Vice President Oconee Nuclear Station Duke Energy · SF-181 since it is slightly further from the...

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DUKEENERG Scott L. Batson

Vice PresidentOconee Nuclear Station

Duke EnergyONO1VP 17800 Rochester Hwy

Seneca, SC 29672

10 CFR 50.90 o: 864.873.3274864.873.4208

June 11, 2013 [email protected]

U. S. Nuclear Regulatory CommissionAttn: Document Control DeskWashington, DC 20555-0001

Subject: Duke Energy Carolinas, LLCOconee Nuclear Station, Units 1, 2 and 3Renewed Facility Operating License Numbers DPR-38, 47 and 55;Docket Numbers 50-269, 50-270 and 50-287;Response to Request for Additional Information Associated with LicenseAmendment Request for Reverse Osmosis System Operation,License Amendment Request No. 2012-05, Supplement 2

On October 30, 2012, Duke Energy Carolinas, LLC (Duke Energy) submitted a LicenseAmendment Request (LAR) requesting Nuclear Regulatory Commission (NRC) approval tooperate a Reverse Osmosis (RO) System to remove silica from the Borated Water StorageTanks (BWSTs) and Spent Fuel Pools (SFPs) during Unit operation. The LAR also requestedapproval of associated proposed new Technical Specifications (TSs) and Bases that imposenew requirements for RO System operation and isolation. Duke Energy submittedsupplemental information on January 21, 2013 in response to additional information requestedduring the NRC Acceptance Review. By letter dated April 12, 2013, NRC requested DukeEnergy provide additional information.

Enclosure 1 provides the additional information. Enclosure 2 provides changes to the proposedTechnical Specification and Bases associated with NRC RAI 14 and RAI 8, respectively. Thechanges proposed by this supplement are bounded by the no significant hazards considerationsubmitted in the October 30, 2012, LAR. Enclosure 3 provides a list of regulatory commitmentsassociated with this letter.

Inquiries on this submittal should be directed to Boyd Shingleton, Oconee Regulatory AffairsGroup, at (864) 873-4716.

I declare under penalty of perjury that the foregoing is true and correct. Executed onJune 11,2013.

Sincerely,

Scott L. BatsonVice PresidentOconee Nuclear Station

www.duke-energy.com

U. S. Nuclear Regulatory CommissionJune 11, 2013

Enclosures:

Enclosure 1 - Duke Energy Response to Request for Additional InformationEnclosure 2 - Revised TS and TS BasesEnclosure 3 - List of Regulatory Commitments

U. S. Nuclear Regulatory CommissionJune 11, 2013

cc w/enclosures:

Mr. Victor McCree, Regional AdministratorU. S. Nuclear Regulatory Commission - Region IIMarquis One Tower245 Peachtree Center Ave., NE, Suite 1200Atlanta, GA 30303-1257

Mr. John Boska, Senior Project Manager(by electronic mail only)Office of Nuclear Reactor RegulationU. S. Nuclear Regulatory Commission11555 Rockville PikeMail Stop O-8G9ARockville, MD 20852-2746

Mr. Ed CroweNRC Senior Resident InspectorOconee Nuclear Site

Ms. Susan Jenkins, ManagerRadioactive & Infectious Waste ManagementDivision of Waste ManagementSouth Carolina Department of Health and Environmental Control2600 Bull St.Columbia, SC 29201

License Amendment Request No. 2011-05, Supplement 2June 11, 2013

ENCLOSURE I

Duke Energy Response to Request for Additional Information

License Amendment Request No. 2011-05, Supplement 2June 11, 2013Page 1

Enclosure 1Duke Energy Response to Request for Additional Information

RAI-1:

In section 4.1, the submittal states, "Duke Energy evaluated the effect of potential failures,identified precautionary measures that must be taken before and during RO System operation,and identified specific required operator actions to protect affected structures, systems, andcomponents important to safety." These operator actions are not identified in the submittal.Please provide the specific required operator actions.

Duke Energy Response:

The October 30, 2012, Reverse Osmosis (RO) License Amendment Request (LAR) identifiestwo specific required operator actions. One is to isolate an RO system pipe break to prevent theBWST from draining below the minimum TS limit. The other is to isolate the RO System fromthe BWST to preclude impacting the assumptions in the design basis LOCA dose analysis. Thespecific discussions from the LAR are restated below.

Section 2.1 of the LAR Enclosure states:

"The BWST water is routed to the RO System from the SF purification loop. This connection isat a lower elevation than the BWST so a break in the RO System piping will cause the BWST todrain if not isolated. Operator action and flow restriction by the orifice is credited to isolate anRO System piping break as described in the November 15, 2010 LAR."

Section 3.1 of the LAR Enclosure states:

"Since the proposed RO System takes suction from the BWST, Duke Energy proposes to use atime critical operator action to isolate the RO system from the BWST at the safety related ClassC seismic boundary valve. With this action, the addition of the RO system does not impact theassumptions in the design basis LOCA dose analysis."

Section 3.2.3 of the LAR Enclosure states:

"Rather than evaluate the impact of the RO System circulating post LOCA fluids in the AuxiliaryBuilding, Duke Energy committed to add a Time Critical Operator Action (TCOA) to isolate theRO System at the safety related Class C seismic boundary valve to preclude intake of postLOCA fluids into the RO system."

RAI-2:

The LAR does not indicate whether the proposed technical specification (TS) changes willpresent any new or increased opportunities for operator error. Please provide information as towhether the new changes might present increased opportunities for operator error and if thereare administrative controls in place to prevent or mitigate such errors.

Enclosure 1 - LAR 2012-05, Supplement 2June 11, 2013Page 2


The proposed TS changes provide upper tier requirements to ensure new equipment installed topermit RO system operation and actual RO system operation does not affect the health andsafety of the public. As with any new system, there will be increased opportunities for errorsthan if the equipment were not installed. Administrative and technical procedural controls will bein place prior to implementation to ensure the proposed TS are met when required. Requiredoperator and maintenance training is provided prior to implementation.

