piping failures in united states nuclear power plants

SKI Report 96:20

Piping Failures in United StatesNuclear Power Plants:

1961-1995

Spencer H. BushMark J. Do

Antoinette L. SlavichAlan D. Chockie

January 1996

ISSN 1104-1374ISRN SKI-R--96/20--SE

STATENS KARNKRAFTINSPEKTION

Swedish Nuclear Powei Inspectorate

SKI Report 96:20

Piping Failures in United StatesNuclear Power Plants:

1961-1995

Spencer H. Bush1

Mark J. Do 2

Antoinette L. Slavich 2

Alan D. Chockie3

1 Review & Synthesis Associates, Richland, Washington, USA2 Battelle Seattle Research Center, Seattle, Washington, USA3 Chockie Group International, Inc., Seattle, Washington, USA

January 1996

This report concerns a study which has been conducted for the Swedish NuclearPower Inspectorate (SKI). The conclusions and viewpoints presented in the report

are those of the authors and do not necessarily coincide with those of the SKI.

SummaryThe Swedish Nuclear Power Inspectorate (SKI) is continuing to improve their processfor the inspection of potential piping failures at Swedish nuclear power plants. As partof this effort SKI requested that the Chockie Group International, Inc. and Review &Synthesis Associates assist in the development of a data base of piping failures at USnuclear power plants. This report describes the data base that was produced andpresents the information in a variety of formats to assist in understanding where andwhen the major piping failures have taken place.

Over 1500 reported piping failures were identified and summarized based on anextensive review of tens of thousands of event reports that have been submitted to theUS regulatory agencies over the last 35 years. The process of locating and assessingthese event reports was made difficult due to the fact that the reports are distributedamong a number of data systems and document storage centers. The data base containsonly piping failures; failures in vessels, pumps, valves, and steam generators or anycracks that were not through-wall are not included. The data base contains publiclyavailable data for events from December 1961 through October 1995.

In the process of reviewing the 1511 reported piping failures it was observed that therehas been a marked decrease in the number of failures after 1983 for almost all sizes ofpipes. This is likely due to changes in the reporting requirements at that time and thecorrective actions taken by utilities to minimize fatigue failures of small lines andIGSCC in BWRs.

One failure mechanism that continues to occur is erosion-corrosion. This mechanismaccounts for most of the ruptures reported and probably is responsible for the absenceof downward trends in ruptures.

A breakdown of the piping failures by failure mechanism, reactor type (BWR or PWR),and year of occurrence shows that fatigue-vibration is also a significant contributor topiping failures. However, most of such events occur in lines approximately one inch orless in diameter. While fatigue-vibration is a major factor in the smaller pipes, erosion-corrosion is a significant factor for both large and small lines. Together, fatigue-vibration and erosion-corrosion account for over 43 per cent of the 1511 reported pipingfailures.

An examination of the data by pipe size and failure type clearly shows that theoverwhelming majority of failures have been leaks and that over half of the failuresoccurred in pipes with a diameter of one inch or less.

Included in the report is a listing of the number of welds in various systems in LWRs.These piping failure data should provide a valuable resource in understanding thenature of piping issues and in the improvement of inspections for potential pipingproblems.

in

Table of Contents

Summary iii

Introduction 1

The Data Sources 2

Description of the Piping Failure DataBase 4Piping Failures Table 4

Commercial Nuclear Plants Table 7

Summary of the Piping Failure Data 8

Appendices

Appendix A: Frequency of Piping Failures per Year inUS Nuclear Power Plants A-l

Appendix B: Cumulative Number of Piping Failures by Plant

Operating-Months B-l

Appendix C: Number of Piping Failures per Year by Failure Mechanism C-l

Appendix D: Number of Welds in Various LWR Piping Systems D-l

Appendix E: Listing of Piping Failures in US Nuclear Power Plants E-l

Appendix F: Information on US Commercial Nuclear Power Plants F-l

IV

Piping Failures inUnited States Nuclear Power Plants:

1961-1995

Introduction

In recent years there has been an increasing interest at the Swedish Nuclear PowerInspectorate (SKI) in the probability of loss of coolant accidents (LOCAs) at Swedishnuclear power plants as a result of piping failures. This report was prepared as part of aprogram to support SKI in the improvement of their inspection activities for potentialpiping failures at the Swedish nuclear power plants.

The focus of this report is on the piping failures that have been experienced atcommercial nuclear power plants in the United States. The information presented in thefollowing sections and appendices of this report represents an extensive assessment ofsafety-significant piping events experienced at US nuclear power plants since 1961. Thedata base contains only piping failures; failures in vessels, pumps, valves, and steamgenerators or any cracks that were not through-wall are not included.

Due to the fact that the event data were obtained from publicly available referencesources, there are very likely other piping failures that have not been reported by theutilities to the regulatory bodies. However, for this program it was possible to developa data base of 1511 piping failures that have been reported to the US regulatory bodiesfrom December 1961 through October, 1995. Failures are defined in this data base asthe release of water ranging from a through-wall crack or a small pinhole leak to a fullpipe rupture.

The following sections present a review of the data sources and the structure of thepiping failure data base. Also presented in the main body of the report are tables of thenumber of piping failures by pipe size, failure type and failure mechanism. Detailedgraphs and tables of the piping failure data are presented in Appendices A through E.

Appendix A consists of a number of figures showing the number of failures per year byplant types, pipe sizes, and types of failure. Appendix B presents a set of figuresshowing the cumulative number of failures over time for pipe sizes less than or equal toone inch, pipe sizes greater than one inch, and for various types of failures. Thenumbers of annual piping failures by various failure mechanisms are given in tables inAppendix C. The tables in Appendix C also provide breakouts of these failures byreactor type and pipe size categories. Appendix D contains a table of the number ofwelds for different systems in both PWRs and BWRs.

An example listing of the 1511 piping failure events is included in Appendix E.Appendix F contains background information on US nuclear power plants that was usedto present the data in this report.

The Data Sources

There are three key issues in attempting to develop a piping failure data base. The firstissue is that an unknown number of piping failures are not usually reported to the USregulatory agencies. Only those failures that are considered to be safety-significant arerequired to be reported. Once reported the event data become publicly available. It wasthese publicly available data that were used in the development of the piping failuredata base for SKI.

The second issue concerns the fact that there is no single reference source where all theevent data are stored. Due to a number of reasons, the piping failure data aredistributed among several US Nuclear Regulatory Commission (NRC) data bases anddocument storage centers. Also, in many cases the information on events that occurredprior to the development of the NRC data base system was not always included in thesystem. The result has been that a great deal of time and effort was expended toidentify the appropriate data reference sources and to access the event records for thedevelopment of the piping failure data base for SKI.

The third issue is the need to carefully sort through the tens of thousands of reportedevents and extract those that could potentially be piping failure events. Each of theserecords must then be read and assessed to determine if it described an actual pipingfailure.

As a consequence of these factors, the project team examined a wide range of referencesources, data bases, and document storage centers to gather the information used inpreparing the piping failure data base. These sources include but are not limited to:

• Licensing Event Reports (LERs),• Abnormal Occurrence Reports (AORs),• Reportable Occurrences (ROs),• Letters from utilities to the NRC,• NUREG-0691: Investigation and Evaluation of Crack and Incidents in

Piping in PWRs,• Special Reports from the utilities to the NRC,• NUREG/CR-2781,• Preliminary Notification of Occurrence Reports (PNO),• The Nuclear Safety Information Center (NSIC),• NRC Information Notices, and• NPE.

The three key reference sources for a majority of the event data are the LER, the AOR,and the RO reporting systems. All three of these reporting systems have been or areoperated by the NRC. When there is an event that has an impact or potential impact onthe safe operation of the plant, the utility must submit a description of the event to theNRC. It is this information that constitutes the majority of piping failure eventsaddressed by this report.

