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: 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | : 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | ||
: 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for the performance of Surveillances. | : 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for the performance of Surveillances. | ||
APPLICABILITY: MODE 3, with reactor steam dome pressure < [the RHR cut in permissive pressure]. | APPLICABILITY: MODE 3, with reactor steam dome pressure < [the RHR cut in permissive pressure]. | ||
ACTIONS | ACTIONS | ||
-----------------------------------------------------------NOTE----------------------------------------------------------- | -----------------------------------------------------------NOTE----------------------------------------------------------- | ||
Separate Condition entry is allowed for each RHR shutdown cooling subsystem. | Separate Condition entry is allowed for each RHR shutdown cooling subsystem. | ||
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem(s) to OPERABLE status. | CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem(s) to OPERABLE status. | ||
AND A.21 Verify an alternate method 1 hour of decay heat removal is available for each inoperable RHR shutdown cooling subsystem. | AND A.21 Verify an alternate method 1 hour of decay heat removal is available for each inoperable RHR shutdown cooling subsystem. | ||
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: 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | : 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | ||
: 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for the performance of Surveillances. | : 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for the performance of Surveillances. | ||
APPLICABILITY: MODE 4. | APPLICABILITY: MODE 4. | ||
ACTIONS | ACTIONS | ||
------------------------------------------------------------NOTE----------------------------------------------------------- | ------------------------------------------------------------NOTE----------------------------------------------------------- | ||
Separate Condition entry is allowed for each shutdown cooling subsystem. | Separate Condition entry is allowed for each shutdown cooling subsystem. | ||
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Verify an alternate method 1 hour shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours thereafter B. Required Action and B.1 Initiate action to restore Immediately associated Completion RHR shutdown cooling Time of Condition A not subsystem(s) to met. OPERABLE status. | CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Verify an alternate method 1 hour shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours thereafter B. Required Action and B.1 Initiate action to restore Immediately associated Completion RHR shutdown cooling Time of Condition A not subsystem(s) to met. OPERABLE status. | ||
CB. No RHR shutdown CB.1 Verify reactor coolant 1 hour from discovery cooling subsystem in circulating by an alternate of no reactor coolant operation. method. circulation AND AND General Electric BWR/4 STS 3.4.9-1 Rev. 4.0 | CB. No RHR shutdown CB.1 Verify reactor coolant 1 hour from discovery cooling subsystem in circulating by an alternate of no reactor coolant operation. method. circulation AND AND General Electric BWR/4 STS 3.4.9-1 Rev. 4.0 | ||
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: 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | : 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | ||
: 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for performance of Surveillances. | : 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for performance of Surveillances. | ||
APPLICABILITY: MODE 3 with reactor steam dome pressure < [the RHR cut in permissive pressure]. | APPLICABILITY: MODE 3 with reactor steam dome pressure < [the RHR cut in permissive pressure]. | ||
ACTIONS | ACTIONS | ||
-----------------------------------------------------------NOTE----------------------------------------------------------- | -----------------------------------------------------------NOTE----------------------------------------------------------- | ||
Separate Condition entry is allowed for each RHR shutdown cooling subsystem. | Separate Condition entry is allowed for each RHR shutdown cooling subsystem. | ||
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem to OPERABLE status. | CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem to OPERABLE status. | ||
AND General Electric BWR/6 STS 3.4.9-1 Rev. 4.0 | AND General Electric BWR/6 STS 3.4.9-1 Rev. 4.0 | ||
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: 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | : 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours per 8 hour period. | ||
: 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for the performance of Surveillances. | : 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours for the performance of Surveillances. | ||
APPLICABILITY: MODE 4. | APPLICABILITY: MODE 4. | ||
ACTIONS | ACTIONS | ||
------------------------------------------------------------NOTE----------------------------------------------------------- | ------------------------------------------------------------NOTE----------------------------------------------------------- | ||
Separate Condition entry is allowed for each RHR shutdown cooling subsystem. | Separate Condition entry is allowed for each RHR shutdown cooling subsystem. | ||
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Verify an alternate method 1 hour shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours thereafter General Electric BWR/6 STS 3.4.10-1 Rev. 4.0 | CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Verify an alternate method 1 hour shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours thereafter General Electric BWR/6 STS 3.4.10-1 Rev. 4.0 | ||
Latest revision as of 03:19, 4 February 2020
ML17317A448 | |
Person / Time | |
---|---|
Site: | Technical Specifications Task Force |
Issue date: | 11/09/2017 |
From: | Technical Specifications Task Force |
To: | Office of Nuclear Reactor Regulation |
Honcharik M | |
Shared Package | |
ML17317A453 | List: |
References | |
Download: ML17317A448 (42) | |
Text
DRAFT BWROG-134, Rev. 0 TSTF-566, Rev. 0 Technical Specifications Task Force Improved Standard Technical Specifications Change Traveler Revise Actions for Inoperable RHR Shutdown Cooling Subsystems NUREGs Affected: 1430 1431 1432 1433 1434 2194 Classification: 1) Technical Change Recommended for CLIIP?: Yes Correction or Improvement: Correction NRC Fee Status: Not Exempt Changes Marked on ISTS Rev 4.0 See attached justification.
Revision History OG Revision 0 Revision Status: Active Revision Proposed by: BWROG Revision
Description:
Original Issue Owners Group Review Information Date Originated by OG: 19-Sep-17 Owners Group Comments (No Comments)
Owners Group Resolution: Approved Date: 06-Oct-17 TSTF Review Information TSTF Received Date: 18-Oct-17 Date Distributed for Review 18-Oct-17 TSTF Comments:
(No Comments)
TSTF Resolution: Approved Date: 01-Nov-17 Affected Technical Specifications Action 3.9.8.A Bases RHR - High Water Level NUREG(s)- 1433 1434 Only Action 3.9.9.A Bases RHR - Low Water Level NUREG(s)- 1433 1434 Only Action 3.4.8.A RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only Action 3.4.8.A Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only Action 3.4.8.B RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only Change
Description:
New Action 01-Nov-17 Copyright(C) 2017, 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.
