IR 05000309/1987010

Insp Rept 50-309/87-10 on 870428-0610.No Violations Noted. Major Areas Inspected:Control Room,Accessible Plant Areas, Plant Operations,Radiation Protection,Physical Security,Fire Protection & Mod Installation,Maint & Surveillance

ML20216H907
Person / Time
Site:	Maine Yankee
Issue date:	06/24/1987
From:	Lester Tripp NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20216H906	List: IR 05000309/1987010 ML20216H901
References
50-309-87-10, NUDOCS 8707010650
Download: ML20216H907 (9)

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U.S. NUCLEAR REGULATORY COMMISSION 4

REGION I

Docket / Report: 50-309/87-10 License: DPR-36 Licensee: Maine Yankee At'omic Power Inspection At: Wiscasset, Maine Dates: April 28, 1987 to June 10, 1987 I Inspectors: Cornelius F. Holden, Senior Resident _ Inspector chard . Freudenberger, Resident Inspector Approved: b 4 /)

t. E. Trflp,i Chief, Reactor Projects Section 3A k' Ddte f/87'

Summary: Inspection on April 28 to June 10, 1987 (Report No. 50-309/87-10)'

' Areas Inspected: ' Routine resident inspection (403 hours0.00466 days <br />0.112 hours <br />6.66336e-4 weeks <br />1.533415e-4 months <br />) of the control room, !ac-Lcessible parts of plant structures, plant operations including refueling operations,

. radiation protection, physical security, fire protection, modification installation, !

maintenance and surveillanc Results: No violations were identified. Housekeeping standards were allowed'to slip during the outage which resulted in a major cleanup effort being necessary at the end of_the outage (Detail 3.f). A licensee initiated audit of Equipment

' Qualification resulted in a number of deficiencies being identified and corrected (Detail 6). Problems identified during the loss of current surveillance test re-quired each refueling interval were tracked and closed following successful retest

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(Detail 3.e).

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DETAILS 1.- PersonsContactef;6 Within this report period, interviews and discussions were conducted with . j various~ licensee i and the licensee' personnel, including s management staff. plant operators, maintenance technicians

' Summary of Facility Activities  !

The plant was.in a refueling outage at the start of the inspection perio l A reactor startup occurred'on June 9, 1987 and low power physics testing wa conducted. _The' reactor was subsequently shutdown on June 10 awaiting comple-tion of the turbine generator maintenanc .

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' Routine Periodic Inspections Daily Inspection During routine facility tours, the'following were checked: manning, ac-cess control, adherence to procedures and LC0's, instrumentation, recor-der traces, protective systems, control rod positions, containment pres- !

sure, control room annunciators, radiation monitors, emergency power l source operability, control room logs, shift supervisor logs, and operat- !

.ing orders. No discrepancies were identified, System Alignment Inspection Operating-confirmation was made of selected piping system v ains. Ac-cessible valve positions and status were examined. Power sucoly and j breaker' alignment was checked. Visual inspection of major coa onents was performed. Operability of instruments essential to system perform-ance was assessed. Included in this check was the operation of systems i required during the outage. The Residual Heat Removal system was re- )

viewed. No discrepancies were identifie Biweekly Inspections During plant tours, the inspector observed shift turnovers, chemistry sample results and the use of radiation work permits and Health Physics !

procedures. No discrepancies were identifie i Plant Maintenance The inspector observed and reviewed maintenance and problem investigation activities to verify compliance with regulations, administrative and maintenance procedures, codes and standards, proper QA/QC involvement, j safety tag use, equipment alignment, jumper use, personnel qualifications,

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, radiological controls for worker protection, fire protection, retest requirements, and reportability per Technical Specifications. No dis-crepancies were identified, e. , Surveillance Testing The inspector observed. parts of. tests.to assess performance in accordance with approved procedures and LC0's, test results, cemoval and restoration of ~ equipment, and deficiency review and resolutio The. inspector reviewed the procedure and results of~a test of.the recir -

culation' actuation signal (RAS) train "B" performed on May 17, 1987 as part of the corrective' actions'to an inadvertent initiation of the RAS

"B" train on April 14. (IR 87-03) The test was performed satisfactorily

.and all systems responded as required. The inspector had no further

. question Additionally,-one major refueling interval surve111ance was observe The loss of alternating current (A/C) procedure was chosen for this re-view. The inspector conducted a review of the procedures involved and witnessed the test. The purpose'of this surveillance'is to test the Emergency Diesel Generator, the degraded grid undervoltage protection scheme and the testing of the emergency core cooling system pumps and

