RS-15-034, Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)

Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)

ML15058A255
Person / Time
Site:	Crane
Issue date:	02/27/2015
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-051, RS-15-034, TMl-15-012
Download: ML15058A255 (35)

Text

RS-15-034 TMl-15-012 February 27, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Three Mile Island Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-50 NRC Docket No. 50-289 Order No. EA-12-051

Subject:

Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)

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 0, dated August 29, 2012

3. NEI 12-02, 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-13-036)

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-13-130)

7. Exelon Generation Company, LLC 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), dated February 28, 2014 (RS 026)

8. Exelon Generation Company, LLC Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), dated August 28, 2014 (RS-14-204)

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-051 February 27, 2015 Page 2

9. NRC letter to Exelon Generation Company, LLC, Three Mile Island Nuclear Station, Unit 1

Interim Staff Evaluation and Request for Additional Information Regarding the Overall Integrated Plan for Implementation of Order EA-12-051, Reliable Spent Fuel Pool Instrumentation (TAC No. MF0866), dated November 13, 2013 On March 12, 201 the Nuclear Regulatory Commission ("NRC" or "Commission") issued an order (Reference 1) to Exelon Generation Company, LLC (EGC). Reference 1 was immediately effective and directs EGC 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 EGC initial status report regarding reliable spent fuel pool instrumentation. Reference 5 provided the Three Mile Island Nuclear Station, Unit 1 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. References 6, 7, and 8 provided the first, second, and third six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Three Mile Island Nuclear Station, Unit 1. The purpose of this letter is to provide the fourth 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 9.

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 271h day of February 2015.

James Barstow Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

1. Three Mile Island Nuclear Station, Unit 1 Fourth Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-051 February 27, 2015 Page 3 cc:

Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region I NRC Senior Resident Inspector - Three Mile Island Nuclear Station, Unit 1 NRC Project Manager, NRR - Three Mile Island Nuclear Station, Unit 1 Ms. Jessica A. Kratchman, NRR/JLD/PMB, NRC Mr. Stephen R. Monarque, NRR/JLD/JPMB, NRC Mr. Robert L. Dennig, NRR/DSS/SCVB, NRC Mr. John D. Hughey, NRR/JLD/JOMB, NRC Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Resources Chairman, Board of County Commissioners of Dauphin County, PA Chairman, Board of Supervisors of Londonderry Township, PA R. R. Janati, Chief, Division of Nuclear Safety, Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection

Enclosure Three Mile Island Nuclear Station, Unit 1 Fourth Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (31 pages)

Three Mile Island Station Unit 1 Fourth 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 Three Mile Island Unit 1, 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 NRC Order EA-12-051 (Reference 2). This enclosure provides an update of milestone accomplishments since submittal of the Third 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 Third Six-Month status report (Reference 12), and are current as of January 27, 2015.

Detailed Engineering approximately 90% complete 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.

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

Update 1 August 28, 2013 Complete Update 2 February 28, 2014 Complete Update 3 August 28, 2014 Complete Update 4 February 28, 2015 Complete with this submittal Page I of 31

I Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Provide Final Safety Evaluation March 31, 2015 Complete (SE) Information Update 5 August28,2015 Not Started Modifications:

Conceptual Design 302012 Complete Issue Exelon Fleet contract to 202013 Complete procure SFPI Equipment Begin Detailed Design 402013 Complete Engineering Complete and Issue SFPI 402014 Started Modification Package Begin Installation 202015 Not Started Complete SFPI Installation and 202015 Not Started Put Into Service 4

Changes to Compliance Method I

I 102015 I

i 402015 I I i 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 Three Mile Island Unit 1, 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 Draft Safety Evaluation (SE) and the status of each item.

Overall Integrated Plan Open Items 01#

Description Status 1

For Level 1, specify how the Started (RAl-1 a, identified location represents the NEI 12-02 section 2.3.1 identifies that Level 1 higher of the two points described Ref. 4) in the NEI 12-02 guidance for this will be the HIGHER of two levels.

level.

The first level is the suction loss due to Page 2 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 2015 Overall Integrated Plan Open Items I

01#

Description Status I

uncovering of the SF cooling suction pipe. This was identified by TMI in a letter dated 7 /24/13 (Reference 4) as elevation 340' 4".

The second level is the loss of SF cooling pump NPSH under saturated conditions. This engineering analysis is in draft form. It will be completed with the SFPI design which is currently scheduled for completion 2/27 /15.

2 Open Item:

Complete.

Continuous level indication will be (Addressed in Reference 6) 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:

Started.

(RAl-1 b, A clearly labeled sketch depicting (Previously addressed in Reference 4)

Ref. 4) the elevation view of the proposed (attached) shows the TMl-1 SF typical mounting arrangement for Pool Elevation Sketch. This attachment has the portions of the instrument been revised to show Level 3 is moved 3" channel consisting of permanent above the gate weir. The 3" allows for measurement channel equipment instrumentation accuracy and is the point (e.g., fixed level sensors and/or below which instrumentation redundancy is stilling wells, and mounting lost.

brackets). Indicate on this sketch Level 2 represents 10' above the SF racks.

the datum values representing Level 1 represents loss of SF cooling suction.

Level 1, Level 2, and Level 3 as well This point will be finalized when item 1 above as the top of the fuel. Indicate on is resolved.

this sketch the portion of the level The exact level sensor measurement range will sensor measurement range that is be finalized during the design phase which is sensitive to measurement of the currently scheduled for completion 2/27 /15.

fuel pool level, with respect to the Level 1, Level 2, and Level 3 datum points.

