Integrated sensor handled by robot for dose rate measurement

Karim BOUDERGUI, Anne Marie FRELIN, Vladimir KONDRASOVS, Stephane NORMAND

CEA, LIST, Sensors & Electronic Architectures Laboratory, 91191 Gif-sur-Yvette CEDEX, FRANCE

INTRODUCTION MEASUREMENTS

SRIP ROBOT DESCRIPTION

CONCLUSION

SPECIFICATIONS

This radiometer has shown good results during the different tests: a good linearity (discrepancies below 10 % for dose rate measurements), angular response about 5% and good real-time performances. With its compact and robust metal case it represents a good tool to be embedded inside drones (aerial or terrestrial).This new warning radiometer will soon be marketed by the French company SDS

New Nuclear and Radiological threats and growing industrial risks have induced new needs as the use of robotic systems. The SRIP research project (Systèmes Robotisés d’Intervention pour sapeurs Pompiers), in the frame of the French ANR program agency, aims to develop a land robotic system with increased detection capabilities adapted to the needs of rescue teams. This development was run by a consortium of complementary partners: ECA Company for robotic, CEA and INERIS bringing their knowledge in detection technologies and ENSOSP and SDIS 13 providing their intervention and rescue skills. The system includes a modular robot base integrating a large choice of sensors (chemical, radioactive…) and more particularly a new radiometer achieving a highly reliable dose measurement even in drastic environment conditions (vibration for instance), specially designed by CEA to fit at the best requirements for security applications.

Technical specifications

Radio or wire controlMotion: 2 tracks + 2 front flippersObstacle clearance: up to 30cmSlope and stairs: up to 45°Payload capability: up to 20kgTemperature : -15°C to +55°CChemical resistance (acids, bases, ammoniac, chlorine….)Explosive atmosphere managementFast robot set-up (<2 min) and easy to use command & control unit

Figure 1. Geiger Müller dosimeter developed at the CEA to equip the prototype

Figure 6 : Geiger Müller dosimeter developed at the CEA to equip the prototype

NuclearDisplay units: µSv/h, µSv or µrem, µrem/h depending on meter connected;

H*(10) ambient gamma dose equivalent rate.Emitter: Gamma.Detector: Energy Compensated Geiger Mueller.Sensitivity: 2.4 c/s for μSv/h (137Cs).Measurement range: 0.1 μSv/h to 40 mSv/h (10 μrem/h to 4 rem/h).Energy range: Gamma 36 keV to 1.5 MeV.Background: Ambient <0.1 μGy/h (10 μR/h), 0.16 c/s.ErgonomicDisplay: Provided by host instrument or PC.Alarm setpoint: Saved in probe memory. It can be charged with a PC.

ElectricalPower: Supplied by PC (USB) or Battery Battery life: up to 10 hours of battery autonomy

MechanicalHousing : Aluminum.Dimensions : 90 x 32 mm (3.5 in. x 1.26 in.) (L x D).Weight: 88 g (0.19 lb), without cable.

EnvironmentalTemperature: -10 °C to +40 °C (14 to +104 °F).Cleaning: Housing easy to decontaminate.Water resistance: Waterproof 1 m deep underwater connected(IP67).

Figure 3 : Angular measurement of dosimeter response

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120%0°

-30°

-45°

-60°

-90°90°

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45°

30°

The angular response is very uniform with a standard deviation of ca. 5 %.

Figure 5 : Real time counting rate and filtered dose rate measured with a 60Co irradiator at 18 μSv/h.

Time response radiometer is less than 10s for dose rates below 100 µSv/h and less than 2s for other dose rates

Figure 4 : Normalized counting rate with regard to the orientation

Figure 2. GAM Portable Gamma-Ray Detector prototype