IR 05000317/1998002
| ML20247L170 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/14/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20247L141 | List: |
| References | |
| 50-317-98-02, 50-317-98-2, 50-318-98-02, 50-318-98-2, NUDOCS 9805220329 | |
| Download: ML20247L170 (17) | |
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U.S. NUCLEAR REGULATORY COMMISSION REGION 1 License Nos.
DPR-53/DPR-69 Report Nos.
50-317/98 02:50-318/98-02 Licensee:
Baltimore Gas and Electric Company Post Office Box 1475 Baltimore, Maryland 21203 Facility:
Calvert Cliffs Nuclear Power Plant Units 1 and 2; Location:
Lusby, Maryland
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Dates:
March 15,1998 to April 18,1998 Inspectors; James S. Stewart, Senior Resident inspector Fred L. Bower lil, Resident inspector Henry K. Lathrop, Resident inspector James Trapp, Senior Reactor Analyst, DRS I
Herb Williams, Senior Operations Engineer, DRS Approved by:
Lawrence T. Doerflein, Chief Projects Brrs h 1 Division of Reactor Projects l
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9805220329 990514 PDR ADOCK 05000317 G
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EXECUTIVE SUMMARY Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Inspection Report Nos. 50-317/98-02and 50-318/98-02 This integrated inspection report includes aspects of BGE operations, maintenance, engineering and plant support. The report covers a five week period of resident inspection and the results of specialist inspections in operations and engineering.
Plant Operations The April 3,1998 shutdown and subsequent cooldown for the Unit 1 refueling outage were safely conducted. Operators were trained on the simulator for conduct of the shutdown and contingencies. Detailed evolution briefings were conducted by operations department supervision and the shutdown was observed by appropriate management and engineering personnel. The shutdown and cooldown were completed without problems.
BGE had established and implemented very good controls for ensuring safety during the reduced inventory condition for installation of steam generator nozzle dams. These controls included redundant instrumentation and core cooling trains, heightened awareness of plant staff to the reduced inventory condition, and extensive management involvement in planning and completing the operation. The nozzle dams were installed without problems.
BGE responded well to the 1B emergency diesel generator failing a surveillance test.
Appropriate engineering and management involvement was observed during troubleshooting. Operability determinations were consistent with NRC Generic Letter 91-18. Operator actions in response to the failure were good and in accordance with technical specification requirements. The operating shift took an active role in the periodic status briefings conducted during the course of the troubleshooting and provided good communications with the maintenance and engineering organizations. BGE maintained a good safety focus throughout the troubleshooting and repair.
BGE did an excellent job in planning and implementing the removal of a 4 kV electrical bus from service. The effectiveness of the planning enhanced safety by rninimizing the time this bus was out-of-service. The operators conducting the evolution had been effectively trained to conduct this activity. The conduct of the operating staff observed in the control room throughout the evolution of de-energizing and re-energizing 4 kV bus 11 was excellent, as demonstrated by thorough briefings, formal communications, continuous self and peer checks of actions, and detailed procedures.
Maintenance Maintenance was conducted safely and in accordance with BGE approved procedures and controls. Workers were knowledgeable and performed work effectively. The observed surveillance testing was performed safely and in accordance with approved procedures.
BGE had established accountability of maintenance supervisors for performance of offsite electrical work groups used in the protected area. Due to this accountability, and with improved training of the groups to site work standards, the performance of offsite electrical groups had improved.
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Executive Summary (cont'd)
During non-radiological work in the Unit 1 intake structure, communications were lost between a dive support team and a diver in the intake canal. The diver was immediately pulled from the water and was found unconscious. Actions taken to resuscitate the diver were futile and the diver was pronounced dead-on-arrival at a local hospital. BGE established a Significant issues Findings Team to review the occurrence. Subsequently, it was determined that the diver died of natural causes. No problems with the planning or conduct of the dive were identifnj.
In 1996, BGE had established a system maintenance improvement initiative with a goal of improving system reliability and reducing corrective maintenance. Since the initiative was started, BGE has reduced the backlog of priority maintenance orders (MOs) and the daily average number of high priority MOs. Also, the number of corrective MOs was reduced while the number of preventive maintenance MOs was increased. Also, the frequency of plant trips and transients has been reduced. Based on the reductions in the number of plant trips and transients, the inspectors concluded that BGE has been successful in improving system reliability and performance.
