ML18317A086
| ML18317A086 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 11/15/2018 |
| From: | Klos L Plant Licensing Branch IV |
| To: | Sawatzke B Energy Northwest |
| Klos L, 301-415-5136 | |
| References | |
| EPID-L-2018-LRM-0070 | |
| Download: ML18317A086 (26) | |
Text
Presubmittal Meeting:
License Amendment Request for Licensing Basis Change to Emergency Chilled Water System November 15, 2018
Participants Alex Javorik - Vice President, Engineering Denise Brandon - Manager, Design Engineering (presenter)
Richard Garcia - Principal Engineer, Licensing (presenter)
Desiree Wolfgramm - Supervisor, Licensing Dwayne Gregory - Principal Engineer, Design Engineering Mechanical 2
Agenda Purpose Proposed Change
Reason for Request
System Description Licensing Basis License Amendment Request (LAR) Approach Conclusion LAR Submittal Schedule Questions 3
Purpose Present approach for LAR to revise the licensing basis to credit the Emergency Chilled Water (CCH) system with the safety-related function of maintaining the Main Control Room (MCR) equipment qualification temperature limit Outline Energy Northwests (EN) evaluation approach Discuss regulatory requirements Summarize technical and regulatory conclusions supporting the proposed change Identify proposed LAR schedule Discuss NRC questions 4
Proposed Change Credit the CCH system with the safety-related function of maintaining the MCR at the equipment qualification limit of 104°F or lower during and following design bases events Encompasses considerations for personnel habitability (85°F)
Requires normal system alignment change but no modifications to the plant No Technical Specification (TS) changes Final Safety Analysis Report (FSAR), TS Bases, and Licensee Controlled Specifications (LCS) Bases changes to clarify the design and licensing basis - provided with LAR for information only 5
Reason for Request
Current Licensing Basis Standby Service Water (SW) system is currently credited to maintain control room temperature within limits for equipment operability ( 104°F)
CCH system credited to meet design condition of 85°F for personnel habitability 6
Reason for Request
Capability of one division of SW to maintain MCR 104°F is limited Future modifications to MCR equipment are planned that could increase MCR heat load, potentially exceeding capability of SW Capability of SW to maintain the MCR 85°F is limited during the warmer months Recapture significant heat load margin using CCH system Establish a well defined licensing basis for the CCH system cooling the MCR 7
Reason for Request
Proposed change requires NRC approval 10 CFR 50.59 evaluation determined the proposed change results in a more than minimal increase in the likelihood of occurrence of a malfunction of a structure, system or component (SSC) important to safety due to an increase in the number of active components required to perform the design function of cooling the MCR 8
Current System Description Temperature control for MCR provided by the Control Room Air Conditioning (AC) System System designator is the Radwaste Mixed Air (WMA) system WMA system consists of two independent, redundant subsystems Each subsystem contains an air handling unit with two cooling coils (one normal and one emergency),
a control room recirculation fan, air filter, ductwork, dampers, and instrumentation & controls 9
Current System Description Current system alignment:
Division 1 emergency cooling coil aligned to SW Division 2 emergency cooling coil aligned to CCH Requires manual start of CCH chiller (Division 2) 10
Current System Description CCH Condenser CCH Evaporator Emergency Cooling Coil Figure 1 - Division 1 Normal Alignment to SW (Current Configuration) 11
Proposed System Description System alignment with proposed change:
Division 1 emergency cooling coil aligned to CCH Division 2 emergency cooling coil remains aligned to CCH Requires manual start for either CCH chillers (the division being used) 12
Proposed System Description CCH Condenser CCH Evaporator Emergency Cooling Coil Figure 2 - Division 1 Normal Alignment to CCH (Proposed Configuration) 13
Licensing Basis History Original licensing basis stated safety-related SW system capable of maintaining MCR temperature 104°F for equipment performance NRC staff expressed concern with 104°F for personnel EN committed to provide redundant, Seismic Category I environmentally qualified chillers for MCR AC Operating License granted with License Condition 2.c.(21) that required chillers to be operable prior to May 31, 1984 14
Licensing Basis Current Licensing Basis SW system credited to maintain control room temperature within limits for equipment operability
( 104°F)
CCH system credited to meet design condition of 85°F for personnel habitability 15
Licensing Basis TS 3.7.4, Control Room Air Conditioning (AC)
System, requires two operable subsystems Limiting Conditions for Operation (LCO) and Action Statements same as NUREG-1434, Standard Technical Specifications - General Electric Plants (BWR/6)
TS Bases 3.7.4 discusses use of either SW or CCH to cool the emergency coil 16
Licensing Basis LCS 1.7.2, Control Room Emergency Chilled Water System, requires two operable CCH subsystems If a CCH subsystem is inoperable, either:
Enter Actions for an inoperable Control Room AC System (TS 3.7.4)
OR Verify SW capable of maintaining MCR temperature of 85°F 17
Licensing Basis 18
Licensing Basis Proposed change results in changes to clarify use of CCH system for MCR equipment qualification limit in:
FSAR Chapter 9 TS Bases 3.7.4 LCS Bases 1.7.2 Markups attached to LAR for information only 19
LAR Approach Technical Evaluation developed using Standard Review Plan (SRP) review areas as guidance SRP 9.2.7, Chilled Water System SRP 9.4.1, Control Room Area Ventilation System Regulatory Evaluation developed using General Design Criteria (GDC) and applicable regulations 20
LAR Approach Technical Evaluation divided into two areas:
Review areas not affected by the proposed change Review areas that are affected by the proposed change and require evaluation 21
LAR Approach SRP review areas met by CCH system:
Equipment procured and maintained safety-related Seismic Category I and housed within Seismic Category I structure Redundant and meets Single Active Failure Powered by 1E safety buses (backed by emergency diesel generators)
Environmentally qualified CCH cooled by safety-related SW system CCH and SW systems are appropriately designed for testing and inspection Internal and external flooding not impacted 22
LAR Approach SRP review areas evaluated for CCH System:
Ability to maintain MCR temperature Protection from internally generated missiles Review for Moderate Energy Line Cracks Ability to isolate and function under fires, failures, and malfunctions Changes to manual actions for Post Fire Safe Shutdown evaluated as acceptable under requirements of License Condition 2.c.(14)
Evaluations were completed for these areas, which show acceptance criteria is met 23
Conclusion LAR to revise the licensing basis to credit the CCH system not only for personnel habitability but to include the safety-related function of maintaining the MCR equipment qualification temperature limit Technical Evaluation based on review areas of SRP 9.2.7 and 9.4.1 and demonstrates CCH system design and operation supports safe plant operation Regulatory Evaluation focused on GDC and applicable regulations demonstrates that proposed change meets applicable requirements No TS changes - FSAR, TS Bases and LCS Bases markups provided with the LAR for information only 24
LAR Submittal Schedule 11/15/18 - Presubmittal meeting 01/31/19 - Target LAR submittal 25
NRC Questions 26