IR 05000266/1993015

Insp Repts 50-266/93-15 & 50-301/93-15 on 931026-1206. Violations Noted.Major Areas Inspected:Plant Operations, Maint,Engineering,Plant Support & Corrective Actions on Previous Findings

ML20059A239
Person / Time
Site:	Point Beach
Issue date:	12/22/1993
From:	Tongue T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20059A228	List: IR 05000266/1993015 ML20059A225 ML20059A230
References
50-266-93-15, 50-301-93-15, NUDOCS 9312300066
Download: ML20059A239 (20)

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U.S. NUCLEAR REGULATORY COMMISSION P

REGION 111  !

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Report Nos. 50-266/93015(DRP); 50-301/93015(DRP)  :

r Docket Nos. 50-266; 50-301 License No. OPR-24; DPR-2 *

Licensee: Wisconsin Electric Power Company  :

231 West Michigan .i Milwaukee, WI 53201 I

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Facility Name: Point Beach Units 1 and 2 i i

Inspection At: Two Rivers, Wisconsin

Dates: October 26 through December 6, 1993 i i

inspectors: K. R. Jury J. Gadzala i J. H. Neisler f

i Accompanying Personnel: K. K. Bristow  ;

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Approved ' . ;Mwv ) @

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. T.'M. Tongue 7ActingChief Date Reactor Projects Section 3A L

Inspection Summary I i

Ln_syection from October 26 throuch December 6. 1993 i 1 Reports No. 50-266/93015(DRP): No. 50-301/93015(DRP) .

Areas inspected: Routine, unannounced inspection by resident inspectors of- ,

plant operations, maintenance, engineering, plant support, and carr::tive [

actions on previous finding Results: One violation of NRC requirements,-four unresolved items, and one .l inspector follow up item were identified. An Executive Summary follows:

Plant Op_erations

A shutdown of both units was initiated December 3 due to.both emergency diesel i generators (EDGs) being inoperable. Power had been reduced by about 8 percent ;

when the shutdown was terminated due to enforcement discretion being granted ;

by the NRC (NDED 93-3-008). The shutdown was averted and the units were returned to full power when EDG G-01 was restored to service. A violation was issued for failing to report the initiation of the shutdown (Paragraphs i and b).

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.i Unit 2 completed a scheduled 36 day refueling outage in 34 days'. The. reactor: f was only able to achieve 98.5 percent power due' to the additional- steam

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generator tube plugging performed during the outage. This plugging necessitated a technical specification (TS) change.to reduce th.e minimum L ;

< allowable flow rate (Paragraph 1.b). j t Shortly after' Unit 2 achieved criticality following the refueling outage, j control rod H2 dropped unexpectedly while changing a rod control system fuse

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(Paragraph 1.c). .. ;

q During the Unit 2 refueling outage, an 8 percent decrease in reactor vessel- -!

water level was experienced while in a reduced inventory condition  !

(Paragraph 1.d). l i

The. minimum allowable temperature for critical operations was identified as an :

unresolved item (Paragraph 1.e). ] i A routine Unit 2 containment inspection on November 23 identified that oil '!

levels for both reactor coolant pump motor upper bearings were low. The alarm I that normally indicates this condition was found disabled and is identified as l an unresolved item (Paragraph 1.f).  !

q Maintenance Good communications and work practices and a high knowledge level'were j displayed by maintenance technicians during valve operator work *

(Paragraph 2.a). I i EDG turbocharger replacement work was delayed several hours due to a . f misconception regarding equipment isolation as specified in the procedur l This caused an unnecessary prolonging of the time spent in a limiting ,

condition for operation (LCO) which ultimately contributed to a condition -

where both diesels were inoperable (Paragraph 2.a).

Several deficiencies were noted in the safety injection actuation with loss of :

engineered safeguards AC test (Paragraph 2.b).

Good communications, coordination, and procedural adherence was observed i!

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during periodic EDG testing (Paragraph 2.b).

'i Enoineerina  ;

Good planning and supervision were evident during the motorized valve (MOV) ,

limit switch modifications, the modification of EDG exhaust piping, and MOV  !

operator replacement. Installation- procedures were well written and contained 1 appropriate precautions and compensatory measures. Responsible engineers wer i knowledgeable of the modification details.and around the clock support was  ;

provided where warranted (Paragraph 3.a). l f

The licensee performed several modifications on the EDG:: involving extensive !

diesel outage times (Paragraph 3.b).

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On November 19, the licensee identified.5 of 40 molded case circuit breakers',

replaced during:the recent Unit 2 refueling' outage, would not have provided i overcurrent trip protection as designed. Although the licensee's circuit .

breaker testing. program was awaiting final approval: in March 1992, the !

complete testing program has not yet ~ been formalized. The adequacy of the ;

licensee's. circuit breaker testing program is identified as.an- unresolved item !

