The Nuclear Regulatory Commission's (NRC) classification of four levels of radiological emergencies: Notification of Unusual Event, Alert, Site Area Emergency, and General Emergency.
The response taken by Westchester, Rockland, Orange
and Putnam counties and New York State will depend on the severity of
the incident described by the NRC’s pre-established classifications.
Because these four classifications are based on specific plant
conditions and measurements, they provide a clear indication of the
seriousness of the event.
Unusual events are in progress or have occurred which indicate a
potential degradation of the level of safety of the plant. No releases
of radioactive material requiring offsite response or monitoring are
expected unless further degradation of safety systems occur.
Events are in progress or have occurred which involve an actual or
potential substantial degradation of the level of safety of the plant.
Any releases are expected to be limited to small fractions of the
Environmental Protection Agency (EPA) Protective Action Guideline (PAG)
Events are in progress or have occurred which involve actual or likely
major failures of plant functions needed for protection of the public.
Any releases are not expected to exceed EPA Protective Action Guideline exposure
levels except near the site boundary.
Events are in progress or have occurred which involve actual or imminent
substantial core degradation or melting with potential for loss of
containment integrity. Releases can be reasonably expected to exceed EPA
Protective Action Guideline exposures
offsite for more than the immediate site area.
Facility where shelter and food is provided to evacuees.
A plan that details comprehensive emergency procedures for all types of
disaster emergencies in the state, i.e., floods, hurricanes, etc. A
portion of the Disaster Preparedness Plan is the Radiological Emergency
The Nuclear Regulatory Commission (NRC)'s classification of four levels of radiological emergencies: Notification of Unusual Event
, Site Area Emergency
, and General Emergency
response taken by Westchester, Rockland, Orange and Putnam counties and
New York State will depend on the severity of the incident described by
the NRC’s pre established classifications. Because these four
classifications are based on specific plant conditions and measurements,
they provide a clear indication of the seriousness of the event.
A designated location at county and/or state headquarters from which a
chief executive and staff can direct the action of state and local
agencies and emergency services.
A facility operated by the power plant licensee for evaluating and
controlling emergency situations and coordinating responses with local
and state representatives; its location normally is outside the plant exclusion area
The area surrounding a nuclear power plant site designated for emergency
planning purposes. The Emergency Planning Zone encompasses a radius of
about 10 miles for the plume exposure pathway
, and about 50 miles for the ingestion exposure pathway
A subdivision of the plume exposure
emergency planning zone. An Emergency Planning Zone
is made up of several Protective Action Areas.
Everyone within specific Protective Action Areas are instructed to leave the area and, if they have Kl-potassium iodide
-to ingest one dose-a 130 mg. tablet. Children under one year should be given a 65 mg does or one half of the adult tablet.
The area surrounding a nuclear power plant facility in which the
facility operator has the authority to determine and control all
activities. No residences exist within a nuclear power plant exclusion
For planning purposes, the area surrounding a site within approximately a 50-mile radius where the principal source of exposure from an accident would be the ingestion of contaminated food or water.
The organization licensed by the Nuclear Regulatory Commission to operate a nuclear facility.
A "cloud" of radioactive material made up of gases or particulates.
The area surrounding a nuclear facility site (usually a radius of approximately 10 miles) where the principal exposure
would be from: (a) whole body exposure to gamma radiation
from the plume and from deposited material, and (b) inhalation exposure from the passing plume.
The first of three designated phases of activity in the state and county plans for radiological emergencies (response
phases follow). Actions during this phase aim to eliminate or reduce
the probability of an emergency situation occurring, and minimize the
impact of an emergency on public health and property.
The phase of activity in a radiological emergency when protective
actions are taken to protect public health and mitigate effects of a
The last phase of activity in the state and county plans for
radiological emergencies; efforts during this phase are to return to
Any action taken to protect the public's health in response to a radiological emergency, i.e., recommending sheltering or evacuation/ingesting KI
A pre-designated location outside the plume exposure pathway
Emergency Planning Zone through which evacuees will pass to receive initial assistance, including personal monitoring
, receive additional Kl-potassium iodide
, first aid or direction to a congregate care center
or medical facility.
This optional public protective action directing people to stay inside
and limit access to outside air would be made by local elected and
health officials. The decision would be based primarily on plant and
meteorological conditions and announced over the Emergency Alert System.
Any radioactive material dispersed in the air in the form of dust, fumes, mist, vapor or gas.
Cosmic rays and natural radiation
are always present in the environment. In addition, man-made sources
also contribute to the background radiation level. The average New
Yorker receives approximately 360 millirem per year from background
The reduction or removal of contaminating radioactive material from a structure, area, object or person.
