ML20034A876
| ML20034A876 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 04/12/1990 |
| From: | Mike Williams NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Novak T NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| References | |
| NUDOCS 9004240467 | |
| Download: ML20034A876 (8) | |
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- l APR 121990 MEMORANDUM FOR
Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation of Operational Data FROM:
Mark H. Williams, Chief Trends and Patterns Analysis Branch Division of Safety Programs Office for Analysis and Evaluation of. Operational Data
SUBJECT:
SUMMARY
OF FEBRUARY 20-21, 1990 MEETING WITH SYSTEMS ENERGY RESOURCES, INCORPORATED REGARDING MAINTENANCE-INDICATOR DEVELOPMENT On February 20-21, 1990, members of the NRC staff met with representatives of Systems Energy Resources, Incorporated (SERI), the licensee for the Grand Gulf plant, and the Nuclear Management and Resources Council (NUMARC) at the Grand Gulf site to discuss maintenance indicator development. A list of meeting attendees is contained in Enclosure 1. contains-the meeting agenda.
This meeting was a followup to the October 13, 1989 meeting of the NRC/ Industry Maintenance Indicator Demonstration Project, The NRC staff presented their proposed Maintenance Indicator (MI). The i
purpose of this presentation was to familiarize. utility personnel.with all of the detail necessary for understanding the proposed indicator.
Two unique programs at Grand Gulf are particularly relevant to-the work on the Demonstration Project. They are the Engineering Review Group'(ERG) and the NPRDS Trend Report, both of which are discussed in detail below.
An Engineering Review Group has been formed within the Grand Gulf Performance.
and System Engineering Department to perform a final, independent review of l
work orders prior to closeout. Grand Gulf management has tasked this group with ensuring work orders reflect adequate details of the identified problem, i
including the overall work scope, cause, corrective actions taken, and comp-L onent failures. The ERG represents a plant improvement with the potential for-l a direct impact on maintenance indicator development, since one-of the concerns expressed about r component failure-based indicator has been the quality of NPRDS reporting. A group such as the ERG provides additional assurance that the failure information documented in the NW0s (and of the subset being re-i ported to the HPRDS) is accurate and complete.
The specific duties of the ERG consist of :
(1) Reviewing completed work orders for consistency,
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. 2) Obtaining predictive maintenance data for~ trending,.
Providing reports to system engineers for. analysis, Maintaining control of the surveillance tracking program, Entering all MW0s into SIMS for component failure. trending.
The NPRDS Trend Report, which has been prepared-and issued periodically since 1987, contains a listing and evaluation of the_. component failures at Grand-Gulf which were entered into.the NPRDS database over the previous period.
This report:- (1) flags repetitive failures, (2) tracks ' corrective actions, (3) plots the failure rate for components which have experienced major _re-petitive failures (e.g., radial well pumps', diesel-generator starting air:
compressor), (4) trends reporting times, and (5) _ tabulates data for easy reference.
Grand Gulf staff described their maintenance organization' and explained their maintenance philosophy. Basically, the responsibility for equipment at the Grand Gulf station is structured around the systems engineering concept. For this reason, they preferred the systems perspective of the NRC's proposed indicator, as opposed to the component type perspective. As far as quality of--
maintenance is concerned, no distinction is made between safety systems and balance-of-plant systems. The only difference in the maintenance of the two types of systems is that maintenance on safety systems receives a higher priority. Their maintenance program is predicated on the premise that its primary objective is to ensure that the plant operators have _available the-equipment necessary to operate the plant in a safe manner in accordance with the Technical Specifications. Grand Gulf tries~to perform as much of the maintenance tasks as possible during normal plant operation, as opposed to accumulating work for outages.
For that work which is performed during a refueling outage, timely closeout of maintenance work during a refueling outage, timely closeout of maintenance work orders (MW0s) and timely reporting to the NPRDS are stressed.
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Grand Gulf staff described how the Grand Gulf outage planning and scheduling group interfaces with the regular maintenance organization. -Outage planning at Grand Gulf starts as a " seed" that pulls in line management to actually 1
manage the outage. During an outage, the Grand Gulf plant is run by this specially constituted outage organization, and the normal plant organizational lines do not exist during this time. The transition to this outage-organization begins about two months before the start of-a refueling outage.
Following the refueling outage, a formal report is prepared which documents any lessons learned during the outage that can be considered in the planning and scheduling for the next refueling outage. The plant staff stated that-they determine whether a refueling outage has been successful from the amott.t of work completed during the outage and how the plant operates after the outage is completed.
In keeping with the systems perspective, Grand Gulf looks one quarter ahead and tries to consolidate all preventive maintenance (PM) and surveillances for a particular system into, for example,)a one-week period, and get all (corrective maintenance, as well as PM of the work done within this time frame - called a " system outage." The purpose of this approach is to minimize the total time that the system is out of service.
i i g Grand Gulf has actively continued a Maintenance Improvement Program since
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J June 1987. A key element of this program is the installation and implementa-tion of the Station Information Management System (SIMS). ~ This system allows Grand Gulf management the opportunity to closely monitor planned work activi-ties at Grand Gulf.
