Information Notice 1986-26, Potential Problems in Generators Manufactured by Electrical Products Incorporated: Difference between revisions

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| issue date = 04/17/1986
| issue date = 04/17/1986
| title = Potential Problems in Generators Manufactured by Electrical Products Incorporated
| title = Potential Problems in Generators Manufactured by Electrical Products Incorporated
| author name = Jordan E L
| author name = Jordan E
| author affiliation = NRC/IE
| author affiliation = NRC/IE
| addressee name =  
| addressee name =  
Line 14: Line 14:
| page count = 5
| page count = 5
}}
}}
{{#Wiki_filter:SSINS No.: 6835IN 86-26UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF INSPECTION AND ENFORCEMENTWASHINGTON, D.C. 20555April 17, 1986INFORMATION NOTICE NO. 86-26: POTENT1AL PROBLEMS IN GENERATORS MANUFACTUREDBY ELECTRICAL PRODUCTS INCORPORATED
{{#Wiki_filter:SSINS No.: 6835 IN 86-26 UNITED STATES
 
NUCLEAR REGULATORY COMMISSION
 
OFFICE OF INSPECTION AND ENFORCEMENT
 
WASHINGTON, D.C. 20555 April 17, 1986 INFORMATION NOTICE NO. 86-26:   POTENT1AL PROBLEMS IN GENERATORS MANUFACTURED
 
BY ELECTRICAL PRODUCTS INCORPORATED


==Addressees==
==Addressees==
:All nuclear power reactor facilities holding an operating license (OL) or aconstruction permit (CP).
:
All nuclear power reactor facilities holding an operating license (OL) or a
 
construction permit (CP).


==Purpose==
==Purpose==
:This notice is to alert recipients to a potentially significant problem involvingthe failure of Electrical Products Incorporated (EPI) diesel generators withoutprior warning during an emergency demand. Actions taken by licensees to preventrecurrence also are discussed. It is expected that recipients will review thisinformation for applicability to their facilities and consider actions, ifappropriate, to preclude a similar problem occurring at their facilities.However, suggestions-contained in this information notice do not constitute NRCrequirements; therefore, no specific action or written response is required.
:
This notice is to alert recipients to a potentially significant problem involving
 
the failure of Electrical Products Incorporated (EPI) diesel generators without
 
prior warning during an emergency demand. Actions taken by licensees to prevent
 
recurrence also are discussed. It is expected that recipients will review this
 
information for applicability to their facilities and consider actions, if
 
appropriate, to preclude a similar problem occurring at their facilities.
 
However, suggestions-contained in this information notice do not constitute NRC
 
requirements; therefore, no specific action or written response is required.