The inspectors found that BGE had not ensured that an emergency diesel generator governor was stored according to the vendor recommendations. Specifically, the governor had not been stored full of oil and periodic checks were not done to evaluate the governor condition. When the governor was removed from the warehouse and placed in service, it failed and the failure contributed to the expiration of the emergency diesel generator Technical Specification limiting condition for operation.
Enaineerina The inspectors independently concluded that BGE's risk assessment for removing the number 114kV bus from service was technically sound. BGE took appropriate action to move the number 114kV bus and the AFW system to "(a)(1)" status for the maintenance rule program ufter the failure of the 13 AFW pump breaker cubicle shutter.
Plant Support BGE identified that a radiation worker had exceeded a Special Work Permit radiation dose.
A BGE Significant issues Findings Team had been established to review the event and determine the contributing causes. During the investigation, BGE identified that a second high radiation area job had been worked without following dosimetry requirements of the applicable Special Work Permit. At the close of the inspection period, the NRC had initiated a specialinspection of these occurrences.
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TABLE OF CONTENTS EX EC UTIVE S U M M A RY.............................................. ii TA B LE O F C O NT ENTS.............................................. iv
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Summary of Plant Status........................................... 1 1. O p e ra tio n s..................................................... 1 O1 Conduct ol Operations.................................... 1 01.1 General Comments (71707)........................... 1 01.2 Unit 1 Reduced inventory Operations..................... 1 01.3 1B Emergency Diesel Generator (EDG) Inoperable............ 2 11. M a i nt e n a n c e................................................... 4 M1 Conduct of Maintenance................................... 4 M 1.1 General Comments.................................. 4 M2 Maintenance and Material Condition of Facilities and Equipment....... 6 M2.1 Maintenance Improvement Initiatives..................... 6 M2.2 1B Emergency Diesel Generator Governor Failures............ 6 111. E n g in e e ri ng.................................................... 9 E2 Engineering Support of Facilities and Equipment.................. 9 E2.1 Removal of 114kV Bus from Service for Maintenance......... 9 I V. Pl a nt S u p p o rt................................................. 1 0 R1 Radiological Protection and Chemistry (RP&C) Controls............ 10 R1.1 Unplanned Radiation Exposure........................ 10 V. Managem e nt Meetings...........................................
X1 Exit Meeting Sum m ary..................................
ATTACHMENT Attachment 1 - Partial List of Persons Contacted-Inspection Procedures Used-Items Opened, Closed, and Discussed I
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Report Details Summarv of Plant Status Unit 1 operated at full power until April 3,1998, when the reactor was shutdown for a refueling outage.
Unit 2 operated at full power throughout the inspection period O1 Conduct of Operations
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01.1 General Comments (71707)
Plant operations were conducted safety with a proper focus on continued nuclear safety. The inspectors conducted daily reviews of ongoing plant operations and observed that the overall conduct was professional and safety-conscious.
Operators were aware of plant conditions and the status of plant equipment.
Supervisory oversight was appropriate.
On April 3, Unit 1 was shutdown and subsequently cooled down in preparation for a planned refueling outage. Nuclear Fuels Management (NFM) engineers planned for the shutdown by determining the optimum control rod positions to minimize the axial symmetry index (ASI) transient. Prior to the power reduction, the operating crew practiced on the plant simulator using the NFM strategy. The shutdown and cooldown included detailed pre-evolution briefings and was observed by appropriate management and engineering personnel. Operations management also scheduled operator license applicants to complete reactivity manipulations on the reactor as power was reduced. The shutdown and cooldown were completed without problems. Operator performance during the plant shutdown and cooldown was very good.
01.2 Unit 1 Reduced Inventory Operations a.
Insoection Scope The inspectors observed the Unit 1 refueling outage activities in preparation of reduced inventory operations.
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Findinas and Observations Unit 1 was placed in reduced inv:.ntory on April 11 for stearn generator nozzle dam installation. In preparation for reduced inventory, the inspectors cbserved that BGE implemented Higher Risk Evolution, Contingency Plan J. The plan. which was prepared jointly by the outage and operations departments, included briefing, training, and communication requirernents for involved personnel; a summary of actions to minimize time in the reduced inventory condition; and specified
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compensatory actions to ensure inventory control throughout the evolution.
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The reduced inventory operation was conducted by control room operators using Operating Procedure, OP-7, Section 6.3, " Entering Reduced Inventory Condition."
