IR 05000271/1993010

Ack Receipt of Informing NRC of Steps Taken to Correct Violations Noted in Insp Rept 50-271/93-10 on 930406-08

ML20056E083
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	08/16/1993
From:	Durr J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:	Reid D VERMONT YANKEE NUCLEAR POWER CORP.
References
NUDOCS 9308190312
Download: ML20056E083 (2)

Text

-_

-;y )

.-

,

f\\

,

~

~

~

.

V AUG 1 G 1993 Docket No. 50-271 Mr. Donald Vice President, Operations Vermont Yankee Nuciear Power Corporation RD 5, Box 169 Ferry Road Brattleboro, Vermont 05301

Dear Mr. Reid:

SUBJECT: INSPECTION REPORT NO. 50-271/93-10

I This refers to your June 11,1993, correspondence, in response to our letter dated l

May 12,1993.

l Thank you for informing us of the corrective and preventive actions documented in your (

i letter. These actions will be examined during a future inspection of your licensed program.

Your cooperation with us in this matter is appreciated.

l

!

Sincerciy, l

Jacque P. Durr, Chief Engineering Branch Division of Reactor Safety OFFICIAL RECORD COPY G:RLVY9310 19007b

-

()\\ I I

9300.90312 930816 y

PDR ADDLK 05000271 G

PDR h

'

w _.

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

. - _

_

o

-

.

4UG 161993

,

.

Mr. Donald !

,

cc:

'

R. Wanczyk, Plant Manager J. Thayer, Vice President, Yankee Atomic Electric Company L. Tremblay, Senior Licensing Engineer, Yankee Atomic Electric Company

!

J. Gilroy, Director, Vermont Public Interest Research Group, Inc.

D. Tefft, Administrator, Bureau of Radiological Health, State of New Hampshir-Chief, Safety Unit, Office of the Attorney General, Commonwealth of Massachuset.-

R. Gad, Esquire G. Bisbee, Esquire R. Sedano, Vermont Department of Public Service T. Rapone, Massachusetts Executive Office of Public Safety Public Document Room (PDR)

,

Local Public Document Room (LPDR)

Nuclear Safety Information Center (NSIC)

K. Abraham, PAO (2) (w/ copy of incoming letter)

NRC Resident Inspector State of New Hampshire, SLO Designee (w/ copy of incoming letter)

State of Vermont, SLO Designee (w/ copy of incoming letter)

Commonwealth of Massachusetts, SLO Designee (w/ copy of incoming letter)

bec:

Region I Docket Rooia (with concurrences)

!

bec (VIA E-MAIL):

,

V. McCree, OEDO D. Dorman, NRR W. Butler, NRR

,

J. Linville, DRP E. Kelly, PRP

,

L. Scholl, DRS W. Ruland, DRS

,

J. Durr, DRS

-~

b5 RI

DRS RI:DRS Scholl Rula L. cr 0fl'f/93 N

08/'4193 08p/9 OFFICIAL RECORD COPY G:RLVY9310

,

f

,

_

.

.

-

.

-

.

. VERMONT YANKEE.

.

NUCLEAR POWER CORPORATION

4'\\

.

/

)

.{[7 s,\\)

Ferry Road. Brattleboro. VT 05301-7002

,

ENGINEER!NG OFFICE i

.

jf sa un sme ( y q/,-

so m,viere j

y m. - p t 11 r

June 11,1993 BVY 93-59 U.S. Nuclear Regulatory Commission

.

Attn: Document Control Desk

-

.

Washington, D.C. 20555

,

References:

a)

License No. DPR-28 (Docket No. 50-271)

b)

Letter, USNRC to VYNPC, inspection Report 93-10, dated 5/12/93 Subject:

Reply to a Notice of Violation - Inspection Report 93-10

!

Dear Sir:

l This letter is written in response to Reference b), which indicates that one of our activities was not conducted in full compliance with NRC requirements. The Violation was identified during an inspection conducted on April 6-8,1993. Our response to this item is provided below, in addition, Reference b) required Vermont Yankee inform the NRC of our " plans to improve the documentation, evaluation and correction of trends and deficiencies associated with the emergency diesel generators".

'

VIOLATION:

"10 CFR Part 50, Appendix B, Criterion XVil. Quality Assur9nce Records, and the licensee's accepted quality assurance program, requires that sufficient records shall be maintained to furnish evidence of activities

,

effecting quality. The records shall include the results of reviews.

,

Contrary to the above, sufficient records were not maintained to furnish evidence of reviews in that Equivalency Evaluation 92-036, dated

,'

April 4, 1992, stated that improved heat transfer was a critical characteristic of replacement liners for the "A" emergency diesel

,

'

generator (EDG) but no record of the review was made concerning the effect on emergency diesel generator support systems or fuel

consumption.

This is a severity level IV violation (Supplement 1)."

bSWt'u9

'

-) y I

_

_

_

_

_

__ _

,

'

.

.

.

r VERMONT YANKEE NUCLEAR POWER CORPORATION

-

l United States Nuclear Regulatory Commission

June 11,1993

!

