Information Notice 1993-99, Undervoltage Relay & Thermal Overload Setpoint Problems

Undervoltage Relay & Thermal Overload Setpoint Problems

ML031060586
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:	12/21/1993
From:	Grimes B K Office of Nuclear Reactor Regulation
To:
References
IN-93-099, NUDOCS 9312150073
Download: ML031060586 (12)

UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 December 21, 1993 NRC INFORMATION

NOTICE 93-99: UNDERVOLTAGE

RELAY AND THERMAL OVERLOAD SETPOINT PROBLEMS

Addressees

All holders of operating

licenses or construction

permits for nuclear power plants.

Purpose

The U.S. Nuclear Regulatory

Commission (NRC) is issuing this information

notice to alert addressees

to continuing

discoveries

of undervoltage

relay and thermal overload setpoints

that are set too low. 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 requirements;

therefore, no specific action or written response is required.Background

In August 1976, the NRC wrote generic letters to all LWR licensees

regarding the need for licensees

to evaluate any generic implications

of several events at the Millstone

site involving

episodes of sustained

degraded grid voltage.On June 2, 1977, as part of multiplant

action MPA-23, the staff stated its position that all licensees

must have a second level of undervoltage

protection

with a time delay. (During degraded grid voltage episodes, undervoltage

relays and thermal overload protective

relays protect the safety equipment.)

In a generic letter dated August 8, 1979, the NRC requested

all licensees

to determine

the capability

of the offsite power system to operate all required loads within their voltage ratings under all conditions

within their design basis. The licensees

reviewed their undervoltage

relay setpoints on each of these occasions.

In 1981, the NRC issued Branch Technical Position, Power System Branch-1, "Adequacy

of Station Electric Distribution

System Voltages," which discussed, among other things, the addition of a second undervoltage

relay with an associated

time delay. Between 1981 and 1992, the NRC issued two information

notices, in which it discussed undervoltage

relay setpoints

and other concerns: 1. IN 84-02, "Operating

a Nuclear Power Plant at Voltage Levels Lower than Analyzed," issued January 10, 1984.2. IN 91-29, "Deficiencies

Identified

During Electrical

Distribution

System Functional

Inspections," issued April 15, 1991.9312150073 PDR E No4tEC 93-0 1 e ' , t

IN 93-99 December 21, 1993 3. IN 91-29, Supplement

1, TDeficiencies

Identified

During

--"VIN 93-99 December 21, 1993 This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact the technical

contact listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Bran K. rimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices

Attachment

1 IN 93-99 December 21, 1993 Representative

List of Undervoltaqe

Relay Set Point Revision Notifications

and Technical

Specification

Change Proposals

for 1988-1993 Event Notification

Number Licensee Event Notification

Date 11374 14043 00000 14780 16540 17121 Pilgrim Pilgrim Pilgrim 1 1 1 January 30, 1988 November 18, 1988 June 30, 1988 1 5 1 Cooper 1 Crystal River 3 Robinson 2 February 17, September

8, November 16, 1989 1989 1989 5 1 1 18322 18466 18892 19023 20021 Oconee 1, 2 and 3 McGuire 1 and 2 St. Lucie 2 Haddam Neck 1 Calvert Cliff 1 and 2 Ft. Calhoun Kewaunee 1 Salem 2 Dresden 2 and 3 Dresden 2 Zion 1 and 2 April 24, 1990 May 14, 1990 July 14, 1990 August 2, 1990 December 6, 1990 February 12, 1991 February 20, 1991 February 27, 1991 August 23, 1991 November 20, 1991 December 19, 1991 5 1 2 5 1 20435 20503 20542 21691 22281 22498 1 5 2 5 1 5 22580 22658 22847 (TOL)22918 23148 23191 23338 23365 23385 23439 (TOL)23452 23576 23784 23932 00000 24229 24384 Indian Point 3 Dresden 3 Washington

