Having become a Party to several European and international treaties and conventions, Poland has paid increased attention to improving methods and techniques of prevention and detection of illicit hazardous materials. The article reviews new scintillation detectors of gamma and neutron radiation as well as presents a concept of dual-energy electron accelerator application in monitoring systems for homeland security. There are several requirements which the instrument should meet: it should be able to operate in a mixed gamma-neutron field as neutrons are a unique signature of the presence of fissile materials, be quite sensitive and highly selective to avoid a misinterpretation, and finally it should be efficient and inexpensive. Detection of hazardous materials (nuclear, explosives, drugs) can be realized by two methods – passive detection of gamma-rays and neutrons from radioactive and nuclear material, and active detection of explosives via neutron activation and/or X-ray radiography. In the paper a series of new scintillators (e.g. LaBr3(Ce), LuAG:Pr, boron-loaded BC523A and EJ309B5) in terms of their sensitivity and selectivity in gamma/neutron detection as well as material discrimination using dual-energy electron accelerator are discussed. Both techniques – X-rays and neutron activation analysis – can offer the possibility of automatic detection of explosives or drugs with the emphasis on an innovative approach to new built systems.