0CAN071301, Response to Request for Additional Information for Overall Integrated Plan in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation

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Response to Request for Additional Information for Overall Integrated Plan in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation
ML13207A269
Person / Time
Site: Arkansas Nuclear  Entergy icon.png
Issue date: 07/25/2013
From: Browning J G
Entergy Operations
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
0CAN071301, EA-12-051
Download: ML13207A269 (17)


Text

S'Entergy--

Entergy Operations, Inc.1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Jeremy G. Browning Vice President, Operations Arkansas Nuclear One OCAN071301 July 25, 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852

SUBJECT:

Response to Request for Additional Information (RAI) for the Overall Integrated Plan (OIP) in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool (SFP) Instrumentation Arkansas Nuclear One -Units 1 and 2 Docket Nos. 50-313 and 50-368 License Nos. DPR-51 and NPF-6

REFERENCES:

1. NRC Order Number EA-12-051, Order Modifying Licenses with Regard to Reliable SFP Instrumentation, dated March 12, 2012 (OCNA031207) (ML12054A679)
2. Entergy letter to NRC, OIP in Response to March 12, 2012, Commission Order Modifying License with Regard to Reliable SFP Instrumentation (Order Number EA-12-05 1), dated February 28, 2013 (OCAN021303) (ML1 3063A01 5)3. NRC letter to Entergy, RAI for the OIP in Response to the Commission Order Modifying Licenses with Regard to Requirements for Reliable SFP Instrumentation (Order Number EA-12-051), dated June 26, 2013, (0CNA061308)(ML1 3156A313)

Dear Sir or Madam:

On March 12, 2012, the NRC issued an order (Reference

1) to Entergy Operations, Inc.(Entergy).

Reference I required submission of an Overall Integrated Plan which was provided via Reference

2. By Reference 3, the NRC issued RAIs due within 30 days of the date of Reference
3. The attachment provides the responses to these RAIs for Arkansas Nuclear One (ANO), Units 1 and 2. The RAI responses provided in the attachment are based on the current preliminary design information/vendor input which is subject to change as the design is finalized.

0CAN071301 Page 2 of 3 This letter contains no new regulatory commitments.

Should you have any questions concerning the content of this letter, please contact Stephenie Pyle at 479.858.4704.

I declare under penalty of perjury that the foregoing is true and correct. Executed on July 25, 2013.Sincerely, JGB/nbm

Attachment:

ANO SFP Order RAI Responses cc: Mr. Arthur T. Howell Regional Administrator U. S. Nuclear Regulatory Commission, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 U. S. Nuclear Regulatory Commission Attn: Director, Office of Nuclear Reactor Regulation One White Flint North 11555 Rockville Pike Rockville, MD 20852 NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Kaly Kalyanam One White Flint North, MS 0-8 B1 11555 Rockville Pike Rockville, MD 20852 U. S. Nuclear Regulatory Commission Attn: Robert J. Fretz Jr.One White Flint North, MS 4A15A 11555 Rockville Pike Rockville, MD 20852 0CAN071301 Page 3 of 3 U. S. Nuclear Regulatory Commission Attn: Robert L. Dennig One White Flint North, MS 10E1 11555 Rockville Pike Rockville, MD 20852 U. S. Nuclear Regulatory Commission Attn: Ms. Lisa M. Regner One White Flint North, MS 11 F1 11555 Rockville Pike Rockville, MD 20852 U. S. Nuclear Regulatory Commission Attn: Mr. Blake A. Purnell One White Flint North, MS 12D20 11555 Rockville Pike Rockville, MD 20852 U. S. Nuclear Regulatory Commission Attn: Mr. Steven R. Jones One White Flint North, MS 10A1 11555 Rockville Pike Rockville, MD 20852 Attachment to OCAN071301 Arkansas Nuclear One (ANO) Spent Fuel Pool (SFP) Order Request for Additional Information (RAI) Responses Attachment to OCAN071301 Page 1 of 10 ANO SFP Order RAI Responses RAI-1 Please provide 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 SFP level, with respect to the Level 1, Level 2, and Level 3 datum points.The requested information is provided in Figure 1 for ANO-1 and Figure 2 for ANO-2.The figures indicate Levels 1, 2, and 3 as well as the approximate location of the proposed mounting bracket incorporating the Seismic Category I attachment.