4 RAI Question:

Started (RAl-2, Provide a clearly labeled sketch or The final locations and cable routings are not marked-up plant drawing of the available at this time. A detailed design will Page 3 of 31

01#

Ref. 4) 5 (RAl-3, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status plan view of the SFP area, depicting include sensor locations and cable routing the SFP inside dimensions, the drawings from the Spent Fuel Pool to each planned locations/placement of the channel indicator. The plan for the design of primary and backup SFP level the SFPI system based on the current Exelon sensor, and the proposed routing Nuclear program schedule for TMl-1 is design of the cables that will extend from completion and acceptance of the design on the sensors toward the location of 2/27/15.

the read-out/display device.

RAI Question:

Started Provide the following:

a} All SFPIS equipment will be designed in a) The design criteria that will be accordance with the TMl-1 Safe Shutdown used to estimate the total loading Earthquake (SSE) design requirements.

on the mounting device(s),

including static weight loads and The vendor, Westinghouse, has evaluated dynamic loads. Describe the the structural integrity of the mounting methodology that will be used to brackets in calculation CN-PEUS-13-24 estimate the total loading, (Reference 20). The GTSTRUDL model, used inclusive of design basis by Westinghouse to calculate the stresses in maximum seismic loads and the the bracket assembly, considers load hydrodynamic loads that could combinations for the dead load, live load result from pool sloshing or other effects that could and seismic load on the bracket. The accompany such seismic forces.

reactionary forces calculated from these b) A description of the manner in loads become the design inputs to design which the level sensor (and the mounting bracket anchorage to the stilling well, if appropriate) will refuel floor to withstand a Safe Shutdown be attached to the refueling floor Earthquake (SSE}.

and/or other support structures for each planned point of Seismic attachment of the probe The seismic loads are obtained from TMl-1's assembly. Indicate in a response spectra curves (Reference 8). The schematic the portions of the following methodology was used in level sensor that will serve as determining the stresses on the bracket points of attachment for assembly:

mechanical/mounting or electrical connections.

c) A description of the manner by Frequency analysis, taking into account which the mechanical the dead weight and the hydrodynamic connections will attach the level mass of the structure, is performed to instrument to permanent SFP obtain the natural frequencies of the structures so as to support the structure in all three directions.

level sensor assembly.

SSE (Safe Shutdown Earthquake) response spectra analysis is performed to obtain member stresses and support Page 4 of31

Three Mile Island Unit 1 Fourth Six-Month Status Report tor the Implementation of SFP LI February 2015 Overall Integrated Plan Open Items 01#

Description Status reactions.

Modal responses are combined using the Ten Percent Method per U.S. NRC Regulatory Guide 1.92, Revision 1, "Combining Modal Responses and Spatial Components in Seismic Response Analysis".

The seismic loads for each of the three directions are combined by the Square Root of the Sum of Squares (SRSS)

Method.

Sloshing analysis is performed to obtain liquid pressure and its impact on bracket design.

The seismic results are combined with the dead load results and the hydrodynamic pressure results in absolute sum. These combined results are compared with the allowable stress values.

Sloshing Sloshing forces were obtained by analysis.

The TIO-7024, Nuclear Reactors and Earthquakes, 1963 (Reference 21), by the US Atomic Energy Commission, approach has been used to estimate the wave height and natural frequency. Horizontal and vertical impact force on the bracket components was calculated using the wave height and natural frequency obtained using TID-7024 (Reference 21) approach.

Using this methodology, sloshing forces have been calculated and added to the total reactionary forces that would be applicable for bracket anchorage design. The analysis also determined that the level probe can withstand a credible design basis seismic event. During the design basis event, the SFP water level is expected to rise and parts of the level sensor probe are assumed to Page 5 of 31

01#

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status become submerged in borated water. The load impact due to the rising water and submergence of the bracket components has also been considered for the overall sloshing impact. Reliable operation of the level measurement sensor with a submerged interconnecting cable has been demonstrated by analysis of previous Westinghouse testing of the cable, and the vendor's cable qualification. Boron build up on the probe has been analyzed to determine the potential effects on the sensor in WNA-TR-03149-GEN (Reference 19).

The following Westinghouse documents provide information with respect to the design criteria used, and a description of the methodology used to estimate the total loading on the device.

a.

To be provided by WEC during detailed design - Pool-side Bracket Seismic Analysis

b.

LTR-SEE-11-13-47, WNA-TR-03149-GEN (Reference 19)

Sloshing Analysis

c.

EQ-QR-269 {Reference 17), WNA-TR-03149-GEN {Reference 19), EQ-TP-353 (Reference 25) - Seismic Qualification of other components of SFPI TMl-l's specific calculations will be developed to address the seismic qualification of the readout display in the Control Building Patio 322' elevation. The design criteria in this calculation will meet the requirements to withstand a SSE. The methods that will be used in the calculation follow IEEE Standard 344-2004 and IEEE Standard 323-2003 for seismic qualification of the instrument.

b) The level sensor, which is one long probe, will be suspended from the launch plate via a coupler/connector assembly. The launch Page 6of11

OI#

6 (RAl-4, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status plate is a subcomponent of the bracket assembly, which will be mounted to the Fuel Handling Building 348" floor via anchors at the South end and attached to the North wall with anchors at the North end of the SF pool. A sketch of the portions of the level sensor that will serve as points of attachment for mechanical/mounting or electrical connections will be provided later.

c) The bracket assembly that supports the sensor probe and launch plate will be mechanically connected to the Fuel Handling Building structure. One type of mechanical connection that may be used consists of four concrete expansion anchors that will bolt the bracket assembly to the SFP structure via the base plate. Another type of mechanical connection is a welded connection between the base plate and existing embedded plates on the SFP structure. The concrete expansion anchors and welds will be designed to withstand SSE and will meet the TMl-1 safety related installation requirements. The qualification details of the bracket will be provided in a Pool-side bracket Seismic Analysis and the qualification of the anchorage to the floor/wall will be provided in a TMl-1 specific calculation Evaluation of SFPI Sensor Mounting Detail Anchorage and Mounting.

