Text

Interim Staff Evaluation and Request for Additional Information Regarding the Overall Integrated Plan for Implementation of Order EA-12-051, Reliable Spent Fuel Pool Instrumentation
	ML13280A326
Person / Time
Site:	Clinton
Issue date:	11/15/2013
From:	Blake Purnell; Plant Licensing Branch III
To:	Pacilio M; Exelon Generation Co
	Blake Purnell, NRR/DORL 415-1380
References
	EA-12-051, TAC MF0791
	Download: ML13280A326 (23)
	v • d • e

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 15, 2013 Mr. Michael J. Pacilio Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO)

. Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

CLINTON POWER STATION, UNIT 1 -INTERIM STAFF EVALUATION AND REQUEST FOR ADDITIONAL INFORMATION REGARDING THE OVERALL INTEGRATED PLAN FOR IMPLEMENTATION OF ORDER EA-12-051, RELIABLE SPENT FUEL POOL INSTRUMENTATION (TAC NO. MF0791)

Dear Mr. Pacilio:

On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued Order EA-12-051,

Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12054A679), to all power reactor licensees and holders of construction permits in active or deferred status. This Order requires the licensee to have a reliable indication of the water level in associated spent fuel storage pools capable of supporting identification of the following pool water level conditions by trained personnel: (1) level that is adequate to support operation of the normal fuel pool cooling system, (2) level that is adequate to provide substantial radiation shielding for a person standing on the spent fuel pool operating deck, and (3) level where fuel remains covered and actions to implement make-up water addition should no longer be deferred.

By letter dated February 28, 2013 (ADAMS Accession No. ML13059A306), Exelon Generation Company, LLC (the licensee) provided the Overall Integrated Plan (OIP) for Clinton Power Station, Unit 1, describing how it will achieve compliance with Attachment 2 of Order EA-12-051 by spriqg 2015. By letter dated June 7, 2013, as supplemented by email dated June 25, 2013 (ADAMS Accession Nos. ML13134A093 and ML13176A332, respectively), the NRC staff sent a request for additional information (RAI) to the licensee. The licensee provided supplemental information by letters dated July 3, 2013 (ADAMS Accession No. ML13186A002), and August 28, 2013 (ADAMS Accession No. ML13241A237).

The NRC staff has reviewed these submittals with the understanding that the licensee will update its OIP as implementation of the Order progresses. With this in mind, the staff has included an interim staff evaluation with this letter to provide feedback on the OIP. The staff's findings in the interim staff evaluation are considered prelimrnary and will be revised as the OIP is updated. As such, none of the staff's conclusions are to be considered final. A final staff evaluation will be issued after the licensee has provided the information requested.

The interim staff evaluation also includes RAis, response to which the NRC staff needs to complete its review. The licensee should provide the information requested in the 6-month

M. Pacilio status updates, as the information becomes available. However, the staff requests that all information be provided by September 30, 2014, to ensure that any issues are resolved prior to the date by which the licensee must complete full implementation of Order EA-12-051. The licensee should adjust its schedule for providing information to ensure that all this information is provided by the requested date.

If you have any questions regarding this letter, please contact me at 301-415-1380 or via e-mail at Blake.Purnell@nrc.gov.

Sincerely, Blake Purnell, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461

Enclosure:

Interim Staff Evaluation and Request for Additional Information cc w/encl: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 INTERIM STAFF EVALUATION AND REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE OVERALL INTEGRATED PLAN IN RESPONSE TO ORDER EA-12-051, RELIABLE SPENT FUEL POOL INSTRUMENTATION EXELON GENERATION COMPANY, LLC CLINTON POWER STATION, UNIT 1 DOCKET NO. 50-461

1.0 INTRODUCTION

On March 12,2012, the U.S. Nuclear Regulatory Commission (NRC) issued Order EA-12-051, "Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool [SFP]

Instrumentation" (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML12054A679), to all power reactor licensees and holders of construction permits in active or deferred status. This Order requires, in part, that all operating reactor sites have a reliable means of remotely monitoring wide-range SFP levels to support effective prioritization of event mitigation and recovery actions in the event of a beyond-design-basis (BDB) external event. The Order required all holders of operating licenses issued under Title 10 of the Code of Federal Regulations (10 CFR) Part 50, "Domestic Licensing of Production and Utilization Facilities," to submit to the NRC an Overall Integrated Plan (OIP) by February 28, 2013.