RAI-3:

In the previous LAR submittal, the NRC asked in an RAI regarding how the 33 minutes requiredfor the credited manual action were calculated and what kind of task analysis was used to runscenarios. Duke responded on August 2, 2011, however, that response is inadequate. Pleasedescribe what kind of task analysis was used, and how many scenarios were run, for thismanual action.


Duke Energy's response to acceptance review issue 4 on January 21, 2013, describes the taskanalysis used. As stated in that response, the original time study for isolating the RO system,described in the August 2, 2011, Duke Energy Response, was consistent with Duke Energyprocedures and industry standards (reference WCAP-16755-NP, Operator Time Critical ActionProgram Standard), which require only one time validation when the completion time is within80% of the TCOA. The original time study determined it would take 16.8 minutes to close asingle valve, which was within 80% of the 33 minute TCOA. The 16.8 minutes included a 25%(3.5 minute) margin for conservatism since the action was not included in a procedure and onlyvalidated with one individual/team.

However, in response to the specific NRC issue, Duke Energy performed 3 additional timevalidations with different operators to obtain an average time to close the valve from the furthestlocation. Please note that the furthest location is fixed since the operators report to the ControlRoom and are always dispatched from that location. The time validation was performed forSF-181 since it is slightly further from the Unit 1 & 2 Control Room than 3SF-181 is from theUnit 3 Control Room. The travel times from the time validations were 2.7 minutes, 2.17minutes, and 3.0 minutes resulting in an average time to close the valve of 2.62 minutes. Asnoted in response to NRC Issue 1 of the January 21, 2013, response, an additional quarter turnball valve will be added within a few feet of SF-181/3SF-181. The new time studyconservatively assumes 0.5 minute to travel to the second valve and 0.5 minute to close asecond quarter turn valve. Using the worst case travel time of 3.0 minutes, the new time studydemonstrates that the time required to isolate the RO System after a LOCA occurs is 14.67minutes. The additional 25% margin is not applied since the time validation was performed 3times with different operators.

A dedicated operator is not used. Rather, the requirement is driven by the EmergencyOperating Procedure (EOP). Within 2 minutes after a LOCA occurs, the EOP has been enteredand Immediate Manual Actions and Symptom Checks are complete. At this point, the SeniorReactor Operator (SRO) performs a notification requirement which sends a plant page for anAP/EOP Nuclear Equipment Operator (NEO) to report to the affected unit's control room and all


other NEOs report to the affected unit's Control Room. At 10 minutes (the new time study used10.17 minutes), a Reactor Operator dispatches an NEO to close SF-181 (time validations wereperformed for SF-1 81 and 3SF-1 81, times for SF-1 81 were used since it is slightly further awayand the times were longer). A stroke time of 30 seconds was conservatively assumed forclosing the 2 inch quarter turn ball valve.

RAI-4:

a. The LAR submittal states that an operator will be available to manually close theboundary valve if a loss-of-coolant accident (LOCA) were to occur with the purificationsystem in operation. It is unclear whether this operator could be assigned additionaltasks that may distract them, or where the operator will be located in the plant while thepurification system is in operation. Please describe the location, role, and other duties ofthe operator. The NRC staff is concerned that with the lack of automatic isolationvalves, the duties of this operator should be closely tied to the task of closing theisolation valves.

b. Please describe the qualifications of the operator which will ensure that he/she is able toperform the manual action.

c. During a LOCA, will there be other operators available to mitigate the LOCA conditionsand also allow for an operator to perform this manual action? Please describe howDuke plans to address this.


a. A dedicated nuclear equipment operator (NEO) will not be used. An NEO, specificallytrained for this time critical task, will be used to isolate the RO System. NuclearEquipment Operators (NEOs) are Nuclear Operations Specialists, Nuclear OperatorTechnicians, or Assistant Nuclear Operator Technicians assigned to a designated shiftto monitor and operate plant equipment. NEOs are the owners of the equipment in theirwatch station area. This means the operators assigned are aware of scheduled workactivities in their area and have input regarding the level of priority placed on equipmentand condition deficiencies identified. The requirement to isolate the RO System will bedriven by the Emergency Operating Procedure (EOP). Within 2 minutes after a LOCAoccurs, the EOP is entered and Immediate Manual Actions and Symptom Checks arecompleted. At this point, the Senior Reactor Operator (SRO) performs a notificationrequirement which sends a plant page for the AP/EOP Nuclear Equipment Operator(NEO) and all other NEOs to report to the affected unit's Control Room. Atapproximately 10 minutes, a Reactor Operator dispatches an NEO trained for thisspecific time critical task to close the boundary valves. At this point, the NEO isdedicated to the task.

b. NEOs are initially trained and qualified in accordance with Employee Training andQualification System (ETQS) Standard 3115.2. This standard, which applies to allnon-licensed operator (NLO) trainees, describes the method used to direct and ensureNLOs are trained and qualified to perform assigned tasks in a safe and efficient manner.Oconee Training Procedure (OTP) 4116.2 provides the proper methods for scheduling,conducting, documenting, and evaluating NEO requalification training.


The Critical Task NEOs are qualified by individual tasks. As such, at least one NEO pershift will be qualified to perform the new time critical action (TCA) of isolating the ROSystem from the BWST when directed to do so by a Reactor Operator. The NEOs arerequired to maintain cognizance of the status of all systems and equipment within theassigned watch stations by conducting two rounds per shift. This frequency is based onevaluating the risks of equipment failure versus the frequency of inspection. This allowsa balance between safety and productivity issues related to available personnelresources.

c. The required minimum number of nuclear equipment operators on shift is in excess ofthe number needed to mitigate a LOCA. As such, during a LOCA, other NEOs will beavailable to mitigate the LOCA conditions and also allow an operator to perform thismanual action.