(Paragraph 3.e). s l

Construction continued on the new EDG building and the new diesel fuel oil system-(Paragraph 3.f).

j Plant Support l

i Performance in this area remained consisten ;

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DETAILS 1. Piant Operations-(71707) (60710) (40500) (93702)

The inspectors evaluated licensee activities to confirm that the facility was being operated safely and in conformance with regulatory requirements. These activities were confirmed by direct observation, facility tours, interviews and discussions with licensee personnel and management ~, verification of, safety system status, and review of. facility-record To verify equipment operability and compliance with TS, the inspectors reviewed shift logs, Operations' records, data sheets, instrument traces, and records of equipment malfunctions. Through work observations and discussions with Operations staff members,-'the inspectors verified the staff was knowledgeable of plant conditions, responded promptly and properly to alarms, adhered to prccedures and applicable administrative controls, was cognizant of in progress surveillance and maintenance activities, and'was aware of inoperable equipment status. The inspectors performed channel verifications and reviewed component status and safety related parameters to verify conformance with TS. Shift changes were observed, verifying that system status continuity was maintained and that proper control room staffing existed. Access to the control room was restricted and operations personnel carried out.their assigned duties in an effective manner. The inspectors noted professionalism in most facets of control' room operatio Plant tours and perimeter walkdowns were conducted to verify eeuipment operability, assess the general condition of plant equipment, and to

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verify that radiological controls, fire protection controls, physical protection controls, and equipment tag out procedures were properly implemente Unit 1 Operational Status The unit operated at full power for most of this period with the exception of requested load following power reductions.. A reduction to 55 percent power was made on November 28 to conduct turbine stop valve testing and repair the lube oil pump attached to the A main feed pum A unit shutdown was initiated December 3 due to'both diesels being inoperable. Additional details appear in paragraph 3.c. Power had been briefly' reduced to 92 percent when the power reductio was terminated due to enforcement discretion'being granted by the NR The shutdown was averted and the unit returned.to full' power when G-01 was restored to' service. The initiation of the shutdown-was not reported to the NRC as required. This is a violation of 10 CFR 50.72(b)(1)(i)(A)-(266/93015-01). This violation does not'

meet the criteria for mitigation of enforcement sanctions'because

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it could have been prevented tur appropriate corrective actions i response to a previous occurrence of. a similar event on January 7, '

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1993,-as documented in NRC inspection report 266/9300 ,

b. Unit 2 Operational Status

The unit began this period in refueling outage 19. -This schedule day outage was completed two days. early. The reactor was ,

restarted on October.29 and the unit was placed on line .:

October 30. The reactor achieved 98.5. percert power on <

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November 6. Due to the additional steam generator tube plugging- 1 performed during this outage, the unit was only able to' achieve i 98.5 percent power with all four turbine governor. valves fully - 1 opened and Tavg at the midpoint of the. normal operating ban ,

Equivalent. tube plugging levels for the Unit 2' steam generators !

are 13.6 percent for-the A steam generator and 13.7 percent for the B steam generato ,

A recent TS change reduced the minimum allowable Unit 2 flow rate from 181,800 gpm to 179,200 gpm. Measured reactor coolant system flow was within the TS requirements. This change required ~

reducing the T r andoverpowerSi(eferencevalueintheovertemperature6T-(OT6T)

OP6T) calculations from 573.9 f to 570 F to

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provide for lower OT6T and OP6T reactor trip setpoints 'i commensurate with the lower allowed flo ;

A unit shutdown was initiated December 3 due to both diesels'being l inoperable. Details appear in paragraph 1.a and c. Inadvertent Control Rod Droo

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Shortly after Unit 2 achieved criticality in the . intermediate l range, control rod H2 dropped unexpectedly while changing a rod .

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control system fus _

Thermography of the rod control system fuses showed that a trigger ;

fuse for the rod H2 stationary gripper coil was ho A trigger '

fuse is wired in parallel with each main circuit fuse for the ,

gripper assemblies to provide early warning of overcurrent probl ems . These fuses have very low amperage ratings and function ;

by blowing when subjected to periods of slightly elevated electrical current. This provides indication of possible problems and allows for corrective action to be taken before the main fuse '

blows. Because this particular fuse exhibited above normal temperatures, it was replace ;

The licensee's review of-this event determined that the main fuse  ;

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in the stationary gripper coil circuit had failed shortly after it was replaced during the outage. As a' result, all~ the current to l the stationary gripper assembly on rod H2 was- flowing through the f trigger. fuse. When this trigger fuse was pulled'to replace.it, i the stationary gripper circuit was opened and the gripper-

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deenergized,. dropping the ro Plant engineers postulated that- . +

full design. current was unavailable to the gripper coil.due to the '

low capacity rating of the fuse. As a result, the stationary ,

grippar was not latched tightly. This allowed the rod drive

mechanism to settle slightly, causing it to be out of. a'ignment 4 with the movable-grippers. This caused the movable grippers to close on the lands of the rod drive mechanism and not properly engage the grooves. The movable grippers are normally relied _upon 3 to restrain the drive. mechanism when:the stationary grippers are ,

released. In this case they were not engaged, thereby allowing  :

, the rod to fall in a manner referred to as-a "ratcheting scram".

