CP-202400471, Application to Revise Technical Specifications to Adopt TSTF-522, Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month
| ML24351A232 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/16/2024 |
| From: | Sewell S Vistra Operations Company |
| To: | Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| CP-202400471, TXX-24088 | |
| Download: ML24351A232 (1) | |
Text
6555 SIERRA DRIVE IRVING, TEXAS 75039 o 214-812-4600 VISTRACORP.COM Comanche Peak Nuclear Power Plant Steven Sewell Site Vice President P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 CP-202400471 TXX-24088 December 16, 2024 ATTN: Document Control Desk Ref 10 CFR 50.90 U. S. Nuclear Regulatory Commission 10 CFR 50.91 Washington, DC 20555-0001 Comanche Peak Nuclear Power Plant (CPNPP)
Docket Nos. 50-445, 50-446 and 72-74
Subject:
Application to Revise Technical Specifications to Adopt TSTF-522, "Revise Ventilation System Surveillance Requirements to Operate For 10 Hours Per Month"
Dear Sir or Madam:
Pursuant to 10 CFR 50.90, Vistra Operations Company LLC (Vistra OpCo) is submitting a request for an amendment to the Technical Specifications (TS) for Comanche Peak Nuclear Power Plant (CPNPP), Units 1 and 2.
The proposed amendment would modify, CPNPP TS requirements to operate ventilation systems with charcoal filters for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> at a frequency controlled in accordance with the surveillance frequency control program, in accordance with TSTF-522, Revision 0, "Revise Ventilation System Surveillance Requirements to Operate for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> per Month."
The enclosure provides a description and assessment of the proposed changes. Attachment 1 provides the existing TS pages marked to show the proposed changes and revised (clean) TS pages. Attachment 2 provides the existing TS Bases pages marked to show revised text associated with the proposed TS changes and is provided for information only.
Vistra OpCo requests that the amendment be reviewed under the Consolidated Line Item Improvement Process (CLIIP). Approval of the proposed amendment is requested within 6 months of completion of the NRCs acceptance review. Once approved, the amendment will be implemented within 90 days.
There are no new regulatory commitments made in this submittal.
In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated State of Texas Official.
Should you have any questions, please contact Nic Boehmisch at (254) 897-5064 or nicholas.boehmisch@vistracorp.com.
TXX-24088 Page 2 of 2 I state under penalty of perjury that the foregoing is true and correct.
Executed on December 16, 2024.
Enclosure:
Description and Assessment : Proposed Technical Specification Changes Sincerely, Steven Sewell (Dec 16, 2024 16:40 CST)
Steven Sewell : Proposed Technical Specification Bases Changes (information only) cc:
John Monninger, Region IV Uohn.Monninger@mc.gov]
Samson Lee, NRR [Samson.Lee@mc.gov]
John Ellegood, Senior Resident Inspector, CPNPP Uohn.Ellegood@mc.gov]
Hemy Strittmatter, Resident Inspector, CPNPP [Hemy.Strittmatter@mc.gov]
Mr. Robert Free [ robert.free@dshs.state. tx. us]
Environmental Monitoring & Emergency Response Manager Texas Department of State Health Services Mail Code 1986 P. 0. Box 149347 Austin TX, 78714-9347
Enclosure to TXX-24088 Page 1 of 3 DESCRIPTION AND ASSESSMENT
1.0 DESCRIPTION
The proposed change revises the Surveillance Requirements which currently require operating ventilation systems with the heaters operating for a continuous 10-hour period at a frequency controlled in accordance with the Surveillance Frequency Control Program. The Surveillance Requirements are revised to require operation of the systems for 15 continuous minutes at a frequency controlled in accordance with the Surveillance Frequency Control Program.
The proposed amendment is consistent with TSTF-522, Revision 0, "Revise Ventilation System Surveillance Requirements to Operate for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> per Month."
2.0 ASSESSMENT
2.1 Applicability of Safety Evaluation Vistra OpCo has reviewed the model safety evaluation for TSTF-522 published in the Federal Register on September 20, 2012. This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-522. Vistra OpCo has concluded that the justifications presented in TSTF-522, and the model safety evaluation prepared by the NRC staff are applicable to Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2, and justify this amendment for the incorporation of the changes to the CPNPP TS.