By letter dated February 28, 2013 (ADAMS Accession No. ML13059A306), Exelon Generation Company, LLC {the licensee) provided the OIP for Clinton Power Station, Unit 1, describing how it will achieve compliance with Attachment 2 of Order EA-12-051 by spring 2015. By letter dated June 7, 2013, as supplemented by email dated June 25, 2013 (ADAMS Accession Nos. ML13134A093 and ML13176A332, respectively), the NRC staff sent a request for additional information (RAI) to the licensee. The licensee provided supplemental information by letters dated July 3, 2013 (ADAMS Accession No. ML13186A002), and August 28, 2013 (ADAMS Accession No. ML13241A237).

2.0 REGULATORY EVALUATION

Order EA-12-051 requires all holders of operating licenses issued under 10 CFR Part 50, notwithstanding the provisions of any NRC regulation or license to the contrary, to comply with the requirements described in Attachment 2 to the Order except to the extent that a more stringent requirement is set forth in the license. Licensees shall promptly start implementation of the requirements in Attachment 2 to the Order and shall complete full implementation no later than two refueling cycles after submittal of the OIP or December 31, 2016, whichever comes first.

ENCLOSURE

Order EA-12-051 required the licensee, by February 28, 2013, to submit to the NRC an OIP, including a description of how compliance with the requirements described in Attachment 2 of the Order will be achieved. of Order EA-12-051 requires the licensee to have a reliable indication of the water level in associated spent fuel storage pools capable of supporting identification of the following pool water level conditions by trained personnel: (1) level that is adequate to support operation of the normal fuel pool cooling system, (2) level that is adequate to provide substantial radiation shielding for a person standing on the SFP operating deck, and (3) level where fuel remains covered and actions to implement make-up water addition should no longer be deferred. of Order EA-12-051, states that the SFP level instrumentation shall include the following design features:

1.1 Instruments

The instrumentation shall consist of a permanent, fixed primary instrument channel and a backup instrument channel. The backup instrument channel may be fixed or portable. Portable instruments shall have capabilities that enhance the ability of trained personnel to monitor spent fuel pool water level under conditions that restrict direct personnel access to the pool, such as partial structural damage, high radiation levels, or heat and humidity from a boiling pool.

1.2 Arrangement

The spent fuel pool level instrument channels shall be 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 spent fuel pool. This protection may be provided by locating the primary instrument channel and fixed portions of the backup instrument channel, if applicable, to maintain instrument channel separation within the spent fuel pool area, and to utilize inherent shielding from missiles provided by existing recesses and corners in the spent fuel pool structure.

1.3 Mounting

Installed instrument channel equipment within the spent fuel pool shall be mounted to retain its design configuration during and following the maximum seismic ground motion considered in the design of the spent fuel pool structure.

1.4 Qualification

The primary and backup instrument channels shall be reliable at temperature, humidity, and radiation levels consistent with the spent fuel pool water at saturation conditions for an extended period.

This reliability shall be established through use of an augmented quality assurance process (e.g., a process similar to that applied to the site fire protection program).

1.5 Independence

The primary instrument channel shall be independent of the backup instrument channel.

1.6 Power supplies: Permanently installed instrumentation channels shall each be powered by a separate power supply. Permanently installed and

portable instrumentation channels shall provide for power connections from sources independent of the plant [alternating current (ac)] and [direct current (de)] power distribution systems, such as portable generators or replaceable batteries. Onsite generators used as an alternate power source and replaceable batteries used for instrument channel power shall have sufficient capacity to maintain the level indication function until offsite resource availability is reasonably assured.

1. 7 Accuracy: The instrument channels shall maintain their designed accuracy following a power interruption or change in power source without recalibration.

1.8 Testing

The instrument channel design shall provide for routine testing and calibration.

1.9 Display

Trained personnel shall be able to monitor the spent fuel pool water level from the control room, alternate shutdown panel, or other appropriate and accessible location. The display shall provide on-demand or continuous indication of spent fuel pool water level. of Order EA-12-051, states that the SFP instrumentation shall be maintained available and reliable through appropriate development and implementation of the following programs:

2.1 Training

Personnel shall be trained in the use and the provision of alternate power to the primary and backup instrument channels.

