Isotopic Abundances Measurements a Key to Understanding the Oklo Phenomenon

1980 ◽  
Vol 35 (2) ◽  
pp. 171-179 ◽  
Author(s):  
J. C. Ruffenach ◽  
R. Hagemann ◽  
E. Roth
Keyword(s):  
Nuclear Reactions ◽  
Nuclear Reactors ◽  
Fission Products ◽  
Chemical Analyses ◽  
Pressurized Water ◽  
Long Term Storage ◽  
Isotopic Abundances ◽  
Water Reactors ◽  
Term Storage

AbstractThe Oklo natural nuclear reactors have been studied mainly by isotopic and chemical analyses of uranium and fission products. Interpretation of these analyses allows parameters which characterize these reactions (flux, fluence,...), and also the age and duration of the nuclear reactions to be evaluated. The mechanisms and extent of fission-product migration can also be discussed. The behaviour of various elements formed in the Oklo uraninite and in oxyde fuels of pressurized water reactors is compared and found to be similar. Therefore, experience gained from the study of the Oklo phenomenon can provide valuable information on the long-term storage of radioactive wastes in geological media.

Preliminary Studies of the Disposition of Cesium in a Glass-Bonded Sodalite Waste form

2002 ◽  
Vol 713 ◽  
Author(s):  
Marsha J. Lambregts ◽  
Steven M. Frank
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Fission Products ◽  
Waste Form ◽  
Resonance Spectroscopy ◽  
Ceramic Waste ◽  
Long Term Storage ◽  
Geological Repository ◽  
Term Storage

ABSTRACTArgonne National Laboratory has developed an electrometallurgical treatment for DOE spent metallic nuclear fuel. Fission products are immobilized in a durable glass bonded sodalite ceramic waste form (CWF) suitable for long term storage in a geological repository. Cesium is estimated to be in the waste form at approximately 0.1 wt.%. The exact disposition of cesium was uncertain and it was believed to be uniformly distributed throughout the waste form. A correlation of X-ray diffractometry (XRD), electron microscopy (EM), and nuclear magnetic resonance spectroscopy (NMR) performed on surrogate ceramic waste forms with high cesium loadings found a high cesium content in the glass phase and in several non-sodalite aluminosilicate phases. Cesium was not detected in the sodalite phase.

scholarly journals The influence of non-normative fuel on its operational properties

2019 ◽  
Vol 178 (3) ◽  
pp. 67-70
Author(s):  
Anna MATUSZEWSKA ◽  
Marlena OWCZUK
Keyword(s):  
Quality Standards ◽  
Chemical Analyses ◽  
Oxidation Processes ◽  
Long Term Storage ◽  
Physico Chemical ◽  
Resistance To Oxidation ◽  
Normative Requirements ◽  
Term Storage

Fuels that do not meet the requirements of quality standards cannot be used to power vehicle engines. The work involved physico-chemical analyses of non-normative fuel and its effect on the operational properties of the powered vehicle. The research fuels were two gasolines, characterized by a reduced resistance to oxidation processes due to their long-term storage. The results were compared to the properties of conventional fuels that met all normative requirements. The studies have shown that the fuel slightly deviating from the standard parameters does not noticeably affect the useful properties of the vehicle.

Applications of Electron Microscopy to Containment of Radio-Nuclides

1982 ◽  
Vol 40 ◽  
pp. 606-609
Author(s):  
Carol M. Jantzen
Keyword(s):  
Nuclear Waste ◽  
Fission Products ◽  
Silica Glasses ◽  
Long Term Storage ◽  
Waste Forms ◽  
High Silica ◽  
Solid Form ◽  
Reference Form ◽  
Term Storage

The long radioactive lifetime of the fission products in nuclear wastes requires that the materials be isolated from the biosphere for periods of 103 to 105 years. One method of accomplishing this is to consolidate the waste into a chemically stable solid form and to contain this within a multiple barrier canister which can be transported to a geologically stable repository for long-term storage. A number of candidate solid waste forms are being assessed to determine their suitability for incorporating various nuclear waste compositions and they include borosilicate glass (the current reference form), ceramics, high silica glasses, and cement.

