Text

Compliance Letter in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order EA-12-051)
	ML15342A113
Person / Time
Site:	Millstone
Issue date:	12/03/2015
From:	Mark D. Sartain; Dominion Nuclear Connecticut
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	14-390D, EA-12-051
	Download: ML15342A113 (17)
	v • d • e

Dominion Nuclear Connecticut, Inc. J,?II DoUmIN.lOfl 5000 Dominion Boulevard, Glen Allen, VA 23060 Web Address: www.dom.com December 3, 2015 U. S. Nuclear Regulatory Commission Serial No.: 14-3900 Attention: Document Control Desk NLOS/DEA: R0 Washington, DC 20555-0001 Docket No.: 50-336 License No.: DPR-65 DOMINION NUCLEAR CONNECTICUT. INC.

MILLSTONE POWER STATION UNIT 2 COMPLIANCE LETTER IN RESPONSE TO THE MARCH 12. 2012 COMMISSION ORDER MODIFYING LICENSES WITH REGARD TO RELIABLE SPENT FUEL POOL INSTRUMENTATION (ORDER EA-12-051)

References:

1. NRC Order Number EA-12-051, "Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," dated March 12, 2012

2. Dominion Nuclear Connecticut, Inc's 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), dated March 2, 2015 (Serial No. 12-390B)

On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Order EA-12-051, "Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," [the Order] (Reference 1) which required the installation of 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. Condition C.3 of the Order requires all licensees to notify the Commission when full compliance with the requirements of the Order is achieved.

This letter provides notification that Dominion Nuclear Connecticut, Inc. (DNC) has completed the requirements of the Order and is in full compliance with the Order for Millstone Power Station Unit 2. The attachments to this letter provide: 1) a summary of how the requirements of the Order were met, and 2) a design elements summary. The responses to Spent Fuel Pool Level Instrumentation (SFPLI) requests for additional information (RAIs) and Safety Evaluation Review Item. 6 for Order EA-12-051 were provided for Millstone Unit 2 in DNC's fourth Six-Month Status Report dated March 2, 2015 (Reference 2).

4o

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Page 2 of 3 Should you have any questions or require additional information, please contact Ms. Diane E. Aitken at (804) 273-2694.

Respectfully, Mark Sartain Vice President - Nuclear Engineering l"" V,wkiL:NWi.

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, . OTAR**PUSLIC) 4 Commowe.*thof Vi'rginia I. e g,#1-40542 " I COMMONWEALTH OF VIRGINIA

y msinE**May 31, 2018 COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. Mark D. Sartain, who is Vice President - Nuclear Engineering, of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.

Ackowldgd bfor mths Ird Acnoldgdbeor e hs . day of , 2015.

My Commission Expires: .5 - ..I--1 . /

Notary Pubi Attachments:

1. Order EA-12-051 Compliance Requirements Summary

2. Compliance Design Elements Summary - Millstone Power Station Unit 2 Commitments contained in this letter: Nn None

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Page 3 of 3 cc: U. S. Nuclear Regulatory Commission, Region I Regional Administrator 2100 Renaissance Blvd.

Suite 100 King of Prussia, PA 19406-2713 Mr. R. Guzman NRC Project Manager - Millstone U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 C-2 11555 Rockville Pike Rockville, MD 20852-2738 Mrs. Lisa M. Regner U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 011 F1 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Blake A. Purnell U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 012 D20 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Steven R. Jones U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 010 Al 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 1 Millstone Power Station Unit 2 Order EA-12-051 Compliance Requirements Summary Dominion Nuclear Connecticut, Inc.

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 1 Millstone Power Station Unit 2 Order EA-1 2-051 Compliance Requirements Summary BACKGROUND Millstone Power Station Unit 2 (MPS2) developed an Overall Integrated Plan (QIP)

(Reference 1), documenting how the requirements for reliable spent fuel pool level instrumentation (SFPLI) would be achieved, in response to Order EA-12-051, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," (Reference 2). The MPS20OIP was submitted to the Nuclear Regulatory Commission (NRC) on February 28, 2013 and was supplemented by Six-Month Status Reports (References 3, 4, 5, 6, and 7), in accordance with Order EA-12-051 (the Order). By letter dated November 1, 2013, the NRC provided its Interim Staff Evaluation (ISE) and Request for Additional Information (RAI) Regarding Order EA-12-051 (Reference 8).

