ML25325A350

RAI - Vogtle 3 and 4 - LARs - Mode Restraints and Shutdown Actions (L-2024-LLA-0171 and L-2025-LLA-0011)

ML25325A350
Person / Time
Site:	Vogtle
Issue date:	09/30/2025
From:	John Lamb NRC/NRR/DORL/LPL2-1
To:	Lowery K Southern Nuclear Operating Co
References
EPID L-2024-LLA-0171, EPID L-2025-LLA-0011
Download: ML25325A350 (0)

Text

From:

John Lamb To:

Lowery, Ken G.

Cc:

Joyce, Ryan M.

Subject:

For Your Action - RAI - Vogtle 3 and 4 - LARs - Mode Restraints and Shutdown Actions (L-2024-LLA-0171 and L-2025-LLA-0011)

Date:

Tuesday, September 30, 2025 8:54:00 PM

Ken,

By letter dated December 19, 2024 (Agencywide Documents and Access Management System (ADAMS) Accession No.ML24354A169), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4. The proposed LAR (L-2024-LLA-0171) would change the Technical Specifications (TS), to increase flexibility in mode restraints. The proposed changes are similar to those described in Technical Specification Task Force (TSTF) 359, Revision 9, Increased Flexibility in Mode Restraints, with changes similar to those identified in TSTF-529, Revision 4, Clarify Use and Application Rules, for Limiting Condition for Operation (LCO) 3.0.4.

By letter dated January 23, 2025 (ML25023A275), SNC submitted a LAR for Vogtle, Units 3 and 4. The proposed LAR (L-2025-LLA-0011) would revise TSs that may unnecessarily restrictive and potentially conflicting Required Actions that may also restrict mode changes while shutdown.

The U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is required for the staff to complete its review. The NRC staffs draft request for additional information (RAI) was sent on September 4, 2025. A clarifying call was held on September 30, 2025. SNC said that it would respond to this RAI by October 31, 2025.

If you have any questions, please contact me.

John G. Lamb, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

REQUEST FOR ADDITIONAL INFORMATION (RAI) QUESTIONS

By letter dated December 19, 2024 (Agencywide Documents and Access Management System (ADAMS) Accession No.ML24354A169), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4. The proposed LAR (L-2024-LLA-0171) would change the Technical Specifications (TS), to increase flexibility in mode restraints. The proposed changes are similar to those described in Technical Specification Task Force (TSTF) 359, Revision 9, Increased Flexibility in Mode Restraints, with changes similar to those identified in TSTF-529, Revision 4, Clarify Use and Application Rules, for Limiting Condition for Operation (LCO) 3.0.4.

By letter dated January 23, 2025 (ML25023A275), SNC submitted a LAR for Vogtle, Units 3 and 4. The proposed LAR (L-2025-LLA-0011) would revise TSs that may unnecessarily restrictive and potentially conflicting Required Actions that may also restrict mode changes

Question #

DRAFT RAI QUESTIONS (AUDIT QUESTION #5)

[Follow up question to the licensees response to Audit Question 5 on Mode Restraints regarding the qualitative risk assessment consistent with attachments to TSTF-359] The TSTF-359 safety evaluation for the Turkey Point license amendment on mode restraints (ML18018A559) states, [i]n evaluating these submittals, the NRC staff applies the guidance in RG 1.174, Revision 3, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, dated January 2018 and in RG 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, dated May 2011. The SER also states, [b]oth the temporary and cumulative risk of the proposed change is adequately limited. The temporary risk is limited by the exclusion of higher-risk systems and components, and completion time limits contained in TS (Section 3.1.1 of this safety evaluation).

In addition, the references to and risk insights from the San Onofre LPSD PRA do not while shutdown.

The U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is required for the staff to complete its review.

Regulatory Basis

Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(c) requires TSs to include the following categories: (1) safety limits, limiting safety system settings, and limiting control settings; (2) LCOs; (3) SRs; (4) design features; (5) administrative controls; (6) decommissioning; (7) initial notification; and (8) written reports.

