N. Mote
NAC International
Atlanta, Georgia, United States

R. S. Dyer
U.S. Environmental Protection Agency
Washington, D.C., United States

V. D. Akhunov
Ministry for Atomic Energy of the Russian Federation

N. S. Yanovskaya
ICC Nuclide
Russia

S. Hoibraten
Norwegian Defence Research Establishment

The United States has been working with the Russian Federation on nuclear waste management problems for several years. With the implementation of international demilitarization agreements, this work has expanded and the U.S. Environmental Protection Agency (EPA) has developed a program to find solutions to specific environmental problems associated with nuclear submarine decommissioning in northwestern Russia. Northwestern Russia is the location of the greatest number of nuclear powered submarines in the world.

One problem being addressed by this program is the lack of a transportable storage cask suitable for management of spent and damaged nuclear fuel from icebreaker operations and submarine decommissioning. Some fuel of these types is currently stored in leaking containers in the Russian Arctic, which presents an environmental security concern for the United States. Consequently, the EPA has started initiatives under which the U.S., Russian and Norwegian governments and their technical experts, possibly with the participation of other Nordic countries, will work together to solve this problem both for fuel under civilian control as well as fuel under military control. The European Commission will also be involved in the development of the program for fuel under civilian control.

Organizations from the nuclear industries in the United States, Russia, Norway and the United Kingdom have united to form the technical team for this development program.

NAC International (NAC) is one of the commercial U.S. companies that has developed spent fuel management systems for nuclear utilities facing spent fuel storage problems at their power station sites. The only spent fuel management system licensed as a B(U) Type package by the U.S. Nuclear regulatory Commission (NRC) for both transportation and storage of spent nuclear fuel is the NAC-STC, which was granted licenses under 10CFR71 and 10CFR72, respectively, in 1995. NAC has been involved in spent fuel management projects worldwide for more than 20 years, including the shipment of spent research reactor fuel from Iraq to Russia following the Gulf War. In 1995, NAC signed an Agreement for Cooperation with the Murmansk Shipping Company (MSCo), operator of Russia’s nuclear powered icebreaker fleet, to help address its spent fuel management needs.

Meanwhile, to meet the future spent fuel management requirements of Russian RBMK power stations, a program to develop a transportable storage cask system was initiated in 1994 by a group of industrial organizations involved in the Russian nuclear industry. Known as the "MBK" (metal-concrete cask), this system is being developed under a project led by ICC Nuclide, a contracting agent and technical support contractor to Minatom. The first application of the cask system was scheduled to be for spent fuel from the RBMK-1000 type reactors at the Leningrad nuclear power plant (LNPP). But that may change with the rapid evolution of this new project.

In early 1997, NAC and the Minatom team started working together on a modification to the MBK system in an unprecedented international collaboration initiative. This modification is directed at providing interim land-based storage capacity in Northwest Russia for spent fuel discharged from nuclear icebreakers, some of which is stored on ships anchored in the Kola Bay close to Murmansk. Currently, there are more than 4,000 spent fuel assemblies stored on these ships, some of which are damaged. The initial funding for this development program was provided by the EPA as part of the U.S. trilateral Environmental Security Initiative between the EPA, the U.S. Department of Energy (DOE) and the U.S. Department of Defense (DOD). In late 1997, the European Commission agreed to contribute to the funding of this development program and, early in 1998, the U.S. Department of State (DOS) also announced that it is making funding available to support the development of the MBK system for fuel under civilian control. Also early in 1998, NAC concluded an agreement with AEA Technology (AEAT) of the United Kingdom under which the extensive environmental licensing and cask testing expertise of AEAT will become integrated into this international collaborative program. The EPA Office of International Activities will perform overall management and development of the program.

