Assessing the variability of tissue-free water tritium and non-exchangeable organically bound tritium in pine needles in Fukushima using atmospheric titrated water vapor.

When conducting environmental tritium monitoring at nuclear and fusion facilities, it is important to understand how tritium concentrations vary within the soil-plant-atmosphere continuum. Past measurements of organically bound tritium (OBT) concentrations have been conducted from the standpoint of ascertaining the persistence of tritium in terrestrial vegetation, and it has been reported that OBT concentrations fluctuate depending on the influence of atmospheric sources and meteorological conditions. The present study provides information on the variability of tritium concentrations in vegetation growing close to atmospheric sources of tritiated water (HTO) in Japan.

PERFORMANCE EVALUATION OF COMMERCIAL SCINTILLATION COCKTAILS FOR LOW-LEVEL TRITIUM COUNTING BY HIGH-CAPACITY LIQUID SCINTILLATION COUNTER.

Low-background liquid scintillation counter is one of the popular measuring instruments used to investigate tritium radioactivity in environmental media. These instruments require the liquid sample and organic solvent to be mixed for tritium measurement. In the European Union, the registration, evaluation, authorization and restriction of chemicals regulation was established to control the use of chemical substances of very high concern.

Radiation exposure to the lens of the eye for Japanese nuclear power plant workers.

In Japan, the radiation-dose limit for the lens of the eye was revised in April 2021. Consequently, for workers, the numerical values of the equivalent dose to the lens of the eye are equal to those of the effective dose. Radiation workers, radiation safety officers and licensees must comply with regulations related to radiation protection and optimize protection.

Assessment of localized and resuspended Cs due to decontamination and demolition in the difficult-to-return zone of Tomioka town, Fukushima Prefecture.

As the next step that occurred more than one decade after the accident at the Fukushima Dai-ichi Nuclear Power Station (FDNPS), decontamination and demolition have been carried out in the Specified Reconstruction and Revitalization Base (SRRB) of the difficult-to-return zone around the FDNPS. However, the risk of internal exposure among workers due to airborne dust inhalation after building demolition operations has not been sufficiently evaluated. To evaluate the working environment and internal exposure risk due to inhalation in the SRRB of Tomioka town, Fukushima Prefecture, the cesium-137 ( Cs) radioactivity levels in the airborne dust at building demolition sites were analyzed using gamma spectrometry.

Japanese population dose from natural radiation.

The radiation doses from natural radiation sources in Japan are reviewed using the latest knowledge. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the Nuclear Safety Research Association report the annual effective doses from cosmic rays, terrestrial radiation, inhalation, and ingestion as natural sources. In this paper, the total annual effective dose from cosmic-ray exposure is evaluated as 0.

214Bi/214Pb radioactivity ratio in rainwater for residence time estimation of cloud droplets and raindrops.

Continuous observation of radioactivity ratio of (214)Bi to (214)Pb as tracers in rainwater was carried out with 15-min cyclic measurement at Nagoya, Japan, from August 2011 to July 2012 to characterise wet deposition. The ratio ranged from 0.55 to 3.

Indoor/outdoor radon decay products associated aerosol particle-size distributions and their relation to total number concentrations.

The activity size distributions of indoor and outdoor radioactive aerosol associated with short-lived radon decay products were observed at Nagoya, Japan, for some periods from 2010 to 2012, following the indoor observation by Mostafa et al. [Mostafa, A. M.

Inverse modeling of Asian (222)Rn flux using surface air (222)Rn concentration.

When used with an atmospheric transport model, the (222)Rn flux distribution estimated in our previous study using soil transport theory caused underestimation of atmospheric (222)Rn concentrations as compared with measurements in East Asia. In this study, we applied a Bayesian synthesis inverse method to produce revised estimates of the annual (222)Rn flux density in Asia by using atmospheric (222)Rn concentrations measured at seven sites in East Asia. The Bayesian synthesis inverse method requires a prior estimate of the flux distribution and its uncertainties.