In addition, SIMS provides more space for. documenting detailed descriptions of problems and the corrective actions taken. SIMS has I
the capability for electronically providing the input for NPRDS failure re-ports. Although this capability is currently not being used, Grand Gulf has future plans to use this system for NPRDS report preparation.
l' The Grand Gulf staff stated that verbatim compliance with written procedures is stressed at all times with maintenance and operations staff, ardpersonal accountability is emphasized.
They instill a feeling of " ownership" in their opcrations, maintenance, and engineering support personnel.
- Another part of the maintenance philosophy at Grand Gulf. is the stated policy that contractors are not employed to perform routine maintenance tasks.
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Another key element of the Maintenance Improvement Program at Grand Gulf is its Predictive Maintenance Program.
Grand Gulf staff presented a discussion of this program. Basically, it consists of the following:
(1) Vibration monitoring of rotational equipment.
(2) Lube oil analysis program.
(3) Motor-operated valve testing.
l (4) Pump and valve testing program.
- 6) Check valve performance monitoring.
- 7) Leakage reduction program.
- 8) Relief valve testing program.
Scram frequency reduction program.
)Humanperformanceevaluationsystem(HPES).
) Plant performance monitoring.
(12)NPRDS.
(13) Erosion /corrosionprogram.
Consistent with a stated management goal to make Grand Gulf a top performer, SERI.has pursued cross-fertilization between Grand Gulf and those U.S. plants, as well as plants outside the U.S., which are considered among the best per-forming units in the country. This exchange of technical expertise has taken place at all levels of plant management.
Discussion of the results of root cause analyses of a selected set of Grand
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Gulf NPRDS failure narratives and the indicator trend led to the identification of a number of issues regarding the NRC staff's proposed maintenance indicator.
(1) Grand Gulf staff expressed concern that the indicator can be skewed by just a few problem components and thereby show maintenance problems.
The NRC staff pointed out that high maintenance equipment can result in indications, but that the indicator looks across a broad spectrum of equipment and a few problems will not make a plant stand out.
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! 1 (2) Grand Gulf staff expressed concern about the usage of the staff's proposed indicator..How it will be used and by whom are major concerns which nave been voiced in previous project meetings. The NRC staff explained that it would be used by the NRC staff to monitor the industry's progress in maintenance and to provide input to senior management regarding plant performance through the following process.
The indicator for a given plant would be compared against the average of its peers, and the indicator trends would also he examined.
If a plant's indicator is consistently higher than the peer group average and displays an adverse trend, the plant operational data for the period (s) where the i
indicator exhibits the unfavorable characteristics would be examined in detail to determine the driving forces behind the component failures experienced during the period.
Also, the staff would check into the plant's NPRDS reporting history to determine whether this had an influence on the indicator. The indicator would be used as a screening tool to trigger a more detailed review of plant data and experience obtainable from many sources (e.g., regional office inspections, maintenance team inspections, diagnosticevaluations,SALPs).
i (3) Grand Gulf staff expressed concern about the characterization of the indicator.
In this respect, they were concerned that each individual indicating flag, or even each individual component failure, could be construed as a sign of maintenance ineffectiveness. The NRC staff explained that the indicator was designed as a programmatic indicator, and as such, was not intended to track individual events.
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(4) Discussion of the failure history for the radial well pumps at Grand Gulf led to identification of a case very similar to that of the charging pumps at San Onofre 2 and 3 (i.e., a case A re original design, engineering support, and traditional maintu4nce have played roles over time in the performance of equipment).
In the case of the radial well pumps, Grand Gulf staff explained that the pumps have had a history of seal failures, in part caused by suspended mud intake from the river water. As river level varied, so did mud intakes. Over a period of l
tire, systems engineering and maintenance staff have formulated an improved maintenance approach, employing PM to "get ahead" of the failures as much as possible, and they expect the pump failure rate to decrease, at which point the proposed indicator would reflect improved-performance resulting from a maintenance program improvement. They also plan to erect a building over the pumps to protect them from the elements and fac W tate detection of seal failures at the incipient stage.
Extensive nintenance had not coped with detecting early failures in the past. However, they pointed out that some random pump failure rate will persist due to ' bursts" of sediment in the wells. Complicating the situation is the fact that, at certain times of the year, work cannot be perforned on the pumps because of the danger to personnel from the high level of the Mississippi River. Therefore, the Grand Gulf staff was con-cerned that individual failures of this nature would be considered as caused by ineffective maintenance, and that some failure rate would always be present, since cost-benefit would not support a zero-failure approach to this problem.
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. The NRC staff explained that for these pumps, the way to demonstrate improvement in the maintenance process was to track the failures before and after those improvements.
In this sense, the failures are related to maintenance, especially within the broad context of the Commission's policy statenent.
