No abstract

In Greater Tokyo, many people commute by train between the suburbs and downtown Tokyo for 1 to 2 h per day. The spread of influenza in the suburbs of Tokyo should be studied, including the role of commuters and the effect of government policies on the spread of disease. We analyzed the simulated spread of influenza in commuter towns along a suburban railroad, using the individual-based Monte Carlo method, and validated this analysis using surveillance data of the infection in the Tokyo suburbs. This simulation reflects the mechanism of the real spread of influenza in commuter towns. Three measures against the spread of influenza were analyzed: prohibition of traffic, school closure, and vaccination of school children. Prohibition of traffic was not effective after the introduction of influenza into the commuter towns, but, if implemented early, it was somewhat effective in delaying the epidemic. School closure delayed the epidemic and reduced the peak of the disease, but it was not as effective in decreasing the number of infected people. Vaccination of school children decreased the numbers not only of infected children but also of infected adults in the regional communities.

Spallation reaction calculation based on the intranuclear-cascade-evaporation model is modified to take into account the pre-equilibrium process by using a closed form exciton model. For the double differential (0, z n ) reaction cross section, the calculation of the exciton model is devised to produce smooth connection of that the cascade process. The result of the exciton model calculation is compared with the neutron energy spectra decomposed from the experimental data by the moving source model analysis. T w o parameters for the transition probability of the excitons and the termination conditions of the pre-equilibrium process are adjusted to reproduce the experimental data. The addition of pre-equilibrium process into the intranuclear-cascadeevaporation model improves the accuracy of the calculation code. The improvement is significant in the backward emission a t incident energy between 20 and 100MeV for target nuclei more massive than aluminum.

Nuclear Data Center at Japan Atomic Energy Research Institute is developing the JENDL High Energy File in cooperating with Japanese Nuclear Data Committee. The JENDL High Energy File includes neutron and proton nuclear data 20 MeV to 3 Gey. In this report, reported are evaluation methods and results of the evaluation and benchmark tests for the JENDL High Energy File.

Massive release of radioactive materials into the atmosphere occurred due to the Fukushima Daiichi Nuclear Power Station (FDNPS) accident in March 2011. The World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported the results of dose estimation to assess the health effect of the accident and both reports state that their assessments of internal and external exposure doses contain certain uncertainties due to uncertainties inherent to the basic data. Therefore, estimation of the internal dose from tap water was conducted in this study by utilizing a database of deposition calculated by an atmospheric transfer, dispersion and deposition model (ATDM) in conjunction with the newly obtained data on the volume of daily water intake obtained by a web-based survey. The median mean and 95-percentile of thyroid equivalent doses were estimated for 1-year and 10-year children and adults in 12 municipalities in the evacuation area in Fukushima prefecture. The present mean thyroid dose estimations for 1-year children (0.4–16.2 mSv) are smaller than the corresponding values in the UNSCEAR 2013 report (1.9–49 mGy). Dose-modifying factors in the Japanese or local community are discussed.