IR 05000528/1992007
| ML17306A679 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 04/09/1992 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17306A678 | List: |
| References | |
| 50-528-92-07, 50-528-92-7, 50-529-92-07, 50-529-92-7, 50-530-92-07, 50-530-92-7, NUDOCS 9204240009 | |
| Download: ML17306A679 (36) | |
Text
U. S.
NUCLEAR REGULATORY COMMISSION
REGION V
SYSTEMATIC ASSESSMENT OF LICENSEE PERFORMANCE REPORT NUMBERS 50-528/92-07, 50-529/92-07, 50-530/92-07 ARIZONA, PUBLIC SERVICE COMPANY PALO VERDE NUCLEAR GENERATING STATION DECEMBER 1, 1990, THROUGH FEBRUARY 29, 1992 9204240009 920409 PDR ADOCK 05000528
~ae Introductlon...............;....................................
II.
Swanary of Results A.
B.
C..
verview..................................................
Results of Board Assessment...............................
Changes in SALP Ratings...................................
3
III.
Performance Analysis A.
B.
C.
D.
E.
F.
.G.
Plant Operations..............;.....
Radiological Controls...............
Haintenance/Surveillance............
Emergency Preparedness..........'....
Security............................
Engineering/Technical Support.......
Safety Assessment/guality Verificati
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17 IV.
Supporting Data and Suaaaries A.
B.
C.-
icensee Ac-.~iv~t~es............;...........:.....:.........
Direct NRC Inspection and Review Activities...............
Enforcement Activity......................................
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1
The Systematic Assessment of Licensee Performance (SALP) program'is an integrated NRC staff effort to collect available observations and data on a
per iodic basis and to evaluate licensee performance on the basis of this information.
The program is supplemental to the normal regulatory processes used to ensure compliance with NRC rules and regulations.
It is intended to be sufficiently diagnostic to provide a rational basis for allocating NRC resources and to provide meaningful feedback to the licensee's management regarding the NRC's assessment of their facility's performance in each functional area.
An NRC SALP Board, composed of the staff members listed below, met on March 12, 1992, to review observations and data on performance, and to assess the licensee's performance in accordance with NRC Hanual Chapter 0516,
"Systematic Assessment of Licensee Performance,"
dated September 28, 1990.
This report is the NRC's assessment of the'icensee's safety performance at the Palo Verde Nuclear Generating Station for the period December 1, 1990, through February 29, 1992.
The SALP Board was composed of:
- R. Zimmerman,
'
R. Scarano, F. Qensl awski;
- T. quay,
- K. Perkins,
- D. Kirsch,
- S. Richards, G.- Yuhas, J.
Reese,
- C.. VanDenburgh, P. Narbut,
- C. Trammell,-
- D. Coe, M. Ang, R. Bocanegra, P. squalls, D. Schaefer, F. Ringwald, Director, Division of Reactor Safety and Projects, Region V
(Board Chairperson)
Director, Division of Radiation Safety and Safeguards, Region V
Deputy Director, Division of Radiation Safety and Safeguards, Region V
Director, Project Directorate V,
NRR Deputy Director,'Division of Reactor Safety and Projects, Region V
Chief, Reactor Safety Branch, Region V
Chief, Reactor Projects Branch, Region V
Chief, Reactor Radiological Protection Branch, Region V
Chief, Safeguards, Emergency Preparedness, and Non-power.
Reactor Branch, Region V
Acting Chief, Reactor ProjectsSection II, Region V
Acting Chief, Engineering Section, Region V
Project Manager, Project Directorate V,
NRR Senior Resident Inspector, Region V
Project Inspector, Region V
Senior Radiation Specialist, Region V
Emergency Preparedness Analyst, Region V
Safeguards Inspector, Region V
Resident Inspector, Region V
Denotes voting members in all functional areas.
Other persons advised the Board in their areas of cognizanc Licensee performance in the Emergency Preparedness functional area remained a
Category 1.. This was attributable to aggressive management involvement which resulted in an effective program.
In addition, the Emergency Preparedness organization was well staffed, response staff training was superior, good relations with offsite agencies were maintained, and guality program involve-Nent was readily apparent.
Licensee performance during the assessment period in the radiological controls functional area improved to a Category 1.
The level of, commitment by all licensee personnel has resulted in superior efforts to control occupational exposure, limit radioactive effluents, reduce the volume of radioactive waste generated, and maintain good water chemistry control.
The board found mixed performance in the area of Safety Assessment/guality Verification.
Continuing improvement in the licensee's performance of guality Assurance (gA) audits and its safety review functions was noted.
However, as the gA audits become more meaningful, full management utilization of those audits is needed for the audits to be effective.
Two gA audits provided early indicators of potential problems with regard to refueling senior reactor operator (SRO) responsibilities, and with regard to maintenance work control.
Kore aggressive followup of these concerns may have precluded later Unit 2
'efueling problems and a partial loss of power event at Unit 3.
Strong support for and utilization of the guality Department in general, and gA t
audits in particular, by all levels of management is needed in order to improve overall in 'the Safety Assessment/guality Verification (SA/gV) func-tional area.
The board also recognized improvement of most of the safety review and oversight groups.
However, the board noted that management attention was still needed to improve the Independent Safety Engineering Group
{ISEG) effectiveness.
This area was rated a Category 2.
Performance in the Naintenance/Surveillance functional area was considered to be good and to have improved, but was still rated at a Category 2.
Manage-ment attention to improve work planning, craft attention to detail in work implementation, and corrective actions taken to address problems, as recom-mended by the previous SALP board, is still warranted.
The lack of sufficient management involvement in work planning and performance were highlighted by the partial loss of offsite power event at Unit 3 that resulted from a mobile crane inadvertently grounding power. lines while performing maintenance work.
Licensee performance in the operations functional area during the assessment period was rated a strong Category 2.
Licensed operator response to most operating events was appropriate.
Management attention to improving the consistency and formality of operating crew communications and of command and control responsibilities is needed.
Licensee performance in the Engineering and Technical Support functional area remained a Category 2.
The increasing utilization of Probabalistic Risk Assessment data and the resultant improvement in safety system availability were considered strengths.
Continued management attention to improving engineering involvement in problem areas in general, and in the maintenan'ce and troubleshooting areas in particular, is still warrante While licensee performance in the Security functional area
'was ultimately rated as a Category 2, considerable board deliberation in this functional area was necessitated by consideration of'eaknesses identified in this area.
increased management attention is considered to be needed to improve problem identification and resolution in the Security area.
The board had one generic concern that management expectations were not being effectively communicated or adopted at all levels or in all functional areas.
Particular attention is w'arranted in assuring effective work planning and-control, effective communications and good adherence to procedures, with attention to detail.