2.2 Variations Vistra OpCo is proposing the following variations from the TS changes described in TSTF-522 or the applicable parts of the NRC staffs safety evaluation:
The Control Room Emergency Filtration/Pressurization System (CREFS) at CPNPP includes two pressurization system trains with heaters and two filtration system trains without heaters. The current SR 3.7.10.1 utilizes different wording than the Standard Technical Specifications (STS) on which TSTF-522 was based. The additional wording Emergency Pressurization Unit and and Emergency Filtration Unit, are included in the current SR. This different wording does not affect the applicability of the traveler to the CPNPP TS.
The current TS 3.7.12 uses different titles than the STS on which TSTF-522 was based. The current TS is titled Primary Plant Ventilation System (PPVS) - ESF Filtration Trains, and the associated SR 3.7.12.1 uses the term ESF Filtration, instead of Emergency Core Cooling System (ECCS) Pump Room Exhaust Air Cleanup System (PREACS) ECCS PREACS.
The existing surveillance frequency is controlled in accordance with the Surveillance Frequency Control Program, CPNPP T.S. 5.5.21.
These differences do not affect the applicability of the traveler to the CPNPP TS.
Enclosure to TXX-24088 Page 2 of 3
3.0 REGULATORY ANALYSIS
3.1 No Significant Hazards Consideration Analysis Vistra OpCo request adoption of an approved change to the standard technical specifications and plant-specific Technical Specifications, to revise Technical Specification (TS) 3.7.10 Control Room Emergency Filtration/Pressurization System (CREFS) and TS 3.7.12 Primary Plant Ventilation System (PPVS) - ESF Filtration Trains to revise the Surveillance Requirement to operate the systems with the heaters operating for a continuous 10 hour1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> period at a frequency controlled in accordance with the Surveillance Frequency Control Program. The Surveillance Requirements are revised to require operation of the systems for 15 continuous minutes at a frequency controlled in accordance with the Surveillance Frequency Control Program.
Vistra OpCo has evaluated if a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
- 1.
Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change replaces an existing Surveillance Requirement to operate the CREFS and PPVS, for a continuous 10-hour period with the heaters operating, at a frequency controlled in accordance with the Surveillance Frequency Control Program; with a requirement to operate the systems for 15 continuous minutes with the heaters operating.
These systems are not accident initiators, and therefore, the changes do not involve a significant increase in the probability of an accident. The proposed system and filter testing changes are consistent with current regulatory guidance for this system and will continue to assure that the system performs its design function which may include mitigating accidents.
Thus, the change does not involve a significant increase in the consequences of an accident.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2.
Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change replaces an existing Surveillance Requirement to operate the CREFS and PPVS, for a continuous 10-hour period with the heaters operating, at a frequency controlled in accordance with the Surveillance Frequency Control Program; with a requirement to operate the systems for 15 continuous minutes with the heaters operating.
Enclosure to TXX-24088 Page 3 of 3 The change proposed for the systems does not change any system operations or maintenance activities. Testing requirements will be revised and will continue to demonstrate that the Limiting Conditions for Operation are met. The change does not create new failure modes or mechanisms and no new accident precursors are generated.
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 amendment involve a significant reduction in a margin of safety?
Response: No The proposed change replaces an existing Surveillance Requirement to operate the CREFS and PPVS, for a continuous 10-hour period with the heaters operating, at a frequency controlled in accordance with the Surveillance Frequency Control Program; with a requirement to operate the systems for 15 continuous minutes with the heaters operating.
The design basis for the systems heater is to heat the incoming air which reduces the relative humidity. The heater testing change proposed will continue to demonstrate that the heaters are capable of heating the air and will perform their design function. The proposed change is consistent with regulatory guidance.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, Vistra OpCo 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.
4.0 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.
Enclosure to TXX-24088 Proposed Technical Specification Changes
CREFS 3.7.10 COMANCHE PEAK - UNITS 1 AND 2 3.7-27 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.10.1 Operate each CREFS trains Emergency Pressurization Unit for 10 continuous hours with the heaters operating and Emergency Filtration Unit 15 minutes.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.10.2 Perform required CREFS testing in accordance with the Ventilation Filter Testing Program (VFTP).
In accordance with the VFTP SR 3.7.10.3 Verify each CREFS train actuates on an actual or simulated actuation signal.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.10.4 Perform required CRE unfiltered air inleakage testing in accordance with the Control Room Envelope Habitability Program.
