scholarly journals Quantification of effluents in the production of nuclear fuel

2021 ◽  
Vol 9 (2A) ◽  
Author(s):  
Mayara Costa de Castro Becca Sakai ◽  
Humberto G Riella ◽  
Elita Fontenele Urano de Carvalho
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Research ◽  
Management Plan ◽  
Social Benefits ◽  
Manufacturing Plant ◽  
Fuel Production ◽  
Nuclear Research Institute ◽  
Maximum Capacity ◽  
Current Concern ◽  
Physical And Chemical

The Brazil with the purpose of becoming self-sufficient in the production of radioisotopes and radioactive sources used in nuclear medicine, agriculture and the environment developed the project of a multipurpose reactor of 30 megawatts of power to meet the national demand. In the Energy and nuclear research Institute (IPEN), Nuclear fuel Center (CCN) is responsible for the manufacture of fuel for the reactor IEA-R1 and, possibly, by the multipurpose reactor fuels. In order to meet the demand for the reactors was designed a new manufacturing plant with a maximum capacity of 60 fuel per year, which currently is 10. The increase in production as a consequence will increase the volume of effluents generated. The current concern with the environment it is necessary to draw up a management plan to make the process sustainable, which will result in environmental, economic and social benefits. The fuel production process generates various types of effluent containing uranium or not – being solid, gaseous and liquid with different physical and chemical characteristics. The objective of this work is to follow the process of nuclear fuel production and to identify, quantify and characterize the effluents, especially liquids, to subsequently draw up a management plan and eventually dispose of responsibly in the environment.

Support of the Nuclear Research Institute Rˇezˇ plc of the Shipment of Spent Nuclear Fuel From Research Reactors to the Russian Federation for Reprocessing in the Frame of the RRRFR Program

2010 ◽  
Author(s):  
Josef Podlaha ◽  
Karel Svoboda
Keyword(s):  
Nuclear Fuel ◽  
Russian Federation ◽  
Research Reactor ◽  
Spent Nuclear Fuel ◽  
Nuclear Research ◽  
Reactor Operation ◽  
Nuclear Research Institute ◽  
The Russian Federation ◽  
First Time ◽  
Research Institute

In 2007, spent nuclear fuel (SNF) from the Nuclear Research Institute Rˇezˇ plc (NRI) was shipped to the Russian Federation for reprocessing. A large amount of SNF of Russian origin has been accumulated after 50 years of research reactor operation. The shipment was realized in the frame of the Russian Research Reactor Fuel Return (RRRFR) program under the US-Russian Global Threat Reduction Initiative (GTRI). SNF shipment from NRI to the Russian Federation represented a very complex and complicated technical, legal and contractual scope of work. The SNF shipment has been realized under specific conditions: 1. High capacity SˇKODA VPVR/M casks were used for transportation for the first time. 2. For the first time, high enriched uranium SNF from a research reactor has been sent to the Russian Federation from a European Union country under the appropriate intergovernmental agreements, legal regulations and conditions. NRI also participates in shipments of SNF from other countries within the framework of the RRRFR program. NRI participated in shipments of SNF from Bulgaria and Hungary in 2008, from Poland in 2009 and 2010, from Ukraine in 2010. Shipments from Belarus and Serbia are planned in 2010. The second shipment of the residue of high enriched SNF from NRI after changeover of the reactor operation to low enriched fuel will be implemented in 2013. The experiences gained during the SNF transportation are described in the paper together with the present and future NRI activities in support of the SNF shipment from other countries.

scholarly journals An algorithms to improve the energy resolution of two-step cascade spectrum

2020 ◽  
Vol 4 (4) ◽  
pp. First
Author(s):  
Nguyen Ngoc Anh ◽  
Nguyen Xuan Hai ◽  
Hồ Hữu Thắng ◽  
Phan Bao Quoc Hieu ◽  
Truong Van Minh
Keyword(s):  
Energy Resolution ◽  
Spectrum Analysis ◽  
Nuclear Research ◽  
Final States ◽  
Nuclear Research Institute ◽  
Peak Deconvolution ◽  
Compound State ◽  
Gamma Spectrum Analysis ◽  
Gamma Coincidence ◽  
Coincidence Spectrometer