The system-is designed to withstand this type even The licensee was initially unable to explain how the trigger fue a was able to survive while passing the gripper circuit current- l without blowing. Later discussions with the vendor indicated-_that such an occurrence is not considered unusual. Both the main and :

trigger fuses were subsequently disassembled for inspection. The 1 licensee's inspection results indicated that the main fuse likely- ,

failed due to a manufacturing defect _rather than from overcurren ;

No abnormalities were found in the trigger fus '

Upon replacement of both fuses, operators drove in all remaining :

control rods and latched rod H2. A normal reactor startup proceeded and was performed without further inciden Reactor Vessel Water Level Control During the recent Unit 2 refueling outage, an 8% d. rease-in reactor vessel water level was experienced while a reduced inventory condition. Level dropned about eight it ses below the .

flange over a one hour period, but remained well asove the' top of L the_ coolant loop connections. The licensee conducted an investigation and determined that the water had sluiced from the-reactor vessel to the A steam generator channel head through the reactor coolant pipin Prior to the inventory reduction, an air bubble was present_in the steam generator channel heads as is normal for the system =

conditions at the time. These channel heads were vented to the

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pressurizer _ relief tank (PRT). However, due to.the vent piping arrangement for the A steam gener:ttor channel head, a loop seal developed which prevented the water level in that channel heaa from fully' equalizing with reactor vessel level. During a-routine draining of the reactor coolant drain _ tank, a slignt vacuum was

. drawn in the PRT (less than 1 psi pressure-drop)-due to the differential pressure . developed _ across the long. length' of PRT . vent

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This slight vacuum was sufficient to empty the water from-

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g the channel head vent piping-loop seal. Once this loop seal was gone, the' air bubble in the channel head was free _ to fully vent-tot the PRT. This allowed water to flow from the reactor vessel

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through the coolant piping into the channel head until vessel ,

level and channel head level equalize t The inspectors' review of this event determined that there was n potential for any loss of inventory from the system. Sufficient level was available in the vessel to equalize with other sections 'i*

o of the reactor' coolant system and to continue to provide adequate

' suction head for the residual heat removal pumps. Operators were-cognizant of the level decrease and had adequate sources of makeup- -

water readily available. Once the cause of the level drop was i identified, additional water was added to the reactor vesse ,

During issue evaluation, the inspectors _ identified that th ,

licensee had relaxed their controls over reactor vessel water -5 level instrumentation alignment. The licensee had committed to [

improving configuration control over this instrumentation in response to a Notice of Violation issued for a loss of' level l indication (IR 266/90022). These controls included red tagging many of the valves in the instrumentation reference and variable 1 legs to assure they remained aligne ;

A recent engineering evaluation identified that several red tagged ;

(i.e. secured) pressurizer vent valves were solenoid valves whose ;

life expectancy would be severely shortened if maintained _ in the energized position required by the lineup. Temporary changes were ;

made to the governing. procedures to provide an alternate flowpath F not involving the subject valves. However, the alternate flowpath -

was not placed under the same rigorous restrictions as the t original, instead being controlled only by the temporary procedure changes. The safety analysis performed by the licensee to support i this change did not adequately consider the company's commitments- j to maintain the strict levels of control committed -to in thei '

response to the Notice of Violation and in GL 88-17, " Loss of Decay Heat Removal". At the end of the inspection period, the ,

licensee was reviewing the procedures governing control of reactor i vessel. level to determine appropriate levels-of control. This

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issue remains unresolved pending completion of the licensee's_ :

evaluation, implementation of resultant procedure changes, and

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subsequent NRC review (301/93015-02).  ;

i e. Minimum Temperature for Critit9 Operations j While evaluating the applicability of an event regarding minimum allowable temperature for critical' operation that occurred at the.- :

Zion Nuclear Power Station, the inspectors noted that Point Beach- ,

has inadequate restrictions in this same area. The. current lTS ;

limit for critical operation is 434 F at 2000 psi.- However, base on information obtained from the Zion event, nuclear-  !

instrumentation accuracy decreases _with temperature-below 570 F and the nuclear instruments are outside their analyzed range below _

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530 F. Although reactor'startups at Point Beach are normally g performed between 530 and 547'F, the startup procedure ' allows !

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reactor startup below these temperatures. This issue remains unresolved pending an evaluation by the licensee'and subsequent t NRC review (266/93015-03). Low Oil level in Unit 2 Reactor Coolant Pumo Motors A routine Unit 2 containment inspection on November 23 identified  !

that oil levels 'in both reactor coolant pump motor upper bearings  ;

were low. Fourteen gallons of oil were required to- be added to  ;

the A motor and 6 gallons to the B motor to restore the proper oil

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level. Oil reservoir capacity is 175 gallons for each moto Even though. oil level was below the site glass range, no alarm wa l received in the control room to alert operators to this conditio l

An investigation revealed that the low oil alarm's for both ' motors i were disabled. Two normally open sliders in the alarm circuitry, .

TNF-10 and TNF-ll, were found closed. The correct slider j positions.were verified in their proper positions October 21 by  !

completion of checklist RF-445, " Verification of Main Control Board Sliders." However, the sliders had subsequently been red  !

tagged open to provide a boundary for maintenance work unrelated *

to this event. When the tags were cleared, the Duty Shift .

