The ANTECH Model G3652 Tray Assay System is a High-Resolution Gamma Assay System specially developed for Magnox Berkeley Licensed Site for the measurement of fissile material to be stored both in product packages and waste containers such as Yellow Box®, MOSAIK and TRU-Shields.
The Tray Assay System consists of an HPGe detector with ultra-high count rate capability (TRP amplifier), closed cycle electro-mechanical cooler and DSPEC 50 high count rate digital signal processor and analyser. The system is designed to view and measure the ⁶⁰co and ¹³⁷Cs content of trays of ILW waste from above, through an aperture in the roof of a highly shielded process area cave. The detector extends down into the aperture and is shielded from the effects of stray radiation by a lead shield designed using MCNP modelling techniques to optimise the performance of the system. The shield is lined with a graded copper and tin liner which absorbs low energy gamma rays generated by the lead due to scattering before they can reach the detector crystal. The detector views the entire tray of waste through a tungsten collimator which has been optimised by MCNP modelling.
The electronics are mounted in a thermostatically controlled heated enclosure next to the detector. The system computer, monitor and printer can be either mounted local to remote from the electronics. The system interfaces with the waste tray weigh scale and in-cell video camera.
Key to performance and flexibility of the system is the software which consists of two dedicated packages which run on a Microsoft Windows 7 Pro® (64-bit) operating platform.
TrayScan has been developed by ANTECH to meet specific requirements for the measurement of ILW and FED, in accordance with Magnox Measurement Quality Requirements.
As well as measuring the ¹³⁷Cs and ⁶⁰Co activity on a tray of waste, the system keeps a running total as waste is added to a container. TrayScan software provides the functions and algorithms to enter information, (both manually and automatically) and facilitates the data acquisition and analysis required for assay. It also reports information both on-screen and in hard copy format, of results for a wide range of storage containers. The TrayScan software also:
AMETEK/ORTEC GammaVision™ 8.0 Spectrum Analyser and MCA Emulator is supplied to analyse the spectra and extract the counts in peak for the gamma lines analysed.