ML13045A228

Request for Additional Information Revision to Technical Specification 3.7.14 Regarding Completion Time

ML13045A228
Person / Time
Site:	Vogtle
Issue date:	04/26/2013
From:	Martin R Plant Licensing Branch II
To:	Pierce C Southern Nuclear Operating Co
Martin R NRR/DORL/LPL2-1
References
TAC ME9666, TAC ME9667
Download: ML13045A228 (7)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 26, 2013 Mr. C. R. Pierce Regulatory Affairs Director Southern Nuclear Operating Company, Inc.

Post Office Box 1295, Bin - 038 Birmingham, AL 35201-1295

SUBJECT:

VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 SUPPLEMENTAL INFORMATION NEEDED FOR ACCEPTANCE OF LICENSE AMENDMENT REQUEST FOR TECHNICAL SPECIFICATION 3.7.14 COMPLETION TIME (TAC NOS. ME9666 AND ME9667)

Dear Mr. Pierce:

By letter dated September 26 2012, Southern Nuclear Operating Company, Inc. (SNC or the licensee), submitted a license amendment request (LAR) to revise the Completion Time (CT) for Technical Specification (TS) 3.7.14, "Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System." The LAR proposes to revise the CT for Condition A, "One ESF room cooler and safety-related chiller train inoperable," from "72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />" to "7 days OR 14 days for chiller overhaul maintenance."

The purpose of this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staff's acceptance review of this LAR. The acceptance review was performed to determine if there is sufficient technical information in scope and depth to allow the NRC staff to continue its detailed technical review. The acceptance review is also intended to identify whether the application has any readily apparent information insufficiencies in its characterization of the regulatory requirements or the licensing basis of the plant.

Consistent with Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), an amendment to the license (including the technical specifications) must fully describe the changes requested, and following as far as applicable, the form prescribed for original applications. Section 50.34 of 10 CFR addresses the content of technical information required.

This section stipulates that the submittal address the design and operating characteristics, unusual or novel design features, and principal safety considerations.

The NRC staff has reviewed your application and concluded that the information delineated in the enclosure to this letter is necessary to enable the staff to make an independent assessment regarding the acceptability of the LAR in terms of regulatory requirements and the protection of public health and safety and the environment.

Therefore, the NRC staff requests that SNC supplement the application to address the information requested in the enclosure within thirty (30) days of the date of this letter. This wi"

C. Pierce - 2 enable the NRC staff to begin its detailed technical review. Should the application be subsequently accepted for review, SNC will be advised of any further information needed to support the staff's detailed technical review by separate correspondence.

Sincerely,

,~ ; /J-p rr-jJi ~

LIi>5efnrM'irtin(Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION VOTGLE ELECTRIC GENERATING PLANT. UNITS 1 AND 2 SOUTHERN NUCLEAR OPERATING COMPANY DOCKET NOS. 50-424 AND 50-425 By letter dated September 26 2012, (Agencywide Documents Access and Management System Accession No. ML12271A229), Southern Nuclear Operating Company, Inc. (SNC orthe licensee), submitted a license amendment request (LAR) to revise the Completion Time (CT) for Technical Specification (TS) 3.7.14, "Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System." The proposed License Amendment Request (LAR) would increase the Completion Time for TS 3.7.14, Condition A, from "72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />" to "7 days OR 14 days for chiller overhaul maintenance."

1. Please provide a complete description of the engineered safety feature (ESF) Essential Chilled Water/Room Cooler System, as follows:

a. Provide a listing of all ESF room coolers/air handling units in the system. If Enclosure 6 to the LAR constitutes such a list, clarify that there is a total of 14 room coolers per train, with several room coolers serving multiple rooms, such as for example 2-1532-A7-002-000 and 2-1561-E7-001-000. Clarify why train 2B lists 13 room coolers whereas trains 1A, 1B, and 2A list 14 room coolers.

b. Provide piping and instrumentation drawings and floor location drawings showing each room cooler in the system. 1

c. The Bases for TS 3.7.14, states in part, the following:

The ESF room cooler and safety-related cht1ler system provides cooling to ESF equipment rooms during abnormal, accident, and post accident conditions. The ESF room coolers supplement the normal HVAC system in cooling certain rooms during normal operations. The essential chilled water system supplies chilled water to the cooling coils for all ESF room coolers and the Control Room Emergency Filtration System (CREFSj . ...

In addition to a manual start capability, automatic cooling of each ESF equipment room is initiated by three possible signals. All room coolers start upon receipt of a high temperature signal from the associated room.

Certain room coolers will start upon receipt of an equipment running 1 Given the current formatting and content of the Vogtle Generating Electric Plant. Unit Nos. 1 and 2 Updated Final Safety Analysis Report (USFAR), the staff noted considerable difficulty in identifying P&ID drawings with the UFSAR sections, even given the information in FSAR Table 1.7.1-1. The staff notes that the drawings referenced in FSAR Section 9.2.9.1.2 do not include drawings for (Unit 2). Please account for comparable drawings for Unit 2.

