties and Setpoint Calculation Program" and developed, in August 1998, an EOl standard grading approach based on the safety significance of the instrument function. This grading process balances the rigor of the methodology used against the safety significance of L
the instrument function, consistent with ISA-S67.04 and NRC BTP HICB-12.
j A cross-disciplinary committee (Expert Panel) was formed using personnel from safety analysis, design engineering, operations, licensing, plant I
V
.s Entergy Commitments on Instrument Uncertainty
. W3F1-99-0053 Page 3-March 31,1999 engir.aering and reactor engineering. The Expert Panel applied the criteria to the
- TS-LCO limits.
The Expert Panel completed their review and established which operational limits associated with TS limits required rigorous methodologies in December 1998. The grading process used by the Expert Panel, although different from the CEOG guideline, applied Waterford 3 specific design information, operational experience, and safety analysis insights to determine the safety significance of the instrument uncertainty with respect to the instrument function. This safety significance was used to determine the level of rigor appropriate for the operating limits.
Instrumentation for which the design margin and the instrument function were determined to be.significant to safety, required a rigorous application of instrument uncertainty for the operating limit.
All instrumentation supporting a TS limit for which the design margins and functions have been determined to be significant to safety had formal calculations consistent with or meeting the intent of ISA S67-.04. These calculations rigorously applied instrument uncertainties. No changes to the Technical Specifications or as-built plant were required as a result of the Expert Panel reviews.
Should you have any questions or comments concerning this letter, please contact me at (504) 739-6242 or Curt Taylor at (504) 739-6725.
Very truly yours,
/
E.C. Ewing Director Nuclear Safety & Regulatory Affairs ECW/CWThtk cc:
E.W. Merschoff, NRC Region IV, C.P. Patel, NRC-NRR, J. Smith, N.S. Reynolds, NRC Resident inspectors Office, Administrator Radiation Protection Division (State of Louisiana),
American Nuclear Insurers