ML20235B744
| ML20235B744 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/20/1987 |
| From: | Russell Gibbs TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML082340470 | List:
|
| References | |
| 10600, 10600-V01-R04, 10600-V1-R4, NUDOCS 8902140401 | |
| Download: ML20235B744 (70) | |
Text
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EMPLO'YEE CONCERNS SPECIAL PROGRAM l
i VOLUME 1 CONSTRUCTION CATEGORY SUBCATEGORY REPORT 10600 BOLTING (CONSTRUCTION) l i
UPDATED l
TVA NUCLEAR POWER r.
{iR fl I'E
7 TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600-SPECIAL PROGFAM REPORT TYPE: Subcategory - Construction' REVISION NUMBER:
4 TITLE: Bolting (Construction)
PAGE 1 0F 38 REASON FOR REVISION:
R1 Incorporate corrective actions and SRP comments R2 Incorporate additional CATDs corrective actions. TAS, and SRP comments R3 Incorporate additional response from line organization, and SRP comments R4 Incorporate additional SRP comments PREPAPlTION
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S SIGNATURE DATE SIGNATURE DATE APPROVED BY s
ildl b h TAK1 A/A ECSP MANAG ER DAT?.' '
MANAGER OF NUCLEAR POWER DATE l
CONCURRENCE (FINAL REPORT ONLY) 1946T I
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t Preface, Glossary, and List of Acronyms for ECTG Subcategory Reports a
HISTORY OF REVISION REV NUMBER PAGES REVISED REASON FOR CURRENT REVISION 3
i To clarify that one or more attachments will help the reader find whe;e a particular concern is evaluated l
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9 TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 SPECIAL PROGRAM FRONT MATTER REY: 3 1
PAGE i 0F vili Preface This subcategory report is one of a series of reports prepared for the.
Employee Corcerns Special Program (ECSP) of the Tennessee. Valley Authority l
(TVA). The ECSP and-the organization which carried out the' program, the Employee Concerns Task Group (ECTG), were established by TVA's Manager of Nuclear Power to evaluate and report on those Office of Nuclear Power (ONP) l employee concerns filed before. February 1, 1986. Concerns filed after that j
date are handled by the ongoing ONP Employee Concerns Program (ECD).
The ECSP addressed over 5800 employee concerns. Each of the concerns was a formal, written description of a circumstance or circumstances that an employee' thought was unsafe, unjust, inefficient, or inappropriate. The mission of the Employee Concerns Special Program was to thoroughly 1
investigate all issues presented in the concerns and to report the results i
of those investigations in a form accessible to ONP employees, the NRC, and the general public. The results of these investigations are communicated by four levels of ECSP reports:
element, subcategory, category,-and final.
Element reports, the lowest reporting level, will be published only for those concerns directly affecting the restart of Sequoyah Nuclear Plant's I
reactor unit 2.
An element consists of one or more closely related issues. An issue is a potential problem identified by ECTG during the evaluation process as having been raised in one or more concerns. For efficient handling, what appeared to be similar concerns were grouped into elements early in the program, but issue definitions emerged from the evaluation process itself. Consequently, some elements did inc1: co only one issue, but often the ECTG evaluation found more than one issue per element.
1-1' 1
Subcategory reports summarize the evaluation of a number of elements.
]
However, the subcategory report does more than. collect element level evaluations. The subcategory level overview of element findings leads to i
an integration of information that cannot take place at the element level.
1 This integration of information reveals the extent to which problems.
j overlap more than one element and will therefore require corrective action for underlying causes not fully apparent at the element level, i
To make the subcategory reports easier to understand, three items have been 1
placed at the front of each report:
a preface, a' glossary of the terminology unique to ECSP reports, and a list of acronyms.
I Additionally, at the end of each subcategory report will be a Subcategory Summary Table that includes the concern numbers; identifies other subcategories that share a concern; designates nuclear safety-related, safety significant, or non-safety related concerns; designates generic applicability; and briefly states each concern.
Either the Subcategory Summary Table or aaother attachment or a combination of the two will enable the reader to find the report section or sections'in which the issue raised by the concern is evaluated.
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TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 i
SPECIAL PROGRAM FRONT MATTER REV:
2 PAGE 11 0F vill j
l The subcategories are themselves summarized in a series of eight category k
reports.
Each category report reviews the major findings and collective significance of the subcategory reports in one of the following areas:
management and personnel relations industrial safety j
construction,
I material control l
4 operations quality assurance / quality control welding engineering A separate report on employee concerns dealing with specific contentions of intimidation, harassment, and wrongdoing.will be released by the TVA Office of the Inspector General.
Just as the subcategory reports integrate the information collected at the element level, the category reports integrate the information assembled in all the subcategory reports within the category, addressing particularly the underlying causes of those problems that run across more than one subcategory.
A final report will integrate and assess the information collected by all of the lower level reports prepared for the ECSP, including the Inspector
{
General's report.
For more detail on the methods by which ECTG employee concerns were j
evaluated and reported, consult the Tennessee Valley Authority Employee 1
Concerns Task Group Program Manual. The Manual spells out the program's objectives, scope, organization, and responsibilities.
It also specifies i
the procedures that were followed in the investigation, reporting, and closeout of the issues raised by employee concerns.
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TVA EMPLOYEE CONCERNS REPORT Nt/MBER:
10600 SPECIAL PROGRAM 8
FRONT MATTER REV:
2 1
PAGE 111 0F viii
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ECSF GLOSSARY OF REPORT TERMS
- classification of evaluated issues the evaluation of an issue leads to one of l
the following determinations:
Class A:
Issue cannot be verified as factual 1
Class B:
Issue is factually accurate, but what is described is not a problem (i.e., not a condition requiring corrective action)
Class C:
Issue is factual and identifies a problem, but corrective action k
for the problem was initiated before the evaluation of the issue '
was undertaken Class D:
Issue is factual and presents a problem for which corrective action has been, or is being, taken as a result of an evaluation Class E: A problem, requiring corrective action, which was not identified by an employee concern, but was revealed during the ECTG evaluation of an issue raised by an employee concern.
collective significance an analysis which determines the importance and consequences of the findings in a particular ECSP report by putting those findinr,s in the proper perspective, concern (see " employee concern")
corrective action steps taken to fix specific deficiencies or discrepancies revealed by a negative finding and, when necessary, to correct causes in order to prevent recurrence, l
criterion (plural:
criteria) a basis for defining a performance, behavior, or quality which ONP imposes on itself (see also " requirement").
element or element report an optional level of ECSP report, below the subcategory level, that deals with one or more issues, employee concern a formal, written description of a circumstance or circumstances that an employee thinks unsafe, unjust, inefficient or inappropriate; usually documented on a K-form or a form equivalent to the K-form.
TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 SPECIAL PROGRAM FRONT MATTER REV:
2 PAGE iv 0F viii evaluator (s) the individual (s) assigned the responsibility to assess a specific grouping of employee concerns.
f i nd i nr.s includes both statements of fact and the judgments made about those facts during the evaluation process; negative findings require corrective action.
issue a potential problem, as interpreted by the ECTG during the evaluation process, raised in one or more concerns.
E-form (see " employee concern")
requirement a standard of performance, behsvior, or quality on which an evaluation judgment or decision may be based.
root cause the underlying reason for a problem.
' Terms essential to the program but which require detailed definition have been defined in the ECTG Procedure Manual (e.g., generic, specific, nuclear safety-relateo, unreviewed safety-significant question).
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TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 l
lPECIAL PROGRAM i
FRONT MATTER REV:
2 I
PAGE v 0F viii Acronyms AI Administrative Instruction l
AISC American Institute of Steel Construction
{
ALARA As Low As Reasonably Achievable ANS American Nuclear Society I
ANSI American National Standards Institute ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials i
AWS Americar. Welding Society l
BFN Browns Ferry Nuclear Plant BLN Bellefonte Nuclear Plant CAQ Condition Adverse to Quality CAR Corrective Action Report I
CATD Corrective Action Tracking Document i
CCTS Corporate Commitment Tracking System CEG-H Category Evaluation Group Head CFR Code of Federal Regulations CI Concerned Individual CMTR Certified Material Test Report COC Certificate of Conformance/ Compliance DCR Design Change Request DNC Division of Nuclear Construction (see also NU CON) l O
TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 SPECIAL PROGRAM FRONT MATTER REY: 2 PAGE vi 0F vili DNE Division of Nuclear Engineering DNQA Division of Huclear Quality Assurance DNT Division of Nuclear Training DOE Department of Energy DP0 Division Personnel Officer DR Discrepancy Report or Deviation Report ECN Engineering Change Notice ECP Employee Concerns Program ECP-SR Employee Concerns Program-Site Representative ECSP Employee Concerns Special Program ECTG Employee Concerns Task Group EEOC Equal Employment Opportunity Commission EQ Environmental Qualification EMRT Emergency Medical Response Team EN DES Engineering Design ERT Employee Response Team or Emergency Response Team FCR Field Change Request u
FSAR Final Safety Analysis Report FY Fiscal Year GET General Employee Training HCI Hazard Control Instruction HVAC Heating, Ventilating, Air Conditioning II Installation Instruction INPO Institute of Nuclear Power Operations IRN Inspection Rejection Not;ee
TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 SPECIAL PROGRAM FRONT MATTER REY:
2 PAGE vii 0F vili L/R Labor Relations Staff-MLAI Modifications and Additions Instruction MI Maintenance Instruction MSPB Merit Systems Protection Board MT Ma6netic Particle Testing NCR Nonconforming Condition Report NDE Nondestructive Examination NPP Nuclear Performance Plan NPS Non-plant Specific or Nuclear Procedures System NQAM Nuclear Quality Assurance Manual NRC Nuclear Regulatory Commission NSB Nuclear Services Branch i
NSRS Nuclear Safety Review Staff NU CON Division of Nuclear Construction (obsolete abbreviation, see DNC)
NUMARC Nuclear Utility Management and Resources Committee OSHA Occupational Safety and Health Administration (or Act)
ONP Office of Nuclear Power OWCP Office of Workers Compensation Program PHR Personal History Record PT Liquid Penetrant Testing QA Quality Assurance QAP Quality Assurance Procedures QC Quality Control QCI Quality Control Instruction j
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TVA EMPLOYEE CONCERNS REPORT NUMBER:
10600 SPECIAL PROGRAM FRONT KATTER REV:
2 PAGE vill 0F vill QCP Quality Control Procedure QTC Quality Technology Company RIF Reduction in Force RT.
Radiographic Testing j
SQN Sequoyah Nuclear Plant SI Surveillance Instruction SOP Standard Operating Procedure SRP Senior Review Panel SWEC Stone and Webster Engineering Corporation TAS Technical Assistance Staff T&L Trades and Labor l
TVA Tennessee Valley Authority 1
TVTLC Tennessee Valley Trades and Labor Council l
UT Ultrasonic Testing l
j VT Visual Testing i
WBECSP.
Watts Bar Employee Concern Special Program WBN Watts Bar Nuclear Plant-WR Work Request or Work Rules WP Workplans 6
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TUA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 2 0F 38 l
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I OUTLINE OF CONTENTS
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PAGE NUMBER 1.0 CHARACTERIZATION OF ISSUES 5
i 1.1 Introduction 1.2 Description of Issues 1.2.1 Material Compatibility - Watts Bar j
Nuclear Plant (WBN) da 1.2.2 Material Adequacy - WBN i
1.2.3 Inadequate.ly Supported Flange - Bellefonte I
I Nuclear Plant (BLN) l 2.0
SUMMARY
5 2.1 Summary of Issues i
2.2 _ Summary of Evaluation Process
?.3 S u r.ma r y of Findings 2.2.1 Material Compatibility 2.3.2 Material Adequacy 2.3.3 Inadequately Supported Flange l
2.4 Summary of Collective Sir.nificance 2.5 Summary of Causes 2.5.1 Material Compatibility 2.5.2 Material Adequacy 2.5.3 Inadequately Supported Flange 2.6 Summary of Corrective Actions 2.6.1 Material Compatibility l
2.6.2 Material Adequacy 2.6.3 Inadequately Supported Flange
e TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 3 0F 38 PAGE NUMBER 3.0 EVALUATION METHODOLOGY 11 3.1 General Methods of Evaluation 3.2 Reautrements or Criteria Established for Individual Issues l
l 3.2.1 Material Compatibility l
3.2.2 Material Adequacy 3.2.3 Inadequately Supported Flange 4.0 FINDINGS 16 4.1 Material Compatibility 4.1.1 Generic Findings l
4.1.2 Site Specific Findings i
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4.2
.a,terial Adequacy 3
4.2.1 Generic Findings 4.2.2 Site Specific Findings 1
4.3 Inadequately Supported Flante i
4.3.1 Generic Findings 4.3.2 Site Specific Findings 5.0 COLLECTIVE SIGNIFICANCE 31 5.1 Significance of Each Issue l
5.1.1 Material Compatibility 5.1.2 Material Adequacy 5.1.3 Inadequately Supported Flange
v TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
A PAGE 4 0F 38 5.2 Collective Sir,nificance of the Subcatorory 5.2.1 Generic Significance 5.2.2 Site Specific 6.0 CAUSE 33 6.1 Material Compatibility 6.2 Material Adequacy 6.3 Inadequately Supported Fla m 7.0 CORRECTIVE ACTIONS 35 7.1 Material Compatibility 7.2 Material Adequacy 7.3 Inadequately Supported Flanr.e j
8.0 ATTACHMENTS 38 8.1 Attachment A. " Subcategory Summary Table and List of Concerns" 8.2 Attachment B, " Improved Technology for Critical Bolting Applications" l
8.3 Attachment C, " List of Concerns by Issue" l
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CONSTRUCTION SUBCATEGORY REPORT 10600 BOLTING EXECUTIVE
SUMMARY
SUMMARY
OF ISSUES This report addresses three issues that were derived from five concerns dealing with bc1 ting applications. Three Watts Bar Nuclear Plant (WBN) concerns were broad in scope and defined an issue that was considered generically applicable to Sequoyah Nuclear Plant (SQN) and Bellefonte Nuclear Plant (BLN). This issue dealt with the use of carbon steel bolts in stainless steel bolted connections. The remaining two issues were defined by one concern and limited in scope to the specific application and plant identified on the concerns.. One WBN concern identified potential deficiencies in the holddown bolt asstmblies used to install borated water tanks. The remaining concern which was identified at BLN expressed reservations about the adequacy of the support of a component cooling pipe spool piece, MAJOR FINDINGS Evaluation of the BLN concern revealed that the. spool piece in question was being installed and temporarily supported at the time the concern was filed.
An investigation conducted by the BLN safety engineer several weeks later found that the spool piece was adequately bolted in place as a result of normal on-going construction activities; consequently, the concern was considered factual but not a problem.
Investigation of the borated water tank holddown bolt assemblies did not confirm the explicit concerns expressed, e.g.
appropriate materials were used and installation tolerances were met.
However, a related issue involving the lack-of.QC documentation on the holddown assembly installation process was identified. The issue alleging j
that carbon steel bolts were used in stainless steel bolted connections was found to be true at WBN, SQN and BLN.
However, the actual use of carbon l
steel bolting in stainless steel bolted connections is an acceptable practice.
l Even in borated water systems, carbon steel bolting has been proven I
reliable unless joint leakage occurs.
Operational nuclear plants have l
l experienced significant carbon steel bolting degradation due to boric acid (R4 corrosive wastage. This degradation and wastage is caused by inadequate or
{
improper joint assembly and not specifically from the use of carbon steel-I bolting. TVA has recognized this problem to a limited extent at WBN and SQN l
but additional corrective actions are required to ensure that the problem is I
adequately addressed. No corrective actions addressing this issue were taken I
at BLN prior to the ECTG investigation.
The boric acid wastage of carbon stoel bolts war determined to be a reliability issue rather than a safety issue. This conclusion was based on the application of the leak-before-break design philosophy which assumes that if pressure boundary degradation occurs detectable leakage will occur before a catastrophic failure of the pressure boundary. With respect to the borated water tank holddown bolt assembly concern, no hardware deficiency was found 1946T Page 1 of 2 l
and no systemic QA/QC deficiency was identified; hence, the concern was not considered safety-related.
Finally, the BLN concern was factual but not a problem.
It was also determined to be not Asfoty-related.
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COLLECTI"E SIGNIFICANCE No issues of collective significance were launtified by the ECTG evaluation.
The small number of concerns and the lack of a common element within the issues precluded the identification and verification of any issue of broad collective significance.
CAUSES i
Given that no broad, programmatic problems were identified, only proximate causes were identified for the two problems documented in this report. The inadequate handling of the issue on boric acid wastage of carbon steel bolts IR4 was attributed to the failure of TVA to assign responsibility and sufficit.>nt l
authority to an organization or manager to resolve the issue for all plants and the failure of technical personnel in design, construction and operations to reach a consensus on corrective actions. The failure to generate adequate QC documentation on the borated water holddown bolt assembly installations was traced to the failure to ask the vendor to provide such documentation.
l CORRECTIVE ACTIONS 1
TVA will comprehensively review all holted connections on the pressur9 boundary of borated water systems at WBN. SQN and DLN, determine those connections that reluira raplaeamont of carbon steel holes and replace them, and ensure that the design inter,rity of modified connections is not compromised. Carbon steel bolting will remain installed in those application's ida where it is either unnecessary or impractical to effect a bolting change out.
I TVA will also evaluate the borated water tank holddown bolts installation and ensure that they are adequate.
Programmatically. TVA has consolidated the nuclear power organization under a single Manater of Nuclear Power. This fundamental change, coupled with other j
organizational changes, provides assurance that the necessary coordination and j
communication among nuclear organizations occurs.
In addition, DNQA will review potentially generic QA problems on a case-by-case basis to determine the appropriate corrective action.
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v TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 l
SPECIAL PROGRAM l
REVISION NUMBER:
4 PAGE 5 0F 38 l
CH'RACTEM12ATION OF ISSUES l
A 1.1 Introduction l
l Five cor.cerns, each involving bolting instal}alion and/or usage, I
have been evaluated. These five concerns were addressed as three l
separate issues.
1.2 Description of Issues 1.2.1 Material Compatibility IN-85-021-X04 (WBN)
IN-85-824-001 IN-86-183-001 Carbon steel bolting was installed in stainless steel flanged I
l connections, to include stainless steel valves.
Replacement l
of the carbon steel bolting was started in the valves but was I
halted before completion.
This issue was determined to be generically applicable to SQN and BLN.
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1.2.2 Material Adequacy i
PH-85-Ot.2 001 (WBN)
The nuts used to bolt down the borated water tanks may be l
l inadequate and there may be insufficient contact between the I
bracket and plates. Also, during tightening of the nuts, a bolt turned due to the nut being too tight.
