ML20059C668
| ML20059C668 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/1990 |
| From: | Israel S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | |
| Shared Package | |
| ML20059C665 | List: |
| References | |
| TASK-AE, TASK-S90-01, TASK-S90-1 AEOD-S90-01, AEOD-S90-1, NUDOCS 9009050250 | |
| Download: ML20059C668 (31) | |
Text
_ _. _ _ _ _..
AE00/S90-01 RECURRENCE OF IMPORTANT SAFETY ISSUES REPORTED IN LERS by:
Sanford Israel August 1990 Office for Analysis and Evcluation of Operational Data U.S. Nuclear Regulatory Commission 28 9009050250 gCpi FDR ORG PDC
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EXECUTIVE
SUMMARY
Over 800 licensee event reports (LERs), having particularly important safety significance, were reviewed to identify issues previously covered in NRC generic i
communications. The selected LERs were previously screened by the NRC staff for 1
significance from about 9,000 LERs reported in 1986 through about the first 1
quarter of 1989.
Over 1,200 NRC generic communications have been published through 1988. Approximately 100 of these comunications contained issues that matched 308 of the initial 800 LERs. Most of the matches (225) occurred for LERs reported within two years of the related generic communication.
Only seven plants had three or more LERs that were matched with communications more than two years old.
Most of the matches occurred with information notices that make up the bulk of i
the generic comunications.
Generic letters and bulletins have a much smaller share of a',1 the matches. However, bulletins make up a disproportionately large share of the older matched comunications.
Seismic design d3ficiencies and equi 3 ment qualification problems are the dominant topics associated with the i
mateled LERs.
Each topic has several generic communications that matched spe-cific LERs.
Both topics had extensive NRC and industry effort and numerous generic communications over several years prior to the study period.
The evidence indicates that the licensees are making a good faith effort to pro-cess the generic communications in a responsible manner.
Inspection reports and discussions with resident inspectors are basically positive about the pro-grammatic espects of the licensees' feedback programs, in addition, the NRC performs some form of audit of the licensees' actions in response to generic letters and bulletins. Consequently, these factors and the small number.of older matched LERs do not indicate any serious deficiency in the utilization of NRC generic communications on a programmatic level.
However, the 78 LERs that were matched to generic communications more than two years old represent important safety issues and indicate the utilization of individual generic communications could be improved. Marginal judgements during the initial implementation of the communication may be one reason for flawed corrective action. This study also highlighted the narrow scope of many generic communications and the difficulty of grasping the essence of the communication from the title alone. Consequently, the long term application of these communi-cations to operational experiences is hampered by the large number of communica-tions and their recall capability.
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TABLE OF CONTENTS
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Eil92 EXECUTIVE
SUMMARY
-1 1.0' INTR 000CTION;......................................................
1 i
1.1 Background......................................:..............
I 1.2 Methodology.....................................!..............
1 1.3 10utline of.the Report........................../..............
2
2.0 DESCRIPTION
OF RESULTS.............................................
3 2.1: LERs..........................................................
3 2.2 Generic Communications........................................
4 2.3 Issues........................................................
6 2.4-P1 ants.........................................................
7 o
3.0 ANALYSIS...........................................................
8 s.
3.1 Recurrence o f I s sues - i n LERs..................................
8 3.2 Generic Communications........................................
11 3.3 Topics........................................................
13 3.4 Plants.........................................................
14
'l 4;0 FINDINGS...........................................................
15 l
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5.0 CONCLUSION
S........................................................
16
6.0 REFERENCES
17 APPENDIX A'- Issue Index for Follow-up Review...
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.i APPENDIX B - Partial Collection of Generic Com nications.
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l' APPENDIX C - Generic Communications on Pipe Pi m
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APPENDIX D - Distribution of Cat 2 LERs for F '
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.l'.0 INTRODUCTION l
1.1-Backaround-The Nuclear Regulatory Comission (NRC) has sent more than 1,200 Generic Letters (GL), Bulletins (Bul.), Information Notices (IN), and Circulars- (Circ.) to licensees and applicants ~ through 1988.
Most of these generic communications i
identify issues having safety implications at a number of plants.
The causes.
of the deficiencies noted in these communications involve design / fabrication /
installation errors, administrative oversights, maintenance defects, and human errors.
The origins of these reports vary, but ir large reasure, they result from-deficiencies observed in plant operations and %r%d to the NRC_ under one of several regulatory requirements.
NRC genery ttudica 'of unresolved safety-issues also initiate these types of communicatient kring this knowledge among the affected utilities improves safety margtas H there is.effectf u iteensee follow-up'on the information and correction of the deficiencies. Requiresnts for licensees to process relevant operating experience and communications, both internal and external to the plants, stem from the TMI Action Plan, Item I.C.5 (Ref.1) implemented in the early 1980's.
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The purpose of this curirent study is to examine the recurrence of important L
safety issues, as reported in licensee event reports (LERs), and previously addressed in NRC generic communications.
1.2 ' Methodoloav On average, each nuclear power plant generates approximately 30 LERs per year that identify a wide variety of situations relevant to plant safety.
These include plant accidents, missed surveillance, failed safety-systems, design deficiencies, and so forth.
The Reactor Operations Analysis Branch (ROAB) of l
the Office for Analysis and Evaluation of Operational Data (AEOD) screens all.
l LERs to identify generic issues important to safety that warrant: additional study
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and possibly corrective action. Each LER is classified by a technical reviewer 4
according to established AE0D procedures and criteria (Ref. 2).
Situations particularly important to safety are designated Category 2 (Cat 2).
J The criteria for classifying _the LERs are documented in AE00 procedures-(Ref.
2), and involve elaborate considerations and engineering judgements to assess safety concerns.
Category 2 events include potential common cause failures, recurring component failures, and plant or system degradations that could result l
in serious events under slightly different circumstances. These latter criteria depend on the reviewer's judgement and insight to identify important generic issues from a description of the event in the LER.
Over 800 Category 2 LERs, out. of approximately 9,000 - LERs in the period 1986 through about the first quarter of 1989, were used in this study.
A screening of these Category 2 LERs was performed to identify the central issue in each report. At the same time, the titles of all NRC generic communications were searched-for issues comparable to those identifled in the LER screening.
If there appeared to be a~ match between a Category 2 LER and an NRC generic communication, the issue was recorded in a database.
About 80 such issues are listed in Appendix A.
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e The-initial screening. process yielded about 410 matched LERs.
Most of'this-select group of matched LERs was. further processed by comparing' the details
.within each. report with -information in the related generic communications; This 1
in-depth examination reduced the set to 308 Category 2 LERs. About 100 different generic comunications were matched iii this process.
i The hjpothesis considered.in the study is that a large number of matched Category 2 LERs (submitted subsequent to a related generic communication) after some grace period could denote inadequacies in the communication process.
1.3 Outline of the ReDort Section 2 of this report describes the results of the matching process in terms of important enaracteristics such as the communications themselves, the topics,'
and the plants.
Section 3 presents an ana' lysis of these results in terms of consistency with other related information and initial expectations.
Section' 4 presents findings based on the analyses and Section 5 contains the conclusions of the study.
The appendices contain inforr.ation on important safety issues, related generic communications, and Category 2 LCR distributions for the dominant issues.
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'2.0- DESCRIPTION OF RESULTS
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Import' ant safety l issues reported in
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LERsLand matched NRC-generic commun-l ications may be reldted in two ways.
First, operating events are reported
.in LERs which~in turn may initiate an 1
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NRC generic communication, usually an um-
-information notice.