DRAFT BWROG-134, Rev. 0 TSTF-566, Rev. 0 Action 3.4.8.B RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only Change
Description:
Renamed C Action 3.4.8.B Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only Change
Description:
Renamed C Action 3.4.8.B Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1433 Only Change
Description:
New Action Action 3.4.9.B RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1433 Only Change
Description:
New Action Action 3.4.9.B RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1433 Only Change
Description:
Renamed C Action 3.4.9.B Bases RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1433 Only Change
Description:
New Action Action 3.4.9.B Bases RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1433 Only Change
Description:
Renamed C Action 3.4.9.A RHR - High Water Level NUREG(s)- 1434 Only Action 3.4.9.A Bases RHR - Low Water Level NUREG(s)- 1434 Only Action 3.4.9.B RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1434 Only Change
Description:
New Action Action 3.4.9.B RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1434 Only Change
Description:
Renamed C Action 3.4.9.B Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1434 Only Change
Description:
Renamed C Action 3.4.9.B Bases RHR Shutdown Cooling System - Hot Shutdown NUREG(s)- 1434 Only Change
Description:
New Action Action 3.4.10.B RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1434 Only Change
Description:
New Action Action 3.4.10.B RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1434 Only Change
Description:
Renamed C Action 3.4.10.B Bases RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1434 Only Change
Description:
Renamed C Action 3.4.10.B Bases RHR Shutdown Cooling System - Cold Shutdown NUREG(s)- 1434 Only Change
Description:
New Action 01-Nov-17 Copyright(C) 2017, 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.
DRAFT TSTF-566, Rev. 0
- 1.
SUMMARY
DESCRIPTIONS The Technical Specification (TS) Actions for inoperable Residual Heat Removal (RHR) shutdown cooling subsystems are revised to reflect the plant design, to provide the needed operational flexibility, and to meet the regulatory requirements. The proposed change modifies NUREG-1433, "Standard Technical Specifications - General Electric BWR/4 Plants," and NUREG-1434, "Standard Technical Specifications, General Electric BWR/6 Plants."1
- 2. DETAILED DESCRIPTION 2.1. System Design and Operation The RHR System in the shutdown cooling mode removes decay heat from the reactor core during shutdown. Irradiated fuel in the shutdown reactor core generates heat during the decay of fission products and increases the temperature of the reactor coolant. Removal of this decay heat by the RHR shutdown cooling system is an important safety function that must be accomplished or core damage could result. However, the RHR shutdown cooling system is not required for mitigation of any event or accident evaluated in the safety analysis.
The two redundant, manually controlled shutdown cooling subsystems of the RHR System provide decay heat removal. Each of the two shutdown cooling subsystems of the RHR System can provide the required decay heat removal. The RHR System design varies, but a typical subsystem design consists of one or two motor driven pumps, a heat exchanger, and associated piping and valves. Only one pump is required to support an operable subsystem. The RHR heat exchangers transfer heat to the RHR Service Water System. Some piping and heat exchangers that are passive components may be common to both subsystems. Each shutdown cooling subsystem is considered operable if it can be manually aligned (remote or local) in the shutdown cooling mode for removal of decay heat.
1 NUREG 1433 is based on the BWR/4 plant design, but is also representative of the BWR/2, BWR/3, and, in this case, BWR/5 designs. NUREG 1434 is based on the BWR/6 plant design, and is representative, in some cases, of the BWR/5 design.
Page 1
DRAFT TSTF-566, Rev. 0 2.2. Current Technical Specifications Requirements There are four TS with requirements on the RHR shutdown cooling subsystems:
NUREG- NUREG- Applicability Title Required 1433 TS 1434 TS RHR Number Number Shutdown Cooling Subsystems 3.4.8 3.4.9 MODE 3, with reactor Residual Heat Removal 2 steam dome pressure < (RHR) Shutdown Cooling
[the RHR cut in System - Hot Shutdown permissive pressure].
3.4.9 3.4.10 Mode 4 Residual Heat Removal 2 (RHR) Shutdown Cooling System - Cold Shutdown 3.9.8 3.9.8 MODE 5 with irradiated Residual Heat Removal 1 fuel in the reactor pressure (RHR) - High Water Level vessel (RPV) and the water level [23 ft/22 ft 8 inches] above the top of the [RPV flange].
3.9.9 3.9.9 MODE 5 with irradiated Residual Heat Removal 2 fuel in the reactor pressure (RHR) - Low Water Level vessel (RPV) and the water level < [23 ft/22 ft 8 inches] above the top of the [RPV flange].
Values in brackets are plant-specific. The TS applicable in Mode 3 or 4 require either a recirculation loop or an RHR shutdown cooling subsystem to be in operation circulating reactor coolant. The TS applicable in Mode 5 require an RHR shutdown cooling subsystem to be in operation circulating reactor coolant.
When one or more RHR shutdown cooling subsystems are inoperable in Mode 3 or 4, the TS require:
- If the plant is in Mode 3, immediately initiating action to restore the RHR shutdown cooling subsystem(s) to operable status;
- Verifying an alternate method of decay heat removal is available for each inoperable RHR shutdown cooling subsystem within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and, if in Mode 4, every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter; and Page 2
DRAFT TSTF-566, Rev. 0
- If the plant is in Mode 3, the plant must be in Mode 4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
When there is no RHR shutdown cooling subsystem or recirculation pump in operation in Mode 3 or 4 (i.e., no forced reactor coolant flow), the TS require:
- If the plant is in Mode 3, immediately initiating action to restore an RHR shutdown cooling subsystem or recirculation pump to operation;
- Verifying reactor coolant circulation by an alternate method within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter; and
- Monitoring reactor coolant temperature and pressure once per hour.
When one or more required RHR shutdown cooling subsystems are inoperable in Mode 5, the TS require:
- Verifying an alternate method of decay heat removal is available for each required inoperable RHR shutdown cooling subsystem within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter; and
- Otherwise, immediately initiate action to restore to operable status the [secondary2]
containment and, in NUREG-1433, one standby gas treatment subsystem, and to restore isolation capability in each required [secondary] containment penetration whose flow path is not isolated.
When there is no RHR shutdown cooling subsystem in operation in Mode 5 (i.e., no forced reactor coolant flow), the TS require:
- Verifying reactor coolant circulation by an alternate method within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter; and
- Monitoring reactor coolant temperature once per hour.
2 In the ISTS, plant-specific differences are placed in brackets. At the majority of BWR plants, the refueling cavity or floor is enclosed by the secondary containment, but not the primary containment. However, at some plants, the refueling cavity or floor is enclosed within a plant-specific enclosure. At some BWR/6 plants the refueling cavity or floor is enclosed within the primary containment. These design differences are reflected in the ISTS by using the term "[secondary] containment" in the BWR/4 ISTS and "[secondary containment]" in the BWR/6 ISTS. In this justification, when the term "secondary" is in brackets as in "[secondary] containment" it is understood that the phrase refers to the plant-specific enclosure around the refueling cavity, including the BWR/6 designs. When the terms "secondary containment" or "primary containment" are used without brackets, they refer to the named structure.
