SBK-L-08058, Three-Month Response to NRC Generic Letter 2008-01, Managing Gas Accumulation in Energy Core Cooling, Decay Heat Removal, and Containment Spray Systems.

Three-Month Response to NRC Generic Letter 2008-01, Managing Gas Accumulation in Energy Core Cooling, Decay Heat Removal, and Containment Spray Systems.

ML081350608
Person / Time
Site:	Seabrook
Issue date:	05/09/2008
From:	St.Pierre G Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-08-001, SBK-L-08058
Download: ML081350608 (8)

Text

0 FPL Energy Seabrook Station FPL Energy RO. Box 300 Seabrook, NH 03874 Seabrook Station (603) 773-7000 May 9, 2008 SBK-L-08058 Docket No. 50-443 U. S. Nuclear Regulatory Commission Attn: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Seabrook Station Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems"

References:

1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," January 11, 2008

2. Letter L-2008-076 to NRC, "Extension Request Regarding the Three Month Response to Generic Letter 2008-01 Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated April 9, 2008 In Reference 1, the Nuclear Regulatory Commission (NRC) requested that each licensee evaluate its Emergency Core Cooling Systems (ECCS), Decay Heat Removal System, and Containment Spray System licensing basis, design, testing, and corrective actions 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 results of these evaluations are requested to be reported within nine months of the date of the Generic Letter (GL) pursuant to 10 CFR 50.54(f) or, if unable to meet the requested response date, respond within 3 months with proposed alternative actions, and provide sufficient justification for such alternatives.

In Reference 2, Florida Power and Light (FPL) requested a 30 day extension of the three month response on behalf of each of their nuclear generating facilities, including FPL Energy Seabrook, LLC (FPL Energy Seabrook).

FPL Energy Seabrook will be unable to meet the nine-month response date and provides the proposed alternative actions and the bases for the acceptability of those actions in Enclosure 1 to this letter.

Commitments made by FPL Energy Seabrook are provided in Enclosure 2.

an FPL Group company

Ugited States Nuclear Regulatory Commission SBK-L-08058 / Page 2 Should you have any questions regarding this information, please contact Mr. Michael O'Keefe, Licensing Manager, at (603) 773-7745.

Very truly yours, FPL Energy Seabrook, LLC JJioe Jo",v Gene St. Pierre Site Vice President Enclosures cc: S. J. Collins, NRC Region I Administrator G. E. Miller, NRC Project Manager, Project Directorate 1-2 W. J. Raymond, NRC Resident Inspector OATH AND AFFIRMATION I, Gene St. Pierre, Site Vice President of FPL Energy Seabrook, LLC, hereby affirm that the information and statements contained within this response to the request for additional information regarding Generic Letter 2008-01 are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

Sworn and Subscribed before me this 9 day of I3/4G*t ,2008 Gene St. Pierre Site Vice President 14 otay Public to SBK-L-08058 Th6 following discusses the proposed alternative actions and the bases for the acceptability of those actions.

For Seabrook Station, the Generic Letter (GL) subject functions correspond to the following plant systems/operating modes:

ECCS: High Head Safety Injection (CS), Intermediate Head Safety Injection (SI) and Low Head Safety Injection (RHR) when operating in post-accident injection and sump recirculation modes.

Shutdown Cooling: Residual Heat Removal (RHR) - normal closed loop shutdown cooling mode.

Containment Spray: - Containment Spray (CBS) during post-accident operation to reduce containment pressure and scrub fission products from the containment atmosphere.

FPL Energy Seabrook will complete a significant number of the requested actions, in particular those involving reviews of plant design, licensing basis documentation and system operating and testing procedures by the required October 11, 2008 date. However, the evaluations requested by the GL also require physical walk downs of the subject ECCS, RHR, and CBS systems to confirm pertinent design details (locations of high point vents) and as-built configurations (pipe locations, elevations, and slope). In addition, performance of non-intrusive examinations such as ultrasonic testing (UT) is suggested to monitor the presence and accumulation of suspected gas in subject piping. Portions of these piping systems are inaccessible during power operation due to radiation environments; some are insulated, and some may require the erection of scaffolding to obtain adequate access for the requested detailed inspections.

