Measurement of radiation distribution for radon (Rn) and thoron (Th) concentrations in heritage Gua Batu and Gua mimpi of maros regency, South Sulawesi

This article as a result with collaboration between Faculty of Mathematics and Natural Sciences of Optical and Spectroscopy Laboratory and Center for Safety Technology and Radiation Metrology, National Nuclear energy agency of IndonesiaMeasurement of natural radiation produced by radioactivity such as radon and thoron has been observed in Gua mimpi and Gua batu caves,Bantimurung. South Sulawesi. This study measured the intensity of the Radon and thoron radiations using Trace Detector Nuclear CR-39 (Baryotrex) as a passive dosimeter. Measurements were performed in two phases, which direct measurements by using RAD 7 at several locations namely in the area of the door and the middle of the cave. It is intended to map the concentration of radon and thoron radiation content in the cave. Passive measurement is done by putting a nuclear trace detector at some point in the cave and kept within 3 months. The data analysis performed at the Center Safety technology and radiation metrology (PTKMR) of National Nuclear Energy Agency. The result of thoron gas concentrations in the mouth of the Gua mimpi shows the average 9.50 pCi / l, while in the middle of the cave by 34,5pCi / l. Result for direct measurements obtained using a sun nuclear of radon gas concentration of 6.33 pCi / l at the mouth of the Gua mimpi swept average 30.02 pCi / l. While in the Gua batu shows the average radon concentration of 6.33 pCi / l. Furthermore, the measurement of passively acquired level of concentration of radon at all points of the gua mimpi average above 200 Bq / m3 with a dose rate above 5 mSv / year which exceeds the threshold as determined by the International commission on radiological protection (ICRP) that is above 5mSv / year