Other generic M
communications are generated by NRC
[ ia-resolutions of unresolved safety-is-R-
sues and 10CFR21 notifications. Sec =
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-ondly, a generic communication may cause a licensee to discover a design deficiency or an unrevicwed safety l
. issue that subsequently is reported in an LER.
Both types of documents were YEAR
- read to identify - similar underlying
- nrst ourter issues and the results organized into different categories to facilitate l:
analysis.
Figure 1 Category 2 LERs Used in Study 1
- 2. l' LER1
'Over 800 Category 2 LERs covering the period from 1986 through.about the first l-quarter of 1989 were reviewed in this study. The= distribution of these LERs is-shown-in Fig. l.
This set represents about 90 percent of all Category 2 LERs in this. time frame.
Subjectivity in the screening process may introduce some ~ bias in the LER classification because reviewers may
' favor issues-related to their own backgrounds.
Similarly, topics cur -
L rently under staff review also tend to a
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influence the designation.
This po-S tential-bias, however, is alleviated e
.by using 16 reviewers to screen -the E"
LERs and independent management re-o views of those LERs classified as
. Category 2s.
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. As noted earlier, the LERs and generic communications were read to identify matches. Using this process, about 40 I
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percent of the Category 2 LERs were yg,l,,clcg,,;cce;,yyl,ycy matched with earlier NRC generic com-l munications.
This group of matched l-LERs was further evaluated to identify Figure 2 Time Elapsed Since the Generic l
those situations where the generic Communication "mmunication was more than two years 1
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older than the LER-(referred to as " older" matches later in the text).
A two j
year time frame allows for licensee reaction-to the comunication.
L About 10 percent of the Category 2 LERs were matched to generic comunications more than two years old (78 total). A two year time interval _ was used as a rea-l sonable expectation for licensee action on or an acknowledgement of a particular l
generic comunication. This assumption is supported by the elapsed time distri-bution shown in Fig. 2.
The time interval used in Fig. 2 was roughly estimated-L by using the year rather than the specific day of publication of the LER and gen-eric comunication. As indicated in Fig. 2, most of the matched LERs occurred within the first two years of the publication of a generic comunication.
L 2.2 Generic Comunicati201 L
Over 1,200 generic-communi-cations have been published by the NRC since 1971.
A chart _ showing the distribu-no tion of these comunications from 1979 through 1988 is 20 ----
l' shown in Fig. 3.
Prior to 1979, 108 bulletins and cir-culars were issued.
Both too P
required action by the licen-N see, but only a bulletin re-U so quired a written response y
.concerning the licensee's a
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action.
In both cases the E
licensee's action was subject R
to _ verification by an NRC in-40 l-spector. Information notices L
were introduced in 1979 to o
l provide safety information to the licensees without requir-ing any specific action on 7s so at s2 as a4 as as a7 as their'part.
Generic letters were started in 1981 to pro.
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mulgate NRC requirements on relatively broad safety is-m m e..
EZ3 cireuer.
sues.
Circulars were dis-El swi.un.
E B o.n. Len.r.
continued in 1981.
ll Only about 60 to 70% of these generic' comunications. are Figure 3 Generic Communications L
directly related to opera-tional events or conditions at a nuclear power plant.
The rest are concerned with non-power nuclear issues and administrative topics such as operator qualifi-cation exams and LER format.
Thus, only about 800 NRC generic communications o
identify issues that are potential matches for Category 2 LERs.
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V Since an issue may have several related generic communications, the following rule was used to select a specific communication for a given LER:
If there war a bulletin or a, generic letter associated with an issue, the latest 1 published document was used to define a match.. This approach is reasonable because these typest of comunications generally require licensee action, whereas information notices.do not require any formal response by the licensee. Also, bulletins and
_ generic letters tend to be more global and hence more likely to cover a general-topic area, while information notices are usually more narrow in scope.
If an issue was. addressed by information notices only, the most recent document was selected.
Selected generic aomunica-Table I Generic Comunication Associations tions issued in 1986 were surveyed to examine the rela-Generic Mentioned in Cat 2 LERs
- tionship between NRC inspec-Comunication Insp. Rpt.
Matches tion activities and licensee
- reporting.-
The results of.
(number)
-(number) this survey are shown in Table I.
The column labelled IEB 86-002 61 3
l mentioned in insp. rpt."-is IEB'86-003 59 0
the number of times..the gen-IN 003 48 7
L eric communication was refer-IN 86-053 46 21 enced in an inspection report IEB 86-001 44 2
as indicated in the NUDOCS h h,-
f5 database. The context of the reference is not character-l IN 86-076 13 16 l
L ized. The number of times it IN 86-005
- 12 2
is mentioned in en inspection 3y.86-108 9
1 report provides a measure of IN 86-001 8
4
- on-site staff follow-up on a IN '86-014 7
3 particular communication.
1 The last column iMicates the IN 86-029 7
1 number of matches with Cate-L gory 2 LERs in. this study.
f 6
About 30 percent of all IN 86-070 2
7 matches
-i nvol ve -
generic IN-86-087 3
1 communintions from 1986.
IN 101 0
1 There wve an additional - 20 l
(1986)IUs sampled that were 2
0 mentionid fewer than eight GL 86-006 3
0 times ii inspection reports GL 86-015 4
0 L
and.had no matches with Cat-egory 2 LERs. Only two Cate-gory 2 LERs, which matched a 1986 generic communication, were more than 2 years old.
These occurred in the L
small group of 1989 LERs that were examined.
Information notices, the most numerous form of communication, usually address narrow issues such as specific component deficiencies or single failure discov-eries.
Although no action is required of the licensee, most utilities process these communications as part of their review of operating experience.
This processing was required by the TMI Action Plan (Ref.1).
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L Information~ notices accounted for about 60% of the prior communications matched h
-with Category 2 LERs.
This fraction is smaller than the IN share (80 to 90%)
of all NRC communications.
In terms of matches with older communications, ins accounted for about 50 percent of the total.
Licensees estimated that about 10% of the ins result in some corrective action, while the NRC staff estimated that the fraction could be as high as 50% (Ref. 3).
Only 21% of the matched Category 2 LERS matched generic letters, while generic letters accounted for about 6 percent of the matches with older communications.
On the other hand, about 13% of the matched Category 2 LERs matched bulletins,
- and bulletins accounted for about 40 percent of the matches with older communi-cations.
About 25 generic letters issued from 1985 to 1988 were identified as potential matches for LERs. Of these, eight were matched to Category 2 LERs from 1986 to 1989. Generic letters associated with seismic problems (GL 87-02), fire protec-
' tion problems (GL 86-10), air system problems (GL 88-14), and loss of RHR (GL - 87-12) were the only GLs to have numerous matches to Category 2 LERs. Similarly, 16 bulletins in the 1985 to 1988 time frame had topics relevant to LER reporting.
Only five of these were connected to any of the selected LERs, with the MOV bul-letin (IEB 85-03) having the most impact. A bulletin on seismic analyses of as-built piping systems (IEB 79-14) also matched a large number of Category 2 LERs.
Individual information notices in this time frame were not matched-to large numbers of Category 2 LERs, except for one on electrical splices (IEIN 86-53).
Overall, about~ 100 different NRC generic communications were matched with Cate-gory 2 LERs.
Individual generic communications had very few " older" matches with LERs except for IEB 79-14.
1 2.3 Issues Over 80 issues (listed in Appendix A)
Table II Topics with Most Cat 2 LERs were identified where one or more Category 2 LERs appeared to match one seismic 51 or more NRC generic communications.
