To prevent nuclear terrorism in major public events, the JAEA is developing radiation detector systems, which survey nuclear and radioactive materials left in a public space. The system is various combinations of a radiation detector, a camera, localization devices for in-and-outdoor survey, and an unmanned vehicle. A network device, Wi-SUN FAN, is being tested to perform efficient survey with several devices. In addition, an artificial intelligent program is being developed to diagnose an observed gamma-ray spectrum to identify U-235 and to eliminate false alert. A fast neutron detection system with a PSD plastic scintillator is also being developed for neutron emitter survey. Although the detector is sensitive to both fast neutrons and gamma rays, fast neutron events can be chosen by using a pulse shape evaluation technique. Taking the advantage of angular dependence of a detector, a detector system consisting of two rod-shaped detectors was numerically studied. The system can find the direction of a radioactive source. This report overviews the development project.