This item is expected to be completed by 2/27/15.

RAI Question:

Started Provide the following:

a) Beyond Design Basis Environment-a) A description of the specific Westinghouse qualified the components method or combination of (probe, connector, cable) of the SFPIS methods that will be applied to located in the SFP area to the beyond demonstrate the reliability of the design basis environment conditions as permanently installed equipment defined in the Exelon specification which is Page 7 of 31

OI#

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status under beyond-design basis based on guidance in NEl-12-02 section 3.4.

ambient temperature, humidity, Components of the system were subjected shock, vibration, and radiation to beyond design basis conditions of heat conditions.

and humidity, thermal and radiation aging b) A description of the testing mechanisms. This testing confirmed and/or analyses that will be functionality of these system components conducted to provide assurance under these beyond design basis that the equipment will perform environmental conditions. Westinghouse reliably under the worst-case performed testing to ensure aging of the credible design basis loading at the location where the equipment components in the SFP area will not have a will be mounted. Include a significant effect on the ability of the discussion of this seismic equipment to perform following a plant reliability demonstration as it design basis earthquake. Exelon has applies to a) the level sensor reviewed the documents and found them mounted in the SFP area, and b) acceptable. Reference Westinghouse any control boxes, electronics, documents EQ-TP-351 (Reference 22),

or read-out and re-transmitting WNA-TR-03149-GEN (Reference 19), and devices that will be employed to EQ-TP-354 (Reference 18) for description of convey the level information specific qualification methods.

from the level sensor to the plant operators or emergency Mild Environment - Westinghouse qualified responders.

the system components (display panel, c) A description of the specific sensor) that reside in the mild environment method or combination of conditions to determine that the methods that will be used to components can satisfactorily perform to confirm the reliability of the permanently installed equipment those conditions. Westinghouse has such that following a seismic determined that aging does not have a event the instrument will significant effect on the ability of the maintain its required accuracy.

equipment to perform following a plant design basis earthquake. Exelon has reviewed the documents and found them acceptable. Reference Westinghouse documents EQ-QR-269 (Reference 17),

WNA-TR-03149-GEN (Reference 19) for description of specific methods.

Display - The methods to be used by the vendor to qualify the readout display follow IEEE Standard 344-2004 and IEEE Standard 323-2003 for seismic qualification of the instrument. For temperature and humidity qualification of the displays IEEE 344-2004, IEEE 323-2003, NRC Regulatory Guides 1.100, Revision 3; 1.209, March 2007; and Page 8 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 2015 Overall Integrated Plan Open Items 01#

Description Status EPRI TR-107330 guidance will be followed.

The readout display will be located in the Control Building Patio 322' elevation and is not expected to be subject to harsh environmental or radiological conditions seen in the Fuel Handling Building.

Shock and Vibration - SFPIS pool side brackets will be analyzed for Safe Shutdown Earthquake design requirements per NRC Order EA-12-051 and NEI 12-02 guidance.

As provided by the NRC Order EA-12-051, the NEI 12-02 guidance and as clarified by the NRC interim staff guidance, the probe, coaxial cable, and the mounting brackets are "inherently resistant to shock and vibration loadings." As a result, no additional shock and vibration testing is required for these components. SFPIS pool side brackets for both the primary and backup Westinghouse SFP measurement channels will be permanently installed and fixed to rigid refuel floors or walls, which are Seismic Category 1 structures. The SFPI system components, such as level sensor and its bracket, display enclosure and its bracket, will be subjected to seismic testing, including shock and vibration test requirements. The level sensor electronics are enclosed in a NEMA-4X housing. The display electronics panel utilizes a NEMA-4X rated stainless steel housing as well. These housings will be mounted to a seismically qualified wall and will contain the active electronics, and aid in protecting the internal components from vibration induced damage.

b) The seismic adequacy of the SFPIS (all components) will be demonstrated by vendor testing and analysis in accordance with below listed standards:

Page 9 of 31

01#

7 (RAl-5, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report tor the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status

• IEEE 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1E Electrical Equipment for Nuclear Power Generating Stations

• IEEE-323-1974, Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations

• USNRC Regulatory Guide 1.100, Rev. 3

• USN RC Regulatory Guide 1.92, Rev. 1

• TMl-1 Calculation - Seismic Qualification of the SFPIS Indicator Seismic adequacy of the level sensor probe supporting bracket within the SFP area will be demonstrated by analysis as discussed in the response to RAl-3 (Ref 4) above.

c) Westinghouse will seismically qualify the SFPI instrument and its components. With the instrument to be seismically qualified and installed as described in section b) above response, including the readout display in the Control Building Patio 322' elevation, the instrument is assured to maintain reliable and accurate indication when required.

This item is expected to be completed by 2/27 /15.

RAI Question:

Started Provide the following:

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

measurement system meet this requirement so that the potential a) Primary level probe will be mounted on the for a common cause event to North wall of the 11A" SFP and the backup adversely affect both channels is probe will be mounted on the South wall of minimized to the extent the "B" SFP and will be separated by a practicable.

distance greater than the span of the b) Further information on how each shortest side of the pool. This meets the NEI level measurement system, 12-02 Revision 1 (Reference 26) guidance consisting of level sensor electronics, cablinQ, and readout for channel separation.

