ML052500004
ML052500004 | |
Person / Time | |
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Issue date: | 09/07/2005 |
From: | Hiland P NRC/NRR/DIPM/IROB |
To: | Schoppman M Nuclear Energy Institute |
Schulten C. S., NRR/IROB/TSS, 415-1192 | |
References | |
Download: ML052500004 (5) | |
Text
September 7, 2005 NEI Setpoint Methods Task Force c/o Mr. Michael A. Schoppman Nuclear Energy Institute 1776 I Street, N. W.
Suite 400 Washington, DC 20006-3708
Dear Mr. Schoppman:
SUBJECT:
TECHNICAL SPECIFICATION FOR ADDRESSING ISSUES RELATED TO SETPOINT ALLOWABLE VALUES
Reference:
Bruce A. Boger (NRC) letter to A. Marion (NEI), "INSTRUMENTATION, SYSTEMS, AND AUTOMATION SOCIETY (ISA) S67.04 METHODS FOR DETERMINING TRIP SETPOINTS AND ALLOWABLE VALUES FOR SAFETY-RELATED INSTRUMENTATION," dated August 23, 2005 In the reference letter, the Nuclear Regulatory Commission (NRC) staff responded to the Nuclear Energy Institute (NEI) Setpoint Methods Task Force (SMTF) issues on instrument settings and the technical specifications (TSs) required for limiting safety system settings related to plant safety limits. The letter also clarified the staff positions on the seven concepts proposed by the NEI SMTF that could be used in the development of a Technical Specification Task Force (TSTF) change traveler for addressing these issues generically. Enclosed are draft changes to plant TSs that are acceptable to the NRC staff for implementing the concepts in the reference letter related to setpoint allowable values for safety related instrumentation.
The staff intends to use these TSs in its reviews of plant-specific license amendment requests and in its review of the TSTF.
Specifically, Part A provides two notes that apply to setpoint verification surveillances needed to address instrument trip setpoint allowable value issues, and Part B is a check list that provides the TS Bases content for the two notes in Part A. We believe that the TS Notes and the discussion of the content for the related TS Bases will satisfactorily address both the NRC staffs and industrys concerns with instrument settings, and ensure compliance with Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36, "Technical Specifications."
Please contact Carl Schulten at (301) 415-1192 or e-mail css1@nrc.gov if you have any questions or need further information.
Sincerely,
/RA/
Patrick L. Hiland, Chief Reactor Operations Branch Division of Inspection Program Management Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/encl: D. Hoffman, EXCEL J. Voss, EXCEL
ML052500004 OFFICE RE:TSS:IROB:DIPM SC:TSS:IROB:DIPM C:IROB:DIPM NAME CSSchulten THBoyce PLHiland DATE 09/07/2005 09/07/2005 09/07/2005 TECHNICAL SPECIFICATIONS FOR LICENSE AMENDMENT REQUESTS RELATED TO SETPOINT ALLOWABLE VALUES FOR SAFETY-RELATED INSTRUMENTATION A. Technical Specification (TS) Notes for SMTF Agreement Concepts Note 1: If the as-found channel setpoint is conservative with respect to the Allowable Value but outside its predefined as-found acceptance criteria band, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service. If the as-found instrument channel setpoint is not conservative with respect to the Allowable Value, the channel shall be declared inoperable.
Note 2: The instrument channel setpoint shall be reset to a value that is within the as-left tolerance of the [Limiting Trip Setpoint*, or a value that is more conservative than the Limiting Trip Setpoint]; otherwise, the channel shall be declared inoperable. The [Limiting Trip Setpoint] and the methodology** used to determine the [Limiting Trip Setpoint], the predefined as-found acceptance criteria band, and the as-left setpoint tolerance band are specified in the UFSAR [or Bases] [or a document incorporated into the UFSAR such as the technical requirements manual].
- Reviewers Note: the words "Limiting Trip Setpoint" are generic terminology for the setpoint value calculated by means of the plant-specific setpoint methodology documented in the UFSAR, or Bases, or a document incorporated into the UFSAR such as the technical requirements manual. The nominal Trip Setpoint (field setting) may use a setting value that is more conservative than the Limiting Trip Setpoint, but for the purpose of TS compliance with 10 CFR 50.36, the plant-specific setpoint term for the Limiting Trip Setpoint must be cited in Note 2. The brackets indicate plant-specific terms may apply, as reviewed and approved by the NRC staff.
- The NRC staff will review and approve the methodology supporting the requested changes in the LAR.
B. Check List for Development of TS Using SMTF Agreement Concepts The items that follow are intended for the review of plant-specific license amendment requests for changes to TS setpoint Allowable Values. The TS Bases shall be included with the license amendment application and will be reviewed by the NRC staff, to ensure consistency with the TS and design bases for the plant.
- 1. Note 1 and Note 2 above pertain to setpoint verification surveillances for instrument functions on which a safety limit has been placed. In accordance with 10 CFR 50.36 these functions are limiting safety system settings (LSSS). Note 1 and 2 can be incorporated into LCO surveillances or the notes can be used as footnotes to surveillances listed in the instrumentation tables for specific functions.
Enclosure
- 2. The TS Bases shall contain a statement that the Limiting Trip Setpoint is based on the calculated total loop uncertainty per the plant-specific methodology documented in the UFSAR [or a document incorporated into the UFSAR such as the technical requirements manual]. Regulatory Guide 1.105, "Setpoints for Safety-Related Instrumentation" provides an acceptable methodology.
- 3. The TS Bases shall include a statement that the Limiting Trip Setpoint is the LSSS required by 10 CFR 50.36. The TS Bases for Note 1 and Note 2 shall explain the basis for the notes including why the notes are applicable to specific instrument functions. The revised Bases shall include a discussion about entering degraded instrument channels into the plant-specific corrective action program. Degraded instruments are those that are not functioning as required.
- 4. As an alternative to a license commitment (reference: NRC letter dated March 31, 2005 from J. Lyons to A. Marion (NEI)) to assess the operability of tested instrumentation for meeting Note 1, the TS Bases may include discussion regarding the evaluation of a channel to verify that it is functioning as required before returning the channel to service when the channels as-found channel setpoint is found to be conservative with respect to the Allowable Value, but outside its as-found predefined acceptance criteria band. This establishes a TS Bases presentation that is consistent with agreement concept 7 of NEI letter dated May 18, 2005 from A. Marion to J. Lyons (NRC). In general, operability of instruments is treated as outlined below:
- 1) If the as-found TSP is found to be non-conservative with respect to the AV specified in TSs, the channel is declared inoperable and the associated TS action statement must be followed.
- 2) If the as-found TSP is found to be conservative with respect to the AV, and outside the as-found predefined acceptance criteria band, but the licensee is able to determine that the instrument channel is functioning as required and the licensee can reset the channel to within the setting tolerance of the limiting TSP, or a value more conservative than the limiting TSP, then the licensee may consider the channel to be operable. If the licensee cannot determine that the instrument channel is functioning as required, the channel is declared inoperable and the associated TS actions must be followed.
- 3) If the as-found TSP is outside the as-found predefined acceptance criteria band, the condition must be entered into the licensees corrective action program for further evaluation.