Information Notice 1986-15, Loss of Offsite Power Caused by Problems in Fiber Optics Systems: Difference between revisions

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| issue date = 03/10/1986
| issue date = 03/10/1986
| title = Loss of Offsite Power Caused by Problems in Fiber Optics Systems
| title = Loss of Offsite Power Caused by Problems in Fiber Optics Systems
| 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 = 3
| page count = 3
}}
}}
{{#Wiki_filter:SSINS No.: 6835 HU OlIN 86-15 UNITED STATES NUCLEAR REGULATORY
{{#Wiki_filter:SSINS No.: 6835 HU       OlIN                     86-15 UNITED STATES


COMMISSION
NUCLEAR REGULATORY COMMISSION


OFFICE OF INSPECTION
OFFICE OF INSPECTION AND ENFORCEMENT


===AND ENFORCEMENT===
WASHINGTON, D.C. 20555 March 10, 1986 IE INFORMATION NOTICE NO. 86-15:  LOSS OF OFFSITE POWER CAUSED BY PROBLEMS
WASHINGTON, D.C. 20555 March 10, 1986 IE INFORMATION


NOTICE NO. 86-15: LOSS OF OFFSITE POWER CAUSED BY PROBLEMS IN FIBER OPTICS SYSTEMS
IN FIBER OPTICS SYSTEMS


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


holding an operating
construction permit (CP).
 
license (OL) or a construction
 
permit (CP).


==Purpose==
==Purpose==
: This notice is to alert addressees
:
This notice is to alert addressees to recent instances of loss of offsite power


to recent instances
caused by problems with fiber optics systems used to control switchyard circuit


of loss of offsite power caused by problems with fiber optics systems used to control switchyard
breakers. Recipients are expected to review the information for applicability


circuit breakers.
to their facilities and consider actions, if appropriate, to preclude similar


Recipients
problems occurring at their facilities. However, suggestions contained in this


are expected to review the information
notice do not constitute NRC requirements; therefore, no specific action or


for applicability
written response is required.


to their facilities
==Description of Circumstances==
 
:
and consider actions, if appropriate, to preclude similar problems occurring
Three recent instances of total loss of offsite power at nuclear power plants
 
at their facilities.
 
However, suggestions
 
contained
 
in this notice do not constitute
 
NRC requirements;
therefore, no specific action or written response is required.Description
 
of Circumstances:
Three recent instances
 
of total loss of offsite power at nuclear power plants were caused by problems with fiber optics control systems. Fiber optics systems are sometimes
 
thought to be immune to radio frequency
 
interference
 
problems.However, at least one of these instances
 
was probably caused by interference
 
from a hand-held
 
radio in close proximity
 
to the tone relaying trip receivers
 
of the fiber optics system.On October 3, 1985, the Palo Verde Unit 1 nuclear power plant tripped from 52 percent power because of a total loss of offsite power. The loss of offsite power was caused by the apparent malfunction
 
of a multiplexer
 
in the fiber optics system that in turn controlled
 
breakers in the plant switchyard.
 
The loss of offsite power caused the starting and loading of the emergency
 
diesel generators


that restored power to the engineered
were caused by problems with fiber optics control systems. Fiber optics systems


safety features buses.On October 7, 1985, while shut down in Mode 3, Palo Verde Unit 1 again experienced
are sometimes thought to be immune to radio frequency interference problems.


a loss of offsite power apparently
However, at least one of these instances was probably caused by interference


because of a failure of the multiplexer.
from a hand-held radio in close proximity to the tone relaying trip receivers of


Although some failed components
the fiber optics system.


were identified, the ultimate cause of these failures of the fiber optics multiplexer
On October 3, 1985, the Palo Verde Unit 1 nuclear power plant tripped from 52 percent power because of a total loss of offsite power. The loss of offsite


was never determined.
power was caused by the apparent malfunction of a multiplexer in the fiber optics


===As a corrective===
system that in turn controlled breakers in the plant switchyard. The loss of
measure, control of the affected switchyard


breakers was hardwired
offsite power caused the starting and loading of the emergency diesel generators


and the multiplexer
that restored power to the engineered safety features buses.


