IR 05000309/1985009

Corrected Insp Rept 50-309/85-09 on 850414-0525.No Violations Noted.Two Problems Noted Re Containment Integrity,Including Failure to Control Vent & Drain Valves for Coolers.Sys Interface Maint Knowledge Lacking

ML20129B452
Person / Time
Site:	Maine Yankee
Issue date:	06/18/1985
From:	Elsasser T, Ferlic K, Holden C, Robertson J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20129B443	List: IR 05000309/1985009 ML20129B438
References
50-309-85-09, 50-309-85-9, NUDOCS 8507150519
Download: ML20129B452 (10)

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U. S. NUCLEAR REGULATORY COMMISSION

REGION I

Docket / Report: 50-309/85-09 License: DPR-36 Licensee: Maine Yankee Atomic Power Company Inspection At: Wiscasset, Maine Dates: April 14 to May 25, 1985 Inspectors: -R sh P IblA / ////n-62 C. Holden, Senior Resident Inspector date A4 9 rze e//r/s K. Ferlic, Project Engineer date

\%GN (a/t4/6 gon,' tor Engineer date Approved: -

1. N" ~ $///[#5 T. C. Elsa ( Chief, Reactor Projects Section 3C 'date ,

Summary: Inspection Report 50-309/85-09 Areas Inspected: Routine resident inspection (147 hours0.0017 days <br />0.0408 hours <br />2.430556e-4 weeks <br />5.59335e-5 months <br />) of the control room, ac-cessible parts of plant structures, plant operations, radiation protection, physi-cal security, fire protection, plant operating records, maintenance, surveillance, radioactive effluent sampling program, open items, and reports to the NRC. No violations were foun Results: Two administrative problems were noted concerning containment integrit One was a licensee identified violation and the other involved the failure to ad-ministratively control vent and drain valves for containment cooler Operator knowledge of some system interfaces during maintenance was lackin Improvements I in the shift turnover practices appear to provide better continuity between shifts.

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0507150519 850708 PDR ADOCK 05000309 G PDR

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DETAILS Persons Contacted Within this report period, interviews and discussions were conducted with various licensee p~ersonnel, including reactor operators, maintenance and surveillance technicians and the licensee's management staf . Summary of Facility Activities Details of the following are included in the body of the repor On April 14, 1985, 120 volt AC bus 3 was lost due to a failure of the con-nector at the outlet of the inverter. The bus was cross connected with vital bus 2 while.the connector was replaced. Vital bus 3 was returned to the in-verter power supply on April 1 n April 24, 1985 at 2:04 p.m., Maine Yankee Nuclear Power surpassed a life-time production goal of 60 billion kilowatt-hour The plant operated at 100 percent power from the beginning of the inspection period until April 30, 1985, when a load reduction was initiated to replace the main generator exciter fuses. A plant' trip occurred while returning the plant to full power later that same day. The trip was caused by a technician who inadvertently grounded contacts in the low suction pressure trip circuit of the turbine driven feed pump-while conducting maintenance. The reactor was returned to full power on May i 09 May 4, 1985, the licensee reduced power and shutdown the plant for main-u.ance. Replacement of the diodes for the main generator exciter was the major maintenance item accomplished. The reactor was taken critical on May 6 and returned to full power on May 8 following delays for chloride cleanup of the steam generator On May 10, 1985, plant power was reduced to place the electric driven feed pumps in service. Plant power was returned to 97 percent (the maximum power l'evel with electric driven feed pumps) for the remainder of the inspection period in order to perform maintenance on the steam driven feed pum . Licensee Action on Previous Inspection Findings (Update) Followup item (IFI 309/85-06-02) Spacing between new fuel rack tube The licensee determined that the spacing needed between each of the spent fuel rack tubes to provide the necessary flux trap for 3.3 weight percent fuel was

.692 inches of water. In order to achieve this spacing on the new phase two racks, holes were drilled in each face of the tubes to remove the air between the boral and the tube fac The inspector will continue to follow this item.

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4. Review of Plant Operations The inspector reviewed plant operation th ough direct observation throughout the reporting perio Except as noted, conditions were found to be in com-pliance with the following licensee documents:

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Maine Yankee Technical Specifications

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Maine Yankee Technical Data Book

-- Maine Yankee Fire Protection Program

-- Maine Yankee Radiation Protection Program

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Maine Yankee Tagging Rules

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Administrative and Operating Procedures Instrumentation Control room process instruments were observed for correlation between channels and for conformance with Technical Specification requirement No unacceptable conditions in process instrumentation were identifie Annunciator Alarms The inspector observed various alarm conditions which had been received and acknowledged. These conditions were discussed with shift personnel who were knowledgeable of the alarms and actions required. Operator re-sponse was verified to be in accordance with procedure 2-100-1,' Response to Panalarms, Revision During plant inspections, the inspector observed the condition of equip-ment associated with various alarms. No unacceptable conditions were identifie Shift Manning The operating shifts were observed to be staffed to meet the operating requirements of Technical Specifications, Section 5, both to the number and type of licenses. Control room and shift manning were observed to be in conformance with 10 CFR 50.5 Radiation Protection Controls Radiation Protection control areas were inspected. Radiation Work Per-mits in use were reviewed, and compliance with those documents, as to protective clothing and required monitoring instruments, was inspected.

