RS-14-018, Second Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)

Second Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order No. EA-12-051)

ML14062A057
Person / Time
Site:	Byron
Issue date:	02/28/2014
From:	Kaegi G Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-051, RS-14-018
Download: ML14062A057 (27)

Text

ti Order No. EA-12-051 RS-14-018 February 28, 2014 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

Subject:

Second 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)

References:

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

2. NRC Interim Staff Guidance JLD-ISG-2012-03, "Compliance with Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation,"

Revision o, dated August 29, 2012

3. NEI12-02, Industry Guidance for Compliance with NRC Order EA-12-051, To Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," Revision 1, dated August 2012

4. Exelon Generation Company, LLC's Initial Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051 ), dated October 25, 2012

5. Exelon Generation Company, LLC Overall Integrated Plan 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, 2013 (RS-13-028)

6. Exelon Generation Company, LLC First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), dated August 28,2013 (RS-13-114)

7. NRC letter to Exelon Generation Company, LLC, Byron Station, Units 1 and 2 -Interim Staff Evaluation and Request for Additional Information Regarding the Overall Integrated Plan for Implementation of Order EA-12-051, Reliable Spent Fuel Pool Instrumentation (TAC Nos. MF0872 and MF0873), dated November 4, 2013

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-051 February 28, 2014 Page2 On March 12, 2012, the Nuclear Regulatory Commission ("NRC" or "Commission") issued an order (Reference 1) to Exelon Generation Company, LLC (EGG). Reference 1 was immediately effective and directs EGG to install reliable spent fuel pool level instrumentation. Specific requirements are outlined in Attachment 2 of Reference 1.

Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (Reference 2) and an overall integrated plan pursuant to Section IV, Condition C. Reference 2 endorses industry guidance document NEI 12-02, Revision 1 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the EGG initial status report regarding reliable spent fuel pool instrumentation. Reference 5 provided the Byron Station, Units 1 and 2 overall integrated plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. Reference 3 provides direction regarding the content of the status reports. Reference 6 provides the first six-month status report pursuant to Section IV, Condition C.2, of Reference 1 for Byron Station. The purpose of this letter is to provide the second six-month status report pursuant to Section IV, Condition C.2, of Reference 1, that delineates progress made in implementing the requirements of Reference 1. The enclosed report provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any. The enclosed report also addresses the NRC Interim Staff Evaluation Request for Additional Information Items contained in Reference 7.

This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact David P. Helker at 610-765-5525.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th day of February 2014.

Respectfully submitted,

~E~

Glen T. Kaegi Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

1. Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation

Enclosure Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (24 pages)

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation 1 Introduction Byron Station, Units 1 and 2, developed an Overall Integrated Plan (Reference 1 in Section 8),

documenting the requirements to install reliable Spent Fuel Pool Level Instrumentation (SFPLI),

in response to Reference 2. This enclosure provides an update of milestone accomplishments since submittal of the First Six-Month status report including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestones have been completed since the development of the First Six-Month status report (Reference 6), and are current as of February 8, 2014.

• None 3 Milestone Schedule Status The following provides an update to the milestone schedule to support the Overall Integrated Plan. This section provides the activity status of each item, and the expected completion date noting any change. The dates are planning dates subject to change as design and implementation details are developed.

The revised milestone target completion dates do not impact the order implementation date.

I Revised Target Activity Target Milestone Completion Date Status I Completion Date Submit 60 Day Status Report October 25, 2012 Complete Submit Overall Integrated Plan February 28, 2013 Complete Submit Responses to RAis July 5, 2013 Complete Submit 6 Month Updates:

Update 1 August 28, 2013 Complete Complete with Update 2 February 28, 2014 this submittal Provide Final Safety Evaluation March 31, 2014 Not Started (SE) Information Update 3 August28,2014 Not Started Page 1 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Revised Target Activity Target Milestone Completion Date Status Completion Date Modifications:

Conceptual Design 302012 Complete '

Begin Detailed Design 102013 Complete Engineering Issue Exelon Fleet contract to 202013 Complete procure SFPI Equipment Complete and Issue SFPI 102014 Started 202014 Modification Package Begin Installation 202014 Not Started Complete SFPIInstallation and 402014 Not Started Put Into Service I

4 Changes to Compliance Method There are no changes to the compliance method as documented in the Overall Integrated Plan (Reference 1).