Page 2

RESPONSE TO THE VIOLATION

,

h The cylinder liner upgrade, as proposed by Coltec in a 1990 letter, "provides improved liner-to-water-jacket sealing" and " improved heat transfer characteristics".

i This allows increased horsepower only if installed as part of the total series conversion i

upgrade package. An evaluation of both of these characteristics was,onducted and is included in the original equivalency evaluation. The cylinder liner upgrade, as (

described by the vendor, makes no mention of the impact on fuel consumption,

!

exhaust gas temperature or jacket coolant temperature since they are not changed.

l

,

Although installation of the entire series conversion modification would realize a 3-8% reduction in fuel usage (due to the improved fuel injector design and air flow),

!

implementing the liner upgrade alone would result in no change. Therefore, the

impact on fuel consumption was not considered to require formal analysis. Vermont i

Yankee's practice was1 that obvious improvements or fundamental engineering l

judgements do not require specific documentation.

!

i A physical modification was made to the cylinder liner to produce improved heat

transfer characteristics. The improved characteristics result in a smoother, less

't localized, transfer of heat. Because of this fact, and since the amount of heat being i

produced within the new cylinder design would remain unchanged, the Procurement

!

Engineer concluded that the amount of heat being transferred to the service water

!

system via the cylinder water jacket coolers would not increase, and any localized j

increase in heat transfer rate caused by the configuration changes would have no i

effect on the support systems.

j

!

'

Vermont Yankee agrees that the discussion of the heat transfer effect on the jacket water cooling system and the service water system should have been more thoroughly documented in the equivalency evaluation by adding clearer statements

,

that overall transfer of heat would not change. However, the conclusions that the " fit, form, function or materials of the cylinder assembly" is not affected and that the

'

upgrade is equivalent to the originalis unchanged. The Vermont Yankee equivalency evaluation procedure (VYP:329) requires the Procurement Engineer to consider the impact of any proposed alteration or substitution of replacement parts and components

,

on interrelated systems (" system interaction"), although it does not presently require this evaluation to be specifically documented.

,

Regarding the applicability of FSAR Section 8.5.3 to the conditions addressed

in this equivalency evaluation, Vermont Yankee does not censider this reference to be

relevant since the cylinder liners do not change the amount of heat being' produced l

or the amount of heat being transferred to the service water system via the cylinder

water jacket coolers.

i I

.

.-

.

.

.

.

.

'

l

.

,

.

,

',

VERMONT YANKEE NUCLEAR POWER CORPOR ATION l

United States Nuclear Regulatory Commission June 11,1993 Page 3

,

.

Finally, Vermont Yankee was aware that the part number of the cylinder liners

'

supplied by Detroit Edison was not identical to that of the liners previously installed.

However, the part number of the improved cylinder liner design was endorsed by Coltec in the 1990 letter as being the correct product for implementation of the diesel generator upgrade program. This was confirmed by telecon with Coltec prior to the

'

installation of the new cylinder liners.

VIOLATION CORRECTIVE ACTION

t immediate corrective actions taken to rectify this deficiency involved providing supplemental written justification to support the original equivalency evaluation

.

worksheet. In addition, formal retraining of the Procurement Engineering staff in the j

requirements of VYP:329 and the need to thoroughly document the impact of any proposed alteration or substitution of replacement parts and components in

performance of equivalency evaluations has occurred.

l Aa additional corrective action was identified to revise VYP:329 to provide for

~

specific documentation of the required system interaction review. This revision to the j

Equivalency Evaluation Procedure (VYP:329) is expected to be issued for use by

June 30,1993. Additionally, Vermont Yankee is performing an independent review of

!

other selected equivalency evaluations to ensure the documentation packages are

"

complete.

l

'

ADDITIONAL CORRECTIVE ACTIONS As stated previously, Reference b) requires Vermont Yankee to inform the NRC I

of our " plans to improve the documentation, evaluation and correction of trends and

"

deficiencies associated with the emergency diesel generators". Vermont Yankee has thoroughly reviewed the concerns of the NRC in the areas of documentation, evaluation and correction of trends and deficiencies associated with the emergency

diesel generators. In response to the specific issues raised by the Inspection Report j

we have identified appropriate commitment items via our commitment tracking system i

to resolve these individual items. These will be resolved by November 1993. Any

,

additional actions and improvements resulting from our review of these specific issues

'

will be tracked and dispositioned via our corrective action process. In addition, we i

have implemented several management controls that will ensure deficiencies are

,

adequately reviewed, documented and resolved in the future. A few of the more noteworthy changes are discussed below:

-

1)

Wcrk Order procedure (AP 0021) has been revised, as of May 21,1993, to include a new form that establishes management's expectations with

}

regard to Work Order documentation. This form requires work parties to

'

d

.

-..

.

. __ _...

_ _..

- -.._.

. -

_

_

__.

. _.. _ _ _

.. _.

_

e

.

.

.

~

~

VERMONT YANKEE NUCLEAR POWER CORPORATION

.

l i

,

United States Nuclear Regulatory Commission

!

June 11,1993

-

l Page 4 i

!

identify discrepancies, make recommendations for resolution, and l

ensures that the repair department supervisor dispositions any identified i

discrepancies.

f

2)

Vermont Yankee issued the Vermont Yankee Observation Program on

May 1,1993. As part of this program ' Material Condition' inspections are

j conducted by management. These inspections require the identification j

i and prompt disposition of material condition deficiencies, as well as,

identification of any additional actions required for follow up.

a 3)

Effective May 10,1993 on an interim basis, work orders will receive a

!

'

closecut review by a Maintenance Engineer, This review includes reviewing all supporting documentation and field notes and data. As part of the review the Maintenance Engineer will ensure any discrepancies

,

are resolved by the responsible foreman and documented. In addition, any long term resolution of identified deficiencies or discrepancies will

be tracked. The Maintenance Engineer will also review to ensure that appropriate failure cause is identified to allow accurate trending via the Maintenance Planning and Control (MPAC) system.