The sensor is a perforated tubular coaxial waveguide that provides continuous level measurement axially and is sensitive over its entire length. These sketches apply to both the primary and backup channels.The SFP level lower instrument span or probe bottom extends down to at least three inches below the upper limit of the range of Level 3 to account for channel accuracy or instrument loop uncertainty.

Therefore, the SFP level probe bottom/span extends down to at least elevation 376'-8.5675" for ANO-1 (see Figure 1) and 379'-0.3125" for ANO-2 (see Figure 2). The SFP level upper instrument span, at a minimum, includes normal water level high alarm. Note that Level 3 datum line is shown in accordance with Nuclear Energy Institute (NEI) 12-02 Revision 1, Industry Guidance for Compliance with NRC Order EA- 12-05 1, "To Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," relative to the top of the rack; the top of the fuel is not shown.RAI-2.a Please provide 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.The loading on the probe mount and probe body includes both seismic and hydrodynamic loading using seismic response spectra that bounds the ANO units'design basis maximum seismic loads applicable to the installation location(s).

The static weight load is also accounted for in the modeling described below but is insignificant in comparison to seismic and hydrodynamic loads. Analytic modeling is being performed by the instrument vendor using Institute of Electrical and Electronic Engineers (I EEE)-344:2004 methodology.

The simple unibody structure of the probe assembly make it a candidate for analytic modeling and the dimensions of the probe and complex hydrodynamic loading terms in any case preclude meaningful physical testing.

Attachment to 0CAN071301 Page 2 of 10 A detailed computational SFP hydrodynamic model has been developed for the instrument vendor by Numerical Applications, Inc., author of the GOTHIC computational fluid dynamics code. The computational model accounts for multi-dimensional fluid motion, pool sloshing, and loss of water from the pool.Seismic loading response of the probe and mount is separately modeled using finite element modeling software.

The GOTHIC-derived fluid motion profile in the pool at the installation site and resultant distributed hydrodynamic loading terms are added to the calculated seismic loading terms in the finite element model to provide a conservative estimate of the combined seismic and hydrodynamic loading terms for the probe and probe mount, specific to the chosen installation location for the probe.RAI-2.b Please provide 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.

The proximal portion of the level probe is designed to be attached near its upper end (refer to Figure 3) to a Seismic Category I mounting bracket configured to suit the requirements of a particular SFP. The bracket may be bolted and/or welded to the SFP deck and/or SFP liner/wall according to the requirements of the particular installation per Seismic Category I requirements.

Installation maintains the level probe and electrical connection/cable below the elevation grade of the SFP area curbing that rises above the elevation grade of the SFP floor.RAI-2.c Please provide 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.See RAI-2.b response above.RAI-3.a Please provide 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 (BDB) ambient temperature, humidity, shock, vibration, and radiation conditions.

As stated in NEI 12-02 and in the SFP Instrumentation (SFPI) Overall Integrated Plan (OIP) provided by 0CAN021303, dated February 28, 2013 (ML13063A015),"Components in the area of the SFP will be designed for the temperature, humidity, and radiation levels expected during normal, event, and post-event conditions...." Components in other areas are planned to be designed for their corresponding maximum conditions.

The discussion below describes the testing and qualification intended to demonstrate equipment reliability as needed for the expected conditions associated with the SFP level channel active components (signal processor and probe assembly including vendor-supplied hard-line coaxial cable pigtail).

Class 1 E nuclear-Attachment to OCAN071301 Page 3 of 10 qualified interconnecting coaxial cable is planned to be utilized between the vendor-supplied probe coaxial cable pigtail and the signal processor

/ display located in the main control room.Temperature:

Signal processor:

Designed for mild environment installation.

Physical testing in an environmental chamber to demonstrate normal operation at the operating temperatures specified for the instrument.

Probe assembly:

Qualification by materials properties and use history of substantially similar probe designs in steam generator applications at significantly higher temperatures and pressures and saturated steam environments.