In some cases, while the piping may be accessible as defined above, some inspections and general work would not be possible during power operations due to risks to other nearby equipment during scaffolding erection and disassembly (for example, instrument racks with sensitive equipment).

Other piping sections are in close proximity to another system's piping or electrical distribution cabinets that would constitute a personnel safety concern due to the temperature of that nearby piping or electrical hazards, respectively, during power plant operation.

Even areas that, based on reviews of existing drawings, appear to be accessible have been found to be inaccessible during certain periods of refueling outages due to elevated contamination levels, or locked high radiation areas.

Typically, emergent scope is included in an outage when the safety and system reliability of the emergent work is commensurate with the late addition to the outage. As noted below, because the design is considered to be sound relative to gas accumulation as borne out by the event free experience in the recent past, forcing emergent work into refueling outage 12 is not justified.

1

Seabrook Station entered refueling outage 12 on April 1, 2008. However, based on the required work scope, inadequate time existed to plan complete walk downs of inaccessible piping during this outage. Preliminary walk downs were completed during refueling outage 12 to pre-plan scaffolding installation and insulation removal required for a full walk down in accordance with the GL during the next refueling outage in the Fall of 2009.

These preliminary walk downs support the approach to project implementation that ensures personnel and nuclear safety. Refueling outage 12 is the first available outage to identify any obvious issues and determine the necessary support for more detailed walk downs.

The inaccessible portions of the systems requiring walk downs constitute only a portion of the overall scope of the GL. Preliminary reviews indicate that Seabrook Station should be able to perform the majority of required piping walk downs within the nine-month period.

FPL Energy Seabrook proposes a two-step submittal. Based on the industry and regulatory information available to date, there appears to be adequate time to complete licensing and design basis reviews, perform drawing & document reviews, review venting and filling procedures, and plan supporting procedural and license basis changes by the October 11, 2008 due date for a 9 month submittal.

FPL Energy Seabrook anticipates providing an initial submittal, based on the completed document reviews and completed walk downs by the requested 9 month due date of October 11, 2008. This submittal will include actions to validate the preliminary walk down analysis results, to complete full walk downs of the GL piping scope and any other required modifications, by the subsequent outage.

This work approach will additionally allow the station to integrate information and criteria currently in development by industry working groups within our response and subsequent action commitments.

A second submittal will be made documenting closure of outstanding items that were not complete at the time of the first submittal. This submittal will be made within 90 days of the Fall 2009 refueling outage and no later than the end of February 28, 2010.

Basis for Acceptability of Alternate Schedule The ECCS, Shutdown Cooling and Containment Spray systems are routinely tested in accordance with the Technical Specifications. In addition, ultrasonic examination is performed monthly to identify voiding at high points in the suction and discharge piping of the ECCS. Technical Specifications 3.5.2, ECCS Subsystems - Tavg Greater than or Equal to 350 degrees F currently require "Verifying that the ECCS piping is full of water" at least once per 31 days. This functional verification is a systematic procedurally driven approach that involves UT measurement of critical areas, both inside and outside Containment, to quantify any gas intrusion. Indications of gas intrusion, above the surveillance limits, are entered into the Seabrook Station Corrective Action Program for resolution.

FPL Energy Seabrook has confidence that the Seabrook Station ECCS, Shutdown Cooling, and Containment Spray Systems can fulfill their required functions, based upon years of operating and 2

testing experience. FPL Energy Seabrook will complete as many of the requested GL actions within the requested nine-month period as is practical based upon in-plant accessibility of the subject systems and the development of consistently applied methodologies for testing, measuring, and evaluating acceptance limits for gas voiding in such systems by industry and regulation.

3 to SBK-L-08058 FPL Energy Seabrook Commitment to Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" Commitments

1. Provide an initial GL 2008-01 submittal by October 11, 2008 that includes the evaluation results for the completed licensing and design basis reviews, the operating and test procedure reviews, and the readily accessible walk down / design reviews, as well as the schedule for any corrective actions that may be required based on these evaluations.

