Text

Application to Revise Technical Specification 3.7.7, Low Pressure Service Water (LPSW) System, to Extend the Completion Time for One Required Inoperable LPSW Pump on a Temporary Basis
	ML21245A210
Person / Time
Site:	Oconee
Issue date:	09/02/2021
From:	Snider S; Duke Energy Carolinas
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	RA-21-0005
	Download: ML21245A210 (37)
	v • d • e

Steven M. Snider Vice President Oconee Nuclear Station Duke Energy ON01VP l 7800 Rochester Hwy Seneca, SC 29672 o: 864.873.3478 f: 864.873.5791 Steve.Snider@duke-energy.com RA-21-0005 10 CFR 50.90 September 2, 2021 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 Duke Energy Carolinas, LLC Oconee Nuclear Station (ONS), Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287 Renewed Facility Operating License Nos. DPR-38, DPR-47, and DPR-55

Subject:

Application to Revise Technical Specification 3.7.7, Low Pressure Service Water (LPSW) System, to Extend the Completion Time for One Required Inoperable LPSW Pump on a Temporary Basis Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) proposes to amend the Technical Specifications (TS) for Oconee Nuclear Station (ONS) Units 1, 2, and 3. The proposed amendment would revise TS 3.7.7, Low Pressure Service Water (LPSW) System to extend the Completion Time associated with one required inoperable LPSW pump on a temporary basis. Specifically, the proposed change would add a Note modifying the Completion Time associated with TS 3.7.7, Condition A, Required Action A.1 to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months during ONS Unit 2, Refuel 31 (Fall 2023) to allow for the tie-in and testing of an alternate suction source to the shared Unit 1 and Unit 2 A and B LPSW pumps.

The alternate suction source to the shared Unit 1 and Unit 2 A and B LPSW pumps is needed to permit draining of the Condenser Circulating Water (CCW) System cross-connect header for the replacement of three CCW valves.

The Enclosure to this letter provides a description and assessment of the proposed change. provides the existing TS pages marked to show the proposed change. provides retyped (clean) TS pages. Attachment 3 provides existing TS Bases pages marked to show the proposed change for information only. Attachment 4 provides simplified diagrams of the CCW crossover header before and after the alternate suction source to the LPSW pumps is placed in service. Attachment 5 provides a markup of LPSW flow diagrams and the ONS abnormal procedure for loss of LPSW.

The proposed change has been evaluated in accordance with 10 CFR 50.91(a)(1) using criteria in 10 CFR 50.92(c), and it has been determined that the proposed change involves no significant hazards consideration. The basis for this determination is included in the Enclosure.

Duke Energy requests approval of the proposed amendment to the ONS TS within one year of the date this submittal is accepted by the Nuclear Regulatory Commission staff for review.

Once approved, Duke Energy will implement the license amendments within 120 days.

There are no regulatory commitments contained in this submittal.

r. DUKE

~ ENERGY

RA-21-0005 Page 2 In accordance with 10 CFR 50.91, Duke Energy is notifying the State of South Carolina of this license amendment request by transmitting a copy of this letter and Enclosure to the designated State Official.

If there are any questions or if additional information is needed, please contact Mr. Art Zaremba, Manager - Nuclear Fleet Licensing at 980-373-2062 or Arthur.Zaremba@duke-energy.com.

I declare under penalty of perjury that the foregoing is true and correct. Executed on September 2, 2021.

Sincerely, Steven M. Snider Vice President Oconee Nuclear Station

Enclosure:

Description and Assessment of the Proposed Change Attachments:

1. Technical Specifications Markup

2. Revised (Clean) Technical Specifications

3. Technical Specifications Bases Markup (Information Only)

4. Simplified Condenser Circulating Water System Crossover Header Diagrams

5. Low Pressure Service Water System Diagrams and Procedure (Markup)

RA-21-0005 Page 3 cc w/enclosure and attachments:

Ms. Laura Dudes, Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Shawn Williams, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, Maryland 20852 Mr. Jared Nadel NRC Senior Resident Inspector Oconee Nuclear Station Ms. Anuradha Nair-Gimmi (by electronic mail only: naira@dhec.sc.gov)

Department of Health & Environmental Control Bureau of Environmental Health Services 2600 Bull Street Columbia, SC 29201

RA-21-0005 Enclosure Page 1 of 13 ENCLOSURE DESCRIPTION AND ASSESSMENT OF THE PROPOSED CHANGE

Subject:

Application to Revise Technical Specification 3.7.7, Low Pressure Service Water (LPSW) System to Extend the Completion Time for One Inoperable LPSW Pump on a Temporary Basis

1.

SUMMARY

DESCRIPTION

2.

DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change

3.

TECHNICAL EVALUATION 3.1 Installation of Alternate LPSW Suction Source 3.2 Defense-in-Depth (Unit 3 LPSW Cross-Connect) 3.3 Risk Insights

3.4 Technical Evaluation Conclusion

4.

REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Determination Analysis 4.3 Conclusions

5.

ENVIRONMENTAL CONSIDERATION

6.

REFERENCES ATTACHMENTS:

1. Technical Specifications Markup

2. Revised (Clean) Technical Specifications

3. Technical Specifications Bases Markup (Information Only)

4. Simplified Condenser Circulating Water System Crossover Header Diagrams

5. Low Pressure Service Water System Diagrams and Procedure (Markup)

RA-21-0005 Enclosure Page 2 of 13

1.

SUMMARY

DESCRIPTION Duke Energy Carolinas, LLC (Duke Energy) proposes to amend the Technical Specifications (TS) for Oconee Nuclear Station (ONS) Units 1, 2, and 3. The proposed amendment would revise TS 3.7.7, Low Pressure Service Water (LPSW) System to extend the Completion Time associated with one required inoperable LPSW pump on a temporary basis.

Specifically, the proposed change would add a Note modifying the Completion Time associated with TS 3.7.7, Condition A (One required LPSW pump inoperable.), Required Action A.1 to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months during ONS Unit 2, Refuel 31 (Fall 2023) to allow for the tie-in and testing of an alternate suction source to the shared Unit 1 and Unit 2 A and B LPSW pumps. The alternate suction source to the shared Unit 1 and Unit 2 A and B LPSW pumps is needed to permit draining of the Condenser Circulating Water (CCW) System crossover header for the replacement of three CCW valves.

2. DETAILED DESCRIPTION 2.1 System Design and Operation LPSW System The ONS LPSW System provides a heat sink for the removal of process and operating heat from safety related components during a transient or accident. The LPSW System also provides this heat sink function during normal operation and normal shutdown for various components. The system provides cooling directly to the Reactor Building Cooling Units, Low Pressure Injection coolers, turbine driven Emergency Feedwater (EFW) pump, High Pressure Injection pump motor coolers and the motor driven EFW pumps.

