ML13164A393

Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 - Request for Additional Information Regarding Overall Integrated Plan for Reliable Spent Fuel Pool Instrumentation, Order EA-12-051 (TAC Nos. MF1140 and MF1141)

ML13164A393
Person / Time
Site:	Calvert Cliffs
Issue date:	06/19/2013
From:	Morgan N S Plant Licensing Branch 1
To:	Calvert Cliffs
Morgan N S
References
EA-12-051, TAC MF1140, TAC MF1141
Download: ML13164A393 (12)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Calvert Cliffs Nuclear Power Plant, LLC Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, MD 20657-4702 June 19, 2013 SUBJECT: CALVERT CLIFFS NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2-REQUEST FOR ADDITIONAL INFORMATION REGARDING OVERALL INTEGRATED PLAN FOR RELIABLE SPENT FUEL POOL INSTRUMENTATION, ORDER EA-12-051 (TAC NOS. MF1140 AND MF1141) Dear Mr. Gellrich: By letter dated February 28, 2013, Constellation Energy Nuclear Group, LLC, submitted an Overall Integrated Plan in response to the March 12, 2012, Commission Order modifying licenses with regard to Reliable Spent Fuel Pool Instrumentation, Order EA-12-051, for Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2. The Nuclear Regulatory Commission (NRC) staff endorsed Nuclear Energy Institute 12-02, "Industry Guidance for Compliance 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 2012-03, "Compliance with Order EA 12 051, Reliable SFP Instrumentation," Revision 0, dated August 29, 2012. The NRC staff has reviewed the February 28, 2013, response by the licensee and determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). The NRC staff is requesting a response to the RAI by July 5, 2013. If any part of your response to the RAI is not available by the July 5, 2013, please provide the date this information will be submitted.

G. Gellrich -2 -If you have any questions regarding this issue, please contact me at (301) 415-1016. Docket Nos. 50-317 and 50-318 Enclosure: RAI cc w/encl: Distribution via Listserv Nadiyah S. Morgan, Project Manager Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation REQUEST FOR ADDITIONAL INFORMATION REGARDING THE OVERALL INTEGRATED PLAN IN RESPONSE TO ORDER EA-12-051, "RELIABLE SPENT FUEL POOL INSTRUMENTATION" CONSTELLATION ENERGY NUCLEAR GROUP. LLC CALVERT CLIFFS NUCLEAR POWER PLANT UNIT NOS. 1 AND 2 DOCKET NOS. 50-317 AND 50-318 1.0 INTRODUCTION By let!er dated February 28, 2013 (Agencywide Documents Access and Management System (,A.. DAMS) Accession No. ML 13066A 172), Constellation Energy Nuclear Group, LLC, submitted an Overall Integrated Plan (OIP) in response to the March 12, 2012, Nuclear Regulatory Commission (NRC), Commission Order modifying licenses with regard to requirements for Reliable Spent Fuel Pool (SFP) Instrumentation, Order EA-12-051 (ADAMS Accession No. ML 12054A679} for Calvert Cliffs Nuclear Power Plant (CCNPP) Unit Nos. 1 and 2. The NRC staff endorsed Nuclear Energy Institute (NEI) 12-02, "Industry Guidance for Compliance NRC Order EA-12-051, to Modify Licenses with Regard to Reliable SFP Instrumentation," Revision 1, dated August 2012 (ADAMS Accession No. ML 12240A307), with exceptions as documented in Interim Staff Guidance (ISG) 201.2-03, "Compliance with Order EA-12-051, Reliable SFP Instrumentation," Revision 0, dated August 29, 2012 (ADAMS Accession No. ML 12221 A339). 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 by the July 5, 2013 response date, please provide the date the information will be submitted. 2.0 LEVELS OF REQUIRED MONITORING The OIP states, in part, that Level adequate to support operation of the normal SFP cooling Indicated water level on either the primary or backup instrument channel of greater than elevation 65'-8.5" (based on ensuring the open end of the normal suction lines will not become uncovered) plus the accuracy of the SFP water level instrument channel, which will be determined during the engineering and design phase (Reference 1 0). Enclosure RAI-1 -2-Level adequate to provide substantial radiation -shielding ,for a person standing on the SFP operating deck-Indicated water level on either the primary or backup instrument channel of greater than elevation 50'-2" plus the accuracy of the SFP water level instrument channel, which will be determined during the engineering and design phase. This elevation is approximately 5' above the top of the fuel racks and ensures a minimum water level of 5' above the top of the Fuel (Reference 10). CCNPP determined that with 5' of water above the top of the racks, the largest calculated dose rate near the edge of the SFP would be well below 100 mrem/hr. Calculations to determine dose rates near the edge of the SFP with 5' of water.above the top of the fuel racks were performed using SAS2HIORIGEN-S or ORIGEN-ARP for source term calculations and MCNP5 code was used to calculate gamma (primary and capture) and neutron dose rates at the locations of interest. MCNP5 is a general-purpose Monte-Carlo Particle code that can be used for neutron, photon, electron, or coupled neutron/ photon/ electron transport. This monitoring level ensures there is adequate water *level to provide substantial radiation shielding for personnel to respond to Beyond-Design-Basis External Events and to initiate SFP makeup strategies. Level where fuel remains covered -Indicated water level on either the primary or backup instrument channel of greater than elevation 45'-2" plus the accuracy of the SFP water level instrument channel, which will be determined during the design and engineering phase. This monitoring level assures that there is . adequate water level above the stored fuel seated in the rack. (Reference 1 0). Please provide the following: a) For level1, 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 3.1 Arrangement The OIP states, in part, that SFP water level sensors will be installed in the northeast comer of Unit 1 SFP (No. 11) and southwest comer of Unit 2 SFP (No. 21 ). Transmitters will be located on the 45' elevation of the Auxiliary Building, which is below the SFP operating level. This location will provide protection from external missiles and RAI-2 -3 -offer lower dose, temperature and humidity levels when compared to equipment located directly above the SFP (Elevation 69'). 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 pi"imary and back-up SFP level sensor and mounting brackets, and the proposed routing of the cables that will extend from the sensors toward the location of the read-out/display device. The OIP states, in part, that CCNPP Unit 1 and Unit 2 discharge irradiated fuel to a set of 2 interconnected SFPs. The gate between the Uri it 1 SFP (No. 11) and the Unit 2 SFP (No. 21) is maintained open under administrative controls in accordance with the applicable procedure, OI-24A, Spent Fuel Pool Cooling Pump and Cooler Operation on Spent Fuel Pool Operating Instructions, Revision 00808. Thus, these SFPs are normally inter-connected and at the same water level when the water level in the SFPs is greater than elevation 42'-8", which is above the top of stored fuel seated in the storage racks. Please provide a description of the conditions under which the two SFPs connected by a channel would be isolated by a gate or other means such that the separated pools would not have independent measurements of wide range SFP level for the respective pools. Provide the justification for not installing independent level indications in each SFP for conditions in which the SFPs are two isolated pools . . 3.2 Mounting The OIP states, in part, that . Mounting will be Seismic Class L Installed equipment will be seismically qualified to withstand the maximum seismic motion considered in the design of the plant area in which it is installed. An engineering analysis will be conducted during the design to ensure any other hardware stored in the SFP area will not create an adverse interaction with the fixed instrument location. 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.

