SARA: System for Automatic Release Autorization

SARA is a measuring instrument designed to measure radioactive contamination in potentially contaminated waste containers quickly and easily. The instrument, consisting of a scale, a plastic detector, the counting electronics and an industrial PC is compact and is housed in a stainless steel AISI304 container easily decontaminated. The container to be monitored is placed on the scale plate at the base of the instrument and the measurement starts automatically. The two measures, weight and activity, are processed to provide the specific activity expressed in Bq/g. When the measured value of the specific activity is above the predefined threshold (settable by the user) the measured value is displayed on a red background, if it is below the threshold it is displayed on a green background (a voice also states whether the measured object is contaminated or not). With an optional printer it is also possible to print the measured value in Bq/g on self-adhesive labels.The plastic detector (PVT) is housed in the vertical structure of the instrument, facing the container that is placed on the scale plate. In the detector housing contains also the signal processing electronics and the lead shielding for the abatement of the background on the non-measuring sides. Finally, the column is equipped with a microprocessor and a touch screen display from which the operator can easily access the display and data management. On the same column is mounted a led with different colours.
SARA is able to perform highly sensitive measurements minimizing the number of false alarms (negative and positive). The measurement is carried out continuously, based on a fixed integration time that can be programmed by the user. With this parameter it is possible to further refine the sensitivity of the instrument; for example, with measurements of 30 seconds, it is possible to estimate concentrations <1 Bq/g in 5 kg of waste1. Each event exceeding the maximum threshold is stored in a searchable database. The alarms are displayed by the integrated optical signaler with high-brightness LEDs. It is possible to specify a calibration coefficient and show the measurement obtained in terms of total Bq or Bq/g. SARA has a self-diagnostic function that continuously checks the status of the electronics. On the console, an indicator indicates the "health status" of the instrument as a whole. There are also additional indicators that detail the status of both the acquisition and the electronics of the detector. The occurrence of a malfunction is reported visually and archived by the management software, as is the case for the alarm states.