Title: Sustainable criticality analysis of PCMSR fuel using thorium as sustainable fuel and low enriched uranium as starting fuel

Authors: Andang Widi Harto

Addresses: Engineering Physics Department, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia

Abstract: PCMSR is designed to utilise thorium. Thorium will be converted to fissile ²³³U. LEU will be used as initial fissile fuel to avoid the use of Pu or HEU. The criticality can be maintained by balancing the production and consumption of ²³³U, and the depletion of ²³⁵U. The composition of initial fuel is 6.3% mole of UF₄, 23.7% mole of ²³²ThF₄ and 70% mole of ⁷LiF. The initial uranium enrichment is 19% mole of ²³⁵U. The fuel composition and criticality will be analysed by solving the simultaneous nuclide balanced equations coupled with multi-group neutron diffusion equation. The calculations are performed for specific power of 9, 18, 27 and 36 MWth/(ton HM). The results show that the PCMSR can maintain its criticality for long-term operation (i.e. 100 years). The criticality depression is recognised at initial operation time and becomes more prominent as the specific power increases.

Keywords: PCMSR; passive compact molten salt reactors; thorium fuel; LEU starting fuel; sustainable criticality analysis; low enriched uranium; nuclear energy; nuclear power; long-term operations; simultaneous nuclide balanced equations; multi-group neutron diffusion equations.

DOI: 10.1504/IJNEST.2015.074098

International Journal of Nuclear Energy Science and Technology, 2015 Vol.9 No.3, pp.224 - 237

Received: 29 Apr 2015
Accepted: 11 Oct 2015
Published online: 08 Jan 2016 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article