PNL-5722

Technical Evaluation Report

Operating Experience and

Aging Assessment of ECCS

Pump Room Coolers

D. E. Blahnik

R. L. Goodman

October 1986

Prepared for

U. S. Nuclear Regulatory Commission

under Contract DE-AC06-76RLO 1830

NRC FIN B2865

Pacific Northwest Laboratory

Operated for the U.S. Department of Energy

by Battelle Memorial Institute

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PLEASE RETURN TO:

A. B. JOHNSON, JR.

PSL/1174/3000

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PNL-5722

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TECHNICAL EVALUATION REPORT

OPERATING EXPERIENCE AND AGING ASSESSMENT

OF ECCS PUMP ROOM COOLERS

Phase I Study

D. E. Blahnik.

R. L. Goodman

October 1986

Prepared for

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

under Contract DE-AC06-76RL0 1830

NRC FIN B2865

Pacific Northwest Laboratory

Richland, Washington 99352

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DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the

United States Government. Neither the United States Government nor any agency

thereof, nor Battelle Memorial Institute, nor any of their employees, makes any

warranty, expressed or Implied, or assumes any legal liability or responsibility for

the accuracy, completeness, or usefulness of any information, apparatus, product,

or process disclosed, or represents that its use would not infringe privately owned

rights. Reference herein to any specific commercial product, process, or service by

trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States

Government of any agency thereof, or Battelle Memorial Institute. The views and

opinions of authors expressed herein do not necessarly state or reflect those of the

United States Government or any agency thereof, or Battelle Memorial Institute.

PACIFIC NORTHWEST LABORATORY

operated by

BATTELLE

for the

UNITED STATES DEPARTMENT OF ENERGY

under Contract DE-AC06-76RLO 1830
ABSTRACT

This report provides a preliminary aging assessment of safety-related

room coolers for the emergency core cooling system (ECCS) pump rooms in nuclear

plants. The assessment conforms to the NRC Nuclear Plant Aging Research (NPAR)

Program strategy. The assessment is based on limited information obtained

through public and private data bases, equipment vendors, utility contacts,

literature searches, and expert opinion.

The ECCS pump room cooler system description was determined by review of

FSARs and vendor supplied information. Data from LERs, review of maintenance

requests at a reactor plant, and discussions with personnel that have utility

maintenance experience were used to determine the operating experience of pump

room coolers. Failure modes, causes, frequency rates, and methods of detection

are summarized from the operating experience. Maintenance actions and modifications needed as a result of the operator experience are addressed to the

extent that information was available. Operational stressors are summarized,

manufacturer recommendations for maintenance and surveillance are listed, and

aging and service-wear monitoring are briefly evaluated.

* iii
ACKNOWLEDGMENTS

The authors appreciated the support of the NRC Nuclear Plant Aging

Research Program manager, Jit Vora, in implementing and completing this study.

The help of A. B. Johnson, Jr., the PNL project manager, was also instrumental

in completing the study.

A number of individuals assisted in collecting data, providing experienced

opinions, making assessments and preparing and reviewing the report. The

assistance was appreciated from the following individuals: *Mano Subudhi,

Brookhaven National Laboratory; George Murphy and Ray Borkowski, Oak Ridge

National Laboratory, James Cleveland, SEA Consultants, Inc.; Dennis Pawlak,

Ellis and Watts; Hunter McCluer and Mike Kippes, WPPSS; and John Vause, Robert

Gruel, and Ben Johnson of Pacific Northwest Laboratory.

The assistance of David Hillard for editing and Lila Valdez and Pat Young

for typing the report is also gratefully acknowledged.

v
EXECUTIVE SUMMARY

Pacific Northwest Laboratory conducted this review of pump room cooler

operating experience under the U.S. Nuclear Regulatory Commission's Nuclear

Plant Aging Research Program. The purpose of Phase I of this study is to make

an interim aging assessment of emergency core cooling system (ECCS) pump room

coolers based on actual operating experience data.

The ECCS pump room coolers prevent excessive temperatures in the room

where the ECCS pumps are operating. The ECCS pumps are used in nuclear plants

to provide reactor core cooling and primary coolant inventory makeup during

emergencies such as a LOCA. The ECCS pumps and pump room coolers are both

important safety-related equipment.

Pump room coolers were selected for the aging assessment because of safety

concerns associated with the failure of a pump room cooler to perform its

designated function. This study was performed to determine whether aging and

service-wear effects substantially reduce safety margins for room cooling.

The equipment boundary selected for examination in this study is defined

as the room cooler system components within the fan/coil enclosure. Most room

coolers are quite similar within this boundary. Because elevated temperatures

and humidities may occur in the pump rooms, electrical components within the

boundary are usually limited to the drive motor and thermostats. The interfacing motor controls and other electrical and electronic components are

located in the central motor control centers, where environmental conditions

are more closely controlled. The water supply for the cooling coils and the

pumps and valves that control the water flow are usually located in other

areas.

Room cooler operating experience data obtained during this study suggest

that pump room cooler operation has been relatively trouble-free. Room cooler

fan motors are subject to more stressors than any other major component, but

available data indicate that failure rates have been low. Not unexpectedly,

the v-belts, a minor component, fail most frequently and cause the most

maintenance problems.

Vibration is the largest cause of rapid aging in room coolers. The v-belt

fan drives seem to be more prone to cause vibration than direct fan drives, but

data are insufficient to substantiate this.

Licensee event report (LER) data indicate that room cooler failures are

rare. Room cooler failures often develop outside the room cooler boundary in

the motor control center electrical components or in the service water system

chiller, valves, or pumps. These components are subjects of aging assessments

in other NPAR Program tasks, and therefore no duplication of effort is being

made. Motors are also being assessed in a separate task.

The lack of available data made it difficult to base the interim aging

assessment of ECCS pump room coolers on operating experience. Part of the

vii
reason for this lack of data is that ECCS pump room coolers were not incorporated into early plant designs. An increasing number of the plants that have

come on line since 1972 have room coolers. Most plants coming on line in the

near future will incorporate ECCS pump room coolers. Limited operating experience and largely trouble-free operation have resulted in a relatively small

data base relating to room cooler service history.

Interim recommendations for minimizing the rate of room cooler aging are

to follow manufacturer recommendations for maintenance and to monitor vibration, temperature, and sound, where practical. It is recommended that the

aging, wear, and performance of pumps, valves, service water chiller, and other

components associated with room cooler systems be investigated by the existing

NPAR tasks to which the components are related. It is further recommended that

Phase II of the ECCS pump room cooler aging assessment be delayed until NPAR

systems assessments now underway have further addressed the significance of

room coolers and more extensive operating experience is available.

viii
CONTENTS

ABSTRACT ............................ *.*.*.*...........****.*..*......*.. iii

ACKNOWLEDGMENTS ....................... * * * * * * * .......... .....* v

EXECUTIVE SUMMARY .......... *** ********* ********...... vii

ACRONYMS AND ABBREVIATIONS ................... .. .................. ..... xiii

1.0 INTRODUCTION ....................... *...*.*..*. ************** *** 1.1

2.0 PUMP ROOM COOLER SYSTEM DESCRIPTION ......... ..................... 2.1

2.1 ROOM COOLER DESIGN .... .................................. o........... 2.3

2.2 ROOM COOLER DESIGN SPECIFICATIONS ............ ................ 2.5

2.3 PRINCIPAL TYPES AND USES OF ROOM COOLERS IN BWRS AND PWRS ... 2.8

2.4 EQUIPMENT BOUNDARY ......................... .. ....... 2.11

2.5 FUNCTIONAL REQUIREMENTS ............ o.......................... 2.11

3.0 DATA SOURCES FOR PUMP ROOM COOLER OPERATING EXPERIENCE ........... 3.1

3.1 LICENSEE EVENT REPORTS (LERs) ......................... o.....o. 3.1

3.2 IN-PLANT RELIABILITY DATA SYSTEM (IPRDS) ..................... 3.1

3.3 NUCLEAR POWER EXPERIENCE (NPE) .............................. 3.2

3.4 VENDOR SURVEY ..................... ....... 3.2

3.5 UTILITY CONTACTS ............................................ 3,2

3.6 PUBLISHED REPORTS ........................................... 3.2

3.7 ONGOING RESEARCH .. o ......... 3.2

3.8 EXPERT OPINION ....................................... 3.2

4.0 TESTING ........................ .................................. 4.1

5.0 OPERATING EXPERIENCE ..................... ; ....... 5.1

5.1 FAILURE MODES AND CAUSES .................... o................. 5.1

5.2 FREQUENCY OF FAILURES ....... o ................. ..... ; 5.4-

ix
5.3 METHODS OF DETECTION ........................

5.4 MAINTENANCE ACTIONS .........

5.5 MODIFICATIONS RESULTING FROM FAILURES .......................

6.0 SUMMARY OF OPERATIONAL STRESSORS .....................

6.1 MECHANICAL STRESSORS ................................

6.1.1 Fan Motor ............................................

6.1.2 Coupling .............................................

6.1.3 V-Belts and Sheaves ..................................

6.1.4 Fan ..................................................

6.1.5 Cooling Coil .........................................

6.1.6 Housing ..............................................

6.2 THERMAL STRESSORS .......................................

6.2.1 Fan Motor ............................................

6.2.2 V-Belts ........... ..........................

6.2.3 Fan ..................................................

6.3 ENVIRONMENTAL STRESSORS ......................................

6.3.1 Fan Motor ............................................

6.3.2 V-Belts ..............................................

6.3.3 Fan ...................................

6.3.4 Cooling Coil .............................

6.4 ELECTRICAL STRESSORS

6.4.1 Fan Motor ................................

6.5 RADIATION STRESSORS ........................

6.5.1 Fan Motor .............................................

6.6 CHEMICAL STRESSORS ..........................................

6.6.1 Fan Motor ............................................

5.4

5.5

5.5

6.1

6.1

6.1

6.1

6.1

6.3

6.3

6.3

6.3

6.4

6.4

6.4

6.4

6.4

6.5

6.5

6.5 [ 6.5

6.5 i

6.5 i.

