ML13172A043

Response to Request for Additional Information Associated with License Amendment Request for Reverse Osmosis System Operation License Amendment Request No. 2012-05, Supplement 2

ML13172A043
Person / Time
Site:	Oconee
Issue date:	06/11/2013
From:	Batson S Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML13172A043 (26)

Text

II,

DUKE ENERG Scott L.

Batson Vice President Oconee Nuclear Station Duke Energy ONO1VP 17800 Rochester Hwy Seneca, SC 29672 10 CFR 50.90 o: 864.873.3274 864.873.4208 June 11, 2013 Scott.Batson@duke-energy.com U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2 and 3 Renewed 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 License Amendment 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 License Amendment Request (LAR) requesting Nuclear Regulatory Commission (NRC) approval to operate a Reverse Osmosis (RO) System to remove silica from the Borated Water Storage Tanks (BWSTs) and Spent Fuel Pools (SFPs) during Unit operation. The LAR also requested approval of associated proposed new Technical Specifications (TSs) and Bases that impose new requirements for RO System operation and isolation. Duke Energy submitted supplemental information on January 21, 2013 in response to additional information requested during the NRC Acceptance Review. By letter dated April 12, 2013, NRC requested Duke Energy provide additional information. provides the additional information. Enclosure 2 provides changes to the proposed Technical Specification and Bases associated with NRC RAI 14 and RAI 8, respectively. The changes proposed by this supplement are bounded by the no significant hazards consideration submitted in the October 30, 2012, LAR. Enclosure 3 provides a list of regulatory commitments associated with this letter.

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

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

Sincerely, Scott L. Batson Vice President Oconee Nuclear Station www.duke-energy.com

U. S. Nuclear Regulatory Commission June 11, 2013 Page 2

Enclosures:

- Duke Energy Response to Request for Additional Information - Revised TS and TS Bases - List of Regulatory Commitments

U. S. Nuclear Regulatory Commission June 11, 2013 Page 3 cc w/enclosures:

Mr. Victor McCree, Regional Administrator U. S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. John Boska, Senior Project Manager (by electronic mail only)

Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop O-8G9A Rockville, MD 20852-2746 Mr. Ed Crowe NRC Senior Resident Inspector Oconee Nuclear Site Ms. Susan Jenkins, Manager Radioactive & Infectious Waste Management Division of Waste Management South Carolina Department of Health and Environmental Control 2600 Bull St.

Columbia, SC 29201

License Amendment Request No. 2011-05, Supplement 2 June 11, 2013 ENCLOSURE I Duke Energy Response to Request for Additional Information

License Amendment Request No. 2011-05, Supplement 2 June 11, 2013 Page 1 Duke 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, and components 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) identifies two specific required operator actions. One is to isolate an RO system pipe break to prevent the BWST from draining below the minimum TS limit. The other is to isolate the RO System from the BWST to preclude impacting the assumptions in the design basis LOCA dose analysis. The specific 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 is at a lower elevation than the BWST so a break in the RO System piping will cause the BWST to drain if not isolated. Operator action and flow restriction by the orifice is credited to isolate an RO 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 a time critical operator action to isolate the RO system from the BWST at the safety related Class C seismic boundary valve. With this action, the addition of the RO system does not impact the assumptions 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 Auxiliary Building, Duke Energy committed to add a Time Critical Operator Action (TCOA) to isolate the RO System at the safety related Class C seismic boundary valve to preclude intake of post LOCA fluids into the RO system."

RAI-2

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

- LAR 2012-05, Supplement 2 June 11, 2013 Page 2 Duke Energy Response:

The proposed TS changes provide upper tier requirements to ensure new equipment installed to permit RO system operation and actual RO system operation does not affect the health and safety of the public. As with any new system, there will be increased opportunities for errors than if the equipment were not installed. Administrative and technical procedural controls will be in place prior to implementation to ensure the proposed TS are met when required. Required operator 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 required for the credited manual action were calculated and what kind of task analysis was used to run scenarios. Duke responded on August 2, 2011, however, that response is inadequate. Please describe what kind of task analysis was used, and how many scenarios were run, for this manual action.

