ML081340312

Duke Energy Corp. - Transmittal of Three Month Response, Alternative Course of Action, and List of Commitments for Oconee, McGuire, and Catawba Nuclear Stations

ML081340312
Person / Time
Site:	Oconee, Mcguire, Catawba, McGuire
Issue date:	05/08/2008
From:	Harrall T Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-08-001
Download: ML081340312 (20)

Text

THOMAS P. HARRALL, JR.

Dukeg Vice President, Plant Support PkEnergye Nuclear Generation Duke Energy Corporation 526 South Church Street Charlotte, NC 28202 Mailing Address:

EC07H / P.O. Box 1006 Charlotte, NC 28201-1006 704 382 3989 704 382 6056 fax May 8, 2008 tpharral@duke-energy.com U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk

Subject:

Duke Energy Carolinas, LLC (Duke)

Oconee Nuclear Station, Units 1, 2 & 3, Docket Nos. 50-269, 50-270, 50-287 McGuire Nuclear Station, Units 1 & 2, Docket Nos. 50-369, 50-370 Catawba Nuclear Station, Units 1 & 2, Docket Nos. 50-413, 50-414 Generic Letter 2008-01, 3-Month Response On January 11, 2008, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01. This GL requests each addressee to evaluate the licensing basis, design, testing, and corrective actions for the Emergency Core Cooling Systems, Decay Heat Removal system, and Containment Spray system, to ensure that gas accumulation is maintained less,than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.

The NRC, in GL 2008-01, requested each addressee to submit a written response in accordance with 10 CFR 50.54(f) within 9 months of the date of the GL to provide the following information:

"(a) A description of the results of evaluations that were performed pursuant to the requested actions of the GL. This description should provide sufficient information to demonstrate that you are or will be in compliance with the quality assurance criteria in Sections !11, V, XI, XVI, and XVII of Appendix B to 10 CFR Part 50 and the licensing basis and operating license as those requirements apply to the subject systems of the GL; (b) A description of all corrective actions, including plant, programmatic, procedure, and licensing basis modifications that you determined were necessary to assure compliance with these regulations; and, (c) A statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule."

www. duke-energy, comr

US Nuclear Regulatory Commission May 8, 2008 Page 2 Additionally, the NRC requested that if an addressee cannot meet the requested 9-month response date, the addressee "shall provide a response within 3 months of the date of this GL" to describe the alternative course of action that it proposes to take, including the basis for the acceptability of the proposed alternative course of action.

By letter dated April 9, 2008, Duke informed the NRC that the 3-month response for Oconee, McGuire and Catawba would be provided on or before May 9, 2008, as previously discussed with the NRC staff.

Duke has determined that it cannot meet the requested response date for all of the required actions of the GL. In accordance with the provisions of the GL, Duke is proposing an alternative course of action. Attachments 1-3 provide the Oconee, McGuire and Catawba 3-month responses to the requested information in NRC GL 2008-01. Attachments 4-6 provide the commitments associated with the responses.

If you have any questions, please contact Mary Shipley at (704) 382-5880.

Very truly yours, Thomas P. Harrall Attachments

US Nuclear Regulatory Commission May 8, 2008 Page 3 Thomas P. Harrall affirms that he is the person who subscribed his name to the foregoing statement, and that all the matters and facts set forth herein are true and correct to the best of his knowledge.

Thomas P. Harrall, Vice President, Plant Support Subscribed and sworn to me:

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US Nuclear Regulatory Commission May 8, 2008 Page 4 xc:

L. A. Reyes, Region II Administrator U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center, 23 T85 61 Forsyth St., SW Atlanta, GA 30303-8931 L. N. Olshan, Senior Project Manager (ONS)

U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 J. F. Stang, Senior Project Manager (CNS & MNS)

U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 Andy Hutto NRC Senior Resident Inspector Oconee Nuclear Station J. B. ýBrady NRC Senior Resident Inspector McGuire Nuclear Station A. T. Sabisch NRC Senior Resident Inspector Catawba Nuclear Station NRC GENERIC LETTER 2008-01 OCONEE 3-MONTH RESPONSE ALTERNATIVE COURSE OF ACTION