The descriptions in Appendix A reflect Equip. Qual.
47 Con. Rs. Vent.
19 the underlying issues in a reasonably Air System 18 narrow form.
Some issues could be
'I p
ygg combined while others could be divided more finely.
Safety Valve 13 RHR 12 To facilitate obtaining a global view, the topics listed in Table 11 are, in most cases, aggregates of the issues listed in Appendix A.
The eight topics in Table 11 account for about 60 percent of the matched LERs. Condensed titles of NRC generic communications associated I
with these topics are listed in Appendix B.
Seismic design and installation deficiencies accounted for 51 Category 2 LERs in this time frame. The major impetus for activity on this topic was GL 87-02 issued in 1987 requiring plant walkdowns to identify inadequate supports for 6
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mechanical and electrical equipment and evaluations of selected components. This -
-issue was previously an unresolved safety' issue that had heavy. industry partici-pation in developing a-resolution.- The matched LERs on this subject prior to.
1987 mainly reflect concerns with piping analyses covered in-Bulletin-79-'14.
Twenty generic communications associated with seismic issues are listed in Appen-dix B.
Five of these were matched to LERs. - The major documents are the bulle-tins on piping stress analyses in 1979 and the more recent generic letters.-
Seventeen of the 51 seismic Category 2 LERs matched generic communications greater than 2 years old.
Equipment qualification deficiencies was the second most prevalent topic. There were 32 NRC generic communications issued under the general topic of equipment qualification since 1978. Five of these documents were generic letters written between 1982 and 1986. Most of the LERs in this category were related to infor-mation notices issued in 1986. Consequently, most of the 47 Category 2 LERs on this topic were matched with communications less than two years old. Eleven of the Category 2 LERs were matched with older communications.
The next three most prevalent topics (control room, ventilation, air sys-tems, and diesel generators) in terms 3
of matches with Category 2 LERs had only a few matches with older com-so U
Distributions of. elapsed time between-U2 a Category 2 LER and its matched gen-E R
eric communication are presented in 40 Appendix D for the eight topics listed g
in Table II. These individual figures 3a are discussed in Section 3.3.1.
P L-2.4 Plants
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The distribution of plants having Cat-
'o r egory 2 LERs with issues greater than M E 2 years old is shown in Fig. 4.
The r
average is about one LER per plant.
NWBER OF LERs As can be seen in Fig. 4, seven of the plants have three or more Category 2 LERs in this category.
Five of these Figure 4 Plant Distribution seven high plants in Fig. 4 are at multi-unit-sites.
Discussions with resident inspectors indicated that one unit sites and small utilities may~ be more likely to be less responsive to processing feedback because of limited resources. However, only two of the seven high plants in Fig. 4 are in that category.
This fractional representation is about the same represen-tation as in the total population. Similarly, two new plants are among the seven high plants. This' fraction also appears to be in line with the general popula-tion. Therefore, the results in Fig. 4 indicate that one unit sites are not less responsive to processing feedback due to perceived limited resources.
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~ 3.0 -ANALYSIS-There have been numerous LERs describing events or conditions important to safety.. Each plant istues about 30 LERs each year and about 10% are classified as Category 2 by ROAB. Thus', these LERs, which are judged important to safety, provide. a source of operational data that can be used to assess the recurrence
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of important safety issues previously identified in NRC generic communications.
3.1 Recurrence of Issues in LERs NRC generic comunications were matched with 308 or about 40 percent of the Category 2 LERs from 1986 to the first quarter of 1989.
These matched LERs entail -important safety concerns considering the threshold for LER reporting, the Category 2 evaluation' process, and the high threshold for issuing generic comunications.
Most of the matches are operational conditions rather than operating events. The distinction between the two is that operating conditions reflect potential failures, such as a design errors or system unavailabilities, while' an operational event is an actual failure on demand, such as loss of all emergency power following a loss of offsite power.
The preponderance of operational conditions in the set of matched LERs is consistent with previous surveys of Category 2 LERs which indicated that design / fabrication / installation (D/F/1) deficiencies dominated (Ref. 4).
Most of the matched Category 2 LERs occurred within 2 years after issuance of a relevant generic comunication as indicated in Fig. 2.
It should be noted that no determination was.made whether the generic comunication actually prompted the LER.
In some instances it may have, and in others it may be coincidental, in any event, assuming that the generic communications did prompt the matched LERs, a burst of Category 2.LERs might be expected shortly after issuing the document for two reasons. First, 50 percent of the Category 2 LERs are related to D/F/1. deficiencies which are latent defects often reportable when found.
Similarly, the dominant topics listed in Table 11 are D/F/I issues. Thus, timely and effective licensee corrective action on these topics initiated by_a gener c i
comunication would generate early LERs (if any) and no late LERs.
The second reason is that other potential corrective actions such as improved maintenance, emergency procedures, and administrative controls would generally not prompt an LER if effectively implemented.
Here again, LERs would continue o
to be reported in the near term until the licensee made a corrective action, and no late LERs reported if the action was effective.
Consequently, the general form of the elapsed time distribution of Category 2 LERs in Fig. 2 is plausible.
3.1.1 Causes of Old Matches Only 78 Category 21.ERs matched communications more than two years old.
The average is less than one match per plant in a three year period compared with an average of about eight Category 2 LERs per plant in the same time span.
Although no specific evaluation was performed, this small group of "old" Category 2 LER matches may be caused by many factors such as disregard for the generic communications, marginal judgements made in implementing the communications, 8
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human errors-in implementing' corrective actions, intractability of the issue, Or success.
The evidence indicates that the licensees tre. making a good faith effort to pro-cess the generic' communications in a responsible manner.
The-licensees have programs for processing NRC generic communications, even information notices that require no formal response.
Generally there are personnel; responsible for screening the document when it is received and forwarding it to appropriate licensee departments for some specified action,. such as evaluation and-resolu-tion.
These programs usually have-some means for. tracking.the disposition of the report.
It is important that the substance of the communication and the expected action be clear, otherwise the initial licensee screening may misdirect or degrade the importance nf the report. A diagnostic report on one plant noted:
"The GL did not require a written response to the NRC, however, [ licensee) procedures required that a dc:umented review be completed for applicability to (the plant].
The GL was routed for information to' various groups without any specific action required and no review was documented."
Thus, this NRC generic letter had apparently no impact at this plant because of the specific language in the letter.
Another diagnostic report at a different utility noted:
"The procedures which implemented the (feedback] program provided effective safeguards to ensure that operating experience documents which were either routed to the wrong technical groups for evaluation or inappropriately designated for ' problem awareness' were caught and rerouted to the appropriate technical groups for the required action."
This approach to follow-up is commendable and should be facilitated by explicit expectations in the communication itself.
Discussions with resi-dent inspectors at several sites indicated that the licen-sees are gener ally doing a responsible job.in processing NRC generic communica-tions.
Some of the licensees amass prior operational experience for review before executing a major component overhaul or plant modification.
They use their own internal databases as well as industry, databases fo'r this purpose.
Resident inspector follow-up on generic communications was removed as a-core module in 1987. However, regional inspectors or headquarters personnel generally audit responses to generic letters and bulletins. ' Based on discussions with several resident inspectors, some of them rely on the licensee's. database to retrieve relevant documents on an issue of-interest at their plant.
Other residents rely on a generic communication index published by the NRC staff several years ago to identify NRC generic communications related to a particular problem at hand. These types of ad hoc feedback are cumbersome because of the large number of documents associated with any topic as shown in Appendix B.
As noted later, these documents may have very narrow information on a given topic that isn't relevant to a particular issue under consideration.
