Criticality Search of an Accelerator Driven System Using the ANET Code

Xenofontos Thalia,Nicolas Catsaros,Jorge Silva,Savva Panayiota,Melpomeni Varvayanni,Jacques Maillard

doi:10.4236/wjnst.2021.111004

Xenofontos Thalia, Nicolas Catsaros + Show 4 more

Open Access

https://doi.org/10.4236/wjnst.2021.111004

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Abstract

One of the most important safety parameters taken into consideration during the design and actual operation of a nuclear reactor is its control rods adjustment to reach criticality. Concerning the conventional nuclear systems, the specification of their rods’ position through the utilization of neutronics codes, deterministic or stochastic, is considered nowadays trivial. However, innovative nuclear reactor concepts such as the Accelerator Driven Systems require sophisticated simulation capabilities of the stochastic neutronics codes since they combine high energy physics, for the spallation-produced neutrons, with classical nuclear technology. ANET (Advanced Neutronics with Evolution and Thermal hydraulic feedback) is an under development stochastic neutronics code, able to cover the broad neutron energy spectrum involved in ADS systems and therefore capable of simulating conventional and hybrid nuclear reactors and calculating important reactor parameters. In this work, ANETS’s reliability to calculate the effective multiplication factor for three core configurations containing control rods of the Kyoto University Critical Assembly, an operating ADS, is examined. The ANET results successfully compare with results produced by well-established stochastic codes such as MCNP6.1.

Highlights

ANET (Advanced Neutronics with Evolution and Thermal hydraulic feedback) is an under development stochastic neutronics code, able to cover the broad neutron energy spectrum involved in Accelerator Driven Systems (ADSs) systems and capable of simulating conventional and hybrid nuclear reactors and calculating important reactor parameters
ANET results were compared to the results obtained by the Kyoto University Critical Assembly (KUCA) laboratory utilizing the well-established stochastic neutronics code MCNP6.1 and MCNPX [18]
The simulation of the proton beam and the spallation reaction were performed by FLUKA and afterwards the full neutronics analysis including the computation of the effective multiplication factor were made by ANET, using exclusively the relevant procedures for the standard stochastic estimators incorporated

Summary

Thalia et al DOI

The Accelerator Driven Systems (ADSs) are considered to be a potential and very practical candidate for attaining nuclear transmutation of high-level radioactive wastes, minor actinides and long-lived fission products They consist of two parts, i.e. an accelerator to create the proton beam which will impact a target to induce a spallation reaction and the conventional reactor core part. During ANET’s development, several tests using international benchmarks and data from various installations have been performed in order to validate its capability for reliable calculations of basic parameters of critical and subcritical reactor systems including ADSs, such as the multiplication factor, neutron fluxes as well as neutron reaction rates [14]. The present work focuses on the steady state ANET applicability to ADSs and in particular to its ability to inherently simulate the spallation process and compute the resulting neutron yield as well as the neutron multiplication factor of an operating ADS utilizing control rods

The Kyoto University Critical Assembly

Simulations

Conclusions