!

Additionally, Vermont Yankee remains confident that the initiatives identified by

,

the Emergency Diesel Generator Reliability improvement Team will meet the goal of

improving EDG reliability. The initiatives of improving performance monitoring and trending and the introduction of Reliability Centered Maintenance concepts will l

respond directly to the NRC's concerns in the area of " documentation, evaluation and correction of trends and deficiencies associated with the emergency diesel generators".

We trust the information provided is adequate; however, should you have any questions or require additional information, please do not hesitate to contact us.

Very truly yours, i

l VERMONT YANKEE NUCLEAR POWER CORP.

O A

Donald Vice President, Operations cc:

USNRC Regional Administrator, Region 1 USNRC Resident inspector, VYNPS USNRC Project Manager, VYNPS

____

.

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

%aQvnE

-+

o UNITED ST ATES

!'

i',j NUCLEAR REGULATORY COMMISSION j

s y, g

t

REGION I

j

!

475 ALLENDALE ROAD

o KING OF PRUSSIA, PENNSYLVANIA 19436 1415

MAY 121993 Docket No. 50-271 Mr. Donald Vice President, Operations Vermont Yankee Nuclear Power Corporation RD 5, Box 169 Ferry Road Brattleboro, Vermont 05301

Dear Mr. Reid:

SUBJECT:

NOTICE OF VIOLATION (NRC INSPECTION REPORT NO. 50-271/93-10)

This refers to the on-site inspection conducted by Mr. William H. Ruland and l

Mr. M. Eugene Immowitz of this office on April 6-8, 1993, and subsequent in-office

'

review and telephone call with your staff on April 12 and 13,1993. The inspection included a review of activities authorized for your Vermont Yankee facility. At the conclusion of the on-site inspection, the inspectors discussed the findings with those members of your staff identified in the enclosed report. Mr. Ruland also confirmed the initial findings with you during a telephone call on April 28,1993, with Mr. R.J. Wanczyk, Plant Manager.

Areas important to nuclear safety examined during the inspection are identified in the report.

Within these areas, the inspection consisted of selective examinations of procedures, equipment and representative records, and interviews with personnel. The purpose of the inspection was to determine whether activities authorized by the license were conducted safely and in accordance with NRC requirements. In particular, this inspection focused on your maintenance and surveillance programs for your emergency diesel generators.

Based on the results of this inspection, certain of your activities violate NRC requirements, as specified in the enclosed Notice of Violation (Notice). This violation is a concern because Vermont Yankee failed to provide adequate records for engineering reviews when you changed the cylinder liners in the "A" emergency diesel generator and Vermont Yankee failed to provide adequate records for other engineering and maintenance reviews.

You are required to respond to this letter and should follow the instructions specified in the enclosed Notice when preparing your response. In your response, you should document the specific actions taken and any additional actions you plan to prevent recurrence. Also, please inform us what actions Vermont Yankee plans to improve the documentation, evaluation and correction of trends and deficiencies associated with the emergency diesel generators. After reviewing your response to this Notice, including your proposed corrective actions and the results of future inspections, the NRC will determine whether further NRC hDhkhh

!

9f-

_

_ - - - - - _ - - _ -

_

!

I'W 1 s 13k3

'

.

.

.

Mr. Donald,

i enforcement action is necessary to ensure compliance with NRC regulatory requirements.

I In accordance with 10 CFR 2.790 of the NRC's " Rules of Practice," a copy of this letter and its enclosures will be placed in the NRC Public Document Room.

The responses directed by this letter and the enclosed Notice are not subject to the clearance procedures of the Office of Management and Budget as required by the Paperwork Reduction Act of 19S0, Pub. L. No. 96.511.

Sincerely,

Marvin W. Hodges, Director Division of Reactor Safety

Enclosures:

1. Notice of Violation 2. Inspection Repon 50-271/93-10 i

l

REGION I==

VERMONT YANKEE NUCLEAR POWER STATION EMERGENCY DIESEL GENERATOR INSPECTION REIORT NO.

93-10 DOCKET NO.

50-271

LICENSE NO.

DPR-28 LICENSEE:

RDS, Box 169

,

Ferry Road Brattleboro, Vermont 05301

'

INSPECTION AT: Vernon, Vermont

!

INSPECTION DATES: April 6-8,1993 INSPECTORS:

William H. Ruland, Chief, Electrical Section M. Eugene Lazarowitz, Reactor Inspector

,

i

!

SUBMrITED BY:

//

E //f7 William H. Ruland, Chief, Electhcal Section Date

,

b f / /7

.

APPROVED BY:

'

'

'Jacque P. Durr, Chief, Engineefing J6 inch 16 ate S^fSOMY

!,

Q y

!

.

...

.

!

.

.

.

.

,

.

Areas Insoected: This was an announced inspection of the Vermont Yankee diesel generators t

by regional personnel to review the status of several previously identified issues and to j

determine the adequacy of the licensee's actions to resolve these issues.

Results The inspectors found no evidence of a current operability problem with the EDGs

,

!

and concluded that there is reasonable assurance that the EDGs are capable of performing their safety function. The inspectors also concluded that the licensee is in the early stages of

.

implementing the recommendations of the " VERMONT YANKEE EMERGENCY DIESEL

[

GENERATOR RELIABILITY IMPROVEMENT TEAM SUMMARY REPORT." One violation regarding the documentation of the basis for an equivalency evaluation was cited.

