Report on Fact-finding Meeting by Diablo Canyon Independent Safety Committee (DCISC) at Diablo Canyon Power Plant (DCPP) on December 19-20, 2005 by Per F. Peterson, Member and R. Ferman Wardell, Consultant [16th Annual Report, Exhibit D.5]
1.0 Summary
The results of the December 19-20, 2005 Fact-finding trip to the Diablo Canyon Power Plant in Avila Beach, CA are presented. The subjects addressed and summarized in Section 3 include:
- Attend NSOC Meeting
- Status of the Emergency Diesel Generators System and System Walkdown
- Results of Steam Generator Inspection in 1R13
- Results of 1R13
- DCISC Member Meeting with DCPP Management
2.0 Introduction
This Fact-finding trip to the DCPP was made to evaluate specific safety matters for the DCISC. The objective of the evaluation was to determine if PG&E’s performance is appropriate and determine if any areas revealed observations which are important enough to warrant further review, follow-up, or presentation at a public meeting. These safety matters include follow-up and/or continuing review efforts by the Committee, as well as those identified as a result of reviews of various safety-related documents.
Section 4-Conclusions highlights the conclusions of the Fact-finding team based on items reported in Section 3-Discussion. These highlights also include the team’s suggested follow-up items for the DCISC, such as scheduling future Fact-finding meetings on the topic, presentations at future public meetings, and requests for future updates or information from DCPP on specific areas of interest, etc.
Section 5-Recommendations list specific recommendations to PG&E proposed by the Fact-finding team. These recommendations will be considered by the DCISC. After review and approval by the DCISC, the Fact-finding report, including its recommendations, is provided to PG&E. The Fact-finding report will also appear in the DCISC Annual Report.
3.0 Discussion
3.1 Attend NSOC Meeting
The DCISC Fact-finding Team attended the December 19, 2005 Nuclear Safety Oversight Committee (NSOC) meeting. The DCISC last attended an NSOC Meeting at the July, 2005 Fact-finding Meeting (Reference 6.1). Those in attendance: DCPP Members present were: Dave Oatley, Jim Becker, Paul Roller, Dave Taggart, Bob Waltos (for Chesnut) and Tim King (for Jack Purkis). The outside Members present were: Jack Martin, Kenneth Strahm and Warren Fujimoto. The outside member absent was D. Mauldin. Also present were: Kent Oliver and Stan Ketelsen. The agenda items discussed were:
- 1. Review Action Items from 7/20/05 Meeting
- 2. Plant Performance Indicators (PIs) and NRC PI’s
- 3. Quality Verification (QV’s) Assessment of Performance
- 4. Performance Improvement Governance
- 5. Overview of Management Review Committee and Committee Metrics
- 6. DCPP Human Performance Standards
- 7. Work Control and Conduct of Maintenance Subcommittee Report
- 8. Corrective Action and Oversight Subcommittee Report
- 9. Operations/Production Subcommittee Report
- 10. Configuration Management Subcommittee Report
- 11. Equipment Reliability Subcommittee Report
- 12. Review Today’s Action Items
A. Review Action Items from 4/27/05 Meeting: The committee reviewed 22 action items in detail from the July 20, 2005 NSOC meeting to discuss status and estimated completion date.
B. Plant Performance Indicators and NRC PI’s: Jim Becker reported the following items on Plant Performance: Unit 1 Year-To-Date Capacity Factor = 87.47%, Unit 2 Year-To-Date Capacity Factor = 99.32%, and Total Plant Capacity Factor = 93.40%. DCPP continues its longest run without an unplanned reactor trip. ALARA results for 1R13 approximately 110 person-rem, which are the best Unit 1 results to date. Mr. Becker reported the current 2005 end-of–year forecast for INPO summary performance index = 98. The unit capacity factor and collective radiation exposure are impacting this indicator. The NRC performance indicators are being met except for Emergency Preparedness which will return to “Green” status at the end of year reporting.
