IR 05000309/1992020
| ML20125D890 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 12/08/1992 |
| From: | Lazarus W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20125D873 | List: |
| References | |
| 50-309-92-20, NUDOCS 9212160081 | |
| Download: ML20125D890 (9) | |
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a U.S. NUCLEAR REGULATORY COMMISSION
REGION I
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Iteport 92-20 License DPit-36
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Inspection At:
Maine Yankee Atomic Power Plant Wiscatet, Maine (Maine Yankee Atomic Power Company)
Conducted:
October 15 through November 19,1992 Inspectors:
Charles S. Marschall, Senior Resident Inspector William '. Olsen, Resident Inspector
/Al[f 2-W Approved:
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w W. [<{$7artkflief, Reactor Project Section 3B Date
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SCOPE Resident inspection of operations, radiation protection, rnaintenance/ surveillance, security, engineering / technical support, and safety assessment / quality verification.
OVEl(VIEW Operations Overall, operators insured safe piant performance. A Plant Shift Supervisor adequately determined operability for a leaking feedwater check valve. He also recognized areas for improving the timeliness and quality of the operability determination.
Radiological Controls in response to a medical emergency drill, plant staff dealt compe ;ntly with the postulated event, and proficiently controlled the spread of simulated contamination.
Maintenancs ana Surveillancs hant staff demonstrated good control of repair and test activities. An electrician insured a high degree of quality during Motor Operated Valve maintenance, and an auxiliary operator properly completed and documented surveillance of an emergency feedwater pump. Maine Yankee's control of scaffolding it,sured that scaffolding did not adversely affect safety related equipment.
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Srsyrity The security staff efficiently controlled access for ambulans
- rsonnel during the Medical Emergency drill.
Engineering and Technical Suonort In responding to a long history of problems with the
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Containment Control Air system, Mair.c Yankee initiated a systematic approach to improving system reliability. Corporate Engineering Department personnel provided significant-assistance during maintenance on a safety related MOV.
Safely _ Assessment and Ouality Verification Inspectors closed an open item associated with.
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mideop operation.
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9212160081 92120e., "
PDR ADOCK 05000309 G
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TABLE OF CONTENTS OV E R V I EW '.............................
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TA B LE OF CONTENTS..................................
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OPERATIONS l'
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l.1 Operability Determination for Feedwater Valve FW-331...........
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RADIOLOGICAL CONTROLS................
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2.1 Radiological Controls for the Medical Emergency Drill..
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M AINTENANCE and SURVEILLANCE
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3.1 Motor Operated Valve (MOV) Maintenance.................
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3.2 Emergency Feedwater Pump (P-25C) Surveillance.....
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3.3 Control of Scaffolding.........
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SECURITY-4
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4.1 Security Force Participation in Medical E.nergency Drill.
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4.2 (Closed) Violation 92-014-001, Inattention to Duty
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ENGINEERING and TECHNICAL SUPPORT.
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5.1 Comainment Control Air......
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5.2 Engineering involvement in MOV Maintenance 6-
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SAFETY ASSESSMENT and QUALITV VERIFICATION
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6.1-(Closed) Open Item 91-17-03, Venting of the Reactor Coclant System During Mid-Loop Operation,,
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A DMINISTRATIVE,................,,.
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7.1 Persons Contacted 3.....
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7.2 Summary of FOlity Activities
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7.3 Interface with the State of Maine
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7.4 Exit Meeting
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-I DETAILS
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1.
O PI'R ATIONS l
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On a daily basis, inspectors verified adequate staffing, appropriate access control, adherence l
to procedures and Limiting Conditions for Operation, operability of protective systems, status
of control room annunciators, status of radiation monitors, emergency power source operability, and operability of the Safety Parameter Display System (SPDS). Each week, the o
inspectors veriGed operability of selected Engineered Safety Features (ESF) trains and I
assessed the condition of the plant equipment, radiological con /ols, security and safety. The
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o inspectors performed biweekly review of a safety-related tagout, chemistry sample results, shift turnovers, portions of the containment isolation valve lineup, the posting of notices to j
workers and operability of selected ESF trains. The inspectors evaluated plant housekeeping
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and cleanliness.