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Superintendent specified the incorrect return to service position 6

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for the sliders. The licensee is conducting an investigation to'

determine the cause of this event. This issue remains unresolved pending completion of the licensee's investigation and subsequent .,

review by the inspector (301/93015-04).  ;

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Discussions with licensee management indicated that a drop in oil level is expected following filling of the system and subsequen l running of the coolant pumps. Past practice has been to rely on ,'

the low oil level alarm to alert personnel to add makeup oil to the reservoir. With the alarm disabled, this mechanism was unavailabl *

i Pump motor operation was unaffected by this minor oil level dro i-There were no-indications of excessive vibration or high bear _ing- '

temperature, which are also annunciated in the control room. No  :

oil leakage indications were found during a subsequent system inspectio j Maintenance (62703) (61726) .j R

Maintenance The inspectors observed safety related maintenance activities on .;

systems,and~ components to ascertain.that these activities were *

conducted in accordance with TS, approved procedures, and appropriate industry codes and standards. The inspectors determined that these' activities did not violate LCOs and that i required redundant components were operabl The inspectors j

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verified that required administrative, material, testing, and radiological and fire prevention controls i were adhered t Specifically, the inspectors observed / reviewed the following maintenance activities:

o MI 5.1.1 (Revision 14), limitorque MOV Torque and Limit Switch Adjustment for Gate and Globe Valves  :

Maintenance technicians displayed a high level of knowledge regarding technicalities of limitorque valve operator The inspector noted good communications and work practice during this evolutio * Emergt acy diesel generator exhaust piping replacement (MWR 932431)

• PBTP-023 (Revision 0), G-01 Service Water Return Piping Replacement

• Replacement of Station Battery D-06 (MWR 934043)

• RMP 45 (Revision 14), Elgar Instrument Bus inverter

• IWP 92-025*C (Revision 1), DC Ammeter Calibration This action was performed to calibrate DC ammeters D105 and D106, and to install calibration switches and test jacks within the D105/D106 circuitry. The new switches and test jacks will provide a simplified means for calibrating the RG 1.97 ammeters from the control roo '

• SMP 1144 (Revision 0), Diesel Generator Turbo Charger Repl acement Commencement of work was delayed several hours due to a misconception regarding equipment isolation as specified in :

the procedure. This caused an unnecessary prolonging of the time spent in a LC0 which ultimately contributed to a condition where both diesels were inoperable simultaneousl Details of this event appear in paragraph 3.0. Diesel vendor representatives were used to assist in maintenance activities and subsequent work was completed in a timely manne b. Surveillance ,

The inspectors observed certain safety related surveillance activities on systems and components to ascertain that these activities were conducted in accordance with license requirement !

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For the surveillance test procedures listed below, the inspectors determined that precautions and LCOs were adhered to, the required administrative approvals and tag-outs were obtained prior to test initiation, testing was accomplished by qualified personnel'in-accordance with an approved test procedure, test instrumentation .

was properly calibrated, the tests were completed at the required frequency, and that the tests conformed to TS requirements. Upon test completion, the inspectors verified the recorded test data ;

was complete, accurate, and met TS requirements; test '

discrepancies were properly documented and rectified; and that the systems were properly returned to servic Specifically, the inspectors witnessed / reviewed selected portions-of the following test activities: ,

• ORT 3A (Revision 28), Safety Injection Actuation With Loss of Engineered Safeguards AC, Unit 2 During performance of steps 5.4.7 d & e, the operator in the field misidentified the position of all the main steam ,

isolt. ' ion valve trip solenoids. Because the apparent valve !

positians were opposite those expected, the operating shift superv.sor verified this informatio He determined that !

the silenoid valves were actually in their expected .

positi'ns and that the valve position indication had been t imprope. 1 %ndwritten on the indicators. The licensee immediately nmoved the writing. During step 5.4.7 i, a i technician attempted to determine if valve 2WL-1723 was closed by voltage indication as directed in a temporary change to the procedure. However, he measured voltage at the wrong terminal and did not obtain the expected readin This error was quickly identified by supervisory personnel and the correct measurement was then made. During section !

5.5, the test director missed the step directing starting of data recorders. Consequently, no data was obtained during a test of the EDG automatic load shedding and restoratio This necessitated repeating the loading and unloading sequence of the EDGs. The inspectors also noted several nomenclature issues in the procedure that were discussed with shift management. Overall test performance was goo * RESP 4.1 (P,evision 9), Initial Criticality and ARO Physics Test

• RESP 6.2 (Revision 7), Precision RCS Flow Rate Measurement !

• TS-2 (Revision 37), Emergency Diesel Generator G-02 Biweekly i Good communication and coordination were noted during the a conduct of this tes Procedural controls were closely adhered t ;

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3. Enoineerina (71707) (37828)

The inspectors evaluated engineering and technical support activities to determine their involvement and support of facility operations. This was accomplished during the course of routine evaluation of facility events and concerns, through direct observation of activities, and discussions-with engineering personnel, Installation and Testina of Modifications The inspectors observed onsite activities and hardware associated with the installation of selected plant modifications to ascertain that modification activities were in conformance with requirements. This inspection included verification of the following items:

• Verification by direct observation that work was being performed by qualified workers and in accordance with approved procedure * Verification that the installation conforms to the as-built drawings.

