ML20206Q626
| ML20206Q626 | |
| Person / Time | |
|---|---|
| Issue date: | 01/15/1999 |
| From: | Beaston V, Federline M, Rossi C NRC |
| To: | |
| Shared Package | |
| ML20206Q280 | List: |
| References | |
| NUDOCS 9905190182 | |
| Download: ML20206Q626 (9) | |
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l AD HOC REVIEW PANEL REPORT ON THE DIFFERING PROFESSIONAL OPINION OF MR. FREDERICK BURROWS 1
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%@ % 'dlr bb Margaret V. rederline, Chair Ad Hoc Review Panel 4
i_ de f [W Charles. E. Rossi, Member Ad Hoc Review Panel 9
9_ 7- L: v' % 3 Virgil L. Beaston, Member Ad Hoc Review Panel l
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l AD-HOC REVIEW PANEL REPORT l ON THE DIFFERING PROFESSIONAL OPINION i OF MR. FREDERICK BURROWS l INTRODUCTION )
, in a memorandum dated March 17,1997, Mr. Frederick Burrows, Electrical Erigineering Branch, NRR, expressed a differing professional view (DPV) regarding technical specifications 4
(TS) trip cetpoints (TSP) and allowable values (AV) for instrumentation. A panel reviewed the concems addressed in the DPV and prepared a report, dated October 31,1997, which was provided to appropriate NRC staff in order to propose actions to address the pansrs recommendations. The DPV panel acknowledged the role that both the TSP and AV have played in the determination of instrument operability. However, the panel concluded that only 4
the TSP satisfies the legal requirements under 10 CFR 50.36. NRR staff responsible for instrumentation and technical specifications, along with senior NRR managers, reviewed the panel's reco'mmendations and conducted further discussions with Mr. Burrows and representatives frorn the Office of General Counsel (OGC) By memorandum dated June 22, 1998, staff documsnted completion of this review and expressed disagreement with the panel's conclusions and concerns over imp!ementation of the panel's recommendations. The staff review documented the basis of disagreement with this view, concluded that the regulations are not clear in this area, and that precedence on how the regulations have been implemented support the view that the AV satisfies the requirement that the TS include the LSSS. Both the DPV panel and the staff agree that there is not a safety issue in that with either approach, instrument settings would be adequately controlled. Finally, OGC has concluded that, while use of the TSP would clearly satisfy the 10 CFR 50.36 requirement, it may be possible to justify the use of other values such as the AV if the staff is able to conclude from a technical standpoint l that the definition of LSSS is satisfied.
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.. I Mr. Collins informed Mr. Burrows in his July 24,1998, memorandum that given no compelling safety or regulatory improvement, it is not an appropriate use of either NRC or industry -
resources to implement the DPV panel's recommendations. He indicated that he considered the NRR review of the DPV to be concluded and that he Intended to take no further action based on the.DPV. Mr. Burrows believed that the above staff resciution represented an ,
unsatisfactory disposition of his DPV, and requested by memorandum to the Executive Director of Operations (EDO), dated August 5,1998, that specific aspects of this issue be further reviewed under formal Differing Professional Opinion (DPO) procedures. Accordingly, the EDO appointed an ad hoc panel to review the DPO. The panel members are M. Federline (RES),
chair, C. E. Rossi (AEOD), and V. Beaston (OE).
ISSUES CONSIDEP.ED BY PANEL The panel met with Mr. Burrows on November 10,1998 to discuss his views regarding the DPO. Mr. B'urrows informed the panel that his original DPV contained a number of issues, but requested that the panel focus on the following issues:
- 1. An instrument channel's trip setpoint should be the Limiting Safety System Setting required by 10 CFR 50.36 to be included in Technical Spectications.
- 2. Technical Specifications should focus on trip setpoints ("as left" value) as the key parameter for determining channel operability. An instrument channelis only capable of performing its intended function when it is adjusted to its trip setpoint since only the trip setpoint was chosen to account for all the instrumentation errors that can occur.
- 3. Although an allowable value should not be required to be in the Technical Specifications, it may be useful to include it since it does provide an acceptance standard for the actual "as-found" measured setpoint value during survailiance testing.
If the "as-found" test value exceeds the specified allowable value, the assumptions of the setpoint methodology should be revisited before the channelis adjusted back to its trip setpoint and declared operable.
- 4. Overall, the current Improved Standard Technical Specifications (ISTS) and associated Bases are not clear, concise nor technically correct in the use and discussion of trip setpoints and allowable values. The ISTS and their Bases should be rewritten to adequately reflect the staff requirements and agree with setpoint methodology and plant procedures.
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1- DISCUSSION The panel met with members of the Office of the General Counsel (OGC), the Technical r
Specifications Branch (TSB), NRR, and the Instrumentation and Controls Branch (HICB), NRR, to obtain input regarding this DPO. The panel also reviewed the documents that comprise the
! record of the previous DPV panel. A list of these documents is given in Attachment 1.