RAI-5:

Section 4.0 of Attachment 1 contains very little information regarding Human Performancereview activities. Please answer the following:

a. What operator actions have been added, deleted or changed as a result of this LARsubmittal?

b. In several locations, the submittal states that operating experience was used to supportthis LAR. Please provide that relevant operating experience information.

c. Have there been changes to training? Please provide any information regardingchanges to training or qualifications as a result of this LAR.

d. Please describe any changes to physical interfaces, such as monitoring instruments forradioactivity, boron concentration, etc.

e. Will there be any changes required to the normal, abnormal and emergency operatingprocedures? If so, please provide a list of those changes.

f. Is a new function allocation needed as a result of this change? If so, please provide anyrelevant information regarding this analysis.

g. Describe the on-site validation of the manual action with the revised procedures, andtrained dedicated operators.

h. Please describe the long term human performance monitoring program, if any, which willprotect the modification from inadvertent change.



a. The EOP will require the SRO to send a plant page for NEOs to report to the affectedunit's control room (this requirement already existed). Approximately 10 minutes into theevent an RO is required to dispatch an NEO to close SF-1 81 and SF-1 96 or 3SF-181and 3SF-196. So there are two new operator actions related to the TCOA; one todispatch the NEO to close the RO System isolation valves and the other for the NEO totravel to the valves location and close the valves. The entire sequence from eventinitiation is a time critical operator action (TCOA). Operator action is also credited toisolate an RO System piping break within 45 minutes (per AB flooding procedure) toprevent the BWST from draining below the minimum TS limit (refer to the response toRAI 1 above).

b. The proposed Technical Specification (TS) Required Action (RA) Completion Times(CTs) and Surveillance Requirement (SR) Frequencies are based on ONS and industryoperating experience. The proposed RA CTs are based on similar ONS TechnicalSpecifications for the same action. TS 3.7.19 RA CTs are based on TS 3.6.3,Containment Isolation Valves, RA CTs. TS 3.9.8 RA CTs are based on TS 3.7.11,Spent Fuel Pool Water Level. The SR frequencies for SR 3.7.19.1 and SR 3.9.8.1 arebased on existing ONS TS SR frequencies for similar equipment. The proposed RA CTsand SR frequencies are consistent with similar Technical Specifications in NUREG 1430,Revision 3, B&W Standard Technical Specifications.

c. Licensed operator training will be provided prior to implementation of the TechnicalSpecifications for the RO system. This will include training on TS 3.7.19, TS 3.9.8, EOPchanges for the new time critical operator action (TCOA), and Abnormal Procedurechanges for Auxiliary Building flooding. As stated in the response to RAI 4.b, at leastone NEO per shift will be qualified to perform the new TCOA of isolating the RO Systemfrom the BWST when directed to do so by a Reactor Operator. Required training foroperation and maintenance of the RO System will be provided prior to RO Systemoperation.

d. The plant computer (OAC) points will be provided to include indication to all three UnitControl Rooms that the RO Unit is 1) running or not and 2) to note if the RO Unit was in"trouble status". The trouble indication alerts the Operators if there is an alarm or ashutdown on the RO Unit so that an Operator can be sent to investigate.

There are no other Operator interfaces added within the scope of this LicenseAmendment Request other than the indication provided by the manufacturer on the ROUnit itself.

e. The EOP will be changed to include a requirement to dispatch an NEO to close the ROisolation valves post LOCA. Changes to the Auxiliary Building flooding AbnormalProcedure are required to address the RO System as a new potential source of flooding.Periodic test procedures will be written and implemented for the new TS SurveillanceRequirements prior to TS implementation. RO System operating procedures will bewritten and implemented prior to RO System operation.


f. No further function allocation is planned. An evaluation was performed as part of theengineering change process which resulted in the decision to install locally operatedmanual valves and credit manual operator actions to close the valves rather than installvalves that could be remotely operated from the control room. The basis for thisdecision was that the RO unit will only be operated periodically (<10% of an operatingcycle and less as the silica levels are reduced), not continually. Additionally, ONS hasan adequate number of nuclear equipment operators on shift to perform the time criticaloperator action of closing the valves post LOCA. Also considered was the fact thatremote valve operation did not preclude operator error.

g. The on-site validation of the manual action was provided in Duke Energy's response toNRC Issue 4 in letter dated January 21, 2013, as summarized in the response to RAI 3above.

h. Engineering Changes are required in order to effect changes to the physical plant or tochange design functions. The Engineering Change process, controlled by a NuclearSystem Directive, ensures that inadvertent changes do not occur. Any changes to theEmergency Operating Procedure, Abnormal Procedures, and RO System operatingprocedure would require an applicability determination and/or a 10 CFR 50.59 screen orevaluation. This process is controlled by Nuclear System Directives and will precludeinadvertent changes to procedures that could change how the system is operated

RAI-6:

Demonstrate that the plant shielding design is sufficient to allow the vital operator actions beingcredited (to isolate the purification system and thereby prevent unanalyzed configurations ofradioactive water from the containment sump during LOCA recirculation) can be performedwithin the dose criterion of GDC 19 as prescribed in NUREG 0737 TMI Action Item ll.B.2.


The Time Critical Operator Action (TCOA) being credited (to isolate the purification system andthereby prevent unanalyzed configurations of radioactive water from the containment sumpduring LOCA recirculation) will be performed prior to the start of sump recirculation. Therefore,contaminated sump fluid in ECCS piping will not contribute to operator dose. A walkdown wasperformed to ensure there are no penetrations (piping or electrical) from the containment to theSpent Fuel Pool Cooling equipment room (where the RO supply manual isolation valves for theRO system are located), or along the operator's travel path. Therefore, since the TCOA occursprior to the initiation of sump recirculation and since there are no containment penetrations inthe room or along the operator's travel path, the only contribution to operator dose will bedirectly from containment (accounting for reactor building shielding of concrete and carbonsteel). The dose to the operator performing the TCOA will be less than 5 rem, or within thedose criterion of GDC19 as prescribed in NUREG 0737 TMI Action Item II.B.2.


