Radiation Portal Monitor Calibration and Startup
J.R. Hoyt; D.B. Shipler; K.R. Ames; R.B. Sitsler; R.A. Jones; E.J. Antonio; and B.C. Gibson (Pacific Northwest National Laboratory)
Pacific Northwest National Laboratory (PNNL) has been supporting U.S. Customs and Border Protection (CBP) for the past three years by designing, installing, calibrating, and commissioning Radiation Portal Monitors (RPM). CBP is installing these radiation portal monitors nationwide - at seaports, land border ports of entry and crossings, including rail crossings, international airports, and international mail and express consignment courier facilities in an effort to screen 100 percent of all incoming goods, people, and conveyances for radiation. Once facilities are designed and constructed, and monitoring equipment installed and checked, the Calibration and Startup Team enters the picture. The Team has two main responsibilities: check the complete and sustainable operation of the systems, and calibrate the systems to detect radioactive materials that could be used by terrorists in dirty bombs and/or nuclear weapons. Calibration of the systems is performed for gamma rays and neutron particles to detect the two types of radioactive materials of interest. The computers and software that manage the systems are complex and time and current background dependent. The objective is to keep the thresholds of detection as low as practicable considering naturally occurring radioactive materials (NORM) and medical use of radioactive isotopes.