IR 05000327/1993043
| ML20058P736 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/02/1993 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20058P719 | List: |
| References | |
| 50-327-93-43, 50-328-93-43, NUDOCS 9312270253 | |
| Download: ML20058P736 (6) | |
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i SALP REPORT - SEQUOYAH NUCLEAR PLANT 50-327/93-43 & 50-328/93-43 i
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BACKGROUND The SALP Board convened on November 8, 1993, to assess the nuclear safety performance of Sequoyah Nuclear Plant for the period of August 2,1992, through October 9, 1993. The Board was conducted pursuant to NRC Management Directive 8.6, " Systematic Assessment of Licensee Performance." Board members were Ellis W. Herschoff (Board Chairperson), Director, Division of Reactor Projects, NRC Region II (RII); J. Philip Stohr, Director, Division of Radiation Safety and Safeguards, NRC RII; Frederick J. Hebdon, Director, Project Directorate 11-4, NRC Office of Nuclear Reactor Regulation; and,.
Albert F. Gibson, Director, Division of Reactor Safety, NRC RII. This'
assessment was reviewed and approved by Stewart D. Ebneter, Regional Administrator, Region II.
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II.
OPERATIONS This functional area consists of the control and execution of activities directly related to operating the plant.
It includes activities such as plant startup, power operation, plant shutdown, and response to transients.. It also includes initial and requalification training programs for licensed operators.
In this area, TVA's attention and involvement have resulted in an acceptable level of performance. However, performance has declined from the previous assessment period.
Operators have typically performed well in responding to several plant
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transients. The prompt and appropriate response to transients initiated by control air problems, the rapid power reduction of Unit 2 during a main bank transformer fire, and the response to the Unit 2 extraction-steam line rupture, demonstrated plant operators were capable of placing the plant in a safe condition.
However, the response to the December 31, 1992, dual unit trip was handicapped by inadequate operator staffing and training, and resulted in several operator errors on Unit 2 which complicated plant response
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and recovery. The decision to maintain minimom operator staffing levels, and-not consistently train at these levels, indicated plant management was not sufficiently involved in day to day operation to recognize the needs of the operating staff.
A general lack of management involvement and safety sensitivity was identified early in the assessment period.
Inappropriate management involvement during steam inlet valve testing resulted in a Unit I turbine runback in August 1992.
Licensee management failed to fully evaluate the consequences of a testing evolution in December 1992, which resulted in the cooldown of the refueling water storage tank. Additionally, a poor safety attitude was exhibited by a refueling senior reactor operator during the recovery of a tilted fuel
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assembly in June 1993.
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9312270253 931202 PDR ADOCK 05000327 G
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During the latter half of the assessment period, the NRC observed an increase.
in management involvement and direction, which resulted in a more conservative approach toward operation of the facility. The oversight and direction provided by the Management Restart Review Committee and Backlog Review Committee were generally conservative. Good progress in the implementation of the restart plan was also a direct result of increased management involvement.
Improvements in this area were due, in part, to the efforts of new senior managers on site, who began to establish a rigorous safety attitude among the staff.
Licensee assessments and audits, after the units were shut down, indicated that plant management was receptive to the identification and resolution of
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longstanding problems. The assessments by an independent management oversight group provided meaningful input to site management that assisted in focusing the restart effort. However, plant management initially did not fully
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recognize the magnitude of longstanding problems that existed at the site.
These problems resulted in an extended dual unit outage.
During the previous SALP assessment, several-problems were identified with configuration control of plant equipment. These problems have persisted during this assessment period.
Examples included incorrect emergency raw cooling water throttle valve settings, an incorrect thermal barrier booster pump switch alignment, and an incorrect discharge throttle valve setting for a reactor coolant drain tank pump.
The continuing problems in configuration control were due, in part, to the lack of a questioning attitude by plant
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personnel and procedural inadequacies. Although management attention was evident late in the assessment period, continued effort is needed in both of these areas.
Weaknesses were also noted in the areas of communications and attention to detail, as exemplified by the failure to maintain the proper refueling water storage tank solution temperature, and the failure of-multiple shift crews to -
recognize this deficiency.
However, observation of operator performance late in the SALP period indicated this area was improving.
TVA continued implementation of an adequate training program, including the initial licensed operator training program and the operator requalification program, as demonstrated by acceptable performance of operators on NRC administered examinations.
The operations area is rated as a Category 3.
III.
MAINTENANCE This functional area includes all activities associated with diagnostic, predictive, preventive, and corrective maintenance of plant structures, systems, and components.
It also includes surveillance testing, inservice inspection and testing, instrument calibrations, equipment operability tests, post-maintenance testing, containment leak rate tests, and special' tests.
