scholarly journals Characteristics of radioactive waste streams generated in HTGR fuel reprocessing

1976 ◽  
Author(s):  
K. H. Lin
Keyword(s):  
Radioactive Waste ◽  
Waste Streams ◽  
Fuel Reprocessing ◽  
Htgr Fuel

REE and TRU Incorporation into Monazite Structure Ceramics

2004 ◽  
Vol 824 ◽  
Author(s):  
S. I. Rovnyi ◽  
G. M. Medvedev ◽  
A. S. Aloy ◽  
T. I. Koltsova ◽  
S. E. Samoylov
Keyword(s):  
Thin Film ◽  
Solid Solution ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Chemical Durability ◽  
Spent Fuel ◽  
Waste Streams ◽  
Oxalate Precipitation ◽  
Spent Fuel Reprocessing ◽  
Fuel Reprocessing

AbstractOne of the high levels of actinide, and in particular Cm, waste streams at the Russian radiochemical Production Association (PA) Mayak was generated during spent fuel reprocessing. Using oxalate precipitation, the rare earth elements (REE) and transuranic elements (TRU) settled out in the form of oxalate residues. Due to in high REE contents in this residue, the mineral-like matrix based on (REE)PO4 solid solution, with monlclinic monazite structure have been proposed to use as a suitable ceramics form for final actinide immobilization. For this purpose the synthetic REE oxalates were first transformed into REE orthophosphates in a thin-film evaporator (TFE). Then the (REE)PO4 powder was compacted both by either hot uniaxial pressing (HUP) or cold uniaxial pressing followed by sintering (CUP). This ceramic with the monazite structure has a high density and exhibits chemical durability by leaching.

Impact of Advanced Fuel Cycles on Geological Disposal

2009 ◽  
Vol 1193 ◽  
Author(s):  
Jan Marivoet ◽  
Eef Weetjens
Keyword(s):  
Radioactive Waste ◽  
Cooling Time ◽  
High Level Waste ◽  
Waste Streams ◽  
Geological Disposal ◽  
Fuel Cycles ◽  
Thermal Output ◽  
Advanced Fuel ◽  
High Level ◽  
The Impact

AbstractIn recent years the increasing oil prices and the need for carbon-free energy to limit global warming have resulted in a revival of interests in nuclear energy. Advanced nuclear fuel cycles are being studied worldwide. They aim at making more efficient use of the available resources, reducing the risk of proliferation of nuclear weapons, and facilitating the management of the resulting radioactive waste. Recently, the Red-Impact project has investigated the impact of a number of representative advanced fuel cycles on radioactive waste management, and more specific on geological disposal. The thermal output of the high-level waste arising from advanced fuel cycles in which all the actinides are recycled is reduced with a factor 3 for a 50 years cooling time and with a factor 5 for a 100 years cooling time in comparison with the spent fuel arising from the once-through fuel cycle. This reduction of the thermal output allows for a significant reduction of the length of the disposal galleries and of the size of the repository. Separation of Cs and Sr drastically reduces further the thermal output of the high-level waste, but it requires a long-term management of those heat generating separated waste streams, which contain the very long-lived 135Cs. Recycling all the actinides strongly reduces the radiotoxicity in the waste, resulting in significantly lower doses to an intruder in the case of a human intrusion into the repository. However, the reduction of radiotoxicity has little impact on the main safety indicator of a geological repository, i.e. the effective dose in the case of the expected evolution scenario; for disposal in clay formations, this dose is essentially due to mobile fission and activation products. The deployment of advanced fuel cycles will necessitate the development of low activation materials for the new nuclear facilities and fuels and of specific waste matrices to condition the high-level and medium-level waste streams that will arise from the advanced reprocessing plants.

scholarly journals Management of radioactive waste from application of radioactive materials and small reactors in non-nuclear industries in Canada and the implications for their new application in the future

2021 ◽  
Vol 8 (6) ◽  
pp. 619-640
Author(s):  
George Sikun Xu ◽  
◽  
Nicholas Chan ◽  
Keyword(s):  
Radioactive Waste ◽  
Management Practices ◽  
Oil And Gas ◽  
Nuclear Reactions ◽  
Industrial Applications ◽  
Nuclear Industry ◽  
International Standards ◽  
Waste Streams ◽  
Energy Agency ◽  
Intermediate Level Radioactive Waste

