RS-14-198, 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)

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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)
ML14248A327
Person / Time
Site: Dresden  Constellation icon.png
Issue date: 08/28/2014
From: Kaegi G
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-051, RS-14-198
Download: ML14248A327 (26)
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Text

AlMOW AMP' ANEEPP- Exelon Generation Order No. EA-12-051 RS-14-198 August 28, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249

Subject:

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)

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-13-030)
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-13-118)
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 020)
8. NRC letter to Exelon Generation Company, LLC, Dresden Nuclear Power Station, Units 2 and 3 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. MF1050 and MF1051), dated October 29, 2013

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-051 August 28, 2014 Page 2 On March 12, 2012, 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 Dresden Nuclear Power Station, Units 2 and 3 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 and 7 provided the first and second six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Dresden Nuclear Power Station. The purpose of this letter is to provide the third six-month status report pursuant to Section IV, Condition 0.2, 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 8.

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 August 2014.

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

Enclosure:

1. Dresden Nuclear Power Station, Units 2 and 3 Third 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 August 28, 2014 Page 3 cc: Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region III NRC Senior Resident Inspector Dresden Nuclear Power Station, Units 2 and 3 NRC Project Manager, NRR Dresden Nuclear Power Station, Units 2 and 3 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. Blake Purnell, NRR/DORULPL3-2, NRC Mr. John Boska, NRR/JLD/MSD, NRC Illinois Emergency Management Agency - Division of Nuclear Safety

Enclosure Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of Order EA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (22 pages)

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 Dresden Nuclear Power Station, Units 2 and 3 Third 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 Dresden Nuclear Power Station, Units 2 and 3, developed an Overall Integrated Plan (Reference 1), documenting the requirements to install reliable spent fuel pool level instrumentation (SFP LI), in response to Reference 2. This enclosure provides an update of milestone accomplishments since submittal of the second 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 Second six month status report (Reference 7), and are current as of August 28, 2014.

  • Begin Detailed Engineering Design for Unit 2
  • Begin Detailed Engineering Design for Unit 3
  • Provided responses to all RAls via ePortal on 6/23/14 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.

Revised Target Completion Activity Target Milestone Date Status Completion Date Submit 60 Day Status Report October 25, 2012 Complete Submit Overall Integrated Plan February 28, 2013 Complete Submit Response to RAls July 18, 2013 Complete Submit 6 Month Updates:

Update 1 August 28, 2013 Complete Update 2 February 28, 2014 Complete Complete with Update 3 August 28, 2014 this submittal Page! of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 Revised Target Completion Activity Target Milestone Date Status Completion Date Update 4 February 28, 2015 Not Started Provide Final Safety Evaluation April 30, 2015 Complete (SE) Info Update 5 August 28, 2015 Not Started Update 6 February 28, 2016 Not Started Update 7 August 28, 2016 Not Started Modifications:

Conceptual Design 302012 Complete Issue Exelon Fleet contract to 102015 Complete procure SFPI Equipment Begin Detailed Engineering 302014 Complete Design for Unit 2 Complete and Issue SFPI 402014 Not Started Modification Package for Unit 2 Begin Detailed Engineering 302014 Complete Design for Unit 3 Complete and Issue SFPI 402014 Not Started Modification Package for Unit 3 Begin SFPI Installation for Unit 2 302015 Not Started Complete SFPI Installation for Not Started 402015 Unit 2 and Put Into Service Begin SFPI Installation for Unit 3 302016 Not Started Complete SFPI Installation for Not Started 402016 Unit 3 and Put Into Service 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 Dresden Nuclear Power Station, Units 2 and 3, expects to comply with the order implementation date and no relief/relaxation is required at this time.

Page 2 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 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 or the Draft Safety Evaluation (SE) and the status of each item.

Overall Integrated Plan Open Items 01# Description Status 1 Open Item: Complete.

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.

2 RAI Question: Complete.

(RAI-1, Please provide the following: (Addressed in Reference 4)

Ref. 3) a) For Level 1, specify how the identified location represents the higher of the two points described in the NEI 12-02 guidance for this level.

b) A clearly labeled sketch depicting the elevation view of the proposed typical mounting arrangement for the portions of the instrument channel consisting of permanent measurement channel equipment (e.g., fixed level sensors and/or stilling wells, and mounting brackets).

