Computational design and characterization of a subcritical reactor assembly with TRIGA fuel

• Published in: Nuclear engineering and technology Vol. 51; no. 2; pp. 337 - 344
• Main Authors: Asuncion-Astronomo, Alvie, Stancar, Ziga, Goricanec, Tanja, Snoj, Luka
• Format: Journal Article
• Language: Korean
• Published: 2019
• Subjects: TRIGA fuel; Subcritical assembly; MCNP; Nuclear reactor
• ISSN: 1738-5733; 2234-358X

The TRIGA fuel of the Philippine Research Reactor-1 (PRR-1) will be used in a subcritical reactor assembly (SRA) to strengthen and advance nuclear science and engineering expertise in the Philippines. SRA offers a versatile and safe training and research facility since it can produce neutrons through nuclear fission reaction without achieving criticality. In this work, we used a geometrically detailed model of the PRR-1 TRIGA fuel to design a subcritical reactor assembly and calculate physical parameters of different fuel configurations. Based on extensive neutron transport simulations an SRA configuration is proposed, comprising 44 TRIGA fuel rods arranged in a $7{\times}7$ square lattice. This configuration is found to have a maximum $k_{eff}$ value of $0.95001{\pm}0.00009$ at 4 cm pitch. The SRA is characterized by calculating the 3-dimensional neutron flux distribution and neutron spectrum. The effective delayed neutron fraction and mean neutron generation time of the system are calculated to be $748pcm{\pm}7pcm$ and $41{\mu}s$, respectively. Results obtained from this work will be the basis of the core design for the subcritical reactor facility that will be established in the Philippines.