In September 1996, the Arctic Military Environmental Cooperation accord (AMEC) was signed by the United States, Russia and Norway with the three countries being represented by the U.S. DOD, the Russian Ministry of Defence and the Norwegian Ministry of Defence, respectively. The focus of AMEC is increasing environmental security at sites in Northwestern Russia where past military activities and current demilitarization programs present a risk of environmental contamination. Under the terms of AMEC, another variant of the MBK system is being developed for storage and transportation of spent nuclear fuel from Russian submarines undergoing decommissioning. The design of this variant of the MBK will be completed during 1998 with licensing projected to be complete, and the first operational unit expected to be available, late in 1999. It will be substantially smaller than the RBMK power station and icebreaker variants, primarily due to the limits of the existing infrastructure characteristics at the sites where it will be handled.

In late 1997, NAC was appointed to act as the integrating contractor for the U.S. government, while early in 1998, ICC Nuclide and the Norwegian Defence Research Establishment were appointed as the integrating contractors for the Russian and Norwegian governments, respectively. These three organizations are now working together to ensure that the modification of the MBK for management of submarine fuel is completed in accordance with the objectives of AMEC.

Both variants of the MBK being developed under these international programs are being integrated with the Russian Special Federal Program defined by the Russian government in 1995 for management of wastes arising from nuclear operations in Russia.

The design comprises a steel-lined concrete structure with a dual lid system that comprises the storage module of the cask system. The system is unlike U.S. concrete storage systems, which employ a single, thin-walled removable canister for the leak tight containment of the fuel, with the concrete merely providing shielding. In the case of the MBK, the canister is integral with the concrete structure which, together with a double lid system, provides the containment for storage.

The MBK system for RBMK fuel is a 70 metric ton (empty) cask unit designed to accept RBMK fuel after separation of full length assemblies into subassemblies about 3.5 meters long. The cask can accommodate 114 RBMK subassemblies, equivalent to 57 fuel assemblies.

The body of the cask uses a corrosion resistant steel and the concrete serves as a high density, high strength shielding material. For transportation, the cask is placed in a fully enclosing steel overpack, designed to be its impact limiter. This overpack is intended to be a sacrificial energy absorber in the event of any impact accidents during transportation.

The Russian regulatory system requires that the MBK system for civilian applications will be licensed by Gosatomnadzor (GAN), in conformance with International Atomic Energy Agency (IAEA) procedures and standards.

Drop testing of a 40 percent scale model of the RBMK power station cask was completed in mid-1997. The design report for the RBMK cask and the results of the scale model drop test program have been submitted to GAN for evaluation.

A comprehensive test program using a full-scale prototype cask is scheduled for 1998 at new, purpose-built cask test facilities close to St. Petersburg. Together with the design report and the results of the scale model test program, the results of the full-scale testing program will form the basis for the license application for the system.

It is expected that the design modification for the MBK variant to be used with icebreaker fuel will be licensed as a modification to the RBMK system as it will use the same technology and have basically similar dimensions for the cask body. While the MBK variant for submarine applications will also use the same technology, it will undergo complete dimensional redesign. Also, the primary responsibility for licensing this variant will lie not with GAN, but with the licensing agency of the Russian Ministry of Defence. Consequently, it is expected that there will be a requirement for a completely independent license submittal for this cask.

In addition to the GAN license for the cask design, review of these two projects will also be required from other Russian ministries prior to the start of site operations. Following completion of the cask design and preparation of the operational and interface documents, they will be submitted together with the site specific project documents for certification by the appropriate Russian regulatory authorities including the Ministry of Ecology (Goskomekologia) and the appropriate regional regulatory bodies. The necessity to submit the documentation to any other Russian agencies will be determined during the design phase of the project.

Development of the MBK for RBMK fuel was started in the early 1990s, with a target of having the first operational cask available in the late 1990s. The first requirement was expected to be for the LNPP, which was projected to need additional storage capacity by about the turn of the century.

The project to modify the MBK design for use with spent fuel from nuclear icebreakers was initiated in January 1997 and is projected to take two years, based on the work already completed on the program for RBMK fuel. The program for development of this variant is outlined in the following sections. The program for the submarine fuel variant of the MBK is currently under development.

This phase included the preparation of the controlling documents that:

• Specify the project requirements;
• Plan the schedules for engineering design and equipment fabrication; and
• List the technical/analytical tools that will be used to evaluate the design for regulatory purposes.