Indicate on this sketch the datum values representing Level 1, Level 2, and Level 3 as well as the top of the fuel.

Indicate on this sketch the portion of the level sensor measurement range that is sensitive to measurement of the fuel pool level, with respect to the Level 1, Level 2, and Page 3 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 Level 3 datum points.

3 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-2, Please provide a clearly labeled Ref.3) sketch or marked-up plant Please see attachment 1 for the preliminary sketch.

drawing of the plan view of the SFP area, depicting the SFP inside dimensions, the planned locations/placement of the primary and back-up 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.

4 RAI Question: Started - Planned completion date is December 15, (RAI-3, Please provide the following: 2014.

Ref.3) a) The design criteria that will be used to estimate the total a) All SFPIS equipment will be designed in loading on the mounting accordance with the Dresden Station Safe device(s), including static Shutdown Earthquake (SSE) design requirements.

weight loads and dynamic loads. Describe the The vendor, Westinghouse, will evaluate the methodology that will be used structural integrity of the mounting brackets in a to estimate the total loading, calculation. The GTSTRUDL model, proposed by inclusive of design basis Westinghouse to calculate the stresses in the maximum seismic loads and bracket assembly, considers load combinations for the hydrodynamic loads that the dead load, live load and seismic load on the could result from pool sloshing bracket. The reactionary forces calculated from or other effects that could these loads will become the design inputs to design accompany such seismic the mounting bracket anchorage to the refuel floor forces. to withstand a Safe Shutdown Earthquake (SSE).

b) A description of the manner Seismic in which the level sensor (and stilling well, if appropriate) will The seismic loads will be obtained from Dresden be attached to the refueling Station's response spectra curves (Reference floor and/or other support TDBD-DQ-1 for Dresden Nuclear Generating structures for each planned point of attachment of the probe Station). The following methodology will be used in assembly. determining the stresses on the bracket assembly:

Indicate in a schematic the portions of the level sensor that

  • Frequency analysis, taking into account the will serve as points of dead weight and the hydrodynamic mass of the attachment for structure, is performed to obtain the natural mechanical/mounting or frequencies of the structure in all three directions.

electrical connections.

  • SSE (Safe Shutdown Earthquake) response c) A description of the manner spectra analysis is performed to obtain member by which the mechanical stresses and support reactions.

Page 4 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 connections will attach the level

  • Modal responses are combined using the instrument to permanent SFP Ten Percent Method per U.S. NRC Regulatory structures so as to support the Guide 1.92, Revision 1, "Combining Modal level sensor assembly. 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 will be obtained by analysis. The TID-7024, Nuclear Reactors and Earthquakes, 1963, by the US Atomic Energy Commission, approach will be used to estimate the wave height and natural frequency. Horizontal and vertical impact force on the bracket components will be calculated using the wave height and natural frequency obtained using the TID-7024 approach.

Using this methodology, sloshing forces will be calculated and added to the total reactionary forces that would be applicable for bracket anchorage design. The analysis will also confirm that the level probe can withstand a credible design basis seismic event.

The following Westinghouse documents will 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 Westinhouse during detailed design phase - Pool-side Bracket Seismic Analysis
b. LTR-SEE-I1-13-47, WNA-TR-03149-G EN -

Sloshing Analysis

c. EQ-QR-269, WNA-TR-03149-GEN, EQ-TP-353 - Seismic Qualification of other components of SFP1 Dresden Station specific calculations will be developed to address the seismic qualification of Page 5 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 the readout display in the Turbine Building. 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 plate is a subcomponent of the bracket assembly, which will be mounted to the refuel floor via anchors or welded to existing embedded plates on the refuel floor. 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 SFP structure. One type of mechanical connection that will be used consists of four concrete expansion anchors that will bolt the bracket assembly to the SFP structure via the base plate. The other 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 Dresden Station 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 will be provided in a Dresden Station specific calculation Evaluation of SFPI Sensor Mounting Detail Anchorage and Mounting.