Page 3
DRAFT TSTF-566, Rev. 0 Several of the Required Actions must be taken "Immediately." Section 1.3 of the TS defines "immediately" as "the Required Action should be pursued without delay and in a controlled manner."
2.3. Reason for the Proposed Change The current TS requirements on the RHR shutdown cooling System in Mode 3 are inconsistent with the BWR design.
- 1. If a required RHR shutdown cooling subsystem is inoperable in Mode 3, 4 or 5, the TS require an alternate method of decay heat removal to be available for each inoperable RHR shutdown cooling subsystem. The TS Bases state that the required cooling capacity of the alternate method should be ensured by verifying (by calculation or demonstration) its capability to maintain or reduce temperature. Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System and the Reactor Water Cleanup System. However, in a typical BWR design, the RHR shutdown cooling System has a heat rejection capability many times greater than the listed alternatives. Therefore, for periods in which there is high decay heat load, the BWR design does not include any system which can satisfy the Required Action.
- 2. In Mode 3 or 4, if there is no alternate method of decay heat removal for each inoperable RHR shutdown cooling subsystem, there is no TS Action to follow. While the situation would be infrequent given the redundancy and reliability of the RHR shutdown cooling system and the number of available alternates, this lack of a terminal action has raised questions from the NRC.
- 3. If one or more RHR shutdown cooling subsystems are inoperable in Mode 3, the plant must be brought to Mode 4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. However, if there is no operable RHR shutdown cooling subsystem and the plant is in a period of high decay heat load, it may not be possible to reduce the Reactor Coolant System (RCS) temperature to the Mode 4 entry condition (typically < 200 °F) within the Completion Time.
- 4. In Modes 3, 4 and 5, circumstances may exist where an RHR shutdown cooling system is inoperable (such as from a loss of seismic qualification or nonfunctional support systems),
but still meets the Bases description of an alternate decay heat removal method. The TS Bases do not list the RHR shutdown cooling system as an alternate method of decay heat removal. The use of an inoperable but functional RHR shutdown cooling subsystem as an alternate method of decay heat removal has been questioned by the NRC.
Because of the redundancy and reliability of the RHR shutdown cooling system, these inconsistencies between the TS Actions and the BWR plant design have rarely presented a problem. However, the Nuclear Regulatory Commission has opened Unresolved Items (URIs) related to the inability to satisfy the Required Actions in all circumstances, and violations related Page 4
DRAFT TSTF-566, Rev. 0 to crediting an inoperable RHR shutdown cooling subsystem as an alternate means of decay heat removal. The TSTF agreed to propose changes to the TS to address these issues.
2.4. Description of the Proposed Change The proposed change revises the standard TS in NUREG-1433 and NUREG-1434 to be consistent with the BWR design:
- In Mode 3, when one or both required RHR shutdown cooling subsystems are inoperable, the Required Action is revised to require verification of an alternate method of decay heat removal for each inoperable RHR shutdown cooling subsystem within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
- In Modes 3 and 4, if an alternate method of decay heat removal cannot be established within the Completion Time, new Action B requires immediate initiation of action to restore the inoperable RHR shutdown cooling subsystem(s) to operable status.
- The Mode 3 requirement to transition to Mode 4 when an RHR shutdown cooling subsystem is inoperable is eliminated.
- The Bases for the Mode 3, 4, and 5 specifications are clarified to acknowledge that an inoperable RHR shutdown cooling subsystem can act as an alternate method of decay heat removal if it is functional and has the capability to maintain or reduce reactor coolant system temperature.
A model application is included. The model may be used by licensees desiring to adopt the traveler following its approval.
- 3. TECHNICAL EVALUATION The following sections describe the proposed changes.
3.1. Revision of the TS Actions to Restore RHR Shutdown Cooling or Establish an Alternate Method of Decay Heat Removal In NUREG-1433 TS 3.4.8, and in NUREG-1434 TS 3.4.9, the existing Required Actions to immediately initiate action to restore the inoperable RHR shutdown cooling subsystem(s) to operable status and verify within one hour that an alternate method of decay heat removal is available for each inoperable RHR shutdown cooling subsystem are reorganized. The revised Action A requires verification within one hour that an alternate method of decay heat removal is available for each inoperable RHR shutdown cooling subsystem.
In NUREG-1433 TS 3.4.8 and TS 3.4.9, and in NUREG-1434 TS 3.4.9 and TS 3.4.10, if the required alternate method of decay heat removal for each inoperable RHR shutdown cooling subsystem cannot be verified, the new Action B requires immediate action to restore the inoperable RHR shutdown cooling.
Page 5
DRAFT TSTF-566, Rev. 0 Appendix A of 10 CFR 50, Criterion 34, requires that a system to remove residual heat be provided. Its safety function is to transfer fission product decay heat and other residual heat from the reactor core at a rate such that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are not exceeded. The BWR design meets this through a combination of low pressure ECCS to maintain RPV level, steam release via the safety/relief valves to the Suppression Pool, and the Suppression Pool cooling mode of RHR.
However, this configuration is reserved for use in the Emergency Operating Procedures. When steam dome pressure is above the RHR cut in permissive pressure, the normal method of removing decay heat is steaming via the steam bypass valves to the Main Condenser, with return to the RPV via the Feedwater and/or Condensate Booster Pumps. Only after reaching the RHR cut in permissive pressure does the preferred means of removing decay heat become the Shutdown Cooling mode of RHR. Due to these other means of decay heat removal, it is not critical that action be taken immediately to restore the inoperability of one or both RHR shutdown cooling subsystems. The BWR design also provides other ways of removing decay heat, such as natural circulation, the Spent Fuel Pool Cooling System, and the Reactor Water Cleanup System. The existing one-hour Completion Time to establish an alternate method of decay heat removal is sufficient to remove decay heat. However, in the unexpected circumstance that an alternate method if not available, the TS should provide an action for licensees to follow.
The reorganization of the Actions applies a logical progression of licensee actions and provides a terminal action applicable in all circumstances, as discussed below:
- The licensees first action when an RHR shutdown cooling subsystem is inoperable is to establish an alternate method of decay heat removal. The BWR design affords a number of alternate methods, although not all methods are capable of maintaining or reducing temperature, depending on the decay heat generation rate.