Preparations for the operation included specific training of reactor operators on conduct of reduced inventory controls, a briefing by operations management to involved personnel on the risk of the evolution, and specific performance briefings for all involved personnel on contingency actions. The inspectors verified that there would be no switchyard work during the reduced inventory condition.
The inspectors also verified availability of the following essential equipment and plant conditions:
i-Two offsite power circuits and two emergency diesel generators l-Two redundant makeup sources for reactor coolant inventory-Pressurizer manway removed to provide a hot leg vent path-Two independent decay heat removal trains
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-Placement of " Safe Shutdown Equipment" warning signs on designated equipment c.
Conclusio_n_s Overall, the inspectors found that BGE had established and implemented very good controls for ensuring safety during the reduced inventory condition for installation of steam generator nozzle dams on Unit 1. These controls included a detailed procedure that specified redundant instrumentation and core cooling trains, protected ele:trical power supplies, limited maintenance that could affect core cooling, and an extensive pre-evolution checkliut. The inspectors observed heightened awareness of plant staff to the reduced inventory condition and extensive management involvement in p'anning and completing the operation. The nozzle dams were installed without problems.
01.3 1B Emergency Diesel Generator (EDG) Inoperable i
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Inspection Scope I
The inspectors observed and assessed the 1B EDG being declared inoperable and BGE compliance with the applicable technical specifications.
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Observations and Findinas At 12:25 a.m. on March 25,in preparation for removing the 1 A emergency diesel generator (EDG) from service for planned maintenance, the 1B EDG failed to start during the performance of surveillance test procedure (STP) O-8B-1. Plant operators documented the problem in an icsue report and entered the appropriate Technical Specification Limiting Condition for Operation (LCO).
I The technical specification includert an action to demonstrate the operability l
of the 1 A EDG. During this operability demonstration, BGE observed a malfunction of the 1 A EDG room ventilation flow inlet modulating dampers.
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The outside air damper was not appropriately opening in response to changes in the 1 A EDG room temperature.
BGE engineering raised the concern that the room temperature could potentially exceed design requirements if the engines were operated continuously and the dampers would not move. Consistent with NRC l
Generic Letter 91-18, BGE operations personnel were notified and a prompt, preliminary engineering evaluation was completed to document that the 1 A EDG building ventilation was degraded, but operable. BGE followed-up the engineering evaluat!on with a formal operability determination in accordance with BGE administrative procedure NO-1-106 and established compensatory actions for warm and cold weather cases. Prior to reaching 72 degrees Fahrenheit (*F) the fresh air damper would be failed to the full open position as a warm weather compensatory measure. The damper would be failed shut prior to reaching 55aF as a cold weather compensatory measure.
Between 55 and 72 degrees, either damper position was allowed. The inspectors reviewed the operability determination and concluded that it was appropriate in scope and detail.
BGE also initiated troubleshooting on the 1B EDG governor actuator. This troubleshooting and the related maintenance activities are discussed further in Report Section M2.2. As a result, several pre-evolution briefings took place between shift operating crews and the troubleshooting personnel.
Operations shift personnel exercised good safety practices while providing the required tag outs and interaction with the troubleshooting personnel.
Very good communication techniques were observed by the inspectors as various stages of the troubleshooting took place. The operating shift remained aware of actions being performed in the field involving the 1B diesel governor troubleshooting and provided support to engineering and maintenance as needed.
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Conclusions BGE responded well to the 1B emergency diesel generator failing a surveillance test. Appropriate engineering and management involvement was observed during troubleshooting. Operator actions in response to the failure were good and in accordance with technical specification requirements. The operating shift took an active role in the periodic status briefings conducted during the course of the troubleshooting and provided good communications with the maintenance and engineering organizations. BGE maintained a good safety focus throughout the troubleshooting and repair. Operability determinations regarding the lA EDG room ventilation dampers were
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consistent with NRC Generic Letter 91-18 and appropriate in scope and detail.
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jl. Maintenance M1 Conduct of Maintenance M 1.1 General Comments a.
Insoection Scone (62707. 61726)
The inspectors reviewea daily maintenance activities and focused on the status of work that involved systems and components important to safety.
