Masters Theses

Keywords and Phrases

Monte Carlo N-Particle (MCNP); STAR CCM+; Two Fluid Reactor; Molten Salt Reactor


"A feasibility study of a two-fluid small modular molten salt reactor (MSR) with in core heat removal was performed. The initial fuel block dimension for the configuration was based on the Fuji MSR. The fuel was a mixed fluoride salt of density 3.25 g/cc, composed of 71 LiF - 16 BeF2 - 12 ThF4- 1 233UF4 molar percentages. The coolant salt was Li4(FLiBe) of density 1.94 g/cc. The work set out to establish whether or not such a reactor is thermodynamically feasible when optimized for various neutronics parameters. A Java based API was developed to facilitate the neutronics optimization of the reactor concept.

In the simulation studies that followed (performed in MCNP), it was established that the optimal block dimension and fuel volume fraction to support under-moderation requirements are 20 cm across flats and 0.15 respectively. Fuel channel diameters varied from 12 cm to 9 cm such that neutron leakage could be suppressed while maintaining a radial power peaking factor of 2.20. In all the simulations except for temperature reactivity calculations, the reactor was assumed isothermal at 900 K. The average temperature coefficient of reactivity was calculated as -5.87E-5 Δk/k-K.

Thermo hydraulic studies performed in STAR CCM+ revealed that complete in core heat removal cannot practically be achieved in a design purely optimized for neutronics. However, it was found that fractional heat removal ranging from 15% - 85% can be achieved with sufficient mass flow rates. Potential improvements necessary for complete in core heat removal are theorized and briefly discussed"--Abstract, page iii.


Alajo, Ayodeji Babatunde

Committee Member(s)

Usman, Shoaib
Castano Giraldo, Carlos Henry


Nuclear Engineering and Radiation Science

Degree Name

M.S. in Nuclear Engineering


Missouri University of Science and Technology

Publication Date



vii, 40 pages

Note about bibliography

Includes bibliographical references (page 39).


© 2014 Brandon James Lahmann, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Molten salt reactors -- Testing
Pressurized water reactors -- Emergency core cooling systems
Two-phase flow -- Mathematical models

Thesis Number

T 10847

Electronic OCLC #