ML053420283

Amendment, Revision to Control Rod Scram Time Testing Frequency

ML053420283
Person / Time
Site:	Browns Ferry
Issue date:	01/09/2006
From:	Ellen Brown Plant Licensing Branch III-2
To:	Singer K Tennessee Valley Authority
Brown E, NRR/DLPM, 415-2315
Shared Package
ML060110296	List: ML053420283 ML060110473 ML060110474
References
TAC MC8037, TAC MC8038
Download: ML053420283 (14)

Text

January 9, 2006 Mr. Karl W. Singer Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT, UNITS 2 AND 3 - ISSUANCE OF AMENDMENTS REGARDING TECHNICAL SPECIFICATION IMPROVEMENT TO REVISE CONTROL ROD SCRAM TIME TESTING FREQUENCY (TAC NOS. MC8037 AND MC8038)

Dear Mr. Singer:

The Commission has issued the enclosed Amendment Nos. 295 and 253 to Facility Operating Licenses Nos. DPR-52 and DPR-68 for the Browns Ferry Nuclear Plant, Units 2 and 3, respectively. These amendments are in response to your application dated July 29, 2005.

These amendments revised the technical specification testing frequency for the Surveillance Requirement 3.1.4.2, control rod scram time testing, from 120 days cumulative operation in MODE 1 to 200 days cumulative operation in MODE 1.

A copy of the Safety Evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely,

/RA Margaret H. Chernoff for/

Eva A. Brown, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-260 and 50-296

Enclosures:

1. Amendment No. 295 to License No. DPR-52

2. Amendment No. 253 to License No. DPR-68

3. Safety Evaluation cc w/enclosures: See next page

ML053420283 Tech Spec 2: ML060110473 NRR-058 OFFICE CLIIP - LPM NRR/LPL2-2/PM NRR/LPL2-2/LA NRR/LPL2-2/BC NAME BVaidya EBrown BClayton MMarshall DATE 12/22/2005 1/9/2006 12/14/2005 1/9/2006 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-260 BROWNS FERRY NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 295 License No. DPR-52

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

A. The application for amendment by Tennessee Valley Authority (the licensee) dated July 29, 2005, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, 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 Commission's regulations; D. The issuance of this 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 Commission's 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. DPR-52 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 295, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance and shall be implemented within 60 days from the date of issuance. The licensee shall incorporate the Technical Specifications Bases changes described in its application dated July 29, 2005, in the next periodic update to the Technical Specifications Bases Section.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Michael L. Marshall, Jr., Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: January 9, 2006

ATTACHMENT TO LICENSE AMENDMENT NO. 295 FACILITY OPERATING LICENSE NO. DPR-52 DOCKET NO. 50-260 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 marginal lines indicating the areas of change.

REMOVE INSERT 3.1-13 3.1-13

TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-296 BROWNS FERRY NUCLEAR PLANT, UNIT 3 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 253 License No. DPR-68

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

A. The application for amendment by Tennessee Valley Authority (the licensee) dated July 29, 2005, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, 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 Commission's regulations; D. The issuance of this 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 Commission's 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. DPR-68 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 253, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance and shall be implemented within 60 days from the date of issuance. The licensee shall incorporate the Technical Specifications Bases changes described in its application dated July 29, 2005, in the next periodic update to the Technical Specifications Bases Section.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Michael L. Marshall, Jr., Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: January 9, 2006

ATTACHMENT TO LICENSE AMENDMENT NO. 253 FACILITY OPERATING LICENSE NO. DPR-68 DOCKET NO. 50-296 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 marginal lines indicating the areas of change.