Oconee Nuclear Station GL 2008-01 3 Month Response GL 2008-01 requests licensees to evaluate four principle areas of concern with regard to managing gas intrusion into Emergency Core Cooling System, Containment Spray, and Decay Heat Removal systems. The evaluations apply to the Low Pressure Injection, High Pressure Injection, and Building Spray systems for all 3 Oconee units. The decay heat removal function for Oconee is performed by the Low Pressure Injection system.

The areas of concern to be evaluated are 1) Licensing Basis, 2) Design, 3) Testing and

4) Corrective Actions. Results of evaluations were requested within 9 months of the GL.

Oconee plans to perform all requested actions and provide all requested information specified in the GL. Three of the four areas of concern will be evaluated within the time requested by the GL. However, Oconee cannot meet the required completion schedule for some of the activities required tosupport the Design evaluation requested by the GL.

Alternative Course of Action:

The design portion of the evaluation scope will require drawing reviews to assess the need for additional venting capability. It will also require procedure reviews to assess venting requirements and the potential for introducing gas into these systems. Drawing reviews and procedure reviews will be completed within the 9-month required response time for all units.

Field walkdowns will also be required to ensure vents are provided as shown on drawings and to verify the sufficiency of existing vents. Surveys of horizontal piping, as required, will be performed to assess the extent of unintended adverse sloping. Some field verifications (surveys and walkdowns) cannot be completed within the 9-month required response time due to a number of factors:

1) Some of the system piping is located in areas which are inaccessible during power operation due to their location inside containment or in high radiation areas. The following portions of these systems will not be accessible until the next refueling outage(s) for each unit:

High Pressure Injection o

Injection lines from the containment penetrations to the RCS injection nozzles.

o Piping in the Letdown Storage Tank Room.

Low Pressure Injection o

Injection lines from containment penetrations to Core Flood System piping tie-in.

o All Core Flood System piping.

o Decay heat drop line from RCS piping tie-in to the containment penetration.

High Radiation Areas o

Localized areas of these systems outside containment may have restricted access from time to time due to changing plant conditions.

Page 1 of 3

2) Essentially all of the accessible piping on these systems is insulated at Oconee.

Insulation removal may be necessary, although other means of verification are being evaluated. Insulation removal must be evaluated and carefully planned so as not to introduce undesired safety consequences. These considerations present uncertainties associated with performing field surveys and limit the amount of this work which can be confidently committed to complete within the requested 9-month schedule.

For reasons noted above, Oconee proposes the following alternate schedule for completion of evaluations requiring field verifications:

UNIT 1

• Oconee will survey accessible and inaccessible piping prior to the end of the fall 2009 refueling outage. Survey results will be evaluated and corrective actions will be identified within 90 days of the end of the outage.

UNIT 2

" Oconee will walkdown inaccessible piping prior to the end of the fall 2008 refueling outage. Walkdown results will be evaluated and corrective actions identified within 90 days of the end of the outage.

" Oconee will survey accessible and inaccessible piping prior to the end of the fall 2008 refueling outage. Survey results will be evaluated and corrective actions will be identified within 90 days of the end of the outage.

UNIT 3

" Oconee will walkdown inaccessible piping prior to the end of the spring 2009 refueling outage. Walkdown results will be evaluated and corrective actions will be identified within 90 days of the end of the outage.

" Oconee will survey inaccessible piping prior to the end of the spring 2009 refueling outage. Survey results will be evaluated and corrective actions will be identified within 90 days of the end of the outage.

In summary, Oconee will provide results of completed evaluations within the 9-month required response time. This will include any corrective actions identified and a schedule for completion of those corrective actions. Results of evaluations not completed within 9 months will be provided within 90 days following the next available refueling outage for each unit as described above.