- If an alternate method cannot be established, the licensee must immediately initiate action to restore the inoperable RHR shutdown cooling subsystem(s) to operable status. This action is consistent with the Pressurized Water Reactor (PWR) standard Technical Specifications (STS) in NUREG-1430, NUREG-1431, and NUREG-1432. The PWR RHR STS require immediate action to restore an inoperable RHR train in the equivalent modes. The Completion Time "immediately" is defined in Section 1.3 of the TS as, "the Required Action should be pursued without delay and in a controlled manner." This Required Action continues to apply until the inoperable RHR shutdown cooling subsystems are restored to operable status, an alternate decay heat removal method is established, or the Applicability of the specification is exited. Therefore, the Required Action provides an appropriate terminal action for the condition.
3.2. Elimination of Requirement to Enter Mode 4 In NUREG-1433 TS 3.4.8 and in NUREG-1434 TS 3.4.9, the Required Action to transition from Mode 3 to MODE 4 is eliminated.
There is no regulatory requirement that a BWR be capable of reducing temperature to Mode 4 (typically 200 or less) with no operable RHR shutdown cooling subsystems. Reducing temperature to less than the boiling point of water eliminates a potential heat-removal Page 6
DRAFT TSTF-566, Rev. 0 mechanism. Further, entering Mode 4 with an inoperable RHR shutdown cooling subsystem would result in immediately entering an Action in the applicable Specification and restarting the Completion Time for establishing an alternate decay heat removal mechanism. Entry into Mode 4 is always an option for the licensee if it is the prudent course of action, but it should not be dictated by the TS when RHR shutdown cooling is inoperable.
3.3. Bases Changes In NUREG-1433 TS 3.4.8, 3.4.9, 3.9.8, and 3.9.9, the Bases are revised to acknowledge that an inoperable RHR shutdown cooling subsystem may act as an alternate method of decay heat removal provided it remains functional and has the capability to maintain or reduce reactor coolant system temperature. In addition, the Bases are revised to remove the statement that the capability of an alternate method of decay heat removal to maintain or reduce temperature be verified by calculation or demonstration.
An RHR shutdown cooling subsystem may be inoperable but still functional and capable of removing decay heat for many reasons, such as:
- Diversion of flow to the wetwell to lower water level;
- Removed or broken snubbers, struts, or supports;
- Nonfunctional pump room cooler;
- Inoperable isolation instrumentation; or
- Nonfunctional or slow primary containment isolation valve.
The RHR shutdown cooling subsystem is still functional and remains as capable as the listed alternate methods of decay heat removal listed in the TS Bases. Further, removal of RCS decay is the primary function of the RHR shutdown cooling system, making it the preferred alternate versus other systems with significantly lower heat removal capability, such as Spent Fuel Pool Cooling and Reactor Water Cleanup Systems. Therefore, it is appropriate to utilize an inoperable but functional RHR shutdown cooling system as an alternate method of decay heat removal as long as it has the capability to maintain or reduce reactor coolant system temperature.
The Bases statement that the effectiveness of an alternate method of decay heat removal to maintain or reduce temperature must be verified by calculation or demonstration is unnecessarily prescriptive. Licensees typically have decay heat generation curves which may be compared with the heat removal capability of an alternate decay heat removal method. The question as to whether this constitutes a "calculation" could be up to debate. In any event, the overriding criteria is that the alternate method of decay heat removal must be capable of maintaining or reducing reactor coolant temperature, which can be determined without an explicit calculation or demonstration. Therefore, the proposed Bases change is considered to be an administrative reduction in level of detail.
Page 7
DRAFT TSTF-566, Rev. 0
- 4. REGULATORY EVALUATION Section IV, "The Commission Policy," of the "Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors" (58 Federal Register 39132), dated July 22, 1993, states in part:
The purpose of Technical Specifications is to impose those conditions or limitations upon reactor operation necessary to obviate the possibility of an abnormal situation or event giving rise to an immediate threat to the public health and safety by identifying those features that are of controlling importance to safety and establishing on them certain conditions of operation which cannot be changed without prior Commission approval.
[T]he Commission will also entertain requests to adopt portions of the improved STS, even if the licensee does not adopt all STS improvements.
The Commission encourages all licensees who submit Technical Specification related submittals based on this Policy Statement to emphasize human factors principles.
In accordance with this Policy Statement, improved STS have been developed and will be maintained for [BWR designs]. The Commission encourages licensees to use the improved STS as the basis for plant-specific Technical Specifications.
[I]t is the Commission intent that the wording and Bases of the improved STS be used to the extent practicable.
As described in the Commissions "Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors," recommendations were made by NRC and industry task groups for new STS that include greater emphasis on human factors principles in order to add clarity and understanding to the text of the STS, and provide improvements to the Bases of STS, which provides the purpose for each requirement in the specification. Improved vendor-specific STS were developed and issued by the NRC in September 1992.
Additionally, 10 CFR 50.36(b) requires:
Each license authorizing operation of a utilization facility will include technical specifications. The technical specifications will be derived from the analyses and evaluation included in the safety analysis report, and amendments thereto, submitted pursuant to [10 CFR] 50.34 ["Contents of applications; technical information"]. The Commission may include such additional technical specifications as the Commission finds appropriate.
The categories of items required to be in the TSs are provided in 10 CFR 50.36(c). As required by 10 CFR 50.36(c)(2)(i), the TSs will include LCOs, which are the lowest functional capability or performance levels of equipment required for safe operation of the facility. Per 10 CFR 50.36(c)(2)(i), when an LCO of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TSs until the condition can be met.
Page 8
DRAFT TSTF-566, Rev. 0 Per 10 CFR 50.90, whenever a holder of a license desires to amend the license, application for an amendment must be filed with the Commission, fully describing the changes desired, and following as far as applicable, the form prescribed for original applications.
Per 10 CFR 50.92(a), in determining whether an amendment to a license will be issued to the applicant, the Commission will be guided by the considerations which govern the issuance of initial licenses to the extent applicable and appropriate.
The NRC staffs guidance for the review of TSs is in Chapter 16, "Technical Specifications," of NUREG-0800, Revision 3, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants" (SRP), dated March 2010 (ADAMS Accession No. ML100351425). As described therein, as part of the regulatory standardization effort, the NRC staff has prepared STS for each of the light-water reactor nuclear designs.
In conclusion, based on the considerations discussed above, the proposed revision does not alter the current manner of operation and (1) there is reasonable assurance that the health and safety of the public will not be endangered by continued operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the approval of the proposed change will not be inimical to the common defense and security or to the health and safety of the public.