==Description of Circumstances==
==Description of Circumstances==
:Washington Public Power Supply System (WPPSS) Unit 2On July 21, 1983, emergency diesel generator (DG) 1A had high vibration levelreadings accompanied by sparks from the rotor shaft bearing area. Upon disas-sembly it was determined that a shim, required to maintain clearance at thethrust bearing, was missing. Inspection of DG 1B showed that the same shim wasmissing. The two generators were returned to EPI (Cleveland, Ohio) where themissing shim was installed and the damaged areas refurbished. The originaldesign, which placed electrical insulation between the rotor shaft and theslip-ring end bearing inner race, was maintained.On July 9, 1984, during monthly surveillance testing, a high vibration alarmwas observed on emergency DG 1B. Investigation after completion of the 4-hourtest revealed that the slip-ring end bearing had turned on the shaft insulationdestroying the insulation. The reduction in insulation cross sectional thick-ness allowed the rotor shaft to drop slightly and rub on the bearing housing.The corrective action employed after this failure was a design modification.The insulation between the bearing and the shaft was removed and the bearingwas mounted directly on the shaft. The bearing housing was insulated to providethe required electrical insulation. No failure has-been reported since thereported test failure in July 1984.8604150542  
:
* IN 86-26April 17. 19v6 Grand Gulf Unit 1 K>At Grand Gulf Unit 1, the high pressure core spray pump is powered by a dedicateuDG. On July 13, 1985, during surveillance testing, the generator failed and wasobserved to be emitting sparks. Power Systems Division (PSD) of Morrison Knudsen,the supplier of the DG unit, determined that the electrical insulation betweenthe inner race of the cylindrical roller bearing at the slip-ring end and therotor shaft had degraded. The degradation allowed the shaft to drop down andrub the inner and outer oil seals causing the sparks. EPI and PSD have developeda procedure to implement the same design modification at Grand Gulf as usedpreviously at WPPSS.Watts Bar Unit 2On June 10, 1983, during the performance of a test, the generator shaft wasobserved to be rubbing against the inner and outer oil seals at the slip-ringend. Examination after disassembly revealed that the thickness of the oilthrower was less than specified, causing a mismatch between the inner and outerraces of the slip-ring end bearing that resulted in the inner race breakingloose and turning on the underlying electrical insulation.The repairs at a Tennessee Valley Authority (TVA) workshop consisted of rebuil-ding oil seals, polishing the shaft under the oil seals, replacing the insula-tion material under the bearing, machining the bearing housing cap to correctthe alignment, adding a shim to restrain the outer race, and installing newbearings. TVA inspected four other generators and made similar modifications.Background:The failures occurred in electrical generators manufactured at EPI located inCleveland, Ohio. EPI was a division of Portec from 1969-1979. In 1979, Portecsold EPI to Northern Electrical Industries-Parsons Peebles (NEI-Peebles) ofGreat Britain. The manufacturing operations at Cleveland ceased in the Fall of1984. Currently, EPI furnishes spare parts and modifications to existing units.Discussion:The failures described above have all occurred at the slip-ring end of the tandemdiesel engine configurations. Installation of the insulation between the rotorshaft and the bearing also is used for single engine applications and in somecases it is installed under the shaft bearing at the other end of the generatoras well. The purpose of the insulation (3M Scotchply brand, type 1009, glass/epoxycomposite tape) is to prevent circulating currents through the generator shaft.This insulation method was limited by EPI to 8-pole 900-rpm machines. Theinitiating failure mechanism of the insulation has been attributed by varioussources to insulation creep fatigue, misalignment of the engines, poor insulationworkmanship, or inadequate original design. The first WPPSS and the Watts Barfailures appear-to be isolated cases of improperly machined pieces; however, thefailures manifest themselves in a similar manner and may be discovered during thechecks for insulation damag IN 86-26April 17, 1986 PSD has stated that a procedure to monitor shaft movement will have to be specificfor each plant because of design differences that impact the allowable movementand the jacking force. Jacking the shaft up and down and recording the movementwill determine the vertical play between the shaft and bearing housing, out careshould be taken to use a load cell or circle force gauge between the jack andthe generator shaft to prevent damage.Other suppliers that have used EPI generators include Stewart & Stevenson, Alcoand Bruce GM (EMD). See Attachment 1 for a list of facilities identified oyEPI and PSD as recipients of the subject generators. Some of the generatorsnave been resold from the original customer or user and some have been cancelled;therefore specific plant applications may be different than originally supplied.No specific action or written response is required by this notice. If you naveany questions regarding this notice, please contact the Regional Aaministratorof the appropriate NRC regional office or this office.X\visli/fEdward L ordan, DirectorDivisior of Emergency Preparednessand Engineering ResponseOffice of Inspection and EnforcementTecnnical Contacts: James C. Stewart, IE(301) 492-9061K.R. Naidu, IE(301) 492-4179
Washington Public Power Supply System (WPPSS) Unit 2 On July 21, 1983, emergency diesel generator (DG) 1A had high vibration level
 
readings accompanied by sparks from the rotor shaft bearing area. Upon disas- sembly it was determined that a shim, required to maintain clearance at the
 
thrust bearing, was missing. Inspection of DG 1B showed that the same shim was
 
missing. The two generators were returned to EPI (Cleveland, Ohio) where the
 
missing shim was installed and the damaged areas refurbished. The original
 
design, which placed electrical insulation between the rotor shaft and the
 
slip-ring end bearing inner race, was maintained.
 