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Proper posting and control of radiation and high radiation areas was re-I

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viewed in addition to verifying requirements for wearing appropriate personnel monitoring device There were no unacceptable conditions identifie The licensee has initiated a program to upgrade the storage and cleanli-ness of the plant. Each department contributed to the workforce used to identify, sort, store and dispose of plant equipment that had accumulate Various crews were assigned to specific areas of the plant for cleaning and decontamination. The result has been a reduction in the radiation levels at a. number of locations throughout the plan Plant Housekeeping Controls Storage of . material and components was observed with respect to preven-tion of fire and safety hazards. Plant housekeeping was evaluated with respect to controlling the spread of surface and airborne contaminatio The inspector conducted a tour of the containment building and noted a number of articles that had the potential of obstructing recirculation flow from the containment sump. These finding were discussed with plant management. Subsequently, the licensee removed the potential obstructions and conducted a cleanup of the area. The inspector had no further com-ments, Fire Protection / Prevention The inspector examined the condition of selected pieces of fire fighting equipment. Combustible materials were being controlled and were not found near vital areas. Selected cable penetrations were examined and fire barriers were found intact. Cable trays were clear of debris. No abnormal conditions were identifie Control of Equipment During plant inspections, selected equipment under safety tag control was examine Equipment conditions were consistent with information in plant control log Plant Operations Review Committee (PORC)

The inspector attended Plant Operations Review Committee (PORC) meeting on April 25, 1985. Technical specification 5.5 requirements for required member attendance were verified. The meeting agenda included procedural

. changes, proposed changes to the Technical Specifications and field changes to design change packages. The meeting was characterized by frank discussions and questioning of the proposed changes. In particular, con-sideration was given to assure clarity and consistency among procedures, items for which adequate review time was not available were postponed to allow committee members time to review and comment. Dissenting

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opinions were encouraged. The inspector had no further comments.

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i. Control Room Atmosphere During this report period, in addition to the normal review of the con-trol room, the inspector reviewed the manner in which the operators car-ried out their daily duties. Recent changes to the Maine Yankee Dress Code have set new standards for operator appearance which has contributed to the professional atmosphere of the control room. Additionally, the licensee has instituted a formal review period prior to actual shift turnover to enhance the information flow between shifts. Each oncoming Plant Shift Supervisor and Shift Operating Supervisor reviews plant con-ditions and then conducts a brief of the oncoming crew. These briefings review plant problems and anticipated evolutions for the shift. Each member of the oncoming shift then conducts an on station turnover with the off going cre j. Loss of 120 Volt Vital Bus 3 On April 14, 1985, while at 100 percent power, the main control board annunciator for channel C Reactor Protective System (RPS) alarmed due to power being lost from the 120 volt AC vital bus 3. Bus 3 was cross-tied to vital bus 2. Further investigation into the failure indicated that the cable connector at the outlet of the inverter had overheated and failed causing loss of the bu The license,e obtained spare parts and repaired the connector. Vital bus 3 was returned to service on April 16. The inspector had no further question k. Steam Driven Feed Pump On May 10, 1985, an increase in the vibration reading for the Steam Driven Feed pump (P-2C) was noticed. The pump was removed from service and the two electric driven feed pumps were placed in service. Investi-gation into the cause of the high vibration in P-2C revealed a piece of a stud and nut had entered the impeller area and were.the source of the vibration. The impeller and pump shaft were replaced and the pump was balance The licensee conducted a search for the source of the stud. One of the heater drain pumps was inspected since the stages of these multistage pumps are bolted together. While inspecting the "B" heater drain pump the remainder of the stud was found. All interstage fasteners were re-torqued and the pump was returned to service. The "A" heater drain pump was removed from service and checked but no deficiencies were note No violations were identifie m