REMOVE INSERT 3.1-13 3.1-13

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 295 TO FACILITY OPERATING LICENSE NO. DPR-52 AND AMENDMENT NO. 253 TO FACILITY OPERATING LICENSE NO. DPR-68 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 2 AND 3 DOCKET NOS. 50-260 AND 50-296

1.0 INTRODUCTION

By letter dated July 29, 2005 (Agencywide Document Access and Management System (ADAMS) Accession No. ML052220325), the Tennessee Valley Authority (TVA, the licensee) submitted a request for changes to the Browns Ferry Nuclear Plant (BFN), Units 1, 2 and 3 Technical Specifications (TSs). The requested changes would revise the TS testing frequency for the Surveillance Requirement (SR) 3.1.4.2, control rod scram time testing, from 120 days cumulative operation in MODE 1 to 200 days cumulative operation in MODE 1.

By letter dated September 20, 2005 (ADAMS Accession No. ML052360292), the U.S. Nuclear Regulatory Commission (NRC) informed TVA that the NRC staff finds that the information presented for BFN, Unit 1, does not support review of this request under the Consolidated Line Item Improvement Process (CLIIP), as no actual plant-specific data for BFN, Unit 1, was provided. The September 20, 2005, letter from NRC has referenced the incorrect Federal Register (FR) Notice of 69 FR 30339, dated May 27, 2004. The correct reference should have been 69 FR 51864, dated August 23, 2004.

The changes for BFN, Unit 2 and 3 are based on TS Task Force (TSTF) change traveler no. 460 (TSTF-460), Revision 0, that has been approved generically for the boiling-water reactor (BWR) Standard TS, NUREG-1433 (BWR/4) and NUREG-1434 (BWR/6), by revising the frequency of SR 3.1.4.2 regarding control rod scram time testing from 120 days cumulative operation in MODE 1 to 200 days cumulative operation in MODE 1. A notice announcing the availability of this proposed TS change using the CLIIP was published in the Federal Register on August 23, 2004 (69 FR 51864).

2.0 REGULATORY EVALUATION

Section 182a of the Atomic Energy Act requires applicants for nuclear power plant operating licenses to include TSs as part of the license. The Commissions regulatory requirements related to the content of the TS are contained in Title 10, Code of Federal Regulations (10 CFR) Section 50.36. The TS requirements in 10 CFR 50.36 include the following categories: (1) safety limits, limiting safety systems settings and control settings, (2) limiting conditions for operation, (3) surveillance requirements, (4) design features, and (5) administrative controls. The requirements for system operability during movement of irradiated fuel are included in the TSs in accordance with 10 CFR 50.36(c)(2), Limiting Conditions for Operation.

The TS requirement governing the control rod scram time surveillance is intended to assure proper function of control rod insertion. Following each refueling outage, all control rod scram times are verified. In addition, periodically during power operation, a representative sample of control rods is selected to be inserted to verify the insertion speed. A representative sample is defined as a sample containing at least 10 percent of the total number of control rods. The current TS stipulates that no more than 20 percent of the control rods in this representative sample can be slow during the post outage testing. With more than 20 percent of the sample declared to be slow per the criteria in Table 3.1.4-1, additional control rods are tested until this 20 percent criterion (e.g., 20 percent of the entire sample size) is satisfied, or until the total number of slow control rods (throughout the core, from all surveillances) exceeds the Limiting Condition for Operation (LCO) limit. For planned testing, the control rods selected for the sample should be different for each test. The acceptance criterion for at-power surveillance testing has been redefined from 20 percent to 7.5 percent and will be incorporated into the TS Bases in accordance with its Bases Control Program. This tightened acceptance criterion for at-power surveillance aligns with the TS 3.1.4 requirement for the total control rods allowed to have scram times exceeding the specified limit.

The proposed change does not affect any current operability requirements and the test frequency being revised is not specified in regulations. As a result, no regulatory requirements or criteria are affected.

3.0 TECHNICAL EVALUATION

3.1 Statement of Proposed Changes BFNPs TS SR 3.1.4.2 states [v]erify, for a representative sample, each tested control rod scram time is within the limits of Table 3.1.4-1 with reactor steam dome pressure $800 psig.

SR 3.1.4.2 has a frequency of 120 days cumulative operation in MODE 1. The proposed change revises the frequency to 200 days cumulative operation in MODE 1. The TS Basis for SR 3.1.4.2 will be revised to reference the new frequency and to reduce the percentage of the tested rods which can be slow from 20 percent to 7.5 percent.

