IR 05000346/1997015

Insp Rept 50-346/97-15 on 971110-980107.No Violations Noted. Major Areas Inspected:Operations,Maint,Engineering & Plant Support

ML20199F466
Person / Time
Site:	Davis Besse
Issue date:	01/28/1998
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20199F438	List: IR 05000346/1997015 ML20199F435
References
50-346-97-15, NUDOCS 9802040016
Download: ML20199F466 (16)

Text

.

- - - - - - - - - - - - -

-

-

-l

..

~.

.

U. S. NUCLEAR REGULATORY COMMISSION REGION 111 Docket No:

50 346 License No:

NPF-3 Report No:

50-346/97015(DRP)

Ucensee:

Toledo Edison Company Facility:

Davis-Besse Nuclear Power Station Location:

5503 N. State Route 2 Oak Harbor, OH 43449

]

Dates:

November 10,1997 - January 7,1998 Inspectors:

8. J. Campbell, Senior Resident inspector K. S. Zellers, Resident inspector Approved by:

Thomas J. Kozak, Chief, Reactor Projects Branch 4 9802040016 900128 PDR ADOCK 05000346 G

PM

,

- - - - -.

_____-

.;.

, _

I

..

,.

EXECUTIVE SUMMARY I

Davis-Besse Nuclear Power Station NRC Inspection Report No. 50 346/g7015(DRP)

This inspection Ir%isi aspeds of licensee operations, maintenance, engineering, and plant

support. The report covers an eight-week period of resident inspection.

Operations Operations activities were conducted in a contielled, conservative menner. Shift briefs

were thorough, operators had good knowledge of plant status and activities, and procedures were consistently complied with. Plant management was aware of and

'

responded to operational issues in an appropriate manner (Ser% 11.1).

.

A reactor operator missed noticing that the computer display for Group 38, which

indicates reactor core nuclear parameters and calculates secondary heat balance power,

,

did not update for a 50-minute period because he became distracted with a problem on the Nuclear Operations Management System (Section 01.2).

,

The inspedors observed that the operators malmained good control of the plant during a

!

failure of the servo control valve for Turbine Control Valve No. 4 (Section 01.3).

-

Valve hne-ups and major flow paths for both engineered safety features and important-to-

safety systems were verified to be consistent with plant procedures / drawings and the Updated Safety Analysis Report (USAR) (Section 02.1).

,

J P.enance

The licensee semoved from service the level controller for both the Train 1 Auxikary Food

-

Pump and the Motor Driven Feed Pump for a maintenance outage. The inspectors determined that operations work control personnel were kr-ris,;:fe of the maintenance rule requiremen's associated with this work, and that risk was appropriately considated in the planning stages (Section M1.t).

Equipment was observed to perform as described by the USAR during surveillance

testing. During surveillance tests, operators were observed using self-checking techniques for procedurai steps before performing them. During the tests, operators followed procedural requirements and were attentive to operating equipment performance (sochon M1.2).

Enaineerina

-

Plant engineering personnel missed an opportunity to predict a turbine control valve servo

control valve failure. They were not aggressive m responding to a 30 megawatt load swing that had occurred the week before. Further, they did not gather and assess available information regarding the siw response of the turt>ine control valve found during previous testing. Consequently, the licensee reacted to the issue rather than

,

managed it. Once the failure occurred, the plant engineering organization responded well l

(Section E2.1).

l

i

--

-

-

-

-

.

.

.

r

• er*

-

-

. _.. _.. _ _ _ _ _ - _ _ _. _ _. _ _ _ _ _ _ _ _. _ _. _ _ _

_ _ _ _ _ _ _ _ _ _-

ll'/

8:stion Review Board members displayed good technical knowledge of the subject matter

_

presented to them. Members solicited feedback from the sponsors of the documentation i

that was reviewed. The members requested additionalinformation be provided when clarification or explanation was needed (Section E7).

Plant Support A thorough ALARA bf.efing was conducted for a containment entry to perform reactor

coolant pump upper thrust beanng resistance temperature detector circuit modlAcations.

General area radiation dose rate estimates closely matched those actually found ki containment. Radiation protection personnel provided excellent assistance and support for the entry team. Total dose received for the entry was low at about 10 mithrem (Section R1.1).