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1. Troubleshooting Loop 1 Temperature Detector On May 22, 1985, the plant conducted a routine entry into containmen One of the maintenance items conducted during this entry was the troubleshooting of Loop 1 Resistance Temperature Detector (RTD) for the cold leg temperature (T cold). The plant had noticed a difference between the three T cold Loop instruments and was investigating the problem. The maintenance involved pulling the penetration cable connector inside con-tainment and measuring the resistance from the connector to the RTD. The inspector observed the maintenance activities inside containment and the quality control coverage that was provided. No problems were identifie The inspector returned to the control room after exiting containment and observed the precautions the control room had taken prior to removal of the penetration connector. All oypass keys were installed in the Reactor Protective System (RPS) for channel A. Train B of the Auxiliary Feedwater Start circuit (AFWS) was also.in test. When questioned, the operators were unsure of the exact interaction of the AFWS with the loop 1 RTD work but knew that both precautions were required to support the RTD trouble-shooting. Further investigation revealed that a steam generator level instrument was also included in the connector that was being pulled to check loop 1 RTD. This level instrument fed the train B of the AFW Inoperability of this level instrument necessitated placing train B in test. The inspector reviewed the Technical Specification requirements for operability of these instruments. No violations were note The inspector expressed the concern to plant management that the opera-tors need detailed knowledge of the plant instrumentation that is affected during maintenanc In this case, the operators were aware that the AFWS system would be affected because the I&C section had briefed them prior to beginning the maintenance. Additionally, these limitations were ad-dressed on the repair order. Because these controls were in place, the operators were aware that some of the capabilities of the AFWS would be temporarily lost. However, as explained above, when questioned as to the exact nature of the system interaction, the operators were not sure of the status of this syste The inspector had no further comments, m. Component Cooling Valves in Containment On May 8, 1985, the licensee identified 52 vent and drain valves in the Primary Component Cooling (PCC) system that were not on the control drawings. As a result, these valves were not being administratively con-trolled by the procedure covering containment integrity. The valves are on the portions of the PCC system that services the reactor containment air recirculation cooler, containment penetration coolers and the return line from the Control Element Assembly (CEA) drive mechanism air coole _

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All but one of the valves are located inside containment. The purpose of these valves is to assist in the draining or venting of the contain-ment cooler Each of the subject valves was verified in the closed position. There were no indications that these valves had been opened based upon the leakage rate of PCC and the lack of any indications of leakage around the cooler The licensee conducted an inspection of the various coolers inside of containment in order to identify any other valves which were not on the plant controlled drawings. The valves in question were labeled, lack wired closed and placed on the containment integrity valve lis The inspector had no further comments, Maintenance Outage The plant conducted a maintenance outage from May 4 to May 6. Two of the nine diodes for the main generator had failed routine surveillance check Based on discussions with the manufacturer, the licensee decided to re-place all nine diodes. A variety of additional maintenance items were accomplished during the outag Plant Trip On April 30, 1985, during maintenance on the steam driven feed pump (P-2C) low suction pressure trip delay circuit, the plant tripped from ap-proximately 95 percent power. All systems functioned normally. Investi-gation revealed that the technician performing the maintenance had grounded a pair of contacts in the low suction pressure circuit and caused pump P-2C to trip. The turbine trips automatically on a loss of pump P-2C and the reactor tripped due to loss of the turbine. The reactor was taken critical at 5:45 a.m. on May 1 and returned to 100 percent powe . Observations of Physical Security The resident inspector made observations, witnessed and/or verified, during regular and backshift hours, that selected aspects of the security plan were in accordance with the regulatory requirements, physical security plan and approved procedures as noted below:

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Maine Yankee Plan, dated October 1979

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15-1, Security Procedures, Revision 11

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15-12 Emergency Contingency Procedures, Revision 1 o

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Observations and personnel interviews indicated that there was sufficient staffing of all three shifts. Selected barriers in the protected area, access control area, and the vital area were observed and random monitoring of the isolation zone was performed. Observations of vehicle searches were mad Observations of badging, escorting and communications were made. The inspector held discussions with plant management concerning the method of providing access control to portions of the protected area during maintenanc No deficiencies were identifie . Plant Maintenance The inspector observed and reviewed maintenance and problem investigation activities to verify compliance with regulations, administrative and mainten-ance procedures, codes and standards, proper QA/QC involvement, safety tag use, equipment alignment, jumper use, personnel qualifications, radiological controls for worker protection, fire protection, retest requirements, and re-portability per Technical Specifications. The following activities were in-cluded: Troubleshooting of the Loop 1 RTD instrument and weld repair of the Emergency Diesel generator air filter support No deficiencies were identifie . Surveillance Testing The inspector observed parts of tests to assess performance in accordance with approved procedures and LCO's, test results, removal and restoration of equipment, and deficiency review and resolution. The timed stroke testing of safeguards valves was reviewed. Test results indicated that LM-A-57, the automatic isolation valve for a variety ~of containment pressure instruments, failed to meet the acceptance criteria. Analysis indicated the valve operated correctly but the indication in the control room was incorrect. A discrepancy report was issued to initiate corrective action. Adjustments to the valve limit switch corrected the indication problem. The inspector had no further question . Review of a Licensee Identified Violation On April 24, 1985, the air regulator filter on BD-T-22 was to be replace BD-T-22 is the containment isolation valve in the blowdown line from Steam Generator No 2. In order to replace the regulator filter, the valve was to be shut and the air to the regulator secured. This process was to take ap-proximately thirty minutes. At 10:00 a.m. BD-T-22 was shut and deactivated by securing the air to the regulator. During reassembly of the regulator a problem was encountered and BD-T-22 was not reactivated until 3:11 p.m. , ap-proximately 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> later. Technical Specification 3.11 states within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> an inoperable containment isolation valve must be returned to service or the affected penetration isolated by use of at least one manual, remotely operated or deactivated automatic isolation valve secured (tagged) in the closed posi-tion or by use of a blind flange. The penetration was isolated by shutting