, valve The test.is conducted by deenergizing one half of the incoming power supply at a time. Simultaneously, the control switches for Safety Injection Actuation Signal and Containment Spray Actuation Signal are placed in the auto position. This causes the Emergency Diesel to auto start on bus undervoltage and close the related output breaker onto~the emergency bu Load sequencing returns the power to the ECCS pumps and the ECCS valves are actuated to their emergency positio Several problems were noted during the."B" train testing. The Emergency Diesel Generator.(DG-1B) started as required but the output breaker did not close onto the emergency bus until 16 seconds after the loss of voltage. The limit for energization of the bus is 10 seconds. Addi-tionally, one of the service water pumps did not deenergize-and one air compressor did not deenergize as required by the sequencing schem '

The instantaneous grid undervoltage relay closed at a voltage higher than specifie The licensee conducted an extensive review of the failures of this sur-veillance test. Included in this review were several other abnormalities that did not constitute a test failur Two technical representatives were called in to assist in troubleshooting the diesel engine. Plant personnel identified a relay (27dp6a) that had failed and replaced i ;

This relay was common to both the service water and the air compressor '

sequencing scheme and was the probable cause of the sequencing problems noted with the service water pumps and air compresso !

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The failure of the diesel to start and load within the required ten q seconds was traced to a magnetic start valve. This valve failed in mid I position which restricted the air flow to the diesel air start motor i This resulted in two problem The first was the inability of the_ start l motors to start the diesel in the required time. The second was the in- i ability of the pinion to retract from the ring gear. This resulted in I damage to the two air start motors. The magnetic start valve was found l to have debris on its seat probably as a result of cleanliness / moisture )

problems in the air start system. The licensee has started blowing down '

the accumulators once per shift to minimize moisture. Also, they in-creased the frequency for preventive maintenance on the air start system i from a frequency of once every two years to every six month j i

A modified Loss of A/C Test was performed on June 5, 1987 in order to retest portions of the diesel start and sequencing network. The diesel i started and energized the bus in 7.3 seconds which is well within the 10 second criteria. Proper sequencing of the service water pumps and air compressors was observed. The inspector had no further questions, Housekeeping During.the refueling outage normal housekeeping activities were suspended due to the heavy workload. Each of the various work areas was assigned to the work party leader to assure that the area was cleaned prior to job completion. During this refueling the system for controlling plant cleanliness did not appear to work well. An inspection of the plant on June 10, 1987 indicated a number of areas requiring better housekeepin In the absence of a good housekeeping program, a degradation in the material condition of the plant can go unnoticed. The licensee initiated an extensive program to clean the plant. This area will be reviewed in depth in future inspection . Observations of Physical Security Checks were made to determine whether security conditions met regulatory re-quirements, the physical security plan, and approved procedures. Those checks included security staffing, protected and vital area barriers, vehicle searches and personnel identification, access control, badging, and compensatory meas-ures when required. Items of concern in this area were turned over to a re-gional security specialist and are covered in Inspection Report 50-309/87-1 i Radiological Controls Radiological controls were observed on a routine basis during the reporting period. Standard industry radiological work practices, conformance to radio-logical control procedures and 10 CFR Part 20 requirements were observe Independent surveys of radiological boundaries and random surveys of nonradio-logical points throughout the facility were taken by the inspecto ,

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, l The licensee identified an Incore Instrument (ICI) that_would not properly seat in its housing.following refueling of the re n tor. After numerous'at-

. tempts to. install the ICI,.the decision was made to conduct a dry removal

'(the normal method of removal is to pull the ICI into the refueling cavity while it is flooded during the refueling).

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Assignments _were made for proce-dural development, cask design and manufacturing, and dose' projection Practice sessions were conducted and Plant Operations Review Committee (PORC)

reviewed and approved the procedur !