RAI-7:

The LAR states that the RO system supply piping will be connected to the spent fuel poolpurification system using two safety-related seismic boundary valves and a flow limiting orifice.In lieu of automatically actuated isolation valves, the LAR proposes to use a time-criticaloperator action (TCOA) to ensure the RO system supply piping boundary valves are closedbefore initiation of containment sump recirculation after a LOCA to prevent potentially highlyradioactive water from entering the RO system, which is an unanalyzed configuration.Proposed Technical Specification (TS) 3.7.19 includes a note that states that the RO systemmay be unisolated intermittently under administrative control. The proposed TS Bases statethat:

The opening of a closed valve in the RO System flow path on an intermittentbasis under administrative control includes the following: (1) stationing anoperator, who is in constant communication with control room, at the valvecontrols, (2) instructing this operator to close these valves in an accidentsituation, and (3) assuring that environmental conditions will not preclude accessto close the valves and that this action will prevent the release of radioactivityoutside the RO System.

The actions stated in the TS Bases are consistent with the NRC staff's position in Generic Letter91-08 regarding acceptable administrative controls for intermittent opening of normally closedcontainment isolation valves. However, the response to NRC Issue 4 in the letter dated January21, 2013, states that a dedicated operator will not be used to ensure the RO system boundaryvalves are closed, because the action will be driven by the Emergency Operating Procedures(EOPs). Resolve the discrepancy between the administrative controls proposed in the TS Basisand the response dated January 21, 2013. Include the basis for how the proposedadministrative controls are adequate to ensure the RO system boundary valves are closed if adesign basis accident were to occur.


A dedicated operator would only be used when an RO supply manual isolation valve isinoperable and continued operation of the RO System is desired. The Note modifies the ActionTable and is only applicable if the affected Oconee unit is in a TS 3.7.19 Condition for aninoperable RO supply manual isolation valve. If the LCO is fully met (both RO supply manualisolation valves operable), the note is not applicable and RO system operation is permitted byrelying solely on the time critical operator action. The administrative controls will allow thecontrol room operator responsible for dispatching the NEO from the Control Room to use theoperator at the valve location to isolate the RO System from the Spent Fuel Purification System.This effectively eliminates the average 2.62 minute TCOA travel time (as described in RAI 3response above) and continues to ensure the RO System is isolated if a design basis accidentwere to occur.

RAI 8:

Proposed TS 3.7.19 states that the RO system may be unisolated intermittently underadministrative control. The proposed TS Bases state that a TCOA will be used to ensure thesystem is isolated so that the plant stays within the bounds of its design basis LOCA analysis.


However, the proposed TS and its Bases do not include any limitations on the duration for whichthe boundary valves may be open (how long is intermittent) or the time limit for the TCOA.Define the duration the RO system will be unisolated under administrative control and providethe basis for this duration. Revise the TS Bases to include limitations on the duration for whichthe RO system may be unisolated and to include the time limit for the TCOA.


There is no specified time limit on the duration for which the boundary valves may be openedintermittently under administrative controls. The time will be limited by resources available toserve as a dedicated valve operator. This note was modeled after the note for containmentisolation valves for TS 3.6.3 action table and is considered appropriate since the RO Systemsupply manual isolation valves are serving the same function as containment isolation valves.However, as stated in response to RAI 3 in Duke Energy letter dated February 18, 2011 (andincorporated by reference in this LAR), procedures controlling RO System operation will limitoperation to a specified time period to prevent the boron concentration in the Borated WaterStorage Tank (BWST) or Spent Fuel Pool (SFP) from going below TS limits. The maximum ROSystem operating period will be specified as 7 days for either alignment.

As stated in the response to RAI 7 above, if the LCO is fully met (both RO supply manualisolation valves operable), the note is not applicable and RO system operation is permitted byrelying on the time critical operator action. TS 3.7.19 Bases have been revised to indicate themaximum time (33 minutes) allowed to complete the TCOA and to indicate the maximum ROsystem operating period (7 days). A copy of the revised TS Bases is included in Enclosure 2.

RAI 9:

The LAR states that the RO system return piping is isolated from the BWST using a singlesafety related check valve. The licensee's NRC-approved design basis Alternate Source Term(AST) analysis for a LOCA (ML041540097), assumes 5 gallons per minute (gpm) back leakageof sump water into the BWST during recirculation. It is unclear to the staff whether failure of orleakage past the safety related check valve on the return piping could create an unanalyzedrelease path for BWST water. Describe the impact of failure of or leakage past the check valveon the ECCS leakage considered in the licensing basis accident analysis and the resultingconsequences.


The pair of isolation valves, *SF-181 and *SF-196, are closed to isolate the RO System fromany emergency sump back leakage. When these two valves are closed, the check valve,*SF-140, only functions to preserve the pressure boundary of the SF Cooling System, which has

not become contaminated by post- LOCA sump back leakage. This is because the *SF-181 and*SF-196 valves will be closed before post-LOCA sump back leakage could occur.


RAI 10:

Please verify whether responses to NRC staff's RAI 1 and RAI 2, as stated in the licensee'sletter dated February 18, 2011, are applicable to the new LAR provided in the licensee's letterdated October 30, 2012. If not, please revise and submit any changes.


The response to RAI 1, as stated in Duke Energy's letter dated February 18, 2011, areapplicable to the new LAR except that now the only remaining work is the implementation of thepiping and supports needed for new isolation valves SF-1 96 and 3SF-1 96.