B.
r nt The SALP Board found the overall performance of NRC licensed activities by the licensee to be acceptable and directed toward safe operation of the 'Palo Verde Nuclear Generating Station.
The SALP Board has made specific recommendations in most functional areas for licensee management consideration.
The results of the SALP Board's assessment of the licensee's performance in each function-al area, including the previous assessments, are as follows:
A.
B.
C.
D; E.
F.
G.
n o
rea Plant Operations Radiological Controls Haintenance/Surveillance Emergency 'Preparedness Security Engineering/Technical Support Safety Assessment/equality Verification Rating Last
~eriod 2 imp.
2
2 1m'
Rating This
~rood
1
1
2
~rend*
The SALP report may include an appraisal of the performance trend in a functional area for use as a predictive indicator.
Licensee performance during the assessment period was examined by the SALP Board to determine whether a trend exists.
Normally, a performance trend will. be indicated only if (1)
a definite trend is discernible and (2) continuation of the trend could result in a change in performance rating.
The performance-trend is intended to predict licensee performance during the next assessment period and should be helpful in allocating NRC resources.
C.
an es n SALP Ratin s
The only significant change in the SALP ratings was in the Radiological Controls functional area, which improved to a Category 1 from a Category 2.
The improved rating was due to superior performance by the licensee in this functional area resulting from initiatives implemented and brought about by the management changes in this area.
The improving Operations and Security functional area performance trends perceived at the end of the previous assessment period did.not continue during this assessment perio III.
C Y
S The following is the SALP Board's assessment of the licensee's performance in each of the functional areas,,
plus the SALP Board's conclusions for each area and its receanendations with respect to licensee actions and management emphasis.
L During the assessment period, the licensee's plant operations
.were observed routinely by both the resident and the regional staff.
The NRC devoted 2742 hours0.0317 days <br />0.762 hours <br />0.00453 weeks <br />0.00104 months <br /> of inspection effort to this functional area,'epresenting approximately 36 per cent of the total inspection effort.
The licensee's performance was rated as Category 2 with an improving trend during the previous SALP rating period.
The previous SALP report emphasized the need for more involvement of supporting organizations; attention to detail during daily operations activities; a critically questioning approach to problems; increased scrutiny of program controls over
CFR Part 55 require-ments; and the need to complete simulator certification by Hay 1991 as required by 10 CFR Part 55.
During this SALP period plant operations included full power operation, two refueling outages, a 39 day 'surveillance test outage, and several short notice outages.
These activities were typically well-controlled, with several t
notable exceptions discussed below.
The licensed operators were called upon to respond to ten automatic or manual reactor trips and four reactor cutbacks as well as approximately 20 other operational events, which included several emergency plan activations (Notification of Unusual Event).,
an inadvertent containment spray, inadvertent Hain Steam Isolation Valve closures, and two losses of forced circulation.
Although failure to follow a procedure contrib-uted to one of the reactor trips, and a non-licensed operator complicated a
loss of forced circulation operational transient, in general, operator responses to events demonstrated effective plant control and compliance with technical specifications and operating and emergency procedures.
Control room demeanor was good, with operators generally limiting the extent of potential distractions to control room operations.
Notable licensee initiatives during this SALP period included the completion of simulator certification on schedule and funding for a second full-scale simulator scheduled for certification in 1993.
New emergency operating procedures (EOPs)
have been written and are scheduled for implementation in Hay 1992.
The licensee also substantially reduced the number of annunciators in alarm during power operation in Unit 3, representing the best results observed to date in any unit at Palo Verde.
Operationally, the licensee responded conservatively to high containment gaseous radioactivity in Unit I,
'dentifying and replacing leaking pressurizer relief valve gaskets and subsequently.identifying a small RCS pressure boundary leak which necessitated a plant shutdown to Node 5 for repair.
These examples reflect a responsive-ness toward immediate operational problems as well as a commitment toward long term improvement in the operations area.
The licensee's approach to technical issues was generally sound, with several exceptions noted.
The unexplained shifting of the steam generator low
- 4-
pressure reactor trip setpoint in a non-conservative direction in early October, 1991, was appropriately identified by a Unit 2 licensed. operator.
However, the licensee was initially slow in seeking a root cause of the problem.
In another instance, a containment airlock door interlock problem was noted by a technician; however, the licensee's initial response did not properly identify the problem or effect prompt corrective action.
In a third case, the licensee's response to a nitrogen system rupture disk failure, which had previously occurred 35 times at the site, represented an inadequate sensitivity to an unmonitored release path.
In these examples, the licensee's slow response to these degraded conditions increased the potential for more serious problems.
The Najority of violations in the operations area resulted from a failure to follow procedures and poor work control, several of which cumulatively resulted in escalated enforcement.
These violations included the lifting of control element assemblies without a senior reactor operator present in Unit 2; licensed operators failing to respond to an abnormal alarm in Unit 2; failure to obtain appropriate samples for boron concentration from the spent fuel pool in Unit 2; and the lowering of the upper guide structure liftrig working platform without establishing the required refueling pool level in
.
Unit 2.
The violations assessed a civil penalty, associated with refueling deficiencies at Unit 2, indicated a failure to ensure adequate control over refueling activities.
However; viewed as a whole, the enforcement history in the Plant Operations area does not indicate significant programmatic problems.
Corrective actions by the licensee were usually effective and timely.
licensee control of operational activities, with the exception of the Unit 2
'efueling issues discussed above, was considered to be generally good.
Management involvement from all levels was routinely noted.
However, several events indicated that this'area can improve.
In one case, an inadequate procedure and weak operator control allowed an over-dilution of the reactor coolant system, causing reactor power to briefly exceed 100 percent power.
Dther examples of weak operational control included using, an unapproved procedure to defeat an interlock in trying to start a reactor coolant pump at Unit 3; overfilling the reactor vessel and refueling canal in Unit 2; and inadvertent actuations of control room ventilation engineered safety features.
Toward the end of the period, the licensee took the positive step of placing operations management-temporarily on shift rotation at all three units to address procedure adherence, command and control, and communications issues discussed above.
Early in this SALP period, the licensee initiated a number of operations management changes.
Since then, staffing has been relatively stable.
Key personnel are experienced and responsibilities are clearly defined.
Suffi-cient licensed operators are maintained to support a five crew rotation.
The licensee's dedicated onsite fire department, supported by qualified fire fighters, is a strength of the fire protection program.
Additionally, the licensee has established a work group dedicated to supporting fire protection problem resolution.
weaknesses identified in the fire protection area included training of fire watches and the fire brigade; maintenance of fire protection hardware; and the need to clarify procedures addressing control of combustibles.
The NRC conducted one requalification program evaluation and two initial license examinations over the SALP interval.
