[en] The following subjects are covered: the basic CANDU fuel design, the history of the bundle design, the significant differences between CANDU and LWR fuel, bundle manufacture, fissile and structural materials and coolants used in the CANDU fuel program, fuel and material behaviour, and performance under irradiation, fuel physics and management, booster rods and reactivity mechanisms, fuel procurement, organization and industry, and fuel costs. (author)

[en] Unique properties, performance and evolution of CANDU fuel are described. The manufacturing conditions, uranium requirements, and fuel costs are discussed. The in-service performance of the fuel has been excellent and defect mechanisms and operating criterion are described. Evolutionary improvements in CANDU fuel and new fuel cycles such as plutonium and thorium are being explored to insure that the CANDU reactor remains competitive in the future. (author)

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[en] I will briefly describe how the original dimensions of the fuel bundle were defined and how that early designs of fuel evolved. I will also touch on some of the historical events of the materials and experiments which effected the fuel programme. Also how I became with Canada's Nuclear Fuel programme. (author)

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[en] This paper addresses some of the CANDU fuel's behaviour which we did or really did not know back then, in the late fifties and early sixties and how we tackled decisions on the various subjects associated with fuel, both real and imagined. (author)

[en] Significant improvements have been made in design of Zircaloy-2 UO₂ fuel for the Canadian power reactors. A replacement 82.5-mm-diameter 19-element bundle (∫λdθ 40 W/cm) for the Douglas Point reactor has been developed using a brazed split spacer design, instead of wire-wrap, thus preventing inter-element fretting of the sheath. Both wire-wrapped and brazed split spacer bundles have reached burnups in the range of 10 000 - 20 000 MWd/t U at heat ratings ∫λdθ 15 to 35 W/cm, with a maximum exposure of 1200 coolant days without failures in the NPD reactor. A 103.4-mm-diameter 28-element bundle (∫λdθ 42 W/cm) has been developed for the 500 MW(e) Pickering Station. Fission gas measurements have indicated a percentage release of less than 5% at ∫λdθ 35 W/cm to 20% at ∫λdθ 50 W/cm. The percentage release decreases with increased density in the range 10.3 to 10.7 and is independent of burnup up to 8000 MWd/t U. Deuterium pickup in operating Zircaloy-2 cladding, exposed to greater than 600 coolant days, has been low. For the Gentilly 250-MW(e) BLW, a fuel bundle (∫λdθ 48 W/cm) hasbeendevelopedto operate at 16% and greater exit steam qualities. Fuel bundles are being tested in the range 40 to 60 W/cm. A cold void volume has been designed into the elements by means of hollow end caps to avoid internal gas pressure exceeding coolant pressure. In-reactor heat transfer tests up to 45% exit quality have shown that the fuel will have a critical power ratio of 1.5. Fuel has been operated at 50% greater than critical power for three hours without significant deterioration of the sheath. Endurance test on fuel bundles under single-phase coolant conditions, and velocities up to 8.8 m/s, have shown that fretting is within acceptable limits. No fretting has been observed with in-pile fuel bundle tests under two-phase coolant conditions at mass velocities up to 440 g/cm² per s. Future programmes for the BLW and PHW reactors will be to increase the fuel rating and the fissile material density. Operation of the BLW fuel elements athigh(500°C) surface temperatures will be attempted. In the longer term, both plutonium and thorium containing fuels will be investigated. (author)

[en] Over 99.5 pc of the 45,000 UO₂-in-Zircaloy fuel assemblies irradiated in the Candu power reactors have performed as designed. The few assemblies that developed leaks in operation were simply discharged from the reactors by the fuelling machines, which normally operate with the reactor at power. Since even these assemblies had already delivered much of their design energy before they were discharged, the resulting loss of burnup has been small. This very satisfactory operating experience has been achieved despite progressive increases in the performance targets, coinciding with steady decreases in total fuel cost, over the Candu fuel's 15-year history. This paper serves to up-date the already presented information and to report experience with the newer Pickering and Gentilly reactors (among all Candu reactors, Gentilly reactor is unique in using light water as coolant). Lessons learned show that close monitoring of the performance of fuel in power reactors allows problems to be identified at an early stage: provided that appropriate facilities and personnel are available, these problems can be solved before they limit the reactor's performance

[en] Considerable progress has been made in the study of proton-emitting nuclei since the first observation of direct proton emission nearly half a century ago. This has led to improvements in our understanding of this rare decay process and provided invaluable nuclear structure data far from the valley of beta stability. This paper reviews the implications of some recent results for exotic iridium, rhenium and tantalum isotopes and considers prospects for future experimental studies of proton-emitting nuclei located at and above the N = 82 neutron shell closure. (authors)