Dose equivalent rate and radiation monitoring results during power distribution measurements of HTTR

Dose equivalent rates around the fuel handling machine, the control rod handling machine, the stand pipe compartment, and the maintenance pit were measured during power distribution measurements, in which gamma ray was measured from HTTR fuel. The power distribution measurements were the first time to handle the fuel blocks and the control rods irradiated in the core. Dose equivalent rate measurement were performed aiming at the check of shielding performance of components, and unexpected streaming paths. The radiation monitoring during operation was carried out. As the results, there was no problem on shielding. The measured data at operation condition were also obtained, which will be useful to predict operation circumstance in the future. (author)