.Although 17 of 19 initial
- 5-
license candidates passed NRC examinations, this represents a pass rate slightly below the national average for initial license examinations.
In addition, although I of the 6 crews evaluated failed the simulator exami-nations and 4 of 25 licensed operators failed one or more portions of the requalification examinations, the program met the requirements for a satisfac-tory program evaluation.
The examiners observed in some instances that opera-tors took actions without reference to the procedures;.applicants were not familiar with the procedural actions of mitigating an uncontrolled reactor plant cooldown; there were significant variations in the crew's coseunications practices; and the senior operators demonstrated weak development of command and control.
The latter concerns were also observed by the resident inspec-tors at Unit I when a crew failed to achieve a successful feedwater swapover due, in part, to weak communications, command, and control.
2.
Performance Assessment Category
3.
mmen s
The Board concluded that the improving trend at the end of the last SALP period has not been sustained, although this'rea continues to exhibit generally good performance.
Continued management attention is needed to reduce the number of examples of procedural noncompliance, to strengthen command and control skills, and to improve communication ability.
A particu-lar need exists for operators to clearly understand their responsibilities for monitoring or controlling specific maintenance activities that may impact license requirements or plant safety.
Greater emphasis is needed to ensure management expectations in these areas are shared by all levels of the organization.
B.
hm~s The licensee's radiation protection (RP) program was evaluated during routine operations and outage periods by both regional and resident inspectors.
The NRC inspection staff devoted 887 hours0.0103 days <br />0.246 hours <br />0.00147 weeks <br />3.375035e-4 months <br /> of inspection effort, representing approximately 12 percent of the total inspection effort, to this functional area.
The licensee's performance in the radiological controls area was very good and continued to improve during this assessment period.
The previous SALP Board recommended that the licensee take a more aggressive role in ensuring that corrective actions were promptly and effectively accomplished, arid that procedures be clearly stated, understood, and implemented.
The previous SALP Board also recommended prompt completion of organizational changes and conservatism in decision making.
The licensee's reorganization of the RP organization was virtually completed during this assessment period.
Key positions, including the Units I and
Radiation Protection managers, Site Chemistry Nanager, and the Operation's Radiation Protection Manager, were filled with competent individuals whose qualifications significantly exceeded the minimum regulatory requirements.
The licensee's management support for radiation protection and chemistry was also evident in the well-equipped laboratories, including state-of-the-art
sampling and counting systems.
Primary and secondary cycle chemistry parame-ters were consistently maintained within industry-established guidelines.
There were no significant chemistry related issues noted during the assessment period.
In 1990, the site's total dose to workers was 503 person-rem.
The 1991 dose was 602 person-rem, reflecting an increase in outage activity.
The total activity released in gaseous effluents was 1730 curies (Ci) in 1990.
Due to poor fuel quality in Unit 1, activity released increased to 5210 Ci in 1991;
.
however, the gamma and beta air dose at the site boundary from this release amounted to only a small fraction (less than 5X) of the Technical Specificati-on limits.
In 1991, the volume of radioactive waste shipped from the site de-creased to approximately one-half of its 1990 value.
The number of personnel contaminations continued a downward trend with 295 recorded in 1991.
Lic'ensee management was frequently involved in tracking personnel contaminations and making the staff aware of their expectations.
The licensee uses a Job Hazard Evaluation System to assure that higher levels of management review and approve radiation exposure permits (REP) that involve substantial potential for exposure.
Licensee management demonstrated ALARA commitment by the use of robotics in steam generator work.
Radiation protection decision making was consistently conservative.
The licensee's investigation of tritium sample results from Sedimentation Basin No. 2 and the circulating water system was thorough and demonstrated their ability to find the root cause of a technical issue.
The licensee's approach to resolving the Unit 2 antimony crud burst problem also was based on sound technical judgment.
Resolutions of technical issues were timely and frequently innovative, e.g. techniques for assessment of noble gas exposure.
Notable progress was made in resolving problems with the process and effluent radiation monitoring system.
Enforcement history in radiological controls was good, with only minor violations issued for infractions having limited safety significance.
The violations included six Severity Level IV violations and three non-cited violations.
During this assessment period, the licensee demonstrated improved performance by promptly identifying the root causes and implementing correc-tive actions.
Corrective actions were effective in that only one identified violation was a repeat from the previous SALP period.
awhile the violations were 'of limited safety significance, they do indicate a -lack of attention to detail in implementing basic radiation protection practices.
Examples of these basic practices included adhering to REP requirements, posting of a high radiation area, and placement of an air sampler.
The RP staff included five certified health physicists and 41 technicians holding certification from the National Registry of Radiation Protection Technnlogists.
The licensee implemented a rotational assignment program to increase flexibilityand expand the knowledge base of the staff.
Radiation protection technician staffing was very good, although the licensee was issued a violation early in the assessment period for assigning RP technicians to work excessive overtime without properly documenting the justification for granting the overtime.
During the assessment period, revised procedures contributed to a significant improvement in the general employee training program and the training and qualification program for the chemistry and radiation protection staff.
Radiation protection managers were actively involved iri conducting the RP
E
technician training classes.
Industry events were addressed in quarterly sessions that typically lasted four hours and were offered five times per quarter.
Responding to identified weaknesses from the previous SALP period, the licensee accomplished a rewrite of the RP program procedures to improve clarity and direction.
The licensee also added a 'bases" section as an appendix to the procedures to enhance their understanding and implementation.
The licensee's well-equipped mockup training facility included aockups for training personnel on reactor coolant pumps, steam generators, electrical panels, and valves.
The facility made a positive contribution to the ALARA program.
2.
Performance Assessment - Category
3.
ns Licensee management is encouraged to continue the positive improvements in this area.
Attention should be directed towards assuring that basic radiation protection practices are consistently implemented and attention is paid to details..
C.
n n e urveillance 1.
~1~i This functional area was observed routinely during the assessment period by both the resident and regional inspection staff.
The NRC devoted 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> of inspection effort to this functional area, representing approximately
percent of the total inspection effort.
Noted strengths observed included the licensee's scheduling and planning of maintenance activities to reduce safety risk for both on-line and outage conditions, the licensee's implementation of.
the Station Condition Identification Program with a low threshold for problem identification, and relatively good performance in correcting identified problems.
Continued good performance was demonstrated in the conduct of major activities which received substantial management oversight, examples of which included replacing the pressurizer code safety valve gaskets and repairing a
reactor coolant system pressure boundary leak on a pressurizer instrument line nozzle during recent forced outages in Unit 1.
Three broad areas of maintenance weakness were identified during the previous SALP period:
inadequate attention to detail in work implementation, inade-.
quate work planning, and inadequate problem resolution.
General improvement has been noted in these areas, and specifically in the a~ca of refueling outage planning.
