Radiometric Drone in Complex GPS Denied Environments

Is this your challenge?

complex environment

Visual inspections for the nuclear sector are often conducted manually by an inspector scrutinising the entirety of an asset. Sometimes crawling robots may be used to automate the process. However, these robots are limited in their ability to access different environments (at height for instance), and mainly useful for small volumes.

Similarly, drones are used to automate the process on large areas but can be limited by constraints especially in complex environments where collision is a real risk.

That is also true when it comes to collecting radiometric data, with the added risk of potential exposure to radiation or incomplete data set when no effective deployment solution can be found.

Understanding the locations and levels of radiation in these same environments is a continuous undertaking and a few drones have been developed to ease that pain. One elegant solution, with the ability to safely map a complex environment in 3D, even in a GPS denied environment, has been upgraded with radiometric capabilities to present an impressive and intuitive solution leading the way for a new generation of inspection tools.

inTechBrew’s insight

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Flyability is a Swiss company launched in 2014. They build solutions for the inspection and exploration of indoor, inaccessible, and confined spaces. By allowing drones to be used safely inside buildings, it enables industrial companies and inspection professionals to reduce downtime, inspection costs, and risks to workers.

Flyability created the first collision-tolerant caged drone for internal inspections, enabling remote data collection with cutting edge hardware and software to help improve safety, reduce downtimes, and cut costs for the inspections of complex environments.

Flyability’s Elios 3 (launched in May 2022) carries a LiDAR sensor and is specifically designed for the inspection of confined spaces. It can survey in live stream and render 3D maps in real-time, even in GPS-denied environments. These 3D maps are detailed enough that inspectors can use them to orient themselves within an environment, and fly only by referencing them. The Elios 3 RAD (available since mid-2023) is an upgrade for the nuclear industry and can perform fast and accurate radiation surveying of indoor spaces while limiting human exposure.

radiometric drone

At inTechBrew, we thought that Flyability’s Elios 3 was already a great tool. Now as the Elios 3 RAD, it has all it takes to perform safely in the most complex environments (such as trenches or silos) and give valuable insights on radiation levels.

Equipped with a Mirion Technologies Perform RDS-32™ WR sensor, it certainly can help nuclear site operators reach higher safety standards infrastructure and asset management either during maintenance or decommissioning operations without having to expose humans to radiation.

The Elios 3 RAD unique design, collision avoidance capabilities and radiation survey capabilities make for a top-notch tool. It also has been successfully tested at 10,000 R/h with up to 4,000 R of cumulated dose. Impressive and off-the-shelf.

User case 1: Capability Testing


Sellafield Ltd – Capability testing

Sellafield Ltd, UK, 2023

  • Sellafield  is a large site on the Cumbrian coast of the UK. It was an active nuclear power plant until 2003. Now it is the site of an immense decommissioning project, one of the biggest in the world, that will last for decades. In July 2023, the Elios 3 RAD drone was tested by Sellafield’s UAV team.
  • The Sellafield UAV team successfully flew the Elios 3 RAD drone (with a radiation activity detection dosimeter). The aim was two-folds. Firstly, to validate what the manufacturer tells us about the drone and its performance. Secondly, to ascertain if the drone could detect changes in radiation as part of a radiological survey and then allow it to investigate in more detail upon a spike. A test area was staged across several rooms where sealed sources were placed.
Sellafield drone use
  • This trial clearly demonstrated that the addition of a radiation mapping capability on the Elios 3 gave another dimension to the already impressive drone. This testing gives the Sellafield team the confidence and understanding of the radiometric performance of the combined system
  • It achieved unparalleled efficiency in mapping and 3D modelling. The test allowed Sellafield to find the optimal flight techniques for this sort of data collection. They also assessed how the sensor performs in various environments to create a clear profile of the use cases this could be applied to.
  • Overall, the reasons to use the Elios 3 RAD on the Sellafield site can be highlighted:
    • Safety is improved by being able to send a drone into environments and either do a pre-survey to test radiation levels before entering, or it can be used to access contaminated environments quickly. This can help to avoid a person going into an area unnecessarily, freeing up operatives for higher priority projects and helping boost safety. 
    • The drone deployment is incredibly simple: it can be deployed rapidly for a variety of reasons: streamline safety inspections, scout an area prior to a person so you can have better situational awareness. The data is almost immediately available and ready to empower decision-making.
    • Safety is built -in. Thanks to the cage, you can be confident in flying up close to assets without fear of a crash which would take a regular propeller UAV out of the sky.
    • Finally, cost savings: you save time and therefore money by being able to work quickly.
 Radiometric Drone use case

