There is a continuing high interest in the development of organic coolant technology for application to future Hanford reactors. In addition to the HAPO organic program, two other programs are being sponsored by the Atomic Energy Commission. These include the Naval Reactor program, aimed at a reactor for ship propulsion, and the Civilian Power Reactor program. Because of the similarity of the technical efforts in the three programs, an attempt is being made to establish effective liaison among the programs. To this end, a visit was made to several sites actively engaged in organic development work. These sites and their primary functions are detailed in this report.

Radiobiological studies were made to determine effects of radioactive effluents from the Hanford reactors upon the aquatic biota of the Columbia River and to evaluate related hazards. Data from studies completed between September, 1945, and December, 1955 are presented and interpreted. All forms of life were many times more radioactive than the water they inhabited. Some radioisotopes were much more readily accumulated than others in living organisms. Differences in the concentration of certain radioisotopes by various species of organisms and kinds of body tissue are described; and geographical, seasonal and annual fluctuations in the concentration of radioisotopes in organisms are discussed.

The following remarks are intended primarily to assist in the orientation of the PRP reactor control development program in a direction consistent with the basic objectives of the program as a whole, and to discuss certain aspects of particular control systems which have a bearing on the capabilities of the reactor with respect to these objectives.

Several studies of power recovery from Hanford pile effluents have been made, from which the conclusion can be drawn that, while recovery of power is feasible, it is costly because of the large volume of vapor which must be handled per kilowatt-hour of energy provided. This note is to call attention to the possibility of developing cheaper machinery than the conventional low-pressure turbine stages considered in previous studies through use of a water expansion cycle.

The desirability of employing leakproof process pumps for handling the corrosive and radioactive process solutions in the H.A.P.O. separations plants has led to the establishment of a program for the development and testing of packless pumps with particular emphasis on evaluation of commercially available units. One such pump, its operating characteristics and behavior, are described in this report.

Cluster fuel elements meet many of the requirements of high temperature recirculating water reactors and have several advantages over solid fuel elements. Operation at higher specific power levels for a given temperature limit are attainable because of the larger heat transfer surface. Failure of a single rod in cluster does not restrict coolant flow as severely as failure of a solid fuel element, hence the number and severity of stuck charges can be reduced.

The letter E. R. Irish/W. H. Swift to R.E. Burns and H. H. Hopkins, dated August 15, 1956, subject Plutonium Concentration Problems, requested information on corrosion of stainless steel, titanium, and tantalum in plutonium nitrate-nitric acid solution, with and without sulfate ion. Experimental conditions and results of tests designed to yield the requested information are given below.

Ultrasonic testing has been investigated as a possible non-destructive method for checking the bond integrity of certain type fuel elements. Equipment has been developed to inspect experimental fuel elements for various research programs. Circuits have been devised to discriminate the size of defects and to map the areas which are unbonded.

The objective of this investigation was to determine the feasibility of centrifugal casting to produce fuel element plates suitable for use in a power reactor. Preliminary investigations involving the centrifugal casting of metal plates suitable for use in a power reactor proved to be successful. Lead plates cast at medium speeds contained very few voids and exhibited a surface which conformed very closely to that of the mold.

From objectives: "The objectives of this investigation were to evaluate the hydraulic forces in the pulse column, and determine their effects on pulse column design."