However, some significant events were attributed to weakness in maintenance worker performance during this period, including a partial loss of power which resulted from routine cleaning around a relay with a loose cover; a damaged vital power supply and an associated forced unit shutdown; and a mobile crane coming into contact with energized power lines.
Other examples of inattention to detail included three instances where work was per-formed on the wrong train of safety-related equipment; incorrect oil being added to an auxiliary feedwater pump; a hydrogen analyzer rendered inoperable by a valve being left in the incorrect position; and a voltage tap set in the wrong position on an engineered safety features service transforme Licensee actions in identifying and correcting deficiencies in this functional area have improved, but warrant additional attention.
Positive examples included the licensee's identification and correction of undersized welds observed in the charging system, and pressure boundary leakage from an instrumentation line nozzle on the pressurizer.
Additionally, maintenance personnel designed and built a unique test stand for testing portions of the control system for feedwater isolation valves and main. steam isolation. valves,
,and then successfully used it to identify a problem and ensure it was correct-ed.
However, an example that indicated improvement can still be sade included a significant history of bolting failures associated with control element drive mechanism fans that did not result in long term corrective action until after the bolting for two ventilation exhaust stacks failed, creating an impact hazard to safety-related components under the stacks.
Also, questions raised by maintenance personnel regarding the quality of motor operated valve grease were not forwarded to engineering in a timely manner, resulting in confusion over the acceptance criteria.
Reduction of safety risks associated with maintenance has been a focus of the licensee.during this period.
The continued use. of a twelve-week schedule for eaintenance helped reduce outage time for safety equipment.
Licensee efforts to reduce the unavailability of the emergency diesel generators (EDGs), the high pressure safety injection system, and the auxiliary feedwater system resulted in improvements over previous years.
Two significant positive programmatic changes were implemented during this period.
They were the use of Probabilistic Risk Assessment (PRA) techniques in developing refueling outage schedules, and maintaining more equipment functional than required by technical specifications during refueling outages.
Although these initiatives were positive, specific instances of weak execution were noted.
On one occasion an EDG was taken out of service while the required parts were not readily available and the lack of.work supervision allowed several hours to pass with no work in progress, and at the same time maintenance on the essential spray pond system was also delayed due to poor planning.
The licensee's risk-reduction intentions can be furthered by more effective coordination of activities and heightened awareness throughout the organization.
The special efforts in Unit l to coamunicate refueling outage risk awareness to all workers was viewed as positive and is recommended for the other units.
Maintenance and surveillance procedures were generally considered to be good, and procedural deficiencies identified during this period did not lead to serious problems.
However, several examples 'of weak procedures were noted.
The acceptance criteria for a surveillance test for undervoltage relay setpoints were found to be less conservative than required by technical specifications an'd the surveillance procedure inappropriately allowed exercis-ing the relays, possibly affecting test results.
The stroke timing criteria for motor-operated valve testing were found not to consi.der degraded voltage conditions.
Finally, the licensee implemented a change to a surveillance procedure for testing the actuation of a spring loaded check valve in the charging system in Unit 1 with an acceptance criterion beyond the range of the instrumentation specified for use.
This event nearly forced a plant shutdown before the procedure was revised and the surveillance test successfully completed.
Although control of surveillance activities was found to be generally well-defined and implemented, some discrepancies in scheduling of surveillance
I It
tests were identified.
An EOG inspection, required by technical specifica-tions to be performed while shutdown, was scheduled and completed while at power; and a surveillance test for spray pond cross-connect valves was missed; As a positive example, the licensee identified and corrected a questionable surveillance interval for a containment structural integrity test.
The number of violations and licensee event reports (LERs) in this functional area was notably lower than in the previous SALP period.
Cited violations decreased From 9 to 6, and LERs decreased from 15 to 7.
The severity of the violations was about the same.with the exception that one violation in this functional area during this period was categorized as Severity Level III, whereas none were so categorized during the last period.
The Level III violation was assessed a civil penalty and involved the loss of offsite power to Unit 3 due to a mobile crane contacting overhead power lines.
An NRC
'ugmented Inspection Team (AIT) determined that the associated work had been poorly planned and poorly controlled and that the event could reasonably have been avoided.
Maintenance staffing during this SALP period was sufficient.
The corrective maintenance backlog was maintained at 'a reasonable level with only about
percent of the corrective mainten'ance work orders open for greater than three months.
Similarly, the overdue preventive maintenance work orders stayed below six percent during the last eight months of 1991.
Although maintenance
.training was not specifically evaluated during the SALP period, the AIT review of the crane operators'raining, relative to the loss of offsite power event in Unit 3, determined that significant weaknesses existed in crane safety and industry event training for crane operators.
Additionally, the AIT determined that weak management oversight of the planning and implementation of crane related work allowed the loss of power event to occur.
Overall, the maintenance program effectiveness has improved from the previous SALP period.
However, improvements in scheduling and problem resolution have been partially offset by examples of inattention to detail in implementation and weak management oversight.
2.
f ance at n Performance Assessment - Category
3.
r omaen ati ns Hanagement awareness of the quality of work planning and implementation needs improvement such that expectations regarding attention to detail are reem-phasized.
Training for work planners and maintenance personnel warrants closer management scrutiny to ensure that maintenance personnel understand the need for strict adherence to clear and correct work documents using ap-propriate precautions and work practices.
Evaluation of events and identified deficiencies should be more consistently performed to ensure timely and full resolution of problems.
D.
mer enc Pre ar dness l.
~na ysis The Emergency Preparedness (EP) functional area was assessed during five routine inspections and by observation of the annual emergency preparedness-10-
exercise.-
Approximately four percent of the total inspection effort was devoted to the licensee's EP program.
The licensee received a SALP category 1 rating in this area during the last appraisal period.
The SALP board at that time recomended that management continue to support the EP program with emphasis appropriate to ensure aggressive problem solving, to validate the effectiveness of corrective actions, and to ensure that plant events are properly classified.
Two significant strengths were identified during this assessment period.
One strength concerned the extent of involvement of the Quality Assurance (QA)
organization in the program and the other involved the strong working rela-tionship between the licensee and the state and county offsite agencies.
No significant weaknesses were identified during the assessment period.
I.icensee management was frequently and effectively involved in the EP program.
This was demonstrated by providing the resources necessary to maintain and enhance the program.
For example, the licensee initiated an Emergency Action Level (EAL) review panel consisting of facility management from several disciplines.
This panel was tasked with developing a basis document for the EALs.
Offsite assembly capability was improved by leasing, building and equipping an assembly area at the Buckeye Airport.
A facility walkthrough program was initiated in order to maintain facility readiness.
Management supported an enhanced drill and exercise program.
Hanagement has supported the inclusion of the PRA group working with EP and Operations to develop severe accident guidelines.