control was bypassed.8603050394 IN 86-15 March 10, 1986 On January 1, 1986, the River Bend nuclear power station experienced
On October 7, 1985, while shut down in Mode 3, Palo Verde Unit 1 again experienced


a total loss of offsite power caused by the tripping of the preferred
a loss of offsite power apparently because of a failure of the multiplexer.


station transformers
Although some failed components were identified, the ultimate cause of these


A and C at 0941, and approximately
failures of the fiber optics multiplexer was never determined. As a corrective


1 hour later, the tripping of the preferred station transformers
measure, control of the affected switchyard breakers was hardwired and the


B and D. The plant was shut down at the time because of a reactor scram that occurred approximately
multiplexer control was bypassed.


6 hours earlier for unrelated
8603050394


reasons.Investigation
IN 86-15 March 10, 1986 On January 1, 1986, the River Bend nuclear power station experienced a total


indicated
loss of offsite power caused by the tripping of the preferred station transformers


that the loss of offsite power event was not caused by a valid signal. Testing did show that hand-held
A and C at 0941, and approximately 1 hour later, the tripping of the preferred


radios could have caused the loss of offsite power event. Two hand-held
station transformers B and D. The plant was shut down at the time because of


radios, one 4 watts at 150 MHz and the other 5 watts at 450 MHz, caused system trips when keyed within 12 feet of the transmitters
a reactor scram that occurred approximately 6 hours earlier for unrelated reasons.


and receivers
Investigation indicated that the loss of offsite power event was not caused by


for the fiber optics system. Mobile radios of greater power located outside the building containing
a valid signal. Testing did show that hand-held radios could have caused the


the fiber optics system would not cause spurious trips.At River Bend, the fiber optics transmitting
loss of offsite power event. Two hand-held radios, one 4 watts at 150 MHz and


and receiving
the other 5 watts at 450 MHz, caused system trips when keyed within 12 feet of


equipment
the transmitters and receivers for the fiber optics system. Mobile radios of


is located in the turbine building and the Fancy Point substation, a distance of about 0.8 miles. The corrective
greater power located outside the building containing the fiber optics system


measures adopted at River Bend include shielding
would not cause spurious trips.


of the fiber optics transmitters
At River Bend, the fiber optics transmitting and receiving equipment is located


and receivers, posting signs that prohibit use of radios near the fiber optics equipment, rewiring the equipment
in the turbine building and the Fancy Point substation, a distance of about 0.8 miles. The corrective measures adopted at River Bend include shielding of the


so that two channels instead of one are required for tripping, providing
fiber optics transmitters and receivers, posting signs that prohibit use of


control room annunciation
radios near the fiber optics equipment, rewiring the equipment so that two


of system status, training personnel
channels instead of one are required for tripping, providing control room


on restricted
annunciation of system status, training personnel on restricted use of radios, installing a sequence-of-events recorder to diagnose any future events, and


use of radios, installing
training personnel on resetting lockouts, including posting of operator aids.


a sequence-of-events
Other problems caused by use of hand-held radios in nuclear power plants were


recorder to diagnose any future events, and training personnel
discussed in IE Information Notice No. 83-83, "Use of Portable Radio Transmitters


on resetting
Inside Nuclear Power Plants," published on December 19, 1983.


lockouts, including
No specific action or written response is required by this information notice.


posting of operator aids.Other problems caused by use of hand-held
If you have questions about this matter, please contact the Regional Adminis- trator of the appropriate NRC regional office or this office.


radios in nuclear power plants were discussed
EdwarqV. Jordan, Director


in IE Information
Divisi of Emergency Preparedness


Notice No. 83-83, "Use of Portable Radio Transmitters
and Engineering Response


Inside Nuclear Power Plants," published
Office of Inspection and Enforcement


on December 19, 1983.No specific action or written response is required by this information
===Technical Contact:===


notice.If you have questions
===Eric Weiss, IE===
                    (301) 492-9005 Attachment: List of Recently Issued IE Information Notices


about this matter, please contact the Regional Adminis-trator of the appropriate
i


NRC regional office or this office.EdwarqV. Jordan, Director Divisi of Emergency
Attachment 1 IN 86-15 March 10, 1986 LIST OF RECENTLY ISSUED