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation Byron Station, Units 1 and 2, expects to comply with the order implementation date and no relief/relaxation is required at this time.

6 Open Items from Overall Integrated Plan and Draft Safety Evaluation The following tables provide a summary of the open items documented in the Overall Integrated Plan (Reference 1) or the Interim Safety Evaluation (IS E) and the status of each item.

Overall Integrated Plan Open Items 01# Description Status 1 For Level 1, specify how the identified location represents Complete.

(RAI*1a, the higher of the two points Level 1 is the level adequate to support Ref.4) described in the NEI 12-02 operation of the normal fuel pool cooling guidance for this level. system. It is the higher of the following two points:

Page 2 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP L1 February 28, 2014 Overall Integrated Plan Open Items 01# Description Status

{1) The level at which reliable suction loss occurs due to uncovering the coolant inlet pipe or any weirs or vacuum breakers associated with suction loss. For Byron, this is the level at which suction loss occurs due to uncovering the inlet pipe strainer.

This level, {1), is elevation 417'-9%, not considering an~ reguired margin as a result of vortex formation.

{2) The level at which the water height, assuming saturated conditions (boiling);

above the centerline of the cooling pump shaft provides the required net positive suction head. This level is 422' -0" at 2.000 gpm per pump and corresponds to the high point elevation of the inside of the suction piping. Water level below this elevation will result in vapor void formation inside the piping for pool temperatures of 212 °F.

The typical margin required to prevent vortex formation at Point 1 is estimated to be less than the difference between Point 1 and Point

2. Thus, the higher of the above points is (2).

Therefore, LEVEL 1 is 422'-0" and is applicable to both units.

2 Open Item:

Complete.

(Ref.1) Continuous level indication will (Addressed in Reference 6) be provided by a guided wave radar system, submersible pressure transducer, or other appropriate level sensing technology that will be determined during the detailed engineering phase of the project.

3 RAI Question:

Complete.

(RAI-1 b, A clearly labeled sketch (Addressed in Reference 4)

Ref. 4) depicting the elevation view of the proposed typical mounting Page 3 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status arrangement for the portions of the instrument channel consisting of permanent measurement channel I equipment (e.g., fixed level I sensors and/or stilling wells, and mounting brackets). l 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.

4 RAI Question: Complete.

(RAI-2, Provide a clearly labeled sketch The marked-up sketch is provided in Ref.4) or marked-up plant drawing of enclosure-1, attached to this Second Six-the plan view of the SFP area, Month update report.

depicting the SFP inside dimensions, the planned locations/placement of the primary and backup SFP level sensor, and the proposed routing of the cables that will extend from the sensors toward the location of the read-out/display device.

5 RAI Question: Started.

(RAI-3, Provide the following: Note that the completion date for design has Ref.4) a) The design criteria that will be changed from January 2014 to April2014. The used to estimate the total requested information is planned to be loading on the mounting provided by March 31, 2014 in accordance device(s), including static with the Interim SEdate. However, if an weight loads and dynamic loads. Describe the extension to the Interim SE date is required methodology that will be used Exelon will contact the NRC.

to estimate the total loading, inclusive of design basis maximum seismic loads and the hydrodynamic loads that could result from pool Page 4 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014

~,

Overall Integrated Plan Open Items 01# Description Status sloshing or other effects that could accompany such seismic forces.

b) A description of the manner in which the level sensor (and stilling well, if appropriate) will be attached to the refueling floor and/or other support structures for each planned point of attachment of the probe assembly.

Indicate in a schematic the portions of the level sensor that will serve as points of attachment for mechanical/mounting or electrical connections.

c) A description of the manner by which the mechanical connections will attach the level instrument to permanent SFP structures so as to supportthelevetsensor assembly.

RESPONSE

Device total loading and mounting will be performed as part of the detailed design process. The current plan for the design of the SFPI system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in April 2014. The requested information will be provided by March 31, 2014 in accordance with the Interim SE date.

