Emergency Classification: 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 the State of Vermont and the EPZ towns will depend on the classification 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 Event: This means a minor problem has occurred at the plant. It may involve injury to a worker, hazardous weather or an equipment problem. Public officials will be notified, but there would be no need to notify the public. People in the area would not need to take any special actions.

Alert: This could affect plant safety but it is not expected to require any special actions by residents. Public officials will be notified. They would monitor the situation and be ready to act if it got worse. As a precaution, public officials may mobilize transportation resources. They may transfer school children to host facilities outside the area and clear state forests and waterways. Emergency Alert System radio or news broadcasts would inform the public of these actions.

Site Area Emergency: This means a more serious problem has occurred. A small release of radioactive materials from the plant is possible. State and local officials will keep persons in the area fully informed about any necessary actions through Emergency Alert System radio stations. As a precaution, public officials would transfer school children to host facilities outside the Emergency Planning Zone. Other precautions would be called for by state officials, as needed.

General Emergency: This is the most serious type of emergency. It could involve serious damage to the plant and the release of radioactive materials. State officials might order persons in the area to shelter-in-place or to evacuate to a safer location. Warning signals (sirens and Weather Alert Radios) would notify persons in the area. Special instructions and other important information would be issued over the Emergency Alert System radio stations.

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Congregate Care Center: Facility where shelter and food is provided to evacuees.

Emergency Operations Plan: A plan that details comprehensive emergency procedures for all types of disaster emergencies in the state, i.e., floods, hurricanes, etc. The Radiological Emergency Response Plan is an annex to the Emergency Operations Plan

Emergency Operations Center (EOC): A designated location at town and/or state headquarters from which staff can direct the action of state and local agencies and emergency services during a response to an emergency in that jurisdiction.

Emergency Operations Facility (EOF): A facility operated by the power plant licensee for evaluating and controlling emergency situations and coordinating responses with local and state representatives.

Emergency Planning Zone (EPZ): 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.

Ingestion Pathway Zone: 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.

Plume: A "cloud" of radioactive material made up of gases or particulates.

Plume Exposure Pathway: 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.

Prevention/Mitigation: The first of three designated phases of activity in the state for emergencies (response and recovery 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.

Response: The phase of activity in an emergency when protective actions are taken to protect public health and mitigate the effects of the emergency.

Recovery: The last phase of activity in the state plans for emergencies; efforts during this phase are to return to pre-emergency conditions.

Protective Action: Any action taken to protect the public's health in response to a radiological emergency, i.e., recommending sheltering or evacuation/ingesting KI.

Reception Center: 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, and direction to a congregate care center or medical facility.

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Airborne Radioactive Material: Any radioactive material dispersed in the air in the form of dust, fumes, mist, vapor or gas.

Background Radiation: 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 US Citizen receives approximately 360 millirem per year from background radiation.

Decontamination: The reduction or removal of contaminating radioactive material from a structure, area, object or person.

Dosimeter: A personal monitoring instrument that measures the radiation dose received by an individual using the device.

Dosimeter of Legal Record (DLR): A Film encased badge that records beta and gamma radiation exposure. This dosimeter provides are legal record of one’s exposure to ionizing radiation

Exposure Pathways: 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.

Exposure Rate: 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.

Half-life: The time required for radioactive material to lose 50% of its activity by radioactive decay.

Isotope: A radioactive form of a chemical element with varying numbers of neutrons in the nucleus.

Potassium Iodide (KI): 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 12 years of age should be given a 65 mg dose – or one half of the tablet. KI is available from the Vermont Department of Health or as an over the counter medicine at many drug stores.

Monitoring: Periodic or continuous measuring of radiation by means of survey instruments that can detect and measure ionizing radiation.

Area Monitoring: Measurement of radiation level or contamination present in a specific area, building, room, etc.

Personal Monitoring: 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 thermoluminescent dosimeters (TLDs), direct reading dosimeters (DRDs), and survey meters. Whole body counting or measurements of breath or excretions may be taken to determine intake of radioactive materials.

Nuclear Reactor: A device in which a fission chain reaction can be initiated, maintained and controlled. Its essential component is a core with fissionable fuel.

Radiation: 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 radiation.

Gamma Radiation: Pure energy emitted from the nucleus of an unstable isotope.

Beta Radiation: An electron emitted from the nucleus of an unstable isotope.

Alpha Radiation: A particle containing 2 protons and 2 neutrons emitted from the nucleus of an aton as it decays.

Radioactive Decay: The process by which an unstable nucleus of an atom spontaneously releases energy through the emission of radiation.

Radioactive Release: Introduction of radioactive materials into an uncontrolled environment.

Thyroid Exposure: Exposure of the thyroid gland to radiation from Iodine-131, a radioactive isotope of iodine, which have either been inhaled, absorbed or ingested. Accumulation of iodine is rapid in the thyroid gland

Thermoluminescent Dosimeter (TLD): A dosimeter 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.

Whole Body Exposure: 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.

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Dose: The amount of energy absorbed by matter received from ionizing radiation per unit mass of matter; expressed in rads.

Exposure: A measure of the ionization produced in air by X- or gamma radiation; expressed in roentgens (R).

Although "dose" and "exposure" are often used interchangeably, the former (dose) is a measurement of energy absorbed in body tissue, the latter (exposure) is a measurement of ionizations in the air due to the presence of radiation.

Rad: Unit of radiation dose

Roentgen (R): Unit of exposure, applicable only to X- and gamma radiations.

Rem: 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.

Curie (Ci): 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.).

Milli-(m): One-thousandth of a unit (10-3), i.e., millirem (mRem) or milliroentgen (mR).

Micro-(u): One-millionth of a unit (10-6).

Pico-(p): One trillionth of a unit (10-12).

Dose Limits: Dose limits are prescribed by the NRC per the Code of Federal Regulations, Title 10, Section 50. They include 5 parameters identified from the second International Conference on Radiation Protection. These parameters are identified and defined below.

Liquid Whole Body Dose: Biological effect to the entire human body, as a result of liquid effluents.

Liquid Critical Organ Dose: Biological effect to an organ most affected by the liquid effluent (Liver, Kidney, Thyroid, Lung, Bone, or the Gastro-Intestinal tract).

Beta Air Dose: A measure of energy (radiation) in air from Beta-emitting noble gas isotopes.

Gamma Air Dose: A measure of energy (radiation) in air from Gamma-emitting noble gas isotopes.

Iodine/Particulate Dose: Biological effect to the human body from airborne radioactive emissions of Iodine or particulate matter.

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RERP: Radiological Emergency Response Program, the branch of Vermont Emergency Management that deals with the radiological planning and response to a Vermont Yankee incident.

VEM: Vermont Emergency Management, This is the division of the Department of Public Safety that is tasked with planning for, responding to, mitigating, and recovering from emergencies within the State of Vermont.

FEMA: Federal Emergency Management Agency, This agency of the Federal Government that is tasked with providing resources and assistance to areas of disaster. They also provide planning guidance for all-hazards.

NRC: Nuclear Regulatory Commission, This government agency oversees and regulates nuclear power plant operations in America.

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VEM Brattleboro Office
230 Main Street
Suite 306
Brattleboro, VT 05301

Phone: 802-251-2172
Fax: 802-251-2173
E-Mail

VEM Headquarters
103 South Main Street
Waterbury, VT 05671
Phone: 800-347-0488
Fax: 802-241-5556
E-Mail VEM Waterbury