MPS2 completed installation of two independent spent fuel pool (SEP) level measurement channels supplied and qualified by Westinghouse in September 2015 in response to Reference 2.

Completion of the elements identified below for MPS2, as well as References 1, 3, 4, 5, 6, and 7, document full compliance with Order EA-12-051 for MPS2.

COMPLIANCE

SUMMARY

NRC RAI, ISE AND AUDIT ITEMS - COMPLETE During the ongoing audit process (Reference 9), Dominion Nuclear Connecticut Inc. (DNC) provided responses for the following items for MPS2:

RAl

ISE Open Items

ISE Confirmatory Items

Licensee Identified Open Items

Audit Questions

Safety Evaluation Review Items The NRC report, "The Millstone Station, Units 2 and 3 - Report for the Onsite Audit Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Pool Instrumentation Related to Orders EA-12-049 and EA-12-051," (Reference 10) delineated the items reviewed during the Millstone onsite audit. Reference 10 identified one additional audit item related to SFPLI for MPS2, specified as Safety Evaluation Review Item 6 (SE 6), which was added following the audit and required supplemental information to be submitted to the NRC.

Page 1 of 4

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 1 As requested by the NRC, DNC's responses, or references to the source document for the responses, to the SFPLI RAIs and SE 6 were provided for MPS2 in the fourth Six-Month Status Report dated March 2, 2015 (Reference 6). It is DNC's position that no further actions related to the SEPLI RAIs or SE 6 are required for MPS2.

MILESTONE SCHEDULE -- ITEMS COMPLETE MPS2 Milestone Completion Date Submit Overall Integrated Plan February 2013 Commence Engineering and Design March 2013 Complete Engineering and Design September 2014 Complete Procurement of SFP Instruments August 2014 Commence Installation of SFP Instruments February 2015 Level Measurement System Functional September 2015 iDENTIFICATION OF LEVELS OF REQUIRED MONITORING - COMPLETE MPS2 has identified the three required levels for monitoring SEP level in compliance with Order EA-12-051. These levels have been integrated into the site procedures for monitoring level during events and responding to loss of SEP inventory.

INSTRUMENT DESIGNED FEATURES - COMPLETE The design of the SEP level measurement instrumentation system installed at MPS2 complies with the requirements specified in Order EA-12-051 and described in NEI 12-02 "Industry Guidance for Compliance with NRC Order EA-12-051" (Reference 11). The instrumentation system has been installed in accordance with the station design control process.

The instruments have been arranged to provide reasonable protection against missiles. The instruments have been mounted to retain design configuration during and following the maximum expected ground motion. The instruments will be reliable during expected environmental and radiological conditions if the SEP is at saturation conditions for extended periods. The instruments are independent of each other and have separate and diverse power supplies. The instruments will maintain their designed accuracy following a power interruption and are designed to allow for routine testing and calibration.

The instrument display is readily accessible during postulated events and allows for SEP level information to be promptly available to decision makers.

Page 2 of 4

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 1 A more detailed Compliance Design Elements Summary of the design features identified in of Reference 2 is provided in Attachment 2 to this letter.

PROGRAM FEATURES - COMPLETE Training of personnel performing maintenance functions including calibration and surveillance associated with the SFP level instrument channels has been completed. Additional or continuing training is performed in accordance with an accepted training process as recommended in NEI 12-02, Section 4.1.

Operating procedures, for use of the SFP level instrument channels have been developed, and integrated with existing procedures. These procedures have been verified and are available for use in accordance with the site procedure control program.

Westinghouse guidelines (procedures and manuals) are currently available for use in conducting maintenance, calibration and testing of the SEP level instrument channels. Site-specific maintenance, calibration and testing procedures have been developed in accordance with the design control program, based on these vendor guidelines.

Site processes have been established to ensure the instruments are maintained at their design accuracy.

REFERENCES The following references support the MPS2 SEPLI Compliance Summary:

1. Millstone Power Station, "Unit 2 Overall Integrated Plan with regard to Reliable Spent Fuel Pool Implementation," February 28, 2013 (Serial No. 12-165B) (ML13064A012).

2. NRC Order Number EA-12-051, "Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," March 12, 2012.

3. "Dominion Nuclear Connecticut, Inc., 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)," dated August 23, 2013 (Serial No. 12-165D)

(ML13242A014).

4. "Dominion Nuclear Connecticut, Inc., 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)," dated February 28, 2014 (Serial No. 12-165D) (ML14069A011).