.

The licensee's response to smoke from a faulted electrical generator for the elevator

machinery room in the radio!ogical restricted area (R8M) was done in accordance with plant procedures. The operators appropriately staffed the brigade, donned proper fire protection equipment and established good communication with control room personnel.

Following the event, the licensee appropriately initiated potential condition adverse to i

quality reports (PCAQRs) to document concoms regarding difficulty of personnel exiting

She RRA due to smoke (Section F1.1).

!

i The inspectors found that surveillance procedures for smoke detectors installed in

+

ventilation ducts were not written in accordance with the vendor's technica! manual

recommendations. Although the detectors were not required by 10 CFR Part 50, j

Appendix R, the licensee failed to meet management's expectations because a PCAQR

,

was not initially written to document this inconsistency until prompted by the inspectors (Section F2.1).

i

,

I

!

,

i i

i

!

i

'

s

-

-

,

,

-

..

-

,,,.,

-

.. _ _ _., _ _ _ _. _ _._... __ _._ __ _ _ _. _. _ _ _ _ _._.. _ _.. _. _ _

L

.l l, ', '

'

.

.

.

I Resort Details

'

Summary of Plant 8tatus

!

The unit opwated at nearly fun power throughout the inspection period. Power was briefly i

reduced to about go percord on November 17,19g7, to repair a failed servo valve to Turt>ine Control Valve No. 4 (Section E2.1).

L Operations l

Conduct of Opera 3ons

-

01.1 General Comments (71707)

!

The inspectors observoo that the plant was onorated in a controlled, conservative manner and that management appropriately responded to operationalissues. Operators

-

conducted thorough shift tumovers, and were cognizard of evolutions in progress.

,

Overall, the operators exhibited good knowledge of plant equipmerd status and property

'

utilized plard operating procedures. Specific events and noteworthy observations are i

detailed in the sections below, i-01.2 Reactor Operator Distracted from Monitoring Plant Parameters a.

Inspection Scope (7170T i

During a review of control room logs, the inspectors learned that the computer display for Group 38 had not updated for a 5We period on November 15,1997. The inspectors -

reviewed the circumstances surrounding the failure of the display and interviewed

.

operators to determine why there was a delay in their recognition of the failure.

c

- b.

Observations and Findinas

. The computa displ.y for Group 38 is in fmnt of the primary reactor opwater station and provides information on core parametws (nuclear power, secondary heat balance power, quadrard power tilt, rod index, etc.). This information is normally automatically updated

'

overy six minutes and licensee managemord expectations are that this information be

monitored by the operators when it is updated. There is no direct indication to operators when Gmup 38 falls; rather, a comparison of the information to real time data is needed

'

to identify a failure has occurred.

in diarmalans with the control room operator who made the bg entry, the inspectors

'

F determined that he had been diverted to a problem with the Nuclear Operations

Management System and had not noticed that Group 38 had ceased updating. The i

inspectors discussed this issue with operations management and found that management expected that the operator be attentive to this display.

~

]

9Amr+-4, op,sations management issued a memorandum to the operators clarifying

this expectation. This problem did not result in an adveme impact on plant operations.

!

j

.

i

,

..

.

-

m

.

.

-

.-

,.

-

,

_ _ _.. _ _.- _ _ _ _... _ _ _ _. _ _ _.

,-

,

i ':.-

i-

!

c.

Conclusions

l-The inspectors concluded that, while operators normally were attentive to the control room panels and plant conditions, a distrection in the control room led to an operator's

l failum to recognize that Group 38 had ceased updating for 50 minutes.

01.3 Turbine Control Valve No. 4 Servo Control Valve Failure (7170M

!

On November 17,1997, the servo valve for Turbine Control Valve No. 4 failed and

caused plant power to slightly decrease. The inspectors observed that the operators maintained good control of plant parameters dur'ng the transient. Shift briefs were per%decally held at appropriate times to discuss the status of the plant and planned

-

i troubleshooting activities for repair of the servo valve (See Section E2.1 for details on the i

servo valve failure). The inspectors concluded that the operators responded well to this I

minor piard transient.