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• Confirmation that the equipment and material being used was corre, * Determination whether the modified equipment was properly prepared for preoperational testin * Verification that preoperational testing was conducted using properly reviewed procedures and the test re.ults were appropriately evaluated against established cr iteri J

• Verification that test performance records received an independent QA audi Selected portions of the following modifications wera reviewed:

• 88-188*I-10, Install 4-Rotor Limit Switch on SW-2817 A thorough work plan was prepared for this evolutio Because the affected valve provides isolation to non-essential service water loads, specific operability concerns and compensatory actions were detailed in the work pla The control operator was briefed and provided with a copy of the work plan to be maintained in the control room. The responsible engineer was very familiar with the modification details. The wark was well supervised and completed in a timely manne * 92-085*A, Emergency Diesel Generator Exhaust Piping This modification installed a flexible coupling in the G-01 diesel exhaust piping to relieve stress on the turbocharger cover bolts. As documented in previous inspection reports (IR), these bolts had been subject to high cyclic stresses

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which caused several of them to fail. As an interim '

measure, the ~ licensee had been replacing these bolts on'an annual basis during the EDGs respective overhauls. Although l installation of this modification resulted in additional out of service time for an emergency generator, the work was performed around the clock to minimize the out of service time and the new coupling was expected to provide enhanced reliability of these diesels. Engineering support was also provided around the clock as a contingency to expedite resolution of any unforeseen problems that might have arisen during the installation. Additional details appear in paragraph 3.b belo * 88-076-4, Motor Operator Replacement for AF-4023 Work on this valve was performed in parallel with the corresponding AF-4022 modificatio These two valves throttle the discharge from the A motor driven auxiliary feedwater pump to their respective steam generators. By '

performing the work on both valves in parallel, the amount of time spent in a LC0 was minimized. Additionally, while this pump was out of service for its modification work, two other maintenance actions were concurrently performed to ,

further reduce the time the pump was out of service. The F inspectors also noted that a detailed analysis to justify -

voluntary entry into a LCO was performed for this modificatio b. Diesel Generator Outaae On November 10, EDG G-01 was removed from service to replace its .

service water (SW) discharge piping. Radiographic tests performed in 1991 indicated some areas of the SW piping to the EDGs contained greater than 75 percent thru wall pitting. The supply ;

piping for both diesels was most significantly corroded and was '

replaced in September 1991. Details of this evolution appear in-IR 91019. The discharge piping replacement was postponed until the present time since it exhibited significantly lower corrosio Concurrent with the SW piping work, a flexible coupling was

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installed in the G-01 exhaust piping as discussed abov As a compensatory measure, a fire hose connector on a flange which could be attached to the outlet of the G-01 cooling system heat exchanger was available to provide sufficient cooling water to the diesel in the event it needed to be run indefinitel This would have enabled operators to direct the discharge water from the EDG ,

heat exchanger outside the' turbine building, thereby allowing !

cooling of the out-of-service EDG. This measure would be effective only during those periods when the service water piping 4 was degraded but exhaust piping work had already been complete Instructions were also written to provide guidance on the

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connection and operation of this compensatory measure. Plant management stated that such an arrangement made the. diesel available but would not have justified declaring the out of- 'a service EDG operable. The inspectors observed.the installation'of *

the flange, the location and length .of .the prestaged hoses, -and '

reviewed _the related instructions prior.to the work initiatio Additionally, precautions in the procedure directed that no work be performed on the gas turbine generator or the portions of the' f'

offsite- electrical distribution system directly affecting the plant during this period to enhance system. stabilit ~i This same project was performed on the other train.EDG the-week of December 6. The inspectors monitored performance of these- -- t

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activities and had no concern ,

c. In_

n operability of Both Diesel Generators On November 29, G-01 was again removed from' service for a scheduled turbocharger and idler stubshaf t replacement. On '

December 2, while G-01 was still out of service, G-02 faile l This resulted in both EDGs being out of service simultaneously, .a condition prohibited by TSs. TS 15.3.0.A requires both units to 1 be placed in hot shutdown within three hours of entry into such'.a ,

condition. Power was reduced at 15% per' hour when it was-  !

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determined that the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> LC0 would not be met. Upon request'

from the licensee, the NRC exercised their discretion not to a enforce compliance with the requirement _to shut down both units -

while G-01 was restored (see details that follow). j During the G-01 outage, G-02 was tested on a daily basi.; to ensure e its operability as required by TS 15.3.7.B. The December 2 test of G-02 was completed at 9:45 a.m. At about 7:20 p.m..that 4 evening, a low fuel oil pressure alarm was received in the control -

room. An investigation determined that the engine's electric fuel :

oil pumps continued to run after the engine was secured following test completio ;

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The EDG has both an electric and a mechanically coupled fuel pum The alarm circuitry senses pressure in the discharge piping of ;

both these pumps, which are separated by. check valves. .With the 9 electric fuel oil pump running, the fuel pressure alarm remains ;

enabled. During the course of.the day, fuel pressure in the q

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discharge piping of the idle mechanical pump slowly bled down via t reverse flow through this positive displacement pump until the low ,

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pressure alarm.setpoint was reached. Operators were_ dispatched to i identify the cause of this unexpected alarm and discovered that :j the electric fuel pump was running. An initial. determination was ,

made that G-02 remained operable because the fuel pump's running- ;

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would not affect the diesel's ability to perform its safety .i function j

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.The cause of the electric fuel . pump continuing to run was'due to j g the contacts in the, engine stop relay (ESTR)-not releasing as .:

expected when the engine sto'p buttons were depressed. This !

caused the circuitry to continue powering the electric fuel pum t Th" problem could' not be duplicated during troubleshootin !