- 5. REFERENCES
- 1. None Page 9
DRAFT TSTF-566, Rev. 0 Model Application
DRAFT TSTF-566, Rev. 0
[DATE] 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 DOCKET NO.PLANT NAME 50-[xxx]
SUBJECT:
Application to Revise Technical Specifications to Adopt TSTF-566, "Revise Actions for Inoperable RHR Shutdown Cooling Subsystems" Pursuant to 10 CFR 50.90, [LICENSEE] is submitting a request for an amendment to the Technical Specifications (TS) for [PLANT NAME, UNIT NOS.].
[LICENSEE] requests adoption of TSTF-566, "Revise Actions for Inoperable RHR Shutdown Cooling Subsystems," which is an approved change to the Improved Standard Technical Specifications (ISTS), into the [PLANT NAME, UNIT NOS] Technical Specifications (TS).
The proposed amendment revises the TS actions applicable when a residual heat removal (RHR) shutdown cooling subsystem is inoperable.
The enclosure provides a description and assessment of the proposed changes. Attachment 1 provides the existing TS pages marked to show the proposed changes. Attachment 2 provides revised (clean) TS pages. Attachment 3 provides existing TS Bases pages marked to show the proposed changes for information only.
Approval of the proposed amendment is requested by [date]. Once approved, the amendment shall be implemented within [ ] days.
There are no 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] Official.
[In accordance with 10 CFR 50.30(b), a license amendment request must be executed in a signed original under oath or affirmation. This can be accomplished by attaching a notarized affidavit confirming the signature authority of the signatory, or by including the following statement in the cover letter: "I declare under penalty of perjury that the foregoing is true and correct.
Executed on (date)." The alternative statement is pursuant to 28 USC 1746. It does not require notarization.]
If you should have any questions regarding this submittal, please contact [NAME, TELEPHONE NUMBER].
Page 1
DRAFT TSTF-566, Rev. 0 Sincerely,
[Name, Title]
Enclosure:
Description and Assessment Attachments: 1. Proposed Technical Specification Changes (Mark-Up)
- 2. Revised Technical Specification Pages
- 3. Proposed Technical Specification Bases Changes (Mark-Up) for Information Only
[The attachments are to be provided by the licensee and are not included in the model application.]
cc: NRC Project Manager NRC Regional Office NRC Resident Inspector State Contact Page 2
DRAFT TSTF-566, Rev. 0 ENCLOSURE DESCRIPTION AND ASSESSMENT
1.0 DESCRIPTION
[LICENSEE] requests adoption of TSTF-566, "Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems," which is an approved change to the Improved Standard Technical Specifications (ISTS), into the [PLANT NAME, UNIT NOS] Technical Specifications (TS).
The proposed amendment revises the TS actions applicable when a residual heat removal (RHR) shutdown cooling subsystem is inoperable.
2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation
[LICENSEE] has reviewed the safety evaluation for TSTF-566 provided to the Technical Specifications Task Force in a letter dated [DATE]. This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-566. [As described herein,]
[LICENSEE] has concluded that the justifications presented in TSTF-566 and the safety evaluation prepared by the NRC staff are applicable to [PLANT, UNIT NOS.] and justify this amendment for the incorporation of the changes to the [PLANT] TS.
2.2 Variations
[LICENSEE is not proposing any variations from the TS changes described in the TSTF-566 or the applicable parts of the NRC staffs safety evaluation dated [DATE].] [LICENSEE is proposing the following variations from the TS changes described in TSTF-566 or the applicable parts of the NRC staffs safety evaluation: describe the variations]
[The [PLANT] TS utilize different [numbering][and][titles] than the Standard Technical Specifications on which TSTF-566 was based. Specifically, [describe differences between the plant-specific TS numbering and/or titles and TSTF-566 numbering and titles.] These differences are administrative and do not affect the applicability of TSTF-566 to the [PLANT]
TS.]
[The [PLANT] TS contain requirements that differ from the Standard Technical Specifications on which TSTF-566 was based, but these differences do not affect the applicability of the TSTF-566 justification. [Describe differences and why TSTF-566 is still applicable.]
3.0 REGULATORY ANALYSIS
3.1 No Significant Hazards Consideration Analysis
[LICENSEE] requests adoption of TSTF-566, "Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems," which is an approved change to the Improved Standard Technical Specifications (ISTS), into the [PLANT NAME, UNIT NOS] Technical Specifications (TS).
Page 3
DRAFT TSTF-566, Rev. 0 The proposed amendment revises the TS actions applicable when a residual heat removal (RHR) shutdown cooling subsystem is inoperable.
[LICENSEE] has evaluated whether or not 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 revises the actions to be taken when a RHR shutdown cooling subsystem is inoperable. The RHR System in the shutdown cooling mode performs the important safety function of removing decay heat from the reactor coolant system during shutdown. The RHR System in the shutdown cooling mode is not an initiator of any accident previously evaluated or assumed to mitigate any accident previously evaluated.
The design and function of the RHR System are not affected by the proposed change.
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 revises the actions to be taken when a RHR shutdown cooling subsystem is inoperable. The proposed change does not affect the design function or operation of the RHR shutdown cooling subsystems. No new equipment is being installed as a result of the proposed change. The proposed change only affects the actions taken when an RHR shutdown cooling subsystem is inoperable, so no new failure mechanisms are created.
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 revises the actions to be taken when a RHR shutdown cooling subsystem is inoperable. The proposed change does not change any specific values or controlling parameters that define margin in the design or licensing basis. No safety limits are affected by the proposed change. The RHR System in the shutdown cooling mode removes decay heat from the reactor coolant system during shutdown. The proposed change does not affect any design or safety limits associated with the RHR System.
Page 4
DRAFT TSTF-566, Rev. 0 Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, [LICENSEE] 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.
- 6. ENVIRONMENTAL CONSIDERATION The proposed change 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 change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or 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 change 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 change.
Page 5
DRAFT TSTF-566, Rev. 0 Technical Specifications and Bases Proposed Changes
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown 3.4.8 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.8 Residual Heat Removal (RHR) Shutdown Cooling System - Hot Shutdown LCO 3.4.8 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.
NOTES-------------------------------------------
- 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
- 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.
APPLICABILITY: MODE 3, with reactor steam dome pressure < [the RHR cut in permissive pressure].
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each RHR shutdown cooling subsystem.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem(s) to OPERABLE status.
AND A.21 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of decay heat removal is available for each inoperable RHR shutdown cooling subsystem.