Selected maintenance activities and surveillance tests were directly observed and included the following:
M01199800974 1B Emergency Diesel Generator Governor MO1199800956 Emergency Diesel Generator 18 MO1199705205 Demolish 11 Saltwater Hangers MO1199705207 Demolish 11 Service Water Heat Exchanger STP-O-73Cl-2 Component Cooling Pump Quarterly Test b.
Observations and Findinas The inspectors found that the selected maintenance activities were performed safely and in accordance with approved procedures and maintenance order packages. Technicians were experienced and knowledgeable of the assigned duties. Supervisory involvement was appropriate. Maintenance and surveillance testing were scheduled so that risk was minimized during periods when equipment was out of service. BGE also considered and minimized reactor trip risk when scheduling maintenance and surveillance testing. Engineering was appropriately involved with the conduct of maintenance and surveillance activities. The demolishment activities were completed as part of the replacement of the Unit 1 service water heat exchangers. During the demolishment activities, essential reactor cooling was maintained, fire protection was appropriately implemented, and personnel safety was included in job planning and implementation.
The observed surveillance test was conducted in accordance with procedures. Involved personnel were knowledgeable. Test details were discussed at a pre-test briefing and the testing was completed without problems.,
NRC Inspection Report 50-317&318/96-02, discussed problems with control of maintenance by offsite work groups. The affected work areas inc!uded j
both the Calvert Cliffs switchyard and the protected area. The inspectors
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reviewed Calvert Cliff's current oversight of these offsite maintenance I
groups performing work in the protected area. Currently, each job included active oversight by on-site maintenance supervision, pre-job planning and scheduling, and detailed procedures to ensure that the work was completed
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to Calvert Cliffs work standards. Selected BGE supervisors completed a qualification for sponsorship of the offsite groups. The qualification provided an understanding of the site performance expectations, including communications, human performance evaluation, radiation and contamination controls, and other maintenance oversight activities. The inspectors noted a marked reduction in reactor trips and transients caused by maintenance activities, with 21 trips in 1992 through 1995 and one trip in 1997. Also, there were no reactor transients in 1997 related to work by offsite work groups. Using these results, the inspectors considered that the efforts to improve sponsorship of the offsite groups to be effective.
On April 4, a non-radiological dive was performed at the intake structure in support of the Unit 1 refueling outage. The diver tasks included aiding in the removal of trash rakes and installation of stop logs for a salt water system train. At 12:50 p.m., the diver was pulled from the Unit 1 intake channel after dive tenders identified that communications between the diver and the dive support team had been lost. The diver was found unconscious. The BGE first-aid team responded and administered cardio-pulmonary resuscitation, the individual was transported to Calvert Memorial Hospital, but was declared dead-on-arrival. The State Medical Examiner's Office determined the cause of the diver's sudden death to be from natural causes.
EGE conducted an investigation of the event. The inspectors reviewed the event and found no problems with the planning or conduct of the dive.
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Conclusions The observed maintenance was conducted safely and in accordance with BGE approved procedures and controls. Workers were knowledgeable and performed work effectively. The observed surveillance testing was performed safely and in accordance with approved procedures.
BGE had established accountability of maintenance supervisors for performance of offsite maintenance groups used in the protected area and the switchyard. Due to this accountability, and with improved training of the groups to site work standards, the performance of offsite electrical groups had improved and both the number and frequency of plant trips and transients caused by offsite work groups had diminished.
During non radiological work in the Unit 1 intake structure, communications were lost between a dive support team and a diver in the intake canal. The diver was immediately pulled from the water and was found unconscious.
Actions taken to resuscitate the diver 'nere futile and the diver was pronounced dead-on-arrival at a local hospital. BGE established a Significant issues Findings Team to review the occurrence. Subsequently, it was determined that the diver died of natural causes. No problems with the planning or conduct of the dive were identified.
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M2 Maintenance anti Material Condition of Facilities and Equipment M2.1 Maintenance Improvement Initiatives a.
insoection Scoce The inspectors reviewed two BGE initiatives aimed at improved maintenance performance.
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Observations and Findinas in 1995, BGE implemented two initiatives to improve equipment reliability and plant performance, the Preventive Maintenance (PM) Optimization Program and the System Maintenance improvement Program. By more closely tailoring preventive maintenance to each specific system, BGE established a process to reduce the amount and severity of corrective maintenance that had been experienced. In a number of NRC inspection reports, the inspectors noted that BGE had reduced the backlog of priority maintenance orders (MOs) to about 60 and that the average number of daily high priority MOs had dropped to less than 10. In a review by BGE, foi the years 1995 -1997, the number of annual corrective MOs dropped from 3402 to 1620, while the annual number of preventive maintenance items increased from 3496 to 5003. Maintenance improvement was evident in the main steam isolation valve, steam generator atmospheric vatve, and main feedwater control systems. These systems historically had been a cause of problems, including reactor transients.