Of the three reporting systems, the LER system has the most extensive set of event data.The current LER reporting system became effective on January 1, 1984. The USFederal Regulation (10 CFR 50.73) currently requires licensees to report any event thatresults in such situations as:

• a deviation from the plant's Technical Specifications.

• a manual or automatic actuation of any engineered safety feature (ESF).(However, individual component failures need not be reported if redundantequipment in the same system was operable and available to perform therequired safety function.)

• any liquid effluent release that, when averaged over a time period of 1 hour,exceeds the limits (defined in an extensive table in the Regulation) for allradionuclides except tritium and dissolved noble gases at the point of entry intounrestricted areas.

• an actual threat to the safety of the nuclear power plant or significantly hamperssite personnel in the performance of duties necessary for the safe operation ofthe plant.

Many of the other data sources listed above were of particular value in identifyingevents that occurred prior to the beginning of the current LER system.

The process of developing the data base involved searching for piping failures andconducting a thorough review of each failure report. The following is a brief summaryof the procedure that was typically used to locate piping failure data in the AORs, ROs,and LERs. Most failures were found by using the computer search system that accessesthe information stored at the NRC Public Document Room (PDR). Finding the pipingfailures was not straight-forward. In many instances multiple key words were needed tolocate the appropriate information. Basically the process followed these steps:

• log onto the PDR data net,• use the "Search" option,• select search fields such as "pipe" + "leak, pipe" + "failures",• modify the search by setting dates,• if information is found, further refine the search by using "RPT=LER-year-

number(s)",

remove the valve piping failures from the list (because the search requestedpiping failures, many valve malfunctions appeared in the list that needed tobe removed),print out the selected set of failure data,use the fiche number to access the LER, AOR, RO, or other document,identify the system involved,determine the pipe size,determine the type of failure, anddetermine the failure mechanism.

Description of the Piping Failure Data Base

The Piping Failure Data Base is an MS Access9 data base. The data base consists oftwo items, a table of the piping failures and a table of background information on theUS commercial nuclear power plants. The Piping Failures table contains informationon each of the piping failures. The Commercial Nuclear Plants table containssupplementary data on the nuclear power plants, including start date and, if appropriate,closure date. These supplemental plant data are used for categorizing and summarizingthe piping failure data.

Piping Failures Table

There are a total of 1511 piping failure events included in the Piping Failures table.The field names and field types used for the piping failures are shown in Table 1.

Table 1: Piping Failures Table - Field Names and Field Types

Reid Name

Plant NameDateSystem NamePipe Size (inch)Small(<1) or Large (>1)Failure TypeReferenceCommentsFailure Mechanism

Reid Type

TextDate/TimeTextNumberTextTextTextTextText

Each of these nine fields is described below.

• Plant Name: This field contains the name of the nuclear power plant at whichthe piping failure occurred.

• Date: This is the date when the piping failure occurred.

• System Name: This field consists of a description of the plant system in whichthe pipe is located.

Almost all nuclear power plant piping systems are covered in this data base.This includes Classes 1, 2, and 3, balance-of-plant (BOP), and protectivesystems such as fire, seal coolant, and emergency diesel cooling. Not includedin the data base are those systems carrying air, oil or hydraulic fluid.

• Pipe Size (inches): This field contains the diameter of the pipe in inches asgiven in the piping failure reference material.

• Small(<1) or Large (>1): When the actual pipe size is not provided by thesource, the description of the pipe or the system in which the pipe is located wasexamined to determine if the pipe is small or large in size. For example, if thepipe is described as a tube within a heat exchanger, then the pipe size isassumed to be "small". If the pipe is located in the service-water balance-of-plant system, then the pipe size is assumed to be "large". In such cases wheresuch a determination could be made, a small pipe is assigned the value "<1" toindicate a size considerably less than one inch and a large pipe is assigned thevalue ">1" to indicate a size considerably greater than one inch. This field isalso used to indicate pipe reducers. An example is a 2 inch by 1 inch reducerwhich is represented by the value of "2x1".

• Failure Type: This field contains the type of piping failure. Information forthis field was determined by project staff by examining the full text descriptionsof each of the piping failures and assigning the failure event to one of sixdifferent categories of piping failures. The six categories are: Breakage,Crack/Leak, Failed, Leak, Rupture, and Severed.

In this report piping failures are defined as any condition from a small reportedleak in any size line to the double-ended guillotine break (DEGB) of a largepipe. A predecessor to many piping failures is thinning of the pipe wall. Wallthinning involves substantial localized loss of pipe wall due to failuremechanisms such as erosion-corrosion, microbiologically-induced corrosion orother such corrosion mechanisms. Wall thinning can be detected by volumetricexamination before any leakage occurs. Such incipient leakage events are notincluded in the Piping Failure Data Base.

The following provides more detail on the failure type categories:

- Crack/Leak: Flaws caused by such factors as construction errors, stresscorrosion, and fatigue. These are flaws that have finite depths andpenetrate the pipe wall creating a leak. In the data base Crack/Leak isconsidered a subset of the Leak category.

- Leak: Wall penetration where a limited but finite amount of water isreleased. Leaks can vary from pinholes where leakage is measured interms of cubic centimeters per hour to larger leaks approaching a liter ormore per minute. Such leaks usually are found during plant walkdownsand the amount of water released is normally below the release limitsstated in the Technical Specification.

- Failed: This is a situation where the pipe has allowed a significantamount of water to be released. The amount of water that is released isgreater than that for a leak but less than that for a full pipe break orrupture. This type of failure is often noticed by leak detection systems.The LERs often cite "failure" or "failed" without quantifying the term.Such citations have been included in this category. Also, failed pipingand leaks tend to be intermixed because of the terminology used bysome utilities in their LERs. In several cases the term failure is used andthe fact that the "failure" is a leak was not apparent until the full text,including supplemental reporting, was perused.

- Rupture: The term rupture is synonymous with other common termssuch as Severed, Breakage, break, double-ended guillotine break, andfishmouth failure. A rupture will fall in the range of the cross-section ofthe pipe (a single-ended pipe break) to a full double-ended guillotinebreak (DEGB).

Reference: This field contains a citation for the information source of thepiping failure.

Comments: This field contains a brief summary of the piping failure event.The information was derived from a detailed review of the full text descriptionof the event and often includes a description of the failure mechanism.

Failure Mechanism: This field contains a code for the cause of the pipingfailure. Values for this field were determined by project staff examining the fulltext descriptions of each of the piping failures, developing a set of eleven typesof failure mechanisms and then assigning one of these eleven values to eachrecord in the Piping Failures table based on the information contained in the"Comments" field. These eleven failure mechanisms and their codes are:

- Corrosion/Fatigue (C/F),- Construction Defects/Errors (CD),- Design-Dynamic Load (DDL),- Water Hammer (WH),- Fatigue-Vibration (FV),- Erosion/Corrosion (E/C),- Stress Corrosion/IGSCC (SC),- Corrosion (COR),

- Thermal Fatigue (TF),- Other Cause (OTH), and- Unknown Cause (UNK).

In the event more than one cause is given in the "Comments" field, the firstcause listed was coded. In many cases the reference source clearly states thatthe cause of the event was unknown. In other cases no cause is identified. Forboth sets of events the failure mechanism was classified as unknown. Also, itshould be noted that only stress corrosion/IGSCC leaks are included in the database.

Commercial Nuclear Plants Table

The Commercial Nuclear Plants table contains information on US commercial LWRnuclear power plants. This information was obtained from the March 1995 issue ofNuclear News (Volume 38, No. 3). Over the last thirty-five years there have been 118LWRs in operation. Since 1975 nine of these have been decommissioned. In 1995there were 109 plants in commercial operation in the US.

The Commercial Nuclear Plants table contains eight fields. These are listed in Table 2.

