ML091480675

Draft - RAI from Human Performance Branch on License Amendment Request 241 Alternate Source Term

ML091480675
Person / Time
Site:	Point Beach
Issue date:	05/28/2009
From:	Justin Poole Plant Licensing Branch III
To:	Hale S Florida Power & Light Co
Poole Justin/DORL/LPL3-1/ 301-415-2048
References
Download: ML091480675 (3)

Text

From:

Justin Poole Sent:

Thursday, May 28, 2009 3:35 PM To:

'Steve_Hale@fpl.com' Cc:

JAMES.COSTEDIO@nexteraenergy.com

Subject:

DRAFT - RAI questions from Human Performance Branch on AST amendment

Steve, By letter dated December 8, 2008, NextEra Energy, LLC (formerly FPL Energy, LLC), submitted a license amendment application for Point Beach Nuclear Plant Units 1 and 2 to revise the current licensing basis to implement the alternate source term through reanalysis of the radiological consequences of the FSAR Chapter 14 accidents.

The Operator Licensing and Human Performance Branch has reviewed the information provided and determined that in order to complete its evaluation, additional information is required. We would like to discuss the questions, in draft form below, with you in a conference call.

This e-mail aims solely to prepare you and others for the proposed conference call. It does not convey a formal NRC staff position, and it does not formally request for additional information.

Justin C. Poole Project Manager NRR/DORL/LPL3-1 U.S. Nuclear Regulatory Commission (301)415-2048 email: Justin.Poole@nrc.gov

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DRAFT

1. The licensee stated in its submittal, Credit is taken for manual operator action to restore Primary Auxiliary Building Ventilation System (VNPAB) within 30 minutes following the alignment of RHR to containment sump recirculation mode of operation. If a LOCA occurs coincident with a LOOP, the VNPAB will be manually restarted to ensure that the auxiliary building vent stack is the source of the release associated with the ECCS leakage phase of the event.

a. What are the cues that alert the operator to initiate these actions, e.g., how will the operator know that action is required? Annunciator? Procedure step sequencing?

Parameter monitoring?

b. Will operators need to know that there is a time-constraint of 30 minutes associated with these actions? If so, how will the time-constraint be communicated to the operator and how will the start time be determined and documented?

c. How have these actions been validated to be feasible and reliable? Who was, or will be, involved in the validation?

d. Describe the changes, if any, to the plant-reference simulator and training that are planned to support these actions.

e. Describe the changes, if any, to the plant procedures that are planned to support these actions. Copies of marked-up procedure pages or procedure change requests should be included if available.

2. Regarding the control room emergency filtration system (CREFS) and Control Room Ventilation (VNCR), the licensee stated in its submittal, A new operational mode for CREFS, known as Mode 5 will be established. This change will provide for a combination of filtered outside air and filtered recirculation. The VNCR accident mode will provide a total flow rate of 4950 cfm +/-10% with a minimum of 1955 cfm of filtered return air.

a. What effect does the new CREFS Mode 5 have on the control room environment when compared to normal control room ventilation? For example, is the noted flowrate of 4950 cfm more, less, or equal to normal flowrate?

b. Is there any effect on control room humidity or temperature?

Elsewhere in the submittal, the licensee stated, The modifications will include redundancy for all CREFS active components and auto-start capability on loss of offsite power from a diesel generator supplied source for the CREFS fans required for the new system alignment. Point Beach will revise PBNP EOPs to address starting the VNPAB fans.

c. Please clarify. For example, what is the functional relationship between the CREFS fans and the VNPAB fans? For a LOCA with concurrent LOOP, describe how the CREFS is put into the accident mode. Which components are auto-started or auto-aligned, and which require manual actions?

3. Regarding modifications to Containment Spray and RHR, the licensee stated, FPL Energy Point Beach will modify the CS and RHR systems to provide throttling capability of CS and RHR during the ECCS recirculation phase. What instrumentation will be provided to support the operators capability to throttle CS and RHR?

a. What cues alert operators to the need to throttle CS and RHR?

b. What feedback is provided to operators?

c. What kind of controls are used and are they consistent with other throttling controls in the CR?

d. What aids are provided to help the operator quickly find the appropriate throttling point, e.g. are appropriate settings pre-determined and labeled?

e. How have these actions been validated to be feasible and reliable? Who was, or will be, involved in the validation?

f. Describe the changes, if any, to the plant-reference simulator and training that are planned to support these actions.

g. Describe the changes, if any, to the plant procedures that are planned to support these actions. Copies of marked-up procedure pages or procedure change requests should be included if available.

h. What methods have been used to minimize the probability of human error?

i. What methods have been used to optimize the probability of recovery from likely human errors?

j. Is there a time-constraint associated with establishing the appropriate flow in the CS and RHR systems? If yes, how will the time-constraint be communicated to the operator(s) and how will the start time be determined and documented?

4. The licensee also stated, For a LOCA, manual operator actions are required to align the CS and RHR systems for CS on recirculation from the containment sump Please list all operator actions involved in aligning CS and RHR for recirculation from the containment sump. Identify any actions that are taken locally and state what the environmental conditions will be at the time and location that the actions are needed.

5. Regarding Emergency Operating Procedures (EOPs) the licensee stated, Point Beach will revise PBNP EOPs to direct continued CS while on sump recirculation, if containment radiological conditions and/or core damage indicates it is required. The dose calculations prepared in support of this submittal assume that CS is maintained throughout the injection phase of a LOCA and continued during the early portions of the recirculation phase with no more than a 20-minute interruption. The ability to maintain spray during the early recirculation phase is essential, as this is the period of highest iodine evolution from a postulated damaged core.

a. How do the EOPs address the conditional statement in the quote above, if containment radiological conditions and/or core damage indicates it is required.?

b. How will the analytical assumptions that CS is maintained throughout the injection phase of a LOCA and continued during the early portions of the recirculation phase with no more than a 20-minute interruption be assured?

c. How will interruptions be timed? What are the consequences of delays greater than 20 minutes? Are any recovery actions feasible?

d. How have the proposed actions been validated to be feasible and reliable? Who was, or will be, involved in the validation?

e. It is also stated in the submittal, The AST LOCA dose analysis assumes CS is operated for three hours while in the ECCS recirculation phase. How will this assumption be confirmed before implementation, and how will it be assured during execution of the EOPs?

f. Is there an inherent conflict possible between the EOP direction to continue CS while on sump recirculation, if containment radiological conditions and/or core damage indicates it is required, and the AST assumption that CS is operated for three hours while in the ECCS recirculation phase. Are criteria included in the EOPs for when to stop or reduce CS flow?

g. Is guidance or training provided regarding how to balance CS and RHR flows? For example, if rad conditions in containment require continued CS flow, but sump level is at or near minimum and RHR pumps are cavitating due to insufficient NPSH, does the operator shut down CS? If so, does the operator count this as part of the twenty minute interruption limit, or does he/she just continue when sump volume returns to greater than minimum and continue until a total of three hours of CS flow is complete?

DRAFT