IR 05000454/1996001
| ML20128H935 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 10/01/1996 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20128H376 | List: |
| References | |
| 50-454-96-01, 50-454-96-1, 50-455-96-01, 50-455-96-1, NUDOCS 9610100123 | |
| Download: ML20128H935 (7) | |
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BYRON SALP 13 l
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Report No. 50-454/455/96001 : INTRODUCTION The Systematic Assessment of Licensee Performance (SALP) process is used to develop the Nuclear Regulatory Commission's (NRC) conclusions regarding a licensee's safety performance. Four functional areas are assessed: Plant Operations, Maintenance, Engineering, and Plant Support. The SALP report documents the NRC's observations and insights on a licensee's performance and communicates the results to the licensee and the public. It provides a vehicle for clear communication with licensee management that focuses on plant performance relative to safety risk perspectives. The NRC utilizes SALP results when allocating NRC inspection resources at licensee facilitie This report is the NRC's assessment of the safety performance at Byron Nuclear I Generating Station for the period August 21, 1994, through August 17, 199 An NRC SALP Board, composed of the individuals listed below, met on August 28, 1996, to assess performance in accordance with the guidance in NRC Management Directive 8.6, " Systematic Assessment of Licensee Perfo> nance."
Board Chairoerson J. L. Caldwell, Acting Director, Division of Reactor Projects, RIII l Board Members G. E. Grant, Director, Division of Reactor Safety, RIII R. A. Capra, Director, Project Directorate III-2, NRR I PERFORMANCE ANALYSIS Operations Performance in operations, although good, declined from the previous perio The primary cause of the decline was the continuation of personnel errors i throughout the SALP period and examples where the safety focus was less
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conservative. Continued emphasis on communications and teamwork was evident and operator response to plant problems and transients continued to be ,
excellent. Management encouraged identification and resolution of problems and emphasis was placed on critical, penetrating self-assessments. However, the efforts to eliminate personal errors have yet to be consistently effectiv Personnel errors occurred intermittently throughout the period, a pattern observed in the previous SALP period. Early in this period, the control room was left unattended without a senior reactor operator for approximately 22 minutes. As a result, the control room was reorganized and responsibilities were changed. Other significant personnel errors included three inadvertent transfers of several hundred gallons of water: from the volume control tank to the refueling water storage tank (RWST); from the RWST to the spent fuel pool; and from the RWST to the auxiliary building floor drains. Recently, the 9610100123 961001 PDR ADOCK 05000454 0 PDR
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l i 1B control rod drive motor generator and the 2A diesel generator were ;
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inadvertently tripped by operators, in separate incidents, due to wrong switch manipulations. Plant events and personnel errors were evaluated and trende ,
Based on these evaluations, the licensee implemented several performance '
improvement initiatives including peer checks, on-the-spot recognition of good l performance, and benchmarking trics to other nuclear facilitie ll l Appropriate consideration of risk and conservative operations was generally ;
i routine at Byron. However, four events demonstrated an occasional?y less ;
conservative risk safety focus while shut down. In April 1995, operators inadvertently vented residual nitrogen from a safety injection accumulator into the Unit 2 reactor vessel head during actor-operated valve testing, causing a significant uncontrolled pressure and level transient. In October 1995, a similar event occurred at Unit I when an inadequately isolated reactor coolant loop was pressurized with nitrogen to drain it, and nitrogen was vented to the reactor vessel head, causing another uncontrolled pressure and level transient. In April 1996, the licensee removed emergency AC power from one of the two required residual heat removal pumps prior to reflooding the reactor cavity. Although this activity was permitted by the technical specifications, the decision demonstrated an acceptance of increased risk for outage schedule considerations. Finally, in June 1996, during the pre-startup dilution of Unit 1, the operators erroneously estimated the volume of the water in the reactor coolant system for an initial dilution calculatio Using too small a volume in the calculation, combined with the failure of chemistry personnel to accurttely sample, resulted in a significantly greater dilution than planned. This error was not recognized at the time. Operators and chemistry technicians repeated the dilution evolution a total of four times, doubling the volume of water during the last two, making similar errors, until an accurate sample was fortuitously taken. This sample showed that the reactor boron concentration, although still safe, had been reduced much lower by the dilutions than planne Operator response to plant transients and events was excellen Examples included, a dual unit event due to a Unit I loss of offsite power and the Unit 2 dropped rod reactor trip from 100 percent power. Interdepartmental communications and teamwork were excellent. These attributes were demonstrated during troubleshooting and repairs to plant equipment, including a circuit card failure on the rod control system, a condenser tube leak which required a plant shutdown, and a steam generator tube leak that resulted in a plant shutdown. Shift briefings were thorough, with excellent discussions of activities planned for the shift, emphasizing communication and safe operation Initial license and requalification programs were found to be very effective, except for a situation found by the licensee which reduced the security of one exam. A loss of exam security occurred for a two day period. The scheduled I exam was postponed for two weeks to write a replacement exam, as a precautio The performance rating is Category 2 in this area.
