Scientists at the Los Alamos National Laboratory measured the critical masses of square prisms of highly enriched uranium diluted in various X/
235
U with matrix material and polyethylene. The ...configuration cores were 22.86 and 45.72 cm square and were reflected with 8.13-cm-thick and 10.16-cm-thick side polyethylene reflectors, respectively. The configurations had 10.16-cm-thick top and bottom polyethylene reflectors. For some configurations, the Rossi-α, which is an eigenvalue characteristic for a particular configuration, was measured to establish a reactivity scale based on the degree of subcriticality. These experiments provided critical mass data in the thermal energy range for systems containing Si, Mg, Al, Gd, and Fe. The measured k
eff
from these experiments was compared with the calculated k
eff
from MCNP using ENDF/B-V and ENDF/B-VI cross-section data. The observed biases were +0.005 Δk and +0.008 Δk for Si, +0.0006 Δk and +0.008 Δk for Al, +0.0023 Δk for Mg, +0.004 Δk and +0.01304 Δk for Gd, and +0.0123 Δk and -0.00106 Δk for Fe.
The delayed neutron activity resulting from the fast induced fission of
235
U and
237
Np has been studied. The six-group decay constants, relative abundances, and absolute yield of delayed neutrons ...from fast fission of
235
U and
237
Np were measured using the Godiva IV fast assembly at the Los Alamos Critical Experiments Facility. The absolute yield measured for
235
U was 0.0163 ± 0.0008 neutron/fission. This value compares very well with the well-established Keepin absolute yield of 0.0165 ± 0.0005. The absolute yield value measured for
237
Np was 0.0126 ± 0.0007. The measured delayed neutron parameters for
235
U are corroborated with period (e-folding time) versus reactivity calculations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
5.
Pragmatism and Idealism Baggio, Guido; Brunson, Daniel J; Colapietro, Vincent ...
European journal of pragmatism and American philosophy,
2018, Letnik:
X, Številka:
2
Journal Article