5 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-4, Please provide the following:

Ref.3) a) A description of the specific a) Beyond Design Basis Environment method or combination of Westinghouse will qualify the components (probe, methods you intend to apply to connector, cable) of the SFPIS located in the SFP demonstrate the reliability of area to the beyond design basis environment.

the permanently installed Components of the system will be subjected to equipment under beyond-beyond design basis conditions of heat and design-basis ambient humidity, thermal and radiation aging mechanisms.

temperature, humidity, shock, This testing will confirm the functionality of these vibration, and radiation system components under beyond design basis conditions.

environmental conditions. Westinghouse will b) A description of the testing perform testing to ensure aging of the components Page 6 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 and/or analyses that will be in the SFP area will not have a significant effect on conducted to provide the ability of the equipment to perform following a assurance that the equipment plant design basis earthquake.

will perform reliably under the Mild Environment Westinghouse will qualify the worst-case credible design basis loading at the location system components (display panel, sensor) that where the equipment will be reside in the mild environment conditions to mounted. Include a discussion determine that the components can satisfactorily of this seismic reliability perform to those conditions. Westinghouse will demonstration as it applies to confirm that aging does not have a significant effect a) the level sensor mounted in on the ability of the equipment to perform following the SFP area, and b) any a plant design basis earthquake.

control boxes, electronics, or read-out and re-transmitting Display The methods to be used by the vendor to devices that will be employed to qualify the readout display follow IEEE Standard convey the level information 344-2004 and IEEE Standard 323-2003 for seismic from the level sensor to the qualification of the instrument. For temperature plant operators or emergency and humidity qualification of the displays IEEE 344-responders. 2004, IEEE 323-2003, NRC Regulatory Guides c) A description of the specific 1.100, Revision 3; 1.209, March 2007; and EPRI method or combination of TR-107330 guidance will be followed. The readout methods that will be used to display will be located in the Turbine Building and is confirm the reliability of the not expected to be subject to harsh environmental permanently installed or radiological conditions seen in the Reactor equipment such that following a seismic event the instrument Building.

will maintain its required Shock and Vibration SFPIS pool side brackets accuracy. 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, 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 Page 7 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 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:

  • IEEE 344-2004, IEEE Recommended Practice for Seismic Qualification of Class lE Electrical Equipment for Nuclear Power Generating Stations
  • IEEE-323-1974, Standard for Qualifying Class lE Equipment for Nuclear Power Generating Stations
  • Dresden 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 RAI-2.

c) Westinghouse will seismically qualify the SFPI instrument and its components. With the instrument to be seismically qualified and installed as described in RAI 5b response, including the readout display in the Turbine Building, the instrument is assured to maintain reliable and accurate indication when required.

6 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-5, Please provide the following:

Ref.3) The two channels of the proposed level a) A description of how the two measurement system will be installed such that:

channels of the proposed level measurement system meet this a) The level probes will be mounted on the east requirement so that the and west side of each SFP and will be separated potential for a common cause by a distance greater than the span of the shortest event to adversely affect both side of the pool. This meets the NEI 12-02 revision channels is minimized to the 1 guidance for channel separation.

b) The information related to physical extent practicable.

separation, is depicted in attachment 1, which b)Further information shows the location of the probe and mounting describing the design and brackets and cable routing to the two individual installation of each level transmitters. Dresden's primary and backup measurement system, instrument channel displays will be located on the consisting of level sensor Main Floor of the Turbine Building along the Page 8 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 electronics, cabling, and Reactor Building wall and will have physical and readout devices. Please spatial separation between the displays. Each address how independence of system's cables will be spatially separated using these components of the Dresden's divisional spatial separation criteria. The primary and back-up channels independent power sources will consist of powering is achieved through the each train from a separate Motor Control Center.

application of independent power sources, physical and spatial separation, independence of signals sent to the location(s) of the readout devices, and the independence of the displays.

