ML20059M138
| ML20059M138 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/24/1993 |
| From: | Zimmerman R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| References | |
| CON-#493-14432 OLA-2-S-001, OLA-2-S-1, NUDOCS 9311180203 | |
| Download: ML20059M138 (8) | |
Text
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NuctiAR REGbl TORY C g# %
UNITED STATES AFFAIRS 4
{ gV 3 NUCLEAR REGULATORY COMMISSION.
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JUN 221992
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93CC:28Phygscf DUN 1619o2 License Nos. DPR-80 and DPR-82 g'g g g 7 j Docket Nos. 50-275 and 50-323 EA 92-086 g
g gic Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention:
Mr. G. M. Rueger, Senior Vice President and General Manager Nuclear Power Generation Business Unit
Subject:
Enforcement Conference This refers to the enforcement conference held with Pacific Gas and Electric Company by N.C Region V at the Region V office on May 19, 1992.
Subjects discussed during the meeting are described in the enclosed Meeting Report.
A copy of the conference agenda is also attached.
The purpose of this enforcement conference was to discuss the circumstances dssociated with the apparent failure to cumply with the Diablo Canyon Techniqal Specification action statements for inoperable containment fan cooler units (CFCU) between March 27, 1991 and February 22, 1992, and the a
apparent lack of corrective actions to preclude recurrence of similar conditions noted in the past.
7 e
Enforcement action related to the 1ssues discussed above and in the enclosed report will be the subject of separate correspondence.
In accordance with 10 CFR 2.790(a), a copy of this letter and the enclosed meeting rep, ort will be placed in the NRC r oblic Document Room.
Should you have any questions concerning this report, we will be pleased to discuss them with you.
Sincerely,
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A R. P.
mmerman, Director Divi n of Reactor Safety and Projects
Enclosures:
1.
Meeting Report No. 50-275/92-19 and 50-323/92-19 2.
Copy of Meeting Agenda 3.
PG&E Viewgraph and Briefing Material
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ENCLOSURE AVAILABLE 9311180243 930824
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cc w/ enclosure:
J. A. Sexton, PG&E C. J. Warner, Esq., PG&E J. D. Townsend, PG&E (Diablo Canyon)
D. A. Taggart, PG&E (Diablo Canyon)
T. L. Grebel, PG&E (Diablo Canyon)
C. B. Thomas, News Services, PG&E State of California R. Hendrix, County Administrator Sandra Silver
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h U. S. NUCLEAR REGULATORY COMMISSION REGION V Report Nos.:
50-275/92-19 and 50-323/92-19 EA 92-086 Docket Nos.:
50-275 and 50-323 F
License Nos.:
Pacific Gas and Electric Company 77 Beale Street, Room 1451-San Francisco, California 94106 Facility Name:
Diablo Canyon Units 1 and 2
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Enforcement Conference at:
Region V Office,. Walnut Creek, California Conference Date: May 19, 1992 I
Prepared by:
W. P. Ang, Project Inspector Approved by:
bv 6l1-92.
P. H. Johnson, Chief Date Signed Reactor Projects Section 1 Summary:
An enforcement conference was held on May 19, 1992 to discuss the circumstances associated with the apparent failure to comply with technical specification action statements for inoperable containment fan coolers from March 27, 1991 to February 22, 1992, and the apparent failure to take adequate l
corrective action to preclude recurrence of similar problems identified in the past.
A copy of presentation slides used by the licensee during the conference is included as an enclosure to this meeting report.
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DETAILS 1.
Meetina ParticiDants Nuclear Reaulatory Commission J. Martin, Regional Administrator K. Perkins, Deputy Director, Division of Reactor Safety and Projects M. Blume, Regional Counsel S. Richards, Chief, Reactor Projects Branch L. Miller, Chief, Reactor Safety Branch P. Johnson, Chief, Reactor Projects Section 1 Wong, Chief, Reactor Projects Section 2 h.
A. Gody, Jr., Acting Chief, Engineering Section W. Ang, Project Inspector Pacific Gas and Electric Company (PG&E)
J. Shiffer, Executive Vice President G. Rueger, Senior Vice President J. Townsend, Vice President and Plant Manager, Diablo Canyon Operations W. Fujimoto, Vice President, Nuclear Techntf'al Services C. Warner, Chief Counsel - Nuclear D. Taggart, Director, Quality Performance and Assessment B. Giffin, Manager, Maintenance Services W. Barkhuff, Quality Control Director R. Powers, Mechanical Maintenance Director M. Tresler, Diablo Canyon Project Engineer J. Tompkins, Nuclear Safety and Regulatory Affairs Director R. Clark, Assistant Diablo Canyon Project Engineer J. Kelly, Mechanical Engineering Group Leader 2.