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All the resident inspectors have microcomputers 'in their offices that could be used to search databases for information relevant to the task of-the moment.
Database programs generally have text search capability which would enhanco an inspectors ability to identify important prior knowledge on any issue. The NRC' generic-comunications could be incorporated into such a database using abbreviated text that explicitly defines the underlying: issue and ' suggested action.
- Use of such-a- database during inspection activities would insure attention was maintained on important safety concerns.
Many of the problems appear to be in the area of marginal or differing judgements made when implementing a specific communication.
A recent NRC inspection at Catawba (Ref. 5) discussed the licensee's actions with respect to GL 89-04,
" Guidance on Developing Inservice Testing Programs." The report states:
"Although the licensee has an IST program approved by an NRC SER, the generic letter states that any changes to procedures or program revisions
'shall be made,.if necessary, to bring the program compliance with the-guidelines presented in the generic letter. The licensee had initiated selected changes; however there was no intent to fully comply with the letter's guidelines. The licensee believed it was not necessary since they-did'have an approved TER for their program."
A similar situation occurred at Comanche Peak where a recent inspection report (Ref. 6) found:
"The = applicant received the (INP0] SER, performed an 10ER review, and resolved the issue as not being a problem at CPSES. The justification for this stemed from an architect-engineer opinion for which no sound technical basis was provided.
Moreover, the applicant missed another opportunity to appreciate the significance of the issue. This opportunity occurred during the applicant's review of NRC Information Notice 85-24,
'f ailure of Protective Coatings in Pipes and Heat Exchangers.' 4 Essential-ly,;the applicant relied merely on the earlier resolution of the initiating report, SER 68-83.
The NRC... documented these shortcomings in...
The applicant resolved the open item by raising the Plant Evaluation group's standards to demand
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technical bases instead of accepting opinions."
Both these examples illustrate types of differing judgements that occur when processing generic communications. Neither case was considered a violation of underlying regulatory requirements: however, they do reenforce the importance of NRC oversight to maintain positive, local guidance for processing these com-munications.
A large number of generic communications on piping problems are listed in Appen-dix C.
There are several separate subjects mixed together under this heading-and several of the communications appear to be redundant based on their titles; however, the large number of documents, especially generic letters, focuses attention on the chronic nature of the subject. Several generic communications on the same issue may signify a level of intractability which leads to " older" matches.
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- Human errors in performing corrective actions are always a problem, but_do not-reflect uniquely on processing generic communications.
The - numerous errors
. reported for deficient electrical splices that are environmentally qualified is such an example. A licensee's administrative controls.for limiting these errors is.outside the scope of processing generic comunications effectively. - Finally, some of _ the: "old" matches are actually successes because of the periodic surveillance initiated by a generic comunication.
3.1.2 Validity-The match between LERs and NRC generic comunications is generally consistent with reports from special diagnostic inspections which examine overall plant operations at sites showing some recent weaknesses and Augmented Inspection Team (AIT)' reports which provide in-depth analyses of.recent events having signifi-cant safety implications.
- Of seven~ diagnostic reports reviewed, one report directly criticized the licen-see's operational experience program in general.
In another diagnostic evalua-tion report, the inspectors noted that the licensee's response to Bulletin _85-03 had incorrectly reported some information and had. failed to follow-up on the generic aspects of problems found.
Fifty AIT reports from 1986 through 1989 were scanned to identify those that had issues discussed in previous NRC generic communications.
The two AIT reports
.that criticized licensee actions presented different facets of the problem.
In one instance, the AIT report simply stated that the earlier licensee response to the relevant generic communication was inadequate.
In the other case, the licensee's initial response to the generic comunication was appropriate, but a procedure upgrade package, implemented at a later time, dropped the corrective action. This deletion had a direct bearing on the subsequent event at the plant that was under investigation.
There are uncertainties in the number of matched LERs because of the Category 2 evaluation process discussed in Section 1.1, LER reporting threshold, and potential oversights in this study. Operational conditions may be underreported because of judgements involved.
This was noted in the reporting of equipment qualification deficiencies discussed below. There may be a bias in the matching process because no attempt was made to resolve all the nuances in the LERs and the generic communications in every case.
This would-tend to overestimate the number of-matches.
Some matches may have been missed entirely.
Although the
- absolute numbers of matches in the different categories may be uncertain, it is believed that the general trends are reasonable and the potential deviations are not overwhelming.
3.2 Generic Communications
_ Correlating generic communications and LERs in this study highlighted some de-
'ficiencies in the communications themselves. First, the titles of the communi-cations quite often do not convey the substance of the issue. For example, one information notice, titled " Potential Failure of all Emergency Diesel Genera-tors," is about the deleterious impact of increased loads added to the emergency bus after the original design approval. A casual reading of the title provides 11
p Q
no clue about the message inside.
This shortcoming is particularly important for. information notices which may get less. attention.
Another IN, titled
" Diesel Generator Failure at Calvert Cliffs Nuclear Station Unit 1,"
is about the mechanical failure of interpolar, connector bars on Louis Allis generators.
' Subsequent reference searches by the licensee for documents on a specific issue may overlook relevant generic comunications because of non-focussed titles, t
The generator bar problem referred to above illustrates another potential diffi-culty with the comunications - too narrow a concern. In this instance, the IN opened up the potential connector bar problem to other manufacturers besides Louis Allis, even though there were no reported failures for other generators.
Thus, the IN properly stretched the concern and hopefully stimulated the reader to' question-other similar situations.
An old circular titled, " Improper Fusei Coordination in BWR Standby Liquid Control System Control Circuits," limits its'
' discussion to this specific topic only. Yet, several Category 2 LERs, processed in this study, were related to fuse or breaker coordination problems that may >
have benefited from this old circular. Restricting the scope of an issue within a comunication may unduly truncate the inquiry performed by the recipient. This may partially explain why ins accounted for only 60 percent of the matches with Category 2 LERs while they represent 80 to 90 percent of the generic communica-tions.
Similar difficulties arise with more global comunications like generic letters.
An example is " Required Actions Based on Generic Implications of Salem ATWS Events" which proposed four actions by the licensees, only one of which was related to ATWS. In this case, the title focuses on the Salem event rather than-the requirements. - Here again the ability to retrieve this information at"a -
future date may be handicapped if only titles are available in a database..
Generic letters accounted for proportionally fewer matches with generic comun-ications greater than 2 years old as noted in Section 2.2.
Without rigorously exploring the issue, one might postulate that the licensees may do a more thor-ough evaluation and implementation of these requirements. Another possibility is that the requirements may be more programatic and thus have a longer lasting impact than suggestions in information notices.
The high recurrence of issues treated in bulletins was also noted in Cection 2.2.
This outcome was unexpected because bulletins receive considerable NRC staff attention after they are issued as indicated by Table 1.
Examination of some of the matched bulletins indicates that they involve potential oversights. One of the largest contributors to this category isBulletin 79-14 dealing with seismic reanalysis of piping systems.
The enormous scope of this issue makes it subject to oversights and late discoveries. Another isBulletin 79-06 dealing with mispositioned switches. This issue provides continuous opportunities for mistakes over the life of the plant.
The pool of HRC generic comunications that could be candidates for matches with Category 2 LERs is on the order of 600 to 700 (allowing for some overlap between the communications). Only about 100 different generic communications actually matched Category 2 LERs in this study.
This low count may be attributed to several reasons.
Licensee corrective actions in response to a particular com-munication may not have exceeded the LER reporting threshold, the action was 12
effective and no'new situations occurred, or the communication didn't have any corrective action.