Humidity: Signal processor:

Designed for mild environment installation.

Physical testing in an environmental chamber to demonstrate normal operation at the operating humidity specified for the instrument.

Probe assembly:

Qualification by materials properties and use history as noted above.Shock: Signal processor:

Physical testing to commercial and/or military standards using shake-table and drop testing.Probe assembly:

Finite element analysis in conjunction with seismic modeling described above.Vibration:

Signal processor:

Physical testing to applicable commercial and/or military standards using shake-table and drop testing.Probe assembly:

The probe assembly and bracket together form a simple static unibody structure with intrinsic vibration resistance that is additionally subject to substantial damping due to the surrounding water medium. This is planned to be modeled using finite element modeling in conjunction with seismic modeling described above.Radiation:

Signal processor:

The electric field perturbation (EFP) signal processor is installed in a mild environment with radiation levels similar to background radiation, with the acknowledgement that the radiation limit for the EFP is similar to other commercial-grade complementary-metal-oxide-semiconductor (CMOS)-based electronics.

Radiation testing is not planned. It should be noted that the instrument performs self-diagnostics before measurements are obtained and the electronics are easily accessible for periodic replacement.

Probe assembly:

Materials properties qualification is used.

Attachment to OCAN071301 Page 4 of 10 RAI-3.b Please provide 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.

Signal processor (electronics):

Triaxial shake-table testing is planned to be performed by the vendor to envelope seismic category 1 safe shutdown earthquake (SSE)conditions or ANO design basis maximum seismic loads (relative to the location where the equipment is mounted) using IEEE-344:2004 methodology.

Probe assembly (level sensor): Seismic and hydrodynamic finite element analysis is performed by the vendor using relevant I EEE-344:2004 methodology (using enveloping seismic category 1 SSE conditions or ANO design basis maximum seismic loads relative to the location where the equipment is mounted), as described in the RAI-2.a response.RAI-3.c Please provide a description of the specific method or combination of methods that will be used to confirm the reliability of the permanently installed equipment following seismic conditions to maintain its required accuracy.With respect to the probe assembly, combined seismic and hydrodynamic analysis is planned to be used to demonstrate that the probe waveguide's geometric dimensions do not change significantly as a result of the seismic conditions.

In the absence of alteration to the geometric configuration of the probe waveguide there is no mechanism for seismic excitation of the probe assembly to alter system accuracy.The accuracy of system electronics is demonstrated following seismic excitation as part of the seismic testing protocol.RAI-4.a Please provide 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.

SFP level measurement system channel independence reasonably precludes (or minimizes to the extent practicable) the potential for a common- cause event to adversely affect both channels as described in the 0IP Section 10 (referencing Sections 6, 7, and 11 and QIP Attachments 1, 2, and 3) summarized as follows. Independence requirements are achieved by incorporation of two permanently installed, physically independent, and physically separated channels (with channel separation in accordance with existing plant design basis requirements) which incorporate independent plant power sources [not only originating from different buses (NEI 12-02 required) but also from different power divisions (NEI 12-02 preferred)]

as well as channel-specific stand-alone replaceable battery power (NEI 12-02 acceptable in and of itself) and which Attachment to 0CAN071301 Page 5 of 10 also incorporate channel interconnecting cabling routed in seismically mounted raceway.Each level measurement channel is physically separate and physically independent from level sensor through the display/read-out device. Each channel includes a level sensor in the SFP, display in the main control room, stand-alone replaceable batteries as backup to normal power sources, and interconnecting cabling between the level sensor and display. In the vicinity of the SFP [or the area potentially subject to a BDB external event (BDBEE)], level sensors and cabling maintain spatial separation to minimize the potential for falling debris or missiles to impact both channels with level sensors located near opposite corners of the SFP (further taking advantage of inherent debris and missile protection near SFP corners and generally below the SFP floor/wall elevation) and with cable routing both maintaining this relative separation and incorporating seismically mounted protective metal raceway until exiting the SFP area. Once exiting the SFP area, cables are routed in seismically qualified plant structures within seismically mounted raceway. In the main control room, display/read-out/signal-processing enclosures and their associated backup battery enclosures are seismically mounted.RAI-4.b Please provide 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.See RAI-4.a response above.RAI-5.a Please provide the sample rate under intermittent monitoring conditions and explain if the sample rate is determined by the instrument, or by plant procedures.