The first paragraph in the answer to RAI 2 no longer applies to the October 30, 2012 submittal.The effects of a postulated high energy line break (HELB) in the high energy portion of the ROsystem were analyzed to determine if a postulated pipe whip or jet impingement has thepotential to damage any safe shutdown target equipment, or safe shutdown system pressureboundary piping. However, the methodology used in the jet impingement evaluation wasrecently discovered to be inconsistent with the guidance provided in ANSI/ANS 58.2-1988. Thisevaluation will be revised to conform with the guidance in ANSI/ANS 58.2-1988 prior to placingthe RO system into service. The revised evaluation is expected to result in no impact on anysafe shutdown target and will be completed prior to placing the RO System in service.

The second paragraph of the answer to RAI 2 remains applicable to the new LAR. The routingof the RO System piping has not changed since the February 18, 2011, response to RAI 2 suchthat the RO System piping would be impacted by any existing postulated HELB.

RAI 11:

In the licensee's letter dated February 18, 2011, the response to RAI 1 indicated that RO pipinggoing through the Hot Machine Shop was not completed. Consequently, the NRC staff auditedONS calculation No. OSC-10167, Revision (Rev) 2, written for that section of RO piping, andfound it acceptable. Please verify whether OSC-10167, Rev 2 is still applicable and valid for thenew LAR provided in the licensee's letter dated October 30, 2012. If this calculation has beenrevised, please provide the level of revision and discuss revised changes.


OSC-10167, Rev 2 is still applicable and valid.

RAI 12:

For the interaction of non-seismic structures, systems, and components (SSCs) with SSCsdesigned for seismic conditions, please provide the following:

a) Describe the method and criteria used which ensure that non-seismic piping connecting toseismic piping will not adversely affect the structural integrity of the seismic piping (i.e. overlapanalysis requirements).


b) Describe the method and criteria used in the piping analysis for connecting proposed newlyadded piping to existing piping (i.e. overlap and/or decoupling requirements).

c) For the interaction of newly proposed SSCs to existing SSCs and vice versa, discuss howthe licensee ensures that excessive movement, collapse or failure of non-seismic SSCs will notadversely affect the structural integrity of seismically qualified SSCs (i.e. seismic two-over-onecriteria).


a) A variety of typical structural isolation techniques are employed. These include structuralanchors and flex hoses. The structural anchors or flex hoses are installed on the non-seismic piping. The structural anchor or flex hose becomes a structural boundary for theanalysis of the seismic piping. The non-seismic piping on the seismic side of the structuralanchor or flex hose is included in the seismic piping analysis and supported with seismicsupports.

b) Standard methods and criteria are used for connecting new piping to existing piping. Inseveral cases the new piping is included in the existing analysis of the existing piping. Inthis situation the analysis is extended to include the new seismic piping and some non-seismic piping to a structural boundary as described in 12a). Decoupling criteria is alsoemployed. The section modulus criterion is used where the ratio of section modulus shallbe less than 0.1. In this case the smaller section pipe is decoupled from the analysis of thelarger section pipe. The connection is considered an anchor in the analysis of the smallersection pipe and appropriate movements of the larger pipe are included in the analysis ofthe smaller pipe.

c) Seismic two-over-one concerns are identified early in the design process while the new SSClayout is determined in the plant. When a seismic two-over-one concern is identified, a newlayout in the plant is determined. When there is no new layout in the plant that does nothave'a two-over-one concern, the Design/Civil group is contacted to protect againstunacceptable interaction. This is achieved by several methods including supporting thenon-seismic SSC to assure interaction does not occur or providing structural barriers toassure that non-seismic SSC failure will not interact with seismic SSCs.

RAI 13:

The following valves are addressed by proposed Technical Specification (TS) 3.7.19, ReverseOsmosis (RO) System Isolation from Borated Water Storage Tank (BWST):

Units 1 & 2:SF-1 81 and SF-1 96, RO System BWST supply manual isolation valves.SF-57, BWST Recirculation Pump suction valve.

Unit 33SF-181 and 3SF-1 96, RO System BWST supply manual isolation valves.3SF-57, BWST Recirculation Pump suction valve.

a. The submittals indicate that these valves will be included in the Oconee InserviceTesting Program, and will therefore be tested in accordance with the applicablerequirements of the American Society of Mechanical Engineers (ASME) Code for


Operation and Maintenance of Nuclear Power Plants (OM Code). Will all of these valvesbe categorized as manual, active, and Category A valves?

b. If these valves will all be categorized the same, is there a reason that the proposedSurveillance Requirement (SR) 3.7.19.2 and SR 3.7.19.3 for the RO System BWSTsupply manual isolation valves and the BWST Recirculation Pump suction valves,respectively, are written differently?

c. If these valves are not all categorized the same, please provide an explanation of whynot?


a. No. The valves will not all be categorized alike. The valves will be categorized asfollows:

SF-1 81, SF-1 96, 3SF-1 81, 3SF-1 96: these valves will be manual, active, Category Avalves.SF-57, 3SF-57: these valves will be manual, passive, Category A valves. These valvesmust be in the closed position in order to operate RO on the BWST. If there is anaccident, the valves will remain closed.

b. Since SF-57, 3SF-57 is closed (passive function); it does not have to be cycled. It isonly required to meet IST leakage requirements when closed for RO system operation.

c. All valves will be Category A, manual valves. Valves SF-1 81, SF-1 96, 3SF-1 81, 3SF-196 will be active because they must be open during RO operation and must be closedin the event of an accident. Valves SF-57 and 3SF-57 must be closed during ROoperation and must remain closed in the event of an accident.

RAI 14:

Logical connector AND between REQUIRED ACTIONS A.1 and A.2 for CONDITION A, "ROsystem not isolated," in proposed LCO 3.9.8, "Reverse Osmosis (RO) System OperatingRestrictions for Spent Fuel Pool (SFP)," is shown between the text of the ACTIONS statements.Since both of these ACTIONS must be completed when in CONDITION A, logical connectorAND needs to be shifted to the left between ACTIONS A.1 and A.2 as shown in example 1.2-1in Oconee's TSs.


The formatting error identified in the RAI has been corrected and a revised copy of the proposedTS is provided in Enclosure 2.

