Nuclear Radiation Detector and Analyser collects and processes the signal by detector and performs the peak detection algorithm and displays the spectrum on graphical LCD panel and the same data is also sent via USB interface for remote monitoring. The Detector and Analyser is portable and light weight in nature and identifies various radioactive isotopes of uranium, thorium etc with concentration levels using gamma spectrometry. The Detector and Analyser is suitable for homeland security applications, border protection, health physics, detecting nuclear material in cargo areas, monitoring of nuclear transportation and in situ measurement of objects, surfaces etc. The Detector and Analyser has the feature of nuclide identification, activity measurement, alarm reporting, spectrum acquistion and analysis. The Detector and Analyser has PC software that supports energy calibration, peak information, peak search, multiple spectra and mathematical operations. The Detector and Analyser has the feature of checking the hospital wastage, health care institutions and nuclear medicine department for alarming levels of radioactive isotope. The Detector and Analyser has software embedded for pulse processing, configuration and interfacing with the PC/ LCD spectrum display and analysis. The Detector and Analyser has programmable and zero dead time and has built-in library. The Nuclear Radiation Detector and Analyser has environmental pollution control and front-end programmable gain amplifier.