Section 50.36(c)(2) of 10 CFR states, in part, that:

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

Section 50.36(c)(3) of 10 CFR states that:

Surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met.

The NRC staffs guidance for the review of the TSs is in NUREG-0800, Standard Review Plan

[SRP] for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light-Water Reactor] Edition, Chapter 16, Technical Specifications, Revision 3, dated March 2010 (ADAMS Accession No. ML100351425).

RAI QUESTIONS

1 necessarily apply to Vogtle 3 & 4, since San Onofre is not an advanced light-water reactor with a passive ECCS. General Design Criterion 34 was met at San Onofre by safety-related pumps that provided the decay heat removal function. In the AP1000 design, GDC 34 is met using the safety-related gravity-driven core cooling system and ADS.

In this context, the qualitative assessment was reviewed, and the staff has the following questions.

a. In revision 10 of the UFSAR, Section 19.59.3, System Importances for At-Power Core Damage, it states that the protection and safety monitoring system (which actuates the safety-related systems) and the Class 1E DC power system are the most important systems for maintaining the low CDF. This section also states that the risk-significant systems are the safety-related systems. The initial version of NUREG-1793, Final Safety Evaluation Report Related to Certification of the AP1000 Standard Design, states, The most important systems for core damage prevention, or equivalently, the systems that are the most worthy in achieving the low CDF level assessed in the PRA (i.e., systems with the highest risk achievement worth), are the PMS, the Class 1E dc power, the ADS, IRWST recirculation, IRWST injection, the CMTs, and the accumulators. How have these risk insights been incorporated into evaluation of the proposed LCO 3.0.4.b?

b. In revision 10 of the UFSAR, Section 19.59.5-1, Summary of Shutdown Level 1 Results, states that the major contributors to risk due a loss of RNS during drained conditions are:

Common-cause failure of the RNS pumps to run Common-cause failure of the recirculation line squib valves Common-cause failure of the ADS 4th stage squib valves Common-cause failure of the IRWST injection squib valves Common-cause failure of the strainers in the IRWST Tank (failing the function of the IRWST)

Common-cause failure of the recirculation sump strainers (failing the function of recirculation)

How have these UFSAR risk insights been incorporated for the evaluation of LCO.

3.0.4.b?

c. Can LCO 3.0.4.b be used to transition between MODES or other specified conditions in the Applicability if they are already in an applicable MODE for an LCO and do not meet the LCO?

d. Scenario 1: If the answer to question c is yes, then consider a scenario where:

1. The Plant is in MODE 5 with RCS pressure boundary open and the reactor has been subcritical for 28 hrs. LCO 3.4.13 requires three flow paths in ADS stage 4 to be operable. One of three required ADS 4 flow paths is found to be inoperable.

a. Can the operators transition the plant to another specified condition in Applicability such as MODE 5 with the level <

20% using LCO 3.0.4.b? Note that Condition B of LCO 3.4.13 requires restoration of the required flow path within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> for both MODE 5 with the RCS open and for MODE 5 with the level < 20%.

b. Explain from what point in time the Completion Time clock would be started for restoration of the required ADS Stage 4 flow path and tracked.

2. LCO 3.4.12 also requires three ADS 4 flow paths to be operable with the plant in MODE 5 with RCS pressure boundary intact and pressurizer level 20%?

a. Can the operators continue to startup and transition the plant to MODE 5 with RCS pressure boundary intact and pressurizer level 20% (i.e., enter LCO 3.4.12)?

b. Explain from what point in time the Completion Time clock would be started for restoration of the required ADS Stage 4 flow path and tracked.

3. If the 36-hour Completion Time to restore the required ADS 4 flow path is not met, the Vogtle 3 and 4 current TS would require immediately exiting the MODE of Applicability (i.e., Condition D would require Initiate action to open the RCS pressure boundary). Based on the Shutdown Actions LAR, LCO 3.4.12 Condition D would require the operator to Initiate action to restore compliance with the LCO with a Completion Time of Immediately.

a. How does the Shutdown Actions LAR affect the ability to use LCO 3.0.4.b in this case? TSTF-359 states, LCO 3.0.4.b should not be used unless there is a reasonable probability of completing restoration such that the requirements of the LCO would be met prior to the expiration of the ACTIONS Completion Times that would require exiting the Applicability.