6.6

6.6

6.6

6.6

x
6.6.2 Motor and Fan Bearings ...............................

6.6.3 Cooling Coil .........................................

6.7 PRINCIPAL VIBRATION CAUSES IN ROOM COOLERS

7.0 MANUFACTURERS RECOMMENDATIONS FOR MAINTENANCE AND SURVEILLANCE

8.0 AGING AND SERVICE-WEAR MONITORING AND ASSESSMENT ................

9.0 EXPERT OPINION ..............

).0 CONCLUSIONS AND RECOMMENDATIONS .............

10.1 RECOMMENDATIONS ....................................

10.2 FUTURE WORK ..............................

1.0 REFERENCES ............

PPENDIX A - GENERAL BEHAVIOR OF AIR-COOLED EQUIPMENT

PPENDIX B - LIST OF FSARs/PSARs REVIEWED ........

6.6

6.6

6.7

7.1

8.1

9.1

10.1

10.2

10.2

11.1

A.1

B.1

4.

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xi
FIGURES

1.1 NPAR Program Strategy ... ....................................... 1.2

2.1 ECCS Pump Room Cooler Functional Design .......................... 2.2

2.2 ECCS Pump Room Cooler ............................................ 2.5

2.3 ECCS Pump Room Cooler Layout .................. ......... * 2.6

2.4 Examples of Building Ventilation and Room Cooler Concepts .... .... 2.9

2.5 Components Located Inside and Outside the ECCS Pump Room

Cooler Boundary .................................................. 2.12

5.1 ECCS Pump Room Cooler LER Review Summary ......................... 5.2

TABLES

2.1 Typical Materials Used in Component Construction ................. 2.4

6.1 Primary Stressors and Aging Mechanisms--Areas of Concern Within

the Room Cooler Boundary ......................................... 6.2

xii

. .. .. I . ......... 1_7 ..... . . . . .. - . . ; - - --: ... : .7. ' , . .:, . . .. . .. . . .. . .-. .- - .7T --
ACRONYMS AND ABBREVIATIONS

BTU - British thermal units

BWR - boiling water reactor

cfm - cubic feet per minute

DBE - design basis earthquake

ECCS - emergency core cooling system

ESF - engineered safety features

FSAR - Final Safety Analysis Report

gpm - gallons per minute

HP - horse power

HPCI - high-pressure coolant injection

h - hour

HVAC - heating, ventilation and air conditioning

Hz hertz (cycles per second)

IEEE - Institute of Electrical and Electronic Engineers

INPO - Institute for Nuclear Power Operations

IPRDS - In-Plant Reliability Data System

LER - Licensee Event Report

LOCA - loss of coolant accident

LPCI - low-pressure coolant injection

MCC - motor control center

NPAR - Nuclear Plant Aging Research

NPE - Nuclear Power Experience

NRC - Nuclear Regulatory Commission

NSIC - Nuclear'Safety Information Center

JRNL - Oak Ridge National Laboratory

PSAR - Preliminary Safety Analysis Report

PWR - pressurized water reactor

1HR - residual heat removal

xi.

xiii~~~~~~~~~ .'.
1.0 INTRODUCTION

Emergency core cooling system (ECCS) pumps are used in nuclear plants to

ovide reactor core cooling and primary coolant inventory makeup during emerncies such as a loss-of-cooling accident. Pump room coolers are often used

maintain room ambient air temperatures within acceptable limits for the pump

tors. The coolers and their related heat exchanger systems also greatly

duce the building heat accumulation and minimize the amount of air that must

exhausted to the environment through filtered systems.

The Nuclear Plant Aging Research (NPAR) Program selected ECCS pump room

olers for an aging assessment because of safety concerns associated with the

ilure of coolers to perform their designated function (Davis et al. 1985).

e present study was performed to determine whether aging and service-wear

fects substantially reduce safety margins for room cooling. Phase I makes an

terim assessment based on actual operating experience.

Pacific Northwest Laboratory (PNL) performed this study for the Nuclear

gulatory Commission (NRC) Office of Research, Division of Engineering Techlogy, Electrical Engineering Branch as part of the NPAR Program. The NRC

tablished the NPAR Program .as a comprehensive research program to resolve

sues related to the impact of aging and service wear of equipment and systems

plant safety at commercial reactor facilities (US NRC 1985). The NPAR goals

garding component and system aging are:

* to identify and characterize aging and service-wear effects that, if

unchecked, could cause degradation of structures, components, and

systems and thereby impair plant safety

* to identify methods of inspection, surveillance, and monitoring--or

of evaluating residual life--of structures, components, and systems

that will ensure timely detection of significant aging effects prior

to loss of safety function

* to evaluate the effectiveness of storage, maintenance, repair, and

replacement practices in mitigating the effects of aging and diminishing the rate and extent of degradation caused by aging and service

wear.

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, accomplish these-goals, the NPAR program strategy illustrated in Figure 1.1

being followed. The major program steps/deliverables are shown in circles,

'd the work activities required to accomplish these activities are provided in

:e boxes. The Phase I steps covered in this study-are indicated by crossitching in the applicable circles and boxes.

This report contains a description of pump room cooler systems, an

:planation of sources for operating experience data, a listing of typical

!sting procedures, an analysis of operating experience, and a summary of

1.1

, . . . . .. :
operational stressors. These sections are followed by sections on manufacturer

recommendations for maintenance and surveillance, aging and service-wear

monitoring and assessment, expert opinion, and conclusions and recommendations.

1.2
Considerations

for

IP US. NPROS. Es.IInteractions Entensions

NPE. etc. EPractical. Colt Interactions Value/ with Code

Experts' National Standards Effective with Impact and

Krnowtedge \ and Inspection Performance Industry Study Standards

es Indicators Committees

Acceptac

Guidetia

Maintennc

Define \ \ v > \ Aging opefednet Chafeeretisation 4 Asessment and | t GuideiinGuideeine

for

Service Life

Predictions

Equipm~oef~nt \ EXP~tlS \ \Analrsis of ol \ nte*im Aeent Comprehensive Aging Apptlicaton

Studnr l :\Knowtedge Operating Aging Charssctsion Asement and Guideftin |

Aging Pra cti e parae ten s M ntenance Analyses tot l > Ongoing 'Artificial Accelerated\ MM I I I I 

: Phase < I ' | Phase i on

.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FIGURE 1.1. NPAR Program Strategy

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2.0 PUMP ROOM COOLER SYSTEM DESCRIPTION

Older nuclear plants (15 to 25 years) do not have ECCS pump room coolers.

Some intermediate-aged plants (5 to 15 yeas old) have room cooler systems,

while others do not. New plants (O - 5 years old) for all four of the U.S.

reactor suppliers have pump room coolers with large cooling capacities to

handle the higher power capacities of the newer reactors.

Designs for pump room cooling systems vary greatly among plants. Coolers

are often interlocked with pumps and operate only when the pumps operate. Some

coolers operate only during a loss-of-cooling while others are left on continuously. Other coolers operate only when room temperatures exceed the thermostat

high setpoint.

The ECCS pump roum coolers prevent excessive temperatures in the room

where the ECCS pumps are operating. The ECCS pumps are used in nuclear plants

to provide reactor core cooling and primary coolant inventory makeup during

emergencies such as a LOCA. The ECCS pumps and pump room coolers are both

important safety-related equipment.

The ECCS pump room coolers are basically safety-related fan coil units

comprised of a steel housing containing an inlet opening, finned cooling coils,

a fan-motor unit, and an outlet opening (Figure 2.1). Sometimes air inlets and

outlets have louvers that can be adjusted to distribute and control air flow.

Sometimes filters are placed in the inlet side.

i; The ECCS pump room cooling system includes the pump room cooler unit

itself, plus a coolant supply system, motor control center and power supply,

and other items, such as a room thermostat, manual switch, drain, and venti-

,. lation dampers.

ECCS room coolers are located in individual rooms housing the following

types of ECCS pumps:

* high-pressure safety injection, charging, and core spray pumps.

* intermediate-pressure safety injection pumps.

* low-pressure safety injection and core spray pumps.

* residual or decay heat removal, pumps.

* containment spray pumps.

Pump names vary with the vintage and supplier of the individual plants. The

ECCS pumps--sometimes called engineered safety feature (ESF) pumps--are safetyrelated equipment that perform an important function during a LOCA. The various ECCS pumps provide the primary cooling water system with high-pressure

water injection for small-break LOCAs, low-pressure (high flow rate) water

injection for large-break LOCAs, and long term core cooling once the reactor is

depressurized and stable. The containment spray function also helps to depressurize and cool the containment and mitigate the spread of contamination. The

ECCS pumps sometimes serve multiple purposes and need to function in normal

operating and shutdown situations as well as emergency situations.

.2.1
Drive Motor*(230/460 Volt AC.

