Information Notice 1993-74, High Temperatures Reduce Limitorque AC Motor Operator Torque

High Temperatures Reduce Limitorque AC Motor Operator Torque

ML031070330
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, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	09/16/1993
From:	Grimes B Office of Nuclear Reactor Regulation
To:
References
IN-93-074, NUDOCS 9309100374
Download: ML031070330 (11)

K-/

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 September 16, 1993 NRC INFORMATION NOTICE 93-74: HIGH TEMPERATURES REDUCE LIMITORQUE AC MOTOR

OPERATOR TORQUE

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information

notice to alert addressees that high ambient temperatures can reduce ac motor

torque capability in Limitorque motor operators. It is expected that

recipients will review the information for applicability to their facilities

and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requiyements;

therefore, no specific action or written response is required.

Background

In order to size a motor operator to a given valve, the expected operator

torque capable of being developed under design-basis conditions is calculated.

The operator torque output is directly related to the torque output of the

operator motor. For dc motor operators, Limitorque has published derating

factors that are applied to high ambient temperature applications. However, until recently, no derating information was available for Limitorque motor

operators equipped with ac motors.

DescriDtion of Circumstances

In response to NRC questions, Limitorque Corporation established a test

program to evaluate whether elevated ambient temperatures could significantly

affect ac motor output torque. In October of 1992, Limitorque completed

testing of five ac motors. This testing indicated that ac motor stall torque

values decreased significantly with increasing ambient temperatures. The

measured torque reductions ranged from 14 to 25 percent for ambient

temperature increases from 24°C [75°F] to 1690C [336*F]. Limitorque

contracted with its main motor supplier, Reliance Motor Co., to calculate the

expected stall torque reduction for all Limitorque/Reliance ac motor designs.

On May 13, 1993, Limitorque issued a report about a potential 10 CFR Part 21 condition. The report contained a tabulation of motor types and expected

0 0

torque reductions for ambient temperature increases from 25*C [77 F] to 180 C

9309100374 xIotNc4~°> c 2

10?- /I.c

IN 93-74'

September 16, 1993 [356°F]. This data is given in Attachment 1. Limitorque has since indicated

that the torque reductions would be applicable only for motors in ambient

conditions above 40*C [104 0F] as the motors are designed to deliver full rated

torque up to 40C [104'F].

Limitorque has stated that the torque reduction is linear with respect to

temperature. The Limitorque table also contains information on the expected

reduction in locked rotor current at elevated temperatures. The reduced

locked rotor current would provide a slightly higher motor terminal voltage.

Although this would improve the calculated reduced voltage motor performance, it would not compensate for the torque reduction resulting from an elevated

temperature. Limitorque further stated that motor temperature rise as a

result of prior motor energization and motor run time (valve stroke time) must

be accounted for.

Additional information concerning motor operator performance can be found in

NRC Inspection Report 99900100/93-01 issued June 28, 1993.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

ast @ A,

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacobson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Attachments:

1. Current/Torque Changes from 25 to 180 Centigrade

2. List of Recently Issued NRC Information Notices

- IN 93-74 September 16, 1993 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Orignal signed by

Al Chaffee for/

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacobson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Attachments:

1. Current/Torque Changes from 25 to 180 Centigrade

2. List of Recently Issued NRC Information Notices

• r~a Prcovimic~ Cnnrijrr~nrP

OFFICE: *RSIB:DRIL *SC:RSIB:DRIL *C:RSIB:DRIL *D:DRIL:NRR

NAME: JBJacobson DPNorkin EVImbro CERossi

DATE: 08/12/93 08/12/93 08/13/93 08/16/93

._, _ _ ,__ , -, _ _ . , _ . .1 OFFICE: *EMEB:DE *OGCB:DORS *Tech Ed *C:OGCB:DORS D:DgRW R

NAME: TGScarbrough RJKiessel DGable GHMarcus BKGrimes

DATE: 1 08/23/93 09/01/93 09/01/93 09/08/93 09//193 Document Name: 93-I4.IN

Attacment 1 IN 93-74 September 16, 1993 Curiznt/Torque Changes from 25 to 180 Centigrade