1.1 Operability Determination for Feedwater Valve FW-33J
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On October 27, during a routine containment inspection, plant staff found FW-331, a
fen! water check valve, leaking steam through the insulation moped around the valve The statf initiated Work Order (WO) 92-6107 to address the leakage. The Plant Shift Supervisor (PSS) tecognized that FW-331 leakage was a potential containment integrity concern as it is a containment insolation valve, l
The containment boundary, for the fe:dwater system, is formed by the feedwater hnes made l
centainment acting as a membrane, and feedwater check valves in each of the feedwater lines (FW-131, 231, and 331). The check valves provide a means of isolating the feedwater lines from the containment atmosphere. In the event that any er the check valves became inoperable, Technical Specification (TS) 3.11 requires Maine Yankee to restore the l
inoperable valve to operable status or isolate the penetration within 'four hours. Technical l
Specifiuenn 3.3. A.2 requires operation of three coolant pumps with their steam generators capable or performing their heat *.ransfer function whenever the reactor is critical. Therefore, an inoperable feedwater containment isolation check valve would require operators to isolate l
feedwater to a steam generator and to begin a plant shut down within four hours.
l The PSS consulted with the Plant Engineering Department (PED) to develop a basis for an operability determination. The PED staff concluded that the valve cemained operable, based L
on a history of leakage for similar valves. Six identical valves. had developed leaks on eight.-
l previous occasions. Each leak path had been through bolted, gasketed flanges in the valve body. Engineering reasoned that the leak in FW-331 probably came from gasket leakage at
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the body-to bonnet or hinge pin cover flange. Based on engineering input, the PSS L
considered FW-331 operable.
On October 28, however, when questioned by the inapector, the PSS was somewhat l
uncomfortable with the engineering basis, since it depended on an assumption of the source l
of the leak. The PSS realized that the source of leakage night have been a weld failure L
upstream of the valve seat, rendering the membrane inoperable. Later that day, in response l
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to the WO initiated on October 27, plant staff removed the insulation and confirmed that a gasketed flange was the source of the leak. The PSS also documented that, based on -
conservative estimation of feedwater leakage, the leakage from containment through FW 331, under accident conditions, would not exceed leakage assumed in the accident analysis.
The PSS concluded, in-retrospcci that he could have improved the timelinessi ad quality of -
the operability determination by immediately requesting that maintenance personnel remove the insulation to identify the source of the leakage.
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IRADIGI,0GICAL CONTitOLS
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inspectors routinely reviewed radiological controls including Organization and Management,-
extcrnal radiation exposure control and contamination control. The inspectors also monitored standard industry radiological work practices, and conformance to radiological control proceduies and 10 CFR 20 requirements.
2.1 Itadiological Controls for the Medical Emergency Drill On No < ember 5, Maine Yankee conducted a medical emergency drill. The drill scenatio involved -injuries to a worker in the radiologically controlled area (RCA). Emergency response personnel administered emergency first aid, and effectively implemented procedures to minimize spread of contamination from the RCA. Operations, radiological controls-technician.e, and security staff responded to the simulated emergency. Drill observers included supervisors from several departments. The response team dealt competently with the postulated event, and demonstrated proqciency in emergency medical and contamination
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MAINTENANCE and SUltVEILLANCE The inspectors observed and reviewed maintenance and problem investigation activities to verify complian.;e with regulatioas, administrative and maintenance procedures, codes and standards, proper QA/QC involvement, safety tag use, equipment alignment, jumper use, personnel qualifications, radiological controls for _ worker protection, retest requirements, and repouability per Technical Specifications.
3.1 Motor Operated Valve (MOV) Maintenance
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On November 4, an electrician replaced the limit switch rotors in the motor operator for high'
pressure safety injection valve HSI-M-5L The electrician used work order (WO) 9MO51,-to
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control the switch replacement. Although operators initiated the WO toxorrect faulty non-
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safety related position indication in the control room, replacement of the limit switch totors
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also affected safety 4 elated valve functions. Plant staff closed and dectrically isolated the
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talve prior to beginning the maintenance activity, ard appropriately entered the action y
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statements of Technical Specifications 3.B and 3.C.2. The electrician replaced the rotors in the motor operator actuator, and adjusted the limit switches using procedure 5-18-1, Limitorque Limit and Torque Switch Adjustment and Checkout, revision 8.
The electrician carefully adhered to the mai".tenance instructions contained in the work order technical instructions and procedures. In several instances, he stopped work to obtain clarification of procedure steps, and in one instance initiated a procedure change to correct an inaccuracy in the procedure for initial limit switch adjustment. The electrician carefully
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documented completion of the maintenance activity, paying particular attention to approp :te use of "Not applicab'a in compiming the procedures. He expended extra effort in ensuring i
quality in the activity, beyond tL cequirements of the procedure, to ensure proper
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de-tern.ination and re-termination of the limit switch electrical leads.
The electrician's efforts to ensure high quality maintenance of a safety related component
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F demons' rated strong motivation to insure a high quality maintenance activity, in addition, the electrician's concerted effort to use and adhere to procedures indicates improved performaace in tlus regard.