Research on the Radioactivity of Thorium Fuel in Different Reactors

2008 ◽  
Author(s):  
Ganglin Yu ◽  
Kan Wang
Keyword(s):  
Fuel Cycle ◽  
Research Work ◽  
Fission Products ◽  
Spent Fuel ◽  
Short Term ◽  
Pressurized Water ◽  
Actual Application ◽  
Water Reactors ◽  
The Difference

It’s very important to estimate the mass and radiotoxicity of isotopes in spent fuel of thorium fuel cycle, which will benefit the application of the thorium fuel. Much research work has been done on the spent fuel and radioactivity of thorium-based fuel before, yet the difference in usage is always ignored. This paper studies the raise of isotopes in spent fuel of thorium-based fuel cycle in pressurized water reactors and fast neutron reactors, focus on the radioactivity level of actinides and fission products, the important nuclides which have long term radiological impact or give the highest contribution to the total dose on short term after different decay periods. The paper discuss the important nuclides in the measurement of thorium fuel burnup, the conclusion will benefit the actual application of thorium fuel.

Application of Synchrotron X-Ray Fluorescence Microscopy to the Study of Multi-Metal Oxide Ceramics

1998 ◽  
Vol 524 ◽  
Author(s):  
Dale L. Perry ◽  
Scott McHugo ◽  
Albert C. Thompson ◽  
Joseph C. Farmer ◽  
Bart B. Ebbinghaus ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Metal Oxide ◽  
Oxide Ceramics ◽  
Chemical Analyses ◽  
Elemental Mapping ◽  
X Ray ◽  
Long Term Storage ◽  
Term Storage ◽  
Actinide Elements

ABSTRACTSynchrotron x-ray fluorescence microscopy has been used to study multi-metal oxide ceramics that have been designed to sequester radioactive actinide elements for long-term storage and disposal. X-ray fluorescent lines for the various elements have been used for lateral elemental mapping of the materials, and the heterogeneity of the samples is discussed with respect to the elements in the crystallographic phases that have previously been documented by other means of structural and chemical analyses.

Selection of Matrices for Immobilization of Actinide Fraction of HLW

2002 ◽  
Vol 757 ◽  
Author(s):  
A. V. Ochkin ◽  
S. V. Stefanovsky ◽  
S. I. Rovny
Keyword(s):  
Storage Time ◽  
Fission Products ◽  
Alpha Activity ◽  
Separation Method ◽  
Fast Reactors ◽  
Long Term Storage ◽  
Perovskite Ceramics ◽  
Term Storage ◽  
Selection Of

ABSTRACTHLW after the separation of U, Pu and Np contains two major radionuclide groups: fission products and TRU elements. The later ones are the most dangerous and should be separated in the special actinide fraction. This process has been realized at PA “Mayak”.The composition of the actinide fraction depends on a separation method:A. Radionuclides of Am and Cm with minor amounts of U, Np and Pu.B. Radionuclides of Am and Cm with minor amounts of U, Np and Pu and also REEs.C. Radionuclides of Am and Cm with minor amounts of U, Np and Pu and also REEs and perhaps some amount of Zr.The fraction with composition A can be burned off in fast reactors whereas the fractions with compositions B and C should be immobilized in stable matrices. Alpha-Activity of actinide fraction is subsequently determined by 244Cm, 241Am, 244Am, 239Pu and 242Pu during a long-term storage. The storage time depends on conditions and can reach several hundreds of thousands years. The main requirements to matrices are chemical and radiation resistances. The fraction with composition B can be incorporated in perovskite ceramics whereas in case of composition C the additional zirconolite and/or pyrochlore phases are necessary.

