ML12129A297

Request for Additional Information, Revision Request for Technical Specification 3.7.12, Engineered Safety Feature Room Cooler and Safety-Related Chiller

ML12129A297
Person / Time
Site:	Vogtle
Issue date:	05/21/2012
From:	Patrick Boyle Plant Licensing Branch II
To:	Ajluni M Southern Nuclear Operating Co
Boyle P
References
TAC ME7723
Download: ML12129A297 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 21.2012 Mr. M. J. Ajluni Nuclear Licensing Director Southern Nuclear Operating Company. Inc.

40 Inverness Center Parkway Post Office Box 1295. Bin - 038 Birmingham, AL 35201-1295

SUBJECT:

VOGTLE ELECTRIC GENERATING PLANT, UNIT NO.2 - REQUEST FOR ADDITIONAL INFORMATION (RAI). REVISION REQUEST FOR TECHNICAL SPECIFICATION 3.7.14. ENGINEERED SAFETY FEATURE ROOM COOLER AND SAFETY-RELATED CHILLER (TAC NO. ME7723)

Dear Mr. Ajluni:

By letter dated December 19. 2011 (Agencywide Document Access and Management System (ADAMS) Accession No. ML113550489). Southern Nuclear Operating Company. the licensee, submitted a license amendment request to change the Technical Specifications (TSs) for Vogtle Electric Generating Plant (Vogtle), Unit 2. Specifically. the amendment would revise the TS 3.7.14 "Engineered Safety Features (ESF) Room Cooler and Safety-Related Chiller System" allowed Completion Time for Condition A from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 9 days.

Responses to the enclosed Request for Additional Information (RAI) are needed for us to continue our review.

Please provide a response within thirty (30) calendar days of the date of this letter.

Sincerely.

Patrick G. Boyle, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-425

Enclosure:

RAI cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION 3.7.14 ENGINEERED SAFETY FEATURES ROOM COOLER AND SAFETY-RELATED CHILLER SYSTEM VOGTLE ELECTRIC GENERATING PLANT, UNIT NO.2 DOCKET NO. 50-425 TAC NO. ME7723 The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by Southern Nuclear Operating Company, Inc., for Vogtle Electric Generating Plant (Vogtle),

Unit No.2 in its letter dated December 19, 2011 (Agencywide Document Access and Management System (ADAMS) Accession No. ML113550489). However, the NRC staff has reviewed the licensee's submittal and determined that additional information is needed to complete the review, as follows:

General Design Criterion 19 (GDC-19) establishes criteria for a control room from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions. Included in these criteria is the requirement that adequate radiation protection be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures more than 5 REM whole body, or its equivalent to any part of the body, for the duration of the accident. Guidance on demonstrating compliance with this regulation is provided in Regulatory Guide 1.78, "Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release," and Standard Review Plan Section 6.4, "Control Room Habitability Systems."

In its review of license amendment applications over the past several years, the NRC staff has identified problems associated with the assessment of control room habitability. These problems have included licensees: (1) inadequately assessing the impact of proposed changes on control room habitability, (2) failing to identify the limiting accident, (3) crediting the performance of control room isolation and emergency ventilation systems in a manner which was inconsistent with the system's design and operation, and (4) lacking the ability to substantiate assumptions regarding control room unfiltered in-leakage.

RAI-1

The licensee is requesting to extend the completion time (CT) of Condition A of Technical SpeCification (TS) 3.7.14 from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 9 days in order to overhaul chiller 28 of the essential chilled water chiller system (ECWS). During the nine days that the "28 train" of the ECWS is out of service, explain how the compensatory actions demonstrate continued compliance with the single failure criteria and the requirements ofGDC-19, specifically:

Enclosure

- 2

1. What impact will the compensatory actions have for any change in the quantity of unfiltered in-leakage that has been found as a result of testing or other acceptable means?

2. How will a change in the factors that affect control room dose that result in an increase in dose or a reduction in the available margin due to incremental increase in radioactive release associates with a design-basis accident (DBA) be impacted?

3. How will the acceptable temperature limits in the control room be supported?

4. What is the impact of a Loss of Offsite Power Transient on control room habitability?

The proposed one-time TS amendment would increase the Completion Time for Unit 2 TS 3.7.14 Condition A from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 216 hours0.0025 days <br />0.06 hours <br />3.571429e-4 weeks <br />8.2188e-5 months <br />.

Page E1-3 of the amendment request states:

This proposed change to the TS is similar to the previous 2A essential chiller emergency TS revision request for the 2A chiller to be inoperable for 14 days to repair water leakage into the refrigerant side and to replace the chiller hermetic compressor motor (SNC letter NL-10-1609 and NL-10-1623 dated August 18, 2010), for which Southern Nuclear Operating Company (SNC) received NRC approval on August 19,2010.

Page E1-5 of the amendment request states that the chiller overhaul planned maintenance activities require substantially more time than the 72-hour CT currently allowed by TS 3.7.14 and therefore such work is typically performed during refueling outages. It is further stated that the work is scheduled to be performed while online.

Page E1-6, of the amendment request states that the PM was originally scheduled for September 18, 2011 with a late date of March 11, 2013.

Page 2 of the amendment request cover letter states that a refueling outage is scheduled to start on March 10, 2013.

Page B 3.0-2 of Vogtle Units 1 and 2 TS Bases States:

The Completion Times of the Required Actions are also applicable when a system or component is removed from service intentionally. The reasons for intentionally relying on the ACTIONS include, but are not limited to, performance of Surveillances, preventive maintenance, corrective maintenance, or investigation of operational problems. Entering ACTIONS for these reasons must be done in a manner that does not compromise safety.

Intentional entry into ACTIONS should not be made for operational convenience.

Alternatives that would not result in redundant equipment being inoperable should be used instead.

RAI-2

Given that the August 2010 amendment was necessary to preclude an unplanned shutdown and that a refueling outage is scheduled to start on March 10,2013, it is not apparent to the

- 3 staff that the operational conditions at the plant in 2010 are similar to conditions at this time.

Please state why current operational conditions justify a one-time amendment.

RAI-3

Please demonstrate how the alternative to intentionally entering Condition A, that is, overhauling the system during the outage, is not possible.

In Section 2 "Detailed Description" the "Background" information includes the statement that:

The proposed technical specification change is for one-time maintenance activities requiring more than the 72-hour CT. VEGP has committed to Risk Informed Initiative 4b (reference letter NL-11-1297). It is expected that implementing Risk-Informed TS Initiative 4b will negate the need for future TS changes regarding ECWS CTs.

As of May 8,2012, the license amendment request (LAR) to implement 4b has not been submitted. Considering the fact that Vogtle is the pilot for the 4b initiative it is possible that issues can develop that would be difficult enough to resolve that the application could potentially be denied or withdrawn. Assuming that the 4b LAR is approved, it is possible that the Limiting Conditions for Operation CT for ECWS could be outside the scope of the Probabilistic Risk Assessment model and would not be included in the Risk Informed Completion Time program.

RAI-4

Based on the lack of an approved amendment for risk informed completion times, what is the justification for the ECWS amendment to be a one-time only request?

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