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Demolition starts at ORNL’s Isotope Row
The Department of Energy reported last week that the demolition of Isotope Row at Oak Ridge National Laboratory has begun. The demolition work follows six years of targeted decontamination efforts and is expected to be completed by the end of this year.
Isotope Row is a group of 10 facilities constructed at ORNL between the late 1940s and early 1960s for the production of radioisotopes that were used in medical, industrial, scientific, and defense applications. Isotope production stopped in the early 1990s, leaving behind buildings with contaminated ventilation systems, hot cells, and other equipment requiring specialized cleanup operations and teardown.
Koshi Mitachi, Takahisa Yamamoto, Ritsuo Yoshioka
Nuclear Technology | Volume 158 | Number 3 | June 2007 | Pages 348-357
Technical Paper | Fission Reactors | doi.org/10.13182/NT07-A3846
Articles are hosted by Taylor and Francis Online.
In this paper, an improved design for a small molten-salt reactor (MSR) that uses neutron flux flattening, which is referred to as FUJI-U3, is proposed. This reactor is a 200-MW(electric) power reactor, and its core contains graphite (as the moderator) and fuel salt. The fuel salt is composed of ThF4 as the fertile material, 233UF4 as the fissile material, and LiF-BeF2 as both the solvent and heat transfer medium. A basic improvement in FUJI-U3 is the introduction of the design concept of a three-region core in order to avoid the replacement of graphite, which is achieved by reducing the maximum neutron flux. Since there is a limit for irradiation growth in graphite, this reduction in the maximum neutron flux contributes to a longer lifetime of the graphite. Based on calculations using the nuclear analysis code SRAC95 and the burnup analysis code ORIGEN2, it is concluded that there is no need to replace the graphite moderator of FUJI-U3 for 30 yr. Further, the chemical-processing interval of the fuel salt is studied for 7.5, 15, and 30 yr. An increase in this time interval will also contribute to reduce maintenance and cost.