Table 2: Commercial Nuclear Plants TableField Names and Field Types

Reid Name

Plant NameReactor TypeStart DateReactor SupplierGenerator SupplierArchitect EngineerConstructorClose Date

Field Type

TextTextDate/TimeTextTextTextTextDate/Time

Each of the eight fields are briefly described below.

• Plant Name: The name or abbreviation of the nuclear power plant.

• Reactor Type: The type of reactor is listed in this field: BWR, boiling waterreactor, and PWR, pressurized water reactor.

• Start Date: This date is the assumed operational start date for the plant. Thedate is constructed from the month and year given in Nuclear News for theplant's initial criticality and by assigning the first day of the month as the startday. This date is used as the beginning date of plant operations in calculatingplant operating time intervals.

• Reactor Supplier: The reactor vendor code for the plant is given in this field:B&W for Babcock and Wilcox, CE for Combustion Engineering, GE forGeneral Electric and W for Westinghouse.

• Generator Supplier: The generator vendor code for the plant is given in thisfield as it is reported in Nuclear News.

• Architect Engineer: The architect engineering company code for the plant isgiven in this field as it is reported in Nuclear News.

• Constructor: The construction company code for the plant is given in this fieldas it is reported in Nuclear News.

• Close Date: This field contains the assumed operations stop date for each ofthe nine decommissioned plants. The date is constructed from the month andyear given in Nuclear News for a plant's closure and by assigning the last day ofthe month for the closure day. This date is used as the end date of plantoperations in calculating plant operating time intervals.

Summary of the Piping Failure Data

The Piping Failure Data Base contains 1511 piping failure event records. The firstevent was in December 1961 and the last event occurred in October 1995. Fifty-five ofthe 1511 piping failures occurred prior to the assumed plant operations start date andseven of the 1511 piping failures occurred after the assumed plant operations stop date.

Several of the charts in Appendix A depict a marked decrease in the number of failuresafter 1983 for almost all sizes of pipes. The charts also show a peak for most failurereport categories in the 1981 to 1983 period and downward trends since then. Whilesome of this decrease can be attributed to corrective actions taken by utilities tominimize fatigue failures of small lines and IGSCC in BWRs, a substantial portion isbelieved due to a modification in the criteria for reporting of incidents. Alsocontributing to this situation are the policies at several reactors that came on-line after1980 where certain classes of failures were not reported to the NRC (e.g., lines equal toor less than 1 inch in diameter regardless of system and safety class). The only notableexception to this downward trend after the mid-1980s is in the number of failures inpipe sizes greater than 12 inches. As shown in Table 3, over fifty percent of allreported piping failures occurred in pipes one inch or smaller in diameter.

Table 3: Number of Piping Failures for Various Pipe Sizes and Pipe Size Categories

Pipe Size/Category

Actual Pipe Size< 1 inch> 1 inch & < 4 inches> 4 inches & < 12 inches>12 inchesSubtotal

Pipe Size Category"<1"">1"ReducerSubtotal

Unknown/UndeterminedSize/Category

Total

Number ofFailures

57425215574

1055

227142

13382

74

1511

The breakout of piping failures by failure type is presented in Table 4. Eighty-eightpercent of the failures were classified as leaks (i.e., the value of Failure Type is "Leak"or "Crack/Leak"). A comparison of failures by pipe size category and reactor type (seeAppendix A) confirms that BWRs, despite the smaller number of plants compared toPWRs, had more leaks and failed piping. The primary failure mechanism for thissituation in the late 1970s and early 1980s was IGSCC.

Table 4: Number of Piping Failures by Type of Failure

Failure Type

LeakLeak

Crack/Leak

Failed

Rupture

Breakage

Rupture

Severed

Total

Number ofFailures

1274

54

64

13

76

30

1511

A breakdown of the piping failures by failure type is presented in Table 5. One failuremechanism that continues to be a significant factor is erosion-corrosion. Thismechanism accounts for most of the ruptures reported and probably is responsible forthe absence of downward trends in ruptures.

Table 5: Number of Piping Failures for Each Failure Mechanism Category

Failure Mechanism (Code)

Corrosion/Fatigue (C/F)

Construction Defects/Errors (CD)

Design-Dynamic Load (DDL)

Water Hammer (WH)

Fatigue-Vibration (FV)

Erosion/Corrosion (E/C)

Stress Corrosion / IGSCC (SC)

Corrosion (COR)

Thermal Fatigue (TF)

Other (OTH)

Unknown Causes (UNK)

Total

Number ofFailures

14

184

8

35

364

295

166

72

38

43

292

1511

A breakdown of the piping failures by failure mechanism, reactor type (BWR or PWR),and year of occurrence (see Appendix C) shows that fatigue-vibration is also asignificant contributor. However, most of such events occur in lines approximately oneinch or less in diameter. While fatigue-vibration is a major factor in the smaller pipes(lines about 1 inch in diameter), erosion-corrosion is a significant factor for both largeand small lines. Together, fatigue-vibration and erosion-corrosion account for overforty-three per cent of the 1511 reported piping failures.

Shown in Appendix C are tables that present the annual number of failures by failuremechanism, reactor type, and pipe size. What is not apparent in these tables is whereerosion/corrosion occurs. Basically, single-phase erosion/corrosion can occur in thefeedwater system for both BOP and Class 2. Two-phase erosion/corrosion is a wetsteam phenomenon occurring downstream of the high pressure turbine and upstream ofthe turbine preheaters. The tables also do not indicate the severity of failure. However,this can be ascertained by reviewing the "System Name" field values in the data base'sPiping Failures table (see Appendix E for a sample listing of the piping failure records).Also, it should be possible to separate the large erosion/corrosion failures from thesmall ones as well as separate single-phase from two-phase erosion/corrosion.

The only way to really interpret the graphs and tables for leaks, failures and ruptures isto cull each class of failures from the total failure population then subdivide them intoBWRs and PWRs and further divide them by failure mechanism and system. The MSAccess® software permits such culling of the data base so one can identify the cause ofruptures, for example, and determine the piping systems sensitive to such ruptures andthe safety significance of the ruptures. Ruptures in the balance-of-plant have much lesssignificance than in unisolable sections. Fortunately the only ruptures in unisolablepiping have occurred in lines one-inch or less in diameter.

10

The Piping Failure Data Base should provide a useful tool in the improvement ofprobabilistic safety analysis as well as for the inspection and mitigation of potentialpiping problems in commercial light water reactors.

11

APPENDIX A

Frequency of Piping Failures per Year inUS Nuclear Power Plants

Frequency of Piping Failures per Year in US NuclearPower Plants

In this appendix information on the number of piping failures by year for various pipesizes has been organized into four groups of bar charts. In these figures five pipe sizeclassifications are used: all pipe sizes (includes all 1511 records even if pipe sizeinformation is not available); pipe diameter less than or equal to 1 inch, including pipeswith "<1" values in the "Small(<l) or Large (>1)" field; pipe diameter greater than 1inch and less than or equal to 4 inches; pipe diameter greater than 4 inches and less thanor equal to 12 inches; and pipe diameter greater than 12 inches.

The first group (Figures A-l through A-10) presents the number of all piping failuresthat occurred at US nuclear power plants each year broken down by plant type and pipesize.

The second group of figures (Figures A-l 1 through A-14) is a breakdown of thenumber of piping leaks in LWRs per year for the various pipe sizes. This categoryincludes the piping failure records in the data base that have the value of "Leak" or"Crack/Leak" for Failure Type.

The number of failed pipes for LWRs per year for the various pipe sizes are shown inthe third set of figures (Figures A-15 and A-16). This category includes the pipingfailure records in the data base that have the value of "Failed" for Failure Type. This isa situation where the pipe has allowed a significant amount of water to be released.The amount of water that is released is greater than that for a leak but less than that fora full pipe break or rupture. This type of failure is often noticed by leak detectionsystems. There were not enough piping failures per year to warrant the generation of afigure for the failed pipes in the two pipe size classifications of 4 to 12 inches andgreater than 12 inches.