3.2 Evaluation of Proposed Change The control rod insertion (scram) time test results at BFNs have shown the control rod scram rates to be highly reliable. In its submittal dated July 29, 2005, the licensee stated that it has performed a review of the control rod drive (CRD) system SCRAM time test results for BFNs.

The CRD scram time test results were reviewed back through July 1998, which is when BFN converted to Standard TSs and incorporated the scram timing criteria presently in TS Table 3.1.4-1. This represents 7 years of operation. BFN has 185 control rods on each unit.

This review further determined the following for each BFN Unit:

a) BFN, Unit 2: During the time period (July 1998 to present) there were approximately 1500 individual rod scram timing tests performed on Unit 2. Of these, there were seven rods total, which tested slow following refuel outages during the performance of the SR 3.1.4.1 full core scram time tests (SR tests all 185 rods). This result is not unexpected, since preventive maintenance on CRDs, CRD hydraulic control units, SSPVs, and scram insert and discharge valves is routinely performed during refueling outages. These maintenance activities may affect scram timing and require adjustments on a small percentage of rods following initial startup scram testing at operating pressure. All seven control rods met the TS Table 3.1.4-1, 90-percent insertion time criteria (position 06) of 3.36 seconds, and were adjusted as necessary and satisfactorily retested at all rod positions shortly following the startup full core scram surveillance. Typically, the insertion limit for position 46 was not met by a small amount.

Position 46 is characteristically the most common position limit to be exceeded for BWRs due to "sticking" of the elastomer diaphragms of the Scram Solenoid Pilot Valves (SSPVs). As mentioned above, the Automatic Switch Company (ASCO) SSPVs are scheduled to be replaced with Automatic Valve Company (AVCO) brand valves, which should show improved performance at position 46 since the AVCO SSPVs do not use elastomer diaphragms.

No rods tested slow during the performance of the 17 SR 3.1.4.2 tests (10-percent representative sample of control rods every 120 days of cumulative operation) that were conducted in this time period. This represents approximately 370 individual rod scram time tests.

b) BFN, Unit 3: During the time period (July 1998 to present) there were approximately 1350 individual rod scram timing tests performed on Unit 3. Similar to Unit 2, there were three rods, which tested slow following refuel outages during the performance of the SR 3.1.4.1 full core scram time tests (SR tests all 185 rods). Of these three rods, one rod (30-59) remained slow during subsequent retests during Cycle 10 operation due to a problem with the CRD flange ball check valve on the affected drive. The maximum position 06 scram insertion time on this rod was 3.780 seconds compared to the TS Table 3.1.4-1 limit of 3.36 seconds. The CRD was subsequently repaired during the Cycle 10 refueling outage.

Aside from rod 30-59, during the performance of the 18 SR 3.1.4.2 tests (10-percent representative sample of control rods every 120 days of cumulative operation) that were conducted in this time period, a single rod tested slightly slow at position 46 (.464 seconds versus TS requirement of .45 seconds) during Cycle 9 operation in October 1999. These 18 SR 3.1.4.2 tests represent approximately 390 individual rod scram time tests.

Additionally, TVA plans to start installing AVCO SSPVs on Unit 3 during the refueling outage in spring 2006 and on Unit 2 in spring 2007. These AVCO SSPVs will replace the existing ASCO SSPVs currently installed. The ASCO valves will be changed out in total over the next several outages on Units 2 and 3. Unit 1 will restart with a full set of AVCO SSPVs. The AVCO design does not utilize elastomer diaphragms as do the ASCO SSPVs. Hence, use of AVCO SSPVs eliminates the potential for diaphragm elastomer degradation and should improve scram time performance. Several domestic and foreign BWRs are using AVCO SSPVs with good results.