In accordance with the Control Room Envelope Habitability Program Amendment No. 150, 156 15 minutes continuous
PPVS - ESF Filtration Trains 3.7.12 COMANCHE PEAK - UNITS 1 AND 2 3.7-32 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.12.1 Operate each ESF Filtration train for 10 continuous hours with the heaters operating.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.12.2 Perform required ESF Filtration Unit filter testing in accordance with the Ventilation Filter Testing Program (VFTP).
In accordance with the VFTP SR 3.7.12.3 Verify each PPVS train actuates on an actual or simulated actuation signal.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.12.4 Verify one PPVS train can maintain a pressure
-0.05 inches water gauge relative to atmospheric pressure during the post accident mode of operation.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.12.5 Not used.
SR 3.7.12.6 Verify each PPVS non-ESF fan stops on an actual or simulated actuation signal.
In accordance with the Surveillance Frequency Control Program.
Amendment No. 150, 156 minutes 15
CREFS 3.7.10 COMANCHE PEAK - UNITS 1 AND 2 3.7-27 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.10.1 Operate each CREFS trains Emergency Pressurization Unit for 15 continuous minutes with the heaters operating and Emergency Filtration Unit 15 continuous minutes.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.10.2 Perform required CREFS testing in accordance with the Ventilation Filter Testing Program (VFTP).
In accordance with the VFTP SR 3.7.10.3 Verify each CREFS train actuates on an actual or simulated actuation signal.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.10.4 Perform required CRE unfiltered air inleakage testing in accordance with the Control Room Envelope Habitability Program.
In accordance with the Control Room Envelope Habitability Program Amendment No. 150, 156, TBD
PPVS - ESF Filtration Trains 3.7.12 COMANCHE PEAK - UNITS 1 AND 2 3.7-32 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.12.1 Operate each ESF Filtration train for 15 continuous minutes with the heaters operating.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.12.2 Perform required ESF Filtration Unit filter testing in accordance with the Ventilation Filter Testing Program (VFTP).
In accordance with the VFTP SR 3.7.12.3 Verify each PPVS train actuates on an actual or simulated actuation signal.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.12.4 Verify one PPVS train can maintain a pressure
-0.05 inches water gauge relative to atmospheric pressure during the post accident mode of operation.
In accordance with the Surveillance Frequency Control Program.
SR 3.7.12.5 Not used.
SR 3.7.12.6 Verify each PPVS non-ESF fan stops on an actual or simulated actuation signal.
In accordance with the Surveillance Frequency Control Program.
Amendment No. 150, 156, TBD
Enclosure to TXX-24088 Proposed Technical Specification Bases Changes (information only)
CREFS B 3.7.10 BASES COMANCHE PEAK - UNITS 1 AND 2 B 3.7-48 Revision 85 BACKGROUND (continued) water droplets present, to prevent excessive loading of the HEPA filters and charcoal adsorbers. Continuous operation of each trains emergency pressurization unit for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> per month, with the heaters on, reduces moisture buildup on the HEPA filters adsorbers. Both the demister and heater are important to the effectiveness of the charcoal adsorbers.
Actuation of the CREFS by a Safety Injection, Loss of Offsite Power or Intake Vent High Radiation signal places the system in the emergency recirculation mode. Actuation of the system to the emergency recirculation mode of operation, closes the unfiltered outside air supply path and the system exhaust dampers, stops normal supply and exhaust fans, and aligns the system for recirculation of the air within the CRE through the redundant trains of HEPA and the charcoal filters. The emergency recirculation mode also initiates pressurization and filtered ventilation of the air supply to the CRE.
Outside air is filtered, and added to the air being recirculated from the CRE.
Pressurization of the CRE minimizes infiltration of unfiltered air through the CRE boundary from all the surrounding areas adjacent to the CRE boundary.
The air entering the CRE is continuously monitored by radiation detectors.
One detector output above the setpoint will cause actuation of the emergency recirculation mode.
A single CREFS train operating at a flow rate of < 800 cfm will pressurize the CRE to about 0.125 inches water gauge relative to external areas adjacent to the CRE boundary. The CREFS operation in maintaining the CRE habitable is discussed in the FSAR, Sections 2.2, 6.4, 6.5, 7.3, and 9.4 (Ref.
1).
