scholarly journals Development of a mobile, automated, optical inspection system for radioactive barrels

2021 ◽  
Vol 1 ◽  
pp. 3-4
Author(s):  
Tania Barretto ◽  
Eric Rentschler ◽  
Sascha Gentes
Keyword(s):  
Early Stage ◽  
Surface Condition ◽  
Inspection System ◽  
Nuclear Facilities ◽  
Damage Development ◽  
Usual Practice ◽  
Measurement Results ◽  
Automated Optical Inspection ◽  
Interim Storage ◽  
Storage Facilities

Abstract. Due to the delayed construction and commissioning of a German repository for intermediate- and low-level radioactive waste, waste inventories from several decades are now located at the interim storage sites, the safe custody of which must also be ensured for an indefinite period of interim storage. The usual practice in the interim storage facilities is recurrent inspections, which are carried out almost exclusively manually and without electronic comparative recordings as well as without mechanical documentation and archiving. Remote or automated inspection does not take place. The inspections are carried out visually and are therefore very subjective and thus subject to errors. Manual performance is labor intensive and requires the use of personnel exposed to radiation. Neither are uniform inspection criteria of the visual inspections applied, nor are the inspections performed uniformly between sites. Based on these facts, the Institute for Technology and Management in Construction, Department of Deconstruction and Decommissioning of Conventional and Nuclear Buildings, together with the Institute for Photogrammetry and Remote Sensing, is developing an automated drum inspection system as part of the funding measure FORKA – Research for the Deconstruction of Nuclear Facilities. EMOS is a mobile inspection unit that remotely and automatically records the entire surface of the drum, including lid and bottom, optically; evaluates it analytically; and both stores it electronically and outputs the results in the form of an inspection report. In this way, recurring inspections of the drum stock can be completed under the same inspection conditions each time. A decisive advantage is the possibility of carrying out the inspection remotely in order to reduce the radiation dose to the employees on site. The optical evaluation, display and output of the results will ensure a more precise inspection and analysis of the drum surfaces through software to be specially developed than is possible through manual and visual inspections as currently performed in the interim storage facilities. The continuous monitoring of the stored drums will be facilitated and also the tracing of possible damage development through the comparison of archived measurement results is a novel and powerful tool that helps to increase and ensure the safety aspects of interim storage in the long term. Changes in drum geometry as well as in the surface condition (e.g. corrosion formation, etc.) can be identified at an early stage with the help of the inspection unit, and measures can be taken at an early stage to counteract the loss of integrity of the storage containers.

Management of Institutional Radioactive Waste in Lithuania

2003 ◽  
Author(s):  
P. Poskas ◽  
J. E. Adomaitis ◽  
R. Kilda
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Former Soviet Union ◽  
Effective Control ◽  
Surface Barrier ◽  
Radioactive Waste Management ◽  
Near Surface ◽  
Interim Storage ◽  
Storage Facilities

The growing number of radionuclide applications in Lithuania is mirrored by increasing demands for efficient management of the associated radioactive waste. For the effective control of radioactive sources a national authorization system based on the international requirements and recommendations was introduced, which also includes keeping and maintaining the State Register of Sources of lonising Radiation and Occupational Exposure. The principal aim of the Lithuania’s Radioactive Waste Management Agency is to manage and dispose all radioactive waste transferred to it. Radioactive waste generated during the use of sources in non-power applications are managed according to the basic radioactive waste management principles and requirements set out in the Lithuanian legislation and regulations. The spent sealed sources and other institutional waste are transported to the storage facilities at Ignalina NPP. About 35,000 spent sealed sources in about 500 packages are expected until year 2010 at Ignalina NPP storage facilities. The existing disposal facility for radioactive waste from research, medicine and industry at Maisiagala was built in the early 1960’s according to a concept typical of those applied in the former Soviet Union at that time. SKB (Sweden) with participation of Lithuanian Energy Institute has performed assessment of the long-term safety of the existing facility. It was shown that the existing facility does not provide safe long-term storage of the waste already disposed in the facility. Two alternatives were defined to remedy the situation. A first alternative is the construction of a surface barrier and a second one is a retrieval solution, whereby the already stored waste will be retrieved for conditioning, characterisation and interim storage at Ignalina NPP. Facilities for the processing of the institutional radioactive waste are required before submittal to Ignalina NPP for storage, since the present facilities are inadequate. Feasibility study to establish a new central facility has been performed by SKB International Consultants (Sweden) with participation of Lithuanian Energy Institute. This study has identified the process applied and equipment needed for a new facility. Reference design and Preliminary Safety Assessment have also been performed. Plans for the interim storage and disposal of the institutional waste are described in the paper. The aspects of finging safe disposal solutions for spent sealed sources in a near surface repositories are also discussed.

