ML16236A095

Callaway Plant and Wolf Creek Generating Station - August 25, 2016, Class 1E Electrical Equipment Air Conditioning System Pre-Application Meeting (CAC No. MF8136)

ML16236A095
Person / Time
Site:	Wolf Creek, Callaway
Issue date:	08/25/2016
From:	Ameren Missouri
To:	Office of Nuclear Reactor Regulation
Lyon C F, 415-2296
References
CAC MF8136
Download: ML16236A095 (28)

Text

CALLAWAY PLANT WOLF CREEK GENERATING STATION Class 1E Electrical Equipment Air Conditioning (A/C) System Pre-Application Meeting August 25, 2016 AGENDA *Introductions

• Purpose *Class 1E Electrical Equipment A/C System Description

• Background

• Proposed Technical Specification (TS)

• Evaluation Basis

• Precedent

• Planned Modifications

• Schedule 2 PURPOSE *Problem statement:

-A loss of a Class 1E electrical equipment A/C train requires the associated electrical TS LCO's to be declared not met, which requires entry into LCO 3.0.3

• Resolution

-License amendment request to incorporate the Class 1E Electrical Equipment A/C System into the TS -Planned modifications developed for either (i.e., one)

A/C train to cool both trains of electrical equipment

-Will minimize challenges to plant systems and to the operators, and will facilitate preventive maintenance activities 3

CLASS 1E ELECTRICAL EQUIPMENT A/C SYSTEM DESCRIPTION

• Design/Licensing Basis

-Design basis function is to provide a suitable atmosphere for the Class 1E electrical equipment during all modes of plant operation, including loss of preferred power and post

-accident operation

-System is safety related and required to function following a DBA to cool components required to achieve and maintain the plant in a post

-accident safe shutdown condition

-Two independent trains operated in continuous recirculation mode maintain room temperatures environmental conditions

-One train (with implementation of mitigating actions) 104°F for maximum accident/faulted environmental conditions 4

CLASS 1E ELECTRICAL EQUIPMENT A/C SYSTEM DESCRIPTION 5 *Equipment Description Cooling Capacity: 30 tons oOne train capable of cooling both trains of electrical equipment rooms Direct expansion refrigeration circuit with evaporator coils in air handling unit Heat rejected through condenser to Essential Service Water System Recirculation only

- no outside air capabilities

CLASS 1E ELECTRICAL EQUIPMENT A/C SYSTEM DESCRIPTION 6 2016 Level

CLASS 1E ELECTRICAL EQUIPMENT A/C SYSTEM DESCRIPTION 7 SECURITY-RELATED INFORMATION

- WITHHOLD UNDER 10 CFR 2.390

CLASS 1E ELECTRICAL EQUIPMENT A/C SYSTEM DESCRIPTION 8 2000 Level

CLASS 1E ELECTRICAL EQUIPMENT A/C SYSTEM DESCRIPTION 9 SECURITY-RELATED INFORMATION

- WITHHOLD UNDER 10 CFR 2.390

BACKGROUND

• Operational issues identified for a loss of one train of cooling

-TS 1.1 Definition of OPERABLE

-OPERABILITY

-Application of LCO 3.0.6

-Single failure criterion

• Class 1E electrical equipment A/C trains support the DC Sources, Inverters, and Distribution Systems -Not addressed in TSs or TS Bases 10 BACKGROUND

• On loss of one train of cooling, the associated supported Class 1E electrical equipment is declared inoperable

-TSs LCOs 3.8.4, 3.8.7 and 3.8.9 are declared not met due to the inoperable Class 1E electrical equipment

-LCO 3.0.3 entered due to no Condition in TS 3.8.7 for two inoperable inverters

• The Operability Determination process is entered and compensatory measures are established for declaring Class 1E electrical equipment OPERABLE/degraded 11 BACKGROUND

• The Class 1E Electrical Equipment A/C System is a support system similar to Component Cooling Water (CCW) System (ISTS 3.7.7) and Service Water System (ISTS 3.7.8) [Essential Service Water System for WCGS and Callaway Plant]

These two systems screened in under Criterion 3 as a support system to various systems which are assumed to function to mitigate various DBAs.