1.2.3 Inadequately Supported Flange l
BNP-QCP 10.35-B-22 (BLN) l A flanged connection on a component cooling (KC) pipe is inadequately supported with only two bolts.
2.0
SUMMARY
2.1 Summary of Issues The cited concerns raised a variety of issues certaining to the installation and/or application of bolting. The specific issues raised were the use of carbon stoel bolts on stainless steel flanted i
I connections, inapproplate nuts and conformance to installation tolerances on chemical volume and control system (CVCS) holdup tanks A and B, and an inadequately supported flange connection.
m TUA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 6 0F 38 2.2 Summary of Evaluation Process The concerns were evaluated by using several approaches: reviewing drawings, specifications, contracts. Tennessee Valley Authority (TVA) General Construction Specifications, Nuclear Safety Review Staff (NSRS) and WBN Project Manager's Office (WBN-FMO) inv.estigation reports, and other appilcable documentation / criteria; interviewing TVA and contractor personnel familiar with bolting code requirements, procedures.. practices, and installations; and l
inspecting the subject bolting where appropriate.
i 2.3 Summary of Findings i
2.3.1 Material Compatibility The use of carbon steel bolts in stainless'stoel flange connections at WBN was confirmed. This was a standard practice that was not disallowed by the American Society of Mechanical Engineers (ASME) Boiler and Pressuro Vessel Code Section III and American National Standards Institute (ANSI)
B31.1 and was therefore allowed under General Construction Specification G-?9M Process Specification 4.M.1.1, Paragraph-3.1.7.4, for all but TVA class A systems. A review of the mechanical bill of material drawing series 47BM, which governs the use of boltingImaterials at Watts Bar, confirmed that stainless, steel bolting material has been required for all TVA class'A systems.- However, TVA has noted since'1979 a potential problem in using carbon steel bolts in borated water systems which also include TVA class B piping.
TVA cone)uded the problem was a reliability problem rather than a safety problem, based on the " leak before break design philosophy. The problem was one of potential degradation and I
wastage of carbon steel bolts by boric acid from leakage IR4 caused by inadequate or improper joint assembly and not i
specifically from the use of carbon steel bolting. Therefore.
I replacement of carbon steel bolts on borated systems class B and C piping was specified, but not immediately required, to improve reliability.
Therefore, the concern was factual but not a safety problem.
1 2.3.2 Material Adequacy The concern, as stated, involved inadequate hold-down bolting hardware and tightening techniques used on borated water-tanks. The investigation determined that the CVCS holdup tanks A and B in unit 1 of the Auxiliary Building-(AB) were the subjnct of the concern.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 l
SPECIAL PROGRAM REVISION NUMBER:
4 PAGC 7 0F 38 1
1 The hold-down boltir.g hardware and bolt tensioning were provided by the Holdup tank vendor, Chicago Bridge and Iron (CBI). The bolting hardware was found to be marked correctly
?!.d in conformance with the vendor's design and technical 4
data provided to satisfy the vendor's contractual I
obligations. Therefore, this aspect of the stated concern l
was not factual.
With respect to the inadequate tightening aspect of the l
concern, two issues were investigated:
insufficient contact between the plates and bracket and the turning of a bolt during tightening. A visual inspection of the holddown bolt assemblies revealed sufficient contact between all components where intimate contact was required within the assembly.
Therefore, the allegation of insufficient contact was not factual.
The bolt turning issue could not be resolved by either in.pection or a review of documentation.
1 Consequently, technically competent personnel were contacted to determine if bolt turning was possible and, if possible, f
what the consequences would be if the bolt did turn during the tightening process.
1 Although there was no ccr.sensus on this point, turning uf
'.he l
l bolt curing the tightening process was determined to be l
pcssible; however, a consensus was reached that, had turning I
occurred, such turning would not acversely affect the ability l
l of tne holddown bolt assembly to perform it's intended l
l function assuming that all bolts were properly tensioned.
Therefore, although bolt turning may have occurred during tightening, this would not be a condition adverse to quality (CAQ).
It should also be noted that a NSRS investigation conducted l
on this concern documented a related CAQ,(
l.e., no vendor QA f
l documentation was found on the tensioning process). A i
I follow-up investigation determined that WBN nonconformance reports (NCRs) 3928R and 6596R1 were written to document I
missing mechanical equipment installation process Quality Assurance / Quality Control (QA/QC) documentation. However, the CVCS Holdup Tanks were specifically excluded from the corrective actions specified in the disposition of the NCRs.
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SPECIAL PROGRAM REVISION NUMBER:
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2.3.3 Inadequately Supported Flange i
The inadequately supported flange concern was determined to l
be a personnel safety concern only..The flanged connection identified in the concern was a temporary two bolt connection that had not received final inspection.
The connection was j
upgraded by adding.eight more bolts and the remaining nine bolts will be added during scheduled construction activities.
I 2,4 Summary of Collective Significance No issues of collective significance were identified by the ECTG evaluation. The small number of concerns'and the lack of a common element within the issues precluded the identification and verification of any issues of broad collective significance.
2.5 Summary of Causes l
2.5.1 Material Compatibility No safety related CAQ was identified with respect to the use I
of carbon stoel bolting in stainless steel bolted connections.
I It was determined that coordination between design, I
construction and operations management' personnel was poor in I
resolving the issue of boric acid wastage of carbon steel 184 bolting on' borated water systems.
In addition, poor I
communication between technical personnel in design, I
construction and operations made reaching a consensus on this l'
issue difficult.
I 2.5.2 Material Adequacy I
The concerns explicitly identified by the CI were unsubstantiated; consequently, no proximate.or root cause analysis on those concerns was performed.
However, a related problem concerning the absence.of QC documentation on the holdown bolt installation was identified. The proximate cause of this deficiency was that, in'accordance with'the QA standards current of the time CBI's contract was issued, no requirement was included in CBI's contract to provide QC document'ation on the installation process.
2.5.3 Inadequately Supported Flange The concern was factual but not a problem; therefore, no cause analysis was required.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 9 0F 38 2.6 Summary of Corrective Actions 2.6.1 Material Compatibility On September 14, 1982, TVA issued ECN 3522 to add bolt replacement criteria to the mechanical bill of materials for WBN.
In addition, the mechanical maintenance section issued Mechanical Section Letter 3.1 which directs the replacement of carbon steel bolts on flanged connections in borated water service.
However, these corrective actions are confined to TVA designed flanted connections. Vendor designed bolted connections are excluded.
A summary of the additional corrective actions specified by WBN management to address this issue follows.
A design review of borated water systems will be performad to identify vendor designed and qualified pressure retainint bolted connections in borated water service.
Carbon steel bolts used on a borated water pressure boundary will be replaced where the aforementioned review
!R4 j
determines replacement is appropriate and any affected l
vonder stress analysis and code data sheets will be revised as necessary.
The WBN mechanical maintenance
- roteouros will be revised to incorporate the design appresoc
- *.antos in vendor designrfd and qualified joint s.
The SQN corrective actions that address this issue were implemented to address Nuclear Regulatory Commission (NKC)
Inspection and Enforcement Bulletin (IEB) 82-02.
The SQN responses to JEB S2-02 indicate that a review of bolted connections in borated water service was conducted but the scope of the review was not clearly established.
Since the scope of the review and corrective actions at WBN were limited to TVA designed bolted connections, the scope of review and corrective actions at SQN should be confirmed to be comprehensive.
A summary of the additional corrective actions specified by SQN management to address this issue follows.
A program will be developed to ensure that all critical bolted closures are identified and included in the bolting replacement program as appropriate. The program will incorporate the recommendations of the AIF/MPC bolting task force on the identification and maintenance of critical bolted closures.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE'10 0F 38 A summary of the corrective >ctions specified by BLN management to address this-issue follows.
l A design review of all TVA and vendor designed bolted closures in borated water service will be performed-to l
identify and priortize the closures that use carbon I
steel. The AIF/MFC bolting task force guidelines for-critical joint identification will be.used te identify and rank the bolted closures.
Bolt replacement or augmented in-service inspections will be specified for critical closures surject to boric acid wastage depending on closure priority ranking and utility operating experience.
In addition, mechanical maintenance practices and procedures will be reviewed to ensure compliance with-the bolting task force guidel'.nes for. critical joint identification, leak detection' criteria, NDE guidelines, and training aids.
2.6.2 Material Adeguacy No corrective actions were required for the concerns explicitly identified in this issue.
However, e'CATD was issued to document the lack of QC documentation'on the holddown bolt installation.
In addition, TVA's Division of Nuclear Quality Assurance was requested to address the programmatic issue of the vetrofit of QA requirements'to quali fy-relatoc activitios.
WBN management's response to the lack of QC documentation is summarized as follows:
l Installation of the holddown bolts was. documented by the vendor in accordance with the vendor's:QA program. TVA's position is that'the holddown bolt-installation is therefore adequate and no corrective actions are required. However, the terque of the holddown bolts will be checked and evaluated.
2.6.3 Inadequately Supported Flange No corrective actions were required to address this issue.
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PAGE 11 0F 38 l
3.0 EVALUATION METHODOLOGY 3.1 General Methods of Evaluation i
As noted in the summary, section 2.2, the concerns were evaluated by using several approaches:
reviewing drawings, specifications, contracts, TVA construction specifications, NSRS and WBN l'MO I
investigation reports and other applicable documentation / criteria; interviewing TVA and CBI personnel familiar with bolting code I
requirements, procedures, practices, and installations; and l
inspection of the subject bolting where applicable.
In addition, the Divialon of Nuclear Engineering's (DNE's) trend analysis data base wam used to assess the incidence of documented CAQs similar to f
the employee concerns. This data base has been maintained since j
1976 and includes most CAQs genersted since that time. The types of l
CAQ decuments included are:
engineering, construction, power, and supplier NCRs; significant condition reports (SCRs); problem l
identification reports (PIRs); engineering, vendor, and joint audit deficiencies (EAUDs, VAUDs and JAUDs); preoperations test deficiencies (PTDs); licensee event reports (LERs); and NSRS report deliciencief (NSRS).
All entries are cataloged by the problem area i
identified on tne CAQ and can be grouped by the resulting identifier code for evaluation. The evaluation strategy pertinent to each issue is dist.ussed in the following sectior.s.
l F rilyonents or Critor:a Established for Individual Issues l
3.2 t
3.2.1 Material Compatibility In composite, the cited concerns allege a WBN design l
inadequacy in that carbon steel bo)ts were used in the i
installation of stainless steel valves and flanges throughout WBN.
Specific systems and one specific location were cited as examples, 1
1 Previous investigation results documented in NSKS Investigation Report I-85-483-WBN were reviewed to determine if the scope of the investigation and the resolution of it's findings were sufficient to resolve the concerns.
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l TVA EMPLOYEE CONCERNS P.EPORT NUMBER:.10600 SPECIAL PROGRAM.
REVISION NUMBER:
A PAGE 12 0F 38 l
Design basis documents were reviewed and design personnel consulted to determine the design requirements pertinent to the' concerns. Design output' documents including TVA General' Construction Specification G-29M (G-29M), the mechanical bill of materials drawing deries 47BM, engineering change notices (ECNs) 3522 dated September 13, 1982 and'6004, dated January 31, 1986 and approximately 20 ASMF forms NPV-1,
" Manufacturers' Data Report for Nuclear Pumps'and Valves,"
were reviewed to determine'if. bolting material construction specifications were consistent with the design requirements.
TVA NCRs BLN NCR-59 and NEB-8017, NRC Information Notice (1N) 80-27 dated June 11, 1980 and IEB 82-02, dated June 2, 1982 i
Institute of Nuclear Power Operations (INPO) Significant Operating Experience Report-(SOER) 84-5 dated September 20, 1984 and the DNE trend analysis CAQ data base were' reviewed to establish the history of reported problems relevant to the i
concern.
Internal TVA memorandums NEB 791030108, i
SWP791109047, NEB 810521264, SWP810611048.. NEB 811223275, L26820205899, MEB820?L9019,'MEB820315014 NEB 820401276 NE5520813251, L44841025603, L33841025804, L29850131894, and B45860113268, which detail the deliberations between design, construction, and power representatives who were involved in the resolution of this issue, were reviewed to 16eitify the magnitude, depth, and direction of the efforts undertaken to resolve the issue.
(Note that the indiceted' memoranda refet >nces encode the date of issuance in the' fourth through the ninth characters, e.g., NEB 791030108 indicates that the Nuclear Engineering Branch issued the memorandum on October 30, 1979). TVA's reports to the NRC'on the use of threaded fasteners in borated water systems at SQN (A27820802028, A27830218011 and A27831121008). were reviewed for comparison to the WBN' disposition. NRC Inspection Report 50-390, 391/85-08 dated March'29,:1985 for W8N was reviewed to determine the basis on which the NRC closed IEB 82-02 for WBN.. Finally, knowledgeable construction personnel were consulted to determine the intent and. extent of bolt replacement activities cited in concern IN-85-021-XO4.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM j
REVISION NUMBER:
4 PAGE 13 0F 38 1
1 The following TVA personnel were interviewed during the I
course of the investigation and made a significant contribution to the conduct of the investigation.
l Design Personnel Supervisor, Nuclear Engineering Branch, Codes, Standards, Materials, Corrosion and Coatings Section:
This individual
{
is a member of the joint Atomic Industrial Forum ( AIF) Metal Properties Council (MPC) Task Group on Bolting and was a j
coeditor of the paper, " Improved Technology for Critical l
Bolting Applications," presented at the 1986 Pressure Vessels and Piping Conference and Exhibition and published by ASME (Attachment B).
The paper summari:es industry wide bulting failure experiences, the AIF bolting program, the results of the work performed under the AIF program and the AIF program recommendations.
He provided a copy of the Aff report, as well as additional documentation., detailing research on boric acid wastage of I
carbon stool bolts.
j Metallurgical Engineer, Nuclear Engineering Dranch, Codes, Standards, Materials, Corrosion and Coatings Section: This incividual was an expert in materials applications and the i
pertinent industry standards and codes.
In addition, he was familiar with 3 - 2 ')M ano its application at JVA nuclear plant:
l and is responsible for interpreting. G-29M for construction I
personnel.
He also authored the design technical position memorandum on the bolt degradation issue.
Construction Personnel Engineering Associate, Nuclear Licensint Unit: Assisted in the search for documents relevant to the subject concern.
Mechanical Engineer, Supervisor, Mechanical Engineering Unit l
at BLN:
Provided background and documentation on i
BLN-NCR-59.
Also provided status on proposed bolt replacement activities at BLN.
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IVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBERi 4
l PAGE.14 0F 38 Meenanical Engineers, Mechanical Engineering Unit (WBN):
Several members of this unit were interviewed to determine if a systematic carbon'stoel bolt replacement program had been-initiated and if any valve body-to-bonnat studs lwere included in the replacement activities. They provided comments on the bill of material notes addrescing bolt change out and assisted in the search for documentation to establish whethor or not bolt replacements occurred on either TVA designed co;.nections or vendor components.
Power Personnel Mechanical Engineer, Design Services: Discussed bolt degradation in general and concurred with the NSRS findings.
Two Mechanical Engineers, Mechanical Maintenance Unit, WBN:
Discussed DNE technical position and impact on. maintenance activities; also, discussed the scope of the problem at WBN and reviewed Westinghouse drawings relevant to the concern.
Later discussions identified the procedures and tracking.
mechanisms used to implement the required corrective actions.
3.2,2 Material Adequacy The subject cencern questions the adequacy of both the boltint hardware and installation-procedures used by the vendor CDI, to rount CVC0 holdup tanks A and B in unit'1Lof the AB at WBN. The' issue was determined to be limited.in scope to the specified components and evaluated.accordingly.
NSRS investigation report I-85-694-WBN was reviewed to determine if.the concern was adequately addressed. :The.
1 WBN PMO response to the NSRS report was reviewed to determine if the recommendations for corrective action supported the the NSRS findings and for references.to. relevant documentation.
CBI documents including drawings 74-3743/4 F1, F2, and F3, received-April 9, 1976; the contract file for contract 4
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PAGE 15 0F 38
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75K54-83115 issued in 1975; letters WBN 770127018, MEB770303119, and other pertinent correspondence were reviewed to determine the vendor's material specifications and installation instructions. WBN NCRs 392BR issued February 1, 1982, and 6596R1 issued March 27,'1986, document the lack of equipment installation QA records for several pieces of equipment including the subject tanks. These NCRs were reviewed to assess their impact on the resolution.of the 4
concern.
Numerous TVA personnel and a CBI representative were interviewed during the course of the investigation. The following personnel made a significant contribution to the conduct of the investigation:
Design Personnel Civil Engineer, Civil Engineering Branch:
Discussed the design requirements for concrete anchorages and the tensioning process.
Construction
]
Civil Engineer, Civil Engineering Unit: Assisted in the a
inspection of the subject bolts.
1 Power Operations 1
Two Mechanical Engineers, Nuclear Services Branch: Initiated NCR 6596 to generate QA documentation required for subject
)
l bolts. Referred evaluator to Modifications Unit for an J
explanation of the disposition of the NCR.
Two Mechanical Engineers, Modifications: Discussed disposition of NCR 6596 and explained why the subject tanks were excluded from the corrective actions taken to resolve the NCR.
Three Mechanical Engineers Mechanical Maintenance: The unit supervisor and two engineers discussed the implications of.a i
bolt turning during the tensioning process and the relative merits of retensioning the bolts.
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PAGE 16 0F 38 CBI Personnel, Mechanical Engineer, Engineering Supervisor:
Approved CBI drawings F1, F2, and F3 detailing the tensioning process. Discussed tensioning operations in theory and practice. Agreed to attempt to locate tensioning documentation in CB1 archives.
The CBI contact was an engineering supervisor at the time of the tanks installation and was intimately involved in the technical administration of the contract and in particular.
-l the tensioning of the subject holddown bolts. He approved i
the CBI drawings that detailed the holddown bolt tensioning procedure and was the signatory on letters from CBI to TVA providing revisions to the tensioning procedure based on experience gained from installing similar tanks. He brought considerable expertise on the subject of bolt tensioning in general and on the installation of WBN CVCS tanks in I
particular.
3.2.3 Inadequately Supported Flange The concern expressed reservations about the adequacy of the support provided by only two bolts installed in a specific flanged e-a action in the BLN component cooling system.
Informal *asorandums sent between the BLN Assistant Quality Manager and the BLN Safety Engineer were reviewed to assess the management actions taken to address the issue. The BLN Assistant Steamfitter Superintendent was interviewed to determine if any unusual practices were evident in this concern and to facilitate examination of the subject flange.
4.0 FINDINGS The findings and conclusions relevant to each of the three issues within l
the bolting subcategory are detailed below.
