ML072770658

License Amendment, Increased Containment Purge Hour Limit

ML072770658
Person / Time
Site:	Sequoyah
Issue date:	10/11/2007
From:	Moroney B NRC/NRR/ADRO/DORL/LPLII-2
To:	Campbell W Tennessee Valley Authority
Moroney B, NRR/DORL, 415-3974
Shared Package
ML072770634	List: ML072770658
References
TAC MD6757
Download: ML072770658 (12)

Text

October 11, 2007 Mr. William R. Campbell, Jr.

Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNIT 2 - ISSUANCE OF AMENDMENT REGARDING CONTAINMENT PURGE HOUR LIMIT (TAC NO. MD6757)

Dear Mr. Campbell:

The Commission has issued the enclosed Amendment No. 308 to Facility Operating License No. DPR-79 for the Sequoyah Nuclear Plant, Unit 2. This amendment is in response to your application (TS-07-06) dated September 17, 2007.

The amendment revises the technical specifications to allow an increase in the purge hour limit from 1000 hours41.667 days <br />5.952 weeks <br />1.37 months <br /> to 1400 hours58.333 days <br />8.333 weeks <br />1.918 months <br /> during 2007. You requested that this amendment be approved on an exigent basis; therefore, the NRC staff has treated it in accordance with paragraph 50.91(a)(6) of Title 10 of the Code of Federal Regulations.

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/

Brendan T. Moroney, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-328

Enclosures:

1. Amendment No. 308 to License No. DPR-79

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

William R. Campbell, Jr. SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:

Mr. Ashok S. Bhatnagar Ms. Beth A. Wetzel, Manager Senior Vice President Corporate Nuclear Licensing and Nuclear Generation Development Industry Affairs and Construction Tennessee Valley Authority Tennessee Valley Authority 4X Blue Ridge 6A Lookout Place 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801 Mr. Glenn W. Morris, Manager Mr. James R. Douet Licensing and Industry Affairs Senior Vice President Sequoyah Nuclear Plant Nuclear Support Tennessee Valley Authority Tennessee Valley Authority P.O. Box 2000 3R Lookout Place Soddy Daisy, TN 37384-2000 1101 Market Street Chattanooga, TN 37402-2801 Mr. Christopher R. Church, Plant Manager Sequoyah Nuclear Plant Mr. H. Rick Rogers Tennessee Valley Authority Vice President P.O. Box 2000 Nuclear Engineering & Technical Services Soddy Daisy, TN 37384-2000 Tennessee Valley Authority 3R Lookout Place Senior Resident Inspector 1101 Market Street Sequoyah Nuclear Plant Chattanooga, TN 37402-2801 U.S. Nuclear Regulatory Commission 2600 Igou Ferry Road Mr. Timothy P. Cleary, Site Vice President Soddy Daisy, TN 37379 Sequoyah Nuclear Plant Tennessee Valley Authority Mr. Lawrence E. Nanney, Director P.O. Box 2000 Division of Radiological Health Soddy Daisy, TN 37384-2000 Dept. of Environment & Conservation Third Floor, L and C Annex General Counsel 401 Church Street Tennessee Valley Authority Nashville, TN 37243-1532 6A West Tower 400 West Summit Hill Drive County Mayor Knoxville, TN 37902 Hamilton County Courthouse Chattanooga, TN 37402-2801 Mr. John C. Fornicola, Manager Nuclear Assurance Mr. Larry E. Nicholson, General Manager Tennessee Valley Authority Licensing and Industry Affairs 3R Lookout Place Tennessee Valley Authority 1101 Market Street 4X Blue Ridge Chattanooga, TN 37402-2801 1101 Market Street Chattanooga, TN 37402-2801 Ms. Ann P. Harris 341 Swing Loop Road Rockwood, TN 37854