RAI 15:

The licensee's proposed SR 3.7.19.1 verifies the RO System seismic boundary valve that is notlocked, sealed, or otherwise secured, is closed, except when the valve is open during RO


System operation. The licensee's proposed SR 3.9.8.1 requires verification that the RO Systemis isolated by breaking the siphon from the Spent Fuel Pool (SFP).

Regarding Frequency for SR 3.7.19.1, the licensee states:

"The Frequency is in accordance with the Surveillance Frequency Control Program (SFCP).The initial 31 day Frequency specified in the Surveillance Frequency List (SFL) will be 31 days.This periodic frequency is based on engineering judgment and was chosen to provide addedassurance of the correct valve position."

Regarding Frequency for SR 3.9.8.1, the licensee states:

"SR 3.9.8.1 requires verification that the RO System is isolated by breaking the siphon from theSFP with a Frequency in accordance with the Surveillance Frequency Control Program. Theinitial Frequency specified in the SFL will be 7 days. This periodic frequency is consideredreasonable since the siphon can only be re-established by deliberate actions and RO operationwill be controlled by unit procedures and are acceptable, based on operating experience."

The licensee's TS Section 5.5.21, "Surveillance Frequency Control Program," specifies controlsfor Surveillance Frequencies. It further states, "The program shall ensure that SurveillanceRequirements specified in the Technical Specifications are performed at intervals sufficient toassure the associated Limiting Conditions for Operation are met."

Please provide details on the engineering judgment which determined that the SurveillanceFrequencies for the seismic boundary valve and verification of RO system isolation should be31 days and 7 days, respectively, and provide justification consistent with the level ofinformation required to establish the SFCP for placing the seismic boundary valve Frequency inthe SFCP.


Regarding SR 3.7.19.1

The 31 day frequency of proposed SR 3.7.19.1 is consistent with current TS 3.6.3.2. TS 3.6.3,Containment Isolation Valves, have the same applicability as proposed TS 3.7.19. Similar toContainment Isolation Valves, the RO System seismic boundary valves are provided toeliminate the potential unanalyzed release pathway and ensure the plant stays within thebounds of the design basis LOCA analysis. When the RO system is not in operation, theseismic boundary valves are required to be closed.

Duke Energy determined the 31 day frequency for verifying the RO System BWST supplymanual isolation valves closed is appropriate since they provided a similar function as thecontainment isolation valves. The containment isolation valves minimize the loss of reactorcoolant inventory and establishing the containment boundary during an accident. The 31 dayFrequency for the ONS containment isolation valves is consistent with the SR Frequency formanual valves located outside of containment (SR 3.6.3.3) in NUREG 1430, Revision 4, B&WStandard Technical Specification. The ONS and BWOG STS SR frequencies both state theyare based on engineering judgment and were chosen to provide added assurance of the correctpositions.


Therefore, this justification is consistent with the level of information required to establish theSFCP for placing the SR Frequency in the SFCP.

Regarding SR 3.9.8.1:

The 7 day frequency of proposed SR 3.9.8.1 is consistent with current TS SR 3.7.11.1. TS3.7.11, Spent Fuel Water Level, has the same applicability as proposed TS 3.9.8: Duringmovement of irradiated fuel assemblies in the Spent Fuel Pool and during movement of caskover the Spent Fuel Pool. SR 3.7.11.1 verifies that sufficient Spent Fuel Pool water is availablein the event of a fuel handling or cask drop accident. The water level in the Spent Fuel Poolmust be checked periodically. The basis for 7 day Frequency of 3.7.11.1 is that the volume inthe pool is normally stable. Water level changes are controlled by unit procedures and areacceptable, based on operating experience.

Duke Energy determined the 7 day frequency for verifying the RO system is isolated from theSpent Fuel Pool is appropriate since there is a physical barrier that must be overcome beforethe RO System can be lined up to the spent fuel pool that takes a deliberate operator action.Since the only time the RO System has the potential for providing an unanalyzed releasepathway is during activities (movement of irradiated fuel assemblies in the SFP and movementof cask over the SFP) that could result in damage to irradiated fuel assemblies, the verificationis only required during these activities. Since the 7 day frequency was considered adequate forwater level monitoring during these type activities, the 7 day frequency was also consideredadequate for verifying the RO system is isolated. Further, the water level monitoring required bySR 3.7.11.1 would likely identify that the RO system is not isolated and in operation since itwould be lowering the SFP water level and requiring makeup to maintain water level. The SRfrequency for ONS TS SR 3.7.11.1 is consistent with the frequency of NUREG 1430,Revision 4, B&W Standard Technical Specification, TS SR 3.7.14.1.

Therefore, this justification is consistent with the level of information required to establish theSFCP for placing the SR Frequency in the SFCP.

License Amendment Request No. 2011-05, Supplement 2

June 11, 2013

ENCLOSURE 2

Revised TS and TS Bases Pages

RO System Operating Restrictions for SFP3.9.8

3.9 REFUELING OPERATIONS

3.9.8 Reverse Osmosis (RO) System Operating Restrictions for Spent Fuel Pool (SFP)

LCO 3.9.8 The RO System shall be isolated from the spent fuel pool by breaking thesiphon from the SFP.

APPLICABILITY: During movement of irradiated fuel assemblies in the SFP,During movement of cask over the SFP.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. RO System not isolated ------------ NOTE--------LCO 3.0.3 is not applicable

A.1 Suspend the movement Immediatelyof irradiated fuelassemblies in the SFP

AND

A.2 Suspend the movement Immediatelyof cask over the SFP

SURvEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.9.8.1 Verify RO System is isolated by breaking the siphon In accordance withfrom the SFP. the Surveillance

Frequency ControlProgram

OCONEE UNITS 1, 2, & 3 3.9.8-1 Amendment Nos.