Historical Waste Products Refurbished in Belgium for Disposal in Germany

2001 ◽  
Author(s):  
Elke.-D. Kohlgarth
Keyword(s):  
Quality Assurance ◽  
Radioactive Waste ◽  
Time Sampling ◽  
German Government ◽  
Waste Products ◽  
Sampling Plans ◽  
Long Time ◽  
Stepwise Procedure ◽  
Interim Storage ◽  
Storage Facilities

Abstract Before 1988 the German service company Transnuklear (TN) had a licence to treat radioactive waste products for interim storage facilities. For this purpose a large amount of radioactive waste was transported to Mol, Belgium. Due to mismanagement at TN all the German waste remained in Belgium until the Belgian and the German government agreed to transfer it back to Germany. By appointment of the licensing and surveillance authorities TÜV Hannover/Sachsen-Anhalt e.V. had been monitoring the quality assurance measures for waste products bound for disposal in a final repository or for interim storage facilities in Germany. Due to insufficient documentation, the characterisation of the different waste types took a long time. Sampling plans were worked out. A stepwise procedure was established to qualify the waste for transportation to Germany. Different techniques have been developed for inspection and sampling of the waste to ensure the fulfilment of the acceptance criteria of the final storage or interim storage facilities. The first waste was transported in 1991. The last waste packages left Belgium in January, 2001.

Conditioning of Plutonium Waste for Long-Term Interim Storage

2001 ◽  
Author(s):  
F.-W. Ledebrink ◽  
P. Faber
Keyword(s):  
Radioactive Waste ◽  
Federal Government ◽  
Storage Facility ◽  
Acceptance Criteria ◽  
Mox Fuel ◽  
Fuel Fabrication ◽  
Interim Storage ◽  
Waste Drums ◽  
Storage Facilities

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).

Evaluation of Dynamic Behavior of Pile Foundations for Interim Storage Facilities Through Geotechnical Centrifuge Tests

2002 ◽  
Author(s):  
Shizuo Tsurumaki ◽  
Hiroyuki Watanabe ◽  
Akira Tateishi ◽  
Kenichi Horikoshi ◽  
Shunichi Suzuki
Keyword(s):  
Dynamic Behavior ◽  
Experimental Studies ◽  
Centrifuge Modeling ◽  
Pile Foundations ◽  
Soil Conditions ◽  
Confining Stress ◽  
Geotechnical Centrifuge ◽  
Centrifuge Tests ◽  
Interim Storage ◽  
Storage Facilities

In Japan, there is a possibility that interim storage facilities for recycled nuclear fuel resources may be constructed on quaternary layers, rather than on hard rock. In such a case, the storage facilities need to be supported by pile foundations or spread foundations to meet the required safety level. The authors have conducted a series of experimental studies on the dynamic behavior of storage facilities supported by pile foundations. A centrifuge modeling technique was used to satisfy the required similitude between the reduced size model and the prototype. The centrifuge allows a high confining stress level equivalent to prototype deep soils to be generated (which is considered necessary for examining complex pile-soil interactions) as the soil strength and the deformation are highly dependent on the confining stress. The soil conditions were set at as experimental variables, and the results are compared. Since 2000, the Nuclear Power Engineering Corporation (NUPEC) has been conducting these research tests under the auspices on the Ministry of Economy, Trade and Industry of Japan.

Nuclear Power Plant Decommissioning in Germany: Projects, Regulation and Experience

2009 ◽  
Author(s):  
Leopold Weil ◽  
Bernd Rehs
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Energy ◽  
Radioactive Decay ◽  
Federal State ◽  
Regulatory Body ◽  
Nuclear Facilities ◽  
Interim Storage ◽  
Near Future ◽  
Selection Of

In Germany, altogether 19 nuclear power plants (NPPs) and prototype reactors have been permanently shut down. For 15 NPPs the dismantling is in progress with “green-field conditions” as planning target. Two units were completely dismantled and two are in safe enclosure. The main legal provision for all aspects of the peaceful use of nuclear energy in Germany is the Atomic Energy Act (AtG), which also contains the basic legal conditions for the decommissioning of nuclear facilities. It stipulates that decommissioning is subject to a licence by the regulatory body of the respective Federal State (Land). An emerging decommissioning practice in Germany is the removal of complete undismantled large components and their transport to interim storage facilities. During the period of storage, the radionuclide inventory of the components will decrease due to radioactive decay and the subsequent segmentation of the components can be done with less radiation protection effort. The commissioning of the Konrad repository in the near future might have consequences on planning of decommissioning, regarding the selection of a decommissioning strategy and the waste management.

Sign in / Sign up

Export Citation Format

Share Document