AND A.3 Be in MODE 4. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> General Electric BWR/4 STS 3.4.8-1 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown 3.4.8 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and B.1 Initiate action to restore Immediately associated Completion RHR shutdown cooling Time of Condition A not subsystem(s) to met. OPERABLE status.
CB. No RHR shutdown CB.1 Initiate action to restore one Immediately cooling subsystem in RHR shutdown cooling operation. subsystem or one recirculation pump to AND operation.
No recirculation pump AND in operation.
CB.2 Verify reactor coolant 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from discovery circulation by an alternate of no reactor coolant method. circulation AND Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND CB.3 Monitor reactor coolant Once per hour temperature and pressure.
General Electric BWR/4 STS 3.4.8-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown 3.4.9 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.9 Residual Heat Removal (RHR) Shutdown Cooling System - Cold Shutdown LCO 3.4.9 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.
NOTES-------------------------------------------
- 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
- 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.
APPLICABILITY: MODE 4.
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each shutdown cooling subsystem.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter B. Required Action and B.1 Initiate action to restore Immediately associated Completion RHR shutdown cooling Time of Condition A not subsystem(s) to met. OPERABLE status.
CB. No RHR shutdown CB.1 Verify reactor coolant 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from discovery cooling subsystem in circulating by an alternate of no reactor coolant operation. method. circulation AND AND General Electric BWR/4 STS 3.4.9-1 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown 3.4.9 CONDITION REQUIRED ACTION COMPLETION TIME No recirculation pump in Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> operation. thereafter AND General Electric BWR/4 STS 3.4.9-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown 3.4.9 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME CB.2 Monitor reactor coolant Once per hour temperature.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.9.1 Verify one RHR shutdown cooling subsystem or [ 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> recirculation pump is operating.
OR In accordance with the Surveillance Frequency Control Program ]
General Electric BWR/4 STS 3.4.9-3 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown B 3.4.8 BASES ACTIONS (continued) inoperable shutdown cooling subsystems provide appropriate compensatory measures for separate inoperable shutdown cooling subsystems. As such, a Note has been provided that allows separate Condition entry for each inoperable RHR shutdown cooling subsystem.
A.1, A.2, and A.3 With one required RHR shutdown cooling subsystem inoperable for decay heat removal, except as permitted by LCO Note 2, the inoperable subsystem must be restored to OPERABLE status within one hourwithout delay. In this condition, the remaining OPERABLE subsystem can provide the necessary decay heat removal. Tthe overall reliability is reduced, however, because a single failure in the OPERABLE subsystem could result in reduced RHR shutdown cooling capability. Therefore, an alternate method of decay heat removal must be provided.
With both RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability.
This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities.
The required cooling capacity of the alternate method should be sufficient to ensured by verifying (by calculation or demonstration) its capability to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, and the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.
However, due to the potentially reduced reliability of the alternate methods of decay heat removal, it is also required to reduce the reactor coolant temperature to the point where MODE 4 is entered.
B.1 If the required alternate method(s) of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem(s) to operable status. The Required Action will restore redundant decay heat removal paths. The General Electric BWR/4 STS B 3.4.8-3 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown B 3.4.8 immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.
CB.1, CB.2, and CB.3 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as permitted by LCO Note 1, reactor coolant circulation by the RHR shutdown cooling subsystem or recirculation pump must be restored without delay.
General Electric BWR/4 STS B 3.4.8-4 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown B 3.4.8 BASES ACTIONS (continued)
Until RHR or recirculation pump operation is re-established, an alternate method of reactor coolant circulation must be placed into service. This will provide the necessary circulation for monitoring coolant temperature.
The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the coolant circulation function and is modified such that the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is applicable separately for each occurrence involving a loss of coolant circulation. Furthermore, verification of the functioning of the alternate method must be reconfirmed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. This will provide assurance of continued temperature monitoring capability.
During the period when the reactor coolant is being circulated by an alternate method (other than by the required RHR shutdown cooling subsystem or recirculation pump), the reactor coolant temperature and pressure must be periodically monitored to ensure proper function of the alternate method. The once per hour Completion Time is deemed appropriate.
SURVEILLANCE SR 3.4.8.1 REQUIREMENTS This Surveillance verifies that one RHR shutdown cooling subsystem or recirculation pump is in operation and circulating reactor coolant. The required flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability. [ The Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient in view of other visual and audible indications available to the operator for monitoring the RHR subsystem in the control room.
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 Surveillance is modified by a Note allowing sufficient time to align the RHR System for shutdown cooling operation after clearing the pressure interlock that isolates the system, or for placing a recirculation pump in operation. The Note takes exception to the requirements of the General Electric BWR/4 STS B 3.4.8-5 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown B 3.4.9 BASES ACTIONS (continued) continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable shutdown cooling subsystems provide appropriate compensatory measures for separate inoperable shutdown cooling subsystems. As such, a Note has been provided that allows separate Condition entry for each inoperable RHR shutdown cooling subsystem.
A.1 With one of the two required RHR shutdown cooling subsystems inoperable, except as permitted by LCO Note 2, the remaining subsystem is capable of providing the required decay heat removal. However, the overall reliability is reduced. Therefore, an alternate method of decay heat removal must be provided. With both RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability. This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities.
Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will provide assurance of continued heat removal capability.
The required cooling capacity of the alternate method should be sufficient ensured by verifying (by calculation or demonstration) its capability to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System and the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.
B.1 If the required alternate method(s) of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem(s) to operable status. The Required Action will restore redundant decay heat removal paths. The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.
CB.1 and CB.2 General Electric BWR/4 STS B 3.4.9-3 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown B 3.4.9 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as permitted by LCO Note 1, and until RHR or recirculation pump operation is re-established, an alternate method of reactor coolant circulation must be placed into service. This will provide the necessary circulation for monitoring coolant temperature. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the coolant circulation function and is modified such that the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is applicable separately for each occurrence involving a loss of coolant circulation. Furthermore, verification of the functioning of the alternate method must be reconfirmed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. This will provide assurance of continued temperature monitoring capability.
General Electric BWR/4 STS B 3.4.9-4 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown B 3.4.9 BASES ACTIONS (continued)
During the period when the reactor coolant is being circulated by an alternate method (other than by the required RHR Shutdown Cooling System or recirculation pump), the reactor coolant temperature and pressure must be periodically monitored to ensure proper function of the alternate method. The once per hour Completion Time is deemed appropriate.