On July 9, 1984, during monthly surveillance testing, a high vibration alarm
 
was observed on emergency DG 1B. Investigation after completion of the 4-hour
 
test revealed that the slip-ring end bearing had turned on the shaft insulation
 
destroying the insulation. The reduction in insulation cross sectional thick- ness allowed the rotor shaft to drop slightly and rub on the bearing housing.
 
The corrective action employed after this failure was a design modification.
 
The insulation between the bearing and the shaft was removed and the bearing
 
was mounted directly on the shaft. The bearing housing was insulated to provide
 
the required electrical insulation. No failure has-been reported since the
 
reported test failure in July 1984.
 
8604150542
 
*                     IN 86-26 April 17. 19v6 Grand Gulf Unit 1                                                                       K>
  At Grand Gulf Unit 1, the high pressure core spray pump is powered by
 
a dedicateu
 
DG. On July 13, 1985, during surveillance testing, the generator failed
 
observed to be emitting sparks. Power Systems Division (PSD) of Morrison and was
 
the supplier of the DG unit, determined that the electrical insulation         Knudsen, the inner race of the cylindrical roller bearing at the slip-ring end     between
 
rotor shaft had degraded. The degradation allowed the shaft to drop and the
 
rub the inner and outer oil seals causing the sparks. EPI and PSD     down and
 
a procedure to implement the same design modification at Grand Gulf have    developed
 
previously at WPPSS.                                                 as  used
 
Watts Bar Unit 2 On June 10, 1983, during the performance of a test, the generator
 
observed to be rubbing against the inner and outer oil seals at theshaft was
 
end. Examination after disassembly revealed that the thickness of slip-ring
 
thrower was less than specified, causing a mismatch between the innerthe oil
 
races of the slip-ring end bearing that resulted in the inner race       and outer
 
loose and turning on the underlying electrical insulation.         breaking
 
The repairs at a Tennessee Valley Authority (TVA) workshop consisted
 
ding oil seals, polishing the shaft under the oil seals, replacing     of rebuil- the
 
tion material under the bearing, machining the bearing housing cap to insula- the alignment, adding a shim to restrain the outer race, and installingcorrect
 
bearings. TVA inspected four other generators and made similar modifications.new
 
Background:
The failures occurred in electrical generators manufactured at EPI located
 
Cleveland, Ohio. EPI was a division of Portec from 1969-1979. In 1979,           in
 
sold EPI to Northern Electrical Industries-Parsons Peebles (NEI-Peebles)       Portec
 
Great Britain. The manufacturing operations at Cleveland ceased in             of
 
the
 
1984. Currently, EPI furnishes spare parts and modifications to existing     Fall  of
 
units.
 
Discussion:
The failures described above have all occurred at the slip-ring end
 
diesel engine configurations. Installation of the insulation betweenof the tandem
 
the rotor
 
shaft and the bearing also is used for single engine applications and
 
cases it is installed under the shaft bearing at the other end of the in some
 
as well. The purpose of the insulation (3M Scotchply brand, type 1009,generator
 
composite tape) is to prevent circulating currents through the generator glass/epoxy
 
This insulation method was limited by EPI to 8-pole 900-rpm machines.         shaft.
 
initiating failure mechanism of the insulation has been attributed by     The
 
sources to insulation creep fatigue, misalignment of the engines, poor   various
 
workmanship, or inadequate original design. The first WPPSS and the         insulation
 
failures appear-to be isolated cases of improperly machined pieces;     Watts    Bar
 
however, the
 
failures manifest themselves in a similar manner and may be discovered
 
checks for insulation damage.                                              during the
 
IN 86-26 April 17, 1986 PSD has stated that a procedure to monitor shaft movement will have to be specific
 
for each plant because of design differences that impact the allowable movement
 
and the jacking force. Jacking the shaft up and down and recording the movement
 
will determine the vertical play between the shaft and bearing housing, out care
 
should be taken to use a load cell or circle force gauge between the jack and
 
the generator shaft to prevent damage.
 
Other suppliers that have used EPI generators include Stewart & Stevenson, Alco
 
and Bruce GM (EMD). See Attachment 1 for a list of facilities identified oy
 
EPI and PSD as recipients of the subject generators. Some of the generators
 
nave been resold from the original customer or user and some have been cancelled;
therefore specific plant applications may be different than originally supplied.
 
