Text

TSTF-558-T, Clarify SR Bases Added by TSTF-523
	ML20302A217
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Site:	Technical Specifications Task Force
Issue date:	10/27/2020
From:	; Office of Nuclear Reactor Regulation
To:	; Technical Specifications Task Force
	Honcharik,M., NRR/DSS, 301-4151774
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ML20302A210	List: ML20302A217; ML20302A218; ML20302A219; ML20302A220; ML20302A221;
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WOG-221, Rev. 0 TSTF-558-T, Rev. 0 Technical Specifications Task Force Improved Standard Technical Specifications Change Traveler Clarify SR Bases added by TSTF-523 NUREGs Affected: 1430 1431 1432 1433 1434 2194 Note: This "T" Traveler has been reviewed and approved by the Technical Specification Task Force and is made available as a template for plant-specific license amendments. This Traveler has not been reviewed and approved by the Nuclear Regulatory Commission. Any plant submitting a license amendment request to adopt this change should inform the industry contact listed below and copy the Technical Specification Task Force on their submittal letter.

Classification: 2) Bases Only Change Recommended for CLIIP?: No Correction or Improvement: Improvement NRC Fee Status:

Changes Marked on ISTS Rev 4.0 See attached.

Revision History OG Revision 0 Revision Status: Active Revision Proposed by: PWROG LC Revision

Description:

Original Issue Owners Group Review Information Date Originated by OG: 17-Mar-16 Owners Group Comments (No Comments)

Owners Group Resolution: Approved Date: 04-Apr-16 TSTF Review Information TSTF Received Date: 02-May-16 Date Distributed for Review 02-May-16 TSTF Comments:

(No Comments)

TSTF Resolution: Approved for Use Date: 17-May-16 Affected Technical Specifications SR 3.4.6.3 Bases RCS Loops - MODE 4 NUREG(s)- 1430 Only SR 3.4.7.4 Bases RCS Loops - MODE 5, Loops Filled NUREG(s)- 1430 Only SR 3.4.8.3 Bases RCS Loops - MODE 5, Loops Not Filled NUREG(s)- 1430 Only SR 3.5.2.3 Bases ECCS - Operating NUREG(s)- 1430 Only 18-May-16 Copyright(C) 2016, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

WOG-221, Rev. 0 TSTF-558-T, Rev. 0 SR 3.6.6.4 Bases Containment Spray and Cooling Systems NUREG(s)- 1430 Only SR 3.9.4.2 Bases DHR and Coolant Circulation - High Water Level NUREG(s)- 1430 Only SR 3.9.5.3 Bases DHR and Coolant Circulation - Low Water Level NUREG(s)- 1430 Only SR 3.4.6.4 Bases RCS Loops - MODE 4 NUREG(s)- 1431 1432 Only SR 3.4.7.4 Bases RCS Loops - MODE 5, Loops Filled NUREG(s)- 1431 1432 Only SR 3.4.8.3 Bases RCS Loops - MODE 5, Loops Not Filled NUREG(s)- 1431 1432 Only SR 3.5.2.3 Bases ECCS - Operating NUREG(s)- 1431 1432 Only SR 3.6.6C.2 Bases Containment Spray System NUREG(s)- 1431 Only SR 3.6.6D.2 Bases QS System NUREG(s)- 1431 Only SR 3.6.6A.4 Bases Containment Spray and Cooling Systems NUREG(s)- 1431 Only SR 3.6.6B.4 Bases Containment Spray and Cooling Systems NUREG(s)- 1431 Only SR 3.6.6E.5 Bases RS System NUREG(s)- 1431 Only SR 3.9.5.2 Bases RHR and Coolant Circulation - High Water Level NUREG(s)- 1431 Only SR 3.9.6.3 Bases RHR and Coolant Circulation - Low Water Level NUREG(s)- 1431 Only SR 3.6.6B.5 Bases Containment Spray and Cooling Systems NUREG(s)- 1432 Only SR 3.6.6A.5 Bases Containment Spray and Cooling Systems NUREG(s)- 1432 Only SR 3.9.4.2 Bases SDC and Coolant Circulation - High Water Level NUREG(s)- 1432 Only SR 3.9.5.3 Bases SDC and Coolant Circulation - Low Water Level NUREG(s)- 1432 Only SR 3.5.2.3 Bases ECCS - Shutdown NUREG(s)- 1433 1434 Only Change

