[en] Result obtained from radiometric research carried out from 1988 - 1995 in the vicinity of a Rare-earth Research and Development Center are provided. Parameters under investigation were gross-alpha, gross-beta, 226 Ra, natural uranium and tritium concentrations in surface, rain and underground water. Radioactivity levels were found relatively low and can be characterized as a local based line. This will enable us in a later stage to monitor the change caused by the Rare-earth Research and Development Center operation

[en] The profiles of ¹³⁷ Cs sediment cores from OAEP pond were measured. Most of ¹³⁷ Cs, due to the release of treated liquid radioactive waste from OAEP waste treatment plant, was found to remain practically fixed in the upper 30 cm of sediment since 1961. The profile has two slopes in semilogarythemic scale, i.e. the sum of two exponentials inconsistent with a number of previous experiment. The concentration of ¹³⁷ Cs in fish, fish bone and snail fish are reported which the result in line with the previous measurement (Kusuma Sriyotha, 1982) confirm the precision of our analytical result

[en] Nowadays there are increasing uses of SSNTD on scientific works in Thailand. Currently we are using SSNTD as an important tool for confirming active fault zones in a province in which a new nuclear research reactor has been proposed to come up. Soil gas radon was measured by both active and passive methods. In the latter case CR-39 SSNTD was installed in a PVC tube of 50 cm long by 5 cm in diameter. The tubes were placed in 50-cm deep holes lining perpendicular to the faults' trace for one week. In this paper we describe the method and the results on calibrating these detectors using a radon chamber and a NIST-traceable radium-226 standard source. (author)