No specific action or written response is required by this notice. If you nave
 
any questions regarding this notice, please contact the Regional Aaministrator
 
of the appropriate NRC regional office or this office.
 
X\visli/f
 
Edward L ordan, Director
 
Divisior of Emergency Preparedness
 
and Engineering Response
 
Office of Inspection and Enforcement
 
Tecnnical Contacts:   James C. Stewart, IE
 
(301) 492-9061 K.R. Naidu, IE
 
(301) 492-4179 Attachments:
 
===I.  List of EPI 900 RPM Generators===
2. List of Recently Issued IE Information Notices
 
Attachment 1 IN 86-26 April 17, 1986 Domestic EPI 900 RPM Generators
 
Customer/Site                      No. Units                D/G Supplier
 
Arkansas P&L/Nuclear 1                    2                  Stewart & Stevenson
 
Boston Edison/Pilgrim 1                  2                  ALCO
 
Duke Power/Oconee                        1                  PSD
 
Florida P&L/St. Lucie                    2                  PSD
 
Houston L&P/Allens Creek                  1 (See Note 1)      PSD
 
Jersey Central P&L/Oyster Creek          2 (See Note 2)      PSD
 
Mississippi P&L/Grand Gulf                2                  PSD
 
Mississippi P&L/Grand Gulf                2                  Bruce GM (EMD)
New York State Power                      4                  Bruce GM (EMD)
  Authority/FitzPatrick
 
Pacific G&E/Diablo Canyon                5                  ALCO
 
Portland G&E/Trojan                      2                  PSD
 
Public Service of Oklahoma/Black Fox      2 (See Note 3)    PSD
 
Puget Sound/Skaggit                      1                  PSD
 
SMUD/Rancho Seco                          2                  Bruce GM (EMD)
TVA/Hartsville, Phipps Bend              6 (See Note 4)    PSD
 
TVA/Sequayah                              4                  Bruce GM (EMD)
TVA/Sequayah                              1                  PSD
 
TVA/Watts Bar                            6                  PSD
 
Vepco/North Anna                          4                  Stewart & Stevenson
 
WPPSS/Hanford 1                          2                  Stewart & Stevenson
 
Notes:    1.  Generator returned to PSD
 
2.  Obtained from TVA
 
3.  One unit sent to foreign plant, one unit spare
 
4.  Two units to Oyster Creek, three units sent to foreign plants, one unit sent to NASA
 
Attachnient 2 IIN 86-26 April 17,  1986 LIST OF RECENTLY ISSUED
 
IE INFORMATION NOTICES
 
Information                                  Date of
 
Notice No.    Subject                        Issue  __Issued to-
86-25          Traceability And Material      4/11/86    All power reactor
 
Control Of Material And                    facilities holding
 
Equipment, Particularly                    an OL or CP
 
Fasteners
 
86-24          Respirator Users Notice:      4/11/86    All power reactor
 
Increased Inspection Frequency            facilities holding
 
For Certain Self-Contained                an OL or CP; research
 
Breathing Apparatus Air                    and test reactor
 
Cylinders                                  facilities; fuel
 
cycle licensees and
 
Priority 1 material
 
licensees
 
86-23          Excessive Skin Exposures Due  4/9/86      All power reactor
 
To Contamination With Hot                  facilities holding
 
Particles                                  an OL or CP
 
86-22          Underresponse Of Radition      3/31/86    All power reactor
 
Survey Instrument To High                  facilities holding
 
Radiation Fields                          an OL or CP and
 
research and test
 
reactors
 
86-21          Recognition Of American        3/31/86    All power reactor
 
Society Of Mechanical                      facilities holding
 
Engineers Accreditation                    an OL or CP and all
 
Program For N Stamp Holders                recipients of NUREG-
                                                          0040 (white book)
86-20          Low-Level Radioactive Waste    3/28/86    All power reactor
 