4.1 Material Compatibility Based on the findings presented below, the concerns addressed in this issue were factual and a corrective action program was implemented on a "no delay to schedule basis." However, the issue was resolved to achieve increased reliability of the affected systems; the issue was not found to adversely affect the safety of the plant.
It should also be noted that the use of carbon steel bolting in stainless steel bolted connections is an acceptable, reliable practice.
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l TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 l
SPECIAL PROGRAM l
REVISION NUMBER: 4 PAGE 17 0F 38 a.1.1 Generic Findings
'l The concerns cited were generic to WBN as stated by the q
concerned individuals (CIs). Furthermore, while a design l
l deficiency was not explicitly identified in the concerns, a i
design deficiency was implied.
Consequently, the objective I
of the investigation was to determine the applicable design requirements and then to ascertain whether they had been l
met.
During the investigation into the history of carbon steel corrosion problems, a review of the documentation associated with NRC Information Notice (IN) 80-27 was performed.
IN 80-27 issued June 11, 1980 documents leakage of borated water from a reactor coolant pump which resulted in the corrosive boric acid wastage of carbon steel bolts. TVA's design personnel reviewed IN 80-27 and documented on an l
internal memorandum (NEB 810521264) dated May 21, 1981 that the problem was generic to SQN, WBN, and BLN.
TVA addressed the problem at SQN and reported the corrective actions to the NRC in a final report dated November 21, 1983 on'IE Bulletin (IEB) 82-02 (A27831121008) since 82-02 addressed the same problem and required a response. WBN was also subsequently addressed and will be uetailed in the following section. A review I
of the documentation on IN 80-27, IEB 82-02 and other documents did not identify any corrective actions undertaken for BLN nor were any individuals contacted aware of any proposed corrective actions.
l 4.1.2 Site Specific Findings A detailed review of the NSRS Investigation Report (I-85-483-WBN) issued January 6, 1986 addressing these concerns for WBN revealed that it addressed directly the subject concerns with respect to l
TVA designed flanged connections and provided adequate documentation to verify the findings and conclusion.
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v TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 18 0F 38 A review of TVA General Construction Specification G-29M revealed that Process Specification 4.M.1.1, paragraph 3.1.7.4, addressed stainless steel flanges but did not directly apply to stainless steel valves. A review of BLN-NCR-59 issued June 28, 1977 revealed that it appli9d to an ASME Class III stainless steel drain tank cooler which had carbon steel bolting in closure connections. The disposition of the NCR was to "use-as-is" since the vendor had supplied the tank with the carbon steel bolting installed.
As stated in the NSRS Investigation Report, NRC-IE Bulletin 82-02 addressed a corrosion wastage problem with carbon steel bolting in systems where borated water was present. This subject was also addressed in NRC Information Notice 80-27.
The correspondence referenced in section 3.2.1 applies directly to carbon steel bolting in stainless steel flanted piping, velve and pump flange connections.
The summary of this correspondence is that carbon steel bolt degradation was an identified / documented reliability problem in borated water systems. TVA based this determination on the extension of the " leak-before-break" design philosophy. TVA design i
I engineers have participated in ad hoc industry task groups working on bolting problems reported at nuclear plants.
Although the final report on these efforts have not yet been published, several papers reporting on the results of the program have been presented, most notably the paper " Improved Technology for Critical Bolting Applications" which was sponsored by the Metal Properties Council, Inc., the Electric Power Research Institute (EPRI), and the PVP i
Materials and Fabrication Committee ASME. This paper was presented at the 1986 Pressure Vessels and Piping Conference and Exhibition, Chicago, Illinois, in July 1986.
The paper presented an overview of the EPh. " Generic Bolted Joint Integrity" project which identified outstanding bolting issues affecting nuclear power plants, one of which was general borated water corrosion. Some of the results currently available as a result of this program are: overall bolting failure and success rates, fracture mechanics (FM) assessment, generalized closure l
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l PAGE 19 0F 38 integrity (leak-before-break) model, bolt up procedure l'
guidelines, thread lubricants evaluation, and mechanica) l maintenance training. tapes. One of the most significant of l
these contributions is the generalized joint integrity model l
which allows the accurate modeling of a bolted joint and incorporates the load shedding and redundancy inherent to bolted connections. The following excerpt from the reference l
paper details the basis upon which the application of the j
" leak-before-break" design philosophy has been extended to i
bolted joints.
"The philosophy behind the model is analogous with the leak-before-break philosophy used in FM-evaluations of other pressure boundary components. The steps required to achieve the desired result, i.e., demonstrate that a degraded joint (due to wastage, cracking, etc.) has ample margin against catastrophic failure when the leakage from the joint reaches levels that have a very high probability of detection, to include:
knowledge of the degree of load shedding to adjacent fasteners due to fastener degradation, knowledge of the joint opening profile accounting for gasket spring back and flange distortion, realistic calculation of leak rates through the degraded joints, margin demonstration in load carrying capability of degraded joint and margin definition."
The paper concludes that joint integrity, ' assuming adequate joint design, is a function of station maintenance activities. Specific recommendations including critical joint identification, leak detection criteria, and nondestructive examination (NDE) guidelines are being developed for industry use as well as training aids to enhance the transfer of technology developed by the project.
TVA has been involved in the EPRI program from its inception, and this experience is reflected in the design guidance included in the TVA internal memorandums listed in section 3.2.1.
As a result, corrective action has been initiated to replace on a "no delay to schedule basis" carbon steel bolting in TVA designed flanged connections during routine surveillance / repair / maintenance
i TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM i
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activities. To this end, ECN 3522 was written on September 14, 1982 to add bolt replacement criteria to the TVA mechanical bills of material (B/Ms). However, in memorandum B45 860113 268 issued January 13, 1986 it was noted that considerable confusion had resulted in the original B/M changes in accordance with ECN 3522, so another ECN (6004) was initiated on January 31,'1986 to clarify the wording and give more specific bolting substitution guidelines.
It should be noted that in Class B and C systems, the SA 193 GR B7 carbon steel bolting was to be replaced with specific stainless
(
l steel bolting material.
However, if the replacement bolting was not l
immediately available, the SA 193 GR B7 carbon steel bolting could l
be substituted. This substitution is also addressed in the f
I aforementioned NSRS report.
A review of the 47 B/M series of drawings for various piping systems and components revealed the following:
1.
For Class A systems, in all cases, SA 453 GR 660 bolting material is specified for stainless rteel flanged connections.
2.
For Class B systems, the note initiated per ECN 6004 allowed substitution of SA 193 GR B7 (carbon steel) for SA 564 Type 630 (stainless) if the latter was not readily available. The stainless bolting was to be installed on a "no delay to schedule basis" as a replacement when it became available.
3..
For Class C systems, if SA 193 GR B7 was installed, it was to be replaced as detailed above also.
An Employee Concerns Task Group (ECTG) review of vendor valve drawings (Westinghouse) for Class A systems check, globe, and gate valves was conducted. Of 18 separate drawings reviewed at random, f
no Class A valves were found to be furnished with carbon steel I
bolting. Also a review of approximately 20 Class B check, gate and globe valve drawings was conducted with the same result'- no carbon steel bolting was furnished for the flanged body-to-bonnet l
l connection.
In addition, a Westinghouse valve specialist located j
onsite corroborated the results of the drawing review.
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l TVA~ EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
A PAGE 21 0F 38 l
However, the results of this review do not constitute a conclusive basis on which to say that no Class A, B, or C stainless steel valves used on borated water systems were supplied with carbon steel studs.
In addition, other vendor supplied components such as flanged pump casings, manway closure studs and heat exchanger connections could also be affected. The ECTG review revealed no evidence of a systematic evaluation of vendor supplied and qualified components to determine if carbon steel studs were used in any I
components that are part of a borated water system pressure j
boundary. This could be a significant omission since the Literature l
Survey of Carbon and Alloy Steel Fastener Corrosion in PWR Plants compiled and issued by Combustion Engineering, Inc. (CE) in April, i
1983 for the EPRI Research Project 2058-7 identified 28 boric acid I
corrosion events (out of 43 total events documented before 1983) i that involved vendor supplied components.
I In addition, one of the SQN responses to the NRC on IEB 82-02 issued August 2, 1982 (A27820802 028) which tabulated the results of a maintenance review of bolted closures identified boric acid crystallization on a reactor coolant pump flange and four isolation valves.
Four bonnet studs were replaced on one valve 1
(1-FCV-62-70).
This indicates that vendor supplied components are i
potentially subject to boric acid corrosive wastage.
Consequently, there is no apparent basis on which to exclude vendor supplied and i
qualified components from a bolt replacement program.
Cognizant personnel in CONST-MEU were interviewed. They had no 1
knowledge of a scheduled bolt change out involving stainless stoel valves. They indicated that had it been a construction activity, they would have initiated the applicable paperwork to document / control the work performed.
A cognizant Nuclear Services Branch (NSB) supervisor who was interviewed also had no knowledge of a bolt change out in stainless valves.
l The cognizant individual.in Mechanical Maintenance Section was interviewed. He was not aware of a scheduled bolt change out, but
)
indicated that it was possible for a bolt change to have taken place per DNE's carbon steel bolt replacement recommendations. He I
verified the findings of the aforementioned NSRS report and indicated that the scope of the memorandum B45 860113 268 issued l
January 13, 1986, was applicable to stainitss flanged connections as I
addressed in the NSRS report and stainless steel valve connections, j
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM q
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4 PAGE 22 0F 38 I
follow-up interviews with Hochanical. Maintenance Section (MMS) personnel deterniined that a section procedure, Maintenance Section Letter (MSL) 3.1, was issued addressing the bolt change out to be performed on TVA designed bolted closures during maintenance activities.
However, it should be noted that MSL 3.1'specifically excludes vendor components from the bolt replacement program.
To implement the! bolt change out, MMS also has documented action items AILMM0201, AILMM0094, and AILMM0203 that will be entered on the Tracking and Reporting of Open Items (TROI) tracking system to revise the appropriate maintenance instructions and requests. The TROI system is utilized by the Office of Nuclear Power to document l
and track outstanding work items and the action items that must be completed to close the lead item.
The file record for each item identifies the scheduled closure date for each item and the organization and the supervisor responsible for implementing the actions necessary to close the item. These actions were the basis on which the NRC closed IE Bulletin 82-02 for WBN in Inspection Report 50-390/85-03 and 50-391/85-03 paragraph 13.c.
The cognizant DNE individual who was the author of memorandum B45860113268 was interviewed.
He indicated that the DNE intent of the memornndum was to include'the valve body-to-bonnet bolted connection with respect to carbon stoel bolting replacement.
Their interpretation of the valve body-to-bonnot connection was that it was also a flanted connection.
He also provided (informally) documentation with respect to DNE's position on carbon stoel bolting used in stainless steel flanges and valvas.
The cognizant site Design Services representative was interviewed.
He concurred with the statement by DNE that the valve body-to-bonnet connection was, in fact, a flanged connection and therefore, requires carbon steel bolting replacement. He also indicated that it was reasonable to assume that the bolt replacement addressed by j
the subject concern on stainless valves was a result of DNE's carbon steel bolting replacement recommendations.
In addition to the bolt replacement activities, memorandum NEB 81052164 issued May 21, 1981 outlined additional actions that should be implemented to maintain the design integrity of the I
affected vendor qualified components if any valve studs are replaced. The memorandum indicated that vendors of affected equipment "shall be notified of the proposed change to permit reconciliation of the affected stress reports with the new material and it's design stress intensity and allowable stress values. Now j
calculations may be required, and decertification of stress or j
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 23 0F 38 design reports by registered PE's, and review of the changes by the owner or his designee are also required to preserve the code-assigned responsibilities.
EN DES will prepare a list of equipment requiring material replacement and will proceed to secure vendor approval for the changes." However, the investigation revealed no evidence of valve body-to-bonnet stud replacement at l
WBN; consequently, these actions have not been required to date.
==
Conclusion:==
In view of these findings the following conclusions are offered:
1.
There is evidence to support the possibility that carbon stoel bolting could have been replaced with stainless steel bolting in TVA designed flanged connections intended for borated water service, including bolted valve connections.
It is conceivable that the CI witnessed valve bolt change-out in accordance with this criteria and it is also conceivable that the change-out was halted before completion because:
(a) All available replacement bolting material had been used -
no more was readily available.
(b) Since the bolting replacement was on a "no delay to schedule basis," more critical work may have required completion and therefore, caused the bolt change-out to be halted for an indeterminate period of time.
2.
A partial review of valve drawings and B/Ms revealed no Class A systems where valves were furnished with carbon steel bolting and in class B and C systems, the use of carbon steel SA 193 GR B7 bolting is acceptable and will only be replaced in borated water pressure boundary systems to increase system reliability.
IR4 According to the revised notes in the B/M the SA 193 GR B7 carbon steel bolting is even considered an acceptable substitute for the replacement stainless bolting until the latter can be installed in the class B and C systems.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 ip SPECIAL PROGRAM' REVISION NUMBER:
4 PAGE 24 0F 38 The statement by the CI may well be a *;ue statement with respect to carbon steel bolting used to install stainless stoel valves and they may also have witnessed a bolt chango-out in the
' subject valves' connections. However, based on the findings of this evaluation, the concern has not identified a' condition adverse to quality. As stated previously, the use of carbon steel bolting in stainless steel bolted connections is an acceptable practice.
Even in borated water systems, carbon steel bolting has been proven reliable unless joint leakage occurs. Also, this evaluation is in agreement with the findings of the NSRS report I-85-483-WBN.
Nevertheless, it should be noted that the safety significance of-this issue ~is mitigated by the application of the leak-before-break (LBB) design philosophy. The use of LBB is justified by reference to the work performed by the AIF Bolting Task Force which assumed a comprehensive preventative maintenance program.
Identification of critical connections, including vendor qualified connections, is an essential component of that. problem and TVA has failed to incorporate a systematic review of vendor qualified components into it's corrective actions directed at this problem.
4.2 Material Adocuacy Based on the findings presented below, the concerns addressed in this issue were not factual.
However, a related deficiency involving missing QA documentation was identified that will require resolution.
A paraphrase of the concern follows:
The nuts used to bolt down the CVCS tanks A and B may be inadequate and there may be insufficient contact between the bracket and plates. Also, during tightening of the nuts, a bolt turned due to the nut being too tight.
4.2.1 Generic Findings No specific generic implications were evident in the stated concern beyond the holddown bolts and installation procedures y
used on the subject tanks.
In addition, the procurement contract on which the tanks and installation services were purchased was limited in scope to the subject tanks.
4 Consequently, the concern was determined to be limited in scope to the subject tank hold-down bolts.
1
{
l I
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 25 0F 38
)
l 4.2.2 Site Specific Findings l
The cited concern was previously investigated by NSRS and their findings were documented in NSRS report I-85-694 WUN.
The ECTG investigator reviewed the report and found that it had addressed the subject concern adequately. The report also determined the subject tanks to be-the CVCS holdup tanks A and B in unit 1 of the AB.
The NSRS report addressed the
)
concern in two parts since the concern was expressed by the 1
CI in two basic parts.
Part one dealt with the adequacy of the holddown hardware and this was evaluated by performing an inspection of the bolting installed. This revealed proper vendor identification marking on the bolting hardware as described in the vendor records package.
Part two addressed l
the. tensioning / tightening of the holddown bolts and the NSRS report recommended retensioning because no documentation could be found that would verify proper tensioning of the holddown bolts by the vendor.
The WBN-PMO response to the NSRS recommendations provided references to documentation relevant to the tensioning procedure, NCR 3928R which was initiated to identify the lack of documentation on the vendor tensioning operation, and the current procedure for inspection documentation.
However, it did not provide sufficient justification for not retensioning the holddown bolts nor did it offer alternatives to a' complete retensioning operation.
It also provided assumptions rather j
than evidence with respect to site procedure compliance and the vendor QA program which would have governed proper application of the bolt tensioning procedure.
Mechanical drawings (47W555 series) were reviewed to determine if any information related to the bolt tensioning /holddown hardware was included, but none was found.
i CBI vendor drawings (74-3743/7a-3744 series) were reviewed, I
which contained information/ criteria relevant to the tanks.
Sheets F1 through F3 of the series detailed the holddown hardware and complete bolt tensioning procedure.
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v TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 25 0F 38 l
l 4.2.2 Site Specific Findings The cited concern was previously investigated by NSRS and their findings were documented in NSRSLreport I-85-694.WBN.
The ECTG investigator reviewed the report and found that it had addressed the subject concern adequately. The report also determined the subject tanks to be the CVCS holdup tanks A and B in unit 1 of the AB.
The NSRS report addressed the
]
concern in two parts since the concern was expressed by the 3
CI in two basic parts.
Part one dealt with the adequacy of j
the holddown hardware and this was evaluated by performing an inspection of the bolting installed. This revealed proper vendor identification marking on the bolting hardware as described in the vendor records package.
Part two addressed q
the. tensioning / tightening of the holddown bolts and the.NSRS l
report recommended retensioning because no documentation j
a could be found that would verify proper tensioning of the l
holddown' bolts by the vendor.
}
The WBN-PMO response to the NSRS recommendations provided references to documentation relevant to the tensioning procedure, NCR 3928R which was initiated to identify the lack of I
documentation on the vendor tensioning operation, and the current procedure for inspection' documentation.
However, it did j
not provide sufficient justification for not retensioning the J
holddown bolts nor did it offer alternatives to a' complete retensioning operation.
It also provided assumptions.rather I
than evidence with respect to site procedure compliance and the vendor QA program which would have governed proper application
' {
of the bolt tensioning procedure.
Mechanical drawings (47W555 series) were reviewed to determine if any <rfprmation related to the bolt tensioning /holddown hardwke, was incitded, but none was found.
CBI vendor drawings (74-3743/74-3744 series) were reviewed, which contained information/ criteria relevant to the tanks.
I Sheets F1 through F3 of the series detailed the holddown hardware and complete bolt tensioning procedure.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 26 0F 38 A comprehensive search of TVA records was made for documented evidence of proper bolt tonsioning performance by the vendor.
Some relevant information was found in the correspondence initiated as a result of the TVA contract with CBI, to wit:
Memorandum WBN 770121 018 dated January 21, 1977 referenced in WBN-PMO response addressed contract completion and Memorandum MEB 770303 119 dated March 3, 1977 from MEB to H. C. Loy, Purchasing Agent, documented all technical data requirements covering the CBI contract as having been met.
In addition. TVA weekly Surveillance Report 26 filed May 12. 1976, on the CVCS holdup tank erection was located which documented the completion of " torquing (sic) activities" on the subject tanks. This document was generated in compliance with WBNP-QCP-4.11 and is l
essentially a checklist of ectivities performed by CBI during l
the week ending May 7,.1976.
However, no quantitative acceptance criteria or holdpoints pertinent to the tensioning process were included. Therefore, it was determined that no QA documentation was readily available in TVA's archives which would clearly establish procedure compliance by CBI on the bolt tensioning process.