3.3 'Tooics I
l
' As noted in Table II, certain topics generated the majority of the matched Cate-gory 2 LERs.
The number of LERs associated with a particular topic probably signifies heightened interest in the subject in the 1986 to 1989 time frame, beyond the issuance of the generic communications alone.
This is particularly
~
germane for equipment qualification which was a protracted concern in the 1980s as evidenced by the number of generic comir"nications (Appendix B) and the special enforcement criteria developed for just c.s issue.
Another example is seis-mic design, which had extensive industry involvement in exploring an unresolved safety issue on this topic.
3.3.-l Patterns The number of opportunities for deficiencies also affect the number of matched LERs on any given topic. Seismic issues cover the whole plant and contain myriad.
details.
Thus the potential. number of flaws is enormous.
The RHR system is fairly well defined and thus has fewer opportunities for recurring safety issuu, Figure 2 presented a profile of time elapsed between a Category 2 LER and its matched generic communication for all the matched LERs.
Similar charts are presented in-Appendix D for the eight most frequent topics identified in Table II.
The profiles are generally the same, namely a burst of LERs in the first two years.
The distribution beyond two years varies because of the non-uni-formity of generic communications on the different topics in terms of number, timing, importance, and opportunities.
For example, there are five generic.
communications -in the seismic matches and eleven in equipment qualification, while only one generic communication is matched for fire protection and one for control room ventilation LERs.
3.3.2. Seismic l
The matched seismic Category 2 LERs were fairly evenly distributed over the time 4
period of interest.
Prior to 1987 there were a series of ins on specific com-
+
ponent seismic qualifications and in 1979 there were bulletins on. seismic calcu-lations as shown in Appendix B.
The seismic LER activity in 1986 indicates a l
high level of licensee internal review ostensibly without significant near term 1
NRC prompting.
Most of the seismic Category 2 LERs from 1987 on were matched to GL 87-02, which required a plant walkdown to identify components not adequately supported or an-chored.
Based on a survey of 1988 Category 2 LERs, many of these problems are L
identified during review of specific plant modifications or from feedback from other plants or from other systems in the same plant.
About one-third of the seismic related Category 2 LERs in 1988 were the result of plant walkdowns (Ref.
4).
l 13 I
m
.
Seismic plant walkdowns preceded the 1987 generic letter.
The impact of these walkdowns was' alluded to in'a 1986 AE00 report on seismic anchors (Ref. 7) which noted:
"Ahchorage, deficiencies continue to be identified Tv multiple, independent programs...and during reinspection by licensec and other parties."
This finding highlights the difficulties associated with the.walkdown process-and infers a potential for oversights which result in " older" matches.
3.3.3 Equipment Qualification Equipment qualification received considerable NRC attention culminating with GL 85-15, which established deadlines (1985) for compliance with the 10 CFR 50.49 and GL 88-07 which established significant civil penalties for non-compliance with the regulation on equipment qualification.
The Category 2 LERs on this topic are fairly uniform in 1986, 1987, and 1988.
A review of about 20 civil penalties levied on this issue indicates that there is no correlation between LERs and the enforcement actions. This circumstance is partly attributed to the multiple items in each action which individually may not warrant an LER. Simi-larly, equipment qualification items reported in LERs may not warrant enforce-ment action because of percei"9d significance of the items in a particular report or aggressive corrective action on the part of the licensee.
3.4 Plants As noted in Section 2.3, only a small fraction of the plants have more than two Category 2 LERs that matched older generic communications. This observation is consistent with the general understanding that the licensees process the NRC generic communications in a timely fashion.
No plant appears to be overly lax in this activity.
14
m
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4 1
4;0 FINDINGS
,p u
1.LThe number of.' Category 2: LERs that match NRC generic; comunications L
greater than two years old is small. Only about 10 percent of the Cate-4, gory 2 LERs or.about one percent of all LERs are in this category.
- 2. The number of plants having.three or more Category 2 LERs matched to older ~
l
' generic comunications is small.
In the three year period investigated, the average is slightly less than one per plant compared to an average of eight Category 2 LERs per plant this period.
Less than ten percent of
?
the plants had more than three matches.
- 3. Only a small fraction of the NRC generic comunications are matched with Category 2 LERs more than two years after they were issued. In the period investigated, information notices made up 50 percent of the matched l
comunications; bulletins 40 percent;' and generic letters 10 percent.
- 4. Only a few topics dominate the matched Category 2 LERs.
These include 4
seismic, equipment qualification, and air system concerns. All of these topics received intensive industry consideration in the time frame of 1
interest.
This interest was outside of the relevant generic comunica-tion.-
'i 5.- The comunication itself may not facilitate its utilization.
In some instances, the titles of the generic comunications do not adequately reflect the substantive message inside the document.
In addition, there may-not be any suggestir-
' possible action within the comunication to t
a act upon, or the sec, the expected action may be very narrow.
(
l6.' Special' inspection teams are used for auditing responses to selected com-munications, generally bulletins - and' generic' letters, not information notices.
There does. not appear to be a correlation between inspections i
and Category 2 LERs.for the generic comunications.
- 7. Old generic comunications may not be routinely consulted for applicabil-Li L
ity to a current plant concern or evolution.
]
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r
(,i l.
/ lP i
15 l
5.0 CONCLUSION
S Within the scope of the LERs. studied, the results do not indicate a serious in-attention to NRC generic comraunications on a' programatic level. This is borne out by the small number of matches between important LERs and generic comunica-tions more than-two years old and the small number of plants having more than a nominal number of LERs matched to older generic comunications. Additionally, -
inspection reports and discussions with resident. inspectors are basically positive about the-programatic aspects of the-licensees' feedback programs.
The number of matches found to be greater than two-years old, although small, represent important safety concerns because of the high thresholds in the LER-reporting process and the AE00 screening process,-and the safety significance of the connunications themselves.
Certain topics such as seismic design deficiencies and equipment qualification flaws dominated the " older" matched LERs.
Collectively,.these " older" matched LERs indicate that the utilization of individual NRC generic comunications could be improved.
16 m
um e
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a ll r
H E
6.0 REFERENCES--
1.
. NRC Action' Plan Developed as a 'Resulti f'the TMI-2 Accident,"
l>
NUREG-0660, August 1980.
j t
]
2.,
K. Seyfrit, "AE00 Recommendation Tracking system," NRC Memo, i
Sept. II, 1985.
3.
- J. Crooks, "An Overview of Nuclear Fower Plant Operating Experience Feedback Programs," AE00/S602, U.S. Nuclear Regulatory Commission, s
.May 9, 1986..
4 '..
S.: Israel, " Overview of Design / Installation / Fabrication Errors in 1988," AE00/T914, September 27,1989.
5.
U.S. Nuclear Regulatory Commission, Inspection Report 50-413/89-27, Catawba, Unit 1, October 26,-1989.
6.-
U.S. Nuclear Regulatory Commission, Inspection Report 50-445/89-l 32, Comanche Peak, Unlt 1, June 19,1989.
7..
N. Thomasson, " Seismic Anchors for Electrical and Control Panels,"
AE0D/E611, October 16,1986.
