My father's contribution to fluid salt reactor technology

I wrote this post in honor of my father's 97th birthday. I discussed it with him on January 27th of last year. He had been in declining health during the previous year, and later in the day I went to the hospital for the last time. He died on January 31, 2009. This post was not meant as a summery of his contribution to the nuclear industry. In fact my father was a true pioneer in nuclear energy, he made numerous an important contributions in areas that had nothing to do with molten salt reactor chemistry. But with the revival of interest in the MSR approach, I wanted to point out my father's very real legacy. I am reposting in honor of my father's 98th birthday. He is missed by many people who were touched by him during his long life.

My father, Dr. Charles J. Barton, Sr. had his 97th birthday last Friday. I wish to make note of his many contributions to fluid salt reactor technology, while he is still with us. He was in on the ground floor of LFTR/MSR development.

I suspect, but it is now beyond verification that my father was consulted on the viability of the molten salt concept, and after a literature review, he supported the project. It is likely that he has forgotten the role he played in the inception of project to develop a molten salt reactor, but typically in Warren Grimes group my father was the one who did the literature reviews. Since Alvin Weinberg says the asked Grimes for his opinion, Grimes would have asked my father to do a literature review, and then sought his opinion. Grimes would have reported back to Weinberg on the basis of what my father found in the literature. At any rate my father began his research on molten salt chemistry in early July 1950. He was administratively transferred from Y-12 to X-10 (ORNL) at the same time. But he continued to work at Y-12, and indeed did not move to X-10 in 1959.

The ANP project had originated at K=25, the gaseous diffusion plant. There was by 1950 a rationalization of research in Oak Ridge, with the K-25 engineering group that had done the initial Aircraft Nuclear Propulsion research, as well Grimes Y-12 materials chemistry group. My father's initial assignment was the chemistry of Fluoride Salt carriers and fuels. Research conducted under my father's supervision showed that a NaF, ZrF4, UF4 salt mixture would make a satisfactory although in some respects not ideal core fluid. Zirconium was available because my father's earlier research at Y-12 had lead to an industrial process for the separation of Zirconium from Hafnium. Because of the danger of working with Beryllium, it was decided to defer use of a superior formula also involving the use of Lithium7. The more satisfactory salt mixture (LiF, BeF2, UF4) had already been identified, but its use was delayed until the molten salt reactor experiment. My father and Warren Grimes held the patent on the NaF, ZrF4, UF4 salt mix. The LiF, BeF2, UF4 mix was not patentable, because the use of BeF2 had been suggested by an outside contractor. So my father must be credited with pioneering research on the two most commonly mentioned fluid salt formulas.

In addition by the mid 1950's my father was also researching chloride salt chemistry, a separate molten salt track that had the potential of eventually yielding a molten salt fast breeder.

Shortly after my father was assigned to investigate the chemistry of plutonium in molten salt reactors. He successfully demonstrated that plutonium could be used as a fuel in MSRs.

By the end of the 1950's he was also investigating the chemistry of extracting protactinium from reactor salts. However that research temporarily stopped when in 1960 he began to assist George Parker on in nuclear safety research. In 1962 my father was asked to research the use of a Molten Salt blanket for the extraction of usable energy from thermonuclear reactors. This research appears to have been pioneering, and although my father did not research thus breeding of thorium in the blanket, this was an obvious next step. Finally in 1964 my father was asked to continue his interrupted protactinium extraction research project. This he continued to do until 1967 when the project was removed from the reactor chemistry division, and transferred to the Chemical Engineering division. That division assigned considerably more researchers to the protactinium project than my father had in support of his research.

At any rate we end up with the following liquid salt credits: for my father:
1. Pioneering research on the NaF, ZrF4, UF4 salt mixture concept, and shared credit for the final reactor formula.
2. Shared pioneering research on the LiF, BeF2, UF4 salt mix, and the creation of the final formula.
3. Pioneering research on Chloride salts for fast reactor use.
4. Pioneering research on the use of plutonium as a MSR fuel.
5. Pioneering research on the extraction of protactinium from blanket and core salts.
6. Pioneering research on the use of molten salts in a blanket to extract power from a thermonuclear reactor.