Molten Salt Reactor MSR

Molten Salt Reactor MSR

Historical Oak Ridge MSR Experiment

From the end of WW2, the MSRE competed against the Light Water Reactor LWR concept. Admiral Hyman Rickover and his chief engineer Alvin Radkowsky built the USS Nautilus nuclear submarine in just a few years. One of the first civilian LWRs, at Shippingport, was in fact a thorium breeder but the bred uranium233 was never separated out of the core.

The MSRE was a huge success. It operated at 8MW thermal for months at a time over five years. Hailed as a practical and safe machine, operators needed only trivial routines for protection.

The original dual fluids’ design was abandoned because of difficulties combining neutron economy and structural integrity. The MSRE was a single fluid machine at the expense of melt volume and processing complexity.

A planned reference 1 GWe MSR Breeder lost the race against the uranium Liquid Metal Fast Breeder simply because the US military needed plutonium for the missiles. The MSRE was terminated but several groups have revisited the concept.

A clean-up problem occurred at the original MSRE site. 20 years later gases leaked from the crystallised melt. However, developing methods for transforming nuclear flourides into geologically acceptable waste forms long before the onset of leaks should today be straightforward.


The MSR is today one of six reactor concepts in the GenerationIV.


The Kurchatov Institute is MSR world leader with a design making civilian energy out of LWR waste.


CNRS has recently reanalysed the MSRE and found the technology intrinsically safe from severe criticality accidents. The MSR needs a start charge and all available fissile materials can in fact be used.


Kazuo Furukawa proposes structural graphite design.