C. QV’s Assessment of Performance: Dave Taggart reported on QV’s assessment since the July NSOC meeting. Mr. Taggart reported on third period (3P2005) Quality Performance Assessment Report (QPAR) summary, key station quality performance issues, performance rating, and 1R13 summary. Mr. Taggart stated that the overall performance of DCPP was “White” which means the Quality Performance continues to improve and plans are in place to address identified performance issues. “White” also indicates that gaps to top tier performance are generally known and understood, and the organization is using established processes to close the performance gaps.
- He reviewed good or improving performance in 12 areas. He identified the 3P2005 quality performance issues as being:
- Outage preparation & execution
- Outage extensions due to equipment failures *
- Project cost estimating · Learning organization
- 1. Benchmarking
- 2. Self-Assessment
- 3. Operating Experience *
- 4. Corrective Action Program *
- 5. Management Observations *
- Long Standing Equipment Issues
* Issues removed or being removed as a "Key Issue"
- Areas also identified as Quality Performance Issues were:
- Inaccurate DEP Performance Indicator
- Emergency Response Organization (ERO) Drill/Exercise Performance
- Outage Scope Control
- Operations Low Level Human Performance Issues
The 3P2005 identified 5 areas in Strategic Projects as being rated Green (which is the best rating), 12 areas as being rated White, 1 area (Emergency Response Organization) as being rated Yellow and 1 area (Emergency Preparedness) as being rated Red.
- The overall performance was evaluated by QV as being satisfactory and improved. Additional improvements require effort in planning. QV identified eleven 1R13 outage performance issues:
- 1. Loading of Wrong Fuel Assembly due to documentation error
- 2. Loss of 230 KV Power due to work practices and package quality
- 3. Inadvertent addition of water to RCS – procedure use issue
- 4. Near-miss Rigging Issue due to sling failure – RCP 1-4 rotor removal
- 5. Equipment challenges to outage - Turbine Building, Polar and Fuel Handling Crane Problems
- 6. Operations – Misposition Errors / ETRs
- 7. Reportable Injuries (RIs) increased (from 0 to 6 from 2R12)
- 8. Contractor performance issues with Low Pressure Turbine retrofit project
- 9. Inconsistency of work package documentation practices
- 10. Mode Transition to Mode 6 Observation – 9 OTSCs associated with L-0
- 11. ALARA Issues
- ALARA Lead process did not work as well as 2R12
- Appeared to be let down after stretch goal was passed
Mr. Taggart also discussed the nine 1R13 outage performance’s that were positives.
D. Performance Improvement Governance: Mr. Cary Harbor discussed Performance Improvement Program Goal and Process Roles & responsibilities.
- The program goal is to:
- 1) monitor performance,
- 2) analyze & determine action, and
- 3) implement improvement.
- The roles & responsibilities of VP & Directors is oversight, Managers is ownership, and CAPCo & Supervisors is implementation.
- The Program Objectives are:
- Focus to improve line ownership
- Establish continuous improvement structure to emphasize improved quality and timeliness
- Recognize & encourage good performance
- Identify & address performance short falls
- Allow leadership to monitor & drive performance
Mr. Harbor discussed the performance improvement process, metric improvement, and performance improvement reviews. He also reviewed results achieved in quality and timeliness.
- Areas further needing action to improve were:
- Continued benchmarking to learn from top performers
- Continue to improve process (2006 goals)
- Continue to improve quality
- Continue to improve timeliness
- In conclusion, Mr. Harbor stated that:
- 1) DCPP is not there (the best) by a long shot. Further process is needed;
- 2) Must continue to climb the oil slick pole and never stop;
- 3) 2006 holds great opportunity;
- 4) Results are being achieved but DCPP must continue with improvement efforts; and
- 5) Need to focus on using the appropriate PI program to make further improvements.
- There were 3 action items identified from this discussion.
E. Overview of Management Review Committee (MRC) and Committee Metrics: Mr. Harbor then reviewed the MRC. The Purpose of the Management Review Meetings (MRM) is to: 1) improve alignment of leadership to goals, objectives and measurements; 2) build ownership for performance improvement lower in the organization; 30 communicate expectations and results; and 4) strengthen accountability at the manager level.