The fourth set of figures (Figures A-17 through A-19) shows the annual number of piperuptures for all LWRs for the various pipe sizes. This category includes the pipingfailure records in the data base that have the value of "Rupture", "Breakage" or"Severed" for Failure Type.

A-l

The following table summarizes the information contained in each of the figures.

All Piping FailuresLWRBWR&PWR

LWRBWR&PWR

LWRBWR&PWR

LWRBWR&PWR

LWRBWR&PWR

Piping LeaksLWR

LWR

LWR

LWR

Failed PipingLWR

LWR

Piping RupturesLWR

LWR

LWR

Pipe Size (Inches)

All SizesAll Sizes

Diameter < 1Diameter < 1

1 < Diameter < 41 < Diameter < 4

4 < Diameter < 124 < Diameter < 12

Diameter > 12Diameter > 12

All Sizes

Diameter < 1

1 < Diameter < 4

4 < Diameter < 12Diameter > 12

All Sizes

Diameter < 11 < Diameter < 4

All Sizes

Diameter < 11 < Diameter < 4

4 < Diameter < 12Diameter > 12

FigureNumber

A-1A-2

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A-16

A-17

A-18

A-19

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Figure A-1: Number ofL WR Piping Failures per Year

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co coi noo

f\000^

00 0~ien

m in

Year

Figure A-12: Number of LWR Piping Leaks per Year - For Pipe Sizes Less Than or Equal to I Inch

26

24

22

20

18

.2 16"iOJ

^ 14O

1 12

I 108

6

4

2

0vO

(Ti (Ti00

<•<•>

00inoo01

00 00

Year

Figure A-13: Number ofL WR Piping Leaks per Year - For Pipe SizesGreater Than I Inch and Less Than or Equal to 4 Inches

Pipe Size 4-12 Inches

M Pipe Size > 12 Inches

1—

00 00•n00 00

CTi

O i00

Year

Figure A-14: Number ofLWR Piping Leaks per Year - For Pipe Sizes Greater Than 4 Inchesand Less Than or Equal to 12 Inches and For Pipe Sizes Greater Than 12 Inches

!§• 5

ul 4O

1 3z

CT1vO

LD Ol-v

OvIX CO CO oo CO <X5

a*(Ti

a>

Year

Figure A-15: Number of Failed LWR Piping per Year

oo

OJD

c

1

E3

Size < or = 1 Inch


i n

Year

Figure A-16: Number of Failed LWR Piping per Year - For Pipe SizesLess Than or Equal to 1 Inch and Between I and 4 Inches

6l"V

Number of Ruptures

0

I"So

i

a

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

8 ,

7-

>

o

3 5

a3

"S 4

1_

Size < or = 1


a.

Year

Figure A-18: Number ofLWR Piping Ruptures per Year - For Pipe SizesLess Than or Equal to I Inch and Between I and 4 Inches


Pipe Size > 12 Inches

Year

Figure A-19: Number ofLWR Piping Ruptures per Year - For Pipe SizesBetween 4 and 12 Inches and Greater Than 12 Inches

APPENDIX B

Cumulative Number of Piping Failuresby Plant Operating-Months

Cumulative Number of Piping Failuresby Plant Operating-Months

This appendix contains six graphs that display the cumulative number of variouscategories of LWR piping failures by plant operating-months.

A plant operating-month is defined as one plant operating one month. Plant operating-months at any given date were calculated by using the Start Date and Close Date ofeach plant (obtained from the Piping Failure Data Base's Commercial Nuclear Plantstable) to determine the total number of months each plant had been operating by thatdate and summing these totals across all plants. For the same date the total number ofpiping failures that had occurred by that date was also calculated. For these graphs,quarterly dates were used in calculating the cumulative numbers.

Figure B-l shows the cumulative number of all piping failures by plant operating-months.

Figures B-2 and B-3 present the cumulative number of failures by plant operating-months for pipe sizes less than or equal to 1 inch and for pipe sizes greater than 1 inch,respectively.

Figure B-2 includes piping failures for which:

• the "Pipe Size" field value is less than or equal to 1 inch, or

• the "Small(<l) or Large(>l)" field value is "<1".

Figure B-3 includes piping failures for which:

• the "Pipe Size" field value is greater than 1 inch, or• the "Small(<l) or Large(>l)" field value is ">1".

The last three figures show the cumulative number of piping failures by plantoperating-months by failure type:

• Figure B-4 gives the number of leaks, which includes piping failures with a"Failure Type" field value of "Leak" or "Crack/Leak";

• Figure B-5 gives the number of failed piping, which includes piping failureswith a "Failure Type" field value of "Failed"; and

• Figure B-6 gives the number of ruptures, which includes piping failures with a"Failure Type" field value of "Rupture", "Breakage" or "Severed".

B-l

COto

1600

1400

1200

a! 1000_3

"(5u_"o 800

E600

400

200

1 1 |

5000 2000010000 15000

Plant Operating-Months

Figure B-l: Cumulative Number ofLWR Piping Failures by Plant Operating-Months

25000

CO

1600

1400

1200

<G 1000

'iLL.

"o 800-

.OE5 600-

400

200

5000 10000 15000


20000 25000

Figure B-2: Cumulative Number ofLWR Piping Failures by Plant Operating-Months- For Pipe Sizes Less Than or Equal to 1 Inch

1600

1400

1200

w 1000

LJ_

"o 800

ro 0)

E600

400

200

5000 10000 15000


20000 25000

Figure B-3: Cumulative Number of LWR Piping Failures by Plant Operating-Months- For Pipe Sizes Greater Than 1 Inch

wI

1600

1400

5000 10000 15000


20000 25000

Figure B-4: Cumulative Number ofLWR Piping Leaks by Plant Operating-Months

140 f

120 -

100- •

CO

c

1LJ_

oO)

"I3

z

80-

60

5000 2000010000 15000


Figure B-5: Cumulative Number of Failed LWR Piping by Plant Operating-Months

25000

140 T

120 -

100-

3"S. 80

3

z

60-

40

20

5000 2000010000 15000


Figure B-6: Cumulative Number ofLWR Piping Ruptures by Plant Operating-Months

25000

APPENDIX C

Number of Piping Failures per Yearby Failure Mechanism

Number of Piping Failures per Yearby Failure Mechanism

In this appendix the piping failure data have been organized into five tables. Withineach table the number of failures per year is broken out by the "Reactor Type" field andthe "Failure Mechanism" field values.

Table C-l provides a listing of the annual number of failures by the eleven failuremechanisms and the two reactor types for all reported events in the data base. Thisinformation is further subdivided by pipe size categories and presented in Tables C-2through C-5.

Table C-2 presents the annual number of failures for pipe sizes less than or equal to 1inch. This category includes piping failures for which the "Small (<1) or Large (>1)"field value is "<1" as well as piping failures for which the numeric "Pipe Size (inch)"field value is less than or equal to 1 inch.

Table C-3 is a breakdown of the annual number of failures for pipe sizes greater than 1inch and less than or equal to 4 inches.

Table C-4 lists the annual number of failures for pipe sizes greater than 4 inches andless than or equal to 12 inches.

Table C-5 presents the breakout of the annual number of failures for pipe sizes greaterthan 12 inches.

C-l

Table C-1: Number of Piping Failures per Year by Failure Mechanism

ni

Failure Mechanism

Corrosion/Fatigue

Construction

Defects

Design-Dynamic

Load

Water hammer

Fatigue-Vibration

Erosion/Corrosion

Stress Corrosion

/ IGSCC

Corrosion

Thermal Fatigue

Other

Unknown Causes

Totals

ReactorType

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

61

1

62 63 64 65 66 67 68

I

!

