RS-13-156, Response to Request for Additional Information - Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)
| ML13186A006 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 07/03/2013 |
| From: | Kaegi G Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| EA-12-051, RS-13-156 | |
| Download: ML13186A006 (15) | |
Text
RS-13-156 Order No. EA-12-051 July 3, 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455
Subject:
Response to Request for Additional Information - Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)
References:
1.
Exelon Generation Company, LLC Letter to USNRC, Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order Number EA-1 2-051), dated February 28, 2013 (RS-13-028) 2.
NRC Order Number EA-12-051, Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated March 12, 2012 3.
USNRC letter to Exelon Generation Company, LLC, Request for Additional Information Regarding Overall Integrated Plan for Reliable Spent Fuel Pool Instrumentation, dated June 7,2013 In Reference 1, Exelon Generation Company, LLC (EGC) provided the Byron Station, Units 1 and 2, Overall Integrated Plan in Response to the March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation, pursuant to NRC Order No. EA-12-051 (Reference 2).
The purpose of this letter is to provide the response to the NRC request for additional information (Reference 3) regarding the Byron Station, Units 1 and 2 Overall Integrated Plan in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051). Subsequent to issuance of Reference 3, the NRC identified that Request for Additional Information Item No. 6.a was also applicable to Byron Station, Units 1 and 2. This item is included and addressed in Enclosure 1 to this letter.
The Byron Station, Units 1 and 2 Spent Fuel Pool Instrumentation design is proceeding on the schedule identified in the Overall Integrated Plan provided in Reference 1. The enclosed responses to the NRC request for additional information are intended not to provide preliminary or conceptual information. The requested information, when fully developed, will be provided upon detailed design completion based on the milestone schedule dates provided in each response.
1 ti RS-13-156 Order No. EA-12-051 July 3,2013 u.s. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455
Subject:
Response to Request for Additional Information - Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)
References:
- 1. Exelon Generation Company, LLC Letter to USNRC, Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), dated February 28,2013 (RS-13-028)
- 2. NRC Order Number EA-12-051, Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated March 12, 2012
- 3. USNRC letter to Exelon Generation Company, LLC, Request for Additional Information Regarding Overall Integrated Plan for Reliable Spent Fuel Pool Instrumentation, dated June 7, 2013 In Reference 1, Exelon Generation Company, LLC (EGG) provided the Byron Station, Units 1 and 2, Overall Integrated Plan in Response to the March 12,2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation, pursuant to NRC Order No. EA-12-051 (Reference 2).
The purpose of this letter is to provide the response to the NRC request for additional information (Reference 3) regarding the Byron Station, Units 1 and 2 Overall Integrated Plan in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051). Subsequent to issuance of Reference 3, the NRC identified that Request for Additional Information Item No. 6.a was also applicable to Byron Station, Units 1 and 2. This item is included and addressed in Enclosure 1 to this letter.
The Byron Station, Units 1 and 2 Spent Fuel Pool Instrumentation design is proceeding on the schedule identified in the Overall Integrated Plan provided in Reference 1. The enclosed responses to the NRC request for additional information are intended not to provide preliminary or conceptual information. The requested information, when fully developed, will be provided upon detailed design completion based on the milestone schedule dates provided in each response.
U.S. Nuclear Regulatory Commission Response to Request for Additional Information (Order EA-1 2-051)
July 3, 2013 Page 2 This letter contains no new regulatory commitments. If you have any questions regarding this response, please contact David P. Helker at 610-765-5525.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 3rd day of July 2013.
Respectfully submitted, Glen T. Kaegi Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC
Enclosure:
1.
Byron Station, Units 1 and 2 - Response to Request for Additional Information - Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051) cc:
Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region III NRC Senior Resident Inspector - Byron Station, Units 1 and 2 NRC Project Manager, NRR - Byron Station, Units 1 and 2 Mr. Robert J. Fretz, Jr, NRRIJLD/PMB, NRC Mr. Robert L. Dennig, NRRIDSS/SCVB, NRC Mr. Blake Purnell, NRC Project Manager, NRR Illinois Emergency Management Agency - Division of Nuclear Safety U.S. Nuclear Regulatory Commission Response to Request for Additional Information (Order EA-12-051)
July 3,2013 Page 2 This letter contains no new regulatory commitments. If you have any questions regarding this response, please contact David P. Helker at 610-765-5525.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 3rd day of July 2013.