7 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-6, Please provide the following:

Ref. 3) a) The primary and backup SFPLI instrument a) A description of the electrical channels will be normally powered from 120 VAC.

ac power sources and Upon loss of normal AC power, individual batteries capacities for the primary and installed in each channel's electronics / UPS backup channels.

enclosure will automatically maintain continuous b) If the level measurement channel operation for at least (3) days. The power channels are to be powered cables will be routed so that spatial and physical through a battery system (either separation is maintained between the primary and directly or through an backup channels. Additionally, a receptacle and a Uninterruptible Power Supply), selector switch are installed in each channel please provide the design electronics / UPS enclosure to directly connect criteria that will be applied to emergency power to the SFPLI.

size the battery in a manner b) The Westinghouse Report, WNA-CN-that ensures, with margin, that 00300-GEN, provides the results of the calculation the channel will be available to depicting the battery backup duty cycle. This run reliably and continuously calculation demonstrates that battery capacity is following the onset of the 4.22 days to maintain the level indicating function to beyond-design-basis event for the display location, located in the Turbine Building.

the minimum duration needed,

' The calculation also determines that the battery will consistent with the plant last for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Dresden will review this mitigation strategies for calculation during the detailed design phase. Based beyond-design-basis external on preliminary assessment, the Dresden readout events (Order EA-12-049).

display of level indication in the Turbine Building will be available for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation.

Therefore, the results of the calculation meet the NEI 12-02 requirements.

8 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-7, Please provide the following:

Ref.3) a) Each instrument channel will be accurate to c) An estimate of the expected within +/-3"during normal spent fuel pool level instrument channel accuracy conditions. This accuracy will be validated in performance (e.g., in percent of detailed design. The instrument channels will retain Page 9 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 span) under both a) normal this accuracy after BDB conditions. The same SFP level conditions channel accuracy requirements are applicable to (approximately Level 1 or the readout display in the Turbine Building.

higher) and b) at the beyond-b) Westinghouse will provide a document design-basis conditions (i.e.,

regarding the methodology for routine radiation, temperature, testing/calibration verification and calibration humidity, post-seismic and methodology. This document will also specify the post-shock conditions) that required accuracy criteria under normal operating would be present if the SFP conditions. Dresden Station calibration and level were at the Level 2 and channel verification procedures will follow the Level 3 datum points, guidance and criteria provided in this document.

d) A description of the Instrument channel calibration will be performed if methodology that will be used the level indication reflects a value that is outside for determining the maximum the acceptance band that will be established in the allowed deviation from the Dresden Station calibration and channel verification instrument channel design procedures. Calibration will be performed once per accuracy that will be employed refueling cycle for Dresden Station. Calibration on under normal operating a SFP level channel is to be completed within 60 conditions as an acceptance days of a planned refueling outage considering criterion for a calibration normal testing scheduling allowances (e.g. 25%).

procedure to flag to operators This is in compliance with the NEI 12-02 guidance and to technicians that the for Spent Fuel Pool Instrumentation.

channel requires adjustment to within the normal condition design accuracy.

9 RAI Question: Started - Planned completion date is November 21, 2015.

(RAI-8, Please provide the following:

Ref.3) a) During the detailed design phase, a) A description of the Westinghouse will provide the calibration procedure capability and provisions the and functional test procedure describing the proposed level sensing capabilities and provisions of SFPI periodic testing equipment will have to enable and calibration, including in-situ testing. Dresden periodic testing and calibration, will review the procedures to ensure the instrument including how this capability can be calibrated/functionally tested/in-situ testing enables the equipment to be can be performed per the Order requirements.

tested in-situ.

b) The level displayed by the channels will be b) A description of how such verified per the Dresden Station administrative and testing and calibration will operating procedures. If the level is not within the enable the conduct of regular required accuracy per Westinghouse channel checks of each recommended tolerances, channel calibration will independent channel against be performed.

the other, and against any other 0 Functional checks will be performed per a permanently-installed SFP level future Westinghouse functionality test procedure at instrumentation. the Westinghouse recommended frequency.

c) A description of how Calibration tests will be performed per a future Westinghouse calibration procedure at the calibration tests and functional Westinghouse recommended frequency. In checks will be performed, and accordance with Dresden Station maintenance and the frequency at which they will operating programs, Dresden Station will develop be conducted. Discuss how Page 10 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 these surveillances will be calibration, functional test, channel verification incorporated into the plant procedures per future Westinghouse surveillance program. recommendations to ensure reliable, accurate and continuous SFPI functionality.

d) A description of what preventive maintenance tasks d) Dresden Station will develop preventive are required to be performed maintenance tasks for the SFPI per future during normal operation, and Westinghouse recommendations to assure that the the planned maximum channels are fully conditioned to accurately and reliably perform their functions when needed.

surveillance interval that is necessary to ensure that the channels are fully conditioned to accurately and reliably perform their functions when needed.