Openina Remarks The enforcement conference convened at 1:00 p.m.
Mr. Martin began the enforcement conference by stating that the purpose of the conference was to ensure that there was a clear understanding of the facts related to the three apparent violations presented in the associated inspection report (50-275/92-17 and 50-323/92-17), and to allow for additional dialogue regarding the safety significance of the apparent
- violations.
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3.
Discussion of NRC Concerns and Accarent Violations Mr. Johnson summarized the events that resulted in the need for the enforcement conference and stated that the Inspection Report identified I
three apparent violations as follows:
a.
TS 3.6.2.3 requires the containment cooling system to be operable in Modes 1, 2, 3 and 4 with either (a) at least three groups of electrically independent containment fan cooler units with a
2 minimum of one unit in each group, or (b) at least two groups of electrically independent containment fan cooler units with a minimum of two units in each group.
From March 27, 1991 until February 19, 1992, Unit 1 operated in Modes 1, 2, 3, and 4 with three of five containment fan cooler units inoperable resulting in operations with only one CFCU operable in two electrically independent groups.
b.
10 CFR 50, Appendix B, Criterion XVI, requires that measures be established to assure that conditions adverse to quality, such as defective equipment, are corrected.
From March 26, 1991 to February 19, 1992, the licensee failed to correct identified CFCU reverse rotation problems.
c.
TS 6.8.1 requires that written procedures be established, implemented and maintained covering activities affecting quality including inspections.
On March 7 and 8, 1992, licensee inspections of the Unit 2 CFCUs were performed without appropriate procedures, and inappropriately concluded that CFCUs 2-2 and 2-5 w:re operable.
s Mr. Perkins then briefly discussed the safety significance of the apparent violations.
He further stated that Diablo Canyon had a recent -
history of identifying problems and then taking an excessive amount of time to address those problems in a systematic manner.
Exampitrr or'"
previous issues that were slow to be fully addressed included sticki~ng of valve 1FCV-95 and deficiencies with regulatory guide 1.97 instrumentation.
4.
Licensee Discussion of Accarent Violations and Safety Sianificance Mr. Rueger stated that PG&E had carefully reviewed the special inspection report, had no disagreement on the technical content of the report but differed slightly on how me problems were characterized.
Specifically, he stated that PG&E agreed with the facts as stated in the first violation, however, continuing analysis by Westinghouse may change the safety significance because preliminary results indicate that the CFCUs may in fact have been operable despite the noted discrepancies.
With regard to the second apparent violation, Mr. Rueger stated that in hindsight it would have been better to more properly have addressed the reverse r.otation of CFCUs.
However, he believed that the condition may have been technically acceptable.
Mr. Martin stated that the second violation, as written, may have been defined too narrowly. The issue was not just reverse rotation but that a series of conditions associated with the CFCUs were not addressed properly.
Mr. Rueger acknowledged the comment and continued by agreeing with the third apparent violation as characterized at the start of the l
meeting by Mr. P. Johnson. Mr. Rueger also stated that they planned to respond to the three principle concerns identified in the special inspection report summary.
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Mr. Clark then discussed PG&E's conclusions regarding the safety significance of the stuck open CFCU backdraft dampers identified in Unit 1.
Viewgraphs used during the discussion are included as an enclosure to this report. A Westinghouse evaluation of the " worst case" post-LOCA effects of the stuck open dampers indicated that a CFCU could be restarted with 400 rpm reverse rotation 32 seconds after the accident.
Furthermore, preliminary Westinghouse analysis results indicated that by crediting operator action to restart two CFCus (if no CFCUs and only one Containment Spray Pump were available during the injection phase), the maximum containment design pressure of 47 psig would not be exceeded if the two CFCUs were restarted within 37 minutes after the accident.
A licensee review of operating procedures and a " blind" simulator run indicated that operators could recognize the conditions assumed and could restart the tripped CFCUs within 20 minutes. Mr. Clark then described why the probability of containment failure is low up to a pressure of about 91 psig, compared to the design pressure of 47 psig.
He also summarized an analysis which indicated that peak containment pressure would be about 58 psig during the recirculation phase if no CFCus were operated. Additionally, the preliminary Westinghouse analysis res'ults indicated that CFCU 1-1,1-2 and 1-5 may not have been inoperable and were still capable of performing their design function.