2. Provide a complete GL 2008-01 submittal based on the final walk downs with completed evaluation results within 90 days of the Fall 2009 refueling outage but no later than February 28, 2010.

Text

0 FPL Energy Seabrook Station FPL Energy RO. Box 300 Seabrook, NH 03874 Seabrook Station (603) 773-7000 May 9, 2008 SBK-L-08058 Docket No. 50-443 U. S. Nuclear Regulatory Commission Attn: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Seabrook Station Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems"

References:

1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," January 11, 2008

2. Letter L-2008-076 to NRC, "Extension Request Regarding the Three Month Response to Generic Letter 2008-01 Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated April 9, 2008 In Reference 1, the Nuclear Regulatory Commission (NRC) requested that each licensee evaluate its Emergency Core Cooling Systems (ECCS), Decay Heat Removal System, and Containment Spray System licensing basis, design, testing, and corrective actions 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 results of these evaluations are requested to be reported within nine months of the date of the Generic Letter (GL) pursuant to 10 CFR 50.54(f) or, if unable to meet the requested response date, respond within 3 months with proposed alternative actions, and provide sufficient justification for such alternatives.

In Reference 2, Florida Power and Light (FPL) requested a 30 day extension of the three month response on behalf of each of their nuclear generating facilities, including FPL Energy Seabrook, LLC (FPL Energy Seabrook).

FPL Energy Seabrook will be unable to meet the nine-month response date and provides the proposed alternative actions and the bases for the acceptability of those actions in Enclosure 1 to this letter.

Commitments made by FPL Energy Seabrook are provided in Enclosure 2.

an FPL Group company

Ugited States Nuclear Regulatory Commission SBK-L-08058 / Page 2 Should you have any questions regarding this information, please contact Mr. Michael O'Keefe, Licensing Manager, at (603) 773-7745.

Very truly yours, FPL Energy Seabrook, LLC JJioe Jo",v Gene St. Pierre Site Vice President Enclosures cc: S. J. Collins, NRC Region I Administrator G. E. Miller, NRC Project Manager, Project Directorate 1-2 W. J. Raymond, NRC Resident Inspector OATH AND AFFIRMATION I, Gene St. Pierre, Site Vice President of FPL Energy Seabrook, LLC, hereby affirm that the information and statements contained within this response to the request for additional information regarding Generic Letter 2008-01 are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

Sworn and Subscribed before me this 9 day of I3/4G*t ,2008 Gene St. Pierre Site Vice President 14 otay Public to SBK-L-08058 Th6 following discusses the proposed alternative actions and the bases for the acceptability of those actions.

For Seabrook Station, the Generic Letter (GL) subject functions correspond to the following plant systems/operating modes:

ECCS: High Head Safety Injection (CS), Intermediate Head Safety Injection (SI) and Low Head Safety Injection (RHR) when operating in post-accident injection and sump recirculation modes.

Shutdown Cooling: Residual Heat Removal (RHR) - normal closed loop shutdown cooling mode.

Containment Spray: - Containment Spray (CBS) during post-accident operation to reduce containment pressure and scrub fission products from the containment atmosphere.

FPL Energy Seabrook will complete a significant number of the requested actions, in particular those involving reviews of plant design, licensing basis documentation and system operating and testing procedures by the required October 11, 2008 date. However, the evaluations requested by the GL also require physical walk downs of the subject ECCS, RHR, and CBS systems to confirm pertinent design details (locations of high point vents) and as-built configurations (pipe locations, elevations, and slope). In addition, performance of non-intrusive examinations such as ultrasonic testing (UT) is suggested to monitor the presence and accumulation of suspected gas in subject piping. Portions of these piping systems are inaccessible during power operation due to radiation environments; some are insulated, and some may require the erection of scaffolding to obtain adequate access for the requested detailed inspections.

In some cases, while the piping may be accessible as defined above, some inspections and general work would not be possible during power operations due to risks to other nearby equipment during scaffolding erection and disassembly (for example, instrument racks with sensitive equipment).