Respectfully submitted, G&iTL~
Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC
Enclosure:
- 1. Byron Station, Units 1 and 2 - Response to Request for Additional Information - Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051) cc:
Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region III NRC Senior Resident Inspector - Byron Station, Units 1 and 2 NRC Project Manager, NRR - Byron Station, Units 1 and 2 Mr. Robert J. Fretz, Jr, NRRIJLD/PMB, NRC Mr. Robert L. Dennig, NRRIDSS/SCVB, NRC Mr. Blake Purnell, NRC Project Manager, NRR Illinois Emergency Management Agency - Division of Nuclear Safety Byron Station, Units 1 and 2 Response to Request for Additional Information Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)
(12 pages)
Byron Station, Units 1 and 2 Response to Request for Additional Information Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)
(12 pages)
Response to Request for Additional Information (Order EA-1 2-051)
Page 1 of 12
1.0 INTRODUCTION
By letter dated February 28, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13063A265), Exelon Generation Company, LLC, submitted an overall integrated plan (OIP) in response to the March 12, 2012, U.S. Nuclear Regulatory Commission (NRC) Order modifying licenses with regard to reliable spent fuel pool (SFP) instrumentation (Order EA-12-051; ADAMS Accession No. ML12054A679) for Byron Station, Unit Nos. 1 and 2. The NRC staff endorsed Nuclear Energy Institute, NEI 12-02, "Industry Guidance for Compliance with NRC Order EA-12-051, to Modify Licenses with Regard to Reliable SFP Instrumentation," Revision 1, dated August 2012 (ADAMS Accession No. ML12240A307), with exceptions as documented in NRC Interim Staff Guidance, JLD-ISG-2012-03, "Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation,"
Revision 0, dated August 29, 2012 (ADAMS Accession No. ML12221A339).
The NRC staff has reviewed the February 28, 2013, response by the licensee and determined that the following request for additional information (RAI) is needed to complete its technical review.
2.0 LEVELS OF REQUIRED MONITORING The OIP states, in part, that:
Key spent fuel pool water levels will be identified as follows:
Level adequate to support operation of the normal fuel pool cooling system (Level 1):
Indicated level on either primary or backup instrument channel of greater than 19 feet (elevation 419'-2") above the top of the storage racks based on the design accuracy of the instrument channel (which is to be determined) and a resolution of 1 foot or better of both the primary and backup instrument channels. This is based on Spent Fuel Pool Cooling Pump suction strainer elevation. A calculation demonstrating adequate water level will be performed as part of the detailed engineering design phase to ensure the level is adequate for normal fuel pool cooling system operation Level adequate to provide substantial radiation shielding for a person standing on the spent fuel pool operating deck (Level 2): Indicated level on either the primary or backup instrument channel of greater than 10 feet (elevation [410'-2"]) plus instrument channel accuracy above the top of the storage racks based on specification of this level as adequate in NRC JLD-ISG-2012-03 and NEI 12-02, the specified design accuracy of the instrument channel, and the relatively low sensitivity of dose rates to changes in water depth at this level. This monitoring level ensures there is an adequate water level to provide substantial radiation shielding for a person standing on the SFP operating deck from direct gamma radiation from stored spent fuel.
Level where fuel remains covered (Level 3): Indicated level on either the primary or backup instrument channel of greater than 0 foot (elevation 400'-2") plus instrument channel accuracy above the top of the storage racks based upon the design accuracy (which is to be determined) of the instrument channel for both the primary and backup instrument channels. This monitoring level assures that water is covering the stored fuel seated in the rack.
Response to Request for Additional Information (Order EA-12-051)
Page 1 of 12
1.0 INTRODUCTION
By letter dated February 28, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13063A265), Exelon Generation Company, LLC, submitted an overall integrated plan (OIP) in response to the March 12,2012, U.S. Nuclear Regulatory Commission (NRC) Order modifying licenses with regard to reliable spent fuel pool (SFP) instrumentation (Order EA-12-051; ADAMS Accession No. ML12054A679) for Byron Station, Unit Nos. 1 and 2. The NRC staff endorsed Nuclear Energy Institute, NEI 12-02, "Industry Guidance for Compliance with NRC Order EA-12-051, to Modify Licenses with Regard to Reliable SFP Instrumentation," Revision 1, dated August 2012 (ADAMS Accession No. ML12240A307), with exceptions as documented in NRC Interim Staff Guidance, JLD-ISG-2012-03, "Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation,"
Revision 0, dated August 29,2012 (ADAMS Accession No. ML12221A339).
The NRC staff has reviewed the February 28, 2013, response by the licensee and determined that the following request for additional information (RAI) is needed to complete its technical review.
2.0 LEVELS OF REQUIRED MONITORING The OIP states, in part, that:
Key spent fuel pool water levels will be identified as follows:
Level adequate to support operation of the normal fuel pool cooling system (Level 1 ):
Indicated level on either primary or backup instrument channel of greater than 19 feet (elevation 419'-2") above the top of the storage racks based on the design accuracy of the instrument channel (which is to be determined) and a resolution of 1 foot or better of both the primary and backup instrument channels. This is based on Spent Fuel Pool Cooling Pump suction strainer elevation. A calculation demonstrating adequate water level will be performed as part of the detailed engineering design phase to ensure the level is adequate for normal fuel pool cooling system operation Level adequate to provide substantial radiation shielding for a person standing on the spent fuel pool operating deck (Level 2): Indicated level on either the primary or backup instrument channel of greater than 10 feet (elevation [410'-2"]) plus instrument channel accuracy above the top of the storage racks based on specification of this level as adequate in NRC JLD-ISG-2012-03 and NEI12-02, the specified design accuracy of the instrument channel, and the relatively low sensitivity of dose rates to changes in water depth at this level. This monitoring level ensures there is an adequate water level to provide substantial radiation shielding for a person standing on the SFP operating deck from direct gamma radiation from stored spent fuel.