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Basis for Acceptability for Alternative Course of Action:

Oconee believes that the proposed alternative course of action described above is acceptable for the following reasons:

1. The scope of deferred evaluation activities is small. The alternative course of action provides for completion of evaluations in three of the four areas of concern in accordance with the schedule required by the GL. In the fourth area, only those evaluation activities involving field verifications are deferred. Those deferrals provide for completion of these evaluations at the first available refueling outage after the requested 9-month due date.

2. Reasonable assurance of operability exists. The deferred field work is confirmatory as opposed to corrective. Drawing reviews will be completed within the schedule requested in the GL. These drawing reviews will provide a strong basis for performing gas intrusion vulnerability evaluations, consistent with the principle of reasonable assurance. Confirmatory walkdowns in accessible areas will provide the additional supporting basis for the adequacy of the evaluation. Discrepancies discovered by walkdown or survey in accessible areas of any unit will be evaluated for extent of condition on the remaining two units on an expedited basis. As walkdown and survey results are obtained, and the need for corrective actions is identified, the principle of reasonable assurance will be continually assessed.

3 A high degree of confidence in Oconee's current gas management practices is supported by operating experience, current testing practices, and past corrective actions that have been performed to manage gas accumulation issues.

For these reasons, Duke concludes that completing performance of walkdowns and surveys on portions of the subject piping systems that require refueling outages and subsequent evaluations outside the requested nine month period is an acceptable alternative course of action for Oconee.

Page 3 of 3 NRC GENERIC LETTER 2008-01 MCGUIRE 3-MONTH RESPONSE ALTERNATIVE COURSE OF ACTION

McGuire Nuclear Station GL 2008-01 3-Month Response GL 2008-01 requests licensees to evaluate four principle areas of concern with regard to managing gas intrusion into Emergency Core Cooling System, Containment Spray, and Decay Heat Removal systems. The evaluations apply to the Residual Heat Removal System, Safety Injection System, Chemical and Volume Control System, Containment Spray System, and Refueling Water System for McGuire Units 1 and 2. The decay heat removal function for McGuire is performed by the Residual Heat Removal system. The areas of concern to be evaluated are 1) Licensing Basis, 2) Design, 3) Testing and 4) Corrective Actions. Results of evaluations were requested within 9 months of the GL. McGuire plans to perform all requested actions and provide all requested information specified in the GL. Three of the four areas of concern will be evaluated within the time requested by the GL. However, McGuire cannot meet the required completion schedule4for some activities required to support the Design evaluation requested by the GL.

Alternative Course of Action The design portion of the evaluation scope will require drawing reviews to assess the need for additional venting capability. It will also require procedure reviews to assess venting requirements and the potential for introducing gas into these systems. Drawing reviews and procedure reviews will be completed within the 9-month required response time for all units.

Field walkdowns will also be required to ensure vents are provided as shown on drawings and to verify the sufficiency of existing vents. Surveys of horizontal piping as required to assess the extent of unintended adverse sloping. Some field verifications (surveys and walkdowns) cannot be completed within the 9-month required response time because some of the piping is located in areas which are inaccessible during power operation due to location inside containment or in high radiation areas. The following portions of these systems will not be accessible until the next refueling outage(s) for each unit:

1. Safety Injection system Cold and Hot Leg injection piping inside containment

2. 'Chemical and Volume Control system Cold Leg injection piping inside containment

3.

Residual Heat Removal system Cold and Hot Leg injection piping inside containment

4. Residual Heat Removal suction piping from the Hot Leg(s) inside containment For reasons noted above, McGuire proposes the following alternate schedule for completion of evaluations requiring field verifications:

Unit 1 The remaining field verifications will be complete during the first available refueling outage, scheduled for fall 2008. Results will be evaluated and corrective actions identified within 90 days of the end of the outage.

Page 1 of 2

Unit 2 The remaining field verifications will be complete during the first available refueling outage, scheduled for fall 2009. Results will be evaluated and corrective actions identified within 90 days of the end of the outage.

