The ANTECH Model G3410-200 LRDGS is a transportable Low Resolution Gamma Scanner for the characterisation and measurement of 200 L drums of waste. It is capable of characterising waste as Low Level Waste (LLW), Exempt or suitable for ‘free release’. The G3410-200 consists of a turntable with a built in weigh scale and an instrumentation enclosure, which houses the system electronics and workstation (Panel PC) mounted on a common chassis.
Next to the turntable a half height 19” rack mount instrumentation enclosure houses three shielded sodium iodide detectors with associated counting electronics, turntable motor drive, power distribution and safety circuitry. A Panel PC with a 15” or 17” LCD screen is mounted on an adjustable arm attached to the instrument enclosure.
All equipment is mounted on a sturdy chassis. The chassis is fitted with castors and jacking feet which enable the system to be easily transported and fixed into position to prevent it moving during drum loading and unloading operations.
The turntable is designed to accept a 200 L (nominally 600 mm diameter) drum of waste. The turntable platter has lip on it to assist with centralising the drum when it is loaded and to ensure that it stays in position during rotation. The turntable is mounted on a load cell arrangement that has the capability to weigh drums of up to 350 kg. The turntable is fitted with a servo motor and can rotate at a speed of up to 5 rpm to ensure a homogenous scan of the drum.
An 1150 mm x 600 mm x 600 mm (H x W x D) screened instrumentation enclosure providing EMC protection is mounted on the chassis next to the turntable. The instrumentation enclosure contains all of the power distribution electronics. It also houses three sodium iodide (NaI) detectors, each fitted with a photo-multiplier that connects to the system computer. Each detector is shielded with 2” of lead to reduce the area background and to provide collimation. The three detectors are fixed in position above each other on a robust frame to provide a scan area that covers the entire drum.
The turntable servo motor drive and associated motor safety circuitry is housed within the enclosure. The motor Start button and a key resettable Emergency Stop button are mounted on the side of the enclosure. Power to the system is provided from a single phase, 110 – 230 Vac, 50/60 Hz supply and is capable of being isolated from the outside of the enclosure.
The panel computer functions as the Operator Interface. It is mounted on an adjustable arm attached to the side of the instrument enclosure. The computer runs a software application, called MasterLRGS, which accepts and analyses spectroscopic and activity data from each of the detectors to determine the drum activity. MasterLRGS carries out analysis of data, displays information about individual detectors, background and measurement counts in both numerical and graphical format, measures drum weight and enables the user to set up a number of different calibration curves, each corresponding to a different waste stream or different waste matrix and activity type or radionuclide type.
The software can use the reported drum weight to apply a density correction to the results. It also has the option to accept fingerprints to enable activity per nuclide to be reported. It enables the user to:
The software is configurable to enable a Bar Code Reader to be used to input drums information, where appropriate. All software runs on a Windows platform.