We have developed the method to detect DNA damage within the polymerase chain reaction (PCR) amplification region and estimate the risk of secondary cancer induction in radiation cancer therapy. DNA samples were irradiated with γ-rays, and oxidative damage and abasic sites were converted into strand breaks using formamidopyrimidine-DNA glycosylase (Fpg) and endonuclease (III), respectively. The yields of DNA damage were subsequently evaluated by PCR. The ratio of strand breaks : abasic sites : oxidative damage was approximately 1.0 : 2.8 : 2.4, revealing the proportions of different apparent DNA damage.

In recent years, a non-destructive elemental analysis method using a muon beam has been developed and applied to various research fields. This method is based on the measurement of high-energy characteristic “muonic” X-rays emitted after muon irradiation on the sample. In this article, the principle, application and feature development of the muon elemental analysis method are presented.

Monte Carlo radiation transport simulation codes are widely used for dose evaluation in various radiation therapies owing to their high precision. Several tools have been developed for automatically converting SPECT/CT and PET/CT images into input files for these Monte Carlo codes. These tools can be used for dose evaluation in nuclear medicine. In this article, we introduce the current status of such tool development and provide an overview of the nuclear medicine-related features of RT-PHITS, which are currently under development.

The MIRD method is a method for evaluating internal radiation doses from radiopharmaceuticals proposed by the MIRD Committee of the Society of Nuclear Medicine and Molecular Imaging (SNMMI). The basic concept of the MIRD method proposed more than half a century ago has not changed significantly to this day, but it has evolved into a highly accurate method with the development of mathematical (or computational) phantoms and Monte Carlo calculations. In addition, the calculation software recently distributed by the MIRD Committee includes some recent efforts. This report outlines the basics of the MIRD method and recent efforts of the MIRD committee.

Dosimetry is essential to evaluate the safety and efficacy of Radionuclide Therapy. Dosimetry requires time-integrated activity (TIA) in the target tissue from multiple Imaging. The accuracy of TIA depends on the quantitatively of the image and the fitting method. This paper is discussed the basics of imaging and TIA necessary for dosimetry, as well as the latest developments in the field.

Internal dosimetry software for radionuclide therapy ranges from stand-alone conventional dose calculations to vendors-provided software that is installed in the workstation of nuclear medicine imaging system and seamlessly supports everything from image reconstruction to dose calculation based on therapeutic or alternative radionuclide imaging. This paper introduces the current state of internal dosimetry software in radionuclide therapy.

We propose the novel source for radiation education using natural nuclides containing in the air. After sampling by air cleaner, remarkable radiation count was found at several survey meters in HEPA filter. These counts showed a gradually increase and reached the steady-state after 90 min collection time. Attenuation of radioactivity showed according to the first-order reaction equation and half-life was estimated about 36 min. Moreover, the energy peaks of ²¹⁴Pb and ²¹⁴Bi as progenies of ²²²Rn were detected in the γ-ray spectral analysis using multi-channel analyzer.

To make the new research reactor meaningful, it is first necessary to clarify its fundamental philosophy and define its objectives. Then, it is important to determine what activities should be undertaken to realize these goals. Since it will take a long time before the facility is operational, it is necessary to consider what activities will be carried out to realize the initial goals. In the main text, the author would like to describe our basic thoughts at this time as best the author can.

Government aims to use the Monju site to build a center of excellence for Japanʼs further nuclear research and development and human resource development. JAEA is the implementing body for the research reactor installation and is promoting the project through cooperation with Kyoto University and the University of Fukui. From FY2023, we began phase I of the detailed design for the reactor core, equipment, and layout.

Many radioisotopes (RI) are produced in research reactors and accelerators, and are making a significant contribution to providing better lives to people through their use in the industrial and medical fields. RI production and distribution using research reactors will continue to be important, and RI production is expected to take place in the new research reactor currently being planned for construction at the Monju site. This article introduces efforts of RI production using the research reactor JRR-3 to contribute to the consideration of RI production in the new research reactor.

The new research reactor at the “Monju” site, which is planned as a 10-MW class medium-power reactor primarily designed for neutron beam utilization, aims to be a valuable research facility that contributes to academic research, industrial applications, and local society development. The neutron instruments are the essential factor that defines the character of the new research reactor as a research facility. Institute for Integrated Radiation and Nuclear Science, Kyoto University (KURNS) is leading the planning of neutron instruments for the new research reactor, working closely with JAEA and Fukui University. The prioritized instruments, selected by their importance in terms of utilization needs, and the instruments located close to the reactor core that affect the reactor design are the primary focus of the neutron instruments study. With the cooperation of experts from domestic universities and research institutions, neutron instruments task forces have been organized to conduct a study on the neutron instruments to be installed at the new research reactor. In addition, prototype instruments development will be promoted to ensure the continuity of academic and technological knowledge and foster human resource, while steadily advancing the neutron instruments study by the task forces.

At the neutron irradiation experimental instruments in research reactors, experiments such as neutron activation analysis, Ar/Ar dating, and radioisotope production can be carried out. This article describes the plans for the instruments to conduct these experiments in the new research reactor at the Monju site.