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Radiation loop –the source of gamma ray

According to the words of the academician J. Stradins, in the period from 1961 to 1998 Latvia was a nuclear state. The construction and maintenance of the nuclear reactor involved many original developments among which the most outstanding is the creation of radiation loop.

Its main authors are:

The loop of gamma ray pile (abbrev.: gamma loop) – a rig transforming the neutron energy into gamma rays – is installed in the enclosure of reactor.

Liquid alloy of Indium-gallium-tin circulates in the gamma loop. In the shower of reactor neutrons radioactive nuclide116 In is formed. Alloy of specific composition that would keep in a liquid and not hard state as usual metals and alloys at room temperature had to be found. Secondly, an element that becomes especially radioactive under the influence of neutrons was necessary in the composition of the alloy.

The radiation loop started to operate in 1963. After the renovation in 1976 two irradiators operated in the loop with the common gamma ray intensity of 20 Mrad/h.

In the following years this kind of radiation loops were built also in other research nuclear reactors in Georgia (Tbilisi) and Russia (Tomsk and Obninsk).

The radiation loop is used to carry out research works in radiation physics, radiation chemistry and radiobiology, as well as in solving such practical tasks as:

  • Sterilization of medical instruments and materials
  • Processing of ration
  • Modification of pulp, polymer- and concrete materials, etc.

Selection of patent documents:

Authors’ certificates of USSR:

  • I.Kirko, V.Gavars, A.Dinduns, V.Kalkis, E.Tomsons. Radiation nuclear reactor. The invention register of USSR, Nr.48549, 1964.
  • A.Dinduns, I.Kirko, V.Kalkis, A.Mikelsons. Radiation loop. Nr.210954, 1967.
  • V.Gavars, A.Dinduns, A.Mikelsons, E.Tomsons, E.Platacis, M.Kramers. Multiirradiator radiation loop. Nr.321172, 1971.
  • A.Dinduns A., V.Gavars, Platacis E., Tomsons E. Regulator of nuclear reactor radiation. Nr 466858, 1974.
  • V.Gavars, A.Dinduns, M.Kramers, E.Platacis, E.Sagildins. Radiator for the radiation loop. Nr.534139, 1976.
  • S.Maļjutins, E.Cistovs, O.Partolins, B.Rahmanov, I.Malkovs, M.Kramers. Device for blocking the entrance door of gamma equipment. Nr.688005, 1979.
  • V.Gavars, A.Dinduns, M.Kramers, E.Sagildins. Method for continuous purification of liquid alloy in circulation loop. Nr.693868, 1979.
  • V.Gavars, M.Kramers, A.Dinduns, E.Sagildins, E.Cistovs, O.Partolins, S.Maļjutins, I.Sprigajievs. Automatic blocking system of work chamber entrance door of radiation loop. Nr.1001815, 1982.
  • V.Gavars., A.Dinduns, M.Kramers, E.Sagildins, N.Kijasovs. Device for the protection of nuclear reactor. Nr.1053644, 1983.

Foreign patents:

  • Patent of Hungary Nr.172806, 1973.
  • Patent of France Nr.7308865, 1973.
  • Patents of Germany: Nr.103752, 1973; Nr.2311525, 1978.
  • Patent of USA Nr.3860825, 1975.
  • Patent of Sweden Nr.7302722-9, 1975.
  • Patent of England Nr.1380529, 1975.
  • Patent of Japan Nr.1193466, 1984.
Picture 1. The scheme of the radiation loop::
  • nuclear core;
  • reflector of the nuclear core;
  • activity generator;
  • communications;
  • irradiator;
  • container of gamma carriers;
  • pump;
  • consumption measuring instrument of gamma carrier;
  • biological protection.
The scheme of the radiation loop
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Picture 2.
The control panel
of the radiation loop RK-LM
(Salaspils, Nuclear Research Centre).
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Picture 3 and 4.
At the manipulators of
the radiation loop chamber.
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Picture 5.
The work chamber of
radiation loop.