4. LCO 3.4.11 requires four ADS 4 flow paths to be operable when in MODE 4.

a. Can operators transition to MODE 4? Note that the plant would now have two required flow paths inoperable.

b. If so, explain from what point in time the Completion Time clock would be started for restoration of the required ADS Stage 4 flow path and tracked.

E. Scenario 2: The Plant is in MODE 5 with one IRWST containment recirculation flow path inoperable and the Boron Concentration is not within limits. Can the plant transition to MODE 4?

If so, explain from what point in time the Completion Time clock(s) would be started

for restoration of the required ADS Stage 4 flow path and tracked.

2 (Revised Audit Question 7)

In the Vogtle 3 & 4 design, general design criterion (GDC) 34 is met in modes 5 and 6 by the automated and passive actuation of the gravity-driven core cooling system combined with actuation of the automatic depressurization system (ADS), which is covered by technical specifications. Per LCO 3.5.7, IRWST - Shutdown, MODE 5, and LCO 3.5.8, IRWST - Shutdown, MODE 5, only one injection flow path and one containment recirculation isolation valve need to be operable in modes 5 and 6 for sustained decay heat removal.

a. How is this lack of redundancy considered in the maintenance rule (a)(4) risk evaluations when in modes 5 and 6?

b. It appears to the staff that ADS stage 4 is necessary for gravity injection using the gravity-driven core cooling flow path and the normal residual heat removal system (RNS) gravity injection flow path. Explain how these dependencies do not result in overcounting the licensees defense-in-depth capability, or explain why there are no dependencies between ADS stage 4 and the gravity-driven core cooling and RNS gravity injection flow paths.

c. The chemical and volume control system (CVCS) is credited as one source of defense-in-depth for the key safety function of inventory control. Is CVCS capable of making up for inventory losses from decay heat during the entire outage?

d. Based on the audit response to New Question 1 (follow-up question to Audit Item

1. 7), due to the shared dependency on ADS stage 4 SNC acknowledges that for a case of less than the full complement of ADS stage 4 paths, overcounting could result.

Since the staffs regulatory finding relies on the adequacy of SNCs tools (B-ADM-OPS-11) and Phoenix to accurately manage the risk of maintenance configurations in lieu of Tech. Spec. Action statements, the staff needs a detailed description of the changes to B-ADM-OPS-11 and to Phoenix to prevent over counting. It appears to the staff that ADS stage 4 is necessary for gravity injection using the PXS gravity-driven core cooling flow path and the normal residual heat removal system (RNS) gravity injection flow path when the RCS is vented via stage 2 and 3 of the ADS valves.

However, the draft markup to B-ADM-OPS-11 shows that ADS stage 4 is not needed for RNS gravity injection. Given the anticipated pressurizer filling and surge line flooding following RCS boiling, the staff is interested if there is a thermohydraulic analysis that supports ADS stage 4 not being needed for RNS gravity injection, especially post RCS boiling, following a loss or interruption of RNS. If an analysis exists, the staff requests to see the results of such an analysis. Alternatively, the staff requests to see a detailed description of changes to B-ADM-OPS-11 and Phoenix which reflects a RNS gravity dependency on ADS Stage 4.

3 (AUDIT QUESTION #15)

L-2025-LLA-0011. Section 2.3 of the LAR makes an argument to justify the change that may not accurately characterize the options operators would have in the situation with conflicting requirements in required actions. Specifically, the LAR states,

When Immediately" is used as a Completion Time, the Required Action should be pursued without delay and in a controlled manner. Thus, actions taken contrary to this direction would not be allowed, i.e., actions taken to exit the Applicability that would necessitate a water level change that conflict with the Required Action.