Duke Energy Response:

Duke Energy's response to acceptance review issue 4 on January 21, 2013, describes the task analysis 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 Energy procedures and industry standards (reference WCAP-16755-NP, Operator Time Critical Action Program Standard), which require only one time validation when the completion time is within 80% of the TCOA. The original time study determined it would take 16.8 minutes to close a single 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 only validated with one individual/team.

However, in response to the specific NRC issue, Duke Energy performed 3 additional time validations with different operators to obtain an average time to close the valve from the furthest location. Please note that the furthest location is fixed since the operators report to the Control Room and are always dispatched from that location. The time validation was performed for SF-181 since it is slightly further from the Unit 1 & 2 Control Room than 3SF-181 is from the Unit 3 Control Room. The travel times from the time validations were 2.7 minutes, 2.17 minutes, and 3.0 minutes resulting in an average time to close the valve of 2.62 minutes. As noted in response to NRC Issue 1 of the January 21, 2013, response, an additional quarter turn ball valve will be added within a few feet of SF-181/3SF-181.

The new time study conservatively assumes 0.5 minute to travel to the second valve and 0.5 minute to close a second quarter turn valve. Using the worst case travel time of 3.0 minutes, the new time study demonstrates that the time required to isolate the RO System after a LOCA occurs is 14.67 minutes.

The additional 25% margin is not applied since the time validation was performed 3 times with different operators.

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

- LAR 2012-05, Supplement 2 June 11, 2013 Page 3 other NEOs report to the affected unit's Control Room. At 10 minutes (the new time study used 10.17 minutes), a Reactor Operator dispatches an NEO to close SF-181 (time validations were performed for SF-1 81 and 3SF-1 81, times for SF-1 81 were used since it is slightly further away and the times were longer). A stroke time of 30 seconds was conservatively assumed for closing the 2 inch quarter turn ball valve.

RAI-4

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

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

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

Duke Energy Response:

a. A dedicated nuclear equipment operator (NEO) will not be used. An NEO, specifically trained for this time critical task, will be used to isolate the RO System. Nuclear Equipment Operators (NEOs) are Nuclear Operations Specialists, Nuclear Operator Technicians, or Assistant Nuclear Operator Technicians assigned to a designated shift to monitor and operate plant equipment. NEOs are the owners of the equipment in their watch station area. This means the operators assigned are aware of scheduled work activities in their area and have input regarding the level of priority placed on equipment and condition deficiencies identified. The requirement to isolate the RO System will be driven by the Emergency Operating Procedure (EOP). Within 2 minutes after a LOCA occurs, the EOP is entered and Immediate Manual Actions and Symptom Checks are completed. At this point, the Senior Reactor Operator (SRO) performs a notification requirement 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. At approximately 10 minutes, a Reactor Operator dispatches an NEO trained for this specific time critical task to close the boundary valves. At this point, the NEO is dedicated to the task.

b. NEOs are initially trained and qualified in accordance with Employee Training and Qualification System (ETQS) Standard 3115.2. This standard, which applies to all non-licensed operator (NLO) trainees, describes the method used to direct and ensure NLOs 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.

- LAR 2012-05, Supplement 2 June 11, 2013 Page 4 The Critical Task NEOs are qualified by individual tasks. As such, at least one NEO per shift will be qualified to perform the new time critical action (TCA) of isolating the RO System from the BWST when directed to do so by a Reactor Operator. The NEOs are required to maintain cognizance of the status of all systems and equipment within the assigned watch stations by conducting two rounds per shift. This frequency is based on evaluating the risks of equipment failure versus the frequency of inspection. This allows a balance between safety and productivity issues related to available personnel resources.

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

RAI-5

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

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

b.

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

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

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

e. Will there be any changes required to the normal, abnormal and emergency operating procedures? 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 any relevant information regarding this analysis.

