ML12137A003

ME7110 Agenda for Draft RAI Clarification Call Re Wednesday 3-4 PM ET - Eicb Input

ML12137A003
Person / Time
Site:	Kewaunee
Issue date:	05/15/2012
From:	Feintuch K Division of Operating Reactor Licensing
To:	Sly C Dominion Generation
References
TAC ME7110
Download: ML12137A003 (5)

Text

NRR-PMDAPEm Resource From: Feintuch, Karl Sent: Tuesday, May 15, 2012 4:30 PM To: 'Craig D Sly' Cc: Alvarado, Rossnyev

Subject:

ME7110 Agenda for draft RAI clarification call Re Wednesday 3-4 PM ET - EICB input Attachments: ME7110-RAII 2nd round-EICB-Alva - 2012-05-15 Compliance with NUREG-0737 LAR.docx Attached is draft RAI set from Reviewer Alvarado. The request by date is 6/15/2012. If practical we would like to discuss at the meeting the information known at this time about the issues.

I am currently preparing a draft set from the Containment and Ventilation Group (Reviewer Torres)

Karl Feintuch 1

Hearing Identifier: NRR_PMDA Email Number: 375 Mail Envelope Properties (26E42474DB238C408C94990815A02F097B32B81C61)

Subject:

ME7110 Agenda for draft RAI clarification call Re Wednesday 3-4 PM ET - EICB input Sent Date: 5/15/2012 4:29:57 PM Received Date: 5/15/2012 4:29:00 PM From: Feintuch, Karl Created By: Karl.Feintuch@nrc.gov Recipients:

"Alvarado, Rossnyev" <Rossnyev.Alvarado@nrc.gov>

Tracking Status: None

"'Craig D Sly'" <craig.d.sly@dom.com>

Tracking Status: None Post Office: HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 321 5/15/2012 4:29:00 PM ME7110-RAII 2nd round-EICB-Alva - 2012-05-15 Compliance with NUREG-0737 LAR.docx 31844 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Items to Discuss During Conference Call Re: EICB Second Round set of draft RAI Questions:

• ME7110-RAII-EICB-Alva-008-2012-06-15

• ME7110-RAII-EICB-Alva-008-2012-06-15

1. Follow up to ME7110-RAII-EICB-Alva-002-2011-12-29 is assigned tracking number ME7110-RAII-EICB-Alva-008-2012-06-15

Background:

NUREG-0737, Clarification of TMI Action Plan Requirements, Item III.D.3.4, Control Room Habitability Requirements, required licensees to assure that control room operators will be adequately protected against the effects of accidental release of toxic and radioactive gas and that the plant can be safely operated or shutdown under design basis accident conditions.

Currently, Dominion Energy Kewaunee (DEK)s Kewaunee Power Station uses either a safety injection (SI) signal or high radiation detection (R-23) to automatically isolate the control room and start 100 percent recirculation (CRPAR). R-23 continuously monitors the Control Room environment for an indication of airborne activity (radiation) entering through the Control Room ventilation system. If R-23 senses a high radiation condition, the monitor initiates closure of the outside air intake, provides a signal that isolates the control room ventilation system and starts the control room post-accident recirculation system. R-23 in conjunction with other radiation monitor demonstrates compliance with NUREG-0737.

R-23 is credited in the current Radiation Accident Analysis (RAA) for mitigating the consequences of an accident. Based on 10 CFR 50.36 criteria, Technical Specification (TS) actions and surveillance requirements for R-23 should be included in Kewaunees TS.

The LAR-244 proposes removing radiation monitor channel R-23 from TS to the Kewaunees Technical Requirements Manual (TRM). DEK is proposing to credit manual actuation of SI to isolate the control room and start CRPAR. Justifications for relocating R-23 to the TRM are:

• Radiation monitor R-23 is not safety grade

• R-23 is a single radiation monitor

• R-23 is a partial signal that will not close all control room inlet and outlet ventilation EICB Question (ME7110-RAII-EICB-Alva-002-2011-12-29) - If R-23 is removed from TS, how will DEK comply with NUREG-0737, Item III.D.3.4?

