Neutronic design study of accelerator driven system (ADS) for Jordan subcritical reactor as a neutron source for nuclear research.
In this paper, a preliminary neutronic design study of an accelerator driven subcritical system for Jordan Subcritical Assembly (JSA) is presented. The conceptual design of coupling the JSA core with proton accelerator and spallation target is investigated, and its feasibility as a neutron source for nuclear research, and possibly for target irradiation and isotope production evaluated. 3D MCNPX model of the JSA reactor, the accelerator beam, and the Pb target was developed, based on actual reactor parameters. MCNPX calculations were carried out to estimate the absolute radial and axial neutron flux in the reactor, and to calculate the multiplication factor Keff and heat generated in the reactor. Numerical results showed an enormous increase in the neutron flux, by seven orders of magnitude, compared to the current JSA core design using Pu-Be source. In this research the results obtained are discussed and compared with those of the JSA, and do confirm the feasibility of utilizing the JSA as a viable nuclear research facility with adequate neutron flux.
Experimental validation of the neutronic parameters in the Jordan subcritical assembly
Abstract Following the construction of the Jordan Subcritical Assembly (JSA) on the campus of the Jordan University of Science and Technology (JUST); a detailed experimental study of the facility was performed to measure different reactor parameters. In this paper, the reactivity and activation reaction rate in JSA were determined experimentally and then validated with the calculated results from Monte Carlo Simulation Radaideh et al. (2018a). The reactivity and criticality analysis were implemented using the source jerk method, while the foil activation technique was used for activation reaction rate and flux characterization. The experimental subcritical reactivity in dollars was −5.498 ± 0.045 while k e f f for the facility was 0.96476 ± 0.00771. The multiplication factor calculated using Monte Carlo codes of JSA was 0.96553 ± 0.00002. In addition, it was found that the source jerk results had large uncertainties due to the counting error. 115In foils were used to measure the activation reaction rate. The absolute axial and radial reaction rates were measured by averaging the measured counts for three photo-peaks of 116mIn. The experimental results were validated by the calculated reaction rates from MCNP5. The error in the activation reaction rate measurements were dominated by the peak area measurement error. The calculated and measured activation reaction rate results demonstrated very good agreement with a maximum deviation of approximately 11% in both directions. In this work, the neutron source strength was experimentally determined using the foil activation technique. The value estimated for the source was 1.02 × 10 6 ± 0.9 % ( n / s ) which is very close to the reported value.
CORRIGENDUM: Capabilities of a DT tokamak fusion neutron source for driving a spent nuclear fuel transmutation reactor
The capabilities of a DT fusion neutron source for driving a spent nuclear fuel transmutation reactor are characterized by identifying limits on transmutation rates that would be imposed by tokamak physics and engineering limitations on fusion neutron source performance. The need for spent nuclear fuel transmutation and the need for a neutron source to drive subcritical fission transmutation reactors are reviewed. The likely parameter ranges for tokamak neutron sources that could produce an interesting transmutation rate of 100s to 1000s of kg/FPY (where FPY stands for full power year) are identified (Pfus ≈ 10-100 MW, βN ≈ 2-3, Qp ≈ 2-5, R ≈ 3-5 m, I ≈ 6-10 MA). The electrical and thermal power characteristics of transmutation reactors driven by fusion and accelerator spallation neutron sources are compared. The status of fusion development vis-a-vis a neutron source is reviewed.