I

1

ii

0 0

1 2

j" ~T""~

1

II !

1 1 2 1 0

69

1

2

1

1

5

70

1

1

3

2

7

71

1

2

1

2

1

2

1

1

1

12

72

1

3

2

1

3

3

2

1

1

2

19

73

1

1

2

3

1

1

4

1

1

2

3

6

26

74

8

6

1

1

11

14

10

2

12

5

2

2

1

17

8

100

YEAR

75

1

11

10

1

1

4

12

23

3

5

5

1

1

1

1

1

11

8

100

76

1

4

8

1

7

26

CJl

13

8

10

2

1

1

2

2

9

103

77

5

4

1

6

27

5

2

1

8

1

1

i7

14

83

78

1

4

5

1

1

6

25

16

3

4

4

2

2

1

3

4

9

91

791

2

4

4

3

4

15

11

4

5

8

4

1

1

4

2

7

8

88

80

1

4

3

21

3

8

7

4

3

2

1

4

2

3

17

83

811

2

2

7

1

20

3

27

5

3

4

10

2

1

4

3

16

111

82

1

6

11

1

16

21

10

39

11

3

4

8

1

4

3

11

14

164

83

1

13

11

1

6

17

4

19

10

2

7

3

2

2

5

13

116

84

2

2

1

1

2

3

2

4

7

1

2

1

1

2

4

10

45

85

1

2

1

3

4

7

1

5

2

2

i2

9

40

86

1

1

1

2

1

8

2

2

1

1

2

1

9

4

36

87

3

2

11

1

1

5

1

1

2

1

2

2

7

39

88

1

1

1

1

1

3

2

5

3

1

2

2

3

26

89

2

1

8

1

1

4

1

1

3

2

24

90

1

3

1

4

3

4

29

2

2

3

1

1

1

1

56

91

2

3

1

5

2

1

8

1

1

2

3

29

92

1

1

5

1

1

1

6

1

1

4

1

2

6

31

93

4

3

1

1

2

2

2

3

1

1

4

24

94

2

6

4

2

2

1

2

1

4

«,

29

95

1

2

1

1

3

2

2

6

18

Total

4

10

74

110

5

3

12

23

109

255

95

200

98

68

27

45

14

24

15

28

108

184

1511

Table C-2: Number of Piping Failures per Year by Failure Mechanism- For Pipe Sizes Less Than or Equal to 1 Inch

n

Failure Mechanism

Corrosion/Fatigue

Construction

Defects

Design-Dynamic

Load

Water hammer

Fatigue-Vibration

Erosion/Corrosion

Stress Corrosion

/ IGSCC

Corrosion

Thermal Fatigue

Other

Unknown Causes

Totals

Reactortype

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

YEAR

61 82 83 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

0 0 0 0 0 0 0 0

2

2

1

1

1

2

1

1

5

1

3

3

7

1

2

1

3

1

2

2

5

17

6

4

00 C

M

1

CM

C

O

1

3

6

46

1

8

8

1

3

10

21

to

to

1

i7

4

69

1

2

6

7

24

in

in

2

1

T1

6

61

4

1

5

21

1

1

4

5

43

1

1

3

5

16

4

2

1

2

2

2

1

3

43

1

1

2

1

3

3

12

5

1

1

3

1

"'"i

1

2

CM

CD

46

4

2

11

1

8

1

1

2

1

1

3

10

45

1

1

5

1

17

2

25

3

1

1

2

2

2

12

75

4

6

15

14

4

28

1

2

4

1

3

2

00

00

100

8

6

4

12

10

1

1

2

1

1

2

9

57

2

1

2

1

CM

ii-

2

1

9

21

1

4

4

1

1

5

16

1

2

2

2

1

1

1

5

2

17

2

1

3

3

1

- 1

1

16

1

1

1

3

2

3

1

....

1

- 2

17

1

7

1

3

1

1

2

16

2

2

2

2

12

1

2

1

24

1

2

tol

4*

3

1

T

2

16

1

1

4

1

1

4

12

3

1

1

1

1

1

1

9

2

3

1

2

1

3

12

1

2

2

1

2

8

Total

4

5

39

65

0

1

1

9

83

193

31

113

13

23

12

16

7

7

6

17

45

111

801

Table C-3: Number of Piping Failures per Year by Failure Mechanism - For Pipe SizesGreater Than 1 Inch and Less Than or Equal to 4 Inches

n

Failure Mechanism

Corrosion/Fatigue

Construction

Defects

Design-Dynamic

Load

Water hammer

Fatigue-Vibration

Erosion/Corrosion

Stress Corrosion

/ IGSCC

Corrosion

Thermal Fatigue

Other

Unknown Causes

Totals

ReactorType

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

YEAR

61 62 63 84 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

—

—

—

-—

0

- —

—-

—

0

—

—

—

—-

—

0

-—

—

— -

— -

0 | 0

- —

1

— -

1

1 1

—"

0 0

-----

1

2

3

1

1

2

1

2

1

1

4

2

7

3

2

- -

2

2

2

5

i

3

8

23

1

1

1

1

2

3

1

1

2

3

3

1

! 1I

1

10

1

1

1

15

1

4

1

1

1

8

1

3

6

1

1

1

13

1

1

2

4

1

1

1

1

1

1

1

15

1

1

5

1

3

2

1

3

1

3

7

I

11

2

1

20

2

4

2

2

2

3

1

1

19

5

3

2

2

1

3

1

2

1

27

- —

2

1

1

1

1

3

-

1

10

1

T

2

col

2

2

11

—

1

-----

1

2

—-

4

"" V

1

T

T

1

i

10

1

1

- —

T

1

4

1

T

—

-----

2

—

—

- 6

2

1

9

- —

-

1

1

6

2

-----

1

2

1

7

1

- - -

- - -

—

1

2

4

1

- -

—

i

1

1

3

—

—

—

2

2

4

Total

0

0

16

18

2

1

4

4

12

34

25

24

29

12

8

18

3

4

1

4

19

14

252

Table C-4: Number of Piping Failures per Year by Failure Mechanism - For Pipe SizesGreater Than 4 Inches and Less Than or Equal to 12 Inches

n

Failure Mechanism

Corrosion/Fatigue

Construction

Defects

Design-Dynamic

Load

Water hammer

Fatigue-Vibration

Erosion/Corrosion

Stress Corrosion

/ IGSCC

Corrosion

Thermal Fatigue

Other

Unknown Causes

Totals

ReactorType

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

61 82 83 04 65 66 67 68 69 70 71 72 73

-----

0 0 0

1

1

-

1

1

—

1

1 0

- -

0

1

1

2

" 1

1

2

1

1

— •

1

1

1

1

2

74

1

5

2

2

1

1

12

YEAR

75 76

2

2

1

1

1

7

3

7

10

77

1

1

6

1

1

10

78

1

1

1

3

6

1

1

1

1

1

1

18

79

1

1

1

2

3

1

9

80

2

2

4

81

1

2

1

1

5

82

1

1

1

4

2

3

1

1

14

83

1

2

2

4

1

10

84

1

1

2

1

5

85

1

1

1

1

2

2

1

1

10

86 87 88 89

2

1

2

5

1

1

1

3

1

1

-

1

90

1

1

1

3

6

91

1

1

- —

1

3

92 93

1

- —

1

1

1

1

1

4

94

1

1

1

3

95

1

1

1

3

Total

0

0

4

6

0

1

3

3

6

7

24

15

32

27

2

3

1

3

3

1

9

5

155

Table C-5: Number of Piping Failures per Year by Failure Mechanism- For Pipe Sizes Greater Than 12 Inches