6 RAJ Question: Started.

(RAI-4, Provide the following: Note that the completion date for design has Ref.4) a) A description of the specific changed from January 2014 to April 2014. The method or combination of requested information is planned to be methods that will be applied provided bv March 31, 2014 in accordance Page 5 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status to demonstrate the reliability with the Interim SE date. However, if an of the permanently installed extension to the Interim SEdate is required equipment under beyond* Exelon will contact the NRC.

design basis ambient temperature, humidity, shock, vibration, and radiation conditions.

b) A description of the testing ancllor analyses that will be conducted to provide assurance that the equipment will perform reliably under the worst*case credible design I 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.

RESPONSE

Device qualification and reliability will be performed as part of the detailed design process. The current plan for the design of the SFPI system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design Page 6 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status completion and 100% acceptance of the design in April 2014. The requested information will be provided by March 31 , 2014 in accordance with the Interim SE date.

7 RAJ Question:

Complete.

(RAI-5, Provide the following:

a) A description of how the two The two channels of the proposed level Ref.4) channels of the proposed measurement system will be installed such level measurement system that:

meet this requirement so that a) The level probes will be mounted on the the potential for a common east wall of the SFP and will be separated I cause event to adversely affect both channels is by a distance greater than the span of the minimized to the extent shortest side of the pool. This meets the practicable. NEI 12-02, Revision 1 guidance for b) Further information on how channel separation.

each level measurement b) The level sensor enclosure and the system, consisting of level electronics/ UPS enclosure for the primary sensor electronics, cabling, instrument channel will be installed in the and readout devices will be designed and installed to Auxiliary Building in Unit 1 Electrical address independence Penetration Area. The level sensor through the application and enclosure and the electronics/ UPS selection of independent enclosure for the backup instrument power sources, the use of channel will be installed in Unit 2 Electrical physical and spatial Penetration Area. Independence, physical separation, independence of and spatial separation of the level sensors signals sent to the location(s) and electronics/UPS enclosures for primary of the readout devices, and and backup instrument channels is the independence of the displays. maintained by routing the associated instrument channel cables through Unit 1 and Unit 2 respectively.

i The 120 VAC power to the primary instrument will be provided from a Unit 1 ESF-Division 2 MCC (132X2), and 120 VAC power to the backup level instrument will be provided from a Unit 2 ESF Division 2 MCC (232X2). The 120VAC distribution I

panels for the primary and backup instruments are powered by different 480V safety buses. Therefore the loss of any one bus will not result in the loss of ac Page 7 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status power to both instrument channels.

Enclosure 1 demonstrates the physical separation between the primary and backup power sources.

An analog level indicator for each channel will be provided in the Main Control Room (MCR). The primary channel indicator will be located on the Unit 1 side of the MCR at panel 1PM06J. The backup channel indicator will be located on the Unit 2 side of the MCR at panei2PM06J. These analog level indicators will be credited as the level indications used by operators to satisfy the NRC Order EA-12-051 requirements. Providing the 120VAC power to primary and backup instrument channels from separate MCCs will address the concerns regarding power supply independence. Also, installing the SFP level indicator displays for primary and backup channels in separate units (Unit 1 for primary and Unit 2 for backup channels) addresses the concerns regarding physical and spatial separation.

All power and instrument cables associated with the primary channel will be routed on the Unit 1 side of Auxiliary Building and Fuel Handling Building; and all power and instrument cables associated with the backup channel will be routed on the Unit 2 side of the Auxiliary Building and Fuel Handling Building to meet the physical and spatial separation requirements.

8 RAI Question: Started.

(RAI-6, Provide the following: Response for part {a):

Ref.4) a) A description of the electrical ac power sources and The primary and backup SFPLI instrument capabilities for the primary and channels will be normally powered from 120 backup channels. VAC Unit 1 and Unit 2 ESF Division 2 MCC b) Please provide the results of respectively. These are on different safety the calculation depicting the buses, which maintains power source battery backup duty cycle independence. Upon loss of normal AC power, requirements demonstrating Page 8 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items I 01# Description Status that its capacity is sufficient to individual batteries installed in each channel's maintain the level indication electronics/ UPS enclosure will automatically function until offsite resource I maintain continuous channel operation for at availability assured.