Level where fuel remains covered (Level 3): Indicated level on either the primary or backup instrument channel of greater than 0 foot (elevation 400'-2") plus instrument channel accuracy above the top of the storage racks based upon the design accuracy (which is to be determined) of the instrument channel for both the primary and backup instrument channels. This monitoring level assures that water is covering the stored fuel seated in the rack.
Response to Request for Additional Information (Order EA-1 2-051)
Page 2 of 12
RAI-1
Please provide the following:
a)
For Level 1, specify how the identified location represents the higher of the two points described in the NEI 12-02 guidance for this level.
b) A clearly labeled sketch depicting the elevation view of the proposed typical mounting arrangement for the portions of instrument channel consisting of permanent measurement channel equipment (e.g., fixed level sensors and/or stilling wells, and mounting brackets). Indicate on this sketch the datum values representing Level 1, Level 2, and Level 3 as well as the top of the fuel. Indicate on this sketch the portion of the level sensor measurement range that is sensitive to measurement of the fuel pool level, with respect to the Level 1, Level 2, and Level 3 datum points.
Response
a) The Byron Spent Fuel Pool has two Spent Fuel Pool Cooling Pumps that take suction from the pool with the top of the suction strainer at the 417'-9-1/4" elevation. Normal Spent Fuel Pool Level is at the 424'-6" and low level at 424'-2". The detailed design will include a calculation to determine adequate water level to maintain normal fuel pool cooling system operation. This information will be available following acceptance of the 100% design, scheduled for December, 2013. The result will be provided in the February 2014, 6-month Integrated Plan update report to the NRC.
b) A sketch is provided as Attachment 1, "Byron Spent Fuel Pool Elevation Sketch."
Instrument probe mounting details in the Spent Fuel Pool area will be provided in accordance with our response to RAI-3.
3.0 INSTRUMENTATION DESIGN FEATURES 3.2 Arrangement The OIP states, in part, that:
The current plan is to install SFP level sensors in the northwest and southwest corners of the SFP separated by a distance in excess of 20 feet. The sensors themselves will be mounted, to the extent practical, near the pool walls and below the pool curb to minimize their exposure to damaging debris and not interfere with SFP activities. Instrument channel electronics and power supplies will be located in seismic and missile protected areas either below the SFP operating floor or in buildings other than the FHB [Fuel Handling Building. The areas to be selected will provide suitable radiation shielding and environmental conditions for the equipment consistent with instrument manufacturer's recommendations. Equipment and cabling for power supplies and indication for each channel will be separated equivalent to that provided for redundant safety related services.
Response to Request for Additional Information (Order EA-12-0S1)
Page 2 of 12 Please provide the following:
a) For Level 1, specify how the identified location represents the higher of the two points described in the NEI 12-02 guidance for this level.
b) A clearly labeled sketch depicting the elevation view of the proposed typical mounting arrangement for the portions of instrument channel consisting of permanent measurement channel equipment (e.g., fixed level sensors and/or stilling wells, and mounting brackets). Indicate on this sketch the datum values representing Level 1,
Level 2, and Level 3 as well as the top of the fuel. Indicate on this sketch the portion of the level sensor measurement range that is sensitive to measurement of the fuel pool level, with respect to the Level 1, Level 2, and Level 3 datum points.
Response
a) The Byron Spent Fuel Pool has two Spent Fuel Pool Cooling Pumps that take suction from the pool with the top of the suction strainer at the 417'-9-1/4" elevation. Normal Spent Fuel Pool Level is at the 424'-6" and low level at 424'-2". The detailed design will include a calculation to determine adequate water level to maintain normal fuel pool cooling system operation. This information will be available following acceptance of the 100% design, scheduled for December, 2013. The result will be provided in the February 2014, 6-month Integrated Plan update report to the NRC.
b) A sketch is provided as Attachment 1, "Byron Spent Fuel Pool Elevation Sketch."
Instrument probe mounting details in the Spent Fuel Pool area will be provided in accordance with our response to RAI-3.
3.0 INSTRUMENTATION DESIGN FEATURES 3.2 Arrangement The OIP states, in part, that:
The current plan is to install SFP level sensors in the northwest and southwest corners of the SFP separated by a distance in excess of 20 feet. The sensors themselves will be mounted, to the extent practical, near the pool walls and below the pool curb to minimize their exposure to damaging debris and not interfere with SFP activities. Instrument channel electronics and power supplies will be located in seismic and missile protected areas either below the SFP operating floor or in buildings other than the FHB [Fuel Handling Building]. The areas to be selected will provide suitable radiation shielding and environmental conditions for the equipment consistent with instrument manufacturer's recommendations. Equipment and cabling for power supplies and indication for each channel will be separated equivalent to that provided for redundant safety related services.
Response to Request for Additional Information (Order EA-12-051)
Page 3 of 12
RAI-2
Please provide a clearly labeled sketch or marked-up plant drawing of the plan view of the SFP area, depicting the SFP inside dimensions, the planned locations/placement of the primary and back-up SFP level sensor, and the proposed routing of the cables that will extend from the sensors toward the location of the read-out/display device.
