ML022250433

License Amendment 148, Reactor Trip System Instrumentation

ML022250433
Person / Time
Site:	Wolf Creek
Issue date:	10/02/2002
From:	Brian Benney NRC/NRR/DLPM/LPD4
To:	Maynard O Wolf Creek
Benney B, NRR/DLPM, 415-3764
Shared Package
ML022810280	List: ML022250433 ML022800231
References
TAC MB5724
Download: ML022250433 (12)

Text

October 2, 2002 Mr. Otto L. Maynard President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839

SUBJECT:

WOLF CREEK NUCLEAR OPERATING CORPORATION - ISSUANCE OF AMENDMENT RE: REACTOR TRIP SYSTEM (RTS) INSTRUMENTATION (TAC NO. MB5724)

Dear Mr. Maynard:

The Commission has issued the enclosed Amendment No. 148 to Facility Operating License No. NPF-30 for the Wolf Creek Nuclear Operating Corporation. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated July 25, 2002 (ET 02-0029).

The amendment revises Surveillance Requirements (SRs) 3.3.1.2 and 3.3.1.3 of the TSs on the RTS instrumentation. The proposed change to SR 3.3.1.2 replaces the reference to the nuclear instrumentation system channel output by a reference to the power range channel output and deletes Note 1 to the SR. The change to SR 3.3.1.3 is editorial.

A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.

Sincerely,

/RA/

Brian Benney, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-482

Enclosures:

1. Amendment No. 148 to NPF-42

2. Safety Evaluation cc w/encls: See next page

October 2, 2002 Mr. Otto L. Maynard President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation Post Office Box 411 Burlington, KS 66839

SUBJECT:

WOLF CREEK NUCLEAR OPERATING CORPORATION - ISSUANCE OF AMENDMENT RE: REACTOR TRIP SYSTEM (RTS) INSTRUMENTATION (TAC NO. MB5724)

Dear Mr. Maynard:

The Commission has issued the enclosed Amendment No. 148 to Facility Operating License No. NPF-30 for the Wolf Creek Nuclear Operating Corporation. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated July 25, 2002 (ET 02-0029).

The amendment revises Surveillance Requirements (SRs) 3.3.1.2 and 3.3.1.3 of the TSs on the RTS instrumentation. The proposed change to SR 3.3.1.2 replaces the reference to the nuclear instrumentation system channel output by a reference to the power range channel output and deletes Note 1 to the SR. The change to SR 3.3.1.3 is editorial.

A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.

Sincerely,

/RA/

Brian Benney, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-482 DISTRIBUTION PUBLIC GHill (2)

Enclosures:

1. Amendment No. 148 to NPF-42 PDIV-2 Reading RidsOgcRp

2. Safety Evaluation RidsNrrDlpmPdiv (WRuland) WBeckner RidsNrrPMBBenney DGraves, RIV cc w/encls: See next page RidsNrrLAEPeyton JCalvo RidsAcrsAcnwMailCenter TS: ML022800231 NRR-100 Package: ML022810280 ACCESSION NO.: ML022250433 NRR-058 OFFICE PDIV-2/PM PDIV-2/PM PDIV-2/LA EEIB/BC OGC NLO PDIV-2/SC NAME BBenney JDonohew EPeyton JCalvo Hoefling SDembek DATE 9/12/02 9/13/02 9/12/02 9/17/02 9/26/02 10/1/02 OFFICIAL RECORD COPY

Wolf Creek Generating Station cc:

Jay Silberg, Esq. Vice President Operations Shaw, Pittman, Potts & Trowbridge Wolf Creek Nuclear Operating Corporation 2300 N Street, NW P. O. Box 411 Washington, D.C. 20037 Burlington, KS 66839 Regional Administrator, Region IV Superintendent Licensing U.S. Nuclear Regulatory Commission Wolf Creek Nuclear Operating Corporation 611 Ryan Plaza Drive, Suite 1000 P.O. Box 411 Arlington, TX 76011 Burlington, KS 66839 Senior Resident Inspector U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Resident Inspectors Office P. O. Box 311 8201 NRC Road Burlington, KS 66839 Steedman, MO 65077-1032 Chief Engineer Utilities Division Kansas Corporation Commission 1500 SW Arrowhead Road Topeka, KS 66604-4027 Office of the Governor State of Kansas Topeka, KS 66612 Attorney General Judicial Center 301 S.W. 10th 2nd Floor Topeka, KS 66612 County Clerk Coffey County Courthouse Burlington, KS 66839 Vick L. Cooper, Chief Radiation Control Program, RCP Kansas Department of Health and Environment Bureau of Air and Radiation 1000 SW Jackson, Suite 310 Topeka, KS 66612-1366

WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION DOCKET NO. 50-482 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 148 License No. NPF-42

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment to the Wolf Creek Generating Station (the facility) Facility Operating License No. NPF-42 filed by the Wolf Creek Nuclear Operating Corporation (the Corporation), dated July 25, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, as amended, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D. The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and Paragraph 2.C.(2) of Facility Operating License No. NPF-42 is hereby amended to read as follows:

2. Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 148, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated in the license. The Corporation shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3. The license amendment is effective as of its date of issuance and shall be implemented within 6 months of the date of issuance, including the incorporation of changes to the Technical Specification Bases as described in the licensees application dated July 25, 2002.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Stephen Dembek, Chief, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: October 2, 2002

ATTACHMENT TO LICENSE AMENDMENT NO. 148 FACILITY OPERATING LICENSE NO. NPF-42 DOCKET NO. 50-482 Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains vertical lines indicating the areas of change.

REMOVE INSERT 3.3-10 3.3-10

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 148 TO FACILITY OPERATING LICENSE NO. NPF-42 WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION DOCKET NO. 50-482

1.0 INTRODUCTION

By application dated July 25, 2002, Wolf Creek Nuclear Operating Corporation (WCNOC or the licensee) requested changes to the Technical Specifications (TSs, Appendix A to Facility Operating License No. NPF-42) for the Wolf Creek Generating Station. The proposed amendment would revise Surveillance Requirements (SRs) 3.3.1.2 and 3.3.1.3 on reactor trip system (RTS) instrumentation. The proposed change to SR 3.3.1.2 would replace the reference to the nuclear instrumentation system channel output by a reference to the power range channel output and would delete Note 1 to the SR. The change to SR 3.3.1.3 is editorial.

The licensee also provided the associated changes to the Bases of the TSs in Attachment 4 to the application.

2.0 BACKGROUND

The nuclear instrumentation system (NIS) power range channels provide indications of reactor power to the RTS. This is for the RTS trip of the reactor on power range high neutron flux. The daily NIS power range surveillance of SR 3.3.1.2 is for the power range channels to accurately reflect the reactor power based on the calorimetric heat balance calculation. A low power indication in the NIS power range channels would affect the RTS, and thus the protection of the reactor.

In its application, the licensee stated that the proposed changes address the potential effects of decalibrating the NIS power range channels at less than 100 percent power operation as discussed in Westinghouse Technical Bulletin (TB) ESBU-TB-92-14-R1, "Decalibration Effects of Calorimetric Power Measurements on the NIS High Power Reactor Trip at Power Levels Less than 70% RTP [Rated Thermal Power]," dated February 6, 1996. The TB identified potential effects for such decalibration, which can occur due to the increased uncertainty of the secondary side power calorimetric when performed at part-power operation. The plant-specific part-power level where this occurs can be determined following the guidance in the TB. The calculation of the power level below which NIS power range channel adjustments in a decreasing power direction become a concern for WCNOC is in Appendix A to the application.

As stated in the application, this power level for WCNOC is less than 45 percent RTP.

The licensee stated that the Westinghouse TB recommends that caution should be exercised if the NIS power range channels are adjusted in the decreasing power direction when the power channels indicate a higher power than the secondary side power calorimetric measurement at power levels below a plant-specific value (which is the 45 percent RTP for WCNOC discussed

above). This recommendation is in conflict with SR 3.3.1.2, which requires channel adjustment when the absolute difference is less than 2 percent RTP and the plant is greater than or equal to 15 percent RTP. In its application, the licensee stated that in accordance with NRC Administrative Letter 98-10, "Dispositioning of Technical Specifications that are Insufficient to Assure Plant Safety," it had implemented administrative controls soon after it had discovered this issue involving the SR. Additional restrictions have been imposed since that time.

