Storage of spent fuel and problem waste
The volume of nuclear waste produced by the nuclear industry is very small compared with other wastes generated. In the OECD some 300 million tones of toxic wastes are produced each year, but conditioned radioactive wastes amount to only 81,000 m3 per year. However; nuclear waste represents a major challenge for all countries. Some countries are storing their waste directly and some after reprocessing which reduce the amount quite a bit.
Uniquely, with NPPs dry cask storage containers, the waste can be disposed directly and retrieved for reprocessing in the future. This will represent a huge advantage for countries that have decided for direct disposal but may reconsider later.
Waste Management for Used Fuel from Nuclear Power Reactors
Country, Policy, Facilities and progress towards final repositories:
Central waste storage at Dessel Underground laboratory established 1984 at Mol Construction of repository to begin about 2035
Nuclear Waste Management Organisation set up 2002 Deep geological repository confirmed as policy, retrievable Repository site search from 2009, planned for use 2025
Central used fuel storage in LanZhou Repository site selection completed by 2020 Underground research laboratory from 2020, disposal from 2050
Program start 1983, two used fuel storages in operation Posiva Oy set up 1995 to implement deep geological disposal Repository under construction near Olkiluoto, open in 2020
TUnderground rock laboratories in clay and granite Parliamentary confirmation in 2006 of deep geological disposal Bure is likely repository site to be licensed 2015, operating 2025
Reprocessing but moving to direct disposal
Repository planning started 1973 Used fuel storage at Ahaus and Gorleben salt dome Geological repository may be operational at Gorleben after 2025
Research on deep geological disposal for HLW
High-level waste storage facility at Rokkasho since 1995 High-level waste storage approved for Mutsu from 2010 NUMO set up 2000, site selection for deep geological repository under way to 2025, operation from 2035
Sites for final repository under investigation on Kola peninsula Various storage facilities in operation
Waste program confirmed 1998 Central interim storage planned from 2016
ENRESA established 1984, its plan accepted 1999 Central interim storage probably at Trillo from 2010 Research on deep geological disposal, decision after 2010
Central used fuel storage facility - CLAB - in operation since 1985 Underground research laboratory at Aspo for HLW repository Site selection for repository in two volunteered locations
Central interim storage for HLW at Zwilag since 2001 Central low & ILW storages operating since 1993 Underground research laboratory for high-level waste repository, with deep repository to be finished by 2020
Low-level waste repository in operation since 1959 HLW from reprocessing is vitrified and stored at Sellafield Repository location to be on basis of community agreement New NDA subsidiary to progress geological disposal
Direct Disposal, but are reconsidering
DoE responsible for used fuel from 1998, $28 billion waste fund Considerable research on repository at Yucca Mountain, Nevada 2002 decision that geological repository be at Yucca Mountain
OECD NEA, 1996, Radioacvtive waste Management in Perspective
IAEA ,1992, Radioactive Waste Management An IAEA Source Book, & IAEA Bulletin 40,1; 1998
OECD NEA 1999, Geological Disposal of Radioactive Waste - review of developments in the last decade.
Dry Cask Storage in the US
In the late 1970s and early 1980s, the need for alternative storage began to grow when pools at many nuclear reactors began to fill up with stored spent fuel. Utilities began looking at options such as dry cask storage for increasing spent fuel storage capacity. See the graph of nuclear fuel storage pool capacity.
Dry cask storage allows spent fuel that has already been cooled in the spent fuel pool for at least one year to be surrounded by inert gas inside a container called a cask. The casks are typically steel cylinders that are either welded or bolted closed. The steel cylinder provides a leak-tight containment of the spent fuel. Each cylinder is surrounded by additional steel, concrete, or other material to provide radiation shielding to workers and members of the public. Some of the cask designs can be used for both storage and transportation. There are various dry storage cask system designs. With some designs, the steel cylinders containing the fuel are placed vertically in a concrete vault; other designs orient the cylinders horizontally. The concrete vaults provide the radiation shielding. Other cask designs orient the steel cylinder vertically on a concrete pad at a dry cask storage site and use both metal and concrete outer cylinders for radiation shielding.
The first dry storage installation was licensed by the NRC in 1986 at the Surry Nuclear Power Plant in Virginia.
Spent fuel is currently stored in dry cask systems at a growing number of power plant sites, and at an interim facility located at the Idaho National Environmental and Engineering Laboratory near Idaho Falls, Idaho. See the map showing the location of existing independent spent fuel storage installations. (vedlagt kap. 10)
Source: Nuclear Regulatory Commission (www.nrc.gov)
US Safety requirements
Each shipping container must be designed to maintain its integrity under normal transportation conditions and during hypothetical accident conditions. The designs must demonstrate protection against radiological release to the environment under the following hypothetical accident conditions:
A 9 meter (30-foot) free fall on to an unyielding surface
A puncture test allowing the container to free-fall 1 meter (40 inches) onto a steel rod 15 centimeters (6 inches) in diameter
A 30-minute, all-engulfing fire at 800 degrees Celsius (1475 degrees Fahrenheit)
An 8-hour immersion under 0.9 meter (3 feet) of water.
Compliance with this sequential series of tests may be demonstrated by computer modeling, scale-model or full-scale tests. An additional hypothetical accident condition is required for spent fuel in which an undamaged package must be subjected to a one-hour immersion under 200 meters (655 feet) of water.