The present paper proposes an algorithm to improve the energy resolution of two-step cascade spectrum. The energy resolution plays an important role in the domain of gamma spectrum analysis. The better the energy resolution is, the better the ability of peak resolving is. The algorithm is constructed based on an analyze of energy resolution of the summation amplitude of coincident pulses spectrometer using the analogue technique. The algorithm proposed has been tested on some two-step cascade spectra of 164Dy nucleus obtained from the (n, ) reaction experiment using the gamma – gamma coincidence spectrometer at Dalat Nuclear Research Institute. Two-step cascade spectra corresponding to the cascade decays from the compound state to final states whose energies are 0, 74, and 242 keV have been evaluated. The results obtained show that the energy resolution of the two-step cascade spectrum has been reduced by 1.05 to 2.04 times within the energy range of 586 to 6830 keV. Our algorithm can therefore be applied to improve the ability of peak deconvolution, the accuracy, and the realibility in analyzing two-step cascade spectra.

scholarly journals Modeling of Phosphorous Load and Transport Pathways in Dhidhessa Catchment, Oromiya, Ethiopia

2019 ◽  
Vol 8 (3) ◽  
pp. 22-33
Author(s):  
Adisu Befekadu Kebede ◽  
Fekadu Fufa Feyessa ◽  
Wakjira Takala Dibaba
Keyword(s):  
Nutrient Loading ◽  
Assessment Tool ◽  
Organic Phosphorus ◽  
Swat Model ◽  
Chemical Properties ◽  
Management Plan ◽  
Transport Pathways ◽  
Best Management ◽  
Run Off ◽  
Physical And Chemical

Pollution of surface water with harmful chemicals and eutrophication with excess nutrients are recent serious environmental concerns. This lends the need of knowing the nutrient loading and transport mechanism that will occur with different spatial and temporal extent. Thus, effective information regarding the nutrients load and transport mechanisms are important to hydrologists, water use planners, watershed managers and decision makers for water resource projects and planet ecosystem. Our study aimed for modeling of phosphorous loading and its transport pathways and to identify the most vulnerable sub basin responsible for a significant phosphorus load in Dhidhessa catchment using Soil and Water Assessment Tool (SWAT) model. The pathways of phosphorus were identified and found that the organic phosphorus was dominant exporting mechanism accounted for 58.89% of the total path in the study area. For all forms of phosphorus, surface run off was the most dominant means of transport agent. The average annual loading of total phosphorus was identified as 20 kg ha-1. The sub basins 17, 23, and 3 were identified as the highest loading area of total phosphorous in the study catchment. Best management plan which is simple, economical and adaptable over the study catchment for managing severe impact of surface run off on water resources should be adopted. It is better to undergo detail re-examination over the physical and chemical properties of P in fertilizers and manures to propose the minimizing, neutralizing, replacing strategies to reduce at the source.

Experiences in the Field of Radioactive Materials Seizures in the Czech Republic

2007 ◽  
Author(s):  
Karel Svoboda ◽  
Josef Podlaha ◽  
David Sˇi´r ◽  
Josef Mudra
Keyword(s):  
Czech Republic ◽  
Raw Materials ◽  
Nuclear Research ◽  
Municipal Waste ◽  
Radioactive Material ◽  
Radioactive Materials ◽  
Nuclear Research Institute ◽  
The Czech Republic ◽  
Other Information ◽  
Radioactive Sources

In recent years, the amount of radioactive materials seizures (captured radioactive materials) has been rising. It was above all due to newly installed detection facilities that were able to check metallic scrap during its collection in scrap yards or on the entrance to iron-mills, checking municipal waste upon entrance to municipal disposal sites, even incineration plants, or through checking vehicles going through the borders of the Czech Republic. Most cases bore a relationship to secondary raw materials or they were connected to the application of machines and installations made from contaminated metallic materials. However, in accordance to our experience, the number of cases of seizures of materials and devices containing radioactive sources used in the public domain was lower, but not negligible, in the municipal storage yards or incineration plants. Atomic Act No. 18/1997 Coll. will apply to everybody who provides activities leading to exposure, mandatory assurance as high radiation safety as risk of the endangering of life, personal health and environment is as low as reasonably achievable in according to social and economic aspects. Hence, attention on the examination of all cases of the radioactive material seizure based on detection facilities alarm or reasonably grounds suspicion arising from the other information is important. Therefore, a service carried out by group of workers who ensure assessment of captured radioactive materials and eventual retrieval of radioactive sources from the municipal waste has come into existence in the Nuclear Research Institute Rez plc. This service has covered also transport, storage, processing and disposal of found radioactive sources. This service has arisen especially for municipal disposal sites, but later on even other companies took advantage of this service like incineration plants, the State Office for Nuclear Safety, etc. Our experience in the field of ensuring assessment of captured radioactive materials and eventual retrieval of radioactive sources will be presented in the paper.