At this point, other methodology was employed to answer the subject concern.
NCR 3928R was initiated in 1982 to document the fact that no inspection documentation existed for several pieces of
. mechanical equipment, including the CVCS Tanks.
Reinspection documentation was generated according to the disposition of NCR 3928R but the documentation did not adequately reflect the equipment evaluation / reinspection.
It was subsequently discovered that NCR 6596 revision 1 had been initiated by CONST NSB and dispositioned by DNP-Modifications to satisfy the recommendations made in the NSRS investigation report with respect to the reinspection evaluation referenced in NCR 3928R.
l i
The disposition of NCR 6596 established a correction method which required retorquing/retightening of bolt studs on the j
aforementioned mechanical equipment.
However, the CVCS Holdup Tanks were excluded from this action because the i
tensioning / torquing of the holddown bolts for the subject tanks
(
was accomplished by CBI while the other mechanical equipment bolts were tightened by TVA personnel.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 27 0F 38 A documented conversation however, between DNP-Mechanical Maintenance Engineering Supervisor and CBI Engineering Coordinator revealed that in their opinion no further action would be required on the holddown bolts for the subject tanks.
It further revealed that the " turning of an anchor bolt" presented no problem with respect to the holddown bolts being properly tensioned. The informal documentation provided by the DNP-Mechanical Maintenance Engineering Supervisor corroborates the statements made by the vendor.
Interviewed cognizant personnel in CONST-NSB who provided comments that indicated their agreement with the content of NSKS Investigation Report I-85-694-WBN.
Reference to NCR 6596 was made but NSB was not aware the CVCS tanks were excluded in the disposition.
Interviewed the individual responsible for disposition of NCR 6596 in DNP-Modifications who provided reasoning for exclusion of CVCS Tanks from the disposition of the NCR.
Interviewed responsible personnel in DNP-Mechanical Maintenance who indicated their willingness to contact the vendor in an attempt to obtain documentation concerning those parameters of the bolt tensioning process not addressed in the bolt tonsioning procedure. Specific information was requested to establish whether the statement in the concern "the bolt turned while a
tightening because the nut was too tight" is, in fact, a condition that would render the tensioning process unacceptable. The responsible DNP-Mechanical Maintenance l
Engineering Supervisor telephoned CBI's Engineering Coordinator who indicated that the turning of the holddown bolts would not create a condition that would cause the tensioning procedure to be unacceptable. The final comment made was that "the CIs observation represented an acceptable condition."
Follow-up cont ~ acts with CBI resulted in the submission of a l
package of documents (B44861016500) from CBI's archives and a letter explaining the QA records requirements that CBI conformed to during the fabrication and erection of the CVCS holdup tanks. The documents submitted indicate that CBI did not j
require " a documentation sign-off that specifically covers the-tensioning instructions on Drawing F-3."
Calibration records of o
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l TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 a?cCIAL PROGRAM 1
REVISION NUMBER:
4 1
PAGE 28 0F 38 l
the tensioning device used on the holddown bolts were included as well as ASME Code data package excerpts that include the signature of CBI QA auditors and Authorized Nuclear Inspectors certifying that the fabrication and erection of the tanks met all ASME code requirements.
Interviewed the Acting Supervisor, DNP-Mechanical Maintenance Engineering who indicated his complete agreement with the comments offered by the vendor.
He explained that a bolt turning was not anticipated because of the double nut arrangement on the embedded end of the bolt assembly and the tensioning process did not require the bolt to be turned to l
accomplish the required preload.
He further. explained that the j
bolt assembly was, in fact, free to turn and could have turned prior to tensioning or during the torquing process but not during tensioning.
His conclusion was that the tensioning i
process would not be affected by the turning of the holddown l
bolts.
]
Visual inspection of the subject tanks revealed sufficient i
contact between each nut and the tank rib or bracket. The I
statement by the CI that there was not sufficient contact between the " plates and bracket" was ambiguous since a plate to bracket installation does not exist. This inspection also revealed that the bolts adjacent to the manhole which were torqued instead of tensioned could not be suspect of turning because the location of the suspect bolts specified by the CI varied considerably from the location of the bolts torqued.
Consideration was given to selecting a random sample of a specific number of bolts on each tank for retensioning or, as a minimum, retorquing as detailed in the CBI procedure (drawing F-3) to verify the original tensioning / torquing process.
However, conversation with site CQC personnel. Mechanical Maintenance and CBI personnel revealed:
a.
A certain degree of bolt relaxation would have occurred since the original tensioning / torquing process was l
performed. Therefore, retensioning/retorquing to the l
original values would not serve as evidence that the process was done correctly.
The installed tension / torque values for I
each bolt today are considerably less than the installed l
tension / torque values applied in 1976 because of this relaxation of the bolts.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 29 0F 38 b.
The tensioning / torquing process required by CBI in the procedure detailed on drawing F-3, employs a segaence methodology.
To summarize, it is not possible to tonsion/ torque only a certain number of bolts. When one bolt is retensioned all remaining bolts would require retensioning. Consequently, none of the holddow.1 bolts have been tested to determine the preload on the bolts.
NCR 6596 was initiated to satisfy the recommendations made in the NSRS investigation report with respect to mechanical equipment having inadequate documentation and, therefore, requiring retightening/retorquing.
The CVCS Holdup Tanks wore excluded from the disposition of NCR 6596 because they wore vendor fabrirated, installed and inspected. While the readily available documentation is inadequate, as addressed in the NSRS report, it was not feasible for TVA personnel to adequately document a tensioning process performed by CBI ten years after completion. The correspondence reviewed shows that TVA accepted whatever technical data was offered by CBI upon completion of the work and the fact that the contract was subsequently closed is not without merit.
This does not provido acceptable documentation for a nuclear construction process, but does infer that the process was performed in a manner acceptable to TVA.
The NSRS report sufficiently answered the subject concern with respect to adequate bolting being used, so it was determined that further evaluation was not required in this area. Visual inspection of the subject bolts revealed sufficient contact between each nut and the tank rib / bracket. The information obtained from the aforementioned vendor representative and the Mechanical Maintenance Supervisor revealed that the turning of a bolt (s) was not possible during the tensioning process but was possible prior to the tensioning or during the torquing process. At this point however, each individual stated that the turning of a bolt (s) did not affect the tensioning process or the preloading of the holddown bolts.
No detailed evaluation was performed on those bolts torqued instead of tensioned because the location of the subject bolts given in the NSRS report precluded the bolts adjacent to the manhole as being those addressed by the CI.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 30 0F 38 4.3 Inadequate.;y Supported Flange Based on the findings presented below, the concern was factual, but was an industrial safety issue only. The concern was stated as follows: A-13 between R and S line.
Flange has 2 bolts. Two bolts won't support flange.
4.3.1 Generic Finding The stated concern had no generic implications.
4.3.2 Site Specific Finding The subject of the concern was a 24-inch diameter component cooling (KC) spool piece located at 10 feet N (A12) and 3 feet W (S) on elevation 640.
The spool piece had been temporarily positioned using temporary supports and 2 bolts installed in the flange.
Shortly after this stage of the installation was reached, a reduction-in-force occurred at the site. The concern was identified in the same time period.
Division of Nuclear Construction (DNC) management evaluated the concern and referred it to the BLN saf ety engineer for ovaluation on October 14, 1985.
When the safety engineer inspected the subject spool piece, eight additional bolts had been placed in the flange in the normal course of construction activities. The safety engineer concluded that no unsafe condition existed and no further action was required.
DNC management was informed of the safety engineer's conclusions, October 14, 1985, and the CI informed thereafter.
No further action was required.
1 TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4-PAGE 31 0F 38 5.0 COLLECTIVE SIGNIFICANCE 5.1 Significance of Each Issue 5.1.1 Material Compatibility The concern was verified to be true. The significance of the issue was mitigated however, by the existonce of a Watts Bar
~
program dedicated to the replacement of carbon stoel bolts in j
l TVA designed flanged connections in borated water systems on a J
l "no impact to schedule" basis. The priority given this program
(
was based on an engineering evaluation of the safety significance of the corrosion of carbon steel bolts exposed to borated water sourcos. The result of this evaluation was that the " leak-before-break" philosophy accepted by NRC justified the replacement of the carbon steel bolts on a normal maintenance schedule. With the exception of this specified usage, carbon l
steel bolting is acceptable for use in stainless steel bolted IR4 connections. The potential for joint leakage, caused by improper I
or inadequate joint assembly, is the only factor which impacts I
the reliability of carbon steel bolting in borated water systems.
The fact that it took almost six years to address this issuo for WBN and SQN and has yet to be addressed for BLN irdicates that l
management effectiveness in dealing with this issue leaves something to be desired.
The failure to document a credib10 l
reason to exclude vendor qualified components from the bolt 1
l replacement program in light of design recommendations to the contrary also raises questions about management effectiveness.
J I
5.1.2 Material Adequacy Of the three problems expressed in this concern, two problems were found to be not factual. The nuts used on the holddown bolts conformed to the approved design specifications provided by the vendor and sufficient contact between bearing i
l members was found on all holddown bolt assemblies. The third L
problem could not be conclusively addressed since the problem involved a transitory phenomena, e.g. the turning of a bolt during the tightening of a nut. Visual inspection of the holddown assemblies would yield no useful information. This problem required either QA documentation of an acceptable installation or rotensioning to generate such documentation.
Such documentation was not readily accessible; therefore, further evaluation and, possibly, corrective actions will be l
required.
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1 TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 32 0F 38 Therefore, the unresolved questions associated with this concern have immediate significance with regard to the "as-constructed" adequacy of the subject tanks; additionally, the lack of readily available QA documentation may require evaluation of QA record generating and record keeping requirements and procedures.
It should be noted however, that the activities in question were performed ten years ago which was very early in the life of the construction project.
Since that time, both as a result of experience gained within TVA and in the industry in general. QA records requirements and practices have evolved far past the standard practices in force at that time. Therefore, the significance of this issue may be diminished in light of current practices.
l 5.1.3 Inadequately Supported Flange The concern in question was limited to a single example of a i
questionably supported spool piece. The issue was determined to be an industrial safety issue that was ultimately addressed within the course of normal construction activities. Therefore, there was no significance to this issue.
5.2 Collectiva Significance of the Subcategory 5.2.1 Generic Significance There is no discernable generic significance of the three issues in the bolting subcategory when they are considered collectively. The small number of issues involved and the lack of any common problems of significance are indicative of l
at least an acceptable level of quality in bolting applications at TVA's nuclear plants.
This conclusion is further supported by the fact that no concerns in this subcategory were identified by SQN or BFN personnel.
Consequently, the bolting subcategory does not have collective generic significance.
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i TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 33 0F 38 5.2.2 Site Specific No site specific issues beyond thoso included in the individual concerns were identiflod. There'were no bolting concerns identified at BFN or SQN and only one non-significant concern identified at BLN. The two WBN issues, contained no common elements. Therefore, site-specific collective significance could not be 1
l established.
6.0 CAUSE 6.1 Material Compatibility Although no safety-related CAQ was identified in this issue, a few comments on the management effectiveness in dealing with this issue would seem to be warranted.
First, the documents that form the j
historical record of the handling of this issue seem to reflect a j
l division of management responsibility and authority between design, construction and operations organizations that does not promote i
cooperation among the parties involved. This situation may have l
1engthened the time required to evaluate and disposition the concern I
and the inconsistent implementation of the corrective actione.
Second, there appears to be no convenient way for technically oriented personnel in different organizations to communicate on l
l complex technical issues and reach a consensus on a solution both l
l adequate and acceptable to all.
(CATD 10603 NPS-01) 1 Since these problems are interdisciplinary and interdivisional in l
nature, the corporate ONP is the appropriate organizationLto. address I
the issue.
The ONP corporate response to this finding is as follows:
The following excerpt from Section IV of the NPP Volume 1 addresses the problem description.
l Conclusions l
TVA has restructured its organization to consolidate all responsibility for its nuclear activities within a single organization headed by the Manager of Nuclear Power. TVA has l
also established functional nuclear divisions and staff departments which have the responsibility and authority for providing 5
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM l
REVISION NUMBER:
4 PAGE 34 0F 38 technical direction for.and assuring the technical adequacy of all TVA nuclear activities within the respective functions, including site activities. As a result, TVA has taken action which provides assurance that lines of responsibility and authority for nuclear
)
activities are clear, that the necessary coordination and communication among nuclear organizations occurs, and that TVA's i
nuclear activities are subject to centralized management direction and control.
1 6.2 Material Adequacy
]
1 The material adequacy issue explicitly identified in the omployee concern was not factual and therefore no proximate or root cause analysis was required. The missing holddown bolt installation documentation cited in the NSRS investigation report is a problem that will require further assessment and corrective actions. The proximate cause of this problem was that TVA did not specify in CBI's contract j
that CBI provide QA documentation on the installation process to TVA.
I Whether or not this currently represents a programmatic weakness is a.
question that should be evaluated and dispositioned by the Division of Nuclear Quality Assurance (DNQA).
(CATD 10604-NPS-01)
{
l DNQAs response to this finding is as follows:
I l
Programmatically, DNQA will recommend, but not provide, a specific corrective action solution to a potential generic problem such as missing or unavailable documentation.
Evaluition must be performed on a case by case basis.
The assessment /f ea'ob situation shoul.d take into consideration such factors a /the item \\or component's importance to safety and whether th ocumentatio is required for
\\
l system compliance.
(% 1
/
I
/
1 To determine the effectiveness o ('
s r ept,, rogram relating to quality requirements for/v g(hot.'se, f the Nuclear Quality Assurance Manual (NQAM)
$h Nu e hgineering Procedures (NEP) were examined.
e een ogejm'isdescribedinthe j
following manual se io(?
il pr ures.
M. co'curement Document Control
$3ebfio1 (1) NQAM, Pa rement [ j /
(2)
NEP-4.
(3) NQA, P II..Qecth'2.1 Procurement of Materials, Spa're Sa ts, phd Servdes NQAM, Ppf td,('tect,idn '2.'4)hdirectly implies that f or design and
(
constettetI6g; NEPA4;1' will apply and for operation phase activities, i
NQAM Part bII, SecMor'2.1 will apply.
i s
NQAM, Part I
ion 2.1, paragraph 4.3.2.8 addresses documentation V, requirements and part C of Appendix C provides a detailed checklist.
l l
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v TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 i
SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 35 0F 38 NEP-4.1, Attachment 9, pac,agraph 5-10,,8.la 1 and Attachmint 12 addres.s doggmentation requirements.
- However, DNE's program is not as clo'ar and detailed ss that of DNQA's.
i To reduce the possibility o recy$nce, ' E
.1 should be evaluated regarding:clatit 66]ief a Q,..,
.,ing documentation requirements:
- - - ~ ~ - - -.....
j 6.3 Inadequately Supported Flange This concern was factual but not a problom; therefore, no cause analysis was requirod.
l 7.0 CORRECTIVE ACTIONS I
\\
7.1 Material Compatibility l
l l
TVA has initiated a bolt replacement program for the replacement of l
carbon steel bolts on stainless steel flanges used'on borated water I
Inadequate or improper joint assembly can I
i cause loakage which results in corrosive wastage of carbon stoel IRA l
bolting. Although this problem may also exist at BLN, no program I
]
exists as yet to change out carbon steel bolts used in'a similar l
appilcation at BLN. The existing programs at SQN and WBN should be l
l uvaluated to determine if vendor qualified components should be l
included in the program.
The AIF bolting task force recommendations l
for improvements in bolted closure maintenance should be reviewed for incorporation into each affected plant's preventive maintenance program.
Review of the ECTG findings on this issue resulted in the identification of additional corrective actions by various project organizations. The corrective actions spocified by line organizations for each project are presented below.
SM Due to investigations associated with SQN Employee Concerns Task Group Element Report 106.03 SQN R1, it has been determined that a l
problem exists concerning the use of carbon steel bolting material in borated water systems flanged connections. The use of carbon or low alloy steel bolting material is a concern due to the potential of material susceptibility to corrosion wastage from leaking boric acid.
SQN ECN L-5691 was written to address replacement of bolting material in borated water systems flanted connections, but specifically excluded flange bolting supplied by vendors on valves, pumps, and other equipment. This exclusion is contrary to DNE technical position memorandum B45 860113 268 and the documented l
scope of the AIF/MPC industry program on bolting wastage problems.
l Additionally, the SQN responses to IEB 82-02 did not indicate that l
l l
TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAA REVISION NUMBER:
4 PAGE 36 0F 38 i
all vendor qualified components in borated water service were reviewed to determine if carbon steel bolts were used inflanged 1
connections, nor was there any evidence to suggest that SQN's maintenance program would be revised to incorporate.the AIF/MPC bolting program recommendations.
Consequently, SQN will develop a program for implementation of the l
AIF/MPC bolting program recommendations. The program will include a i
review of vendor supplied bolted closures and flanged connections to i
ensure that all critical connections are identified and included in the bolting replacement program, as appilcable (CATDs 10603-SQN-01,02).
I l
WM Problem Identification Report (PIR) SQN NEB 8723 was ir.itiated to address this concern at Sequoyah. This PIR was determined to be I
generically applicable to Watts Bar (WBN) and a potential generic i
condition evaluation has been initiated for WBN.
The purpose of this PIR is to address the exclusion of vendor components from the bolt replacement program.
A review of vendor designed and qualified l
pressure retaining bolted connections in borated water service (Class 1, 2, and 3) includingJh.qse-f ( gvalve body-to-bonnet flanges, will be perf,9tmed tf NEB-CSM to identify those l
conneer16fis~
An 6Talua,tl.en M 11 be performed to determine those connections.
i whac
~~ippropriateb y'p{eF//p'lacedeht of low alloy steel bolts is 7
,0 ECN 4111 t e initiat d to control the
)
0 y, V(.g,s' rapigeement Yf endoA p,p1 14ey its, including reviow of
) p(p gt,g'"',,,(s'th'e'vendorstre er}fp-sa re o code data sheets, if r.eeed$'.i %pproj -etfH ng y a r T n"Et I will be incorporated by the 8echadical'{" p,jsefrs1Tce Section (MMS) a into the WBN vendor bolt
-I replacer thT rogram. MMS will maintain the status of vendor bolt L
"'r~oplacements to ensure that all authorized changes to low alloy steel bolts in borated water service are replaced on a "no delay to schedule basis".
Approved changes on Unit 2 will be incorporated by DNC for replacement of low alloy steel bolts on a "no delay to schedule basis" prior to system transfer.
Any Unit 2 vendor bolts i
not replaced at the time of system transfer are to be tracked under the OWIL list, and added to the MMS bolt replacement program for tracking until replacement.