12 BACKGROUND

• Satisfies Criterion 3 in 10 CFR 50.36(c)(2)(ii)

-"A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a Design Basis Accident or Transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier." -Discussion of Criterion 3 in NRC Final Policy Statement on TS Improvements states, in part:

"It is the intent of this criterion to capture into Technical Specifications only those structures, systems, and components that are part of the primary success path of a safety sequence analysis. Also captured by this criterion are those support and actuation systems that are necessary for items in the primary success path to successfully

function." [emphasis added

] 13 PROPOSED TECHNICAL SPECIFICATION 14 PROPOSED TECHNICAL SPECIFICATION 15 PROPOSED TECHNICAL SPECIFICATION

• Approval of TS

-Allows use of TS Conditions/Required Actions and associated Completion Times in lieu of Operability Determination (OD) Process or entry into LCO 3.0.3 for a loss of one train of cooling

-Minimizes challenges to plant systems and to the operators, and will facilitate preventive maintenance activities 16 EVALUATION BASIS *GOTHIC Calculation (Temperature Analysis)

-GOTHIC model developed

-Evaluates capability of one cooling train to supply adequate area cooling for both trains of electrical equipment with mitigating actions

-Calculation assumes loss of one cooling train, LOCA heat loads, and an initial room temperature of 80ºF

-Calculation assumes an acceptance value of 104

°F room temperature based on the accident/faulted environmental conditions 17 EVALUATION BASIS *Calculation Sensitivity Case Results

-Room temperatures remain less than 104ºF for 30

-day duration *Mitigating Actions (TS 3.7.20, Required Action A.1) -Start single train of recirculating fans corresponding with OPERABLE cooling train 18 PLANNED MODIFICATIONS

• Planned modifications

- promote circulation of cool air from one OPERABLE A/C train to maintain temperatures in both trains of electrical equipment rooms

-2016 Level:

oOne seismically qualified recirculating fan per train powered by Class 1E power ducted across the hallway with fire and control dampers oInstallation of fire dampers between rooms

-2000 Level: two seismically qualified recirculating fans per train powered by Class 1E power

-LED lighting in Class 1E electrical equipment rooms for heat load

reduction 19 PLANNED MODIFICATIONS SGK05A Single Unit Operation

- 2016 Level 20 PLANNED MODIFICATIONS 21 SECURITY-RELATED INFORMATION

- WITHHOLD UNDER 10 CFR 2.390

22 PLANNED MODIFICATIONS SGK05A System Operation

- 2000 Level

23 PLANNED MODIFICATIONS SECURITY-RELATED INFORMATION

- WITHHOLD UNDER 10 CFR 2.390

PLANNED MODIFICATIONS

• Operator Actions

-Operator Actions would be taken in the Emergency Operating Procedures (EMGs) to shed specified loads IF a DBA (LOCA) were to occur during single A/C train mode of operation

-IF an A/C train were to fail subsequent to a DBA (LOCA), then plant operators would continue plant shutdown/cooldown utilizing the OPERABLE A/C train 24 PRECEDENT

• Farley Nuclear Plant Amendment 176/169 dated June 27, 2008: The NRC approved non

-STS LCO 3.7.19, "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."

-The NRC acknowledged in the Safety Evaluation (Section 3.0) the use of procedural actions taken upon declaring the LCO not met and entry into the applicable Condition/Required Action to assure the compensatory measure is taken 25 PLANNED SCHEDULE

• Submit simultaneous License Amendment Requests before end of December 2016

• Planned modifications will be implemented online and during refueling outages

- Spring 2018 (WCGS) and Fall 2017 (Callaway Plant)

• Approval of LARs requested by March 2018 26 SUMMARY *Planned modifications ensure one Class 1E electrical equipment A/C train is capable of providing area cooling for both trains of Class 1E electrical equipment with minimal mitigating actions

• Proposed TS results in use of TS Conditions/Required Actions and associated Completion Times in lieu of Operability Determination (OD) Process or entry into LCO 3.0.3 for a loss of one train of cooling

• Proposed TS and planned modifications will minimize challenges to plant systems and to the operators, and will facilitate preventive maintenance activities 27 QUESTIONS

QUESTIONS ?