<abstract> <p>A large number of artificial-origin radionuclides from irradiation in small reactors and/or nuclear reactions in accelerators are currently used in non-nuclear industries such as education, oil and gas, consumer merchandise, research, and medicine. Radioactive wastes from the use of these radionuclides in non-nuclear industries include expired sealed radioactive sources, biological materials, radionuclide-containing chemicals, contaminated equipment, and very small quantities of used nuclear fuel. Although being less challenging and complex than nuclear energy production and research waste streams, these wastes are subject to the common nuclear regulations by the Canadian Nuclear Safety Commission, and are managed following domestic and international standards and guidelines made by the Canadian Standards Association, International Atomic Energy Agency, and International Organization for Standardization. Management practices used in the nuclear industry in Canada are commonly applied to the non-nuclear industry radioactive waste streams, such as waste handling, treatment, packaging, storage, transportation, clearance and exemptions, and disposal. The half-lives of radionuclides in non‑nuclear applications range from hours to thousands of years, and their activities in non-nuclear industrial applications can be as low as their clearance level or as high as the upper limits for intermediate level radioactive waste. Waste containing only short half-life radionuclides is placed in temporary storage to allow decay, and then is cleared and disposed of through non-radioactive waste routes. Non‑clearable waste materials are treated, consolidated, and managed along with radioactive waste generated from the nuclear industries at designated radioactive waste management sites.</p> </abstract>

scholarly journals PREDIS: innovative ways for predisposal treatment and monitoring of low and medium radioactive waste

2021 ◽  
Vol 1 ◽  
pp. 9-10
Author(s):  
Ernst Niederleithinger ◽  
Vera Lay ◽  
Christian Köpp ◽  
Erika Holt ◽  
Maria Oksa
Keyword(s):  
Radioactive Waste ◽  
Organic Waste ◽  
Pressure Sensors ◽  
Current Data ◽  
Added Value ◽  
Machine Learning Techniques ◽  
Waste Streams ◽  
Integrity Assessment ◽  
Technical Work ◽  
Global Vision

Abstract. The EURATOM PREDIS project (http://www.predis-h2020.eu, last access: 25 October 2021) targets the development and implementation of activities for predisposal treatment of radioactive waste streams other than nuclear fuel and high-level radioactive waste. It started on 1 September 2020 with a 4 year duration. The consortium includes 47 partners from 17 member states. The overall budget of the project is EUR 23.7 million, with EC contribution of EUR 14 million. The PREDIS project develops and increases the technological readiness level (TRL) of treatment and conditioning methodologies for wastes for which no adequate or industrially mature solutions are currently available, including metallic materials, liquid organic waste and solid organic waste. The PREDIS project also develops innovations in cemented waste handling and predisposal storage by testing and evaluating. The technical work packages align with priorities formulated within the Roadmap Theme 2 of EURAD (https://www.ejp-eurad.eu/sites/default/files/2021-09/2_Predisposal_Theme_Overview.pdf, last access: 15 October 2021), Nugenia Global Vision (https://snetp.eu/wp-content/uploads/2020/10/Global-vision-document-ves-1-april-2015-aa.pdf, last access: 15 October 2021) and with those identified by the project's industrial end users group (EUG). The PREDIS will produce tools guiding decision making on the added value of the developed technologies and their impact on the design, safety and economics of waste management and disposal. Four technical work packages are focusing on specific waste types: metallic, liquid organic, solid organic, and cemented wastes. For the first three, the main aim lies in processing, stabilizing, and packaging the different waste streams, e.g. by using novel geopolymers, to deliver items which are in line with national and international waste acceptance criteria. In contrast, the fourth technical work package has a different focus. To provide better ways for a safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during predisposal activities, several digital tools are evaluated and improved. Safety enhancement (e.g. less exposure of testing personnel) and cost-effectiveness are part of the intended impact. The work includes but is not limited to inspection methods, such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring, such as remote fiber optic sensors. The sensors applied will go beyond radiation monitoring and include proxy parameters important for long-term integrity assessment (e.g. internal pressure). Sensors will also be made cost-effective to allow the installation of many more sensors compared to current practice. The measured data will be used in digital twins of the waste packages for specific simulations (geochemical, integrity) providing a prediction of future behavior. Machine learning techniques trained by the characterization of older waste packages will help to connect the models to the current data. All data (measured and simulated) will be collected in a joint database and connected to a decision framework to be used at actual facilities. The presentation includes detailed information about the various tools under consideration in the monitoring of cemented waste packages, their connection and first results of the research.

35 Years of Incineration in Studsvik: Lessons Learned and Recent Modifications and Improvements

2011 ◽  
Author(s):  
Maria Lindberg ◽  
Joakim Lo¨vstrand ◽  
Karin von Kronhelm
Keyword(s):  
Radioactive Waste ◽  
Control Systems ◽  
Lessons Learned ◽  
Nuclear Industry ◽  
Academic Institutions ◽  
Waste Streams ◽  
Gas Treatment

Since the incinerator in Studsvik was taken into operation in 1976 it has been operating at a level of 350–500 tonnes per year. The incinerator treats waste from both the nuclear industry and from other sectors generating radioactive waste such as hospitals, research companies/facilities and academic institutions. The incineration facility has been upgraded several times during its lifetime. The upgrades includes, change of off gas treatment as well as new control systems and currently the commissioning of a sister pyrolysis plant. Several new waste streams have also been approved for treatment in the last few years.

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