What is Radiation?

radiation



Energy particles called atoms make up everything on earth. As these atoms change to become more stable, they give off invisible energy waves or particles called radiation. Radiation is energy that travels in the form of waves or high speed particles.

Radiation in daily life can include:

There are different types of radiation that have a range of energy that forms an electromagnetic spectrum and some are more energetic than others. Two types of radiation are, non-ionizing radiation which has enough energy to move atoms but not enough to alter them chemically and ionizing radiation. Ionizing radiation is the radiation that may harm our bodies and our food.
There are three main kinds of ionizing radiation:

Alpha particles, which include two protons and two neutrons;
Beta particles, which are essentially electrons;
Gamma rays and x-rays, which are pure energy (photons).


When humans are exposed to radiation, doses are measured in units called rem. It is estimated that the average person in the United States receives a dose of about 360 millirem of radiation per year. Eighty percent of that exposure comes from natural sources: radon gas, the human body, outer space, rocks and soil. The remaining 20 percent comes from man-made radiation sources, primarily medical x-rays.


Air Transport of Radiation

Stability of the Atmosphere

Under different conditions, the atmosphere can be stable or unstable. This stability or instability influences how pollution spreads after it leaves a nuclear power plant's smoke stack or a radiation source.

Under stable conditions, airborne pollution diffuses relatively slowly. In the air near the ground, this tends to occur more often in the winter, especially during the night. Emissions that occur at night when the air is cooler at ground-level tend carry more radiation beyond the release site.

Under unstable conditions, pollution diffuses relatively rapidly. In the air near the ground, this tends to occur more often in the summer, especially during the day.


Wind Speed and Direction

The primary factors in determining where radiation releases to the air will go are the speed and direction of the wind. The wind's importance is symbolized by the fact that people who may be exposed to radiation are referred to as "downwinders."


Radioactive Materials and Hot Spots

It might be thought that as one moves farther from a pollution source there is a decrease in the amount and concentration of pollution. This is due to some of the material falling back to earth and the remainder becoming more mixed with the surrounding air. However, this was not always true.

Because of variations in the wind patterns and the earth's surface (hills, valleys, etc.), the spread of radiation, even in the downwind direction, may not be uniform. The term "hot spot" refers to an area that has more contamination than does the surrounding area.

Four main factors lead to the creation of hot spots: precipitation, wind patterns, stagnation and impaction.


Precipitation

Snow and rain can wash radioactive substances from the air and deposit the contamination on vegetation and the ground. When the wind carries radioactive material from a site over an area where it was raining or snowing, the area can receive a greater concentration than the areas around it. The surrounding areas might not have experienced any precipitation or were not in the path of the wind-blown radioactive plume.


Wind Patterns

In the case of releases of pollution lasting many minutes or hours, the wind direction could change during this time. In some instances, the change in wind could send the pollution plume in two or more directions. Later, the winds could change speed and direction again and cause the plumes to combine over a particular area and form a hot spot. This combining of plumes could be part of a regular weather pattern. If this were the case, then a particular area could become a hot spot.


Stagnation

When the wind carrying radioactive material becomes calm, the radioactive plume may remain over an area for a longer time. The lack of wind would allow more radiation to deposit in one particular area, possibly creating a hot spot.


Impaction

Impaction occurs when the pollution plume meets the side of a hill or mountain. The contamination is deposited in greater amounts where the plume meets the side of a mountain than in other areas at the same elevation.


Regulation of Radiation

The Clean Air Act, in 40 CFR 61, requires the EPA to regulate airborne emissions of hazardous air pollutants (HAPs) (including radionuclides) from a specific list of industrial sources called "source categories." Each source category that emits radionuclides in significant quantities must meet technology requirements to control them and is required to meet specific regulatory limits. These standards are the National Emission Standards for Hazardous Air Pollutants for Radionuclides (Rad NESHAPs).

Hazardous air pollutants are regulated because they are pollutants that cause or may cause cancer or other serious health problems, such as reproductive effects or birth defects, or adverse environmental and ecological effects. This is why radionuclides are among those pollutants.

There is specific sections to regulate uranium mining that are enforceable. When uranium mines are operating, their ventilation systems emit large amounts of radon into the atmosphere. Radon in an unventilated mine is hazardous to miners. Ventilating the mine to reduce radon exposure to the miners increases exposure to the general population. This is an important part of the NESHAP program. When uranium mines are not operating, there may be problems with old mine tailings and radioactive dust being blown into communities and water sources they rely on. There are many regulations regarding uranium mining and these can be accessed at http://epa.gov/radiation/neshaps/index.html

A few 40 CFR 61 subpart regulations that govern working uranium mines and abandoned tailings are:

Subpart B protects the public and the environment from the radon-222 emissions to the ambient air from underground uranium mines. A limit is set on the emission of radon-222 that ensures that no member of the public in any year receives an effective dose equivalent of more than 10 mrem/year.