L i

O2 Operational Status of Foollities and Equipment l

02.1 Enaineered Safety Feature System Walkdowns (7170D

!

The inspectors walked down the accessible portions of the following engineered safety l-features (ESF) and important-to-safety systems during the inspection period:

!

Emergency Diesel Generators Nos.1 and 2

-

i Low Pressure triection Trains 1 and 2

-

High Pressure triection Trains 1 and 2 l

-

Containment SprayTrains 1 and 2 L

-

.

i System kneups and major flowpaths were verified to be consistent with plant

!

procedures / drawings and the Updated Safety Analysis Report (USAR). Pump / motor fluid i

levels were within th* normal bands. Vibration and to' aporatures of running equipment

.

were normal. Only very minor oil and fluid leaks were noted on occasion. Local and

remote controllers were property positioned and instrumentation appeared to be functioning correctly. No substantive concoms were identified as a result of the

,

l walkdowns.

!

i 11. Maintenance

'

M1 Conduct of Maintenance

+

L M1.1 Feedwater System Outanes (6270D

The l6censee removed from service the level controller for both the Train 1 Auxiliary Food Pump and the Motor Driven Feed Pump for a maintenance outage. The inspectors

'

determined that operations work control personnel were knowledgeable of the

.

maintenance rule requirements associated with this work and that risk was appropriately

j considered in the planning stages, i

I f

e

!

I l'

.

-

..

,

. -.

.

..

.

-

.

- - - - - - - - - - - - - - - - - - - -

o

.,,

M1.2 Maintenance and SurvelRance Activities (61726)f62707)

The fouowing maintenance and surveillance testing activities were observed / reviewed during the inspection period:

DB 8C 03070 Emergency Diesel Generator No.1 Monthly DB-88 03042 Control Room Emergency Ventuation Train 2 Monthly Test MWO 1-97 075.-A Install Temporary Mod 97-0010 for RCP 21 Upthrust Bearing Spam Thermocouple MWO 1-97 0760-CS Instan Temporary Mod 97-0010 for RCP 2 2 Upthrust Bearing Spare Thermocouple Equipment was observed to perform as described by the USAR and within the Precautions and limitations of their operating procedures. Addl.lona#y, support equipment was verified to be performing as required. Operators were observed using self-checking todmiques before performing procedure steps during surveillance tests and diligently following procedure requirements. The inspectors concluded that these maintenance and surveillance testing activ!*les were thoroughly and professionauy conducted.

M3 Maintenanoe Procedures and Documentation M3.1 Post Maintenance Testing for Class 1E Undervoltaae Relavs a.

Inspection Scope (61726)

The inspectors reviewc Joenses activities roiating to a Technical Specifbetion (TS)

surveillance requironwnt compliance question concoming the Class 1E 4160 volt (V)

undervoltage relays.

,

b.

Observations and Findinas Class 1E 4160 V undervoltage relays function to sense a loss of voltage on the 4160 V Class 1E essential buses, resulting in a load shed of a bus, and a start of its===u=*M emergency diesel generator. Two undervoltage relays and an auxiliary relay form part of a logic that is described as a functional unit in the Technical Specifications (T8s). Within the functional unit logic, the output contacts for the two undervoltage relays are arranged in parallel such that actuation of either undervoltage relay win result in energizing the auxihary relay. The actuation of two functional units is required for a load shed of a bus and a start of an emergency diesel generator.

The inspectors questioned how the post maintenance testing for the undervoltage relays was conducted ana whether this post maintenance testing was adequate to demonstrate that an undervoltage relay had been property reinstalle1 following its removal for bench calibration. The licensee stated that the post maintenance testing procedures required an injection of a test signal into both of the undervoltage relays in the functional unit and that the ulumination of a downstream light was used to prove operability. However, this testing only verified that one of the two parallel undervoltage relays operated correctly, but not necessarily the one that had been recently installed after bench testing.

Maintenance personnel initiated PCAQR 98-0020 when they real! zed that the post maintenance testing procedures may not have been adequate.

.

.

.

.

....

.

.

,

._

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

,

.

J

.,

I l

The licensee detennined that the undervoltage relay functional units (which contain undervoltage relays) were operable based on the functional units passing their most

,

roosntly performed channel functional tests as required by T8s.