===Preparedness===
IE INFORMATION NOTICES
and Engineering


Response Office of Inspection
Information                                  Date of


and Enforcement
Notice No.    Subject                        Issue  Issued to


Technical
86-14          PWR Auxiliary Feedwater Pump  3/10/86 All power reactor


Contact: Eric Weiss, IE (301) 492-9005 Attachment:
Turbine Control Problems              facilities holding
List of Recently Issued IE Information


Notices
an OL or CP


i Attachment
86-13          Standby Liquid Control        2/21/86 All BWR facilities


1 IN 86-15 March 10, 1986 LIST OF RECENTLY ISSUED IE INFORMATION
System Squib Valves Failure            holding an OL or CP


NOTICES Information
To Fire


Date of Notice No. Subject Issue Issued to 86-14 86-13 86-12 86-11 84-69 Sup. 1 PWR Auxiliary
86-12          Target Rock Two-Stage SRV      2/25/86 All power reactor


Feedwater
Setpoint Drift                        facilities holding


Pump Turbine Control Problems Standby Liquid Control System Squib Valves Failure To Fire Target Rock Two-Stage
an OL or CP


SRV Setpoint Drift Inadequate
86-11          Inadequate Service Water      2/25/86 All power reactor


Service Water Protection
Protection Against Core Melt          facilities holding


Against Core Melt Frequency Operation
Frequency                             an OL or CP


Of Emergency
84-69          Operation Of Emergency Diesel 2/24/86  All power reactor


===Diesel Generators===
Sup. 1        Generators                             facilities holding
Safety Parameter


===Display System Malfunctions===
an OL or CP
Failure Of Check And Stop Check Valves Subjected


===To Low Flow Conditions===
86-10          Safety Parameter Display      2/13/86 All power reactor
Licensee Event Report (LER)Format Modification


===Lack Of Detailed Instruction===
System Malfunctions                    facilities holding
And Inadequate


Observance
an OL or CP


Of 3/10/86 2/21/86 2/25/86 2/25/86 2/24/86 2/13/86 2/3/86 2/3/86 2/3/86 All power reactor facilities
86-09          Failure Of Check And Stop      2/3/86 All power reactor


holding an OL or CP All BWR facilities
Check Valves Subjected To              facilities holding


holding an OL or CP All power reactor facilities
Low Flow Conditions                    an OL or CP


holding an OL or CP All power reactor facilities
86-08          Licensee Event Report (LER)    2/3/86  All power reactor


holding an OL or CP All power reactor facilities
Format Modification                    facilities holding


holding an OL or CP All power reactor facilities
an OL or CP


holding an OL or CP All power reactor facilities
86-07          Lack Of Detailed Instruction 2/3/86    All power reactor


holding an OL or CP All power reactor facilities
And Inadequate Observance Of          facilities holding


holding an OL or CP All power reactor facilities
Precautions During Maintenance        an OL or CP


holding an OL or CP 86-10 86-09 86-08 86-07 Precautions
And Testing Of Diesel Generator


===During Maintenance===
Woodward Governors
And Testing Of Diesel Generator Woodward Governors OL = Operating


License CP = Construction
OL = Operating License


Permit}}
CP = Construction Permit}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Latest revision as of 03:06, 24 November 2019

Loss of Offsite Power Caused by Problems in Fiber Optics Systems
ML031220597
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, 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: 03/10/1986
From: Jordan E
NRC/IE
To:
References
IN-86-015, NUDOCS 8603050394
Download: ML031220597 (3)
v • d • e


SSINS No.: 6835 HU OlIN 86-15 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 March 10, 1986 IE INFORMATION NOTICE NO. 86-15: LOSS OF OFFSITE POWER CAUSED BY PROBLEMS

IN FIBER OPTICS SYSTEMS

Addressees

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

construction permit (CP).

Purpose

This notice is to alert addressees to recent instances of loss of offsite power

caused by problems with fiber optics systems used to control switchyard circuit

breakers. Recipients are expected to review the information for applicability

to their facilities and consider actions, if appropriate, to preclude similar

problems occurring at their facilities. However, suggestions contained in this

notice do not constitute NRC requirements; therefore, no specific action or

written response is required.

