Calibration of detectors (Protection Level Instruments) and the NNRA SSDL

Abstract

CALIBRATION OF DETECTORS (PROTECTION LEVEL INSTRUMENTS) AND THE NNRA SSDL Radiation monitoring requires the use of detectors which could be active or passive (Survey meters and Dosimeters). There are hundreds of survey meters in Nigeria. Standard Dosimetry. Survey meters can either be analogue or digital form which can be used to measure radiation either background or elevated level in an environment, facilities such as gamma irradiators, industrial gauges, well logging tools, radioactive sources etc Primary Standard Dosimetry Laboratory (PSDL) is a national standardizing laboratory designated by the government for the purpose of developing, maintaining and improving primary standards in radiation dosimetry whereas Secondary Standard Dosimetry Laboratory is designated by competent authorities to provide calibration services and which is equipped with at least one secondary standard that has been calibrated against a primary standard The SSDL in Nigeria is located at the National Institute of Radiation Protection and Research (NIRPR) which was set up by section 11 of the Nuclear Safety and Radiation Protection Act and has been designated by NNRA to undertake the duties of a calibrating laboratory. There are two (2) SSDL at NIRPR namely: Therapy Lab and Protection Lab Traceablity is the measurement of the radiation characteristics that is traceable to IAEA PSDL in Sieberdorf, Austria The SSDL facilities has the following; X-ray irradiator,Cs-137 and Co-137 Gamma Irradiators, Thermometers, Barometers, Ion Chambers. Check sources and Water Slab Phantom The SSDL has the following capabilities; Calibration of Survey instruments, contamination monitors, Personnel dosimeters TL Readers and ionization Chamber, Verification of Radiation bleepers and environmental alarms, Irradiation of Samples including TL Materials and Testing of Radiation Control Devices It can be concluded that calibration is required to ensure that the measurements of radiation measuring instruments are reliable and give accurate reading within certain uncertainties. SSDL-NIRPR is the focal point for the calibration of radiation measuring instrument and also maintains national standards of exposure, air kerma and absorbed dose which are disseminated to users through the calibration of radiation measuring instrument used in radiation protection

Abejide Olugbenga Adekunle