Information Notice No. 81-34: Accidental Actuation of Prompt Public Notification System
SSINS No.: 6835
Accession No.:
8107230038
IN 81-34
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
November 16, 1981
Information Notice No. 81-34: ACCIDENTAL ACTUATION OF PROMPT PUBLIC
NOTIFICATION SYSTEM
Description of Circumstances:
Recently the Maine Yankee prompt notification system was inadvertently
activated. The Maine Yankee system consists of three subsystems, one of
which uses radio controlled fixed sirens to alert the public to the
existence of a regional emergency. The regional emergency signal, which
would be used in the event of an emergency at Maine Yankee or any other type
of regional emergency requiring public notification, can be activated by
Maine Yankee plant personnel, by the county Sheriff, and by the State
Police. In a regional emergency, all fixed sirens are activated
simultaneously by a single radio signal carrying a two tone sequential
command encoded at the transmitter and decoded at each siren's radio
receiver. The public has been instructed that when they hear the regional
emergency alert signal, they should tune in the Emergency Broadcast System
(EBS) and/or the local National Oceanic & Atmospheric Administration (NOAA)
station to get information about the nature of the emergency and what they
are to do.
The fixed sirens can develop more than one sound. In addition to a common
regional emergency sound, each siren can also produce a different,
distinctive sound which is used by local fire companies to signal a fire.
The controls for fire calls are independent of the regional alert control.
Recently the fixed sirens were activated three times in rapid succession by
radio signals generated by the State Police in the course of routine police
radio pager operations not connected with a regional emergency.
For a time neither Maine Yankee personnel, the county Sheriff, nor the State
Police realized that the regional emergency signal had been triggered. No
emergency instructions or announcements were broadcast to the public via EBS
or NOAA, so some concerned citizens telephoned the plant and the State
Police for further information. In all, about one hour elapsed between the
first siren system activation and the first media announcement indicating no
emergency existed.
Since this event, the State Police, who have the authority to activate EBS
and NOAA, have developed "no emergency" messages and procedures which can be
quickly aired should another emergency signal be produced in the absence of
an emergency. They have also altered their radio operations plan to assure
an offending signal will not be generated. Maine Yankee has altered the
tone sequencing scheme to render it unlike tone sequences typical of
commercially
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IN 81-34
November 16, 1981
Page 2 of 2
available paging systems. These steps will reduce the likelihood of a
recurrence and provide for rapid announcements to the public over EBS
stations and NOAA weather radio in the event a "no emergency" message is
needed. Thus, the "no emergency" message will reach the public in the same
way emergency instructions would, and just as rapidly. These are interim
steps.
In the longer term, an encoded digital message will be used to activate the
sirens. This offers far more security than the sequenced tone system it
will replace. The "no emergency" announcement capability will be retained.
This information notice is provided to make licensees and applicants aware
of this event and its associated problems. We expect that licensees will
review this information for applicability at their facilities.
No written response to this information notice is required. If additional
information is desired regarding this matter, please contact the Director of
the appropriate NRC Regional Office.
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