The majority of high-level radioactive waste is the fuel from the hot core of commercial nuclear power plants. This irradiated fuel is the most intensely radioactive material on the planet, and unshielded exposure gives lethal radiation doses. It accounts for 95% of the radioactivity generated in the last 50 years from all sources, including nuclear weapons production. Uranium is processed into fuel rods and loaded into nuclear power reactors where it undergoes the nuclear fission reaction. This increases the radioactivity due to the formation of intensely radioactive elements known as fission products, such as cesium and strontium, resulting from the physical splitting of uranium-235 atoms. Heavier elements, known as transuranics, are also formed — including plutonium. Each 1000 megawatt nuclear power reactor annually produces about 500 pounds of plutonium, and about 30 metric tons of high-level waste in the form of irradiated fuel. After several years, when removed from the reactor core, the fuel is about one million times more radioactive than when it was loaded. This irradiated fuel is currently stored at the reactor sites.
HALF-LIFE AND HAZARDOUS LIFE
The half-life of a radioactive element is the amount of time it takes for one-half of the quantity of that element to decay–either to a stable form, or to another radioactive element in the “decay chain.” After ten half-lives, one thousandth of the original concentration is left; after 20 half lives, one millionth. Generally 10–20 half lives is called the hazardous life of the waste. Example: Plutonium-239, which is in irradiated fuel, has a half-life of 24,400 years. It is dangerous for a quarter million years, or 12,000 human generations. As it decays, uranium-235 is generated; half-life: 710,000 years. Thus, the hazard of irradiated fuel will continue for millions of years. This material must be isolated from the biosphere so it will not contaminate or irradiate living things during that time.
WASTE CLASSIFICATION
Radioactive waste classification in the U.S. is misleading and needs reassessment. The regulatory definition of high-level radioactive waste includes only irradiated fuel and the liquid and sludge from reprocessing fuel to recover plutonium (including solids resulting from stabilization of reprocessing wastes). Reprocessing of commercial fuel proved not to be economical or technically feasible in the U.S. There are components and other wastes from nuclear reactors that become intensely radioactive, can deliver a lethal dose, and yet are regulated separately as “low-level” waste.
VOLUME vs. RADIOACTIVITY
Irradiated fuel makes up only about 1% of the total volume of all radioactive wastes generated in the U.S., but it contains about 95% of the radioactivity. As of 1996 there was a cumulative total of 32,000 metric tons of irradiated fuel from commercial nuclear power generation in the United States, nearly all of it at the reactor sites. If all U.S. reactors continue to operate through their current license period, the inventory of high-level irradiated fuel will more than triple.
This fuel contains approximately 25 billion curies of radioactivity. Some of the radioactive elements decay quickly, but even after 1000 years, there will be 1,752 curies in each ton of irradiated fuel.
A curie is a large unit: 2,224,000,000,000 (over 2 trillion) radioactive emissions, or ‘counts’ per minute. Natural radiation measured with a simple Geiger counter is typically between 2 and 20 counts per minute. Each of these emissions has the potential to initiate a cancer.
CURRENT WASTE STORAGE
On-reactor-site fuel pools hold most of the high-level waste that has been generated by the reactor since starting operations. Fuel pools were not designed for more than temporary storage. Many utilities have consolidated the storage racks to hold the irradiated fuel more densely. There are many hazards associated with fuel pools, including the potential for loss of coolant which could result in spontaneous combustion of the fuel, or in some circumstances, nuclear meltdown of the pool.
Reactors that have reached pool capacity, have installed on-site dry cask storage. These concrete and metal containers had no full-scale testing prior to their first installation. A number of cask problems due to shoddy construction as well as heat from the waste have raised concerns about this storage technology. Dry casks are initially licensed for 20 years. Dry cask installation substantially changes the land-use of the site. The majority of nuclear reactors are sited on bodies of water or above aquifers.
CENTRALIZED INTERIM STORAGE
Between 1991 and 1995, the program to site an interim dump for high-level waste was the Monitored Retrievable Storage (MRS) program, under the Nuclear Waste Policy Act (NWPA). This campaign was spearheaded by the Nuclear Waste Negotiator (whose authorization expired in 1994). The effort to find a volunteer community to take a high-level waste dump showed that where democracy is functioning, communities reject proposals that threatened their homes and health. More that 30 MRS proposals were defeated by local communities between 1991 and 1994.
Since the public defeat of voluntary siting of centralized storage, Congress has attempted to pass bills that would force a facility into the Nevada Test Site, very close to Yucca Mountain. The current bills call for the temporary dump to open by or before the year 2001. They also establish policies for both the interim and permanent dumps in Nevada which gut existing environmental laws and standards, and eliminate or change established guidelines and regulations regarding the determination of site suitability and licensing. In addition, these bills initiate a nationwide transportation campaign that would bring waste through 43 states and within ½ mile of 52 million people — with no assurance that the waste would not have to be moved again.
Note: both transport and centralized interim storage would employ the same cask technologies that are currently problematic at reactor sites.
GEOLOGIC “DISPOSAL”
The term “disposal” simply does not apply to materials that will remain hazardous virtually forever. The English Channel did not exist 5 thousand years ago, and within the last 10,000 years a volcano near Yucca Mountain erupted. Recognizing Earth as a constantly changing, dynamic system is new to Western Science. There is no place on Earth where one can confidently predict that if we were to place the high-level waste in a hole, it would remain isolated.
Yucca Mountain, NV is the site specified for study as a possible repository in the 1987 amendments to the NWPA. This site should be rejected as unsuitable since it is classified in the highest risk category for earthquakes. Further, it will not retain radioactive gases, such as Carbon-14 and thus could not meet the original repository standards set by the Environmental Protection Agency. It also sits on top of a major aquifer shared by a nearby farming community, including a large dairy, serving Los Angeles markets.
References Available upon Request
Prepared June 1997
Nuclear Information and Resource Service
Radioactive Waste Project
6930 Carroll Avenue, #340
Takoma Park, MD 20912
301-270-6477; fax: 301-270-4291;
E-mail: nirs@nirs.org