10 RAI Question: Replaced by Interim SE RAI #11 (Ref. 5).

(RAI-9, Please provide the following:

Ref. 3) a) The specific location for each 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." Include consideration of various drain-down scenarios.

11 RAI Question: Replaced by Interim SE RAI #12 (Ref. 5).

(RAI- Please provide the following:

10, a) A list of the operating (both Ref.3) normal and abnormal response) procedures, calibration/test procedures, Page II of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 maintenance procedures, and inspection procedures that will be developed for use of the SFP instrumentation in a manner that addresses the order requirements.

b) A brief description of the specific technical objectives to be achieved within each procedure. If your plan incorporates the use of portable spent fuel level monitoring components, please include a description of the objectives to be achieved with regard to the storage location and provisions for installation of the portable components when needed.

12 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI- Please provide the following:

11, Response for a,b:

a) Further information Ref 3) describing the maintenance Performance tests (functional checks) and Operator and testing program the performance checks will be described in detail in the licensee will establish and vendor operator's manual, and the applicable implement to ensure that information is planned to be contained in plant regular testing and calibration is performed and operating procedures.

b)verified by inspection and Operator performance tests are planned to be audit to demonstrate performed periodically as recommended by the conformance with design and equipment vendor.

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

maintenance will be conducted Manual calibration and operator performance for the level measurement system and its supporting checks are planned to be performed in a periodic equipment. scheduled fashion with additional maintenance on an as-needed basis when flagged by the system's c) A description of how the automated diagnostic testing features.

guidance in NEI12-02, Section 4.3 regarding compensatory Channel calibration tests per maintenance actions for one or both non- procedures with limits established in consideration functioning channels will be of vendor equipment specifications are planned to addressed. be performed at frequencies established in d) A description of what consideration of vendor recommendations.

Page 12 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 compensatory actions are SFPI channel/equipment maintenance/preventative planned in the event that one of maintenance and testing program requirements to the instrument channels cannot ensure design and system readiness are planned to be restored to functional status be established in accordance with Exelon's within 90 days.

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.

Response for c, d:

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:

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

Page 13 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 2 Initiate action Immediately within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> initiate action in to restore one accordance with channel to Note below 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 /> 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.

Draft Safety Evaluation Open Items 01# Description Status 1 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-3, For RAI 2(a) above, The following Westinghouse documents will provide the analyses used Ref. 5) please provide the to verify the design criteria and describe the methodology for seismic analyses used to testing of the SFP instrumentation and electronics units, inclusive of verify the design design basis maximum seismic loads and hydrodynamic loads that criteria and could result from pool sloshing and other effects that could accompany methodology for such seismic forces:

seismic testing of the SFP instrumentation a. To be provided by Westinghouse during detailed design phase -

and the electronics Pool-side Bracket Seismic Analysis units, including

b. LTR-SEE-II-13-47, WNA-TR-03149-GEN - Sloshing Analysis design-basis maximum seismic c. EQ-QR-269, WNA-TR-03149-GEN, EQ-TP-353 - Seismic loads and Qualification of other components of SFPI hydrodynamic loads Dresden Station specific calculations will address the seismic smic pool could result from pool sloshing or qualification of the turbine building indicators. The design criteria that other effects that will be used in this calculation will satisfy the requirements to withstand could accompany a SSE and will meet the Dresden Station safety related installation such seismic forces. requirements for mounting the readout displays in the turbine building.