The purpose of the implementation plan is to learn from others, engage stakeholders, and build on success. To learn from others, they have reviewed MRM reports and procedures from Clinton Power Station, Monticello and James A. Fitzpatrick Nuclear Power plants and have attended an MRM at Monticello and Fitzpatrick.
- To engage Stakeholders they:
- Utilized a team with representatives from Maintenance, Operations, Engineering and Performance Improvement
- Introduced Managers to Station Level Metric review in 4th Quarter 2005
- Reviewed proposed metrics with Directors and Managers in December 2005 and January 2006.
To build on success, the Performance Improvement Board introduced a formal review process of results and modeling metric presentation format after the Problem Prevention and resolution report. Mr. Harbor then reviewed the schedule for the MRM with the first MRM scheduled for February 2006.
- The meeting agenda for the MRM will include:
- Station Summary of Performance
- Station Metrics
- Key Program Reviews
- Department Level Metric Reviews
- Performance Plan Initiative Reviews
- One action item was identified during this discussion
F. DCPP Human Performance Standards: Mr. Jim Becker discussed DCPP Human Performance Standards. The 2005 Human Performance goals for 2005 were: institutionalize the Human Performance Program and instill line ownership of human performance. The Human Performance improvements in 2005 were:
G. DCPP has created a more formal Human Performance Program and station and department metrics are monitored monthly at officer level.
- The Management Observation Program was modernized for prompt trending of behaviors and increased management presence in the field. Observations numbers are up five-fold
- DCPP has improved the root cause analysis to address the organizational factors contributing to human performance problems.
- A new, higher standard has been implemented for independent verification.
Mr. Becker reviewed charts showing the cumulative errors by day of outage for outages 2R11 thru 1R13 with fewer errors for 1R13 than the others and a chart of human performance trends for outages 1R10 thru 1R13 with fewer errors for 2R12 and next fewest number for 1R13. He also discussed noteworthy Human Performance accomplishments in 1R13.
- The key plans for 2006 are:
- 1) use INPO error criteria to match DCPP performance against industry best standards, as part of the pilot program with INPO, and
- 2) Perform a common cause evaluation of the human performance errors that occurred during 1R13.
- The Department Goal for 2006 is to strengthen the Leader’s role in improving Human Performance with the DCPP objective #1 to improve line ownership of Human Performance.
Two action items were identified during this presentation.
H. Work Control and Conduct of Maintenance Subcommittee Report: Mr. King and Mr. Fujimoto presented the results of the observations and conclusions of the Work Control and Conduct of Maintenance Subcommittee interviews held during December 2005. The subcommittee conducted interviews with three asset team supervisors, the Assistant to the Maintenance Director, and the Work Management and Maintenance Services Directors. Observations from field interviews pertaining to 1R13 outage were:
I.
- There was significantly more emphasis placed on implementing the outage schedule and accountability. Schedule rigor was enforced; supervisors indicated that the schedule did not "bounce around" as in some previous outages.
- Supervisors also indicated that schedule accountability had some possible unintended consequences. It appeared to them that production was emphasized over preparation and error prevention
- Supervisors and directors indicated that some parts of the schedule and logic ties were not fully developed or correct.
- Work package quality needs attention. Deficiencies were noted in attention to detail, procedures missing from work packages, and insufficient time to review work packages. There appears to be a recurring issue with both outage and online work package review quality and the resources that are allocated.
- The directors indicated that the plant and outage organization needs improvement on process rigor, OCC effectiveness, command, and control, and accountability within the outage organization.
From an outside NSOC member perspective the plant’s direction for the conduct of outages is on track. The plant needs more work to improve the misperception that the schedule does not provided sufficient time for preparation, human performance, and prevention. It is also apparent that the organization requires much more rigor in implementing the outage process.
- The subcommittee has the following recommendations:
- Address shortfalls in outage and online work package review
- Comprehensively communicate with supervisors and workers the direction, strategy, philosophy, and industry results with implementing the "new outage process rigor."