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

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

- LAR 2012-05, Supplement 2 June 11, 2013 Page 5 Duke Energy Response:

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

b. The proposed Technical Specification (TS) Required Action (RA) Completion Times (CTs) and Surveillance Requirement (SR) Frequencies are based on ONS and industry operating experience. The proposed RA CTs are based on similar ONS Technical Specifications 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 are based on existing ONS TS SR frequencies for similar equipment. The proposed RA CTs and 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 Technical Specifications for the RO system. This will include training on TS 3.7.19, TS 3.9.8, EOP changes for the new time critical operator action (TCOA), and Abnormal Procedure changes for Auxiliary Building flooding. As stated in the response to RAI 4.b, at least one NEO per shift will be qualified to perform the new TCOA of isolating the RO System from the BWST when directed to do so by a Reactor Operator. Required training for operation and maintenance of the RO System will be provided prior to RO System operation.

d. The plant computer (OAC) points will be provided to include indication to all three Unit Control 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 a shutdown 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 License Amendment Request other than the indication provided by the manufacturer on the RO Unit itself.

e. The EOP will be changed to include a requirement to dispatch an NEO to close the RO isolation valves post LOCA. Changes to the Auxiliary Building flooding Abnormal Procedure 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 Surveillance Requirements prior to TS implementation. RO System operating procedures will be written and implemented prior to RO System operation.

- LAR 2012-05, Supplement 2 June 11, 2013 Page 6

f.

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

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

h. Engineering Changes are required in order to effect changes to the physical plant or to change design functions. The Engineering Change process, controlled by a Nuclear System Directive, ensures that inadvertent changes do not occur. Any changes to the Emergency Operating Procedure, Abnormal Procedures, and RO System operating procedure would require an applicability determination and/or a 10 CFR 50.59 screen or evaluation. This process is controlled by Nuclear System Directives and will preclude inadvertent 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 being credited (to isolate the purification system and thereby prevent unanalyzed configurations of radioactive water from the containment sump during LOCA recirculation) can be performed within the dose criterion of GDC 19 as prescribed in NUREG 0737 TMI Action Item ll.B.2.

Duke Energy Response:

The Time Critical Operator Action (TCOA) being credited (to isolate the purification system and thereby prevent unanalyzed configurations of radioactive water from the containment sump during 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 was performed to ensure there are no penetrations (piping or electrical) from the containment to the Spent Fuel Pool Cooling equipment room (where the RO supply manual isolation valves for the RO system are located), or along the operator's travel path. Therefore, since the TCOA occurs prior to the initiation of sump recirculation and since there are no containment penetrations in the room or along the operator's travel path, the only contribution to operator dose will be directly from containment (accounting for reactor building shielding of concrete and carbon steel). The dose to the operator performing the TCOA will be less than 5 rem, or within the dose criterion of GDC19 as prescribed in NUREG 0737 TMI Action Item II.B.2.

- LAR 2012-05, Supplement 2 June 11, 2013 Page 7

RAI-7

The LAR states that the RO system supply piping will be connected to the spent fuel pool purification 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-critical operator action (TCOA) to ensure the RO system supply piping boundary valves are closed before initiation of containment sump recirculation after a LOCA to prevent potentially highly radioactive 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 system may be unisolated intermittently under administrative control. The proposed TS Bases state that:

The opening of a closed valve in the RO System flow path on an intermittent basis under administrative 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 to close the valves and that this action will prevent the release of radioactivity outside the RO System.

The actions stated in the TS Bases are consistent with the NRC staff's position in Generic Letter 91-08 regarding acceptable administrative controls for intermittent opening of normally closed containment isolation valves. However, the response to NRC Issue 4 in the letter dated January 21, 2013, states that a dedicated operator will not be used to ensure the RO system boundary valves 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 Basis and the response dated January 21, 2013. Include the basis for how the proposed administrative controls are adequate to ensure the RO system boundary valves are closed if a design basis accident were to occur.

Duke Energy Response:

A dedicated operator would only be used when an RO supply manual isolation valve is inoperable and continued operation of the RO System is desired. The Note modifies the Action Table and is only applicable if the affected Oconee unit is in a TS 3.7.19 Condition for an inoperable RO supply manual isolation valve. If the LCO is fully met (both RO supply manual isolation valves operable), the note is not applicable and RO system operation is permitted by relying solely on the time critical operator action. The administrative controls will allow the control room operator responsible for dispatching the NEO from the Control Room to use the operator 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 3 response above) and continues to ensure the RO System is isolated if a design basis accident were to occur.