.

c.

Conclusions

!

The inspectors determined that post maintenance testing procedures for the Class 1E undervoltage relays may not be adequate to provide assurance that they had been

,

installed correctly following their removal. This is an unresolved item

,

j (50 346/97015 01(DRP)) pending further inspector review.

-

,

!

IIL Enaineerina l

l E2 Engineering Support of Faoliities and Equipment i

!

E2.1 Enoineerina Response to Turbine Control Valve Servo Valve Failure

!

j a.

inspection Scone (37551)

I l

The inspectors reviewed the engineering department's response to the November 17, i

1997 failure of the servo valve for Turbine Control Valve No. 4.

!

i b.

Observations and Findings

The turbine control valves throttle to modulate steam flow to the main turbine. They are

!

Positioned to throttle by increasing or decreasing electro hydraubc control fluid (EHC)

i pressure to the turbine control valve cylinders. Each turbine control valve has an

':M ^i controlled servo valve that positions to control EHC fluid pressure to the

'

j turbine control valve cyhnders. The servo control valves have a small irt line filter which l

reme<os impurities in the EHC fluid.

t j

On November 17,1997, Turbine Control Valve No. 4 started to drift in the closed direction i

and caused an EHC load limit alarm as well as a lowering of turbine load and reactor power, due to reduced steam flow, in response, the operators decreased demanded load i

i to 90 percent in order to close Turbine Control Valve No. 4 for troubleshooting and

!

repairs. The licensee investigated the problem and found that the cause of Turbine Control Valve No. 4 drifung closed was a clogged servo control valve filte. Within

13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> of the servo valve failure, the servo valve was replaced and tested, and the unit

!

was retumed to full power.

i-

PCAQR 97-1499, which was generated to document and investigate the servo valve l

failure, documented that a similar event had occurred on November 12,1997. During the November 12,1997, event, Turbine Control Valve No. 4 modulated in the closed direction

for 20 seconds and then modulated open to its demanded position resulting in about a l

30 megawatt (MW) turbine load sw'.ng.

.l The inspectors interviewed several plant engineering personnel regarding the November 12,1997, issue. The inspectors found that a backup Integrated Control i

System (ICS) engineer initially reviewed the event because the primary ICS engineer was

!

i

I i

!.

.

-

_,

-

-

- a

! '..

'

i

not at the site. He concluded that the ICS operated property and decided to pass the information to the primary system engineer for a more detailed review when he retumed

to the alte. The primary ICS engineer retumed to the site on November 14,1997, and i

performed a cursory review of the 30 MW load swing, but deferred a more detailed review

to the following week due to plant cleanup day. As a result, no rigorous investigation into the cause of the November 12,1997, event was performed until the servo va!ve failed on November 17,1997. Following the November 17,1997, failure, the primary IC8 engineer

,

indicated that, had he performed a more detailed review of the November 12,1997, MW load swing, he would have recognized that Turbine Control Valve No. 4 had a material

]

degradation.

i

Addecidi, Turbine Control Valve No. 4 had reopened slowly during recent testing of its

fast acting closing feature. The inspectors questioned the turbine engineer about the unusual performance of the valve during the test. The turbine engiaeor stated that the

slow opening of the valve was attributed to presumed degradation of system test valves.

The inspectors concluded this was reasonable and determined that this explanation did not correlate to a problem with the turbine control valve itself.

!

The inspectors determined that had plant engineering more aggressively investigated the

.

November 12,1997, MW load swing caused by Turbine Control Valve No. 4 modulating

!

In the closed direction, the servo valve's imminent failure could have been predicted. ~ ~he

inspectors concluded that communication of the dcgraded status of the valve to the j

organization would have resulted in the initiation of plans to troubleshoot and repair the valve much eartier. This would have resulted in the organization managing the issue,

'

i rather than reacting to the issue.

i An apparent root cause of the plugged filter is the station conversion to a 24-month

'

operating cycle. The original General Electric recommendation was to replace the filters as a 12-month preventive maintenance action. The licensee reviewed the preventive

,

j maintenance history of all four servo control valves and found that all four of the servo

control valves had been replaced during the last refueling outape. The plugged filter was

sent to an independent lab for testing with the results expected in January 1998. The

"

other sorvo cor%I valve filters will be examined during the next refueling outage,

scheduled to begin in April 1998, to determine the extent of filter clogging, if any.