Technical Specification (TS) Actions only apply when the plant is operating within an applicable mode. This is consistent with 10 CFR 50.36 which specifically requires a licensee to either shut down or follow any remedial action permitted by their TS when an LCO is not met. Based on the regulation shutting down the reactor (or exiting the applicable mode) should always be an option. Vogtle, Units 3 and 4, LCO 3.0.2 states:

Upon discovery of a failure to meet an LCO, the Required Actions of the associated Conditions shall be met, except as provided in LCO 3.0.5 and 3.0.6.

If the LCO is met, or is no longer applicable prior to expiration of the specified Completion Time(s), completion of the Required Action(s) is not required, unless otherwise stated. [Emphasis added]

This is further supported by the Vogtle, Units 3 and 4, Bases for LCO 3.0.2 which state, Completing the Required Actions is not required when an LCO is met, or is no longer applicable, unless otherwise stated in the individual Specifications. [Emphasis added]

a. Please explain whether the intent of the above statement from Section3.2 of the LAR is stating that in the example case provided in the LAR, the licensee does not believe that exiting the Applicability is an option or if they believe that any time the plant is in a Condition with a specified immediate action, operators are prevented from exiting the Applicability.

b. If, as stated in the LAR, a Completion Time of Immediately prevents operator from taking any other action than the specified Required Action, doesnt the portions of the proposed change to revise the Required Actions to Initiate action to restore [compliance with the LCO] with an Immediately Completion Time result in the same problem? The only choice would be to restore compliance with the specified LCO.

Section3.0 of the LAR states that exiting the Applicability would be an option with the proposed structure, but exiting the Applicability does

mean the LCO is met. It places the plant in a mode where the LCO is not required to be met. If exiting the Applicability is acceptable with the proposed revision, then why isnt it acceptable with current technical specification requirements? The NRC notes that the licensee is obligated to enter all applicable LCOs concurrently along with Required Actions and Completion Times for each associated LCO Condition.

For example, LCO 3.5.3, CMTs - Shutdown, RCS Intact, Action E could be entered in Mode 5 with the RCS intact after failure to restore the inoperable CMT to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this case, the current requirement is to exit the applicability by venting the RCS. The current action seems appropriate if the IRWST is operable.

Under the proposed change, the operator would E.1 Initiate Action to be in MODE 5, (which would already be complete in this case) AND E.2 Initiate action to restore required CMT to OPERABLE status. The proposed addition of ActionE.2 tells the operator to keep trying to restore after they have already been unable to do so for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Would the operator (based on the discussion in Section 2.3 of the LAR) be prevented from venting the RCS to exit the Applicability in this case?

4 (AUDIT QUESTION #21)

L-2025-LLA-0011. The default actions proposed for revision in the LAR, in some cases, can only be entered after having already failed to restore operability (or compliance with the LCO) for a period of time. The default actions in these cases are proposed to be revised to state initiate action to restore operability or compliance with the LCO. Why are the words initiate action to necessary? The action to restore would have already been started in response to the previous Required Actions. Why wouldnt it be more appropriate to state restore operability or compliance with an immediate CT? For instance, LCO 3.5.3 provides at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (and as much as 72hours) to restore the required CMT to operable status prior to entry into ConditionE. ConditionE cannot be entered without having failed to restore operability in accordance with Required Actions A.1, B.1 and D.1.

As stated in Section 1.3 of the Vogtle, Units 3 and 4, TS, [w]hen Immediately is used as a Completion Time, the Required Action should be pursued without delay and in a controlled manner. Initiate action to makes sense when the default Condition can be entered directly. But if the default Condition can only be entered after having time to restore compliance with the LCO, its unclear as to why the words are necessary.

[Revised Audit Question 23)

There are multiple examples in the Vogtle 3 & 4 shutdown actions LAR where a potential conflict is identified with the LCOs for TS 3.6.7, Containment Penetrations.

