scholarly journals Technology Development Strategy for Volume Reduction and Recycling of the Removed Soil and Waste during Construction/Operation Process of Interim Storage Facility Aimed at Final Disposal

2019 ◽  
Vol 30 (1) ◽  
pp. 21-30
Author(s):  
Masaaki Hosomi
Author(s):  
Jennifer McTeer ◽  
Jenny Morris ◽  
Stephen Wickham ◽  
Gary Bolton ◽  
James McKinney ◽  
...  

Interim storage is an essential component of the waste management lifecycle, providing a safe, secure environment for waste packages awaiting final disposal. In order to be able to monitor and detect change or degradation of the waste packages, storage building or equipment, it is necessary to know the original condition of these components (the “waste-storage system”). This paper presents an approach to establishing the baseline for a waste-storage system, and provides guidance on the selection and implementation of potential baselining technologies. The approach is made up of two sections; assessment of baselining needs and definition of baselining approach. During the assessment of baselining needs a review of available monitoring data and store/package records should be undertaken (if the store is operational). Evolutionary processes (affecting safety functions), and their corresponding indicators, that can be measured to provide a baseline for the waste-storage system should then be identified in order for the most suitable indicators to be selected for baselining. In defining the approach, identification of opportunities to collect data and constraints is undertaken before selecting the techniques for baselining and developing a baselining plan. Baselining data may be used to establish that the state of the packages is consistent with the waste acceptance criteria for the storage facility and to support the interpretation of monitoring and inspection data collected during store operations. Opportunities and constraints are identified for different store and package types. Technologies that could potentially be used to measure baseline indicators are also reviewed.


2021 ◽  
Author(s):  
Ryan M. Meyer ◽  
Jeremy Renshaw ◽  
Jamie Beard ◽  
Jon Tatman ◽  
Matt Keene ◽  
...  

Abstract This paper describes development and demonstration of remote crawling systems to support periodic examinations of interim dry storage system (DSS) canisters for spent nuclear fuel in the USA. Specifically, this work relates to robotic crawler developments for “canister” based DSS systems, which form the majority population of DSSs in the USA for interim storage of spent nuclear fuel. Consideration of potential degradation of the welded stainless-steel canister in these systems is required for continued usage in the period of extended operation (PEO) beyond their initial licensed or certified terms. Challenges with performing the periodic examinations are associated with physical access to the canister surface, which is constrained due to narrow annulus spaces between the canister and the overpack, tortuous entry pathways, and high temperatures and radiation doses that can be damaging to materials and electronics. Motivations for performing periodic examinations and developing robotic crawlers for performing those examinations remotely will be presented, and several activities to demonstrate robotic crawlers for different DSS systems are summarized.


1998 ◽  
Vol 27 (3) ◽  
pp. 157-161
Author(s):  
John H. Sanders ◽  
Barry I. Shapiro ◽  
Sunder Ramaswamy

This article proposes a strategy for agricultural technology development for semi-arid West Africa. The strategy evaluation consists of two aspects: a) a review of the successes in the region; and b) analysis with mathematical programming of the potential impacts and constraints to various new technologies tested in the region. The technology development strategy indicates how further productivity gains can be made by responding to the two principal constraints of water availability and soil fertility. These constraints must be simultaneously resolved but the strategy needs to be adapted for different soil characteristics and economic environments. The major emphasis is on the importance of the rapid introduction of inorganic fertilizers combined with techniques to increase water availability; organic and inorganic fertilizers need to be considered complements in the semi-arid regions. Farmers are already introducing labour intensive variations of these techniques in the most degraded regions. The policy concern is to encourage government policymakers to put a high priority on fertilizer and increase the availability of inorganic fertilizer while research efforts continue to develop improved methods for complementary use of organic fertilizer.


Author(s):  
V. Wittebolle

Abstract In Belgium 57% of the electricity is presently generated by 7 nuclear units of the PWR type located in Doel and Tihange. Their total output amounts to 5632 MWe. Part of the spent fuel unloaded from the first three units has been sent till 2000 for reprocessing in the Cogema facility at La Hague. As the reprocessing of the spent fuel produced by the last four units is not covered by the contracts concluded with Cogema, Synatom, the Belgian utilities’ subsidiary in charge of the front- and back-end of the nuclear fuel cycle for all PWR reactors in Belgium, decided to study the possible solutions for a temporary storage of this spent fuel. End of 1993, the Belgian government decided that reprocessing (closed cycle) and direct disposal (open cycle) of spent fuel had to be considered as equal options in the back-end policy for nuclear fuel in Belgium. The resolution further allowed continued execution of a running reprocessing contract (from 1978) and use of the corresponding Pu for MOX in Belgian NPP’s, but requested a reprocessing contract concluded in 1990 (for reprocessing services after 2000) not to be executed during a five-year period. During this period priority was to be given to studies on the once-through cycle as an option for spent fuel management. Figure 1 is a chart showing the two alternatives for the spent fuel cycle in Belgium. In this context, Synatom entrusted Belgatom1 to develop a dedicated flask (called “bottle”) for direct disposal of spent fuel, to perform a design study of an appropriate encapsulation process and to prepare a preliminary feasibility study of a complete spent fuel conditioning plant. Meanwhile preparation works were made for the construction of an interim storage facility on both NPP sites of Doel and Tihange in order to meet increasing storage capacity needs. For selecting the type of interim storage facility, Belgatom performed a technical-economical analysis. Considerations of design and safety criteria as well as flexibility, reversibility, technical constraints, global economical aspects and construction time led to adopt dry storage with dual purpose casks (in operation since end 1995) for the Doel site and wet storage in a modular pool for the Tihange site (in operation since 1997). In parallel, ONRAF/NIRAS, the Belgian Agency for the management of radioactive waste and enriched fissile materials and the Belgian nuclear research centre, SCK•CEN, conduct underground investigations in view of geological disposal. The paper describes the methodology that Belgatom has developed to provide the utilities with appropriate solutions (reracking, dry storage in casks, wet storage in ponds, etc.) and how Belgatom demonstrated also the feasibility of spent fuel conditioning with a view to direct disposal in clay layers. The spent fuel storage facilities in operation in Belgium and designed and built by Belgatom are then briefly presented.


