DEVELOPMENT OF IN-SITU SYSTEMS FOR 13CO2 EXPOSURE AND DETERMINATION OF 13C NET ASSIMILATION RATE OF FRUIT-BEARING SHOOTS AND WHOLE TREE AND CHAMBER FOR PRECISION 13CO2 EXPOSURE OF YOUNG POTTED TREES. Issue 13 (9th September 2022) - Tako, Yasuhiro
Abstract: 14 C is the most important radionuclide for assessing exposure dose around the Rokkasho nuclear fuel reprocessing plant, Aomori Prefecture, Japan. A simplified model with ample margins has been used so far for the assessment of the dose derived from 14 C. Realistic dose estimate of 14 C using more realistic model is necessary for safety. Apple production is an important core industry in Aomori Prefecture. To construct the dynamic model for apple, using 13 C as a tracer to substitute for 14 C, we collected data on 13 C abundance in organs including fruit after 13 CO2 exposure at various fruit growth stages. We developed 13 CO2 exposure systems for three intact fruit-bearing shoots (1), whole mature tree (2) and young potted trees (3). Systems (1) and (2) also can determine net amounts of carbon and 13 C photoassimilated. System (3) is capable of precise feedback control of 13 CO2 and 12 CO2 concentrations based on on-time determination.