RAI 8

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

- LAR 2012-05, Supplement 2 June 11, 2013 Page 8 However, the proposed TS and its Bases do not include any limitations on the duration for which the 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 provide the basis for this duration. Revise the TS Bases to include limitations on the duration for which the RO system may be unisolated and to include the time limit for the TCOA.

Duke Energy Response:

There is no specified time limit on the duration for which the boundary valves may be opened intermittently under administrative controls. The time will be limited by resources available to serve as a dedicated valve operator. This note was modeled after the note for containment isolation valves for TS 3.6.3 action table and is considered appropriate since the RO System supply 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 (and incorporated by reference in this LAR), procedures controlling RO System operation will limit operation to a specified time period to prevent the boron concentration in the Borated Water Storage Tank (BWST) or Spent Fuel Pool (SFP) from going below TS limits. The maximum RO System 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 manual isolation valves operable), the note is not applicable and RO system operation is permitted by relying on the time critical operator action. TS 3.7.19 Bases have been revised to indicate the maximum time (33 minutes) allowed to complete the TCOA and to indicate the maximum RO system 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 single safety 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 leakage of sump water into the BWST during recirculation. It is unclear to the staff whether failure of or leakage past the safety related check valve on the return piping could create an unanalyzed release path for BWST water. Describe the impact of failure of or leakage past the check valve on the ECCS leakage considered in the licensing basis accident analysis and the resulting consequences.

Duke Energy Response:

The pair of isolation valves, *SF-181 and *SF-196, are closed to isolate the RO System from any 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.

- LAR 2012-05, Supplement 2 June 11, 2013 Page 9

RAI 10

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

Duke Energy Response:

The response to RAI 1, as stated in Duke Energy's letter dated February 18, 2011, are applicable to the new LAR except that now the only remaining work is the implementation of the piping 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 RO system were analyzed to determine if a postulated pipe whip or jet impingement has the potential to damage any safe shutdown target equipment, or safe shutdown system pressure boundary piping. However, the methodology used in the jet impingement evaluation was recently discovered to be inconsistent with the guidance provided in ANSI/ANS 58.2-1988. This evaluation will be revised to conform with the guidance in ANSI/ANS 58.2-1988 prior to placing the RO system into service. The revised evaluation is expected to result in no impact on any safe 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 routing of the RO System piping has not changed since the February 18, 2011, response to RAI 2 such that 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 piping going through the Hot Machine Shop was not completed. Consequently, the NRC staff audited ONS calculation No. OSC-10167, Revision (Rev) 2, written for that section of RO piping, and found it acceptable. Please verify whether OSC-10167, Rev 2 is still applicable and valid for the new LAR provided in the licensee's letter dated October 30, 2012. If this calculation has been revised, please provide the level of revision and discuss revised changes.

Duke Energy Response:

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

RAI 12

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

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

- LAR 2012-05, Supplement 2 June 11, 2013 Page 10 b) Describe the method and criteria used in the piping analysis for connecting proposed newly added 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 how the licensee ensures that excessive movement, collapse or failure of non-seismic SSCs will not adversely affect the structural integrity of seismically qualified SSCs (i.e. seismic two-over-one criteria).

Duke Energy Response:

a) A variety of typical structural isolation techniques are employed. These include structural anchors 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 the analysis of the seismic piping. The non-seismic piping on the seismic side of the structural anchor or flex hose is included in the seismic piping analysis and supported with seismic supports.

b) Standard methods and criteria are used for connecting new piping to existing piping. In several cases the new piping is included in the existing analysis of the existing piping. In this 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 also employed. The section modulus criterion is used where the ratio of section modulus shall be less than 0.1. In this case the smaller section pipe is decoupled from the analysis of the larger section pipe. The connection is considered an anchor in the analysis of the smaller section pipe and appropriate movements of the larger pipe are included in the analysis of the smaller pipe.

c) Seismic two-over-one concerns are identified early in the design process while the new SSC layout is determined in the plant. When a seismic two-over-one concern is identified, a new layout in the plant is determined. When there is no new layout in the plant that does not have'a two-over-one concern, the Design/Civil group is contacted to protect against unacceptable interaction. This is achieved by several methods including supporting the non-seismic SSC to assure interaction does not occur or providing structural barriers to assure 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, Reverse Osmosis (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 3 3SF-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 Inservice Testing Program, and will therefore be tested in accordance with the applicable requirements of the American Society of Mechanical Engineers (ASME) Code for

- LAR 2012-05, Supplement 2 June 11, 2013 Page 11 Operation and Maintenance of Nuclear Power Plants (OM Code). Will all of these valves be categorized as manual, active, and Category A valves?

b. If these valves will all be categorized the same, is there a reason that the proposed Surveillance Requirement (SR) 3.7.19.2 and SR 3.7.19.3 for the RO System BWST supply 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 why not?

