Fast Reactor Plants Research Articles

Operating experience of desalination units in Schevchenko

The paper discusses the main disign and process features of desalination units of three types built at the largest in the USSR system in Schevchenko and operated at the atomic thermoelectric fast reactor plant. Data are also presented on the experience gained in operation of natural and forced circulation evaporators, adjustment of specially designed circulation pumps and initial sea water cleaeration, impronement of non-condensing gas removal system and method of preventing scale from depositing in regeneration heaters through carbon dioxide stabilization of sea water and in evaporators through the introduction of chalk.

Liquid metal cooled fast breeder reactor development and its mechanical-structural requirements and problems

After a brief survey about the history and the present status of liquid metal cooled fast reactors the paper explains the specific properties of liquid sodium and the principal layout of sodium-cooled fast reactor plants. The most important mechanical-structural requirements and problems are broken down into fields of sodium containment, core structure, and special mechanisms to be operated in sodium and the cover gas atmosphere. With respect to sodium containment, the main difficulties raised concern mechanical and thermal cycling stresses during transient operational conditions and creep effects appearing in the walls which are subjected to high temperatures. The requirements for the core structure have become extremely complicated due to swelling of the structural material at high neutron doses. In the field of mechanisms special attention must be given to all questions of material pairing with respect to diffusion welding, friction and wear.

Characteristics of the Aerosol Produced from Burning Sodium and Plutonium

Safety analysis of sodium-cooled plutonium-fueled fast reactor plants must be concerned with the possibility of fires involving these materials. Design of an air cleaning system for such a facility requires basic data defining the aerosol characteristics of sodium and plutonium released during a fire. Size characteristics of the aersol produced during sodium and plutonium fires were determined for different atmospheres ranging from 20.8% oxygen, 79.2% nitrogen to 100% nitrogen. The aerosol produced by burning gram quantities of sodium was compared with that produced by a fire involving 600 lb of sodium. Sodium aerosol count median diameter ranged from 0.07 to 1.09 µ and was independent of oxygen concentration. Small and large scale fires produced an aerosol with comparable size characteristics. Plutonium aerosol count median diameter ranged from 0.02 to 0.09 µ and was also independent of oxygen concentration. When plutonium alloy was burned under reduced oxygen conditions, the fraction airborne ranged from 2. × 10-7 to 4. × 10-6. Fires involving plutonium alloy and sodium together produced airborne plutonium-sodium ratios ranging from 0.34 to 0.008%.

Frequency Response of Linear Counterflow Heat Exchangers

Expressions for the frequency response of linear counterflow heat exchangers are derived in non-dimensional terms. Calculated responses for a number of cases are presented in the form of complex plots. The effect of sinusoidal variation of inlet temperature is to set up two systems of temperature waves, one travelling in the direction of the primary-side flow, the other in the direction of the secondary-side flow. The attenuation and velocity of these wave systems is a function of the forcing frequency. Interference between these systems leads to some rather unusual frequency response loci. The examples are typical of sodium-sodium heat exchangers used in fast-reactor power plants, but the formulae developed are suitable for more general use.