ML072770658 PKG:ML072770634 T.S.: ML072850175 NRR-058 OFFICE PM:LPL2-2 LA:LPL2-2 BC:SCVB BC:IHPB(A) BC:AADB(A) OGC BC:LPL2-2 NAME BMoroney RSola RDennig RPedersen MHart NLO as revised TBoyce by memo by email by email STurk DATE 10/04/07 01/04/07 09/26/07 10/04/07 10/04/07 10/05/07 10/10/07 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-328 SEQUOYAH NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 308 License No. DPR-79

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

A. The application for amendment by the Tennessee Valley Authority (the licensee) dated September 17, 2007, 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 Title 10 of the Code of Federal Regulations (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-79 is hereby amended to read as follows:

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 308, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3. This license amendment is effective as of the date of its issuance, and shall be implemented no later than 45 days from the date of its issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Thomas H. Boyce, Branch Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to License No. DPR-79 and the Technical Specifications Date of Issuance: October 11, 2007

ATTACHMENT TO LICENSE AMENDMENT NO. 308 FACILITY OPERATING LICENSE NO. DPR-79 DOCKET NO. 50-328 Replace page 3 of Operating License No. DPR-79 with the attached page 3.

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 area of change.

REMOVE INSERT 3/4 6-15 3/4 6-15

(4) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required any byproduct, source or special nuclear material without restriction to chemical or physical form, for sample analysis or instrument calibration or associated with radioactive apparatus or components; and (5) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the Sequoyah and Watts Bar Unit 1 Nuclear Plants.

C. This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1) Maximum Power Level The Tennessee Valley Authority is authorized to operate the facility at reactor core power levels not in excess of 3455 megawatts thermal.

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 308 are hereby incorporated into this license. The licensee shall operate the facility in accordance with the Technical Specifications.

(3) Initial Test Program The Tennessee Valley Authority shall conduct the post-fuel-loading initial test program (set forth in Section 14 of Tennessee Valley Authoritys Final Safety Analysis Report, as amended), without making any major modifications of this program unless modifications have been identified and have received prior NRC approval. Major modifications are defined as:

a. Elimination of any test identified in Section 14 of TVAs Final Safety Analysis Report as amended as being essential;

b. Modification of test objectives, methods or acceptance criteria for any test identified in Section 14 of TVAs Final Safety Analysis Report as amended as being essential;

c. Performance of any test at power level different from there described; and Facility Operating License No. DPR-79 Amendment No. 308

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 308 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-328

1.0 INTRODUCTION

By letter dated September 17, 2007, the Tennessee Valley Authority (TVA), the licensee for the Sequoyah Nuclear Plant (SQN), Unit 2, proposed to increase the number of hours that the containment may be purged and vented in a year. The SQN, Unit 2 Technical Specifications Limiting Condition for Operation (LCO) 3.6.1.9 limits purging or venting to 1000 hours41.667 days <br />5.952 weeks <br />1.37 months <br /> in each calendar year. The licensee is proposing to increase the limit to 1400 hours58.333 days <br />8.333 weeks <br />1.918 months <br /> during 2007 because of the need for additional venting and purging due to the presence of formaldehyde in the containment. The additional venting and purging is necessary to make the containment atmosphere acceptable for personnel entry to carry out functions necessary for the proper and safe operation of Unit 2. Notice of this amendment was given in the Federal Register on September 26, 2007 (72 FR 54691)

2.0 REGULATORY EVALUATION

Section 182a of the Atomic Energy Act (Act) requires applicants for nuclear power plant operating licenses to include TSs as part of the license. The licensee provides TSs in order to maintain the operational capability of structures, systems and components that are required to protect the health and safety of the public. The regulatory requirements related to the content of the TSs are contained in Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36, and 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.

In accordance with 10 CFR 50.90, licensees may propose changes to the TSs. The proposed change is to a TS LCO. As stated in 10 CFR 50.36(c)(2)(i), the Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications . . . In determining the acceptability of proposed changes, the U.S. Nuclear Regulatory Commission (NRC) staff considers the requirements of 10 CFR 50.36, using generically approved guidance, to ensure that the requirements of the plant licensing bases as described in the UFSAR continue to be satisfied.