Page 10 of31 I

Three Mile Island Unit 1 Fourth Six-Month Status Report tor the Implementation of SFP LI February 2015 Overall Integrated Plan Open Items 01#

Description Status devices will be designed and The level sensor enclosure and the installed to address electronics/ UPS enclosure for the primary independence through the instrument channel and backup instrument application and selection of channel will be installed in the Control independent power sources, the Building Patio of TMll. The exact locations use of physical and spatial have not been finalized; therefore, spatial separation, independence of separation of the level sensors and signals sent to the location(s) of electronics/UPS enclosures for primary and the readout devices, and the backup instrument channels and routing of independence of the displays.

the associated instrument channel cables have not been completed. It will be completed with the SFPI design which is currently scheduled for completion by 2/27/15.

b) The 120 VAC power to the primary and backup instruments will be provided from separate TMI 1 non-lE power panels. The 120VAC distribution panels for the primary and backup instruments are powered by different 480V buses. Therefore, the loss of any one bus will not result in the loss of ac power to both instrument channels.

This item is expected to be completed by 2/27/15.

8 RAI Question:

Started (RAl-6, Provide the following:

a) The primary and backup SFPLI instrument Ref. 4) a) A description of the electrical ac channels will be normally powered from power sources and capabilities for separate non-lE 120 VAC breaker panels.

the primary and backup channels.

b) Please provide the results of the These are powered from separate 480V calculation depicting the battery buses which are ultimately powered from backup duty cycle requirements separate Auxiliary transformers, which demonstrating that its capacity is maintain power source independence.

sufficient to maintain the level indication function until offsite Upon loss of normal AC power, individual resource availability assured.

batteries installed in each channel's electronics/ UPS enclosure will automatically maintain continuous channel operation for at least three (3) days. The power cable routings are not yet defined. It will be completed with the SFPI design Page 11 of31

01#

9 (RAl-7, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status which is currently scheduled for completion by 2/27/15.

Additionally, a receptacle and a selector switch are installed in each channel electronics/ UPS enclosure to directly connect emergency power to the SFPLI.

During an HAP (Extended Loss of AC Power) and before the batteries are discharged, the cabinets will be connected via the above receptacle and selector switch to power provided by the FLEX diesel generators.

b) The Westinghouse Report, WNA-CN-00300-GEN (Reference 23), provides the results of the calculation depicting the battery backup duty cycle. This calculation demonstrates that battery capacity is 4.22 days to maintain the level indicating function to the display location, located in the Patio Area at Control Building at TMI. Therefore, the TMl-1 Station readout display of level indication will be available for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation. The results of the calculation meet the NEI 12-02 Revision 1 (Reference 26) requirements.

RAI Question:

Started Provide the following:

a) The Westinghouse documents WNA-CN-a) An estimate of the expected 00301(Reference9) and WNA-DS-02957-instrument channel accuracy GEN (Reference 10) describe the channel performance under both (a) normal accuracy under both (a) normal SFP level SFP level conditions conditions and (b) at the Beyond Design (approximately Level1 or higher)

Basis (BOB) conditions that would be and (b) at the beyond design-basis present if SFP level were at Level 2 and conditions (i.e., radiation, Level 3 datum points. Each instrument temperature, humidity, post-channel will be accurate to within +/-3"during seismic and post-shock conditions) that would be present if the SFP normal spent fuel pool level conditions. The level were at the Level2 and Level3 instrument channels will retain this datum points.

accuracy after BOB conditions, in Page 12 of 31

01#

10 (RAl-8, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status b) A description of the accordance with the above Westinghouse methodology that will be used for documents.

determining the maximum allowed b) The Westinghouse document WNA-TP-deviation from the instrument channel design accuracy that will 04709-GEN (Reference 11) describes the be employed under normal methodology for routine testing/calibration operating conditions as an verification and calibration methodology.

acceptance criterion for a This document also specifies the required calibration procedure to flag to accuracy criteria under normal operating operators and to technicians that conditions. TM! calibration and channel the channel requires adjustment to verification procedures will follow the within the normal condition design guidance and criteria provided in this accuracy.

document.

Instrument channel calibration will be performed if the level indication reflects a value that is outside the acceptance band established in the TMI calibration and channel verification procedures.

Calibration will be performed once per refueling cycle for TMI. Per Westinghouse document WNA-TP-04709-GEN (Reference

11) calibration on a SFP level channel is to be completed within 60 days of a planned refueling outage considering normal testing scheduling allowances (e.g., 25%). This is in compliance with the NEI 12-02 Revision 1 (Reference 26) guidance for Spent Fuel Pool Instrumentation.

These items will be completed by 3/31/15.

RAI Question:

Started.

Provide the following:

a) During the detailed design phase, a) A description of the capability Westinghouse will provide the calibration and provisions the proposed level procedure and functional test procedure sensing equipment will have to describing the capabilities and provisions of enable periodic testing and SFPI periodic testing and calibration, calibration, including how this including in-situ testing. TMl-1 will review capability enables the equipment to the procedures to ensure the instrument be tested in-situ.

can be calibrated/functionally tested/in-situ b) A description of how such testing can be performed per the Order testing and calibration will enable requirements. This item will be completed the conduct of regular channel by 3/31/15.

Page 13 of 31

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11 (RAl-9, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status checks of each independent channel against the other, and b) The level displayed by the channels will be against any other permanently-verified per the TMl-1 administrative and installed SFP level instrumentation.

operating procedures. If the level is not c) A description of how functional within the required accuracy per checks will be performed, and the Westinghouse recommended tolerances, frequency at which they will be channel calibration will be performed.

conducted. Describe how calibration tests will be performed, c) Functional checks will be performed per a and the frequency at which they will future Westinghouse functionality test be conducted.

procedure at the Westinghouse d) A discussion as to how these recommended frequency. Calibration tests surveillances will be incorporated will be performed per a future into the plant surveillance program.