. Ad 'tional troubleshooting identified that with relay ESTR !

L r- ining energized, one of the two EDG start circuit lock out !

r .ys, STLO-2, also remained energized. . This disabled one'of the ;!

d wsel's redundant ~ start circuits. Based on this discovery, G-02

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was declared inoperable at 10:56 p.m. on December 2. 'With no - E operable diesels, both units were required to be placed in ho ;

shutdown within three hours. The NRC was notified of the diesel- !

inoperability as require ;

At the time of the G-02 failure, G-01 had been in the process of: l being restored to service. Restoration activities were- .

i accelerated and the diesel operability test began'about two ho'urs ;i into the three hour' time limit for unit shutdown. - Plant management had recognized that G-01 would not be returned to :

service prior to the expiration of the three hour time limit and i requested enforcement discretion. In conjunction with this~ .i request, a load reduction was commenced on both units at  !

12:57 a.m. in preparation for a possible shutdown. The .

enforcement discretion was subsequently granted and the load ;

reduction was terminated at 1:38 a.m. with Unit 1 at 92 percent- i and Unit 2 at 90 percent. The inspectors had responded to the i site and noted excellent coordination between engineering:andL {

maintenance personnel in the accelerated return to service of G-01 !

and in the continued troubleshooting of G-02. - The operability 1 test was completed at 2:30 a.m., about one-half hour after !

expiration of the three hour time limit. Once.G-01 was restored a to service, both units were returned to full power. The- j inspectors monitored the licensee's restoration activities and had i no additional concerns. Compensatory measures were again implemented, including testing of the G-05 gas turbine generator ;

prior to removing the diesel from service and assuring that no i work affecting stability of offsite power was performed during the ;

diesel outag The affected ESTR relay contact block was replaced later that day , l and G-02 was successfully tested and returned.to-service. .Because l the licensee's inspection of the replaced relay did not reveal.an j obvious fault indication, the licensee decided to also replace the :

affected STLO-2 relay contact block as a precautionary measure; l Subsequent testing of the STLO-2 relay ' revealed the plunger to be .]

stickin Sticking of this relay could have prevented'the ESTR 3 relay from denergizing. Based.on this information, the licensee !

believed that the faulty STLO-2 relay was the cause of this event'. C Part of the basis for the NRC granting enforcement discretion in this event was the desire to preclude an unnecessary transient on both units. In this respect, the NRC determined that the'

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' licensee's TS 15.3.0, General Considerations', could be improved to !

allow a more orderly and safe shutdown of both units. The

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change to this TS to allow more time for a more orderly shutdown.

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this area. This is considered an inspection followup item  :

(266/93015-05(DRP)).

l Replacement of Station Battery D06 l Station battery 006 replacement commenced November 8. - Battery DOS - ,

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was replaced in July 1993. These batteries, which were last i replaced in 1989, were expected to have a life of about 20 year t However, they had shown visible signs indicating excessive i

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sulfation, and the manufacturer replaced them under warranty.

l Other than the precipitate which had built up on the cell bottoms, I

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there had been no measurable deterioration in battery performance such as capacity or. individual cell voltages. The~ inspectors .!

monitored replacement of the battery, the ensuing. battery tests, and had no concern Molded Case Circuit Breaker Testina On November 19, the licensee identified that 5 of 40 molded case circuit breakers replaced during the previous Unit 2 refueling i outage would not have provided overcurrent trip protection at ,

designe These Westinghouse HFA 30 amp breakers, which were {

removed from 480 VAC safety related motor control centers 2B32'and -

2B42, had been in service since the plant began operation. -The ,

breakers were being tested for requalification when it wa di.scovered that 5 of 40 failed to open. Disassembly of the failed

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j breakers indicated that hardening of grease internal to the l I breaker assembly was causing the trip mechanism to bind and thereby preventing it from actuatin .

J An issue identified by the NRC.during an Electrical Distribution .<

System Functional Inspection performed at Point Beach during  !

May 1990, regarded testing of molded case circuit breakers. In  ;

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maintenance program be developed. Little progress was made to

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advance this program past its preliminary stages. A schedule.was developed in July 1993, with a timeline for initial breaker  ;

l cycling and testing that extended through 2004. The recent 1

L . breaker deficiencies were identified during the initial schedule implementation. ' A six year cycle' for. periodic breaker cycling w'as- .!