Response
A sketch is provided as Attachment 2, "Byron Spent Fuel Pool Plan View Sketch". Note that the locations of the level sensors have changed since the submittal of the overall integrated plan.
The detailed design will include cable routing drawings from the Spent Fuel Pool to each channel indicator. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.3 Mounting The OIP states, in part, that:
Design of the mounting of the sensors in the SFP shall be consistent with the seismic Class I criteria. Installed equipment will be verified to be seismically adequate for the seismic motions associated with the maximum seismic ground motion considered in the design of the plant area in which it is installed.
RAI-3
Please provide the following:
a) The design criteria that will be used to estimate the total loading on the mounting device(s), including static weight loads and dynamic loads. Describe the methodology that will be used to estimate the total loading, inclusive of design basis maximum seismic loads and the hydrodynamic loads that could result from pool sloshing or other eff ects that could accompany such seismic forces.
b) A description of the manner in which the level sensor (and stilling well, if appropriate) will be attached to the refueling floor and/or other support structures for each planned point of attachment of the probe assembly. Indicate in a schematic the portions of the level sensor that will serve as points of attachment for mechanical/mounting or electrical connections.
c) A description of the manner by which the mechanical connections will attach the level instrument to permanent SFP structures so as to support the level sensor assembly.
Response to Request for Additional Information (Order EA-12-051)
Page 3 of 12 Please provide a clearly labeled sketch or marked-up plant drawing of the plan view of the SFP area, depicting the SFP inside dimensions, the planned locations/placement of the primary and back-up SFP level sensor, and the proposed routing of the cables that will extend from the sensors toward the location of the read-ouVdisplay device.
Response
A sketch is provided as Attachment 2, "Byron Spent Fuel Pool Plan View Sketch". Note that the locations of the level sensors have changed since the submittal of the overall integrated plan.
The detailed design will include cable routing drawings from the Spent Fuel Pool to each channel indicator. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.3 Mounting The 01 P states, in part, that:
Design of the mounting of the sensors in the SFP shall be consistent with the seismic Class I criteria. Installed equipment will be verified to be seismically adequate for the seismic motions associated with the maximum seismic ground motion considered in the design of the plant area in which it is installed.
Please provide the following:
a) The design criteria that will be used to estimate the total loading on the mounting device(s), including static weight loads and dynamic loads. Describe the methodology that will be used to estimate the total loading, inclusive of design basis maximum seismic loads and the hydrodynamic loads that could result from pool sloshing or other effects that could accompany such seismic forces.
b) A description of the manner in which the level sensor (and stilling well, if appropriate) will be attached to the refueling floor and/or other support structures for each planned point of attachment of the probe assembly. Indicate in a schematic the portions of the level sensor that will serve as points of attachment for mechanical/mounting or electrical connections.
c) A description of the manner by which the mechanical connections will attach the level instrument to permanent SFP structures so as to support the level sensor assembly.
Response to Request for Additional Information (Order EA-12-051)
Page 4 of 12
Response
Device total loading and mounting will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.4 Qualification The OIP states, in part, that:
Temperature, humidity and radiation levels consistent with conditions in the vicinity of the SFP and the area of use considering normal operational, event and post-event conditions for no fewer than seven days post-event or until off-site resources can be deployed by the mitigating strategies resulting from Order EA-12-049 will be addressed in the detailed design phase of the project. Examples of post-event (beyond-design-basis) conditions to be considered are:
radiological conditions for a normal refueling quantity of freshly discharged (100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />) fuel with the SFP water level 3 as described in Order EA-12-051, temperature of 212 degrees F and 100% relative humidity environment, boiling water and/or steam environment, a concentrated borated water environment, and the impact of FLEX mitigating strategies [diverse and flexible coping strategies].
For seismic effects on instrument channel components used after a potential seismic event for only installed components (with the exception of battery chargers and replaceable batteries), the following measures will be used to verify that the design and installation is adequate. Applicable components are rated by the manufacturer (or otherwise tested) for seismic effects at levels commensurate with those of postulated design basis event conditions in the area of instrument channel component use using one or more of the following methods:
instrument channel components use known operating principles and are supplied by manufacturers with commercial quality programs (such as IS09001). The procurement specification and/or instrument channel design shall include the seismic requirements and specify the need for commercial design and testing under seismic loadings consistent with design basis values at the installed locations; substantial history of operational reliability in environments with significant vibration, such as for portable hand-held devices or transportation applications. Such a vibration design envelope shall be inclusive of the effects of seismic motion imparted to the components proposed at the location of the proposed installation; adequacy of seismic design and installation is demonstrated based on the guidance in Sections 7, 8, 9, and 10 of IEEE [Institute of Electrical and Electronics Engineers]
Standard 344-2004, "IEEE Recommended Practice for Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating Stations," or a substantially similar industrial standard; Response to Request for Additional Information (Order EA-12-0S1)
Page 4 of 12
Response
Device total loading and mounting will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.4 Qualification The alP states, in part, that:
Temperature, humidity and radiation levels consistent with conditions in the vicinity of the SFP and the area of use considering normal operational, event and post-event conditions for no fewer than seven days post-event or until off-site resources can be deployed by the mitigating strategies resulting from Order EA-12-049 will be addressed in the detailed design phase of the project. Examples of post-event (beyond-design-basis) conditions to be considered are:
radiological conditions for a normal refueling quantity of freshly discharged (100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />) fuel with the SFP water level 3 as described in Order EA-12-0S1, temperature of 212 degrees F and 100% relative humidity environment, boiling water and/or steam environment, a concentrated borated water environment, and the impact of FLEX mitigating strategies [diverse and flexible coping strategies].
