Notizen: Diffusion of Non-Gaseous Fission Products in UO2 Single Crystals

1964 ◽  
Vol 19 (11) ◽  
pp. 1331-1332 ◽  
Author(s):  
Noboru Oi ◽  
Jinzaburo Takagi
Keyword(s):  
Single Crystals ◽  
Fission Products ◽  
Gaseous Fission

Diffusion of Non-Gaseous Fission Products in UO2 Single Crystals II

1965 ◽  
Vol 20 (5) ◽  
pp. 673-675 ◽  
Author(s):  
Noboru Oi ◽  
Jinzaburo Takagi
Keyword(s):  
Diffusion Process ◽  
Single Crystals ◽  
Process Analysis ◽  
Diffusion Constant ◽  
Fission Products ◽  
Post Irradiation ◽  
Temperature Range ◽  
Gaseous Fission ◽  
Kinetics Of

The release of short-lived non-gaseous fission products from UO2 single crystals was studied in the temperature range of 1400 —2500°C by means of post-irradiation annealing. The release of the fission products studied appears to follow the kinetics of a diffusion process. Analysis of the data obtained gives the following diffusion constant,DΜο = 3.9 × 10-4 exp(-54,000/RT), DI = 1.5 x 10-3 exp(-59,000/RT), DTe = 6.6 × 10-3 exp(— 70,000/RT), DLa (tentative) =2.2 x 10-6 exp (— 35,000/RT)where the dimensions of D and RT are cm2/sec and cal/mol, respectively.

scholarly journals Features of methods for monitoring the fuel cladding tightness in lead-cooled fast breeder reactors

2021 ◽  
Vol 7 (4) ◽  
pp. 319-325
Author(s):  
Anastasiya V. Dragunova ◽  
Mikhail S. Morkin ◽  
Vladimir V. Perevezentsev
Keyword(s):  
Liquid Metal ◽  
Fission Products ◽  
General Description ◽  
Fuel Cladding ◽  
Reactor Plant ◽  
Reactor Unit ◽  
Basic Principles ◽  
Gaseous Fission ◽  
Breeder Reactors ◽  
Fuel Elements

To timely detect failed fuel elements, a reactor plant should be equipped with a fuel cladding tightness monitoring system (FCTMS). In reactors using a heavy liquid-metal coolant (HLMC), the most efficient way to monitor the fuel cladding tightness is by detecting gaseous fission products (GFP). The article describes the basic principles of constructing a FCTMS in liquid-metal-cooled reactors based on the detection of fission products and delayed neutrons. It is noted that in a reactor plant using a HLMC the fuel cladding tightness is the most efficiently monitored by detecting GFPs. The authors analyze various aspects of the behavior of fission products in a liquid-metal-cooled reactor, such as the movement of GFPs in dissolved and bubble form along the circuit, the sorption of volatile FPs in the lead coolant (LC) and on the surfaces of structural elements, degassing of the GFPs dissolved in the LC, and filtration of cover gas from aerosol particles of different nature. In addition, a general description is given of the conditions for the transfer of GFPs in a LC environment of the reactor being developed. Finally, a mathematical model is presented that makes it possible to determine the calculated activity of reference radionuclides in each reactor unit at any time after the fuel element tightness failure. Based on this model, methods for monitoring the fuel cladding tightness by the gas activity in the gas volumes of the reactor plant will be proposed.

Rapid monitoring of gaseous fission products released from nuclear power stations

1998 ◽  
Vol 233 (1-2) ◽  
pp. 281-284 ◽  
Author(s):  
C. Chung ◽  
C. Y. Chen ◽  
C. S. Lin ◽  
W. W. Yeh ◽  
C. J. Lee
Keyword(s):  
Nuclear Power ◽  
Fission Products ◽  
Power Stations ◽  
Rapid Monitoring ◽  
Gaseous Fission

On Nanoceramic Fuel for Perspective Nuclear Reactors

2008 ◽  
Author(s):  
Pavel N. Alekseev ◽  
Alexander A. Proshkin ◽  
Alexander L. Shimkevich
Keyword(s):  
Amorphous Matrix ◽  
Stable State ◽  
Fission Products ◽  
Defective Structure ◽  
Ceramic Structure ◽  
Component Systems ◽  
Dense Part ◽  
Gaseous Fission ◽  
Reactor Materials ◽  
Swelling Factor

In developing methods for designing reactor materials with reference to nuclear fuel, a task for micro-structural suppressing the processes of swelling, corrosion, and forming macroscopic defects (phase inclusions, pores, gaseous bubbles, cracks) in the fuel is formulated. For managing the defective structure of materials under irradiation, it is offered to choose their composition that fuel oxide ceramics have consisted of steady-state fractal tetrahedral clusters as the dense part of amorphous matrix (the nano-ceramic structure). In this connection, the search of multi-component systems providing this stable state can become a perspective direction for designing fuel with small swelling and corrosion factor. Such the materials will have high density of equilibrium vacancies that effectively absorb solid and gaseous fission products, and reduce the fuel swelling factor, physical, chemical, and thermal properties.

Half-lives of some short-lived mass-separated gaseous fission products and their daughters

1969 ◽  
Vol 125 (2) ◽  
pp. 267-275 ◽  
Author(s):  
G.C. Carlson ◽  
W.C. Schick ◽  
W.L. Talbert ◽  
F.K. Wohn
Keyword(s):  
Fission Products ◽  
Gaseous Fission
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