!

At the close of the inspection period, the licensee was evaluating corrective action proposals that would maintain stricter EHC chemistry controls per Electric Power

i Research Institute guidelines, and proposals to have online cleaning of the EHC reservoir

!

performed once during each operating cycle using a temporary purification skid.

I c.

Conclusions j

The plant engineering organization responded well to the failure of the servo control valve on November 17,1997. However, plant engineeritig missed an opportunity to predict the

.

servo control valve failure because they did not aggressively review the 30 MW load

,

swing that had occurred the week before, and did not gather and assess available

]

information regarding the past performance of the turbine control valve during routine testing. Corrective actions to prevent future clogging of turbine control valve filters

!

appear to be adequate to prevent recurrence.

'

,

I

)

J

'

.,. _

,

.

.

-

.

.-.

-.

_ _.

_. _ _ _ _ _ _. _ _ _ _. _ _. _ _. -

_______ _ _

<<

.

E7 Quality Assuranee in Engineering Activities

-

The inspectors attended several Station Review Board meetings throughout the

i inspection period. Station Review Board members displayed good technical knowledge

of subject matter presented to them. Members solicited feedback from the sponsors of

associated documentation and the feedback was appropriately reviewed. The members requested additional information be obtained when clarification or explanation was l

needed. The Station Review Board conducted a good evaluation of Safety Evaluation 97-0069 Temporay Modification for Emergency Diesel Generator No.1

(EDG No.1) Speed Sensing Circuit (See Section F2.2).

!

E4 Miscellaneous Engineering issues

.

!

(Closed) Urresolved item 50-346/96007-01(DRS): Acceptability of no 10 CFR 50.59 l

safety avaiustions for attadiment of Data Acquisition System (DAS) units to the Safety i

Features Actuation System (SFAS) and the ICS was questioned. During the original

!-

. Inspection, engineering persc nnel stated that sufficient electrical isolation had been provided such that a failure of the DAS units or other plausible failures would not affect

,

the functionality of the SFAS and ICS. Although the attachment of DAS units was

!

considered a tr.. defication, the attachment of DAS units was not considered a change to i

the facility as described in the Updated Safety Analysis Report (USAR) because the

,

functionality of equipment described in the USAR (e.g., the SFAS and ICS) was not

!

affected. Consequently,10 CFR 50.59 did not apply to the modifications and therefore 10 CFR 50.59 safety evaluations did not need to be conducted.

IV. Piart Suceert l

R1 Radiologloal Protection and Chemistry (RP&C) Controls i

R1.1 Containment Entry At Power (83750)

!

!

The inspectors accompanied the licensee during a ocwitainment entry at 100 percent l

power to observe a maintenance evolution. The maintenance involved performing

_

temporary modifications to reactor coolant pump upper thrust bearing resistance l

temperature detectors for reactor coolant pumps 2-1 and 2-2. The ALARA briefing for the

!

containment entry was thorough. Predicted area radiation dose rates closely matched L

those actually found in containment. Radiation protection personnel provided excellent

!-

assistance and support for the entry team. Total dose received for the entry was about i

10 millirem. The inspectors concluded that the entry and maintenance work was effectively coordinated and controlled with minimal dose expended for the job.

Miscellaneous Security and Safeguards issues

.

!

(Closed) Violation (50-346/95010-04(DRS)): Contrary to the requirements in 10 CFR 26, i-the licensee imposed fitness-for-duty sanctions that were not aescribed in its written policies or procedures, and did not provide prior training on these matters. This issue j

. involved a violation that was issued on April 19,1996, i

!

i

,

l

-.

-

-

..

--

,

,

,.

'

,

!

The inspectors con 6rmed that, following identi6 cation of these deficiencies, the licensee

!

revised Procedure 18-AO 00018, " Drug and Alcohol Testing Program," effective l

October 13,1995, and Procedure NG-IS 00004, " Fitness for Duty Program," effective l

March 19,1996. The revised procedures stated that urine specimen testing to the limit of L

detection (LOD) wlR be done when specimen dilution is suspected. In addition, the

possible sanctions due to a positive LOD test were speci6ed. Before carrying out these procedure changes, all site personnel were required to read and Wrc;id-;;= having

!

read the updated procedures. These corrective actions resolve allissues manaalaiad with i

this violation.

