Two chapters that were in the previous edition of Shreir and that relate to specialist alloys of iron and nickel have been combined to form this chapter. The first, by Flint and Oldfield, discusses the general corrosion behavior of Fe–Ni alloys, while the second, by Dautovich, discusses the nature and corrosion properties of maraging steel. No attempt has been made to update the chapters. However, it is felt that they provide information that is otherwise difficult to obtain elsewhere, and therefore, the editors are pleased to retain them in this form.

An overview of the various tritium research and operational activities in Canada is presented. These activities encompass tritium processing, tritium measurement, tritium interactions with materials, and tritium health and safety, and are applied to the operation of both domestic and international facilities in support of nuclear fission and fusion.

Progress is reported on a study to define a “pilot plant” to demonstrate the production of high grade heat in a fusion power plant configuration at the lowest possible capital cost. We are considering several driven reactor tokamak designs with fusion power production levels in the 15–50 MWth range, using demountable copper coils. We conclude that it is acceptable for such facilities to be net consumers of electricity as a trade-off to achieve low capital cost, which we estimate to be in the $1 billion range. These designs are based on currently accepted physics models. Even lower cost designs may be possible, if we depart somewhat from the current physics database.

Considering the experiments which have been listed as convincing in Fig. 1, two groups have provided evidence for the existence of an unidentified small heat source. The low level of heat that is produced in the Texas A&M and Stanford work, can most plausibly be explained by a chemical explanation. The absence of helium and neutrons is consistent with this explanation, however, the high tritium level observed by Texas A&M is not.

The development of fusion as a future energy alternative continues to be a matter of international importance. Research on controlled thermonuclear fusion began in the 1950s, but the commercial application of this technology may be as far away as 2020 or longer. However, in the 1990s, both in Europe and the United States, experiments are scheduled to demonstrate energy breakeven with about 30 MW of fusion power, and international planning and conceptual design are now under way for a 1,000-MW ignition experiment to begin operation at the end of the 1990's. With the final breakeven experimental campaigns, the facilities and operations will undertake a limited nuclear transition as the machines are fueled with small quantities of tritium. Fusion reactions will activate structures, and additional shielding and diagnostic hardening will be required. The future ignition facility will be as large and as costly and will require similar nuclear considerations to a full-scale nuclear fission power plant. The Canadian Fusion Fuels Technology Project (CFFTP) was established in 1982 as one of the elements of Canada's National Fusion Program. CFFTP has undertaken to apply and extend selected nuclear technologies for use in fusion projects abroad. Carefully selected R&D programs, the provision of key staff and reliance on the skills and knowledge base within the Canadian nuclear industry have resulted in broad recognition and acceptance of Canada's involvement in important joint tasks. This involvement is expected to continue as the major programs abroad engage in tritium/nuclear design and operation. Keywords: fusion energyalternate energyCanadaCanadian Fusion Fuels Technology Project (CFFTP).

The Canadian Fusion Fuels Technology Project was formed in 1982 to undertake research and engineering in Tritium Technology and robotics for Fusion applications. The total current program is about $10 million per annum including contributions from subcontractors and cost sharing with external projects. The present paper gives an overview of the scope of the program and focuses on the safety related work.

The corrosion performance of copper has been evaluated in saline groundwaters. Immersion tests in deaerated solutions at 150°C have been performed with exposures lasting to 180 days. The long-term corrosion rate under these conditions was less than 10 μm/yr for all water compositions tested. General pitting was absent, but some crevice corrosion was noted. Electrochemical tests were performed over a 40-day period at 75°C. In de aerated solutions at this temperature the long-term corrosion rate was generally less than 10 μm/yr and some pitting was observed. In aerated solutions, however, a rate of 70 μm/yr was observed. These results suggest that copper would have sufficient corrosion resistance for use as a container material, however, further investigation is still required to quantify pitting kinetics. Résumé La résistance du cuivre à la corrosion a été évaluée avec des eaux salines souterraines. Des tests d'immersion durant jusqu'à 180 jours ont été effectués avec des eaux désaerées a 150°C. Pour to utes les solutions aqueuses utilisées dans ces essais à long terme, le taux de corrosion observé est inferieur à 10 μm/an. D'une façon générale, on observe aucune piqûre mais un peu de corrosion fissurante. Des tests électrochimiques d'une durée de 40 jours ont été effectués a 75°C. Pour des eaux desaerees, on observe quelques piqûres mais un taux de corrosion généralement inférieur à 10 μm/an. Par contre, pour des eaux aérées, on a observé un taux de corrosion de 70 μm/an. Ces résultats indiquent que le cuivre aurait une résistance à la corrosion suffisante pour être utilisé comme matériau de fabrication de réservoirs, cependant, une recherche plus poussée est necessaire pour l'évaluation de la cinétique de corrosion par piqûres.

Laboratory corrosion studies of the steam generator tubing materials Inconel Alloy 600, Incoloy 800, and Monel 400 have been performed. Tests were carried out at 288°C on tubing sections that were internally heated to provide heat transfer through the tube wall. In exposures to lakewater, pitting attack was apparent in crevice regions and under deposits. A crystallographic pitting morphology was usually found on Alloy 600 and Incoloy 800 and was likely caused by acid chloride attack. Attack on Monel 400, however, was mainly intergranular in nature. In tests performed on Alloy 600 in solutions of specific anions, attack was found to occur in silicate solutions in the presence of magnetite sludge. Although these tests were performed in solutions more concentrated than those likely to be found in operating steam generators, they do suggest that strict adherence to secondary water chemistry specifications is required to protect against the possibility of pitting corrosion. In comparing the performance of three alloys tested, Incoloy 800 appears to exhibit greater resistance to pitting corrosion than Alloy 600 or Monel 400 in lakewater environments.

A test technique has been developed to determine the stress intensity for slow crack growth in hydrogen precharged steels. Measurements on several grades of maraging steel and a 300M steel show that hydrogen contents on the order of 2 ppm reduce the stress intensity for slow crack growth by 50 pct or more of theK Ic values. At equivalent hydrogen contents the 300M steel was more severely embrittled than the mar aging steels. Comparison of the present results with aqueousK Iscc data indicates that the amount of hydrogen “picked up by the steels in stress corrosion increases with increasing yield strength.

The intermetallic compound TiNi has been observed to undergo a martensitic transformation preceded by a second-order diffusionless transformation. Electron metallographic and X-ray evidence is presented in support of this view. Crystal structure data are presented for the displacive transformation products. The possibility of defect ordering in the parent phase is discussed.