There were two action items identified during this discussion.
J. Corrective Action and Oversight Subcommittee Report: Mr. Taggart and Mr. Martin discussed the activities of the Corrective Action and Oversight Subcommittee. They reported on Audit Program, Performance Improvement Activities, Training, and Shutdown Outage Safety.
The audit program continues to deliver insightful assessments with good findings. The QPAR continues to be an excellent document. The plant QA group (Maintenance, RP, Chemistry, Security, Operations, etc.) is currently only performing the required regulatory audits due to staffing in this group. There are few assessments of a discretionary nature which gives limited visibility – especially in the Maintenance area. The outside member expressed concern in the staffing of the QA group to be able to perform necessary audits.
- Performance Improvement Activities:
- Correction Action Program (CAP): Quality of cause evaluations is currently judged satisfactory and timeliness of evaluations is approaching satisfactory. There needs to be more emphasis on timely completion of the corrective actions on the important ARs. Many corrective actions are being extended such that they are no longer very timely.
- Self-Assessment and Benchmarking: This area is currently weak and not making much of a contribution. The self-assessment and benchmarking plan for 2006 should be developed with a clear logic.
- Observation Program: The Management Observation Program has significantly improved during the 1R13 outage.
- Hunan Performance: Progress continues to be made. Human error data is available for all work groups and is being acted upon.
- Training: Training activities should be included in the subcommittee activities. This would assess how line organizations are using training to improve performance in problem areas.
- Shutdown Outage Safety: The 1R13 outage safety plan is a great improvement over that for previous outages. A good cross section of operating experience is considered. The content of the plan was also used to develop training for all operations personnel and for maintenance personnel. There was a clear line of sight from the 1R13 outage safety plan to training and human performance.
K. Operations/Production Subcommittee Report: Mr. Roller and Mr. Fujimoto presented the activities since the last NSOC meeting. The subcommittee attended a 1R13 refueling brief and observed operator clearance tailboards conducted by task coordinators.
1R13 refueling brief: The purpose of the brief was to provide an overview of refueling activities and to discuss goals, procedure changes, and SWPs. The subcommittee concluded that, in general, important activities were highlighted and discussed. The outage stretch dose goal is 100 REM. The prevention of Foreign Material Exclusion (FME) caused fuel failures was discussed. Procedures for the spent fuel gate, core unloading, fuel movement sequence, and fuel handling building ventilation was also discussed.
Clearance tailboards for a feedwater isolation valve and for an In-Service Inspection (ISI) hydrostatic test were observed. The "OPS Tailboard Guidance" sheets were followed during both tailboards. Overall, the tailboards appeared satisfactory and were interactive.
- The subcommittee had the following recommendations:
- 1. The refueling brief should have had an agenda and clearly stated objectives and expectations. The meeting room had insufficient seating for the attendees. Interactions with the participants were limited.
- 2. During the clearance tailboards, additional discussion of human error techniques should be considered, specifically, the use of STAR ( Stop, Think, Act & Review).
Two action items were identified during this presentation.
L. Configuration Management Subcommittee Report: Bob Waltos presented the report for the Configuration Management Subcommittee. The subcommittee reviewed the following issues:
- Corrective actions pertaining to the power block structure civil as-built design problem (AR A0615686). A number of corrective actions were reviewed including additional training, DCM revision and procedure revisions to provide additional special guidance to the engineers on their use of the civil design drawings during design. The subcommittee stressed the importance to ensure such guidance and training is also provided to the primary design contractors supporting PG&E.
- The process made to date to address the issues raised at the January 2005 NRC low margin/risk significant inspection. There has been sufficient progress to date on the remaining items.
- The modification process metrics and the subcommittee noted a significant drop in the field preference field change request. From July 2005 to November 2005, there was only one field preference field change request, a significant improvement from a year ago.
- Status and action plan for the vendor manual program. The actions have been completed as scheduled and a contract has been issued for external assistance to review vendor manual changes.
