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Presents a new method for the numerical simulation of diffusion with phase‐change. The method is able to handle hysteresis and finite‐rate kinetics in the phase‐change reaction. Such phenomena are frequent in solid‐solid phase transitions. The model problem discussed concerns hydrogen migration and hydride precipitation in zirconium and its alloys, a problem of interest to the nuclear industry. With respect to previous ones, our method is the first to incorporate an implicit treatment of diffusion, thus avoiding mesh‐dependent stability limits in the time step. The CPU time can in this way be reduced by a factor of 10–20 in applications. Addresses, through numerical studies, convergence with respect to mesh refinement and reduction of the time step. Also reports on an application of the method to the simulation of laboratory experiments. Shows that the method is a powerful tool to deal with general phase‐change problems, extendable to other physical systems.

MANY of the corrosion problems in the nuclear energy field are similar to those found in more conventional industries, for instance the corrosion of structural steelwork, cooling towers and services. Such problems will not be dealt with here. Instead it is intended to outline some aspects of corrosion where nuclear engineering presents rather special problems. Some of the reasons for these special problems are outlined below.

The Symposium on Corrosion in the Nuclear Power Industry, held in Paris on October 19–20, 1961, was particularly concerned with corrosion in sheath materials. It was held at the Maison de la Chimie, organised by the Société de Chimie Industrielle, and formed the 16th manifestation of the European Federation of Corrosion.

HEAVY ATTENDANCES AT OUR FIRST CONVENTION. CORROSION TECHNOLOGY's first Convention can fairly be judged to have been an unqualified success. Of the 517 registered delegates, over 450 actually attended at the Central Hall, Westminster, and throughout the two days, when 13 papers were presented and discussed, the Hall seldom contained less than 300. Delegates included a fair sprinkling from overseas and the following countries were represented: Canada, Denmark, France, Germany, Holland, Italy, Norway, Portugal, Sweden, Switzerland, United States and the U.S.S.R.

Under this heading are published monthly news of recent professional appointments, industrial developments and business changes, etc.

Construction work is due to start next month on Hanker Siddeley's first export Jason, ordered by the Dutch Reactor Centre near Amsterdam

After a year's joint experimental research by the Pressed Steel Co. Ltd. and I.C.I. Ltd. (Paints Division), details have now been released regarding a new technique developed by these two companies for the automatic application of paint. This is the Electrocoat process, in which the metal to be coated is electrically charged as one of the electrodes in a tank containing water‐borne paint. It is said to possess advantages over conventional methods of paint application to complex shapes such as car bodies, domestic appliances, etc., and to give improved corrosion resistance. It provides the basis of an overall simplification in total painting processes.

Hydrogen pick‐up during corro‐sion of zirconium alloys. Several factors such as alloy composition, hydrogen content of the alloy, surface hydrides and hydrogen content of the water have been investigated for their effect upon the amount of hydrogen picked up by zirconium alloys during corrosion in 680°F. water. Metallic additions of nickel increase hydrogen pick‐up, antimony, chromium, and iron appear to decrease the hydrogen pick‐up, while the addition of tin has little or no effect. The hydrogen content of the metal (50 to 4,000 p.p.m.) or of the water (0 to 2 atm. of hydrogen pressure) does not appreciably change the amount of hydrogen picked up by the alloys covered in the report (B.M.I.X. 1380, price $0.75).

In the anticorrosion field the rise of zirconium has been remarkable, especially since the oxide zirconia was regarded for some years as the main industrial outlet as it became applied in furnace linings and in refractory crucibles. Zircon in precious stones was the sole use before this, yet a first move towards identifying zirconium came when Martin Klaproth, a most efficient analyst of his period, analysed zircon and noted the presence of a new element. While Humphry Davy failed to decompose zirconia during his work on electrolysis, Berzelius reduced a zirconium compound by reduction with potassium metal within a closed tube, thus preparing impure zirconium as a black powder.

Although a comprehensive review on the corrosion of alloyed uranium has previously been made no comparable account of the corrosion of unalloyed metal is available. Since such metal is still a possible fuel for some types of water‐cooled reactors, available information is summarised in this article. Protective coatings are also considered, since a mechanical barrier is the only known means by which unalloyed uranium may be protected from attack by high‐temperature water.