2.2 Procedures

Procedures shall be established and maintained for the testing, calibration, and use of the primary and backup spent fuel pool instrument channels.

2.3 Testing and Calibration: Processes shall be established and maintained for scheduling and implementing necessary testing and calibration of the primary and backup spent fuel pool level instrument channels to maintain the instrument channels at the design accuracy.

On August 29, 2012, the NRC issued an Interim Staff Guidance document (the ISG),

JLD-ISG-2012-03, "Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation" (ADAMS Accession No. ML12221A339), to describe methods acceptable to the NRC staff for complying with Order EA-12-051. The ISG endorses, with exceptions and clarifications, the methods described in the Nuclear Energy Institute (NEI) guidance document NEI 12-02, Revision 1. "Industry Guidance for Compliance with NRC Order EA-12-051, 'To Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, "' dated August 2012 (ADAMS Accession No. ML12240A307). Specifically, the ISG states:

The NRC staff considers that the methodologies and guidance in conformance with the guidelines provided in NEI 12-02, Revision 1, subject to the clarifications and exceptions in Attachment 1 to this ISG, are an acceptable means of meeting the requirements of Order EA-12-051.

3.0 TECHNICAL EVALUATION

3.1 Background and Schedule Clinton Power Station has an upper containment fuel storage pool located in the containment building and a SFP and fuel cask storage pool located in the fuel building. The licensee stated in its OIP that during normal, on-line operation irradiated fuel is only stored in the SFP and not in either the upper containment fuel storage pool or the fuel cask storage pool.

The OIP states that installation of the SFP level instrumentation for Clinton Power Station will be completed by the end of the second refueling outage following submittal of this integrated plan which is scheduled for spring 2015.

The NRC staff has reviewed the licensee's schedule for implementation of SFP level instrumentation provided in its OIP. If the licensee completes implementation in accordance with this schedule, it would appear to achieve compliance with Order EA-12-051 within two refueling cycles after submittal of the OIP and before December 31, 2016.

3.2 Spent Fuel Pool Water Levels of Order EA-12-051 states, in part, that All licensees identified in Attachment 1 to this Order shall have a reliable indication of the water level in associated spent fuel storage pools capable of supporting identification of the following pool water level conditions by trained personnel: (1) level that is adequate to support operation of the normal fuel pool cooling system [Level 1], (2) level that is adequate to provide substantial radiation shielding for a person standing on the spent fuel pool operating deck

[Level 2], and (3) level where fuel remains covered and actions to implement make-up water addition should no longer be deferred [Level 3].

NEI 12-02 states, in part, that Level 1 represents the HIGHER of the following two points:

The level at which reliable suction loss occurs due to uncovering of the coolant inlet pipe, weir or vacuum breaker (depending on the design), or

The level at which the water height, assuming saturated conditions, above the centerline of the cooling pump suction provides the required net positive suction head specified by the pump manufacturer or engineering analysis.

In its OIP, the licensee stated that Level 1 is the indicated level on either the primary or backup instrument channel of greater than 26 feet (ft.) 8/'4 inches (in.) (elevation 754ft.) above the top of the storage racks. The licensee stated that this elevation is based on the height of the SFP weir, demonstrating that this elevation is adequate for normal fuel pool cooling system operation.

In its letter dated July 3, 2013, the licensee stated, in part, that The Spent Fuel Pool at Clinton Power Station has skimmers and scuppers located at the [754ft.] elevation that water must flow into. From there the water is routed to surge tanks from which the Fuel Pool Cooling and Cleanup (FC) pumps draw suction. The suction trip is at an approximate [720.75 ft.].elevation.

Thus the [754ft.] elevation reflects the higher of the two points noted in NEI 12-02, Section 2.3.1 The NRC staff notes that Level 1 at plant elevation 754ft. is adequate for normal SFP cooling system operation and it is also adequate to ensure the required fuel pool cooling pump net positive suction head. The staff also notes that this level represents the higher of the two points described in NEI 12-02 for Level 1.