Partitioning of High-Level Waste as Pretreatment in Waste Management

1983 ◽  
Vol 26 ◽  
Author(s):  
M. Kubota ◽  
I. Yamaguchi ◽  
K. Okada ◽  
Y. Morita ◽  
K. Nakano ◽  
...  
Keyword(s):  
Fission Products ◽  
High Level Waste ◽  
Flow Sheet ◽  
Storage Requirement ◽  
Solid Materials ◽  
Long Term Storage ◽  
Deep Geological Disposal ◽  
High Level ◽  
Term Storage

ABSTRACTRemoval of the long-lived radionuclides from high-level waste (HLW) is a potential means not only for making wastes more acceptable in terms of long term hazards, but also for alleviating storage requirement. From these points, the authors are developing a method of partitioning actinides, Sr-90 and Cs-137 from HLW. A chemical flow-sheet has been constructed and experiments with actual HLW were initiated in 1982. Through the partitioning, active elements in HLW can be fractionated into 3 groups. Total volume of the solid materials of the 3 groups was calculated and found to be reduced to less than one-third of the volume of the vitrified material containing 10 wt% of fission products as oxide. Such volume reduction seems to facilitate the long term storage or the deep geological disposal of HLW.

Disposing of Excess Weapons Materials: Past and Future of Belgian Plutonium Technology

2001 ◽  
Author(s):  
Yvon Vanderborck ◽  
Jacques Basselier
Keyword(s):  
Fission Products ◽  
Point Of View ◽  
Spent Fuel ◽  
Economic Point ◽  
Long Term Storage ◽  
Transfer Of Technology ◽  
The Us ◽  
Further Development ◽  
Term Storage

Abstract Long term storage of plutonium separated from fission products is not a good solution according to the current non-proliferation criteria as well as from an economic point of view. This material has thus to be converted to the equivalent of the “spent fuel standard”. Only one technique has so far reached the industrial maturity necessary to convert the important existing plutonium stockpiles: it is the use of plutonium to manufacture and irradiate MOX fuel. The paper reviews the existing information over the separated plutonium stockpiles and the various International Agreements, which are implemented to cover the peaceful use of plutonium. The dual track solution retained in U.S. in mentioned. The situation U.S. and Russia is updated, the roles of Europe and Belgium are presented. The activities of BELGONUCLEAIRE on the US and Russian sides will be described and its experience in fabrication technology, quality, safety, environmental issues, non-proliferation, safeguards and transport will be considered. The transfer of technology to France, Japan and US makes the MIMAS BELGONUCLEAIRE fabrication process equivalent to an international standard. This forms a sound basis for further development and for a transfer to Russia. The paper will demonstrate by this way the commitment of BELGONUCLEAIRE to participate to the peaceful uses of plutonium, as well as its contribution safely to non-proliferation and disarmament international policy.

Anticipated Improved Performance of Advanced Steel Cladding Under Long Term Dry Storage of Spent Fuel

2015 ◽  
Author(s):  
Raul B. Rebak ◽  
Shenyan Huang
Keyword(s):  
Zirconium Alloys ◽  
Nuclear Waste Repository ◽  
Ferritic Steels ◽  
Spent Fuel ◽  
Dry Storage ◽  
Long Term Storage ◽  
Water Reactors ◽  
Improved Performance ◽  
Term Storage

In current light water reactors the nuclear fuel rods are dependent on zirconium alloys cladding. Used fuel bundles are generally stored in water pools for approximately twenty years and then they may be transferred to a dry casket for an interim storage until reprocessing or the final disposition in a permanent nuclear waste repository. The delay in opening a permanent repository in the US says that the used fuel bundles would need to be stored in dry casks for unanticipated extended periods (maybe 100 years). Under dry storage several mechanisms were identified for the degradation of zirconium based cladding. The vulnerabilities of zirconium alloys would limit their subsequent fuel retrievability and transportation after the long term storage. As part of the DOE Accident Tolerant Fuel (ATF), advanced ferritic steels such as Fe-Cr-Al alloys are being investigated to replace the zirconium alloy cladding. Previous performance in storage of austenitic stainless steel cladding suggests that the proposed ATF ferritic steels would perform well under long term storage in dry casks.

Sign in / Sign up

Export Citation Format

Share Document