F1 Control of Fire Protection Activities

!

F1.1 Smoke in the Radiological Restricted Area (RRA)

j a.

inspection Scope (93702)

!

The inspectors observed the licensee respond to the presence of smoke in the i

Radiological Restricted Area.

i b.

Observations and Findinas i

On December 4,1997, the licensee evacuated personnel from the Radiological

!

Restricted Area (RRA) when smoke was reported on Elevation 603' of the auxihary

b#1&ng near the elevator. Procedure DB-OP-2529," Fire Procedure,"was entered and tne designated control room and zone operators manned the fire brigade. During its

l Investigation, the licensee determined that off-site fire assistance was not needed when the source of the smoke was determined to be from the electrical generator for the

,

j auxiliary building elevator machinery room and not an actual fire, Subsequently, the

control room operators appropriately classified the event as a smake irritant. The smoke l

from the generator stopped propagating when its rcpply power breakers were opened, j

Smoke was then cleared from the area by starting Radweste Supply Fan C013.

"

!

During the event, the inspectors observed good communication, appropriate donning of

'

fire p,e;ecuen gear (coats, pants, boots and respirators), timely manning of the fire

brigade, and appropriate use of procedures. Two PCAQRs were written to document

!

activation of the station fire brigade and to document a concem regarding the blocked exit of personnel on Elevation 545' due to the presence of smoke in the stairweN. Regardless

'

i of the blocked exit, all individuals were accounted for at the RRA exit following the evacuation.

I c.

Conclusion

!

The licensee appropriately responded to the smoke la the RRA por station procedures.

l

!

!

i

,

it I.

!

..

-

-.

~ ~

.

.

-

..

-

..

-

-

--

. _ _. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -

__.

.,

'

o, F2 Status of Fire Protnotion Paoluties and Equipmerd

.

- F2.1 Testing Ventilation Smoka Detectors

!

a.

Inspection Scope (64704)

'

The inspectors questioned the adequacy of the Boonsee's testag of ventuation amonw detectors.

o

.

!

b.

Observations and Findinas

!

i The inspectors questioned whether surveillanos procedures for testing smoke deter; tors

installed in plant ventuation ducts provided instructions to check for blockage of the smoke detector sensor tubes. The sensor tubes, which are connected to the smoke detectors and are installed perpendicular to the process stream of ventilation flow,

,

'

,

contain holes to sense ventuation flow for smoke.

l:

In response to the inspectors' questions, the licensee found that this check was not done.

- Further, the licensee confirmed that the vendor technical manual recommended that i

sensor tubes be periodically checked for blockage and subsequentry generated i

17 maintenance work orders to perform this check. However, the licensee did not

'

generate a PCAQR documenting this problem.

Concemed that suveillance procedures did not incorporate the vendor's i

reccmmendasms, the inspectors discusset! with plant management the expectations for

'

initiating a PCAQR for this issue. The inspectors found that management expected a -

l PCAQR be written. Subsequently, PCAQR g7-166C was written to document potential f

blockages of smoke detectors. The inspectors reviewed the Davis-Besse Fire Hazard i

Analysis Report and noted that credit was taken for detector operation in the analysis.

Irdarviews with fire protection personnel regarding this observation determirm.1 that l<

smoke detectors in ventuation systems were not needed to respond to a fire postulated by 10 CFR Part 50, Appendix R. The licensee stated the test procedures would be improved

i to check for sensor tube blockage.

+

l c.

Conclusions I-Ventilation smoke detector surveillance procedures did not include vendor recommendations for testing. The smoke detectors were not required by the fire t,azard

,

anarysis report for a fire postulated by 10 CFR Part 50, Appendix R. Nevertheless, individuals involved in this issue did not originally initiate a PCAQR which did not meet j

management's expectations regarding the threshold for writing PCAQRs.

F.2.2 Ememenu Diesel Generator (EDG) Speed Sensing Circuit Not Protected fo/ Hot Shorts a.

