Information Notice 1983-83, Use of Portable Radio Transmitters Inside Nuclear Power Plants

Use of Portable Radio Transmitters Inside Nuclear Power Plants

ML070180072
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, 05000496, 05000497, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Clinch River, Skagit, Marble Hill
Issue date:	12/19/1983
From:	NRC/IE
To:
References
IN-83-083, NUDOCS 8311010034
Download: ML070180072 (4)

SSINS No.: 6835 IN 83-83 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 December 19, 1983 IE INFORMATION NOTICE NO. 83-83: USE OF PORTABLE RADIO TRANSMITTERS

INSIDE NUCLEAR POWER PLANTS

Addressees

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

construction permit (CP).

Purpose

This information notice is to apprise you of reported instances in which

portable radio transmitters caused system malfunctions and spurious actuations

in nuclear power plants. No specific action is required in response to this

information notice, but it is expected that recipients will review the

information for applicability to their facilities.

Description of Circumstances

Events over the past few years have caused concern in the NRC staff regarding

the potential of portable radio transmitters (commonly referred to as walkie- talkies) to cause system malfunctions and spurious actuations. The following

four examples describe two events in which a safety-related system was affected

and two in which a non-safety-related system was affected.

The first example occurred at Grand Gulf on July 25, 1983, in which shutdown

cooling loop B was lost for 30 minutes because of a spurious isolation trip.

The isolation was initiated by an RHR equipment area high temperature trip which

immediately cleared. Rather than restart the loop immediately, the operators

first verified that no leak was present and thus the area high temperature

indication was false. Since shutdown cooling loop A was inoperable at the time, the reactor water clean up system was used as the alternate heat removal system.

The licensee conducted an investigation, including an after-the-fact interview

with personnel who were in the vicinity of the trip circuitry. The licensee

concluded that the most plausible cause was an accidental keying of a two-way FM

radio near the trip unit. The licensee has and continues to forbid the use of

.the radios for transmission in the vicinity of the control room or near panels.

The walkie-talkie that was used has a power output of approximately 4 watts in

the frequency range of 451-456 MHz. The walkie-talkie was accidently keyed in

the upper cable spreading room which is the location of the RHR equipment area

high temperature trip unit (a Riley temperature switch model PTGF-EG.) This

temperature switch is a solid state device that is connected by 16 AWG copper

shielded cable to a thermocouple.

IN 83-83 December 19, 1983 The second example of a spurious actuation caused by a walkie-talkie occurred

at Sequoyah 1 on May 31, 1979. A health physics technician who was in the

in-core instrument room was attempting to communicate with the control room

when he keyed his walkie-talkie resulting in a spurious sigial to all four

channels of pressurizer pressure initiating a safety injection. The incore

instrument i,.om is located inside containment. The event was duplicated

intentionally with the same results.

The third example occurred at Three Mile Island on February 19, 1982. Workers

were preparing to enter the containment for some cleanup work when combustible

gas monitors they were carrying indicated the presence of hydrogen and low

levels of oxygen. The workers became suspicious when the readings varied with

the use of their face mask radios. Later gas sampling outsir: of containment

verified that the face mask radios caused false readings on the combustible gas

monitors.

The fourth example occurred at Farley in 1975. During initial energization of

a 600-V load center, a false operation of the transformer differential relay

was observed. The licensee determined that the Differential Relay Type 12 STD 15B5A is radio frequency sensitive and trips with an activated transceiver

located within approximately five feet of the relay. A test revealed that the

activated transceivers, having frequencies between 150 MHz and 470 MHz with

power ratings of 5-watt input to the final radio frequency amplifier and

placed within a radius of approximately 5 feet of the relay, caused the dif- ferential relay operation. As a further test, the relay was subjected to test

currents of 0.5 amp and 5 amp applied to the restraint windings to determine if

the relay was less sensitive to radio frequencies under simulated operating

conditions. This test again resulted in a false operation of the relay.

This GE Type STD differential relay is a solid state device with certain

parts mounted on a printed circuit board which apparently pick up a signal from

a transceiver and feed it into the relay amplifier. This would result in the

amplified signal passing into the operate section of the relay which causes the

false operation.

