ML13141A622

RAI Re. Overall Integrated Plan in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (EA-12-051)

ML13141A622
Person / Time
Site:	Brunswick
Issue date:	05/23/2013
From:	Gratton C Plant Licensing Branch II
To:	Annacone M Carolina Power & Light Co
Gratton, Chris NRR/DORL/LPL2-2
References
EA-12-051, TAC ME9623, TAC ME9624
Download: ML13141A622 (10)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 May 23, 2013 Mr. Michael J. Annacone, Vice President Brunswick Steam Electric Plant Carolina Power & Light Company Post Office Box 10429 Southport, North Carolina 28461

SUBJECT:

BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING OVERALL INTEGRATED PLAN IN RESPONSE TO THE COMMISSION ORDER MODIFYING LICENSES WITH REGARD TO REQUIREMENTS FOR RELIABLE SPENT FUEL POOL INSTRUMENTATION (ORDER NUMBER EA-12-051) (TAC NOS. ME9623 AND ME9624)

Dear Mr. Annacone:

By letter dated February 28, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13086A096), Carolina Power & Light Company submitted an Overall Integrated Plan (OIP) in response to the March 12,2012, Commission Order modifying licenses with regard to requirements for reliable spent fuel pool (SFP) Instrumentation (Order Number EA-12-051) for Brunswick Steam Electric Plant, Units 1 and 2. Further, the staff endorsed NEI 12-02, "Industry Guidance for Compliance with U. S. Nuclear Regulatory Commission (NRC) Order EA-12-051, To Modify Licenses with Regard to Reliable SFP Instrumentation," Revision 1, dated August 2012, with exceptions, as documented in Interim Staff Guidance JLD-ISG-2012-03 "Compliance with Order EA-12-051, Reliable SFP Instrumentation," Revision 0, dated August 29,2012.

The NRC staff is reviewing the submittal and has determined that additional information is required to complete its evaluation. This request was discussed with Mr. William Murray of your staff on May 21,2013, and it was agreed that a response to the enclosed request for additional information would be provided within 30 days of the date of this letter.

If you have any questions regarding this matter, I can be reached at 301415-1055.

Sincerely,

~~

Christopher Gratton, Senior Project Manager Plant licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-325 and 50-324

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION OVERALL INTEGRATED PLAN IN RESPONSE TO ORDER EA-12-051! "RELIABLE SPENT FUEL POOL INSTRUMENTATION" CAROLINA POWER & LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT UNITS 1 AND 2 DOCKET NO. 50-324 AND 50-325

1.0 INTRODUCTION

By letter dated February 28, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13086A096), Carolina Power & Light Company submitted an Overall Integrated Plan (OIP) in response to the March 12,2012, U.S. Nuclear Regulatory Commission (NRC), Commission Order modifying licenses with regard to requirements for Reliable Spent Fuel Pool (SFP) Instrumentation (Order Number EA-12-051; ADAMS Accession No. ML12054A679) for Brunswick Steam ElectriC Plant Units 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 24,2012 (ADAMS Accession No. ML12240A307), with exceptions as documented in Interim Staff Guidance JLD-ISG-2012-03, "Compliance with Order EA-12-051, Reliable SFP 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. If any part of this information is not available within the 60-day response period for this RAI, please provide the date this information will be submitted.

2.0 LEVELS OF REQUIRED MONITORING The OIP states, in part, that Level 1 - The water level adequate to support operation of the normal fuel pool cooling system is approximately 37 feet 9 inches (116 feet 4 inches plant elevation).

Level 2 - The water level adequate to provide substantial radiation shielding for a person standing on the SFP operating deck (Le., greater than 10 feet above the highest point of any fuel racks) is approximately 105 feet 7 % inches plant elevation.

Level 3 - The water level where fuel remains covered but actions to implement make-up water addition should no longer be deferred will be established based on the accuracy of the chosen instrumentation and the highest point of any fuel racks at approximately 95 feet 7 % inches plant elevation.

-2 The approximate range of the instrumentation system will be from 95 feet 7 ~ inches to 116 feet 4 inches plant elevation.

RAI-1

Please provide the following:

a) The specific functional reasons for identification of the elevations within the SFP as levels 1, 2, and 3. 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.

3.0 INSTRUMENTATION DESIGN FEATURES 3.2 Arrangement The OIP states, in part, that:

In accordance with the guidance in NEI 12-02, the level instrument channels will be installed in diverse locations and physically arranged in a manner that provides reasonable protection of the level indication function against missiles that may result from damage to the structure over the SFP.

Sensing Component: The sensing component of each level instrument channel will be installed separately within the SFP in order to reduce common susceptibility to missiles and other external events. The final location and mounting will be determined by the detailed design.

Electronics: Electronics associated with the level instrumentation will be located outside the SFP operating area due to sensitivity to radiation. The final location will be determined by the detailed design.

Cable Routing: Cable routings will be installed that will provide reasonable protection from missiles that may result from damage to the structure over the SFP and refuel floor. The conduit and cable routing will be determined by the detailed design.

- 3

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.

3.3 Mounting The DIP states, in part, that:

Each permanently installed instrument channel will be mounted to retain its design configuration during and following the maximum seismic ground motion considered in the design of the SFP structure in accordance with the guidance in NRC JLD-ISG-2012-03 and NEI 12-02.

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 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.