O

Failure Mechanism

Corrosion/Fatigue

Construction

Defects

Design-Dynamic

Load

Water hammer

Fatigue-Vibration

Erosion/Corrosion

Stress Corrosion

/ IGSCC

Corrosion

Thermal Fatigue

Other

Unknown Causes

Totals

ReactorType

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

BWR

PWR

YEAR

61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

0 0 0 0 0 0

I

0 0 0 0

1

1

1

1

1 | 3

1

1

1

1

1

3

1

1

1

3

1

2

2

5

1

1

1

3

-

1

1

1

3

1

- - - •

1

i

3

1

1

- -

- -

1

1

1

T4

1

7

1

1

2

5

1

1 i

IiI

1

2

5

1

2

3

1

4 0

1

—-

1

2

1

- • -

2

3

1

3

1

5

1

1

2

1

2

2

1

6

2

1

1

4

1

• —

—

~~T

2

-

0

Total

0

2

5

1

2

0

1

3

0

0

S

18

11

0

0

0

2

3

1

0

11

9

74

APPENDIX D

Number of Welds in Various LWR Piping Systems

Number of Welds in Various LWR Piping Systems

The following table contains a listing of the number of welds in US LWRs by bothreactor type and pipe size. Presented in Table D-l is an extensive breakdown of thenumber of welds by pipe sizes for various piping systems. The weld counts are basedon the following references and information sources:

• The PNL work on the risk assessment of Surry-1, a three-loop WestinghousePWR,

• NUREG/CR-4407,• EPRI TR-102266 (Proprietary Report),• Private communication between S.H. Bush and General Electric Company, and• ASME Section XI report on Category BJ welds.

The report of Category BJ welds by the American Society of Mechanical Engineers(ASME) includes a survey of several GE BWRs. It also includes a review of theCategory BJ welds in Babcock and Wilcox, Combustion Engineering andWestinghouse PWRs.

There is no indication in the ASME report of the pipe sizes. Since these are CategoryBJ welds, a reasonable assumption is that the "one-inch exemption" applies and that allthe lines listed in the ASME report are greater than one-inch in diameter. This meansthat the ASME information would cover all or parts of systems listed in Table D-l andthat many of these welds are in unisolable portions of systems.

D-l

Table D-l: Number of Welds by Pipe Size for Various BWR and PWR Systems

SYSTEM

PIPE SIZE(Inches)

D=Diameter

NUMBER

OF WELDSCOMMENTS

BWR - GENERAL ELECTRIC

(Source: ASME Section XI Report on Category BJ Welds)

Core Spray

per 1992 ASME Section XI

10 45 2 Category BF and 43

Category BJ Welds in Core

Spray Loops A & B

(Source: Private Communication - S.H. Bush and GE)

BWRs 1 and 2

BWRs 3 and 4

2

4

6

8

other

4

8

10

other

328

198

246

249

798

1013

425

642

4535

GE BWR Weld Counts by System (Source: EPRI TR-102266)

Main/Auxiliary Feedwater Systems and

Condensate

Main Steam, Other Steam and Turbine

Lines

Recirculation System

Safety Injection System

Other Safety Related Systems

Other

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

732

363

308

1369

772

1091

200

22

82

436

105

309

2440

998

1270

4000

2000

3000

Excludes Condenser

(All Systems Containing

Steam)

(Includes RCIC, RHR, HPSI,

LPSI)

(Includes CCW, ESW,

RWCU, etc.)

(Includes Fire Water, Water

Purification,Spent Fuel Pool,

Miscellaneous Chemical and

Rad Waste)

D-2

Table D-l: Number of Welds by Pipe Size for Various BWR and PWR Systems(Continued)

SYSTEM

PIPE SIZE(Inches)

D=Diameter

NUMBEROF WELDS

COMMENTS

GE BWR Weld Counts by System (Source: NUREG/CR-4407)

Component Cooling Water

Condensate

Core Spray

Feedwater

HPSI

Main Steam

Raw Cooling Water

Recirculation

RCIC

RHR

Standby Liquid Control

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

D>6

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

515

608

433

175

205

51

276

51

401

101

214

Unknown

Unknown

173

96

160

49

360

215

39

0

To 24 Inches

To 39 Inches

To 16 Inches

To 24 Inches

To 24 Inches

To 26 Inches

To 24 Inches

To 28 Inches

To 18 Inches

To 24 Inches

To 4 Inches (no pipes >4

inches)

PWR SYSTEMS

PWR Weld Counts by System (Source: NUREG/CR-4407)

Auxiliary Feedwater

Condensate

CCW

CVCS

2<D<6

D>6

D>6

2<D<6

D>6

2<D<6

D>6

48

159

1500

1155

504

928

19

To 12 Inches

To 16 Inches

To 12 Inches

To 6 Inches

D-3


SYSTEM

Emergency Core Cooling (ECCS)

HPSI

LPSI

RHR

Essential Raw Cooling Water

Main Feedwater

Main Steam

Primary Reactor Coolant

PIPE SIZE(Inches)

D=Diameter

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

2<D<6

D>6

D>6

D>6

D>6

NUMBER

OF WELDS

372

559

468

122

468

172

710

1719

1900

2177

973

COMMENTS

To 10 Inches

To 10 Inches

To 14 Inches

To 30 Inches

To 20 Inches

To 42 Inches

To 36 Inches

PWR - BABCOCK & WILCOX

B & W Class-1 Category BJ Piping Systems (Source: ASME Section XI Report on Category BJ Welds)

Decay Heat Removal

High Pressure Safety Injection System

(HPSI)

Low Pressure Coolant Systems

12

2.5

8

12

14

15

109

9

3

22

Basically the Same as RHRSystem

47 Unisolable and 62 Isolable

B&W PWR Weld Counts by System (Source: EPRI TR-102266)

Main and Auxiliary Feed Water System

Main and Miscellaneous Steam Systems

OSR

Reactor Coolant System

SIR

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

213

99

439

962

402

1251

1673

1841

771

182

104

37

174

49

D-4


SYSTEM

Other

PIPE SIZE(Inches)

D=Diameter

D>6

0.5<D<2

2<D<6

D>6

NUMBEROF WELDS

121

4500

3500

4000

COMMENTS

PWR - COMBUSTION ENGINEERING

CE Class-1 Category BJ Piping System (Source: ASME Section XI Report on BJ Welds)

Decay Heat Shutdown Cooling

Safety Injection System

3

8

14

3

6

8

12

31

5

18

24

19

70

94

CE PWR Weld Counts by System (Source: EPRI TR-102266)

Main and Auxiliary Feedwater plus

Condensate

Main and Miscellaneous Steam Systems

OSR


SIR

Other

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

619

398

1160

1549

711

1710

1896

1658

1029

172

76

182

132

218

280

6000

4000

5000

(Similar to Westinghouse

PWRs with Decay Heat

Removal)

D-5


SYSTEM

PIPE SIZE(Inches)

D=Diameter

NUMBEROF WELDS

COMMENTS

PWR - WESTINGHOUSE

Westinghouse PWR Weld Counts by System (Source: EPRI TR-102266)

Main and Auxiliary Feedwater and

Condensate

Main and Miscellaneous Steam and

Turbine


Other Safety Related Systems

Other Systems

SIR

HPSI, LPSI, RHR, Accumulators, etc.

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

0.5<D<2

2<D<6

D>6

602

416

622

1517

1062

1403

227

104

93

1429

1558

765

5000

4000

4000

443

205

310

(All Systems Carrying Steam)

(Includes CCW, ESW, CVCS,

CRD, etc.)

