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Oral presentation

Comments on $$^{40}$$K data of FENDL-3.1c

Konno, Chikara; Kwon, Saerom*

no journal, , 

The KERMA factor (energy-balance method) and DPA cross section of $$^{40}$$K in FENDL-3.1c are much smaller than those of other nuclear data libraries. In order to identify reasons of the smaller KERMA factor and DPA cross section, I examined energy-balance, energy distributions of charged particles, yield and energy distribution of $$gamma$$ in the (n,p) and (n,$$alpha$$) reactions, which contribute to KERMA and DPA cross section data much, for low energy neutrons. As a result, it is found out that the energy distributions of charged particles, and yield and energy distribution of $$gamma$$ for low energy neutrons in the (n,p) and (n,$$alpha$$) reactions are too small, which causes the smaller KERMA factor and DPA cross section.

Oral presentation

Dimension-reduced cross-section adjustment method

Yokoyama, Kenji; Yamamoto, Akio*; Kitada, Takanori*

no journal, , 

no abstracts in English

Oral presentation

Current status and issues of the AESJ Education Committee's CPD Registration System

hamasaki, manabu*; Yoshinaka, Kazuyuki

no journal, , 

In 2008, the Atomic Energy Society of Japan (AESJ) launched its own Continuing Professional Development (CPD) registration system. But the system was not largely used by the Society members, which obliged to cease it only one year after the launch. In 2015 the AESJ Education Committee renewed and resumed its CPD registration system under the "Sunshine Policy", reflecting the lessons learned from the past failure. The renewed system has already attracted many users. On the other hand, some issues are emerging, including that the repeat users are quite limited.

Oral presentation

Radiation measurements associated with lightning and thunderclouds in winter at the coastal area of the Japan Sea

Tsuchiya, Harufumi; Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Okuda, Kazufumi*; Makishima, Kazuo*; Sato, Mitsuteru*; Sato, Yosuke*; et al.

no journal, , 

no abstracts in English

Oral presentation

Calculation of cross section in resonance region using the statistical properties of the resonance parameters

Furutachi, Naoya; Minato, Futoshi; Iwamoto, Osamu

no journal, , 

Except for extremely light nuclei and neutron rich nuclei, generally the density of nuclear excited states around neutron threshold energy is very high, and therefore it is very difficult to predict energy and width of resonance precisely. On the other hand, it has been known that the resonance parameters have statistical property with high density of excited states. There is a theoretical method to calculate cross section in resonance region by generating resonance parameters randomly utilizing the statistical properties of the resonance parameters. Such a method can reflect a theoretical information of resonance on a nuclear data evaluation for nuclei with no experimental data, such as fission products. However, studies for how to determine a representative value of the cross section randomly calculated, and what is an uncertainty from the randomness, are insufficient. Therefore, in this study, we calculated the cross section in the resonance region using randomly generated resonance parameters, and derived the probability distribution of the cross section by calculating cross section repetitively using resonance parameter sets generated from different random seeds. By using this density distribution, we discuss the behavior of the statistically reasonable cross section, and uncertainty from statistical fluctuation.

Oral presentation

Theoretical calculation of neutron cross sections for Zr isotopes

Ichihara, Akira

no journal, , 

In JAEA we are in charge of the revision of the Japanese Evaluated Nuclear Data Library, JENDL-4.0. An evaluation activity of the next JENDL project is being carried out for structural materials in nuclear power plants. Zirconium is an important element which is used in the fuel rods and the channel boxes of fuel assemblies in light-water reactors. In this study, we calculated neutron cross sections theoretically in the incident energy range between 0.1 and 20 MeV. In the next JENDL, metastable state production data will be supplemented substantially in order to contribute to the evaluation of radioactivities. By adjusting parameters of nuclear reaction models, we could obtain the metastable state production cross sections which are consistent with the experimental data in the (n,2n) and (n,p) reactions of Zr-90.

Oral presentation

Development of automatic detection and measurement system for the Pu spot in the MOX fuel pellet

Tazawa, Yuto; Hosogane, Tatsuya; Ishikawa, Fumitaka; Kayano, Masashi; Matsuyama, Kazutomi; Saito, Kosuke; Oishi, Shinichi*; Nakajima, Hiroshi*

no journal, , 

no abstracts in English

Oral presentation

Impact of the uncertainty of the PIE analysis on the criticality analysis

Tada, Kenichi; Suyama, Kenya

no journal, , 

To investigate the applicability of the burnup calculation code SWAT4.0, we calculated the post irradiation examination which is 8$$times$$8 BWR fuel assembly and loaded in Fukushima Daini Nuclear Power Plant unit 2. In this study, we investigate the impact of the difference of the number density of nuclide on the criticality analysis for the fuel debris. The calculation was carried out by the infinite pin-cell geometry and calculation results indicates that the impact of the difference of the number density of nuclide on the k-effective is less than 3%$$Delta$$k/k. Since we adopt the upper subcriticality limit of 0.95 in usual criticality safety evaluation, this result indicates that SWAT4.0 has adequate prediction accuracy of the isotopic composition to be adopted in the burnup credit analysis of the fuel debris from the Fukushima Daiichi Nuclear Power Plant.