NUREG-0737 requires safety grade radioactivity monitors required for automatic isolation purpose. SRP 6.4 habitability systems, Section 2.0, item B states that: Single failure of an active component should not result in loss of the system's functional performance. All the components of the control room emergency filter train should be considered active components. Even though DEK recognized inconsistency with these requirements, DEK justified use of a single radioactivity monitor installed in the control room HVAC system air supply. This was justified because the automatic isolation function is accomplished by actuation 1

of safety injection or high radiation in the control room air supply. These signals are diverse and provide adequate protection.

Further, in 1983 Kewaunee performed an analysis to show how the control room would be isolated during design basis accidents (DBA) if R-23 fails. In this analysis, KDE explained that failure of R-23 would cause an alarm in the control room alerting the control operators of loss of its function, and other radiation monitors (R-1 and R-5) will detect and confirm the presence of unusual levels of radiation at the radiation monitoring panel located in the control room, or a control room ventilation system isolation signal would occur, such that the single monitor in the air intake would never be the sole means of isolating that system. However, R1 and R-5 only warns operators to the presence of an abnormal condition. Thus, the operator would have to manually isolate the control room.

The NRCs safety evaluation (SE) for NUREG-0737 found that the control room habitability system were acceptable and would provide a safe, habitable environment under DBA radiation and toxic gas conditions. In this SE, the staff stated that for radiation monitor, a radiation monitor in addition to R-23 should alarm in the control room or a control room ventilation system isolation signal would occur, such that the single monitor in the air intake would never be the sole means of isolating that system. High radiation signal detected by R-23 and SI signal would initiate the CRPAR system LAR-244 is proposing relocating R-23 from TS to TRM. R-23 would remain part of the control room isolation logic and control room post-accident recirculation system (CRPAR), providing defense-in-depth for the control room isolation function.

LAR-244 and RAI response received on January 25, 2012 justified relocating R-23 based on a revised RAA without crediting the isolation function provided by R-23. DEK is proposing to credit operator actions to isolate the control room or a SI signal to perform isolation of the control room. DEK states that this is sufficient to meet the requirements in NUREG-0737.

Further, if R-23 is not credited in the revised RAA, R-23 wont meet the criteria in 10 CFR 50.36 to remain in TS Based on this information, the NRC staff has the following follow up question:

ME7110-RAII-EICB-Alva-008-2012-06-15 a) If an SI signal is not actuated and there is a radiation release, how will DEK meet the NUREG-0737 requirement for automatic isolation capability?

b) The basis to TS 3.12 indicates that the recirculation filter system is designed to automatically start on a safety injection signal or a high radiation signal. How will the design of the recirculation filter system be modified if R-23 is relocated to TRM?

c) The current design considers the safety injection signal providing a diverse means of post-accident actuation for R-23. If R-23 is relocated to the TRM, what component will provide diverse means for the SI signal?

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2. Radiation monitor use for incoming fresh air (New Question):

ME7110-RAII-EICB-Alva-009-2012-06-15

Background:

KPS UFSAR Rev 23, page 9.6-12 states:

The operator can add fresh air to the Control Room under post-accident conditions by first verifying that conditions at the intake plenum will not cause contamination of the Control Room atmosphere, then manually opening the selected outside air damper and the damper at the suction of the post-accident recirculation fans. Excess air is exhausted to the Turbine Room through a backdraft damper. The operator can confirm the incoming fresh/recirculation air mix is not contaminating the Control Room atmosphere by observing a radiation monitor channel in the Control Room. Damper control switches are spring return to the normal position so that when the damper control switches are released the dampers automatically return to the recirculation configuration.

ME7110-RAII-EICB-Alva-009-2012-06-15 Since this is an isolation design, the control room needs to supplement the breathable air after a week to 10 days to keep the air habitable. Please explain if the radiation monitor credited in the UFSAR for fresh air is R-23.

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