ML14119A303

Response to Request for Additional Information - Revision of Normal Heat Sink Technical Specification to Remove the 24-Hour Average Temperature Limit with No Change to the Peak Maximum Temperature

ML14119A303
Person / Time
Site:	Peach Bottom
Issue date:	04/28/2014
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML14119A303 (16)

Text

10 CFR 50.90 April 28, 2014 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278

Subject:

Response to Request for Additional Information - Revision of Normal Heat Sink Technical Specification to Remove the 24-Hour Average Temperature Limit With No Change to the Peak Maximum Temperature

References:

1) Letter from M. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, ~~Revision of Normal Heat Sink Technical Specification to Remove the 24-Hour Average Temperature Limit With No Change to the Peak Maximum Temperature,~~ dated July 18,2012

2) E-mail from R. Ennis (U.S. Nuclear Regulatory Commission) toT.

11 Loomis (Exelon Generation Company, LLC), Draft RAI - Peach Bottom Normal Heat Sink Operability Requirements (TACs ME9085 & 86), 11 dated November 5, 2012

3) Letter from M. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, Response to Request for Additional II Information- Revision of Normal Heat Sink Technical Specification to Remove the 24-Hour Average Temperature Limit With No Change to the Peak Maximum Temperature,~~ dated January 17, 2013

4) E-mail from R. Ennis (U.S. Nuclear Regulatory Commission) toT.

Loomis (Exelon Generation Company, LLC), uDraft RAI - Peach Bottom Normal Heat Sink Operability Requirements (TACs ME9085 & 86), 11 dated March 8, 2013

U.S. Nuclear Regulatory Commission Response to Request for Additional Information Revision of Normal Heat Sink Technical Specification April 28, 2014 Page 2

5) Letter from D. Helker (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Response to Request for Additional Information- Revision of Normal Heat Sink Technical Specification to Remove the 24-Hour Average Temperature Limit With No Change to the Peak Maximum Temperature," dated April 23, 2013

6) E-mail from R. Ennis (U.S. Nuclear Regulatory Commission) to T.

Loomis (Exelon Generation Company, LLC), "Draft RAI - Peach Bottom Normal Heat Sink Amendment- T ACs MEg085 & 86," dated February 24,2014

7) Letter from J. Barstow (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Response to Request for Additional Information- Revision of Normal Heat Sink Technical Specification to Remove the 24-Hour Average Temperature Limit With No Change to the Peak Maximum Temperature," dated April 8, 2014 In the Reference 1 letter, Exelon Generation Company, LLC (Exelon) requested a proposed change to modify the Technical Specifications (TSs). The proposed change revises the Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, TS Section 3. 7.2, "Emergency Service Water (ESW) System and Normal Heat Sink," to change the requirements for determining the operability of the Normal Heat Sink (NHS). Specifically, this change is proposing to revise TS Section 3. 7.2 to remove the maximum 24-hour average temperature limit of gooF with no change to the peak maximum NHS temperature of g2oF.

In the Reference 2, 4 and 6 e-mails, the U.S. Nuclear Regulatory Commission Staff requested additional information. Attachments 3, 5, and 7 were our responses to these requests.

Based upon further review, Surveillance Requirement 3.7.2.2 has been revised to require that the average water temperature will be monitored hourly when the normal heat sink temperature goes above gooF. Attached are corresponding Technical Specification and Bases pages.

Exelon has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the U.S. Nuclear Regulatory Commission in Reference 1. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the additional information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.

U.S. Nuclear Regulatory Commission Response to Request for Additional Information -

Revision of Normal Heat Sink Technical Specification April 28, 2014 Page 3 There are no regulatory commitments contained in this submittal.

Should you have any questions concerning this letter, please contact Tom Loomis at (610) 765-5510.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 281h day of April 2014.

Respectfully, James Barstow Director - Licensing and Regulatory Affairs Exelon Generation Company, LLC Attachments: Revised Technical Specification and Bases Pages cc: USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Senior Project Manager, PBAPS R. R. Janati, Commonwealth of Pennsylvania S. T. Gray, State of Maryland

Attachment Revised Technical Specification and Bases Pages Revised Pages (Units 2 and 3) 3.7-3 3.7-4 8 3.7-7 8 3.7-8 8 3.7-8a 8 3.7-9

[SitJ ~~tem r~nd Normdl lledt ~)ink J. I.?