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L
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.i-APPENDIX A ISSUE INDEX FOR FOLLOW-UP REVIEW-
. 1 SAFETY VALVE SET POINT-TOO HIGH 2
SEISMIC DESIGN ERRORS 3
CONTROL ROOM VENTILATION 4
SERVICE WATER FOULING 5
WESTINGHOUSE RELAY SEISMIC PROBLEM 6
EQ OF ELECTRICAL EQUIPMENT 7
LIMITORQUE SWITCHES-8 CHECK VALVES 9-SLOW BUS TRANSFER 10 SHUTDOWN MARGIN 11-CONTAMINATED FUEL OIL-13 CORROSION OF COOLING WATER SYSTEMS 14 MONITOR DOES NOT PROCESS FLUID STREAM 15 THIMBLE TUBE -THINNING-16 FR0 ZEN INSTRUMENT LINES 17 ITE RELAY PROBLEMS 18 UNQUALIFIED SPLICES 19' UNQUALIFIED MOTOR OPERATORS FOR VALVES 20 dg ROOM VENTILATION FAILURE 21 PIPE CRACKS IN BWRS 22 STICKING SOLEN 0 IDS 23 STICKING PILOTS'IN RELIEF VALVES 24 CONTAMINATED-AIR SYSTEMS IN DGS 25 SNUBBERS 26 SUPPRESSION POOL VACUUM BREAKERS
'27 LOGIC FOR CLOSING ON EMERGENCY BUSES 29 SYSTEM MISALIGNMENT 30 INADEQUATE MINIFLOW IN ECCS 31 FLAWED FASTENERS 32 EROSION'FROM-THROTTLED VALVE-33.
FLAWED ~ HANGER CLAMPS 35 WATER'IN STEAM LINE TO AFW TURBINE 38 PROBLEMS WITH-AGASTAT RELAYS 39 COOLANT DRAIN TO SUPPRESSION P0OL WHILE ON RHR 40 HPCI CONTROLLER' PROBLEMS PUMP SHAFT FAILURE 43 DG OVERLOAD 44 BATTERY OVERLOAD 45 HIGH TEMPERATURE IN ULTIMATE HEAT SINK 47-BATTERY 0VERFILL 48 PROBLEP WITH AFW TURBINE CONTROLLER 49 PROBLEh '/ITH PRESSURE SWITCHES 50
.MSIV FAILURE-51 LOSS OF TURBINE CONTROL OIL 52 LOSS 0F RHR 53 VALVE PACKING. PROBLEM 54 SBGTS PROBLEMS Al
-i--i--------
55 GAS BINDING OF ECCS PUMPS 57 ROSEMOUNT PROBLEMS-
-58 AIR SYSTIM PROBLEMS 591 LPCI SWIIG BUS SINGLE FAILURE 60-FIRE DAMPERS 61-BOLT PR0blEM ON TERRY TURBINES L62 INADEQUATE ECCS FLOW 63 EXCESSIVE GREASING OF VALVES 64 SINGLE FAILURE IN AFW SYSTEM 65 SINGLE FAILURE IN RHR SYSTEM 66 POWER OSCILLATIONS-IN BWRS 67 CABLE SEPARATION PROBLEM 68 FAILURE OF WESTINGHOUSE TRIP BREAKER (DB-416) 69 HOT PARTICLE CONTAMINATION 70 FLOOR DRAIN PROBLEMS 71 FIRE PROTECTION PROBLEMS 72 RELAY CALIBRATION PROBLEMS 73 WRONG UNIT WRONG TRAIN 74 RHR PUMP INTERNALS FAILURES 75 UNDERSIZED VALVE ACTUATORS 76 INADEQUATE NPSH IN HPSI 77 LEAKAGE PAST CAVITY SEAL-RING
'78 INADEQUATE NPSH IN LPSI 79 SPENT FUEL P00L DRAIN DOWN P
82 LTOP 83 INCORRECT INSTRUMENT CALIBRATIONS 84-EQUIPMENT CLASSIFICATION 86 DC GROUNDS 87 LOSS OF BORIC ACID FLOW PATH 88 LEAK IN RCS 89 SG TUBE PLUG FAILURE l'
90 FUSE COORDINATION 9I LOSS OF RCS INVENTORY 92 STATIC "0" RING 95 FAULTY FUSES 96 VALVE SPRING FAILURE o
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. 3; APPENDIX B PARTfAL COLLECTION'0F GENERIC COMMUNICATIONS 2 J
SEISMIC i
c GL-89-16 Installation of-' Hardened Wetwell Vent GL; 87-03 Verification of Seismic Adequacy of Mechanical and - Electrical Equipment
-GL 87-02 Verification of Seismic Adequacy-of Mechanical and Electrical Equipment
<GL>
81 Seismic Qualification of Auxiliary feedwater Systems (PWRs)
-IEB 79-14 Seismic Analyses for As-Built Safety-Related Piping Systems IEB 79-07 Seismic Stress Analysis of Safety-Related Piping IEB 74-03 Failure of Structural or Seismic Support Bolts on Class I Components IEC 81-05 Self-Aligning Rod End Bushings for Pipe Supports IEC: 81-03 Inoperable Seismic Monitoring Instrumentation
'IN.
89-29 Potential Failure of ASEA-Brown ~ Boveri Circuit Breakers During Seismic Event IN ' 88-14 Potential Problems with Electrical Relays IEIN 87-02 Inadequate Seismic Qualification of Diaphragm Valves by Mathematical Modeling and Analysis IEIN 85-82 Diesel Generator Differential Protection Relay Not Seismically Qualified
'IEIN 85-45 Potential Seismic Interaction Involving the Movable In-Core Flux Mapping System Used in Westinghouse Designed Plants IEIN 83 Defective Heat Sink Adhesive, and Seismically Induced Chatter In
' Relays Within Printed Circuit Cards IEIN 82-55 Seismic Qualification of Westinghouse AR Relay with Latch Attach-ments Used in Westinghouse Solid State Protection System i
IEIN 83-13 Design Misapplication-of Bergen-Paterson Standard Strut Restraint if
,C1 amp IEIN 83-11 Possible Seismic Vulnerability of Old Lead Storage Batteries IEIN 80-21 Anchorage and Support of Safety-Related Electrical Equipment
' IEIN. 79231: Use of Incorrect Amplified Response Spectra (ARS)
'I EQUIPMENT QUALIFICATION GL 86-15 Info Re Compliance w/10cfr50,49 " Environ Qualification of Electrical GL' 85-06 QA Guidance for ATWS Equipment Not Safety-related GL
'84-24 Certification of Compliance to 10cfr50.49, Environ Qualification of J
Electrical Equipment GL 82-09 Environ Qualification of Safety-related Elec Equipment GL 81-05 Info Re Program for Qual of Safety-related Elec Equip
.IEB 79-OlB Environmental Qualification of Class' IE Equipment IEB. 78-04 Environmental Qualification of Certain Stem Mounted Limit Switches 1
Inside Reactor Containment l:
'IEB 78-02 Terminal Block Qualification 2
Condensed titles B1 l
'c IEC 78 Environmental Qualification of Safety-Related Electrical Equipment at Nuclear Power Plants IEC' 80-10. Failure to Maintain Environmental Qualification of Equipment IN 89-57 Unqualified. Electrical Splices in Vendor Supplied Environmentally Qualified Equipment IN: 89-30 High Temperature Environments at Nuclear Power Plants c
IN.
89-23 Environmental' Qualification of = Litton-Veam CIR Series Electrical-Connectors IN 88-81 Failure of Amp Window Indent Kynar Splices and Thomas and Betts Nylon Wire Caps During EQ Testing IN 88 Inadequate Qualification and Documentation of Fire Barrier Penetration Seals IEIN 86-104 Unqualified Butt Splice Connectors identified in Qualified Penetrations IEIN 86-65 Malfunctions of ITT Barton Model 580 Series Switches During-Requalification Testing.