Nuclear 2 Washington

Nuclear 2 Vermont Yankee Quad Cities 1 and 2 LaSalle 1 and 2 LaSalle 2 Crystal River 3 Grand Gulf Comanche Peak 2 Crystal River 3 Zion 1 and 2 Byron 1 and 2 Callaway Crystal River 3 Dresden 2 and 3 January 9, 1992 January 22, 1992 February 19, 1992 March 1, 1992 April 1, 1992 April 7, 1992 April 27, 1992 April 29, 1992 May 1, 1992 May 11, 1992 May 13, 1992 June 4, 1992 July 2, 1992 July 24, 1992 July 23, 1992 September

14, 1992 October 6, 1992*TOL -Thermal Overload

Attachment

1 IN 93-99 December 21, 1993 Event Notification

Licensee Event Notification

Date Class Number 00000 Prairie Island 1 & 2 November 6, 1992 1 00000 St. Lucie 1 November 30, 1992 1 24757 Maine Yankee December 15, 1992 5 00000 Diablo Canyon 1 and 2 December 22, 1992 1 24845 Point Beach 1 and 2 January 7, 1993 1 25248 (TOL) Pilgrim March 29, 1993 5 25362 South Texas April 6, 1993 5 Events Notification

Number-00000

Licensees

whose undervoltage

relay setpoint notifications

to the NRC were reported by LERs, licensee letter, etc., and event notification

numbers if any, were not known.Class Definitions:

1. Undervoltage

Relay setpoints

were found to be incorrect

because of design errors.2. Undervoltage

Relay setpoints, as found, were not the same as required by the technical

specification.

3. Safety load circuit breaker thermal overloads

or other trip setpoints were too low because of design errors.4. Safety load circuit breaker thermal overload, or other trip setpoints, as found, were not the same as required by the technical

specification.

5. Membership

in one of the preceding

four classes could not be definitely

established

because of incomplete

information

in the event notification.

Att~ehment

2 IN 93-99 December 21, 1993 LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Information

Date of Notice No. Subject Issuance Issued to 93-98 93-97 93-96 93-95 93-94 93-93 Motor Brakes on Valve Actuator Motors Failures of Yokes Installed

on Walworth Gate and Globe Valves Improper Reset Causes Emergency

Diesel Generator

Failures Storm-Related

Loss of Offsite Power Events due to Salt Buildup on Switchyard

Insulators

Unauthorized

Forced Entry into the Pro-tected Area at Three Mile Island Unit 1 on February 7, 1993 Inadequate

Control of Reactor Coolant System Conditions

During Shutdown Plant Improvements

to Mitigate Common Depend-encies in Component Cooling Water Systems Inadequate

Quality Assurance

Program of Vendor Supplying Safety-Related

Equipment 12/20/93 12/17/93 12/14/93 12/13/93 12/09/93 12/08/93 12/07/93 12/07/93 All holders of OLs and CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors located close to a large body of salt water.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors and all recipients

of NUREG-0040, 'License Con-tractor and Vendor Inspec-tion Status ReportR (White Book)..93-92 91-21, Supp. 1 OL -Operating

License CP = Construction

Permit

IN 93-99 December 21, 1993 This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact the technical

contact listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Odginal signed by Brian K. Grimes Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices E plion: The stress laid by the initial reviewer on the licensees

and the staff should feel for such a preblem, viz. low UVR set points, has been all present IN.degree of concern that widespread

and persistent

but eliminated

from the (SEE PREVIOUS CONC.)*C.MORRIS 15 NOV. 93 (S/D)*SEE PREVIOUS CONCURRENCES

• DO RS/OGCB

• C/OGCB:DORS:NRR

D/DORS:NRR

NCampbell

GHMarcus 07/30/93 08/10/93 12//$193*EELB:DE:NRR

CMorris 04/28/93*SC/EELB:DE:NRR

EWWeiss 95/19/93*C/EELB:DE:NRR

CHBerlinger

05/19/93*D/DE: NRR JTWiggins 07/23/93*RPB:ADM Tech Ed 07/13/93# Concurred

in electronically

by JMain.DOC NAME: 93-99.IN

IN 93-XX November 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 the technical

contact 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

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices Exception:

The stress laid by the initial reviewer on the degree of concern that licensees

and the staff should feel for such a widespread

and persistent

problem, viz. low UVR set points, has been all but eliminated

from the present IN. G4'C.MORRIS 15 NOV. 93 Document Name: G:\SHARED\R3UNRELS.IN

• SEE PREVIOUS CONCURRENCES

1. Concurred

in electronically

by D/DORS:NRR

• C/OGCB: DORS:NRR BKGrimes GHMarcus 11/ /93 A 08/10/93*C/EELB:DE:NRR

• D/DE:NRR CHBerlinger

JTWiggins 05/19/93 07/23/93 JMain.*OGCB:DORS:NRR

NCampbell 07/30/93*RPB:ADM Tech Ed 07/13/93*EELB:DE:NRR

CMorris 04/28/93*SC/EELB:DE:NRR

EWWeiss 05/19/93&Wp: & 4 Lso1 IN 93-XX November 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 the technical

contact 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

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices Document Name: G:\SHARED\R3UNRELS.IN

• SEE PREVIOUS CONCURRENCES

1. Concurred

in D/DORS:NRR

BKGrimes ll/ /93*C/EELB:DE:NRR

CHBerlinger

05/19/93 electronically

by*C/OGCB:DWRS:NRR

GHMarcus 08/10/93*D/DE:NRR JTWiggins 07/23/93 JMain.*OGCB: DORS:NRR NCampbell 07/30/93*RPB:ADM Tech Ed 07/13/93*EELB:DE:NRR

CMorris 04/28/93*SC/EELB:DE:NRR

EWWeiss 05/19/93 IN 93-XX August 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 the technical

contact 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

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices*SEE PREVIOUS CONCURRENCES

Document Name: UNRELSET.IN

DORS/OGCB NCampbell 07/30/93 D/DORS: BKGrime 08/ /93 C/OGCB: DORS:NRR GHMarcus6#/W

08/to /93*EELB:DE:NRR

CMorris 04/28/93*SC/EELB:DE:NRR

EWWeiss 05/19/93*C/EELB:DE:NRR

CHBerlinger

05/19/93*D/DE : NRR JTWiggins 07/23/93*RPB:ADM Tech Ed 07/13/93# Concurred

in electronically

by JMain.

IN 93-XX August 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 the technical

contact listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices*SEE PREVIOUS CONCURRENCES

Document Name: UNRELSET.IN

DRS/OGCB NCampbell 07/8* /93 D/DORS:NRR

BKGrimes 07/ /93 C/OGCB:DORS:NRR

GHMarcus 07/ /93*EELB:DE:NRR

CMorris 04/28/93*SC/EELB:DE:NRR

EWWeiss 05/19/93*C/EELB:DE:NRR

CHBerlinger

05/19/93*D/DE:NRR JTWiggins 07/23/93*RPB:ADM Tech Ed 07/13/93# Concurred

in electronically

by JMain.

_> K_> IN 93-XX July 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 the technical

contact listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

contact: C. Morris, NRR (301) 504-2778 Attachments:

1. Representative

List of Undervoltage

Relay Setpoint Revisions

1988-1993 2. List of Recently Issued NRC Information

Notices*SEE PREVIOUS CONCURRENCES

Document Name: UNRELSET.IN

DORS/OGCB

D NCampbell

BI 07/ /93 0,*C/EELB:DE:NRR

CHBerlinger

05/19/93/DORS:NRR KGrimes 7/ /24*EELB:DE:NRR

CMorris 04/28/93*SC/EELB:DE:NRR

EWWeiss 05/19/93 Marcus T/ /93*RPB:ADM Tech Ed 07/13/93# Concurred

in electronically

by JMain.