ICO J./ .? r'.f./() f c,ubsy~i tprrs dnd normal hAa t ink ha II tw OPERAI3LE.

\ P P L_ I CA13 [ L I r Y

M0 fJ ES l , ? , ,J n d 3.

1\ c: r r oN s CONDITION I~EOU I I~ EO ACT I ON COMPLETION TIME A. ()np ESW ';ubsystt:rn A. l l<r~storr~ FSW -;:,ubsystern I days inoperable. to OPERABLE status.

MODE 3. 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />'s MODE 4. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> Goth ESW subsystems inoperable.

PBAPS UNIT 2 Amendment No. 244

SW tern and Normal H at ink

. l.

SURV ILLANCE REQUIREMENTS SURVEILLANC FREQUENCY SR .3.7 . . 1 Verify the wat r 1 vel in the pump bays of In accordance the pump tructure i 98.5 ft Conowingo with trH~

Datum CCD) and $ 113 ft CD. Surveillance Frequency Control Program.

SR .7.2.2 Verify the of In accordance normal hea with the Surveillance Frequency Control Program.

SR 3.7.2.3 NOTE------------- --

Isolation of flow to individual components Hourly when water does not render ESW System inoperable. temperature of normal heat sink is> 90° F.

Verify each ESW subsystem manual and power In operated valve in the flow paths servicing with the safety related systems or components, that Surveillance is not locked, sealed, or otherwise secured Frequency in position, is in the correct position. Control Program.

SR 3.7.2.4 Verify each ESW subsystem actuates on an In accordance actual or simulated initiation signal. with the Surveillance Frequency Control Program.

PBAPS UNIT 2 3.7-4 Amendment No. 278

ESW System and Normal Heat Sink B 3.7.2 BASES APPLICABLE The ability of the ESW System to provide adequate cooling to SAFETY ANALYSES the identified safety equipment is an implicit assumption (continued) for the safety analyses evaluated in Reference 1. The ability to provide onsite emergency AC power is dependent on the ability of the ESW System to cool the DGs. The long term cooling capability of the RHR and core spray pumps is also dependent on the cooling provided by the ESW System.

ESW provides cooling to the HPCI and RCIC room coolers; however, cooling function is not required to support HPCI or RCIC System operability.

The ESW System, together with the Normal Heat Sink, satisfy Criterion 3 of the NRC Policy Statement.

LCO The ESW subsystems are independent to the degree that each ESW pump has separate controls, power supplies, and the operation of one does not depend on the other. In the event of a DBA, one subsystem of ESW is required to provide the minimum heat removal capability assumed in the safety analysis for the system to which it supplies cooling water.

To ensure this requirement is met, two subsystems of ESW must be OPERABLE. At least one subsystem will operate, if the worst single active failure occurs coincident with the loss of offsite power.

A subsystem is considered OPERABLE when it has an OPERABLE normal heat sink, one OPERABLE pump, and an OPERABLE flow path capable of taking suction from the pump structure and transferring the water to the appropriate equipment.

The OPERABILITY of the normal heat sink is based on having a minimum and maximum water level in the pump bay of 98.5 ft Conowingo Datum {CD) and 11~f~CD respectively and a maximum water temperature o~~

The isolation of the ESW System to components or systems may render those components or systems inoperable, but does not affect the OPERABILITY of the ESW System.

APPLICABILITY In MODES 1, 2, and 3, the ESW System and normal heat sink are required to be OPERABLE to support OPERABILITY of the equipment serviced by the ESW System. Therefore, the ESW System and normal heat sink are required to be OPERABLE in these MODES.

(continued)

PBAPS UNIT 2 B 3.7-7 Revision No. 11

ESW System and Normal Heat Sink f3 3. 7. z 8ASES

/\PPLICA8ILITY In MODES 4 and 5, the OPERABILITY requirements of the ESW (continued) stem and normal heat sink are determined by the systems they support, and therefore the requirements are not the arne for all facets of operation in MODES 4 and 5. rhus, the LCOs of the systems supported by the ESW System and normal heat sink will govern ESW System and normal heat sink OPERABILITY requirements in MODES 4 and 5.