For seismic effects on instrument channel components used after a potential seismic event for only installed components (with the exception of battery chargers and replaceable batteries), the following measures will be used to verify that the design and installation is adequate. Applicable components are rated by the manufacturer (or otherwise tested) for seismic effects at levels commensurate with those of postulated design basis event conditions in the area of instrument channel component use using one or more of the following methods:
instrument channel components use known operating principles and are supplied by manufacturers with commercial quality programs (such as IS09001). The procurement specification and/or instrument channel design shall include the seismic requirements and specify the need for commercial design and testing under seismic loadings consistent with design basis values at the installed locations; substantial history of operational reliability in environments with significant vibration, such as for portable hand-held devices or transportation applications. Such a vibration design envelope shall be inclusive of the effects of seismic motion imparted to the components proposed at the location of the proposed installation; adequacy of seismic design and installation is demonstrated based on the guidance in Sections 7,8, 9, and 10 of IEEE [Institute of Electrical and Electronics Engineers]
Standard 344-2004, "IEEE Recommended Practice for Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating Stations," or a substantially similar industrial standard;
Response to Request for Additional Information (Order EA-1 2-051)
Page 5 of 12 demonstration that proposed devices are substantially similar in design to models that have been previously tested for seismic effects in excess of the plant design basis at the location where the instrument is to be installed (g-levels and frequency ranges); or seismic qualification using seismic motion consistent with that of existing design basis loading at the installation location.
RAI-4
Please provide the following:
a) A description of the specific method or combination of methods you intend to apply to demonstrate the reliability of the permanently installed equipment under beyond-design-basis ambient temperature, humidity, shock, vibration, and radiation conditions.
b) A description of the testing and/or analyses that will be conducted to provide assurance that the equipment will perform reliably under the worst-case credible design basis loading at the location where the equipment will be mounted. Include a discussion of this seismic reliability demonstration as it applies to a) the level sensor mounted in the SFP area, and b) any control boxes, electronics, or read-out and re-transmitting devices that will be employed to convey the level information from the level sensor to the plant operators or emergency responders.
c) A description of the specific method or combination of methods that will be used to confirm the reliability of the permanently installed equipment such that following a seismic event the instrument will maintain its required accuracy.
Response
Device qualification and reliability will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100%
acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.5 Independence The OIP states, in part, that:
The primary instrument channel will be independent of the backup instrument channel.
This independence will be achieved through physical and electrical separation of each channels' components commensurate with hazard and electrical isolation needs.
RAI-5
Please provide the following:
Response to Request for Additional Information (Order EA-12-051)
Page 5 of 12 demonstration that proposed devices are substantially similar in design to models that have been previously tested for seismic effects in excess of the plant design basis at the location where the instrument is to be installed (g-Ievels and frequency ranges); or seismic qualification using seismic motion consistent with that of existing design basis loading at the installation location.
Please provide the following:
a) A description of the specific method or combination of methods you intend to apply to demonstrate the reliability of the permanently installed equipment under beyond-design-basis ambient temperature, humidity, shock, vibration, and radiation conditions.
b) A description of the testing and/or analyses that will be conducted to provide assurance that the equipment will perform reliably under the worst-case credible design basis loading at the location where the equipment will be mounted. Include a discussion of this seismic reliability demonstration as it applies to a) the level sensor mounted in the SFP area, and b) any control boxes, electronics, or read-out and re-transmitting devices that will be employed to convey the level information from the level sensor to the plant operators or emergency responders.
c) A description of the specific method or combination of methods that will be used to confirm the reliability of the permanently installed equipment such that following a seismic event the instrument will maintain its required accuracy.
Response
Device qualification and reliability will be performed as part of the detailed design process. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100%
acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.5 Independence The OIP states, in part, that:
The primary instrument channel will be independent of the backup instrument channel.
This independence will be achieved through physical and electrical separation of each channels' components commensurate with hazard and electrical isolation needs.
Please provide the following:
Response to Request for Additional Information (Order EA-12-051)
Page 6 of 12 a) A description of how the two channels of the proposed level measurement system meet this requirement so that the potential for a common cause event to adversely affect both channels is minimized to the extent practicable.
b) Further information on how each level measurement system, consisting of level sensor electronics, cabling, and readout devices will be designed and installed to address independence through the application and selection of independent power sources, the use of physical and spatial separation, independence of signals sent to the location(s) of the readout devices, and the independence of the displays.
