[en] The invention relates to a method for preparing a liquid mixture of isomers of bis-phenoxy-phenyl-methane. That method is characterized in that it comprises the steps of inducing the isomeric change of bis-phenoxy-phenyl-methane in the presence of a Friedel-Crafts catalyst in an aromatic solvent likely to be involved in the transfer reaction, then separating, in known fashion, the thus obtained mixture of bis-phenoxy-phenyl-methane. The product as obtained can be used as coolant fluid

[en] Between January and May 1977 a prolonged leak of organic coolant occurred from the Whiteshell Nuclear Research Establishment's nuclear reactor, and a minimum of 1450 kg of coolant entered the Winnipeg River and was deposited on the riverbed. The level of radioactivity associated with this coolant was low, contributing less than 0.2 μGy (0.02 mrad) a year to the natural background gamma radiation field from the riverbed. The concentration of coolant in the water samples never exceeded 0.02 mg/L, the lower limit of detection. The mortality of crayfish, held in cages where the riverbed was covered with the largest deposits of coolant, was not significantly different from that in the control cages upstream of the outfall. No evidence of fish kill was found. (author)

[en] The described coolant consists of a mixture of n-alkanes of chain lengths between 12 and 20 carbon atoms and of up to 30 weight per cent of compounds containing aromatic rings, e.g., terphenyls, hydroterphenyls, biphenyl, alkyl aromatics

[en] The potential for organic coolants in nuclear reactors and other use in the Whiteshell WR-1 reactor in Canada are reviewed. The properties of the organic coolant HB40 and its use in an LPR (Low Pressure Reactor) are described. The differences between an LPR and a PWR, and the major features of an LPR are described. The economic advantages of organic coolants are also discussed. (U.K.)

[en] The solubility problems raised by some components of the polymeric residue of irradiated polyphenolic coolants, which make it necessary to operate with very small samples, have been solved by means of a differential cryoscopic technique using a thermoelectric thermometer (thermal) as sensitive element. The method is based on the direct measurement of the difference between the freezing points of the investigated solution and of a reference solution whose concentration may be changed at will. The change of Δ V (mV) versus c(molal) is linear, the equivalent point being determined either analytically or graphically depending on the required accuracy. The method has been tested by measurements on pure polyphenyls, using diphenyl ether as solvent. It has been also applied to the main prospective coolants for the DON reactor. Working with 10² molal solutions the accuracy is better than ± 2 per cent. (Author) 2 refs

[en] Contamination can be controlled in chemical analyses by the use of suitable containers, cleanliness, appropriate apparatus design, isolation of the analysis process from air, and in-situ analysis. Examples based on analyses of organic reactor coolant, metals, and underground natural waters are given. (LL)

[en] The coolant chemistry during the X-726 fuel irradiation is described. This was the first fuel irradiation in HB-40. The fouling potential remained ≤ 0.2 μg.cm^-2.h^-1 throughout the test and other impurities were acceptably low. The high boiler content increased from 2 to 12% during the irradiation. No problems were encountered during the changeover from Santowax OM to HB-40. (author)

[en] Twenty scoping experiments were performed to investigate the behavior of nominally 0.5 g molten lithium drops when released into 0.7 L of the organic coolant Therminol 66 at local atmospheric pressure using a vortex insertion technique. Diagnostics consisted of video and photographic imaging and several chemical analyses. Six coolant/Li temperature pairs were used: 300/300; 300/530; 300/770; 464/530; 600/530 and 600/770, all nominal in K. Because the coolant: Li weight ratio was 10³, only rapid (∼0.5 s) quenching reactions could be studied when T_Li > T_c; when T_Li ≤ T_c, however, both rapid and slower (min) interactions could be investigated. In none of the experiments was there any indication of (a) a vigorous, self-sustaining chemical reaction between the lithium and the organic coolant, or (b) the formation of water-insoluble debris, in particular carbon. This work confirms the benign behavior at similar temperatures reported earlier by others

[en] The results of measuring the viscosity of ditolylmethane coolant (ν) have been analyzed to find the approximate relation, allowing to determine the concentration of high-boiling products (Csub(Hb)), using results of ν measurements. A simple approximate formula of the form: ν=exp(1.599+0.03924Csub(HB))[mm²/s] has been found which describes the experimental data array at 20 deg C and Csub(HB) ranging from 0 to 20% with a standard mean-square deviation of 4.3%

[en] Physical property data are summarized for organic coolant mixtures formed from the terphenyl feed mixture, Santowax OM and from the hydrogenated terphenyl feed mixture HB-40. Particular attention was given to the coolant mixtures of stationary composition, including about 30% high boiler decomposition products, formed by prolonged use under reactor conditions. Properties depended to some extent on the manner of operation of the system. (author)