Power From Motor Control Center*

and Emergency Diesel Generator*

Backup)

Louvers (Optional)

Belt Driven or

Direct Drive

Fans

Screen and

Filters (if used)

Coil Inlet-Service Watel*

(Closed Loop or

River, Ocean, Lake)

Air Flow Af

_ Fan Unit

(Centrifugal or

Vaneaxial)

Fins (Copper or

Aluminum)

_ Plenum

Zone

Condensate

Drain

Coil Section

(Copper or CopperNickle Tubes w/

Fins)

FIGURE 2.1. ECCS;Pump Room Cooler Functional Design. Components indicated

) are being evaluated elsewhere in the NPAR program. D. k

The room 'coolers protect the pumps from excessive ambient room tempera- tures, which are detrimental to the pump life. The room coolers usually meet Seismic Category I and Safety Class 3 requirements, which ensure that room coolers remain functional during and after a reactor shutdown on account of an earthquake. The room coolers are usually in redundant pump trains so that loss of a room cooler, although it may disable one train, will not jeopardize emergency operations. Room coolers are also usually on the emergency diesel gene- rator safety busses so that they can operate during losses of offsite power.

2.2

T
I :

! only thing common among pump room cooling systems from plant to plant is

3t they recirculate and cool the air within a given room. However, the

:ual room cooler units within a given plant are often of the same or very

nilar design and may be manufactured by a common vendor.

The rooms are normally heated and ventilated by the building central sysn. The ventilation system helps to keep the room cool and prevent excessive

nidity buildup. During a radiation release in the room, either the central

)m air exhaust is diverted to a central filtered exhaust system or the conninated room is isolated from the central air flow by closing room dampers.

The ECCS pump rooms are usually located outside of the primary containment

ea. They are usually located in the secondary containment of BWR buildings

in the auxiliary building of PWRs. The pump rooms are usually located in

a basements of buildings, so they are sometimes subject to cool, damp

vironments created by sumps, condensation, etc. One plant reported that

eam leaks were also of concern.

1 ROOM COOLER DESIGN

A typical pump room cooler is shown in Figure 2.1. Warm air flows in at

e bottom left through a screen and medium density filter (if one is used).

xt, the air passes through the cooling coils, where it is cooled. It contins through a plenum zone into a fan. The electric motor-driven fan moves the

oled air into a short duct and returns it to the room through the outlet.

metimes louvers are placed on the outlet to direct the air flow towards the

CS pump and piping.

Filters are optional, although they are usually installed for at least the

nstruction stage to protect internal components from dust and other debris.

dium efficiency filters are sometimes used to protect the surface of the coil

om dust and dirt when the room cooler is operating.

The cooling coil water is supplied either from a river, lake, ocean, or

rough a recirculating closed loop system. In southern states, the closed

op system uses a refrigerated chiller to remove the heat. In some cases, the

ter flow through the coil is left on continuously. In other cases, it comes

only when the ECCS pump comes on or the fan is manually started. Vents and

ains are placed in the coil headers to provide a completely drainable, self-

!nting coil. Drain pans are located below the coils to drain away the conden-

.te water that results from the air cooling process. The power for the fan

itor is supplied from a motor control center located in a separate airrnditioned room. Backup power is available from a safety-related emergency

esel generator bus (same supply as for the ECCS pump it cools) when there is

loss of offsite power.

Typical materials used in construction of the components are summarized in

ible 2.1. The cooling coils are finned to improve cooling efficiency. The

)Als are usually made of seamless copper or copper-nickel tubing. The fin

iterial is aluminum, copper, or 90/10 copper-nickel. The coil casing is

2.3

I.

I..

I.....

- ---------------------------------------------- -
TABLE 2.1. Typical Materials Used in Component Construction

Component

Motor Stator

Motor Rotor

Materials

Copper, Steel, Silicon'Steel, Aluminum,

-Insulating Materials

Copper, Steel, Insulating Materials

Motor Accessories

Motor and Fan Bearings

Fan

Steel, Cast Iron, Brass, Copper, Seals and Gaskets,

Mica, Plastics, Cable, Insulating Material, Graphite

Steel, Brass, Bronze, Grease, Lube Oil

Galvanized, Carbon and Stainless Steel; Aluminum

Cooling Coil

Room Cooler Housing

Sheaves, Pulleys

V-Belts

Tubes--Copper and Copper-Nickel

Headers--Copper and Copper-Nickel

Fins--Aluminum, Copper, and Copper-Nickel

Casing--Galvanized and Stainless Steel, Cast Iron

Inlet/Outlet Connectors--Steel

Galvanized, Carbon, and Stainless Steel

Steel

Cord (cotton, rayon, synthetic, steel) Fabric, Rubber

usually constructed of stainless steel, cast iron, or galvanized steel.

Headers are made of drawn copper or copper-nickel. They are brazed to the

tubes, or the tubes are hydraulically expanded into die-formed collars in the

fins. Lap joint steel stubs and flanges are used for the coil water supply and

return connections.

The fan unit is usually either a centrifugal or vaneaxial type design.

The fan is often constructed of galvanized or painted carbon steel. Fan blades

are often constructed of aluminum or stainless steel. The fan bearings are

standard anti-friction or sleeve types. The anti-friction type is available

with either ball or roller bearings.

The fan is driven by a motor which is either directly coupled or indirectly coupled via a v-belt drive with sheaves. The fan is typically driven by

a 60 Hz 3-phase horizontal induction-type motor. An excellent description of

this motor is contained in a report, generated under the NPAR program, that

summarizes aging characteristics of motors (Subudhi et al. 1985).

The room cooler air outlet may have a short section of duct or no duct at

all. Small ducts or louvers can direct the cool air across the pump and

related pipework.

2.4
i.

1'...

The frame and housing cover for the room cooler are usually constructed of

epoxy-coated carbon steel or galvanized steel, but stainless steel is used

occasionally.

A photograph of a pump room cooler is provided-by Figure 2.2. An example

of room cooler layout is provided in Figure 2.3. The capacity of the unit

shown is about 720,000 BTU/h based on a 29,000 cfm airflow and a 96 gpm coolant

water flow rate. The centrifugal type fan is v-belt driven by a 20 HP motor.

2.2 ROOM COOLER DESIGN SPECIFICATIONS

The testing requirements for the room ECCS pump cooler and related systems

are identified in U.S. NRC Regulatory Guide 1.68 in the category of heating,

cooling, and ventilation systems that serve spaces housing engineering safety

features. The room coolers are part of the systems reviewed in the Standard

Review Plan, NUREG-0800, under Section 9.4.5 (Engineers Safety Feature Ventilation System). Room coolers are generally built to meet the quality assurance

requirements of 10 CFR 50 Appendix B or ANSI N 45.2. The design codes and

standards used for the room cooler components are listed below:

I

I

FIGURE 2.2. ECCS Pump Room Cooler (as supplied by Ellis and Watts)

2.5
"US" Upblast

900 Rotating Cowl

With Double Deflecting I-.. Il Grills

-/ f

am . R.H. Coil Conn.

Outlet 2 1/2" M.P.T.

-Sectionalized

Housing

R.H. Coil Conn.

Inlet 2 1/2" M.P.T.

3/4' Dia. Mtg. Holes

t {for 1/2" Dia. Bolts)

- - -7.

Front Grounding Pad Wlue

(2) Places

Copper Plated Steel

FIGURE 2.3. ECCS Pump Room Cooler Layout (as supplied by Ellis and Watts)

... .. --------- .
ans

Air Moving and Conditioning Association (AMCA)

* AMCA, Publication 99, Standards Handbook

* AMCA, Publication 201, Fan Application Manual: Fans and Systems

* AMCA, Standard 210, Laboratory Methods of Testing Fans for Rating

Purposes

* AMCA, Publication 211, Certified Ratings Program Air-Performance

* AMCA Standard 300, Test Code for Sound Rating

* AMCA, Standard 500, Test Method for Louvers, Dampers and Shutters

Anti-Friction Bearing Manufacturers (AFBMA)

* ANSI/AFBMA, Standard 11, Load Ratings and Fatigue Life for Roller

Bearings

* ANSI/AFBMA, Standard 9, Load Ratings and Fatigue Life for Ball

Bearings

an Motors

National Electric Manufacturers Association (NEMA MG-1)

Institute of Electrical and Electronic Engineers (IEEE)

* IEEE Standard for Qualifying Class 1E(a) Equipment for Nuclear

Power Generating Stations (IEEE-323)

* IEEE Recommended Practices for Seismic Qualification of Class 1E

Equipment for Nuclear Power Generating Stations (IEEE-344)

soling Coils

Air-Conditioning and Refrigeration Institute (ARI 410 Standard for ForcedCirculation Air-Cooling and Air-Heating Coils)

American Society of Mechanical Engineers

(ASME Section III, Class 2 or 3, "N" stamped)

i) Class lE - electrical equipment and systems that are essential for

emergency reactor shutdown, containment isolation, reactor core cooling,

etc. to prevent release of radioactive material into the environment,

2.7
2.3 PRINCIPAL TYPES AND USES OF ROOM COOLERS IN BWRS AND PWRS

Final Safety Analysis Reports (FSARs) and Preliminary Safety Analysis

Reports (PSARs) for 49 U.S. nuclear power plants were reviewed to determine th

types of ECCS pump room coolers and the extent of their use. The FSAR/PSAR

Chapter 9.0, "Heating, Air Conditioning and Ventilation," was reviewed (See

Appendix B).

Information gathered from the FSAR/PSARs indicates that pump room cooler

system designs are plant-specific. Early nuclear plants do not have pump room

per se, but large rooms that contain an entire train of each of the types of

ECCS pumps. During a LOCA, all ventilation from nonessential areas in the

building is forced through the ECCS pump area for cooling purposes. The evolu

tion of ventilation and the pump room coolers is illustrated in Figure 2.4.

Only a few of the ventilation room cooler schemes in use are illustrated.