ACTIONS With one ESW subsystem inoperable, the ESW subsystem must be restored to OPERABLE status within 7 days. With the unit in this condition, the remaining OPERABLE ESW subsystem is adequate to perform the heat removal function. However, the overall reliability is reduced because a single failure in the OPERABLE ESW subsystem could result in loss of ESW function.

fhe 7 day Completion Time is based on the redundant ESW System capabilities afforded by the OPERABLE subsystem, the low probability of an event occurring during this time period, and is consistent with the allowed Completion Time for restoring an inoperable DG.

With water temperature of the normal heat sink > gooF a~

~ gzoF, the design basis assumptions associated wit~th~

initial normal heat sink temperature are bounde~~ovided the temperature of the normal heat sink whe~eraged over the previous 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period is~ gooF. T ensure that the g2oF normal heat sink temperature limi is not exceeded, Required Action B.l is provided to ore frequently monitor the temperature of the normal h~ sink. The Unit 2 normal heat sink temperature is me~red from the Unit 2 intake canal. The once per hou ~ompletion time takes into consideration normal at sink temperature variations and the increased man* oring frequency needed to ensure design basis assumptj~ and equipment limitations are not exceeded ~(his condition. If the water temperature of the no;::w-cf'l heat sink exceeds gooF when aver aged over the pre~6us 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period or the water temperature of the normal heat sink exceeds gzoF, Condition C must be entered immediately.

continued PBAPS UNIT 2 B 3.7 8 Revision No. 56

SW stc::m nd Normal Heat ink f3 3.7.

ES ION (continued)

If th E tern cannot be restored to OPERABLE status within th ociated Completion Time, or both ESW ubsy terns ar in rable, or the normal heat sink is ina rable, the un must be placed in a MODE in which the oe not apply. ro achieve this status, the unit must b placed in at lea t MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. rhe allowed Completion Times are reasonable, ba ed on operating experience, to reach the requir unit conditions from full power conditions in an orderly manner and without challenging unit systems.

SURVE I LL_ANCE r~ QUIRFMENTS This SR verifies the water level in the pump bay of the pump structure to be ufficient for the proper operation of the ESW pumps (the pump's ability to meet the minimum flow rate and anticipatory actions required for flood conditions are PBAPS UNIT 2 B 3.7-Sa Revision No. 33

SW tern and Normal Heat Sink B 3.7.

BA S SURVEILLANC (continued)

R QUIREMENTS consid re(j in determining these limits). fhe Surveil1ance Frequ ncy i controlled under the Surveillance Frequency Control Program.

SR 3.7.2.3 Verification of the normal heat sink temperature ensures that the heat removal Verifying the corre alignment for each manual and power capability of the ESW and HPSW systems operated valve in ach ESW subsystem flow path provides is within DBA analysis. The water assurance that t e proper flow paths will exist for ESW temperature is determined by using operation. Th's SR does not apply to valves that are instrumentation that averages multiple locked, seal , or otherwise secured in position, since inputs that measure the normal heat sink these valv were verified to be in the correct position temperature. The Surveillance Frequency prior to ocking, sealing, or securing. A valve is also is controlled under the Surveillance allowed o be in the nonaccident position, and yet Frequency Control Program. Additionally, consi red in the correct position, provided it can be to ensure that the 92°F normal heat sink aut~atically realigned to its accident position within the temperature is not exceeded, this ~ired time. This SR does not require any testing or surveillance requires hourly monitoring of alve manipulation; rather, it involves verification that the normal heat sink when the temperature hose valves capable of being mispositioned are in the is greater than 90°F. The once per hour rrect position. This SR does not apply to valves that monitoring takes into consideration normal annot be inadvertently misaligned, such as check valves.

heat sink temperature variations and the increased monitoring frequency needed to his SR is modified by a Note indicating that isolation of ensure design basis assumptions and he ESW System to components or systems may render those equipment limitations are not exceeded in omponents or systems inoperable, but does not affect the this condition. PERABILITY of the ESW System. As such, when all ESW pumps, alves, and piping are OPERABLE, but a branch connection off he main header is isolated, the ESW System is still PERABLE.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

continued PBAPS UNIT 2 8 3.7-9 Revision No. 86

ESW stern and Normal Heat Sink

3. I. 2

'3

• I PLAN r (; YSTF. MS J. I. 'j tc~m and Normal Heat Sink LCO 3.1. fwo ESW ubsystems and normal heat sink sha 11 be OPERABLE.

r 1\ P P L I C/\ 13 I L I Y: HODES l, ;? *. md 3.

