Spent fuel storage

BStW-O igned Close-Spaced Fuel Storage J. S. Olszewski, R. H. Clark (BAW), 

Systematic errors caused by biases in the calculational techniques were identified by comjiaring Cbenchmarking) calculated values with experimental values. For 002 calculations systematic errors were found to be conservative by about 2% in keff, but no credit was taken for 

NEUTRON SHIELDING bLTC RAILS STRIKER PLATE-  

Static and seismic loads are transmitted by bolts to floor embedments and/or to the k o1 walls by horizontal compressive beams. During a safe shutdown, earthquake (SSE),. stored fuel integrity is maintained following im SSE, fuel is removable. Following a SSE, stored fuel is reusable. 

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The licensing process consists of two steps construction and operating license that must be completed before fuel loading. Licensing covers radiological safety, environmental protection, and antitru,st considerations. Activities not defined as production or utilization of special nuclear material (SNM), use simple one-step. Materials Licenses, for the possession of radioactive materials. Examples are uranium mills, solution recovery plants, UO fabrication plants, interim spent fuel storage, and isotopic separation plants. 

Answer Review the plant s design to determine how radioactive water could get from the plant to the river. Some ways are i) through the heat exchanger and through the condenser, ii) from the closed circuit water into the service water, iii) from the spent fuel storage pool, and iv) from the sump. Prepare fault trees or adapt existing fault trees to determine the probability of each of these release paths. Obtain reliability data for the components that are involved and evaluate the fault trees to determine the probability of each type of failure. For those pathways with a probabilit >7/y,... 

As of March 2003, there were 26 spent fuel storage facilities in the United States located in 21 states. A total of about 160,000 spent fuel units containing about 45,000 short tons (41,000 metric tons) of radioactive waste were stored on-site at nuclear power plants and off-site at special storage areas. More than 97 percent of the wastes were still being held at on-site facilities the rest had been transported to off-site locations. 

Solid waste comes from the mining and milling of uranium ore and the sludge from spent fuel storage. It also includes contaminated equipment and structures. High-level solid waste includes the hulls from the dissolving of spent fuel, ion exchange resin, and the like. 

Spent Fuel The largest single radioactive waste disposal problem is the spent fuel from military and commercial reactors. As discussed earlier, the spent fuel from commercial reactors is stored in water ponds at the reactor sites. The spent fuel storage facility consists of a cooling and cleanup system for the water along with equipment to safely transfer the fuel rods from the reactor to the storage area. A typical pool will have a volume of 400,000 gal. The water will contain 2000 ppm boron that acts as a neutron absorber and will be maintained at a temperature of <70°C. 

Implementation of the spent fuel storage provisions of the act is predicated upon the primary responsibility for storage remaining with the utilities. Federal actions are limited to ... 

As directed by the act, DOE intends, within one year, to enter into a cooperative agreement with one to three utilities desiring DOE assistance in at-reactor demonstrations of spent fuel storage technologies. The DOE is authorized to do unlicensed demonstrations for dry storage at DOE sites using up to 300 metric tons of spent fuel. 

The act stipulates that it shall be the policy of the United States to cooperate with and provide technical assistance to nonnuclear weapon states in the field of spent fuel storage and disposal. 

Fuel cycles utilizing this method of reprocessing will extend our uranium reserves, decrease the spent fuel storage requirements and decrease the amount of waste requiring storage in a Federal Repository for environmental isolation. AIROX reprocessing is applicable to both light-water reactor fuel cycles as well as fast breeder fuel cycles. 

The decay heat is considerable at short cooling times due to the very high decay rate (see Fig. 19. IS). Before unloading spent fuel from a reactor, the used fuel elem ts are first allowed to cool in the reactor by forced circulation. Within a few weeks they are th transferred under water to the cooling basin at the reactor site for an additional cooling time, usually 6—12 months, after which they may be transferred to a central spent fuel storage facility. In the absence of such facilities, sp it fuel elemrats can be stored in the reactor pools for many years. During this time the radiation level and heat production decrease considerably. 

Ex-vessel sodium storage for removal of decay heat of SA has been avoided and the SA are stored in in-vessel storage locations within the main vessel. The spent fuel subassemblies are stored inside the main vessel for a period of 8 months till the decay power reduces to less than 5 kW and are then shifted to spent fuel storage bay (SFSB). SFSB is a water filled double concrete walled tank. 

After the replacement the FPU with full radioactive waste and spent fuel storage tanks is to be towed to specialized repair works at the dock for overhaul, fuel unloading and hull docking. 

Spent fuel storage, transportation and handling safety ... 

Fuel fabrication Enriched U fuel Conversion and LEU MOX fuel Spent fuel storage... 

The accuracy of decay heat calculations depends on the individual heat generation rate from fission product decay nuclides and actinides, and the burnup calculation for its production and transmutation. To obtain experimental data and to improve the accuracy of related calculations, the decay heat of MK-II spent fuel subassemblies was measured at the JOYO spent fuel storage pond [7], The fuel burnup was approximately 66 GWd/t and the cooling time was between 40 and 385 days. The measured decay heat is shown in Fig. 9. 

Spent fuel storage in-vessel storage, sodium and water pools... 

FIGS 12. and 13. Pictures of the internal of the SPX spent fuel storage vessel after the... 

Spent-fuel system The use of an intermediate spent-fuel storage system consisting of multiple containers, cooled by natural air circulation is envisaged. Removal of the containers need to be investigated. 

ANSI/ANS-54.2-1985, "Design Bases for Facilities for LMFBR Spent Fuel Storage in Liquid Metal Outside the Primary Coolant Boundary."... 

ANSI/ANS-57.2-1983, "Design Requirements for Light Water Reactor Spent Fuel Storage Facilities at Nuclear Power Plants."... 

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