SURVEILLANCE SR 3.4.9.1 REQUIREMENTS This Surveillance verifies that one RHR shutdown cooling subsystem or recirculation pump is in operation and circulating reactor coolant. The required flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability. [ The Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient in view of other visual and audible indications available to the operator for monitoring the RHR subsystem in the control room.
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.
]
REFERENCES None.
General Electric BWR/4 STS B 3.4.9-5 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR - High Water Level B 3.9.8 BASES LCO (continued) core flow to allow for accurate average reactor coolant temperature monitoring, nearly continuous operation is required. A Note is provided to allow a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> exception for the operating subsystem to be removed from operation every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
APPLICABILITY One RHR shutdown cooling subsystem must be OPERABLE and in operation in MODE 5, with irradiated fuel in the reactor pressure vessel and with the water level [23] feet above the top of the RPV flange, to provide decay heat removal. RHR System requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS);
Section 3.5, Emergency Core Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System; and Section 3.6, Containment Systems. RHR Shutdown Cooling System requirements in MODE 5 with irradiated fuel in the reactor pressure vessel and with the water level
< [23] ft above the RPV flange are given in LCO 3.9.9.
ACTIONS A.1 With no RHR shutdown cooling subsystem OPERABLE, an alternate method of decay heat removal must be established within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In this condition, the volume of water above the RPV flange provides adequate capability to remove decay heat from the reactor core. However, the overall reliability is reduced because loss of water level could result in reduced decay heat removal capability. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will ensure continued heat removal capability.
Alternate decay heat removal methods are available to the operators for review and preplanning in the unit's Operating Procedures. The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem. For example, this may include the use of the Reactor Water Cleanup System, operating with the regenerative heat exchanger bypassed. The method used to remove the decay heat should be the most prudent choice based on unit conditions.
B.1, B.2, B.3, and B.4 General Electric BWR/4 STS B 3.9.8-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR - Low Water Level B 3.9.9 BASES APPLICABILITY Two RHR shutdown cooling subsystems are required to be OPERABLE, and one must be in operation in MODE 5, with irradiated fuel in the RPV and with the water level < [23] ft above the top of the RPV flange, to provide decay heat removal. RHR System requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS);
Section 3.5, Emergency Core Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System; and Section 3.6, Containment Systems. RHR Shutdown Cooling System requirements in MODE 5 with irradiated fuel in the RPV and with the water level [23] ft above the RPV flange are given in LCO 3.9.8, "Residual Heat Removal (RHR) - High Water Level."
ACTIONS A.1 With one of the two required RHR shutdown cooling subsystems inoperable, the remaining subsystem is capable of providing the required decay heat removal. However, the overall reliability is reduced.
Therefore an alternate method of decay heat removal must be provided.
With both required RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability. This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of this alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will ensure continued heat removal capability.
Alternate decay heat removal methods are available to the operators for review and preplanning in the unit's Operating Procedures. The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem. For example, this may include the use of the Reactor Water Cleanup System, operating with the regenerative heat exchanger bypassed. The method used to remove decay heat should be the most prudent choice based on unit conditions.
B.1, B.2, and B.3 With the required decay heat removal subsystem(s) inoperable and the required alternate method(s) of decay heat removal not available in accordance with Required Action A.1, additional actions are required to General Electric BWR/4 STS B 3.9.9-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown 3.4.9 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.9 Residual Heat Removal (RHR) Shutdown Cooling System - Hot Shutdown LCO 3.4.9 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.
NOTES-------------------------------------------
- 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
- 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for performance of Surveillances.
APPLICABILITY: MODE 3 with reactor steam dome pressure < [the RHR cut in permissive pressure].
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each RHR shutdown cooling subsystem.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem to OPERABLE status.
AND General Electric BWR/6 STS 3.4.9-1 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown 3.4.9 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME A.12 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of decay heat removal is available for each inoperable RHR shutdown cooling subsystem.
AND A.3 Be in MODE 4. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> B. Required Action and B.1 Initiate action to restore Immediately Completion Time of RHR shutdown cooling Condition A not met. subsystem(s) to OPERABLE status.
CB. No RHR shutdown CB.1 Initiate action to restore Immediately cooling subsystem in one RHR shutdown cooling operation. subsystem or one recirculation pump to AND operation.
No recirculation pump in AND operation.
CB.2 Verify reactor coolant 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from discovery circulation by an alternate of no reactor coolant method. circulation AND Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND CB.3 Monitor reactor coolant Once per hour temperature and pressure.
SURVEILLANCE REQUIREMENTS General Electric BWR/6 STS 3.4.9-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown 3.4.10 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.10 Residual Heat Removal (RHR) Shutdown Cooling System - Cold Shutdown LCO 3.4.10 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.
NOTES-------------------------------------------
- 1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
- 2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.
APPLICABILITY: MODE 4.
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each RHR shutdown cooling subsystem.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR A.1 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter General Electric BWR/6 STS 3.4.10-1 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown 3.4.10 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and B.1 Initiate action to restore Immediately associated Completion RHR shutdown cooling Time of Condition A not subsystem(s) to met. OPERABLE status.
CB. No RHR shutdown CB.1 Verify reactor coolant 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from discovery cooling subsystem in circulating by an alternate of no reactor coolant operation. method. circulation AND AND No recirculation pump in Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> operation. thereafter AND CB.2 Monitor reactor coolant Once per hour temperature and pressure.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify one RHR shutdown cooling subsystem or [ 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> recirculation pump is operating.
OR In accordance with the Surveillance Frequency Control Program ]
General Electric BWR/6 STS 3.4.10-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown B 3.4.9 BASES ACTIONS (continued)
A.1, A.2, and A.3 With one required RHR shutdown cooling subsystem inoperable for decay heat removal, except as permitted by LCO Note 2, the inoperable subsystem must be restored to OPERABLE status within one hourwithout delay. In this condition, the remaining OPERABLE subsystem can provide the necessary decay heat removal. Tthe overall reliability is reduced, however, because a single failure in the OPERABLE subsystem could result in reduced RHR shutdown cooling capability. Therefore an alternate method of decay heat removal must be provided.
With both RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability.
This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities.
The required cooling capacity of the alternate method should be sufficient to ensured by verifying (by calculation or demonstration) its capability to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, or the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.
However, due to the potentially reduced reliability of the alternate methods of decay heat removal, it is also required to reduce the reactor coolant temperature to the point where MODE 4 is entered.
B.1 If the required alternate method(s) of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem(s) to operable status. The Required Action will restore redundant decay heat removal paths. The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.
