[3F05-07] Radiation (Radioactivity) Measurement and Dosimetry 1

[3F07] Study on a monitoring technique of radionuclide concentrations in rainwater with continuous filtration method.

*Jun Moriizumi¹, Keiho Kaneko¹, Hiromi Yamazawa¹ (1. Nagoya Univ.)

Keywords:wet deposition, continuous monitoring, radioactivity in rainwater, gamma ray spectrum

A monitoring technique that enables observation of temporal variation in radionuclide concentrations in rainwater with a time resolution of several minutes was studied. To overcome upper and lower limits of measurable sample volume for conventional measurements that introduce rainwater into a vessel such as a Marinelli beaker or a small cell, the studied method continuously filtrate rainwater through an absorbent to accumulate the dissolved/suspended radionuclides on it and calculates variations in the nuclides’ in-flow rates from variation in gamma ray spectrum. By using natural radon decay series nuclides of Pb-214 and Bi-214 in rainwater as a model case, their collection efficiencies and detection efficiencies were determined, and feasibility of the monitoring technique was discussed.