In early plants, ventilation air is concentrated in the ECCS pump area if

a LOCA occurs. Later plants used schemes with pump room coolers (shown in Con

cepts B and C). In Concept B, ventilation continues even during a LOCA. In

Concept C, the rooms can be isolated during a LOCA, with the pump room cooler

performing all of the cooling.

The coolers are often interlocked with the ECCS pumps and operate only

when the pumps operate. Some coolers operate only during a LOCA or other

emergency. Others operate when the reactors are in operating, transient, and

shutdown modes. Some are left on continuously. Others have the provision for

manual operation to enable maintenance workers to work at lower temperatures.

Some operate strictly by thermostat. Others operate by a combination of these

modes.

Sometimes a cooler is in a separate room or cubicle with an individual

pump. Other coolers serve more than one pumping system in a room or area. Th,

pump rooms are usually separated by a heavy wall to assure that a redundant

pump train will not be affected by a local debilitating situation.

ECCS pump room cooler maximum airflow rates range between 1,600 and

30,000 cfm, and maximum heat removal rates range between 50,000 and

800,000 BTU/h. The cooling water flow rate for coolers varies between 15 and

100 gpm. The newer plants have the larger capacity cooler systems. The coole

systems are designed to keep maximum pump room temperatures below 104 to 1500F

(the maximum temperature varies from plant to plant but is usually in the

104 to 1200F range) after shutdown or isolation of other building ventilation

and cooling systems. In a particular plant, the capacities and designs may be

nearly identical for the different pump rooms (e.g., HPCS, LPCS, RHR, CS).

Other plants have a broader range of cooler sizes and designs.

Sometimes, if the room is large and has additional equipment, the coolers

have ductwork to the different equipment locations. In other cases there is n

ductwork. If cooling is needed close to the pump, an outlet duct and/or

louvers are focused on the pump and piping.

