Segregated Waste Drum Monitor G3321-200-VLLW

Low density low level waste (LLW) and very low level waste (VLLW)  can be segregated and measured by the ANTECH model G3321-200-VLLW Segregated Waste Drum Monitor. The significant differential in the cost of disposing of LLW versus VLLW makes the G3321 a cost effective tool for waste assay where low density waste is generated in nuclear facilities such as nuclear power stations. In the United Kingdom, the G3321 can be used to sentence VLLW to land fill disposal saving the cost of the more expensive disposal at the national Low Level Waste Repository at Drigg .

The model G3321 is designed to measure low density radioactive waste in 200 litre drums. It can be employed both for screening and assay of waste drums and waste boxes or objects which fit into the volume envelope of a 200 litre drum. The G3321 employs both plastic scintillation detectors for sensitive gross gamma ray measurements and a large volume sodium iodide spectroscopic scintillation detector for radionuclide identification and waste fingerprint verification.

VLLW Datasheet


The ANTECH G3321 VLLW Segregated Waste Drum Monitor is designed to measure low density radioactive waste generated in nuclear facilities and to segregate VLLW from LLW contained in 200 litre drums.

The ability to measure and segregate VLLW (very low level waste) from LLW (low level waste) brings significant cost savngs as the storage, handling and disposal costs of VLLW are much less than the equivalent costs for LLW.

The Segregated Waste Drum Monitor is designed for simplicity of use, safe operation and high detection sensitivity to facilitate rapid and accurate waste measurements for the identification and segregation of VLLW.

The G3321 measures gamma ray emitting low-density radioactive waste in bags, boxes and drums up to a drum volume of 200 litres (55 US gallons). Six plastic scintillator detectors provide the gross gamma ray measurement with 4π coverage to allow fast, accurate measurements. In order to confirm radioactive waste fingerprints and identify individual radionuclides, the G3321 also incorporates a high efficiency sodium iodide spectroscopic scintillation detector in the measurement chamber to detect the radionuclides present in the waste and to confirm the waste fingerprint. A built-in weigh scale allows the specific activity of the sample to be determined in units of Bq/g or pCi/g. An embedded microprocessor performs data acquisition, background discrimination and system diagnostics.

The results are displayed via a software interface on a local laptop PC or on an optional built-in touch screen PC. When LLW is measured the G3321 generates the waste manifest for LLWR (Drigg Form D4) as a PDF document. The software provides 60 configurable protocols (waste fingerprints) for the material to be assayed, with associated detection limits. An audible alarm and warning light indicate if the selected predetermined clearance level is exceeded. An Ethernet connection allows remote data processing and analysis.

Features & Benefits


  • Plastic scintillator configuration provides 4π coverage
  • Spectroscopic sodium iodide detector for isotope identification and fingerprint confirmation
  • Up to 60 configurable measurement protocols (waste fingerprints)
  • Normalisation check source to confirm spectroscopic detector energy scale calibration and overall measurement performance
  • Optional bar code reader for drum ID input
  • Continuous automatic background determination and averaging
  • Simplified drum and sample loading using an extending shelf
  • Lead (38 mm) and steel (12.5 mm) shielded chamber to reduce background count rate



  • Identifies VLLW waste for segregation and cost effective disposal
  • Verifies uncontaminated waste can be cleared as free-release waste rather than LLW, considerably reducing disposal costs
  • Verifies that items to be removed from controlled areas are free from contamination and can be safely handled
  • When LLW is measured the G3321 generates the waste manifest for LLWR as a PDF document (Drigg Form D4)
  • Password protected system and configuration menus provide extra security
 External dimensions (H x W  x D) 1520 mm x 920 mm x 1060 mm (60 in x 36.2 in x 41.8 in)
 Internal dimensions (H x W x D) 1050 mm x 650 mm x 850 mm (41.4 in x 25.6 in x 33.5 in)
Weight 4120 kg (9064 lb)
Operating temperature 5-40 ˚C
Network connection Ethernet
Weigh scale range 0-200 kg (0-440 lb)
Shielding 38 mm (1.5 in) lead,  12.5 mm (0.5 in) steel
Chamber capacity 580 L (21.46 cu ft)
Detectable activity range 137Cs 120 Bq in chamber
60Co 55 Bq in chamber
Minimum detectable activity (typical) 137Cs 120 Bq (3.24 nCi)
60Co 55 Bq (1.49 nCi)
Specific activity typically detected at 3.3 standard deviations for wastes of 1.5 kg or more 137Cs 0.08 Bq/g
60Co 0.04 Bq/g
Power supply 110 – 240 VAC, 50-60 Hz
Power consumption < 200 W (including PC)
Analysis software Windows operating platform, ANTECH MasterWCDM user interface
Plastic Scintillator Detectors 6 panels providing 4 π detector coverage
Spectroscopic Scintillation Detector Sodium Iodide
Normalisation check source Eu-152 point source 37 kBq (1 microCi)