Because the control room door ingress/egress is to a stairwell which is equivalent to a two-door vestibule, backflow will not occur with the CPSES CREFS design and the 10 cfm is not applicable per SRP 6.4. The ductwork has all welded joints which were leak tested prior to operation. Therefore, the assumed unfiltered inleakage from adjacent areas is conservative with respect to the SRP review criteria.
The Control Room Habitability is maintained by limiting the inleakage of potentially contaminated air into the Control Room Envelope. The potential leakage paths for the Control Room Envelope include the control room enclosure (e.g., walls, penetrations, floors, ceilings, joints, etc.), and other potential paths such as pressurized ductwork from other HVAC systems, pressurized air systems (e.g., instrument air) or isolated HVAC intakes.
(continued)
CREFS B 3.7.10 BASES COMANCHE PEAK - UNITS 1 AND 2 B 3.7-53 Revision 85 ACTIONS D.1, D.2.1, and D.2.2 (continued)
CRE. This places the unit in a condition that minimizes the accident risk.
This does not preclude the movement of fuel to a safe position.
E.1 and E.2 In MODE 5 or 6, or during movement of irradiated fuel assemblies, with two CREFS trains inoperable or with one or more CREFS trains inoperable due to an inoperable CRE boundary, action must be taken immediately to suspend activities that could result in a release of radioactivity that might require isolation of the CRE. This places the unit in a condition that minimizes the accident risk. This does not preclude the movement of fuel to a safe position.
F.1 If both CREFS trains are inoperable in MODE 1, 2, 3, or 4, for reasons other than an inoperable CRE boundary (i.e., Condition B), the CREFS may not be capable of performing the intended function and the unit is in a condition outside the accident analyses. Therefore, LCO 3.0.3 must be entered immediately.
SURVEILLANCE REQUIREMENTS SR 3.7.10.1 Standby systems should be checked periodically to ensure that they function properly. As the environment and normal operating conditions on this system are not too severe, testing each train periodically provides an adequate check of this system. Periodic heater operations dry out any moisture accumulated in the charcoal from humidity in the ambient air.
Filtration units with heaters must be operated for > 10 continuous hours with the heaters energized. Filtration units without heaters need only be operated for > 15 minutes to demonstrate the function of the system. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
SR 3.7.10.2 This SR verifies that the required CREFS testing is performed in accordance with the Ventilation Filter Testing Program (VFTP). The CREFS filter tests are in accordance with Regulatory Guide 1.52 (Ref. 3). The VFTP includes testing the performance of the HEPA filter, charcoal adsorber efficiency, (continued)
Operation (with the heaters on) for 15 continuous minutes demonstrates OPERABILITY of the system. Periodic operation ensures that heater failure, blockage, fan or motor failure, or excessive vibration can be detected for corrective action.
PPVS B 3.7.12 BASES COMANCHE PEAK - UNITS 1 AND 2 B 3.7-64 Revision 85 ACTIONS C.1 (continued)
The 7 day Completion Time is appropriate because the risk contribution is less than that for the ECCS (72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time), and this system is not a direct support system for the ECCS. The 7 day Completion Time is based on the low probability of a DBA occurring during this time period, and ability of the remaining train to provide the required capability.
Concurrent failure of two PPVS trains would result in the loss of functional capability; therefore, LCO 3.0.3 must be entered immediately.
D.1 and D.2 If the PPVS train or negative pressure envelope cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in 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 REQUIREMENTS SR 3.7.12.1 Standby systems should be checked periodically to ensure that they function properly. As the environment and normal operating conditions on this system are not severe, testing each train periodically provides an adequate check on this system. Periodic heater operations dry out any moisture that may have accumulated in the charcoal from humidity in the ambient air.
Systems with heaters must be operated 10 continuous hours with the heaters energized with flow through the HEPA filters and charcoal adsorbers. Operation is to be initiated from the Control Room. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
SR 3.7.12.2 This SR verifies that the required PPVS testing is performed in accordance with the Ventilation Filter Testing Program (VFTP). The ECCS PREACS filter tests are in accordance with Reference 4. The VFTP includes testing HEPA filter performance, charcoal adsorbers efficiency, minimum system flow rate, and the physical properties of the activated charcoal (general use and following specific operations). Specific test Frequencies and additional information are discussed in detail in the VFTP.
(continued)
Operation (with the heaters on) for 15 continuous minutes demonstrates OPERABILITY of the system. Periodic operation ensures that heater failure, blockage, fan or motor failure, or excessive vibration can be detected for corrective action.