ML16342D702
| ML16342D702 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/05/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML16342D701 | List: |
| References | |
| NUDOCS 9706110321 | |
| Download: ML16342D702 (12) | |
Text
D,R RE00 UNITED STATES O
NUCLEAR REGULATORY COMMISSION Y
0 Cy SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTONi D.C. 2055&4001 REGARDING COMPLETION OF ASLB ISSUES CONCERNING THE CONSTRUCTION PACIFIC GAS 8
ELECTRIC COMPANY DOCKET NOS.
50-275 AND 50-323 PERIOD RECOVERY OF THE DIABLO CANYON NUCLEAR POWER PLANT UNIT NOS.
1 'AND 2
1.0 BACKGROUND
On November 4, 1994. the Atomic Safety Licensing Board (ASLB) in the Diablo Canyon license amendment proceeding concerning the construction period recovery issued its initial decision.
The ASLB resolved all issues in favor of granting Pacific Gas 8 Electric Company (PG&E) the requested license amendment to, extend the operating license for Diablo Canyon Nuclear Power Plant, Units 1 and 2 to 2021 and 2025, respectively.
The ASLB originally admitted an intervenor, San Luis Obispo Mothers for Peace (MFP). and two contentions for hearing in this matter.
One contention challenged the adequacy of PG8E's maintenance and surveillance program and the other challenged the adequacy of PG&E's interim fire protection measures to compensate for defective Thermo-Lag passive fire barriers.
The evidentiary hearing was held in San Luis Obispo on August 17-21 and 23-24, 1993.
and the record was closed on August 24, 1993.
After the record was closed, MFP filed a motion to reopen the record based on NRC inspection reports IR 50-275/93-36 and 50-323/93-36, dated January 12.
1994.
The ASLB denied this motion because the matters in the inspection report relied on by MFP were still "unresolved items." but stated it would entertain a later motion based on the same matters when the staff completed action on the unresolved items.
MFP filed a renewed motion to reopen the record on August 8.
1994, following the issuance by the staff of a Notice of Violation dated July 22.
1994.
In its initial decision, the ASLB denied the renewed motion to reopen the record.
The ASLB found the overall maintenance and surveillance program at Diablo Canyon adequate.
The ASLB found that the incidents referenced by MFP were a
small percentage of the maintenance tasks performed at the facility and that error -free maintenance is not required to provide the reasonable assurance necessary to approve the requested license extensions.
The ASLB noted three discrete areas in which corrective action was necessary.
The first area concerned the Teletemp program in which PG&E had to take the following actions:
(1) have adequate procedures in place to define all the equipment on which Teletemp stickers are placed; (2) set forth the number and location of the stickers to be used for each piece of designated equipment:
(3) specify the time, method and precise nomenclature for recording the temperature data:
and (4) ensure that the information is not erroneous or misleading.
9706ll032i 970605 PDR ADQCK 05000275 P
The second area in which corrective action was necessary involved instances of inadvertent containment ventilation isolation (CVI).
Four of the CVI events resulted from errors by personnel working on energized equipment.
The ASLB found that these errors warranted a specific list of'recautions for affected personnel.
In addition, the ASLB directed that ongoing replacement of the radiation monitoring system be completed to avoid the undesirable actuation of engineered safety features.
The radiation monitoring system had for some time been oversensitive to electrical noise.
The third area that needed corrective action involved the improvement of communication between the Maintenance Department and other departments.
The ASLB found several examples in which the response of the maintenance and surveillance program as a whole needed improvement.
Therefore.
the ASLB directed that PG&E undertake a study to be submitted to the staff for review concerning methods for improving communications between the Maintenance Department and other departments.
With respect to the Thermo-Lag contention, the ASLB found nothing in the record to suggest that PG&E's implementation of the Thermo-Lag interim compensatory measures was so flawed that denial of the license amendment.
or even imposition of license conditions, was warranted.
The ASLB delegated the NRR staff to schedule and confirm completion of the three areas of corrective action.