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Conclusions Since the system maintenance improvement initiative was started, BGE has I
reduced the backlog of priority maintenance orders (MOs) and the daily average number of high priority MOs. Also, the number of corrective MOs
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was reduced while the number of preventive maintenance MOs was
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increased. The frequency of plant trips and transients has been reduced.
Based on the reductions in the number of plant trips and transients, the inspectors concluded that BGE has been successful in improving tha
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reliability and performance of several systems.
M2.2 1B Emergency Diesel Gener; tor Governor Failures a.
Insoection Scoce The inspectors reviewed BGE actions associated with the failure of two governors for the 1B EDG and BGE's request for Enforcement Discretion.
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b Observations and Findinas As described in Report Section 01.2,in preparation for taking the 1 A EDG out-of-service for maintenance, the 1B EDG failed to start during an operability test run at 12:25 a.m. on Maich 25. Troubleshooting identified that the governor was the !Wely cause of the EDG's failure to start.
Subsequent inspection and rcot cause analysis by the EDG vendor detennined that the problem was a piece of nylon ma9tiallodged in the governor control oil system shutdown solenoid valve.
During the repair activity, BGE attempted to start the 1B EDG several times using a governor taken from the 3GE warehouse. These attempts were unsuccessful. On March 27, a new governor was obtained frnm the vendor.
The new govemor was installed and testing was begun on March 27; however, BGE did not expect that the testing would be completed within the allowed outage time (AOT) which ended at 12:25 a.m. on March 28,1998.
BGE requested NRO enforcement discretion. The exercise of enforcement discretion was documented in an NRC Notice of Eriforcement Discretion (NOED) 98-01-002, dated March 31,1998.
The inspectors reviewed the history of the spare EDG governor. Records indicated that this governor had been installed on a diesel during troubleshooting in 1987. At that time, BGE suspected that the governor was air bound and the governor was removed from the engine and returned to storage with a note stating that it was air bound, but acceptable for use once venting was completed.
Procurement engineering and warehouse personnelindicated that storage procedures and preventive maimonance instructions did not exist for diesel governors m storage until July 199'/, The vendor technical rnanual for the governor stated to fill the governor with oil and install the shipping plugs if the governor was stored for periods in excess of 90 days to protect the unit agsinst rust and contaminants. In 1996, BGE quality assurance personnel identified concerns regarding storage of safety related parts in the warehouso. In response to th6 quality assurance audit finding, procurement engineering personnel developed procedures, including one to annuntly verify that EDG govemors in the warehouse were filled with oil and stored in an upright position. BGE personnel stated that the maintenance for EDG governors stored in the warehouse had been completed for the f rst time,in Ju;y 1997. However, the documentation for this activity was not sufficiently detailed to positively link the maintenance record with the specific EDG governor that failed on March 25. Resolution of vendor recommendations during storage of other safety related equipment was either fully implemented or under development.
Discussions with maintenance and engineering personnelindicated that a
. spare governor was removed from the warehouse in December 1997 after the installed governor on the 18 EDG failed. Maintenance and engineering
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personnel indicated to the irispectors that at that time, the spare governor was not found full of oil. After examining that spare governor, another spare governor was removed from the warehouse and installed on the 1B EDG.
The original spare was again returned to the warehouse, but not filled with oil. Procurement Engineering and warehouse personnel stated that the receipt inspection pm.aess for restocking the spare governor would be a verification of traceability and an inspection for obvious physical damage.
The inspection and restocking process would not verify that the preventive maintenance concerning oillevel and storage position was completed. This would not be expected to be verified until the scheduled annual periodicity, due in July 1998. The inspectors concluded that this was a poor receipt inspection practice.
The inspectors noted that cause of the December governor failure had not been resolved at the time of this inspection. In March, the governor was sent to a vendor for a root cause determination. BGE told the inspectors that the root cause determination for the December governor failure was delayed to select and qualify a vendor. The inspectors considered that BGE was not aggressive in identifying a root cause for the December failure.
