Naoki Yamano

JENDL High Energy File

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 GeV. In this report, reported are evaluation methods and results of the evaluation and benchmark tests for the JENDL High Energy File.

JENDL-3.2 Covariance File

Covariances of neutron nuclear data have been estimated for 16 nuclides contained in JENDL-3.2. The physical quantities for which covariances are deduced are cross sections, resolved and unresolved resonance parameters, the first order Legendre-polynomial coefficients for the angular distribution of elastically scattered neutrons, and fission neutron spectra. As for 233,235,238U and 239,241Pu, covariances were obtained also for the average number of neutrons emitted in fission. Least-squares methods were applied to obtain the covariances of those cross sections which were based on experimental data. A simultaneous evaluation method yielded uncertainties in the fission cross sections of 235U, 238U, 239Pu, 240Pu and 241Pu. Covariances of nuclear model calculations were determined from uncertainties in model parameters. The covariance file thus obtained is processed by a system which has been developed, and used for the adjustment of group cross sections.

Integral Test of JENDL-3.3 with Shielding Benchmarks

Integral test of neutron and gamma-ray production data for the latest version of Japanese Evaluated Nuclear Data Library, Version 3.3 (JENDL-3.3) has been performed by using shielding benchmarks. An evaluation scheme for shielding benchmark analysis established in Japanese Nuclear Data Committee (JNDC) was applied to the integral test for medium-heavy nuclei such as Aluminum, Sodium, Titanium, Vanadium, Chromium, Iron, Cobalt, Nickel, Copper, Niobium and Tungsten. Calculations were made based on a continuous-energy Monte Carlo code MCNP4B/4C and multi-group discrete ordinates codes ANISN and DORT. The latest version of NJOY99 was employed to generate cross-section libraries for these transport codes. Calculations with JENDL-3.2, ENDF/B-VI, FENDL-1 and FENDL-2 were also made for comparison. In the present study, benchmark results of neutron and gamma-ray production data are shown for Sodium, Iron, Vanadium, Tungsten, Nickel, Titanium, Chromium, Niobium and Cobalt

The IRAC Code System to Calculate Activation and Transmutation in the TIARA Facility

A computer code system IRAC has been updated to calculate nuclide transmutation and induced radioactivity for incident particles of neutron, proton, deuteron, alpha up to 150 MeV, and l2C, l4N, l6O,20Ne, 40Ar up to 500 MeV in arbitrary multi-layer target system of three-dimensional geometry. The system provides four libraries that consist of ACSELA for isotope production cross-sections, DECAYLIB for decay data, GAMMALIB for photon emission data, and MASWPS for atomic mass data. Features and the system performance have been presented. To validate accuracy of the code system, radioactivities of residual isotopes for incident 260-MeV 20Ne ions on cobalt target were measured by using gamma-spectrometry. Comparison of radioactivity has been shown between calculated results and experimental data for each cooling time.

JSSTDL-300 : The Standard Shielding Cross Section Library Based on JENDL-3.2

A common group cross-section library JSSTDL based on Japanese Evaluated Nuclear Data Library, Version 3 Revision 2 (JENDL-3.2) has been updated in Japan Atomic Energy Research Institute (JAERI) under the cooperation of the Working Group on Standard Group Constants affiliated by the Subcommittee of Group Constants of Japanese Nuclear Data Committee (JNDC). Up to now, JSSTDL-295 based on JENDL-3.2 was developed for shielding applications, however some users pointed out a difficulty of the JSSTDL-295 for applying configurations including polyethylene slabs. It was caused from inadequate group structure for the thermal energy region and the weighting function. In the update version of JSSTDL (JSSTDL-300), we increased number of thermal energy groups from 5 to 10, and also determined the energy boundaries much carefully. The JSSTDL-300 was tested with various shielding benchmark problems, and the validity was confirmed. The integral test scheme established in JNDC was applied in this study. In the present paper, we describe the result of integral test of JSSTDL-300 for applying benchmarks of Japanese-American Shielding Program for Experimental Research (JASPER). It has been concluded that JSSTDL-300 is highly applicable for shielding applications such as configurations in which thermal neutrons were enhanced.