NEI 12-02 states, in part, that Level 2 represents the range of water level where any necessary operations in the vicinity of the spent fuel pool can be completed without significant dose consequences from direct gamma radiation from the stored spent fuel. Level 2 is based on either of the following:

10 feet (+I- 1 foot) above the highest point of any fuel rack seated in the spent fuel pools, or

a designated level that provides adequate radiation shielding to maintain personnel radiological dose levels within acceptable limits while performing local operations in the vicinity of the pool. This level shall be based on either plant-specific or appropriate generic shielding calculations, considering the emergency conditions that may apply at the time and the scope of necessary local operations, including installation of portable SFP instrument channel components.

In its OIP, the licensee stated that Level 2 is the indicated level on either the primary or backup instrument channel of greater than 10ft. (elevation 737.31 ft.) above the top of the storage racks.

In its letter dated July 3, 2013, the licensee provided a sketch showing the approximate location of the elevations identified as Levels 1, 2, and 3, and the top of the tallest fuel storage rack. The NRC staff notes that the sketch shows Level 2 is more than 10ft. above the top of the fuel racks. The staff also notes that the licensee designated Level 2 using the first of the two options described in NEI 12-02 for Level 2.

NEI 12-02 states, in part, that Level 3 corresponds nominally (i.e., +/- 1 foot) to the highest point of any fuel rack seated in the spent fuel pool. Level 3 is defined in this manner to provide the maximum range of information to operators, decision makers and emergency response personnel.

In its OIP, the licensee stated that Level 3 is the indicated level on either the primary or backup instrument channel of greater that 0 ft. (elevation 727.31 ft.) above the top of the storage racks.

In its letter dated July 3, 2013, the licensee provided a sketch showing the approximate location the elevations identified as Levels 1, 2, and 3, and the top of the tallest fuel storage rack. The NRC staff notes that the sketch shows that Level 3 is above the highest point of any spent fuel storage rack seated in the SFP.

The licensee's proposed plan, with respect to identification of Levels 1, 2, and 3, appears to be consistent with NEI 12-02, as endorsed by the ISG.

3.3 Design Features: Instruments of Order EA-12-051, states, in part, that The instrumentation shall consist of a permanent, fixed primary instrument channel and a backup instrument channel. The backup instrument channel may be fixed or portable. Portable instruments shall have capabilities that enhance the ability of trained personnel to monitor spent fuel pool water level under conditions that restrict direct personnel access to the pool, such as partial structural damage, high radiation levels, or heat and humidity from a boiling pool.

NEI 12-02 states, in part, that A spent fuel pool level instrument channel is considered reliable when the instrument channel satisfies the design elements listed in Section 3

[Instrumentation Design Features] of this guidance and the plant operator has fully implemented the programmatic features listed in Section 4 [Program Features].

In its OiP, the licensee stated that the primary and backup instrument channel level sensing components will be located and permanently mounted in the SFP. Both instrument channels would monitor the SFP water level continuously over a minimum range of approximately 26.86 ft. from the high pool level elevation of 754.17 ft. to the top of the spent fuel racks at elevation 727.31 ft.

The NRC staff notes that the monitoring range specified for the instrumentation will cover Levels 1, 2, and 3 as described in Section 3.2 above. The licensee's proposed plan with respect to the number of channels and the range of the instrumentation for its SFP appears to be consistent with NEI 12-02, as endorsed by the ISG.

3.4 Design Features: Arrangement of Order EA-12-051, states, in part, that The spent fuel pool level instrument channels shall be 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 spent fuel pool. This protection may be provided by locating the primary instrument channel and the

fixed portions of the backup instrument channel, if applicable, to maintain instrument channel separation within the spent fuel pool area, and to utilize inherent shielding from missiles provided by existing recesses and corners in the spent fuel pool structure.

NEI 12-02 states, in part, that The intent of the arrangement requirement is to specify reasonable separation and missile protection requirements for permanently installed instrumentation used to meet this order. Although additional missile barriers are not required to be installed, separation and shielding can help minimize the probability that damage due to an explosion or extreme natural phenomena (e.g., falling or wind-driven missiles) will render fixed channels of SFP instrumentation unavailable.

Installation of the SFP instrument channels shall be consistent with the plant-specific SFP design requirements and should not impair normal SFP function.

Channel separation should be maintained by locating the installed sensors in different places in the SFP area.

In its OIP, the licensee stated, in part, that The current proposed plan is to install SFP level sensors in the southwest corner and on the east side of the SFP separated 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 Fuel 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.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel arrangement (RAI-2). The NRC staff notes that the information regarding final sensor locations and cable routings for the SFP instrumentation has not been provided. In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. The staff has identified this request as:

RAI #1 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 these sensors toward the location of the read-out/display device.