(Includes Fire Water, Water

Purification,Spent Fuel Pool,

Miscellaneous Chemical and

Rad Waste)

PWR-Westinghouse (Source: Surry-1 Risk-Based Study by PNL)


Hot Leg

Cold Leg

Pressurizer

Spray Lines

Surge Line

Safety/Relief Line

Auxiliary Spray Line

Drain Header

Cubicle A

Cubicle B

Cubicle C

29

27.5

31

4

6

12

6

2

2

2

2

5

6

10

37

24

9

43

16

53

43

40

4 Welds in 90° Elbows

To 27.5-Inch Cold Leg

Sizes 1,2,3 No Weld Count

RCS Hot Leg

1-Inch No Weld Count

(From Hot Leg to 31-Inch Cold

Leg)

D-6


SYSTEM

Common to A, B, C

Fill Header

Cubicle A

Cubicle B

Cubicle C

Bypass Line

Cubicle A

Cubicle B

Cubicle C

Bypass Equalizer Line

Loop A

LoopB

Loop C

CVCS (Incomplete; Missing 0100A3Z,

0100AZZ-1, 1105C3)

RHR

Safety Injection System (SIS)

Loop A

Loop B

PIPE SIZE(Inches)

D=Diameter

2

2

2

2

8

8

8

2

2

2

2

10

10

14

14

14

14

2

6

12

2

6

12

2

6

12

2

6

12

NUMBER

OF WELDS

26

17

15

21

8

8

8

17

17

17

17

7 Class 1

13 Class 2

10 Class 1

3 Class 2

12 Class 2

26 Class 2

2 Class 1

11 Class 1

21 Class 1

7 Class 2

12 Class 2

5 Class 2

2 Class 1

10 Class 1

21 Class 1

17 Class 2

11 Class 2

5 Class 2

COMMENTS

Part of CVCS? From 2-Inch

Line to 31-Inch Cold Leg

)From 27.5-Inch Cold Leg to

Hot Leg; Lateral is Equalizer

Line)

(Connects to Bypass Line and

27.5 Inch Cold Leg)

From 27.5-Inch Cold Leg

To Loop A SIS

Incomplete; From Loop A;

Connects to 0117A1-2 (not

available); Connects to Loop A

SIS

To Pump 1A

To Pump 1B

Missing 0127J5 and 1106A4Z

D-7


SYSTEM

Loop C

Low Head Safety Injection System

(LHSI)

Loop A - Cold Leg

Loop A - Hot Leg

Loop B - Cold Leg

Loop B - Hot Leg

Loop C - Cold Leg

Loop C - Hot Leg

HPSI From LPSI at Raw Water StorageTank

PIPE SIZE(Inches)

D=Diameter

2

6

12

2

6

12

CM

C

D

1

2

6

10

12

2

6

8

10

2

6

10

12

2

6

10

CN

C

D

10

NUMBER

OF WELDS

2 Class 1

8 Class 1

16 Class 1

12 Class 2

12 Class 2

5 Class 2

46

8

19

34

16

18

31

91

14

25

33

20

13

82

22

3

43

2

COMMENTS

Surry-1; Unless cited as

Class-1, the welds are Class-2

From HPSI

12 Class-1, 34 Class-2

From HPSI


From HPSI


From HPSI


From HPSI


From HPSI


HPSI? Or LPSI?

D-8

APPENDIX E

Listing of Piping Failures in US Nuclear Power Plants

Listing of Piping Failures inUS Nuclear Power Plants

This appendix contains an excerpt of a chronological listing of the 1511 data recordscontained in the Piping Failure Data Base. That is, Table E-1 provides an example ofthe information contained in this data base.

E-1

Table E-l: Piping Failures in US Nuclear Power Plants from 1961 to 1995

(Example List)

Plant Name

Trojan

Ginna

Quad Cities 2

Cook 1

Quad Cities 2

Hatch 1

Beaver Valley 1

Cook 2

Cook 1

Vermont Yankee

Three MileIsland 1

Big Rock Point

Cook 2

Cook 1

Oconee 2

Crystal River 3

Crystal River 3

McGuire 1

EventDate

1/11/82

1/13/82

1/15/82

1/15/82

1/18/82

1/19/82

1/19/82

1/19/82

1/23/82

1/25/82

1/28/82

1/28/82

1/28/82

1/28/82

1/28/82

1/29/82

2/1/82

2/12/82

System

Main steam

Containmentheat removal

Reactor watercleanup

Instrument air

Reactor watercleanup

Coolantrecirculation


Containmentheat removal

Componentcooling

Main steam

Feedwater


Service water

Service water

Main steam

Reactorcoolant

Reactorcoolant

High pressurecore injection

PipeSize

6

6

6

0.5

6

1

6

2

24

2.5

2.5

1

<1or Failure>1 Type

Failed

Leak

>1 Leak

<1 Leak

Leak

Leak

<1 Crack/Leak

Leak

Failed

Leak

Leak

<1 Leak

>1 Leak

>1 Leak

Rupture

Leak

Leak

Severed

Reference

AEOD/E4 16

82-002

82-001

82-005

PNO III 82-009

82-006

82-002

82-003

82-006

82-001

82-002

82-003

82-011

82-009

PNO-ll-82-72A.AEOD/E4 16

82-004. PNO11-82-013

IN 82-09

82-017

Comments

Erosion/corrosion

Stress corrosion

Stress corrosion

Broken threadednipple, unknowncause

Erosion/corrosion

3 pinhole leaksnext to a weld.Sensing linereplaced, unknowncause

Frozen pipe

Fatigue-vibrational

Valve failed toclose, unknowncause

Erosion/corrosion

Stress corrosion

Corrosion

Erosion/corrosion,cavitation fromthrottling ofbutterfly valve

Water hammer, linefailure, cavitation

Erosion/corrosion

cracked weld,Constructiondefects/errors

Thermal fatigue

Instrument line toHPCI, unknowncause

E-2

APPENDIX F

Information on US Commercial Nuclear Power Plants

Information on US Commercial Nuclear Power Plants

This appendix contains background data on US commercial LWRs. The data wereobtained from the March 1995 issue of Nuclear News (Volume 38, No. 3) and reside inthe Commercial Nuclear Plants table of the Piping Failure Data Base. Table F-l is alisting of the contents of this data base table.

The Reactor Type (i.e., BWR or PWR), Start Date and Close Date values were used toorganize the piping failure data into various categories for the graphs and tables of thisreport. The Start Date is constructed from the month and year given in Nuclear Newsfor a plant's initial criticality and by assigning the first day of the month as the startday. This date is used as the beginning date of plant operations in calculating plantoperating time intervals. The Close Date is derived from the month and year given inNuclear News for a plant's closure and by assigning the last day of the month for theclosure day. This date is used as the end date of plant operations in calculating plantoperating time intervals.

Figure F-l is a bar chart indicating the number of LWRs in operation each year from1961 through 1995. In this chart a plant is considered operating for a given year if itsStart Date is before or during the year and if its Close Date (if the plant has closed) isduring or after the year. Over the last thirty-five years there have been 118 LWRs inoperation. Since 1975 nine of these have been decommissioned. In 1995 there were109 plants in commercial operation in the US.