/\CffONS CONDITION rn () UI RED ACT I 0 N COMPLETION TIME A. One ESW ubsystem 1\ . l Restore ESW subsystem 7 days inoperal)Je. to OPERABLE status.

MODE 3. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> MODE 4. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> Both ESW subsystems inoperable.

PBAPS UNIT 3 3.7-3 Amendment No. 248

sw tern and Normal Heat Sink

3. 7.

URVEILLANCE: FREQUENCY SR . 7. . 1 V rify the water level in the pump bays of In accordance U1e pump tru ture i 98.5 ft Conowingo with the Datum (CD) and 113 ft CD. Survei 11 ance Frequency Control Program.

SR 3.7.2.2 Verify the of In accordance normal rH~a with the Surveillance Frequency Control P rogyam.

c' SR 3.7.2.3 ~~-~--NOTE-----------------

Isolation of flow to individual components Hourly when water does not render ESW System inoperable. temperature of normal heat sink is> 90° F.

Verify each ESW subsystem manual and power rn accor ance operated valve in the flow paths servicing with the safety related systems or components, that Surveillance is not locked, sealed, or otherwise secured Frequency in position, is in the correct position. Control Program.

SR 3. 7.2.4 Verify each ESW subsystem actuates on an In accordance actual or simulated initiation signal. with the Surveillance Frequency Control Program.

PBAPS UNIT 3 3.7-4 Amendment No. 281

ESW System and Normal Heat Sink B 3.7.2 BASES APPLICABLE The ability of the ESW System to provide adequate cooling to SAFETY ANALYSES the identified safety equipment is an implicit assumption (continued) for the safety analyses evaluated in Reference 1. The ability to provide onsite emergency AC power is dependent on the ability of the ESW System to cool the DGs. The long term cooling capability of the RHR and core spray pumps is also dependent on the cooling provided by the ESW System.

ESW provides cooling to the HPCI and RCIC room coolers; however, cooling function is not required to support HPCI or RCIC System operability.

The ESW System, together with the Normal Heat Sink, satisfy Criterion 3 of the NRC Policy Statement.

LCO The ESW subsystems are independent to the degree that each ESW pump has separate controls, power supplies, and the operation of one does not depend on the other. In the event of a DBA, one subsystem of ESW is required to provide the minimum heat removal capability assumed in the safety analysis for the system to which it supplies cooling water.

To ensure this requirement is met, two subsystems of ESW must be OPERABLE. At least one subsystem will operate, if the worst single active failure occurs coincident with the loss of offsite power.

A subsystem is considered OPERABLE when it has an OPERABLE normal heat sink, one OPERABLE pump, and an OPERABLE flow path capable of taking suction from the pump structure and transferring the water to the appropriate equipment.

The OPERABILITY of the normal heat sink is based on having a minimum and maximum water level in the pump bay of 98.5 ft Conowingo Datum (CD) and 113 t CD respectively and a maximum water temperature ofi The isolation of the ESW System to components or systems may render those components or systems inoperable, but does not affect the OPERABILITY of the ESW System.

APPLICABILITY In MODES 1, 2, and 3, the ESW System and normal heat sink are required to be OPERABLE to support OPERABILITY of the equipment serviced by the ESW System. Therefore, the ESW System and normal heat sink are required to be OPERABLE in these MODES.

(continued)

PBAPS UNIT 3 B 3.7-7 Revision No. 11

ESW System and Normal Heat Sink B 3. 7.

BASES APPLICABILITY In MODES 4 and 5, the OPERABILifY requirements of the ESW (continued) System and normal heat sink are determined by the systems Ulcy support, and thE~rr:~fore the rf~quirernents are not the Jrne for all facets of operation in MODES 4 and 5. Thus, the LCOs of the ysterns supported by the ESW System and normal heat sink wi 11 qovern ESW System and normal heat sink OPERABILITY requirements in MODES 4 and 5.

ACTIONS With one ESW subsystem inoperable, the ESW subsystem must be restored to OPERABLE status within 7 days. With the unit in this condition, the remaining OPERABLE ESW subsystem is adequate to perform the heat removal function. However, the overall reliability is reduced because a single failure in the OPERABLE ESW subsystem could result in loss of ESW function.

fhe 7 day Completion Time is based on the redundant ESW System capabilities afforded by the OPERABLE subsystem, the low probability of an event occurring during this time period, and is consistent with the allowed Completion Time for restoring an inoperable DG.