- Results accomplished from the changes made to the Seismically Induced Systems Interaction Program (SISIP). The change management plan used for the roll out was very effective. No Action Requests (ARs) were written on SISIP issues during 1R13 and plant quality stated that SISIP simplification is working.
One action item was identified during this discussion.
M. Equipment Reliability Subcommittee Report: Mr. Waltos and Mr. Strahn presented the Equipment Reliability Subcommittee (ERS) Report.
The overall DCPP equipment reliability performance was reviewed. The discussion and response used the triangle analogy with three tiers.
- The upper tier performance is very good and trending up:
- INPO index
- Equipment clock resets
- Forced outage rate
- Reactor trips
- Mid-Tier performance is favorable but is mixed:
- INPO PIC
- ER Program Health and critical equipment failures are good and improving
- The number of maintenance rule (a)(1) SSCs is very high and trending the undesirable direction
- Lower tier performance is mixed:
- PI window for Emergency Diesel Generators (DG) and Auxiliary Feed-Water (AFW) are OK for the NRC but red in comparison with industry best, other PIs are good
- Longstanding equipment issues are in the mill but not corrected
- Operator workarounds are high but trending down
- Chemistry indicator has been red all year
- Work control has mixed performance
- Corrective Maintenance (CM) backlog is steady and white window
- The subcommittee also reported on their review of the following areas:
- Equipment Failure Trending Report
- Plant Health Committee
- Generic Letter 2004-02 Impact of Debris on Containment Sumps
- Security Equipment Reliability
- ER Health Report Rating Criteria
- Rework Program
- Troubleshooting Program
During the security equipment reliability discussion, the subcommittee noted that the security equipment falls outside the purview of the Reliability Engineering analysis of plant equipment. Similarly, other important non-mainstream plant equipment in support of fire protection program, emergency preparedness program, and the training simulator may warrant similar attention and evaluation from an equipment reliability perspective. The subcommittee recommended that the VP - Nuclear Services evaluate any action needed to be taken on this topic.
N. Review Today’s Action Items: The NSOC committee then reviewed the 13 action items identified today.
This was the last NSOC Meeting for Mr. Kenneth Strahm as he was retiring from the Committee after this meeting. PG&E is making plans to replace him in the near future.
NOTE: The DCISC Fact-finding Team observed that apparently the tall metal cabinets in the hall of the learning building are not bolted to the wall for seismic support. Seismic bracing is necessary for safety for furniture of this height, so these cabinets should be seismically supported. Similar problems may exist elsewhere in the training building.
- Conclusions:
- Overall, the NSOC meeting was well-planned, organized and important items discussed. The agenda for the NSOC meeting allows for the sub-committee reports on major issues and full discussion on items of concern. This allows NSOC to focus on bigger picture safety, oversight, and strategic issues.
- There was a good exchange of observations, opinions, and suggestions and good participation by the DCPP members and three outside members. The outside member who was not able to attend the NSOC meeting today was also not able to attend the July 2005 NSOC meeting. DCPP should encourage all members and schedule meetings such that all outside members could participate.
- The sub-committee reports were very good and having an external member on each of the sub-committee is important.
- The plant QA group is currently only performing the required regulatory audits due to staffing in this group. There are few assessments of a discretionary nature which gives limited visibility – especially in the Maintenance area. The outside member expressed concern in the staffing of the QA group to be able to perform necessary audits.
- DCISC members should continue to observe the NSOC meeting when they are having a Fact-finding meeting at the same time. The NSOC Meetings are a very good opportunity for the DCISC Fact-finding members to learn a lot of details of what the NSOC in concerned with.
- Recommendation:
- It is recommended that DCPP review the staffing of the QV Department to be sure they have sufficient staffing to perform the necessary audits (both regulatory required and others as needed) to ensure DCPP continues to operate in a safe and effective manner.