F-l

Table F-l: US Commercial Nuclear Power Plants

Want Name

ANO 1ANO2Beaver Valley 1

Beaver Valley 2Big Rock PointBraidwood 1Braidwood 2Browns Ferry 1Browns Ferry 2Browns Ferry 3Brunswick 1Brunswick 2Byron 1Byron 2CallawayCalvert Cliffs 1Calvert Cliffs 2Catawba 1Catawba 2ClintonComanche Peak 1Comanche Peak 2Cook 1Cook 2CooperCrystal River 3Davis BesseDiablo Canyon 1Diablo Canyon 2Dresden 1Dresden 2Dresden 3Duane ArnoldFarley 1

Farley 2

Fermi 2

FitzpatrickFort CalhounGinnaGrand Gulf 1Haddam Neck 1

ReactorType

PWRPWRPWR

PWRBWRPWRPWRBWRBWRBWRBWRBWRPWRPWRPWRPWRPWRPWRPWRBWRPWRPWRPWRPWRBWRPWRPWRPWRPWRBWRBWRBWRBWRPWR

PWR

BWR

BWRPWRPWRBWRPWR

Start Date

8/1/7412/1/785/1/76

8/1/879/1/625/1/873/1/888/1/737/1/748/1/76

10/1/763/1/752/1/851/1/87

10/1/8410/1/7411/1/761/1/855/1/862/1/874/1/903/1/931/1/753/1/782/1/741/1/778/1/774/1/848/1/857/1/601/1/701/1/713/1/748/1/77

5/1/81

6/1/85

11/1/748/1/73

11/1/698/1/827/1/67

ReactorSupplier

B&WCEW

WGEWWGEGEGEGEGEWWWCECEWWGEWWWWGE

B&WB&W

WW

GEGEGEW

W

GE

GECEWGEW

GeneratorSupplier

wGEW

WGEWWGEGEGEGEGEWWGEGEWGEGEGEAllisAllisGE

BBCWWGEWW

GEGEGEW

W

GEC/Alsthom

GEGEW

AllisW

ArchitectEngineer

BechtelBechtelS&W

S&WBechtelS&LS&LUtilityUtilityUtilityUE&CUE&CS&LS&LBechtelBechtelBechtelUtilityUtilityS&LG&HG&HUtilityUtilityB&RGilbertBechtelUtilityUtility

S&LS&LBechtelUtility/BechtelUtility/BechtelUtility

S&WG&HGilbertBechtelS&W

Builder CloseDate

BechtelBechtelS&W/UtilityUtilityBechtelUtilityUtilityUtilityUtilityUtilityBrownBrownUtilityUtilityDanielBechtelBechtelUtilityUtilityBaldwinBrownBrownUtilityUtilityB&RJonesBechtelUtilityUtility

10/31/78UE&CUE&CBechtelDaniel

Daniel

Daniel

S&WG&HBechtelBechtelS&W

F-2

Table F-l: US Commercial Nuclear Power Plants (Continued)

PJaat Name

Hatch 1

Hatch 2Hope CreekHumboldt Bay 3Indian Point 1Indian Point 2Indian Point 3KewauneeLaCrosseLaSalle 1LaSalle 2Limerick 1Limerick 2Maine Yankee 1McGuire 1McGuire 2Millstone 1Millstone 2Millstone 3MonticelloNine Mile Point 1Nine Mile Point 2North Anna 1North Anna 2Oconee 1

Oconee 2

Oconee 3

Oyster CreekPalisadesPalo Verde 1Palo Verde 2Palo Verde 3Peach Bottom 2Peach Bottom 3Perry 1PilgrimPoint Beach 1Point Beach 2Prairie Island 1Prairie Island 2Quad Cities 1

ReactorType

BWR

BWRBWRBWRPWRPWRPWRPWRBWRBWRBWRBWRBWRPWRPWRPWRBWRPWRPWRBWRBWRBWRPWRPWRPWR

PWR

PWR

BWRPWRPWRPWRPWRBWRBWRBWRBWRPWRPWRPWRPWRBWR

Start Date

9/1/74

7/1/786/1/868/1/631/1/635/1/734/1/763/1/74

11/1/696/1/823/1/84

12/1/848/1/89

10/1/728/1/815/1/83

10/1/7010/1/751/1/86

12/1/709/1/695/1/874/1/786/1/804/1/73

11/1/73

9/1/74

5/1/695/1/715/1/854/1/86

10/1/879/1/738/1/746/1/866/1/72

11/1/705/1/72

12/1/7312/1/7410/1/71

ReactorSuppler

GE

GEGE

WWW

GEGEGEGECEWWGECEWGEGEGEWW

B&W

B&W

B&W

GECECECECEGEGEGEGEWWWWGE

GeneratorSupplier

GE

GEGE

GEWW

GEGEGEGEWWWGEGEGEGEGEGEWWGE

GE

GE

GEWGEGEGEGEGEGEGEWWWWGE

ArchitectEngineer

Utility/BechtelBechtelBechtel

UE&CUE&CFluor

S&LS&LBechtelBechtelS&WUtilityUtilityEbascoBechtelS&WBechtelUtilityS&WS&WS&WUtility/BechtelUtility/BechtelUtility/BechtelB&R/GEBechtelBechtelBechtelBechtelBechtelBechtelGilbertBechtelBechtelBechtelFluorFluorS&L

Builder CloseDate

Utility

UtilityBechtel

7/31/7610/31/74

WedcoWedcoFluor

4/30/87UtilityUtilityBechtelBechtelS&WUtilityUtilityEbascoBechtelS&WBechtelS&WS&WS&WS&WUtility

Utility

Utility

B&RBechtelBechtelBechtelBechtelBechtelBechtelUtilityBechtelBechtelBechtelUtilityUtilityUE&C

F-3

Table F-l: US Commercial Nuclear Power Plants (Continued)

Want Name

Quad Cities 2Rancho SecoRiver BendRobinson 2Salem 1Salem 2San Onofre 1San Onofre 2San Onofre 3SeabrookSequoyah 1Sequoyah 2Shearson HarrisSouth Texas 1South Texas 2St. Lucie 1St. Lucie 2SummerSurry 1Surry 2Susquehanna 1Susquehanna 2Three Mile Island 1Three Mile Island 2TrojanTurkey Point 3Turkey Point 4Vermont YankeeVogtle 1

Vogtle 2

Waterford 3Wolf Creek

WPPSS 2Yankee RoweZion 1Zion2

ReactorType

BWRPWRBWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRPWRBWRBWRPWRPWRPWRPWRPWRBWRPWR

PWR

PWRPWR

BWRPWRPWRPWR

Start Date

4/1/724/1/75

10/1/859/1/70

12/1/768/1/801/1/687/1/828/1/836/1/897/1/80

11/1/811/1/873/1/883/1/894/1/766/1/83

10/1/827/1/723/1/739/1/825/1/846/1/74

12/1/785/1/76

10/1/726/1/733/1/723/1/87

3/1/89

3/1/855/1/85

1/1/847/1/616/1/73

12/1/73

ReactorSupplier

GE

GEWWW

CECEWWWWWWCECEWWWGEGE

B&W

WWGEW

W

CEW

GE

WW

GeneratorSupplier

GE

GEWWGE

GECGECGEWW

wwwwwGE

wwGEGEGE

W

wGEGE

GE

WGE

W

W

w

ArchitectEngineer

S&L

S&WEbascoUtilityUtility

BechtelBechtelUE&CUtilityUtilityEbascoBechtelBechtelEbascoEbascoGilbertS&WS&WBechtelBechtelGilbert

BechtelBechtelEbascoUtility/BechtelUtility/BechtelEbascoBechtel/S&LB&R

S&LS&L

Builder

UE&C

S&WEbascoUE&CUE&C

BechtelBechtelUE&CUtilityUtilityDanielEbascoEbascoEbascoEbascoDanielS&WS&WBechtelBechtelUE&C

BechtelBechtelEbascoUtility

Utility

EbascoDaniel

Bechtel

UtilityUtility

CloseDate

6/30/89

11/30/92

3/31/7911/30/92

9/30/91

F-4

vOm

(Tv

r~COCTi

CO mCO CO CO CTi enenmenen

Year

Figure F-l: Number ofLWRs in Operation by Year

STATENS KARNKRAFTINSPEKTION

Swedish Nuclear Power Inspectorate

Postadress/Postal address Telefon/Telephone

SKIS-106 58 STOCKHOLM

Nat 08-698 84 00Int +46 8 698 84 00

Telefax

Nat 08-661 90 86Int +46 8 661 90 86

Telex

11961 SWEATOMS

piping failures in united states nuclear power plants

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