Response
Device channel independence evaluation will be performed as part of the detailed design process. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.6 Power supplies The OIP states, in part, that:
Each channel will be normally powered from a different 120Vac [120 volts-alternating current] bus. Upon loss of normal ac power, individual channel installed batteries will automatically maintain continuous channel operation. The batteries will be replaceable and be sized to maintain channel operation until off-site resources can be deployed by the mitigating strategies resulting from Order EA-12-049. Additionally, each channel will have provisions for connection to another suitable power source.
RAI-6
Please provide the following:
a) A description of the electrical ac power sources and capabilities for the primary and backup channels.
b) If the level measurement channels are to be powered through a battery system (either directly or through an uninterruptible power supply), please provide the design criteria that will be applied to size the battery in a manner that ensures, with margin, that the channel will be available to run reliably and continuously following the onset of the beyond-design-basis event for the minimum duration needed, consistent with the plant mitigation strategies for beyond-design-basis external events (Order EA-12-049).
Response
Device total power supply configuration will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and Response to Request for Additional Information (Order EA-12-0S1)
Page 6 of 12 a) A description of how the two channels of the proposed level measurement system meet this requirement so that the potential for a common cause event to adversely affect both channels is minimized to the extent practicable.
b) Further information on how each level measurement system, consisting of level sensor electronics, cabling, and readout devices will be designed and installed to address independence through the application and selection of independent power sources, the use of physical and spatial separation, independence of signals sent to the location(s) of the readout devices, and the independence of the displays.
Response
Device channel independence evaluation will be performed as part of the detailed design process. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.6 Power supplies The 01 P states, in part, that:
Each channel will be normally powered from a different 120Vac [120 volts-alternating current] bus. Upon loss of normal ac power, individual channel installed batteries will automatically maintain continuous channel operation. The batteries will be replaceable and be sized to maintain channel operation until off-site resources can be deployed by the mitigating strategies resulting from Order EA-12-049. Additionally, each channel will have provisions for connection to another suitable power source.
Please provide the following:
a) A description of the electrical ac power sources and capabilities for the primary and backup channels.
b) If the level measurement channels are to be powered through a battery system (either directly or through an uninterruptible power supply), please provide the design criteria that will be applied to size the battery in a manner that ensures, with margin, that the channel will be available to run reliably and continuously following the onset of the beyond-design-basis event for the minimum duration needed, consistent with the plant mitigation strategies for beyond-design-basis external events (Order EA-12-049).
Response
Device total power supply configuration will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and
Response to Request for Additional Information (Order EA-12-051)
Page 7 of 12 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.7 Accuracy The OI P states, in part, that:
The instrument channels will be designed to maintain their design accuracy following a power interruption or change in power source without recalibration. Instrument channel accuracy, to be determined during detailed design, will consider Spent Fuel Pool conditions (e.g., saturated water, steam environment, concentrated borated water), as well as, other applicable radiological and environmental conditions and include display accuracy. Instrument channel accuracy will be sufficient to allow trained personnel to determine when the actual level exceeds the specified lower level of each indicating range (levels 1, 2 or 3) without conflicting or ambiguous indications.
RAI-7
Please provide the following:
a) An estimate of the expected instrument channel accuracy performance under both (a) normal SFP level conditions (approximately Level 1 or higher) and (b) at the beyond design-basis conditions (i.e., radiation, temperature, humidity, post-seismic and post-shock conditions) that would be present if the SFP level were at the Level 2 and Level 3 datum points.
b) A description of the methodology that will be used for determining the maximum allowed deviation from the instrument channel design accuracy that will be employed under normal operating conditions as an acceptance criterion for a calibration procedure to flag to operators and to technicians that the channel requires adjustment to within the normal condition design accuracy.
Response
Device channel accuracy analysis will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.8 Testing The OIP states, in part, that:
Instrument channel design will provide for routine testing and calibration consistent with the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02. Details will be determined during detailed design engineering.
Response to Request for Additional Information (Order EA-12-0S1)
Page 7 of 12 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.7 Accuracy The OIP states, in part, that:
The instrument channels will be designed to maintain their design accuracy following a power interruption or change in power source without recalibration. Instrument channel accuracy, to be determined during detailed design, will consider Spent Fuel Pool conditions (e.g., saturated water, steam environment, concentrated borated water), as well as, other applicable radiological and environmental conditions and include display accuracy. Instrument channel accuracy will be sufficient to allow trained personnel to determine when the actual level exceeds the specified lower level of each indicating range (levels 1, 2 or 3) without conflicting or ambiguous indications.
Please provide the following:
a) An estimate of the expected instrument channel accuracy performance under both (a) normal SFP level conditions (approximately Level 1 or higher) and (b) at the beyond design-basis conditions (Le., radiation, temperature, humidity, post-seismic and post-shock conditions) that would be present if the SFP level were at the Level 2 and Level 3 datum points.
b) A description of the methodology that will be used for determining the maximum allowed deviation from the instrument channel design accuracy that will be employed under normal operating conditions as an acceptance criterion for a calibration procedure to flag to operators and to technicians that the channel requires adjustment to within the normal condition design accuracy.