Inspection Scope (64704)

!

On December 5, igg 7, the inspectors questioned the licensee as to whether the speed

-

sensing circuit foi the safe shutdown of EDG No.1 had isolation and protection circuitry

(siectrical disconnects and/or resistors) as required by 10 CFR Part 50, Appendix R, Ill, j

L, 7.

i

11

,

.

-,

.. -

_

-.

-...,

.

- -

-. - -... - - - - -.. -.. -. _ _

_ _ _ - -. _ - - -

.g

e e

b.

Discussion The EDG speed sensing circuN provides speed indicadon for tachometers in the EDG

.

room and in the oor, trol room. Further, the speed sensing circuN funchons to start the j

EDG room supply fans at 40 revo6utions per minute (rpm), disenga0s the air start motors

at 200 rpm, and flash the generator at 400 rpm. The inspectors gave the licensee another utility's condition report describing that the speed sensing circuN was vulnerable

to a hot short condition (125 VAC or DC ourrent apphed to one leg of the speed sensing

r swhch). Davis-Besse and the other utility had EDGs manufactured by the same vendor.

The hot short condition could have occurred during a control room and/or cable spreading

)

.

'

room fire which could have caused a fault in the circuitry and rondered the EDG Inoperable if the circuit remained unprotected.

l On December 12, igg 7, after its review, the licensee confirmed that an electrical disconnect was installed as required by 10 CFR Part 50, Appendix R but that resistors were not installed in the circuitry to provide hot short protection. Subsequently, the licensee initiated PCAQR g7-1624 to document the design deficiency and entered

'

TS 3.3.3.5.2.b which permitted the inoperable electrical disconnect and control circuit

'

provided that a Special Report was issued to the NRC if the circuit was not restored to operable status within 30 days.

,

,

!

The inspectors reviewed the control room fire procedure and found that N directed

operators to open the electrical ' isconnect to isolate and protect circuits from faults caused by fires in the control triom. The inspectors were concemed that since resistors

were not installed in the circu.ry, a hot short could occur in the speed sensing dreuitry r

j before the disconnect was of ened. As a result, the inspectors questioned a shift

'

supervisor if entry into this Til was app'icable given that the circuN was not designed for j

hot short protection. Also, the inspectors questioned if a one-hour report should be mede per 10 CFR 50.72(b)(li)(B) since the circuitry was not designed according to 10 OFR

'

Part 50, Appendix R, Ill, L,7. The shift supervisor contacted regulatory affairs personnel and described the inspectors' concems. Regulatory affaire personnel stated they were

- not outside the design requirements of 10 CFR Part 50, Appsndix R, since TS 3.3.3.5.2.b

.

f

. applied.

'

On December 18, igg 7, the inspectors clarified the concoms to regulatory affairs personnel that the tachometer was not protected per the requirements of 10 CFR Part 50, i

Appendix R, lil, L,7 and that TS 3.3.3.5.2.b did not apply in this case. The licensee again i

reviewed electrical schematics and confirmed that the speed sensing circuitry was the only Appendix R circuit that did not have resistors installed. The licensee realized that the plant was outside the design basis and declared EDG No.1 inoperable and made a

[

one-hour report. Compisance with 10 CFR Part 50, Appendix R, Ill, L,7 was restored by taking the disconnect switch for the speed sensing circuit to local. This removed the

'

concem that a hot short caused by a control room fire would possibly affect the speed

l sensor circuit. Subsequently, a temporary modification was performed on the speed j

sensing circuit to open the connection to the control room and allow placing the i

disconnect switch back to normal to eliminate a control room annunciator alarm.

)

[

The inspectors confirmed that the control room tachometer was only needed to vertfy the i

EDG was running and not for speed indication. The inspectors verified other parameters

-

(frequency, synchronizing lights) were availatsle to the operators necessary to make th s

.

4

.

,. -, _ _ _.

.

.

_.

__

.

.

.

_ ____ _ _ __ _ _____________

.,.

/*

vascation. Thwefore, the inspectors concluded that isolation of the circuitry by disconnecting the control room tachometer was acceptable.

c.