RO System Isolation from BWSTB 3.7.19

B 3.7 Plant Systems

B 3.7.19 Reverse Osmosis (RO) System Isolation from Borated Water Storage Tank (BWST)

BASES

BACKGROUND The RO System removes silica from the Spent Fuel Pools (SFPs) andBWSTs by using a reverse osmosis filtering process.

The RO System, which consists of an RO unit and supply and returnpiping from the BWSTs and SFPs, is located in the Unit 2 Pipe TrenchArea Room (Room 349) directly below the Unit 2 West Penetration Room(WPR). A single RO unit is shared by all three Oconee Nuclear Station(ONS) units. The RO unit is capable of being aligned to the Unit 1 & 2SFP, the Unit 3 SFP, the Unit 1 BWST, the Unit 2 BWST, or the Unit 3BWST. RO System piping and existing Spent Fuel (SF) Purification Looppiping are used for these alignments.

To establish a path from the Unit 1 and Unit 2 BWSTs, RO System pipingis connected to the Unit 1 & 2 Spent Fuel (SF) Purification Loop. The RObranch line contains two safety related seismically qualified manualisolation valves. Unit 1 & 2 share common manual isolation valves,SF-1 81 and SF-196. To establish a path from the Unit 3 BWST, ROSystem piping is connected to the Unit 3 SF Purification Loop. The RObranch line contains two safety related seismically qualified manualisolation valves, 3SF-181 and 3SF-196.

The return piping from the RO unit is routed back to the purificationportion of the SF Cooling Systems (Units 1 & 2 and Unit 3). The ROSystem return piping is non-seismic up to the point where connectionsare made to the SF purification piping. An isolation valve and a checkvalve are installed in series in each of the return lines to the SFpurification piping. The check valve and its downstream piping areseismically qualified. BWST Recirculation Pump Suction Valves (SF-57for Unit 1 & 2 or 3SF-57 for Unit 3) will be closed while the RO System isoperating on the respective unit to ensure post-LOCA fluids cannot reachthe top of the BWST through the piping as aligned for RO Systemoperation. The location where the discharge piping connects to thepurification loop is such that the return flow can be aligned to the samesource supplying the RO unit.

The BWST water is routed to the RO System from the SF purificationloop. This connection is at a lower elevation than the BWST so a breakin the RO System piping will cause the BWST to drain if not isolated.

OCONEE UNITS 1, 2, & 3 B 3.7.19-1 Amendment Nos.


BASES

BACKGROUND(continued)

Operator action is credited to isolate an RO System piping break. Creditis also taken for a 33 minute time critical operator action (TCOA) toisolate the RO system from the BWST by closing the two safety-relatedmanual isolation valves to preclude sump back-leakage and ensure theplant stays within the bounds of the design basis loss of coolant accident(LOCA) analysis. This action is initiated after receipt of an EngineeredSafeguards (ES) actuation signal.

APPLICABLE The large break LOCA assumes back-leakage from the sump to theSAFETY ANALYSES borated water storage tank (BWST). Since the RO system takes suction

from the BWST, a 33 minute TCOA is used to isolate the RO systemfrom the BWST at the safety related/non safety related boundary.Additionally, the BWST Recirculation Pump Suction Valve is closed priorto RO system operation to ensure post LOCA back-leakage cannot reachthe top of the BWST through the piping as aligned for RO Systemoperation. With the isolation of these pathways, the use of the ROsystem does not impact the assumptions in the design basis LOCA doseanalysis. The 33 minute TCOA isolates the pathway prior to increasingradiation levels making the location inaccessible and before post-LOCAfluids can reach the BWST. This operator action, isolation ofcomponents that are part of the primary success pathway which functionsto mitigate the LOCA, meets 10 CFR 50.36, Criterion 3 (Reference 2).The isolation of the RO system credits two safety related manual isolationvalves to ensure the plant stays within the bounds of the design basisLOCA analysis.

LCO This LCO requires that the two manual isolation valves (SF-181 andSF-1 96 for Unit 1 and 2 and 3SF-181 and 3SF-1 96 for Unit 3) used toisolate the RO System from BWST to be OPERABLE. The valves areconsidered OPERABLE when they are closed or capable of being closedprior to initiation of ECCS recirculation. The LCO is modified by a noteindicating that the BWST Recirculation Pump Suction Valve (SF-57 forUnit 1 & 2 or 3SF-57 for Unit 3) shall be closed and meet InserviceTesting Program leakage requirements while the RO System is inoperation to ensure post-LOCA fluids cannot reach the top of the BWSTas a result of the piping alignment during RO System operation

APPLICABILITY The RO System isolation valves are required to be OPERABLE inMODES 1, 2, 3, and 4, consistent with emergency core cooling system(ECCS) recirculation OPERABILITY requirements. The RO Systemisolation valves must be OPERABLE to ensure the plant stays within thebounds of the design basis LOCA analysis.



BASES (continued)

ACTIONS The ACTIONS are modified by a Note allowing the RO System flow path tobe unisolated intermittently under administrative controls. The opening of aclosed valve in the RO System flow path on an intermittent basis underadministrative control includes the following: (1) stationing an operator,who is in constant communication with control room, at the valve controls,(2) instructing this operator to close these valves in an accident situation,and (3) assuring that environmental conditions will not preclude access toclose the valves and that this action will prevent the release of radioactivityoutside the RO System. In this way, the flow path can be rapidly isolatedwhen a need for isolation is indicated. The maximum RO systemoperating period is 7 days. Procedures controlling RO System operationlimit operation to a specified time period to prevent the boronconcentration going below the limit in the Borated Water Storage Tank(BWST).

A. 1 and A.2

In the event one RO System BWST supply manual isolation valve isinoperable, the flow path must be isolated within 4 hours. The method ofisolation must include the use of at least one isolation barrier that cannot beadversely affected by a single active failure. Isolation barriers that meetthis criterion are a closed and de-activated automatic isolation valve, aclosed and de-activated non-automatic power operated valve, a closedmanual valve, or a blind flange. For the RO System flow path isolated inaccordance with Required Action A. 1, the device used to isolate the flowpath should be the closest available to the inoperable RO System BWSTsupply isolation valve. The 4-hour Completion Time is consideredreasonable, considering the time required to isolate the flow path and thelow probability of an accident occurring during this time period requiringisolation of the RO system from the BWST.

