Self-controlled reactor of heat power supply MASTER
Nowadays safe and reliable reactors of small power are in increasing demand as independent power sources. Such reactors may be used widely enough. For example, they may be placed in distant and difficult for access regions for independent power supply of different objects. At last, independent small power sources operating for a long time in the self-controlled mode may be used in the countries that have no domestic nuclear power industry.
Taking into account the increasing demand in sphere of small power industry, SSL’s specialists developed the heat power supply reactor “MASTER”. The principal scheme of the reactor facility, its neutron-physical and thermo-hydraulic characteristics have been suggested in designing. The possibility of reactor self-control and compensation of reactivity loss during the fuel burning have been considered.
Requirements of the reactor of small power
The independent reactor facility may be in demand if it is economical expedient, self-controlled, safe, reliable for the long lifetime and simple in construction.
This reactor facility should be completely assembled at the manufacturing plant, moved to the place of operation and put into operation.
To avoid proliferation of the fissible materials and to localize relieves of the radioactive products in emergencies the reactor facility should be located underground.
Duration of operation should not be less than 60 years – it is the lifetime of buildings and constructions before the capital repair, and in power industry it is a period of the accepted decisions obsolescence, it is a period of two generations’ life. Obviously that duration of operation period is one of main components of the facility economy.
Reliability of the reactor facility particularly is defined by simplicity of its construction. To achieve high reliability it is desired to avoid all mechanical devices and control systems. For example, if the natural circulation is used, the pumps and valves are not necessary. Self-control allows avoiding the system of the reactor control and protection, and in the extreme case to reject constant attendance of the personnel.
Restriction of the pressure value in the heat removal system also improves safety and reliability of the reactor facility.
It is possible to present the above general thoughts as the engineering requirements to the reactor facility development:
- range of heat power from 0.3 to 3.0 MW;
- consumer’s water temperature not more than 80 °Ñ;
- life-time with no re-fuelling is equal to 60 years;
- coolant temperature is below the point of boiling;
- impossibility to destroy the reactor case in any emergency;
- self-controlled operation mode around the life-time period;
- inherent safety due to the negative feedbacks and absence of high pressure in the circuits;
- impossibility of hard emergencies and using the reactor as an explosive object;
- underground location.
The following construction decisions have been accepted in development of the concrete reactor scheme:
two-circuit system of heat removal: the primary closed circuit with natural circulation and the secondary consumer’s circuit – with forced circulation;
heat is transferred from the nuclear fuel to the first circuit coolant via the heat conductivity of the core material (so called “one fuel rod” reactor).Heat is transferred from reactor with relatively small volume of the core, i.e. with large heat load kW/l. It may be realized by two suggested versions of the reactor:
- In heat neutrons reactor with high heat conductive fuel (UBe13 + Mg) and moderator (Âå) in which heat is transferred to the reactor vessel by heat conductivity. This version of construction has the name “MASTER-IATE” .
- In fast neutrons reactor with high heat conductive fuel elements made from U-Mo alloy liquid metal coolant. This version of construction has the name “MASTER-JM” .
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