Neutron fluences in lunar habitats

2015 ◽  
Author(s):  
Lawrence Heilbronn ◽  
Ashwin Srikrishna ◽  
Daniel Peffley
Keyword(s):  
Neutron Fluences

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.

Crystallographic Characterization of Dislocation Loops in Irradiated Tungsten

1968 ◽  
Vol 26 ◽  
pp. 290-291
Author(s):  
Robert C. Rau
Keyword(s):  
Electron Microscope ◽  
Ambient Temperature ◽  
Dislocation Loops ◽  
Polycrystalline Specimen ◽  
Post Irradiation ◽  
Neutron Fluences

Previous work has shown that post-irradiation annealing, at temperatures near 1100°C, produces resolvable dislocation loops in tungsten irradiated to fast (E > 1 MeV) neutron fluences of about 4 x 1019 n/cm2 or greater. To crystallographically characterize these loops, tilting experiments were carried out in the electron microscope on a polycrystalline specimen which had been irradiated to 1.5 × 1021 n/cm2 at reactor ambient temperature (∼ 70°C), and subseouently annealed for 315 hours at 1100°C. This treatment produced large loops averaging 1000 Å in diameter, as shown in the micrographs of Fig. 1. The orientation of this grain was near (001), and tilting was carried out about axes near [100], [10] and [110].

Neutron fluences and dose equivalents measured with passive detectors on LDEF

1996 ◽  
Vol 26 (6) ◽  
pp. 833-839 ◽  
Author(s):  
A.L. Frank ◽  
E.V. Benton ◽  
T.W. Armstrong ◽  
B.L. Colborn
Keyword(s):  
Neutron Fluences

Neutron fluences and doses behind shielded environments in space

2014 ◽  
Author(s):  
Lawrence Heilbronn ◽  
Lawrence Townsend ◽  
Chelsea Burnham ◽  
Hailey Green ◽  
Pi-En Tsai ◽  
...  
Keyword(s):  
Neutron Fluences

Irradiation creep of nano-powder sintered silicon carbide at low neutron fluences

2014 ◽  
Vol 455 (1-3) ◽  
pp. 73-80 ◽  
Author(s):  
T. Koyanagi ◽  
K. Shimoda ◽  
S. Kondo ◽  
T. Hinoki ◽  
K. Ozawa ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Irradiation Creep ◽  
Nano Powder ◽  
Neutron Fluences ◽  
Sintered Silicon

scholarly journals Study of Fiber Bragg Grating Samples Exposed to High Fast Neutron Fluences

2018 ◽  
Vol 65 (9) ◽  
pp. 2494-2501 ◽  
Author(s):  
G. Cheymol ◽  
L. Remy ◽  
A. Gusarov ◽  
D. Kinet ◽  
P. Megret ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Neutron Fluences

Effect of Additional Irradiation at Different Fluxes on RPV Embrittlement

2009 ◽  
Author(s):  
Kenji Dohi ◽  
Kenji Nishida ◽  
Akiyoshi Nomoto ◽  
Naoki Soneda ◽  
Hiroshi Matsuzawa ◽  
...  
Keyword(s):  
Neutron Flux ◽  
Solute Atom ◽  
Volume Fraction ◽  
Neutron Fluence ◽  
Three Dimensional ◽  
Atom Probe ◽  
Atom Clusters ◽  
Neutron Fluences ◽  
The Difference ◽  
Test Reactor

The effect of the neutron flux at high fluence on the microstructural and hardness changes of a reactor pressure vessel (RPV) steel was investigated. An accelerated test reactor irradiation of a RPV material, previously irradiated in commercial reactors, was carried out at the lowest possible neutron fluxes in order to obtain neutron fluences up to approximately 1×1020 n/cm2 (E>1MeV). State-of-the-art experimental techniques such as three-dimensional atom probe were applied to carry out advanced quantitative characterization of defect features in the materials. Results for the same material irradiated in both high and low flux conditions are compared. For neutron fluences above 6×1019 n/cm2 (E>1MeV) the difference in the neutron fluence dependence of the increase in hardness is not seen for any neutron flux condition. The volume fraction of solute atom clusters increases linearly with neutron fluence, and the influence of neutron flux is not significant. The component elements and the chemical composition of the solute atom clusters formed by the irradiation do not change regardless of the neutron fluence and flux. The square root of the volume fraction of the solute atom clusters is a good correlation with the increase in hardness.

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