The LPSW System for Unit 1 and Unit 2 is shared and consists of three LPSW pumps (i.e., A, B and C) which can supply multiple combinations of pathways to supply required components.

The shared Unit 1 and 2 pumps take suction from the 42-inch cross-connection between the condenser inlet headers of all three units; two LPSW pumps (A and B) are supplied by one suction branch line and the other pump (C) is supplied by the other suction branch line. The LPSW System for Unit 3 consists of two LPSW pumps and like the Unit 1 and 2 pumps, also take their suction from the CCW 42-inch cross-connection header. The 42-inch cross-connection is also referred to as the CCW crossover header or CCW crossover line.

Additional information about the design and operation of the LPSW System, along with a list of the components served by the system, is presented in Section 9.2.2.2.3 of the ONS Updated Final Safety Analysis Report (UFSAR).

CCW System The CCW System is designed to supply suction to the LPSW pumps from the 42-inch crossover header during normal operation and during emergencies. The CCW crossover header is embedded in the Turbine Building basement mat floor. Manual isolation valves are provided so that service water may be supplied from any or all the inlet headers.

RA-21-0005 Enclosure Page 3 of 13 There are four CCW crossover header isolation valves (1CCW-40, 2CCW-41, 3CCW-42, 3CCW-94) that are normally open to provide suction to the LPSW pumps from any unit via the 42-inch crossover header. These 42-inch CCW crossover valves are also used as isolation valves for maintenance activities and in support of LPSW System flow testing. The crossover valves are located in valve pits where the piping and valves are exposed.

Valve CCW-72 provides isolation of the shared Unit 1 and Unit 2 LPSW Pump A and B suction headers. Similarly, valve CCW-73 provides isolation of the shared Unit 1 and Unit 2 LPSW Pump C suction header.

The Unit 2 crossover header isolation valve, 2CCW-41, will be replaced upon installation of an alternate suction source to the Unit 1 and Unit 2 shared LPSW pumps. Valves CCW-72 and CCW-73 will also be replaced.

Figure 1 of Attachment 4 provides a simplified diagram of the CCW crossover header along with the CCW valves discussed above. The diagram also displays the interconnection between the CCW System and LPSW System.

Additional information about the design and operation of the CCW System is provided in Section 9.2.2.2.1 of the ONS UFSAR.

2.2 Current Technical Specifications Requirements The Limiting Condition for Operation (LCO) for TS 3.7.7 specifies that for the LPSW System shared by ONS Units 1 and 2, three LPSW pumps are required to be OPERABLE. However, the LCO is modified by a Note which requires only two LPSW pumps to be OPERABLE for Unit 1 or Unit 2 if either unit is defueled and one LPSW pump can mitigate a design basis accident on the fueled unit. The shared Units 1 and 2 LPSW System requires only two pumps to meet the single failure criterion provided that one of the units has been defueled and the following LPSW System loads on the defueled unit are isolated: Reactor Building Cooling Units, Reactor Building Auxiliary Coolers, Component Cooling, Main Turbine Oil Tank, Reactor Coolant Pumps and Low Pressure Injection Coolers. The LCO further requires that one flow path be OPERABLE for Unit 1 and one flow path be OPERABLE for Unit 2. Per the TS 3.7.7 Bases, an LPSW flow path is considered OPERABLE when the associated piping, valves, heat exchangers and instrumentation and controls required to perform the safety related function are also OPERABLE. Any combination of pathways to supply the required components is acceptable, provided there is no single active failure which can prevent supplying the necessary loads.

Although not directly related to the proposed change in this license amendment request, the LCO for TS 3.7.7 specifies that two LPSW pumps are required to be OPERABLE for Unit 3.

One flow path for Unit 3 is also required to be OPERABLE.

The LCO for TS 3.7.7 is required to be met in Modes 1, 2, 3 and 4 (i.e., the Applicability for TS 3.7.7).

TS 3.7.7, Condition A is the condition for one required LPSW pump inoperable. For Units 1 and 2, Condition A is entered when one of the three required LPSW pumps is inoperable unless Unit 1 or Unit 2 is defueled with the appropriate loads isolated. With Unit 1 or Unit 2 defueled with the appropriate loads isolated, Condition A would only be entered for Unit 1 or Unit 2 if two LPSW pumps are inoperable. Required Action A.1 specifies that action must be taken to

RA-21-0005 Enclosure Page 4 of 13 restore the required LPSW pump to OPERABLE status within the Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

By applying the existing Applicability NOTE to the proposed change that is described below in Section 2.4, only two LPSW pumps are required to be OPERABLE to support Unit 1 since ONS Unit 2 will be defueled with the appropriate loads secured.

2.3 Reason for the Proposed Change CCW crossover header isolation valve 2CCW-41 is original to ONS and inspection of the valve internals is not possible due to system configuration and lack of available isolations. Efforts have been underway since 2008 to replace this valve due to gross leakage past the valve seat.

During ONS Unit 2, Refuel 27, a variable speed portable pump was used to remove water from the Unit 2 CCW intake pipe leaking past valve 2CCW-41. Valves CCW-72 and CCW-73 are also original plant equipment. Duke Energy has determined that the risk of operating these valves as part of the proposed isolation boundary for the replacement of the 42-inch valve 2CCW-41 is too high. Specifically, CCW-72 and CCW-73 have been in service for over forty years and are currently locked in the open position. They are butterfly valves with a small gear operator and there is no plant record of these valves ever being manipulated. There are other identical valves at ONS which are manipulated and have a history of failing the gear operator or coupling between the valve stem and the gear operator. With no history of manipulation for CCW-72 and CCW-73, the concern is that if one of these valves were to be operated and failed, whether full open, full close, or in a partial position, there would be no easy way to replace the valve within the existing 72-hour Completion Time of TS 3.7.7, Condition A, Required Action A.1. Valves CCW-72 and CCW-73 are also in need of full replacement.

The CCW crossover header isolation valve for Unit 1 (1CCW-40) will also be replaced.

However, the proposed change described in this license amendment request is only needed for the replacement of valves 2CCW-41, CCW-72 and CCW-73.

To affect the replacement of the 42-inch diameter Unit 2 CCW crossover header isolation valve (2CCW-41), the 30-inch diameter suction header isolation valve (CCW-73) and the 36-inch diameter suction header isolation valve (CCW-72), an alternate suction source to the shared Units 1 and 2 A and B LPSW pumps must first be installed. Once the alternate suction source is installed, with the final tie-in and testing complete, isolation of the 42-inch CCW crossover header can commence while meeting the LCO for TS 3.7.7. Then the three CCW valves (2CCW-41, CCW-72, CCW-73) may be replaced after the header is isolated.

