Key Issues
Experience, Testing Confirm Transportation of Used Nuclear Fuel Is Safe, Reliable
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The NRC Requires Tests Of Used Fuel Containers
The NRC must approve containers that transport used nuclear fuel. Before the agency certifies container designs, they must meet rigorous engineering and safety criteria. In addition, the container designs must be shown, by test or analysis, to survive a sequence of four hypothetical accident conditions simulating the cumulative effects of impact, puncture, fire and submersion.
The test sequence involves:
Separate, undamaged containers are also subjected to immersion in 50 feet of water.
Furthermore, casks must survive greater than 600 feet of water pressure for one hour without collapse, buckling or inleakage of water.
In addition to the tests required for NRC certification, engineers and scientists at Sandia National Laboratories in New Mexico conducted a wide range of tests on used nuclear fuel transportation containers in the 1970s and 1980s. These tests included:
In all cases, post-crash assessments showed that the containers, although slightly dented and charred, would not have released their contents.
The NRC also conducted a study in 1987 to evaluate further the ability of used fuel transport containers to withstand real accidents. Using data from severe accidents of all kinds, the NRC concluded that transport containers designed to NRC requirements would withstand actual accidents.
Other Sandia tests evaluated a terrorist attack, subjecting a container to a device 30 times more powerful than a typical anti-tank weapon. The test resulted in a quarter-inch-diameter hole through the primary containment wall.
The NRC estimates that such a hole would have resulted in the release of less than 10 grams—about one-third of an ounce—of used fuel.
In combination with actual testing, transportation container manufacturers use computer programs and scale models to evaluate the containers’ protective capabilities and verify—with a substantial margin of safety—that the containers meet NRC and international requirements. For example, drop testing of full-scale and partial-scale transportation containers in Germany and Japan have validated previous simulations.
NRC regulations also require the establishment of a security plan to ship used nuclear fuel safely to the used fuel repository at Yucca Mountain, Nev., and implementation of this plan before shipments begin. The shipper will track and monitor these shipments carefully over the entire route. The agency must review and approve in advance the plan and procedures to protect against radiological sabotage or theft.
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The NRC Requires Tests Of Used Fuel Containers
The NRC must approve containers that transport used nuclear fuel. Before the agency certifies container designs, they must meet rigorous engineering and safety criteria. In addition, the container designs must be shown, by test or analysis, to survive a sequence of four hypothetical accident conditions simulating the cumulative effects of impact, puncture, fire and submersion.
The test sequence involves:
- a 30-foot free fall onto an unyielding surface, which would be equivalent to the cask being struck by a train traveling 60 miles per hour
- a puncture test allowing the container to fall 40 inches onto a steel rod 8 inches long and 6 inches in diameter
- a 30-minute exposure to fire at 1,475 degrees Fahrenheit that engulfs the entire container
- submerging the same container under 3 feet of water.
Separate, undamaged containers are also subjected to immersion in 50 feet of water.
Furthermore, casks must survive greater than 600 feet of water pressure for one hour without collapse, buckling or inleakage of water.
In addition to the tests required for NRC certification, engineers and scientists at Sandia National Laboratories in New Mexico conducted a wide range of tests on used nuclear fuel transportation containers in the 1970s and 1980s. These tests included:
- running a flatbed tractor-trailer carrying a container into a concrete wall at 84 miles per hour
- placing a container on a rail car and driving it into a concrete wall at 81 miles per hour
- placing a container on a tractor-trailer and broad-siding it by a train traveling at 80 miles per hour.
In all cases, post-crash assessments showed that the containers, although slightly dented and charred, would not have released their contents.
The NRC also conducted a study in 1987 to evaluate further the ability of used fuel transport containers to withstand real accidents. Using data from severe accidents of all kinds, the NRC concluded that transport containers designed to NRC requirements would withstand actual accidents.
Other Sandia tests evaluated a terrorist attack, subjecting a container to a device 30 times more powerful than a typical anti-tank weapon. The test resulted in a quarter-inch-diameter hole through the primary containment wall.
The NRC estimates that such a hole would have resulted in the release of less than 10 grams—about one-third of an ounce—of used fuel.
In combination with actual testing, transportation container manufacturers use computer programs and scale models to evaluate the containers’ protective capabilities and verify—with a substantial margin of safety—that the containers meet NRC and international requirements. For example, drop testing of full-scale and partial-scale transportation containers in Germany and Japan have validated previous simulations.
NRC regulations also require the establishment of a security plan to ship used nuclear fuel safely to the used fuel repository at Yucca Mountain, Nev., and implementation of this plan before shipments begin. The shipper will track and monitor these shipments carefully over the entire route. The agency must review and approve in advance the plan and procedures to protect against radiological sabotage or theft.
Pages 1 2 3