The extensive historical database substantiates the claim of high reliability of the BFNs control rod drive system. The current TS SR 3.1.4.2 requires that a representative sample of control rods be tested every 120 days of cumulative operation in Mode 1. Bases for SR 3.1.4.2 states that a representative sample contains at least 10 percent of the control rods. The current TS Bases also indicates that the acceptance criteria showing that the sample remains representative is met if 20 percent or fewer of the control rods in the sample tested are found to be slow, per the criterion in TS Table 3.1.4-1. This acceptance criterion will be re-defined for at-power surveillance testing from 20 percent to 7.5 percent when the surveillance period is extended to 200 cumulative days of operation in Mode 1. This tightened acceptance criterion for at-power surveillance aligns with the TS 3.1.4 requirement for the total control rods allowed to have scram times exceeding the specified limit. The licensee will incorporate the revised acceptance criterion value of 7.5 percent into the TS Bases in accordance with its Bases Control Program, as a portion of the implementation of these license amendments.

The NRC staff considers the extended surveillance interval to be justified by the demonstrated reliability of the control rod insertion system, based on historical control rod scram time test data, and by the more restrictive acceptance criterion for determining whether the sample of control rods tested remains representative. Further, the amendments do not change the LCO limits for the number and location of operable control rods that can be slow. Therefore, the NRC staff finds the proposed TS change acceptable.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Alabama State official was notified of the proposed issuance of the amendments. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve 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 amendments involve no significant hazards consideration, and there has been no public comment on such finding (70 FR 56504, dated September 27, 2005). Accordingly, the amendments meet 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 amendments.

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 Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: Bhalchandra K. Vaidya Date: January 9, 2006

SUBJECT:

BROWNS FERRY NUCLEAR PLANT, UNITS 2 AND 3 - ISSUANCE OF AMENDMENTS REGARDING TECHNICAL SPECIFICATION IMPROVEMENT TO REVISE CONTROL ROD SCRAM TIME TESTING FREQUENCY (TAC NOS. MC8037 AND MC8038)

Date: January 9, 2006 Distribution:

PUBLIC LPL2-2 R/F RidsNrrLpld RidsNrrPMEBrown BClayton (paper copy)

RidsOgcRp RidsAcrsAcnwMailCenter G Hill (4 copies)

TBoyce BVaidya RidsRgn2MailCenter RidsNrrDorlDpr Mr. Karl W. Singer BROWNS FERRY NUCLEAR PLANT

Tennessee Valley Authority cc:

Mr. Ashok S. Bhatnagar, Senior Vice President Corporate Nuclear Licensing Nuclear Operations and Industry Affairs Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place 4X Blue Ridge 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801 Mr. Larry S. Bryant, Vice President Mr. Robert Jones, General Manager General Manager Browns Ferry Site Operations Nuclear Engineering & Technical Services Browns Ferry Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place P.O. Box 2000 1101 Market Street Decatur, AL 35609 Chattanooga, TN 37402-2801 Mr. William D. Crouch, Manager Brian OGrady, Site Vice President Licensing and Industry Affairs Browns Ferry Nuclear Plant Browns Ferry Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority P.O. Box 2000 P.O. Box 2000 Decatur, AL 35609 Decatur, AL 35609 Mr. Robert J. Beecken, Vice President Senior Resident Inspector Nuclear Support U.S. Nuclear Regulatory Commission Tennessee Valley Authority Browns Ferry Nuclear Plant 6A Lookout Place 10833 Shaw Road 1101 Market Street Athens, AL 35611-6970 Chattanooga, TN 37402-2801 State Health Officer General Counsel Alabama Dept. of Public Health Tennessee Valley Authority RSA Tower - Administration ET 11A Suite 1552 400 West Summit Hill Drive P.O. Box 303017 Knoxville, TN 37902 Montgomery, AL 36130-3017 Mr. John C. Fornicola, Manager Chairman Nuclear Assurance and Licensing Limestone County Commission Tennessee Valley Authority 310 West Washington Street 6A Lookout Place Athens, AL 35611 1101 Market Street Chattanooga, TN 37402-2801 Mr. Bruce Aukland, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 Mr. Glenn W. Morris, Manager