Duke Energy Response:

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

SF-1 81, SF-1 96, 3SF-1 81, 3SF-1 96: these valves will be manual, active, Category A valves.

SF-57, 3SF-57: these valves will be manual, passive, Category A valves. These valves must be in the closed position in order to operate RO on the BWST. If there is an accident, the valves will remain closed.

b. Since SF-57, 3SF-57 is closed (passive function); it does not have to be cycled. It is only 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 closed in the event of an accident. Valves SF-57 and 3SF-57 must be closed during RO operation 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, "RO system not isolated," in proposed LCO 3.9.8, "Reverse Osmosis (RO) System Operating Restrictions 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 connector AND needs to be shifted to the left between ACTIONS A.1 and A.2 as shown in example 1.2-1 in Oconee's TSs.

Duke Energy Response:

The formatting error identified in the RAI has been corrected and a revised copy of the proposed TS 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 not locked, sealed, or otherwise secured, is closed, except when the valve is open during RO

- LAR 2012-05, Supplement 2 June 11, 2013 Page 12 System operation. The licensee's proposed SR 3.9.8.1 requires verification that the RO System is 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 added assurance 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 the SFP with a Frequency in accordance with the Surveillance Frequency Control Program. The initial Frequency specified in the SFL will be 7 days. This periodic frequency is considered reasonable since the siphon can only be re-established by deliberate actions and RO operation will 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 controls for Surveillance Frequencies. It further states, "The program shall ensure that Surveillance Requirements specified in the Technical Specifications are performed at intervals sufficient to assure the associated Limiting Conditions for Operation are met."

Please provide details on the engineering judgment which determined that the Surveillance Frequencies for the seismic boundary valve and verification of RO system isolation should be 31 days and 7 days, respectively, and provide justification consistent with the level of information required to establish the SFCP for placing the seismic boundary valve Frequency in the SFCP.

Duke Energy Response:

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 to Containment Isolation Valves, the RO System seismic boundary valves are provided to eliminate the potential unanalyzed release pathway and ensure the plant stays within the bounds of the design basis LOCA analysis. When the RO system is not in operation, the seismic boundary valves are required to be closed.

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

- LAR 2012-05, Supplement 2 June 11, 2013 Page 13 Therefore, this justification is consistent with the level of information required to establish the SFCP 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. TS 3.7.11, Spent Fuel Water Level, has the same applicability as proposed TS 3.9.8: During movement of irradiated fuel assemblies in the Spent Fuel Pool and during movement of cask over the Spent Fuel Pool. SR 3.7.11.1 verifies that sufficient Spent Fuel Pool water is available in the event of a fuel handling or cask drop accident. The water level in the Spent Fuel Pool must be checked periodically. The basis for 7 day Frequency of 3.7.11.1 is that the volume in the pool is normally stable. Water level changes are controlled by unit procedures and are acceptable, based on operating experience.

Duke Energy determined the 7 day frequency for verifying the RO system is isolated from the Spent Fuel Pool is appropriate since there is a physical barrier that must be overcome before the 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 release pathway is during activities (movement of irradiated fuel assemblies in the SFP and movement of cask over the SFP) that could result in damage to irradiated fuel assemblies, the verification is only required during these activities. Since the 7 day frequency was considered adequate for water level monitoring during these type activities, the 7 day frequency was also considered adequate for verifying the RO system is isolated. Further, the water level monitoring required by SR 3.7.11.1 would likely identify that the RO system is not isolated and in operation since it would be lowering the SFP water level and requiring makeup to maintain water level. The SR frequency 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 the SFCP 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 SFP 3.9.8 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 the siphon 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 Immediately of irradiated fuel assemblies in the SFP AND A.2 Suspend the movement Immediately of cask over the SFP SURvEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.8.1 Verify RO System is isolated by breaking the siphon In accordance with from the SFP.

the Surveillance Frequency Control Program OCONEE UNITS 1, 2, & 3 3.9.8-1 Amendment Nos.