2.8
2000

CFM

2000

CFM

2000

CFM

I

2000

CFM

l

2000

CFM

2000

CFM

2000

CFM

2000

CFM

Non- NonECCS ECCS

ECSS NonPumps ECCS

Non- NonECCS ECCS- -1--_

-1 2000

CFM

_* 2000

CFM

2000

CFM

12.000

CFM 4

2000 -

CFM

+ ~~~~~~~~~~~~I . + I

ECCS

Pumps

4-- -

I t I t . 2000 2000

CFM CFM

LOCA Operation

_ 2000

CFM

2000

CFM

2000

* CFM

2000

CFM

Normal Operation

Concept A. Early Plant-Ventilation Only, Without Pump

Room Coolers

Typical Damper

a, HPSI

Pump

Filtered

Exhaust

Concept B. Later Plants - Continuous

Ventilation (Supply and

Exhaust Fans May Be Turned

Off During LOCA). With Pump

Room Coolers

Concept C. Later Plants - Room Isolation

From Ventilation During LOCA,

With Pump Room Coolers

FIGURE 2.4. Examples of Building Ventilation and Room Cooler Concepts..

(R. C. indicates room cooler).

2.9
The FSAR/PSAR review covered a wide spectrum of plant ages, sizes, and

reactor suppliers (See Appendix B). The designs, layouts, and nomenclature

room coolers vary from plant to plant. A total of 49 plants were reviewed,

some were multiple reactor units at a single site. Plant age ranged from th

that came on line as early as 1968 to some that recently went into commercia

operation or may soon be going into operation. Plant sizes ranged from 470

1250 MWe. Plants designed by all four U.S. reactor suppliers were reviewed.

The review indicated that 26 of the 49 plants have ECCS pump room coole

It is uncertain how many of the remaining 23 plants have them. One plant,

which has a central cooling system for its pump rooms, did not have pump roo

coolers. Some of the plants that had pump room coolers also had central ven

lating sources. Appendix B summarizes by reactor vendor the plants that wer

reviewed.

The newer plants all have pump room coolers with larger capacities to

handle the higher reactor power capacities. Of the plants examined, most of

the General Electric plants, over half of the Combustion Engineering plants,

about one third of the Westinghouse plants, and one third of the Babcock and

Wilcox plants definitely have pump room coolers.

Pump room coolers serve a variety of ESF and ECCS pump rooms in the

reactors. The pumps they service are listed under the following names and

acronyms:

General Electric Reactors

high-pressure core spray pump (HPCS)(a)

high-pressure coolant injection system pump (HPCIS)

low-pressure core spray pump (LPCS)

low-pressure coolant injection system pump (LPCIS)

residual heat removal pump (RHR)

decay heat removal pump (DHR)

core spray pump (CS)

reactor core isolation cooling pump (RCIC)

Combustion Engineering Reactors , high-pressure W safety injection pump (HPSI)(a)

hlow-pressure safety injection pump (LPSI)

containment spray pump (CS)

Westinghouse Reactors

centrifugal charging pump (CC)(a)

safety injection pump (SI)

residual heat removal pump (RHR)

containment spray pump (CS)

(a) Most-common terminology for high-pressure injection pumps.

2.10
Babcock and Wilcox Reactors

high pressure injection pump (HPIP)(a)

6 low-pressure injection pump (LPIP)

emergency injection cooling pump (EIC)

g reactor spray pump (RS)

decay heat removal pump (DHR)

1 2.4 EQUIPMENT BOUNDARY

The equipment boundary selected for the Phase I effort is the area within

the fan/coil enclosure. The room cooler housing and its immediate attachments

are included. Most room coolers have similar components within this boundary

+ (Figure 2.5). Components include the following items:

¶ * Frame Structure and Sheet Metal Housing

* Inlet Screen and Filter (Optional)

* Finned Cooling Coil

* Plenum Zone

{A * Fan Unit

* Fan Drive System

I * Drive Motor

* Outlet Duct (Optional)

* Louvers (Optional).

Figure 2.5 shows the typical components located both inside and outside

the chosen boundary. Because elevated temperatures and humidities may occur in

the pump rooms, electrical components are usually limited to the drive motor

and thermostats. The interfacing motor controls and other electrical and

electronic components are located in the central motor control center (MCC),

where environmental conditions are more closely controlled. Components in the

motor control center include cables, wires, transformers, fuseboxes, breakers,

switchgear, relays, and other electrical control and readout components. The

offsite power and onsite emergency diesel generator busses also interface with

the pump room cooler at the MCC. The water supply for the cooling coils,

chillers, and the pumps and valves that control the water flow are usually

located outside the room. Other items in the pump room, but outside the

boundary, include a room thermostat, manual switch, drain, and, ventilation

dampers.

2.5 FUNCTIONAL REQUIREMENTS

The functions required of the ECCS pump room cooler are usually one or

more of the following:

* Maintain the room ambient temperature low enough so that the ECCS

pumps can respond properly in the event of a LOCA or Design Basis

Earthquake (DBE).

(a) Most-common terminology for high-pressure injection pumps.

2.11

7- k j. ._. - - - - _ _ _
- .-.. __. .6.. .- - 0 -"'  _'.. , . '. .. _. . I I . . . . .. .

Pump Room Items (Outside)

Room Temperature Thermostat

Manual On-Off Switch

Condensate Drain

Room Ventilation Dampers (optional)

r'a

N)

Coolant System (Outside)

Pipe

Pump(s)

Valve(s)

Controls System

Coolant Source

- River

- Lake

- Ocean

Recirculating Source

- Chiller (Optional)

- Heat Exchanger (Optional)

Motor Control Center (Outside)

Offsite Power Bus

Onsite Emergency Diesel Generator Bus

Switchgear and Breakers

Transformer

Relays and Other Control Components

Cables and Wires

Fuses

ECCS Pump Interlock Relay

FIGURE 2.5. Components Located Inside and Outside the ECCS Pump Room Cooler Boundary
I

* Maintain the room ambient temperature low enough so that ECCS pump

life is not degraded during normal operating and shutdown periods.

Some ECCS pumps (e.g., RHR) operate during nonemergency periods also.

* Maintain room temperatures in a tolerable range for personnel to perform maintenance and surveillance work.

* Prevent building heat accumulation.

* Minimize the amount of air that must be exhausted to the environment

-' through filtered systems.

2.13 I

rj u- r - . ;- .-

. - . :__ --- W q I
3.0 DATA SOURCES FOR PUMP ROOM COOLER OPERATING EXPERIENCE

The sources of room cooler operating data are discussed in this section.

In general, the data bases reviewed were not rich in information about the ECCS

pump room coolers. The review of limited public and private information indicated that room cooler components within the defined boundary have not been a

major problem in plant operations.

Data to assess aging of room coolers was sought from the following

sources:

o Licensee Event Reports (LERs)

* In-Plant Reliability Data System (IPRDS)

* Nuclear Power Experience (NPE)

* Vendor Survey

* Utility Contacts

* Published Reports

* Ongoing Research

* Expert Opinion.

Each source will be briefly discussed in this section. Section 5.0 will discuss the operating experience data gathered from these sources.

3.1 LICENSEE EVENT REPORTS (LERs)

LERs are reports of significant operational events at nuclear power

plants. The reports are submitted to NRC by licensees according to federal

regulations. Prior to January 1984 LERs were filed based on NRC Regulatory

Guide 1.16 and NUREG-0161 for the individual plant Technical Specifications.

Since January 1984 the LERs are based on rule 10 CFR 50.73 and NUREG-1022. The

new rule requires more detail and uniformity, but some of the component failure

events previously reportable are no longer reportable. All LERs submitted

under the old and new systems are computerized in an LER data file of the

Nuclear Safety Information Center (NSIC) maintained by Oak Ridge National

Laboratory (ORNL). A search of this file indicated that reported failures of

the ECCS pump room coolers are rare and come from a small percentage of the

plants.

3.2 IN-PLANT RELIABILITY DATA SYSTEM (IPRDS)

The ORNL-IPRDS data base is primarily for use in nuclear power plant

probabilistic risk assessment and reliability studies. Maintenance work

request records from representative operating commercial reactors were the

source of data. The data on ECCS pump room coolers found in a search of the

IPRDS were limited to one plant for a period of nine years.

3.1

:
3.3 NUCLEAR POWER EXPERIENCE (NPE)

The NPE data base is an accumulation of operating experience for U.S.

light-water nuclear plants compiled by the S. M. Stoller Corporation. A very

4 limited number of failure reports were obtained from this source.

3.4 VENDOR SURVEY

A telephone survey was the first attempt to acquire vendor information.

Seven room cooler vendors were contacted, but very little information was.

obtained. The next approach was to send letters to 14 companies that have be

involved in manufacturing of pump room cooler components and assemblies. Onl

two companies responded with information in writing, and one company telephon

a response. The three vendors who responded were very helpful in providing

general design information; they expressed an interest in manufacturing equip

ment in the future.

The market for pump room recirculating air coolers has dropped to virtually nothing, so most heating, ventilation, and air conditioning companies ar

no longer in the room cooler business. Information and experienced personnel

are difficult to locate. Some vendors indicated that they would provide the

information only if under contract.

3.5 UTILITY CONTACTS

Utility personnel were contacted, but they were reluctant to provide

information because of the procedures, time, and cost involved. Because of t

wide range of cooling system designs, a significant number of utilities woulc

have to be contacted, and cost arrangements would have to be worked out. Thi

will be deferred until Phase II.

3.6 PUBLISHED REPORTS

No published reports addressing room coolers were found through several

library searches.

3.7 ONGOING RESEARCH

No public information was found relating to ongoing research programs

pertaining to room coolers.

3.8 EXPERT OPINION

Knowledgeable people from vendors and utilities were interviewed. This

source is addressed in Section 9.0.

3.2
4.0 TESTING

Room cooler testing has been performed by the manufacturers and independent laboratories. Conformance to codes and standards for seismic and other

safety requirements is determined by pre-operational testing or analysis

calculations.

Usually, seismic qualification is established by testing a room cooler on

a shake table to meet IEEE-344 performance requirements. The test is carried

out in accordance with a seismic qualification test plan agreed to by the buyer

and seller of the equipment.

After the room coolers are installed in the nuclear plant, the units are

tested prior to startup to ensure that required design operating parameters are

satisfied. One plant required that each cooling unit be tested dS follows:

* Verify that control room panels work properly and indicate the

corresponding equipment function (e.g., equipment running or

stopped).

* Perform an audio/visual inspection of intake and discharge areas for

; excessive vibrations or obstructions.

* Measure and record the discharge air flow rate.

* Measure and record the fan total static pressure.

* Test fan and motor vibration at the bearings. Measure and record the

axial, horizontal, and vertical vibration for each bearing.

* Measure and record the fan motor operating current and voltages.

* 0 f

II

Verify MCC controls and interlock operability (e.g., ECCS pump

interlock relay and emergency power breaker).

Verify ECCS pump room temperature alarm settings performance.

4.1
p 5.0 OPERATING EXPERIENCE

As indicated in Section 3.0, only limited information is available regarding room cooler operating experience. Because room coolers are used more

extensively in newer plants and in plants still under construction, eventually

a broader data base will emerge. LOCA experience at Three Mile Island Unit 2

was reviewed, and it was determined that pumps were serviced by only a centralized ventilation system. In general, there appear to have been no significant

room cooler aging problems, except for wear in bearings and sheaves caused by

fan drive V-belts. Air-cooled equipment in other industrial sectors also

appear to be relatively free of aging problems (Appendix A).

5.1 FAILURE MODES AND CAUSES

Results of the LER review are summarized in Figure 5.1. The LERs were

accumulated from the RECON, SCSS, NPE and PDR data bases. The results indicate

that most of the failures occurred outside the ECCS pump room cooler boundary.

Most of the failures had electrical sources. A total of 45 reported failures

occurred over about a 10-year period. Thirteen of the failures were within the