3.4 Qualification The DIP states, in part, that:

Sensing components and cables for the channels will be reliable at temperature, humidity, and radiation levels consistent with the SFP water at saturation conditions over an extended period of time.

Sensing components and cables will be qualified for expected conditions at the installed location assuming the SFP has been at saturation for an extended period.

- 4 Sensing components and cables located at the SFP will be qualified to withstand peak and total integrated dose radiation levels for their installed location based on post-event SFP water level equal to Level 3 for an extended period of time.

Additionally, the instrument channels will be tested, where possible, and analytically evaluated to remain functional after a potential seismic event with the exception of the battery charger and replacement batteries.

Augmented Quality provisions will be applied to ensure that rigor of the qualification documentation reviews and in-plant modification installation oversight is sufficient to ensure compliance with the qualification requirements described above. This approach to quality assurance is consistent with the guidance in NRC JLD-ISG-2012-03 and NEI 12-02.

The channels will be capable of performing their function and maintaining the required accuracy, except during the period when a potential seismic event is occurring, including harsh conditions where the equipment is installed.

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 during and following seismic conditions to maintain its required accuracy.

3.5 Independence The OIP states, in part, that:

Independence will be established in accordance with the guidance in NRC JLD-ISG-2012-03 and NEI12-02. Both instrument channels for each SFP will be of the same technology, permanently installed, separated by distance, and electrically independent of one another. Both channels for each SFP will have their own sensing component reasonably separated in accordance with

- 5 NEI 12-02, separate cable routes, and separate electronics.

RAI-5

Please provide the following:

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 precluded.

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.

3.6 Power Supplies The OIP states, in part, that:

Instrument channels will each be powered normally by a separate station power source and will have rechargeable or replaceable batteries with sufficient capacity to maintain the level indication function until the normal power is restored, consistent with the guidance in NEI 12-02.

RAI-6

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 (BDB) event for the minimum duration needed, consistent with the plant FLEX Program plans.

3.7 Accuracy The OIP states, in part, that:

Instrument channels will be designed such that they will maintain their design accuracy without recalibration following a power interruption or change in power source. Accuracy wi.1I consider SFP post-event conditions, e.g., saturated water or steam environment.

Additionally, instrument accuracy will be sufficient to allow trained personnel to determine when the actual level exceeds the specified level of each indicating range (Levels 1, 2, and 3) without conflicting or ambiguous indication. The accuracy will be within the resolution requirements of Figure 1 of NEI 12-02.

-6

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 BOB 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.

3.8 Testing OIP states, in part, that:

Testing and calibration will be consistent with the guidelines of NRC JLD-ISG-2012-03, NEI 12-02 guidance and vendor recommendations. Channel degradation due to age or corrosion is not expected but can be identified by monitoring trends. Station procedures and preventive maintenance tasks will be developed to perform required surveillance testing, calibration, backup battery maintenance, functional checks, and visual inspections of the sensing components.

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.

-7 3.9 Display The OIP states, in part, that:

The instrument displays for the channels will be located in a mild environment under normal and expected beyond design basis conditions that are accessible to plant personnel properly trained in the use of the equipment. The display will be conSistent with the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02.

RAI-9

Please provide the following:

a) The specific location for the primary and backup instrument channel display.

b) If the primary or backup display location is other than the main control room, then 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.

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 SFP level instrumentation. Procedures will also address strategy to ensure SFP water addition is initiated at an appropriate time consistent with implementation of NEI 12-06, Diverse and Flexible Coping Strategies (FLEX)

Implementation Guide.

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.

-.8 4.3 Testing and Calibration The OIP states, in part, that:

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. A maintenance procedure will be written to direct calibration and repair of the instruments.

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 NE112-02 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.

May 23,2013 Mr. Michael J. Annacone, Vice President Brunswick Steam Electric Plant Carolina Power & Light Company Post Office Box 10429 Southport, North Carolina 28461

SUBJECT:

BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING OVERALL INTEGRATED PLAN IN RESPONSE TO THE COMMISSION ORDER MODIFYING LICENSES WITH REGARD TO REQUIREMENTS FOR RELIABLE SPENT FUEL POOL INSTRUMENTATION (ORDER NUMBER EA-12-051) (TAC NOS. ME9623 AND ME9624)

Dear Mr. Annacone:

By letter dated February 28, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13086A096), Carolina Power & Light Company submitted an Overall Integrated Plan (OIP) in response to the March 12, 2012, Commission Order modifying licenses with regard to requirements for reliable spent fuel pool (SFP) Instrumentation (Order Number EA-12-051) for Brunswick Steam Electric Plant, Units 1 and 2. Further, the staff endorsed NEI 12-02, "Industry Guidance for Compliance with U. S. Nuclear Regulatory Commission (NRC) Order EA-12-051, To Modify Licenses with Regard to Reliable SFP Instrumentation," Revision 1, dated August 2012, with exceptions, as documented in Interim Staff Guidance JLD-ISG-2012-03 "Compliance with Order EA-12-051, Reliable SFP Instrumentation," Revision 0, dated August 29,2012.

The NRC staff is reviewing the submittal and has determined that additional information is required to complete its evaluation. This request was discussed with Mr. William Murray of your staff on May 21,2013, and it was agreed that a response to the enclosed request for additional information would be provided within 30 days of the date of this letter.

If you have any questions regarding this matter, I can be reached at 301-415-1055.

Sincerely, IRA!

Christopher Gratton, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-325 and 50-324

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:

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