5. "Dominion Nuclear Connecticut, Inc., 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)," dated August 26, 2014 (Serial No.14-390)

(MLI14245A400).

Page 3 of 4

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 1

6. "Dominion Nuclear Connecticut, Inc., 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)," dated March 2, 2015 (Serial No. 14-3908)

(MLE 5069A230).

7. "Dominion Nuclear Connecticut, Inc., 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)," dated August 24, 2015 (Serial No. 14-390C)

(ML15244B182).

8. "Millstone Power Station, Units 2 and 3: NRC 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," dated October 29, 2013 (MLI13291A1 15).

9. NRC letter to All Operating Reactor Licensees and Holders of Construction Permits, "Nuclear Regulatory Commission Audits of Licensee Responses to Mitigation Strategies Order EA-12-049," dated August 28, 2013 (ML13234A503).

10."Millstone Power Station, Units 2 and 3 - Report for the Onsite Audit Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Instrumentation Related to Orders EA-12-049 and EA-12-051," dated November 17, 2014 (ML14275A017).

11.Nuclear Energy Institute (NEI) Report 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.

Page 4 of 4

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 2 Compliance Design Elements Summary Dominion Nuclear Connecticut, Inc.

Millstone Power Station Unit 2

Serial No. 14-3900 Docket No. 50-336 Compliance with EA-12-051 Attachment 2 Compliance Design Elements Summary In accordance with NRC Order EA-12-051, Attachment 2, "Requirements for Reliable Spent Fuel Pool Level Instrumentation at Operating Reactor Sites and Construction Permit Holders," Millstone Power Station Unit 2 (MPS2) shall have a reliable indication of the water level in associated spent fuel storage pool 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, This level is based on the elevation at which the top of the Spent Fuel Pool (SFP) cooling pump inlet suction lines penetrate the pool walls. It is the indicated level of greater than elevation 36'-0" plus the accuracy of the SFP Level Instrumentation (SEPLI) channel (Reference 1).

(2) Level that is adequate to provide substantial radiation shielding for a person standing on the spent fuel pool operating deck, and This elevation is approximately 10' above the top of the fuel racks. It is the indicated level of greater than elevation 23'-0" plus the accuracy of the SFP level instrument. This water level ensures there is sufficient depth such that any necessary operations in the vicinity of the SFP can be completed without significant dose consequences from direct gamma radiation from stored spent fuel (Reference 1).

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

This level corresponds to one foot above the highest point of any fuel rack seated in the SEP. It is the indicated level of elevation 14'-0", which is one foot above the highest point of any fuel rack in the SEP based on field measurements (elevation 13'-0"), plus the accuracy of the SEP level instrument. This is the water level at which the fuel remains covered (Reference 1).

1. The spent fuel pool 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.

Two independent, redundant instrument channels are installed. Both instrument channels are of the same technology, manufacturer, and model.

Page 1 of 8

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 2 The Westinghouse SFPLI system uses Guided Wave Radar (GWR) technology.

GWR level measurement instruments work based on the Time Domain Reflectometry (TDR) principle. The level measurement instrumentation sends low intensity microwave electromagnetic pulses along a flexible conductor where pulses travel at the speed of light. When the pulses reach the surface of the medium to be measured, a portion of the signal is reflected back to the electronics. The electronics calculate the SEP water level by measuring the time elapsed between the initial pulse and the reflected one. One complete measurement cycle is made up of several thousand pulses. The measurement cycles are made two times per second and processed by special filtering techniques before generating a current output proportional to the SEP water level. The current output of the electronics is representative of the measured level and converted for use in displaying level information.

1.2 Arrangement

The spent fuel pool level ins trument 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.

The level sensor probes in the pool are on opposite sides of the SFP and separated by a distance greater than the shortest length of a side of the pool. The transmitters and display cabinets for each channel are installed in separate locations within the Auxiliary Building. Instrumentation cables installed in the Auxiliary Building are routed independently in accordance with MPS2 design specifications to meet the physical separation requirements for redundant safety-related channels.

The concrete and steel superstructure of the Auxiliary Building above elevation 38'-6" provides protection against the tornado missile spectrum as defined in Final Safety Analysis Report (ESAR), Section 5.4.3.3.6. In addition, a defense-in-depth strategy is employed. The separation of the components of each independent channel provides additional reasonable protection against missiles. Per Section 3.2 of 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',"

(Reference 2) reasonable channel separation is maintained by separating the components of each channel by a distance comparable to the shortest length of a side of the pool. The sensors are located on opposite corners of the SEP and located greater than 25'-0" apart, the shortest width of the SEP. Additionally, the new equipment and associated cabling are not located within the line of sight of the steel rollup doors in the MPS2 Auxiliary Building (Reference 1).