Response
Device channel accuracy analysis will be performed as part of the detailed design process.
The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
3.8 Testing The 01 P states, in part, that:
Instrument channel design will provide for routine testing and calibration consistent with the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02. Details will be determined during detailed design engineering.
Response to Request for Additional Information (Order EA-12-051)
Page 8 of 12
RAI-8
Please provide the following:
a) A description of the capability and provisions the proposed level sensing equipment will have to enable periodic testing and calibration, including how this capability enables the equipment to be tested in-situ.
b) A description of how such testing and calibration will enable the conduct of regular channel checks of each independent channel against the other, and against any other permanently-installed SFP level instrumentation.
c) A description of how functional checks will be performed, and the frequency at which they will be conducted. Describe how calibration tests will be performed, and the frequency at which they will be conducted. Provide a discussion as to how these surveillances will be incorporated into the plant surveillance program.
d) A description of what preventative maintenance tasks are required to be performed during normal operation, and the planned maximum surveillance interval that is necessary to ensure that the channels are fully conditioned to accurately and reliably perform their functions when needed.
Response
Device testing requirement analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. Following the issue of the design, procedures will start being developed with a projected July 2014 completion date.
The requested information will be provided in the August 2014, 6-month Integrated Plan update.
3.9 Display The OIP states, in part, that:
The primary and backup instrument displays will be located at the control room, alternate shutdown panel, or other appropriate and accessible location. The specific location will be determined during detailed design. An appropriate and accessible location will include the following characteristics:
occupied or promptly accessible to the appropriate plant staff giving appropriate consideration to various drain down scenarios, outside the area surrounding the SFP floor (e.g., an appropriate distance from the radiological sources resulting from an event impacting the Spent Fuel Pool),
inside a structure providing protection against adverse weather, and outside of any very high radiation areas or LOCKED HIGH RAD AREA during normal operation.
Response to Request for Additional Information (Order EA-12-051)
Page 8 of 12 Please provide the following:
a) A description of the capability and provisions the proposed level sensing equipment will have to enable periodic testing and calibration, including how this capability enables the equipment to be tested in-situ.
b) A description of how such testing and calibration will enable the conduct of regular channel checks of each independent channel against the other, and against any other permanently-installed SFP level instrumentation.
c) A description of how functional checks will be performed, and the frequency at which they will be conducted. Describe how calibration tests will be performed, and the frequency at which they will be conducted. Provide a discussion as to how these surveillances will be incorporated into the plant surveillance program.
d) A description of what preventative maintenance tasks are required to be performed during normal operation, and the planned maximum surveillance interval that is necessary to ensure that the channels are fully conditioned to accurately and reliably perform their functions when needed.
Response
Device testing requirement analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. Following the issue of the design, procedures will start being developed with a projected July 2014 completion date.
The requested information will be provided in the August 2014, 6-month Integrated Plan update.
3.9 Display The 01 P states, in part, that:
The primary and backup instrument displays will be located at the control room, alternate shutdown panel, or other appropriate and accessible location. The specific location will be determined during detailed design. An appropriate and accessible location will include the following characteristics:
occupied or promptly accessible to the appropriate plant staff giving appropriate consideration to various drain down scenarios, outside the area surrounding the SFP floor (e.g., an appropriate distance from the radiological sources resulting from an event impacting the Spent Fuel Pool),
inside a structure providing protection against adverse weather, and outside of any very high radiation areas or LOCKED HIGH RAD AREA during normal operation.
Response to Request for Additional Information (Order EA-1 2-051)
Page 9 of 12
RAI-9
Please provide the following:
a) The specific location for each of the primary and backup instrument channel displays.
b) If the primary and backup display location is other than the main control room, provide justification for prompt accessibility to displays including primary and alternate route evaluation, habitability at display location(s), continual resource availability for personnel responsible to promptly read displays, and provisions for communications with decision makers for the various SFP drain down scenarios and external events.
c) The reasons justifying why the locations selected enable the information from these instruments to be considered "promptly accessible" to various drain-down scenarios and external events.
Response
Device channel display location will be finalized during the detailed design process. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
4.0 PROGRAM FEATURES 4.2 Procedures The OIP states, in part, that:
Procedures will be developed using guidelines and vendor instructions to address the maintenance, operation and abnormal response issues associated with the primary and backup channels of Spent Fuel Pool instrumentation.
RAI-10
Please provide a description of the standards, guidelines and/or criteria that will be utilized to develop procedures for inspection, maintenance, repair, operation, abnormal response, and administrative controls associated with the SFP level instrumentation, as well as storage and installation of portable instruments.
Response
Device program features analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. Following the issue Response to Request for Additional Information (Order EA-12-051)
Page 9 of 12 Please provide the following:
a) The specific location for each of the primary and backup instrument channel displays.
b) If the primary and backup display location is other than the main control room, provide justification for prompt accessibility to displays including primary and alternate route evaluation, habitability at display location(s), continual resource availability for personnel responsible to promptly read displays, and provisions for communications with decision makers for the various SFP drain down scenarios and external events.
c) The reasons justifying why the locations selected enable the information from these instruments to be considered "promptly accessible" to various drain-down scenarios and external events.