Maintenance Section Letter (MSL) 3.1 will be revised to include the approved changes in vendor designed and qualified components in the WBN bolt replacement program as ECNs'are issued identifying vendor joints to be changed.
l l
0 TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 37 0F 38 In addition, the ASME Paper "MPC-Vol.26", " Improved Technology for Critical Bolting Applications" will be jointly reviewed by DNE-UES and WBN Mechanical Maintensnee for application to bolted, flanged, pressure boundary joints for TVA Piping Classes A, B, C, and D.
l This review wil' be completed by July 30, 1987. Any improvements identified by this joint review will be incorporated in the appropriate Maintenance Instructions or Plant Procedures by 1
Janue.ry 1, 1988.
(CATDs 10603-WBN-01, 02) l EkN BLN's proposed corrective action will be to systematically, identify j
and prioritize all af fected TVA designed and vendor supplied bolted l
closures (i.e., those with carbon steel bolting used in borated i
water systems).
Guidelines for critical joint identification developed by AIF/MPC bolting task force will be used for the f
identification process and closure priority ranking.
It is anticipated that criteria such as code class, size, function, etc.,
will establish the ranking procedure. Once the ranking process has been completed, DNE will recommend either material replacement or augmented in-service inspection procedure alternatives based on closure priority ranking and utility operating experience.
DNE will either develop an inspection program based on the bolting task force guidelines and industry experience, or write an ECN for bolting material replacement, as applicable.
As recommendations become available from the AIF/MPC bolting task force, site mechanical maintenance procedures and practices will be reviewed to determine if deficiencies or inconsistencies exist between task force guidelines and plant policies. Task force recommendations should include criteria for critical joint identification, leak detection criteria, NDE guidelines, training aids, etc.
Bolting task force guidelines identified as not included in present site maintenance policies should subsequently be incorporated into appropriate procedures. Training modules for maintenance / craft personnel, ISI and QA inspections, and engineering procurement and receipt inspection should be developed.
Also, experience gained by addressing this concern et SQN and WBN and related industry experience will be applied by BLN.
(CATD 10603-BLN-01, 02) 1
TVA EMPLOYEE CONCERNS REPORT NUMBER: 10600 SPECIAL PROGRAM REVISION NUMBER:
4 PAGE 38 0F 38 7.2 Material Adequacy The only outstanding question remaining on this concern is the lack of QA installation documentation on the holddown bolt tensioning process. The generation of NCR 6596 underscores the fact that this documentation is required for the Life of Plant (LOP) records. The disposition of NCR 6596 does not satisfactorily explain why the CVCS holdup tanks should be excluded from the requirement to produce such documentation; therefore, the lack of holddown bolt tensioning documentation should either be justified or the documentation produced.
(CATD 10604-WBN-01)
]
Upon review of the ECTG findingsc-WBN"QA managers concluded that no has been'*lo,acti.ons--str"rTg~u' ired.. TheT 7easoned that {TVA's polic corrective acpapt iteg'.puilt 'and/ce' installed by vanders with approvedtQA programs. It ha's not*be quired that kVA personnel rever.ify'. items whic'h fall cio/gq,a edven4or,QA(program. This er is the reasoning'sbehind t Wag R* 6T CVCS, tanks were.oel.tted: ~To' Miol.ve-this'~c'on'9.6.11 +ven thoug cern, maintenance request (MR),5J39a6-wes-#Fitten to have the torque (tensioning) of l
the holddo'wn bolts on the CVCS tanks checked and evaluatod.
l t
7,3 Inadequately Supported Flante i
J The concern was factual but not a problem; thorofore, no corrective 1
actions were required.
4 i
8.0 ATTACHMENTS 8.1 Attachment A. " Subcategory Summary Table and List of Concerns" 8.2 Attachment B, " Improved Technology for Critical Belting Applications" 8.3 Attachment C " List of Concerns by Issue"
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ATTACPJ ENT B improved a ee.,nnology ir-Cr' C PIT.;2 cal Bolting Applications I
l 1
1 presented at THE 1986 PRESSURE VESSELS AND PIPING CONFERENCE AND EXHIBITION CHIC AGO, ILLINOIS JULY 20 - 24,1986 soonsored by THE METAL PROPE RTIES COUNCIL. INC.
iornity with THE ELECTRIC POWER RESEARCH INSTITUTE THE PVP MATERIALS AND FABRICATION COMMITTEE, ASME ecitec oy E. A. MERRICK TENNESSEE VALLEY AUTHORITY M.PRAGER THE METAL PROPERTIES COUNCll. INC.
I l
THE AMERIC AN SOCIETY OF MECH ANIC AL E N GIN E E R S United Engineering Cer.ter 345 Eest 47th Street New York, N.Y.10017
o
- o OVERVIEW OF ISSUES REL ATED TO NUCLEAR BOLTING APPLICATIONS E. A Mornss Tenneuse veoer Awinorett Knosvitie Tennessee T. U. Meestem E weine Power Reneeren instaure Paeo Alto Caldoen.a K. L. Mgsihsgy Tennente Venev Avinorrt, ano voie tenneim 1
Assina:T ine se*vice nistory of colting is geoe: however.
curing tne cast several years, tne U.S. Nuclear Tmis sace -ill furnise. it.fo*matier en tre 'as experience, an over. view of the AIF prograe., sunna*,
indsstry nas experienced an increase ir the numoer of recce:ec bolt failures. Failure or cegracation nas some of the results of the work ogeformec, anc ;*cs recommendations en the issues.
eeen recor**c in several generic a*eas unich may im act clant safety or reliability. The generic colting BOLTING [XPERIEh0E IN U.S. NUOLEAR PLANT!
a::lications wnece failures or degradation nave been experiences ey tne incastry incluce presswee bouncary The*e are millions of bolts usec ia man =ays anc flanges, component succorts, anc nuclear elaats. Ir escn weit, ta: ce t**ee thessaa:
- cw eac*a' ettecments, as nell as colting usec in componeet inte*nais, an aggressive program to asssee the tasse are wsec in the ceima*y *ea: toe ec:iae c*ess.*
bouncacy components, their 'nternals, anc swC3o*ts coe.tinvec integrity cf Colted joints is nearieg completion, While tne 9WmDe,r of atto'tec Celting failw es nas a
increasec over recent years. there is sc*e ev'ae**e INT 100J: TION wnicn incicates
- at tne increase is a 'w.: tier c' t-a increasec numoe* cf insta11ec telts. lt a:oea's a's
- nts oncer uccates reference (1), creviously inat as cient maintenance personnel gair ex:eetea:e c'esentec at tne 8tn ! rte *maticeal Conference on curing early cleat c:eration, tne incicepts cf ietr a
Structural *ec*anics in seactor Tecnnology, in
- oints anc repeates failures cecrease. Tne sw::ess Brussels Belgium. Novemoer. 1985. Tne atomic nistory of fasteneas *s excelleat wne- ::m: ares te t-nwmeer of 'ailures, in:sstatal forum ( A;r}, in coe;sn tion.3tn tne
[lectric Do, ar Researen lestitste (EPR!), Tme "ateriais Tne U.S. Nwelear Regulate *y Comriss':
arecerties Ocwncil. Inc. ("DC), the utilities anc ciner P ( 6:.:
incastry organizations, responcec to tre coltir; neec k.'8.13* 923 :esignatec tre Generic Safety issue li 4-ey formulatteg a ccmcremensive crogram to accress the nign priority issue "Boltieg Degradation o* r ilwat a
issues. Tne goals of tnis crogram are to crovice hwelear &cwer plants" [2] anc incteatec ats conce**
"Tn cefinition of the critical issues irvolvec anC to ere are numerous Colting aosaicatices tn nugigge come* Clants...."
consolidate inewstry resources in orcer to sucoly an dooropriate response to the bolt integrity cuestion.
kora inc1wces corrosion and fracture mechanics stucies, "The number of bolting *related inciceets mas increasec..
mon
- destructive examination (NDE) cevelopmeet, coces therefore, there is increases concean regarcing the integrity of the crimacy cressure anc stancaras activities, and maintenance anc training bouncary in coerating nuclear co-er clants anc tne tasas.
Technology exchange has eeen effective in
- assuring increased attentton to the eehavior of bolting reliability of the comoonent swoooet structures following a LOCA (loss of coolant accicent) or in U.S. nuclear plants. Nothing has been discoverec to earthouake."
raise concern regarding bolting integrity, ortmarily owe to the recundant nature of bolting in critical closure joints, There are four cistinct bolting isswes groutec e acolication anc accarent cause as oescrioes colow:
1
v.
o e
Geess !
- Deg*aca*.icn O' f ailu'e cf cressu'e C 0; ram anc est'aiets De*r C'essJre 00w ca'y an; e
D9yngary 001tteg cse 10 general Doratec mate
- strw:tural S.,00cet :Citec coenecticas tc assess t*e c0**csi0m (nastage O' tecsion/ccPreston). Ine ceg'aCa*10n c' tne Cve'*Il 201:e3 Conne *1c*..
- e I
cause Cf failw'e is att*itet'C 10
"'9" 'at's CI C8"s'Od'"C's Cf.ciat ceg'scattca ie te**s c' *ee,a;e
{
c e rec s wa of low alley steels ia tne cresence cf aac leas-pefore-creas ma gie Sr presss e :sse:aq a
- ratec. ate. inis ts ;*tmaci1y a maietenaace
- cirts, an
- ss:ce : stiaess ae: fa.ite: icae
'* st s:tural sa:ecrt ;cirts, 's g,c:le..
- en:stier marg &
ceing esa**ee:.
'" s eco ca:e is an alternat we :
Oegeacatice ce failw e c' e'essw's incivic.a1 'astener integrity assesbea:
Sir:e : e :'
G*e.e ::
i tre crircical cesign featu es of a Deltec : cane::te s
I counca*y ect:ing cse se stress corresten cracting r
(s::), *re cause of tnese failures can ce its stew:tural recancan:y, inis alternative seems r: e j
attributec to an uncestracle cor:ination of realistic, province inat acce:tance crite*ia 'er ::t*
stress, environment, anc material concition.
safety anc reliability can ce met.
Generatly, snese types cf failures are associated
.ite 1 eating gasne:s o+ tae use of certain ine witimate scal is to use :ne gene 1c anab:i:a' I
Iwe icants anc/or sealants. Failures :an ce metnocologies cevelece: cy ECR1 for ecite: jeiat eliminated inrowga Cr00er use of tensioning integrity assessmeet, sap:lementec py incastay l
- ecnricses, Iwe 1 cants anc sealants, experience anc casa ectn nu: lear anc non-rweiea comonstrate the safety margins ir bote cressure l
G* eve f M - Ceg*a:ation er f ailure cf irternals bouncacy anc strue: weal jetets, anc to rece-enc j
esitteg c.e to fatigue ano stress cerroston realistic inspectier er maintenance cregrams for Fattw es are generally relatec to utilities, e
cra:ues.
aate*tals, reat ea:-eat, ':* ring tetanicwe, nign stes:y-state s
- esses, ce cyclic service.
- URRitii a::MPLI$dwiNTS Failures cae ce eitminatec :y,alteenate materials sele::ica ar: cesign mocifi:stiens.
Tne integ*atec sciting c'e; ram is scae:.le: f*
w y 4E(.
Ca" eetly, mes: :' tae
- om:letion in a
Geese TV Degradation ce failure of succcets and icentifie celiveratief are availa:1e. Tne P st emoecment = citing cse to 500. Failure can te notacle are overall colting failure anc suc:ess att*1 cute: := a comeinatice of nign stress, rates, fracture me:nanics ( W) assessment, gererait:e:
sus:ectitle ate *ial cen:ition, and a wet closure iete;*ity (leat-cefere*ereat) mecei, t:i w:
t envireement iney cae ce eliminatec ey attention crotecure gwicelines, in eac iwericants evaluatica. a*:
to cre:easion anc materiais'.
mecnanicalaateterance traintn; tapes.
Failu e ; cw:s 1. !:, ae: IV a:ove nave been Ove an a,e ts re s,*, D* eta:P '*ies a
a::* esse: ge*e" : ail s*:e* t*e asseices c' a joia:
A; & :* Tast Gacw: ca E:::";. teessa*e ecwnca*y an evee m er:e :ase c' 2:lt 'ailures an:<c' c:1 tin; (G* cats : aac : ) eat a greatee taf;wence en
- c:te-S nas :eea geae*a:== are anal;,:e:.
C' t e .e system integ**ty see tne rigmes; catority in tae types c
- essare councary cicswees stacie:,
d
- ecast7 c' grat lrteerais : citing (Growc ll1) is spect'ically :resssei:e*s, stea~ generate-s, *ea:::'
- eia; effe::tveiy a::resse: ty :: seneet veaco's anc coolant :w s, ae: vaives, steam generator ean sy owne's' ;*:.:s sac s act teta; acasiceaec generically, colting ennitt:ec tre aignest t: tai *e;e::
- ate.
- e i
i Sw:Deetsie=:ecaeat toiting (Geowo lV) creseetly nas a reje:: rate ':* man =ay =cittag at;*itute: ::.asta;e 10 ' a*: ;*e rate ': c'a:uir; aas *.2 a
sec:ncary :" c 1:y " tas inesstay cac;eam.
- ne aa p.:
a eemain:er c' ;"s :a:ee n'il f t:ws or ne :'ess.*e
- w :a*y an: sa:co*ts/ e*ce==eet generic : c;*at
- a:: + **:*aa :: H s e t s+ e" a
l 5! Nit ll lN;Utiiv ::;;ta" 0*i C:!!!;;! 1:UCatv 10
! :* R*5 10.*:h3 e tr't al te:ncic;;;ai :.s; *e;a*:t ; :: te:
- tn **:egesty.as cirectec towaac :ne eva1watten :f Tae cwes:10m cf #astene' iPtegrity is ve*y ::"Cita
'acivic.ai fassene's wsir; 'cCatilistic fra** sat l
49c involves mary Sistitlines (e.g., Petaliw gy, aecnant:s analys's, as aitn aey M eval atice. Ica:s, e
3
- '10 w'e meenant:s. metnanical anc :DerClica gecperties. are :'aca si:es Bac to De anc e.
- g ha eng1 Peering) and activities swen as Colt tensi0n recwirements for tee M Dasec accecten exceecec tre coe: Pol, N:(, :esign, speci'itatters anc stancarcs, state ef tae a*t
- acabilities. It soon ee:ame evicent f
manufaCtweirg, anc cJality assurance / control. Aesearen tna a more crw0ent anc simDler aDDrea:n 10 001:e:
j activities nave f ccusec cm uncerstancir$. icentif yteg
- cint integ'ity assess'ent was CCssiele an
- cesi'a:ie.
j are imoiementing s.iutions to tne issues. vne researen neversneless, tne f racture meenanics researen nas wO'k on 00lting is in tnree key aress = structural greatly improvec the state of inf0rmation regarcing integrity analysis (inc1wcing nondestructive colts anc ctner tnrenced fasteners. CiColla (3) nas l
examination) corres,Cn stweits, anc maletenance stwdied the ADDlicatten of fracture mettanics te l
improvements, f asteners, anc mas c'esented a simclifiec analysts metnoc for accronimating tne stress intensifica ice ESRI is comeleting a
- Generic 6 cited Joint factor for an ellictical surface crats at tne root o' a Integrity" p*oject =mict integrates the inewstry tnreac. Tnts appros:n will ee integratec into cesi;*.
1 w
. _ _ _. _ - _ _ _ _ _ _ _ _ _ - _ _ _ - _ _ = _ _ _ _ _ _ _ - _ - _ _
e -
e i
),f, 4,c fa m re creveet4.B ae,.ses.
.e..
%.n
',ne*a18te! /09at fatte-1*> Me' _
Ime egg; cesiracle att**bute c# a cc tec,*c'*;
its leaa 199mtmess. 4 Pecent he sie r ey *8[
v peccaciy tae most signif* -; coatn ew*'o* c' tne.
cemonstratec inat ever 90% cf a'l teltec scaaett cat
- egratec *c'ttng pecg'am is ceveltcmeet cf t*e tee primacy cresssee counca*y are leak t';*t.
- e.e, gent al:2ec,'clet integty me
. wnerein tne clesw e elemeets test conteigute te lean tigetness 4*e:
e
- s *oceIec acCw ately, inco*Cc' itag the Ioac saeccing aceowa'e joint cesige, cec 0er cleanliness. cecce*
e anc *eosecancy innerent to col-connectives, uth gasketing, uniform anc sufficient crelcat. :: s*c.'
19e evaIwalioP Dasec u006 the
- aII ClosdPe t*e Ce noted that all Cut the first element are ccet*c
't e
cetails of inciv-1cual fastener 'gracation are not Dy station maintenance. Tne integratec cCltec j:t**
-ecyirec. as a result. ne CC" eXity of tne orogram accresses two as0ects; the unifo**ity c' cai slations anc casa eurcens.
swDstantially reesced ceelcac and an evaluation of tnreac lutricaats. S t
I e
anc many of tne areas of greate uncertainty are findings incicate tr.at a joint can be prestrec 5t*
avoices. Eitner wastage or st-
.s corrosion cracateg uniform preload in the toits even with stacie teac.t can ce accommocatec in tne moet (coally impor*4nt is wrenenes. if carticular attention is psic tc coltNe the fact that tne NDE recuireme is of tne generalized Recomencations incluce steCDec torose values
't*
- oint integrity mocol are well Inin tne multicie passes and verification of proper crelcae e state of tne act capabilities.
ultrasonic or ciner metnoc. Stucs are prefer *ec cie-colts for many apolicatiers. Leat tigntness can ce Tne ontlesoony tenine tne cel is analogous with assured with procer care.
l
- ne less-cefore orest chilosoc-ssed in FM evaluations
{
cf eteer cressure councary com: ents. Tne stecs A seconc tast eval 6ates inrenc lucticarts.
- e recairec te acrieve tne cesire; esult, i.e.,
wort incluces laceratory anc fiele tests anc iacteau '
cemenstrate test a cegracee je-(cue to wastage, tnat the nietel casec lucricants can ce sacstit tec
- l t
- actieg, etc.; nas amole mars' against catasteccnic nese using molycaenum cissicnices (Mos,) witne :
l I
fa'ilure w en tne leatage from joint reacnes levels mocifying tne nut factor and, tnws, tne'tcecwe valvec !
n
- nat nave a very hign probabil' of detection.
A recommendation is made to no* use these kos( Casec ucivee; anowiecge of tne cegr* of loac sneccing to lubricants wnen dissociation is even suscecteB. i.e.
acjaceat f astenees cue to f aste
- cegracation.
wnen tne joint will te excosed to nater anc higa anonieege of tne joint opening ofile accounting for temperatures. Reviews oy Rurgte anc Majuicar (O aisc
- ataet scrirg tact and flange c tortion, realistic inclucee worn in Inis area. Tne Mate *iais 8 ooert'ee calc lation cf lest rates
- Pro, tne cegracec joints.
council nas come extensive stacies on va*icas in eac ma gin ce castration in ioac-c: vir; cacatility cf luericants anc their cent *icution tc 50" *C.
ceg*acec *cint anc ma*gir cefia
'on.
