No abstract available

[en] A liquid metal cooled nuclear reactor is described which has an equal number of fuel sub-assemblies and sensing instruments. Each instrument senses temperature and rate of coolant flow of a coolant derived from a group of three sub-assemblies so that an abnormal value for one sub-assembly will be indicated on three instruments thereby providing for redundancy of up to two of the three instruments. The abnormal value may be a precurser to unstable boiling of coolant

[en] A method of monitoring a material for strains and cracks is described comprising attaching a stress detecting member to the material in such manner that elongation of the material imparts a tensile strain on the detecting member, transforming acoustic energy emissions from the member into electrical signals and displaying the signals on an oscilloscope. The stress detecting member may comprise a metallic tube containing compacted ceramic powder, such as Al₂O₃ or SiO₂. (author)

No abstract available

[en] The invention described relates to a liquid metal cooled fast breeder nuclear reactor in which the fuel assembly has an inner zone comprised mainly of fissile material and a surrounding outer zone comprised mainly of breeder material. According to the invention the sub-assemblies in the outer zone include electro-magnetic braking devices (magnets, pole pieces and armature) for regulating the flow of coolant through the sub-assemblies. The magnetic fields of the electro-magnetic breaking devices are temperature sensitive so that as the power output of the breeder sub-assemblies increases the electro-magnetic resistance to coolant flow is reduced thereby maintaining the temperature of the coolant outlets from the sub-assemblies substantially constant. (UK)

[en] A transducer for use in hostile environments has an externally threaded rod slidable in an internally threaded tube. The threads of rod and tube are of two-start form and define slots in which inductively coupled mineral insulated conductors are located, the conductors being of hairpin form secured at the ends of the rod and tube at the hairpin bend with the hairpin tails in the slots. End diaphragms make a sealed transducer in which the rod can move axially relative to the tube by one half of one pitch of the threads without straining the diaphragms. In a modification rod and tube are arranged to rotate relative to each other up to +-180⁰ which effectively also causes a one half pitch movement of the conductors. (author)

[en] Materials properties and procedures are presented for use in conjunction with the CYGRO5 computer program which calculates the performance of fuel rods. Agreement between calculated and measured diameter and length changes of test fuel rods containing duplex fuel pellets is demonstrated. A Zircaloy fast flux growth correlation for 51% coldworked cladding is also presented

[en] Fuel clusters for LMFBR reactors are designed so that should a flow restriction develop then the resultant local temperature rise will be held at a safe value at least until the outlet temperature transducer responds to the defective condition. (U.K.)

[en] A model has been devised for incorporating into the thermal feedback procedure of the PDQ few-group diffusion theory computer program the explicit calculation of depletion and temperature dependent fuel-rod shrinkage and swelling at each mesh point. The model determines the effect on reactivity of the change in hydrogen concentration caused by the variation in coolant channel area as the rods contract and expand. The calculation of fuel temperature, and hence of Doppler-broadened cross sections, is improved by correcting the heat transfer coefficient of the fuel-clad gap for the effects of clad creep, fuel densification and swelling, and release of fission-product gases into the gap. An approximate calculation of clad stress is also included in the model

No abstract available