Response
Device channel display location will be finalized during the detailed design process. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. The requested information will be provided in the February 2014, 6-month Integrated Plan update.
4.0 PROGRAM FEATURES 4.2 Procedures The 01 P states, in part, that:
RAI-10
Procedures will be developed using guidelines and vendor instructions to address the maintenance, operation and abnormal response issues associated with the primary and backup channels of Spent Fuel Pool instrumentation.
Please provide a description of the standards, guidelines and/or criteria that will be utilized to develop procedures for inspection, maintenance, repair, operation, abnormal response, and administrative controls associated with the SFP level instrumentation, as well as storage and installation of portable instruments.
Response
Device program features analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. Following the issue
Response to Request for Additional Information (Order EA-1 2-051)
Page 10 of 12 of the design, procedures will start being developed with a projected July 2014 completion date.
The requested information will be provided in the August 2014, 6-month Integrated Plan update.
4.3 Testing and Calibration The OIP states, in part, that:
The testing and calibration of the instrumentation will be consistent with vendor recommendations or other documented basis. Calibration will be specific to the mounted instruments and the displays. Calibration will be performed to an Instrument Maintenance Procedure (BIP/BISR series). A Passport PMID will be used to direct frequency for performance of the instrument calibration.
RAI-11
Please provide the following:
a) Further information describing the maintenance and testing program the licensee will establish and implement to ensure that regular testing and calibration is performed and verified by inspection and audit to demonstrate conformance with design and system readiness requirements. Include a description of your plans for ensuring that necessary channel checks, functional tests, periodic calibration, and maintenance will be conducted for the level measurement system and its supporting equipment.
b) A description of how the guidance in NEI 12-02, Section 4.3 regarding compensatory actions for one or both non-functioning channels will be addressed.
c) A description of what compensatory actions are planned in the event that one of the instrument channels cannot be restored to functional status within 90 days.
Response
Device testing and calibration requirements analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. Following the issue of the design, procedures will start being developed with a projected July 2014 completion date. The requested information will be provided in the August 2014, 6 -
month Integrated Plan update.
Response to Request for Additional Information (Order EA-12-051)
Page 10 of 12 of the design, procedures will start being developed with a projected July 2014 completion date.
The requested information will be provided in the August 2014, 6-month Integrated Plan update.
4.3 Testing and Calibration The OIP states, in part, that:
RAI-11
The testing and calibration of the instrumentation will be consistent with vendor recommendations or other documented basis. Calibration will be specific to the mounted instruments and the displays. Calibration will be performed to an Instrument Maintenance Procedure (BIP/BISR series). A Passport PMID will be used to direct frequency for performance of the instrument calibration.
Please provide the following:
a) Further information describing the maintenance and testing program the licensee will establish and implement to ensure that regular testing and calibration is performed and verified by inspection and audit to demonstrate conformance with design and system readiness requirements. Include a description of your plans for ensuring that necessary channel checks, functional tests, periodic calibration, and maintenance will be conducted for the level measurement system and its supporting equipment.
b) A description of how the guidance in NEI12-02, Section 4.3 regarding compensatory actions for one or both non-functioning channels will be addressed.
c) A description of what compensatory actions are planned in the event that one of the instrument channels cannot be restored to functional status within 90 days.
Response
Device testing and calibration requirements analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the SFPI design of the system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in December 2013. Following the issue of the design, procedures will start being developed with a projected July 2014 completion date. The requested information will be provided in the August 2014, 6-month Integrated Plan update.
Response to Request for Additional Information (Order EA-12-051)
Page 11 of 12 ATTACHMENT1 Byron Spent Fuel Pool Elevation Sketch Response to Request for Additional Information (Order EA-12-051)
Page 11 of 12 ATTACHMENT 1 Byron Spent Fuel Pool Elevation Sketch Floor Elevation 426'.IJ'"
-91/2" SpentFuelPool~
~~ormal Level 424'-6 "
I--
span 424'-91/2" Le'Ii'el)to Lo Level 424' ?"
I--
400' -2" (Top of Fuel Rack)
-~
Levell 419' -r I--
Top SFP Pump Suttio 1'\\
Strainer 417-9-1/4" I--
410' I--
-2"
~
-2'~
~
Fuel Ponl FI1:>or 385' ~
f'........
Nnte:
Response to Request for Additional Information (Order EA-1 2-051)
Page 12 of 12 ATTACHMENT 2 Byron Spent Fuel Pool Plan View Sketch Secondary Channel 62'-0" Shipping Cask Area 33'-1" Spent Fuel Pit Primary Channel w
Response to Request for Additional Information (Order EA-12-051)
Page 12 of 12 A IT ACHMENT 2 Byron Spent Fuel Pool Plan View Sketch Secondary Channel
.. 4-------------- 62'-0" Shipping Cask Area I Spent Fuel Pit I Primary Channel w
_____ -r ___ --. N 33'-1"