Decommissioning of Obsolete Nuclear Facilities in the UJV Rez, a. s.

2014 ◽  
Author(s):  
Milan Tous ◽  
Josef Podlaha
Keyword(s):  
Czech Republic ◽  
Nuclear Research ◽  
Nuclear Facilities ◽  
Nuclear Research Institute ◽  
Nuclear Program ◽  
The Czech Republic ◽  
Dominant Position ◽  
Ultrasonic Bath ◽  
The Past ◽  
Dry Ice Blasting

More than 55 years of activities in the company UJV Rez, a. s. (Nuclear Research Institute Rez a.s. in the past) which is a leading institution in all areas of nuclear R&D in the Czech Republic and had a dominant position in the nuclear program since it was established (1955), there are several obsolete nuclear facilities that shall be decommissioned. The total amount of radioactive waste (RAW) resulting from decommissioning for the next processing will be ∼ 1500 m3 and the expected amount RAW for releasing into the environment is 240 tons after the decontamination. For the RAW processing several decontamination methods such as high press water jetting, chemical treating in ultrasonic bath, dry ice blasting and abrasive blasting were performed. Decommissioning started in 2003 and will be finished in 2016. This decommissioning of nuclear facilities in UJV is the only ongoing decommissioning project in the Czech Republic.

New PLIM Program for Czech NPPs

2009 ◽  
Author(s):  
Petr Kadecˇka
Keyword(s):  
Czech Republic ◽  
Implementation Process ◽  
Nuclear Research ◽  
Program Structure ◽  
Nuclear Research Institute ◽  
Implementation Phase ◽  
Good Practices ◽  
Database Application ◽  
Plant Life ◽  
Ageing Management

Nuclear Research Institute (NRI) Rez, Czech Republic have worked together with Czech NPPs (Dukovany and Temelin) on preparation of a new Plant Life Management (PLIM) Program that is currently for these NPPs in implementation phase. This presentation describes the new PLIM program structure and whole implementation process that covers: - preparation of specific guidelines and strategies based on analysis of Czech Regulator’s and IAEA requirements, and different good practices, - ageing management (AM) review carried out for selected structures and components, existing AM programs and other already used practices related to AM, - performance of technical-economical study that adds economical planning to PLIM, - design and usage of supporting database application called INFOZ.

Over Limit Oxygen Effect on Crack Propagation of WWER 440 RPV Steel in Primary Circuit Water

2009 ◽  
Author(s):  
Miroslava Ernestova ◽  
Anna Hojna
Keyword(s):  
Crack Propagation ◽  
Nuclear Power ◽  
Power Plants ◽  
Water Environment ◽  
Nuclear Research ◽  
Compact Tension ◽  
Oxygen Effect ◽  
Primary Circuit ◽  
Nuclear Research Institute ◽  
Primary Water

Experience with operating nuclear power plants worldwide reveals that many failures may be attributed to fatigue associated with mechanical loading due to vibration and with corrosion effect due to exposure to high-temperature environment. In order to clarify the simultaneous influence on reactor pressure vessel (RPV) material testing of ferritic steel 15Ch2MFA used for RPV of WWER 440 was performed at Nuclear Research Institute (NRI) autoclaves. Cyclic and constant loadings were applied to Compact Tension (CT) specimens in WWER primary water environment at 290°C and simultaneous effect of different oxygen levels (< 20 ppb, 200 ppb, 2000 ppb) on crack propagation has been evaluated. Obtained crack growth rates are compared with ASME XI Code and VERLIFE curves and crack behaviour is discussed.

3D hierarchical porous amidoxime fibers speed up uranium extraction from seawater

2019 ◽  
Vol 12 (6) ◽  
pp. 1979-1988 ◽  
Author(s):  
Xiao Xu ◽  
Hongjun Zhang ◽  
Junxuan Ao ◽  
Lu Xu ◽  
Xiyan Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Nuclear Fuel ◽  
Specific Surface Area ◽  
New Technology ◽  
High Specific Surface Area ◽  
Fuel Production ◽  
Uranium Extraction ◽  
Hierarchical Porous ◽  
Speed Up

The development of high specific surface area amidoxime-based polymeric (H-ABP) fibers presents a new technology for the synthesis of highly efficient adsorbents for uranium extraction from seawater (UES), thus opening a whole new means of nuclear fuel production from the ocean.

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