The ORNL Graphite Reactor operated very well during 1955. The downtime was low, only 8.6%. The fuel in the bonded slugs did not perform as well in 1955 as in 1954. Much of the trouble was undoubtedly due to growth of slugs which were not beta-transformed. It is known that some slugs had grown over 1/2 in. The automatic central system installed in 1954 continued to operate satisfactorily. The cooling system gave minor trouble when one of the 900-hp fan meters had to be replaced because of shorts in the rotor. The high radiation in the canal was the largest source of trouble. Approximately 55 tons of slugs discharged from the reactor in 1952 was sent to the Metal Recovery Plant. Enough slugs had raptured, due to their long exposure in the canal and reactor, to badly contaminate of water. Most of the contamination was removed by the end of the year, but the radioactivity which had soaked into the canal wells was enough to give high radiation fields. A solution to this problem was being sought at the end of the year. A study is under way on the possibility of increasing the flux of the ORNL Graphite Reactor …

Construction of the HRT reactor shield tank was completed, and the inside surfaces were painted. The roof structure for the tank is being assembled in preparation for an acceptance pressure test. Service piping and instrument lines are being installed in the central room area by ORNL craft forces. This work is approximately 50% complete. Fabrication of all temperature system components, except the blanket outer storage tanks, has been completed.

A preliminary chemical flowsheet is presented of a fluoride volatility process for recovering and decontaminating uranium from heterogeneous reactor fuels after dissolution in a fused salt. In laboratory work, a gross β decontamination factor of > 10 4 was obtained in the fluorination of a UF4-NaF-ZrF4 melt by passing the product UF6 through NaF at 650°C. The solubility of UF6 in molten NaF-ZrF4 was shown in kinetic studies to cause a lag in the evolution of UF6 from the fluorinator. Corrosion of nickel in the fluorination step appeared to be 2-4 mils/hr during the time that uranium was present. The average corrosion rate over the process as a whole was less than O.4 mil/hr. Earlier studies were reported in ORNL-1709 and 1877.

Technical report describing a rapid and quantitative radiochemical method for the analysis of neptunium (237). This method is based on the extraction of neptunium (IV) with thenoyl-trifluoracetone in xylene. Neptunium (237) is separated free from other alpha emitters and from non-radioactive interferences, and the method may be readily adapted to remote control. [From Abstract]

Technical report outlining the reconstitution of the Homogeneous Reactor Experiment Project (HRE) as the Homogeneous Reactor Project. Report covers the need for a broader developmental program to establish the feasibility of obtaining the potential advantages of homogeneous reactors for the production of fissionable materials and power. Details the ultimate objective of the ORNL program to provide the technical information required to determine the feasibility of a full scale plutonium power producing homogeneous reactor. [From Summary]

Quarterly technical report including reports on chemistry of source, fissionable, and structural elements, nuclear chemistry, radio-organic chemistry, chemistry of separations processes, chemical physics, radiation chemistry, and instrumentation. [From Abstract]

In-pile loop experiments L-2-15 and L-4-16 were two of a series designed to test the radiation corrosion of Zircaloy-2 and other possible reactor construction materials in UO2SO4 solutions under various conditions of radiation intensities, temperatures, solution compositions, and velocity flow past specimens.

Report issued by the Oak Ridge National Laboratory discussing quarterly progress made by the Homogeneous Reactor Program. Descriptions of progress and studies conducted are presented. This report includes tables, illustrations, and photographs.

Report summarizing ongoing nuclear work performed by the ORNL for the United States Army.

Report issued by the Oak Ridge National Laboratory discussing quarterly progress made by the Homogeneous Reactor Program. Descriptions of progress and studies conducted are presented. This report includes tables, illustrations, and photographs.