Sample rate when the instrument is under battery power is determined by the instrument and/or plant procedures according to operator preference.

Sample rate can be set so that the battery life extends to the desired duration of use following loss of normal power. The instrument is equipped in its standard configuration with batteries sufficient to support automated intermittent and on-demand sampling at an estimated average sample rate of at least one sample per three-to-five minutes for at least seven days, or proportionately more rapid sampling over shorter time periods. The instrument configuration is planned to be established for an automated sample rate when under battery power consistent with seven days continuous operation.

See RAI-5.b response below for additional information.

Attachment to OCAN071301 Page 6 of 10 RAI-5.b 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 BDBEE for the minimum duration needed, consistent with the plant Diverse and Flexible Coping Strategies (FLEX) Program plans.The sample rate estimates have been developed by the vendor using conservative instrument power requirements and measured battery capacity with draw-downs during and following exposure of the batteries to their maximum operating temperature for up to seven days. The instrument configuration is planned to be established for an automated sample rate when under battery power consistent with seven days continuous operation.

Permanent installed battery capacity for seven days continuous operation is planned consistent with NEI 12-02 duration without reliance on or crediting of potentially more rapid FLEX Program power restoration.

Batteries are readily replaceable via spare stock without the need for recalibration to maintain accuracy of the instrument.

These measures ensure adequate power capacity and margin.RAI-6.a Please provide an estimate of the expected instrument channel accuracy performance (e.g., in percentage of calibrated span) under both a) normal SFP level conditions (approximately Level 1 or higher) and b) at the BDB 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.The SFP level instrument channel accuracy across the entire measured span (including Levels 1, 2, 3) under all applicable conditions

[i.e., normal as well as BDBEE (radiation, temperature, humidity, post-seismic, and post-shock)]

is planned to be specified to be< three inches. Minimum level sensor range or measured level span is depicted on Figure 1 for ANO-1 (24'-3.4325")

and Figure 2 for ANO-2 (22'-7.6875").

As such, minimum instrument channel accuracy in terms of percent measured level span is approximately 1.03% span for ANO-1 and 1.10% span for ANO-2. This is a conservative bounding instrument channel accuracy with the vendor estimating expected instrument channel accuracy to be considerably better (i.e., vendor expected accuracy is approximately one-third of the above bounding accuracy).

RAI-6.b Please provide 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.In general relative to normal operating conditions, any applicable calibration procedure tolerances (or acceptance criterion) are planned to be established based on manufacturer's stated/recommended reference accuracy (or design accuracy).

The methodology used is planned to be captured in plant procedures and/or programs which are yet to be developed.

Attachment to OCAN071301 Page 7 of 10 RAI-7.a Please provide 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.The instrument automatically monitors the integrity of its level measurement system using in-situ capability.

Deviation of measured test parameters from manufactured or as-installed configuration beyond a configurable threshold prompts operator intervention.

Periodic calibration checks of the signal processor electronics to extrinsic National Institute of Standards and Technology (NIST)-traceable standards can be achieved through the use of standard measurement and test equipment.

The probe itself is a perforated tubular coaxial waveguide with defined geometry and is not calibrated.

It is planned to be periodically inspected electromagnetically using time-domain reflectometry at the probe hardline cable connector to demonstrate that the probe assembly meets manufactured specification and visually to demonstrate that there has been no mechanical deformation or fouling.RAI-7.b Please provide 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.

Each instrument electronically logs a record of measurement values over time in non-volatile memory that is compared to demonstrate constancy, including any changes in pool level, such as that associated with the normal evaporative loss/refilling cycle.The channel level measurements can be directly compared to each other (i.e., regular cross-channel comparisons).

Any existing permanently installed SFP level instrumentation or other direct measurements of SFP level may be used for diagnostic purposes if cross-channel comparisons are anomalous.

RAI-7.c Please provide a description of how functional checks will be performed, and the frequency at which they will be conducted.