least three (3) days. The power cables will be

RESPONSE

routed on the Unit 1 side for the primary Device total power supply channel and on the Unit 2 side for the backup configuration will be performed as channel so that spatial and physical separation part of the detailed design process. is maintained between the primary and backup The current plan for the design of channels. These ESF MCCs have also been i the SFPI system based on the identified as part of the FLEX strategy to current Exelon Nuclear program ensure that the SFPLI will have ac power I schedule for Byron started the restored if a Beyond Design Basis External design phase in June 2013 with Event would occur. Additionally, a receptacle design completion and 100% and a selector switch are installed in each I acceptance of the design in April channel electronics/ UPS enclosure to directly 2014. The requested information connect emergency power to the SFPLI.

will be provided by March 31, 2014 Response for (b):

in accordance with the Interim SE date. Note that the completion date for design has changed from January 2014 to April 2014. The requested information is planned to be provided by March 31, 2014 in accordance with the Interim SEdate. However, if an extension to the Interim SE date is required Exelon will contact the NRC.

9 RAI Question: Started.

i Provide the following:

(RAI-7, Ref.4) a) An estimate of the expected Note that the completion date for design has changed from January 2014 to April2014. The I

instrument channel accuracy requested information is planned to be performance under both (a) provided by March 31, 2014 in accordance normal SFP level conditions with the Interim SEdate. However, if an II (approximately Level1 or higher) and (b) at the beyond design- extension to the Interim SE date is required basis conditions (i.e., radiation, Exelon will contact the NRC.

temperature, humidity, post-seismic and post-shock conditions) that would be I present if the SFP level were at the Level2 and Level3 datum points.

b) A description of the methodology that will be used for determining the maximum allowed deviation from the Page 9 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status 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 I design accuracy.

RESPONSE

Device channel accuracy analysis will be performed as part of the detailed design process. The current plan for the design of the SFPI system based on the current I Exelon Nuclear program schedule for Byron started the design phase I

in June 2013 with design completion and 100% acceptance of the design in April2014. The requested information will be provided by March 31, 2014 in accordance with the Interim SE date.

10 RAI Question: . Started. '

(RAI-8, Provide the following: Note that the completion date for design has Ref.4) a) A description of the capability changed from January 2014 to April 2014. The and provisions the proposed requested information is planned to be level sensing equipment will provided by March 31, 2014 in accordance have to enable periodic testing with the Interim SEdate. However, if an and calibration, including how this capability enables the extension to the Interim SE date is required equipment to be tested in-situ. Exelon will contact the NRC.

b) A description of how such testing and calibration will enable the conduct of regular channel checks of each independent channel against the I other, and against any other permanently-installed SFP level instrumentation.

c) A description of how functional checks will be Page 10 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP U February 28, 2014 Overall Integrated Plan Open Items 01# Description Status 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.

d) A discussion as to how these surveillances will be incorporated into the plant surveillance program.

e) A description of the preventive maintenance tasks required to be performed during normal operation, and the planned maximum surveillance interval that is necessary to assure that the channels are fully conditioned to accurately and reliably perform their I functions when needed.

RESPONSE

i Device testing requirement analysis will be performed as part of the detailed design process just prior to turnover to Operations. The current plan for the design of the SFPI system based on the current Exelon Nuclear program schedule for Byron started the design phase in June 2013 with design completion and 100% acceptance of the design in April2014.

Following the issue of the design, procedures will start being developed with a projected July 2014 completion date. The requested information will be developed early and will be provided by March 31, 2014 in accordance with the Interim SE date.

11 RAI Question: Complete.

(RAI-9, Please provide the following: (Addressed in Reference 6) a) The specific location for each Page 11 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status Ref.4) of the primary and backup instrument channel displays.

b) If the primary and backup display location is other than the main control room, provide justification for prompt accessibility to displays including primary and alternate route evaluation, habitability at display location(s), continual resource availability for personnel responsible to promptly read displays, and provisions for communications with decision makers for the various SFP drain down scenarios and external events.

c) The reasons justifying why the locations selected enable the information from these instruments to be considered "promptly accessible" to various drain-down scenarios and external events.