Subpart T protects people and the environment from radon-222 emissions from uranium mill tailings piles that are no longer operational. The radon-222 emission rate from a uranium mill tailings pile to the surrounding (ambient) air must not exceed 20 pico curies per square meter per second. As with Subpart I, Subpart T does not apply to Nuclear Regulatory Licensees, because they are covered by NRC's regulatory system.

CASE STUDIES:

The regulation on uranium mines in 40 CFR 61 is important because presently, a company, Landmark Alaska Limited Partnership, which is a U.S. subsidiary of Ucore Uranium Inc from Canada, is spending $4 million this year on an exploration program at Bokan Mountain. This Prince of Wales Island site is where Alaska's only producing uranium mine was in operation from 1957 to 1971.

Discovered in 1955, Bokan Mountain produced about 1.3 million pounds of uranium during three mining periods beginning in 1957 and ending in 1970-71. The uranium mined there was purchased under contract by the U.S. government. There now a renewed potential for permitting and construction to occur between 2011 and 2013 for a mine to target uranium and rare earth metals at the site above Kendrick Bay, about 40 miles from Ketchikan.

For more information you can review the document:

Guidance for the Control of Radiation Hazards in Uranium Mining (PDF) (60pp, 3,964 Kb), Federal Radiation Council, 9/67. This report contains background material used in the development of the Federal Guidance Document, Underground Mining of Uranium Ore.
http://www.epa.gov/radiation/docs/federal/frc_rpt8.pdf

Other potential radiation issues issue affecting Alaska could be the proposed Galena Nuclear Power Plant to be constructed in the Yukon River village of Galena. If built, it would be the first non-military nuclear power plant built in Alaska to be utilized for public utility generation.
http://www.primidi.com/2005/02/06.html
http://www.alaskajournal.com/stories/042708/hom_20080427006.shtml

There is also a closed nuclear reactor located at Fort Greely, Alaska. This reactor is closed and is maintained by the Army Corps of Engineers. Which is a unique situation. This nuclear reactor and its waste material located on the 1,200 square mile Fort Greely military base, near Delta Junction, Alaska. The Army operated a nuclear reactor from about 1962 until 1972, which was thought to produce small scale nuclear weapons for the battlefield.


Removal of 1500 cubic yards of soil contaminated with nuclear waste. Fort Greely, Alaska.


Suspected sources of radionuclides include liquid radioactive wastes released into the ground water; radioactive steam used in the laundry and to heat the military base; a control rod accident and subsequent cleanup process; fallout near reactor from accident that caused permanent closing; improper methods of disposal of solid radioactive wastes; radiation remaining in containment structure of decommissioned reactor

There has been some discussion among some residents of Delta Junction who suspect that there is a relationship between the reactor and high cancer rates in the community. The area that lies just north of Delta Junction has been dubbed "cancer row" by residents of the area.

Another potential concern is the Bilibino Nuclear Power Plant (BNPP) in Northeastern Siberia.
http://insp.pnl.gov/-reports-pocketbook-russia.htm#bi

Another site with a significant radiation history in Alaska was part of the Vela Uniform Program. Nuclear tests were conducted near Fallon, Nevada (Project Shoal), on Amchitka Island, Alaska (Project Long Shot), and near Hattiesburg, Mississippi, (Projects Salmon and Sterling).

The Amchitka Islands projects Long Shot was designed to determine the behavior and characteristics of seismic signals generated by nuclear detonations and to differentiate them from seismic signals generated by naturally occurring earthquakes.

Amchitka Island is the southernmost island in the Aleutian chain and is about 1400 miles (2,300 km) southwest of Anchorage. Amchitka Island was the site of three nuclear detonations conducted in October 1965, October 1969, and November 1971.

Long Shot was a nuclear detection research experiment detonated at a depth of 700 meters (2,300 feet). It had a yield of about 80 kilotons.

Milrow was a high-yield seismic calibration test detonated at a depth of 1,220 meters (4,000 feet). It had a yield of about one megaton.

Cannikin, a test of a proposed warhead for the Spartan missile, was detonated at a depth of about 1,790 meters (5,875 feet), with a yield of less than five megatons.