The licensee's QA program was actively involved in the EP area as was evi-denced by an in-depth annual QA audit.
Additionally the EP staff routinely utilized QA evaluations for review of EP exercises and drills.
The licensee's EP action item (EPAIL) tracking system was utilized effectively in tracking to completion,identified. program improvements.
Mhen technical issues were identified the licensee demonstrated a cleat understanding of the issues involved.
Mhen potential safety significance existed, the licensee routinely exhibited a conservat'ive attitude.
Resolu-tions have generally been timely and sound, and problems have seldom recurred.
Examples included the correction of problems identified during exercises and drills, inclusion of the PRA group into the emergency response organization to assess possible plant'egradations, making the clarifications needed for EALs, effective and timely resolution of deficiencies identified by QA, and upgrades to the facility public address (PA) system including installation of PA systems in each operations support building (OSB) and at other locations nnsite.
There were no violations identified during this SALP period.
The licensee properly classified nine Unusual Events during this evaluation period.
These included a containment spray actuation at power, two reactor coolant system (RCS) unidentified leakage classifications, two Technical Specification required shutdown initiations, two safety injections due to a
single grid disturbance, a fire lasting longer than 10 minutes, and a small RCS pressure boundary leak.
There were no examples identified of unconserv-ative event classification.
h Performance 'of the 1991 emergency exercise generally indicated good perfor-mance. during a challenging scenario.
An NRC Region V Site Team participated
in the exercise.
The licensee also used backup staff members at key response positions to demonstrate the depth of their capability.
While it appeared that the major goals and objectives of the exercise were met, unit personnel did not respond in a manner to maximize the benefits of exercise performance; for example, it took 55 minutes to transfer the Operations Support Center (OSC) to an alternate location and the Shift Supervisor (SS) did not aggres-sively pursue plant status and thus failed to classify. the alert without controller action.
The failure of the SS to classify the Alert was an-=
exercise weakness.
EP staff and emergency response positions were clearly identified, and authorities and responsibilities were clearly defined.
The licensee staffs key emergency response positions using a duty officer system to ensure fitness for duty during off hours and each position has a primary responder designated
=
and four qualified backup responders.
The licensee continued to provide ade-quate levels of dedicated staff to implement the programs and to interact with local offsite agencies.
Hinimal use of consultant personnel has been re.--
quired. During this period the licensee enhanced the management of EP by placing fire protection under'
separate manager and by creating EP Supervisor positions for both offsite and onsite portions of the program, thus enhancing the management oversight of the program.
The licensee's training program met or exceeded NRC requirements.
The licensee used a combination of computer-based and classroom based training for emergency response personnel.
In addition to the required annual exercise, the licensee is conducting a quarterly training exercise such that each unit participates annually.
The licensee is also conducting smaller scale training exercises that activate selected emergency response facilities to ensure that the backup responders for each position have practiced at that position.
An NRC concern was identified during a licensing examination involving the training that Senior Reactor Operators (SROs) receive regarding upgrading an event from a Site Area to a General Emergency.
The licensee included addi-tional training for. the SROs in this area, but this action had not been evaluated at the end of the SALP period.
2.
~F Performance Assessment - Category
3.
r rwe The board recommends that management assure response personnel participate in a manner that will maximize the effectiveness of exercise performance.
1.
~a~s During the assessment period, Region V conducted four physical security inspections, three special security inspections, one fitness-for-duty inspec-tion, and one enforcement conference.
Over 400 inspector hours, representing approximately 5 percent of the total inspection effort, were expended by regional inspectors.
In addition, the resident inspectors provided continuing observations in this area.
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The previous SALP report rated the licensee as Category 2, Improving.
The board receanended that licensee management complete their review of closed circuit television (CCTV) camera designs to improve the performance character-istics of the alarm assessment system.
During this SALP period, the licen-see's performance generally declined.
Hultiple enforcement actions, accompa-nied by an enforcement conference, were the primary indications of the decline.
Strengths identified during this SALP period.included the licensee's Security Equipment Improvement Plan, the centralized background investigation program, and ihe fitness-for-duty program.
The previous SALP report encouraged the licensee to complete their review of.
CCTV camera designs to improve the performance, characteristics of the alarm assessment system.
The licensee has scheduled replacement of all CCTV cameras by September 1993.
The new CCTV cameras, together with the planned realign-ment of the security fencing, should provide an increased capability for assessment of perimeter alarms.
Mith regard to management's involvement in assuring quality, corporate and the plant's quality assurance staffs continued to effectively review the operation of the overall security program.
However, as evidenced by an increase in human errors by Nembers of the security organization and in violations, security management's oversight of activities appeared lacking.
As evidenced by a continually increasing number of security officer human errors, the licensee's corrective actions in many instances were narrowly focused and often addressed symptoms rather than root causes.
Additionally, licensee management was not fully responsive to guality Assurance findings indicating potential progranmatic problems within the security organization.
The licensee security implementing procedures and policies were poorly understood by members of the security force.
Following an enforcement conference at the end of the SALP period, the licensee implemented pr'ograms to identify and correct their shortcomings.
During this period, in response to a violation, and in response to continuing recurring problems with vital door 1ocking mechanisms, CCTV cameras, and perimeter security alarm equipment, the licensee developed a Security Equip-ment Improvement Plan which focused upon improving the reliability of this equipment.
The licensee also established a Reliability Improvement Team for resolving long term concerns with this equipment, and for streamlining the engineering process of correcting equipment deficiencies.
The majority of Plan actions remain ongoing.
At the end of the SALP period, the licensee had completed upgrading the electromagnetic locks at Units 1 and 3.
The licensee continued to maintain an effective centralized background
'nvestigation program.
This program provides accurate and timely results, and assures as much as possible, that only trustworthy and reliable employees are granted permanent unescorted site access.
The enforcement history for this period included identification of nine Severity Level IV violations, and two non-cited violations.
The violations focused primarily upon the licensee's failure to:
maintain positive access control of individuals entering into vital areas; maintain required compensa-tory security measures; protect safeguards information; and properly escort visitors.
During this SALP period, it was evident from the repetitive nature of some of the security violations, that past corrective actions had been less than fully effective and often addressed symptoms rather than root causes.
Additionally, licensee management has failed to emphasize the importance of-13-
strict adherence to all provisions of'the security implementing procedures.
After NRC had initiated enforcement actions emphasizing the significance of these violations, the licensee initiated root cause evaluations and implement-ed meaningful corrective actions.
Dur.ing the SALP period, the NRC modified the threshold for reporting safe-guards events.
As a result, the licensee reported only three events to the NRC.
Two events pertained to fitness-for-duty matters, and one event reported the probability that the proprietary security force may initiate a labor action.
All events were reported in a timely Ianner.