Description of Circumstances

Three recent instances of total loss of offsite power at nuclear power plants

were caused by problems with fiber optics control systems. Fiber optics systems

are sometimes thought to be immune to radio frequency interference problems.

However, at least one of these instances was probably caused by interference

from a hand-held radio in close proximity to the tone relaying trip receivers of

the fiber optics system.

On October 3, 1985, the Palo Verde Unit 1 nuclear power plant tripped from 52 percent power because of a total loss of offsite power. The loss of offsite

power was caused by the apparent malfunction of a multiplexer in the fiber optics

system that in turn controlled breakers in the plant switchyard. The loss of

offsite power caused the starting and loading of the emergency diesel generators

that restored power to the engineered safety features buses.

On October 7, 1985, while shut down in Mode 3, Palo Verde Unit 1 again experienced

a loss of offsite power apparently because of a failure of the multiplexer.

Although some failed components were identified, the ultimate cause of these

failures of the fiber optics multiplexer was never determined. As a corrective

measure, control of the affected switchyard breakers was hardwired and the

multiplexer control was bypassed.

8603050394

IN 86-15 March 10, 1986 On January 1, 1986, the River Bend nuclear power station experienced a total

loss of offsite power caused by the tripping of the preferred station transformers

A and C at 0941, and approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> later, the tripping of the preferred

station transformers B and D. The plant was shut down at the time because of

a reactor scram that occurred approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> earlier for unrelated reasons.

Investigation indicated that the loss of offsite power event was not caused by

a valid signal. Testing did show that hand-held radios could have caused the

loss of offsite power event. Two hand-held radios, one 4 watts at 150 MHz and

the other 5 watts at 450 MHz, caused system trips when keyed within 12 feet of

the transmitters and receivers for the fiber optics system. Mobile radios of

greater power located outside the building containing the fiber optics system

would not cause spurious trips.

At River Bend, the fiber optics transmitting and receiving equipment is located

in the turbine building and the Fancy Point substation, a distance of about 0.8 miles. The corrective measures adopted at River Bend include shielding of the

fiber optics transmitters and receivers, posting signs that prohibit use of

radios near the fiber optics equipment, rewiring the equipment so that two

channels instead of one are required for tripping, providing control room

annunciation of system status, training personnel on restricted use of radios, installing a sequence-of-events recorder to diagnose any future events, and

training personnel on resetting lockouts, including posting of operator aids.

Other problems caused by use of hand-held radios in nuclear power plants were

discussed in IE Information Notice No. 83-83, "Use of Portable Radio Transmitters

Inside Nuclear Power Plants," published on December 19, 1983.

No specific action or written response is required by this information notice.

If you have questions about this matter, please contact the Regional Adminis- trator of the appropriate NRC regional office or this office.

EdwarqV. Jordan, Director

Divisi of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

Technical Contact:

Eric Weiss, IE

(301) 492-9005 Attachment: List of Recently Issued IE Information Notices

i

Attachment 1 IN 86-15 March 10, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

86-14 PWR Auxiliary Feedwater Pump 3/10/86 All power reactor

Turbine Control Problems facilities holding

an OL or CP

86-13 Standby Liquid Control 2/21/86 All BWR facilities

System Squib Valves Failure holding an OL or CP

To Fire

86-12 Target Rock Two-Stage SRV 2/25/86 All power reactor

Setpoint Drift facilities holding

an OL or CP

86-11 Inadequate Service Water 2/25/86 All power reactor

Protection Against Core Melt facilities holding

Frequency an OL or CP

84-69 Operation Of Emergency Diesel 2/24/86 All power reactor

Sup. 1 Generators facilities holding

an OL or CP

86-10 Safety Parameter Display 2/13/86 All power reactor

System Malfunctions facilities holding

an OL or CP

86-09 Failure Of Check And Stop 2/3/86 All power reactor

Check Valves Subjected To facilities holding

Low Flow Conditions an OL or CP

86-08 Licensee Event Report (LER) 2/3/86 All power reactor

Format Modification facilities holding

an OL or CP

86-07 Lack Of Detailed Instruction 2/3/86 All power reactor

And Inadequate Observance Of facilities holding

Precautions During Maintenance an OL or CP

And Testing Of Diesel Generator

Woodward Governors

OL = Operating License

CP = Construction Permit


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