[2L08-13] Decommissioning of 1F

3:30 PM - 3:45 PM JST(6:30 AM - 6:45 AM UTC)

[2L11] Design of a Monitoring System for Fuel Debris Retrieval Operations at the Fukushima Daiichi Nuclear Power Station: Proposal of Physical Quantities to be Measured on Worksite

*Tessai Sugiura¹, Hajime Asama¹, Qi An¹, Atsushi Yamashita¹ (1. UTokyo)

Keywords:

Fukushima daiichi nuclear power station,Nuclear decommissioning,Risk analysis,Objective tree,Failure mode and effect analysis

At the Fukushima Daiichi Nuclear Power Station, a monitoring system is necessary to perform fuel debris (FD) retrieval while maintaining safety and operational functions. It is crucial to define the physical quantities to be measured at the worksite as design specifications. Risk analysis methods combining Fault Tree Analysis (FTA) and Failure Mode and Effects Analysis (FMEA) are useful for determining them. However, due to the lack of operational experience in FD retrieval, using FTA is difficult. Therefore, this study combines Objective Tree with FMEA to examine methods for deriving potential root cause. Applying this method to the partial submersion method of retrieving FD, we proposed physical quantities to be measured at the worksite as design specifications for the monitoring system.