3.2 Emergency Feertwatcc Pump (P-25C) Surveillance On November 2, plant staff performed the monthly surveillance of P-25C as required by Technical Specification 4.6.B. The plant staff performed the test as required by procedure 3-1-5.4, Emergency Feed Pump P-25C Test, resision 1, with acceptab'e results,
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demonstrating operability of the emergency feedwater (EFW) gump and the associated
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auxiliary shutdown panel EFW controls.
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After completion of the surveillance, the inspectors independently verified that operators correctly restored EFW alignment.for normal operation. In addition. the inspectors reviewed
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the completed procedure to verify that it adequately ccurolled the activity, and that operators adhered to the procedure and properly documented performance of the test.
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3.3 Control of Scaffolding
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Maintenance staff instahed scaffolding to faciiitate repair or the FW-331 leak. Mainicnance personnel used procedure 24-103-l, Scaffolding Safety, revision 2, to control the scaffolding y
installation. The inspector reviewed the procedure to insure that Maine Yankee had adequate controls in place to prevent an adverse impact ou plant or personnel safety from the installation of scaffolding. The procedure requires that plant staff secure stationary scaffolding to a building or structure at intervals not to exceed 30 feet horizontally and 26 feet vertically to prevent movement or tipping, requires Plant Engineering Department (PED)
approvai prior to attaching scaffolds to any system or equipment. and that PED conduct a seismic evaluation prior to building scaffo!ds on or around safety related equipment.
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Maine Yankee uses the Work Order (WO) process to implement procedure 24103-1 when a maintenance activity requires construction of scaffolding. The mechanical maintenance -
section head indicated that maintenance personnel have responsibility to notify PED when installing scaffolding on or around safety related equipment. The inspector noted, however, that responsible maintenance personnel may not have training to enable them to recognize safety related equipment. The maintenance department sation head mplemented a.
temporary change to the WO process to insure that PED evaluates all scaffolding instruction until a permanent measure can be implemented to address the weakness in ' control of scaffolding.
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The Plant Engineering Department aggressively pursues evaluation of scaffolding, frequently initiating communication with maintenance personnel. The maintenance staff routinely implements measures to present movement or tipping of stationary scaffolding regardless of.
its proximity to safety related equipment. Although the scaffolding control process had a' few minor areas for improvement, conservative implementation of the process insured that installed scaffolding did not adversely impact safety related equipment.
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SECURITY The inspectors veri 6ed that security conditions met regulatory requirements, the requirements of the physical security plan, and complied with approved procedures. The checks included security staf6ng, protected and vital are: Sarricrs, vehicle searches and personnel identification, access controi, badging, and compensatory measures when required. No
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discrepancies were identified.
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4.1 Security Force Participation in Medical Emergency Drill As discussed in section 2.1, above, on November 5, Maine Yankee conducted a medical emergency drill. The scenario called for transportation of a contaminated worker offsite for treatment at medical facility. Following the requirements of security orocedures, the security
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staff admitted the ambulance and medical personnel into the turbine hall'to retrieve the plant
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worker with simulated injuries. Security staff ef6ciently permitted ent_ry to the plant while
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maintaining the security requirements. The security shift supervisor oversaw the evolution and effectively directed the response of guard force personnel, and senior security management monitored the effectiveness of the guard force.
4.2 (Closed) Violation 92-014-001, Inattention to Duty The inspector observed a Naine Yankee security of6cer inattentive to duty at his post during.
deep back shift inspection on August 28,1992. Maine Yankee immediately replaced the officer and placed the officer on administrative leave pending the outcome of an investigation. Based on the investigation, Maine Yankee concluded that the inattentiveness
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was an isolated problem associated with the officer's general performance. No other
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-instances of inattentiveness have been noted, and Maine Yankee had adequate measures in place to mitigate the effects of fatigue on the security staff. As a result of the officer's-performance problems, Mainc Yankee terminated his employment.
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Maine Yankee discussed the occurrence with the entire security force and reiterated the severity if this siteation and the seriousness of being inattentive to duty.
The inspector concluded that Maine Yankee took appropriate immediate and long term correcti"e actions. This item is closed.
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ENGINEERING nnd TECIINICAL SUPPORT
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5.1 Contninment Control Air The containment control air (CCA) system consists of two independe,it trains of reciprocating air compressors, receiver tanks, aftercoalers, 61ters, and refrigerant type dryers located inside containment. These components supply 100 psi air to independent headers serving air loads including blowdown trip valves, duct dampers, letdown control valves, and reactor coolant pump motor air cooler primary component cooling trip valves. Maine Yankee has
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experienced numerous difficulties with the CCA system since initial plant startup. Loss of containment control air, with no operator actior., would result in a plant trip on high pressuriter pressure, due to isolation of the letdown control valves, and might eventually-result in damage to the reactor coolant pump motors and seals, leading to a loss of coolant l
acident. Loss of CCA with operator action requires immediate operator response to restore L
air pressure. On many occasions, failure of the standby compressor to restore pressure reqtared emergency cortainment entry. Inability to start the standby compressor or restart the tripped compressor can be mitigated by opening normally closed containms aclatis *i valves to cross-connect the service air header, outside containment, with the CCA syaem.