Please 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.Operator performance tests (functional checks) are automated and/or semi-automated (requiring limited operator interaction) and are performed through the instrument menu software and initiated by the operator.

There are a number of other internal system tests that are performed by system software on an essentially continuous basis without user intervention but can also be performed on an on-demand basis with diagnostic output to the display for the operator to review. Other tests such as menu button tests, Attachment to OCAN071301 Page 8 of 10 level alarm, and alarm relay tests are only initiated manually by the operator.

Operator performance checks are described in detail in the Vendor Operator's Manual, and the applicable information is planned to be contained in plant operating procedures.

Operator performance tests are planned to be performed periodically as recommended by the equipment vendor, for instance quarterly but no less often than the calibration interval of two years.Channel functional tests per operations procedures with limits established in consideration of vendor equipment specifications are planned to be performed at appropriate frequencies established equivalent to or more frequently than existing SFPI.Manual calibration tests are as described above in RAI-7.a response.Manual calibration and operator performance checks are planned to be performed in a periodic scheduled fashion with additional maintenance on an as-needed basis when flagged by the system's automated diagnostic testing features.Channel calibration tests per maintenance procedures with limits established in consideration of vendor equipment specifications are planned to be performed at frequencies established in consideration of vendor recommendations.

RAI-7.d Please provide 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 the accurately and reliably perform their functions when needed.Periodic (e.g., quarterly or monthly) review of the system level history and log files and routine attention to any warning message on the system display is recommended by the vendor. Formal calibration checks are recommended by the vendor on a two-year interval to demonstrate calibration to external NIST-traceable standards.

Formal calibration check surveillance interval and timing would be established consistent with applicable guidance [i.e., NEI 12-02 Section 4.3; on a refueling outage interval basis and within 60 days of a planned refueling outage considering normal testing scheduling allowances (e.g., 25%)]. Items such as system batteries are planned to be assessed under the Preventive Maintenance (PM) Program for establishment of replacement frequency.

Surveillance/PM timing/performance are planned to be controlled via tasks in the PM Program.

Attachment to 0CAN071301 Page 9 of 10 RAI-8 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.

Vendor recommended inspection, maintenance, and repair procedures for the EFP liquid level measurement system have been developed through the vendor's 30-year experience developing and manufacturing liquid level measurement and cable testing instrumentation.

These are for the most part specific to the system's proprietary electronics, subject to relevant industry standards for electronics fabrication and inspection and vendor's quality management system.Where relevant, standards for naval shipboard liquid level indicating equipment have been used to develop procedures for operation, abnormal response, and administrative controls.Portable instrumentation is not utilized.

Both primary and backup SFPI channels incorporate permanent hard-wired installation.

The specific procedures to be used to capture the required activities described in this RAI response have not yet been developed but are planned to be developed in accordance with the vendor recommendations and Entergy processes and procedures.

RAI-9.a Please provide 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.

See RAI-6, 7, and 8 responses for related descriptions of associated maintenance and testing program details. SFPI channel/equipment maintenance/preventative maintenance and testing program requirements to ensure design and system readiness are planned to be established in accordance with Entergy's processes and procedures and in consideration of vendor recommendations to ensure that appropriate regular testing, channel checks, functional tests, periodic calibration, and maintenance is performed (and available for inspection and audit). Subject maintenance and testing program requirements are planned to be developed during the SFPI modification design process.

Attachment to OCAN071301 Page 10 of 10 RAI-9.b Please provide 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.

Both primary and backup SFPI channels incorporate permanent installation (with no reliance on portable, post-event installation) of relatively simple and robust augmented quality equipment.

Permanent installation coupled with stocking of adequate spare parts reasonably diminishes the likelihood that a single channel (and greatly diminishes the likelihood that both channels) is (are) out-of-service for an extended period of time.Planned compensatory actions for unlikely extended out-of-service events are summarized as follows:# Channel(s)

Out-of-Service 1 2 Required Restoration Action Restore channel to functional status within 90 days (or if channel restoration not expected within 90 days, then proceed to Compensatory Action)Initiate action within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore one channel to functional status and restore one channel to functional status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Compensatory Action if Required Restoration Action not completed within Specified Time Immediately initiate action in accordance with Note below Immediately initiate action in accordance with Note below Note: Present a report to the on-site safety review committee within the following 14 days. The report shall outline the planned alternate method of monitoring, the cause of the non-functionality, and the plans and schedule for restoring the instrumentation channel(s) to functional status.RAI-9.c Please provide 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.See RAI-9.b response above.