room cooler boundary (a little more than one per year in the entire industry).

Only 17 of the 83 operating plants have filed room cooler LERs. The majority,

31 of the 45 LERs (69%), were from 5 plants. Twenty-six of the 45 LERs

occurred in BWRs; the balance occurred in PWRs. There is no apparent explanation for the concentration of LERs at a small percentage of the plants.

The bulk of the failures that could be linked to a particular system

occurred in the RHR system, which is a heavily utilized system in most plants.

It is usually used for normal decay-heat removal when the reactor is shutdown.

The LERs *for events inside the boundary were attributed to a variety of

causes. Three occurred as a result of small coil leaks, and three were due to

thermostat problems. The rest were miscellaneous one-time occurrences.

The IPRDS data for one plant over a span of nine years indicated that

27 maintenance requests were made for a total of eight ECCS room coolers. It

should be noted, however, that maintenance requests are usually written and

action is taken before failures occur. Maintenance requests are often the

result of preventive maintenance (PM) checks or surveillance activities. The

requests were issued for the following items:

Drive Belt Adjustment or Replacement 10

Temperature Sensor Adjustment or Replacement 7

Coil Repair or Replacement 5

Coil Cleaning 2

Motor Control Center Service 2

Unknown 1

Total Requests 27

5.1
*..:: .*.:-'ioo ,:: * A v;.go7¢w.u.'.'' hi, ... 'a..

Event Category

Electrical

Procedural and

Electrical

Procedural

::N

en

.1 Procedural and

Mechanical

Mechanical c~J Inside Boundary

Outside Boundary

I I I I

0 5 10 1 5 20 25

Number of Events

Boundary - Coil, motor, fan, drive system, housing and housing attachments.

FIGURE 5.1. ECCS Pump Room Cooler LER Review Summary
__ - - __ - __ - -- - - - - - --

I ~~~~~~~~~~~~

IPROS data for the coolers used for rooms and areas outside of the ECCS

pump rooms were also reported. The non-ECCS coolers are usually built to less

stringent standards. Most had belt-driven centrifugal fans. Over 60 units

were covered by 132 maintenance requests spaced over 9 years--about 0.25

requests/coolerfyear. Again, this is a very low rate. The breakdown for

maintenance requests is as follows:

Quantity Percentage

Belt Adjustment or Replacements 53 40

Fan and Motor Bearing Replacements 17 135

Coil Cleaning 15 11%

Sheave Repair or Replacement 10 8%

Coil Leak Repair 8 6%

Filter Change 8 6% 1

Mechanical, Miscellaneous 6 5%

Damper Adjustment or Repair 5 4%

Temperature Sensor Repair or Replacement 4 3%

Coil Replacement 3 2%

Electrical, Miscellaneous 3 2%

Total Maintenance Requests 132 100%

As with maintenance requests for ECCS coolers, the non-ECCS cooler

maintenance involved drive belt and vibration-related items as the most

frequent entries (61%). Sheave and bearing replacement is primarily due to

vibration-related problems. Some bearing replacements were due to inadequate

lubrication.

LER data from an ORNL search from 1976 to 1983 indicate that a total of

30 fan motor failures occurred in the following areas:

Stator 15

Bearing 8

Accessories 6

Rotor 1

Total LERs 30

The data were not sufficiently detailed for these fan motor failures to be

identified with ECCS pump room coolers.

Room cooler analysis would benefit from the acquisition of maintenance

data from more plants, especially from those that have more direct-driven,

rather than belt-driven, fans. A comparison of vaneaxial and cen'trifugal fan

experience would also be desirable, especially regarding vibration-induced

problems.

A few utility contacts indicated that the primary maintenance concerns are

with the belt-driven fans, which induce vibration. Direct-driven fans appear.

to have fewer vibration problems. Vibration generated from water flow through

cooling coils does not appear to be a significant problem.

5.3

A -,;-- - - . ~~ ..~~~.,'. -- *-...~~~~~~- off- -1 .-- - - -- '. : . ;- - -. ;,I'- -,
5.2 FREQUENCY OF FAILURES

The frequency of reported failures for ECCS pump room coolers is very

More extensive surveys of utility experience may reveal some plants that ha

experienced higher failure levels.

The available LERs cover a time span of about 9 years (1974 to 1983).

that period, approximately 588 plant operating years were accumulated. It

uncertain how many of the plants do not have ECCS pump room coolers. The

frequency rate for LERs on ECCS pump room coolers is as follows:

LER Frequency per

LERS Plant Operating Year

Within the Boundary 13 0.022

Outside the Boundary 32 0.054

Total Reported LERs 45 0.076

The LER failure frequency of 0.022 LERs per plant operating year appears to

very low. The number of unreported failures is unknown.

The maintenance request rate, addressed by IPRDS data, was about 0.375

ECCS pump room cooler operating year. This is a very low maintenance volume

and most of these maintenance requests did not concern a failed room cooler

se. The non-ECCS cooler maintenance request rate was even lower. That rat(

was about 0.25 maintenance requests per non-ECCS cooler operating year.

The fan motor LER failure rate is difficult to assess. There are many

safety-related fan motors in a nuclear plant in addition to the ECCS pump r(

cooler fan motors.

5.3 METHODS OF DETECTION

The primary failures and maintenance needs for ECCS pump room coolers

ter around vibration problems created by units with belt-driven fans. Vibri

tion causes excessive belt, sheave, and motor- and fan-bearing wear.

Such problems can usually be detected by vibration and acoustic testin(

equipment. The vibration and sound could also be continuously monitored for

deterioration trending. Poor alignment can sometimes be detected visually,

alignment jigs can be used. Excessive'vibration can also be seen or heard V

motor mounts and other fasteners start to fail or loosen. The IPRDS data

indicated that most vibration and misalignment was detected by operators an(

craftsmen in the vicinity. Squawking, squealing, wailing and other noises

usually indicate excessive wear and potential failure of V-belts, bearings,

sheaves.

Slow coil leaks inside the housing may be hard to distinguish from ordi

nary condensation. Larger leaks can be detected visually by inspection of t

coil and the pump room cooler sight drain.

5.4

e ~ ~ . ~ ~ ~-.
5.4 MAINTENANCE ACTIONS

The IPRDS information indicates that most maintenance actions are based on

visual and noise observations by plant personnel. Fan and motor bearings are

usually lubricated on a routine basis. It appears that coils are-cleaned occasionally on a campaign basis.

Most room cooler maintenance can be performed before the deteriorating

component fails. When there are downtime limitations listed in the technical

specifications for room coolers, 12 hours to 14 days are generally allowed for

repair of the equipment before a plant shutdown must be implemented. This

amount of time--possible because of redundant ECCS pump trains--is sufficient

to replace V-belts, a motor, a fan, or a coil.

Continued adherence to vendor maintenance recommendations will minimize

maintenance work and equipment failure.

5.5 MODIFICATIONS RESULTING FROM FAILURES

If justified, monitors could be used to sense changes in vibration, sound,

and temperature to provide faster response to.a deteriorating or failed component. This phase of the study has not examined monitoring options closely.

The sensors and transmitters used in this function would have to be designed

for a variety of environmental conditions (e.g., high humidity, high temperature) in different plants and pump rooms. Simple peak vibration, acoustic, and

temperature indicators may provide ample monitoring.

Actual modifications could not be identified in the data bases reviewed.

No evidence was found where failures were severe enough to warrant design

changes. Insufficient data was found to conclude that motor direct-drive fans

would be substantially better than belt-driven fans.

5.5 A.

A"-

7,-- I", -x , _ - . , -
6.0 SUMMARY OF OPERATIONAL STRESSORS

The stressors of primary concern are listed in Table 6.1. The degree of

stress will vary according to the design and operation of specific plants and

pump rooms. Many variations are described in Section 3, (e.g., the maximum

room temperature limit varies from 1040F to 1500F). As seen in the table,

vibration can effect all of the .components; it is the principal stressor

affecting room coolers. The motor is susceptible to the most stressors, and

the motor insulation is particularly vulnerable.

6.1 MECHANICAL STRESSORS

Severe vibration is caused by moving components that are out of alignment

or balance or by other sources of vibration that impact stability. The vibration can be externally or internally generated and can readily be transmitted

to all components by the housing and drive system.

6.1.1 Fan Motor

The main effect of vibration on the fan motor is deterioration of the

bearings. Vibrations can also loosen rotor bars, cause laminations in stator

or rotor cores, cause chafing of insulation, and cause fatigue of metallic

components because of cyclic stresses.

Loose motor mount bolts and armature unbalance can cause fan motor vibration and noise. Worn bearings can cause the armature to rub against the

stator. Too little lubricant, too much lubricant, or the wrong lubricant can

cause damage to the bearings.

Since the effects of mechanical and other stressors on motors are

described thoroughly in another report generated under the NPAR program

(Subudhi, M., E. L. Burns and J. H. Taylor, June 1985), they are not treated

in depth in this report.

6.1.2 Coupling (For Direct Drive)

Direct couplings between the shafts

vibration from one to the other. If the

generate vibration itself. Misalignment

failure of the coupling and parts in the

of the motor and fan can transmit

shafts are misaligned the coupling can

between shafts can ultimately lead-to

motor and fan.

6.1.3 V-Belts and Sheaves (For Belt Drive)

The V-belts can transmit vibration between sheaves, and they can generate

-vibration if the sheaves are misaligned or if the belts are too tight or too

loose. Excessive belt tension will reduce belt life and may cause bearing and

shaft damage.

6.1

a'

-- - .. - .. -- - --- - - -
. .. , .. .:. - .

TABLE 6.1. Primary Stressors and Aging Mechanisms--Areas of Concern Within the Room Cooler Boundary

Component

Fan Motor

Mechanical

Vibration

Lubrication

Thermal

Insul atIon

Lubrication

Environmental

Insul ation

Off-on Operation

El ectrical

Insul atIon

Dielectric Strength

Radiation

Insul ation

Chemical

Insul ation

Lubricant

Coupl Ing Vibration

Mlsal Ignment

0

"3

V-Bel t & Sheaves Vibration

Misal ignment

Belt Tightness

Start-Stop

Vibration

Lubrication

Bel t Temperature Belt Materlal

Fan Lubrication Humidity Lubricant

Cool Ing Coll Vibration Aluminum Fins Salt In water

water Impurities

Corrosion

Housing Vibration
12

Multi-belt units that do not have uniform belt tension can also generate vibration. Vibration, misalignment, and improper tensioning cause V-belts to be the

largest problem in the maintenance and operation of room coolers.

Sheaves and bearings can wear faster when they are misaligned. Starting

and stopping (particularly heavy starting) decrease V-belt life. Frequent

cycling will require more frequent adjustments and replacements.

6.1.4 Fan

Lack of proper static and dynamic balance in the fan can cause vibration throughout the room cooler unit. The fan bearings themselves are subject to

deterioration because of vibration and improper lubrication.

6.1.5 Cooling Coil

1 ~The coil can generate vibration through water flow if it is not properly

designed; however, experience does not suggest that coil vibration has been a

problem. The most significant vibration is that transmitted from other room

l1 cooler components through the housing to the coil. Vibration can cause

mechanical and brazed joints to fail and subsequently leak.

6.1.6 Housing

The housing can transmit vibration throughout the room cooler unit from

other internal components or external sources. External vibration sources can

be reduced some by using resilient floor mounts. Vibration generated from

internal components cannot be isolated so easily, although resilient mountings

may help in some cases.

Since it is designed to meet Class 1 seismic requirements, the housing

should not deteriorate rapidly from vibration. Usually, loosening of bolts is

the main concern.

6.2 THERMAL STRESSORS

The amount of thermal stress to room cooler components is somewhat plantspecific because maximum specified room temperatures vary between 104 and

150'F. During a LOCA, temperatures exceeding the maximum specifications are