On March 25, the spare governor was the only EDG governor remaining in the Calvert Cliffs warehouse. This governor was taken for installation on the 1B EDG. Maintenance and engineering personnelindicated to the inspectors that the spare governor was again found not full of oil.10 CFR Part 50, Appendix B, Criterion Xlli, " Handling, Storage, and Shipping," required that equipment be stored in accordance with work instructions to prevent deterioration. Further, protective environments shall be specified and provided, when necessary. The protective environment for the governor was
" full of oil and shipping plugs installed." BGE Vendor Technical Manual 37708J, Woodward EG-B10C Governor Actuator, specified that units be protected against rust and contamination if stored for more than 90 days before installing. The inspectors found that BGE had not provided a protective environment for the diesel governor when stored in excess of 90 days and this failure was a violation of NRC requirements. (VIO 50-317&318/98-02-01)
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Conclusions The inspectors found that BGE had not ensured that an emergency diesel generator governor was stored according to the vendor recommendations.
Specifically, the governor had not been stored full of oil and periodic checks were not done to evaluate the governor cordition. When the governor was removed from the warehouse and placed in service, it failed and the failure contributed to the expiration of the emergency diesel generator Technical l
Specification limiting condition for operation.
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l E2 Engineering Support of Facilities and Equipment i
E2.1 Removal of 114kV Bus from Service for Maintenance
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Insoection Scope J
Two specialist inspectors from NRC Region I reviewed the BGE's preparations and conduct in removing a safety-related 4kV Bus from service.
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Findinas and Observations Following breaker maintenance, BGE identified that the 13 auxiliary feedwater (AFW) pump breaker could not be racked into the breaker housing on 4kV Bus 11. The cause was determined to be a faulty shutter located in
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the 13 AFW breaker cubical. The shutter would not fully open and prevented racking in the 13 AFW pump breaker. To facilitate repairs, the bus needed to be de-energized to protect maintenance personnel. Ewasive planning and reviews were used to specify plant conditions that allowed the bus to be de-energized. On March 19, BGE removed the shutter from the breaker cubicle and successfully racked in the AFW pump breaker.
Bus 11 provided electrical power for one of the two safety-related trains of plant equipment for Unit 1. The removal of 4 kV Bus 11 from service increased plant risk. BGE probabilistic risk assessment (PRA) engineers conducted a detailed assessment of the risk associated with this maintenance activity. The risk associated with the removal of bus 11 from service, including other equipment which was also unavailable, resulted in a core damage frequency increase by a factor of approximately 10. The baseline CDF for Unit 1 is approximately 2E-4. However, the conditional core damage probability associated with this activity was small, because the time to conduct this maintenance was very short (~ 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />). The inspectors conducted independent risk calculations using the accident sequence
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precursor models (ASP) and verified that BGE's risk assessment was technically sound.
BGE had developed detailed plans for removal of Bus 11 from service. The plans included detailed instructions for de-energizing bus 11, contingency plans, expected plant alarms, and applicable Technical Specification action statements. BGE used the plant simulator to validate these instructions. The inspectors concluded that the plans were appropriate for conducting this evolution.
BGE used an administrative procedure for special high risk evolutions to complete this activity. This procedure required extensive planning and a pre-job briefing by supervision. The procedure also specified enhanced management oversight of plant conditions and the work. The inspectors l
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found that the briefing conducted by operations management was detailed
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I and thorough. The PRA engineers also provided risk insights to the operations staff during the briefing. The coordination and communications among plant work organizations during the pre-job briefing was excellent.
On March 19, the inspectors observed control room operator performance during the downpower and re-power of the 4 kV bus. The operations staff consistently used 3-way communication and used self checking techniques throughout this evolution. Operations management oversight and technical support were constantly available throughout this evolution. All operator l
steps observed were conducted in accordance with plant procedures. When procedure steps were encountered that were not applicable, the operator actions to stop and temporarily revise the procedures were appropriate.
Effective planning and conduct by the plant staff minimized the time the 4 kV bus was out of service. The maintenance was conducted effectively and no problems were encountered.
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Conclusions The inspectors concluded that BGE operations department did an excellent job in planning the removal of 4 kV bus from service. The effectiveness of the planning enhanced safety by minimizing the time this bus was out-of-service. The operators conducting the evolution had been effectively trained to conduct the activity. The conduct of the operating staff observed in the control room throughout the evolution of de-energizing and re-energizing 4 kV bus 11 was excellent. The maintenance was conducted effectively and no problems were encountered.