CB.1, CB.2, and CB.3 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as is permitted by LCO Note 1, reactor coolant General Electric BWR/6 STS B 3.4.9-3 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown B 3.4.9 circulation by the RHR shutdown cooling subsystem or one recirculation pump must be restored without delay.
Until RHR or recirculation pump operation is re-established, an alternate method of reactor coolant circulation must be placed into service. This will provide the necessary circulation for monitoring coolant temperature.
The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the coolant circulation function and is modified such that the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is applicable separately for each occurrence involving a loss of coolant circulation. Furthermore, General Electric BWR/6 STS B 3.4.9-4 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Hot Shutdown B 3.4.9 BASES ACTIONS (continued) verification of the functioning of the alternate method must be reconfirmed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. This will provide assurance of continued temperature monitoring capability.
During the period when the reactor coolant is being circulated by an alternate method (other than by the required RHR shutdown cooling subsystem or recirculation pump), the reactor coolant temperature and pressure must be periodically monitored to ensure proper function of the alternate method. The once per hour Completion Time is deemed appropriate.
SURVEILLANCE SR 3.4.9.1 REQUIREMENTS This Surveillance verifies that one RHR shutdown cooling subsystem or recirculation pump is in operation and circulating reactor coolant. The required flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability. [ The Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient in view of other visual and audible indications available to the operator for monitoring the RHR subsystem in the control room.
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 Surveillance is modified by a Note allowing sufficient time to align the RHR System for shutdown cooling operation after clearing the pressure interlock that isolates the system, or for placing a recirculation pump in operation. The Note takes exception to the requirements of the Surveillance being met (i.e., forced coolant circulation is not required for this initial 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> period), which also allows entry into the Applicability of this Specification in accordance with SR 3.0.4 since the Surveillance will not be "not met" at the time of entry into the Applicability.
REFERENCES None.
General Electric BWR/6 STS B 3.4.9-5 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown B 3.4.10 BASES ACTIONS (continued)
A.1 With one of the two required RHR shutdown cooling subsystems inoperable except as permitted by LCO Note 2, the remaining subsystem is capable of providing the required decay heat removal. However, the overall reliability is reduced. Therefore, an alternate method of decay heat removal must be provided. With both RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability. This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities.
Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will provide assurance of continued heat removal capability.
The required cooling capacity of the alternate method should be sufficient ensured by verifying (by calculation or demonstration) its capability to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, or the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.
B.1 If the required alternate method(s) of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem(s) to operable status. The Required Action will restore redundant decay heat removal paths. The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.
CB.1 and CB.2 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as is permitted by LCO Note 1, and until RHR or recirculation pump operation is re-established, an alternate method of reactor coolant circulation must be placed into service. This will provide the necessary circulation for monitoring coolant temperature. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the coolant circulation function and is modified such that the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is applicable separately for each occurrence involving a loss of coolant circulation. Furthermore, verification of the General Electric BWR/6 STS B 3.4.10-3 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR Shutdown Cooling System - Cold Shutdown B 3.4.10 functioning of the alternate method must be reconfirmed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. This will provide assurance of continued temperature monitoring capability.
During the period when the reactor coolant is being circulated by an alternate method (other than by the required RHR shutdown cooling system or recirculation pump), the reactor coolant temperature and pressure must be periodically monitored to ensure proper function of the alternate method. The once per hour Completion Time is deemed appropriate.
General Electric BWR/6 STS B 3.4.10-4 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR - High Water Level B 3.9.8 BASES LCO (continued) allow a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> exception for the operating subsystem to be removed from operation every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
APPLICABILITY One RHR shutdown cooling subsystem must be OPERABLE in MODE 5, with irradiated fuel in the RPV and with the water level [22 ft 8 inches]
above the top of the RPV flange, to provide decay heat removal. RHR System requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS); Section 3.5, Emergency Core Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System; and Section 3.6, Containment Systems. RHR Shutdown Cooling System requirements in MODE 5, with irradiated fuel in the reactor pressure vessel and with the water level < [22 ft 8 inches] above the RPV flange, are given in LCO 3.9.9, "Residual Heat Removal (RHR) -
Low Water Level."
ACTIONS A.1 With no RHR shutdown cooling subsystem OPERABLE, an alternate method of decay heat removal must be established within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In this condition, the volume of water above the RPV flange provides adequate capability to remove decay heat from the reactor core. However, the overall reliability is reduced because loss of water level could result in reduced decay heat removal capability. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will ensure continued heat removal capability.
Alternate decay heat removal methods are available to the operators for review and preplanning in the unit's Operating Procedures. The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem. For example, this may include the use of the Reactor Water Cleanup System, operating with the regenerative heat exchanger bypassed. The method used to remove the decay heat should be the most prudent choice based on unit conditions.
B.1, B.2, B.3, and B.4 General Electric BWR/6 STS B 3.9.8-2 Rev. 4.0
TSTF-566, Rev. 0 DRAFT RHR - Low Water Level B 3.9.9 BASES APPLICABILITY Two RHR shutdown cooling subsystems are required to be OPERABLE in MODE 5, with irradiated fuel in the RPV and with the water level < [22 ft 8 inches] above the top of the RPV flange, to provide decay heat removal.
RHR System requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS); Section 3.5, Emergency Core Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System; and Section 3.6, Containment Systems. RHR Shutdown Cooling System requirements in MODE 5, and with the water level [22 ft 8 inches] above the RPV flange, are given in LCO 3.9.8, "Residual Heat Removal (RHR) - High Water Level."
ACTIONS A.1 With one of the two required RHR shutdown cooling subsystems inoperable, the remaining subsystem is capable of providing the required decay heat removal. However, the overall reliability is reduced.
Therefore an alternate method of decay heat removal must be provided.
With both RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability.
This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will ensure continued heat removal capability.
Alternate decay heat removal methods are available to the operators for review and preplanning in the unit's Operating Procedures. The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability.
Alternate methods that can be used include (but are not limited to) the Spent Fuel Pool Cooling System, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.For example, this may include the use of the Reactor Water Cleanup System, operating with the regenerative heat exchanger bypassed. The method used to remove decay heat should be the most prudent choice based on unit conditions.
B.1, B.2, and B.3 With the required decay heat removal subsystem(s) inoperable and the required alternate method(s) of decay heat removal not available in accordance with Required Action A.1, additional actions are required to minimize any potential fission product release to the environment. This General Electric BWR/6 STS B 3.9.9-2 Rev. 4.0