3.2 Status of the Emergency Diesel Generators System and System Walkdown
The DCISC Fact-finding Team met with Krystyna Kubran, System Engineer to review the status of the Emergency Diesel Generators (EDG) system and conduct a system walkdown. The EDG System has been reviewed at the September 21 & 22, 2005 Fact-finding Meeting (Reference 6.2). Ms. Kubran reviewed the Health Report for both the EDG System and Diesel Fuel Oil System.
The current system health for the DG Fuel Oil System is White for both units 1 & 2. The reason for the White standing and the actions required to restore the system to green was discussed. DFOTP 0-2 failed to start from the DG 1-1 local control station due to a poor electrical connection between fuse FU-01 and its fuse holder. This event caused the system to exceed its PC2 criteria of 1 MPFF within 24 months. Investigation found the fuse clips loose. Because the fuses are located in fuse boxes mounted approximately 20 feet above the floor, and access is obstructed by light fixtures and ventilation ducts, side pressure could be inadvertently applied while installing a fuse causing slight deformation of the clips. If the tension is not verified, it can lead to loss of circuit function.
The immediate corrective action consisted of performing fuse holder inspections for the remaining fuses for both DFOTP 0-1 & 0-2. Additional actions include installing lamacoids near the fuse boxes to advise operators of the problem and direct the operators to verify tension between the fuse and fuse holder to ensure a proper connection. Additionally, training will be provided to operators on how to properly install fuses and verify proper tension. Also a 10 year PM will be established for each fuse and fuse holder that will replace the fuse and verify proper fuse holder tension.
The current system health for the EDG is Yellow for both Units 1 & 2 whereas the September 21-22, 2005 Fact-finding report reported the EDG Health Report for both Units as Red. DCPP has performed some corrective action to improve the Health Report to Yellow. The actions required to restore the system to Green were discussed.
- The problems leading to the current status were:
- DG 1-3 exceeded PC1 limit of 200 hr/yr of unavailability.
- Diesel lube oil temperature below Tech Spec limit for DG 1-2.
- DG 2-3 Lube oil leak.
- Long standing equipment issues were:
- Lube oil coking
- Lube oil upper header check valve not seating properly.
ARs have been issued to resolve all of these problems with completion dates of 2005/2006 and outages 2R13 and 1R14. Ms. Kubran reviewed the problem with the lube oil coking and corrective action in great detail. The problem is with the heaters in the lube oil system. The control system is not very good and allows over heating of the lube oil. A design is in process to replace the existing heater with a new unit and an accurate control system. The new heater will be mounted horizontally, and lower in elevation; having a lower watt-density, and a feedback control that monitors heater element skin temperature. These design changes are to be completed in 2R13 and 1R14.
- Additional actions to help solve the lube oil coking problems are:
- 1) Procedure change to specify inspection and cleaning of all piping and components downstream of the lube oil heater,
- 2) move the flow switch upstream of the lube oil heater to prevent clogging by lube oil coking, and pressure gauge installation for routine monitoring of pre-circ pump output pressure. Increase frequency of lube oil pre-circ system cleaning to twice per refueling cycle.
Ms. Kubran also discussed the EDG monthly tests for fast start and time checks. DCPP performs EDG maintenance work on two EDGs pre-outage and maintenance work on one EDG during the outage. He stated they are planning major maintenance on EDG 2-3 during unit operating prior to outage 2R13. This work will probably take 7 days out of the 14 days allowed by the Tech Spec.
The System Health report also stated that the DCPP EDGs unavailability performance is in the INPO worst quartile. This information was furnished in the Sept. 21-22, 2005 Fact-finding Report (Reference 6.3).
Ms. Kubran escorted the DCISC Fact-finding Team on a tour of one of the EDG to observe the condition of the unit. She also described the design change for the lube oil heater and the location for the installation. The housekeeping and material condition for the EDG and the EDG room was very good. The EDGs and EDG rooms for both units had leaks repaired, major cleaning, and painting in the last year.
- Conclusions:
- The system health report for the Diesel Fuel Oil System appeared to be satisfactory as the system was rated White for both Units and minor action was required to restore the system to Green.