Scaling Factors, 10 CFR                    facilities holding
 
Part 61                                    an OL or CP
 
86-19          Reactor Coolant Pump Shaft    3/21/86    All power reactor
 
Failure At Crystal River                  facilities holding
 
an OL or CP
 
86-18          NRC On-Scene Response During  3/26/86    All power reactor
 
A Major Emergency                          facilities holding
 
an OL or CP
 
OL = Operating License


===Attachments:===
CP = Construction Permit}}
I. List of EPI 900 RPM Generators2. List of Recently Issued IE Information Notices Attachment 1IN 86-26April 17, 1986 Domestic EPI 900 RPM GeneratorsCustomer/SiteNo. UnitsD/G SupplierArkansas P&L/Nuclear 1Boston Edison/Pilgrim 1Duke Power/OconeeFlorida P&L/St. LucieHouston L&P/Allens CreekJersey Central P&L/Oyster CreekMississippi P&L/Grand GulfMississippi P&L/Grand GulfNew York State PowerAuthority/FitzPatrickPacific G&E/Diablo CanyonPortland G&E/TrojanPublic Service of Oklahoma/Black FoxPuget Sound/SkaggitSMUD/Rancho SecoTVA/Hartsville, Phipps BendTVA/SequayahTVA/SequayahTVA/Watts BarVepco/North AnnaWPPSS/Hanford 122121222452212641642(See Note 1)(See Note 2)(See Note 3)(See Note 4)Stewart & StevensonALCOPSDPSDPSDPSDPSDBruce GM (EMD)Bruce GM (EMD)ALCOPSDPSDPSDBruce GM (EMD)PSDBruce GM (EMD)PSDPSDStewart & StevensonStewart & StevensonNotes: 1. Generator returned to PSD2. Obtained from TVA3. One unit sent to foreign plant, one unit spare4. Two units to Oyster Creek, three units sent to foreign plants,one unit sent to NASA Attachnient 2IIN 86-26April 17, 1986LIST OF RECENTLY ISSUEDIE INFORMATION NOTICESInformation Date ofNotice No. Subject Issue __Issued to-86-25Traceability And MaterialControl Of Material AndEquipment, ParticularlyFasteners4/11/8686-24Respirator Users Notice: 4/11/86Increased Inspection FrequencyFor Certain Self-ContainedBreathing Apparatus AirCylinders86-2386-2286-21Excessive Skin Exposures DueTo Contamination With HotParticlesUnderresponse Of RaditionSurvey Instrument To HighRadiation FieldsRecognition Of AmericanSociety Of MechanicalEngineers AccreditationProgram For N Stamp HoldersLow-Level Radioactive WasteScaling Factors, 10 CFRPart 61Reactor Coolant Pump ShaftFailure At Crystal RiverNRC On-Scene Response DuringA Major Emergency4/9/863/31/863/31/863/28/863/21/863/26/86All power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CP; researchand test reactorfacilities; fuelcycle licensees andPriority 1 materiallicenseesAll power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CP andresearch and testreactorsAll power reactorfacilities holdingan OL or CP and allrecipients of NUREG-0040 (white book)All power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CPAll power reactorfacilities holdingan OL or CP86-2086-1986-18OL = Operating LicenseCP = Construction Permit}}


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Latest revision as of 03:04, 24 November 2019

Potential Problems in Generators Manufactured by Electrical Products Incorporated
ML031220661
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Skagit, Marble Hill
Issue date: 04/17/1986
From: Jordan E
NRC/IE
To:
References
IN-86-026, NUDOCS 8604150542
Download: ML031220661 (5)
v • d • e


SSINS No.: 6835 IN 86-26 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 April 17, 1986 INFORMATION NOTICE NO. 86-26: POTENT1AL PROBLEMS IN GENERATORS MANUFACTURED

BY ELECTRICAL PRODUCTS INCORPORATED

Addressees

All nuclear power reactor facilities holding an operating license (OL) or a

construction permit (CP).

Purpose

This notice is to alert recipients to a potentially significant problem involving

the failure of Electrical Products Incorporated (EPI) diesel generators without

prior warning during an emergency demand. Actions taken by licensees to prevent

recurrence also are discussed. It is expected that recipients will review this

information for applicability to their facilities and consider actions, if

appropriate, to preclude a similar problem occurring at their facilities.