-4-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. 3.3 Qualification The OIP states, in part, that Components of the instrument channels will be qualified for shock and vibration using one or more of the following methods:

• Components will be supplied by manufacturers using commercial quality programs (such as IS09001, Quality management systems-Requirements) with shock and vibration requirements included in the purchase specification at levels commensurate with portable handheld device or transportation applications;

• Components will have a substantial history of operational reliability in environments with significant shock and vibration loading, such as portable hand-held device or transportation applications; or

• Components will be inherently resistant to shock and vibration loadings, such as cables. The following measures will be used to verify that the design and installation is

• adequate for seismic effects on instrument channel components used after a potential seismic event for installed components (with the exception of battery chargers and replaceable batteries). Applicable components of the instrument channels will be rated by the manufacturer (or otherwise tested) for seismic effects at . levels commensurate with those of postulated design basis event conditions in the

• location of the instrument channel component using one or more of the following methods: *

• a 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 will be inclusive of the effects of seismic motion imparted to the components proposed at the locations of the proposed installation;

• adequacy of seismic design and installation will be demonstrated based on the guidance in Sections 7, 8, 9, and 10 of IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating Stations, (Reference 9) or a substantially similar industrial standard;

• proposed devices will be demonstrated to be substantially similar in design to models that have been previously tested for.seismic effects in excess of the

-5-plant design basis at the locations where the instruments will be installed (g-levels and frequency ranges); or

• the capability to withstand seismic motion consistent with that of existing design basis loads at the installed locations will be demonstrated. 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 such that following a seismic event, the instrument will maintain its required accuracy. 3.4 Independence The OIP states, in part, that The primary instrument channel will be redundant to and independent of the backup instrument channel. 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 sentto the location(s) of the readout devices, and the independence of the displays.