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The Commission's regulation that specifies what information is to be included in technical specifications is 10 CFR 50.36. According to the Commission's regulation, each applicant for a license to operate a nuclear power plant must submit to the Commission in writing technical specifications that include " limiting safety system setting" (LSSS) for automatic protective devices that are found to be necessary to protect the integrity of the physical barriers that guard against an uncontrolled release of radioactivity. According to the Commission's regulation,-
where an LSSS is specified for an automatic protective device, the setting must be chosen so that the automatic protective action will correct an abnormal situation before any safety limit placed upon an important process variable to protect against an uncontrolled release of ;
radioactivity is exceeded. If any safety limit is exceeded, the reactor must be shut down.
l The main issue, as indicated above, is whether only an instrument channel's trip setpoint can be considered the Limiting Safety System Setting under 10 CFR 50.36, and, therefore, must be included in the Technical Specifications to satisfy a legal requirement. Therefore, th's panel ponsidered this issue primarily a legal question and requested input from Mr. Lawrence Chandler, Associate General Counsel for Hearings, Enforcement, and Administration, OGC.
_ The panel was advised by OGC that while the use of TSP is one clear way of fulfilling the requirement, it may be possible to conclude, from a technical standpoint, that other approaches i
. such as allowable values could be used (Attachment 2). After a review of the technical aspects 3
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of this issue, involving discussion with management and staff of TSB and HICB, the panel concluded that if a trip occurs at the allowable value, or a setting more conservative than the allowable value, the applicable safety limits will not be exceeded. Thus, it is possible to justify the use of AV to satisfy the requirement that the TS include the LSSS.
l The panel also considered the procedure for setting instrument set points if only the AV is lacluded in the TS. The panel recognized that licensees whose TS include only AVs control protective device settings in accordance with piant procedures consistent with a setpoint methodology and these procedures would require protective settings that are consistent with the TSP. Further, the panel was informed by management and staff of TSB and HlCB that, for i
such plants, the trip setpoint is determined by a setpoint methodology that provides margin
- i between the TSP and AV to account for drift and other uncertainties. For plants with the improved standard technical specifications, the setpoint methodology is a reference in the TS
" Bases." At operating plants, licensees may commit to setpoint methodologies in the Final Safety Analyses Report or licensee reports with or without a staff Safety Evaluation Report.
Furthermore, it is understood that licensees may make changes to the setpoint methodology under plant procedures without approval of the NRC. The requirements of 10 CFR 50.59 will apply to such changes at some plants, but not at others depending upon what commitments have been made by the licensee and how the licensee has documented the setpoint methodology. The panel notes the additional 'assurance of safety provided by NRC Administrative Letter 98-10, "Dispositioning of Technical Specifications That are Insufficient to Assure Safety," issued December 29,1998, which reiterates the NRC staff's expectations regarding correction of facility technica! specifications when they are found to contain nonconservative values or specify incorrect actions.
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.l' In cases where only the trip setpoint (TSP) is specified in the TS, the instrument nominal trip setpoint rnust be set more conservatively than the TSP. If only the AV is included in the TS, then the instrument would be set to a nominal trip setpoint value determined by the plant-specific setpoint methodology. If during peripdic surveillance testing, an instrument setpoint is discovered to have drifted to a loss censervative value outside the TSP tolerance band but a more conservative value than the NV, the instrument would remain OPERABLE. However, the
- instrument setpoint would be required to be reset to the TSP. If an instrument setpoint drifted to a less conservative value than the AV, the instrument would be INOPERABLE and would be required to be reset to the TSP within the tolerance band. When the instrument was reset, it -
would again be OPERABLE.
CONCLUSIONS We agree with the DPV panel and the staff that use of either the trip setpoint or allowable value as the LSSS. required by 10 CFR 50.36 does not pose a safety issue. Yowever, we believe that the staff should more clearly document its basis for accepting the inclusion of allowable values rather than trip setpoints as LSSS in ISTS such that automatic protective devices function as required ensuring that safety limits are met. We, therefore, recommend that the staff clearly document t'his basis. The staff's documentation should be made available to Mr. Burrows and the public. We also recommend that this basis be included in the bases section of future plant ISTS.
In addition to the conclusions and recommendations above, we find the following regarding the four issues specifically identified by Mr. Burrows:
- 1. An instrument channel's trip setpoint or allowable value can be considered the Limiting j Safety System Setting required by 10 CFR 50.36.
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- 2. The Technical Specifications need not focus on only the trip setpoints ("as-left" value) as the key parameter for determining channel operability. The use of the' allowable values
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for determining channel operability is acceptable.
