Transport Cask for Radioactive Waste
Develop a Transport Cask for Transportation, Storage and Burial of Spent Nuclear Fuel and Radioactive Waste Using Cast CERMET Based on Dioxide of Depleted Uranium and Steel
Tech Area / Field
- MAT-ALL/High Performance Metals and Alloys/Materials
- ENV-RWT/Radioactive Waste Treatment/Environment
- FIR-NSS/Nuclear Safety and Safeguarding/Fission Reactors
3 Approved without Funding
VNIIEF, Russia, N. Novgorod reg., Sarov
- VNIIKhT (Chemical Technology), Russia, Moscow\nAll-Russian Scientific Research Institute of Non-Organic Materials named after A. Bochvar, Russia, Moscow
- HOLTEC International, USA, NJ, Marlton\nOak Ridge National Laboratory, USA, TN, Oak Ridge
Project summaryThe objective of this project is development and test of a reduced-size (scale 1:4) objective of unified multi-purpose TC for transportation, storage and burial of SNF from power reactors and RW. The new depleted uranium dioxide– steel cermet material, developed by ISTC Project 2693, will be used. The final goal of the Project is market promotion of new generation SNF cask based on cermet, thereto cermet cask must be licensed. To get the license it is necessary to manufacture and to test two ¼ scale prototypes of multipurpose TC. The manufacturing of two cask prototypes is planned to be done in the framework of a separate project, which cost will be about 600,000$. The plant that will manufacture the cask prototypes will be defined according to competition among private Russian companies. It will be possible after development of general drawings of a unified multipurpose TC in the framework of the proposed Project.
This project will be performed by the team formed under aegis of Oak Ridge National Laboratory (USA) from the American and Russian organizations within the framework of solving the problem related to the beneficial use of stockpile of surplus depleted uranium for creating new generation of multi-purpose containers for SNF and RW. The U.S. company, Holtec International, will be a partner in this collaboration and will be responsible for commercial cask design and licensing in the U.S.
Both Russia and the USA are now facing an acute problem of safe storage (burial) of huge stocks of spent nuclear fuel accumulated for more than 30 years of atomic power plant (APP) operation. Currently the accumulated amount of SNF is stored mainly by a “wet method” in cooling ponds, located within an APP area or at SNF storage facilities.
With this cooling pool method of SNF storage it is very difficult to provide meeting all the requirements of safety, especially thinking of possible terrorist attacks. The consequences of a radiation accident can have large scales, comparable with those of Chernobyl accident.
Thus, in order to increase the level of SNF storage (burial) safety, to improve terrorist assault resistance, and to decrease possible consequences of radiation accident, the concept of dry SNF storage in casks was developed. According to this concept NSF storage (burial) must be done using multipurpose transport casks (TC) intended for NSF transportation, storage and burial at the same time.
In accordance with the concept of dry SNF storage multipurpose casks provide the basic advantage in terms of safeguards and SNF safety as compared to a “wet method” of NSF storage: spent nuclear fuel is handled once, when it is loaded into TC. It should be noted that the amount of SNF loaded into a single cask is limited, thus, possible consequences of any accident are limited as well
However, it should be noted that the dry method requires production of a large batch of multipurpose TC. In accordance with the American data to bury all US spent nuclear fuel in the storage facility of the Yucca Mountain, about 15000 containers will be required. In Russia, since it uses a close fuel cycle, there is not such a big demand for TC. However, to provide safe transportation and dry temporary SNF storage (not less than 50 years) it will be necessary to produce several hundreds of multipurpose TC. In this connection the cost of fabricating these casks should be low enough to prove economic attractiveness and benefits of transition to dry storage method. It will be a challenge to provide such low cost of fabricating using only traditional materials like steel or cast iron. More promising are new composite materials that functionally are both more structural and protective. Such smart material can be a composite material based on stainless steel and depleted uranium dioxide DUO2, called CERMET.
The potential benefit of using the composite material CERMET in design of unified multi-purpose TC for transportation and temporary storage of SNF consists in the following:
- Providing the maximal loading concerning SNF at given size-weight characteristics of casks;
- Improving consumer qualities of TC at the expense of increase of capacity for fuel at the same size-weight characteristics;
- Amplifying the degree of protection of spent nuclear fuel in comparison with usual steel containers;
- Decreasing the consequences caused by unpredicted accidents, including terrorist attacks, in comparison with conventional steel containers.
Currently, RFNC-VNIIEF together with scientific centers of the RF Minatom – VNIIKhT and VNIINM, within the framework of functioning ISTC project # 2693, conducts research and development of a new constructional and protective material – DU-steel CERMET. This cermet is a composite consisting of DUO2 particulates suspended in a steel matrix Research is conducted related to cermet material properties with reference to use it in TC of new generation for transportation and storage of SNF. This work is carried out under aegis of Oak Ridge National Laboratory (USA) and at total financial support of the US State Department through the ISTC project # 2693.
The most promising area of application of the new DU-steel cermet composite materialis its use for creation of a modern design of the unified dual-purpose TC for transportation and temporary storage of SNF.
The full benefits of using the new composite material CERMET can only be determined after production and testing of an experimental batch of this composite material, development of cask design based on this material, production of two cask prototypes of the scale not less than ¼ scale. Fabrication of prototype cask will be performed under a separate project at Chepetsk mechanical plant, Glazov that has a melting furnace with a cool crucible of the required capacity, which can be redesigned for production of large- scale items of cermet. Once the prototype casks are fabricated, tests will be conducted that will demonstrate IAEA safety requirements Economic and other advantages of replacement of conventional steel transport casks with unified multi-purpose TC will be conducted. Test information of prototype will be used in licensing.
As a result of this Project, it is planned to:
- Develop (together with ORNL and HOLTEC Int) company the concept of unified multi-purpose TC based on CERMET and issue a preliminary design for it.
- Develop technique of producing large-scale TC components made of CERMET.
- Using this technique fabricate two ¼ scale prototypes of the unified multi-purpose TC based on CERMET (under the separate contract). One prototype will be tested in Russia, the other will be provided to ORNL for testing in the U.S.
- Perform tests of a small-size prototype of TC for compliance with the safety requirements for licensing the developed design of unified multi-purpose TC based on CERMET.
- Perform evaluations of economical and other advantages of replacement of steel transport TC by the unified multi-purpose TC for transportation, storage and burial of SNF produced of composite CERMET based on depleted uranium.
Fulfillment of this ISTC proposal will allow us to obtain all necessary information on effective use of composite CERMET in design of unified multi-purpose TC for transportation, storage and burial of SNF.
Urgency of this work is caused by the following reasons:
- For the US Department of Energy, the necessity to produce the efficient multi-purpose TC of increased SNF capacity by the time of loading SNF storage facility in Yucca-Mountain.
- For the RF Minatom, the necessity to complete replacement of out-of-date transport park of steel TC by the modern unified dual-purpose TC for transportation and temporary storage of SNF by 2015.
In case of getting positive results giving opportunity to start industrial manufacturing of TC made of CERMET, long-term commercial prospect appears for:
- producing in the USA, the park of multi-purpose TC of CERMET intended for SNF burial in the Yucca-Mountain storage facility.
- replacement of out-of-date park of transport TC of Russia by unified dual-purpose TC made of CERMET for transportation and temporary storage of SNF, complying with all IAEA requirements on safety and providing high loading of SNF, and improved stability to unpredicted accidents, including terrorist attacks.
The results of this project also will help to solve international technical problems associated with transportation, storage and burial of SNF.