scholarly journals Radiochemical Methodologies Applied to Analytical Characterization of Low and Intermediate Level Wastes from Nuclear Power Plants

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Roberto Pellacani Monteiro ◽  
Aluísio Souza Reis Junior ◽  
Geraldo Frederico Kastner ◽  
Eliane Silvia Codo Temba ◽  
Thiago César De Oliveira ◽  
...  
Keyword(s):  
Radiochemical Separation ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
Analytical Characterization ◽  
Low Level ◽  
Nuclear Techniques

The aim of this work is to present radiochemical methodologies developed at CDTN/CNEN in order to answer a program for isotopic inventory of radioactive wastes from Brazilian Nuclear Power Plants.  In this program  some radionuclides, 3H, 14C, 55Fe, 59Ni, 63Ni, 90Sr, 93Zr, 94Nb, 99Tc, 129I, 235U, 238U, 238Pu, 239+240Pu, 241Pu, 242Pu, 241Am, 242Cm e 243+244Cm, were determined  in Low Level Wastes (LLW) and Intermediate Level Wastes (ILW) and a protocol of analytical methodologies based on radiochemical separation steps and spectrometric and nuclear techniques was stablished.

scholarly journals Application of a Specifi c Indicator for the Estimation of Radioactive Wastes Generation Volumes During Normal Operation of Nuclear Power Plants in Russia

2020 ◽  
Vol 11 (2) ◽  
pp. 66-74
Author(s):  
A. A. Ekidin ◽  
◽  
K. L. Antonov ◽  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Radiation Safety ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
Normal Operation ◽  
Low Level ◽  
Retrospective Assessment ◽  
High Level

Generation of radioactive wastes (RW) is viewed a most urgent problem of radiation safety under normal operation of nuclear power plants (NPP). The paper demonstrates the application of a specifi c indicator (rate) of RW generation per unit of generated power (m3/GW·h) for a retrospective assessment and forecasting of RW generation volumes at Russian NPPs. Mean and median values of annual specifi c RW generation rates were calculated for each NPP based on published environmental reports of JSC Rosenergoatom Concern for the period of 2008—2018. Advantage of applying median values in retrospective and forecast assessments was shown. Medians for solid very low-level, low-level, intermediate-level and high-level radioactive waste amounted to 1.5·10−2 m3/GW·h, 3.3·10−2 m3/GW·h, 3.3·10−3 m3/GW·h and 2.8·10−4 m3/GW·h, respectively; for liquid low-level and intermediate-level waste these values accounted for 1.4·10−3 m3/GW·h, 2.5·10−3 m3/GW·h, respectively. NPPs with RBMK reactor units are characterized by the highest mean and median values of specifi c RW generation rates for all RW categories. Given various types of reactor facilities and their characteristic specifi c rates, retrospective estimates for the total volume of liquid RW was increased by 8 % and for solid RW — by 12 %. The forecast estimates based on specifi c rate medians, as well as on increased power generation planned for Russian NPPs indicates probable increase in RW generation volumes by 0.8—7.1 % (depending on waste category) from 2020 to 2027.

ISO Standardization of the Scaling Factor Method for Low- and Intermediate Level Radioactive Wastes Generated at Nuclear Power Plants

2007 ◽  
Author(s):  
Makoto Kashiwagi ◽  
Hideki Masui ◽  
Yasutaka Denda ◽  
David James ◽  
Bertrand Lante`s ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Scaling Factor ◽  
Project Team ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
International Standard ◽  
Factor Method ◽  
International Standardization

Low- and intermediate-level radioactive wastes (L-ILW) generated at nuclear power plants are disposed of in various countries. In the disposal of such wastes, it is required that the radioactivity concentrations of waste packages should be declared with respect to difficult-to-measure nuclides (DTM nuclides), such as C-14, Ni-63 and α-emitting nuclides, which are often limited to maximum values in disposal licenses, safety cases and/or regulations for maximum radioactive concentrations. To fulfill this requirement, the Scaling Factor method (SF method) has been applied in various countries as a principal method for determining the concentrations of DTM nuclides. In the SF method, the concentrations of DTM nuclides are determined by multiplying the concentrations of certain key nuclides by SF values (the determined ratios of radioactive concentration between DTM nuclides and those key nuclides). The SF values used as conversion factors are determined from the correlation between DTM nuclides and key nuclides such as Co-60. The concentrations of key nuclides are determined by γ ray measurements which can be made comparatively easily from outside the waste package. The SF values are calculated based on the data obtained from the radiochemical analysis of waste samples. The use of SFs, which are empirically based on analytical data, has become established as a widely recognized “de facto standard”. A number of countries have independently collected nuclide data by analysis over many years and each has developed its own SF method, but all the SF methods that have been adopted are similar. The project team for standardization had been organized for establishing this SF method as a “de jure standard” in the international standardization system of the International Organization for Standardization (ISO). The project team for standardization has advanced the standardization through technical studies, based upon each country’s study results and analysis data. The conclusions reached by the project team was published as ISO International Standard 21238:2007 “The Scaling Factor method to determine the radioactivity of low- and intermediate-level radioactive waste packages generated at nuclear power plants” [1]. This paper gives an introduction to the international standardization process for the SF method and the contents of the recently published International Standard.

