METHOD OF CONTROL OF MASS FRACTION OF URANIUM-235 ISOTOPE IN GASEOUS PHASE OF URANIUM HEXAFLUORIDE AND SYSTEM OF MEASUREMENT FOR IMPLEMENTATION OF THIS METHOD Russian patent published in 2008 - IPC G01T1/00 G01N23/00 

FIELD: analysis of nuclear materials.

SUBSTANCE: method of control of a mass fraction of uranium-235 isotope in a gaseous phase of uranium hexafluoride consists in measurement of intensity of gamma radiation at a chosen time interval with simultaneous measurement of pressure and temperature of gases in a measurement chamber; at that each measurement of a mass fraction of uranium-235 isotope in a gaseous phase of uranium hexafluoride is performed in two stages; during the first stage there is measured the intensity of gamma radiation from control sources - uranium protoxide-oxide-introduced in the space between the measurement chamber and a detector; during the second stage there is registered a radiation directly from uranium hexafluoride placed in the measurement chamber at various values of pressure of uranium hexafluoride, while the mass fraction of uranium-235 isotope in a gaseous phase is determined by calculation. Additionally to the known control system there are introduced control sources of uranium protoxide-oxide located on the gate with a mechanical drive, a valve of a sample splitting for mass spectrometric analysis and a sample splitter attached thereto, at that an inlet and outlet valves are controlled with electron keys to a command of a master controller. Energy of an analytical peak is 185.7 kiloelectronvolt.

EFFECT: development of such method and a control system that provide elimination of instability in time of the parameters of detecting blocks and allow to take in a complete consideration a background constituent under the basic analytical peak and to reduce equipment costs with simultaneous upgraded measurement accuracy.

2 cl, 2 dwg