possible if the room coolers fail. This could be caused by the recycling of

containment sump water, which can be above 200'F, through some or. all of the

ECCS pumps. During normal reactor shutdown, systems such as the RHR or LPCI

pumps are used to recirculate and cool the reactor primary water, which can

also reach relatively high temperatures. The pumps and fan motor also add heat

to the rooms. Most pumps, however, have local coolers for their bearings and

seals. Certain ECCS pumps in some plants are capable of operating in the 200

to 350'F range for limited periods, but the details are not clear and would

have to be examined on a plant-specific basis with cooperation from the. utilities.

6.3

.1 -
6.2.1 Fan Motor

Fan motors must be designed to withstand room temperatures up to 1500F i

some plants. Most plants require motor operation in ambient temperatures up

the 1040 to 1201F range. Subudhi, Burns, and Taylor (1985) elaborate on the

effects of thermal stressors on motors. The report points out that temperati

is the key parameter that can affect motor performance over the long term--or

for a short duration at excessive temperatures. As with vibration, high temperatures can be internally as well as externally generated. Manufacturers

must design motors for specific temperature and humidity conditions, with am[

margins of tolerance. Insulation material selection is very important to

prevent temperature degradation.

Proper lubrication and lubrication material are important in preventing

bearing burnout at high ambient temperatures. Insufficient or excessive ltbr

cation can cause internally generated heat.

6.2.2 V-Belts

High ambient temperatures require selection of belts properly designed

the application. Materials selection is particularly important when ambient

temperatures approaching 140OF are anticipated.

6.2.3 Fan

Selection of high temperature bearing lubricant is required for ambient

temperatures approaching 150'F. As with the motor bearings, the proper amou:

of lubricant is also important in minimizing internal heat generation.

6.3 ENVIRONMENTAL STRESSORS

The most important environmental concerns for room coolers are high tem

ratures (previously discussed in Section 6.2) and high humidities. Pump roo:

are usually located at lower levels of the building, where water accumulates

sumps, condensation forms on concrete walls, etc. increasing humidities abov

those elsewhere in the building. Air that passes through the pump rooms is

usually cleaned and conditioned by a central ventilating system. Air passes

through only once in the ECCS pump rooms. Some plants control the humiditie

at about 50%, but a survey of utilities would be necessary for an accurate

assessment of humidity experience.

During a LOCA, humidity may increase because of leaks in containment pe

tration seals or ECCS pumps and pipeworks, or from sump water accumulations.

All of these items occurred to some extent at Three Mile Island-2.

6.3.1 Fan Motor

The room cooler component most affected by high humidity is the fan mot

The presence of actual water in the insulation of a motor can accelerate the

degradation process by reducing electrical life and dielectric strength. Bo

6.4

. I 9 - ml - __ -- PNF11VP1"W'6P)0
the dissipation factor and the dielectric constant change considerably when an

insulating material is exposed to humid air. Volume resistivity also declines

at high relative humidities.

Humidity should be no problem for motors with heaters. Modern Class 1E

motors windings with class B, F or H insulation, would be impervious to

humidity unless extremely abused by thermal overload. Only a porous or hygroscopic winding would be significantly affected by humidity. Prolonged storage

or idleness in an area of high humidity will cause corrosion of mounting bolts,

lead connections, conduit boxes, bearings, and housing enclosures.

6.3.2 V-Belts

Data on V-belts in high humidities were not found. High humidities,

especially when coupled with high temperatures, may cause problems in V-belts.

6.3.3 Fan

Varying humidities and condensation may cause problems with the bearings

if lubrication is not properly maintained.

6.3.4 Cooling Coil

Some coils use aluminum fins on copper tubing. Experience with such coils

in industrial areas with fumes and marine air have shown that aluminum fins may

deteriorate, degrading their heat transfer capabilities (Appendix A). This has

not seemed to be a problem in nuclear plants because the environment is usually

clean, but aluminum fins should be monitored periodically.

6.4 ELECTRICAL STRESSORS

The fan motor is the only room cooler component subject to electrical

stressors.

6.4.1 Fan Motor

Maintenance of dielectric strength is an important requirement for motor

insulating material to perform its function. In most insulating materials, the

ability to withstand electrical stress declines with increasing temperature,

dust, dirt, and humidity. With an increasing combination of temperature, dust,

dirt, and humidity the insulating capabilities of the dielectric is lost due to

arcing (corona type discharge) across the surface area of the insulating

material.

Voltages below or above specific ranges can cause.rapid deterioration of

the motor. An overload of the motor can cause high internal temperatures that.

will draw too much current and burn out the motor.

6.5

i

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6.5 RADIATION STRESSORS

Radiation levels in pump rooms during normal operations vary from plan

plant. During a LOCA, radiation levels may increase, and in some plants th

design basis LOCA will cause radiation levels to greatly exceed safety limi

for personnel. The radiation levels will increase greatly if some fuel mel

down materials and water are pumped by the ECCS system from the containment

sump or suppression pool. The FSAR of one plant indicated that radiation

levels, 9n a 6-month integrated basis after a LOCA, could accumulate up to

3.1 x 10° rads in the RHR pump room.

An extended LOCA may cause deterioration of all organic materials used

room coolers. V-belts, rubber motor mounts, and motor insulation are examp

of these materials. Again, the fan motor would probably be stressed the mo:

6.5.1 Fan Motor

Since chemical changes rearrange the molecular structure of the materi,

organic insulation in motors deteriorates both mechanically and electricall

a result of irradiation.

6.6 CHEMICAL STRESSORS

Chemical stressors primarily apply to the fan motor and cooling coil c(

ponents. Stressors occur from chemical changes that can be induced by exte:

chemical effects and chemical change to the material itself. The most comm(

result of chemical stress is degradation of a material by oxidation

(corrosion). Corrosion is discussed in greater depth in reference to dry

cooling applications (Johnson, Pratt, and Zima 1976) and general behavior it

air-cooled equipment (Appendix A).

6.6.1 Fan Motor

Insulation degradation, lube oil decomposition (i.e., viscosity breakdown), and overall corrosion are the most significant forms which degrade m'

performance with time. Oxidation plays a major role in the breakdown of in!

lation. Lubricant deterioration and contamination are also caused by the o

dation process, which acidifies the lubricant medium and reduces the viscos

Subsequently, metal-to-metal contact may degrade bearings.

6.6.2 Motor and Fan Bearings

Extended shutdowns can cause condensation that promotes corrosion.

Special lubricant is needed for extended shutdown or intermittent operation

6.6.3 Cooling Coil

Corrosion of tubing and build up of scale can occur when salt and brad

water are used in some plants to cool the coils. Also, impurities in water

pumped directly from rivers, lakes, etc. can cause corrosion. Plants with

closed loop cooling water have treated water, which is less likely to cause

6.6
a corrosion. LERs have shown that corrosion is a problem in containment coolers,

but the extent of corrosion in room coolers has not been determined.

PRINCIPAL D6.7 VIBRATION CAUSES IN ROOM COOLERS

The largest source of stress and aging in room coolers appears to be

vibration. In room coolers the principal sources of vibration are from the

following conditions:

* Fan wheel out of balance due to damage, corrosion, or accumulated

material

* Fan delivering more than the rated capacity

* Fan rotating in the wrong direction

* Motor out of balance or damaged

* Sheaves eccentric or out of balance

t * Drive misalignment

* Bent shaft

I.* Belts too loose or too tight

I * Mismatched drive belts

* Sheaves or fan wheel loose on shaft

* Worn coupling

* Loose bearings

• Loose mounting bolts

* Loose set screws

* Loose dampers

* Vibration isolators improperly adjusted

* Insufficient, excessive, or incorrect lubricant

* Unstable foundation

* Vibration from other equipment.

6.7

V.
7.0 MANUFACTURER RECOMMENDATIONS FOR MAINTENANCE AND SURVEILLANCE

The general maintenance and surveillance guidelines recommended by manufacturers of room coolers are listed below:

* Establish a time schedule for routine inspection of all rotating

parts and accessories. The inspection frequency depends on factors

such as the severity of operations and environment. Initially,

inspections should be frequent. With experience, the frequency can

be optimized.

* Keep shafts and sheaves in good alignment.

* Check fan and motor bearings and lubricate according to the manufacturer recommendations. Do not over lubricate. If lubricant

breaks down or becomes dirty, flush and replace it.

* Check the bearing pillow block temperatures while operating to ensure

that it is within specifications.

* Check tightness of all bolts and set screws.

* Inspect fan wheel blades for accumulations of dust and dirt. Clean

thoroughly. Check the wheel balance. Make certain the wheel turns

in proper direction and that it turns no faster than the rated

speed. Ensure that the fan does not turn hard. Hard turning may

cause motor overload.

* Check belt wear, belt tension, and alignment of the sheaves. When

multiple belts are used, replace all the belts simultaneously with

new belts if one or more are deteriorated. Belts must be kept free

of grease.

* Repaint the exterior and interior parts of fans and duct work as

needed.

* Inspect motors and load condition occasionally.

* Blow out open type motor windings with low pressure air to remove

dust and dirt.

* Check current and voltage against nameplate values and compare with

previous readings.

* Keep motors dry. If motors are idle for extended times, space

heaters or heater strips might be helpful to prevent water

condensation on the windings.

* Screens and filters should be cleaned or replaced periodically.

Ensure there are no obstructions to flow.

7.1

- ,'A7** Te *i " IF 7 .7 --.- -1 - - -
* Do not permit vibration. Check for misalignment, imbalance, loose

bolts, bent shaft, etc.

* Periodically inspect, clean, and dry the cooling coil internal and

external surfaces.

* Follow component manufacturer maintenance and surveillance

guidelines.

7.2
8.0 AGING AND SERVICE-WEAR MONITORING AND ASSESSMENT

The information available to assess room cooler aging is limited, as

pointed out in previous sections. Available evidence suggests that there are

few failures and problems associated with the ECCS room coolers if they are

properly installed and maintained.

Vibration is the stressor that causes the most maintenance problems,

accelerated aging, and failures within the room cooler boundary. Vibration

arises from several sources inside the room cooler. The room coolers are constructed to handle external vibrations (such as a seismic event), but internal

vibration sources, perhaps caused by poor maintenance and surveillance practices, are the principal problem. If the manufacturers recommendations are

followed closely, acing and wear are held to a minimum.

Vibration and acoustic monitoring of room coolers may reduce wear and

failures in plants where surveillance by workers is not available every shift.

Such monitoring would allow corrective action to be taken before failure or

before component replacement is required. Periodic checks of motor and fan

bearing pillow block temperatures would also help to prevent bearing failure.

These monitoring steps would have to be implemented on a plant specific basis.

Many plants with good ECCS room access and routine surveillance during normal

operations may not need to use monitoring equipment. Monitoring of room

coolers during and after LOCAs would be difficult in many of the plants.

8.1
9.0 EXPERT OPINION

Access to expert opinion was limited for this study. Vendor personnel

involved in room cooler manufacturing, sales, and service were difficult to

locate. The market for sales of ECCS room coolers has been nonexistent for