Westinghouse calibration procedure at the e) A description of the preventive Westinghouse recommended frequency. In maintenance tasks required to be accordance with TMl-1 maintenance and performed during normal operation, operating programs, TMl-1 will develop and the planned maximum calibration, functional test, and channel surveillance interval that is verification procedures per future necessary to assure that the Westinghouse recommendations to ensure channels are fully conditioned to reliable, accurate and continuous SFPI accurately and reliably perform functionality. This item will be completed their functions when needed.

by 11/30/15.

d) TMl-1 will develop preventive maintenance tasks for the SFPI per future Westinghouse recommendations to assure that the channels are fully conditioned to accurately and reliably perform their functions when needed. This item will be completed by 11/30/15.

RAI Question:

Started Please provide the following:

a) TM l's primary and backup instrument a) The specific location for each of channel displays are planned to be located the primary and backup on the second floor of the control building.

instrument channel displays.

Precise location within the second floor of b) If the primary and backup display the control building will be finalized during location is other than the main the detailed design process.

control room, provide b) As stated above, TM l's primary and backup justification for prompt instrument channel displays are planned to accessibility to displays be located on the second floor of the including primary and alternate control building. Precise location within the route evaluation, habitability at second floor of the control building will be Page 14 of 31

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Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status display location{s), continual finalized during the detailed design process.

resource availability for This location was selected due to the fact personnel responsible to that this area will be manned during any promptly read displays, and BDBEE where the FLEX RCS makeup pump is provisions for communications located as well. Also, the area is in close with decision makers for the proximity to the main control room, and various SFP drain down alternate shutdown panel. The display can scenarios and external events.

be accessed from the main control room on c) The reasons justifying why the demand if the FLEX RCS makeup station is locations selected enable the information from these not being manned as well. It will take up to instruments to be considered 3 minutes to reach the display location, for "promptly accessible" to various both the primary and backup channels, drain-down scenarios and when an operator is dispatched from the external events.

control room (down 2 floors).

Radiological habitability at this location has been evaluated against TMI UFSAR Table 11.A-2 and Figure 11.A-5. The peak radiation post LOCA is 480mRem/hr in this location. Also the estimated dose rates from SFP drain-down conditions to Level 3, (calculation BYR13-187 (Reference 24))

were evaluated. Therefore the exposure to personnel monitoring SFP levels due to radiation in the display location for both channels would remain less than emergency exposure limits allowable for emergency responders to perform this action. Heat and humidity from SFP boil-down conditions have been evaluated for this location. The location is in a different building physically separated by concrete walls, closed air lock/fire doors from the SFP such that heat and humidity from a boiling SFP would not compromise habitability at this location.

Spent Fuel Pool Level monitoring will be the responsibility of Operations personnel who will monitor the display periodically once dispatched from the Control Room. As stated above, travel time from the Control Room to the primary and secondary displays is approximately 3 minutes based on walkdown by Engineering. Radiological Page 15 of3 I

01#

12 (RAl-10, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status habitability for the transit routes to both displays has been evaluated against TMI Station UFSAR Table 11.A-2 and Figure 11.A-5 in the Control Building for post LOCA scenario conditions as well as estimated dose rates from SFP drain-down conditions to Level 3, (calculation BYR13-187 (Reference 24)) and exposure to personnel monitoring SFP levels would remain less than emergency exposure limits allowable for emergency responders to perform this action. Heat and humidity from SFP boil-down conditions have been evaluated for access to this location, and the access routes are located in a different building physically separated by dosed air lock/fire doors from the SFP such that heat and humidity from a boiling SFP would not compromise habitability concerns with accessing these displays. The walkthrough to access the display locations is within the robust seismic category I structures, from the control room to the display locations, located near the TMl-1 remote shutdown room.

Operators will be able to use the sound powered phone system to communicate to the control room with the display information immediately. Being able to provide the indicated SFP level within approximately 10 minutes is not considered an unreasonable delay.

Final verification of the readout locations will be verified by 2/27 /15.

RAI Question:

Started Please provide the following:

Appropriate quality measures will be selected a) A list of the operating (both normal for the SFPIS required by Order EA-12-051, and abnormal response) consistent with Appendix A of NEI 12-02. Site procedures, calibration/test procedures will be developed for system procedures, maintenance inspection, calibration and test, maintenance, procedures, and inspection repair, operation and normal and abnormal Page 16 of 31 I

01#

13 (RAl-11, Ref. 4)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status procedures that will be developed responses, in accordance with Exelon's for use of the SFP instrumentation procedure control process. Technical in a manner that addresses the objectives to be achieved in each of the order requirements.

respective procedures are described below:

Procedure Objectives to be achieved b) A brief description of the specific

1. System Inspection: To verify that system technical objectives to be achieved components are in place, complete, and in within each procedure. If your plan the correct configuration, and that the incorporates the use of portable sensor probe is free of significant deposits.

spent fuel level monitoring

2. Calibration and Test: To verify that the components, please include a description of the objectives to be system is within the specified accuracy, is achieved with regard to the functioning as designed, and is storage location and provisions for appropriately indicating SFP water level.

installation of the portable

3. Maintenance: To establish and define components when needed.

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 defined in NEI 12-02 Revision 1 (Reference 26).

All procedures will be in place before the system is considered operable 11/30/15 RAI Question:

Started Provide the following:

Response for a:

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

with design and system Operator performance tests are planned to be Page 17 of 31

01#

Three Mile Island Unit 1 Fourth Six-Month Status Report tor the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status readiness requirements. Include performed periodically as recommended by a description of your plans for the equipment vendor.

ensuring that necessary channel Channel functional tests per operations checks, functional tests, periodic calibration, and maintenance will procedures with limits established in be conducted for the level consideration of vendor equipment measurement system and its specifications are planned to be performed at supporting equipment.

appropriate frequencies established equivalent b) A description of how the to or more frequently than existing SFPI.

guidance in NEI 12-02 section 4.3 regarding compensatory actions Manual calibration and operator performance for one or both non-functioning checks are planned to be performed in a channels will be addressed.

periodic scheduled fashion with additional c) A description of what maintenance on an as-needed basis when compensatory actions are flagged by the system's automated diagnostic planned in the event that one of testing features.

the instrument channels cannot be restored to functional status Channel calibration tests per maintenance within 90 days.

procedures with limits established in consideration of vendor equipment specifications are planned to be performed at frequencies established in consideration of vendor recommendations.

