ML20059M896
| ML20059M896 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/18/1993 |
| From: | PACIFIC GAS & ELECTRIC CO. |
| To: | |
| References | |
| OLA-2-I-MPF-041, OLA-2-I-MPF-41, NUDOCS 9311190427 | |
| Download: ML20059M896 (9) | |
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1854 Onsite Safety Review Group (OSRG) 93 tCT 28-M ll' November 1991 Monthly Summary The OSRG reviewed the following items at OSRG meetings conducted in November. During these meetings, the OSRG Chairman was present'and'a i
quorum was established and maintained.
Items of interest.are discussed l
below, and all items reviewed are listed in Attachment 1.-
Detailed-information on any item included in this summary can be obtained by-reviewing the referenced document or by contacting the OSRG.
The following items summarize the concerns, items.of interest or significant items identified by the OSRG. Where concer.ns exist, they have been discussed with the appropriate TRG Chairman or responsible department head and an AR has been initiated, if applicable.
1.
NCR DC2-91-TN-N087: Post LOCA Recirculation Leakage from ITT Grinnell l
Diaphragm Valves (CVCS-2-548 and CVCS-2-8471).
OSRG Conce n: Based on discussions in the 10/14/91 TRG, virtually no root cause evidence was preserved or documented.
Body-to-bonnet
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leakage was surmised based on leak reduction after bonnet bolt tightening, but insulation precluded a positive leak. path l
identification.
Since the as-found bolt torque values were not recorded and the valve diaphragms were discarded prior ~to a thorough examination, it is unlikely that the root cause will ever-be determined.
This event, as well as others, indicates that there is a lack of effective controls to ensure that causal evidence is preserved for examination for critical plant equipment failures.
~
i OSRG Resolution:
Due to the above-' concern, the following' items were provided to the TRG Chairman for discussion at the next TRG:' 1) a more accurate means is required to assess leen.oge rates for post LOCA
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recirculatYon path components, 2) post LOCA recirculatioE path 3
components should be identified and appropriately flagged in PIMS'such that leakage-type AR's for each of these components.will receive the necessary visibility and evaluation, 3) since the root cause wil1 remain indeterminate, corrective actions for this event will have to l
address all possible root causes, and 4) an upper bound for the. actual l
expected post LOCA leakage rate should be determined to ensure that the safety analysis for this event (site boundary and control room dose I
analyses using the " expected" LOCA versus the DBA LOCA) will encompass such leakage.
i It is the OSRG's understanding that a procedure is being develope'd to provide guidelines for problem investigation. This procedure and the-associated training should stress evidence preservation.
The OSRG plans to review this procedure when it is issued.
Discussion:
Installation of a new charging pump suction gate valve required post modification hydro testing of the charging pumps' suction piping. The hydro test was also being utilized to fulfill the requirements of STP M-86G. This STP requires pressurization and leak' rate determinations for charging pump suction components in the post l
LOCA recirculation path.
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4 OSRG November 1991 Monthly Sununary 185489.s Page 2 of 6 135488 During the hydro test, external leakage was observed from boundary valves CVCS-2-548 and CVCS-2-8471.
Body-to-bonnet leakage was suspected (insulation covered the valves) and was substantiated when the bonnet bolts were tightened and leakage was reduced. Combined as-found leakage was estimated at 1.3 gpm (one gpm for Valve 548 and 0.3 gpm for Valve 8471). This value is greater than the 0.1 gpm unfiltered allowable leakage rate.
Unfiltered leakage of greater than 0.1 gpm would result in exceeding the allowable analyzed control room radiaticn exposure limits.
2.
NCR DC1-91-0P-N082: Missed Surveillance (leak test on Unit I containment personnel airlock door seals).
OSRG Observation / concern: The TRG determined that the root cause was human error due to inadequate knowledge after being assisted via OSRG comments. The TRG chairman then conducted a barrier analysis which provided a broad scope of corrective actions that addressed multiple r
broken barriers involved in the event. The corrective actions appeared to be thorough.