- 3. It is useful to include allowable values in the Technical Specifications to provide an "as-found" acceptance standard. If the "as-found" test value is less conservative than the allowable value, we believe that such cases should be handled in accordance with the j l
plant's procedure for addressing situations where equipment required by the Technical i l
Specifications is found to be inoperable. ]
- 4. We believe that the staff's current approach of including allowable values in ISTS to satisfy the requirements of 10 CFR 50.36 is technically adequat'e. However, we believe '
that'th'estaff should more clearly document its basis for accepting inclusion of allowable values rather than trip setpoints as LSSS in ISTS such that automatic protective devices function as required ensuring that safety limits are met. To resolve this issue, we have
' recommended that the bases section of future plant ISTS be written to provide a clear basis for accepting allowable values as the LSSS required by 10 CFR 50.36.
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L' ATTACHMENT 1 DOCUMENTS REVIEWED BY AD-HOC PANEL ON THE DIFFERING PROFESSIONAL OPlNION OF MR. FREDERI,CK BURROWS NO. DATE DESCRIPTION /(PAGE COUNT)
- 1. 9/94 ISA S67.04, Part 1, Setpoints for Nuclear Safety Related Instrumentation (23 pages)
(COPYRIGHTED, WILL BE RELEASED TO THE PDR FOR INSPECTION ONLY)
- 2. 3/6/96 Memorandum to J Wermlel from F Burrows,
Subject:
Westinghouse Standard Technical Specifications - Requirements for l Electrical / Instrumentation and Control Systems (9 pages)
- 1. 4/2/96 Memorandum'for F Burrows from C Grimes and J Wermiel
Subject:
Technical Specification Requirements for instrumentation and Control Systems (4 pages)
- 4. 8/9/96 Memorandum to J Wermiel and C Grimes from F Burrows,
Subject:
Proposed Revision 3 to Regulatory Guide 1.105, ' Instrument Setpoints for Safety Systems (2 pages)
- 5. '8/29/96 Memorandum to F Burrows from J Wermiel and C Grimes,
Subject:
' Proposed Revision 3 to Regulatory Guide 1.105, " Instrument Setpoints for Safety Systems" (12 pages)
- 6. 3/17/97 Memorandum to D Thatcher from F Burrows,
Subject:
Differing Professional View concerning Technical Specification Setpoints and Allowable Values for instrumentation (4 pages) l
- 7. 3/24/97 Memorandum to R Zimmerman from S Collins,
Subject:
Differing Professional View (DPV) Panel with enclosures (6 pages) l
- 2. 5/23/97 Memorandum to L Callan from R Zimmerman,
Subject:
Notification of Delay in Completion Review of Differing Professional View (1 page)
- 3. 9/16'97 Memorandum to L Callan from R Zimmerman,
Subject:
Notification of Delay in Completing Review of Differing Professional View (1 page)
- 10. 10/31/97 Memorandum to S Collins from R Zimmerman,
Subject:
Differing Professional View Concerning Technical Specification Trip Setpoints and Allowable Values for Instrumentation (39 pages) attaching COPYRIGHTED ATTACHMENT. WILL BE RELEASED TO THE PDR ;
FOR INSPECTION ONLY (10 PAGES) w
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- 11. 10/31197 Memorandum to F Burrows from S Collins,
Subject:
Differing Professional View Concerning Technical Specification Trip Setpoints and Allowable Values for Instrumentation (1 page)
- 12. 10/31/97 Memorandum to B.Sheron and R Zimmerman from S Collins,
Subject:
Follow-Up Actions to NRR Ad Hoc Review Panel on the Differing Professional View on Technical Specification Trip Setpoints and Allowable Values for Instrumentation (2 pages) i
- 13. 6/22/98 Memorandum to Scollins imm B Sheron, and B Boger,
Subject:
Follow-Up Actions to NRR Ad Hoc Review Panel on Differing Professional View on Technical Specification Trip Setpoints and Allowable Values for Instrumentation (7 pages) )
14, 7/24/98 Memorandum to F Burrows from S Collins,
Subject:
Differing Professional View and Differing Professional Opinion Regarding Technical Specification Setpoints and 1 Allowable Values for Instrumentation (9 pages) l
- 15. 7/24/98 Memorandum to L Callan from S Collins,
Subject:
Differing professional View and Differing Professional Opinion Regarding Technical Specification Setpoints and Allowable Values for Instrumentation (9 pages) j
- 16. 8/24/98 Memorandum to M. Federline and C.E. Rossi from L.J. Callan,
Subject:
Differing Professional Opinion Concerning Technical Specification Set Points anJ Allowable Values for Instrumentation (10 pages)
- 17. 3/16/98 Note to File from G.S. Mizuno,
Subject:
Meaning of " Limiting Safety System Settings"in 10 CFR 50.36 (8 pages)
- 18. 11/10/98 List of four items submitted by Mr. Frederick Burrows to be considered by the DPO I panel
- 19. 12/17/98 Memorandum to M. Federline from L Chandler,
Subject:
Differing Professional Opinion Regarding use of Trip Setpoints and Allowable Values for Instrumentation
- 20. 12/29/98 NRC Administrative Letter 9810: Dispositioning of Technical Specifications That are insufficient to Assure Plant Safety (5 pages)
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