[en] The experimental work done to evaluate the performance of commercially available fire extinguishants and powders for sodium fires is described. Dry chemical powder with sodium bicarbonate base was found very effective. Another effective method of extinghishing fire by using perforated covered tray is also discussed. (auth.)

[en] The magnetic saturation method can be used to determine absolute delta ferrite content of an austenitic weld metal. This report describes an apparatus based on above method that has been developed at Reactor Research Centre. With this apparatus ferrite measurements can be carried out to an accuracy of +- 1% ferrite. The report also briefly reviews other methods of measuring absolute ferrite content. Results obtained with the apparatus developed at RRC are compared with results from metallographic method and ferritescope and from a similar equipment in another laboratory. (author)

[en] Multiple impurities of reactor sodium circuits and other sodium test loops detected by plugging indicators are discussed. Attempts have been made to identify the nature of these impurities by studying their precipitation kinetics and its comparison with published literature. It has been possible to identify impurities by studying the flow traces and comparing their characteristics with those available in the literature, thanks to detailed studies conducted by C.E.G.B., U.K

[en] Results of experiments carried out with sodium fires to develop extinguishment techniques are presented. Characteristics, ignition temperature, heat evolution and other aspects of sodium fires are described. Out of the powders tested for extinguishment of 10 Kg sodium fires, sodium bi-carbonate based dry chemical powder has been found to be the best extinguisher followed by large sized vermiculite and then calcium carbonate powders distributed by spray nozzles. Powders, however, do not extinguish large fires effectively due to sodium-concrete reaction. To control large scale fires in a LMFBR, collection trays with protective cover have been found to cause oxygen starvation better than flooding with inert gas. This system has an added advantage in that there is no damage to the sodium facilities as has been in the case of powders which often contain chlorine compounds and cause stress corrosion cracking. (M.G.B.)

[en] The Prototype Fast Breeder Reactor (PFBR) currently under design in India is a 500 MWe sodium cooled reactor plant of pool design. The reactor will have four heat transport loops in the primary as well as the secondary. The total primary coolant flow is expected to be 32000 cubic metres/hr and the total pressure drop in the circuit within 80 mic. Primary sodium will be circulated by four pumps immersed in the cold sodium pool (400 deg. C) and supported from the roof structure. This paper discusses the design of the primary sodium pumps with particular reference to cavitation performance requirements. An outline of the experimental programme for the hydraulic development is also given

[en] Plugging indicators have been used as impurity monitoring devices in liquid metal systems. Behaviour of impurities detected by plugging indicators in two different sodium systems is described. The impurity behaviour was studied in filtered sodium before the cold trap was set into operation. In the two systems, the impurities associated with higher temperature break were distinctly different. The low temperature break however, corresponded to oxide impurity as verified by chemical analysis. Attempts were made to identify the nature of impurities associated with the high temperature breaks by studying their rates of plugging the orifice and comparing them with the correlations reported in the literature. One of them is identified as hydride. It is concluded that the plugging indicators, although not specific to one impurity, give useful information on different impurities and are vital in cold trap operations. (orig.)

[en] The proceedings contains papers presented at the National Symposium on Pumping Equipment in Nuclear Industry and Thermal Power Plants held at Bombay during February 1994. Various aspects relating to pumps in nuclear plants, heavy water plants and thermal plants are discussed. The papers are grouped under the following headings: (1) Invited talk, (2) Design, (3) Pump design system interaction, (4) Testing, and (5) Operation and maintenance. Papers relevant to INIS are processed separately. (original)

[en] The paper outlines the problems of designing the top shield structure of fast reactor, which will essentially consist of two rotating plugs with eccentric housings in each. The plugs will contain shielding materials. The plugs should withstand an internal test pressure of 1 bar. At normal working conditions, the plug bottom will be around 400⁰C whereas the top will be maintained at 40⁰C. Considering each rotating plug as a pressure vessel, it has a unique structure. Three horizontal plates and four vertical shells form two chambers. The plates have an eccentric hole each. Vertical tubes traverse the height of the plug structure and are fixed at the two ends to the plates. The available literature does not provide means to analyse the stresses in the components; therefore simulated studies will be needed to design such structures. (author)

[en] Sodium, because of its good heat transfer and nuclear properties, is used as a coolant in fast reactors. It is also used largely as a reducing agent in pharmaceutical, perfumery and general chemical industries. Its affinity to react with air and water is a strong disadvantage. However, this is fully understood and the design of engineering systems takes care of this aspect. With several experimental and test facilities established over the years in this country and abroad, 'sodium technology' has reached a level of maturity. The design of sodium systems considering all the physical and chemical properties and the development work carried out in this country are broadly covered in this article. (author)

[en] Commercially available dry chemical powder (sodium bicarbonate based) was tested exhaustively on deep pool and medium scale pool fires. The efficacy of this powder was evaluated by comparing the quantity of powder required per unit weight of sodium and the quantity of powder required per unit surface area of sodium fire. Carbon monoxide levels were also measured. These investigations conclusively indicate the potential of this powder. (orig.)