RO System Isolation from BWST B 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) and BWSTs by using a reverse osmosis filtering process.

The RO System, which consists of an RO unit and supply and return piping from the BWSTs and SFPs, is located in the Unit 2 Pipe Trench Area 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 & 2 SFP, the Unit 3 SFP, the Unit 1 BWST, the Unit 2 BWST, or the Unit 3 BWST. RO System piping and existing Spent Fuel (SF) Purification Loop piping are used for these alignments.

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

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

The BWST water is routed to the RO System from the SF purification loop. This connection is at a lower elevation than the BWST so a break in 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.

RO System Isolation from BWST B 3.7.19 BASES BACKGROUND (continued)

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

APPLICABLE The large break LOCA assumes back-leakage from the sump to the SAFETY 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 system from the BWST at the safety related/non safety related boundary.

Additionally, the BWST Recirculation Pump Suction Valve is closed prior to RO system operation to ensure post LOCA back-leakage cannot reach the top of the BWST through the piping as aligned for RO System operation. With the isolation of these pathways, the use of the RO system does not impact the assumptions in the design basis LOCA dose analysis. The 33 minute TCOA isolates the pathway prior to increasing radiation levels making the location inaccessible and before post-LOCA fluids can reach the BWST. This operator action, isolation of components that are part of the primary success pathway which functions to mitigate the LOCA, meets 10 CFR 50.36, Criterion 3 (Reference 2).

The isolation of the RO system credits two safety related manual isolation valves to ensure the plant stays within the bounds of the design basis LOCA analysis.

LCO This LCO requires that the two manual isolation valves (SF-181 and SF-1 96 for Unit 1 and 2 and 3SF-181 and 3SF-1 96 for Unit 3) used to isolate the RO System from BWST to be OPERABLE. The valves are considered OPERABLE when they are closed or capable of being closed prior to initiation of ECCS recirculation. The LCO is modified by a note indicating that the BWST Recirculation Pump Suction Valve (SF-57 for Unit 1 & 2 or 3SF-57 for Unit 3) shall be closed and meet Inservice Testing Program leakage requirements while the RO System is in operation to ensure post-LOCA fluids cannot reach the top of the BWST as a result of the piping alignment during RO System operation APPLICABILITY The RO System isolation valves are required to be OPERABLE in MODES 1, 2, 3, and 4, consistent with emergency core cooling system (ECCS) recirculation OPERABILITY requirements. The RO System isolation valves must be OPERABLE to ensure the plant stays within the bounds of the design basis LOCA analysis.

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

RO System Isolation from BWST B 3.7.19 BASES (continued)

ACTIONS The ACTIONS are modified by a Note allowing the RO System flow path to be unisolated intermittently under administrative controls. The opening of a closed valve in the RO System flow path on an intermittent basis under administrative 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 to close the valves and that this action will prevent the release of radioactivity outside the RO System. In this way, the flow path can be rapidly isolated when a need for isolation is indicated. The maximum RO system operating period is 7 days. Procedures controlling RO System operation limit operation to a specified time period to prevent the boron concentration 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 is inoperable, the flow path must be isolated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and de-activated automatic isolation valve, a closed and de-activated non-automatic power operated valve, a closed manual valve, or a blind flange. For the RO System flow path isolated in accordance with Required Action A. 1, the device used to isolate the flow path should be the closest available to the inoperable RO System BWST supply isolation valve. The 4-hour Completion Time is considered reasonable, considering the time required to isolate the flow path and the low probability of an accident occurring during this time period requiring isolation of the RO system from the BWST.