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L also proposed, but implementation was not scheduled until 199 The complete testing program had not yet been fr,rmalize On March 12, 1992, the circuit breaker supplying lighting transformer XL10 failed to open as required during an electrical fault in that transformer. As described in IR 266/92007, this- t

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caused the upstream circuit breaker supplying the entire motor  ;

control center to open which deenergized all loads served by tha motor control center. The faulty breaker had a similar failur mechanism to that found in the latest batch of breakers. At the ,

time 'of the March 1992 breaker failure, plant management stated-that the Point Beach circuit breaker testing program was awaiting ,

final. approval and was expected to be the' tool to identify any other faulty breakers that may be installed in the plant. .The-  ;

inspector's review of the succession of these past events '

indicated that the timeliness of the licensee's corrective actions .

was slo _[

~i Although the licensee had proposed periodic manual cycling of circuit breakers as a preventive measure, this is not likely to _ '

avert the failure mechanism of these type breaker's-because it does-not exercise their; trip mechanism. Additionally, the proposed-breaker cycling periodicity of six ' years exceeds the recommended interval recommended in standard TSs. The adequacy of the circui .

breaker testing program remains unresolved pending additional j progress in program implementation and subsequent review by the -; .

inspector (266/93015-06).

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f. Construction of New Emeraency Diesel Generator Buildina

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Construction of the building to house two new EDGs and the new diesel fuel oil system began the week of ' June 7. Initial .

observations of this activity are discussed in-IR 266/301/9301 During this inspection period, concrete pours continued for.the  !

main building structural walls. - Conduit for a section of.the new diesel generator cable run was laid down in a trench excavated  :

through the turbine building. Installation and fit up of. the new

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fuel oil _ tanks continue ,

The inspectors monitored excavation and grading activities, -

placement of structural concrete, installation of reinforcement-

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bar (rebar), laying of conduit, concrete testing, pipe .

i installation, and welding. Discussions were held with craft .

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workers and supervisors to evaluate their knowledge of the job  ;

requirements. The inspectors will' continue to monitor progress of ;j this constructio !

Specific observations included concrete placement'in the _ wall .

l forms for the north' east wall pour between th_e 28 foot and 48 foot elevations. Forms were clean, rebar 'and embeds adequately- secured l and the concrete was being handled in accordance with~ accepted- *

industry practice and American Concrete Institute requirements ~.

Testing of the fresh concrete was being performed at the' pour l location. Slump test and-air entrainment test'results were within

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Form removal from concrete walls was monitored on the south side E of the structure between elevations 28 and 48. No significant i i

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voids or honeycombs were noted in the concrete subsequent to form !

removal. The licensee-immediately applied an approved curing compound to the bare concrete. Quality control inspectors were ;

present during each activity relative to placement and curing ofi ~

safety related concret The inspectors reviewed concrete testing' records. Compression ,

strength test records indicated that each~ test cylinder breaker-exceeded the mix design strength-of 4000 psi at 28 day '

Pipe welding was observed on the fuel' oil transfer pipe being installed between the new diesel generator building and the; existing EDG rooms. Piping was being installed according to the- 4 ANSI /ASME B31.1-89 Power Piping Code. Visual inspection indicated ;

that joint fit ups were correct and that completed welds met the?

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code for socket welds. Welders were qualified to the weld  ;

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procedure specifications to which they were welding and all ,

qualifications were curren ,

f 4. Plant Support (71707)

The inspectors routinely observed the licensee's radiological controls and practices during normal . plant tours and the inspection of work .

i activitie Inspection in this area includes direct observation of the i use of Radiation Work Permits; normal work practices inside contaminated i barriers; maintenance of radiological barriers and signs; and healt physics (HP) activities regarding monitoring, sampling, and surveyin ,

The inspectors also observed portions of the radioactive waste system ;

controls associated with radwaste processin From a radiological standpoint the plant is in. good condition, allowing access to most sections of the facility. Du' ring tours'of the facility,

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the inspectors noted that barriers and signs also were in' good condition. When minor discrepancies were identified, the HP staff .

quickly responded to correct any problem :

An inspection of. emergency preparedness activities was performed to  :

assess the licensee's implementation of the site emergency plan and . 1

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implementing procedures. The inspection included a monthly review and tour of emergency-facilities and equipment,. discussions with company e staff, and a review of selected procedures, j The inspectors, by; direct observation and interview, verified that

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j portions of the physical security program were being implemented in !

accordance with the station security.. plan. =This included checks that' '!

identification badges were properly displayed, vital areas were locked !

and alarmed, and personnel and packages entering the protected area.were- d appropriately searched. The inspectors also monitored any compensatory l measures that may have been enacted by the license j l

All activities were conducted in a satisfactory manner during this [

inspection perio l

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, Corrective Action on Previous Inspection Findinos and Licensee Event j Reports (92701) (92702) (92700) (90712)- (Closed) Unresolved Item (266/91024-01): Service Water. Technical- i Specification Interpretatio ;

On December 15, 1991, the west SW header isolation valve SW-2869'

was taken out of service for maintenance. -Although-TS 15.3. ~

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addresses SW system valve operability, the licensee had not considered entering the appropriate LCO. Previously, a very ;

narrow interpretation of TS in this area were used, limiting the? j

- definition of an inoperable valve to one that had experienced i gross catastrophic failur !