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inoperable due to a maintenance activity, and testing performed following maintenance failed to determine that the pump was inoperable. Also, TVA failed to recognize that during quarterly safety injection pump testing, the acceptance criteria for the pump suction pressure could allow testing with potentially inadequate suction pressure. This condition could have resulted in pump damage. Also, problems were identified involving conduct of required
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testing.
Examples included boron sampling of water in the refueling cavity and failing to control post maintenance testing activities as required.
TVA maintained an adequate inservice inspection program during this assessment period. However, need for additional improvement was demonstrated by a weakness associated with management oversight and lack of attention to detail by TVA technical personnel.
Specifically, TVA failed to perform some pressure test visual inspections on several safety related systems. A Waiver of Compliance was necessary to extend the time limit required for a plant shutdown to perform the tests. The inservice testing program was found to be generally adequate.
The maintenance area is rated as a Category 3.
IV.
ENGINEERING The functional area of engineering addresses the adequacy of technical and
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engineering support for all plant activities. Design control and modifications are encompassed as is engineering and tecnnical support for operations, maintenance, outages and testing.
TVA's attention and involvement in the area of engineering and technical support have resulted in good overall performance.
The quality of design change packages was adequate. Safety evaluations were generally satisfactory and modifications were properly implemented in accordance with licensee procedures.
Design engineers had a good understanding of design changes. However, some problems were identified involving modification of the chemical and volume control system heat trace and modification of the control room ventilation system.
Engineering support to operations was weak. Operators were challenged by deficiencies in design documentation. An error in a Category I drawing caused a personnel error which resulted in the actuation of engireered safety features, drawings of piping in the balance of plant were incomplete,. Category
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2 and 3 drawings were not updated in a timely manner, anti the Final Safety.
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Analysis Report was inconsistent with the as-built plant.
Engineering i
solutions to operational problems were not always timely or effective, and -
documentation of some technical evaluations performed prior to Unit 2 restart i
did not contain sufficient information to support conclusions.
Engineering support to maintenance improved over this assessment period.
- 1 Early in the period, significant deficiencies were apparent.
Examples.
included a deficient program for predicting piping degradation due to erosion and corrosion and failure to include appropriate environmental qualification
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3 TVA's attention and involvement have resulted in an acceptable level of performance in this area. However, performance has declined from the previous assessment period.
During the assessment period it was noted that some equipment was not adequately maintained.
For example, failurc to properly maintain control air receivers resulted in blockage of a drain line and water injection into the control air system, initiating a *ial unit transient. An extraction t uam line rupture event revealed tha :. % balance of plant equipment was degraded, which resulted in challenges to u(4 ey systems. These examples indicated that plant management had not provided wfficient oversight, resources, and emphasis in maintaining secondary equipment. The overall condition of the safety related portion of the plant was generally adequate.
However, the lack of a periodic corrosion inspection to identify potential degradation of the containment liner indicated improvement could be achieved in primary plant maintenance as well.
Several examples were identified that indicated a lack of attention to detail during maintenance activities.
For example, a sump pump was decoupled, the pump motor electrically disconnected, and a refurbished motor installed with the pump capable of being electrically operated.
Subsequent review determined that the craft performed work on a pump other than the one identified in the work package. Also, a maintenanco error resulted in the improper installation of a containment blind flange air lock penetration, resulting in a failure to maintain primary containment integrity within required limits. ~ Problems with procedural adherence and quality of procedures were identified as well.
Lack of detailed testing procedures for replacement of a breaker in the switchyard resulted in unnecessarily bypassing many levels of primary fault protection.
This condition resulted in a dual unit trip.
Inadequate administrative procedural guidance resulted in more than 50 safety-related instrument calibrations not being performed as required.
Late in the assessment period, procedures were not followed during maintenance on a 6.9 KV unit board. The above examples of lack of attention to detail and procedural problems during maintenance indicated that management involvement and oversight have not been fully effective in instilling the appropriate sensitivity among plant personnel as to the importance of procedural adherence and quality of maintenance activities.
Lack of configuration control during maintenance was evident for some plant activities. A system engineer and auxiliary unit operator performed maintenance (field tuning) on a heater drain tank level controller without a procedure or work request, resulting in a unit transient.
In addition, failure to maintain configuration control while performing corrective maintenance on a drtin tank level control bypass valve resulted in a. wiring error, an air supply piping error, and removal of a check. valve without proper-documentation.
Also, foreign material in the Unit I reactor vessel was not identified and removed prior to core reload. Again, these problems are-reflective of management's ineffective oversight at ensuring quality and maintaining control of maintenance activities.