The inspectors found several other examples where documentation was inadequate and did not permit proper management review or identification and correction of deficiencies.

,

,

,

'

l

-

-

-

.

.

.

.

.

DETAIIS 1.0 BACKGROUND Vermont Yankee Nuclear Power Station (VYNPS) completed a review of their maintenance and surveillance programs for their emergency diesel generators (EDG) in September 1992.

,

'

They produced a document titled, " Emergency Diesel Generator Reliability Improvement Team Summary Report" (Summary Report). The review was part of the long-term

.

corrective action for two EDG "A" failures in May and June 1992.' Vermont Yankee (VY),

in that LER, attributed the failures to original flaws in the cylinder liner castings. These flaws propagated due to below specification tensile strength material in combination with fatigue cycles and engine overload events. There were also other instances were the EDGs did not start as designed. VY's team was to review the current maintenance and surveillance programs for the EDGs and to identify potential areas for improvement and recommend changes that could improve EDG reliability.

i VY has two standby emergency diesel-generators. Each generator has a continuous rating of 2750 kW and is driven by a Fairbanks-Morse (now a division of Coltec Industries) Model i

38D Series 8-% twelve-cylinder, two-cycle, opposed-piston, turbocharged diesel engine.

2.0 INSPECTION SCOPE The inspection goal was to determine the adequacy of VY current EDG maintenance and i

surveillance, including actions to resolve previously identified problems.

The inspectors reviewed the Summary Report, including selected recommendations, and subsequent licensee actions on those recommendations. The inspectors also examined several maintenance and operational questions involving the EDGs to determine the licensee's commitment to meet the Summary Report's goal ofimproving EDG reliability. In addition, the inspectors conducted a walk-down of both EDGs and interviewed selected personnel

concerning EDG maintenance and surveillance.

'

3.0 STANDARDS The inspectors used the following codes, standards, and requirements in reviewing the licensee's activities:

10 CFR Part 50

i l

'D. letter to USNRC, " Reportable Occurrence No. LER 92-017 Rev.1, February 19, 1993.

i

_

_

'

.

.

.

,

,

s

.

.

Vermont Yankee Technical Specifications 3.10 and 4.10, through amendment 128, i

IEEE 387-1977, "IEEE Standard Criteria for Diesel-Generator Units Applied as

<

Standby Power Supplies for Nuclear Power Generating Stations,"

IEEE 500-1977 " Guide to the Collection and Presentation of Electrical, Eectronic, and Sensing Component Reliability Data for Nuclear-Power Generating Stations."

-

ASTM D-975-90, " Standard Specifications for Diesel Fuel Oils",

4.0 RESOLUTION OF TECIINICAL ISSUES 4.1 Recommendations in Summary Repon The VY team made several recommendations in the following areas: PM (preventative,

maintenance) program / reliability-centered maintenance, cognizant individuals, vendor

,

and industry information, trending and condition monitoring, hardware, and j

surveillance program. The more noteworthy initiatives included the establishment of a reliability-centered maintenance program (end of 1993), establishment of a D/G

'

Perforraance Review Group (charter issued October 1992), and the evaluation of reliability-enhancing modifications / replacements (various). Since these initiatives are new, the inspectors could not judge the present or future effectiveness of the programs.

t

,

The rest of the recommendations were characterized by the inspectors as items

'

correctly identified by VY for accomplishment to bring the EDG maintenance and

surveillance programs up to general industry practice. Examples of this class of

>

recommendations were inclusion of missing vendor-recommended PMs in the VY procedures, incorporation of Fairbanks-Morse (FM) Service Information Letter (SIL)

recommendations, providing training to cognizant individuals, establishment of a

'

trending program, participation in the Devonrue FM Owner's Group, and modifying the Technical Specification to limit fast starts. Based on the inspectors' review of VY i

documents, VY is starting to implement the vast majority of these recommendations.

4.2 Actions For Problems Related to Summary Repon Recommendations 4.2.1 Turbocharger Inspection

,

Summary Report recommendation 5.1 (commitment UND9273 MT 1-9) was implemented and incorporated the PM in maintenance procedure OP 5223.06, revision 12, dated March 19, 1993. That PM was made part of the 18-month maintenance starting 9/92 for EDG "A" and 4/93 for EDG "B." The exhaust side of i

the turbochargers has not been inspected for twenty years. The turbocharger

.

_ _ _ _ _ _ _ _ _ _ _ -

.

,,

.

,

-

.

manufacturer, Elliott, recommends a complete inspection, including the exhaust side, every 8000 hours0.0926 days <br />2.222 hours <br />0.0132 weeks <br />0.00304 months <br /> run time. The VY EDGs have about 3100 hours0.0359 days <br />0.861 hours <br />0.00513 weeks <br />0.00118 months <br /> run time each.

The inspection - and cleaning if needed - of the turbocharger, a 4%-to-5-year vendor-recommended PM, has also not been completed for either EDG.

VY plans to perform the PM during the next refueling outage starting August 1993.

