The remote-controlled system, called GammaCam, shows concentrations of gamma rays superimposed on a video image. It features a sensor head and a portable PC-compatible computer that controls data analysis and data storage.
ITT Exelis said the system is small, lightweight, easy to set up and doesn't require heavy or bulking shielding.
"We're honored to be supporting the Japan (military) with a system that makes invisible gamma rays visible," said Rich Sorelle, vice president and general manager of the ITT Exelis integrated electronic warfare systems business.
"Our close relationship with the customer, combined with the best available equipment, will help speed recovery efforts, minimize radiation exposure for recovery workers, and significantly reduce risk radiation exposure to all nearby."
GammaCam systems have been supplied to TEPCO, operator of the Fukushima nuclear plant, following last year's earthquake
The new order for GammaCam from Japan's military is worth $6 million, ITT Exelis said, but details as to the number of units or delivery schedule weren't disclosed.