However, suggestions-contained in this information notice do not constitute NRC

requirements; therefore, no specific action or written response is required.

Description of Circumstances

Washington Public Power Supply System (WPPSS) Unit 2 On July 21, 1983, emergency diesel generator (DG) 1A had high vibration level

readings accompanied by sparks from the rotor shaft bearing area. Upon disas- sembly it was determined that a shim, required to maintain clearance at the

thrust bearing, was missing. Inspection of DG 1B showed that the same shim was

missing. The two generators were returned to EPI (Cleveland, Ohio) where the

missing shim was installed and the damaged areas refurbished. The original

design, which placed electrical insulation between the rotor shaft and the

slip-ring end bearing inner race, was maintained.

On July 9, 1984, during monthly surveillance testing, a high vibration alarm

was observed on emergency DG 1B. Investigation after completion of the 4-hour

test revealed that the slip-ring end bearing had turned on the shaft insulation

destroying the insulation. The reduction in insulation cross sectional thick- ness allowed the rotor shaft to drop slightly and rub on the bearing housing.

The corrective action employed after this failure was a design modification.

The insulation between the bearing and the shaft was removed and the bearing

was mounted directly on the shaft. The bearing housing was insulated to provide

the required electrical insulation. No failure has-been reported since the

reported test failure in July 1984.

8604150542

  • IN 86-26 April 17. 19v6 Grand Gulf Unit 1 K>

At Grand Gulf Unit 1, the high pressure core spray pump is powered by

a dedicateu

DG. On July 13, 1985, during surveillance testing, the generator failed

observed to be emitting sparks. Power Systems Division (PSD) of Morrison and was

the supplier of the DG unit, determined that the electrical insulation Knudsen, the inner race of the cylindrical roller bearing at the slip-ring end between

rotor shaft had degraded. The degradation allowed the shaft to drop and the

rub the inner and outer oil seals causing the sparks. EPI and PSD down and

a procedure to implement the same design modification at Grand Gulf have developed

previously at WPPSS. as used

Watts Bar Unit 2 On June 10, 1983, during the performance of a test, the generator

observed to be rubbing against the inner and outer oil seals at theshaft was

end. Examination after disassembly revealed that the thickness of slip-ring

thrower was less than specified, causing a mismatch between the innerthe oil

races of the slip-ring end bearing that resulted in the inner race and outer

loose and turning on the underlying electrical insulation. breaking

The repairs at a Tennessee Valley Authority (TVA) workshop consisted

ding oil seals, polishing the shaft under the oil seals, replacing of rebuil- the

tion material under the bearing, machining the bearing housing cap to insula- the alignment, adding a shim to restrain the outer race, and installingcorrect

bearings. TVA inspected four other generators and made similar modifications.new

Background:

The failures occurred in electrical generators manufactured at EPI located

Cleveland, Ohio. EPI was a division of Portec from 1969-1979. In 1979, in

sold EPI to Northern Electrical Industries-Parsons Peebles (NEI-Peebles) Portec

Great Britain. The manufacturing operations at Cleveland ceased in of

the

1984. Currently, EPI furnishes spare parts and modifications to existing Fall of

units.

Discussion:

The failures described above have all occurred at the slip-ring end

diesel engine configurations. Installation of the insulation betweenof the tandem

the rotor

shaft and the bearing also is used for single engine applications and

cases it is installed under the shaft bearing at the other end of the in some

as well. The purpose of the insulation (3M Scotchply brand, type 1009,generator

composite tape) is to prevent circulating currents through the generator glass/epoxy

This insulation method was limited by EPI to 8-pole 900-rpm machines. shaft.

initiating failure mechanism of the insulation has been attributed by The

sources to insulation creep fatigue, misalignment of the engines, poor various

workmanship, or inadequate original design. The first WPPSS and the insulation

failures appear-to be isolated cases of improperly machined pieces; Watts Bar

however, the

failures manifest themselves in a similar manner and may be discovered

checks for insulation damage. during the

IN 86-26 April 17, 1986 PSD has stated that a procedure to monitor shaft movement will have to be specific

for each plant because of design differences that impact the allowable movement

and the jacking force. Jacking the shaft up and down and recording the movement

will determine the vertical play between the shaft and bearing housing, out care

should be taken to use a load cell or circle force gauge between the jack and

the generator shaft to prevent damage.