Final connection of the alternate suction line to the Units 1 and 2 A and B LPSW pump suction headers may only occur after ONS Unit 2 is defueled and begins with securing any running pump(s) in the A/B suction header. The only remaining OPERABLE LPSW pump in this configuration to support Unit 1 (Mode 1) is the C LPSW pump. An entry into TS 3.7.7, Condition A is required for Unit 1 and Required Action A.1 dictates that a required LPSW pump must be restored to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The final connection (i.e., tie-in) and testing of the alternate suction source piping is estimated to require a window of 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months , which is 216 hours0.0025 days 0.06 hours 3.571429e-4 weeks 8.2188e-5 months beyond the existing Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months for Required Action A.1.

Therefore, the proposed Note for a 288-hour Completion Time associated with Required Action A.1 is necessary to allow for tie-in and testing of the alternate suction source while also allowing continued operation at full power on Unit 1.

Once the functional testing of the alternate suction source is complete, the source will be placed in service providing a flow path to both the shared A and B LPSW pumps for Units 1 and 2.

Unit 1 can then declare the LCO for TS 3.7.7 met and exit the TS Action statement.

RA-21-0005 Enclosure Page 5 of 13 2.4 Description of the Proposed Change The following Note is proposed to be added to the Completion Time of Required Action A.1:

NOTE-------------

During Unit 2, Refuel 31 with Unit 2 defueled and appropriate LPSW loads secured, the Completion Time is 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months for the tie-in and testing of an alternate suction source to the shared Unit 1/2 LPSW Pumps A and B.

There are no other proposed TS changes associated with this license amendment request.

Only the Completion Time for Required Action A.1 (Restore required LPSW pump to OPERABLE status.) would be modified during ONS Unit 2, Refuel 31 with the proposed change.

Duke Energy is not requesting NRC approval of the plant modification to install the alternate LPSW suction source.

The proposed change is supported by changes to the TS Bases. In addition to reflecting the proposed change to the TS, the TS 3.7.7 Bases are revised for clarity and consistency. The regulation at Title 10 of the Code of Federal Regulations (10 CFR), Part 50.36, states, A summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the technical specifications. Changes to the TS Bases will be made in accordance with the Technical Specifications Bases Control Program following approval of the requested amendment. The proposed TS Bases changes are consistent with the proposed TS change and provide the purpose for each requirement in the specification consistent with the Commissions Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 2, 1993 (58 FR 39132). Therefore, the TS Bases changes are provided for information in Attachment 3 and approval of the TS Bases is not requested.

3. TECHNICAL EVALUATION 3.1 Installation of Alternate LPSW Suction Source To affect the replacement of valves 2CCW-41, CCW-72 and CCW-73, an alternate suction source for the Unit 1/2 A and B LPSW pumps must first be installed to allow for the isolation of the 42-inch CCW crossover header.

Prior to Unit 2, Refuel 31 (O2R31), a new endbell at the inlet of the 1B condensate cooler will be installed, as well as approximately 30 feet of QA-1, 36-inch diameter pipe from the 1B condensate cooler to the A and B LPSW pump suction header. Preparation will also take place prior to O2R31 for the installation of a 36-inch line stop fitting on the suction header between the suction line for the A high pressure service water (HPSW) pump and B LPSW pump.

RA-21-0005 Enclosure Page 6 of 13 During Unit 2, Refuel 31 (O2R31) with no fuel in the Unit 2 reactor vessel (i.e., Unit 2 not in a TS MODE), installation of the 36-inch line stop fitting (i.e., line stop) on the suction header between the suction line for the A HPSW pump and B LPSW pump will commence. At the point that the line stop fitting activity is commenced, Unit 1 will enter TS 3.7.7, Condition A since the A and B LPSW pumps will be secured and only the C LPSW pump will remain OPERABLE.

Once the line stop fitting installation is complete, the Unit 1/2 A and B LPSW pump suction header will be drained, and installation of a piping T fitting will be commenced at the opposite end of the A and B LPSW pump suction header. Completion of piping T fitting will connect the A and B LPSW suction header to the new 36-inch alternate suction pipe from the 1B condensate cooler.

Once watertight, the LPSW System will be returned to Operations for functional testing of the alternate LPSW suction source. Upon successful completion of testing, the alternate suction source will be placed in service, providing a flow path to both the A and B LPSW pumps. Unit 1 can then exit the TS 3.7.7 Action statement because the LCO would be met for Unit 1 with two LPSW pumps and a flow path OPERABLE.

The following list contains the activities that are scheduled to take place during the proposed 288-hour TS 3.7.7 Action statement, along with the projected time allotted for each:

Tag Out of LPSW Pumps A and B (enter TS 3.7.7 Action statement) - 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Install Line Stop - 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months Drain A and B LPSW Header section of pipe - 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Remove A and B LPSW Header blind flange at dead end of header pipe - 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Install 36 valve to pipe Header - 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Torque 36 valve - 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months Connect alternate suction pipe - 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Torque connections - 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months Connect to 1B Condensate Cooler (i.e., water supply) - 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Clear Tags, fill and vent A and B LPSW Header and alternate suction source line - 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Test LPSW A and B Pumps - 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months Estimates for each activity above are provided to the nearest half shift (i.e., 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ). The total duration of the above activities is 192 hours0.00222 days 0.0533 hours 3.174603e-4 weeks 7.3056e-5 months . Applying a 50% contingency factor, Duke Energy is requesting a TS 3.7.7, Required Action A.1 Completion Time of 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months .

The configuration of the CCW system and the Unit 1/2 A and B LPSW suction header with the alternate suction source installed will permit for the isolation of the 42-inch CCW crossover header whereby valves 2CCW-41, CCW-72 and CCW-73 may be replaced.

Figures 2 through 8 of Attachment 4 depict the activities associated with installation of the alternate LPSW suction source, the replacement of the CCW valves and final return to service of the LPSW System following the O2R31 refueling outage.

RA-21-0005 Enclosure Page 7 of 13 3.2 Defense-in-Depth (Unit 3 LPSW Cross-Connect)

The alternate suction source described in Section 3.1 above will be placed into service to meet the LCO of TS 3.7.7 while the CCW valves are replaced. However, prior to placing the alternate suction source into service to meet the LCO, only the shared Units 1 and 2 C LPSW pump will be OPERABLE to support Unit 1 (see Figure 5 of Attachment 4). The required window to complete the tie-in and perform a functional test of the alternate suction source is projected to require 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months , which exceeds the TS 3.7.7 Completion Time for Required Action A.1 of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . Although operability of the single Units 1 and 2 C LPSW Pump can provide for the specified safety function of the system for Unit 1, ONS has the capability to procedurally cross connect the ONS Unit 3 LPSW pumps to the ONS Unit 1 and 2 LPSW header by opening valve LPSW-1095 should the C LPSW Pump become inoperable. This cross connect is the ACTION/EXPECTED RESPONSE for a loss of Unit 1 and 2 LPSW pumps in ONS procedure AP/1/A/1700/024, Loss of LPSW. Refer to the markup of LPSW System flow diagrams and procedure steps provided in Attachment 5 of this license amendment request. This cross connect capability provides defense-in-depth during the proposed 288-hour temporary Completion Time of Require Action A.1 with Unit 2 defueled and required loads isolated.