- The system health report for the Emergency Diesel Generator System listed a large amount of work required on the system for it to be changed from Yellow to Green. Many of these problems had been identified in prior years, 2003, but had not been corrected and will not be fixed until 2R13 and 1R14 (2006 & 2007). Also the DCPP EDGs unavailability performance is in the INPO worst quartile.
- The DCISC should follow the corrective actions being performed to see if they are completed in a timely manner. This item should be reviewed at a future Fact-finding Meeting in the 3rd or 4th quarter of 2006.
3.3 Results of Steam Generator Inspection in 1R13
The DCISC Fact-finding Team met with Mr. David Beals, Steam Generator Engineer to review the results of the Steam Generator (SG) Eddy Current inspection during 1R13. DCISC has reviewed the SG inspections after each refueling outage at Fact-finding meetings and Public Meetings.
Mr. Beals first described the Bobbin and Plus Point type of inspections. He stated that the Bobbin inspection is more of a gross inspection and the Plus Point is used if the Bobbin inspection identifies something. The Plus Point does a better job of identifying any indication or crack. DCPP plugged a total of 116 tubes as a result of the tube inspection during 1R13. There were 38 tubes plugged in SG 1-1, 43 tubes plugged in SGF 1-2, 16 tubes plugged in SG 1-3, and 19 tubes plugged in SG 1-4. Including the tubes plugged during 1R13, there are now a total of 825 or 6.09% tubes plugged for all four SG. The total tubes plugged in each SG are 232 tubes plugged in 1-1 SG for 6.85%, 315 tubes plugged in 1-2 SG for 9.30%, 92 tubes plugged in 1-3 SG for 2.72%, and 186 tubes plugged in 1-4 SG for 5.49% and a total of 825 tubes plugged. By Tech Spec. they are allowed to plug 25% maximum in any one SG and 15% plugged for all four SG.
They did not unplug any tubes during 1R13 and do not have any plans to unplug any more tubes in 1R14 before the SG are replaced in 1R15. The new SG will have Eddy Current inspection for all tubes to provide a base line for future inspections.
- Conclusions:
- DCPP continues to perform the necessary Steam Generator inspections at each refueling outage to determine the condition of the tubes and plug the identified tubes to prevent future tube leakage. The DCISC should continue to review the results of the Steam Generator tube inspections after each refueling outage. DCISC should also continue to follow the progress being made to replace the Steam Generators.
3.4 Results of 1R13 Outage
The DCISC Fact-finding Team met with Dennis Peterson, Unit 2 Outage Manager to discuss the results of 1R13 refueling outage. Mr. Peterson highlighted the major accomplishments during 1R13. The outage was 41 days vs. the outage goal of 39 days. The unit was shut down one day early due to the unit being down to 25% power because of a winter Pacific Ocean storm forecast. The radiation dose was 116 person-rem vs. the goal of 120 person-rem and a stretch goal of 100 person-rem. The cost was $4 million under the estimate of $35 million. The sludge removed from the Steam Generators was only 14 lbs. They may not do sludge removal during 2R13 since only a small amount was removed and the radiation dose was 5-6 person-rem.
They did not have the trouble with equipment problems during start-up like they have had during previous outages. They changed how they managed emergent work and it worked a lot better than in the past. They changed how the work was prioritized and all ARs were given a rating and if the rating was 40 or higher, then the AR would be worked. The prioritization Matrix was also reviewed. One of the major problems that could have effected duration was the line-up piping into the low pressure turbines that were being replaced. They were able to develop work around to resolve the problem.
- Mr. Peterson listed the significant events during 1R13 as being:
- Rigging practices – sling failure while rigging reactor coolant pump motor
- Core reload sequence document incorrect – wrong fuel assembly loaded which was found and corrected before they completed reload.