Numerous LCOs require the opening of a containment air flow path 6 inches, the containment equipment hatch, or the containment airlock while LCO 3.6.7 requires the capability of closing the containment prior to steaming (e.g., loss of decay heat

5 removal that would lead to steaming in containment). The staff need to understand what guidance on opening a containment air flow path 6 inches the operators have during shutdown operations to ensure that there are appropriate restrictions on dominant risk significant configurations and determine if the defense-in-depth assessment can inform any operator action in the absence of a prescriptive LCO action.

a. How does the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011, Outage Risk Assessment Monitoring, evaluate the need to create an opening of a containment air flow path? As part of the response, discuss any potential impacts to the key safety functions, including containment closure.

b. If the defense-in-depth assessment does not evaluate the need to create an opening of a containment air flow path, identify the procedures or guidance that directs operators or informs them of the need to assess opening a containment air flow path, or justify why the defense-in-depth assessment does not evaluate the need to create an opening of a containment air flow path.

6 (Revised Audit Question 24)

There are multiple examples within the Vogtle 3 & 4 shutdown actions LAR where it states that events requiring actuation of ADS stage 1, 2, and 3 or ADS stage 4 do not assume a minimum reactor coolant system (RCS) water level. The staff need to understand what guidance on RCS level and plant configuration the operators have during shutdown operations to ensure that there are appropriate restrictions on dominant risk significant configurations and determine if the defense-in-depth assessment can inform any operator action in the absence of a prescriptive LCO action.

a. How does RCS level impact the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011? As part of the response, discuss any potential impacts to the key safety functions, including inventory control, containment closure, and decay heat removal.

b. How is a 20% pressurizer water level (or any comparable level) in the pressurizer credited in the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011? As part of the response, discuss any potential impacts to the key safety functions, including inventory control, containment closure, and decay heat removal.

7 (Revised Audit Question 25)

There are multiple examples within the Vogtle 3 & 4 shutdown actions LAR where it states that once the RCS is vented, the complement of safety systems available to respond to an event is reduced.

How are the RCS vented and RCS pressure boundary intact states credited in the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011? As part of the response, discuss any potential impacts to the key safety functions).

8 (Revised Audit Question 26)

There are multiple examples within the Vogtle 3 & 4 shutdown actions LAR where it states that the removal of the upper internals would preclude normal outage progression to proceed to mode 5 with the reactor vessel head on, which also precludes establishing an additional fission product barrier. Based on audit responses, the staff agree that plant configurations in mode 6 with the upper internals installed should be evaluated as drained conditions, which have the highest risk, since the RCS inventory may not communicate with the volume in the refueling cavity for decay heat removal.

How is the removal of the upper internals credited in the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011?

As part of the response, discuss any potential impacts to the key safety functions.

9 (Revised Audit Question 27)

There are multiple examples within the Vogtle 3 & 4 shutdown actions LAR where mode 6 LCO actions to initiate action to establish water level 23 feet above the top of the reactor vessel flange are eliminated. The staff need to understand what guidance on RCS level and plant configuration the operators have during shutdown operations to ensure that there are appropriate restrictions on dominant risk significant configurations and determine if the defense-in-depth assessment can inform any operator action in the absence of a prescriptive LCO action.

a. How does refueling cavity water level impact the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011? As part of the response, discuss any potential impacts to the key safety functions including inventory control, containment closure, and decay heat removal.

b. How is a 23-foot level (or any comparable level) in the refueling cavity credited in the defense-in-depth assessment performed in accordance with NUMARC 91-06 and B-ADM-OPS-011? As part of the response, discuss any potential impacts to the key safety functions, including inventory control, containment closure, and decay heat

removal.

10 (Revised Audit Question 28)

On page E-20 of the Vogtle 3 & 4 shutdown actions LAR, the following statement is made with respect to TS 3.3.9, Function 7, ADS Stage 4 Actuation - Manual Initiation, Actions H & I: Once the RCS is vented (i.e., the first portion of Required Action H.2) the remaining requirement to establish 20% pressurizer level is not required to be completed since the Applicability would be exited.

To exit the mode of applicability (mode 5) for this function and action (H.2), operators would need to take the plant to either mode 4 or mode 6. Vented is defined in the Vogtle 3 & 4 TS as a condition when all required flow paths in ADS stage 1, 2, and 3, or alternative flow path with equivalent area Mode 4 and mode 6, as defined in section 1.1 of the Vogtle 3 & 4 TS, do not require the RCS to be vented.