S it chiicsceny was initia f successfully accliec tc a stes* gene *ator manway ces tc snow its loac Incustry resolution cf the generic 4stses 's
- araying cacattlity. Exa-ole e culations incicate senecslec for 1966, anc is clarre to De ace: sliseet "at 'er a tyr,1 cal sixteen colt ciet, about tnree utilizing AIF anc EcR1 guicelines, anc Areetcan Sce't-
- C:s.sst 'an eefere a "cetec cle" leat (10 gem) is f er Testing anc % teriais ( ASTw) anc Aait** can Sc"etj
- erecatec, ine stresses in ne cjacent eclts increase of Meenarical lagineers (AS*!) stancarcs activities, cy less tnan 20% (well ceio-t*
fieic strengtn of ne j
colts).
j
> Secte-ce* ::. '9Ba, tee lastitute cf % ctea-J Dower Opera ices (380) isswee 10ER he 64-5 e-itlac
- 'ccM a sec c-ecter [
cc m ec !" s acat see
~5 citing ;e;*acation c' Tatis.es 'n %clea* "c-ee w
eave cropesec a metnoc to esta: sn le.it rate margins Diaats."
h D0 cenesttec ar iececercent rev*e-cf
- a*: noncest*9ctive esa-ination
-its 'or coltie; tssses anc arcivec at :cnciasices weich ee *f c* cec 1
j aterials comenly usec in oei*
v.cressure cosncary crevious alF recomensatters, ine 50ER se*ves to cieswees. analysis meteces fo*
eterminteg tne nignliget anc provice a " read map inrowgn tae isswes
- s; wetura) tenavior anc lestage ' a coltec clesure 'cr stilities," The McC 50!R cepenas neavily en AIF FC*
l
.a-inss amosets c' telt cegraca' cn.ere refinec a*:
anc EcR1 crogra'rs.
calcuistions completec for save I acettional essential components (ceect valve flanges *eactor coolant sumD ASTM comittees, naving responsibility ovee main flange, anc cressuriter ma-ay flange). ' Initial bolting material scocifications, have reviewec
.I
- esults incicatec tnat lean rat +. cetween I som anc 10 specifications uncer ineir jurisdiction to cetermine som are cessiele without compec-sing tne closure need for modifications casec on comercial nuclear i
integrity. Tnese analyses show crevice sufficient incustry experience and incut from sne inewstry
' tasis f or recommencing revistore to present Coce NDE program. Several specificatiers eave alreacy been reowirements, use of leat befe n-creat criterion is mocified. At tne hovemoer 1925 meeting of the 45TM coesidered an effective metnoc c assuring closure Saecomittee F16.C2 (on structural colting), it was integrity wnile reeweing cemanes on NDE. These recomencec that a een Subcomittet be formee within calculations clearly comonstrate the cegracation ASTM to rationalize. ASTM structural colting CA tolerance of boltec connections.
requirements. This recomencation is uncer consideration by Comittee F 16.
3 i
y_-_-_____---_._
l eor! is ceveloping two refe*ence manuals to inegstates excettec to bene'it ' rom E' t e e n'.o : c t, accress now to ideetify safety-relatec joints, tec16ces tre faste*ee, ceemical, cet*oiew ae* s:a:e.
selection of aspeccriate procedures, assemoly anc rweiea* oo.er, automotive anc man factweses +rewst u w
cissemoly procedwres wsteg various methocs, instectice aec verification of peevious procecures to solve c*ctie-s anten oave occurrec in tne past, Tnese 00s;al$;n ennweis will seave as a repository of wseful j
ir'ormation learnes free EpU analytical and Tne cure:se c' te.e AlF/wo. Tast Grow: as :-
esce*$ mental crograms anc. w3en puolisned, they will coveloo anc esecwte tee A;F program for resci.t ce c d give the utility incustry guicelines for coltec joints.
generic colting isswes. Since inis ras peer Seve*al utilities are already usin; crafts of these accomplisnec anc all wert is nearing com:let ca,
- e guicelines te their efforts to enhance their bolting Task Growe was cise,ancec in hovemoer 1985. Tse A:
c*o;eam, It is believec that the Dotting reference
$wbcomittee en Mate *ials Reswirements mill ee manuals will satisfy the inewstey's neec for guicance available to mancle any resicwal p*oclems, in tris area.
Plans a*e to cevelop two compeenensive ccewmeats
!8R! is covelocing an interpretive caper on cressure cowncary toits and strwetural ec1ts 'c' sse explaining tee current ASME Boiler and Pressure Vessel by utilities. These wowie ce censicerec the ' wai Coce Rules for Bolting. AN51/A5MI Section !!!, Nuclear crocucts from tae pre;*ae. Taty will be at:*ovec :)
Gewer Clant Commenents, has been reviewee anc the AIF $wecomittee on Materials Reowireme*ts an*
- ecomencations have been covelooec for clarification cistritwiec to utilities anc tne NR; for t*eir use anc anc amplification of existing requirements. AN51/ASME information in resolution of tne issues.
Sectice II, Rules foe Inservice Inspection of hoclear Power Blant Compoeents, is considering recomencations Tne colting issue is an example of a cocecar ve to eationalite boltiag inscoction requirements to focus effo*t between the utilities, the vence*s, anc tne N::
on *at**isk" applicatices in stevice sensitive lines.
to resolve a creciem with pctential safety
)
Results f rom the !8R1 generic joint integrity program significance. Shortcomings in cesign, material will be used as incut to covelop empirical rules for specification, crocuremert, anc maintenance were inscettien frecuency and accectance recairements. NDE icentifisc. ' ses to alleviate concerns regarcing j
rules will te mocifisc to accomecate recent pressure oowncary telt integrity we'e formi atec anc cevelc: rents in ND! technology.
are being molementec. Tne ie:1ementatice c' the recomencatiens will result in tr:rovec claet I
An EDR:/M!A: workshoc was hele in hovemoer 1925 availability anc relia:ility, wite recueec mairtenarce, 4r 0*ad ette, N: te ennance techeology trarsfee. Tnis mae-rem ex:cswee, anc inscoction ecsts.
worasaec aas aimec crimarily at informing maintenance ce-se**e1 of tne issues and alerting them to tne E!r!REN0!5 i
tract ca; ::cis ein; cevelopec in this c*egram to att tse- 'e achieving leak free joi*ts. Tre wonsnec was a 1.
we ~ick. E. A, anc Marston T U.. "!*cust*v t*e*enceus success nith particionets agreeing that nesocnst te 19e !ssue cf Bolting Legracapo* :*
acciticea; wertsnoes woule te useful.
Failu*e," Dace
- Ac. 06/1, Seesentec at 5*.:Riii.
E*wsseis. Eelstut., Aw;ws: 19E1.
l Tae telt'ng tec n ology Council was 'er*ec to l
- cvice ecoc-tunities for tnreaced fastene* anc teo) 2; W RIG ;922. "A **ier+tteatien cf Gene *1c Safet, users to e* gage te coecerative activities. As statec
- sswes," Sa'et) 5* ;*a. Evaha tion !*aac*.
te tae u tylaws, tae ow*::se cf the Cowecil is "t Oivisice cf Sa'ety Teca*c1cgy, U.S. NR; *ece-:e*
s:cas:* *esea*ce; te *ecemenc :*actices; to act as a
'i!2, Ne-5ece*te ;ssue 29, "5:ltte; *egaacat':*
c'earie;*owse 'ce tefeemation; anc to trovice ecucat en
- r r ilwre ir hwele v Go.ee clants."
a ternieg tne art anc science of tne installation e c a m ter of meenanical fastene's anc tnete inte*actien
.2.
Cioc11a, R. C., " Stress Intensity Facte'
)
atte tne joirts taey are uses in."
Accrostnatices for Semi-!)1 :tical *rao s at "e Tereac Rect of rastenes,1 eaevee Te***C ea.
Altnow;n a i n ge numo s cf ergieeeria; anc
" Ucai H$* W 4 i :st es4 ASME Geessw*e t
incastrial societies have ceen organiced to coal with vesse) anc Gicia; Conference, Chicago, Juiy '956.
vartows aspects of fasteners and jcints, very litt e i
attention is psic to the imoortant job of installing a.
Cicella, R. C. anc Drector, R. R., " Acc14 cati:* C' fasteners correctly. It is the*efore tne intent of tne Leat 6efere !* eat Analysis Methocs to sevaa*>
Cowncil to complement rather than ewolicate tne work of System Boltec CloSuces," l'e'evee TecaneHo '"
cthers.
Ca m cal to)D ae aerdicaDeas, ASM! G* essure vessei anc F)cing i.onterence, Ca.icago, M y Mi6 1he bolting Tecnnology Cowncil is affiliatec alth Tne Matertels Froperties Counct). Inc. (MDC), formerly 5.
t5 %chea 8eoulate** Com issien, huRIG 1091+
Tne Metal Preperties Council. Specific areas of "Eva1watton c' Response to !! Bw11etin E N,
interest incluce achieving, maintaining anc cost-Pwelisnec May 1985.
assembly changes in creload, eenavior of the joint m tal Drecerties Counct), Inc., accogress I
6.
ime e
uncer Itac, anc jotnt fatture moces. A partial list cf g,,,,ts anc Escageounc Tecnnical Information on f
MDC toltteg issa Geowo 5tway of Lworicants anc 4
Sealants," Decemee*, 1995.
_J
y 3 _.
j q
1 APPLICATION OF LEAK.BEFORE. BREAK ANALYSTS METHOOS TO PRIMARY SYSTEM Bof.TED CLOSURES.
R. C. Cipons. Naciosi Inemeer end R. R. Proctor, E ng.neer i
Apteen Eneinsermg services Inc.
Psic Ane, cWornia AE5n A;t basis for integrating acerceriate rittgatir; measu*u sucn as creleac certect. n ncestructive ena-ir.atica A strategy is proposed that will estaclish leak (t.0(), anc leat cetection capabilities, in crcer 1:
rate margins and nondestructive examination limits for assure the integrity of the primary pressure ocurea*>
coltir; materials co rionly usec in primary pressure A Ecitec Joint :ntegrity Program nas ceer councary closuces. In the application of leat.Defore.
sponsorec ey the Electric Power Resear:n '!cstitute breat analysts methocs to closures. an analogy is (EPRI) with ine main objective of 0:taining a :ette*
erawn eetween a welcee joint anc a colted joint witn' uncerstancing of tne behavior of coltec cletures.
{
recarc to structural recuncancy, load sneccing Primary.eacnasis is :lacee on the safety a::ectar:e " [
eenavior, anc early warning cetection createc of the the cegraced boltec closure. but it is expe::tec trat cresence of a leak. Analysis metnocs for ceterminin0 improvements in clesure reliability will oc:ua as the structural tenavior anc leanage of a coltec well, ine corpose c' inis cacer is tc teesen a ha" c'.esu*e fo* va*1cus amounts cf colt cegrecation are
- efore trean steateCy for resolvirg ec)tec ci: Sat
- rese tec. Calculations have eeen comcletec f o' two integrity issues as tne continuation of
- ast wee Q n
stes generator /cressuri:er mani.ay cover cesigns. two anc to sno-now tnis approa:t coulc be 1e:ieaente:
cre:k valve flanges, anc a reactor coolant pueo main
'Isece. Aesults incicate tnat, leak rates in excess of th*ougn the ASME Soiler anc Pressure Vessel *:ce 1 1 P (0.042 69fs) anc as hign as 10 GD" (0.42 kg/s)'
LIAK.EEFORI E4E AK E', AWATJ045 FOR 0;05'$!!
are :ess1:le =ttneut :omprcmising the closurt
'nteg*1ty e gnificantly.
Tr.e leat-t,ef o e. creak criterien was 'criginally
- h7 ;TJ T!05 croposec in tne late 360s as a means of estimatir; the necessary t ugnness cf cressure vessel steels s
that a surf ace cract covic grow tnrougn tne.all.
te: eat se*vice entersen:e with e-ima y oressure causing ledsage c'.essel contents to cete:ta:ie
(
- un:a y ::lt&; 1r retsurt:ec water reactces f M )
levels :ef:*e #ratt e n g.
15 a res.lt, tu s en11t-~
h incitates car:en steel f astene-s can Deceme cegrace:
Sceny nas :een ef'ettively usec in tne assess ent :#
'l as tne *esult Of :rolcngec :cetect with cetmary
&tegrity 'ssues f c weicec ;* essure vesse;s anc 2
- clant water at elevatec *emocratures Q.1. the 31 ping c conents f a ricatec f rom cu: tile r'aterials.
- losures tnat have emperiencec bolting cegrecation
!f a componert tani:1ts a leatage f ailure mocs pric' in:Iuce primary s1ce manway Cove *s of stean 9enerators to tre coir
- wnere the actbal inte9etty becomes anc *essurt:eet, coolant cume main #14 mees, anc sDme cuestionacie, t*ee tre cemancs on !OI melno:5. tner 1
3 primary valve flanges. Of tne closures 11stec, tne inan less cetection can De reoucec. Hence, the j steaf generator manway covers have ogen the most oojective of any leat-offere*bPeak analysis is tC sn0-troweltsome @l f asteners have been observec to su'f er
- hat le86. age will always precece f ailure by a Wita b
- ncivicua safe margm.
f rom general corrosion Awastage) at the snant or ine casic s1mlarities tetween a boltec closure tnreaceo sections or from stress corrosion cractin9 anc a welcee jcint with respect to material select tet (5:0) at the threac root. Althougn cegracation of cesign requirements, control of f abrication processes,. indivicual f asteners nas raisee some cuestions with anc preservt:e iatoc: tion tuggest that an assessment regarc to closure integrity, ocerating expertence also plan for closures coulc make use of a leak.eefore. Suggests that only a small numoer of closures have creak eniloscony in mucn the same f ashion as with actually cegracec wnile in service. By focussing on welcea pipes or vessels. Since one of the principal these " service sensitive" closures, a generic plan for cesign features of a bolted connection is its accreasing the integrity of a joint coulv De ceve-structural recundancy, it seems plausible that a lopec.. Such a plan would also provice a rational Deltec closure, even with some cegraced or f ailec 1 5 1 I i 1 { __]
l l e l j daneners, coul: eet a:ceptance criteria cors1 stent 're re*aaete-s * *at ;overr ci :e:re:a! c* a closu e.c,,;; ra;, ; >1tn Cur'ert 1*0i.st*y practi:e r*0v1Ce: trat a*:le blti-steiy !* e * **.eget t, r v safety r.argins 4".* :losu*e reliaD111ty CCsic te i n:I dt U t ate # 's. cce:it t e, tre cias.,ev .a :.
- ea0rstrated. 4 ae alternative to cuere" e-enas11 se: ;*e em ie:n e" Being centa1*e:. Ee:a.se
- e
- 0 4::03 t;ee:s v reaset.-
.ttrin tae :5I ::ce on in:1vicual faste^e' 1rtecrit). s sce:11p i er assettaen st*ategy 's :":cese: that ** II esta"I'ir ' r:*e asie; s; t';t*, ',:se :eea et ees
- tet 4*
+ :
- t re et are tme a:st 1 ::*t!"
ty t*e a:ce: tan:e c' a C;cse*e :covice: trat * *e sa ta: tre:1 f t :a y, mat e-e; s:e:111c at *:r, reat im;* *- d:licwing :enttiens are met an: *0-tral stre gt* :evei, ice stress.*ei tte; a e Leas be'cee-D' eat of ine cl:so'e is assu"e: sartables tr:1.:e Orelcacia; metnce, preica: 1,.. uncer inc cesign tasis concitters *
- ne plant anti:1cate: seest:e Ica:1rgs, an: the ;cin; st *< e;.
an: loac recistr1:. tion cnara:te 1sti:s c' " e ne saf ety consecuea:es of closure leatage are c l c s u re. G1ver s.*te:le numerical raetne:5, e e at:e:taDie elesure cis;la:e ens anc colt stresses co- :e ceSputet for a *1:e range of cegrace: Delt ::*: *
- I e Tre nargir against treen di tne C01r.! wnen tre f inally, tee environment variables in:)ute te-;e's-1eanage ce: -es cete: acle excee:s an lure,nanicity, a : ine :resence cf ccrees ne a;e-a *tCtante level iPese environmeMal ef f ects are UseC te est1* ate *
- t I
range cf pess1 le 1rttial cegraced 0:lting ::*: A D" 00se: assessment strategy 'or Ocited cle. CP1Cr to tne a 01:st106 cf se*vice loaciegs. inte: l 1 sures inat exploits tne leam.tef ore-trean grilese:ny on tnese restulate: cencitions, recuiremerts 'M l 1s cepicte: in Figure 1. ine sultatility of this alternative C[ reasures can ce procesec ente "e resulting lea, rates anc ava114:le safety mae;"s a*e l strategy te clesu e evaluations will cepea: r on availa:ie reagias as cittate: Dy t'ie cc9:11cas esta iisne: na a ;3ver elesure cesign, e
- eau 1ree f:* clesuae f allv e, Ine amunt ef ente *nal a
leanage from tee ticsure, an: tne avasiastlity cf : eat ![r m t m i: "c! O suc[I Cetection ins *"e*eMat1Cn. Cl ea rly, *.ne Onara:ter. 'stics :ea a: t % 1:s c' ;oint eenav1er in ter s cf tre fe:Us1*; ef irsee: tion one na, rte,a.:e j lea: re:istricution anc gastet unica:Ing f olio e* ty a:tivities o' se*vi:e sensitive ciesures .1 a :. n :tive resolutter c' ecutement leas.e;e flange separation rust be cuantiftec fce a valic and fer n:ce e e a::v at e :ete*-"* ation of saf ety rargirs. Loa:
- reele 5,
%r,rg the investigation Of cri-a** e
- ranges within t*e ;cint are eve to Ccstu'ia* e: OCII cressure t; **ary toiting p* Die 55, tre AlI'
- !!i
- egracan en
...e age ce tra: ting cue 10 c:r*:st *! Great er Scipeg are IFM ceveiecec a hit fa*..'t: i inat will Cause tn'a cegrace: reg 1:n cf the cicture IC 7,ata Base w1*.e a see if t: 00)ectiv* cf ice ***dy ice f ailure cate were :: :'.e: uni:ac at tre er:e*se of reign:cn ng regi:as.ni:n now tecutlesc9e 01:5'res, g *; N st :ar*y a ;*eate* ;catier cf ine ress.re ica:Ings.