DOE manages the Amchitka Site according to a site specific Long-Term Surveillance and Maintenance Plan to ensure that site conditions continue to be protective of the environment. Under provisions of this plan, DOE conducts inspections of the site to evaluate the condition of surface features, performs site maintenance as necessary, and collects samples of biota. LM monitors seismic activity from the U.S. Geologic Survey Earthquake Hazard website to document activity that may impact the site. Documents related to the Amchitka Site are available on the DOE Office of Legacy Management website at http://www.lm.doe.gov/land/sites/ak/ak.htm

For more information about DOE Legacy Management
activities at the Amchitka Site, contact
U.S. Department of Energy
Office of Legacy Management
2597 B¾ Road, Grand Junction, CO 81503
(970) 248-6070 (monitored continuously), or
(877) 695-5322 (toll-free)


Another site which can be found at the DOE Legacy site is the Chariot site located in the Ogotoruk Vally in the Cape Thompson Region of Alaska, the site is 125 miles north of the Arctic Circle and bounded on the southwest by the Chuckchi Sea. Point Hope is 32 miles northwest of the site and Kivalina is 41 miles to the southeast. The concerns in this area are the remaining tracer contamination from a USGS experiment to evaluate the mobility of radioactive fission products in saturated soils, sediment and surface water subjected to simulated conditions of rain and runoff. Even though there has been data to show that exposure risks are lowered due to short half lives of the radiation, community members should be informed about the site based on the high winds in the region and subsistence living and contamination concerns. http://www.lm.doe.gov/land/sites/ak/ak.htm


Risks from exposure to Radiation

Radiation exposure can be internal or external. Internal exposure comes from eating or drinking contaminated food or water, or from breathing contaminated air. Alpha and beta radiation contribute to internal exposure. External exposure can come from beta, gamma and X-ray radiation that penetrates the body.

Radioactive substances can also enter the body through cuts in the skin. When we breath radioactive particles they can also become lodged inside the body and expose internal organs as the radionuclides decay.

There are three main routes of exposure or exposure pathways:

Inhalation exposure occurs when people breathe radioactive materials into the lungs. The chief concerns are radioactively contaminated dust, smoke, or gaseous radionuclides such as radon.

Ingestion exposure occurs when someone swallows radioactive materials. Alpha and beta emitting radionuclides are of most concern for ingested radioactive materials. They release large amounts of energy directly to tissue, causing DNA and other cell damage. Ingestion can expose the entire digestive system and some raditaion can also be absorbed and expose the kidneys and other organs, as well as the bones.

External or direct exposure can be of concern about exposure to different kinds of radiation and the type varies. There is limited concern about alpha particles. They cannot penetrate the outer layer of skin, but if you have any open wounds you may be at risk. There is greater concern about beta particles. They can burn the skin in some cases, or damage eyes.



The greatest concern is about gamma radiation. Different radionuclides emit gamma rays of different strength and gamma rays can travel long distances penetrating entirely through the body.

Gamma rays can be slowed by dense material (shielding), such as lead, and can be stopped if the material is thick enough. Examples of shielding are containers; protective clothing, such as a lead apron; and soil covering buried radioactive materials.

Direct exposure to radiation is known to cause cancer. In this respect, it is similar to many hazardous chemicals found in the environment that can cause cancer. The report Pollution and Cancer in Alaska ( http://www.peer.org/docs/ak/06_6_6_pollution_&_cancer.pdf ) has shown that Alaska exceeded the national cancer incidence rate for all types of cancer in 2004. The Alaska, female cancer incidence rate for all types of cancer was found to be higher and statistically significant when compared to the national, female cancer incidence rate for all types of cancer. However, the cancer incidence rate for Alaskan males was found to be similar to the national incidence rate for all types of cancer.

Radiation exposure may also cause other adverse health effects, including genetic defects in the children of exposed parents or mental retardation in the children of mothers exposed during pregnancy. However, the risk of developing cancer due to radiation exposure is much higher than the risk of these other effects.

Much recent knowledge about the risks from radiation is based on studies of over 100,000 survivors of the atomic bombs at Hiroshima and Nagasaki. In these studies, which have continued over the last 40 years, scientists have been able to observe the effects of a wide range of radiation doses, including doses comparable to an average person's lifetime dose from naturally-occurring background radiation (about 20,000 millirem). Many things have been learned from these studies. Some of the most important are:

The more radiation dose a person receives, the greater the chance of developing cancer
It is the chance of cancer occurring, not the kind or severity of cancer, that increases as the radiation dose increases.
Most cancers do not appear until many years after the radiation dose is received (typically 10 to 40 years).


Current evidence suggests that any exposure to radiation poses some risk. This means that there is no level below which we can say an exposure poses no risk. When we breath in radiation,the particles may lodge in our lungs or digestive tract and continue to emit radiation directly to living tissue.

Some of the ways radiation can directly affect the human body are:



For more information on health implications that would have resulted from fallout from weapons testing through 1961 you can access the document below:

Health Implications of Fallout from Nuclear Weapons Testing Through 1961 (PDF) (13pp, 504 Kb), Federal Radiation Council, 5/62

This report evaluates the health implication of fallout from nuclear weapons testing conducted through 1961. It concluded that nuclear testing through 1961 increased by small amounts the normal risks of adverse health effects to the general population.
http://www.epa.gov/radiation/docs/federal/frc_rpt3.pdf

Some if the possible health effects: of radiation may include leukemia, bone, liver, nasal cavity cancers, thyroid disorders, lung cancers, liver damage and genetic changes.