NRC Branch Technical Position CSB 6-4, Containment Purging During Normal Plant Operations, provides guidance on the capability of purge and vent valves to close under accident conditions (high containment pressure) and thus comply with 10 CFR Part 50 Appendix A General Design Criterion 54, Piping systems penetrating containment.

10 CFR Part 20, Standards For Protection Against Radiation, provides regulations for protection against ionizing radiation resulting from activities conducted under licenses issued by the NRC. The purpose is to control the receipt, possession, use, transfer, and disposal of licensed material in such a manner that the total dose to an individual does not exceed the standards for protection against radiation prescribed in the regulations in this part. Appendix B to Part 20 provides annual limits for effluents.

10 CFR Part 100, Reactor Site Criteria, establishes siting criteria to ensure that radiological doses from normal operation and postulated accidents will be acceptably low. Subpart A states

. . . it is expected that reactors will reflect through their design, construction and operation an extremely low probability for accidents that could result in release of significant quantities of radioactive fission products. In addition, the site location and the engineered features included as safeguards against the hazardous consequences of an accident, should one occur, should insure a low risk of public exposure.

The Commission will normally provide at least 30 days for public comment on proposed amendments. However, pursuant to 10 CFR 50.91(a)(6), where the Commission finds that exigent circumstances exist, in that the licensee and the Commission must act quickly and that time does not permit the Commission to publish a Federal Register notice allowing 30 days for prior public comment, and it also determines that the amendment involves no significant hazards considerations, it may issue a Federal Register notice allowing for a hearing and provide at least two weeks for prior public comment.

3.0 TECHNICAL EVALUATION

Sequoyah Unit 2 LCO 3.6.1.9 currently states:

Operation with purge or exhaust isolation valves open for either purging or venting shall be limited to less than or equal to 1000 hours41.667 days <br />5.952 weeks <br />1.37 months <br /> per 365 days. The 365 day cumulative time period will begin every January 1.

The licensee is proposing a one-time increase in the allowable time that the vent and purge valves may be open from 1000 hours41.667 days <br />5.952 weeks <br />1.37 months <br /> to 1400 hours58.333 days <br />8.333 weeks <br />1.918 months <br /> in calendar year 2007. This would be accomplished by adding the following footnote to LCO 3.6.1.9:

400 additional hours is allowed for calendar year 2007 for operation of the containment ventilation system with purge isolation valves open.

The 1000-hour limit for SQN Unit 2 was established in Amendment No. 10 dated December 23, 1982. The limit had initially been established for SQN Unit 1 in Amendment No. 5 dated April 15, 1981. The safety evaluation for this amendment stated that the purpose of the allowance for purging and venting is to:

1. Limit, for safety reasons, the buildup in containment during normal operations:

and

2. Promote as low as reasonably achievable exposure from airborne radioactivity to personnel entering containment during normal operation to perform safety-related maintenance and surveillance.

The staff's basis for finding the 1000-hour limit acceptable was that the design of the systems conforms with the provisions of Branch Technical Position CSB 6-4, that is, the valves satisifed certain operability criteria and the associated dose criteria. The number of hours that venting may be performed is limited so that the time that a loss-of-coolant accident could occur with the purge and vent valves open to the atmosphere is limited. The NRC staffs April 15, 1981, safety evaluation also limited operation of the purge/vent system to only one pair of purge/vent lines open at one time.

The licensee has proposed the change due to an increase in the concentration of formaldehyde in containment, which has resulted in additional purging to protect personnel entering containment during normal operation to perform safety-related maintenance and surveillance.

The proposed change does not require a physical change to the plant and the valve actuation isolation times remain unchanged. Thus, the site boundary dose limits of 10 CFR Part 100 will not be exceeded in the event of an accident during containment purge operations.

Also, the licensee stated that the history of gaseous releases from SQN Unit 2 has been well below the limits of 10 CFR Part 20. In 2006 the releases were less than 1 percent of the 10 CFR 20 limits. The licensee has evaluated the proposed increase of 400 hours16.667 days <br />2.381 weeks <br />0.548 months <br /> in purge operation and has determined that under expected effluent release levels, the activity should also remain below 1 percent of the 10 CFR Part 20 limits in 2007.