% Current  % Torq

'a#1 P8 Frame Mu2e3# Loss

2'#/1800 56 M2735A 27.8% 20.7%

5'#/1800 48 M2734 29.0% 18.6%

5'#/1800 56 M1658 21.8% 21.9%

7.5'#J1800 56 M2925 22.4% 5.7%

10'#/1800 56 M1468 26.9% 27.7%

15'#/1800 56 M1476 23.7% 23.1%

25'#/1800 56 M1480 23.1% 23.2%

40'#/1800 56 M1488 21.1% 23.4%

60'#/1800 58 M5204 20.8% 20.9%

60'#/1800 180 SK-59454 19.6% 18.2%

80'#/1800 210 SK-59423 16.1% 15.8%

100'#/1800 210 SK-59419A 17.0% 13.1%

200'#/1800 256 SK-4177 13.5% 9.0%

250'#/1800 256 SK-34193 11.8% 6.9%

300'#I1800 326 SK-34183 11.7% 5.8%

2'#/3600 48 413018-03 28.3% 16.0%

5'#13600 48 M199 27.7% 18.5%

5'#/3600 56 M1454 24.7% 26.8%

7.5'#/3600 56 M1457 27.6% 16.7%

10'#13600 56 M1458 23.5% 30.8%

15'#/3600 56 M1460 19.2% 21.4%

25'#13600 56 M1463 16.2% 24.1%

40'#/3600 56 M4635 27.9% 15.9%

40'#/3600 180 SK-59450 16.2% 11.8%

60'#/3600 210 SK-59446 18.2% 16.5%

80'#/3600 210 SK-59448 18.0% 18.3%

100'#/3600 256 SK-34176 14.1% 9.8%

150'#/3600 256 SK-34184 13.9% 10.0%

200'#/3600 326 SK-34188 10.5% 3.4%

250'#/3600 326 SK-34173 9.3% 3.4%

300'#/3600 326 SK44171 10.8% 2.9%

400'#/3600 365 SK44800- 8.8% -1.8%'

Z

a

I

Z

n

bC)

- -

• 0

-I Attachment 2 IN 93-74

0 0 September 16. 1993 Page I of I

Nm Xn =

(30

o02 (0

CQ)

LIST OF RECENTLY ISSUED

o _1 NRCINFORMATION NOTICES

m o

C

0' o- 0V-1 Information Date of

Notice No. Subject Issuance Issued to

o0c

z -

0 09/15/93 All NRC licensees.

Criminal Prosecution of

(

93-73 Nuclear Suppliers for

ow Wrongdoing

93-72 Observations from Recent 09/14/93 All holders of OLs or CPs

Shutdown Risk and Outage for nuclear power reactors.

Management Pilot Team

Inspections

93-71 Fire at Chernobyl Unit 2 09/13/93 All holders of OLs or CPs

for nuclear power reactors.

93-70 Degradation of Boraflex 09/10/93 All holders of OLs or CPs

Neutron Absorber Coupons for nuclear power reactors.

93-69 Radiography Events at 09/02/93 All holders of OLs or CPs

Operating Power Reactors for nuclear power reactors

and all radiography

licensees.

93-68 Failure of Pump Shaft 09/01/93 All holders of OLs or CPs

Coupling Caused by for nuclear power reactors.

Temper Embrittlement

during Manufacture

92-16, Loss of Flow from the 08/23/93 All holders of OLs or CPs

Supp. 2 ResIdual Heat Removal for nuclear power reactors.

Pump during Refueling

Cavity Oraindown

93-67 Bursting of High 08/16/93 All holders of OLs or CPs

Pressure Coolant for nuclear power reactors.

Injection Stem Line

Rupture Discs Injures

Plant Personnel

93-66 Switchover to Hot-Leg 08/16/93 All holders of OLs or CPs

Injection Following for pressurized water

A Loss-of-Coolant reactors.

Accident in fres- surized Water Reactors

'I L Operat'ng License

CP

• Construction Permit

IN 93-xx

September xx, 1993 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacobson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Enclosures:

1. Current/Torque Changes from 25 to 180 Centigrade

2. List of Recently Issued NRC Information Notices

• C^i^ Dy-pA,4wIc rnnemitronra

OFFICE: *RSIB:DRIL *SC:RSIB:DRIL I*C:RSIB:DRIL *D:DRIL:NRR

NAME: JBJacobson DPNorkin EVImbro CERossi

nATr.

I L. I

no Iaii 9S. /02

. I rIe

Rl/I,_2 /IQ

-- r, I

08/13/93

- -

08/16/93 I

OFFICE: *EMEB:DE _ *OGCB:DORS *Tech Ed C:OGCB:_ORS D:DORS:NRR

NAME: TGScarbrough RJKiessel DGable GHMarCus K BKGrimes

DATE: 1 08/23/93 9/ 1/93 9/ 1/93 9/,?/93 9 Document Name: NKL1IN.3!0

for.

in

Additional information concerning motor operator performance can be found

NRC kIspection /eport 99900100/93-01 issued June 28, 1993.

If

This information notice requires no specific action or written response.

