15 research outputs found
Ultraslow Wave Nuclear Burning of Uranium-Plutonium Fissile Medium on Epithermal Neutrons
For a fissile medium, originally consisting of uranium-238, the investigation
of fulfillment of the wave burning criterion in a wide range of neutron
energies is conducted for the first time, and a possibility of wave nuclear
burning not only in the region of fast neutrons, but also for cold, epithermal
and resonance ones is discovered for the first time.
For the first time the results of the investigation of the Feoktistov
criterion fulfillment for a fissile medium, originally consisting of
uranium-238 dioxide with enrichments 4.38%, 2.00%, 1.00%, 0.71% and 0.50% with
respect to uranium-235, in the region of neutron energies 0.015-10.0eV are
presented. These results indicate a possibility of ultraslow wave
neutron-nuclear burning mode realization in the uranium-plutonium media,
originally (before the wave initiation by external neutron source) having
enrichments with respect to uranium-235, corresponding to the subcritical
state, in the regions of cold, thermal, epithermal and resonance neutrons.
In order to validate the conclusions, based on the slow wave neutron-nuclear
burning criterion fulfillment depending on the neutron energy, the numerical
modeling of ultraslow wave neutron-nuclear burning of a natural uranium in the
epithermal region of neutron energies (0.1-7.0eV) was conducted for the first
time. The presented simulated results indicate the realization of the ultraslow
wave neutron-nuclear burning of the natural uranium for the epithermal
neutrons.Comment: 35 pages, 19 figures (v2: Fig12 and some misprints in the text are
fixed
Fukushima plutonium effect and blow-up regimes in neutron-multiplying media
It is shown that the capture and fission cross-sections of 238U and 239Pu
increase with temperature within 1000-3000 K range, in contrast to those of
235U, that under certain conditions may lead to the so-called blow-up modes,
stimulating the anomalous neutron flux and nuclear fuel temperature growth.
Some features of the blow-up regimes in neutron-multiplying media are
discussed.Comment: 15 pages, 8 figures. (v2: numerous corrections and style
improvements). arXiv admin note: substantial text overlap with
arXiv:1207.369
On some fundamental peculiarities of the traveling wave reactor
On the basis of the condition for nuclear burning wave existence in the
neutron-multiplicating media (U-Pu and Th-U cycles) we show the possibility of
surmounting the so-called dpa-parameter problem, and suggest an algorithm of
the optimal nuclear burning wave mode adjustment, which is supposed to yield
the wave parameters (fluence/neutron flux, width and speed of nuclear burning
wave) that satisfy the dpa-condition associated with the tolerable level of the
reactor materials radioactive stability, in particular that of the cladding
materials.
It is shown for the first time that the capture and fission cross-sections of
U and Pu increase with temperature within 1000-3000K range,
which under certain conditions may lead to a global loss of the nuclear burning
wave stability. Some variants of the possible stability loss due to the
so-called blow-up modes (anomalous nuclear fuel temperature and neutron flow
evolution) are discussed and are found to possibly become a reason for a
trivial violation of the traveling wave reactor internal safety.Comment: 44 pages, 19 figures, 2 table
KamLAND-experiment and Soliton-like Nuclear Georeactor. Part 1. Comparison of Theory with Experiment
We give an alternative description of the data produced in the KamLAND
experiment, assuming the existence of a natural nuclear reactor on the boundary
of the liquid and solid phases of the Earth's core. Analyzing the uncertainty
of antineutrino spectrum of georeactor origin, we show that the theoretical
(which takes into account the soliton-like nuclear georeactor) total reactor
antineutrino spectra describe with good accuracy the experimental KamLAND-data
over the years of 2002-2007 and 2002-2009, respectively. At the same time the
parameters of mixing ({\Delta}(m21)^2=2.5\cdot 10^-5 eV^2,
tan^2{\theta}12=0.437) calculated within the framework of georeactor hypothesis
substantially differ from the parameters of mixing ({\Delta}(m21)^2=7.49\cdot
10^-5 eV^2, tan^2{\theta}12=0.436) obtained in KamLAND-experiment for total
exposure over the period of 2002-2009. By traingulation of KamLAND and Borexino
data we have constructed the coordinate location of soliton-like nuclear
georeactors on the boundary of the liquid and solid phases of the Earth core.
Based on the necessary condition of full synchronization of geological
(magnetic) time scale and time evolution of heat power of nuclear georeactor,
which plays the role of energy source of the Earth magnetic field, and also the
strong negative correlation between magnetic field of the solar tachocline zone
and magnetic field of the Earth liquid core (Y-component) we have obtain the
estimation of nuclear georeactor average heat power ~30 TW over the years
2002-2009.Comment: 50 pages; 17 figures; 1 table. A substantially revised, corrected and
enhanced editio