How does the act of taking the RCS to a vented status affect the requirement to establish a level in the pressurizer?

11 (Revised Audit Question 31)

As part of the Vogtle 3 & 4 shutdown actions LAR, an elimination of RCS level requirements has been requested as part of proposed changes to TS 3.6.7, Containment Penetrations. The proposed changes impact TS 3.6.7 required actions B.1.1 and B.1.2, which are only entered if it is found that a containment penetration cannot be closed prior to steaming in containment and the penetrations cannot be restored in one hour (action A.1). The staff need to understand what guidance on RCS level and plant configuration the operators have during shutdown operations to ensure that there are appropriate restrictions on dominant risk significant configurations and determine if the defense-in-depth assessment can inform any operator action in the absence of a prescriptive LCO action.

a. An entry into required actions B.1.1 and B.1.2 of TS 3.6.7 represents a loss of the containment closure safety function, which is a significant loss of defense-in-depth and a loss of a fission product barrier. What guidance and restrictions are there on entering dominant risk significant configurations when there is an inability to maintain containment closure?

b. For a complete loss of the containment closure safety function, how would changes to the time to boil based on changes to RCS level impact the defense-in-depth assessment performed in accordance with NUMARC 9106 and B-ADM-OPS-011?

c. For a complete loss of containment closure safety function, how would changes to the other key safety functions of the defense-in-depth assessment inform any operator decision on plant configuration in the absence of a prescriptive LCO action?

d. If the defense-in-depth assessment does not inform operator action for a complete loss of the containment closure safety function, are there any procedurally-driven processes or actions that would inform any operator decision on plant configuration in the absence of a prescriptive LCO action?

12 (Revised Audit Question 34)

GL 88-17 in conjunction with NUMARC 91-06 were found to reduce risk significantly enough that a proposed rule on shutdown and low-power operations for nuclear power reactors was found to be unnecessary. GL 88-17 has numerous recommendations, particularly with respect to operating in a reduced inventory condition. The staff need to understand what guidance on RCS level and plant configuration the operators have during shutdown operations to ensure that there are appropriate restrictions on dominant risk significant configurations and determine if the recommended actions of GL 88-17 are being implemented at Vogtle 3 & 4.

a. Expeditious action 2 in the Recommended Actions attachment to GL 88-17 recommends that plants Implement procedures and administration controls that reasonably assure that containment closure will be achieved prior to the time at which a core uncovery could result These procedures and administrative controls should be active and in use: (a) prior to entering a reduced inventory condition for NSSSs supplied by Combustion Engineering or Westinghouse and should apply whenever operating in those conditions. Regarding closure before steaming inside containment, GL 88-17 also states, "The 200 F temperature identified above provides assurance that containment is closed prior to the existence of such conditions.

If a complete loss of the containment closure safety function were to occur (such as when LCO 3.6.7 is entered), what guidance is provided to operators to implement the above referenced expeditious action 2 from GL 88-17?

b. Expeditious action 6 in the Recommended Actions attachment to GL 88-17 recommends that Prior to operating in a reduced inventory condition provide at least two available or operable means of adding inventory to the RCS that are in addition to pumps that are a part of the normal DHR systems. NUMARC 91-06 guidance states that Prior to entering a reduced inventory condition, equipment requirements that provide or support key safety functions should be verified.

Is the operability or availability of two means of adding inventory to the RCS verified before entering reduced inventory operation? As part of the response describe how

ADS stage 4 is verified prior to entering reduced inventory operation or provide a justification if it is not verified.

c. Expeditious action 7 in the Recommended Actions attachment to GL 88-17 recommends that Prior to operating in a reduced inventory condition Implement procedure and administrative controls that reasonably assure that all hot legs are not blocked simultaneously by nozzle dams unless a vent path is provided that is large enough to prevent pressurization of the upper plenum of the reactor vessel.

What procedures and administrative controls does Vogtle 3 & 4 have to implement 88-17 expeditious action 7?