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f Maintenance l
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Performance in maintenance continued to be excellent. Material condition of ;
the plant was excellent with high safety system availability and reliabilit Execution of maintenance-and surveillance activities were typically conducted
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in a professional manner with no safety concerns. Effective management and first line supervisory involvement were evident. Self-assessment activities ;
were effectively used for the identification and resolution of problem i However, some areas for improvement were noted. These areas were: the scheduling of risk-significant outage related maintenance tasks, consistently implementing foreign material exclusion controls, and the continuance of :
isolated personnel error l In most cases, the risk and consequences of performing both on-line and outage j maintenance were evaluated through the concept of protected components / trains and the development of contingency plans. However, during the most recent Unit I refueling outage, challenges to the operations staff were created which a could have been avoided by less aggressive scheduling. Maintenance activities
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on both the 1A diesel generator and DC battery bus Ill, which both supplied power to one of two residual heat removal pumps, were initiated approximately four days prior to reflooding the refueling cavity, with significant decay heat present in the reactor. As a consequence, an increased number of compensatory actions were necessary to assure safe mitigation of a loss of
, offsite powe Management fostered excellent interdepartmental communication and teamwork, and continued to be self-critical by identifying and resolving performance problems. Strong management oversight was observed in the assessment of operating experience information and in the development of a material condition monitoring and improvement program for the station. First line supervision was present in the field to assure maintenance activities were conducted properl Effective and critical self-assessments were performed by the line organization and the quality oversight organization Problem identification and resolution of technical issues were strong; however, some isolated instances of untimely writing of problem identification forms (PIFs) were noted. Programs and procedures for the conduct and execution of maintenance and surveillance activities were good including the inservice inspection and testing, preventive maintenance, and erosion / corrosion programs. Where weaknesses were identified, timely corrective action and procedural enhancements were executed as necessar Although an adequate foreign material exclusion (FME) program was put into effect, there were several examples throughout the SALP period where problems were experienced in consistently implementing effective FME control Plant equipment was well maintained to support safe operation of the plan Safety system availability and reliability were excellen Safety-related corrective maintenance was scheduled and executed in timely manner. As noted above, the licensee developed a program for monitoring and assessing plant material condition on a system basis. Action plans were developed and j implemented for systems with less than optimum performance. Examples included i implementation of an auxiliary power system breaker refurbishment program and
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I an electronic card replacement program for the reactor protection and radiation monitoring system The overall quality of work planning, scheduling and execution was excellen Routine corrective, planned and preventative maintenance activities were effectively scheduled within the 12 week maintenance windows. Scheduled outage maintenance work was completed and equipment returned to service as planned. The coordination and execution activities by operations, maintenance and engineering of the root cause investigation after the loss of offsite power to Unit I and restoration of the Unit I station auxiliary transformer were particularly notable. However, isolated personnel errors continued to occur during the SALP period that involved procedural adherence and configuration control. Management recognized these problems and initiated effective corrective action The performance rating is Category 1 in this are Enaineerina Engineering performance continued to be excellent. Activities were characterized by effective implementation of programs and procedures, an excellent safety focus, proactive identification of problems, and generally very good quality in engineering work. Some exceptions to this were noted in the timeliness and thoroughness of certain operability assessments. Support and communication to other plant and corporate organizations also continued to be excellen Engineering-related issues were usually treated with a conservative approach that demonstrated excellent safety focus. Notable examples included the detection and conservative evaluation of Unit I steam generator tube degradation and the timely operability evaluation of a Westinghouse notice regarding potential damage to the pressurizer power operated relief valves in the event of an inadvertent safety injection actuation at powe The licensee's engineering and technical oversight of the steam generator repair effort for the Unit I steam generators was very good. Although early in the period some problems were noted with contractor oversight and in the development of a quality leak rate test program in support of Commonwealth Edison's request for approval of a 3-volt steam generator voltage-based repair criteria, substantial improvement was noted during the SALP period. Overall, the licensee was proactive and innovative in addressing steam generator degradation issues. Additionally, the licensee's request to use the ABB/CE steam generator tube sleeving methodology as a repair technique exhibited a thorough understanding of industry problems in this area. The program established for the replacement of the Unit I steam generator was well develope Engineering performance regarding identification and resolution of technical issues continued to be very good. The system monitoring and trending activities yielded good results in identifying programmatic component problems, such as the diesel generator relay solder joint problem. Another example of good performance included the identification and evaluation of a
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potential seismic concern affecting the auxiliary feedwater system. System walkdowns by system engineers, however, varied in quality, due in part to a lack of standardized training and guidance on how to conduct system walkdowns to identify problem The quality of engineering work was very good, but some exceptions were note The engineering _ support provided to operations, maintenance, and other plant functional areas continued to be of high quality and included good coordination with the corporate offices and other sites. In particular, engineering support for maintenance and technical evaluation of the breaker levering-in device and motor cutout switch circuit breaker problems was excellent. Good engineering was also performed on operability issues associated with containment peak pressure recalculation; the emergency diesel generator intake manifold cracks; and the evaluation of thermal-hydraulic binding on containment sump recirculation gate valves. However, the initial safety evaluation supporting the repair of the station auxiliary transformer !