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacobson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Enclosures:

1. Current/Torque Changes from 25 to 180 Centigrade

2. List of Recently Issued NRC Information Notices

Document Name: nrcin.391

• Previously Concurred

OFFICE: *RSIB:DRIL *SC:RSIB:DRIL *C:RSIB:DRIL *D:DRIL:NRR

NAME: JBJacobson DPNorkin EVImbro CERossi

nATFPe

VF_ IL._ ___-

I

I __

0lR12/QA

__ _ __ _

I n8/12/93

___I____ ___

I 08/13/93

____ __ - -

1 08/16/93 T - -__ _ _

OFFICE: *EMEB:DE OGCB:DORV gTech Ed C:OGCB:DORS D:DORS:NRR

NAME: TGScarbrough RJKiesse __77___ GHMarcus BKGtimes

DATE: 08/23/93 09/) /93 09// /93 09/ /93 09/l g 3

IN 93-XX

August 18, 1993 On May 13, 1993, Limitorque issued a "Potential 10 CFR 21 Condition" report

which contained a tabulation of motor types and expected torque reductions for

ambient temperature increases from 250C to 1800C. This tabulated data is

attached as Enclosure (1). Limitorque has since Indicated that the torque

reductions would only be applicable for motors in ambient conditions above

40°C as the motors are designed to deliver full rated torque up to 40C.

Limitorque has stated that the torque reduction is linear with respect to

temperature. The Limitorque table also contains information on the expected

reduction in locked rotor current at elevated temperatures. The reduced

locked rotor current would provide a slightly higher motor terminal voltage.

This would improve the calculated reduced voltage motor performance, however, not nearly enough to compensate for the torque reduction due to elevated

temperature. Also, Limitorque stated that motor temperature rise due to prior

motor energization and motor run time (valve stroke time) must be accounted

for.

Additional information concerning motor operator performance can be found in

NRC inspection report 99900100/93-01 issued June 28, 1993.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacobson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Enclosure 1: Current/Torque Changes from 25 to 180 Centigrade

Distribution:

JBJacobson DPNorkin EVImbro RPZimmerman

CERossi BKGrimes Central Files DOEA R/F

RSIB R/F

• Previously Concurred_ I

OFFICE: RSIB:DRIL SC:RSIB:DRIL TECH EDITOR C:RSIB:DRIL

NAME: JBJacobson* DPNorkin* EVImbro*

DATE: 08/12/93 08/12/93 08/ /93 08/13/93 OFFICE: D:DRIL:NRR E D:DOEA:NRR

CERossi* TGScarbrough BKGrimes l

NAME:

DATE:_08/16/93 /93

08/1930 I 08/ /93 8

.1R.1 As- . n^rllrMKIT UMAME. * \ TJFnNfnT

UVI-WIL11 I IVIVIL. U. N&I'll %#lawI .---

OFFICIAL RECORD COPY

IN 93-XX

August 13, 1993 3 On May 13, 1993, Limitorque issued a 'Potential 10 CFR 21 Condition report

which cottlined a tabulation of motor types and expected torque reductions for

ambient temperature increases from 25"C to 180"C. This tabulated data is

attached as Enclosure (1). Limitorque has since indicated that the torque

reductions wouMd only be applicable for motors in ambient conditions above

400C as the moto.ds are designed to deliver full rated torque up to 40*C.

Limitorque has stat that the torque reduction is linear with respect to

temperature. The torque table also contains information on the expected

reduction in locked rotor current at elevated temperatures. The reduced

locked rotor current wou'd provide a slightly higher motor terminal voltage.

This would improve the cal ulated reduced voltage motor performance, however, not nearly enough to compen ate for the torque reduction due to elevated

temperature. Also, Llmitorq stated that motor temperature rise due to prior

motor energizatlon and motor r time (valve stroke time) must be accounted

for.

Additional Information concerning tor operator performance can be found in

NRC inspection report 99900100/93-01 ssued June 28, 1993.

This information notice requires no spe ific action or written response. If

you have any questions about the informa on in this notice, please contact

one of the technical contacts listed belo or the appropriate Office of

Nuclear Reactor Regulation (NRR) project ma ger.

Brian K. Gmines, Director1 .

Division of Operat

Office of Nucear Reactor Regulation

Technical contacts: Jeffrey B. Jacboson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Enclosure 1: Current/Torque Changes from 25 to 180 Centlgr e

Distribution:

JBJacobson DPNorkin EVImbro RPZlmmerman

CERossi BKGrimes Central Files DOEA R/F

RSIB R/F \

• Previously Concurred

OFFICE: RSIB:DRIL / SC:RSIB:DRIL TECH EDITOR C:RSIB:oRIL

NAME: JBJacobson* DPNorkin* EVImbro*

DATE: 0812/93 [08/12/93 08/ /93 08/13/93 OFFICE: D:DRIL:NRR D:DOEA:NRR

lNAME: C05; BKGrimes

DATE: 08//ip93 08/ /93 I__Tat ______ __.____

OFFICIAL RECORD COPY DOUMENT NAME: G;\ INFONO I .d JJ

IN 93-XX

August 13, 1993 0 May 13, 1993, Limitorque issued a 'Potential 10 CFR 21 Condition" report

whi contained a tabulation of motor types and expected torque reductions for

amble t temperature increases from 250C to 1800C. This tabulated data is

attach as Enclosure (1). Limitorque has since indicated that the torque

reductio would only be applicable for motors in ambient conditions above

400C as th motors are designed to deliver full rated torque up to 400C.