Discussion:

To date, solid state devices istalled in nuclear power plants have been

responsible for all of the known cases of radio frequency interference (RFI)

generated by portable radio transmitters. Three of the four examples cited in

this information notice occurred during preoperational testing or early in

plant operation.

Many of the older nuclear power plants have so few solid state devices that

this explains their apparent invulnerability to RFI generated by portable radio

transmitters. As newer plants are built that use more solid state equipment

and asý older plants retrofit solid state equipment, more cases of RFI by

portable radio transmitters are likely to result.

The use of portable radio transmitters, e.g., walkie-talkies, has been common

practice at many operating nuclear power plants, and for the most part, nuclear

IN 83-83 December 19, 1983 power plants have shown themselves to be largely, although not entirely, invulnerable to the RFI that such radios generate. When such RFI has been

demonstrated to be a problem, nuclear power plants have successfully dealt

with the problem by prohibiting the use of portable radio transmitters in

certain areas. Nevertheless, the vulnerability of safety systems and nonsafety

systems to inadvertent actuation or malfunction poses a significant threat to

safe operation of the plant if the measures to prevent use of radio transmitters

fail under emergency situations.

Emergency situations in which posted restrictions on the use of portable radio

transmitters are likely to break down include those instances in which indivi- duals other than plant operating personnel may L* present in the plant or in

which operating personnel are performing non-routine functions. Such situa- tions include but are not limited to firefighting, bomb searches, and local

operation of equipment normally performed from the control room.

Plans for dealing with such emergency situations require consideration of the

possibility for RFI if the nuclear power plant has a demonstrated or implied

vulnerability. When solid state equipment is retrofitted into an existing

plant, the potential for RFI vulnerability suggests that the licensee should

evaluate the impact on plant operation and safety.

The use of the increasingly popular cordless telephones presents another possible

source of RFI.

If plant operations make the use of portable radio transmitters near RFI-

sensitive equipment either necessary or likely in an emergency, then admini- strative prohibitions are not adequate and the licensee should consider hardware

fixes. Typically such fixes include use of filters, shielded cables, and

modification of the affected equipment. Although there are many industrial

standards regarding RFI protection techniques, the NRC has not formally adopted

or endorsed any, nor are there any nuclear standards that specifically address

RFI protection.

As part of a wider program, the NRC is conducting research in the area of

electromagnetic interference (EMI), itlJuding RFI as one of its aspects.

- Edward L. Jordan, Director

Division of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

Techhical Contact: Eric Weiss, IE

(301) 492-4973 Attachment:

List of Recently Issued IE Information Notices

Attachment

IN 83-83 December 19, 1983 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

83-82 Failure of Safety/Relief 12/16/83 All power reactor

Valves to Open at BWR - facilities holding

Final Report an OL or CP

83-81 Entry Into High Radiation 12/7/83 All licensees autho- Areas From Areas Which Are rized to use portable

Not Under Direct ,urveillance radiography devices

in radiography

programs

83-80 Use of Specialized "Stiff" 11/23/83 All power reactor

Pipe Clamps facilities holding

an OL or CP; NSSS

and AEs

83-79 Apparently Improper Use of 11/23/83 All power reactor

Components in Safety-Related facilities holding

Systems an OL or CP

83-78 Apparent Improper Modifica- 11/17/83 All power reactor

tion of a Component Affect- facilities holding

ing Plant Safety an OL or CP

83-77 Air/Gas Entrainment Events 11/14/83 All power reactor

Resulting in System Failures facilities holding

an OL or CP

83-76 Reactor Trip Breaker Malfunc- 11/2/83 All power reactor

tions (Undervoltage Trip facilities holding

Devices on GE Type AK-2-25) an'OL or CP

83-75 Improper Control Rod Mani- 11/03/83 All power reactor

pulation facilities holding

an OL or CP

83-74 Rupture of Cesium-137 11/03/83 All NRC licensees auth- Source Used in Well-Logging orized to possess and

Operations use sealed sources

containing byproduct

or special nuclear

material in well-logging

operations.

OL = Operating License

CP = Construction Permit