SFPI channel/equipment maintenance I 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 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.

These program requirements are expected to be completed by 3/31/15.

Resgonse for b, c:

Page 18 of 31 I

01#

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status Both primary and backup SFPI channels will 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:

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) 2 Initiate action Immediately within 24 initiate action hours to in accordance restore one with Note Page 19 of 31

01#

01#

1 (RAl-2 Ref. 5)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Overall Integrated Plan Open Items Description Status 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 /> below Note: Initiate an Issue Report to enter the condition into the Corrective Action Program. Identify the equipment out of service time is greater than the specified allowed out of service time, develop and implement an alternate method of monitoring, determine the cause of the non-functionality, and the plans and schedule for restoring the instrumentation channel(s) to functional status.

Draft Safety Evaluation Open Items Description Status RAI Question:

Complete Please describe the Complete redundant monitoring of the pools will not be available impact of the when the gate is installed. The gate is not normally installed. There installation of the is an existing procedure 1507-2, Fuel Handling Building Crane gate on the Operations, which installs and removes the gate. To address the reliability of the SFP level concern when the gate may be installed the procedure 1507-2 will instrumentation for be revised to establish administrative guidance/controls to follow each SFP, and what the NEI 12-02 Rev. 1 (Reference 26) section 4.3 guidance for the 90-compensatory day out of service criterion. Action will be tracked by AR evaluation measures would be A2322479-08. The elevation for the bottom of the gate opening for taken to ensure TMI is 321ft. Level 3 for TMI is revised to elevation 321ft. 3 in.,

reliable level which is slightly above the bottom of the gate opening, rather than, indication in each the top of the Fuel rack elevation 319ft. 1 in. This will provide SFP when the gate assurance that both the primary and backup SFP level instrument is installed.

channels can measure the same Level 3 elevation in both SFPs. See revised Attachment 1.

Page 20 of 31

2 (RAI 5, Ref. 5) 3 (RAl-6, Ref. 5)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 RAI Question:

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

RAI Question:

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

St;:irted The following Westinghouse documents will provide the analyses used to verify the design criteria and describe the methodology for seismic testing of the SFP instrumentation and electronics units, inclusive of design basis maximum seismic loads and hydrodynamic loads that could result from pool sloshing and other effects that could accompany such seismic forces:

a.

To be provided by WEC during detailed design phase - Pool-side Bracket Seismic Analysis

b.

LTR-SEE-11-13-47, WNA-TR-03149-GEN (Reference 19) -

Sloshing Analysis

c.

EQ-QR-269 (Reference 17), WNA-TR-03149-GEN (Reference 19), EQ-TP-353 (Reference 25) Seismic Qualification of other components of SFPI TMl-1 specific calculations will address the seismic qualification of the Control Building 322' Patio indicators. The design criteria that will be used in this calculation will satisfy the requirements to withstand a SSE and will meet the TMl-1 safety related installation requirements for mounting the readout displays in the Control Building 322' elevation.

This information will be available when the design work is complete on 2/27/15.

Started The structural integrity and mounting of SFP level equipment will be based on formal calculations, plant drawings, and approved work plans per Exelon procedures and processes.

Design Inputs will 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 probe mounting bracket.

4. Concrete properties

5. Seismic accelerations requirements for electrical equipment

6. Allowable stresses for structural bolts.

Methodology to qualify the safety related structural integrity will include, 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, configuration and size, which will make it suitable for transferring Page 21 of31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 2015 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 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 CEA plate. Reactions for the attached component (applied to the plate at the centroid of 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 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 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, Page 22 of 31

4 (RAl-8, Ref. 5)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 RAI Question:

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

Junction Boxes and Junction Box supports is evaluated by determining loads, calculating member forces and joint reactions, checking member stresses, checking connections, checking expansion anchor assemblies, checking attachments to structure and resolving overstresses.

6. Cable Tray Loading Violations (CTLVs)

If cable trays are used then the structural evaluation of cable tray supports for potential increase in design basis loading will be performed by identifying the hangers affected by the routing point. For each affected hanger controlling routing point will be determined. Then actual load associated with the routing point will be computed. Then 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.

Final verification of these methods will be available 2/27 /15.

Started Below is a summary of the test conditions used by Westinghouse to qualify the SFPIS. These test conditions are also documented in References 13 to 16. Environmental Conditions for SFPIS Components installed in the Spent Fuel Pool Area at TMI are bounded by below test conditions, except for radiation TID 12" above top of fuel rack for beyond design basis conditions (BDB).

The BDB radiation TID, 12" above top of fuel rack for Byron Station is 4.E07 Ry, per calculation BYR13-051 - NEI 12-02 Spent Fuel Pool Doses. (Calculation BYR13-187, "Radiation Doses in the vicinity of the Spent Fuel Pool at Reduced Water Level" (Reference 24) proves that calculation BYR 13-051 bounds the Exelon Fleet for these values.) The BDB radiation value to which the Westinghouse equipment is qualified to is 1.E07 Ry, per Section 5.1.1 of WNA-TR-03149-GEN (Reference 19). The radiation value of 4.E07 Ry is higher than 1.E07 Ry to which Westinghouse qualified the Page 23 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 2015 instrument to. However, this value of 4.E07 R v is applicable only when the water is at Level 3. At Level 2 the TIO reduces to 2.E07 R v and it further reduces to 8.E06 at Level 1 and above. With SFP water level at Level 3 the only components of SFPI that are exposed to high radiation are the stainless steel probe and the stainless steel anchor. The materials with which the probe and the anchor are manufactured are resistant to radiation effects. The I

stainless steel anchor and stainless steel probe can withstand 40 year dose. Westinghouse updated the design specification (WNA-OS-02957-GEN (reference 10)) and LTR-SFPIS-13-35, Revision 1 documentation to include the above technical justification.