Description:

Refers to SR 3.5.1.1 which is revised SR 3.4.8.2 Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only SR 3.4.9.2 Bases RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1433 Only SR 3.5.1.1 Bases ECCS - Operating NUREG(s)- 1433 Only SR 3.5.3.1 Bases RCIC System NUREG(s)- 1433 Only SR 3.6.2.3.2 Bases RHR Suppression Pool Cooling NUREG(s)- 1433 Only SR 3.6.2.4.2 Bases RHR Suppression Pool Spray NUREG(s)- 1433 Only SR 3.9.8.2 Bases RHR - High Water Level NUREG(s)- 1433 Only 18-May-16 Copyright(C) 2016, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

WOG-221, Rev. 0 TSTF-558-T, Rev. 0 SR 3.9.9.2 Bases RHR - Low Water Level NUREG(s)- 1433 Only SR 3.4.9.2 Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1434 Only SR 3.4.10.2 Bases RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1434 Only SR 3.5.1.1 Bases ECCS - Operating NUREG(s)- 1434 Only SR 3.5.3.1 Bases RCIC System NUREG(s)- 1434 Only SR 3.6.1.7.2 Bases RHR Containment Spray System NUREG(s)- 1434 Only SR 3.6.2.3.2 Bases RHR Suppression Pool Cooling NUREG(s)- 1434 Only SR 3.9.8.2 Bases RHR - High Water Level NUREG(s)- 1434 Only SR 3.9.9.2 Bases RHR - Low Water Level NUREG(s)- 1434 Only 18-May-16 Copyright(C) 2016, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

TSTF-558, Rev. 0

1.

SUMMARY

DESCRIPTION On January 15, 2014, the NRC published the Notice of Availability (i.e., the approval) of TSTF-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation," in the Federal Register. The proposed change modifies the Surveillance Requirement (SR) Bases added by TSTF-523 to clarify the application of the SR when accumulated gas is identified and vented during SR performance.

2. DETAILED DESCRIPTION 2.1. Background Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," (Ref. 1) addresses the issue of gas accumulation in the Emergency Core Cooling System (ECCS), Decay Heat Removal (DHR)

(also called Residual Heat Removal (RHR) or Shutdown Cooling (SDC)) System, and Containment Spray (CS) System to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified. The Nuclear Regulatory Commission (NRC) requested that licensees perform evaluations and submit information regarding gas management activities in response to the GL.

TSTF-523, Revision 2, modified the existing SRs related to gas accumulation for the ECCS and added new SRs on entrained gas to the specifications governing the DHR, RHR, SDC and CS systems to require periodic verification that system locations susceptible to gas accumulation are sufficiently filled with water. Similar changes were made to the existing SR on the Boiling Water Reactor (BWR) Reactor Core Isolation Cooling (RCIC) System to maintain consistency within the TS. Other existing SRs were revised to provide allowances for performance of the gas accumulation SRs. The Bases were revised to reflect the change to the SRs. On January 15, 2014, the NRC published the Notice of Availability (i.e., the approval) of TSTF-523, Revision 2 (Ref. 2).

Page 1

TSTF-558, Rev. 0 2.2. Current Requirements The third paragraph of the Bases for the associated SRs states:

The [XXX] System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the [XXX]

System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.

The bracketed term "[XXX]" differs according to the system to which the SR applies (e.g., RHR, DHR, SDC, etc.)

2.3. Reason for the Proposed Change A common method of checking a system for accumulated gas is to open a high point vent. If any gas is present, it is vented during the SR performance. Licensees have questioned the appropriate Technical Specifications (TS) actions to be taken when accumulated gas in excess of the acceptance criteria is discovered during performance of the SR and the gas is vented to within the acceptance criteria (typically, completely vented) during performance of the SR.

2.4. Description of the Proposed Change The third paragraph is revised to state (inserted words are in italics):

The [XXX] System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump), the Surveillance is not met. If the accumulated gas is eliminated or brought within the acceptance criteria limits during performance of the Surveillance, the Surveillance is met and past system OPERABILITY is evaluated under the Corrective Action Program. If it Page 2

TSTF-558, Rev. 0 is determined by subsequent evaluation that the [XXX] System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.