1i....l.

With water temperature of the normal heat sink > 90o~~.afid//

~ 92°F, the design basis assumptions associated wi~ the initial normal heat sink temperature are boundo'~rovided the temperature of the normal heat sink w~veraged over the previous 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period is ~ gooF. / ,;f'o ensure that the g 2o F no r ma 1 he a t s i n k t em pe r a t u r e l tJWft i s not ex c e e de d ,

Required Action B.l is provided_.--Mmore frequently monitor the temperature of the normayfleat sink. The Unit 3 normal heat sink temperature is~sured from the Unit 3 intake canal. The once per ~r completion time takes into consideration normJYr heat sink temperature variations and the increased r,rJ.e1fitoring frequency needed to ensure design

,/

basis assu~ions and equipment limitations are not exceedey(n this condition. If the water temperature of the~ormal heat sink exceeds gooF when averaged over the previous 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period or the water temperature of the normal heat sink exceeds g2oF, Condition C must be entered 1 immediately .

.o'"-.-"""-----"----f~~

PBAPS UNIT 3 B 3.7-8 Revision No. 57

ESW tern and Normal Heat ink B 3. 7.

f5/\

1\CfiON

( o n t i n u (! d )

If th !SW tem annot be restored to OPERABLE status within th ociated Completion Time, or both ESW ub ~~ y t r.: m a r i no pc~ r a b I e , o r t h no r ma l he a t s i n k i s inop rable, the unit must be placed in a MODE in which the 0 doe not apply. To a chi eve this status, thE? unit must be pla ed in at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in MODE 4 within 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> . fhe allowed Completion Times are rea onabl , ba ed on operating experience, to reach the r uir d unit condition from full power conditions in an o (~rly mann rand without chall(~nging unit systems.

SLJf~VE I LLANC f~EOU I f~EMEN fS lh is SR veri f>i es the water 1eve l >in the pump bay of the pump tructure to be sufficient for the proper operation of the SW pumps (the pump's ability to meet the minimum flow rate and anticipatory actions required for flood conditions are PBAPS UNIT 3 B 3.7-Sa Revision No. 35

ESW t(~rn and Normal Heat Sink B 3./.

BASES SURVEILLANCE (continued)

REOUIREMENTS con iclered in det rmining these limits). The Surveillance Frequency is controlled under the Surveillance Frequency Control Proqrarn.

Verification of the normal heat sink

!temperature ensures that the heat removal

!capability of the ESWand HPSWsystems Verifying the corre t alignment for each manual and power jis within DBA analysis. The water operated valve i n;each ESW subsystem flow path provides

!temperature is determined by using assurance that e proper flow paths will exist for ESW linstrumentationthataveragesmultiple operation. Th"s SR does not apply to valves that are inputsthatmeasurethenormalheatsink locked, seale, or otherwise secured in position, since temperature. TheSurveillanceFrequency these valve were verified to be in the correct position is controlled under the Surveillance P r i or to l c k i n g , seal i n g , or sec uri n g . A val ve i s a l so FrequencyControiProgram. Additionally, allowed o be in the nonaccident position, and yet toensurethatthe92°Fnormalheatsink consid ed in the correct position, provided it can be I

'temperatureisnotexceeded,this tically realigned to its accident position within the surveillancerequireshourlymonitoringof req ired time. This SR does not require any testing or the normal heat sink when the temperature v e man i P u l at i on ; rather , i t i n v o l v e s veri f i cat i on that 1

isgreaterthan90oF. Theonceperhour those valves capable of being mispositioned are in the lmonitoringtakesintoconsiderationnormal correct po~ition. This SR does not apply to valves that

!heatsinktemperaturevariationsandthe cannot be 1nadvertently misaligned, such as check valves.

jincreased monitoring frequency needed to ensure design basis assumptions and This SR is modified by a Note indicating that isolation of 1

jequipment limitations are not exceeded in the ESW System to components or systems may render those lthis condition. components or systems inoperable, but does not affect the OPERABILITY of the ESW System. As such, when all ESW pumps, valves, and piping are OPERABLE, but a branch connection off the main header is isolated, the ESW System is still OPERABLE.

The Surveillance Frequency is controlled under the b-----------------------------~surveillance Frequency Control Program.

PBAPS UNIT 3 B 3.7-9 Revision No. 87