The FM vendor recommendation is, " Clean turbocharger impeller and diffuser if drop in air receiver pressure indicates. Check impeller for excessive end float." In a memo from S. Naeck to the Plant Operations Review Committee (PORC), dated and reviewed on April 15, 1993, VY stated that end float was checked but not recorded (no date given) for EDG "A." The memo stated that it was determined to be not excessive. VY also stated that they had talked to Colt on several occasions about the needed for turbocharger inspections and performance. Colt had suggested that any degrading performance could be detected by scavenging air pressure changes. The licensee could not show the inspectors any records regarding the Colt review or subsequent VY action that were made prior to the inspection. Thus, the licensee could not show that these conclusions regarding the acceptability of the turbochargers without PM completion had been documented and reviewed by management.

Through the above memo and PORC review, VY has now documented and reviewed the issues surrounding turbocharger PMs and feels that the turbochargers exhibit satisfactory performance with no negative trends apparent.

After a thorough independent review of operational data, vendor technical data, and discussions with the vendor representatives, the inspectors concluded that no data existed that would warrant immediate turbocharger inspection.

4.2.2 Jacket-Water Coolant Chemistry Summary Report recommendations 5.4, (UND 9273 CH2, MT6 & 9, OP3) numbers 4) through 8), were all related to jacket-water coolant chemistry.

These recommendations were accepted by VY and resulted in trending of coolant ion concentrations, periodic chemical analysis, and periodic renewal of the coolant.

The inspectors reviewed the "A" jacket-water coolant chemistry problem that was raised in a July 7,1992, memo found in the report. The memo and its attachments note that the diesel jacket coolant (DJC) chemistry is specified by the vendor. While the licensee met most of the requirements, there was room for improvement. The inspectors interviewed plant personnel in this area and found that a program now exists and is achieving success in reducing the iron concentrations in the DJC.

e

..

_ _ _ _ _ _ _ _ _

_

e

.

.

.

.

.

.

During an interview, the inspectors discovered that about four inches of black material, later identified as magnetite, was removed from the " A" EDG expansion tank. VY did not provide the inspectors any information about the effect of the removal of the material on the diesel engine.

One finding from the failed "A" cylinder liner examinations was that some graphitic corrosion had occurred on the coolant side of the cylinder liners. The liners and other parts of the engine coolant surfaces could have been donors for this material with a resultant decrease in component strength. The licensee stated that they would examine the data and determine if the source of the material could be found and if it would have any impact on EDG reliability. This item will remain unresolved pending VY and subsequent NRC review of the technical aspects of this issue. (50-271/93-10-01).

The inspectors did not have an immediate concem with engine integrity since the cylinder liners for the 'A' EDG were replaced in 1992.

4.3 Previously Identified Problem Review 4.3.1

"A" cylinder liner modification The inspectors reviewed Equivalency Evaluation No.92-036, dated June 2,1992, that was performed when the licensee replaced the "A" cylinder liners with a new design after the EDG cylinder liner failures in May and June 1992. The equivalency evaluation identified the critical design characteristics as improved heat transfer and improved seal arrangement.

The justification for the equivalency-therefore not requiring a design change or modification--was based on: the new o-ring and o-ring arrangement was fully interchangeable, and the improved heat removal allowed more or increased heat transfer. The equivalency evaluation did not address the effect of the new liner on fuel consumption, exhaust gas temperature, increased or decreased jacket-coolant temperature or the ability of the engine to meet the FSAR requirement, section 8.5.3, to run for one minute without cooling. VY also provided the inspectors a letter from the vendor to the licensee that originally purchased the liners stating that this change was a like-for-like replacement. The letter identified the old cylinder liner part number that did not match the installed liner number for VY EDG "A."

At the end of the inspection, VY provided the inspectors a memo from K. R.

Swanger and D. C. Girroir, dated April 8,1993, that documented the engineering review performed as part of the equivalency evaluation. 'Ihe memo addressed the VY basis and revision 1 of the memo incloded the vendor concurrence on the equivalency evaluation.

.

_

._

...

.

.

.

.

.;

,

The inspectors concluded that the licensee violated the requirements of 10 CFR 50 l

Appendix B, Criterion XVII - Quality Assurance Records, which requires that sufficient records be maintained to furnish evidence of activities affecting quality and

that those records include records of reviews. The original records did not include a record of the engineering basis for the equivalency evaluation for the replacement cylinder liners. This is violation (50-271/93-10-01).

,

4.3.2 EDG 'A' Oscillations (Closed) Unresolved Item 50-271/92-21-02, Transformer Maintenance - Effect on EDG Reliability In October 1992, EDG 'A' was secured by control room operators due to electrical

.

oscillations one hour into a routine surveillance run. Subsequent investigation by VY revealed a bent contact to a potential transformer (PT) in the voltage regulator sensing

,

circuitry. At the close of the original inspection, VY had not completed their

'

evaluation of the event.

i The inspectors reviewed the evaluation and other industry information to determine the adequacy of VY's actions to resolve an EDG reliability question soon after the

.

issuance of the Summary Report. The inspectors found that the licensee's calculation to demonstrate a rrmimum voltage excursion was based on the EDG in parallel with off-site power. Tnis is not the design basis accident condition. Generator voltage could have risen to a voltage above the machine rating if maximum field current was applied with the machine operating independently during an accident. Loss of the FT l

signal to the voltage regulator would cause maximum field current. After the

!

inspectors questioned the calculation, the licensee reported that relays in the PT circuitry monitors for a blown PT fuse. The relays would shift the voltage regulator

,

to manual operation to prevent an overvoltage event to protect against a failed open contact. However, the oscillations suggested that the contact was making and breaking, causing the variations in KVARs.

e The inspectors noted that there was a similar event with PT connections at another facility.2 VY, in their operating experience review dated September 14, 1987, classified the issue as "no impact on plant operation or safety" since "VY does not

,

have the type of arrangement described."

l

!