12 RAI Question:

Complete.

(RAI-10, Please provide a description of The modification review process will be used Ref.4) the standards, guidelines and/or to ensure all necessary procedures are criteria that will be utilized to developed for maintaining and operating the develop procedures for spent fuel level instruments upon installation.

inspection, maintenance, repair, These procedures will be developed in operation, abnormal response, accordance with Exelon's procedure control and administrative controls process.

associated with the SFP level instrumentation, as well as The objectives of each procedural area are storage and installation of described below:

portable instruments.

Procedure Objectives to be achieved

1. System To verify that system Page 12 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status Inspection components are in place, complete, and in the correct configuration, and that the sensor probe is free of significant deposits of crystallized boric acid.

2. Calibration To verify that the and Test system is within the specified accuracy, is functioning as designed, and is appropriately indicating SFP water level.

3. Maintenance To establish and define scheduled and preventive maintenance requirements and activities necessary to minimize the possibility of system interruption.

4. Repair To specify troubleshooting steps and component repair and replacement activities in the event of system malfunction.

5. Operation To provide sufficient instructions for operation and use of the system by plant operation staff.

6. Responses To define the actions to be taken upon observation of system level indications, including actions to be taken at the levels Page 13 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP L1 February 28, 2014 Overall Integrated Plan Open Items 01# Description Status I 1 defined in NEI 12-02. I 13 RAI Question:

Complete.

(RAI-11 I Provide the following:

Response for a:

Ref.4) a) Further information describing the maintenance Performance tests (functional checks) and and testing program the Operator performance checks will be licensee will establish and described in detail in the vendor operator's implement to ensure that manual, and the applicable information is regular testing and calibration planned to be contained in plant operating is performed and verified by inspection and audit to procedures.

demonstrate conformance Operator performance tests are planned to be with design and system performed periodically as recommended by the readiness requirements.

equipment vendor.

Include a description of your plans for ensuring that Channel functional tests per operations necessary channel checks, procedures with limits established in functional tests, periodic consideration of vendor equipment calibration, and maintenance specifications are planned to be performed at will be conducted for the level appropriate frequencies established equivalent measurement system and its supporting equipment. to or more frequently than existing SFPI.

b) A description of how the Manual calibration and operator performance guidance in NEI12-02 section checks are planned to be performed in a 4.3 regarding compensatory periodic scheduled fashion with additional actions for one or both non-maintenance on an as-needed basis when functioning channels will be addressed. flagged by the system's automated diagnostic c) A description of what testing features.

compensatory actions are Channel calibration tests per maintenance planned in the event that one procedures with limits established in of the instrument channels consideration of vendor equipment cannot be restored to functional status within 90 specifications are planned to be performed at days. frequencies established in consideration of vendor recommendations.

SFPI channel/equipment maintenance/preventative maintenance and testing program requirements to ensure design and system readiness are planned to be established in accordance with Exelon's processes and procedures and in consideration of vendor recommendations to ensure that appropriate regular testing, channel checks, functional tests, periodic Page 14 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status 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.

Res12onse for b, c:

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:

1. Required Compensatory Channel(s) Restoration Action if Out-of- Action Required Service Restoration Action not completed within Specified Time 1 Restore Immediately channel to initiate action functional in accordance status within with Note 90 days (or if below channel restoration not expected within 90 days, then proceed to Compensatory Action)

Page 15 of 24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Overall Integrated Plan Open Items 01# Description Status 2 Initiate action Immediately within 24 initiate action hours to in accordance restore one with Note channel to below I 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 /> i

Note: Present a report to the on-site Plant Operations Review Committee (PORC) 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.

Page 16 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Interim Safety Evaluation Open Items 01# Description Status 1 RAI Question: Complete.

(RAI1, Please provide the results of the Byron Calculation NED-M-MSD-041, Rev.

Ref. 5) calculation used to determine the 2 shows that a water level of 424'-2" water elevation necessary for the (corresponding to the low water level pump's required NPSH to confirm alarm) provides adequate water level to that Level 1 has been adequately maintain normal fuel pool cooling system identified. operation. Normal operation of this system is with one pump operating at 4,500 gpm with a pool temperature less than 140 °F. The calculation also shows that this water level is adequate to maintain proper pump flow up to 192 °F.

