High-level nuclear waste storage

Fig. 1. Decay of high level nuclear wastes from spent fuel as a function of storage time. Radioactivity in curies per ton of spent fuel (PWR, 3.3% enriched 2 5U, burnup 33,000 MWD/MTU at 30 MW/MTU, 5 year cooling, 99.5% U, Pu recovered)...

Along with these power plants, the U.S. could build up a fuel reprocessing capability to allow spent nuclear fuel to be reused which would lower fuel cost and eliminate the storage of high-level nuclear waste. Fuel for the reactors has been estimated to be available for 1,000 years using standard reactors with high breeding ratios and breeder reactors where more fuel is produced than consumed. 

The amount of radiation emitted varies with the particular compound, and a speck of some of these compounds can be very hazardous. However, the volume of wastes is not measured in specks, but in thousands of tons and millions of gallons. In one specific temporary storage facility, where almost 12 tons of spent reactor fuel rest in steel cylinders, the radiation can kill unprotected life in minutes (see Reference [1]). Further, it is estimated that high level nuclear wastes are now piling up at a rate of over 2000 tons per year. 

Before Yucca Mountain can become the nuclear waste repository for the nation, a license must be issued by the US Nuclear Regulatory Commission. Evaluation of the site for safe storage of high-level nuclear wastes for at least 10 000 years requires abroad spectrum of scientific disciplines. Mathematical models are developed to calculate the amount and type of radioactive materials that could be released into the environment due to different processes and events. 

Sales BC, Boatner LA (1984) Lead-iron phosphate glass a stable storage medinm for high-level nuclear waste. Science 226 45-48... 

Storage tanks at Hanford, Washington, contain 55 million gallons of high-level nuclear waste. Each tank pictured here holds 1 million gallons. 

Transuranic Waste. It has been proposed that in the future the transuranic (plutonium-containing) wastes be placed in deep mined vaults. This includes the high-level nuclear wastes. The vaults are expected to be about 1000 meters below the earth s surface and will be backfilled and sealed as they are filled. It appears that the repository capacity for high-level wastes will be heat-limited to one kilowatt/acre. This is equivalent to one ton of fuel after storage for ten years. The spent fuel discharged by the year 2000 will require about 2700 subterranean acres. This would... 

Handling of Spent Nuclear Fuel and Final Storage of Vitrified High Level Reprocessing Waste" KambrSnslesakerhet Stockholm, 1977. 

Handling of Spent Nuclear Fuel and Final Storage of Vitrified High-level Reprocessing Waste", Part I-V, Dec. 7, 1977, and "Handling of Spent Nuclear Fuel and Final Storage of Unreprocessed Spent Fuel", Part I-II, June 28, 1978. 

Nuclear fuel reprocessing and partitioning allow recycling of useful fissionable materials such as uranium and plutonium, and remove harmful long-lived minor actinides (americium and curium). It is necessary also for safety storage of high-level liquid wastes(l). In order to improve efficiency of mutual separation between lanthanide and actinide elements, design of useful extractants are requisite. 

In the United States, permanent storage sites for high-level radioactive wastes win prohahly he deep underp-ound in rock formations. Shown is the kind of nuclear waste facility desired for Yucca Mountain, which would he a three-square-mile complex of interconnected tunnels located in dense volcanic rock 30 meters (1000 feet) beneath the mountain. 

These distillation units, with capacities of typically up to 50 m /d, have played a major role in the treatment of radioactive waste since their steady and reliable operation over many years has ensured that the high-level hquid waste from the nuclear fuel cycle routinely has been reduced in volume for safe storage prior to further treatment to condition it for disposal and long-term isolation from the biosphere. 

Only 4-5 % of the utilized nuclear fuel worldwide is reprocessed. Commercial, nonmilitary, reprocessing of nuclear fuel takes place in France, Japan, India and the United Kingdom. Other reprocessing plants defined as defense-related are in operation and producing waste but without discharges. For example in the USA, at the Savannah River Plant and the Hanford complex, about 83 000 m and 190 000 m, respectively, of high-level liquid waste was in storage in 1985. 

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