User case 2: Waste Storage Vault

US dept of energy

INTEC – Storage Vault 3D Mapping (2022)

Nuclear Technology and Engineering Center, Idaho National Laboratory Site, USA

  • In the 1950s, the Department of Energy (DoE) contracted with the state of Idaho to store 4,400 cubic metres  (14,436 cubic feet) of nuclear waste at a secure facility called the Idaho Nuclear Technology and Engineering Center.
  • The waste is called calcine, and it is a highly radioactive, granular solid made from spent nuclear fuel. This waste is stored in six underground vaults, which hold bins made to store the calcine.
  • The inspection was completed on a 50-meter culvert (164 feet) using a 4k wide angle camera and 10,000 lumens light).
  • The first major milestone in the IEC’s planning was to develop a method for removing the waste. The approach they created involves drilling holes into the top of the storage vault, then robotically welding pipes to the top of each bin before using a plasma cutter to cut into each one.
  • The only problem is that the blueprints for the vaults do not provide the necessary detail for locating the holes and extraction pipes, so the IEC does not know the exact layout inside each one, making it impossible to plan where to drill the holes for the extraction pipes.
  • To address this need, the IEC lowered a handheld LiDAR sensor into one of the vaults on a lowering tripod to 3D map the area, but the resulting map had gaps in the data since the sensor could only be located in one place.
  • The IEC needed a way to create 3D maps inside the vaults facility so it could ascertain the equipment necessary to begin extracting the waste. After identifying the Elios 3 as the right tool for the job, IEC tested it in a high-radiation environment (in June 2022), exposing the drone to up to 10,000 Roentgen per hour of radiation to ensure it would be able to operate inside the vault.
  • Upon the first flight, in the first seven-minute, the IEC was able to collect sufficient LiDAR data for high-quality 3D mapping the interior of the vault, representing the culmination of over a year of research and preparation.
Project doe radiometric use
DOE use case

The technology : Elios 3 RAD

Radiometric drone

In 2022, the Elios 3 was the first mapping and inspection indoor drone which offered an unmatched combination of intelligence, versatility, and stability.

In 2023, with the Elios 3 RAD, and its radiometric payload, Flyability gave professionals new options for improved safety and access – from measuring radiation levels to identifying maintenance needs.

Comprehensive in-flight radiation reading:

Instant reading. No exposure.

Get an instant reading of current and cumulative dose rate along with max recorded value and measurement history to understand measurement trends and help you find high radiation sources.

Post-flight radiation reading, localisation, and reporting:

Locating and characterising hot spots.

While in flight, all measurements captured by the sensor are recorded along with visual and mapping information. In post-processing, the drone’s trajectory is colourised based on the instant dose rate reading, allowing the user to precisely locate radiation sources on a 3D map of the asset.

Detachable and swappable sensor (Mirion RDS32).

Critical applications like radiation surveying should not be left to uncertainties. For reliable information, the Elios 3 is equipped with a Mirion Technologies RDS-32™ WR sensor with a range covering from µSv/h to Sv/h. Elios 3 is compatible with every RDS-32 so you can swap them as needed.

remote drone

With a radiometric capability on-board, the Elios 3 RAD has also kept the impressive list of capabilities of the Elios 3:

  • Collision resilience: Reliable operations in any situation.
  • Confined space accessibility: Fly where no other drone can.
  • Robust transmission: Inspect beyond line of sight.
  • FlyAware: powered by a new engine called FlyAware that incorporates LiDAR and visual data to make it incredibly stable while in flight and supports the creation of 3D models in real time, while the drone is in flight.
  • Intuitive to fly: GPS-free stabilisation allows you to stay in control at all times.
  • Easy to use: Someone who has never flown before can pick up the controller and perform for the first time and perform an inspection flight on the same day.
  • New LiDAR sensor: The high resolution Ouster OS0-128 Rev 7 LiDAR sensor in combination with the world’s leading FARO Connect SLAM algorithm create incredibly accurate 3D maps and digital twins of the most inaccessible spaces with centimeter precision – for accurate measurements and greater insights.
  • Accurate data capture with HD streaming and 10k lumens built-in.
  • Next level visualisation: Using Inspector, simply draw a line of the image and get a 2D measurement. Create digital twins using 3rd party photogrammetry software (e.g., Pix4D Mapper, Agisoft Photoscan).
  • Inspector 4.0: Elios 3 is accompanied by a of Flyability’s inspection software, Inspector can create 3D reports, which show exactly where defects found in an asset are located in a 3D model.