,The inspector witnessed the practice sessions and the transfer of the ICI on May 24,-1987.' Initial.. source projections used for calculating personnel'ex-posures was 5000 Rem on contac As measured readings were 1400 Re ~

The evolution was well rehearsed and the actual transfer went smoothly. . The ICI was withdrawn into a special' cask and transferred to a storage bunker. Final-transfer of the ICI to the spent fuel-pool will be conducted when conditions permit. The inspector had no further question . Equipment Qualification i

During the current outage.the licensee conducted an inspection of the elec-trical systems. subject to the Equipment Qualification rule. The purpose of the inspection was to identify any abnormalities in the qualification of the equipment. This was the fourth audit conducted in this area. _During the refueling the licensee took advantage of the access provided to all environ -

mentally qualified: equipment to conduct this inspection. Several problem

' areas were identifie The licensee found_two splices that appeared either to have been worn or have i less than the minimum bend radius and elected to replace the splice joints 4 involved with environmentally qualified splices. Following these repairs, the licensee conducted a detailed inspection of these splice joints. The ends of..these splices did not appear to provide a tight seal. The splice; joints- >

were butt connected and encased with heat shrink tubing. The licensee re-- i viewed the manufacturers instructions for selection of the proper diameter tubin The manufacturer recommended a splice joint that was different from the : installation that the licensee was utilizin .

A review was made of the installation instructions used for the initial installatio These instruc-

.tions referenced the manufacturers chart which dictated, among other criteria, the correlation between wire gauge and tubing size. This information was correctly incorporated into licensee work packages. The licensee determined that'certain instruments use kapton wire insulation which is smaller in diameter than other insulation for wires of the same wire gauge. These _'

splices were originally installed in 198 Current insulation instructions provide an application guide which lists the maximum and minimum diameter for each tubing siz For tube WCSF-070-N, which is-the tubing used for the original installation, the saximum and minimum diameters are .07 and .14 inches. The outside diameter (including the kapton insulation) for 16 (AWG) gauge wire is .069 plus or minus .003 and for 18 !

(AWG) gauge wire it is .058 plus or minus .00 ,

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The licensee decided to replace all splice ~ connections using current.manufac- l turers' instructions and current test data to maintain the certification of the splices.. All smaller. diameter wire was first. shimmed using WCSF-050-N tubing prior to the installation of the larger diameter tubing. The inspector witnessed portions of this repair effor ]

l The second area where the. licensee identified a discrepancy was the contain- 1-ment sump level instrument. The licensee identified two terminal strips that did not meet the equipment qualification standards. These terminal strips were determined unqualified because they did not pass a direct impingement i' tes The application in which the licensee used these terminal strips was inside a junction box located inside the cable penetration room. It is un-likely that these terminal strips would be subject to direct impingemen The licensee decided.to correct this discrepancy by splicing the wires around the terminal stri The third item identified by the Equipment Qualification inspection was four !

resistance temperature detectors (RTD's) which did not utilize qualified cabling. These four RTD's were hot leg and cold leg temperatures for loop and 3 in the Reactor Regulating System. These RTD's provide indication of natural circulation flow for post accident conditions. Previous design change packages had called for the replacement of these cables. Apparent ~iy, these '

changes were not implemente Previous system walkdown procedures were not explicit enough to require verification'of each componen The licensee in-stalled.new cabling to correct this deficienc These Equipment Qualification deficiencies are considered an Unresolved item pending further review by the NRC during an upcoming inspection of this area-(UNR 50-309/87-10-01). Overpressurization of a Steam Generator While Filling to Wet Layup On May 27, Steam Generator #1 was put into a wet layup condition using an emergency feedwater pum Approximately one hour later the root valve to the pressure transmitter for that steam generator was found to be closed. When l the transmitter was unisolated the instrument read 565 psig. Peak pressure !

was estimated to have reached approximately 750 psia. The temperature of the {

water used from the demineralized water storage tank to fill the steam genera-tor was approximately 70 F. The minimum temperature for pressurization above 230 psig is 100 F as required by Technical Specification The licensee conducted a review of this event as required by Technical Speci-fications. This investigation concluded that the proceduce involved allcwed the use of a large capacity high head pump. Water level in the steam genera-tor rises above the normal level indication so that the'enly method of deter-mining level is to observe water coming out the vent. Wie vent size chosen for this operation may have not been sufficient. The operator who was con-ducting the filling operation was distracted from observing the vent pat He had calculated that there was sufficient time for him to conduct another evolution before the level would be close to the top of the generatn t

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I The licensee also contacted the manufacturer of the steam generator. The '

manufacturer provided an analysis that showed the generator could withstand full design pressure at 70 F. The temperature of the generator on.the day of the event was in excess of 80 F. Based on this review the licensee deter- I mined'that no further review of the design'was warrante l

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Corrective actions for this event included procedural changes allowing use I of only.the smaller capacity primary water pumps capable of developing peak f l head of less than 230 psig for filling the generators above the normal level I indicating band. The' licensee's corrective actions were discussed at the