The proposed change is applied to the following Technical Specification Bases sections:

NUREG-1430 (Babcock and Wilcox Plants) 3.4.6, RCS Loops - MODE 4 Revise SR 3.4.6.3 Bases 3.4.7, RCS Loops - MODE 5, Loops Filled Revise SR 3.4.7.4 Bases 3.4.8, RCS Loops - MODE 5, Loops Not Filled Revise SR 3.4.8.3 Bases 3.5.2, ECCS - Operating Revise SR 3.5.2.3 Bases 3.6.6, Containment Spray and Cooling Systems Revise SR 3.6.6.4 Bases 3.9.4, DHR and Coolant Circulation - High Water Level Revise SR 3.9.4.2 Bases.

3.9.5, DHR and Coolant Circulation - Low Water Level Revise SR 3.9.5.3 Bases.

NUREG-1431 (Westinghouse Plants) 3.4.6, RCS Loops - MODE 4 Revise SR 3.4.6.4 Bases 3.4.7, RCS Loops - MODE 5, Loops Filled Revise SR 3.4.7.4 Bases 3.4.8, RCS Loops - MODE 5, Loops Not Filled Revise SR 3.4.8.3 Bases 3.5.2, ECCS - Operating Revise SR 3.5.2.3 Bases 3.6.6A, Containment Spray and Cooling Systems (Atmospheric and Revise SR 3.6.6A.4 Bases Dual) 3.6.6B, Containment Spray and Cooling Systems (Atmospheric and Revise SR 3.6.6B.4 Bases Dual) 3.6.6C, Containment Spray System (Ice Condenser) Revise SR 3.6.6C.2 Bases 3.6.6D, Quench Spray System (Subatmospheric) Revise SR 3.6.6D.2 Bases 3.6.6E, Recirculation Spray System (Subatmospheric) Revise SR 3.6.6E.5 Bases 3.9.5, RHR and Coolant Circulation - High Water Level Revise SR 3.9.5.2 Bases.

Page 3

TSTF-558, Rev. 0 3.9.6, RHR and Coolant Circulation - Low Water Level Revise SR 3.9.6.3 Bases.

NUREG-1432 (Combustion Engineering Plants) 3.4.6, RCS Loops - MODE 4 Revise SR 3.4.6.4 Bases 3.4.7, RCS Loops - MODE 5, Loops Filled Revise SR 3.4.7.4 Bases 3.4.8, RCS Loops - MODE 5, Loops Not Filled Revise SR 3.4.8.3 Bases 3.5.2, ECCS - Operating Revise SR 3.5.2.3 Bases 3.6.6A, Containment Spray and Cooling Systems (Atmospheric and Revise SR 3.6.6A.5 Bases Dual) 3.6.6B, Containment Spray and Cooling Systems (Atmospheric and Revise SR 3.6.6B.5 Bases Dual) 3.9.4, SDC and Coolant Circulation - High Water Level Revise SR 3.9.4.2 Bases.

3.9.5, SDC and Coolant Circulation - Low Water Level Revise SR 3.9.5.3 Bases.

NUREG-1433 (BWR/4 Plants) 3.4.8, RHR Shutdown Cooling System - Hot Shutdown Revise SR 3.4.8.2 Bases 3.4.9, RHR Shutdown Cooling System - Cold Shutdown Revise SR 3.4.9.2 Bases 3.5.1, ECCS - Operating Revise SR 3.5.1.1 Bases 3.5.3, RCIC System Revise SR 3.5.3.1 Bases 3.6.2.3, RHR Suppression Pool Cooling Revise SR 3.6.2.3.2 Bases 3.6.2.4, RHR Suppression Pool Spray Revise SR 3.6.2.4.2 Bases 3.9.8, RHR - High Water Level Revise SR 3.9.8.2 Bases 3.9.9, RHR - Low Water Level Revise SR 3.9.9.2 Bases NUREG-1434 (BWR/6 Plants) 3.4.9, RHR Shutdown Cooling System - Hot Shutdown Revise SR 3.4.9.2 Bases 3.4.10, RHR Shutdown Cooling System - Cold Shutdown Revise SR 3.4.10.2 Bases 3.5.1, ECCS - Operating Revise SR 3.5.1.1 Bases Page 4

TSTF-558, Rev. 0 3.5.3, RCIC System Revise SR 3.5.3.1 Bases 3.6.1.7, RHR Containment Spray System Revise SR 3.6.1.7.2 Bases 3.6.2.3, RHR Suppression Pool Cooling Revise SR 3.6.2.3.2 Bases 3.9.8, RHR - High Water Level Revise SR 3.9.8.2 Bases 3.9.9, RHR - Low Water Level Revise SR 3.9.9.2 Bases The proposed change is a change to the TS Bases. 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." A licensee may make changes to the TS Bases without prior NRC review and approval in accordance with the Technical Specifications Bases Control Program.