(This information was previously requested as RAI-2 in the NRC letter dated June 7, 2013)

3.5 Design Features: Mounting of Order EA-12-051 states, in part, that Installed instrument channel equipment within the spent fuel pool shall be mounted to retain its design configuration during and following the maximum seismic ground motion considered in the design of the spent fuel pool structure.

NEI 12-02 states, in part, that The mounting shall be designed to be consistent with the highest seismic or safety classification of the SFP. An evaluation of other hardware stored in the SFP shall be conducted to ensure it will not create adverse interaction with the fixed instrument location(s).

The basis for the seismic design for mountings in the SFP shall be the plant seismic design basis at the time of submittal of the Integrated Plan for implementing NRC Order EA-12-051.

In its OIP, the licensee stated, 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.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel mounting (RAI-3). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. The staff has identified this request as:

RAI#2 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.

(This information was previously requested as RA/-3 in the NRC letter dated June 7, 2013)

In addition, the NRC staff plans to verify the results of the licensee's seismic testing and analysis when it is completed. The staff has identified these requests as:

RAI#3 For RAI 2(a) above, please provide the analyses used to verify the design criteria and methodology for seismic testing of the SFP instrumentation and the electronics units, including design-basis maximum seismic loads and the hydrodynamic loads that could result from pool sloshing or other effects that could accompany such seismic forces.

RAI#4 For each of the mounting attachments required to attach SFP level equipment to plant structures, please describe the design inputs and the methodology that was used to qualify the structural integrity of the affected structures/equipment.

3.6 Design Features: Qualification of Order EA-12-051 states, in part, that The primary and backup instrument channels shall be reliable at temperature, humidity, and radiation levels consistent with the spent fuel pool water at saturation conditions for an extended period. This reliability shall be established through use of an augmented quality assurance process (e.g. a process similar to that applied to the site fire protection program).

NEI 12-02 states, in part, that The instrument channel reliability shall be demonstrated via an appropriate combination of design, analyses, operating experience, and/or testing of channel components for the following sets of parameters, as described in the paragraphs below:

conditions in the area of instrument channel component use for all instrument components,

effects of shock and vibration on instrument channel components used during any applicable event for only installed components, and

seismic effects on instrument channel components used during and following a potential seismic event for only installed components ...

The NRC staff assessment of the instrument qualification is discussed in the following subsections below: (3.6.1) Augmented Quality Process and (3.6.2) Qualification and Reliability.

3.6.1 Augmented Quality Process Appendix A-1 of the guidance in NEI 12-02 describes a quality assurance process for non-safety systems and equipment that is not already covered by existing quality assurance requirements. Within the ISG, the NRC staff found the use of this quality assurance process to be an acceptable means of meeting the augmented quality requirements of Order EA-12-051.

In its OIP, the licensee stated, in part, that Reliability will be established through the use of an augmented quality assurance process (e.g., a process similar to that applied to the site fire protection program).

The licensee's proposed augmented quality assurance process appears to be consistent with NEI 12-02, as endorsed by the ISG.

3.6.2 Qualification and Reliability NEI 12-02 states, in part, that The 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 should be considered. Examples of post-event (beyond-design-basis) conditions to be considered are:

radiological conditions for a normal refueling quantity of freshly discharged

( 100 hours0.00116 days 0.0278 hours 1.653439e-4 weeks 3.805e-5 months ) fuel with the SFP water level 3 as described in this order,

temperatures of 212 degrees F and 100% relative humidity environment,

boiling water and/or steam environment

a concentrated borated water environment ...

In its OIP, the licensee stated, consistent with NEI 12-02, in part, that Temperature, humidity and radiation levels consistent with the conditions in the vicinity of the SFP and the area of use considering normal operation, 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 (FLEX) (Reference 4) will be addressed in the detailed design engineering 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 (1 00 hours0 days 0 hours 0 weeks 0 months ) fuel with the SFP water level 3 as described in Order EA-12-051,

temperatures of 212 degrees F and 100% relative humidity environment,

boiling water and/or steam environment ...

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel qualification (RAI-4 ). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. The staff has identified this request as:

RAI#S 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 BOB 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.