However for saturated conditions (boiling),

in order to maintain adequate net positive suction head the level will have to be at least 422'-0" at 2000 gpm per pump.

2 RAI Question: Started.

(RAI-4, For RAI 3(a) above, provide the Ref. 5) analyses used to verify the design criteria and methodology for seismic testing of the SFP instrumentation and the electronics units, including design basis maximum seismic loads and the hydrodynamic loads that could result from pool sloshing or other effects that could accompany such seismic forces.

3 RAI Question: Complete.

(RAI-5, For each of the mounting The structural integrity and mounting of Ref. 5) attachments required to attach SFP SFP level equipment is based on formal level equipment to plant structures, calculations, plant drawings, and please describe the design inputs, approved work plans per Exelon and the methodology that was used procedures and processes.

to qualify the structural integrity of the affected structures/equipment. Design Inputs include, but not limited to, the following:

1. Component weights and dimensions, core hole locations and support details.

2. The capability of concrete expansion anchors.

3. The loads (dynamic and static) for the Page 17 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Interim Safety Evaluation Open Items 01# Description Status probe mounting bracket.

II 4. Concrete properties

5. Seismic accelerations requirements for electrical equipment

6. Allowable stresses for structural bolts.

Methodology to qualify the safety related structural integrity includes, but not limited to the following:

1. Structural Weldments - Qualifying the weld design entails the selection of a weld's physical attributes, such as type, 1 configuration and size, which will make I it suitable for transferring the prescribed loads within appropriate limits. This process involves determining the maximum unit forces on the weld and comparing them with the weld capacity. The methodology I determines weld design forces by assuming nominal linear stress/strain distribution. For each design, the engineer must confirm that the distribution of stiffness within the joint is consistent with this assumption. In some cases more refined techniques may be required to predict appropriate distribution of weld forces.

2. Concrete Expansions

• The design methodology of concrete expansion anchor assemblies involves 1) application of component attachment loads to the plate, 2) analysis of the assembly to determine the resultant tension and shear forces on individual anchors, 3) evaluation of the anchor forces relative to anchor allowables and

4) computation and evaluation of bending stresses in the Concrete Expansion Anchor (CEA) plate.

Reactions for the attached component (applied to the plate at the centroid of Page 18 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Interim Safety Evaluation Open Items 01# Description Status the attachment weld) shall be resolved into moments, shears and axial loads  !

(about the major axes of the expansion anchor plate).

3. Local Stress Effects - The member local stresses for open sections are computed according to specific procedures for flange attachments, web attachments, attachments to flanges of beams supporting concrete, and attachments to webs of beams I!

supporting concrete.

4. Existing Embedment Plate Evaluation -

Embedment plates for mechanical/electrical component support attachments (i.e., pipe supports, conduit supports, HVAC supports, etc.) are evaluated as follows:

• Determine embedment plate detail based on the component support design drawing and appropriate structural drawings.

• Determine an allowable load for the embedment plate detail per plant design tables.

• Ensure that the attachment location satisfies the location tolerances used in determining the embedment plate allowables.

• Calculate reactions at face of embedment plate.

• Determine if the embedment plate I

can be qualified per criteria.

5. Conduit and Conduit Supports-Structural adequacy of rigid conduit is evaluated by determining the critical span condition, loads, checking conduit stresses and verifying structural adequacy of conduit clamps. Structural adequacy of Conduit, Junction Boxes and Junction Box supports is evaluated by determining loads, calculating Page 19 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Interim Safety Evaluation Open Items 01# Description Status member forces and joint reactions, checking member stresses, checking I connections, checking expansion anchor assemblies, checking attachments to structure and resolving overstresses.

6. Cable Tray Loading Violations {CTLVs) l

- The structural evaluation of cable tray I supports for potential increase in design basis loading will be performed by identifying the hangers affected by the routing point. For each affected hanger the controlling routing point will be determined. Then actual load associated with the routing point will be computed. The actual load will be compared to the load used in the hanger design. An evaluation of cable tray hanger for any increased load will be performed.

