Monitoring of External Gamma and Beta Exposures

In this chapter, an overview of individual monitoring of external gamma and beta exposures is described with a focus on its relevance in radiological protection and operational aspects. The principles of radiological protection are addressed in the beginning, underlining the necessity for personnel monitoring to adhere to radiological safety and regulatory guidelines. The rationale for monitoring radiation exposure is discussed, with an emphasis on the types of monitoring and the foundational radiological protection quantities, interrelationship and conversion coefficients. Towards operational aspects, requirements of calibration of personal dosimeters, design of monitoring program, guidelines on who should be monitored and length of monitoring period, considerations for skin, extremity and eye lens monitoring, recording and investigation levels, accuracy requirements and periodic performance evaluation of the monitoring system along with an example of CaSO4:Dy based personnel monitoring system is described. In addition, various recent studies carried out for the CaSO4:Dy based TLD badge system towards improving dosimetric performance are briefly presented. The chapter ends with brief description of recent advances in the field of personal dosimetry such as recommendation of new operational quantities for individual monitoring and Personal Online Dosimetry Using computational Methods (PODIUM).