' Management Meeting (see Detail Section 9 below) and found acceptabl .- Refueling Water Storage Tank Repair As a result of the Seismic Design Margins Program an. upgrade to the anchor bolt chair supports on the Refueling Water Storage Tank (RWST) was installed during the current refueling outage. .After the new anchor bolt chairs wer . welded to the tank, ultrasonic examinations in the vicinity of the new chairs were performed. Three-(3) indications were found in the vicinity of chair-eight (8), on the outside of the tank,-which were repaired by grinding out 4 the defect and re-filling the area with weld material. The first indication was of sufficient depth that the remaining material after the defect was ground out was less than the minimum wall thickness require Two (2) more indications were found near chair two (2), one on the inside of the tank and one on the outside. The indication on the outside was repaired by the same method as the others. The indication on the inside was found to be 'an arc-strike from construction and was repaired by brushing the mark ou Since the minimum wall thickness requirements were exceeded during the repair of the RWST, it was.hydrostatically tested in accordance with ASME section XI (IWA-4000/5000) on-May 1 The hydrostatic test was witnessed by the inspector and completed satisfac-torily. However, the nuts on the anchor bolts were found to be loose. The licensee determined that the nuts were loose because they were originally tightened with the RWST empty. During the hydrostatic. test the tank was-filled to its greatest capacity. The weight of the liquid caused the tank to settle and the tension to be removed from the studs. The licensee properly tightened the nuts when the level in the tank was returned to normal operating level. The inspector had no further question l

. Management Meeting A Management Meeting was. held on June 4, 1987 in the Region I Office of the !

NRC between the NRC and Plant Management to discuss various aspects of prob-lems identified during this refueling outage. The purpose of the meeting was to determine if a common cause was at the root of the observed problems. The !

meeting was characterized by open discussion of each area and the reason for the problem. The areas discussed included; Environmental Qualification of j l

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Equipment, Overpressurization of a steam generator, the discovery of a rag l in the suction of a charging pump and the identification of a piece of an j incore instrument under the the refueling canal inside containmen . Storage of Transient Equipment The inspector reviewed the licensee's practices and methods of controlling I the storage of transient equipment in safety-related areas in accordance with l Region I Temporary Instruction (RI-87-03, Revision 0). )

The licensee has three programs in place which, together control the storage of equipment throughout the plant. These programs are the containment storage plan, the management weekly area inspection program and the " Cleaning Assign-ment" procedur The containment storage plan identifies which equipment may be stored in the l

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containment building during plant operations and lists requirements and re- ]

strictions that apply. The-plan also designates which individuals are re- i sponsible for the coordination and implementation of the requirements of the j pla .

The management weekly area inspection program establishes guidelines to de-velop a plant inspection program addressing material condition, industrial safety, cleanliness / housekeeping, radiological protection, and fire protectio During plant operation, on a weekly basis, each member of the plant management is assigned an inspection area. The areas to be inspected cover all areas inside the plant except the containment building. Examples of unsatisfactory conditions provided in the inspection procedure include, among others; equip-ment stored in other than designated area; scaffolding, improperly installed or secured; compressed gas bottles - unsecured, caps missing, improper en- l vironment, or unlabeled. All deficiencies noted are assigned to the respons- )

ible department for resolution and checked on subsequent inspection l The third method the licensee uses during plant operation to control plant cleanliness and proper storage of equipment is procedure 1-300-9 " Cleaning Assignments". This procedure assigns specific areas to operations department shift personnel as cleaning stations. As part of the responsibility of being assigned a cleaning station, the shift personnel are to ensure that materials stored in their area are in locations designated for that purpose. To estab-lish new areas designated for storage of equipment requires Plant Shift Supervisor approval. If there is any question of the permissibility of a proposed Storage, the Facilities Section Head is required to be contacted to make determinations as to the suitability of a particular storag Based on plant tours by the inspector prior to the refueling outage, where equipment is stored in safety-related areas, proper restraints were in place to ensure that the effects on the installed equipment during design basis events will be minimized. Therefore the managerial programs and procedures in place appear to be adequate to control the storage of transient equipment in safety related area _ _______ ______ ________ _

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e 11. Exit Interview Meetings were periodically held with senior facility management to discuss I the' inspection scope and. findings. A summary of. findings for the report period was also discussed at the conclusion of the inspection.

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