In January 1991, the licensee's proprietary security force voted to establish a guard union, and in February 1992, licensee management and the guard union agreed upon the provisions of the. final labor contract.
During the negotia-tion period, the licensee hired and trained a'security contingency force to be utilized in the event the proprietary security force initiated a labor action.
These temporary contract security officers completed their training in July 1991, and remain employed at the facility.
During the last half of the SALP period, these temporary security officers were involved in multiple viola-tions.
During an enforcement conference the licensee's root cause analysis identified weak on-the-job (OJT) training for these temporary security officers as one of the causes of these violations.
During the enforcement conference the licensee also identified that their implementation of the contingency force was narrowly focused on contingency planning for strike mitigation and did not include consideration of human, issues.
As a result, the frequency of security officer human errors increased.
.
Mith respect to staffing, key positions were identified and, although limited by resource considerations, were filled the majority of the time.
Position responsibilities were gener ally well defined.
During this SALP period the licensee's security training staff was responsible for continuing the routine training of proprietary security officers.
Additionally, during the last half of the SALP period, the security training staff was assigned added responsibility for training the security contingency force of temporary contract security officers.
As a result of weak OJT, these
.contract officers occasionally violated procedures and policies.
At the end
'f the SALP period, the licensee was developing an enhancement training program for the contingency force officers (temporary contract security officers) to improve their personal knowledge of site specific security features and requirements.
The initial inspection of the licensee's fitness-for-duty program early in the SALP period noted numerous strengths, including the use of a lower cutoff level for marijuana, testing for a larger number of drugs than NRC requires, and a strong self-assessment program.
2.
Performance assessment
- Category
3.
pard ecommendations Licensee security management should implement a program to effectively identify and evaluate the root cause of problems, assure implementation of identified corrective actions, and increase the frequency of involvement in-14-
I I
the day-to-day operation of the uniformed security force.
Licensee management should stabilize the security organization, and continue their efforts with the Security Equipment Improvement Plan.
F.
8mb~i This functional area was reviewed routinely by both the regional, resident, and headquarters inspection staffs.
The NRC devoted 427 inspection hours to.
this functional area, representing approximately 6 percent of the overall inspection effort.
These reviews focused primarily on the effectiveness of the engineering organizations and in the quality of their work.
In addition, a actor-operated valve (HOV) team inspection was conducted.
Engineering was responsive in assessing major plant transients, significant equipment failures, and industry reported deficiencies.
These assessments
,included the root cause of failure analyses of events such as dual-unit,-
concurrent reactor trips; feedwater isolation valve failures; and electrical relay failures.
In. another example, engineering evaluation of an NRC informa-tion notice identified a postulated RCS leak not included in the design basis.
Independent engineering reviews also identified other design related deficien-cies such as a potential loss of an air handling unit and-potential RCS leakage greater than makeup capacity, both due to a postulated Appendix R fire in the control room; a core protection calculator design weakness; and numerous fire barrier discrepancies.
These efforts are viewed as positive indicators of thorough and proactive engineering involvement.
Strong management comaitment to support the erosion/corrosion program was considered a strength.
Except for minor discrepancies with data input of computer codes, the licensee erosion/corrosion program met or exceeded the requirements of Generic Letter 89-08.
The licensee has comnitted to continu-ously upgrade and expand the program to include all the components that could be subjected to erosion/corrosion degradation.
The licensee also developed a
sound program to address the reliability of motor-operated valves (NOV).
The licensee made a strong comnitment to staff the HOV program with well-qualified personnel.
Nevertheless, some weaknesses were identified in the implementa-tion of this program regarding HOV testing.
The system engineer program has increased in effectiveness
.and is trending in the. positive direction.
However, specific weaknesses still exist.
For example, system engineering had limited involvement in design change package preparation, material non-conformance reports, and failure data trending.
Also, system engineers were not always being involved in problems on a tim'ely basis so that they could identify and/or prevent recurrence of problems.
These weaknesses continue to undermine the ability of the system engineer to be considered the focal point of system-related problems.
Although typically considered. to be good, engineering evaluations of known problems were noted to be weak in several cases.
Previous design modifica-tions to reduce the occurrences of nitrogen supply system rupture disk actuation did not reveal the potential for an unmonitored gaseous activity release path until identified by the NRC.
Engineering monitoring of control element drive mechanism (CEDM) cooling fan failures was not sufficient to preclude total fan failure at one unit, forcing a rapid reactor shutdown.
Reliability problems persist with nitrogen pressure regulators on atmospheric-15-
dump valves even after extensive, engineering review and modification.
Additionally, the evaluation of plant electrical circuits for compliance with industry codes was found to be weak.
weakness was also observed in the depth of engineering involvement with certain maintenance activities.
Although the licensee's staffing of a maintenance engineer position at each unit is considered an improvement, NRC inspectors identified the need for greater engineering involvement as indicat-ed by issues such as NV grease evaluations, undervoltage relay replacement and surveillance procedures, and review of the impact of floor drain coverings on the flooding analysis.
In each of these cases, maintenance personnel did not seek, appropriate engineering involvement, nor did engineering identify the need for engineering review.
Only minor violations were identified in this area, and included inadequate technical input to an operations procedure resulting in a reactor power excursion above the licensed limit, and surveillance test requirements for undervoltage relays which continued.to be non-conservative with respect to technical specifications despite previous engineering'esolution.
Hinor violations were also identified associated with motor-operated valves.
In-service testing activities were found to be adequately planned and execut-ed.
In-service inspection (ISI) activities performed on the steam generator and reactor coolant pump piping were satisfactorily performed by qualified inspectors in accordance with, approved plant procedures.
The reliability and performance of the emergency lightingrsystem has been a
topic of concern for the past two years.
To address these concerns, the l,icensee implemented an emergency lighting team which has been effective at focusing emergency lighting system improvements.
This was evident from the numerous design modifications that have significantly improved the available design margin in the emergency lighting system.
Although these. actions are viewed in a positive manner, concerns regarding the 1icensee's management of the emergency lighting program continue to exist.
In particular, the licensee does not appear to have effectively implemented a method to monitor whether recent system modifications are actually resulting in improved emergency lighting system performance.
In addition, several types of emergency lighting system deficiencies, similar to those noted during previous NRC inspections, appear to be recurring.
These deficiencies involved the use of incorrect low voltage cutout relays for emergency lights and repetitive examples of incor-rect battery cell specific gravities.
Furthermore, appropriate licensee engineering and management personnel do not appear to be properly involved in the timely evaluation and correction of these recurring deficiencies.
II 2. ~t Performance Assessment - Category
3.
rd eco endat'ons The licensee should continue its efforts to ensure timely involvement of both site and corporate engineering organizations in plant problems.
