Test facility for studying kinetics of release of gaseous radioactive fission products from irradiated materials

1974 ◽  
Vol 36 (1) ◽  
pp. 89-91
Author(s):  
D. M. Skorov ◽  
A. I. Dashkovskii ◽  
A. G. Zaluzhnyi ◽  
O. M. Storozhuk
Keyword(s):  
Fission Products ◽  
Test Facility ◽  
Kinetics Of

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

Development of High Efficiency Containment Venting System by Using AgX

2016 ◽  
Author(s):  
Tadashi Narabayashi ◽  
Yuuhei Sugano ◽  
Hiroki Imaeda ◽  
Go Chiba ◽  
Nobuaki Sato ◽  
...  
Keyword(s):  
High Efficiency ◽  
Water Injection ◽  
Heat Removal ◽  
Fission Products ◽  
Radioactive Material ◽  
Severe Accident ◽  
Test Facility ◽  
Silver Coating ◽  
Fukushima Daiichi ◽  
Filter Thickness

Fukushima Daiichi NPP accident would be terminated, if sufficient accident countermeasures, such as water proof door, mobile power, etc [1, 2]. In case of Europe, it had already installed the heat removal system and filtered containment venting system (FCVS) from the lessons of TMI and Chernobyl Accidents. The new regulatory standard in Japan, the filtered vent system (FCVS) should be installed, and prevent the radioactive material in case of the severe accident and the overpressure breakage prevention of a primary containment vessel (PCV) and also the robustization of the FCVS. The authors examined the severe accident process in the 2nd unit of Fukushima Daiichi NPS, and found the vent by FCVS should be done before water injection into the core. The PCV spray and water injection into the pedestal basement should be also the countermeasures to the severe accident. Countermeasures for an intentional aircraft collision should be installed too. Upon occurrence of a severe accident (SA), vent gas with radioactive fission products is blown out to a scrubbing pool through numerous venturi nozzles. Mist in steam moves upward to a metal fiber filter through a multi-hole baffle plate. After the mist is removed by that filter, radioactive methyl iodine (CH3I) is captured on the surface of a molecular sieve or AgX, made from zeolite particles with silver coating. A FCVS visualized test facility was installed at Hokkaido University. An AgX filter is used down-stream of the scrubbing pool and metal fiver filter. Thickness of AgX filter is very important parameter to obtain enough decontamination factor (DF). The DF for the radioactive iodine exceeds 10,000 at bed depth (AgX filter thickness) greater than 75mm.

The Dissolution of Irradiated Fuel Under Hydrothermal Conditions

1981 ◽  
Vol 6 ◽  
Author(s):  
Lawrence H. Johnson ◽  
Henry H. Joling
Keyword(s):  
Experimental Studies ◽  
Fission Products ◽  
Redox Chemistry ◽  
Hydrothermal Conditions ◽  
Product Release ◽  
Reducing Conditions ◽  
Dissolution Behaviour ◽  
Low Ionic Strength ◽  
Kinetics Of ◽  
Irradiated Fuel

ABSTRACTUranium dioxide, the major component of irradiated CANDU fuel, shows good hydrothermal stability under the appropriate redox conditions. The thermodynamic stability of UO2 in low ionic strength granite groundwater at 150°C under oxidizing and reducing conditions is briefly reviewed in order to provide a basis for discussion of the results of irradiated fuel dissolution experiments. Fuel chemistry characteristics that influence the kinetics of fission product release are also discussed.Experimental studies demonstrate the influence of redox chemistry on irradiated fuel dissolution behaviour. Undero9 trongly reducing conditions, both uranium and 99Tc concentrations in solution decrease to the detection limit, whereas appreciable concentrations of both elements accumulate under oxidizing conditions. The release of some fission products, such as 90Sr and 137Cs, does not seem to be strongly affected by changes in redox chemistry. Under oxidizing conditions, the rate of 90Sr release to solution increases by a factor of ten to twenty between 25 and 150°C.These studies indicate the need for further work in certain areas, in particular on the relative amounts of important fission productsreleased by leaching versus matrix dissolution, and on the effect of the products of α–radiolysis of water on the dissolution of irradiated fuel.

scholarly journals Irradiation performance of pyrolytic silicon carbide coatings on fissile fuel particles

1984 ◽  
Vol 42 ◽  
pp. 418-419
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Product ◽  
Fission Products ◽  
Carbide Coatings ◽  
Fuel Particles ◽  
Irradiation Performance ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of

Fuel particles for the High Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC coating with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) the combined effects of irradiation and fission product interactions. This paper reports the behavior of SiC deposited on fissile fuel particles and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

scholarly journals The Effects of Nitric Acid on Extraction Properties of TODGA During Fission Product Management

MRS Advances ◽  
2016 ◽  
Vol 2 (10) ◽  
pp. 563-568
Author(s):  
Michael A. Bromley ◽  
Colin Boxall
Keyword(s):  
Nitric Acid ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
Product Management ◽  
Extraction Kinetics ◽  
Solvent Phase ◽  
Extraction Properties ◽  
Organic Extractant ◽  
Kinetics Of ◽  
Solvent Extraction Kinetics

ABSTRACTIn the context of management of the wastes arising from the reprocessing of spent nuclear fuel, studies have been conducted into the solvent extraction kinetics of lanthanide fission products by TODGA and the effects of solvent phase acidity on the effectiveness of this organic extractant molecule. In this study we observe an increase in organic phase viscosity increasing acidity and, potentially by consequence, that the rate of cerium extraction is summarily decreased.

Kinetic Study of Intermetallic Formation on Die Material in Aluminum Molten Alloy Containing Various Additional Elements

2012 ◽  
Vol 630 ◽  
pp. 45-49
Author(s):  
Bong Hwan Kim
Keyword(s):  
Molten Metal ◽  
Intermetallic Phase ◽  
Test Facility ◽  
Molten Alloy ◽  
Manufacturing Processes ◽  
Intermetallic Formation ◽  
Formation Behavior ◽  
Die Material ◽  
Kinetics Of ◽  
Intermetallic Layers

The formation behavior of intermetallic layers on die material immersed in aluminum molten metal was investigated by using dipping test facility. And the metallurgical parameters affecting on the kinetics of intermetallic formation were discussed as functions of additional elements such as Fe, Mn and Cr in order to propose a practical guideline for control of molten metal in manufacturing processes. It was found that the intermetallic layers consist of α-AlFeSi, β-AlFeSi and θ-AlFe. The kinetic of intermetallic formation was highly dependent on not only the gradient of iron content through the interface between die material and molten alloy but also the relative formation temperature of primary intermetallic phase.

Release Kinetics of Volatile Fission Products Under Severe Accident Conditions

1992 ◽  
Vol 99 (3) ◽  
pp. 330-342 ◽  
Author(s):  
Brent J. Lewis ◽  
Fernando C. Iglesias ◽  
C. E. Laurence Hunt ◽  
David S. Cox
Keyword(s):  
Release Kinetics ◽  
Fission Products ◽  
Severe Accident ◽  
Accident Conditions ◽  
Kinetics Of
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