For a manual isolation valve that cannot be restored to OPERABLE statuswithin the 4 hour Completion Time and that has been isolated inaccordance with Required Action A. 1, the flow path must be verified to beisolated on a periodic basis. This periodic verification is necessary toensure that the flow path is isolated should an event occur requiring it to beisolated. This Required Action does not require any testing or devicemanipulation. Rather, it involves verification, through a system walkdown,that an isolation device capable of being mispositioned is in the correctposition. The Completion Time of "once per 31 days" is appropriateconsidering the fact that the device is operated under administrativecontrols and the probability of its misalignment is low.



BASES

ACTIONS B..1(continued)

In the event two RO System BWST supply manual isolation valves areinoperable, the flow path must be isolated within 1 hour. The method ofisolation must include the use of at least one isolation barrier that cannot beadversely affected by a single active failure. Isolation barriers that meetthis criterion are a closed and de-activated automatic isolation valve, aclosed and de-activated non-automatic power operated valve, a closedmanual valve, or a blind flange. For the RO System flow path isolated inaccordance with Required Action B. 1, the device used to isolate the flowpath should be the closest available to the RO System BWST supplymanual isolation valves. The 1-hour Completion Time is consideredreasonable, considering the time required to isolate the flow path and thelow probability of an accident occurring during this time period requiringisolation of the RO system from the BWST.

In the event the affected RO System flow path is isolated in accordancewith Required Action B.1, the flow path must be verified to be isolated on aperiodic basis per Required Action A.2, which remains in effect. Thisperiodic verification is necessary to ensure that the flow path is isolatedshould an event occur requiring it to be isolated. The Completion Time ofonce per 31 days for verifying the flow path is isolated is appropriateconsidering the fact that the device is operated under administrativecontrols and the probability of its misalignment is low.

C.1 and C.2

In the event the RO System is operating and the BWST RecirculationPump suction valve is discovered not closed or it is determined theInservice Testing (IST) Program leakage requirements are not met, theflow path must be isolated and RO system operation must be discontinuedwithin 1 hour. The 1-hour Completion Time is considered reasonable,considering the time required to isolate the flow path and discontinue ROSystem operation and the low probability of an accident occurring duringthe time period requiring this action. If the suction valve is discovered notclosed, the requirement is to isolate the flow path with the suction valve.In this case, the requirements of the LCO are met and the Condition nolonger applies. However, if the suction valve is discovered to not meetIST Program leakage requirements, the flow path must be isolated usinga valve that meets these requirements and RO System operation must bediscontinued. This is necessary to ensure that the flow path to the top ofthe BWST is isolated.



BASES

ACTIONS D.1 and D.2(continued)

If the Required Actions and associated Completion Times of Condition A,B, or C are not met, the unit must be brought to a MODE in which the LCOdoes not apply. To achieve this status, the unit must be brought to at leastMODE 3 within 12 hours and to MODE 5 within 36 hours. The allowedCompletion Times are reasonable, based on operating experience, toreach the required unit conditions from full power conditions in an orderlymanner and without challenging unit systems.

SURVEILLANCE SR 3.7.19.1REQUIREMENTS

This SR requires verification that RO System BWST manual isolationvalves (SF-181 and SF-1 96 for Unit 1 & 2 and 3SF-1 81 and 3SF-196 forUnit 3) not locked, sealed, or otherwise secured in the closed position, areclosed. The SR helps to ensure that post accident leakage of radioactivefluids do not impact the offsite dose analysis. This SR does not require anytesting or valve manipulation. Rather, it involves verification, through asystem walkdown, that each manual isolation valve is closed. TheSurveillance Frequency is based on operating experience, equipmentreliability, and plant risk and is controlled under the SurveillanceFrequency Control Program. The SR specifies that the manual isolationvalve is not required to be closed during RO System operation. During thetime period the manual isolation valves are open, a 33 minute TCOA iscredited to close the valves should an accident occur requiring isolation ofthe flow path. This SR does not apply if a valve is locked, sealed, orotherwise secured, since it was verified to be in the correct position uponlocking, sealing, or securing.

SR 3.7.19.2

This SR verifies that the RO System supply manual isolation valves(SF-1 81 and SF-1 96 for Unit 1 & 2 and 3SF-1 81 and 3SF-1 96 for Unit 3)that are used to isolate the BWST from the RO System are OPERABLEin accordance with the Inservice Testing Program. The specifiedFrequency is in accordance with the Inservice Testing Programrequirements.



BASES

SURVEILLANCE SR 3.7.19.3REQUIREMENTS

(continued) This SR verifies that the BWST Recirculation Pump suction valve (SF-57for Unit 1 & 2 or 3SF-57 for Unit 3) meets Inservice Testing Programleakage requirements when closed for RO System operation. Thespecified frequency is in accordance with the Inservice Testing Programrequirements.

REFERENCES 1. UFSAR, Section 9.1.3.

2. 10 CFR 50.36.


License Amendment Request No. 2011-05, Supplement 2June 11, 2013

ENCLOSURE 3

REGULATORY COMMITMENTS

The following commitment table identifies those actions committed to by Duke EnergyCarolinas, LLC (Duke Energy) in this submittal. Other actions discussed in the submittalrepresent intended or planned actions by Duke Energy. They are described to the NuclearRegulatory Commission (NRC) for the NRC's information and are not regulatory commitments.

Commitment Completion Date

1 The Reverse Osmosis System High Energy Line Break (HELB) Prior to Reverseevaluation will be revised to conform with the guidance in Osmosis SystemANSI/ANS 58.2-1988. Operation

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