Development of Disposal Option for Radioactive Waste

2013 ◽  
Author(s):  
Anthony Shadrack ◽  
Chang-Lak Kim
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
Radioactive Waste Disposal ◽  
Pressurized Water ◽  
Disposal Option ◽  
First Time

The development of a lasting solution to radioactive waste management is a critical issue for future nuclear applications. When assessing radioactive waste disposal options factors such as volume of waste and sustainability of the plan must be considered. This paper describes basic plans for the disposal of Low- and intermediate-level radioactive wastes (LILW) expected to be generated from nuclear power plants for countries starting nuclear power program for the first time. The purpose of this paper was to develop a disposal option for Low- and intermediate level radioactive wastes for new comer countries planning to build at least two nuclear power units. A LILW disposal plan was developed by considering countries’ radioactive waste generation data from pressurized water nuclear reactors. An on-site storage facility of 1,000 m3 for LILW at NPPs sites for a period 10 years pending final disposal was recommended. It was concluded that storage and disposal processes are complementary with each other, therefore; both programs should be complemented for effective management and control of radioactive wastes. This study is important as an initial implementation of a national Low- and intermediate level wastes (LILW) disposal program for countries planning to build nuclear power plants for the first time.

Utilization of Radioactive Waste for Solidifying Material to Fill Waste Forms

2001 ◽  
Author(s):  
Takeshi Ishikura ◽  
Daiichiro Oguri
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Filling Ratio ◽  
Improved Method ◽  
Low Level ◽  
Waste Forms ◽  
Disposal Facility ◽  
Low Level Radioactive Waste

Abstract Minimizing the volume of radioactive waste generated during dismantling of nuclear power plants is a matter of great importance. In Japan waste forms buried in shallow burial disposal facility as low level radioactive waste (LLW) must be solidified by cement with adequate strength and must extend no harmful openings. The authors have developed an improved method to minimize radioactive waste volume by utilizing radioactive concrete and metal for mortar to fill openings in waste forms. Performance of a method to pre-place large sized metal or concrete waste and to fill mortar using small sized metal or concrete was tested. It was seen that the improved method substantially increases the filling ratio, thereby decreasing the numbers of waste containers.

A Study on the Vitrification Tests of the Low Level Radioactive Wastes Using Plasma Arc Melter System

2004 ◽  
Author(s):  
Boo Ho Yoon ◽  
Jae Hak Cho ◽  
Sang Chul Lee ◽  
Dong Woo Kang ◽  
Yong Joon Choi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Nuclear Power ◽  
Power Plants ◽  
Radioactive Wastes ◽  
Plasma Arc ◽  
Micro Hardness ◽  
Radioactive Materials ◽  
Low Level ◽  
Glass Density ◽  
Glass Formulation

For the research on the vitrification of the low-level radioactive wastes (LLRW) produced in nuclear power plants, one pilot plant with plasma arc melter system was built and several tests were done on it. Some surrogate wastes, which were spiked with several materials and were made very similar to the real LLRW, were used for these tests. For the vitrification of the surrogate wastes, the surrogate wastes were classified into the combustible, the non-combustible and the resin. Then each waste was spiked with special materials and was melted in separate. Off-gases produced in each test were picked up and analyzed. Real radioactive materials cesium (Cs) and cobalt (Co) were spiked in each wastes. Data gained from the final glass formulation were follows. Glass density is 2.42 ∼ 2.95(g/cm3), the compressive strength is 30 ∼ 175 Mpa, micro hardness is 5.5 ∼ 5.8 Gpa. The leaching ratio for Co is 1.27×10−4 ∼ 1.08×10−3 (10mL/g) and that for Cs is 2.46×10−3 ∼ 3.23×10−2 (10mL/g). The leaching speed for Co is 4.14×10−7 ∼ 5.53×10−6 (g/m2) and that for Cs is 4.58×10−5 ∼ 3.87×10−4 (g/m2). In off-gas, dioxin & furan is 0.016 mano gram on the average, CO is about 20 ppm, NO2 is about 15 ppm and SO2 is about 15 ppm.

A semi-supervised method for the characterization of degradation of nuclear power plants steam generators

2021 ◽  
Vol 131 ◽  
pp. 103580
Author(s):  
Luca Pinciroli ◽  
Piero Baraldi ◽  
Ahmed Shokry ◽  
Enrico Zio ◽  
Redouane Seraoui ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Steam Generators
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