!

' NRC INFORMATION NOTICE NO. 87-42:

DIESEL GENERATOR FUSE

<

CONTACTS, September 4,1987.

t i

.-

,

-

, o

.

.

.

.

The inspectors found that the arrangement was, in fact, similar based on inspector document review, PT cabinets are normally designed with this arrangement to prevent electrical shock when opening a PT drawer to replace fuses. Since VY reached the wrong conclusion regarding similarity, no other PT cabinets were examined for a similar problem.

The original unresolved item is closed since the effect of the open contact on EDG reliability was mitigated by the installed relays. However, two additional questions were raised by the inspection: the adequacy of the review of the IN; and the adequacy of the review of the October 1992 EDG oscillations. In each case, the inspections uncovered significant technical information that would have changed VY actions in response to issue had that information been known. This item is Unresolved:

Adequacy of Technical Reviews (50-271/93-10-02) pending further NRC revit.w of VY operating experience reviews.

4.3.3 EDG Fuel Oil Quality The inspectors reviewed Appendix E of the Summary Report titled, " Diesel Fuel Oil, Lubricating Oil and Air Requirements for Fairbanks Morse Emergency Diesel Generators," to verify that the appropriate standards were applied and problems identified and corrected. VY had identified that the cetane number for the fuel in the main diesel fuel oil storage tank had dropped to 38.9 for the July 29,1992, sample.

The trend had been steadily downward since the October 31,1991, sample.

VY stated that they discussed this matter with FM. Based on this discussion, they determined that they had no evidence of engine damage due to low cetane fuel. They also determined that the vendor cetane number of 45 for winter operation was not a rule, but a recommendation. Because of the decreasing cetane number, they have implemented a program of fuel sampling before delivery. They use Saybolt Laboratory's test engirse to get exact cetane ratings before putting the new fuel in their tank.

VY noted that the main fuel oil tank also supplies the on-site boiler units, ensuring a frequent turnover of fuel. They stated that they are having difficulty in finding fuel with a cetane rating higher than the minimum required (40). VY stated that the tank has been at or above the minimum since the July 29,1992, sample. The inspectors reviewed recent sample results and verified that the cetane number has been maintained above 40 since July 1992. Also, the inspectors could not identify any clear link between the low cetane number and any significant deleterious effects on the engine.

The inspectors concluded that once the low cetane number was found, VY's actions were appropriate.

.

-

.

.

-

.

'

.

4.3.4 EDG "A" Speed Switch Replacement The inspectors reviewed the problems thot arose when the licensee tried to replace their speed switch on the "A" machine. The licensee found that the old speed switch was out of calibration. They elected to replace the old switch with a new one obtained from the vendor. They verified that the part numbers were the same, and Maintenance checked out the switch for calibration. The licensee noted that when they attempted to install the switch, the wiring in the switch connector was different from the engine wiring harness. The licensee investigated the differences and determined that although the part numbers were the same, the switch supplied was different from the originally installed switch. The licensee reported that they plan to file a 10 CFR 21 report on this item. The inspectors concluded that based on the evidence supplied by the licensee, the licensee handled the issue in a correct and

{

timely manner.

l The licensee decided to reuse the old speed switch since they did not have the exact replacement on-site. They decided to recalibrate the switch, and attempted to determine the tolerance on the calibrated settings. The high setting, 800 RPM, is used for the field flashing permissive. This setting can affect the time reqd J for the machine voltage to build up to the proper value. The licensee chose a value without providing any engineering evaluation to demonstrate that the machine speed and voltage would not cause an overvoltage transient or an under frequency transient when the machine loads. This is unresolved item pending further NRC review (50-271/93-10-02).

4.4 Maintenance The inspectors reviewed the documentation for the 'B' EDG maintenance performed March 29-31,1993, to determine the adequacy of work and to verify that identified problems were resolved. Other maintenance documents were reviewed along with personnel interviews to determine the adequacy of maintenance. The inspectors reviewed the following areas:

4.4.1 Overtorquing to Stop Leaking Fittings and Corroded Fittings and Surfaces There were several areas where the maintenance log showed that a bolt or fitting was torqued to a specific value but, during the hydrostatic test, the fitting or bolt was again tightened to stop a leak. A specific log entry that their review of the log for March 29 showed one place where maintenance torqued the listed fitting metal-to-metal at 0620, and maintenance personnel retightened the fitting at 0645 because it had loosened in the intervening interval of 25 minutes. The inspectors question how the fitting could have loosened in 25 minutes. This discrepancy could also be the result of imprecise log-keeping practices.

_

_ _ _ _ _ _ _ _ -

e

.

,.,

,.

,

.

-

.

.

The maintenance log shows that maintenance personnel found an *O" ring surface with heavy corrosion and noted that they would " clean it up as best we can." The licensee needs to determine what impact the corrosion products on seal surface will have on the boundary leakage over time. The failure of the seal could allow leakage of coolant during operation.

The inspectors were unable to determine the resolution to the above discrepancies during the document review or interviews. These are additional examples of failure to document a problem along with adequate resolution.