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Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 2 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-4, For each of the The structural integrity and mounting of SFP level equipment will be Ref. 5) mounting based on formal calculations, plant drawings, and approved work plans attachments required per Exelon procedures and processes.

to attach SFP level Design Inputs will include, but not limited to, the following:

equipment to plant structures, please 1. Component weights and dimensions, core hole locations and describe the design support details.

inputs and the 2. The capability of concrete expansion anchors.

methodology that

3. The loads (dynamic and static) for the probe mounting bracket.

was used to qualify the structural 4. Concrete properties integrity of the 5. Seismic accelerations requirements for electrical equipment affected

6. Allowable stresses for structural bolts.

structures/equipment 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 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 Page 15 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 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, 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) - 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.
  • lithe 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.

3 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-6, For RAI #5 above, Below is a summary of the test conditions that will be used by Westinghouse to qualify the SFPIS. These test conditions are also Ref. 5) please provide the documented in Attachment 2 items 3, 4, 5, 6, 7, and 8. Environmental results for the Conditions for SFPIS Components installed in the Spent Fuel Pool Area selected methods, will be verified during detailed design. The materials with which the tests and analyses probe and the anchor are manufactured are to be resistant to radiation Page 16 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 used to demonstrate effects. The stainless steel anchor and stainless steel probe are to be the qualification and designed to withstand 40 year dose.

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

Parameter Normal BDB Temperature 50-140°F 212°F Pressure Atmospheric Atmospheric Humidity 0-95% RH 100% (saturated steam)

Radiation TID y 1E03 Rads 1E07 Rads (above pool)

Radiation TID y 1E09 Rads (12" above top of (probe and weight 1E07 Rads fuel rack) only)

Environmental Conditions Outside of the Spent Fuel Pool Area The level sensor transmitter and bracket, electronics display enclosure and bracket are to be designed and qualified to operate reliably in the below specified environmental conditions.

BDB Parameter Normal BDB (Level Sensor Electronics Only)

Temperatur 50- 140°F 140°F e 120°F Pressure Atmosp Atmospheric Atmospheric heric Humidity 0-95% 0-95%

0-95%

RH (non- (non-condensing) condensing)

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Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 Duration 3 days 3 days 3 days Radiation 5 1E03 5 1E03 R 5 1E03 R TID y Ry Dresden specific calculations which support the seismic installation and environmental analysis of the display enclosures and transmitters will be included in the detailed design.

Thermal and Radiation Aging organic components in SFP area Westinghouse will provide thermal and radiation aging program details for the SFPI components and will be reviewed during detailed design.

Seismic Category I Testing Seismic qualification testing will be performed by Westinghouse along with the technical evaluations will be performed by Westinghouse 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 the Dresden's seismic installation requirements.

Westinghouse will analyze the pool side bracket to 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.

4 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI-8, Please provide the a) The primary and backup SFPLI instrument channels will be following: normally powered from 120 VAC. Upon loss of normal AC power, Ref. 5) a) A description of individual batteries installed in each channel's electronics / UPS the electrical ac enclosure will automatically maintain continuous channel operation for power sources and at least (3) days. The power cables will be routed so that spatial and capabilities for the physical separation is maintained between the primary and backup primary and backup channels. Additionally, a receptacle and a selector switch are installed channels. in each channel electronics / UPS enclosure to directly connect b) Please provide emergency power to the SFPLI.

the results of the b) The Westinghouse Report, WNA-CN-00300-GEN, provides the calculation depicting results of the calculation depicting the battery backup duty cycle. This Page 1 8 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 the battery backup calculation demonstrates that battery capacity is 4.22 days to maintain duty cycle the level indicating function to the display location, located in the Turbine requirements Building. The calculation also determines that the battery will last for 72 demonstrating that hours. Dresden will review this calculation during the detailed design its capacity is phase. Based on preliminary assessment, the Dresden readout display sufficient to maintain of level indication in the Turbine Building will be available for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the level indication operation. Therefore, the results of the calculation meet the NEI 12-02 function until offsite requirements.

resource availability is reasonably assured.

5 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI- a) Dresden's primary and backup instrument channel displays will Please provide the be located on the Main Floor of the Turbine Building along the Reactor 11, following: Building wall.