Page 2 of 8

Serial No. 14-3900 Docket No. 50-336 Compliance with EA-12-051 Attachment 2

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 pooi structure.

All components of each instrument channel are mounted using Seismic Category I criteria except for the station I 2OVAC power feeds.

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).

The primary and backup instrument channel reliability has been demonstrated by design, analyses, and/or testing, as discussed below.

Conditions Beyond Design Basis (BDB) event environmental conditions were determined for temperature, humidity, and radiation levels in locations where instrument channel components are installed. These conditions form the basis for ensuring the equipment operates during and after a BOB event.

Temperature The probe, bracket, and coaxial cable are located in the Spent Fuel Pool area of the Auxiliary Building and are subject to abnormal BOB conditions in the SFP area up to 212 °F. The probe and bracket are comprised of stainless steel, which is inherently resistant to environmental effects. Westinghouse Design Verification Testing Summary Report, EQ-QR-269, "Design Verification Testing Summary Report for the Spent Fuel Pool Instrumentation System," (Reference 3) demonstrates that the probe, coaxial cable, and coupler are able to perform at a temperature of 212 °F for 185 hours0.00214 days 0.0514 hours 3.058862e-4 weeks 7.03925e-5 months . The coaxial cable installed in the Auxiliary Building is rated for 221 °F (105 °C).

The temperature ratings for the sensor electronics and display cabinets (transmitter, control box, Uninterruptible Power Supply (UPS), and display) are 120°F based on a continuous duty rating and 140 0F under abnormal conditions per Westinghouse report WNA-TR-03149-GEN (Reference 4). The Rockbestos power and instrumentation cables installed in the Auxiliary Building are rated for 194 0F (90 °C).

Page 3 of 8

Serial No. 14-3900 Docket No. 50-336 Compliance with EA-12-051 Attachment 2 Humidity Westinghouse report EQ-QR-269, demonstrates that the probe, coaxial cable, and coupler are able to perform in a 100% saturated steam environment for 185 hours0.00214 days 0.0514 hours 3.058862e-4 weeks 7.03925e-5 months .

Equipment testing for the sensor electronics and the level display cabinets under normal and abnormal conditions with humidity levels up to 95% was performed by Westinghouse. The results were documented in report EQ-QR-269. The sensor probe and mounting bracket are comprised of stainless steel, which is not adversely affected by relative changes in temperature, humidity, radiation, or continuous exposure to borated water.

Radiation Radiation test results supplied by Westinghouse in test report EQ-QR-269 have qualified the coupler and coaxial connecting cable to greater than 107 Rads.

The SFP level instrumentation electronics utilize commercial off-the-shelf components containing Complementary Metal Oxide Semiconductor (CMOS) devices which have been found to be capable of withstanding ionizing radiation dose levels up to 103 Rads as described in EPRI 1021067, "Nuclear Power Plant Equipment Qualification Reference Manual," Revision 1 (Reference 5), and discussed in RG 1.209, "Guidelines for Environmental Qualification of Safety-Related Computer Based Instrumentation and Control Systems in Nuclear Power Plants" (Reference 6). The calculated integrated dose for both the short-term post-BDB event and the long-term normal operating conditions is within the industry accepted limit, thus confirming the reliability of the permanently installed sensor transmitter equipment located within the Auxiliary Building under post-BOB event radiological conditions.

Shock and Vibration Components of both instrumentation channels are permanently installed and fixed to rigid, structural walls or floors of Seismic Category I structures and are not subject to anticipated shock or vibration inputs. The display enclosure utilizes a NEMA-4X rated stainless steel housing to aid in protecting internal components from vibration induced damage according to Westinghouse report WNA-TR-03149-GEN (Reference 4). Therefore, in accordance with Nuclear Regulatory Commission (NRC) Order EA-1 2-051, NEI guidance (Reference 2), and as clarified by the Interim Staff Guidance (Reference 7), the probe, coaxial cable, and mounting brackets are inherently resistant to shock and vibration loadings.