In summary, McGuire will provide results of completed evaluations within the 9-month required response time. This will include any corrective actions identified and a schedule for completion of those corrective actions. Results of evaluations not completed within 9 months, will be provided within 90 days following the next available refueling outage for each unit as described above.

Acceptability of Alternative Course of Action McGuire believes that the proposed alternative course of action described above is acceptable for the following reasons:

1. The scope of deferred evaluation activities is small. The alternative course of action provides for completion of evaluations in three of the four areas of concern in accordance with the schedule required by the GL. In the fourth area, only those evaluation activities involving field verifications are deferred. Those deferrals provide for completion of these evaluations at the first available refueling outage after the requested 9-month due date..

2. Reasonable assurance of operability exists. The deferred field work is confirmatory as opposed to corrective. Drawing reviews will be completed within the schedule requested in the GL. These drawing reviews will provide a strong basis for performing gas intrusion vulnerability evaluations, consistent with the principle of reasonable assurance.

Confirmatory walkdowns in accessible areas will provide the additional supporting basis for the adequacy of the evaluation. Discrepancies discovered by walkdown or survey in accessible areas of any unit will be evaluated for extent of condition on the remaining unit on an expedited basis., As walkdown and survey results are obtained, and the need for corrective actions-is identified, the principle of reasonable assurance will be continually assessed.

3: A high degree of confidence in McGuire's current gas management practices is supported by operating experience, current testing practices, and past corrective actions that have been performed tomanage gas accumulation issues..

For these reasons, Duke concludes that completing performance of walkdowns and surveys on portions of the subject piping systems that require refueling outages and subsequent evaluations outside the requested nine month period is an acceptable alternative course of action for McGuire.

Page 2 of 2 NRC GENERIC LETTER 2008-01 CATAWBA 3-MONTH RESPONSE ALTERNATIVE COURSE OF ACTION

Catawba Nuclear Station GL 2008-01 3-Month Response GL 2008-01 requests licensees to evaluate four principle areas of concern with regard to managing gas intrusion into Emergency Core Cooling System, Containment Spray, and Decay Heat Removal systems. The evaluations apply to the Residual Heat Removal System, Safety Injection System, Chemical and Volume Control System, Containment Spray System, and Refueling Water System for Catawba Units 1 and 2. The decay heat removal function for Catawba is performed by the Residual Heat Removal system. The areas of concern to be evaluated are 1) Licensing Basis, 2) Design, 3) Testing and 4) Corrective Actions. Results of evaluations were requested within 9 months of the GL. Catawba plans to perform all requested actions and provide all requested information specified in the GL. However, Catawba, Unit 2 cannot meet the required completion schedule for some activities required to support the Design evaluation requested by the GL. The requested actions will be complete for Catawba Unit 1 by October 11, 2008.

Three of the four areas of concern for Catawba Unit 2 will be evaluated within the time requested by the GL. However, Catawba Unit 2 cannot meet the required completion schedule for some activities required to support the Design evaluation requested by the GL.

Alternative Course of Action The design portion of the evaluation scope will require drawing reviews to assess the need for additional venting capability. It will also require procedure reviews to assess venting requirements and the potential for introducing gas into these systems. Drawing reviews and procedure reviews will be completed within the 9-month required response time for all units.

Field walkdowns will also be required to ensure vents are provided as shown on drawings and to verify the sufficiency of existing vents. Surveys of horizontal piping will be required to assess the extent of unintended adverse sloping. Some field verifications (surveys and walkdowns)

• cannot be completed within the 9-month required response time because some of the piping is located in areas which are inaccessible during power operation due to location inside containment or in high radiation areas. The following portions of these systems will not be accessible until the next refueling outage for Unit 2:

1. Safety Injection system Cold and Hot Leg injection piping inside containment

2. Chemical and Volume Control system Cold Leg injection piping inside containment

3.

