Yudha Satya Perkasa

Comparative studies on thorium fuel cycles of BWR with JENDL 3.2 and JEF 2.2 nuclear data libraries

Comparative studies of thorium fuel cycles in boiling water reactor (BWR) with JENDL 3.2 and JEF 2.2 nuclear data libraries have been performed. The once through cycle (OTC) and the all heavy metals (HMs) confining scenarios were evaluated. In this study, we have utilised the time independent fuel burnup scheme, that we called equilibrium burnup. OTC case with JEF 2.2 results in the higher required U-233 concentration for criticality compared to that of JENDL 3.2. In contrast, the required U-233 concentration for criticality becomes smaller for the all HMs confining case with JEF 2.2 compared to that of JENDL 3.2. Conversion ratio increases with the boosting of void fraction for both scenarios of the two nuclear data libraries. JENDL 3.2 gives the harder neutron spectra compared to that of JEF 2.2 for both scenarios.

Implementation of New Fission Barrier Model in TALYS Code

This paper is aimed to calculate neutron induced fission cross section using TALYS nuclear reaction code by utilizing new fission barrier model parameter. The new fission barrier model is based on minimization method of action functional of deformed nucleus fission trajectory in configuration of space from ground state to the exit barrier. New fission barrier parameter that obtained from this new model will be fed into the TALYS code to calculate the fission cross section of Th-232 and U-238 through statistical method. The result shows a better agreement with ENDF data compared to that of ETFSI (Extended Thomas-Fermi and Strutinsky Integral) or Mamdouh model of fission barrier for energy between 2 and 10 MeV.

A classical approach in simple nuclear fusion reaction 1H2 + 1H3 using two-dimension granular molecular dynamics model

Molecular dynamics in 2-D accompanied by granular model provides an opportunity to investigate binding between nuclei particles and its properties that arises during collision in a fusion reaction. A fully classical approach is used to observe the influence of initial angle of nucleus orientation to the product yielded by the reaction. As an example, a simplest fusion reaction between 1H2 and 1H3 is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary 2He4 nucleus.

Neck curve polynomials in neck rupture model

The Neck Rupture Model is a model that explains the scission process which has smallest radius in liquid drop at certain position. Old fashion of rupture position is determined randomly so that has been called as Random Neck Rupture Model (RNRM). The neck curve polynomials have been employed in the Neck Rupture Model for calculation the fission yield of neutron induced fission reaction of 280X90 with changing of order of polynomials as well as temperature. The neck curve polynomials approximation shows the important effects in shaping of fission yield curve.

Prediction of natPb and 209Bi neutron induced fission cross section using TALYS for energy up to 200 MeV

In this work, neutron induced fission cross section of natPb and 209Bi that obtained using experimental method through white-spectrum neutron source measurement at CERN n_TOF facility has been evaluated theoretically using statistical formalism that integrated in TALYS nuclear reaction code. This calculation carried out up to 200 MeV considering some properties that involved in fission mechanism such as fission barrier, level density, and collective enhancement. This calculation is aimed to evaluate the validity of TALYS nuclear reaction code with its optical model implementation at energy range up to 200 MeV. The results then were compared with former experimental data and also with ENDF data.

Calculation of fission yield using fission barrier from optimal shapes of liquid drop model

Fission barrier parameter that obtained from the liquid drop model framework does not involve any optimal shapes that based on minimization of liquid drop energy at fixed volume and elongation. In this work, fission yield of 238U and 232Th have been calculated using TALYS nuclear reaction code by implementing fission barrier height that obtained from minimization of liquid drop energy without using any shape parameterization. Fission yield model that has been employed in this calculation was derived from multi modes of random neck rupture model (MM-RNRM) proposed by Brosa et. al. This model is based on Lawrence shapes of deformed nuclei at scission mechanism and has been integrated in TALYS code. The calculation results were compared with the fission yield from ENDF at 0.5 MeV, 10 MeV, and 14 MeV in both cases. The discrepancy between calculation results and ENDF data are probably due to invalid fission parameter that included in the input file.

Computational Approach in Determination of {sup 233}U and {sup 233}Th Fermi Energy

There are several methods to get Fermi energy such as hermit polynomial expansion and Wigner‐Kirkwood expansion, these are analytical method. In this paper will be discussed numerical approach of calculating Fermi energy of 233Th and 233U nuclei. Our work demonstrates the simple technique of determining Fermi energy.

Level Density Calculation using Collective Enhanced Parameter on Several Deformed Light Nuclei

Level density parameter (LDP) has been provided to calculate level density on several deformed light nuclei. These LDP are calculated using collective enhancement including rotational and vibrational ground state modes at neutron binding energy and obtained by equidistant method of collective coupled state bands each nucleus [1]. Level density from these calculation has been compared with other result from different model and found many agreement in their values.

Fission Cross Section Calculation Using TALYS Based on Two Different Level Density Models

Fission cross sections in statistical model of fission are calculated using one of important parameter such as transmission coefficients. This parameter calculated using optical model parameter and level density. There are several models of level density that can be used to predict fission cross section. They are Constant Temperature Model, Fermi Gas Model, Back‐Shifted Fermi Gas Model, and Generalized Superfluid Model. In this work, fission cross section would be calculated using two different model of level density, such as Constant Temperature Model Plus Fermi Gas and Generalized Superfluid Model on Th‐232 (n,f) fission reaction. Calculation result from two different model then would be compared with experimental data from ENDF B/VI. Analysis of result would lead to the conclusion of spesific characteristic for each model in every fission cases. This work has became a preliminary study to calculate fission cross section using different set of level density models. Further work will be implemented to ca...

Fission Cross Section and Fission Yield Calculation of Am‐241 (n,f), Th‐232 (n,f), and U‐235 (n,f) using TALYS

Nuclear data evaluation for fission cross section and fission yield had been performed by many investigators using different model approximation theoretically. These models are encapsulated and implemented into computer codes to perform more robust nuclear reaction data calculations. TALYS is one of most successful nuclear reaction codes that used to determine fission cross section and fission yield. In this paper, TALYS was used to calculate some fission reaction including Am‐241 (n,f), Th‐232 (n,f), and U‐235 (n,f). These calculations are performed using different set of reaction mechanism and optical model parameter adjustment, such as fission barrier parameter, level density parameter, transmission mechanism, and so on. Reaction mechanism and parameter adjustment are selected based on reaction characteristics to obtain more accurate and reasonable result. The accuracy of calculation result are heavily depends on the reaction mechanism selection and parameter adjustment. All obtained result will be com...