scholarly journals Application of Power Reactors for Transmutation of Actinides

Author(s):  
B. R. Bergelson ◽  
A. S. Gerasimov ◽  
G. V. Tikhomirov

Heavy-water and light-water power reactors can be used for partial transmutation of radwaste. Such transmutation allows us to limit on relatively low level the radiotoxicity accumulated in long-term storage of spent fuel. At transmutation in PHWR-880 reactor operating in the mode of self-service, equilibrium radiotoxicity in storage facility and the time of its achievement are 4–5 times less than for the transmutation in power reactor VVER-1000.

Author(s):  
Jan Medved ◽  
Ladislav Vargovcik

The paper deals with experience, techniques and new applied equipment durig undergoing decommissioning process of the A-1 NPP long-term pool storage and the follow-up decommissioning plan. For rad-waste disposal of the long-term pool storage (where most of the contaminants had remained following the removal of spent fuel) special equipment has been developed, designed, constructed and installed. The purpose of this equipment is the restorage, drainage and fragmentation of cartridges (used as a spent fuel case), as well as treatment of sludge (located at the pool bottom) and of the remaining liquid radwaste. The drainage equipment for cartridges is designed for discharging KCr2 solution from cartridges with spent fuel rods into the handling storage tank in the short-term storage facility and adjustment of the cartridges for railway transport, prior to the liquidation of the spent fuel rod. The equipment ensures full remote visual control of the process and exact monitoring of its technical parameters, including that of the internal nitrogen atmosphere concentration value. Cartridges without fuel and liquid filling are transferred to the equipment for their processing which includes fragmentation into smaller parts, decontamination, filling into drums with their sealed closing and measurement of radioactive dose. For the fragmentation, special shearing equipment is used which leaves the pipe fragment open for the following decontamination. For cleaning the cartridge bottom from radioactive sludge water jet system is used combined with slow speed milling used for preparing the opening for water jet nozzle. The sludge from the cartridge bottom is fixed into ceramic matrix. Nuclear Power Plant JE A-1 (since 1980 in decommissioning) is situated in the locality of Jaslovske´ Bohunice. So far the decommissioning of the Long-term storage was carried out within Stage I of A-1NPP decommissioning. This year the Stage I of decommissioning finished, and the performance of Stage II of decommissioning was started. Decommissioning of the long-term storage facility continues within Stage II of the A-1 NPP decommissioning process.


Author(s):  
Aleksander S. Gerasimov ◽  
Boris R. Bergelson ◽  
Tamara S. Zaritskaya ◽  
Georgy V. Tikhomirov

Accumulation and subsequent storage of actinides from uranium, plutonium, and thorium spent fuel of PWR type reactor is discussed in the paper. During period of accumulation 100 or 300 years, actinides are periodically introduced in the storage facility. Subsequent period of 300 000 years is long-term storage without introduction of new portions of spent fuel. This time includes both period of controllable storage and ultimate geological storage. Decay heat power of actinides was calculated. It affects heat removal system of the storage facility. Maximal decay heat power of actinides from plutonium spent fuel corresponding to the end of the period of accumulation of 100 years is 2.5 times higher than that of uranium spent fuel. Maximal decay heat power of actinides from uranium spent fuel is 1.2 times higher than that of thorium spent fuel.


Author(s):  
Narendra K. Gupta

In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410°C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410°C. This paper discusses the thermal models and the results for the extended fire conditions (1500°F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.


Author(s):  
Robert S. Dyer ◽  
Ella Barnes ◽  
Randall L. Snipes ◽  
Steinar Ho̸ibra˚ten ◽  
Valery Sveshnikov ◽  
...  