- rwav31y fr
- Wultty ces;e.ses to ;; y ;at an: U :erste [ve*! *t00"ts u: 10 fe:te te'. id.
l was tre inern? :< ine A:F/w' Tas 5-eu; "at - s fleic 1Pft '"a** ', SIO*g with ristorical Oata 0*
- t
]l','[ See:ific :lesure rerder ar:e fro-Oreservi:e a*: l 'yc'*!es'.'eg,.): rel; ce'ine tre stav1Ce se's*!.e I
- i cs u *e *,.
Ine E: *ati #e "ata f.ase.4s.se: 1: est*-ste i ]
- elC'.110r at es * :* ? gstentes.se: 1r dive * :..*e1
) i 4,, stea" ;e*e aste* an avs, * *essur* :e* a".a 5, 1 1 I ~ ,Q'[ ** .3 .aives. ' tat:P * ::. a r t OL*.: .k'!- Itals, 4*: j .n e n, mm 9, 'iaeget. - ssTa *y :' ::11 re;e:p en rates *: 4 i re:Orte: *awses 'n*luciry Doric atic Ocr"Csier,
- e* nan 1:4I *a.a:e. *ra:stry, e*.*.,
is given te atie..
- e
'e;c:t*:r *ates e e ::::.te: :* t.; Oases:
- !! ** IPe t*ta. *. Oe' C
- Its at
1' a** l ~ I w acate
- t* e
- 0t 4 s e'.
- e v e e rs * ' *.* e *
- a *.
/ I ' eist. Un e1**e' 04515,
- e
'anoing d ; :s.*e '. t l
- ne s ame.itt ;* e st C a* ge*e'a t C' a*'.ays e *
- i ' *
- l tre *1:ntst d'eG.e*:y Cf f astener 'e:iate*tMt.
- t
- ? Main f iaege. *ressu") er Pan.4), an: valwet
- Peete' inae sia 1*.
- res Cn. in Clemete'.v'e. s:
l e
- r:.tiesCAe :.t s' tant:1*.e: rele:*1er 'ates 'e!.
Inan nelf inst 1:e int steam generater man a. l
- e tasse 10r 'eje: tion cf ;enerator ran.4y s '.. : s
( m., .as Crin:10aily :Je tc 00r1: acic :oregst r as t*:.* l [,*[.
- 7.g l.
in *atie 2 e 'aliing arc *e:nanical Ca. age t: t**! aft s l .ere disc majc' cCetr1Dwtcrs te stuc reje:11:n l l Suggesting inrcac lacticatter pretiems..; 15 1~ s-tart to ncte that !,00 as cnly a snell :er:e*;a;e I ct the Causes f ** f tject1Cr.. altnowg* Cet Can arg.e on the CvereII C nti.st l trat can te reacte: drc0 trese 11*11e: :sta, t* r infomation sees nenc to f ccus the types cf conconents '"'.,'.l'.*, recuiring ttitty attention for imerevec rai*tena*.:e .m pra:11Cc as well as identifying can:)cate ti;s.re Cesigns f or evalbat10e Cy lean Befere Dreas anai sts f 'ttatea.. ric t ncC s. (1gare.. *.lcsw e.rteQ*ity assessment e a 6
v e l '8bl' !
- ne ;astet. :ne <1e3:e eiemer: rese <:,..,
- C'"
' 5 5"
- '" P'"5 Ct'd ' ' " ' "
Me.. s tues e e,'*ce t i ec d,"ea ei e e :s.1:. .:tr5s:c. BOu% =RY. I n.E5 ,=.%rn..u m h at:n FC: cn* N o - a :, t ... s ... % $ n. ) (crne:tec cirectly IC the 5:11 eseme*,. ,e
- 1cte '1r= 5 ere c:w::e: :.ne :e,,,.e.
l .(.i. "'CO's i: 'Pcu~e stu: :e":17; ee* c vea sa: ' a- ...,3 y., .. 8 --
- e l
- :t,-
surdaces c: net re.mair :e-pe :icular. :.., ;o
- l
,-<r* a* $ae +:e '*e-s g)p; -g,g 3 q, was moelle: as er e;asti: <:f.:atier,e ,,s c a ; l Steam GeneratCr wan ays i.dl. .gst O'strete uniani a; elat:' ;;rtngs.
- r.e elas; ;
I I ac1Pg anC unIcac1Pg Dena.'Or c' a s: ira;.:,r: C seac er,00)ae,. v. .g, 2
- am Gange ascestes fillec gascet.as mferrec 5,:. e,:,, m.
i cy:ji: 3;,,33 e,f;,:. n g;,,,,3 gg ,n ,3,; Gres surif er *'anways I.' 2 '. 1.20; Cefine the spring ele ea 1:1 f f neis) es, '*e reflections f rom tne tests were mat *ne: t: :*e e::. " ' cf','!. manway cy relating *ne gastet ceceer:1es :- :,;- l I' O r) ratics involving stress area anc gastet to:, est. l Seactor ;ociant Fsm: 0.62* 0.25s Secause of the massiveness cf :ne vesse; #:ar;e:, l 5eal Mange flange surf ace was assumec to :e rigic,
- p.. : : -c.
j was estaeltsnec in tne eccel by im:051rg a l
- [stimatec :o All Drimary Valves By Statistical Analysis Q) c1fferential temperature tet.cen gne s;,;g gn: ;.g l
(hete: Bolts at. isk is the total coDulation of bolts irser-cover. A nominal prelcac of accrorimateiy 3; es. I vice for the given clesure curing the reporting ;erloc) (207 MPa) anc internal pressure of 2225 ;st ;5.4 I MPa) were use In the stacy. StLe cegra:atie.as l .,, g mocelle: by changing tre area cf incivid at ::1t elements to simulate cartial -astage : : ee :.1 - 5?tAv G!%i n iOR w N av bolt ele-ents to me:el :ce:lete f astene 'al;.*e. ' 1 5*UD RIJI;T:DNS SY ;F si Cover separatter =as prec10tec in tre 2;.s:.: I mocel wnen a:Oren1mately two stucs.eee assu e: I hhs t '/ tave f alle:; anereas. in :ne 16-stue man.ey, e Cause O' Sejection s fe:tec
- 0:al CcVer first liftec away frOm the geste wnen cre :
e was assumed to have fatleg..nen in:reese: a**.* 50 ic a:10 :o** sicn .6 of cegracation were per 1:tec, inclue1rg mult.:ie Gallecmepanical camage/ f5 21,3 stuc f ailures, a re:istricu, ton ir ::;r ;is,e: a,: tareac camage/ removal camage stuc 104:s was c: serve:. ine enange ir gaste; ica: i l Pitting / removal camage U.D in a 20-stuc eenway fee-the 'ere1ca: eniy :ase a Steess c0rection cracktrg 5;
- .3 throw;n to various ceg'ees Of st.
- fat' ores.
- e-I j'ic's near indications 1(
!.5 3rterral pressure e' 2235 :stg ( $,: ":a 5 s.3, fares'a'e*sion/steat 1.6 F$;ure 3. Tne untf e-m geste ioac tece-es n:...ea.
- e cut a
.2 as the stu:s cegrace an: e::en: 1: ; essu-e.:e: -
- .: *i ettanical camage 3
.3
- auses gaste: : :ressier t: snift, he ar;.:,,
pes' tion at :er: gasmet loac inc1 cates :*e este i l
- ver secaration.
"O y 5* : lea: eecistritutien as -es; s : a's:3r; e i e ..-.s
- ne #1ve sta:s reares; :
b tne cegrace: ee t. gn,g3ng,,;:,,,,,,, at :ae,a:111ty 'er one evert
- 1gur, 313ust.,;,3 ;7, );,g o
3-t1CM C*a*acteristics of *he 20-stue man ay d** a MA' '5
- 5 OI ?YDIO*L CL^5@!!
t 1 Desmaev "an av C0ver , < ~~~-
- 1 s
} 4
- .;* tr e re a re o'e
- ar !!O
- ""a'y
".a naay ' v e's i r. s e i n s t eam gene'a t 0's # 9c :Pessurtze s Of i. l '. r t t e : States :lants. :ne casic cest;n is very similar I i ) $n ail a::li:ations. Mest Ocvers are typically \\s
- g, Y _
E7-1rch :f9 Cy Clemeter Circular :'a:e5 ::ver1Pg a / A
- I 16*ince (40.6 cm) cDening.
- ne cover 's $.75 intres A
i i ..f C"O :n1CK and hese to the vessel Oy 16 stu s. "l b A',,! ,/'[ [ y' g, Y,i' / "*e 16 stucs are detricatec **:n ::C 22:0 steel \\ e,/ v[' a::ce:trg te eitner ASTM A193 E7 er A32* 6:3 sce:1-f M6 'V '/ ', fications anc are 1.875 inenes (4.76 cm) ir :tameter. f A 20.stuc manway cover of sin 11ar geometry ts also \\/f p' y W f 'j l vsec ey are par vencor. The 20 stucs are smaller in ~ 5 "d.! "" stre typically 1.3 inenes (3.3 cm) in ciameter anc f aer*:stec f rom similar matertals. ,\\.i i A three-dimensional finite element nocel was H-- i..,.. crvelc0ec to stucy the reformation oenavior of both ! /' l I cover cesigns as a function of stuc prelcac anc c1f f erent cegrees of stuc cegracation. A general I i j .m.imm purpose finite element *omputer program callec ANSYS W was used to solve for cover displacements as a f unction of circumferential position. and tne concttions uncer which the cover woule secarate from Figure 2 - Six:een Stuc "an.ay ;cver *ccel. 7
1
- 1 ne l
l l l l I t. I l i q l l .....:.,..~.. 4 n..: 8 A e. / 1 1 1 2 i 1 I a \\ 1 -,u. . c... I \\ n.. u.n s... u.n j i i a.s., in. A.,
- ,,v.n c:r :sfe eent Etv-Fail;*e ;oe-t ices.
hgure 2 - Lasiet Lea: Sectstrituttoa e (h;TE: : k!P e 4.'5 Kf0 3 1 range cf :en:1 tiers in:la:1m; a weast :ase c' sever ire 'inite eleme#1 "Oce' *e0'95e* ting II " segaen cf the ou ; casing, flange, an: cove is s* v a.1 ace *t o' C ".196:gs stu:s mpletely f aile: f100% r I eegracec). ;t is ceservec tnat tne two stu:s nearest te tee f aile: regior re:eives the greatest ir:* ease in loac, we le the se:one at: nirc nearest rei;*>to's J re:five a s94}}er #ratttCf. Ine 104c in IPt f ogrin .. a,, 3. ar: d 'te closest sta: ce:* eases witn the u i a:1rg l ca;se ty ine reew:e: Stiffness of tre cove"'lange , :.n m a,.:, j n I I ' ;' m. Tre a:pi,e: ;*esscee loa:1ng :e f:-s a
- -e at e r 4-
- v.t of me la cefee-ing tne more fiestele a
I
- cegra
- ec) 0 rticas of tne :lesure. wnile s'1gntly less. ora is cone en tne ;* eater s*1fdaesses of ne
+ i j un:grgraced DeMions of the ClosVre. A similar teer: in loac chanQt is 0:se'se: in the '6-stu: cestqn en: tat trat tnt 1040 i' Crease ir Ine .nearest stu: ts greate* :se to tae fewer ae e* Of / f s'.scs an: g3 eater angslar c1 stance between t"e #aste. / aers. were. i?a: recistritation mas m st s i ;*i f i
- a n*.
doe tae treet nearest sts:s to tne cegracec region, as / / se3 n ir *st.re E. '. e. ' f t' e # * *i* tw s t L *.s s * ! *e a
- i M.
l in:reast: 40 =*e'eas tre *Pl*: *eares* 's 0:i***e: j .,a tc wnica. *eateatage. wise,
- e sta: st*ess Orgases l
'4!*.e* '* tre M as*L "an-ey 'O' a *'ve' 4* b*I 7 clCsu e canaCt. 2Jt Iarger a.oJ*ts
- leastge ac lc
.'a j r 415e :e especte:. l
- ca:tre ::l e - t: r " air *:aa e s
e ain iange an: :ove* ef a 7 ;e * :3 was i evaluate in *ne saae c.anner as tne **anaay CICsyre. en / '+N Tee esso cover is ccesosed of an irsect plate anc bolting ring w1*n a bolt ete:lc cianeter cf 4;presi. i. nately 51 incnes U47 cm). ine insert an: 'ng is I nele to tne ownp casing by 16 stwes. 4.75 intnes (;2 cm) in cianeter anc approximately 36 incnes (91 cm) long. The opening of tne evnp ccsing is AS incnes (122 cm) in ciame'.ee anc the outstee clameter of the { rieg it 40Drosinately 80 intnes (203 cm). itie stues are f aDricatec f rom A1514340 steel. Eecause the w.....n............n.n nating flance en the casing is of co paraole size tc the Cover, the pump casing was also nocelled so 1.Jt figure 4 - Loac kectstrib. tion in Five *.earest the compliance of the ma'ing flange is weil repre. 5tw:s te ;egracec negton in a s ent tJ. 20 5twa Manas). B
v o r. it stu:s (bedast anc tre i ;
- ocy t r. give ar e:. :.
P. ate stretCn of.1 * * ' s (.,. t 4.T. ) tearslette : 't.: apie C C,c styg strest ;f ap g; ;[,g3 ,a-org,, ,r.,,, j O pressure.as assumec 10 te ;2M psi
- t.1 p.,
O .C ine unicacirl r* "e *.ance at s tw:s * .o mas siniide tc that g.se.t: *:r
- C anac..
u s.eoe t.e* ... :.. o e ente;t :nat Oa s* C v i. 6 " O'*..a s r o r e, e ' * ;. *- "
- n ts u
.18 * * * 'ittle or nc 1*:*tr>- 1r a?ert
- pr essive r
j ...,n. i ng / i n s e *: : late -nDe **; 10 sepee *t **. av em one stuc $s assu w '. t Pave *ailec.
- ne te;ee:i, 5;ve stress fCr ve"isus :et'ees 01 stu; Ce'.'
s*2. y' * ' ~ ~ shown in figure
- nt ':ur clesest stuct Ce9 Pace: re91Cn are C0$e'vec to carry intresse; i
l' amounts of loac acove
- beir cesginal leve; a
se c ean a,...it nately 25 vst (2n ",;. :s i:n :ne.an a, ; e. /
- ne two stu:s acia:e..t t: tre cegrace: re;':
a:t 4 tne largest increa** ir ica:. :ne 1:a: rat se1 i t. greater than the r.an a.vs oe:ause tne :-esswee aDout nine times $reater f or tne Ou ; c: vee. / ca .......i os 8' r ,t.o / c: i .t i i / ~...o........,......u.., \\ l l Tigu e ! 'ca: Recistri:wtier 1r :ne inace r 'eerest it :s ; e te !!v: :e;*a:atten / - ~ -.. In a '6 Stue hanway. / /
- f
/ / 3r r3;,, e c. ine :ce) 13 :: ;e3se: c ';;; 5:'1: / e e'e e ts anc a :a:ne: te tne selle :::y ir, he sa e l. [/ e'e eets mita
- e s:v:s teing re:rese.;e: :. :ea-
- .i rarre* as t*e ma* ay P. :el.
we ;-essure re;a rt a; .4
- assets are use
- 1r tne a:: val asse.:iy cf :nis : :;
et-ev e. a s '*;ie line of gasi et 's:rt e;; eie e-;s cf e: iwalent arca anc ic:a: ion is e-:i:ye: tr
- e P.ccel 3
- si :lify tre P::e1 ;e:me:*y.
ae stu:s are x r eticace: ty a :1f f erential te.:e a:vre te:meer e i i i l i '\\ l l l s,, . eu - t j/ i e *.
- s ie l
'.g< x; *. 4- , m:; f. r, l ,a . I ,a I 6f N v ., ',. o'.,'. s N(.., t .;v ?. e s.: e n.
- ~; \\,
',,., /
- s. s/.
p t 'j' l.,S' , *.,%..q,.*i,,,,., nian ev : "atr riange. NN I 17.ere I *. ac Fe01s *itut10* In keat;-' 4,'..., [', * < .A.
- g
- d,
~ .{,.# i 3 .b '/ I teC flan $e Cne: i
- g,,,/
vaives, one s al' sir-8 f A7% in:n ll5 C9) smiry Cnect an: anC:ner lar e* te.'*P g (25 cd eneck, were analy:e: in similar nanae* as l %c .' N C1% erevious cictures. The valve flanges co riiec.it-l '?Qb Ah 'N," A%f 1.N51 016.5 steel 01De flance ces19n. lE00 1: :last. { \\O e N N Cneck valves were selectec f:r evaluatice te:ause **e l /N d einit1tec the rics: fiange iesta;e er:ble s as ;;:. I l mentec in the bolts 0,ata case. l The sia. inch (1E cr) valve has a 14.25 1r:n iH cn) cisneter cover with a ne:,. clameter cf ?.1;;i Figure 6 Eeactor *.colant puno nocel. iner.es (19.9 cm). Twelve 1.25 inch (3.2 c1) cla eter i i 9 i
1 l e ine unloacing cf tne 'large eve t: stue ceg a:a. stu s noic tne cove
- to the bocy with a specified preicac tercue cf G3 't les (68C J;. Tne ten-trer tioe was simler : ine aan-sy cove analys s en:e:-
(25 :r) va)ve nas a '.9.E75-te:n (50.5 cm) bonnet t*at toe ten-in:n (25 c > valve was less utide, 51steen recoatis Deca se of tee reesvaret ic valve fler;e.. cove Ing a 1:.te:r (Zi cm ctamete epening. 'ne re:istri w.tcr c' *re er,gir.41 27 is-siv:s. ;.E2t m:ces 4.. *-; in c149eter. 4*e usec 1r geomet y. Figu es ;; an: r
- a: cesig*,
're stu: -aterial ts tne same for 00*n '255 u:a) col
- stress is tao
- .ie over seceratica is ente:te: :: c :ur at some *:
valves, see: #i: ally AS*" 4 H-87. A tnree.cinerst:nal #1 tite element mocel cf eacn after t.e centigu xs stu:s rave feilee altre gr..e valve is sne,,n in figures E anc 9. ictn nocels are sce:1fic analysis :: trea conciti:ns for Ocanet off was net pe*fe'se:. ine Icac re:1stricutter ir
- e
- B0' sy riet-ic re *esent at t oas coita n ning a;r"o21-l
' eaV Becaust cf the inDor-ten.iecn (2! c*.) valve was relatively uneven Oetwee" tance cf flange st etst 7".!ue loac, tne valve two anc f our contigu0.s stuc f ailures; newever. l
- ately 7CO e eatert!