IEIN 86-53 Improper Installation of Heat Shrinkable Tubing IEIN 86-25 Traceability and Material Control of Material and Equipment, Particularly Fasteners IEIN 86-03 Potential Deficiencies in Environmental Qualification of Limitorque Motor Valve Operator Wiring IEIN 85-40 Deficiencies in Equipment Qualification Testing and Certification Process IEIN 85-39 Auditability of Electrical Equipment Qualification Records at Licensees' Facilities IEIN 84-90 Main-Steam Line Break Effect on Environmental Qualification of Equipment IEIN 84-57 Operating Experience Related to Moisture Intrusion in Safety-Related Electrical Equipment At Commercial Power Plants IEIN 84-47. Environmental Qualification Tests of. Electrical Terminal Blocks IEIN 84-44 Environmental Qualification Testing of Rockbestos Cables IEIN 83-72 Environmental Qualification Testing-Experience IEIN 83-45 Environmental Qualification Test-of General Electric Company "CR-2940" Position Selector Control Switch.
IEIN 83-40 Need to Environmentaly Qualify Epoxy Grouts and Sealers IEIN 82-52 Equipment Environmental Qualification Testing Experience - Updating of Test Summaries Previously Published in IN 81-29 IEIN 82-03 Environmental Tests of Electrical Terminal Blocks IEIN 81-29' Equipment Qualification Testing Experience IEIN 79-22 Qualification of Control Systems CONTROL ROOM VENTILATION IN 88-61 Control Room Habitability - Recent Reviews of-Operating Experience IEIN 86-76 Problems Noted in Control Room Emergency Ventilation Systems IEIN 83-62 Failure of Redundant Toxic Gas Detectors Positioned at Control Room Ventilation Air Intakes IEIN 82-43 Deficiencies in LWR Air Filtration / Ventilation Systems AIR SYSTEMS GL 88-14 Instrument Air Supply Sys Problems Affecting Safety-Related Equipment B2
q
- w IEB. 80-01 Operability of/ ADS Valve Pneumatic Supply
'l IN-89-26. Instrument Air Supply-to Safety-Reiated Equipment
.IN ; -. 88-24. Failures of Air-0perated Valves Affecting Safety-Related Systems 1
' IN 28l Air Systems Problems at U. S. Light Water Reactors IEIN 87-09 Emergency Diesel Generator Room Cooling Design Deficiency j
T IEIN 86-51 Excessive Pneumatic Leakage in the Automatic Depressurization System 1
IEIN 86-50 Inadequate Testing to Detect Failures of Safety-Related Pneumatic Components or Systems IEIN 82-43 Deficiencies in LWR Air Filtration / Ventilation Systems IEIN 82-25 Failures of Hiller Actuators upon Gradual Loss of Air Pressure n'
IEIN 81-38 Potentially Significant Equipment Failures Resulting from Con-tamination-of Air-0perated Systems IEIN 81-12 Guidance on Order Issued January 9,1981 Regarding Automatic Control Rod Insertion on Low Control Air Pressure IEIN 80-30 Potential for Unacceptable Interaction-between Control Rod Drive Scram...and Non-Essential Control Air at GE BWRs DIESELS GL 88-15 Electric Power Sys - Inadequate Control Over Design Processes GL 84-15 Proposed Actions to Improve, Maintain Diesel Gen Reliability GL 83-41 Fast Cold Starts of Diesel Generators (0Ls)
GL 83-30 Deletion:STS Sury Requirement 4.8.1.1.2.d.6/ Diesel Generator Testing
-GL 83-26 Surveillance Requirements / Diesel Fuel Impurity Level Tests IEB 79-23 Potential Failure of Emergency Diesel Generator Field Exciter Transformer IEB 74-16 Improper Machining of Pistons in Colt Industries (Fairbanks-Morse) e Diesel-Generators IEC-80-23 Potential Defects in Beloit Power Systems Emergency Generators IEC 80-11 Emergency Diesel Generator Lube Oil Cooler Failures IEC 80-05 Emergency Diesel-Generator Lubricating Oil Addition and Onsite Supply IEC 79-13 Replacement of Diesel Fire Pump Starting Contactors IEC 79-12 Potential Diesel Generator Turbocharger Problem IEC 77-16 Emergency Diesel Generator Electrical Trip Lock-Out Features IEC 77-15 Degradation of Fuel. Oil Flow to the Emergency Diesel Generator IN 89-50 Inadequate Emergency Diesel Generator Fuel Supply IN 89-07 Failures of Small-Diameter Tubing in Control Air, Fuel Oil, and Lube Oil Systems Render Emer9:acy Diesels Inoperable
'IN 88-75 Disabling of Diesel Generator Output Circuit Breakers by /Mti-Pump-Circuitry IN 87-42 Diesel Generator Fuse Contacts IEIN 87-04 Diesel Generator Fails Test Because of Degraded Fuel IEIN 86-73 Recent Emergency Diesel. Generator Problems IEIN 86-70 Potential Failure of All Emergency Diesel Generators IEIN 86-07 Lack of... Instruction and...
Observance of Precautions During Maintenance and Testing of Diesel Generator... Governors i
IEIN 85-91 Load Sequencers for Emergency Diesel Generators IEIN 85-32 Recent Engine Failures of Emergency Diesel Generators IEIN 85-73 Emergency Diesel Generator Control Circuit logic Design Error IEIN 85-68 Diesel Generator Failure at Calvert Cliffs Nuclear Station Unit 1
~IEIN 85-28 Partial loss of AC Power and Diesel Generator Degradation B3 y
4 IEIN 85-25 E Consideration of Thermal Conditions of the Design and Installation for Diesel Generator Exhaust Silencers IEIN 84-92; Cracking of Flywheels On Cummins, Fire Pump Diesel Engines IEIN 86-70' Potential Failure of All Emergency Diesel Generators IEIN-84-69 Operation of Emergency Diesel Generators IEIN 83 Transamerica Delaval Diesel Generator Crankshaft Failure IEIN 83-51 Diesel Generator Events IEIN 83-17 Electrical Control Logic Problem Resulting in Inoperable Auto-Start of Emergency Diesel Generator Units IEIN 79-23 Emergency Diesel Generator Lube Oil Coolers FIRE PROTECTION GL 86-10 Implementation of Fire Protection Requirements GL 81-12 ' Fire Protection Rule (pre-1979 Licensees)
IEB 75-4B Cable Fire at Browns Ferry Nuclear Power Station IEC 78-04 -Installation Errors That Could Prevent Closing of Fire Doors IEC 77-03 Fire Inside a Motor Control Center IN 89-52 Potential Fire Damper Operational Problems IN-88-56 Potential Problems with Silicone Foam Fire Barrier Penetration Seals IN 88-05 Fire in Annunciator Control Cabinets IN 87-50 Potential LOCA at High-and Low-Pressure Interfaces from Fire Damage' IEIN 86-35 Fire in Compressible Material at Dresden Unit 3 IEIN 85-09 Isolation Transfer Switches and Post-Fire Shutdown Capability IEIN 84-09 Lessons Learned from NRC Inspections of Fire Protection Safe Shutdown Systems-(10 CFR 50, Appendix R)
IEIN 83-69 Improperly Installed Fire Dampers at Nuclear Power Plants SAFETY / RELIEF VALVES-IEB 80-25 Operating Problems with Yarget Rock Safety-Relief Valves at BWRs