(This information was previously requested as RAI-4 in the NRC letter dated June 7, 2013)

In addition, the NRC staff plans to verify the results of the licensee's testing and analysis used to demonstrate the qualification and reliability of the installed equipment when it is completed.

The staff has identified this request as:

RAI#6 For RAI #5 above, please provide the results for the selected methods, tests and analyses used to demonstrate the qualification and reliability of the installed equipment in accordance with the Order requirements.

3.6.3 Qualification Evaluation Summary Upon acceptable resolution of the RAis in Section 3.6, the NRC staff will be able to make a conclusion regarding the instrument qualification.

3. 7 Design Features: Independence of Order EA-12-051 states, in part, that The primary instrument channel shall be independent of the backup instrument channel.

NEI 12-02 states, in part, that Independence of permanently installed instrumentation, and primary and backup channels, is obtained by physical and power separation commensurate with the hazard and electrical isolation needs. If plant AC or DC power sources are used then the power sources shall be from different buses and preferably different divisions/channels depending on available sources of power.

In its OIP, the licensee stated that the primary instrument channel will be independent of the backup instrument channel and that independence will be achieved through physical and electrical separation of each channel's components commensurate with hazard and electrical isolation needs.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel independence (RAI-5). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. The staff has identified this request as:

RAI#7 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 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.

(This information was previously requested as RAI-5 in the NRC letter dated June 7, 2013) 3.8 Design Features: Power Supplies of Order EA-12-051, states, in part, that Permanently installed instrumentation channels shall each be powered by a separate power supply. Permanently installed and portable instrumentation channels shall provide for power connections from sources independent of the

plant ac and de power distribution systems, such as portable generators or replaceable batteries. Onsite generators used as an alternate power source and replaceable batteries used for instrument channel power shall have sufficient capacity to maintain the level indication function until offsite resource availability is reasonably assured.

NEI 12-02 states, in part, that The normal electrical power supply for each channel shall be provided by different sources such that the loss of one of the channels primary power supply will not result in a loss of power supply function to both channels of SFP level instrumentation.

All channels of SFP level instrumentation shall provide the capability of connecting the channel to a source of power (e.g., portable generators or replaceable batteries) independent of the normal plant AC and DC power systems. For fixed channels this alternate capability shall include the ability to isolate the installed channel from its normal power supply or supplies. The portable power sources for the portable and installed channels shall be stored at separate locations, consistent with the reasonable protection requirements associated with NEI12-06 (Order EA-12-049). The portable generator or replaceable batteries should be accessible and have sufficient capacity to support reliable instrument channel operation until off-site resources can be deployed by the mitigating strategies resulting from Order EA-12-049.

If adequate power supply for either an installed or portable level instrument credits intermittent operation, then the provisions shall be made for quickly and reliably taking the channel out of service and restoring it to service. For example, a switch on the power supply to the channel is adequate provided the power can be periodically interrupted without significantly affecting the accuracy and reliability of the instrument reading. Continuous indication of SFP level is acceptable only if the power for such indication is demonstrably adequate for the time duration specified in section 3.1 [.]

In its OIP, the licensee stated, 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.

By letter dated June 7, 2013, as supplemented by email dated June 25, 2013, the NRC staff requested additional information regarding instrument channel power supplies (RAI-6). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. However, based on feedback from licensees, the staff revised this RAI as follows:

RAI#8 Please provide the following:

a} A description of the electrical ac power sources and capabilities for the primary and backup channels.

b) Please provide the results of the calculation depicting the battery backup duty cycle requirements demonstrating that its capacity is sufficient to maintain the level indication function until offsite resource availability is reasonably assured.

3.9 Design Features: Accuracy of Order EA 12 051 states, in part, that The instrument channels shall maintain their designed accuracy following a power interruption or change in power source without recalibration.

NEI 12-02 states, in part, that Accuracy should consider operations while under SFP conditions, e.g., saturated water, steam environment, or concentrated borated water. Additionally, instrument accuracy should be sufficient to allow trained personnel to determine when the actual level exceeds the specified lower level of each indicating range (levels 1, 2 and 3) without conflicting or ambiguous indication.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel accuracy (RAI-7). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. The staff has identified this request as:

RAI#9 Please provide the following:

a} An estimate of the expected instrument channel accuracy performance under both (a} normal SFP water 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 water 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.