Northwest Russia contains large quantities of spent nuclear fuel (SNF) that potentially threaten the environmental security of the surrounding Arctic Region. The majority of the SNF from Russian decommissioned nuclear submarines is currently stored either onboard submarines or in floating storage vesssels in Northwest Russia. Some of the SNF is damaged, stored in an unstable condition, or of a type that cannot currently be reprocessed. Most of the existing storage facilities being used in Northwest Russia do not meet health and safety and physical security requirements. Existing Russian transport infrastructure and reprocessing facilities cannot meet the requirements for moving and reprocessing this fuel. Therefore, additional interim storage capacity is required. The removal, handling, interim storage, and shipment of the fuel pose technical, ecological, and security challenges. The U.S. Environmental Protection Agency (EPA), in cooperation with the U.S. Department of Defense and the Department of Energy’s (DOE) Oak Ridge National Laboratory, along with the Norwegian Defence Research Establishment, is working closely with the Ministry of Defense and the Ministry of Atomic Energy of the Russian Federation (RF) to develop an improved and integrated management system for interim storage of military SNF in NW Russia. The cooperative effort consists of three subprojects involving the development of: (1) a prototype dual-purpose, metal-concrete container for both transport and long-term storage of RF military SNF, (2) the first transshipment/interim storage facility for these containers, and (3) improved fuel preparation and cask loading procedures and systems to control the moisture levels within the containers. The first subproject, development of a prototype dual-purpose container, was completed in December 2000. This was the first metal-concrete container developed, licensed, and produced in Russia for both the transportation and storage of military SNF. These containers are now in serial production. Russia plans to use these containers for the transport and interim storage of military SNF from decommissioned nuclear submarines at naval installations in the Arctic and Far East. The second subproject, the design, construction, and licensing of the first transshipment/interim storage facility in Russia, was completed in September 2003. This facility can provide interim storage for up to nineteen 40-tonne SNF containers filled with SNF for a period not to exceed two years. The primary objective of building this transshipment/interim storage facility in Murmansk, Russia was to remove a bottleneck in the RF transportation infrastructure for moving containers, loaded with SNF, from the arctic region to PO “Mayak” for reprocessing or longer-term storage. The third subproject addresses the need to improve fuel conditioning and cask operating procedures to ensure safe storage of SNF for at least 50 years. This will involve the review and improvement of existing RF procedures and systems for preparing and loading the fuel in the specially designed casks for transport and long-term storage. This subproject is scheduled for completion in December 2003. Upon completion, these subprojects are designed to provide a physically secure, accountable, and environmentally sound integrated solution that will increase the capacity for removal and transfer of SNF from decommissioned RF submarines in the Russian Federation to PO “Mayak” in central Russia.


Author(s):  
Luc Ooms ◽  
Vincent Massaut ◽  
L. Noynaert ◽  
M. Braeckeveldt ◽  
G. Geenen

The BR3 reactor was the first PWR plant installed in Europe. Started in 1962, BR3 was definitely shut down on June 30th, 1987. Used at the beginning of its life as a training device for commercial plant operators, it was also used during its whole life as test-reactor for new fuel types and assemblies. Most of the spent fuel was stored in the deactivation pool of the plant for more than 15 years. The reactor being now in decommissioning, it was decided to remove the spent fuel from the plant. After comparison of different solutions, the long term storage in dual purpose storage casks was selected in 1997. The selected CASTOR-BR3® cask is designed as a transport and storage cask for accommodating 30 spent fuel assemblies. As a type B(U) cask fitted with shock absorbers, it meets the transport requirements according to the IAEA guidelines and fulfils also the conditions for cask storage.


1981 ◽  
Vol 11 ◽  
Author(s):  
B. Allard ◽  
U. Olofsson ◽  
B. Torstenfelt ◽  
H. Kipatsi ◽  
K. Andersson

The long-lived actinides and their daughter products largely dominate the biological hazards from spent nuclear fuel already from some 300 years after the discharge from the reactor and onwards . Therefore it is essential to make reliable assessments of the geochemistry of these elements in any concept for long-term storage of spent fuel or reprocessing waste, etc.


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