Individual failures are also filtered through the staffisexp$orithm,whichtendstoscreenrandomfailures.oring additional ways to ad indicator al However the inherent failure rate, such as the use of a tolerance band around the indicator trend.
(5) Discussion of the failure narratives associated with the Grand Gulf LPRM system led to identification of another similar case.
In this situation, the LPRM detectors (which are the first of a kind and unique to the BWR/6 design) were failing with an NPRDS failure description of "out of calibration," and a cause category of " dirty connections." The Grand Gulf staff explained that this condition was not caused by dirty connections as indicated, but actually was a design peculiarity unique to these specific detectors. The detectors were not field repairable, since the internals were not accessible. After much interaction between the NS$$
vendor and SERI, it was found that the root cause of the detector going out of calibration was a buildup on the internal connections in the instrument. The corrective action recomended for the problem was a capacitive discharge test which would burn off the buildup on the connections. Since there was no way to anticipate this type of failure, i
the Grand Gulf staff eventually implemented a PM task that performs the test before the performance of the instrunent progresses to the degraded stage. Grand Gulf staff maintained that failures of this type should not be tracked by the indicator since there was no way that the first failure of the detectors could have been prevented, and then the uniqueness of the design and inaccessibility of the detector internals made it impossible to perform any sort of preventive maintenance until a failure history of the instruments could be compiled over a long enough span of time upon which to base appropriate PM.
i (6) A number of cases were discussed which consisted of the reporting of incipient conditions as degraded failures. The Grand Gulf staff explained that past NPRDS reporting practices may have been somewhat conservative, and commented that incipients would today be recognized and categorized more readily.
(7) " Ghost ticks' should be eliminated.
The Grand Gulf staff uses the following activities and documents at the frequency indicated to assess maintenance at the Grand Gulf plant.
Daily (1) Plant Status Report.
(2) Plant Tours to monitor maintenance activities and housekeeping / plant material conditions.
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Weekly (1
Work Order Status Report.
Plant Contamination Report.
Maintenance Task Tracking.
l Quality Deficiency Status Report..
Material Nonconformance Report.
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' Monthly i
Maintenance Performance Report.
Performance Monitoring Report.
Thermal Performance Report.
1 Operational Analysis Report.
(5 Health Physics Sumary Report.
Quarterly (1) Quality Programs Status and Trend Analysis Report.
(2) NPRDS Trend Report.
Of particular interest is the Maintenance Performance Report, which is issued on a monthly basis, and is made available to all maintenance personnel for their review. This report tracks the following maintenance related information: (1)maintenancegoalsversusactualachievements.(2)majorwork itemsduring)LERs,(6), violations,(7)radiolo(3) safety report, (4) occupational injury and the month personnel contamination report with details, (gical deficiency reports, (8) illness,(5 i
9)personnelexposure,(10) quality deficiency reports, (11) security response to insecure doors. (12) maintenance outages, (13)(maintenance work status (14) task tracking, (15) department overtime, and 16) budget.
g Nark H. Williams, Chief Trends and Patterns Analysis Branch Office for Analysis and Evaluation of Operational Data
Enclosures:
As stated cc:
L. Kintner, NRR H. O. Christensen, RII F. Cantrell, Ril Distribution:
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ENCLOSURE 1 r
ATTENDANCE LIST t
FEBRUARY 20-21, 1990 MEETING WITH SYSTEMS ENERGY RESOURCES, INCORPORATED H&gg AFFILIATION Bill Angle SERI i
W. T. Cottle SERI Joel P. Dimmette, Jr.
SERI Chuck Dugger SERI Norman G. Ford SERI t
Randy Hutchinson SERI M. A. Krupe, SERI Ron Moomaw SERI Jerry C. Roberts SERI Steve Saunders SERI i
Warren J. Hall NUMARC Walt Smith NUMARC r
H. O. Christensen NRC/RII-SRI I
Bob Dennig NRC/AEOD l
J. L. Mathis NRC/RII-RI l
T. M. Novak NRC/AEOD Patrick O'Reilly NRC/AEOD Mark Williams NRC/AEOD
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i ENCLOSURE 2 l
AGENDA FEBRUARY 20-21, 1990. MEETING Wi1H SYSTEMS ENERGY RESOURCES, INCORPORATED REGARDING MAINTENANCE INDICATORS i
(1) NRC Presentation - Performance Indicator Development, Analysis Assumptions and Purpose of Meeting.
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(2) Discussion of Interim Indicator Results.
(3) NPRDS Reporting of Component failures Involving Outage-Dominating Equipment.
(4) Root Cause Analysis of Individual Component Failures of Outage-Dominating i
Equipment.
(5) Discussion of Northeast Utilities / Northeast Nuclear Energy Programs / Approaches for Trending Equipment failures and Failure Causes as They Relate to Maintenance.
(6) Comparison of Maintenance Trend Information.
(a) Trends Calculated with the NRC's Indicator (b) Trends Calculated with Northeast Utilites/ Northeast Nuclear Energy Indicator (s).
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