Ref. 5) a) The specific location for each of b) Dresden's primary and backup instrument channel displays are the primary and located outside of the control room. As described above, they are backup instrument located in the Turbine Building. This location was selected due to the channel display location proximity to the main control room.

displays. Dresden Station UFSAR section 3.8.4 states that the turbine building b) If a display will be portion of the structural complex is a Class II structure as explained in located somewhere Section 3.8.5. Section 3.8.5 states that Class II structures supporting other than the Class I structures, systems and components were designed to Class II control room or requirements and have been investigated to assure that the integrity of alternate the Class I items is not compromised. The instrument channel display shutdown panel, location will be investigated to assure that the integrity of the display please describe the items is not compromised. Both primary and backup instrument evaluation used to channel display locations are selected to reduce the likelihood of missile damage to the displays.

validate that the display location can Dresden Station UFSAR figure 3.11-4 shows the Main Floor of the be accessed without Turbine Building as zone 38 and would include the display location and unreasonable delay the access to the displays from the Control Room. UFSAR table 3.11-2 following a BDB shows zone 38 with a normal maximum temperature of 120°F which event. Include the would allow emergency responders to perform level display monitoring.

time available for Travel time from the Control Room to the primary and secondary display personnel to access is approximately 5 minutes based on walkdowns. There are alternate the display as paths if the primary path is blocked or is not habitable. The maximum time to reach the display locations via the alternate paths is 8 minutes.

credited in the evaluation, as well Per the preliminary evaluation, radiological habitability at the display as the actual time location and the path to the display location was evaluated against (e.g., based on walk- estimated dose rates from SFP draindown conditions to Level 3 and throughs) that it will exposure to personnel monitoring SFP levels are expected to remain take for personnel to less than emergency exposure limits allowable for emergency access the display. responders to perform this action. Also, for severe accidents scenarios Additionally, please involving core damage and increased radiological exposure levels, include a access to these SFP level displays for short term can be achieved (see description of the UFSAR Appendix 12A). Exposure duration to personnel monitoring SFP levels would be limited to remain less than emergency exposure limits radiological and allowable for emergency responders to perform this action. The SFP environmental electronics and displays are not expected to take radiation dose higher conditions on the Page 19 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 paths than the qualified TID 1.0E03 rads. This is because the location is personnel might outside secondary containment and not near any piping systems that take. Describe could contain fission products. (see UFSAR Appendix 12A). Heat and whether the display humidity from SFP boildown conditions was preliminarily evaluated for location remains this location. The location is at an elevation below the SFP operating habitable for floor and physically separated by secondary containment such that heat radiological, heat and humidity from a boiling SFP is not expected to compromise habitability at this location and the path to the display locations.

and humidity, and other environmental conditions following a BDB event.

Describe whether personnel are continuously stationed at the display or monitor the display periodically.

6 RAI Question: Started - Planned completion date is December 15, 2014.

(RAI- Appropriate quality measures will be selected for the SFPIS required by Please provide a list Order EA-12-051, consistent with Appendix A of NEI 12-02. Site 12, of the procedures procedures will be developed for system inspection, calibration and test, Ref. 5) addressing operation maintenance, repair, operation and normal and abnormal responses, in (both normal and accordance with Exelon's procedure control process. Technical abnormal response), objectives to be achieved in each of the respective procedures are calibration, test, described below:

maintenance, and Procedure Objectives to be achieved inspection procedures that will 1. System Inspection: To verify that system components are in be developed for use place, complete, and in the correct configuration, and that the sensor of the spent SFP probe is free of significant deposits.

instrumentation. 2. Calibration and Test: To verify that the system is within the Please provide a specified accuracy is functioning as designed, and is appropriately brief description of indicating SFP water level.

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

achieved within each

4. Repair: To specify troubleshooting steps and component repair procedure.

and replacement activities in the event of system malfunction.We would not do this in a procedure

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.

Page 20 of 22

Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 Note: RAls not included in the Interim Staff Evaluation Open Items Table are duplicate to the RAls in Reference 3 and are listed in the Overall Integrated Plan Open Item Table.

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 Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)," dated February 28, 2013 (RS 030)
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, "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 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 18, 2013 (RS-13-176).
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 October 29, 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-13-118).
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-14-020).

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Dresden Nuclear Power Station, Units 2 and 3 Third Six-Month Status Report for the Implementation of SFP LI August 28, 2014 Attachment 1: Preliminary Plan View of Spent Fuel Pool Area Page 22 of 22

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