Development of "in-situ" alpha-ray dust monitors for fuel debris dismantling and decommissioning

Tsubota, Yoichi; Honda, Fumiya; Tokonami, Shinji*; Tamakuma, Yuki*; Nakagawa, Takahiro; Ikeda, Atsushi

no journal, , 

Aerosol behavior differs greatly depending on the generation history and processing method of NFDs. Especially for aerosols containing alpha ray emitting nuclides (alpha aerosols), which have a large internal dose upon inhalation, confinement and monitoring in the PCV are important. JAEA has been developing instruments to measure alpha aerosols in the 1F-PCV. The In-situ Alpha Air Monitor (IAAM), which was designed and developed to measure alpha aerosols "in-situ" in the harsh environment of the 1F-PCV, operates in a high-humidity, high gamma ray environment and can measure alpha aerosol concentrations 30 times The IAAM operates in a high humidity, high gamma ray environment and has demonstrated alpha aerosol measurement performance of more than 30 times the expected concentration in the 1F-PCV.

Development of an alpha air monitor in a harsh environment

Tsubota, Yoichi; Kimura, Yasuhisa; Nagai, Yuya; Kojima, Sho*; Tokonami, Shinji*; Nakagawa, Takahiro

no journal, , 

Measurement of alpha dust "in-situ" in harsh environments

Tsubota, Yoichi

no journal, , 

In decommissioning work, it is essential to evaluate (internal) exposure of workers and dust dispersion. In this report, we describe a sensor under development to measure alpha dust in situ during fuel debris removal in the damaged core (PCV) of the Fukushima Daiichi Nuclear Power Plant in a harsh environment (high humidity and high radiation dose).