Other piping sections are in close proximity to another system's piping or electrical distribution cabinets that would constitute a personnel safety concern due to the temperature of that nearby piping or electrical hazards, respectively, during power plant operation.

Even areas that, based on reviews of existing drawings, appear to be accessible have been found to be inaccessible during certain periods of refueling outages due to elevated contamination levels, or locked high radiation areas.

Typically, emergent scope is included in an outage when the safety and system reliability of the emergent work is commensurate with the late addition to the outage. As noted below, because the design is considered to be sound relative to gas accumulation as borne out by the event free experience in the recent past, forcing emergent work into refueling outage 12 is not justified.

1

Seabrook Station entered refueling outage 12 on April 1, 2008. However, based on the required work scope, inadequate time existed to plan complete walk downs of inaccessible piping during this outage. Preliminary walk downs were completed during refueling outage 12 to pre-plan scaffolding installation and insulation removal required for a full walk down in accordance with the GL during the next refueling outage in the Fall of 2009.

These preliminary walk downs support the approach to project implementation that ensures personnel and nuclear safety. Refueling outage 12 is the first available outage to identify any obvious issues and determine the necessary support for more detailed walk downs.

The inaccessible portions of the systems requiring walk downs constitute only a portion of the overall scope of the GL. Preliminary reviews indicate that Seabrook Station should be able to perform the majority of required piping walk downs within the nine-month period.

FPL Energy Seabrook proposes a two-step submittal. Based on the industry and regulatory information available to date, there appears to be adequate time to complete licensing and design basis reviews, perform drawing & document reviews, review venting and filling procedures, and plan supporting procedural and license basis changes by the October 11, 2008 due date for a 9 month submittal.

FPL Energy Seabrook anticipates providing an initial submittal, based on the completed document reviews and completed walk downs by the requested 9 month due date of October 11, 2008. This submittal will include actions to validate the preliminary walk down analysis results, to complete full walk downs of the GL piping scope and any other required modifications, by the subsequent outage.

This work approach will additionally allow the station to integrate information and criteria currently in development by industry working groups within our response and subsequent action commitments.

A second submittal will be made documenting closure of outstanding items that were not complete at the time of the first submittal. This submittal will be made within 90 days of the Fall 2009 refueling outage and no later than the end of February 28, 2010.

Basis for Acceptability of Alternate Schedule The ECCS, Shutdown Cooling and Containment Spray systems are routinely tested in accordance with the Technical Specifications. In addition, ultrasonic examination is performed monthly to identify voiding at high points in the suction and discharge piping of the ECCS. Technical Specifications 3.5.2, ECCS Subsystems - Tavg Greater than or Equal to 350 degrees F currently require "Verifying that the ECCS piping is full of water" at least once per 31 days. This functional verification is a systematic procedurally driven approach that involves UT measurement of critical areas, both inside and outside Containment, to quantify any gas intrusion. Indications of gas intrusion, above the surveillance limits, are entered into the Seabrook Station Corrective Action Program for resolution.

FPL Energy Seabrook has confidence that the Seabrook Station ECCS, Shutdown Cooling, and Containment Spray Systems can fulfill their required functions, based upon years of operating and 2

testing experience. FPL Energy Seabrook will complete as many of the requested GL actions within the requested nine-month period as is practical based upon in-plant accessibility of the subject systems and the development of consistently applied methodologies for testing, measuring, and evaluating acceptance limits for gas voiding in such systems by industry and regulation.

3 to SBK-L-08058 FPL Energy Seabrook Commitment to Three-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" Commitments

1. Provide an initial GL 2008-01 submittal by October 11, 2008 that includes the evaluation results for the completed licensing and design basis reviews, the operating and test procedure reviews, and the readily accessible walk down / design reviews, as well as the schedule for any corrective actions that may be required based on these evaluations.

2. Provide a complete GL 2008-01 submittal based on the final walk downs with completed evaluation results within 90 days of the Fall 2009 refueling outage but no later than February 28, 2010.