For a manual isolation valve that cannot be restored to OPERABLE status within the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time and that has been isolated in accordance with Required Action A. 1, the flow path must be verified to be isolated on a periodic basis. This periodic verification is necessary to ensure that the flow path is isolated should an event occur requiring it to be isolated. This Required Action does not require any testing or device manipulation. Rather, it involves verification, through a system walkdown, that an isolation device capable of being mispositioned is in the correct position. The Completion Time of "once per 31 days" is appropriate considering the fact that the device is operated under administrative controls and the probability of its misalignment is low.

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

RO System Isolation from BWST B 3.7.19 BASES ACTIONS B..1 (continued)

In the event two RO System BWST supply manual isolation valves are inoperable, the flow path must be isolated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and de-activated automatic isolation valve, a closed and de-activated non-automatic power operated valve, a closed manual valve, or a blind flange. For the RO System flow path isolated in accordance with Required Action B. 1, the device used to isolate the flow path should be the closest available to the RO System BWST supply manual isolation valves. The 1-hour Completion Time is considered reasonable, considering the time required to isolate the flow path and the low probability of an accident occurring during this time period requiring isolation of the RO system from the BWST.

In the event the affected RO System flow path is isolated in accordance with Required Action B.1, the flow path must be verified to be isolated on a periodic basis per Required Action A.2, which remains in effect. This periodic verification is necessary to ensure that the flow path is isolated should an event occur requiring it to be isolated. The Completion Time of once per 31 days for verifying the flow path is isolated is appropriate considering the fact that the device is operated under administrative controls and the probability of its misalignment is low.

C.1 and C.2 In the event the RO System is operating and the BWST Recirculation Pump suction valve is discovered not closed or it is determined the Inservice Testing (IST) Program leakage requirements are not met, the flow path must be isolated and RO system operation must be discontinued within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The 1-hour Completion Time is considered reasonable, considering the time required to isolate the flow path and discontinue RO System operation and the low probability of an accident occurring during the time period requiring this action. If the suction valve is discovered not closed, 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 no longer applies. However, if the suction valve is discovered to not meet IST Program leakage requirements, the flow path must be isolated using a valve that meets these requirements and RO System operation must be discontinued. This is necessary to ensure that the flow path to the top of the BWST is isolated.

OCONEE UNITS 1, 2, & 3 B 3.7.19-4 Amendment Nos.

RO System Isolation from BWST B 3.7.19 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 LCO does not apply. To achieve this status, the unit must be brought to 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 to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

SURVEILLANCE SR 3.7.19.1 REQUIREMENTS This SR requires verification that RO System BWST manual isolation valves (SF-181 and SF-1 96 for Unit 1 & 2 and 3SF-1 81 and 3SF-196 for Unit 3) not locked, sealed, or otherwise secured in the closed position, are closed. The SR helps to ensure that post accident leakage of radioactive fluids do not impact the offsite dose analysis. This SR does not require any testing or valve manipulation. Rather, it involves verification, through a system walkdown, that each manual isolation valve is closed. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program. The SR specifies that the manual isolation valve is not required to be closed during RO System operation. During the time period the manual isolation valves are open, a 33 minute TCOA is credited to close the valves should an accident occur requiring isolation of the flow path. This SR does not apply if a valve is locked, sealed, or otherwise secured, since it was verified to be in the correct position upon locking, 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 OPERABLE in accordance with the Inservice Testing Program. The specified Frequency is in accordance with the Inservice Testing Program requirements.

OCONEE UNITS 1, 2, & 3 B 3.7.19-5 Amendment Nos.

RO System Isolation from BWST B 3.7.19 BASES SURVEILLANCE SR 3.7.19.3 REQUIREMENTS (continued)

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

REFERENCES

1.

UFSAR, Section 9.1.3.

2.

10 CFR 50.36.

OCONEE UNITS 1, 2, & 3 B 3.7.19-6 Amendment Nos.

License Amendment Request No. 2011-05, Supplement 2 June 11, 2013 ENCLOSURE 3 REGULATORY COMMITMENTS The following commitment table identifies those actions committed to by Duke Energy Carolinas, LLC (Duke Energy) in this submittal. Other actions discussed in the submittal represent intended or planned actions by Duke Energy. They are described to the Nuclear Regulatory 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 Reverse evaluation will be revised to conform with the guidance in Osmosis System ANSI/ANS 58.2-1988.

Operation