The TRG was held as a very open forum with opportunity to discuss details of the problem and corrective actions.
Many departments participated.
It seemed to be very effective in getting cooperation from many organizations.
The AR initiated to identify the problem with the containment airlock autotester correctly identified the tester as non-Q, but did not indicate that the tester was required to satisfy Technical Specifications in any MODE.
The AR reviewer, and subsequent reviewers, did not note the conditional surveillance that is required when the auto leak tester is not worki.., because of the coding and description in the AR.
This is another instance of equipment utilized to satisfy Technical Specifications not receiving appropriate attention due to the equipment being Class II.
OSRG Resolution: The OSRG is including this event in OSRG Open Item 091-12 on equipment classified as Class II and relied upon to support FSAR assumptions, implement Technical Specifications, etc. and will provide recommendations as appropriate.
Discussion: Sixteen out of 23 cantainment entries.in Unit I between June 5 and Sept' ember 27, 1991 were found not to have the necessary door seal leak test performed due to:
- 1) automatic leak tester being out of l
service, 2) a lack of knowledge on how the automatic tester functioned and 3) inadequate documentation on the AR and review of the AR.
A procedure reviewer in the Plant Engineering department happened to notice some STP M-8F's were being filled out intermittently. When Operations department was asked about this, the problem was discovered.
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1 185489 OSRG November 1991 Monthly Summary 1.55488 Page 3 of 6 3.
NCR DC2-91-TI-N088, LER 2-91-007: Safety Injection Signals Due to Inadvertently Arming both SSPS Trains in MODE 5.
OSRG Concern: The cause of the event is incomplete since it does not address the reasons why procedural compliance did not occur nor why the verification practices failed. The technicians directly involved with the event were not at the TRG and this information was not provided via j
the NCR/LER process.
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i The effectiveness of the NCR/LER corrective actions are doubtful since:
- 1) counseling and issuing a memo are administrative barriers; more effective physical barriers were not provided. 2) the corrective actions for the subject event are essentially identical to several similar events; by virtue of the subject event's occurrence, previous
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corrective actions have not been effective, and 3) the corrective actions are not based on causes; but rather upon generalized problem i
statements (e.g., personnel not following procedures.)
j OSRG Resolution: The above root cause and corrective action deficiencies were identified to management via the OSRG independent LER review for this event. These deficiencies were not corrected in the final LER. DCPP Action Plan 3000.04/020.1, " Human Error Reduction,"
has been issued. This concern was previously identified by the OSRG to GONPRAC.
Discussion: While in MODE 5 during 2R4, two I&C technicians were in i
the process of reconfiguring SSPS Trains A and B per STP I-1604 from
" inputs in normal / outputs in test" to " inputs inhibited / outputs in operate." Each technician was independently reconfiguring a d Mferent train.
Each technician placed the Mode aesector switch.to " Operate" prior to plEcing the Input Error Inhibit switch to " Inhibit." This sequence is the opposite of that required by the STP and resul.ts'in
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" arming" the affected SSPS train.
Since numerous plant protection inputs were active at the time, arming each of the SSPS trains resulted in separate SI signals being generated and automatic operation of various safety related plant equipment.
The NCR/LER root cause was failure of the involved personnel to use the procedure. One technician did not have the procedure in-hand. The other technician had the procedure sumary sheet in-hand but was not following the sumary sheet steps. The contributory causes were failure to perform self verification per I&C policy and failure to perform concurrent verification per NPAP C-104.
The NCR/LER corrective actions to prevent recurrence included: 1) a l
tailboard was held for the I&C Department emphasizing the importance of verbatim compliance, self verification, and concurrent verification,
- 2) a memo was issued by the DCPP Plant Manager emphasizing procedural compliance and verification requirements, and 3) the. involved personnel were disciplined in accordance with the PG&E Positive Discipline Program.
i OSRG November 1991 Monthly Summary 185489 Page 4 of 6 1.65488 I
4.