several years, so personnel have left or are involved in other more active

market areas. Vendors have not had many problems with their equipment in the

field; they feel that if their maintenance instructions are followed, the

equipment will be very reliable. Persons with utility experience indicated

that room coolers have been relatively trouble-free and have experienced fewer

problems than most other nuclear plant safety equipment. The only concern

voiced was about vibration in belt-driven room coolers.

Because room cooler design and operation is plant-specific, the best

approach to a more comprehensive assessment ot room cooler aging would be to

survey all of the utilities directly. Additional funding and authorization

would be required to perform such a survey. Unless room coolers begin to

develop more problematic operational history, a broader survey does not seem to

be justified.

9.1

;
10.0 CONCLUSIONS AND RECOMMENDATIONS

Room coolers are important safety-related nuclear plant components, which

serve other safety-related components such as ECCS pumps. The room cooler

function is to maintain room ambient temperatures below specified limits. The

limits differ for various plants and applications, but generally range from 104

to 1200F. The highest values are up-to 150'F.

In LWR's of early design, component cooling is provided by centralized

systems. Use of multiple smaller units, each directed to specific components

(e.g., pumps) is a more recent development. Consequently, the time frame of

room cooler experience is shorter than for other safety-related plant components such as pumps, valves and motors.

The boundary selected for this study involves the room cooler housing and

includes the cooler frame, housing, fan, fan drive, drive motor, cooling coil,

filter, and louvers. Other important equipment that influences room cooler

operation includes the coolant supply system and motor control center. Most

key equipment outside the boundary (service water system, pumps, valves,

electrical components, etc.) and some inside the boundary (principally drive

motors) are being addressed by aging studies elsewhere in the NPAR program

(referenced in this study).

This investigation of room cooler aging employs a systematic strategy that

is applied to nuclear plant components and systems addressed under the NPAR

program. The major elements of the strategy applied to this investigation are:

* evaluation of operating-experience

* interim assessment of aging characteristics.

Sources of operating experience include LERs, IPRDs, NPRDs, and NPE. The

interim aging evaluation draws from vendors, utility contacts, and expert

opinion. The experience survey resulted in. limited data regarding room cooler

operating problems. The limited data base appears to arise from two

considerations:

* more recent incorporation of room coolers into plant designs

* room cooler operation that to date is relatively trouble-free, based

on evidence from the survey.

The data suggest that vibration, particularly in units with belt-driven

fans, has caused the most room cooler maintenance and aging problems. Fan

motors are vulnerable to the greatest number of stressors. The LERs suggest

that room cooler failures are rare. When they do fail to operate, it is

usually because of malfunctions outside the room cooler boundary, in the

interfacing motor control center or in the service water chiller, valves, or

pumps.

10.1
Because the plant ECCS pump room cooler designs and operations vary so

much from plant to plant, it is difficult to focus on specific aspects of

equipment aging. Room cooler aging assessments must be performed essentially

on a plant-specific basis. As plants get older, more aging-related problems

may develop. However, cooperation by the utilities to provide assistance and

data is needed if aging studies are to be successful.

10.1 RECOMMENDATIONS

Recommendations for minimizing the rate of aging of room cooler components

within the defined equipment boundary are as follows:

* Follow manufacturer recommendations for installation, surveillance,

and maintenance of parts, components, and assemblies.

* Add vibration isolation mounts (if practical) at locations where

vibration is a problem.

* Where justified, use vibration, acoustic, and temperature monitoring

methods. Use practical methods.

* Spot check vibration amplitudes and frequencies on a monthly basis.

Also check bearing temperatures. Keep records to identify trending.

* Add strip heaters on motors and bearings if the room coolers are only

used intermittently or infrequently in high-humidity rooms. The

heater should operate only when the room cooler is idle.

10.2 FUTURE WORK

It is recommended that Phase II of the ECCS pump room cooler aging assessment be delayed until further study is justified by NPAR systems assessments

regarding room cooler interactions in safety systems. Incorporation of containment coolers in future assessments or an independent assessment of

containment-coolers should be considered. In some plants, containment coolers

are important safety-related equipment for a design basis accident.

10.2

MOOMMEMMM-MMW
11.0 REFERENCES

Davis, T., A. Shafaghi, R. Kurth, and F. Leverenz. 1985. Importance Ranking

Based on Aging Considerations of Components Included in Probabilistic Risk

-Assessments. NUREG/CR-4144 (PNL-5389), Battelle Columbus Laboratories,

Columbus, Ohio.

Johnson, A. B. Jr., D. R. Pratt and G. E. Zima. 1976. A Survey of Materials

and Corrosion Performance in Dry Cooling Applications. BNWL-1958, Pacific

Northwest Laboratory, Richland, Washington.

Subudhi, M., E. L. Burns, and J. H. Taylor. 1985. Operating Experience and

Aging-Seismic Assessment of Electric Motors. NUREG/CR-4156 (BNL-NUREG51861), Brookhaven National Laboratory, Upton, New York.

Serada, P. J. 1974. Weathering Factors Affecting Corrosion of Metals in

Corrosion in Natural Environments. ASTM STP 588, American Society for

Testing and Materials.

Uhlig, H. H. 1967. Corrosion and Corrosion .Control, p. 226. John Wiley and

Sons, New York.

US NRC. 1985. Nuclear Plant Aging Research (NPAR) Program Plan. NUREG-1144.

U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research.

11.1
I

II. - 5

1

I

1,I

i

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I

I

APPENDIX A

GENERAL BEHAVIOR OF AIR-COOLED EQUIPMENT

L_

_ _ C_ X~~~~~
APPENDIX A

GENERAL BEHAVIOR OF AIR-COOLED EQUIPMENT

In essence, room coolers in nuclear plants comprise finned tubes for heat

transfer and fans to move air. In those respects, nuclear plant room coolers

are similar to air-cooled equipment in other industrial applications. A survey

of materials behavior in non-nuclear air-cooled equipment focused on equipment

longevity and factors that contribute to air-cooled equipment deterioration

(Johnson, Pratt, and Zima 1976). Results of the survey are briefly reviewed in

respects potentially relevant to room cooler applications.

In benign (e.g. rural) environments, air coolers servicing gas pipe line

pumps have been durable and reliable for service exceeding thirty years. The

range of materials (Table A.1). largely parallels the range of nuclear room

cooler materials (Table 2.1). The small number of units that were susceptible

to severe fin corrosion were generally sited in marine environments, where

industrial pollution was also a factor. An exception involved a case at a

rural location where residual fin cleaning solution may have been the source of

accelerated corrosion. Fin corrosion resulted in a gradual deterioration of

heat transfer capacity.

A major factor in fin corrosion is the cooler operating cycle. While

coolers operate at temperatures above the dew point, fin corrosion is minimized. During periods when coolers are out of service, the fins are more

susceptible to corrosion. This is particularly true in humid environments,

where moisture condensation occurs on fin surfaces. "Time-of-wetness" is

recognized as an important atmospheric corrosion parameter (Serada 1974).

Corrosion due to atmospheric moisture also may cause deterioration of other

equipment that interfaces with room coolers, such as motors and electrical

controls. However, those aspects are subjects.of investigation in other

elements of the NPAR program.

TABLE A.1. Materials in Conventional Dry Coolers

Dry Section

Fins: aluminum(a)

steel

stainless steel

copper alloys

Tubes: steel

stainless steel

copper nickel

admiralty

(a) Coated fins can be

specified.

J

A. 1
Material selection is another important consideration in finned tube

durability, particularly in environments where corrosion rates are significant

(Uhlig 1967). Copper ions have a demonstrated accelerating effect on aluminum

corrosion. Aluminum fins interface satisfactorily with copper tubes in relatively dry conditions. When moist conditions result in some dissolution of

copper ions, accelerated corrosion of adjacent aluminum may result, depending

on several factors, including time-of-wetness, temperature, and impurities in

the environment. Under dry conditions, copper alloy tubes with aluminum fins

have operated without problems over extended periods.

In coolers operating with good water quality control and flow design,

water-side corrosion of tubes has not been a significant problem. Fouling of

interior tube surfaces also has not limited thermal performance. If cooler

water quality is marginal, or if sea water serves as the coolant, materials

selection becomes a key consideration. The survey provides a review of corrosion behavior of candiddte air cooler materials, including aqueous and air

environments.

From the survey, additional problems and considerations in air-cooled

equipment operation are summarized below:

* Vibration generally was due to loose supports and unbalanced fans.

* Fan motor failures were due to sub-standard motors and to inadequate

maintenance; some motor bearing failures were indicated.

* Gear box failures have occurred due to shock loads and loss of

lubricant.

* Some fan blade failures have occurred, principally from stress corrosion cracking of stainless steel blades; steel and plastic blades

performed satisfactorily.

* Tube failures caused by freezing, and fouling of fin surfaces by

airborne debris are not problems likely to be encountered by room

coolers in nuclear plants.

From the standpoint of room cooler operation, the most relevant insights

from the survey are:

* Air-cooled equipment has a history of high reliability over extended

operation (>30 y).

* Slow, rather than sudden, deterioration of heat transfer capacity has

occurred in the few cases where corrosion and fouling have been

severe.

* Air-side corrosion generally was more significant when equipment was

not operating, particularly in humid environments; the key aspect is

water condensation on corrosion-prone surfaces; air contaminants also

were important in cases of severe air cooler corrosion.

A.2
* For coolers with corrosion-prone materials or combinations of materials, periodic inspections are suggested (including inspection of

contacts between fins and tubes when dissimilar metals are involved).

* Room cooler water quality is an important consideration; if sea water

or other potentially aggressive waters are involved, a review of

expected compatibility with tube materials is recommended. If tube

corrosion and/or deposition is suspected or indicated, the need for

further inspection or nondestructive evaluation is suggested.

REFERENCES

Johnson, A. B. Jr., D. R. Pratt and G. E. Zima. 1976. A Survey of Materials

and Corrosion Performance in Dry Cooling Applications. BNWL-1958, Pacific

Northwest Laboratory, Richland, Washington.

Serada, P. J. 1974. Weathering Factors Affecting Corrosion of Metals in

Corrosion in Natural Environments. ASTM SIP 588, American Society for

Testing and Materials.

Uhlig, H. H. 1967. Corrosion and Corrosion Control, p. 226. John Wiley and

Sons, New York.

A.3
APPENDIX B

LIST OF FSARs/PSARs REVIEWED
If t

*

APPENDIX B

LIST OF FSARs/PSARs REVIEWED

The following list contains nuclear system suppliers and original nuclear

plant FSARs/PSARs reviewed during the ECCS pump room cooler assessment:

General Electric

Arnold

Browns Ferry 1, 2, & 3

Brunswick 1 & 2

Fitzpatrick

Grand Gulf 1 & 2

Oyster Creek

Perry 1 & 2

Pilgrim

Babcock and Wilcox

Arkansas One -1

Davis Besse-1

Midland 1 & 2

Oconee 1, 2, & 3

Rancho Seco

Combustion Engineering

Arkansas One-2

Calvert Cliffs 1 & 2

Maine Yankee

Millstone 2

Palo Verde 1,.2, & 3

St. Lucie 1 & 2

Westinghouse

Beaver Valley 1 & 2

Byron 1 & 2

Connecticut Yankee

Farley 1 & 2

Ginna

Indian Point #3

Kewaunee

Point Beach 1 & 2

Salem 1

Sequoyah 1 & 2

Trojan

Turkey Point 3 & 4

B.1
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