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TRPG181 Gamma-radiometer for 235U enrichment control

TRPG181 is a portable scintillation gamma-rays radiometer of spectrometric type designed for field radiometric measurements using various techniques, involving preliminary measurement of 256/1024 channel gamma ray pulse height spectrum and processing of counts in energy windows.

This device is used at Russian nuclear industry facilities for 235U enrichment measurements and fissile and radioactive material control.


TRTG181 components:

  • Control unit;
  • Scintillation detection unit of the base of ∅25×25 mm NaI(Tl) crystal;
  • Collimators and fittings for enrichment measurements and 235U holdup control;
  • Batteries with battery charger;
  • Mains adapter ̴220 V, 50Hz;
  • Software CD;
  • Equipment certificate and operation manual.
  • The main TRPG specifications checked when releasing from production:

  • 235U enrichment measurement range – from low enriched to high enriched uranium, the relative measurement error doesn’t exceed 10 % (error value is confirmed using the reference materials of uranium isotopic composition without taking off the containers);
  • Gamma-ray energy range of interest is from 40 to 3000 kEV (energy range is set programmatically depending on the task);
  • Relative integral non-linearity of photon energy conversion to the channel number is less than 1 %;
  • Sensitivity to photons with 662 keV energy is more than 2 pulse.·cm2/photon;
  • Relative energy resolution at 662 keV is less than 10 % (standard value is 8 %);
  • Basic relative error of 662 keV photon flux density measurement is less than 10 %;
  • Operating temperature range is from -10 to +40 °С (additional error is 1 %/10 0С);
  • Number of channels is 256 / 1024; channel capacity is 2∙109 pulses;
  • Variation of radiometer readings during integral spectrum acquisition is defined by statistical deviation (device instability is negligible);
  • Power consumption is less than 0.6 W; continuous operation without charging is about 20 hours; mains adapter (220 V, 50 Hz) is provided;
  • Weight of control unit (including batteries) with detection unit is not more than 0.9 kg;
  • Upper limit of counting rates is at least 30,000 pps (counts loss is less than 6%);
  • Gain adjustment with program;
  • Spectrometric circuit stabilization is provided;
  • Communication with external PC is through USB 2.0, delivery set includes CD with software for radiometer control from PC.
  • Device software provides basic functions of pulse-height analyzer, namely:

  • Setting the parameters required for spectrum measurement: gain, exposure duration, spectrum measurement mode with termination by exposition time or counts accumulated, etc.;
  • Displaying the spectrum on LCD and PC monitor when exposing, viewing the spectrum by channels, selecting the window of interest on the spectrum with calculation of counts in window, etc.;
  • Automatically determining the coefficient of readings variation, energy resolution, calibrating the “channel-energy” scale;
  • In addition, the TRPG181 software supports the following methods:
  • Determination of 235U enrichment in “thick” and “thin” samples taking into account the enclosure wall material;
  • Determination of uranium-235 holdup density on inner walls of process equipment and pipelines;
  • Simultaneous counting rate measurements in 4 regions of interest;
  • Search and identification of radioactive isotopes;
  • Determination of equivalent dose rate, etc.
  • The additional functions required by Customer can be added to TRPG181 software.

    TRPG181 radiometer is included in the State Register of Measuring Instruments with the number 69976-17 (Certificate of Measuring Instrument Type Approval RU.C.38.769.A №68629) and allowed for use in Russian Federation.

    TRPG181 radiometer is certified for compliance with safety requirements in the atomic energy use area as a commercially-produced device (Certificate of Compliance №ОИАЭ.RU.156 OC.00194).