.IEB.76-06 Diaphragm Failures in Air Operated Auxiliary Actuators for Safety / Relief Valves-IEB-74-o4 Malfunction of Target Rock Safety Relief Valves IEC' 79-18 Proper Installation of Target Rock Safety-Relief Valves IN 88-68 ~ Setpoint Testing of Pressurizer Safety Valves with Filled Loop Seals Using Hydraulic Assist-Devices IN 88-30 Target Rock Two-Stage SRV Setpoint Drift Update IEIN 86-92 Pressurizer Safety Valve Reliability-IEIN 86-56 Reliability of Main Steam Safety Valves IEIN 86-12 Target Rock Two-Stage SRV Setpoint Drift IEIN 86-05 Main Steam Safety Valve Test-Failures and Ring Setting Adjustments
.IEIN 84-33 Main Steam Safety Valve: Failures Caused By Failed Cotter Pins IEIN 83-82 Failure of Safety / Relief Valves to Open at BWR - Final Report IEIN 83-39 Failure of Safety / Relief Valves to Open at BWR - Interim Report IEIN 83-26 Failure of Safety /Relef Valve Discharge Line Vacuum Breakers IEIN 83-22 Boiling Water Reactor Safety / Relief Valve Failures IEIN 82-41 Failure of Safety / Relief Valves to Open at a BWR IEIN 80-40 Excessive Nitrogen Supply Pressure Actuates Safety-Relief Valve Operation to Cause Reactor Depressurization B4
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T 1
.,;- ~ s
'8
=
LOSS OF RNR~
GL-87-12 Loss of RHR while-RCS Partially Filled IEB 80-12 Decay Heat Removal System Operability IEC. 81-11 Inadequate-Decay Heat Removal During Reactor Shutdown IEC 81-10 ~ Steam Voiding in the Reactor Cool:nt System During Decay Heat Removal i
Cooldown IN 87-59' Potential-RHR Pump Loss IN 87-23 Loss of Decay Heat Removal During. Low Reactor Coolant Level Operation IEIN'87-10' Potential for Water Hammer During Restart of Residual. Heat Removal
. Pumps IEIN 87-01 RHR Valve Misalignment Causes Degradation of ECCS in PWRs
. lEIN.86-101 Loss of Decay Heat Removal Due to Loss of Fluid Levels in Reactor-
. Coolant System IEIN 8S-51 Inadvertent loss or Improper Actuation of Safety-Related Equipment
.i
- IEIN 81 Degradation of Residual Heat Removal (RHR) System
'lEIN 80-20 Loss of Decay Heat Removal Capability at Davis-Besse Unit I while-
-in a Refueling Mode 4
B5
4 5
APPENDIX C 2
GENERIC COMMUNICATIONS ON PIPE PROBLEMS GL 89-08f Erosion / Corrosion-Induced Pipe Wall Thinning - 10CFR50,54(f)
GL 88-01 NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping GL 87-11 Relaxationiin Arbitrary Intermediate Type Rupture Requirements GL 86-61 Safety Concern Associated w/ Pipe Breaks in BWR Scram System GL' 85-20 Resolution of Generic Issue 69 High-Pressure Injection Makeup Nozzle GL 84-11 Inspections of BWR Stainless Steel Piping GL 84-07 Procedural Guidance for Pipe Replacement at BWRs GL 84-04 SER of Westinghouse Topical Reports re Pipe Breaks in PWR Primary Main Loops GL 81-35_ Safety Concerns - Pipe Breaks in BWR Scram System 4
GL 81-34 Safety Concerns - Pipe Breaks in BWR Scram System (GE BWRs)
GL 81-30 Safety Concerns - Pipe Breaks in BWR Scram. System =
GL 81-26 Safety Concerns - Pipe Breaks in BWR Scram System GL 81-20. Safety Concerns - Pipe Breaks in BWR Scram System
-GL 81-03 NUREG-0313,Rev 1 re BWR Coolant Pressure Boundary Piping IEC 79-24 Proper Installation and Calibration of Core Spray Pipe Break Detection Equipment on BWRs IEC 76-06 Stress Corrosion Cracks in Stagnant, Low Pressure Stainless Piping-Containing Boric Acid Solution at PWRs BULL 88-11 Pressurizer Surge Line Thermal Stratification BULL 88-08 Thermal Stresses in Piping Connected to Reactor Cooling Systems BULL 88-02 Rapidly Propagating Fatigue Cracks in. Steam Generator Tubes BULL 87-01 -Thinning of Pipe Walls in Nuclear Power Plants IEB 83-02 Stress Corrosion tracking in Large-Diameter Stainless Steel Recirculation System Piping.at BWR Plants IEB 82-03 Stress Corrosion Cracking in Thick-Wall, Large Diameter, Stainless Steel, Recirculation System Piping at BWR Plants IEB 80-13 Cracking in Core Spray Spargers IEB 79-17. Pipe' Cracks in Stagnant. Borated Water Systems at PWR Plants IEB 79-13 Cracking in Feedwater System Piping IEB 76-04 Cracks'in Cold Worked Piping at BWRs IEB 76-01 BWR Isolation Condenser Tube Failure IEB 75-OlA Through-Wall Cracks in Core Spray Piping at Dresden-2 IEB 74-10A Failures. in 4-Inch Bypass Piping at Dresden 2 IEB 71-03 No Title - Involves Catastrophic Failure of Main Steam Line Relief Valve' Headers IN 89-36 Excessive Temps in ECCS Piping Located Outside Containment IN 88-80 Unexpected Piping Movement Attributed to Thermal Stratification IN 88-08 Thermal Stresses in Piping Connected to Reactor Coolant Systems IN 88-01 Safety injection Pipe Failure IN 87-44 Thimble Tube-Thinning in Westinghouse Reactors IN-87-36 Significant Unexpected Erosion of Feedwater Lines IN 86-108 Degradation of Reactor Coolant System Pressure Boundary Resulting from Boric Acid Corrosion IEIN 85-34 Heat Tracing Contributes to Corrosion Failure of Stainless Steel Piping 2
Condensed titles C1
7..
IEIN 85-33 Undersized Nozzle-To-Shell Welded Joints in Tanks and Heat Exchangers Constructed Under The Rules of the ASME B&PV Code LIEIN 85-30 Microbiological 1y Induced Corrosion of1 Containment Service Water
' System IEIN 84-87 = Piping Thermal Deflection Induced by Stratified Flow-
.IEIN 84-71 Graphitic Corrosion of Cast Iron in Salt Water IEIN 84-63 Defective RHR Replacement Piping IL!N; b 35 Seal Table Leaks at PWRs IFIN 94445 Intergranular Stress Corrosion Cracking Leading To Steam Generator Tube Failure
-Itit $4-4:
- IEld 82 '7. or vice' Degradation of Thick Wall Stainless Steel Recirculation System Piping at a BWR Plant IEIN 84-!C Stress Corrosion Cracking in PWR Systems IE14:St+14 TMI-1 Steam Generator / Reactor Coolant System Chemistry / Corrosion Problem IEIN 82-09 Cracking in Piping of Makeup Coolant Lines' at B&W Plants IEIN 81-04 Cracking in Main Steam Lines IEIN 80-15 Axial (Longitudinal) Oriented Cracking in Piping IEIN 80-05 Chloride Contamination of Safety Related Piping and Components IEIN 79-19 Pipe Cracks-in Stagnant Borated Water Systems at PWR Plants IEIN 79-06 Stress Analysis of Safety-Related Piping C2
7.,. &
APPENDIX D.-
.j DISTRIBU7 ION OF CAT 2 LERS FOR SELECTED TOPICS l,.
\\
l t
SEISMIC TOP!CS EQ TOPICS li se.
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