System and component engineers should also be more actively involved in modifications, deficiency resolution, and trending of problems within their assigned systems or component areas.
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G.
Snab~
During this assessment period, the resident, region-based, and headquarters inspection staffs devoted 1572 inspection hours to this area, representing approximately 21 percent of the total inspection effort.
The effort was primarily focused on the inspection of the Quality Assurance,(QA)
and Quality Control groups, Indepen'dent Safety Engineering Group (ISEG), Plant Review Board, Nuclear Safety Group, Offsite Safety Review Committee (OSRC), Plant Safety Assessment Group, and the licensing organization.
The licensee continues to have a relatively strong QA audit program which has identified performance deficiencies in areas such as maintenance, correct'ive action adequacy, and refueling operations.
Several QA findings were related to and preceded the Unit 3 loss of power event due to improper crane opera-tion, and the Unit 2 core alteration without a senior reactor operator present.
In these cases, the QA audits did not identify progratmatic issues related to the deficiencies= which allowed these events to occur, and line management failed to recognize the underlying weaknesses and missed the opportunity to preclude refueling operations problems and maintenance work control problems that were subsequently experienced.
Additionally, in some cases, management action to correct identified deficiencies was later found by QA to have been ineffective.
The QA findings in these areas indicate that the audit teams are sensitive to potentially significant performance problems and to corrective action effectiveness, however line management is not always.
fully utilizing QA audit results.
Significant changes to the licensee's self-assessment programs were proposed and partia11y implemented during this SALP period.
A proposed technical specification (TS) change transfers the independent review and audit responsi-bilities to OSRC.
This group has already been functioning, consisting of the Palo, Verde affiliated Vice Presidents, the QA Director and three industry-recognized consultants, and reports directly to the Executive Vice-President Nuclear.
High level licensee management participation 'in the OSRC,gave it more stature and capability to recomend and implement effective action while ensuring better coordination and focus in the licensee's safety review responsibilities.
Industry-recognized, non-licensee members provided a
significant contribution of past experience and broad industry perspective.'I Improvements have also been noted in the performance of the Plant Review Board (PRB) functions.
Inclusion of the Unit. Plant Managers and the Director of Site Technical Support in the PRB resulted in more substantive and appropriate reviews and improved PR8 actions.
Open PRB action assignments have been reduced and appeared to be more timely.
The PRB discussions included appro-priate material including probabilistic risk assessment considerations.
The Independent Safety Engineering Group (ISEG) appeared to be fulfillingits technical specification (TS) review responsibilities and its composition and personnel qualifications met the TS requirements.
However, no significant improvements to plant safety were noted to have resulted from ISEG activities.
During this SALP period, the licensee's resolution of safety issues was generally sound.
One example involved safety system availability and the use of probabilistic risk assessment data.
Although NRC interest was necessary to
~
~
prompt licensee responsiveness to their preliminary Probabilistic Risk
- 17-
Assessment results, the data the licensee subsequently submitted showed significant improvement in minimizing the overall probabilistic plant risk.
This reduction was accomplished by minimizing the number of hours that safety system components were unavailable due to maintenance or testing.
In 1991, the actual hours that systems were unavailable were typically better than the licensee goals.
The licensee's 1992 unavailability goals are generally more aggressive than their goals in 1991.
Conversely, the NRC identified a
violation nf a technical specification surveillance requirement to perform ea5or emergency diesel generator (EDG) inspections only during plant.shutdown periods.
In this case, the licensee's practice of performing partial EDB disassembly inspections during power operation also indicated inadequate
'ensitivity toward minimizing overall plant risk associated with removing safety-related equipment from service for maintenance.
Licensee investigations into the hardware causes of plant events have generally been thorough and resulted in adequate corrective actions.
Examples included feedwater valve and controller problems, inappropriate main generator protection and exciter circuit response,. inadvertent containment spray, and reactor coolant system pressure boundary leakage; Other hardware problems have recurred indicating further improvement can be gained.
Examples included
'main feed pump trips, inadvertent main steam isolation valve closure, reactor trip setpoint shifts, and core operating limit supervisory system failures, for which the licensee has not determined the cause.
The licensee responded thoroughly to several industry notifications of equipment deficiencies including potentially defective pressure transmitters, controller modules, and licensee-identified electrical relay deficiencies.
However, the licensee's response was notably inadequate regarding the issue of controlling mobile equipment near plant transmission lines.
A recent indus-try-wide increase in occurrences of the loss of incoming plant power due to inadequate mobile equipment control prompted the NRC to issue a warning to all nuclear uti1ities to ensure adequate control of maintenance activities near important power transmission lines.
As previously discussed in Section III.C.1 of the repo'rt, the NRC's Augmented Inspection Team concluded that the licensee's review of this issue was inadequate.
A civil penalty was assessed and was escalated to stress the lack of thorough response to the prior NRC notification and the initial licensee failure to address the underlying management control issues, which gave rise to weak procedures, weak work control processes, and failure to follow procedures.
A separate civil penalty was assessed for similar management control weaknesses which led to violations of technical specifications related to refueling core alterations.
During the SALP period, the NRR staff received 20 requests for license amend-ments.
Four of -the
) equests for ',.icense amendments resulted in Requests for Additional Information (RAI) and were the result of inadequate or incomplete licensee requests that lacked thoroughness.
A large number of the submittals required conference calls with the licensee, and supplemental information was often requested.
Very few of the submittals could be reviewed without follow up discussions or formal requests for additional information.
For example, the licensee's response to Generic Letter 90-06 regarding enhanced require-ments for low-temperature over-pressure protection. required two RAIs to clarify how the proposed changes conform to the guidance in the generic letter, and to clarify inconsistencies in the application of the guidance of the generic letter to the licensee.
The staff has also observed that several licensing requests did not contain complete and accurate disclosure of relevant information..
Two examples involved submittals regarding steam
- 18'-
.
generator tube inspection frequency and the visual inspection of pipe snub-"
bers.
Overall, it appears that careful attention to the quality and prepara-tion of these amendment requests was not usually evident.
However, more recent submittals show an improving trend and.the licensee appears to be making an effort to improve the quality of documents sent to the NRC.
No LERs or. enforceme'nt items were directly attributed to this functional area.
However, many LERs and violations, although assessed primarily against the nther SALP functional areas, were at least partially a result of weaknesses in this functional area.
The most noteworthy example of this was the Unit 3 event involving the mobile crane.
2.
Performance Assessment - Category 2,
3.
-.
The licensee should continue-its efforts to better utilize lessons learned from its own experiences and from industry experience.
Strong support of the guality Department and full utilization of gA audits by all levels of manage-ment ls still warranted.
Licensee management attention to the improvement of the effectiveness of ISEG is recomended.