Environmental Conditions for SFPIS Components in the Spent Fuel Pool Area Level sensor probe, coax coupler and connector assembly, launch plate and pool side bracket assembly, and coax cable are designed and qualified to operate reliably in the below specified environmental conditions.

I Parameter I I I Temperature I

Pressure Humidity Radiation TIO v (above pool)

Radiation TIO v (12" above top of fuel rack)

Normal for Exelon Plants 50-140°F Atmospheric 0-95% RH 1E03 Rads 1E09 Rads (probe and weight only)

BOB 212°F Atmospheric 100% (saturated steam) 1E07 Rads 1E07 Rads Environmental Conditions Outside of the Spent Fuel Pool Area The level sensor transmitter and bracket, electronics display enclosure and bracket are designed and qualified to operate reliably in the below specified environmental conditions.

Normal BOB BOB Parameter (Level Sensor Page 24 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 Thermal and Radiation Aging organic components in SFP area Westinghouse documents EQ-QR-269, EQ-TP-354, WNA-TR-03149-GEN (References 17, 18 & 19) provide thermal and radiation aging program details for the SFPI components. Westinghouse completed their thermal and radiation aging testing programs to qualify the SFPI components to 1.25 years. Exelon has reviewed the documents and found them acceptable.

Additionally, Westinghouse is continuing their aging tests to age the system components to 10 years. These tests were completed in Summer 2014. Final test reports were provided to Exelon. TMI will complete the test report reviews by 2/27 /15.

Seismic Category I Testing Seismic qualification testing will be performed by Westinghouse along with the technical evaluations during detailed design.

Vibration Justification Components of the system (i.e., bracket, transmitter, display enclosure) will be permanently installed to meet the requirements to withstand a SSE and will meet TM l's seismic installation Page 25 of 31

5 (RAI-10, Ref. 5)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 requirements. Westinghouse will analyze the pool side Lr dLkc:c withstand design basis SSE. Other components of the SFPIS will be subjected to shock and vibration during the seismic testing.

Sloshing Justification A sloshing calculation will be performed by Westinghouse during detailed design. Sloshing forces will be taken into consideration for the anchorage design of the pool side bracket to ensure the bracket is rigidly mounted to include sloshing affects.

RAI Question:

StartPrl Please provide the a)

The primary and backup SFPLI instrument channels will be following:

a) A description of normally powered from separate non-lE 120 VAC breaker the electrical ac panels. These are powered from separate 480V buses which power sources are ultimately powered from separate Auxiliary transformers, and capabilities which maintain power source independence. Upon loss of for the primary normal AC power, individual batteries installed in each and backup channels.

channel's electronics/ UPS enclosure will automatically maintain b) Please provide continuous channel operation for at least three (3) days. The the results of the power cable routings are not yet defined. It will be completed calculation with the SFPI design which is currently scheduled for depicting the completion by 2/27 /15.

battery backup duty cycle Additionally, a receptacle and a selector switch are installed in requirements demonstrating each channel electronics/ UPS enclosure to directly connect that its capacity emergency power to the SFPLI. During an ELAP (Extended Loss is sufficient to of AC Power) and before the batteries are discharged, the maintain the level indication cabinets will be connected via the above receptacle and selector function until switch to power provided by the FLEX diesel generators.

offsite resource availability is b)

The Westinghouse Report, WNA-CN-00300-GEN (Reference 23),

reasonably provides the results of the calculation depicting the battery assured.

backup duty cycle. This calculation demonstrates that battery capacity is 4.22 days to maintain the level indicating function to the display location, located in the Patio Area at Control Building at TMI. Therefore, the TMl-1 Station readout display of level indication will be available for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation. The results of the calculation meet the NEI 12-02 Page 26 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 2015 requirements.

6 RAI Question:

Started (RAI-Please provide the a)

TM l's primary and backup instrument channel displays are 13, following:

planned to be located on the second floor of the Control Ref. 5) a) The specific Building. Precise location within the second floor of the control location for each building will be finalized during the detailed design process.

of the primary This will be completed by 2/27 /15.

and backup instrument As stated above, TMl's primary and backup instrument channel channel b) displays.

displays are planned to be located on the second floor of the Control Building. Precise location within the second floor of the b) For any SFP control building will be finalized during the detailed design level process. This location was selected due to the fact that this area instrumentation will be manned during any BDBEE where the FLEX RCS makeup displays located pump is located as well. Also, the area is in close proximity to outside the main control room, the main control room, and alternate shutdown panel. The please describe display can be accessed from the main control room on demand the evaluation if the FLEX RCS makeup station is not being manned as well. It used to validate will take up to 3 minutes to reach the display location, for both that the display the primary and backup channels, when an operator is location can be dispatched from the control room (down 2 floors).

accessed without Radiological habitability at this location has been evaluated unreasonable delay following a against TMI UFSAR Table 11.A-2 and Figure 11.A-5. The peak BOB event.

radiation post LOCA is 480mRem/hr in this location. Also the Include the time estimated dose rates from SFP drain-down conditions to level 3, available for (calculation BYR13-187 (Reference 24)) was evaluated.

personnel to Therefore the exposure to personnel monitoring SFP levels due access the to radiation in the display location for both channels would display as remain less than emergency exposure limits allowable for credited in the emergency responders to perform this action. Heat and evaluation, as humidity from SFP boil-down conditions have been evaluated well as the actual for this location. The location is in a different building physically time (e.g., based on walk-separated by concrete walls, closed air lock/fire doors from the throughs) that it SFP such that heat and humidity from a boiling SFP would not will take for compromise habitability at this location.

personnel to access the Spent Fuel Pool Level monitoring will be the responsibility of display.