4.4.2 Bolting Based on a previous violation, (see inspection report 92-21), VY established additional controls on bolt torquing. The inspectors reviewed the maintenance log and other records to verify appropriate controls on the torquing process. Work order

1. 93-01722-00, dated April 1,1993, showed that bolts on EDG 'B' were checked for proper torque after maintenance. However, the maintenance log documented bolt-hole thread damage without indicating the cause or the corrective action. The inspectors identified the failure to document the resolution or cause of the damage was a weakness in VY's bolting program.

4.4.3 Maintenance Program Weaknesses The maintenance log showed that before the "B" EDG was removed from service, the

"A" EDG was tested, and the "A" speed switch was found out of calibration. The

"B" EDG was tested at the end of the maintenance inspection and its speed switch was also found out of calibration. These switches were just recently added to the surveillance testing in response to an NRC non-cited violation (see inspection report 93 '4). The switches provide a permissive to allow the EDG breaker to close when the EDG reaches rated speed and voltage. The inspectors have no current concerns with the testing of the speed switch.

The post-maintenance data sheet used to log the various engine parameters during the post-maintenance engine run for the March 31,1993, EDG 'B' showed that the lube oil temperature out of the engine was 190*F. This was less than the acceptance criterion of 195-215*F. There was no indication that the licensee had identified the out-of-specification value. VY reported that the log entry was in error, and the value should have been 195*F. The licensee stated that they contacted the person who made the log entry to confirm that the data was incorrectly logged. This is a weakness in the maintenance program in that the review performed was inadequate to identify an out-of-specification value.

-

_ - _ _ _ _ _ _

r

,...

.,

,

-

.

.

I1 The inspectors uviewed the general condition of the machines. They found several discrepancies with the "B" machine, which had been returned to service after maintenance less than one week before the inspection.

These discrepancies included:

several fuel injector pumps had safety wire holding the fuel plug in place, but

a larger number did not have the safety wire conduit that contains the field cable from the exciter to the generator field was e

,

broken and had a sharp edge rubbing the field cable a broken weld on the drip pan under the "Rootes" blower casing e

several copper fuel and air lines were crimped e

electrical tape had been used as a cushion material between an instrument line

and a clamp. In several cases, the electrical tape had fallen away exposing the instrument line to the chaffing action of the clamp.

The inspectors discussed these items with the licensee. The licensee stated that although the "B" unit had undergone an inspection, they did not clean or inspect it completely. This is a weakness in the maintenance program in that all discrepancies on the EDGs were not identified or corrected.

The inspectors found several fuel oil valves in the fuel oil daytank rooms had not been cleaned with dried fuel oil residue around the packing and valve body. without removing the residue, additional or continuing leaks are more difficult to detect. This observation applied to leaking lubricating oil valves underneath the exhaust and intake piping for the EDGs.

Regarding the safety wire issue, VY stated that the vendor had changed their design, and current injection pumps do not need safety wire because of a self-locking feature associated with the plug. The inspectors were not shown any evidence that VY had previously identified the difference. This item remains unresolved pending the inspector's verification of the self-locking feature (50-271/93-10-04).

VY was shown the damaged conduit and was not aware of the damage. They are investigating why the damage was not caught during the maintenance inspection.

The above deficiencies remain unresolved pending inspector review of licensee corrective actions, for the individual items and any generic action taken to address EDG deficiencies. (50-271/93-10-05).

.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -

_-

__

-

,..

.

.

-

.

.

5.0 PROGRAMMATIC ISSUES

,

5.1 Overall Responsibility for the Emergency Diesel Generator The inspectors found that the licensee is using a team approach for review / oversight

,

i of the EDG program. The appointed team, the EDG Performance Review Group, has been chartered, per R. J. Wanczyk memo dated October 20,1992, to meet i

periodically, discuss the current problems, discuss resolution of old problems,

,

recommend future actions such as reliability centered maintenance actions, and list open items and report status semiannually to management.

The inspectors had two questions with this approach. First, formal meeting minutes were not required. This prevents a careful internal or external review of the group's actions. Second, overall responsibility for the EDGs at the working level has been shared by several portions of the organization. While this is not the typical industry arrangement, only future EDG performance can demonstrate the organization's t

effectiveness.

5.2 Trending The inspectors reviewed the "B" EDG surveillance run that was performed after the j

maintenance inspection. This run was performed on the morning of March 31,1993.

'

The inspectors noted that the scavenging air pressure has a downward trend during the run, while the individual cylinder exhaust temperatures and the average cylinder exhaust temperatures demonstrate an upward trend. The inspectors reviewed the turbocharger temperatures shown on the maintenance run and noted that the temperature difference across the turbochargers seems low while the exhaust temperature seems high. The inspectors reviewed the "A" EDG cylinder exhaust temperatures and noted that they were stable under the same load and chronological conditions.

The inspectors asked the licensee to address the questions of continued exhaust temperature rise and turbocharger airbox trends. The licensee stated that the major temperature trends that they are concerned with are the water and lube oil temperatures. They consider the machine to be in equilibrium at the end of one hour.

They do not review the temperatures after one hour for changing conditions since they use the one hour data to satisfy Technical Specification (TS) requirement 4.10 A.I.a that requires that "cach diesel generator shall be started and loaded once a month for sufficient time for the diesel engine and generator to reach equilibrium temperatures at expected maximum emergency loading not to exceed the continuous rating to demonstrate operational readiness." They contacted the vendor, and in a conference call with the vendor, the licensee, and the NRC, the vendor stated that they did not feel that any turbocharger problems existed.

- _ _ _ _ _ _ _

i

-...

,

,

-

.

.