The decision authorized the Director of NRR to issue the amendment requested by PG&E in its application of July 9,
- 1992, subject to the three conditions set forth above.
The ASLB stated that the decision becomes effective and constitutes the final agency action 40 days after the date of its issuance, subject to any review pursuant to the Commission's regulations.
2.0 STAFF EVALUATION
- 2. 1 Im rovement of the Teletem Sticker Pro ram The Teletemp program is used by the Electrical Maintenance Section at Diablo Canyon to monitor electrical equipment and hot spots.
Teletemp stickers are
. placed on components to monitor the local ambient temperature.
The stickers turn color at certain temperatures.
The ASLB required PG&E to take the following actions:
(1) have adequate procedures in place to define all the equipment on which the Teletemp stickers are placed:
(2) set forth the number and location of the stickers to be used for each piece of designated equipment; (3) specify the time, method and precise nomenclature for recording the temperature data:
and (4) ensure that the information is not erroneous or misleading.
In its letter of'eptember 28, 1995. the licensee documented that it had reviewed its Teletemp sticker program and revised the appropriate maintenance g
rocedure to ensure that environmental qualification requi rements continue to e met.
In November 1993, this procedure was revised to include the I&C
equipment with Teletemp recording stickers as Appendix 8.3 and Appendix 8.4, respectively.
The appendices are specific in terms of addressing the equipment to be monitored in addition to the number, location, and temperature range of the stickers to be used.
The revised procedure also incorporates more detailed instruction in Section 7.0 on the installation, removal.
and data recording of the Teletemp stickers.
Steps were also included to further define the use of the term "N/A" (not applicable/available),
including a
discussion of its use in the remarks section of the revised data sheet.
This revision ensures that the information recorded on the data sheet is accurate.
understandable.
and meets the requirements of the ASLB.
- Further, the licensee indicated that in an effort to continually monitor and enhance its program by applying state-of-the-art technology, the procedure was again revised in August 1994.
This latest Revision 7 incorporated the use of miniature temperature data loggers.
The data loggers are calibrated 'test equipment that can be left in place to digitally record a temperature profile for any predetermined length of time.
Because it is traceable test equipment.
there is more control over the accuracy associated with the measured temperature profile.
In addition to describing the use of these new data loggers.
the revised procedure includes new data sheets to control the installation, reading.
and removal of these data logger devices.
On the basis of'he information discussed
- above, the staff concludes that the licensee has completed corrective actions relating to the Teletemp sticker program.
2.2 Radiation Monitorin S stem and Re ui rements for Workin on Ener ized
~Eui ment 2.2. 1. Radiation Monitoring System The ASLB directed that ongoing replacement of the radiation monitoring system be completed to avoid the undesirable actuation of engineered safety features.
The radiation monitoring system had for some time been oversensitive to electrical noise.
In response to the ALSB's concern, the licensee documented that it had completed installation of those portions of the new radiation monitoring system that will minimize the sensitivity of the system to electrical noise to reduce inadvertent CVI in the plant.
The ASLB was concerned with numerous inadvertent CVIs resulting from personnel error during calibration of the radiation monitors associated with the previously installed CVI logic.
The prior CVI logic initiates a CVI if.certain designat'ed radiation monitors reached thei r alarm setpoint or their output relays were deenergized.
The licensee also stated that previously it was not uncommon for the calibration rocedures to specify as an initial step that the CVI outputs be neutralized y lifting the leads or pulling the output relays.
Accidentally shorting the leads or touching the wrong terminals with a screwdriver had been, in many
Completion of an upgrade to the digital radiation monitoring system resolved
0
these concerns.
The new system is a more reliable microprocessor-based system with a built-in bypass capability.
This bypass capability allows the CVI actuation circuit to be disabled while technicians are preparing for the routine calibrations.
These features of the new monitors have prevented inadvertent CVIs from recurring.
On the basis of this information, the staff concludes that the licensee has completed the corrective actions on the radiation monitoring system.
2.2.2 Requirements for Working on Energized Equipment The ASLB required that a set of rules for working on energized equipment be promulgated.