Operations personnel who will monitor the display periodically Additionally, once dispatched from the Control Room. As stated above, travel please include a time from the Control Room to the primary and secondary description of displays is approximately 3 minutes based on walkdown by the radiological and Engineering. Radiological habitability for the transit routes to environmental both displays has been evaluated against TMI Station UFSAR Page 27 of 31

7 (RAl-14, Ref. 5)

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI conditions on the paths personnel might take. Describe whether the display location remains habitable for radiological, heat and humidity, and other environmental conditions following a BOB event. Describe whether personnel are continuously stationed at the display or monitor the display periodically.

RAI Question Please provide a list of the procedures addressing operation (both normal and abnormal response),

calibration, test, maintenance, and inspection procedures that will be developed for use of the SFP instrumentation.

The licensee is requested to include a brief description of the specific technical objectives to be achieved within each procedure.

February 2015 Table 11.A-2 and Figure LOCA scenario conditions as well as estimated dose rates from SFP drain-down conditions to Level 3, (calculation BYR13-187 (Reference 24)) and exposure to personnel monitoring SFP levels would remain less than emergency exposure limits allowable for emergency responders to perform this action.

Heat and humidity from SFP boil-down conditions have been evaluated for access to this location, and the access routes are located in a different building physically separated by closed air lock/fire doors from the SFP such that heat and humidity from a boiling SFP would not compromise habitability concerns with accessing these displays. The walkthrough to access the display locations is within the robust seismic category I structures, from the control room to the display locations, located near the TMl-1 remote shutdown room.

Operators will be able to use the sound powered phone system to communicate to the control room with the display information immediately. Being able to provide the indicated SFP level within approximately 10 minutes is not considered an unreasonable delay.

Started Appropriate quality measures will be selected for the SFPIS required by Order EA-12-051, consistent with Appendix A of NEI 12-02 Revision 1 (Reference 26). Site procedures will be developed for system inspection, calibration and test, maintenance, repair, operation and normal and abnormal responses, in accordance with Exelon's procedure control process. Technical objectives to be achieved in each of the respective procedures are described below:

Procedure Objectives to be achieved

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

2.

Calibration and Test: To verify that the 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 Page 28 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 27, 2015 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 036).

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. USN RC letter to Exelon Generation Company, LLC, Request for Additional Information Regarding Overall Integrated Plan for Reliable Spent Fuel Pool Instrumentation, dated June 26, 2013.

4. Exelon Generation Company, LLC, letter to USN RC, "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 24, 2013 (RS-13-095).

5. USN RC 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 13, 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-13-130).

7. Second Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated February 28, 2014 (RS-14-026).

8. 42105-R-001, Summary of Conservative, Design In-Structure Response Spectra for Resolution of Unresolved Safety Issue A-46 for Three Mile Island Nuclear Generation Station, Unit 1.

9. Westinghouse Document, WNA-CN-00301-GEN, "Spent Fuel Pool Instrumentation System Channel Accuracy Analysis," Revision 1.

Page 29 of 31

Three Mile Island Unit 1 Fourth Six-Month Status Report for the Implementation of SFP LI February 2015

10. Westinghouse Document, WNA-DS-02957-GEN, "Spent Fuel Pool Instrumentation System (SFPIS) Standard Product System Design Specification," Revision 4.

11. Westinghouse Document, WNA-TP-04709-GEN, "Spent Fuel Pool Instrumentation System Calibration Procedure, Revision 4.

12. Third 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, 2014 (RS-14-204)

13. VSDS Web Report viewer for TMl-1 Survey Maps - 348' FHB on 6/8/14.

14. ES-010T, TMl-1 Environmental Parameters.

15. TMl-1 UFSAR section 9.4.1 SF Cooling System.

16. BYR13-051NEI 12-02 Spent Fuel Pool Doses.

17. Westinghouse Document, EQ-QR-269, "Design Verification Testing Summary Report for the Spent Fuel Pool Instrumentation," Revision 1.

18. Westinghouse Proprietary Document, EQ-TP-354, "Mechanical Preconditioning, Thermal Aging, and Radiation Aging Procedure for the Spent Fuel Pool Instrumentation System Coaxial Cables and Couplers," Revision 0.

19. Westinghouse Document, WNA-TR-03149-GEN, "SFPIS Standard Product Final Summary Design Verification Report," Revision 1.

20. Westinghouse Calculation CN-PEUS-13 Seismic Analysis of the SFP Mounting Bracket at Byron and Braidwood Nuclear Stations (Similar analysis will be done for TMI or this analysis will be verified to be applicable).

21. TID-7024, Nuclear Reactors and Earthquakes, 1963, by the US Atomic Energy Commission (Appendix F - Dynamic Analysis of Fluids in Containers Subjected to Acceleration).

22. Westinghouse Proprietary Document, EQ-TP-351, "Environmental Qualification Test Procedure for the Spent Fuel Pool Instrumentation System Coaxial Cable and Connectors Inside the Spent Fuel Pool Area," Revision 0.

23. Westinghouse Document, WNA-CN-00300-GEN, "Spent Fuel Pool Instrumentation System Power Consumption Calculation," Revision 1.

24. BYR13-187 - Radiological Does in the Vicinity of the Spent Fuel Pool at Reduced Water Level.

25. Westinghouse Proprietary Document, EQ-TP-353, Revision 0, "Static Pull Test Procedure for Spent Fuel Pool Instrumentation System Connector," December 2013.

26. 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".

Page 30 of 31

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