Radiation and Subsistence

Arctic areas of Alaska are especially vulnerable to nuclear accidents that can release radioactivity into the atmosphere within the circumpolar north. Atmospheric fallout and the resultant bioconcentration in the lichen-caribou-human food chain are of great concern for those living a subsistence lifestyle. Once released into the environment radionuclides find their way into food along innumerable pathways. Some examples that have been found are:

In the sea, small marine creatures concentrate radionuclides which have been absorbed on to seabed sediments. As predators eat their prey the radionuclides pass, in turn, from shrimps to crabs to fish, many varieties of which are eaten by humans.

Seaweeds and other algae have a remarkable capacity to concentrate radionuclides. Some seaweed has been identified as being badly contaminated by ruthenium-106.

Fungi and mosses concentrate radionuclides. Reindeer meat in Lapland, since Chernobyl, has been identified as being highly contaminated with radionuclides from the fallout.


Radiation Monitoring Project and Sites in Alaska

RADNET http://www.epa.gov/enviro/html/erams/
The goal of RADNDET is to monitor environmental radioactivity in the United States in order to provide high quality data for assessing public exposure and environmental impacts resulting from nuclear emergencies and to provide baseline data during routine conditions.

RadNet has three specific objectives:


Alaska has two monitoring sites in Anchorage for near real-time gamma radiation and in Fairbanks for air particulates, precipitation and drinking water.

In general, data generated from RadNet provides the information base for making decisions necessary to ensure the protection of public health. The system helps EPA determine whether additional sampling or other actions are needed in response to particular releases of radioactivity to the environment. RadNet can also provide supplementary information on population exposure, radiation trends and other aspects of releases.

Prepartory Comission for the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) http://www.ctbto.org/

Alaska currently has 5 radiation monitors throughout the state that were placed by the Preparatory Comiccion for the Comprehensive Nuclear Test Ban Treaty Organization.

The sites in Alaska are :
Sand Point, AK – Radionuclide monitor
Kodiak Island, AK- Auxiliary Seismic Monitor
Fairbanks, AK – Infrasound monitor
Eielson, AK – Primary Seismic Monitor
Salchaket, AK – Radionuclide Monitor


Radionuclide monitors monitor for isotopes with an unstable nucleus that disintegrates and emits energy in the process. Radionuclides may occur naturally, but they can also be artificially produced. Radionuclides are often called radioisotopes.

Auxiliary seismic monitors provide data on a seismic event to the CTBTO’s International Data Center (IDC) in Vienna that supplements information gathered by primary seismic stations. The data from the 120 auxiliary seismic stations are available upon request by the IDC.

Infrasound monitors detect very low frequency sound waves in the atmosphere produced by natural and man-made events. The sound waves are inaudible to the human ear and can originate from atmospheric explosions, explosive volcanoes, meteorites entering the atmosphere, rocket launches and other phenomena.


Atmospheric Radiation

The atmospheric radiation group at University of Alaska Fairbanks investigates the optical properties of the atmosphere to understand the global radiation balance. Members of this group are actively involved with the Atmospheric Radiation Monitoring (ARM) project. Gerd Wendler- has investigated the net radiation in the Antarctic pack ice and is developing a climatology of contrails in Alaska, which is thought to have an impact on the radiative balance of the atmosphere.

A network of meteorological and radiological monitoring stations, central data storage, and processing systems. Sites are located in Alaska at the following locations: Fairbanks, Seward, Nome, Point Hope and Kotzebue

The data collected from these monitors are wind direction and speed, ambient temperature, atmospheric pressure, humidity, and gamma radiation.

Each (DCP) station transmits the data to a satellite, which then transmits the data to earth stations at Los Alamos, New Mexico, or Las Vegas, Nevada.

Access to the data can be gained via the Internet or through an onsite readout directly from the Data Collection Platform (DCP). Interested citizens, schools or researchers have access to the stations and can observe the results at any time. At Los Alamos the data are processed and made available over the Internet.

For more information on Radiation issues that may affect Tribal communities you can look at the following sites:
Human Radiation Effects Group
H. H. Wills Physics Laboratory,
Tyndall Avenue,
Bristol BS8 1TL, UK
Tel: +44 (0) 117 926 0353 Fax: +44 (0) 117 925 1723
http://www.electric-fields.bris.ac.uk

Alaska Ocean Observing System
Solar Radiation Information
http://ak.aoos.org/op/data/index.php?param=avgsrad®ion=AK