Limitorque h stated that the torque reduction is linear with respect to

temperature. e Limitorque table also contains information on the expected

reduction in 1c-ted rotor current at elevated temperatures. The reduced

locked rotor curr t would provide a slightly higher motor terminal voltage.

This would improve he calculated reduced voltage motor performance, however, not nearly enough to ompensate for the torque reduction due to elevated

temperature. Also, Iitorque stated that motor temperature rise due to prior

motor energization and tor run time (valve stroke time) must be accounted

for.

Additional information conce ing motor operator performance can be found in

NRC inspection report 99900100 3-01 issued June 28, 1993.

This information notice requires specific action or written response. If

you have any questions about the in Qrmation in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) proJed4 manager.

Brian . Grimes, Director

Divisioh of Operation Events Assessment

Office o#?Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacboson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Enclosure 1: Current/Torque Changes from 25 to 180 Cent grade

Distribution:

JBJacobson DPNorkin EVImbro RPZimmerman

CERossi BKGrimes Central Files DOEA R/F

RSIB R/F

• Previously Concurred _

OFFICE: RSIB:DRIL SC:RSIB:DRIL TECH EDITOR C:RSIB'.-DRIL

NAME: JBJacobson* DPNorkin* Vlmbro

DATE: 08/12/93 08/12/93 08/ /93 08 93 OFFICE: D:DRIL:NRR D:DOEA:NRR _

NAME: CERossi BKGrimes

DATE: 08/ /93 08/ /93 ___________ _____________

i mIir

IE u;zeu1u,.uuu

1-; 1 OFFICIAL RECORD COPY ECOR

LUP

OFFIIAL UULI.Ip4in

UU6UMtNj MM; U;\JL11rV1'4V1.VUU

IN 93-XX

August 12, 1993 On Ma 13, 1992, Limitorque issued a "Potential 10 CFR 21 Condition" report

which ontained a tabulation of motor types and expected torque reductions

from 25 to 1800C. This tabulated data is attached as Enclosure (1).

Limitorqu has since indicated that the torque reductions would only be

applicable or motors in ambient conditions above 40eC as the motors are

designed to eliver full rated torque up to 40C.

Limitorque has lso stated that the torque reduction is linear with respect to

temperature. Th Limitorque table also contains information on the expected

reduction in locatd rotor current at elevated temperatures. The reduced

locked rotor curren would provide a slightly higher motor terminal voltage.

This would improve t calculated reduced voltage motor performance, however, not nearly enough to mpensate for the torque reduction due to elevated

temperature. Also, LimUtorque stated that motor temperature rise due to prior

motor energization and m or run time (valve stroke time) must be accounted

for.

Additional information conce ing motor operator performance can be found in

NRC inspection report 99900100 3-01 Issued June 28, 1993.

This information notice requires o specific action or written response. If

you have any questions about the i formation in this notice, please contact

one of the technical contacts liste below or the appropriate Office of

Nuclear Reactor Regulation (NRR) pro ct manager.

Brian K. Grimes, Director

Divisi of Operation Events Assessment

Office Nuclear Reactor Regulation

Technical contacts: Jeffrey B. Jacboson, NRR

(301) 504-2977 Thomas G. Scarbrough, NRR

(301) 504-2794 Enclosure 1: Current/Torque Changes from 25 to 180 Ce tigrade

Distribution:

JBJacobson DPNorkin EVImbro RPZimmerma

CERossi BKGrimes Central Files DOEA R/F

RSIB R/F

OFFICE: RSIB:DRIL RIL TECH EDITOR RSI:DRILl

NAME: JBJacobJ0#o r Hhtnbk

DATE: 108/)I J_____ 939 _93 08/ /93 08/

OFFICE: D:DRIL:NRR D:DOEA:NRR m

NAME: CERossi BKGrimes \

DATE: 08/ /93 08/ /93 \

nfFITTlAI DFrnR) rAYDVI

wvv

HlAlIIMFCT WAMF-. n. TUFlAflT Io"I

...... ovrd -o-v u'.J'.uIEIcn1 I *leriL. U. X LIS I % UVI.U IV