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BD-T-22, the deactivated automatic isolation valve, but it was not tagge This event was reported to the NRC inspector on site and is a license identi-fied violation which meets the criteria of NRC policy for not issuing a vio-latio Inspector review of the circumstances indicated the valve, BD-T-22, was not tagged when deactivated because it had not been identified as a containment isolation valve with Technical Specification limitations on the discrepancy report (No. 1426) issued to replace the air regulator filte This oversite appeared to be due, in part, to the issuance of an earlier discrepancy report (No 1401) for inspection of the air supply filters on 450 air operated safety and non-safety related valves. On this earlier discrepancy report (No. 1401),

the 450 valves were identified generically as containing Technical Specifica-tion valves. Individual safety related valves were not identified. The Shift Operating Supervisor or Plant Shift Supervisor was left with the responsibil-ity for determining the classification (safety /non-safety) for each of the valves. A priority for changing the air filters was established based on the valves ability to degrade a safety function or interrupt plant operations if the filters clogge The licensee indicated that the violation was caused by the failure of opera-tions personnel to properly identify the tagging requirements for the valv Management also felt the issuance of the discrepancy report with 450 safety and non-safety valves contributed, if not, caused the erro Corrective ac-tion completed by the licensee include: (1) the immediate separation of the safety related filters from the non-safety related filters on the discrepancy report, (2) review of the overall process for handling similar problems to ensure a generic program or procedural inadequacies do not exit, and (3) re-view of the event by plant operator The inspector had no further question . Review of Low Pressure System Interfaces In response to recent industry problems with the isolation systems between low pressure safety injection systems and high pressure safety injection sys-tems, the resident inspector conducted a review of the licensee's surveillance and maintenance programs covering those valves which isolate primary coolant from low pressure Emergency Core Cooling System (ECCS) piping and component If low pressure ECCS piping outside of containment is overpressurized and then ruptures, the cooling water it supplies will not be available for recircula-tion during an acciden Maine Yankee had received a Confirmatory Order from the NRC on April 23, 1981, which required the installation of additional check valves in the low pressure safety injection system to protect it against overpressurization. The inspec-tor verified the as-built isolation interfaces between high and low pressure piping, reviewed and evaluated the isolation valve surveillance and mainten-

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ance procedures, verified the proper application of procedures and reviewed plant specific and industry wide experience to ensure the lessons learned were incorporated into the licensee's progra ;

The interfacing systems reviewed included the High Pressure Safety Injection system (HPSI), the Low Pressure Safety Injection system (LPSI) , the Residual Heat Removal (RHR) system, and the Safety Injection Tanks (SIT). The two sys-tems that had an interface which could result in an overpressurization of low pressure systems was the interface between the HPSI and LPSI systems. Prior to cycle 7 operations, Maine Yankee installed an additional check valve in the LPSI piping and the capacity to conduct surveillance tests of these check valves. During an accident condition, this check valve is the only barrier between the high pressure and the low pressure system The discharge of the LPSI pumps is via piping designed to withstand 600 pounds of pressure. The HPSI system is designed to withstand full accident pressure of 2485 pounds. These two systems combine before entering containment. A check valve protects the low pressure system from the high pressure system. During normal operation a motor operated valve in each of the high pressure and low pressure piping provides an additional barrier between the two system The inspector reviewed the licensee's surveillance testing of these system In addition to the routine time testing of the motor operated ECCS valves, the licensee monitors the pressure in the piping between the check valve and the motor operated valve in the LPSI system to detect any leakage past the check valve. The In Service Testing program conducts leak checks and flow checks of these systems during refueling outages. The inspector reviewed the test results and the maintenance history of these pressure barrier component During the refueling in June, 1975, leakage of these barriers (check valves and motor operated valves) was detected and correcte The inspector had no further questions in this are . Exit Interview Meetings were periodically held with senior facility management to discuss the inspection scope and findings. A summary of findings was presented to the licensee at the end of the inspection.

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