-6-3.5 Power supplies The OIP states, in part, that RAI-7 The primary and backup channels will be powered from dedicated batteries and local battery chargers. The battery chargers for both channels will normally be powered from non-safety related 120V AC power. Minimum battery life of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> will be provided. The battery systems will include provision for battery replacement should the battery charger be unavailable following the event. During the loss of normal power the battery chargers will be connectable to another 120V AC power source. This will be from portable generators stored onsite, consistent with the reasonable protection requirements associated with NEI 12-06 (Reference 5), or from generators deployed from off-site by the mitigating strategies resulting from Order EA-12-049, at approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the event.

• Please provide the following: a) A description of the different electrical AC power sources and capacities 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 l.Jninterruptible Power Supply (UPS)), 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 (BOB) event for the minimum duration needed, consistent with the plant mitigation strategies for BOB external events (Order EA-12-049). 3.6 Accuracy The OIP states, in part, that The accuracy will be consistent with the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02. Instrument channels will be designed such that they will maintain their des!gn accuracy following a power interruption or change in power source without_ recalibration. Accuracy will consider SFP conditions, e.g., saturated water, steam environment, or concentrated borated water. Additionally, instrument accuracy will be sufficient to allow trained personnel to*determine when the actual water level exceeds the specified lower level of each indicating range (levels 1, 2 and 3) without conflicting or ambiguous indication. The accuracy will consider the resolution requirements of Figure 1 of NEI 12-02.

-7-Please provide the following: a) An estimate of the expected instrument channel accuracy performance (e.g., in %span) 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. 3.7 Testing The OIP states, in part, that Testing will be consistent with the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02. Instrument channel design will provide for routine testing and calibration that can be performed in-situ consistent with Order EA-12-051 and the guidance in NEI 12-02. Details will be determined during the engineering and design phase. Additional testing and calibration information is provided in Section XV of this plan. _ 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 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 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.

-8 -3.8 Display The OIP states, in part, that RAI-10 Credited SFP water level indication will be provided in the common Control Room. The display will be consistent with 'the guidelines of NRC JLD-ISG-2012-03 and NEI 12-02. Pre-event indication will be continuous. Post-event indication may be continuous or intermediate. The requirement for continuous or intermittent indication and the frequency of readings will be determined during the engineering and design phase. Please provide the following: a) The specific location for the primary and. backup instrument channel displays. b) If the location for the backup displays is other than the common Control Room, please 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 location selected enables the information from these instruments to be considered "promptly accessible" to various drain-down scenarios and external events. 4.0 PROGRAM FEATURES 4.1 Procedures The OIP states, in part, that RAI-11 Procedures will be developed using guidelines and vendor instructions to address the maintenance, operation, and abnormal response issues associated with the new SFP instrumentation. Procedures will address a strategy to ensure SFP water level addition is initiated at an appropriate time consistent with implementation of NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide (References 5 and 7). 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.

-9 -4.2 Testing and Calibration The OIP states, in part, that RAI-12 Processes will be established and maintained for scheduling and implementing necessary testing and calibration of the primary and backup SFP water level instrument channels to maintain the instrument channels at the design accuracy. Testing and calibration of the instrumentation will be consistent with vendor recommendations and any other documented basis. Calibration will be specific to the mounted instrument and the monitor. Out of service time as identified in NEI 12-02 will be incorporated consistent with the programmatic process used for compliance with NRC Order EA-12-049, Issuance of Order to Modify Licenses with Regard to Requirements forMitigation Strategies for Beyond-Design* Basis External Events (Reference 2). Functionality testing will be performed at the frequency specified in NEI 12-02. Additional testing and calibration information is provided in Section XI of this plan. 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. fnclude 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.

G. Gellrich -2-If you have any questions regarding this issue, please contact me at (301) 415-1016 .. Sincerely, /RAJ Nadiyah S. Morgan, Project Manager Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-317 and 50-318 Enclosure: RAI cc w/encl: Distribution via Listserv DISTRIBUTION: PUBLIC LPL 1-1 R/F RidsNrrDoriDpr RidsOGCMaiiCenter DRahn RidsNrrDorllpl1-1 RidsNrrLAKGoldstein RidsRgn1 MaiiCenter RidsNrrDssSBPb RidsNrrPMCalvertCiiffs RidsAcrsAcnw_MaiiCTR MWaterman, RES CRoque-Cruz, NRR ADAMS A ccess1on N ML 13164A393 o.: *S ee memo ae ay ' d t d M 24 2013 OFFICE LPLI-1/PM LPLI-1/LA DSS/SBPB/BC LPLI-1/BC NAME NMorgan KGoldstein GCasto RBeall (A) DATE 06/18/13 06/18/13 05/24/2013* 06/19/13 OFFICIAL RECORD COPY