Since the licensee is not changing in any way the ability of the affected valves to close upon a containment isolation signal or to close in the required time, and the limits of 10 CFR Part 20 and 10 CFR Part 100 will continue to be met, the NRC staff finds the proposed one-time increase in the allowable purge and vent time to be acceptable.

4.0 EXIGENT CIRCUMSTANCES

The Commissions regulations, as stated in 10 CFR 50.91, provide special exceptions for the issuance of amendments when the usual 30-day public notice cannot be met. One type of special exception is an exigency. An exigency exists when the NRC staff and the licensee need to act quickly and time does not permit the staff to publish a Federal Register notice allowing 30 days for prior public comment, and the staff also determines that the amendment involves no significant hazards consideration. In accordance with 10 CFR 50.91(a)(6)(i)(A), the NRC staff published a notice in the Federal Register on September 26, 2007 (72 FR 54691),

regarding this amendment to be issued under exigent circumstances. No comments were received.

The licensee has been experiencing an accumulation of formaldehyde gas in the containment atmosphere, which has necessitated more than normal purging in order to provide protection for personnel entering the containment for maintenance or surveillance activities. The source of the formaldehyde has not been positively identified. Since the licensee had not experienced such an increase in formaldehyde concentrations prior to the current operating cycle, the

occurrence was unanticipated. The licensee has installed a high-efficiency particulate air and charcoal filter bank in the upper containment to aid in the removal of formaldehyde. This has been successful in reducing the overall concentration, but additional purging is still necessary.

The limit on purge hours has been in effect since 1982 and, historically, has not been exceeded. However, based on the current need for purging, the licensee projects that the 1000-hour limit will be exceeded by October 15, 2007. Approval of the increase in containment purge hours before then will avoid an unnecessary unit shutdown and allow the licensee to perform detailed leak identification and corrective action in the spring 2008 refueling outage.

Based on the preceding discussion, the Commission concludes that exigent circumstances exist.

5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION

DETERMINATION The Commissions regulations in 10 CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards considerations if operation of the facility in accordance with the amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. As required by 10 CFR 50.91(a), the licensee has provided its no significant hazards analysis which is presented below:

1. The proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.

TVAs proposed change is not considered to be a significant departure from the current requirements. The containment purge and ventilation system is qualified and designed to isolate in the event of a design basis accident. The probability of occurrence of an accident is not increased as the increase in purge/ventilation system operation does not affect the systems capability for purge valve closure or containment isolation. The increase in system operation for the remainder of calendar year 2007 would continue to be governed by the limits of 10 CFR 20.

In addition, purge system isolation capability remains unchanged. Consequently, the 10 CFR 100 limits for site boundary dose would not be exceeded in the event of an accident during containment purge operation. Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

The possibility for a new or different kind of accident from any accident previously evaluated does not exist as a result of the proposed increase in purge/ventilation system operation time. The system design remains unchanged for performing isolation of containment for accident mitigation and does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. The proposed amendment does not involve a significant reduction in a margin of safety.

The proposed increase in purge system operation is an increase that does not affect existing safety margins. Additional purge operation time will also continue to comply with effluent release limits in 10 CFR 20. In addition, the proposed change does not increase the risk for an accident because no physical changes to the plant are being made and design features associated with purge system isolation remain unchanged. Accordingly, TVA concludes that the margin of safety has not been reduced.

The NRC staff has reviewed the licensees analysis given above. Based on its review, the NRC staff concludes that the three standards of 10 CFR 50.92(c) are satisfied and, therefore, the amendment request involves no significant hazards consideration. Therefore, the staff has made a final determination that the proposed amendment does not involve a significant hazards consideration.

6.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Tennessee Bureau of Radiological Health was notified of the proposed issuance of the amendment. The State official had no comments.

7.0 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 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 amendments involve no significant hazards consideration, and there has been no public comment on such finding (72 FR 54691). 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 amendments.

8.0 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 amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: R. Lobel B. Moroney Date: October 11, 2007