Page 4 of 8

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 2 Seismic The instrumentation meets the MPS2 design and licensing basis requirements for Seismic Category I components and includes consideration of static weight loads and hydrodynamic loads. Seismic testing has been performed by Westinghouse on the sensor probe, coaxial cable, transmitter, and display cabinet in accordance with IEEE 344-2004, "IEEE Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations" (Reference 8). Results of the seismic testing have been documented in Westinghouse Testing Summary Report EQ-QR-269 (Reference 3). Seismic and hydrodynamic qualification of the level sensor mounting bracket is shown by analysis in Westinghouse Calculation CN-PEUS-14-3 (Reference 9).

1.5 Independence

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

Independence of the instrument channels is achieved by the physical separation of components and use of separate station power sources. Each channel is powered by different lighting panels fed from different buses. The components for each channel have been physically installed in separate locations and the cable routes meet the physical safety-related separation guidelines within the MPS2 design specifications.

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 ac and dc 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.

The instrument channels are normally powered from separate 120VAC lighting panels that are powered from different 480VAC buses. Use of these power sources ensures that, during normal operating conditions, the loss of one bus will not result in the functional loss of both instrument channels.

Back-up power for each instrument channel is provided by a sealed lead acid battery located in each display cabinet, which is maintained in a charged state by commercial-grade UPS's (electrical switchover unit). At full charge, the batteries are capable of supporting the channel operations for approximately 101 hours0.00117 days 0.0281 hours 1.669974e-4 weeks 3.84305e-5 months or 4.2 days, per Westinghouse calculation WNA-CN-00300-GEN (Reference 10).

Onsite BDB equipment includes several small electric generators, which can provide, if necessary, a portable power source within the 4.2 day battery operating timeframe Page 5 of 8

Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 2 and maintain instrument channel operation until off-site resources can be deployed.

Each display cabinet is furnished with an external connection and manual transfer switch, which provides the ability to use an alternate 120 VAC power source to re-power the channel.

1.7 Accuracy

The ins trument channels shall maintain their designed accuracy following a power interruption or change in power source without recalibration.

The level measurement channels provide measurement accuracy to within +/- 3 inches of the actual surface of the SEP water. Actual instrument channel accuracy is documented within Westinghouse calculation WNA-CN-00301-GEN (Reference 11).

This accuracy is maintained without the need for recalibration following an interruption or change in power source as described in Westinghouse report WNA-TR-03 149 (Reference 4).

1.8 Testing

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

The new SFPLI system is comprised of fixed sensors, transmitters, and display cabinets. This system can be tested and calibrated in-situ without removing the sensor probe from the pool or removing other equipment from the permanently installed locations, or may be remotely calibrated using a calibration fixture.

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.

The level indicators are mounted within display cabinets installed in the Auxiliary Building. Level display indicator LI-7013 and display cabinet 0547 are located on the 25'-6" elevation of the Auxiliary Building in the Cable Vault Room near column lines K.6-15.9. Level indicator LI-7014 and display cabinet C3548 are located on the 36'-6" elevation of the Auxiliary Building in the East 480V Switchgear Room near column lines F.8-1 5.9.

The internal electronics of the display cabinets include an Electromagnetic Compatibility (EMC) surge protection filter, a 24 VDC3 power supply module, a 24 VDC3 UPS module (electrical switching unit), a 24 VDC Valve Regulated Lead Acid (VRLA) Absorbent Glass Mat (AGM) battery, a signal duplicator (4-20 mA loop splitter), a power selection switch, and a door mounted digital display indicator. The 5-digit level indicator displays SFP level in terms of "POOL LEVEL (FEET ABOVE FUEL RACKS)" to at least one decimal point (1/10 of a foot). The 4-20 mA signals Page 6 of 8

Serial No. 14-3900 Docket No. 50-336 Compliance with EA-12-051 Attachment 2 from the transmitters are scaled to encompass the entire measured range for the displays.

2. The spent fuel pooi 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.

To provide sufficient instructions for operation and use of the system by plant staff personnel, Knowledge Based Training is conducted during initial Operator Qualification and has been integrated into the Continuing Operations Training Program. Training includes FLEX Support Guideline, FSG-11, "Alternate SFP Makeup and Cooling" (Reference 12), that defines the actions to be taken upon observation of system level indications, including actions to be taken at the levels defined in NEI 12-02. FSG-1 1 also addresses the alternate power provisions for the SFP level instruments.

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.