POOL LEVELS AND REFERENCES ELEVATION REFERENCE HAIGH LEVELEk &AR NORMA P .O....E[ -- ---- ---404'-0*...............

401'-0*----------------

1 400'-6"-- ----- M -0...LQ.WAL"RILWkW 0 0 C LU E 399'-6" 397'-5.21" E-607 R13 Embedded Conduit Auxiliary Building Plan at EL. 404'-0" STM 1-07 R8 Spent Fuel Cooling System (Top Min. Sensitive Range, Normal Level High Alarm)STM 1-07 R8 Spent Fuel Cooling System OP-1502.004 R50 ANO1 Refueling STM 1-07 R8 Spent Fuel Cooling System OP-1 502.004 R50 ANO1 Refueling M-235 Sh. 1 R68 P&ID Spent Fuel Pool Cooling SPEC-ANO-M-555 R2 ULD-0-SYS-03 R5 15-FPC-14 Sh. 1 R5 Crane Tech Paper #410, 25th Print 1991 Horizontal pipe centedine 397'-0"; Pipe Sched, 10S with I.D. 10.42" & 1/2 I.D. 5.21"------ 385'-11.5675"----- 377"-0.1875"...... 376'-8.5675"..... 375'-11.5675" Top of Liner.... 362'-0.1875" Top of Concrete 362'-0" NEI 12-02 (Level 3 + 10')C-214 R9 Aux. Bldg. Sections -B and C Bottom Min. Sensitive Range, 3" below LEVEL 3 upper limit 1W062A-017(4)

RO SFP Rack Elevation

-165.5" + 1.88" high (13'-11.38")

C-231 Sh. 1 RI 1 SFP Liner Plan & Sections C-206 Sh. I R17 Concrete Aux. Bldg. Plan at EL. 404'-0" FIGURE 1 (ANO Unit 1 SFP Elevation View with Levels Indicated)

POOL LEVELS AND REFERENCES MOUNTING BRACKET ELEVATION OPERATING FLOOR LEVEL -404'-0"---------- -V .A ...........................................

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I378'-3.31 275 WTroM OF P LEVE Top of Liner REFERENCE E-2869 Sh. I R49 Containment Aux. Bldg. Area 24 at EL. 404'-0" OP-1015.003B R73 Unit 2 Operations Log At. B pg. 30 of 46 (Top Min. Sensitive Range, Normal Level High Alarm)M-2235 Sh. 1 R73 P&ID Fuel Pool System OP-1015.003B R73 Unit 2 Operations Log Att. B pg. 30 of 46 M-2235 Sh. I R73 P&ID Fuel Pool System ANO2 SAR Amd 24 9.1.3.3.1 SFP Cooling Sys.ANO2 SAR Amd 24 Fig. 9.1-1 SFP Sys.ST 2-07 R20 Spent Fuel Systems OP-2502.001 R48 Refueling Shuffle OP-2503.003 R53 Op of Fuel Equip.2HCC-53-1 Sh. 1 R18 NEI 12-02 (Level 3 + 10')Bottom Min. Sensitive Range, 3" below LEVEL 3 upper limit M-2001-H1-391 Sh. 2 Extract 195.125- (16'-3.125")

C-2251 R17 Aux. Bldg. Spent Fuel Pool Liner Plate Plan and Sections C-2251 R17 Aux. Bldg. Spent Fuel Pool Liner Plate Plan and Sections---------- ----------------------

-- -- -362'-0.1875" I Top of Concrete 362'-0" FIGURE 2 (ANO Unit 2 SFP Elevation View with Levels Indicated) 0 0 0 0-PROBE HEAD-FLANGE MOUNT Figure 3 (Probe Schematic)