Occles were JIso r oce s'* Ine eas1C noCelling of tne because Cf tne greater censity cf stucs. s19mif1*4** stucs aM gast et 10ile= tna6 4 1:e Drtvleus analyses. IoaC 15 Carriec D) the tac stycs nearest the cegea:e: region Cf the CIC$v e as.CCf"Darec tC the Snalle' A unif era preloac cf a0Crcutmateiy 35 ksi (24C Na) r .as a::11ec te tne stu:s en: tre internal pressure was valve. 2250 est (15.5 Mc ;. a 2,; l u - p. a t e _
- 2 st.,es., o e-r,,.we,
j 5,. ;m w. :s .y / f 1 / k l l ~ Y [/, QQe sgy j l is$ h '" r.n:,.. x, ~ ) > e'<<e. ;, l~ 'h 4 's I v ,,s .) ~~ s. v. t. ,x. s % y wn I w %_. x e.. ,,,, - As ' i 3, y,.,,,, u } / ,n...a.. n.c.n ~1gure E - tin-;e:n (15 cm) Cre:m valve "ccel.
- a
/ .......n l
- e
.) i i M -- = i i r n... g ve, c. vi...w 's ~,c n.n j &j' /, 2 "N i //
- .00" "'0"
'"'''0' D)' N J -- l'l',a ! "'76" * *' 1 m :t :.et a:ec cegier 1r a t. l fr- . *' /n' )
- !
- ', "r e:e.a'se.
~' p. I l ( ._.4-s.IAL uii nit:::1 N l A ~ ~ l nece1 *esce* we 5eichien of an atore:riate mocel 'er tre:1:*1*: a Y flow inrougn a sitt will ceoene on the flute ::n:1tt:as i anC geometric enaracterts*1cs Of ine cract (Fi< jure 12). le ttis case, ae sitt is represcrie '.. ) I tne nap between tne unicacee :criton of tne cap et s.:a ine fresic siy nating flange su f a:e. Tre ratie
- r flow catn length to charactee stic cimensien (i.e..
nycrawli: c'.a-eteel ce*16ec as L/0, is usec to s:e:1fy J ine cegree :' nemal nonecuilibrium cf tne esc 4 Ling f?uic. A lean rate nocel f ollowing this accroa:r F igure 9. Ten.Incn (?5 cc) Onett Yalve "ocel. casec ca etery's t090geneous nonecui t strium critical to
v s s. -s 2; s' 3 j ). l.. . c u. e s. " a c-i * <... e ** e-s
- e. 4
/
- s-n,
't j Q. L i
- a
,: -*ast .'. e ,.:.et / l 2; (a) Two.Pnase flo. Through a LCng, 8. art:.
- t.s a,e e s t te
' n ' * ** rev e* $ lit, I 4 = e eIA01E 9 a':
- 'g k
seco*s averent
- 12
/ h. 41 4 !*'t
- 8*'
{ / s' 2~ ], ,, e .e g 4
- vt ** e ** t t Y'
1.dete et p / p s tte *
- e * +p
...'**tt ,i 4 *g e / cs / / ,,:,....,,, u. c. (b) Critical :lo. Mocel For '.eatage "ne: : i ve
- e' :eam.m i... e..si
, $jg. Figure ;;
- Leac Fe:istri:utice in a Ten.in:n figure 12. Critical Flow r.ocel Fe* Leasa;e
- 25 cm) Che
- valve.
inreugn a Slit. fio. no:el.1 nas beee cevelecec by ::ilie 'E an: wnece c' is tne c eatum censity e:.,ai 1: -:st."e sa:se:vently :: Wie; ey Abcolianian anc Cnemai 1 1. censity ic_} for tne ecm0genecus #10. ass.-:t Tae gene *a) featt,res of the cischarge of initially i cu a *. l on C) can *e irtegrate: alcng tne 'io. :at" sve:ociec ce saturatec 11culc inaeugn a slM *s snown evaluate the ove-all cressu e cact a:e::s tee 5 r in Figure 12, in tre re;1on 0 < L/0 < 3. a l'osic,;et tne sum of incivicuai cro co.conents 1: give: suerounce: by a vapor annulus is fer9ec. For leng*as
- P e a
- :P Octween L/C a 3 anc L/0
- 12. **e 11ou1C,5et 0* tats uD
- P, g
1etc c:rcolets at tne surfa:e an: sr.all tu :les 4*e entraire:.1 nia t r e ' et. 11 15 assu e: l'at *: .a s s =w 9 , is *ne e q ace O Mssu n ess. : g 44 :
- eat ;-a as
- e* taae's : a:e :et-ter e* Par:e a':
a 9 I M W era = Pcssu n cues he M,.. u m ' Lit = 12 an: als: Ine f el: tion :ressu e cc:: it this r
- r.ange anc area enarge. *es:e:tively, an: :, 's to region is negligible.
I"' CD.C" C 75 5W" IC55* ine flo. 15 assunec t be 15eetnal:1c an: P ~o. e !m ea e m i *s W T Otae:.;s, a*C a II 9Cnecu111* *i '9 ed'et's a*e 1**
- utir
. U a f Mn s p P M a {s,t a F UAtin WeM 5*PC.gn a st agie : ara 9eter wnt?r *s a '.* 110* 0, 4 ge e Py..
- e t a i,. P, {* e M ns 5
e:elli:Piu C al*tv anc fl0n : ate leagt' 10 C' a*tter I I I 'M* 3 Pat 1C, L/D.
- le one.CineasiCnal "'1sture nass an, C s i t u at i on s w ne,re '* n e f i o i s n"* c"r ea e * * **
- e aonettu Co*servation ecuattens are.sec t: evaivate a
singie DBase *elati:ns mi'*
- s CaiCuiatec
- 9 tre pressu7 P OD C09:0nents.
- ne : ntinu1*v e: vat 10m
'rt:11:n in: luce:: i 1 s,. 'D. en* c, J,a r -,. gg: Q i1) a, a e s s, c. where 6 is the Fass flux. A is the slit ::entrg area. wnere g is gravitational aCCeleraM on. 8 at: *. a' anc is the cirection cf flow toorcinate. ,ne ressure ano specif1: volume at stagnetier, an: 't nonentum ecuation 15: tne baCL pressure. Calculatec leak eates Oy t*e a: methces nave agree: well witn empert-ental st :ie CD 1 'l -,c ?: ' C* (10). e.- --r +w-(2) ,a et p su C c. 9: g comeutee C1esure teataces ine seas rate ter each clesu e.as :al:ulate: r a PICEP (am.2) wnich was recifiec to accomocate the 1= 11 r .j w-
v w q 'exDetteC slot openings for the bCl*,ec flange re)aggvely ntge ma, gin; a; ;te ; pv.g,;;;,; ; -g, connections as etter"ined f rom tne finite element
- page, results. The suDcooled 'lu1C Conc 1tions for a cressure of 2235 rsi ;15.4 "Pa) anc 2:50 csi (15.5 Ivp CT OF C CIP I lhiE*,k ALittuth;; Os "Pa) of a temperature o' 600'T (31P C) were assuneC.
n;ctSisgc; lit tu. tlNA ICN
- ean rate estimates f or all ine Cicsures analyze
- eevicss O are creserteC in Figu e ;3.
- ne t e: rair
,,ite re,rene, te on,,, ;3r,.9..$ g,, e r < arge sro.,e: tne ;*eatest CaDa:1ty f0* r*0:w In7 se: tier > l
- tre ;c: ;,c:e, u areas one,e :I:5.,
tar;e lean rates owle; 10 ite lar9e Ciamete' Of the in,eg ity assessmen.5 0,,e a f e:t s;I are tne este a staiing surf e:e aeC s alle* nunoer of stu s ;er ar: of end-inat icas, ' 4.g;;;) ane tne <14,, a;;,;;,7:e l en;t r.. Tne man ay Covers and valve Donnets enn1Dit stancarcs (m.2000). he extent cf exa-anation *:- sic 11a* lean rates anC trenes. Eein; a smaller cressure retaining bolting 15 Civicec sete 1 0 examination o' he! *i.
- ate;;**
CI:Sure, tne sia.in n,16 Cm', valve is CrtC1Cted to Cate9e"tes as C1C*ateC ty bolt 51:e. lt**; pro vce smaller leak rates at lesse" levels of stud Covers Crin:1oaily volumetri: Cegradationi nowever, 519hif1 Cant Ieakages are wncse Cla"iete" is greatee ther twc intnes 55.1 ;- possicle on:e cegra:ation res extenceC te a large* tatege,y E.3.; 35 for gelting twe 3.:nes ;5,, : percentage cf the colting. Cismeter or less with visual surf e:e examina 1en see:1fied only. Tnese 40! recuiremer.ts were Cevel::,: f rom Conven*ional t,oltec,loint f aDet a 1on 5 [ 8CCI1Cationsi nunever, nu:Iear Cower plant fiei: l exce*1 ente Dresentec ea* lier su99ests tho' **e s volumetr1C/ visual examination CutCf f at tw0 in:*es [ .,...g ( 6.1 cm) may recut re reassessme'.t. If these fiel j r aeo. e.., ca* a provice a statistically representative measu e c' r ~ d" i primary pressure councary Ciesure perf ee* ant &, se*vi e sensitive closures :ould be icentifiec and \\, [*[ ' case 0 on known Clcsure perf omance anc on.'aeis 4:0PODeletely range: an: C [ re:Wirements esta;1.sre; g f failure moces, ine NDE recutrements Cevelece: 4 r-m...,,,,,, su:n an a:peca:n would net eetesser'ly te tre sa e as .m.., those in the present 19E3 eCition of tne C::e. :t / would be ex:ecte: tnat any alternative ace * ::n we.i: em nas12e volumetric examinati:n wit
- su:;ie ertai j
f E visual /volueetr1C NDE for incse situations wren l leakage f rom tne Cicsvre nas oCevere: ourir; sere :e. / i flaws are C.250 ta:n (C.6: :N anc one in:*.1:.5 :- l C3*egory B-G 1 a:Ce:tance stanCarcs f
- renariti i
, 'f/ /,[ -l 10- axially orientec flaws. :1:sure assess ert :sse: l t en lese.:efc-e.deeam will reevice a reisti: sn : / / I ce*.een leas rate an; lespe integetty as eag, e: { // f -.. j
- er"s Cf LCit Cei'a atiCn. if selt: ting a -'r1 u-
/ / p/ z e:uire: safety -a gin, ri:* av sa 3 e e q<ere t s / n / J service loaC)*: leveis, **e "es.its f*. 4 li:ssre l J 7 / assessren! aceI* give tre : asis f er esta:Iistia; ' f i re:gier-ge*s. ne i:91: :1 1*te;'at1P; a Ita.. e#**e* / ~
- ' Car P.11:s :*y t et a :e'e-tnatte* Of "et.'*e e'!s f
h / anc Crite*1a f;* '.;I is sno.r. in F iggre is, :
- a*
I [ / f e!!atIlsne se* Cf safety ra";1as, a ran;e :( Cey'a:e: /
- Mit10rs a ul: te 0:5*.Ittet that main *tias a
/
- P s' a',1. eve. Cf Cics.re sately. Leat rates are I
= l 2 009 Cute f C* the range cf gestulate: CONC 1tions #*: i l t
- e '- s e t y.. eat rate use: :: esta:lish Cete:
mit. a s e-ise, t*e ty;e eae exte -.* E I 9 'O O IE* bIIE II EI IEI ?III fP 'II" I I ' I
- i., n.
-t,..s'44 et '.n Cr0v1Ces the : asis f or sele: ting O! reOutreme*ts a** Ievels cf a:ce: tan;e. :learly, tne exam:le anat,'se: rigure.;. Lear. Aate Lee: ut*:rs 'e* 011'e ea;
- reserte: rere1r :revice su"t:1ea.: tases <:-
- *imary tyste *'
- sures.
tru tatin; ;,::e eevist:ns, f' ine closures anaiy*et, a Itat rate f :*e $ ;*t'. AE ) A'C ;;N;; G ON$ gallon rer minute or 1 GPM (0.042 69/5) is 4:6)evec Clesu e irtegelty assessments will pr;vice a .nen approx 1mately one to three stuCs nave f A11ec. r The avallaole margins at : CPP (C.C'2 kg/s) are snown rational : asis for re:o nencing revistens t: : eseet in Taole 3 wnere tne safety f actor is casec on leaC Co:e MI requirements. Satisfying a ieaa.:e ore :'eas d recutred to f ail the stuc nearest the cegraceC region criterion is an ef f ective strategy f or assur1r; by net section t, ens 11e overloaC. In this ceterruna-ciesure integrity while at tne same time reco:1r; tion. Ine Cire:t (,,,; ano cencing (,) stresses were Cemanc or CI. Prelimir.ary analysis cf sario.s Conseewatively aC0ef and Comparec with sDe:1fteC primary pressure bouncery CICsures (steam 9ene'at0* minimum steength properties. The six-inCn (15 Cn) anc reessur12er canaays. CP main flanges, an: :ne:6 valve exhitits t'e smallest margin fee the Cencitton valves) suggests tnat integrity Can te assu e: :y r where 2M of tee stucs are gone, Ni tecause of tne monitoring Cicsure leakage in excess of operational smaller pressure loac, a saf ety f actor cf 0.2 still I1mits. '.arga leak rates 3re prect:teC wnen a fe= exists. Tre pump ene man.ay severs all exnient fasteners are assumeo to nave fa11ec. Acecuate 12
,.c q er j r Iable 3 a55!!!"!hi Or MAks'st ;- ONE op* (0.'.42 69/51.! A..;t e
- Cur ; ace
., a,. a A s s u'* c IA1I*C it i 'J:1. $c'tir0 IP (Be $EW it's', I*. a. Ju
- 10$wre *.as "ete*th!
.?** aa's*' l 'l 16 Stuc Man.sy (ove-SA320 L43
- 18. 91 2{ 5tu: Man-ey Cover Sh40*624
}E.6 E: Fump Flarge A193 E7 '.Bi 6 in:n (!! cm) Cnech valve A193 67 2 *, E ', { 10 In:n (25 cm) Cnect valve A193-67 l',2 ".? f i safety riarg1ms Car be cerionstrated croviced that 3. Hall, g, F, " A Survey cf :ne ;,* terat.*e of .N. Closure calage 15 local anc tnat Dolting materials are Allow Steel pastener CC*rcsior in G.: ::wer suf ficiently cuttile as 10 tolerate neavy camage Plants," Electric Co.,er E esearch les*11 16, Induced Dy Cceresion. Topical Eecort NF-37S4 t;e:emper 1934;. i 4 Capener, E. L., aa: F. C. 01:c11a. "!value:1:r Eolt eg Service lepe see:es in Primary $ress.-e j .. u,, m....-u Eounca ry Closu.n.s.,ac.te.:n. i.nginee. ri ng Serv i:e t, t . w"' re i Inc., leport. r m,.". " e.a : Decemoer MBA;. I t 5. Nickell, F. *.,. O.
- W a, er: !.A.*e-
) ,, u.. i. o.....e "ine use cf Lea tef e-e-i.reak Criteria ar: i Assessment of t'argins in Accressing "lcsure a+om Integ** y !ssues,* Saeer 05/2, 5";A*-? Conf erence, Brussels, Eeigte ( Au;ust 1325 '. E. American So:iety of Me:nanical Eagineers, E: *,- n o.. i.in anc caetsure vessel t::e, Se:u ca 1:, kuies -- l tre.nservice.nL:e: 1Cr of %,:leae Lo er P ar; ( Components," ;9E3 i 1*10n. I I 7. DeSalv0,3.f..,a*:.... ; ats:", "i W " - I j engineering er,anysis Sy3;g s, gst,'g uge,gj, n .q, Sevis,ier 4.;, Owars:n Anai,s t s 'y'* e s s.. i tun 4,. I l : m ne..n.4,..w.u l l i.n..n.. i. C L inn.y
- n. enm, j pg g,a,,.
y, ..3, e I. Eate*gui, A., "En 't *e* [*tti at: elskati:t ig.,re 14 flowenart Sno.'.ance Recutre9ents an:, ing One Dete minat109 !CnaviO' Cf Lasrets,' emeI01rg :esese:r ;cun ', f Cf hl[ Oe M Cr" iu',ietir. D4.' 91!.. I Acce: ance Crite-ton. l 9. -ea y,
- ., "*re
- c Cr ate Orl:1:ai :15:na-;t, I
A;K'iC.".EO G E"I NT S
- < Ie): ally Snucate: :- Sue:ceie: Li:vi:,"
Nucleae 5:seace er: !* sece-'re,,ol. :; ;;s?;,
- ns.ers.as ces: ee w :er ne ::as e.:-s m: :'
e tre T.e: ric Do ee :esear:n !rs:* ute, :#io A;;;, ellier,.. e; al., o Pease ric. ** :.,:- i
- alif c*nt a U.'54. Research Pro.ie: 20!5-5. *ne
- ntergran.,iar ',
- ress ; esion ;raer s an:
I autnces aise =isn to acunowle:ge the assistance esulting Acc.,s: : Emissier,' Ile:1 i: ::.e-t Croviced oy the AIF/MPO Iast CroWC on Ecl* lhg witn Fesearch Insitute, s 00e:.in Cuti) at1Cn '. ? e see:ial thancs extencec to "r. Kenneth " core of t9e L a,oc oc k and.ilcom *: :any, "*. I:paa Lan:erman :f
- ',.
- ccellanian. :... ar.: !.
nes a'. ':al: ;&t1:a e' .est ingnovse it ectr *: *:rse a:1on, anc "r.. alter Ear . ear :ates *ar:.:. ; -n t s
- e. :.;es ar:
.,;e s, '- of Comoustion Engineering, ;n:. Electric :o,.er Lesearen ;nstitute, :ercet '--2n
- ecemoer 19E23.
4 RIFEREk;ES )
- 12. Norri s. O.,. C 6 amoto E. Orem el, en:
.i 1. Merrict, I. A., anc T. U. Marston, "Sackgrounc Orieseacn, "Pl !P: Pice track Evalue:1on and Incustry Response to the issue of Bolting p rogran,* Ilect-ic Po.er 8 esea r:n Inst ute, I Degradation or Failure in U.S. Cc 19ercial Nuclear See:1al Fecer: '.? 2196 5R ( August 133 1 l Power Plants," Paper 06/1, SMIRT-6 Conf erence, Brussels, Eelgium (August 1925). 2. Anderson, W., anc P. Sterner, *(valuation of Responses to II Eulletin E2 02," NUREG-1095 (May 1985). 13
w = ATTACHMENT C Issue 1.2.1 - Material Compatibility Concern t; umber I!J-8 5 -021 -X04 1N-85-824 001 IN-86-184-001 Issue 1.2.2 - Material Adequacy ~ Concern Number PH-85-042-001 Issue 1.2.3 - Inadequately Supported Flange Concern Number BNP-QCP 10.35-8-22 e. 6 .}}