Licensee management should continue to focus on ensuring that submittals and communications with the NRC be suffi-ciently complete to allow independent NRC assessments of significance and technical adequacy.
Licensee management should ensure that their expectations are fully communicated to and adopted by all working levels.
IV.
P G
A UMHAR S
A.
ee v
s 3hdi.l The unit operated at 100 percent power through most of the SALP period.
However, several events and power variations occurred as follows:
On December 17, 1990, a core'perating limit supervisory system (COLSS)
failure forced a down power to 75 percent for several hours.
On January 12, 1991, the unit entered a 39 day surveillance outage.
On June 20, 1991, and again on June 27, 1991, the unit was down powered to 99 percent and 80 percent respectivoly, for short durations, due to COLSS failures.
On September 14, 1991, a part length control element assembly partially slipped.
During the subsequent down power, an economizer valve failed open resulting in increasing steam generator level, a main steam isolation valve closure, and a unit trip.
Repairs were performed and the unit returned to 100 percent power on September 28, 1991.
On October 27, 1991, power was decreased to 68 percent for one day to repair a low pressure steam inlet check valve for one of the main feedwater pumps.
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On October 27, 1991, an offsite power grid disturbance caused power oscillations that resulted in two main turbine control valves closing, quick opening of the steam bypass control valves, reactor power oscilla-tions, a variable overpower'eactor trip, and initiation of safety injection actuation and containment isolation actuation signals, for which the licensee declared an Unusual Event as required by their proce-dures.
The unit returned to 100 percent power on November 2, 1991.
On December 22, 1991, a feedwater system transient resulted in a reactor power increase to 103.7 percent for a short duration.
This was identi-fied by the licensee, and reactor power was reduced to 97 percent for 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />, on December 27, 1991.
On January 3, 1992, a pressurizer level instrument nozzle leak resulted in a forced shutdown and an Unusual Event was declared.
The nozzle was repaired and the unit restarted.
However, during the increase of reactor power on January 14, 1992, problems with the swapover of the feedwater system were encountered.
The unit reached 100 percent power on January 20, 1992.
On February 15, 1992, the unit was shutdown and a 70-day refueling outage was started.
The unit operated at 100 percent power through-most of the SALP period.
However, several events and power variations occurred as follows:
On December 21, 1990, reactor power was reduced to 65 percent for several hours when a main steam isolation valve inadvertently closed due to a failed solenoid for an air valve that controlled valve position.
On August 9, 1991, the unit was down powered and manually tripped from 40 per cent power when all control element drive mechanism cooling fans
.failed.
The unit returned to mode 1 on August 15, 1991.
On August 16, 1991, while the unit was at 60 percent power, the "B" main feedwater (MFM) pump discharge piping was over-pressurized to approxi-mately 7500 psig.
On the same day, with the unit at 64 percent power, a
generator excitation system malfunction resulted in a main turbine trip and reactor trip.
The unit was restarted and reached 100 percent power on August 19, 1991.
On August 22, 1991, an inadvertent main steam isolation valve closure resulted in a power reduction to 70 percent power.
The unit was re-stored to full power on August 23, 1991, and stayed at 100 percent until October 17, 1991.
On October 17, 1991, the unit started a 70 day refueling outage.
The unit ended its refueling outage on January 9, 1992, but experienced a
reactor trip at 20 percent power during a main feedwater system swap-over.
The trip was attributed to a broken switch on the feed system controller.
The unit returned to full power on January 21, 1992, where it remained until the end of the SALP period.
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~
.
The unit started the SALP period at 100 percent power, but reduced power to 40 percent on December 25, 1990, due to condenser tube leakage.
The unit returned to 100 percent power on December 27, 1990.
On Narch 5, 1991, an overspeed trip of the "B" main feedwater pump resulted in a reactor cutback; power was stabilized at 70 percent.
Power was reduced on Harch 15, 1991 and the plant shutdown for its.
second refueling outage which began on March 16, 1991.
The outage was
,
completed and the unit reached 100 percent power on June 2,
1991.
On June 19, 1991, an improperly assembled test push button resulted in an inadvertent containment spray.
The reactor, and subsequently the reactor coolant pumps, were manually tripped, natural circulation cooling was established and an unusual event was declared.
Subsequent to inspection, troubleshooting, and repair, the unit was restarted and full power was attained on June 23, 1991.
On July 5, 1991, an overspeed trip of the "B" HFM pump resulted in a reactor cutback to 70 percent.
The unit returned to full power on July 7, 1991.
On August 30, 1991, a failed vital 120 VAC invertor resulted in a technical specification required shutdown and a declaration of an unusual event.
The unit returned to full power on September 5,
1991',
but decreased power back to 90 percent on September 7,
1991, due to a failed heater drain pump.
The unit returned to fu11'ower on September 12,= 1991.
On October 27, 1991, an offsite power grid disturbance caused all four main turbine control valves to close, a variable overpower reactor trip, a safety injection actuation signal and a containment isolation actua-tion signal, and a subsequent declaration of an unusual event.
The unit returned to full power on November 1,
1991, but an electrical surge was experienced by the main transformer
"A". phase on November 14, 1991, resulting in a reactor trip.
On November 15, 1991, two partial losses of offsite power, and a loss of forced circulation cooling, were experienced by the unit when a mobile crane that was being used for repairs on the main transformer, came in contact with a 13.8 KV offsite power line.
An NRC Augmented Inspection Team was dispatched to the site to review the event.
The unit was returned to full power on December 1,
1991.
Although the unit began the SALP period at 100 percent power, several events and power variations occurred as follows:
On January 24, 1992, a manual trip of a main feedwater pump resulted in a reactor cutback and a subseq'uent reactor trip.
A broken instrument air -line was repaired and the unit returned to full power on January 27, 1992.
On February 5, 1992, loss of a condensate pump resulted in a main feedwater pump trip and reactor cutback.
A failed circuit card was re-placed and the unit returned to 100 percent, power on February 6,
1992.
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~
The unit ended the SALP period operating at full power.
B.
s Three resident inspectors were assigned to the Palo Verde Nuclear Generating Station during the SALP assessment period.
Approximately 8224 hours0.0952 days <br />2.284 hours <br />0.0136 weeks <br />0.00313 months <br /> of 'direct inspection were perforaed during 'this SALP period.
In.addition, two enforce-aent conferences and eight aanagement meetings were held with the licensee.
A total of 53 routine and special inspections were conducted during this period.
Significant team inspections included:
~
Augmented Inspection Team - Unit 3 Partial Loss of Offsite Power Event
~
HOV Testing and Surveillance Inspection Team C.
The 53 inspections conducted during this assessment'period identified 41 cited violations and 13 non-cited violations.
Although counted individually, sever al of those violations were co@son to multiple units.
The significant violations are discussed in the individual performance analysis sections of this report.
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