Other suppliers that have used EPI generators include Stewart & Stevenson, Alco

and Bruce GM (EMD). See Attachment 1 for a list of facilities identified oy

EPI and PSD as recipients of the subject generators. Some of the generators

nave been resold from the original customer or user and some have been cancelled;

therefore specific plant applications may be different than originally supplied.

No specific action or written response is required by this notice. If you nave

any questions regarding this notice, please contact the Regional Aaministrator

of the appropriate NRC regional office or this office.

X\visli/f

Edward L ordan, Director

Divisior of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

Tecnnical Contacts: James C. Stewart, IE

(301) 492-9061 K.R. Naidu, IE

(301) 492-4179 Attachments:

I. List of EPI 900 RPM Generators

2. List of Recently Issued IE Information Notices

Attachment 1 IN 86-26 April 17, 1986 Domestic EPI 900 RPM Generators

Customer/Site No. Units D/G Supplier

Arkansas P&L/Nuclear 1 2 Stewart & Stevenson

Boston Edison/Pilgrim 1 2 ALCO

Duke Power/Oconee 1 PSD

Florida P&L/St. Lucie 2 PSD

Houston L&P/Allens Creek 1 (See Note 1) PSD

Jersey Central P&L/Oyster Creek 2 (See Note 2) PSD

Mississippi P&L/Grand Gulf 2 PSD

Mississippi P&L/Grand Gulf 2 Bruce GM (EMD)

New York State Power 4 Bruce GM (EMD)

Authority/FitzPatrick

Pacific G&E/Diablo Canyon 5 ALCO

Portland G&E/Trojan 2 PSD

Public Service of Oklahoma/Black Fox 2 (See Note 3) PSD

Puget Sound/Skaggit 1 PSD

SMUD/Rancho Seco 2 Bruce GM (EMD)

TVA/Hartsville, Phipps Bend 6 (See Note 4) PSD

TVA/Sequayah 4 Bruce GM (EMD)

TVA/Sequayah 1 PSD

TVA/Watts Bar 6 PSD

Vepco/North Anna 4 Stewart & Stevenson

WPPSS/Hanford 1 2 Stewart & Stevenson

Notes: 1. Generator returned to PSD

2. Obtained from TVA

3. One unit sent to foreign plant, one unit spare

4. Two units to Oyster Creek, three units sent to foreign plants, one unit sent to NASA

Attachnient 2 IIN 86-26 April 17, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue __Issued to-

86-25 Traceability And Material 4/11/86 All power reactor

Control Of Material And facilities holding

Equipment, Particularly an OL or CP

Fasteners

86-24 Respirator Users Notice: 4/11/86 All power reactor

Increased Inspection Frequency facilities holding

For Certain Self-Contained an OL or CP; research

Breathing Apparatus Air and test reactor

Cylinders facilities; fuel

cycle licensees and

Priority 1 material

licensees

86-23 Excessive Skin Exposures Due 4/9/86 All power reactor

To Contamination With Hot facilities holding

Particles an OL or CP

86-22 Underresponse Of Radition 3/31/86 All power reactor

Survey Instrument To High facilities holding

Radiation Fields an OL or CP and

research and test

reactors

86-21 Recognition Of American 3/31/86 All power reactor

Society Of Mechanical facilities holding

Engineers Accreditation an OL or CP and all

Program For N Stamp Holders recipients of NUREG-

0040 (white book)

86-20 Low-Level Radioactive Waste 3/28/86 All power reactor

Scaling Factors, 10 CFR facilities holding

Part 61 an OL or CP

86-19 Reactor Coolant Pump Shaft 3/21/86 All power reactor

Failure At Crystal River facilities holding

an OL or CP

86-18 NRC On-Scene Response During 3/26/86 All power reactor

A Major Emergency facilities holding

an OL or CP

OL = Operating License

CP = Construction Permit


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