Conclusion The inspectors concluded that the speed sensi.'.0 circuit for EDG No.1 was not protected for a hot short condition per 10 CFR Part 50, Appendix R, lil, L,7 requ!iernents and concluded the piant was outside its design basis. Initially, the licensee did not recognize this fact because it erroneously thought TS 3.3.3.5.2.b applied in this case. The licensee's immediate corrective action to disconnect the tachometer was acceptable.

This issue will be tracked as ai, unresolved item (50-364/g7015-02(DRP)) pending the inspectors' final review of the circumstances surrounding this issue.

l V. Manaaement Meetinas X1 Exit Meeting Summary The inspectors presented the inspection resu'.ts to members of licensee mana0ement at the conclusion of the inspection on January 7,1998. The licensee acknowledged the findags presented. The inspectors asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identified.

,

-,

_

-

..

~.

o

- PARTIAL UST OF PERSONS CONTACTED Lloannee J. H. Lash, Plerd Manager R. E. Donnellon, Director, Engineering & Services D. L Esholman, Manager, Operations J. L Michaelis, Manager, Maintenance P. R. Hess, Manager, Supply C. A. Prios, Manager, Business Services H. W. Stevens, Manager, Nuclear Safety & Inspections R. J. Scott, Manager, Radiation Protection J. W. Rogers, Manager, Plant Engineering M. C. Beier, ?fr+=, Quality Assessment l

L M. Dohrmann, ??.r+;+, Quality Services

J. L Freels, Manager, Regulatory Affairs l

F. L 8wanger, Manager, Design Basis Engineering l

G. A. Skeel, Manager, Security l

D. P. Riool, Supervisor, Operations D. H. Lockwood, Suoervisor, Comphance o W. omespie, Supwinter. dent, Chemistry T. J. Chambers, Shift Manager W. J. BenW, Shift Manager 8. M. Uvingston, Shift Manager 8. W. Roberts, shift Supervisor J. L McGee, Shift Supervisor C. A. Gillig, Shift Supm.h-C. 8. Strumsky, Assistant Shift Supervisor R. 8. Lawrence, Assistard Shift Supervisor V. J. Patton, Fire Protection Advisor C. A. Kraemer, Engineer, Ucensing A. Conway, Student T. Kozlowski, Student

.

.

.

. _ _

,

,,

INSPECTION PROCEDURES USED

'

d IP 37651:

Onsite En0neerine i

IP 61726:-

SurveWence Observations IP 62707:

Maintenanos Observation l

'IP 64704 Fire Protection Program

IP 71707:-

Plant Operations

IP 93702:

Prompt Onsite Response to Events at Operating Power Reactors i

l ITEM 3 QPENED, CLOSED, AND DISCUSSED

'

Qascad

,

50 346/97015-01 (DRP)

URI Inadequate Testing of Uederverege Devices l

50364/97015 02 (DRP)

URI Inadequate Hot Short Protection of EDG Tachometer Closed 50 346/96007-01 (DRS)

URI - No Safety Evaluation to Connect DAS Equipment

- 50346/95010 04 (DRS)

VIO Suspected Specimen Dilution

,

4-i f

i

A e

,

%

i

J

[

!

I

'

-.

.

, - -

-

.,

.,.

-,

.

.

.-

.

_

_ _ _ _ _ _. _ _ _ _ _..

_ _. _

_

_.

._. __.. _. _ _

_

... _.

_-_

>

r

-

...

i UST OF ACRONYMS AND INITIALISMS USED ALARA As Low As Reasonably AcNevable CFR Code of Federal Regulauons DAS Data Acquisluon System Do Dirou Current EDG Emergency Diesel Generator EHC Electro 4 ydraulic Control ESF Engineered Safety Feature LOD Umit of Detection

<

ICS Integrated Control System MW Megawatts MWO Maintenance Work Order NRC Nuclear Regulatory Commission PCAQR Potential Condition Adverse to Quality Report

POR Public Document Room

.

RCP Reactor Coolant Pump

rpm Esvolutions per minute RRA Radiological Restricted Area

'

SFAS Safety Features Actuation System TS Technical Specification URI Unresolved item USAR Updated Safety Analysis Report V

Vd

.

VAC Volts-Altemating Current VIO Violation

i s

a

k j

l 16