ML20133P443
| ML20133P443 | |
| Person / Time | |
|---|---|
| Issue date: | 01/21/1997 |
| From: | Rosenthal J NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rossi C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20133P446 | List: |
| References | |
| NUDOCS 9701240249 | |
| Download: ML20133P443 (3) | |
Text
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UNITED STATES p
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NUCLEAR REGULATORY COMMISSION
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%,***++/g January 21, 1997 MEMORANDUM TO: Charles E. Rossi, Director Safety Programs Division Office for Analysis and Evaluation of Operational Data FROM:
Jack E. Rosenthal, Chief I/
4 Reactor Analysis Branch Safety Programs Division Office for Analysis and Evaluation 1
of Operational Data i
l
SUBJECT:
TECHNICAL REVIEW REPORT - DESIGN ERRORS IN NUCLEAR POWER PLANTS e
Attached for your information and use is a technical review report on design errors in nuclear power plants. This report provides observations about how design errors at operating nuclear facilities have been discovered, and the potential impacts of regulatory or industry actions. The results of the 1985 through 1995 review indicate the following 1
conclusions:
(1)
The number of reported design errors has been steadily dropping since the early 1990s even though the number of NRC inspector-hours in performing engineering related inspection modules has increased during the same time period.
4 (2)
The number of reported design errors discovered as a result of design-basis review efforts steadily decreased by 1995, presumably due in part, to diminishing licensing i
resources allocated to this effort and the lessening number of undiscovered latent design errors.
(3)
The number of design errors discovered at any given time was dependent on the extent of initiatives taken by the NRC and the industry. Major NRC initiatives l
included design-related team inspections which began during the mid-1980's and many design-related generic communications. During this same time period, industry had initiated indepth design-basis reviews which resulted in an increase in the i
discovery of design problems.
l (4)
There appeared to be a relation between the number of design-related generic t
communications issued by the NRC and the number of licensee reported design e
2 orrors. However, licensee event reports infrequently attributed generic communications as the initiator for the discovery of design errors.
J 9701240249 970121
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Sadanandan V. Puliani, AEOD/SPD/RAB (301) 415-6843 x qnWtw?
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(5)
Approximately two percent of the reviewed licensee event reports containing design errors were found significant enough to be evaluated under the Accident Sequenca Precursor (ASP) program. Of those design error events that were in the ASP 4
database, the majority had conditional core damage probabilities between 10 and 10-8
Attachment:
As stated I
cc w/att.:
V. Chexal, EPRI P. Lewis, INPO D. Queener, NOAC a
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DOCUMENT NAME: C:WP51 \\WPD O C S\\STU DI ES\\DS N ERRO R. SVP
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NAME SPullani:mmM} f RLloyd IP h JRosentifal DATE 01/02/97 01/p/97 01[J/97
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OFFICIAL RECORD COPY
MEMORANDUM TO: Chrrl;s E. Rossi, Dir:ctor Safsty Progrcms Division Office for Analysis and Evaluation of Operational Data FROM:
Jack E. Rosenthal, Chief Reactor Analysis Branch Safety Programs Division Office for Analysis and Evaluation of Operational Data
SUBJECT:
TECHNICAL REVIEW REPORT - DESIGN ERR RS IN NUCLEAR POWER PLANTS Attached for your information and use is a technical revie report on design errors in nuclear power plants. This report provides observations out how design errors at operating nuclear facilities have been discovered, and t e potential impacts of regulatory or industry actions. The results of the 1985 through 19 5 review indicate the following conclusions:
(1)
The number of design errors discovered at ny give time was proportional to the extent of the initiatives taken by the Nu ear Regulatory Commission and the industry.
(2)
Design oriented team inspections re very effective in discovering design errors.
(3)
A number of reported design err r events were of relative high risk significance.
(4)
There appeared to be a dire correlation between the number of design-related generic communications is ued by the NRC to the number of licensee reported design errors. However, license event reports infrequently attributed generic communications as the eason for discovery of design errors.
(5)
The number of desi errors discovered as a result of design-basis reconstitution efforts was shrink' g, apparently due to diminishing resources allocated to this effort by licensees.
Attachment:
As st ted cc w/att.:
V. Chexal, EP P. Lewis, INP -
D. Queener NOAC CONTA Sadanandan V. Pullani, AEOD/SPD/RAB (301)415-6843 Dis ibution w/att.: See attached list OCUMENT NAME: C:WP51 \\WPC O CS\\STU D I ES\\D S N E RRO R.SVP o receive a copy of this document, Indicate in the box:
"C" a Copy without attachment /enclosur "E" = Copy with attachment / enclosure "N" = No copy g[ j OFFICE RAB E
RAB lE C:RAB p'l LC NAME SPullani:mmkg.RLloyd Q pf](p JRosenthal DATE. 01/2/97 01/2/97' J
01/7/97 OFFICIAL RECORD COPY