Procedures for calibration and test, maintenance, repair, operation, and normal and abnormal responses have been provided by Westinghouse. Corresponding site-specific procedures have been developed based on these vendor guidelines (see 2.3 below) and a Recurring Task Evaluation (RTE) has been prepared and approved to evaluate, prepare, and implement the stated Preventative Maintenance procedures at the vendor recommended frequencies.

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.

Calibration and testing procedures necessary to verify that the system is within specified accuracy, is functioning as designed, and is properly indicating SFP level have been developed and implemented. Checks that the systems are indicating properly are performed on a regular basis.

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Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Attachment 2

References:

1. DC-MP2-13-01011, "Beyond Design Basis Spent Fuel Pool Level Instrument Installation / Millstone / Unit 2."

2. NEI 12-02, Rev. 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.

3. EQ-QR-269, "Westinghouse Design Verification Testing Summary Report."

4. WNA-TR-03149-GEN, "Westinghouse Final Summary Design Verification Report."

5. EPRI 1021067, "Nuclear Power Plant Equipment Qualification Reference Manual," Revision 1, September 16, 2010.

6. RG 1.209, "Guidelines for Environmental Qualification of Safety-Related Computer Based Instrumentation and Control Systems in Nuclear Power Plants," March 2007.

7. JLD-ISG-2012-03, Revision 0, Interim Staff Guidance, "Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation," August 2012.

8 IEEE 344-2004, "IEEE Recommended Practice for Seismic Qualification of Class I1E Equipment for Nuclear Power Generating Stations."

9. 59-0-W893-CN-PEUS-14-3, "Seismic Analysis of the SFP Mounting Bracket for Surry Power Station, Millstone Power Station Unit 3, & North Anna Power Station."

10. WNA-CN-00300-GEN, "Spent Fuel Pool Instrumentation System Power Consumption Calculation."

11. WNA-CN-00301-GEN, "Spent Fuel Pool Instrumentation System Channel Accuracy Analysis."

12. FLEX Support Guideline, FSG-11, Revision 0, "Alternate SFP Makeup and Cooling" Note: References I and 12 has been previously provided to the staff for review.

Other references are available for review upon request.

Page 8 of 8

Dominion Nuclear Connecticut, Inc. J,?II DoUmIN.lOfl 5000 Dominion Boulevard, Glen Allen, VA 23060 Web Address: www.dom.com December 3, 2015 U. S. Nuclear Regulatory Commission Serial No.: 14-3900 Attention: Document Control Desk NLOS/DEA: R0 Washington, DC 20555-0001 Docket No.: 50-336 License No.: DPR-65 DOMINION NUCLEAR CONNECTICUT. INC.

MILLSTONE POWER STATION UNIT 2 COMPLIANCE LETTER IN RESPONSE TO THE MARCH 12. 2012 COMMISSION ORDER MODIFYING LICENSES WITH REGARD TO RELIABLE SPENT FUEL POOL INSTRUMENTATION (ORDER EA-12-051)

References:

1. NRC Order Number EA-12-051, "Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," dated March 12, 2012

2. Dominion Nuclear Connecticut, Inc's 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), dated March 2, 2015 (Serial No. 12-390B)

On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Order EA-12-051, "Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," [the Order] (Reference 1) which required the installation of 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. Condition C.3 of the Order requires all licensees to notify the Commission when full compliance with the requirements of the Order is achieved.

This letter provides notification that Dominion Nuclear Connecticut, Inc. (DNC) has completed the requirements of the Order and is in full compliance with the Order for Millstone Power Station Unit 2. The attachments to this letter provide: 1) a summary of how the requirements of the Order were met, and 2) a design elements summary. The responses to Spent Fuel Pool Level Instrumentation (SFPLI) requests for additional information (RAIs) and Safety Evaluation Review Item. 6 for Order EA-12-051 were provided for Millstone Unit 2 in DNC's fourth Six-Month Status Report dated March 2, 2015 (Reference 2).

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Serial No. 14-390D Docket No. 50-336 Compliance with EA-12-051 Page 2 of 3 Should you have any questions or require additional information, please contact Ms. Diane E. Aitken at (804) 273-2694.

Respectfully, Mark Sartain Vice President - Nuclear Engineering l"" V,wkiL:NWi.

.. I II*

, . OTAR**PUSLIC) 4 Commowe.*thof Vi'rginia I. e g,#1-40542 " I COMMONWEALTH OF VIRGINIA

y msinE**May 31, 2018 COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. Mark D. Sartain, who is Vice President - Nuclear Engineering, of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.