NCR DC2-91-0P-N089, LER 2-91-006:
CRVS Shift to MODE 4 Due to Inadvertently Opening the Output Breaker of Instrument AC Inverter IY-23 Instead of IY-24.
OSRG Concern:
The effectiveness of the NCR/LER corrective actions (OSRG Open Item 089-14) is uncertain since:
- 1) the corrective actions related to pre-job procedure reviews are based on an after-the-fact barrier that may have not prevented the event 2) the corrective action to require OTSC's for generic components was only applied to Operations procedures; the applicability to other DCPP procedures was not addressed, and 3) the NCR/LER incorrectly assumes that the verification processes will prevent such events if component specific information is-utilized. Contrary to this conclusion, the involved personnel were not even aware that they could not properly perform self or concurrent verification with the generic procedural guidance being used.
Furthermore, the involved personnel did not implement the verification processes using the component-specific information that was provided in the clearance, OSRG Resolution: The recurrence of events involving misoperation of plant equipment and of events classified as " wrong unit / wrong component " and the ineffectiveness of corrective actions to preclude such events, was previously identified by the OSRG to GONPRAC (OSRG Open Item 091-06). The OSRG will continue to follow'such events and will evaluate the results of plant efforts for resolution.
Discussion:
Two operators were in the process of clearing IY-24.
Following the transfer of PY-24 to the backup inverter per OP J-10:III, the operators were required to open the IY-24 output breaker. Lhe IY-23 output breaker was opened instead, since the operator preconceived his intent to clear IY-23, causing RM-26 to be de-energized and resulted in t u CRVS shifting to MODE 4 (pressurization). The operators were using the generic (inverter numbers not specified) portion of the procedure rather than the appropriate inverter-specific procedure attachment.
5.
Assessment of Timely Closure of NCR's Associated with NOV's.
The OSRG is required by a commitment to the NRC to periodically assess the timeliness of resolution of major problems. This assessment of the timeliness of NCR's associated with NOV's is part of that commitment.
l This assessment looked at eight 1990 NOV-NCR's. The following criteria were used to assess timeliness as well as thoroughness:
1.
The difficulty involved in determining the cause, 2.
The thoroughness and scope of the corrective action.
l 3.
The requirement for outage work, 4.
The revision of_ procedures _ prior to their next intended use.
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OSRG November 1991 Monthly Summary 185488 Page 5 of 6 185489 All of the responses / corrective actions were judged'to be timely except as noted:
a.
NCR DC2-90-TN-N015: Fuel Movement Without the Fuel Handling Building (FHB) Ventilation System Operable - Failure to recognize and control personnel doors as part of the FHB pressure boundary.
The immediate corrective action was appropriate. However, long term action has not been effective in restoring either FHB to ops.able status due to additional problems encountered. Door labeling control was not effective since the NRC, on follow-up, discovered doors open and labels missing.
In addition,'all corrective actions should have been completed prior to 1R4, but j
were not.
1 b.
NCR DC1-90-TN-N018: STP Adherence - Failure to issue On-The-Spot (OTSC) procedure changes when procedure could.not be followed.
The TRG failed to deal adequately with the issue of other departments not issuing OTSC's as required. The training conducted, based upon the training guide, did not appear to address the NRC concerns. Therefore, the response was not timely nor thorough. However, subsequent issuance of PD AD2, rev. O, the training normally associated with revised administrative procedures, and the closure of QA Audit 90815T should adequately address these concerns, c.
NCR DCO-90-TC-NO33: Radioactive Sealed Source not Smear Trited -
The database used to track smear testing was inaccurate.
Procedure revision was not completed until after the next six-month smear check was required, which did not meet the timeliness criteria above.
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'I OSRG November 1991 Monthly Summary Page 6 of 6 185488-yj The OSRG continues to monitor Plant activities by conducting Plant tours:
and surveillances, reviewing the daily Shift Foreman / Control Operator's i
logs, all significant Action Requests / Quality Evaluations and by attending appropriate Plant TRG, PSRC, Staff, NRC Exit and Scheduling meetings.= In addition, DCNs are screened and those having a significant' potential impact:
upon operations are identified for a more thorough review.