i The licensee has since conducted extensive reviews of their.TSs ;

resulting in the submission of numerous change requests. =In ,

addition to content revisions, a broader definition of equipment ;

operability was adopted to include assessing the affect on a ,

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system due to any of.its components being removed from service for maintenance or testing. The inspectors observations have  :

confirmed this heightened sensitivity to operability considerations as evidenced by recent maintenance performed-on ;

valve SW-2817 as discussed in paragraph 3.a. The safety ,

evaluation associated with this maintenance included detailed-comments on the acceptability of declaring the . service water i system operable while SW-2817 was removed from servic ~

Inadequate Corrective Action'

' (Closed) Violation (266/93009-01):

On June 11, 1993, a violation was cited for-inadequate corrective

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action. The violation stated that inadequate measures were taken .

to prevent recurrence of the temporary third door on the Unit I containment personnel hatch from being blosked open during refueling operations; and failure of a diesel generator fuel oil ,

sump level control switch was not reported to appropriate levels; -l of managemen '

The licensee subsequently changed their procedures to require that-security personnel stationed at-the containment hatch be. notified-of refueling operations and to ensure the thi_rd door remains shut !

during this period. Additionally, a modification was being - ;

evaluated to provide alarm capability for' the third containment -j door. A recent Unit 2 refueling outage was completed withou '

incident in this area. The example regardirg the diesel sump _ .t level control switch was withdrawn'in that a maintenance work 1 request documenting the failure served as notification to a managemen i

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(Closed) LER 266/301/93-007 (throuah sucolement 11: Inadvertent- L'

Emergency Diesel Start and Loss of- a Station Battery Charger  !

During meter _ calibration work on July 27, 1993, a technician from the company's Appleton work group caused.a short circuit when ,

verifying the position-of _ a slider. This resulted in loss of-- 1 power to the 1A06 electrical safeguards bu This loss of power ;

caused the EDG to start as designed and supply. emergency power to

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the bus. Bus IA06 provides B train safeguards' power _for Uni .

Station battery charger D-108, which is powered from bus:1A06, was j stripped from the bus on the undervoltage signal as designe t Details are contained in IR 266/301/9301 ,

Following repair of the affected circuit, operators restored normal power to bus IA06 and secured the emergency diese As an ,

initial corrective action, the licensee temporarily changed the _ i meter calibrating procedure to verify.a slider is open by use of a portable voltmeter to check for the no voltage condition. Final corrective action stated in supplement I to_the report include conducting prejob briefings prior to Appleton personnel working '

inside the protected area. Additionally, the licensee committe to. review work control documents for activities performed by i Appleton personnel to ensure they contain adequate instructions '

for performing the activity. Additional work instruction improvements will be tracked via violation 301/93014-0 Inspection Follow UD ltems -

Inspection follow up items are matters which have been discussed with )

Wisconsin Electric management, will be reviewed further by the ,

inspector, and involve some action on the part of the NRC, the licensee l

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or both. A follow up item disclosed during the inspection is discussed o in paragraph >

Unresolved Items h

Unresolved items are matters about which more information is required in !

order to. ascertain whether they are acceptable items, items of: _ '!

noncompliance, or deviations. Unresolved items disclosed'during 'the '

inspection are discussed in paragraphs 1.d, 1.e, 1.f, and J 6. Exit Interview (71707)

A verbal summary of preliminary findings was provided to the Wisconsin '

Electric representatives denoted in Section 7.on December 13, at the conclusion of the inspectio Information_ highlighted during the '

meeting is contained in the Executive Summary and no dissenting comments were received. No written inspection material was'provided to compan i

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personnel during the inspectio The likely informational content of the inspection report' with regard to !

documents or processes reviewed during the inspection was also  !

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-or-processes that were reported on as proprietar a l Persons Contacted (71707) I(30702)1 )

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• F. Baumann,' Manager, Licensing and Radiological Engineering- '!

J. F. Becka, Regulatory. Services Manager- l J. J. Bevelacqua, Manager - Health Physics l l

• F. A. Flentje, Administrative Specialist- ,

l W. B. Fromm, Sr. Project Engineer.- Plant Engineering  ;

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C. M. Gray, Duty Shift Superintendent '

L. D. Halverson, Site Services Manager  ;

F. P. Hennessy, Manager - Chemistry  :

W. J. Herrman, Sr. Project Engineer - Construction Engineering-  !

N. L. Hoefert, Manager - Production Planning ..

• T. J. Koehler, Site Engineering Manager

• G. M. Krieser, Industry and' Regulatory Services Section Manager ,

T. G. Malanowski, Project Engineer, Licensing r

• G. J. Maxfield, . Plant Manager ,

J. A. Palmer, Manager.- Maintenance .;

• J. C. Reisenbuechler, Manager - Operations .l J. G..Schweitzer, Maintenance Manager j R. D. Seizert, Training Manager D G. R. Sherwood,-Manager - Instrument & Controls T. G. Staskal, Sr. Project Engineer - Performance Engineering i

Other company employees were also contacted including members of the i technical and engineering staffs, and reactor and auxiliary operator i

• Denotes the personnel attending the management. exit interview for i summation of preliminary finding !

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