VM-250AG/VM-250AGN

RAVEN compatible

Description

TSA’s vehicle portal radiation monitor VM-250AG consists of two self-contained weather resistant pillars placed on either side of the roadway to be protected. Each pillar contains two organic plastic scintillator detectors, an occupancy detector, and an amplifier/controller. The master pillar also has a battery, power supply/battery charger, and an SC-770 system controller.

Model VM-250AGN adds neutron detection capability to the basic VM-250AG. Both models are equipped with RS-232 and Ethernet communications capability.

TSA’s VM-250AG/AGN systems require two conduits, one to provide ac power to the battery charger, and one for the pillar to pillar connections. A third conduit may be required to route signals to TSA’s AM-270 alarm monitor. A relay output is available for connection to TSA’s AM-270 or other on site security system. TSA’s RAVEN (Radiation Alarm and Video Event Notification) monitoring system connects through wired or wireless Ethernet.

The pillars are usually bolted to a concrete footing, with the interconnecting conduits installed under the roadway. The pillar spacing varies from 10 feet (3m) to 15 feet (4.6m) depending on local requirements for sensitivity and traffic.

The VM-375AG system (not shown) is essentially a VM-250AG with a third pillar positioned horizontally between the two upright pillars. The third pillar can be mounted above or below the other pillars. The VM-375AG provides improved sensitivity over the VM-250AG. Please contact TSA Systems to discuss configuration and requirements for VM-375 systems.

OPERATION: When the system is powered up, it takes twenty seconds to acquire an initial background count. The background count is continually updated until the system is occupied.

When the detector senses occupancy, the system starts comparing the current count to the most recent background data. Alarm comparisons are made every 200ms. If the count exceeds the alarm level, both audible and visual alarms will be triggered. The system monitors itself and indicates low and high background conditions. System status is continuously updated on TSA’s SC-770 system controller, located in the master pillar.

Applications

These radiation portal monitors are designed to automatically scan vehicular traffic without the need for frequent calibration. They are intended for applications where the relatively low energy emissions from ²³⁵U and ²³⁹Pu are the main concern.

They are currently in use in installations such as uranium enrichment plants, weapons manufacturing and storage plants, nuclear laboratories, and nuclear waste disposal and storage sites where protection of Special Nuclear Materials (SNM) is essential. The units can be insulated, heated and/or cooled for use in severe environmental conditions.

Specifications