Enclosure

-2 signal or a safety injection (SI) signal. The equipment running signal is used to provide supplemental cooling for the normal ventilation system in some ESF equipment rooms. The high room temperature signal supplements the normal cooling system function and does not constitute a credited safety function. The SI signal or the equipment running signal is the credited safety function automatic start and will start only those ESF room coolers which are required to operate during an SI. In addition the safety-related chillers receive an automatic start from the Control Room Isolation (CRI) signal to provide chilled water to the CREFS. In addition, the containment spray pump room coolers start when the containment spray pumps start. Containment spray is actuated when containment pressure reaches the Hi-3 setpoint, which may occur following a loss of coolant accident or a steam line break.

This could imply that some of the room coolers in the ESF chiller/room cooler system are not required in response to accidents and transients as analyzed in the VEGP USFAR. For each of the room coolers/AHUs listed in response to item 1.a above, identify the UFSAR transient, accident analysis or condition for which its function is required. Also include identification of what start Signal each room cooler/AHU responds to.

d. Discuss the licensing basis mission time for the ESF chillerlroom cooler system.

If other coolers have a different mission time than the period of thirty days discussed in BASES 3.7.10 please discuss their mission time(s). Please discuss this with respect to each room cooler/AHU in the ESF chiller/cooler system.

2. The LAR states that "The ESF room coolers are designed to maintain the ambient air temperature below the environmental qualification rating of the ESF equipment served by the system." For each cooler, provide a discussion of the structure, system or component SSC protected by that cooler, its equipment qualification limit and the margin to that limit determined in the licensing basis accident analysis for both cases of the chiller being in operation and the chiller being inoperable during the extended CT as proposed by the LAR. Include the time after initiation of the event that the peak temperature occurs.

3. Compensatory Measures

a. Compensatory measures are proposed for the duration of TS 3.7.14 Condition A for overhaul maintenance. Are compensatory measures proposed for the extension to 7 days? As such, please describe these additional compensatory measures.

b. Discuss plans for the provision of a governing requirement for implementation of compensatory measures such as inclusion in the TS Bases, the UFSAR or in the TS Administrative Controls section.

c. Discuss the basis for the assumed effectiveness of the compensatory measures.

For example, regarding the placement of fans, discuss prior experience that

- 3 supports that the fans would have the desired result on room temperatures during abnormal, accident, and post accident conditions.

d. The last item in the Enclosure 4 Table discusses actions to be taken if the remaining ESF train is out of service. Discuss the action required by TS 3.7.14, Condition B in this case with respect to whether this represents a TS 3.0.3 condition.

4. Risk Assessment

a. Provide a list of the rooms addressed by the following statement "Room heat-up evaluations were performed for every room that contains PRA credited components." Identify any rooms with equipment having a safety function that are not evaluated by a heat-up calculation. How is the impact of heat-up determined in these rooms and what is the time to action? Also, identify the specific action and how long the action must be maintained.

b. Are rooms R-B61 , Unit 1 Train 1Band R-B18, Unit 2 Train 2B the only two rooms requiring the compensatory action of opening doors and placing fans?

c. Does the information provided for room R-B18 on page E1-11(as well as all other rooms) indicate that the results of the room heatup calculations - for abnormal, accident, and post accident conditions - are that compensatory measures must be implemented by 11.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> into the event? Without recovery of room cooling how long must the compensatory measures be maintainted?

5 No Significant Hazards Consideration Determination (NSHC)

The FSAR 9.2.9.1.1.1, Safety Design Basis C, discusses the loss of ESF switchgear and the emergency safeguard feature pumps. Please discuss any change in the probability of a loss of function for these components due to the proposed CT extension and its impact on the NSHC determination.

6 Technical Specifications The LAR would increase the Completion Time for 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 7 days or 14 days for chiller overhaul maintenance. Page E1-3 of the LAR 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 E 1-7 of the amendment request states that the chiller overhaul planned maintenance activities require substantially more time than CT currently allowed by TS

- 4 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.

On December 19, 2011, the licensee submitted an amendment request for a similar change (ADAMS Accession No. ML113550489). Page E1-6 of the December 2011 amendment request states that a chiller overhaul was originally scheduled for September 18, 2011 with a late date of March 11, 2013 and that the overhaul was deferred from the fall 2011 outage. Page 2 of the December 2011 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 6.1: Given that the August 2010 amendment was necessary to preclude an unplanned shutdown and that the chiller overhaul was deferred in the fall 2011 outage and that a refueling outage was completed in the Spring of 2013, it is not apparent to the staff that the operational conditions at the plant in 2010 are similar to conditions at this time. Please state why the current operational conditions justify this amendment.

RAI 6.2: Please demonstrate how the alternative to intentionally entering Condition A, that is, overhauling the system during an outage, is not possible.

ML13045A228 OFFICE DORLlLPL2-1/PM DORLlLPL2-1/LA DSS IITSB/BC DSS/SBPB/BC NAME RMartin SFigueroa RElliot GCasto DATE 04/23/13 02/15/13 02/26/13 03/13/13 OFFICE DSS/SCVB/BC DRAlAPLAlBC DORLlLPL2-1/BC NAME RDennig DHarrison RPascarelli DATE 02/22/13 03/12/13 04/26/13