(This information was previously requested as RAI-7 in the NRC letter dated June 7, 2013)

3.10 Design Features: Testing of Order EA-12-051 states, in part, that The instrument channel design shall provide for routine testing and calibration.

NEI 12-02 states, in part, that Static or non-active installed (fixed) sensors can be used and should be designed such that testing and/or calibration can be performed in-situ. For microprocessor based channels the instrument channel design shall be capable of testing while mounted in the pool.

In its OIP, the licensee stated that the instrument channel design will provide for routine testing and calibration consistent with the guidelines of NRC JLD-ISG-2012-03 and NEI12-02.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel testing (RAI-8). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the February 2015, 6-month status report. The staff has identified this request as:

RAI #10 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 preventive 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.

(This information was previously requested as RAI-8 in the NRC letter dated June 7, 2013)

3.11 Design Features: Display of Order EA-12-051 states, in part, that Trained personnel shall be able to monitor the spent fuel pool water level from the control room, alternate shutdown panel, or other appropriate and accessible location. The display shall provide on-demand or continuous indication of spent fuel pool water level.

NEI 12-02 states, in part, that The intent of this guidance is to ensure that information on SFP level is reasonably available to the plant staff and decision makers. Ideally there will be an indication from at least one channel of instrumentation in the control room.

While it is generally recognized (as demonstrated by the events at Fukushima Daiichi) that SFP level will not change rapidly during a loss of spent fuel pool cooling scenario more rapid SFP drain down cannot be entirely discounted.

Therefore, the fact that plant personnel are able to determine the SFP level will satisfy this requirement, provided the personnel are available and trained in the use of the SFP level instrumentation (see Section 4.1) and that they can accomplish the task when required without unreasonable delay.

SFP level indication from the installed channel shall be displayed in the control room, at the alternate shutdown panel, or another appropriate and accessible location (reference NEI 12-06). An appropriate and accessible location shall have the following characteristics:

occupied or promptly accessible to the appropriate plant staff giving appropriate consideration to various drain down scenarios,

outside of the area surrounding the SFP floor, e.g., an appropriate distance from the radiological sources resulting from an event impacting the SFP,

inside a structure providing protection against adverse weather, and

outside of any very high radiation areas or LOCKED HIGH RAD AREA during normal operation.

If multiple display locations beyond the required "appropriate and accessible location" are desired, then the instrument channel shall be designed with the capability to drive the multiple display locations without impacting the primary "appropriate and accessible" display.

In its OIP, the licensee stated that the primary and backup instrument displays will be located at the control room, alternate shutdown panel, or other appropriate and accessible location and that the specific location will be determined during detailed design.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel displays (RAI-9). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the August 2014, 6-month status report. Based on feedback from licensees, the staff has revised this RAI as follows:

RAI #11 Please provide the following:

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

b) If a display will be located somewhere other than the control room or alternate shutdown panel, please describe the evaluation used to validate that the display location can be accessed without unreasonable delay following a BOB event.

Include the time available for personnel to access the display as credited in the evaluation, as well as the actual time (e.g., based on walk-throughs) that it will take for personnel to access the display. Additionally, please include a description of the radiological and environmental conditions on the paths personnel might take. Describe whether the display location remains habitable for radiological, heat and humidity, and other environmental conditions following a BOB event. Describe whether personnel are continuously stationed at the display or monitor the display periodically.

3.12 Programmatic Controls: Training of Order EA-12-051 states, in part, that Personnel shall be trained in the use and the provision of alternate power to the primary and backup instrument channels.

NEI 12-02 states, in part, that The personnel performing functions associated with these SFP level instrumentation channels shall be trained to perform the job specific functions necessary for their assigned tasks (maintenance, calibration, surveillance, etc.).

SFP instrumentation should be installed via the normal modification processes.

In some cases, utilities may choose to utilize portable instrumentation as a portion of their SFP instrumentation response. In either case utilities should use the Systematic Approach to Training (SAT) to identify the population to be trained. The SAT process should also determine both the initial and continuing elements of the required training.

In its OIP, the licensee stated, in part, that Personnel performing functions associated with these SFP level instrumentation channels will be trained to perform the job specific functions necessary for their assigned tasks (maintenance, calibration, surveillance, etc.). This training will be consistent with equipment vendor guidelines, instructions and recommendations.