Specific to the Elios 3 RAD, the drone offers indoor remote radiation detection and mapping to identify, locate, and monitor radiological dose fields and hot spots (while keeping operators out of harm’s way) anywhere inside a facility or asset, giving you a clear picture of radiological conditions and helping with your personnel dose exposure to plan interventions. The Elios 3 RAD offers a new way to gather more data from previously inaccessible areas all while improving safety:

  • Access: Using the Elios 3 RAD to detect contamination helps create heat-maps of radiation without a person having to enter potentially hazardous environments.
  • Comprehensive data: With the RAD payload, drone pilots can gather data to create a “heat map” of a potentially radioactive or contaminated environment in a range of confined spaces.
  • Site management: The Elios 3 RAD works as both a scout and inspector, providing information that can be used in site management and operational planning.
  • Safety: This workflow empowers safer operations with better situational awareness through the RAD payload’s data collection without exposing humans.

Nominal Specifications: Elios 3 RAD

Elios 3 RAD specifications Because of the weight added to the aircraft by the payload (radiation sensor), the Elios 3’s specifications are altered as stated below when flown with the radiometric payload.
Easy maintenanceElios 3 is engineered to be easily serviceable.
DimensionsFits in a < 400 mm sphere; 15.75 in
Motors4 fast reversing electric brushless motors
Take-off weight (without dosimeter)< 1450 g; < 3,2 lbs. Includes battery, payload (not the dosimeter) & protection
Flight control sensorsIMU, magnetometer, barometer, 7 vision and distance sensors
Fail-safeAuto-landing on signal lost, Forced-descent when battery critically low
Ingress protectionSplash and dust resistant
Battery typeLiPo 5S HV Smart Battery, 5200 mAh, 19V
Drone materialsCarbon fibre composites, magnesium alloy, aeronautical grade aluminium, high-quality thermoplastics
Protection cage materialsCarbon fibre cage with soft coating, modular subcomponents for maintenance ease, thermoplastic elastomer suspensions, front opening dimensioned for easy battery access.
Collision toleranceUniform all around the drone, up to 3 m/s on flat objects, up to 1.5 m/s on sharp objects
Nominal to the Elios 3 RAD With radiometric sensor mounted
Flight time (in ideal flight conditions, with a new battery)7min30s w/ Lidar 9min45s w/o Lidar
Max operating temperature45 °C (113° F) w/ Lidar; 50 °C (122° F) w/o Lidar
Max wind resistance4 m/s (13.1 ft/s) in assist mode; 6 m/s (19.7 ft/s) in sport mode
Maximum altitude2000 m (7,218 ft) w/ Lidar; 3000 m (9,843 ft) w/o Lidar
CrashworthinessMax 1 m/s for direct frontal contact on the sensor
Outdoor compliance  Limit to indoor use only in the US (when mounted on the drone, the radiation sensor blocks the GPS signal of the Remote ID module preventing outdoor flight in the USA)
Radiation payload The complete specification of the RDS-32™ WR are available on Mirion’s website here. The sensor will yield an attenuated dose rate result when the heavy components of the drone such as the battery or main body are standing in the way between the detector and the radiation source
Detector supportedMirion RDS-32TM WR
TechnologyEnergy-compensated GM tube and energy compensated Si diode
IEC energy range55 keV GM tube / 65 keV, Si diode to 1.8 MeV
High energy response to Cs-137  4.4 MeV: GM tube 220%, Si diode 120% 6.7 MeV: GM tube 260%, Si diode 200%
Dose rate measurement range0.05 µSv/h to 10 Sv/h
IEC dose rate measurement range0.3 µSv/h to 10 Sv/h
Dose rate linearity15% to +22% 0.3 µSv/h to 10 Sv/h

Any questions ? Interested in any other radiometric drone inspection ? Do not hesitate to contact us directly, we will help you find a fit-for-purpose, cost-efficient solution to your challenge.

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