Analysis of I-129 in radwastes by neutron activation

Determination of I-129 activity of low-level waste has become important from the standpoint of radiation safety and environmental concern. The I-129 generated from power plants could be released into the environment through the subsequent fuel reprocessing and waste disposal. In order to minimize this impact, the concentrations of I-129 and some affiliated radionuclides in the wastes to be disposed of should be determined and put in compliance with the stipulated regulations. In this work, neutron activation analysis is proposed to determine I-129/I-127 and I-129 in radwastes. The long-lived I-126, activated from I-127, is selected to replace I-128 as an indicator of stable iodine. Longterm neutron irradiation and gamma-ray counting are permitted and the related detection limit can be improved. In addition, the proposed method has related advantages of low-counting interferences and convenience for chemical operation over traditional methods; these make it a practical alternative for analyzing I-129 in radwastes in a facility near a research reactor. (C) 1999 Elsevier Science Ltd. All rights reserved.