Examples were also identified in which more care is needed when developing tests that are designed to determine operability.
A safety injection pump was L.
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requirements in maintenance and surveillance procedures.
Engineering support improved later in the period. System engineers performed walkdown inspections of their assigned systems to identify needed maintenance and actively
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participated in the prioritization of maintenance and modifications to upgrade these systems. Additionally, steps were taken to strengthen other technical programs including the program for predicting erosion and corrosion.
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Performance in the areas of problem identification and corrective actions improved over the assessment period.
Early in the period, many deficiencies in plant condition and engineering programs were not recognized and a large backlog of identified deficiencies had not been properly prioritized.
By the end of the period, the threshold for problem identification had been lowered, items in the backlog had been properly prioritized, and appropriate corrective actions had been completed. Corrective actions taken in response to erosion and corrosion problems illustra+ed this change. The scope of the licensee's self-assessments and corrective actions in this area extended well beyond the erosion and corrosion issue.
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The engineering area is rated as a Category 2.
V.
PLANT SUPPORT
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The Plant Support functional area covers all activities related to the plant-support function including radiological controls, emergency preparedness, security, chemistry, fire protection, and housekeeping controls.
The radiological controls program effectively controlled both internal and -
external radiation exposures during this period. A well supported, aggressive As Low As Reasonably Achievable (ALARA) Program achieved a continued downward trend in person-rem / reactor with the current fiscal year goal of 200 person-rem / reactor projected to be met which will be the lowest annual dose in Sequoyah history.
Particularly noteworthy this period was the low exposure achieved as a result of excellent planning for the core barrel removal and reinstallation for its ten year inservice inspection.
Professional and technical radiation protection staff were knowledgeable and committed to minimizing personnel radiation doses. The contamination control program was strong with personnel contamination events well below the goal. Housekeeping and contaminated area controls were generally good during normal operations and also during the outage.
Good planning allowed a significant reduction in the use of respirators, helping to reduce external dose with no significant internal uptakes. Although the overall program was strong, there were some failures to adhere to radioactive material control requirements which indicated room for improvement in this area.
Liquid and gaseous radioactive effluents were also effectively controlled and monitored during this period. The projected offsite doses resulting from
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effluents were well within applicable limits. The radiological environmental monitoring program was well conducted and confirmed the low levels of effluents released from the plant. Management directed increased attention to the reliability problems with the Post-Accident Sampling System which had been experienced throughout the period. The effective processing, packaging,
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storing and shipping of radioactive wastes was a strength.
Solid radwaste generation was reduced during the period through a good level of management attention.
Effective audit programs were conducted in both the radiological protection areas and also the physical security area.
Prompt corrective actions were
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taken for audit findings.
In general, the physical security program was well supported and effectively implemented, although there were some problems identified during this period.
Management continued to provide strong support for this program as evidenced by the ongoing extensive program upgrade.
Significant improvements during this period included an alarm station computer simulator for training on the
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new system and upgraded firing range facilities.
Security staff training and qualification was considered a strength.
Response force training was t
conducted with local law enforcement authorities, and training was added in
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hostage negotiations and terrorist countermeasures. This was reflected in well performed drills. Early in the period, there were some significant failures to properly protect safeguards information. These problems were properly addressed and effectively corrected, as confirmed by inspection later
in the period.
Problems identified with the initial implementation of the access authorization rule were also promptly corrected.
TVA continued to provide strong support for the emergency preparedness-program. Training and exercise performance were considered a strength.
Shift personnel demonstrated a comprehensive knowledge of emergency duties and responsibilities. There was continued support training provided for offsite responders. Off-hours staff augmentation drills were performed to ensure activation times could be met :or all times of the day.
Facilities and
equipment were maintained in a state of readiness. The Operations Support Center was moved and improved, and an additional environmental monitoring van-was added during the period. Sequoyah responded well to actual events during
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the period.
Four emergency declarations occurred, and all were appropriately classified with proper notifications.
The fire protection program was adequately implemented during the period.
Progress continued with regard to the fire protection improvement-plan.
Management's monitoring of fire protection issues was good and innovations to improve fire operations performance were being successfully tested and implemented. Sequoyah identified a number of through wall leaks in carbon steel fire protection piping as a result of their problem trending program.
As a result, repair and replacement were planned with extensive compensatory measures. However, review of this issue and significant leakage through fire protection system valves at another TVA facility in the past identified an i
initial lack of effective communication between the TVA sites on this matter.
Management attention focusing on communication of potential generic issues in the company is warranted. An inspection and evaluation program for microbiological corrosion of the fire protection system was initiated during
this period.
The plant support area is rated as a Category 1.
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