ML12241A292

Class 1E AC Meeting Slides August 29, 2012

ML12241A292
Person / Time
Site:	Callaway
Issue date:	08/29/2012
From:	Ameren Missouri
To:	Lyon C Plant Licensing Branch IV
Lyon C
References
TAC ME9233
Download: ML12241A292 (13)

Text

Overview Ameren Missouri Callaway Plant Class 1E Electrical Equipment Air-Conditioning System August 2010 2012

AMEREN MISSOURI CALLAWAY PLANT License Amendment Request 11-0010:

Class 1E Electrical Equipment A/C 2

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C Class 1E Electrical Equipment A/C trains (SGK05A/B) support DC Sources, Inverters, and Distribution Systems Currently governed by FSAR Section 16.7.13 (Callaways TRM equivalent)

LAR will discuss the following areas of need as well as industry interest:

TS 1.1 Definition of OPERABLE-OPERABILITY Application of LCO 3.0.6 Single failure criterion Room temperature rise analysis Recent Industry LERs and License Amendment Precedents 3

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C Definition of "A system, subsystem, train, component, or device OPERABLE- shall be OPERABLE or have OPERABILITY when it OPERABILITY: is capable of performing its specified safety function(s) and when all necessary attendant instrumentation, controls, normal or emergency electrical power, cooling and seal water, lubrication, and other auxiliary equipment that are required for the system, subsystem, train, component, or device to perform its specified safety function(s) are also capable of performing their related support function(s). [emphasis added]

The DC sources, inverters, and distribution systems supported by SGK05A/B have their own TS 3.8 LCOs.

The SGK05A/B trains do not currently have their own TS LCO, nor are they discussed in the TS 3.8 Specifications or Bases.

4

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C When a supported system LCO is not met solely due to an inoperable support system, LCO 3.0.6 allows the inoperability to be addressed only within the support system LCO if the support system has a TS LCO.

LCO 3.0.6 cannot be applied to non-TS support systems. Given the requirements of TS 3.8.7 (covering only one inoperable inverter), Callaway currently enters LCO 3.0.3 for one inoperable train of Class 1E electrical equipment A/C until room doors are opened.

Similarly, the rules of usage for TS Conditions stipulate that a single failure need not be postulated when operating with an inoperability covered by a TS Condition entry.

The single failure provision does not apply to non-TS LCOs.

5

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C ESF Switchgear Rooms 6

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C DC Switchgear and Battery Rooms 7

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C Proposed resolution is to add new TS LCO 3.7.20.

Conditions and Required Actions to be structured similarly to TS 3.7.10 (Control Room Emergency Ventilation System) and TS 3.7.11 (Control Room Air Conditioning System) with respect to Applicability and corresponding actions.

With one train (SGK05A or SGK05B) inoperable, recurring Required Action to verify room temperatures are within limits.

Directed cascade Note to enter LCO 3.8.4, 3.8.7, or 3.8.9 if room temperatures are not within limits. The limits will be based on manufacturer design/purchase specification requirements, EQ test results, and the EQ discussions in FSAR Sections 3.11(B).2.3 and 3.11(B).5.7 on control building electrical equipment and mild environments.

7-day A/C train restoration Completion Time (much less than 30-day CT for CRACS in TS 3.7.11).

8

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C GOTHIC 7.2(b) room temperature rise calculation for various door opening times and HVAC air delivery temperatures. Updated since 11/3/11 LAR to reflect current design heat loads and HVAC parameters. Final update prior to submittal.

This is not a loss of safety function issue. Opening room doors will allow the operable Class 1E electrical equipment A/C train to serve both trains of supported electrical equipment.

HVAC design temperature for delivered air flow is 60F. Calculation assumes a conservative initial temperature for all air and concrete. Additional equipment modeling still ongoing.

Room temperatures will stay below values that would challenge equipment operability for 30-day ESFAS loading if compensatory measures are implemented (e.g., opening room doors). Specified safety functions will be accomplished.

9

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C New structure of proposed TS 3.7.20 Condition A will address several NRC concerns on the 11/3/11 LAR. The rest of new TS 3.7.20 will remain the same.

Instead of specifying Required Actions to implement mitigating measures within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, the revised Condition A will specify Required Action A.1 to periodically verify room temperatures are within limits.

The room temperature limits will be located in FSAR Table 16.7-2 (consistent with their relocation under Callaway License Amendment 103 dated 10/20/95). The verification is accelerated from once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> under normal plant operation.

Prior to LA103 the Area Temperature Monitoring specification allowed a room to exceed the listed temperature limit by up to 30F for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> while invoking a Special Report. If the limit was exceeded by more than 30F, room temperature had to be restored within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> otherwise affected equipment was declared inoperable.

10

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C Callaway LER 2010-010-00 (ULNRC-05760 dated 3-31-11). LAR dated 11/3/11 withdrawn on 4/30/12.

We are aware of at least 3 other utilities that have filed LERs in 2012 and one other utility that has withdrawn an amendment request this year.

11

AMEREN MISSOURI CALLAWAY PLANT Class 1E Electrical Equipment A/C Precedents Joseph M. Farley Nuclear Plant Amendment 176/169 dated June 27, include: 2008: The NRC approved a non-STS LCO 3.7.19 entitled Engineered Safety Feature (ESF) Room Coolers. The NRC Safety Evaluation cited Vogtle Electric Generating Plant TS 3.7.14, Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System.

Kewaunee Power Station ITS Conversion Amendment 207 dated February 2, 2011: The NRC approved non-STS ACTIONS Notes in TSs 3.8.4, 3.8.7, and 3.8.9 that allow a 24-hour delay time prior to ACTION entry when the supported electrical equipment is inoperable solely due to non-functional room cooling.

TSTF-477-A Revision 3, Add Actions for Two Inoperable Control Room AC Subsystems, which revised the BWR STS to allow all control room A/C to be lost for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> as long as temperature was verified to be within limits every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Approved for Hope Creek in Amendment 191 dated February 8, 2012.

12

AMEREN MISSOURI CALLAWAY PLANT License Amendment Request 11-0010:

Class 1E Electrical Equipment A/C Questions?

13