In a scenario where all Units 1 and 2 LPSW pumps are inoperable (i.e., the Units 1 and 2 C LPSW Pump becomes inoperable during the temporary Completion Time), Unit 1 and 2 LPSW would be cross connected to Unit 3 LPSW, and there would be two Unit 3 LPSW Pumps (i.e.,

the Unit 3 A and B LPSW Pumps) available to provide LPSW in the event of a design basis accident for either Unit 1 or Unit 3 during the temporary Completion Time of Required Action A.1.

The specified TS safety function of the LPSW System will be maintained for the duration of the proposed temporary Completion Time of Required Action A.1 with only the Units 1 and 2 C LPSW Pump OPERABLE. Furthermore, with the loss of LPSW procedure in place, two LPSW pumps from Unit 3 would be available to support Unit 1 should the remaining Units 1 and 2 C LPSW Pump become inoperable and the specified TS safety function of the LPSW System would still be maintained. Specifically, the LPSW System, in conjunction with a 100% capacity reactor building cooling system (a combination of the reactor building spray and reactor building air coolers), will be capable of removing core decay heat following a design basis LOCA on either Unit 1 or Unit 3. The defense-in-depth provided by the availability of the procedural action to cross-connect Units 1 and 2 LPSW with Unit 3 LPSW will continue to afford the capability of the LPSW System to perform its function with a single failure of the Units 1 and 2 C LPSW Pump.

3.3 Risk Insights Duke Energy evaluated the risk associated with extending the Completion Time for one required LPSW pump inoperable (TS 3.7.7, Action A) during O2R31 from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months on a temporary, one-time basis. The results are summarized in the following sections.

3.3.1 Methodology To obtain risk insights for the operating Unit 1 in the proposed configuration, the ONS probabilistic risk assessment (PRA) models of record for internal events and fire were used.

Modifications to the models were made to reflect the proposed configuration. For both internal events and fire, Core Damage Frequency (CDF) results were obtained and deltas between the

RA-21-0005 Enclosure Page 8 of 13 proposed configuration and baseline CDF values were then determined. From these delta values, a total Incremental Conditional Core Damage Probability (ICCDP) was calculated for the 216-hour period beyond the 72-hour allowed outage time that is being requested to perform the work. In addition to quantification, cutsets were reviewed and risk insights were obtained.

An explicit Large Early Release Frequency (LERF) / Incremental Conditional Large Early Release Probability (ICLERP) analysis was determined to not be necessary for the proposed configuration since CDF / ICCDP is the bounding risk metric in this case. ONS has a large, dry containment and the LPSW and CCW systems do not provide accident mitigation functions for LERF scenarios beyond their functions to mitigate core damage. No additional beneficial risk insights would be obtained from quantifying the ONS PRA models for LERF.

3.3.2 Internal Events Analysis With the shared Units 1 and 2 A and B LPSW pumps inoperable and Unit 2 not in a Mode of Applicability, the C LPSW Pump remains as a single dedicated running LPSW pump on Unit 1.

The internal events model was quantified for this configuration with one remaining LPSW pump, and the resulting CDF was determined to be 3.08E-5 per year of reactor operation. The internal events base case CDF is 2.87E-5 per year of reactor operation. By subtracting the baseline CDF value of 2.87E-5 from the proposed configuration case CDF of 3.08E-5 resulted in a delta CDF of 2.11E-6. Multiplying this by the fractional portion of the year represented by the proposed 216-hour Completion Time extension (i.e., 216/8760) resulted in an internal events (IE) ICCDP of 5.2E-8. Table 1 displays the numerical results.

Table 1. Internal Events Analysis Results LAR Configuration IE CDF 3.08E-5 Base Case IE CDF 2.87E-5 Delta IE CDF 2.11E-6 IE ICCDP 5.2E-8 Dominant accident sequences involve failure of the only running LPSW pump aligned to the operating Unit 1, resulting in a loss of LPSW. The accident sequences involve failure of the operators to implement the Standby Shutdown Facility (SSF) strategies, failing to trip reactor coolant pumps, and failing to utilize Protected Service Water (PSW) to provide cooling water flow to the High Pressure Injection (HPI) pump motor coolers. A reactor coolant pump seal leak develops which ultimately leads to core damage.

Other sequences involve failure of the only running LPSW pump aligned to the operating Unit 1, resulting in a loss of LPSW. A loss of main feedwater occurs following the turbine trip. The turbine-driven Emergency Feedwater pump fails. Operators fail to establish secondary side cooling by cross-tying another unit, using PSW, or by using the SSF. A complete loss of secondary side heat removal results.

RA-21-0005 Enclosure Page 9 of 13 3.3.3 Fire Analysis The fire PRA model was also quantified for the configuration with one remaining LPSW pump supporting Unit 1, and the resulting CDF was determined to be 3.69E-5. The resulting base case fire CDF is 3.39E-5. Subtracting the base case fire CDF from the license amendment request evaluation case resulted in a delta fire CDF of 3.0E-6. Multiplying this delta value by the fractional portion of the year represented by the proposed 216-hour Completion Time extension (i.e., 216/8760) results in a fire ICCDP of 7.4E-8. Table 2 displays the numerical results.

Table 2 Fire Analysis Results LAR Configuration Fire CDF 3.69E-5 Base Case Fire CDF 3.39E-5 Delta Fire CDF 3.0E-6 Fire ICCDP 7.4E-8 For the fire risk analysis, the dominant accident sequences were Main Control Room fires affecting Engineered Safeguards channels, which in turn fails the running C LPSW Pump.

3.3.4 Risk Evaluation Results and Conclusions The total risk increase associated with extending the Completion Time for TS 3.7.7, Condition A, Required Action A.1 during O2R31 from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months on a one-time, temporary basis was calculated to be an ICCDP of 1.26E-7, which includes contributions from internal events and fire. CDF was the bounding risk metric. The accumulated risk is below the 1.0E-6 ICCDP and 1.0E-7 ICLERP thresholds established by Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decision Making: Technical Specifications, Revision 1. The risk increase is acceptable, and the analysis supports the proposed change for an extension of the Completion Time associated with one required LPSW pump inoperable on a one-time, temporary basis during O2R31. No risk management actions are required to obtain acceptable PRA results.

3.4 Technical Evaluation Conclusion

The design and licensing basis mitigation function of the LPSW System is not affected by the proposed change. The LPSW System capability for performing its specified safety function is the same during the proposed temporary Completion Time of 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months as it is during the existing Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months for TS 3.7.7, Condition A, Required Action A.1.