The vendor felt that the exhaust temperatures were caused by load changes or environmental changes. The inspectors noted that the "A" machine did not have these trends and that it appears that the "B" machine never reached equilibrium temperature during the surveillance run. The inspectors noted that the surveillance run on December 23,1991 showed an average exhaust temperature rise of about 5.5 over a two hour period with the load listed as 2630 kW at both times. The inspectors noted that if this rate of rise is ansumed to be linear, the average exhaust temperature would reach 1100*F in about 113 hours0.00131 days <br />0.0314 hours <br />1.868386e-4 weeks <br />4.29965e-5 months <br /> or about five days of running.

The inspectors did note that not enough is known about the dynamics of this condition to determine the shape of any curve for the heat rise. The FM representative stated j

that he did not see any unacceptable trends. FM stated that additional information l

regarding outside air temperature, fuel rack position and exact engine load would be needed to completely evaluate any trend. The inspectors are concerned that equilibrium conditions may not have been reached for the "B" machine. This item remains unresolved pending the licensee's fm' al resolution of any tempe:ature trends during current EDG runs and establishment of criteria that meets the TS surveillance requirement (50-271/93-10-06).

5.3 SIL Recommendations The inspectors note'l that the Task Force Summary Report made several observations about the methods used to handle SIL recommendations. Several recommendations regarding improved incorporation of vendor SILs were made including incorporating SIL references in procedures and additional review of previous SILs for current

,

'

applicability. The inspectors did not perform a detailed review of SIL imph: mentation but did find one example where review appeared inadequate. In SIL Volume A, Issue 25, dated August 1,1991, fast start engines, i.e. engines in nuclear service, were recommended to have the overspeed trip reset to 115% to 117% (from 112% to 115%) of rated speed to prevent inadvertent engine shutdown. No satisfactory explanation was provided to the inspector on why this recommendation was not implemented. The inspectors questioned the licensee's initial response that no problems had occurred with overspeed trips since this was the same response not deemed adequate in the Summary Report. The incorporation of vendor SILs into the maintenance program was correctly identified by VY as warranting improvement.

The inspectors found no conditions regarding SIL implementation that showed a r

current problem existed with the EDGs. However, the resolution of VY SILs will

'

remain an unresolved item pending further inspections in this area (50-271/93-10-07).

_ _ ________________

__

g

..,

.

..

.

.

,

-

.

~

-

6.0 CONCLUSIONS Based on the information supplied by the licensee and the vendor, the inspectors found no

evidence of a current ooerability problem with either EDG and that there was reasonable assurance that the EDGs are capable of performing their safety function.

The inspectors found numerous examples wem a particular problem or review was not documented for resolution or management / technical review. These examples include:

Turbocharger end fioat inspection not documented (see { 4.2).

• I Discussions about turbocharger maintenance and acceptability of turbocharger

performance not documented in Summary Report or other document for management r

review (see 6 4.2).

i Evaluations performed to justify the equivalency evaluations were not documented and

thus could not be reviewed (see Q 4.3.1).

!

Magnetite removed from "A" EDG expansion tank was not documented or evaluated

'

(seef4.2).

i Not all maintenance deficiencies were documented and therefore planned for j

u correction (see f 4.4.3).

The inspectors concluded that there are areas within the licensee's EDG program that have i

not yet been implemented or warrant additional licensee attention. VY needs to develop a

!

more rigorous approach to documenting and reviewing EDG data.

7.0 UNRESOLVED ITEMS Unresolved items are matters about which more information is required to ascertain whether they are acceptable items or violations.

8.0 EXIT MEETING The inspectors discussed the inspection with the licensee on April 29,1993, and summarized the scope and results of the inspection. In particular, the inspectors informed the licensee about the basis of the potential violation of 10 CFR Part 50 Appendix B Criterion XVII and the importance of finding the equilibrium conditions for the "B" EDG. The inspectors noted the need to maintain correct records of engine data taken during Maintenance runs. The inspectors noted the need for increased diligence in the area of EDG cleanliness and the need for observing the physical condition of the EDGs. The inspectors noted that they obsen'ed the implementation of the goals in the licensee's report, but it appears that the implementation is in a very early stage.

i

.....

...

'

~

.

,;

ATTACIBiENT 1 l

l Persons Contacted Vermont Yankee

'

,

i I

1. • Frank Helin, Prcject Engineer - Coord.

• Gary Cappuccio, ME&C Supervisor

>

R. P. Grippardi, QA Supervisor

1. M. Metell, Principal Engineer

• Richard Lopriore, Maintenance Manager

1. • R. D. Pagodin, Ops Superintendent

• S. J. Jefferson, Assistant to Plant Manager

"S. K. Naeck, Maintenance Engineer

,

• William T. Penniman, Procurement for Supervisor l

!

Craig Nichols, Maintenance Production Supenisor

'

• Wayne M. Limberger, Materials Manager

• Bernard Buteau, Engineering Director

• Thomas F. Schimelpfenig, Director, Procurement and Info. Systems

1. S. Primavera, Maintenance Production Supenisor

,

1. R. J. Wanczyk, Plant Manager US Nuclear Regulatory Commission

1. • Harold Eichenholz, Senior Resident Inspector

• Paul Harris, Resident Inspector (

Other Oreanizations i

Thomas Stull, Fairbanks Morse Co.

'

Don Kelso, Elliott Co.

[

i

!

!

• Attended pre-exit meeting on April 8,1993

,

1. Participated in telephone exit on April 29,1993

!

t

,

k