A personal monitoring instrument that measures the radiation dose received by an individual using the device.
The ways in which the presence of radioactive materials in the
environment lead to potential exposure to humans, i.e., inhalation of airborne radioactive material
, ingestion of contaminated food or drink, and whole body exposure
to a passing plume
or ground contamination.
Amount of exposure received per unit of time, i.e., roentgens
per second or roentgens
per hour. A radiation detection instrument such as a Geiger counter or an ionization chamber measures the exposure rate.
Film encased in a badge-like holder that record radiation exposure for
personnel monitoring purposes. The film usually is processed monthly for
calculation of the absorbed dose. Results are reported in millirems (mRem)
The time required for radioactive material to lose 50% of its activity by radioactive decay.
A radioactive form of a chemical element with varying numbers of neutrons in the nucleus.
A substance taken as a protective measure to reduce the uptake by the
thyroid of radioiodine, i.e., potassium iodide (KI). KI is not an
alternative to evacuation. It protects one organ - the thyroid - from
one form of radiation
– radioiodine. A 130 mg tablet is the recommended dose. Children
under one year of age should be given a 65 mg dose – or one-half of the
tablet. KI is available from the counties' emergency management
offices, or as an over-the-counter medicine at many drug stores.
Periodic or continuous measuring of radiation
by means of survey instruments that can detect and measure ionizing radiation.
Measurement of radiation
level or contamination present in a specific area, building, room, etc.
Measurement of radiation
levels that may have been received by an individual to the whole body
or specific organs or body parts. The most common devices used for
measuring exposure from external sources are film badges
, thermoluminescent dosimeters (TLDs)
and pocket dosimeters
. Whole body counting or measurements of breath or excretions may be taken to determine intake of radioactive materials.
A device in which a fission chain reaction can be initiated, maintained
and controlled. Its essential component is a core with fissionable fuel.
The emission of energy through a material medium in the form of
electromagnetic waves or particles that may impart their energy to the
medium through the creation of electrically charged ion pairs. X- and
gamma rays and alpha and beta particles are examples of ionizing
Pure energy emitted from the nucleus of an unstable isotope
An electron emitted from the nucleus of an unstable isotope
The process by which an unstable nucleus of an atom spontaneously releases energy through the emission of radiation
Introduction of radioactive materials into an uncontrolled environment.
Exposure of the thyroid gland to radiation from radioactive isotopes
of iodine, which have either been inhaled, absorbed or ingested. Accumulation of iodine is rapid in the thyroid gland
made of material that when heated emits light in amounts proportional
to the amount of radiation dose it received. Placed in a badge-type
holder, it can be worn by an individual to measure his/her possible
exposure to ionizing radiation
Exposure of a major portion of the body to an external radiation
field or radioactive material distributed throughout the body. Exposure
of blood forming organs, reproductive organs, head, trunk and lenses of
the eyes is also considered exposure of the whole body.
The amount of energy absorbed by matter received from ionizing radiation
per unit mass of matter; expressed in rads
A measure of the ionization produced in air by X- or gamma radiation
, and expressed in roentgens (R)
. Although "dose" and "exposure" are often used interchangeably, the former (dose
) is a measurement of energy absorbed in body tissue, and the latter (exposure
) is a measurement of ionization in the air due to the presence of radiation.
Unit of exposure
, applicable only to X- and gamma radiations.
A unit used to express all types of ionizing radiation
on a common scale to indicate relative biological effects.
For beta and gamma radiation: exposure to 1 roentgen delivers a dose of 1 rad, which is equivalent to 1 rem.
Amount of radioactive material in which 37 billion atoms decay per
second. The rate at which radioactive material is released to the
environment may be expressed in units of curies per second (Ci/sec.).
One-thousandth of a unit (10-3), i.e., millirem (mRem) or milliroentgen (mR).
One-millionth of a unit (10-6).
One trillionth of a unit (10-12).
Dose limits are prescribed by the NRC per the Code of
Federal Regulations, Title 10, Section 50. They include five (5)
parameters identified from the second International Conference on
Radiation Protection. These parameters are identified and defined below.
Biological effect to the entire human body, as a result of liquid
Biological effect to an organ most affected by the liquid effluent
(Liver, Kidney, Thyroid, Lung, Bone, or the Gastro-Intestinal tract).
A measure of energy (radiation
in air from Beta
noble gas isotopes
A measure of energy (radiation
in air from Gamma
noble gas isotopes
Biological effect to the human body from airborne radioactive emissions
of Iodine or particulate matter.