The evaluation of the LPSW cross connect procedural action as defense-in-depth and the results of the risk insights described above provide assurance that the equipment required to safely shutdown the plant and mitigate the effects of a design basis accident will remain capable of performing their safety functions when Unit 1/2 LPSW pumps A and B are out-of-service during the proposed temporary Completion Time.

RA-21-0005 Enclosure Page 10 of 13

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria The following regulatory and ONS licensing basis requirements are applicable to the proposed change.

The regulations at Title 10 of the Code of Federal Regulations (10 CFR) Part 50.36, Technical specifications, establish the requirements related to the content of the TS. Section 50.36(c)(2) states:

Limiting conditions for operation. Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.

10 CFR 50.36 sets forth the regulatory requirements for the content of TS, as quoted above.

The regulations require, in part, that the TS contain LCOs and that remedial actions are prescribed for when a nuclear power plant cannot meet an LCO. The proposed change described in this license amendment would increase the time allotted to perform the remedial action associated with TS 3.7.7, Condition A, Required Action A.1. However, Completion Times are not specified by the regulation. Therefore, 10 CFR 50.36 will continue to be met for the proposed change.

The principal design criteria for ONS were developed in consideration of the seventy General Design Criteria (GDC) for Nuclear Power Plant Construction Permits proposed by the Atomic Energy Commission (AEC) in a proposed rule-making published for 10 CFR 50 in the Federal Register on July 11, 1967. The ONS Units 1, 2 and 3 construction permits were issued on November 6, 1967, preceding the issuance of the GDC specified in 10 CFR 50, Appendix A.

The following criteria from Chapter 3 of the ONS UFSAR are applicable to the proposed amendment and constiute the ONS licensing basis with respect to compliance with the GDC.

Criterion 1 - Quality Standards Those components of reactor facilities which are essential to the prevention of accidents which could affect the public health and safety or to mitigation of their consequences shall be identified and then designed, fabricated, and erected to quality standards that reflect the importance of the safety function to be performed. Where generally recognized codes or standards on design, materials, fabrication, and inspection are used, they shall be identified. Where adherence to such codes or standards does not suffice to assure a quality product in keeping with the safety function, they shall be supplemented or modified as necessary. Quality assurance programs, test procedures, and inspection acceptance levels to be used shall be identified. A showing of sufficiency and applicability of codes, standards, quality assurance programs, test procedures, and inspection acceptance levels used is required.

RA-21-0005 Enclosure Page 11 of 13 The Engineered Safeguards System is listed as one of the Essential Systems and Components whose integrity essential to accident prevention and to mitigation of accident consequences has been included in the reactor design evaluations. The Engineered Safeguards System consists of structures, systems (SSC) and components necessary to provide emergency cooling to assure structural integrity of the core, maintain the integrity of the Reactor Building and provide for the collection and control of Reactor Building penetration leakage. These SSCs have been designated QA-1 in Section 3.1.1.1 of the ONS UFSAR. One of the support systems necessary to ensure that these Engineered Safeguards System SSCs can perform their intended safey functions is the LPSW portions necessary to supply water to the Reactor Building cooling units, decay heat removal coolers and high pressure injection pump motors. These portions of the LPSW System are also designated QA-1. The proposed change described in this license amendment request does not alter compiance with Criterion 1 in the UFSAR.

Criterion 4 - Sharing of Systems Reactor facilities shall not share systems or components unless it is shown safety is not impaired by the sharing.

As previously discussed in Section 2.1 above, portions of the LPSW System are shared by Units 1 and 2. The LPSW System for Unit 3 is separate. For the proposed change, safety is not impaired by the sharing of LPSW between Units 1 and 2 because the LPSW System capability for performing its specified safety function is the same during the proposed temporary Completion Time of 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months as it is during the existing Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months for TS 3.7.7, Condition A, Required Action A.1.

Should the procedural action described above in Section 3.2 to cross connect Unit 3 LPSW with Units 1 and 2 be utilized during the proposed temporary Completion Time due to a loss of the Units 1 and 2 C LPSW Pump, two LPWS pumps would still be available to support Units 1 and 3 while Unit 2 is defueled. Therefore, the specified safety function of the LPSW System will be maintained with the sharing of the Units 1 and 2 and Unit 3 LPSW Systems and safety will not be impaired.

Conclusion of Regulatory Evaluation The proposed change does not affect plant compliance with these regulatory and licensing basis requirements and will continue to ensure that the lowest functional capabilities or performance levels of equipment required for safe operation are met.

4.2 No Significant Hazards Consideration Determination Analysis Duke Energy Carolinas, LLC (Duke Energy) requests an amendment to the Technical Specifications (TS) for Oconee Nuclear Station (ONS) Units 1, 2, and 3. The proposed amendment would revise TS 3.7.7, Low Pressure Service Water (LPSW) System, to extend the Completion Time associated with one required inoperable LPSW pump on a temporary basis.

Specifically, the proposed change would add a Note modifying the Completion Time associated with TS 3.7.7, Condition A, Required Action A.1 to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months during ONS Unit 2, Refuel 31 (Fall 2023) to allow for the tie-in and testing of an alternate suction source to the shared Unit 1 and Unit 2 A and B LPSW pumps. The alternate suction source to the shared Unit 1 and Unit 2 A

RA-21-0005 Enclosure Page 12 of 13 and B LPSW pumps is needed to permit draining of the Condenser Circulating Water (CCW)

System crossover header for the full replacement of three CCW valves.

Duke Energy has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, Issuance of Amendment, as discussed below:

1.

Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change revises the LPSW System TS to extend the Completion Time associated with one required inoperable LPSW pump from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months on a temporary basis during ONS Unit 2, Refuel 31 (O2R31). The LPSW System is not an initiator of any accident previously evaluated. Rather, the system provides a heat sink for the removal of process and operating heat from safety related components during a transient or accident. As a result, the probability of an accident previously evaluated is not increased. The consequences of an accident during the proposed 288-hour Completion Time of O2R31 for the tie-in and testing of an alternate suction source to the LPSW pumps are no different than the consequences of an accident in Modes 1, 2, 3, and 4 during the existing 72-hour Completion Time. For both the existing 72-hour Completion Time and the proposed 288-hour Completion Time, the consequences of an evaluated accident are determined by the operability of the plant systems designed to mitigate those consequences. The consequences with one required inoperable LPSW pump for Units 1 and 2 is not altered by the proposed change and will not affect the consequences of an accident previously evaluated.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed change revises the LPSW System TS to extend the Completion Time associated with one required inoperable LPSW pump from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months on a temporary basis during ONS refueling outage O2R31. The proposed change will not alter the design or function of the LPSW System. For both the existing 72-hour Completion Time and the proposed 288-hour Completion Time, if Required Action A.1 is not met in the allotted time, a Unit 1 shutdown is required by TS 3.7.7, Action C.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3.

Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed change revises the LPSW System TS to extend the Completion Time

RA-21-0005 Enclosure Page 13 of 13 associated with one required inoperable LPSW pump from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months on a temporary basis during ONS refueling outage O2R31. The margin of safety is related to the ability of the fission product barriers to perform their design functions during and following an accident. These barriers include the fuel cladding, the reactor coolant system, and the containment. The performance of these fission product barriers is not adversely affected by the proposed change. A deterministic evaluation of the proposed Completion Time extension during O2R31 demonstrates there is sufficient margin to safety during the extended period (i.e., beyond 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ) of one required LPSW pump being inoperable. To support the temporary Completion Time extension of Unit 1 for one required LPSW pump inoperable while Unit 2 is defueled, defense-in-depth is provided by the capability to procedurally cross connect the two ONS Unit 3 LPSW pumps to the ONS Unit 1 and 2 LPSW header. By taking this procedural action, there would be two LPSW pumps available (the Unit 3 A and B LPSW Pumps) to provide LPSW in the event of a design basis accident for either Unit 1 or Unit 3 during the temporary extended Completion Time. The specified safety function of the LPSW System will be maintained for the proposed change even for a scenario where the shared Units 1 and 2 C LPSW Pump becomes inoperable.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, Duke Energy concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of no significant hazards consideration is justified.

4.3 Conclusion In conclusion, based on the considerations discussed above: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner; (2) such activities will be conducted in compliance with the Commissions regulations; and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5. ENVIRONMENTAL CONSIDERATION A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

RA-21-0005 ATTACHMENT 1 MARKED-UP TECHNICAL SPECIFICATIONS PAGES

[2 pages follow this cover page]

LPSW System 3.7.7

3. 7 PLANT SYSTEMS

3. 7. 7 Low Pressure Service Water (LPSW) System LCO 3.7.7 For Unit 1 or Unit 2, three LPSW pumps and one flow path shall be OPERABLE.

For Unit 3, two LPSW pumps and one flow path shall be OPERABLE.

The LPSW Waterhammer Prevention System (WPS) shall be OPERABLE.

NOTE------------

With either Unit 1 or Unit 2 defueled and appropriate LPSW loads secured on the defueled Unit, such that one LPSW pump is capable of mitigating the consequences of a design basis accident on the remaining Unit, only two LPSW pumps for Unit 1 or Unit 2 are required.

APPLICABILITY:

MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME

/

rs 3.7.7-1 INSERT!

A.

One required LPSW A.1 Restore required 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months pump inoperable.

LPSW pump to OPERABLE status.

B.

LPSWWPS 8.1 Restore the LPSW 7 days I

inoperable.

WPS to OPERABLE status.

C.

Required Action and C. 1 Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months associated Completion I

Time of Condition A or AND B not met.

C.2 Be in MODE 5.

60 hours6.944444e-4 days 0.0167 hours 9.920635e-5 weeks 2.283e-5 months OCONEE UNITS 1, 2, & 3 3.7.7-1 Amendment Nos. JSS, JQO, & JSQ

TS 3.7.7-1 INSERT

NOTE-------------

During Unit 2, Refuel 31 with Unit 2 defueled and appropriate LPSW loads secured, the Completion Time is 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months for the tie-in and testing of an alternate suction source to the shared Unit 1/2 LPSW Pumps A and B.

RA-21-0005 ATTACHMENT 2 REVISED (CLEAN) TECHNICAL SPECIFICATIONS

[3 pages follow this cover page]

LPSW System 3.7.7 (continued)

OCONEE UNITS 1, 2, & 3 3.7.7-1 Amendment Nos. XXX, XXX, & XXX 3.7 PLANT SYSTEMS 3.7.7 Low Pressure Service Water (LPSW) System LCO 3.7.7 For Unit 1 or Unit 2, three LPSW pumps and one flow path shall be OPERABLE.

For Unit 3, two LPSW pumps and one flow path shall be OPERABLE.

The LPSW Waterhammer Prevention System (WPS) shall be OPERABLE.

NOTE---------------------------------------------

With either Unit 1 or Unit 2 defueled and appropriate LPSW loads secured on the defueled Unit, such that one LPSW pump is capable of mitigating the consequences of a design basis accident on the remaining Unit, only two LPSW pumps for Unit 1 or Unit 2 are required.

APPLICABILITY:

MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required LPSW pump inoperable.

A.1 Restore required LPSW pump to OPERABLE status.

NOTE------------

During Unit 2, Refuel 31 with Unit 2 defueled and appropriate LPSW loads secured, the Completion Time is 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months for the tie-in and testing of an alternate suction source to the shared Unit 1/2 LPSW Pumps A and B.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.

LPSW WPS inoperable.

B.1 Restore the LPSW WPS to OPERABLE status.

7 days

LPSW System 3.7.7 ACTIONS (continued)

OCONEE UNITS 1, 2, & 3 3.7.7-2 Amendment Nos. XXX, XXX, & XXX CONDITION REQUIRED ACTION COMPLETION TIME C.

Required Action and associated Completion Time of Condition A or B not met.

C.1 Be in MODE 3.

AND C.2 Be in MODE 5.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 60 hours

LPSW System 3.7.7 OCONEE UNITS 1, 2, & 3 3.7.7-3 Amendment Nos. XXX, XXX, & XXX SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.7.1 Verify LPSW leakage accumulator level is within Water levels between 20.5 to 41. During LPSW testing, accumulator level > 41 is acceptable.

In accordance with the Surveillance Frequency Control Program SR 3.7.7.2

NOTE--------------------------

Isolation of LPSW flow to individual components does not render the LPSW System inoperable.

Verify each LPSW manual, and non-automatic power operated valve in the flow path servicing safety related equipment, that is not locked, sealed, or otherwise secured in position, is in the correct position.

In accordance with the Surveillance Frequency Control Program SR 3.7.7.3 Verify each LPSW automatic valve in the flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.

In accordance with the Surveillance Frequency Control Program SR 3.7.7.4 Verify each LPSW pump starts automatically on an actual or simulated actuation signal.

In accordance with the Surveillance Frequency Control Program SR 3.7.7.5 Verify LPSW leakage accumulator is able to provide makeup flow lost due to boundary valve leakage.

In accordance with the Surveillance Frequency Control Program SR 3.7.7.6 Verify LPSW WPS boundary valve leakage is In accordance with the Surveillance Frequency Control Program s 20 gpm

RA-21-0005 ATTACHMENT 3 TECHNICAL SPECIFICATIONS BASES MARKUP (INFORMATION ONLY)

[1 page follows this cover page]

LPSW System B 3.7.7 BASES OCONEE UNITS 1, 2, & 3 B 3.7.7-3 12/10/14 LCO The LPSW WPS is considered OPERABLE when the associated leakage (continued) accumulator, relief valves, seat leakage limits for check valves and pneumatic discharge isolation valves, closure capability of pneumatic discharge isolation valves, and opening capability of the controllable vacuum breaker valves are OPERABLE.