Author(s):  
F.-W. Ledebrink ◽  
P. Faber

Abstract In the period since Germany’s experimental final repository ASSE was closed in 1978, around 5000 drums of conditioned plutonium-bearing radioactive waste from mixed-oxide (MOX) fuel fabrication have accumulated in the interim storage facilities of Siemens AG’s MOX fuel fabrication plant in Hanau, Germany — formerly ALKEM GmbH, now Siemens Decommissioning Projects (Siemens DP). Another 5000 drums will arise in the course of decommissioning and dismantling the MOX plant which has now been underway for some months. Hopes that a final waste repository would soon be able to go into operation in Germany have remained unfulfilled over the last 20 years. Also, the agreements reached between Germany’s electric utilities and the Federal Government regarding the future of nuclear energy have not led to any further progress in connection with the issue of radwaste disposal. A concrete date for a final repository to start operation has still not been set. The German Federal Government estimates that a geologic repository will not be needed for at least another 30 years. Since the opening of a final storage facility is not foreseeable in the near term, Siemens is taking the necessary steps to enable radwaste to be safely stored in aboveground interim storage facilities for a prolonged period of time. Conditioning of radwaste from MOX fuel fabrication by cementing it in drums was started in 1984 in the belief — which was justified at that time — that final storage at the Konrad mine would be possible as of 1995. The quality requirements specified for the waste drums were therefore based on the Konrad acceptance criteria. The operating license for the storage facilities at Hanau at which these drums are presently in interim storage is limited to 20 years and will be expiring in 2004. The drums have not suffered any corrosion to date and, according to past experience, are not expected to do so in the future. However, permission to keep the drums in interim storage for a longer period of time in their current form would be extremely difficult to obtain as their corrosion resistance would have to be demonstrated for a further 30 years. The present goal is therefore to create a waste form suitable for interim storage which needs no maintenance over a long-term period, incorporates state-of-the-art technology and will probably not require any further treatment of the waste packages prior to emplacement in a final storage facility. At the same time, the highest possible degree of safety must be assured for the time during which the waste remains in interim storage. This goal can be attained by conditioning the drums such that they satisfy the requirements currently specified for final storage at the Konrad repository (1). In practice, this means immobilizing the cemented waste drums in concrete inside steel “Konrad Containers” (KCs). The KCs themselves and the concrete backfill represent two further barriers which not only serve as radiation shielding but also protect the drums against corrosion as well as any possible release of radioactive materials in the event of accidents occurring during interim storage. As the KCs are cuboid in shape, they can be stacked in space-saving configurations and are thus particularly suitable for interim storage. Also, due to their extremely heavy weight, theft of the waste packages can be practically ruled out. Despite the fact that the agreements with the German Federal Government have failed to bring opening of the Konrad repository within reach, it is nevertheless a good idea today to condition radwaste in a manner that renders it suitable for ultimate storage there. The agreements between the Government and the utilities are expected at least to result in a land use permit being issued for the Konrad mine before the end of 2001. At present there are no facts known that could cause the safety of this facility to be questioned. Only recently, Germany’s International Nuclear Technology Commission (ILK) confirmed Konrad’s suitability and demanded that it be placed in operation without further delay (2). Even if its operation should, in fact, be blocked by political lobbies, potential legal action or economic considerations, the alternative repository at Gorleben could possibly become operable in approximately 30 years’ time. Gorleben was planned right from the start to be able to accommodate waste packages based on the Konrad acceptance criteria. This means that any waste packages designed for storage at Konrad could likewise be handled and stored at Gorleben. The processes used by Siemens for conditioning of radwaste conform to the recommendations of the “Guidelines for the Control of radioactive Waste with negligible Heat Generation” issued by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) in 1989 (3).


Author(s):  
Donald Wayne Lewis

In the United States (U.S.) the nuclear waste issue has plagued the nuclear industry for decades. Originally, spent fuel was to be reprocessed but with the threat of nuclear proliferation, spent fuel reprocessing has been eliminated, at least for now. In 1983, the Nuclear Waste Policy Act of 1982 [1] was established, authorizing development of one or more spent fuel and high-level nuclear waste geological repositories and a consolidated national storage facility, called a “Monitored Retrievable Storage” facility, that could store the spent nuclear fuel until it could be placed into the geological repository. Plans were under way to build a geological repository, Yucca Mountain, but with the decision by President Obama to terminate the development of Yucca Mountain, a consolidated national storage facility that can store spent fuel for an interim period until a new repository is established has become very important. Since reactor sites have not been able to wait for the government to come up with a storage or disposal location, spent fuel remains in wet or dry storage at each nuclear plant. The purpose of this paper is to present a concept developed to address the DOE’s goals stated above. This concept was developed over the past few months by collaboration between the DOE and industry experts that have experience in designing spent nuclear fuel facilities. The paper examines the current spent fuel storage conditions at shutdown reactor sites, operating reactor sites, and the type of storage systems (transportable versus non-transportable, welded or bolted). The concept lays out the basis for a pilot storage facility to house spent fuel from shutdown reactor sites and then how the pilot facility can be enlarged to a larger full scale consolidated interim storage facility.


Sign in / Sign up

Export Citation Format

Share Document