Residual Heat Removal system Cold and Hot Leg injection piping inside containment

4. Residual Heat Removal suction piping from the Hot Leg(s) inside containment For reasons noted above, Catawba proposes the following alternate schedule for completion of Unit 2 evaluations requiring field verifications:

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Alternative Course of Action Unit 2 The remaining field verifications will be complete during the first available refueling outage, scheduled for spring 2009. Results will be evaluated and corrective actions identified within 90 days of the end of the outage.

In summary, Catawba will provide results of completed evaluations within the 9-month required response time. This will include any corrective actions identified and a schedule for completion of those corrective actions. Results of evaluations not completed Within 9 months will be provided within 90 days following the next available refueling Outage as described above.

Acceptability of Alternative Course of Action

1. The scope of deferred evaluation activities is small. The alternative course of action provides for completion of evaluations in three of the four areas of concern in accordance with the schedule required by the GL. In the fourth area, only those evaluation activities involving field verifications are deferred. Those deferrals provide for completion of these evaluations.

at the first available refueling outage after the requested 9-month due date.

2. Reasonable assurance of operability exists. The deferred field work is confirmatory as opposed to corrective. Drawing reviews will be completed within the schedule requested in the GL. These drawing reviews will provide a strong basis for performing gas intrusion vulnerability evaluations, consistent with the principle of reasonable assurance.

Confirmatory walkdowns in accessible areas will provide the additional supporting basis for the adequacy of the evaluation. Discrepancies discovered by walkdown or survey in accessible areas of any unit will be evaluated for extent of condition on the remaining unit on an expedited basis. As walkdown and survey results are obtained, and the need for corrective actions is identified, the principle of reasonable assurance will be continually assessed.

3. A high degree of confidence in Catawba's current gas management practices is supported by operating experience, current testing practices, and past corrective actions that have been performed to manage gas accumulation issues.

For these reasons, Duke concludes that completing performance of walkdowns and surveys on portions of the subject piping systems that require refueling outages and subsequent evaluations outside the requested nine month period is an acceptable alternative course of action for Catawba.

Page 2 of 2 NRC GENERIC LETTER 2008-01 OCONEE 3-MONTH RESPONSE LIST OF COMMITMENTS

Oconee Nuclear Station Generic Letter 2008-01 3-Month Response List of Commitments COMMITMENT COMMITMENT DATE OR OUTAGE Complete field verification activities on Within 90 days after the end of the fall 2009 Unit 1. Evaluate results and identify refueling outage.

corrective actions. Send this information to NRC by follow-up submittal.

Complete field verification activities on Within 90 days after the end of the fall 2008 Unit 2. Evaluate results and identify refueling outage.

corrective actions. Send this information to NRC by follow-up submittal.

Complete field verification activities on Within 90 days after the end of the spring 2009 Unit 3. Evaluate results and identify refueling outage.

corrective actions. Send this information to NRC by follow-up submittal.

Page 1 of 1 NRC GENERIC LETTER 2008-01 MCGUIRE 3-MONTH RESPONSE LIST OF COMMITMENTS

McGuire Nuclear Station Generic Letter 2008-01 3-Month Response List of Commitments COMMITMENT COMMITMENT DATE OR OUTAGE Submit supplemental response to the NRC documenting the Unit 1 field verifications and Within 90 days following the end of the next refueling any impact on the GL 2008-01 response as a outage scheduled forFall 2008 result of these evaluations.

Submit supplemental response to the NRC documenting the Unit 2 field verifications and Within 90 days following the end of the next refueling any impact on the GL 2008-01 response as a outage scheduled for Fall 2009 result of. these evaluations.

Page 1 of 1 NRC GENERIC LETTER 2008-01 CATAWBA 3-MONTH RESPONSE LIST OF COMMITMENTS

Catawba Nuclear Station Generic Letter 2008-01 3-Month Response List of Commitments COMMITMENT COMMITMENT DATE OR OUTAGE Submit supplemental response to the NRC documenting the Unit 2 field verifications and Within 90 days following the end of the next refueling any impact on the GL 2008-01 response as a outage scheduled for Spring 2009 result of these evaluations.

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