Mr. Clark indicated that the analysis would be completed and reviewed by PG1E within a month and that if the preliminary results are confirmed, LER 50-275/91-19 would be revised accordingly to state that the noted CFCus remained operable.
The licensee evaluation of the CFCU inspection performed by maintenance engineering personnel, and associated with the third violation was discussed by Mr. Powers. A copy of the viewgraphs used during the discussion is included as an enclosure to this report. Mr. Powers described the required inspections, the deficiency in the performance of the inspections and the root cause determination performed for the deficient inspections.
Interviews with the engineers, supervisors and craft personnel involved were conducted by various Diablo Canyon managers, including the Senior Vice President. A formal Human Performance Evaluation System review was also performed.
The most significant root cause of the deficient inspections'was poor individual performance in that the inspections were not thorough; erroneous assumptions were made; and it lacked objectivity and professionalism.
As corrective action, the engineers have been formally disciplined, the l
operabiltty evaluations for the affected CFCus were being evaluated and j
revised, and a policy memorandum was being prepared regarding expectations for prompt closure of work orders. A discussion regarding the need for better instructions ensued. Mr. Shiffer agreed that it would be good to improve the instructions, but commented that performance also needed to be improved. Mr. Rueger added that Diablo Canyon has operated very well but there is a need to get the message across that employees need to keep performance up.
Mr. Martin commented that this was a troubling situation in that PG&E should have been able to send two engineers out with good instructions and be able to expect them to perform a good inspection. He questioned whether this was I
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indicative of a somewhat informal working atmosphere or whether there was a need for clearer communications of management expectations. The licensee acknowledged the comment.
Mr. Kelly then described the findings and recommendations of the Integrated Problem Response team that was formed to review the problems associated with the CFCUs. Mr. Fujimoto discussed an evaluation of the engineering programs in relation to the CFCU problems.
Copies of viewgraphs used for both discussions are enclosed.
Mr. Barkhuff described the quality organization's involvement with the CFCUs and the associated problems identified. A copy of the viewgraphs used during his discussion is enclosed. Mr. Barkhuff discussed the quality organization weaknesses and the corrective actions being taken in relation to the CFCU problems.
He noted, however, that QC had been widely involved by citing several examples, and that it could not be involved in every work order, and was not involved in the recent ones which resulted in the problems identified. Mr. Shiffer commented that lowering the threshold for QA/QC involvement was not always the answer and that 6 hey had to more intelligently select the issues with which they needed-to get involved. Mr. Martin expressed a concern that multiple engineering and oversight cn;anizations were involved but failed to identify the problems earlier. This appeared to indicate a need for more accountability and personal responsibility to ensure that equipment operated as designed.
Mr. Giffin discussed the maintenance lessons learned from the CFCU issues and described corrective actions being taken including discussions with Maintenance Supervisors and continuing evaluations of the potential for other systems / components to be receiving inadequate attention. Mr. Martin agreed that it was a good idea to canvass people to determine whether there are other systems which could be vulnerable to similar subtle problems.
Mr. Rueger concluded the licensee presentations and Mr. Perkins expressed the staff's appreciation for the licensee's comments and stated that those comments would be taken into account in the determination of enforcement action. Mr. Blume offered to discuss the enforcement policy with the licensee, but Mr. Shiffer responded that it 4
would not be necessary.
Mr. Martvn-concluded the meeting by stating that the problems discussed
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were not only an enforcement issue.
He was concerned, as on previous occasions, that this was another significant equipment issue that was not aggressively resolved. He stated that the comments heard during the meeting would be considered. Mr. Rueger reaffirmed that the Westinghouse analysis results would be provided in a revised LER. The meeting was adjourned at 5:20 pm.
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ENFORCEMENT CONFERENCE PACIFIC GAS AND ELECTRIC COMPANY May 19, 1992 l
AGENDA J. B. Martin, Regional 1.
Opening Remarks, Purpose of Conference Administrator and J. D. Shiffer, PG&E Executive Vice President 2.
Review of Apparent Violations Related to Containment Fan Cooler System --
P. H. Johnson, Chief, Reactor Projects Section 1 1
3.
Discussion of Safety Significance of Apparent Violations --
i K.D. Perkins, Director, Division of Reactor Safety and Projects j
l 4.
Licensee Response to, and Discussion of, Apparent Violatie~ --
Pacific Gas and Electric 5.
Review of NRC Enforcement Policy -- M. B. Blume, Regional Attorney 6.
Other Discussion 7.
Concluding Remarks -- J. D. Shiffer and J. B. Martin
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