The licensee documented that it had reviewed and appropriately enhanced existing requirements for working on energized equipment.
This effort included the development of a specific list of precautions to be followed by personnel working on energized equipment.
The policy for "Enhanced Technical Maintenance" for working on energized equipment was issued on August 29, 1995.
Additional work procedures and maintenance bulletins contain appropriate precautions to alert technicians to special problems that might be encountered in specific situations when working on energized equipments The staff identified the following strengths relative to the new procedures:
(1) it discusses some of the key reasons for prior electrocution fatalities at nuclear power plants, (2) it defines "potentially energized equipment."
(3) it assigns responsibility for ensuring adherence to the procedure.
and (4) it references previously published information on electrocutions at nuclear power plants.
On the basis of this discussion, the staff concludes that the li'censee has in place a list of rules and precautions for working on energized equipment.
2.3 Im rovement in Maintenance Communication The ASLB stated that the licensee must undertake a study concerning methods for improving communication between the Maintenance Department and other departments, to the extent the Maintenance Department uses other department personnel in conducting its maintenance and surveillance program activities.
The licensee documented that it has performed a study to examine methods for improving communications between the Maintenance Department and other departments.
Common root causes of problems in maintenance communications with other departments have been reviewed and assessed, and corrective actions have been implemented.
Other initiatives are ongoing to improve communications involving maintenance activities.
The staff evaluated the licensee's "Maintenance Communication Study," that was sent as Enclosure 4 to its letter of September 28, 1995, against the instructions by the ASLB.
In addition, the staff'eviewed a sample of
lp inspection reports and LERs that were issued between January 1.
1995.
and February 28, 1997. specifically to identify human performance errors relevant to communications.
The staff evaluated the licensee's "Maintenance Communication Study" against the guidelines in NUREG-1545, "Evaluation Criteria for Communications-Related Corrective Action Plans" (February 1997).
The licensee stated in its letter of September 18, 1995, that the trend relative to maintenance-related communications is downward.
The staff found that the licensee's root cause analysis relative to past communications events conformed to the guidelines used by the staff and considered it excellent.
The staff found that the licensee's development of corrective actions conformed to the guidelines used by the staff and considered it satisfactory.
The staff found that the information submitted by the licensee on how the corrective actions will be implemented and evaluated for effectiveness was considered satisfactory.
The staff found that a few LERs issued between January 1,
- 1995, and February 27,
- 1997, were relevant to communications issues.
In LER 275/95-008, the licensee stated that utility personnel who were planning and performing maintenance on the HEPA filter and charcoal adsorber system did not recognize that the subject maintenance created an infiltration path for airborne radioactivity.
LER 1-94-S02-00 involved communication errors between the vendor and the licensee that resulted in an individual being improperly granted unescorted access to the protected area.'ER 95-014-00 dealt with an electrical bus that was energized while it was grounded.
The licensee's investigation found that the event was caused by ineffective/inadequate procedures related to the control of grounding procedures; and that different terminology was used by operations and technical maintenance personnel regarding the definition of bus and load.
Consequently.
Operations prepared a
written instruction that incorrectly specified that the grounding device should be on the load side of a transformer; whereas, it was actually installed correctly on the bus side of a transformer.
Further, control room personnel were not clear on how the ground device was grounded.
The staff found that a few inspection reports issued during the period January 1.
1995 to February 27, 1997 were relevant to communications issues.
For example. the staff concluded in inspection reports 50-275/95-08 and 50-323/95-08 that pyrocrete repairs were performed without procedures and documented work instructions which were appropriate to the circumstance.
In
- contrast, inspection reports generally rated'ommunications in the control room from good to excellent.
On the basis of this discussion, the staff concluded.
overall. that the licensee has completed the corrective actions on maintenance communications
1
%4
3.0 CONCLUSION
'n the basis of its review of the licensee's submittal of September 28,
- 1995, the staff concludes that the licensee has completed all corrective actions to resolve issues raised by the ASLB.
Principal Contributor:
D.
Nguyen G.
West Date:
0une 5, 1997
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