7. Category I Partition Walls- When qualifying a wall for a new/revised attachment, the following method is utilized:

• If the loads on the existing critical design strip are larger in magnitude than the loads on the design strip containing the new attachment, then the wall can be qualified by this comparison.

• If the wall cannot be qualified by comparison of loading, moment and shear due to the attachment shall be calculated and their effects added to the critical design strip. New stresses or moment and shear will be compared to the allowable stresses/capacities.

• If this results in an unacceptable overstress condition, detailed evaluation of the design strip containing the attachment is required. All existing attachments and core holes in the strip will be accounted for in this evaluation.

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Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28,2014 Interim Safety Evaluation Open Items 01# Description Status 4 RAI Question: Started.

(RAI-7, For RAI #6 above, provide the results Ref. 5) from the selected methods, tests and analyses used to demonstrate the qualification and reliability of the installed equipment in accordance I with the Order requirements. I 5 RAI Question: Comglete.

(RAI-13, Provide a list of the procedures Appropriate quality assurance measures Ref. 5) addressing operation (both normal will be selected for the SFPIS required by and abnormal response), calibration, Order EA-12-051, consistent with test, maintenance, and inspection Appendix A-1 of NEI12-02. Site procedures that will be developed for procedures will be developed for system use of the spent SFP inspection, calibration and test, instrumentation. Provide a brief I maintenance, repair, operation and description of the specific technical normal and abnormal responses, in 1 objectives to be achieved within each procedure. accordance with Exelon's procedure control process.

Technical objectives to be achieved in each of the respective procedures are I described below:

Procedure Objectives to be achieved

1. System To verify that Inspection system components are in place, complete, and in the correct configuration, and that the sensor probe is free of significant deposits of crystallized boric acid.

2. Calibration To verify that the and Test system is within the specified accuracy, is functioning as desiqned, and is Page 21 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 Interim Safety Evaluation Open Items 01# Description Status appropriately indicating SFP water level. I I 3. Maintenance To establish and define scheduled and preventive maintenance requirements and activities necessary to minimize the possibility of system interruption.

4. Repair To specify I troubleshooting I steps and component repair I and replacement activities in the event of system malfunction.

5. Operation To provide sufficient instructions for operation and use of the system by plant operation staff.

6. Responses To define the actions to be taken upon observation of system level I indications, including actions to be taken at the levels defined in NEI 12-02.

Note: RAis not included in the Interim Staff Evaluation Open Items Table are duplicate to the RAisin Reference 3 and are listed in the Overall Integrated Plan Open Item Table.

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Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 7 Potential Draft Safety Evaluation Impacts There are no potential impacts to the Draft Safety Evaluation identified at this time.

8 References The following references support the updates to the Overall Integrated Plan described in this enclosure.

1. Exelon Generation Company, LLC, letter to USNRC, "Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)," dated February 28, 2013 (RS 028)

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

3. USNRC letter to Exelon Generation Company, LLC, Requestfor Additional Information Regarding Overall Integrated Plan for Reliable Spent Fuel Pool Instrumentation, dated June 7, 2013.

4. Exelon Generation Company, LLC, letter to USNRC, "Response to Request for Additional Information- Overall Integrated Plan in Response to Commission Order Modifying License Requirements for Reliable Spent Fuel Pool Instrumentation (Order No. EA 051)", dated July 3, 2013 (RS-13-156).

5. USNRC letter to Exelon Generation Company, LLC, "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 November 4, 2013.

6. First Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated August 28, 2013 (RS-13-114).

Page 23 of24

Byron Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of SFP Ll February 28, 2014 ENCLOSURE- 1 BYRON Station, Units 1 and 2 SFPI LAYOUT IN PLAN VIEW Fuel Handling Building Elevation 426' OJ OJ c:: c::

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Auxiliary Building Elevation 426' Unit 1 Electrical Unit 2 Electrical Penetration Area Penetration Area Unit 1 Lower Cable Unit 2 Lower Cable Spreading Room Spreading Room Elevation 439' Elevation 439' Main Control Room Elevation 451' Byron Spent Fuel Pool Level Instrumentation Layout Sketch Page 24 of24