3. TECHNICAL EVALUATION In GL 2008-01, the NRC provided a detailed discussion of the regulatory basis for requiring licensees to ensure that the operability of the subject systems is not impaired by gas accumulation. TSTF-523 implemented TS controls to require accumulated gas to be managed and monitored to ensure system operability.

The SR requires verification that the subject system locations susceptible to gas accumulation are sufficiently filled with water to support system operability. The SR acceptance criteria are specified in plant procedures because accumulated gas limits will vary by plant, system, and location. If the performance of the SR has eliminated the accumulated gas or reduced the accumulated gas to within the acceptance criteria, then the system has been verified to be "sufficiently filled" and the SR acceptance criteria are met as specified in the associated plant procedures. If accumulated gas in excess of the acceptance criteria was removed from the system during performance of the SR, the licensee must perform an evaluation to determine if the system was operable prior to performance of the SR. That evaluation should be documented in the Corrective Action Program and, if required, reported in accordance with 10 CFR 50.72 and 10 CFR 50.73.

Page 5

TSTF-558, Rev. 0 If the SR is not met, then the appropriate Conditions and Required Actions will be followed. If subsequent evaluation determines that the accumulated gas does not render the subject system inoperable (i.e., the system is "sufficiently filled with water"), the Surveillance may be declared met and the Conditions and Required Actions be exited. However, it is intended that the accumulated gas be eliminated or reduced to within the procedural acceptance criteria even if the system is determined to be operable.

Conclusion The proposed Bases change is consistent with the concerns discussed in GL 2008-01 and the Surveillance Requirement. It provides necessary clarification of the purpose and implementation of the SR.

4. REGULATORY EVALUATION A regulatory evaluation is not required for a TS Bases change.

5. REFERENCES

1. Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008.

2. Federal Register, 29 FR 2700, dated January 15, 2014, "TSTF-523, 'Generic Letter 2008-01, Managing Gas Accumulation,' Using the Consolidated Line Item Improvement Process."

Page 6

TSTF-558, Rev. 0 RCS Loops - MODE 4 B 3.4.6 BASES SURVEILLANCE REQUIREMENTS (continued)

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

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

This SR is modified by a Note that states the SR is not required to be performed until 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after a required pump is not in operation.

SR 3.4.6.3 DHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the required DHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.

Selection of DHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration. Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.

The DHR System is OPERABLE when it is sufficiently filled with water.

Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump),

the Surveillance is not met. If the accumulated gas is eliminated or brought within the acceptance criteria limits during performance of the Surveillance, the Surveillance is met and past system OPERABILITY is evaluated under the Corrective Action Program. If it is determined by subsequent evaluation that the DHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water),

Babcock & Wilcox STS B 3.4.6-5 Rev. 4.0

TSTF-558, Rev. 0 RCS Loops - MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.7.4 DHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the required DHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.

Selection of DHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration. Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.

The DHR System is OPERABLE when it is sufficiently filled with water.

Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump),

the Surveillance is not met. If the accumulated gas is eliminated or brought within the acceptance criteria limits during performance of the Surveillance, the Surveillance is met and past system OPERABILITY is evaluated under the Corrective Action Program. If it is determined by subsequent evaluation that the DHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water),

the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.

DHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.

Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location. Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY. The accuracy of Babcock & Wilcox STS B 3.4.7-6 Rev. 4.0

TSTF-558, Rev. 0 RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that redundancy for heat removal is provided. The requirement also ensures that an additional loop can be placed in operation if needed to maintain decay heat removal and reactor coolant circulation. Verification is performed by verifying proper breaker alignment and power available to each required pump. Alternatively, verification that a pump is in operation also verifies proper breaker alignment and power availability. [ The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.

