ML050380283

Summary of Conference Call with TVA Status of Amendments Using Method 3

ML050380283
Person / Time
Site:	Browns Ferry
Issue date:	02/16/2005
From:	Chernoff M NRC/NRR/DLPM/LPD2
To:	Singer K Tennessee Valley Authority
Chernoff, M H, NRR/DLPM, 301-415-4041
Shared Package
ML050480652	List: ML050380283 ML050590036
References
ISA-S67.04-1994, ML041690604, TAC MC1330, TAC MC1427, TAC MC2305, TAC MC3743, TAC MC3744, TAC MC3812, TAC MC4070, TAC MC4071, TAC MC4072, TAC MC4161 10 CFR 50.36, 10 CFR 50.59, TS-418, TS-431, TS-434, TS-437, TS-443, TS-447
Download: ML050380283 (5)

Text

February 16, 2005 LICENSEE:

Tennessee Valley Authority FACILITIES:

Browns Ferry Units 1, 2 and 3

SUMMARY

OF FEBRUARY 1, 2005, CONFERENCE CALL REGARDING REQUEST FOR INFORMATION REGARDING STATUS OF AMENDMENTS USING METHOD 3 (TAC NOS. MC1330, MC1427, MC2305, MC3812, MC4070, MC4071, MC4072, MC4161, MC3743, MC3744)

On February 1, 2005, the U.S. Nuclear Regulatory Commission (NRC) staff conducted a conference call with the Tennessee Valley Authority (TVA, the licensee) representatives. The call was conducted at the licensees request and served as the licensees response to the Nuclear Regulatory Commission (NRC) staffs January 6, 2005, letter, which discussed six amendments proposed by TVA. These proposed amendments involved setpoints calculated using Instrumentation, Systems and Automation Society of America (ISA) Standard, ISA-S67.04-1994, Setpoints for Nuclear Safety-Related Instrumentation, Method 3. is a list of attendees and Enclosure 2 is a copy of TVA viewgraphs presented during the meeting.

BACKGROUND TVA submitted six license amendment requests (TS-418, TS-431, TS-434, TS-437, TS-443, TS-447) using instrumentation setpoints established using a methodology about which the NRC staff has concerns. The NRC staff has identified that the methodology does not provide adequate assurance that a plant will operate in accordance with the assumptions upon which the plant safety analyses have been based under certain conditions. The NRC staffs safety concerns were described in a letter from Mr. Ledyard Marsh to Mr. Alex Marion of the Nuclear Energy Institute [ADAMS Accession Number ML041690604]. The issue was also discussed in various public meetings held in June and July 2004.

TVA calculated multiple setpoint Allowable Values (AVs) by means of ISA Standard, ISA-S67.04-1994, Setpoints for Nuclear Safety-Related Instrumentation. The NRC staff determined that setpoint AVs established by means of ISA 67.04 Part 2 Method 3 (Method 3) may not be calculated conservatively enough to ensure that instrument uncertainty and routine drift will not result in challenging the analytical limits. Since the six amendments were based on a methodology about which the NRC staff has concerns, the NRC issued a letter dated January 6, 2005, requesting TVA to address how they wanted to proceed. The letter requested that TVA either revise the applications to address the NRC staffs safety concerns and provide a schedule for submittal of the revised applications, or withdraw the requests and resubmit when the generic issue has been resolved.

2 DISCUSSION The NRC staff described ongoing efforts to resolve concerns with Method 3. The staff is developing a generic resolution that will be presented to NRR senior management by March 31, 2005. The focal point of the NRC staffs proposed resolution is the issue of re-setting instruments to the calculated Trip Setpoint following periodic Channel Operational Testing. This aspect is of particular concern to the staff when Method 3 is employed due to the less conservative nature of the definition of the AV as the operability limit and potential challenges that could result in transgressing Analytical Limits as a result of loop uncertainty and instrument drift. The NRC staff agrees that ISA Method 3 is an acceptable method for determination of instrument setpoints, provided that the trip setpoint and the AV are set appropriately and reset of the instrument to the calculated trip setpoint is accomplished at the completion of surveillance testing. The difference between the licensees proposed solution and the NRC staffs position involves the mechanism of regulatory controls over the practice of resetting the instrument at the conclusion of surveillance testing (i.e., the as-left value) and the regulatory controls needed to determine instrument technical specification (TS) operability.

The NRC staff indicated to the licensee that the requirement for re-set needs to be reflected in the plant TSs in accordance with Title 10, Code of Federal Regulations (10 CFR) Section 50.36.

Recognizing that the re-set is currently captured in TS Bases and plant procedures for a significant number of affected plants, the NRC staff is considering development of a Consolidated Line Item Improvement Process to insert regulatory controls over a requirement to re-set the instruments after surveillance testing into the TSs. The NRC staffs proposed solution would not require any licensee to recalculate/revise the setpoints or to change setpoint calculation methodology. However, it would provide a regulatory control that ensures equipment would be capable of performing its intended safety function.

The licensee provided a history of the correspondence surrounding the generic review of this concern and then presented an interim plant-specific solution. TVA 's proposed interim plant-specific solution is the addition of statements to the applicable TS Bases section clarifying what constitutes instrument operability, and stating that setpoints should be adjusted to within the established calibration tolerance band at the completion of testing. Deviations from the process would constitute a change to the approved methodology and, therefore, would require review and approval by the NRC staff. The licensee provided assurances that appropriate control of the practice can be performed through 10 CFR 50.59.

The NRC staff did not agree with the licensees rationale that 10 CFR 50.59 would be adequate to ensure compliance with the requirements nor did the staff agree that a change to information in the TS Bases would require NRC staff review per 10 CFR 50.59. The NRC staff reiterated that reliance on settings or practices outside the TS, and not mandated by the TS, is not consistent with 10 CFR 50.36.

3 The licensee indicated their intent to delay revision of these submittals until the generic issue is resolved, and that the delay would not adversely affect site scheduled activities.

The NRC staff considered this conference call as the licensees response to the January 6, 2005, letter. No commitments were made by the licensee and no regulatory decisions were made by the NRC staff during the proceedings of this conference call.

/RA/

Margaret H. Chernoff, Project Manager, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260 and 50-296

Enclosures:

1. List of Participants

2. TVA Presentation Slides w/ enclosures: See next page

ML050380283 Enclosure No.: ML050590036 NRC-001 OFFICE PDII-2/PM PDII-2/PM PDII-2/LA PDII-2/SC PDII-1/SC NAME EBrown MChernoff BClayton MMarshall JNakoski DATE 2/ 16 /05 2/ 16 /05 2/ 16 /05 2/ 16 /05 2/ 10 /05

Participant List Conference Call FEBRUARY 1, 2005 NRC TENNESSEE VALLEY AUTHORITY Paul Rebstock Rich DeLong Ed Hackett Tony Langley John Nakoski Dave Burrell Tom Boyce Jim Ballard Carl Shulten Bert Morris Bob Clark Tim Abney Michael Marshall Chris Gratton Hukam Garg Steve Cahill Margaret Chernoff Eva Brown