APPLICABILITY In MODES 1, 2, 3, and 4, the LPSW System is a normally operating system that is required to support the OPERABILITY of the equipment serviced by the LPSW System. Therefore, the LPSW System is required to be OPERABLE in these MODES.

In MODES 5 and 6, the OPERABILITY requirements of the LPSW System are determined by the systems it supports.

ACTIONS A.1 If one required LPSW pump is inoperable, action must be taken to restore the required LPSW pump to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . In this Condition, the remaining OPERABLE LPSW pump(s) are adequate to perform the heat removal function. However, the overall reliability is reduced because a single failure in the OPERABLE LPSW pump(s) could result in loss of LPSW system function. The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time is based on the redundant capabilities afforded by the OPERABLE pump, and the low probability of a DBA occurring during this period.

The Completion Time is modified by a NOTE indicating that the Completion Time during Unit 2, Refuel 31 is 288 hours0.00333 days 0.08 hours 4.761905e-4 weeks 1.09584e-4 months for the tie-in and testing of an alternate suction source to the shared Unit 1 and Unit 2 LPSW Pumps A and B. An alternate suction source to the shared Unit 1 and Unit 2 LPSW Pumps A and B is needed for replacement of Condenser Circulating Water (CCW) System valves. This 288-hour Completion Time is an exception to the normal 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time and shall only be utilized during Unit 2, Refuel 31 when Unit 2 is defueled with appropriate LPSW loads secured for the final tie-in and testing of the alternate suction source. For all other instances of an inoperable required LPSW pump, the 72-hour Completion Time applies.

B.1 If the LPSW WPS is inoperable, action shall be taken to restore the required LPSW WPS components to OPERABLE status within 7 days.

RA-21-0005 ATTACHMENT 4 SIMPLIFIED CONDENSER CIRCULATING WATER SYSTEM CROSSOVER HEADER DIAGRAMS

[4 pages follow this cover page]

FIGURE 1 FIGURE 2 U3CCW 3A LPSW 3B LPSW 3CCW-94 Manwav Condenser U3 RCW 3ALPSW 38 LPSW KCW*94 JCCW-341

,CCW... 67 UJRCW U3 Condenser Simplified CCW Crossover C&DChiller 3CCW-42 U2CCW 2CCW-41 Manway Jockey Pump B HPSW Condenser A&B Chillers CLPSW Normal Operation CCW-73 Jod.eyPump 8HPSW C LPSW A&8 Chill~

U2 Condenser C&ORCW A&BRCW Ul CCW Coolers Coolers lCCW-92 lCCW*

lCCW*

419 418 lCCW-40 CCW-72 AHPSW Manway Condenser C&ORCW A&.8RCW 1CCW* l CCW 4 1~

4 18 t CCW-40 l CCW-43 Ul Condenser

FIGURE 3

1) Provide an alternate suction source to the Unit 1 and Unit 2 LPSW pumps via the 1B condensate cooler in order to dewater the CCW crossover header for replacement of valves 2CCW-41, CCW-72 and CCW-73.

FIGURE 4 3ALPSW 38LPSW C&OChiffer 3CCW-341 3CCW-467 U3RCW U3 Condenser 3A LPSW 38 LPSW C&D Chikr 3CCW-9*

3CCW-S4l SCCW-467 U3RCW U3 Condenser Normal Operation 1B Condensate Cooler Remove from Service C&DRCW A&eRCW 1CCW*92 CCW-72 AHPSW U2 Condenser Normal Operation ccw Ohcharce Make new connection for alternate suction source at 1B Condensate Cooler 8LPSW ALPSW CCW Oischarce t CCW-lCCW 419

18 1CCW-40 lCCW-43 Ul Condenser C&DACW CCW* 1CCW

19

18 tCCW-92 U2 Condenser CCW*72 AttPSW Ul Condenser

FIGURE 5 FIGURE 6 3A LPSW 38 LPSW C&OChilln K CW*94 U311CW U3 Condenser 3ALPSW 38LJ>SW C&DChilfer 3CCW*94 3CCW-341 3CCW-467 UlflCW U3 Condenser U2 Outage

Install Line Stop

& Remove A&B LPSW C&.OIICW

...,ocw CCW* 1CCW 419 ua 1CCW-92 1CCW *O CCW*7S Jodi:eyPump IIHPSW C LPSW A&8Chiler U2 Condenser CCW*72 AHPSW ccw Oisdwlr,e l CCW--40 Ul Condenser U2 Outage. Make Connection at LPSW suction header and place in service C&DflCW A&8flCW l ine Stop U2 Condenser 1CCW-92 CCW-72 AHPSW BLPSW ALPSW ccw Dkdwlre:e 1CCW* 1CCW 419

-118 1CCW--40 l CCW-43 Ul Condenser

FIGURE 7 FIGURE 8 lA LPSW 3B U'SW C&DC.hllll!r 3CCW*341

.KCW-467 U3M:W 0

U3 Condenser 3A LPSW 38 LPSW C&DChillcr 3CCW*94 3CCW*341 3CCW-467 U3RCW U3 Condenser U2 Outage - Dewater CCW Including crossover to Replace 2CCW-41, CCW-72, & CCW-73 CCW*73 Jod:e,,Pump BHPSW CIJ'SW AUChller U2 Condenser Une Stop CCW*7l AHPSW BlPSW ALPSW U2 Post Outage - Return to Service CCW*73

>odtcy Pump BHPSW CIJ'SW A&BChiDu U2 Condenser CCW-71 AHPSW BLPSW ALPSW C&O RCW A&BRCW 1CCW* 1CCW 419 4 11 Ul Condenser C&ORCW A&B RCW 1CCW* 1CCW 419 418 tCCW-40 Ul Condenser

RA-21-0005 ATTACHMENT 5 LOW PRESSURE SERVICE WATER SYSTEM DIAGRAMS AND PROCEDURE (MARKUP)

[6 pages follow this cover page]

: :*:.-:.:::..*:r7 ~.;--=~*-*=* ~*-**

52

~.-1'(11.u,,

QA CON* IT ION I D

W i< i, ENE M CJ Y OCONEE NUCLEAR STATION -

U nit s 1 & 2 FLOW DIAGfw.il OF LOW PRESSURE seMCE WATER $Y$"TEM TURBINE BLOG.

1J-ON PRESSURE SERVICE WATER PUMPS)

OFD-124A; 1.1

@--9 Q

@)

1. ~W,... ~12JJ.._fl&.!JL1""-" C.OS.,..,..SU:ll<t<O

" l1o~l~~l~.""1s.....,<<>.,....,.....,..,....,..,..,.,

3.