However, opening the containment isolation valves requires entry into the containment integrity Technical Specification Limiting Condition of Operation, and would require a plant i shutdown within four hours, if the isolation valves could not be re closed sooner.
Recently, plant management initiated a coordinated effort to wdyze CCA nerformance and improve reliability. Plant htaff completed a rigorous analysis of the history of problems with the CCA system. The analysis concluded that contaminants in the air system have interfered with discharge valves, unloading suction valves, pilot valves, ad small instrument lines.
The analysis found that contaminants accumulate in the receivers, then migrate Lack to the compressors where they interfere with suction and discharge valve assemblies. In addition, plugged or stuck open float pilot valves caused moisture trap malfunctions.
The analysis recommended removing all sources of contaminants by upgrading equipment in the air flow path. Specifically, the analysis recommended installing replacement air receivers with manways to permit preventive maintenance. In addition, the analysis recommended
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improved monitoring of v :ompressor performance, increased frequency for preventive
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maintenance, and proposed several other possible courses of long term m. tive action. - At-the conclusion of the inspection report, the Plant Engineering Departn :m vas dueloping a close out plan for management consideration.
The systematic approach to resolution of e long history of poor containment control air system performance represents an improved focus on long terni reliability by the.,meering and maintenance organizations.
5.2 Engineering involvement la MOV Maintenance.
During the MOV maintenance, described in section 3.1, above, Corporate Engineering Department (CED) personnel observed and contributed to the maimenance activity. The CED enginects supplied clarincation of limit s'vitch adjustments, and assisted the electrician in verifying that electrical leads were properly re-terminated. In one instance, however, a CED engineer proposed to change a limit switch setting specification by making a change to the speciScation sheet during the,naintenance activity. When the inspector noted that a technical evaluation justified the limit switch settings, the engiacer stopped the maintenance activity, revised the technical evaluation, and obtained the necessary review and approval.
Althrigh the engineer initially overlooked the required review for the setting sheet change, overall, the CED personnei provided significant assistance to maintenance in restoring -
HSI-M-51 to reliable condition.
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SAFETY ASSESSMENT and QUALITY VERIFICATION 6.1 (Closed) Open item 91-17-03, Venting of the Reactor Coolant System During Mid-Loop Operation in September 1991, an NRC inspector evaluated Maine Yankee's response te Generic Letter 88-17, Loss of Decay Heat Removal. The Generic Letter (GL) discussed loss of decay heat removal during non-power operation and recommended that licensees pro Je short term expcaitious actions and long term programmed enhancements t > resolve Le issue.
The inspector found that Maine Yankee had not included a provision to vent the reactor coolant syaem (RCS) in a procedure for mid-loop operation. Maine Yankee n anagement stated their intent to include a vent path requirement in the station procedure prior to the next refueling outage.
.The inspector reviewed station procedure 1-17-7, Lowering Reactor Vessel Level From (19').
to (15') for Maintenance Work, revision 8, dated April 8,- 1992. Step 7.2.21 requires that maintenance personnel remove the pressurizer manway, during reduced inventory operation,.
to insure an adequate vent path. The procedure change provided acceptable assurance that
Maine Yankee will provide an adequate RCS vent path during reduced inventory operation.
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ADMINISTRATIVE 7.1 Persons Contacted During this report period, interviews and discussions weie conducted with various licensee personnel, including plant operators, maintenance technicians and the licensee's management staff.
7.2 Summary of Facility Activities Maine Yankee operated at power throughout the inspection period. On October 21 through October 23, a team of Region I inspectors observed and evaluated Maine Yankee's performance during the annual Emergency Preparedness exercise.
7.3 Interface with the State of Maine Periodically, the resident inspectors and the onsite representative of the State of Maine discussed findings and activities of their corresponding organizations. No unacceptable plant conditions were identified, 7.4 Ihit Meeting Meetings were peiiodically beld with senior facility management to discuss the inspection scope and findings. A summary of findings for the re;crt period was also discussed at the conclusion of the inspection.
During the inspection period the inspectors conducted backshift inspection on October 19,20, 21,22,27,28 and November 15 and deep backshift on October 18, 21, 24, 25, 26, 27, 28, 31, November 11, and 14.
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