The Systematic Approach to Training (SAT) will be used to identify the population to be trained and to determine the initial and continuing elements of the required training. Training will be completed prior to placing the instrumentation in service.

The licensee's proposed plan with respect to the training personnel in the use and the provision of alternate power to the primary and backup instrument channels, including the approach to identifying the population to be trained, appears to be consistent with NEI 12-02, as endorsed by the ISG.

3.13 Programmatic Controls: Procedures of Order EA-12-051 states, in part, that Procedures shall be established and maintained for the testing, calibration, and use of the primary and backup spent fuel pool instrument channels.

NEI 12-02 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 new SFP instrumentation.

In its OIP, the licensee stated 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 SFP instrumentation.

By letter dated June 7, 2013, the NRC staff requested additional information regarding procedures for the instrumentation (RAI-1 0). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the February 2015, 6-month status report. Based on feedback from licensees, the staff has revised this RAI as follows:

RAI #12 Please provide a list of the procedures addressing operation (both normal and abnormal response}, calibration, test, maintenance, and inspection procedures that will be developed for use of the spent SFP instrumentation. The licensee is requested to include a brief description of the specific technical objectives to be achieved within each procedure.

3.14 Programmatic Controls: Testing and Calibration of Order EA-12-051 states, in part, that Processes shall be established and maintained for scheduling and implementing necessary testing and calibration of the primary and backup spent fuel pool level instrument channels to maintain the instrument channels at the design accuracy.

NEI 12-02 states, in part, that Processes shall be established and maintained for scheduling and implementing necessary testing and calibration of the primary and backup SFP level instrument channels to maintain the instrument channels at the design accuracy. The testing and calibration of the instrumentation shall be consistent with vendor recommendations or other documented basis.

In its OIP, the licensee stated, 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 as determined during the modification review process.

By letter dated June 7, 2013, the NRC staff requested additional information regarding instrument channel testing and calibration (RAI-11 ). In its letter dated July 3, 2013, the licensee indicated that the requested information was not yet available, but it will be provided with the February 2015, 6-month status report. The staff has identified this request as:

RAI #13 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 the non-functioning instrument channel cannot be restored to functional status within 90 days.

(This information was previously requested as RA/-11 in the NRC Jetter dated June 7, 2013) 3.15 Instrument Reliability NEI 12-02 states, in part, that A spent fuel pool level instrument channel is considered reliable when the instrument channel satisfies the design elements listed in Section 3 [Instrument

Design Features] of this guidance and the plant operator has fully implemented the programmatic features listed in Section 4 [Program Features].

In its OIP, the licensee stated that reliability of the instrument channels will be assured by conformance with the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02.

Upon acceptable resolution of the RAis noted above, the NRC staff will be able to make a conclusion regarding the reliability of the SFP instrumentation.

4.0 CONCLUSION

The NRC staff is unable to complete its evaluation regarding the acceptability of the licensee's plans for implementing the requirements of Order EA-12-051 due to the need for additional information as described above. The staff will issue an evaluation with its conclusion after the licensee has provided the requested information.

ML13280A326 *via memo OFFICE NRR/DORLILPL3-2/PM NRR/DORLILPL3-2/LA NRR/DSS/SBPB/BC NAME BPurnell SRohrer GCasto*

DATE 10/7 /13 10/7/13 10/1/13 OFFICE NRR/DE/EICB/BC OGC NAME JThorp* BKiukan DATE 10/1/13 10/ 21 /13 OFFICE NRR/DORLILPL3-2/BC NRR/DORLILPL3-2/PM NAME TTate BPurnell DATE 11/8/13 11/15/13

v t e Letter Sequence RAI
TAC:MF0791, (Approved, Closed)
Initiation Acceptance Administration Questions 7 June 2013 25 June 2013 15 November 2013 Answers 3 July 2013 Results Approval Other: ML13338A656, ML15042A557, ML15100A051, RS-13-029, 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), RS-13-116, First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), RS-13-117, First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), RS-14-197, Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), RS-14-207, Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), RS-15-018, Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), RS-15-027, Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), RS-15-137, Provides Report of Full Compliance with March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), RS-15-138, Report of Full Compliance with March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)
MONTHYEAR2013-07-03 [Table View]

ML13280A326