112'"T>fll*i-110. '"

"~~ r.:: ll-'. ~~:

._ =--111.--... _,oo, mo,o:,.,,.! r,io,.,.e, '"'*

QA CONDITION 1 0 UK E E" EAG Y

OCONEE N UCLEAR STATIO N U nit 3 FLOW DIAGRAM OF LOW PRESSURE SERVICE WATER SYSTEM TURBINE BLDG.

(LOW PRESSURE SER\\1CE WATER PUMPS)

OFD-124A-3.1 39

Duke Energy Procedure No.

Oconee Nuclear Station AP/1/A/1700/024 Revision No.

Loss of LPSW 029 Excerpt from Loss of LPSW procedure is provided to highlight key steps for the cross connect procedural action described in the license amendment request Enclosure.

!Go to page 3 I

AP/1/A/1700/024 Page 3 of 27

4. Subsequent Actions ACTION/EXPECTED RESPONSE RESPONSE NOT OBTAINED NOTE Unit 1 normally handles LPSW System operation unless otherwise directed by the CRS.

4.1

__ Verify Unit 1 is going to handle LPSW system operations.

__ GO TO Step 4.51.

NOTE Indications of LPSW pump cavitation may vary depending on the length of time since the event occurred. Indications of cavitation may be any of the following: {4}

Pump amps erratic Pump amps below normal LPSW header pressure fluctuating 4.2

__ IAAT any LPSW pump is cavitating, THEN perform Steps 4.3 - 4.4.

__ GO TO Step 4.5 4.3

__ Place the Unit 1/2 STANDBY LPSW PUMP AUTO START CIRCUIT in DISABLE.

4.4 Stop the affected pumps:

__ A LPSW PUMP

__ B LPSW PUMP

__ C LPSW PUMP 4.5 psig.

__ GO TO Step 4.7.

4.6

__ Ensure the Unit 1/2 STANDBY LPSW PUMP AUTO START CIRCUIT is in DISABLE.

NOTE If an LPSW is stopped due to cavitation, it is NOT available until filled and vented.

4.7

__ IAAT a non-operating LPSW pump is available, AND pump start is desired, THEN start the available pump.

~

Verify LPSW header pressure is :S 70

AP/1/A/1700/024 Page 5 of 27 ACTION/EXPECTED RESPONSE RESPONSE NOT OBTAINED NOTE 1LPSW-1121, 1122, 1123, and 1124 will close to isolate RB LPSW loads when LPSW header pressure is 18 psig lowering and re-open at 25 psig rising.

4.8

__ IAAT LPSW to all RBCUs has been

isolated, AND LPSW header pressure is

> 25 psig, THEN perform Step 4.9.

__ GO TO Step 4.10.

4.9 Ensure all the following are open using the CR switch:

A. __ 1LPSW-1121 B. __ 1LPSW-1122 C. __ 1LPSW-1123 D. __ 1LPSW-1124

__ IF a failed valve is preventing flow to RB components, THEN dispatch an operator to PERFORM Encl 5.4 (Manual Restoration of LPSW Waterhammer Prevention System).

4.10 __ Verify LPSW is maintaining normal system parameters (pressure/flow).

__ GO TO Step 4.15.

NOTE 1LPSW-1054, 1055, 1061, and 1062 will close to isolate RB Auxiliary Coolers on low LPSW pressure.

If RB Auxiliary Coolers are aligned for outage cooling with the portable chiller, sliding links have been positioned such that 1LPSW-1054, 1055, 1061, and 1062 will NOT close.

4.11 Verify that RB Auxiliary Coolers have isolated:

__ 1LPSW-1054 closed

__ 1LPSW-1055 closed

__ 1LPSW-1061 closed

__ 1LPSW-1062 closed

__ GO TO Step 4.14.

4.12 __ Restore RB Auxiliary Coolers to service using "Startup of RB Aux Coolers" portion of "LPSW Shutdown and Return to Service of RB Aux Coolers" Encl of OP/1/A/1104/010 (Low Pressure Service Water). {3}

AP/1/A/1700/024 Page 9 of 27 ACTION/EXPECTED RESPONSE RESPONSE NOT OBTAINED 4.15 __ Dispatch an operator to perform Encl 5.1 (Local Operator Actions).

4.16 __ Notify WCC SRO to evaluate any work in progress that could result in degraded or loss of LPSW.

4.17 __ IAAT a LPSW leak is identified, THEN take appropriate action to isolate the leak.

4.18 __ IAAT NO Unit 1 & 2 LPSW pumps are available, AND Unit 3 LPSW system is available, THEN perform the following:

A. __ Direct Unit 3 to start an additional LPSW pump, as required.

B. __ Notify the operator performing Encl 5.1 (Local Operator Actions) to cross-tie Unit 1&2 LPSW to Unit 3 per Step 1.

4.19 __ IAAT CC is in service, AND CC related temperature alarms

exist, THEN initiate AP/20 (Loss of Component Cooling).

4.20 __ Monitor RCP parameters using OAC for in service RCPs (Turn-on code "RCP").

4.21 __ IAAT RCP alarms are received on an operating RCP, THEN initiate AP/16 (Abnormal RCP Operation), as necessary.

Dispatches Auxiliary Operator

~----------**

(AO) with enclosure that operates valve LPSW-1095 This step directs the AO to operate valve LPSW-1095.

Refer to the preceding LPSW flow diagrams for a depiction of the LPSW-1095 cross connect valve.

v t e Letter Sequence Request
EPID:L-2021-LLA-0157, Application to Revise Technical Specification 3.7.7, Low Pressure Service Water (LPSW) System, to Extend the Completion Time for One Required Inoperable LPSW Pump on a Temporary Basis (Approved, Closed)
Initiation Request, Request, Request, Request, Request Acceptance... Administration Questions 4 March 2022 Answers 14 April 2022 Results Approval, Approval Other: ML21270A250, ML21362A753, ML22046A088, ML24338A248
MONTHYEAR2022-03-04 [Table View]

RA-21-0005, Application to Revise Technical Specification 3.7.7, Low Pressure Service Water (LPSW) System, to Extend the Completion Time for One Required Inoperable LPSW Pump on a Temporary Basis

Text

Subject:

Enclosure:

Subject:

SUMMARY

3.4 Technical Evaluation Conclusion

SUMMARY

3.4 Technical Evaluation Conclusion

Navigation menu

RA-21-0005, Application to Revise Technical Specification 3.7.7, Low Pressure Service Water (LPSW) System, to Extend the Completion Time for One Required Inoperable LPSW Pump on a Temporary Basis

Text

Subject:

Enclosure:

Subject:

SUMMARY

3.4 Technical Evaluation Conclusion

SUMMARY

3.4 Technical Evaluation Conclusion

Navigation menu

Search