The proposed amendment removes the requirement to adjust the NIS power range channels in the decreasing power direction when the indicated power is greater than the calorimetric heat balance calculation by more than 2 percent RTP. The licensee stated that compliance with SR 3.3.1.2 may result in a non-conservative channel calibration during reduced power operation. The licensees presentation of the changes to TS Bases for SR 3.3.1.2 provides a description of the potential decalibration of the NIS power range channels at part-power operation.

3.0 EVALUATION The licensee has proposed to revise SR 3.3.1.2 to (1) move the content of Note 1 to the body of the SR, and (2) state that the NIS power range channel would be adjusted if the results of the calorimetric heat balance calculation are greater than the channel output by more than 2 percent RTP of the reactor core. The revised SR 3.3.1.2 would state the following:

Compare results of calorimetric heat balance calculation to the power range channel output. Adjust power range channel output if calorimetric heat balance calculation results exceed power range channel output by more than +2% RTP.

The NIS channel for SR 3.3.1.2, as shown in item 2.a of TS Table 3.3.1-1, is the power range channel. The current SR 3.3.1.2 requires the power range channel output to be adjusted when the absolute difference between the channel output and the calorimetric heat balance calculation is greater than 2 percent RTP. With the content of Note 1 moved to the SR, the revised SR 3.3.1.2 is the same as the current SR 3.3.1.2 except that the revised SR would require the power range channel to be adjusted only when the calorimetric heat balance calculation results exceed the power range channel output by 2 percent RTP. Therefore, if the power range channels are underestimating reactor power by more than 2 percent RTP, the channels are required to be adjusted to indicate power more accurately. The 2 percent RTP limit and the 24-hour surveillance frequency is to ensure that the power range high neutron flux high setpoint reactor trip signal will be generated prior to the safety analysis limit. The calorimetric heat balance calculation is considered the more accurate determination of reactor power.

As stated above, the Westinghouse TB addresses potential effects of decalibrating the NIS power range channels at part-power operation. The licensee has proposed to require the readjustment of the power range channel output only if the channel output is less than the calorimetric heat balance calculation result when the channel input to the RTS for reactor power could be too low for a reactor trip. The revised SR 3.3.1.2 would act to have the channel outputs overestimate the reactor power, which would be a conservative input to the RTS, and compensate for the potential decalibration addressed in the TB.

The licensee further stated in its application that it also considered the effect of the potential decalibration of the NIS power range channels addressed in the TB on the following RTS design functions: power range indications, power range RTS trip functions (other than the high neutron flux), power range RTS permissive functions, power range control functions, and miscellaneous alarm functions. None of these RTS design functions were adversely impacted by the potential decalibration addressed in the TB.

For SR 3.3.1.3, the licensee has proposed to move the content of Note 1 to the body of SR 3.3.1.3 for consistency with the proposed change to SR 3.3.1.2. The proposed change to SR 3.3.1.3 is editorial in nature because the requirements of SR 3.3.1.3 are not being changed.

The proposed change moves the requirement in Note 1 of SR 3.3.1.3 into the body of the SR and the acronym NIS is spelled out because it no longer appears in SR 3.3.1.2. The surveillance requirement in SR 3.3.1.3 remains that the excore NIS channels are adjusted every 31 effective full power days if the absolute difference between the incore and excore axial flux difference is greater than or equal to 3 percent RTP.

Based on the above evaluation, the staff concludes that the proposed change to SR 3.3.1.2 is conservative, accounts for potential effects of decalibrating the NIS power range channels at part-power operation, and will ensure that the power range high neutron flux high setpoint reactor trip signal will be generated prior to the safety analysis limit. For the proposed change to SR 3.3.1.3, the staff concludes that the change is editorial in nature and does not change the requirement of SR 3.3.1.3. Based on these conclusions, the staff further concludes that the prosed amendment is acceptable.

In its July 25, 2002, application, the licensee presented the changes to be made to the TS Bases that address the potential decalibration of the NIS power range channels at part-power operation. The staff agrees with the changes to be made to the TS Bases and concludes that it is necessary to have this description in the TS Bases for SR 3.3.1.2.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Kansas State official was notified of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendment changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (67 FR 53992). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: Brian Benney Date: October 2, 2002