Improvement of Conversion Ratio of Thorium Fuel in LWR by Adding Neutron Absorber

2021 ◽  
Author(s):  
Taichi Takeishi ◽  
Satoshi Takeda ◽  
Takanori Kitada
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Capture Cross Section ◽  
Capture Rate ◽  
Base Material ◽  
Conversion Ratio ◽  
Resonance Capture ◽  
Capture Cross ◽  
Neutron Absorber ◽  
Capture Reaction

Abstract The reproduction factor of Th232 is high in the thermal energy range and there is a possibility to achieve the breeding in LWRs. However, it is necessary to improve the conversion ratio since the breeding is difficult in LWRs. The conversion ratio can be improved by suppressing capture rate of Pa233 and by promoting capture rate of Th232. In addition, these capture rates can be modified by adding neutron absorber. Therefore, the neutron absorber is focused for improving the conversion ratio in this study. The high resonance peaks of Pa233 capture cross section exist around 1∼100 eV. The resonance peaks of Th232 are higher than 10 eV. Thus, when the 1∼10 eV neutrons are suppressed in the fuel, the Pa233 resonance capture reaction is suppressed and the Th232 resonance capture reaction is promoted by neutron spectrum hardening. Therefore, six neutron absorbers that have high capture cross section peaks at 1∼10 eV were selected. The PWR pin cell calculations were carried out by Monte Carlo code MVP. The fuels are composed of a base material and an absorber. The base material is an oxidized fuel composed of U233(10 wt%), Th232(89.95 wt%), and Pa233(0.05 wt%). The amount of neutron absorber was adjusted so that the infinite multiplication factor becomes 1.33. The impact of adding neutron absorber on the reaction rate was evaluated. As the result, the hardening of the neutron spectrum leads increase of the capture rate of Pa233, and the capture rate of Th232 in the epithermal energy range is increased. The change of capture rate of Th232 is greater than that of Pa232. Therefore, the conversion ratio is found to be improved by adding neutron absorber.

THE PURIFICATION, DETERMINATION, AND NEUTRON CAPTURE CROSS SECTION OF ACTINIUM-227

1959 ◽  
Vol 37 (6) ◽  
pp. 1094-1103 ◽  
Author(s):  
M. J. Cabell
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Exchange Chromatography ◽  
Thermal Neutron Capture ◽  
Resonance Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section

Procedures are described for (a) the separation by ion exchange chromatography of submicrogram quantities of Ac227 from its daughters and (b) the absolute determination of Ac227 by measurement of the rate of growth of α-particle emission from an initially pure source. These procedures are utilized in the determination of the reactor and thermal neutron capture cross sections and the resonance capture integral of Ac227 by an activation method.Assuming 36.5 barns for the thermal neutron capture cross section of Co59, a value of σ2200 = 814 ± 13 barns has been obtained for Ac227. The resonance capture integral (from 0.5 ev to ∞) was found to be 1177 ± 19 barns relative to 48.6 barns for the resonance capture integral of Co59.

EFFECTIVE AND THERMAL NEUTRON CAPTURE CROSS SECTION AND RESONANCE CAPTURE INTEGRAL OF Pr-143

1959 ◽  
Vol 37 (8) ◽  
pp. 907-915 ◽  
Author(s):  
J. C. Roy ◽  
L. P. Roy
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Thermal Neutron Capture ◽  
Resonance Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Cross Section Formula ◽  
Effective Neutron

The effective neutron capture cross section,[Formula: see text]; the 2200 meters/sec neutron capture cross section, σ0, and the resonance capture integral, RI, of Pr-143 have been measured by an activation method. The values are: [Formula: see text], σ0 = 89 ± 10, and RI = 190 ± 25 barns respectively. The neutron fluxes have been measured with cobalt monitors. All these values have been calculated according to the Westcott convention, which has been outlined insofar as it can be applied to activation work.

THE THERMAL NEUTRON CAPTURE CROSS SECTION AND THE RESONANCE ABSORPTION INTEGRAL OF Th230 (IONIUM)

1958 ◽  
Vol 36 (8) ◽  
pp. 989-996 ◽  
Author(s):  
M. J. Cabell
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Neutron Capture ◽  
Half Life ◽  
Capture Cross Section ◽  
Resonance Absorption ◽  
Thermal Neutron Capture ◽  
Resonance Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section

The thermal neutron capture cross section and the resonance capture integral of Th230 have been determined by an activation method. Assumptions are made that the thermal capture cross section and the resonance capture integral of Co59 are 36.5 barns and 48.6 barns respectively, that the half-life of Th230 is 8.00 × 104 years, and that Th230 behaves as a 1/v absorber in the subcadmium region. Based on these assumptions values of σ2200 = 21.4 ± 0.3 barns and of 937 ± 32 barns for the resonance absorption integral (from 0.5 ev to ∞) have been obtained for Th230.The half-life of Th231 has been determined as 25.52 ± 0.01 hours.

scholarly journals Trends on major actinides from an integral data assimilation

2020 ◽  
Vol 239 ◽  
pp. 13002
Author(s):  
Gerald Rimpault ◽  
Gilles Noguère ◽  
Cyrille de Saint Jean
Keyword(s):  
Data Assimilation ◽  
Energy Range ◽  
Cross Section ◽  
Capture Cross Section ◽  
Critical Mass ◽  
Nuclear Data ◽  
Data Uncertainty ◽  
Capture Cross ◽  
Plateau Region ◽  
Integral Data

The objective of this work is to revisit integral data assimilation for a better prediction of the characteristics of SFR cores. ICSBEP, IRPhE and MASURCA critical masses, PROFIL irradiation experiments and the FCA-IX experimental programme (critical masses and spectral indices) with well-mastered experimental technique have been used. As calculations are performed without modelling errors (with as-built geometries) and without approximations with the TRIPOLI4 MC code, highly reliable C/E are achieved. Assimilation results suggest a 2.5% decrease for 238U capture from 3 keV to 60 keV, and a 4-5% decrease for 238U inelastic in the plateau region. For this energy range, uncertainties are respectively reduced to 1-2% and to 2-2.5% for 238U capture and 238U inelastic respectively. The increase trends on 239Pu capture cross section of around 3% in the [2 keV-100 keV] energy range come from a low PROFIL 240Pu/239Pu ratio C/E. For 240Pu capture cross section, the increase trend of around 4% in the [3 keV-100 keV] energy range goes in the same direction as the recent ENDF/B.VIII evaluation though at a much lower level. The nuclear data uncertainty associated to SFR ASTRID critical mass is reduced to 470 pcm.

Sign in / Sign up

Export Citation Format

Share Document