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

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

This SR is modified by a Note that states the SR is not required to be performed until 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after a required pump is not in operation.

SR 3.4.8.3 DHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the DHR loops and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.

Selection of DHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration. Susceptible locations Babcock & Wilcox STS B 3.4.8-4 Rev. 4.0

TSTF-558, Rev. 0 RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE REQUIREMENTS (continued) depend on plant and system configuration, such as stand-by versus operating conditions.

The DHR System is OPERABLE when it is sufficiently filled with water.

Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump),

the Surveillance is not met. If the accumulated gas is eliminated or brought within the acceptance criteria limits during performance of the Surveillance, the Surveillance is met and past system OPERABILITY is evaluated under the Corrective Action Program. If it is determined by subsequent evaluation that the DHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water),

the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.

DHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.

Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location. Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY. The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.

[ The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the DHR System piping and the procedural controls governing system operation.

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. The Surveillance Frequency may vary by location susceptible to gas accumulation.

REVIEWERS NOTE-----------------------------------

Babcock & Wilcox STS B 3.4.8-5 Rev. 4.0

TSTF-558, Rev. 0 ECCS - Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued) operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.

SR 3.5.2.3 ECCS piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the ECCS and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.

Selection of ECCS locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration. Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.

The ECCS is OPERABLE when it is sufficiently filled with water.

Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump),

the Surveillance is not met. If the accumulated gas is eliminated or brought within the acceptance criteria limits during performance of the Surveillance, the Surveillance is met and past system OPERABILITY is evaluated under the Corrective Action Program. If it is determined by subsequent evaluation that the ECCS is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.

ECCS locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety.

For these locations alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.

Babcock & Wilcox STS B 3.5.2-8 Rev. 4.0

TSTF-558, Rev. 0 Containment Spray and Cooling Systems B 3.6.6 BASES SURVEILLANCE REQUIREMENTS (continued)

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

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

SR 3.6.6.3 Verifying that each [required] containment cooling train provides an essential raw water cooling flow rate of [1780] gpm to each cooling unit provides assurance that the design flow rate assumed in the safety analyses will be achieved (Ref. 1). [ The Frequency was developed considering the known reliability of the Cooling Water System, the two train redundancy available, and the low probability of a significant degradation of flow occurring between surveillances.

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

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

SR 3.6.6.4 Containment Spray System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the required containment spray trains and may also prevent water hammer and pump cavitation.

Selection of Containment Spray System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is Babcock & Wilcox STS B 3.6.6-11 Rev. 4.0

TSTF-558, Rev. 0 Containment Spray and Cooling Systems B 3.6.6 supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration.

Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.

The Containment Spray System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criteria for gas volume at the suction or discharge of a pump), the Surveillance is not met. If the accumulated gas is eliminated or brought within the acceptance criteria limits during performance of the Surveillance, the Surveillance is met and past system OPERABILITY is evaluated under the Corrective Action Program. If it is determined by subsequent evaluation that the Containment Spray System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met.

Accumulated gas should be eliminated or brought within the acceptance criteria limits.

Containment Spray System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location. Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY. The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.

[ The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the Containment Spray System piping and the procedural controls governing system operation.

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. The Surveillance Frequency may vary by location susceptible to gas accumulation.

REVIEWERS NOTE-----------------------------------

Babcock & Wilcox STS B 3.6.6-12 Rev. 4.0

TSTF-558, Rev. 0 DHR and Coolant Circulation - High Water Level B 3.9.4 BASES ACTIONS (continued)

With DHR loop requirements not met, the potential exists for the coolant to boil and release radioactive gas to the containment atmosphere.

Performing the actions stated above ensures that all containment penetrations are either closed or can be closed so that the dose limits are not exceeded.

The Completion Time of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months allows fixing of most DHR problems and is reasonable, based on the low probability of the coolant boiling in that time.

SURVEILLANCE SR 3.9.4.1 REQUIREMENTS This Surveillance demonstrates that the DHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. [ The Frequency of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the DHR System.

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

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

SR 3.9.4.2 DHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the required DHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.

Selection of DHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the Babcock & Wilcox STS B 3.9.4-4 Rev. 4.0

TSTF-558, Rev. 0 DHR and Coolant Circulation - High Water Level B 3.9.4 location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration. Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.