During this phase of the project, the appropriate range of fuel parameters to be used as the basis for the cask design were defined. All of the icebreaker and other fuel types under civilian control for which the cask system may be used must be bounded by the selected design basis parameters.

This phase was completed early in 1997. During 1997, discussions were also held with GAN to ascertain any special requirements that need to be considered.

This task comprises the main design scope of the project. It includes:

• Production of the design drawings;
• Identification of material specifications;
• The thermal, structural, shielding, criticality and containment/confinement analyses to validate the design against the related requirements;
• Preparation of licensing documents.

The work necessary to complete this task for the icebreaker and civilian fuel cask system has started, based on the technical design of the RBMK cask completed in 1997. The nuclear technical analysis and verification of the design modification for the icebreaker variant is being undertaken by some of the Minatom technical institutes, primarily the All-Russian Scientific Research Institute of Experimental Physics (VNIIEF or "Arzamas-16"), the Institute of Physics and Power Engineering (FEI) and the All-Russian Planning and Design, Research and Technological Association (VNIPIET). The non-nuclear mechanical and structural design work will be completed by other qualified organizations involved in nuclear projects in Russia, including the Special Mechanical Engineering Design Office (KBSM) in St. Petersburg, and some of the design offices of the Ministry of Defence.

Throughout the project, the Russian team will be able to utilize the experience of their international partners to support the development of the MBK system. This integration is exemplified by one of the tasks which will be undertaken in Phase 2. In this task, the nuclear design codes used in Russia, the United States and Norway will be compared, to allow any differences to be identified and their impact to be assessed. Also, the QA programs used for nuclear projects in each of these three countries will be evaluated against each other to identify any significant differences.

In this phase, the construction plans and specifications and site interface documentation will also be produced. These are necessary for orders to be placed for fabrication of a full-size prototype cask and the appropriate supporting hardware. Documentation will also be produced for fabrication of a scale model cask, in case this is necessary to meet GAN requirements for licensing of this design modification.

In order to use the MBK cask at an operational facility, site systems and support services will be required. These interface requirements (e.g. heavy haul vehicles and utility services) must be identified and provision made for any site specific adaptation of the MBK handling equipment. Also, the use of equipment and services must be planned in advance of operations to ensure that they are available in time to meet the program requirements and that no conflict arises with other site operations. This phase also provides the planning and coordination required to ensure the MBK fuel loading and handling operations are effectively integrated with other operations on the site.

To support the license application for the full-scale RBMK power station cask system, scale model testing has been completed and a test program using a full-size prototype cask will be performed in accordance with GAN requirements during the first half of 1998. To what extent additional test programs are needed to support the design of the icebreaker and submarine variants of the MBK will be determined during the design phase (Phase 2) of each of these projects.

The fabrication equipment and plant capacity at the Izhorsky Zavod cask fabrication facility is already available to support any requirement for scale model or full-size prototype casks to meet testing requirements determined by the regulatory bodies to be necessary. This capability is also sufficient to allow fabrication of limited numbers of production casks. However, to support serial production of casks, additional plant and equipment will need to be installed as well as separate licensing for serial production.

This project has developed from the combination of two independent initiatives: an industrial initiative taken by NAC together with a group of enterprises of the Russian nuclear industry; and an environmental and policy initiative being implemented by the U.S. DOS, the U.S. EPA and the U.S. DOD working with the Russian Ministry of Atomic Energy, with Norway as a partner in the AMEC cask development project.

The technology at the center of the project is the Russian MBK system which is already at an advanced stage of development for RBMK spent fuel management. With financial and technical support from other countries, this technology is being applied to management of spent nuclear fuel from civilian icebreaker operations and military submarine decommissioning.

Development of these new applications meets a number of international objectives, including:

• improving environmental security
• building Russian infrastructure for solving nuclear waste management problems
• providing support for commercialization of Russian technology
• assisting the implementation of demilitarization programs
• providing defense conversion assistance to the emerging Russian economy

However, the main benefit, in the long term, may be that these programs demonstrate the willingness and the ability of international partners to collaborate and cooperate on complex, technical projects of this type.

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