The inspectors independently concluded that the BGE risk assessment for removing the number 114kV bus from service was technically sound. PRA engineers provided good risk insights to the operations staff during briefings for the maintenance. Following the work, BGE took appropriate action to move the number 114kV bus and the AFW system to "(a)(1)" status for the rnaintenance rule program after the failure of the 13 AFW pump breaker cubicle shutter.
IV. Plant Support R1 Radiological Protection and Chemistry (RP&C) Controls R1.1 Unplanned Radiation Exposure a.
Insoection Scope The inspectors reviewed aspects of an event involving an unplanned radiation exposur ;
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Observations and findinas
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On April 9,1998, BGE identified that an instrument and controls technician had received an unplanned radiation exposure during work to install excore nuclear instrumentation in the Unit 1 reactor vessel annulus area. The exposure was in excess of the exposure limit specified by BGE in the special work permit (SWP), but was within the limits specified by 10 CFR 20, Occupational Dose Limits. The BGE technician had been working in the annulus region for approximately 10 minutes in radiation fields that ranged from two to six rem per hour. The work had been considered by BGE to be high radiological risk and was subject to prejob planning and a briefing. Pre-job preparations included specification of multiple, alarming dosimeters to ensure that the individual's exposure remained within pre-established limits.
Subsequent to the event, BGE identified that although the I&C technician had
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been wearing alarming dosimetry, the individual could not hear the alarms in the work environment. Additionally, a radiation technician overseeing the I
radiological aspects of the work was aware that some of the l&C technician's dosimeters had alarmed, but took no protective actions. The radiation technician did not use the available procedure for the dosimetry.
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The inspectors noted that the procedure did not specify actions to be taken k
when the dosimetry alarmed.
BGE established a Significant issue Findings Team (SIFT) to review the event, determine the causes, and make corrective action recommendations.
During the SIFT review, BGE identified that earlier on April 8, a radiological event occurred where a number of individuals entered the reactor vessel annulus area without any alarming dosimetry. This was contrary to the BGE Special Work Permit for work in the area. Based on these preliminary findings which were identified at the end of the inspection period, the NRC initiated a special inspection of high radiation area work at Calvert Cliffs.
This inspection would include a review of both April 8 and April 9 occurrences. The findings of this inspection would be provided in a separate inspection report.
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Conclusions BGE identified that a radiation worker had exceeded a Special Work Permit radiation dose. A BGE Significant issues Findings Team had been established to review the event and determine the contributing causes.
During the investigation, BGE identified that a second high radiation area job had been worked without following dosimetry requirements of the applicable Special Work Permit. At the close of the inspection period, the NRC had initiated a specialinspection of these occurrences.
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.V. Manaaement Meetinas X1 Exit Meeting Summary
During this inspection, periodic meetings were held with station management to discuss inspection observations and findings. On May 8,1998, an exit meeting was held to sumrnarize the conclusions of the inspection. BGE
management in attendance acknowledged the findings presented.
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ATTACHMENT 1 PARTIAL LIST OF PERSONS CONTACTED ILQE
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P. Katz, Plant General Manager
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K. Cellers, Superintendent, Nuclear Maintenance f
K. Neitmann, Superintendent, Nuclear Operations
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T. Pritchett, Director, Nuclear Regulatory Matters S. Sanders, General Supervisor, Radiation Safety T. Sydnor, General Supervisor, Plant Engineering C. Cruse, Vice President - Nuclear N!!C L. Nicholson, Deputy Director, Division of Reactor Safety, Region 1 J. White, Chief, Radiation Safety Branch, DRS, Region 1
L. Doerflein, Chief, Reactor Projects Branch 1, DRP, Region 1 S. ~ Bajwa, Director, Project Directorate 1-2, NRR A.. Dromerick, Senior Project Manager, Calvert Cliffs, NRR INSPECTION PROCEDURES USED IP 71707 Plant Operations IP 61726 Surveillance Observations IP 62707 Maintenance Observations IP 71750 Plant Support Activities IP 37551 Onsite Engineering ITEMS OPENED, CLOSED, AND DISCUSSED O.ng_ogd 50-317&318/98-02-01 VIO Failure to store a diesel generator governor in accordance with vendor recommendations I
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