did not have a sufficient basis to support the conclusion that the temporary modification did not involve an unreviewed safety question. Alsc, a lack of timeliness and thoroughness was noted on some operability assessments involving: equipment qualification of the MSIVs, certain Regulatory Guide 1.97 post-accident monitoring instruments, and diesel generator expansion limiter bolts. Errors were noted on some modification calculations that were not identified during the calculation review proces Engineering programs and procedures were very good. Effective implementation l of the temporary alteration process and the workaround program was noted. The motor operated valve program effectively established the design basis capability of motor operated valves, and was acceptable to the NRC for Generic j Letter 89-10 closeout. Performance of inservice inspection activities was ;
excellen The licensee's efforts in support of license amendments and relief requests were very goo Licensee submittals were typically complete with followup required for clarification onl Engineering was aggressive in proposing acceptable solutions, including an innovative variation on a Westinghouse methodology for resolution of the positive moderator temperature coefficient ;
amendmen Site Quality Verification continued to provide strong licensee self-criticism l in the engineering functional area, which benefitted engineering programs such as temporary alterations, operability assessments, and MOV The performance rating is Category 1 in this are Plant Support Plant support performance was good but declined from the previous perio Although performance in radiation protection, security and emergency preparedness was strong, significant weaknesses in chemistry performance contributed to two operational events. Performance in fire protection was hindered by some material condition problem _
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l Performance in radiation protection (RP) continued to be very good with the exception of some radioactive waste processing evolutions. A comprehensive mock-up training program and the use of dose reduction techniques such as robotics and remote monitoring effectively minimized the dose expended during the extensive Unit 1 steam generator inspection and repair activitie Oversight of other radiohgical work was good and the total station dose, although relatively high, was reasonable considering the work scop .
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, Radiation work practices were also good and contamination was effectively 4 l
controlled as plant equipment was readily accessible. Station oversight and the material condition of the environmental monitoring program was excellen The RP staff implemented necessary procedure revisions to reflect changes in regulatory requirements and to correct self-identified performance problems during steam generator repairs. Early in the assessment period, much higher than normal radiation levels were caused in the vicinity of the spent resin l l tank after a highly radioactive resin tank was incorrectly transferred to it 1 and, in a second event, liquid containing low levels of radioactivity was inadvertently discharged to the environmen Chemistry program performance was acceptable but declined significantly during the period. Inadequate procedures and poor direction by the chemistry department contributed to an over-addition of hydrogen to Unit 1 and the unexpected Unit I reactor coolant boron dilution discussed earlier in this report. While station water chemistry control programs continued to be aggressive in preventir.g and reducing corrosion, the chemistry staff did not always effectively correct known problems. For example, although sample line purge times were known to be deficient, comprehensive corrective actions were not taken and this subsequently contributed to the boron dilution even During the last half of 1995, the chemistry staff failed to maintain the quality control program for the post-accident sampling system. In addition, chemistry technicians demonstrated weak analytical techniques and radiation protection practice Security performance continued to be excellent. Past performance weaknesses i concerning inadequate procedures and staff knowledge of procedure requirements were effectively corrected. Security force performance trends were consistently positive. Although maintenance support was generally effective in ensuring operability of security equipment, the security staff was not aggressive in addressing maintenance needs for a security component that required compensatory measures for several months. Implementation of a hand geometry system for access control, installation of the vehicle barrier system, and a new security computer enhanced security operations. Sel f-assessment efforts effectively identified performance problems and corrective actions were timely and effective.
l The emergency preparedness (EP) program and the emergency response facility
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condition were very good. Response to an actual event (loss of offsite power)
l was proper. Performance during the December 1995 NRC evaluated exercise and I
the July 1996 utility-only exercise was very good. Exercise classifications, offsite notifications and offsite protective action recommendations were correct and timely. The 1995 and 1996 annual audits and peer reviews of the
EP program were very good. Overall management support and attention to the EP program, including response to audits and peer reviews, was excellen . . . . -
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. o Performance in fire protection was good. Strengths continued to be observed in control of combustibles, fire brigade responsiveness, and assessments of the fire protection program. Management support was evident as the number of impaired fire doors was reduced and resources were committed to reduce other fire protection impairments. However, the material condition of fire protection equipment, including fire doors, continued-to be a weakness. In addition, problems in the implementation of the impairment system were also observe The performance rating is Category 2 in this area.
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