Any questions on the above items should be directed to the OSRG Chairman.
WALKER T. RAPP Chairman, OSRG The signatures below indicate r ew and concurrence.
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D. D. Christensen u
B. A. LoConte Nb M dhz -
.l K. W. Riches A
P. G. Sarafian a..d., h,.
j D. A. Taggart A
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t Onsite Safety Review Group-185488
,l4 November 1991 Monthly Summary 185489 1.
Nonconformances The OSRG either attended TRGs for the following NCRs or, if the TRG was not attended, reviewed the comp _leted NCR package. Specific critique comments have been provided to the responsible Chairman and will appear in the OSRG Quarterly Trend and Critique Summary.
DC2-91-M-N072: MS-2-RV-225/60 (out'of liftpoint tolerance following test equipment being found out of tolerance).
DCl-91-OP-N082: Missed Surveillance ('eak test on Unit 1 containment s
personnel airlock door seals).
DC2-91-TN-H083: Steam Generator 2-1 UT Flaw Indication.
DC2-91-TN-N087:
Post LOCA Recirculation Leakage from ITT Grinnell Diaphragm Valves (CVCS-2-548 and CVCS-2-8471).
DC2-91-TI N088: Safety Injection Signal: Due to Inadvertently Arming both SSPS Trains in MODE 5.
n DC2-91-0P-N089: CRVS Shift in MODE 4 Due to Inadvertently Opening the Output Breaker of Instrument AC Inverter.IY-23 Instead of IY-24.
DC2-91-EM-N095:
52-HH-13 Failure to Open.
DCl-91-TC-N098: Unit 1 Containment Atmosphere Sampling.
2.
Regulatory Correspondence NRC Inspection Report No. 91-27, dated November 8, 1991.
r NRCInspe31onReportNo.91-34,datedNovember 1,19917Chron180110.-
l
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NRC Inspection Report No. 91-35, dated ~0ctober 31, 1991.
)
l NRC letter to PG&E, Management Meeting, dated November 6, 1991.-
l PG&E letter to NRC, Reply to Notice of Violation in NRC Inspection Report No. 91-22, dated November 1, 1991. PG&E Letter No. DCL-91-269 -
i Chron179946.
l PG&E letter to NRC, Response to Additional Questions Related to PG&E's Purchase and Dedication of an Additional Emergency Diesel Generator -
(EDG),detedOctober 23; 1991, Chron179354.
.c 1854894 OSRG November.1991 Monthly Summary 185488:~<v Page 2 of 2 3.
Licensee Event Reports LER #
Event Date Description /NCR 2-91-006-00 10/03/91
-Momentary Loss'ofiPower to Radiation Monitor RM-26 Causes Control Room Ventilation System Mode-Shift"(ESF Actuation) Due.to Personnel Error..
(NCRDC2-91-0P-N089)-
2-91-007-00 10/06/91
. Inadvertent Safety Injection While?
in MODE 5 Due.to Personnel Error.
(NCR DC2-91-T1-N088) 1-91-009-00 09/26/91-
-10CFR100 Dose Limits:Potentially.
Exceeded in the Event of a Design
' Basis Loss of Coolant Accident Recovery as a Result of Valve Leakage.
?'
(NCRDC2-91-TN-N087) 1-91-016-00 09/27/91 Missed Surveillance of Airlock: Door.,
Seals Due to Personnel Error' Caused by Inadequate Knowledge of Leak-Rate Monitor Operation.-
(NCRDC1-91-0P-N082)'
4.
Miscellaneous Items a) Justification for Continued Operation (JCO) 88-11 R3,' Unit 2 Non-Conforming Circuit Breaker In Vital-Battery Charger..#231.
b). Action Request (AR) A0241228 Entry into RCA Without Proper-Dosimetry. AT-R0R type AR.