- Work package quality and work practices – loss of 230 kV power during relay testing
- Procedure use – inadvertent addition of water to Reactor Coolant System due to using wrong section of procedure
- Industrial Safety – six recordable injuries
- Conclusions:
- The 1R13 refueling outage appears to have been planned and managed well. The outage was only 2 days longer than planned and the cost was $ 4 million less than the estimate. The radiation dose was over the stretch goal but under the original estimate and the best ever for Unit 1. DCPP believed they managed emergent work better than in the past. DCPP should review all of the significant events during 1R13 and perform root cause analysis on the most important ones to prevent them from happing during future refueling outages. DCISC should continue to review plans and results for all future refueling outages.
The replacement of the low pressure turbines resulted in an increase of about 35 to 40 MW of electrical output from the generator.
3.5 DCISC Member Meeting with DCPP Management
The DCISC Member, Dr. Peterson met with Jim Becker, Vice-President Diablo Canyon Operations & Station Director, to discuss items reviewed in this Fact-finding meeting and other items of interest to the Committee.
4.0 Conclusions
- 4.1
- Overall, the NSOC meeting was well-planned, organized and important items discussed. The agenda for the NSOC meeting allows for the sub-committee reports on major issues and full discussion on items of concern. This allows NSOC to focus on bigger picture safety, oversight, and strategic issues.
- There was a good exchange of observations, opinions, and suggestions and good participation by the DCPP members and three outside members. The outside member who was not able to attend the NSOC meeting today was also not able to attend the July 2005 NSOC meeting. DCPP should encourage all members and schedule meetings such that all outside members could participate.
- The sub-committee reports were very good and having an external member on each of the sub-committee is important.
- The plant QA group is currently only performing the required regulatory audits due to staffing in this group. There are few assessments of a discretionary nature which gives limited visibility – especially in the Maintenance area. The outside member expressed concern in the staffing of the QA group to be able to perform necessary audits.
- DCISC members should continue to observe the NSOC meeting when they are having a Fact-finding meeting at the same time. The NSOC Meetings are a very good opportunity for the DCISC Fact-finding members to learn a lot of details of what the NSOC in concerned with.
- 4.2
- The system health report for the Diesel Fuel Oil System appeared to be satisfactory as the system was rated White for both Units and minor action was required to restore the system to Green.
- The system health report for the Emergency Diesel Generator System listed a large amount of work required on the system for it to be changed from Yellow to Green. Many of these problems had been identified in prior years, 2003, but had not been corrected and will not be fixed until 2R13 and 1R14 (2006 & 2007). Also the EDGs unavailability performance is in the INPO worst quartile.
- The DCISC should follow the corrective actions being performed to see if they are completed in a timely manner. This item should be reviewed at a future Fact-finding Meeting in the 3rd or 4th quarter of 2006.
- 4.3
- DCPP continues to perform the necessary Steam Generator inspections at each refueling outage to determine the condition of the tubes and plug the identified tubes to prevent future tube leakage. The DCISC should continue to review the results of the Steam Generator tube inspections after each refueling outage. DCISC should also continue to follow the progress being made to replace the Steam Generators.
- 4.4
- The 1R13 refueling outage appears to have been planned and managed well. The outage was only 2 days longer than planned and the cost was $ 4 million less than the estimate. The radiation dose was over the stretch goal but under the original estimate and the best ever for unit 1. DCPP believed they managed emergence work better than in the past. DCPP should review all of the significant events during 1R13 and perform root cause analysis on the most important ones to prevent them from happing during future refueling outages. DCISC should continue to review plans and results for all future refueling outages.
5.0 Recommendations
- 5.1
- It is recommended that DCPP review the staffing of the QV Department to be sure they have sufficient staffing to perform the necessary audits (both regulatory required and others as needed) to ensure DCPP continues to operate in a safe and effective manner.
- 6.0 References
- 6.1 “Diablo Canyon Independent Safety Committee Fifteenth Annual Report on the Safety of Diablo Canyon Nuclear Power Plant Operations, July 1, 2004 – June 30, 2005”, Approved October 12, 2005, Exhibit D.1, Section 3.1, “Attend NSOC Meeting.”
- 6.2 Ibid., Exhibit D.3, Section 3.8, “EDG System Update and Lessons Learned from Brunswick Operating Experience.”