Oral presentation

Oral presentation

A New kind of radiation-detector dead-time

Hales, B. P.; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu

no journal, , 

It is necessary to account for detector and data acquisition system dead-time in time-dependent radiation detection experiments. Until now, the paralyzable and non-paralyzable models, in which an event occurring in the detector causes the detector to be unable to detect another event for a short period of time. (That is to say, deadtime occurs after an event). However, during a time-of-flight experiment with the new DAQ system for the Ge detector at J-PARC/MLF/ANNRI, we have found a phenomenon which is entirely unexplainable by these models. In this talk, we will discuss this new type of dead-time, its causes, and how to correct for it.

Oral presentation

Development of active neutron NDA apparatus for nuclear non-proliferation and nuclear security, 1; Project overview and development of Prompt Gamma-ray Analysis system

Toh, Yosuke; Furutaka, Kazuyoshi; Ozu, Akira; Tsuchiya, Harufumi; Kitatani, Fumito; Maeda, Makoto; Komeda, Masao; Koizumi, Mitsuo; Seya, Michio

no journal, , 

no abstracts in English

Oral presentation

Investigation of a low cost neutron detector for an active neutron system

Komeda, Masao; Ozu, Akira; Toh, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Development of discrete transport theory with anisotropic neutron streaming effect

Maruyama, Shuhei; Oki, Shigeo

no journal, , 

This study proposes the discrete transport theory with anisotropic neutron streaming effect which is cased by cell heterogenity. The anistropic diffusion theory is developed by P1 approximation on this transport theory. It is found by the numerical analyses that the anisotropic neutron streaming effect expressed as Benoist's anisotropic diffusion coefficients makes a little difference between transport and diffusion theory.

Oral presentation

Level 1 PRA for design works of external vessel storage tank in advanced loop-type sodium-cooled fast reactor

Yamano, Hidemasa; Naruto, Kenichi*; Kurisaka, Kenichi; Nishino, Hiroyuki

no journal, , 

Spent fuels are kept in an external vessel storage tank (EVST) filled with sodium for fuel handling in sodium-cooled fast reactors. This study performed Level 1 PRA for the EVST designed in an advanced loop-type reactor in order to identify dominant accident sequences leading to fuel failure and to quantify fuel damage frequency.

Oral presentation

Establishing emergency response framework for newly organized Fukushima Research Institute of JAEA

Endo, Yuya; Suzuki, Takashi; Uezu, Yasuhiro

no journal, , 

In order to contribute for decommissioning of the Fukushima Daiichi Nuclear Power Station and remediation of Fukushima, Fukushima Research Institute had held by Japan Atomic Energy Agency (JAEA). The emergency response system was developed to improve a risk management in the early stage. The emergency response training with this system was also carried out.

Oral presentation

Measurements of magnetic dipole strength in Pu-239 using nuclear resonance fluorescence

Shizuma, Toshiyuki; Angell, C.*; Hajima, Ryoichi; Ludewigt, B.*; Quiter, B. J.*; Koizumi, Mitsuo

no journal, , 

Nuclear resonance transmission $$gamma$$-rays through a Pu-239 target were measured, as a part of a development project of nuclear material non-destructive detection and assay using quasi-monoenergetic laser Compton scattering (LCS) photon beams. The experiment was carried out at Duke University. We used photon beams at energies of 2.14 with energy width of about 4% to irradiate absorber and scattering targets of Pu-239. We measured scattered $$gamma$$ rays from the scattering target using high-purity Ge detectors. As a result, we found the average integration cross section of 13 eV barn at excitation energies from 2.12 to 2.19 MeV. The sum of the branching ratio from the excited state to the ground and first excited states are 0.4. This enables us to quantify Pu-239 in a assembly with an error of approximately 3% in four-hour measurement with 10$$^{13}$$ photon/s beams. In this presentation, we will report on the measurement method and the experimental results. We will also talk about the future plan for development of non-destructive assay using mono-energetic LCS $$gamma$$-ray beam. (This development was carried out under "the subsidiary for promotion of strengthening nuclear security or the like of MEXT".)

Oral presentation

Collecting, storage, and usage of information resources about Fukushima Daiichi Nuclear Power Station Accident; Current status of the "Fukushima Nuclear Accident Archive"

Hayakawa, Misa; Kunii, Katsuhiko; Mineo, Yukinobu; Yonezawa, Minoru

no journal, , 

JAEA Library has been providing the "Fukushima Nuclear Accident Archive (FNAA)" to support R&D activities such as environmental recovery, or reactor decommissioning. Applying an access log analysis on FNAA, the trends figured out are access increases to the oral presentation and the ones of websites already closed, implying needs of the information toward the future.

Oral presentation

Oral presentation

Development of a Monte Carlo solver Solomon for criticality safety analysis, 1; Implementation of a collision analysis model based on the ACE format

Nagaya, Yasunobu; Hagura, Hiroyuki*

no journal, , 

Careful criticality management must be required for the removal of fuel debris generated at the accident in the Fukushima Daiichi Nuclear Power Station; the uncertainties in fuel debris properties such as amount, composition, location, densities, etc. must be taken into account. For determining the policy of such criticality management, it is important to build the fundamental criticality safety database (criticality maps) for as many fuel debris conditions as possible. In order to contribute the building of the database, the development of a novel Monte Carlo solver has been initiated to perform criticality calculations of fuel debris with flexible randomized models. In this work a model of collision analysis with the ACE formatted nuclear data has been implemented and verified with criticality calculations for simple spherical geometries.

Oral presentation

Development of high sensitive laser absorption spectroscopy system using optical cavities for isotope analysis

Kuwahara, Akira; Nankawa, Takuya; Matsui, Makoto*

no journal, , 

no abstracts in English

176 (Records 1-20 displayed on this page)