Validation of gamma-ray production data of iron in JENDL-3.2 with shielding benchmark

An integral test of γ-ray production data of iron in the latest version of Japanese Evaluated Nuclear Data Library (JENDL-3.2) has been performed by means of a shielding benchmark analysis of KfK leakage neutron and γ-ray spectrum measurements from iron spheres with a 252Cf source in the center. Two comprehensive systems which consist of a continuous-energy Monte Carlo method and a multi-group Sn transport method have been adopted in this benchmark analysis. For comparison, analyses with JENDL-3.1, FENDL-1 and ENDF/B-IV have been also carried out. The calculation using JENDL-3.2 showed a good agreement with the experiment. It has been concluded that the γ-ray production data of iron in JENDL-3.2 were applicable for use of shielding designs and analyses of the fission neutron source problem.

A Community-Based Risk Communication Approach on Low-Dose Radiation Effect

A community-based risk communication approach for risk and risk-related factors regarding low-dose radiation has been started in 2013. In this approach, three groups that consist of local citizens, health nurse, midwife and nutritionist, and media reporters have been coordinated, and they discuss and examine a guidebook of health effects on low-dose radiation prepared by experts. Then they will revise the contents and expressions of the guidebook under expert’s support by themselves. An improved guidebook implementing stakeholders’ input will be expected through this process. In parallel to the community-based risk communication, an opinion survey has been conducted for the inhabitants of Tsuruga City in the Fukui prefecture to obtain people’s cognition about ionizing radiation and risk on health effects. The inhabitants of about 43 % show strong anxiety for radiation. They also show strong requirement for the risk criteria that should be specified by government/specialists. The current status and progress of the community-based risk communication approach are discussed, and a necessity of risk education regarding trans-science problem is presented.

Recent activities in the field of General Issues

The Journal of Nuclear Science and Technology and the Transactions of the Atomic Energy Society of Japan (in Japanese) consist of 11 classified areas of expertise which include a wide range of topics in social science, natural science, engineering and technology-relating nuclear issues. The first category of these areas is classified as General Issues. The General Issues cover philosophy, ethics, justice, politics, policy, international relations, economics, sociology, environment, education and training, information and database, and nuclear nonproliferation and safeguards. The authors describe the recent research articles and reviews in the two journals to highlight research trends in this research area. In the field of economics and strategy of nuclear fuel cycle, research activities for cost analysis, and partitioning and transmutation issues have proceeded. A cost analysis for a new type of nuclear fuel, BeO-UO2, was studied in the nuclear fuel cycle [1], an evaluation of depreciation cost in replacement of nuclear power plant (NPP) [2] and a long-term outlook for uranium and uranium enrichment supply [3] were presented. Cost analysis and evaluation are essential for feasibility studies of innovative reactor concept and future nuclear fuel cycle, so that the authors will hope these contributions become active. Scenario analysis of partitioning and transmutation issues of the UK, France, the USA and Japan have also been studied [4–8]. The energy security and nuclear security issues that have become important since the 2011 earthquake off the Pacific coast of Tohoku, and the severe nuclear accident of 11March 2011 have also been discussed [9–11]. In the field of geological repository, a comprehensive review of Japan’s situation was recently presented [12]. In addition, social issues relating high-level radioactive waste, which is a major concern in Japan, have been actively discussed [13–15]. Regarding social communication including public opinion surveys, activities in this area have been

Isotope Production Cross Section Library for Use of Transmutation Calculation in the IRAC Code System for the TIARA Facility

An isotope production cross-section library for 57 elements and 136 nuclei has been produced by using ALICE-F code based on a Geometry Dependent Hybrid model for incident particles of neutron, proton, deuteron, alpha, C-12, N-14, O-16, Ne-20 and Ar-40. Maximum energy of incident particles for neutron, proton, deuteron and alpha is 150 MeV, and 500 MeV for the other projectile ions. Using the data, a cross-section library, ACSELAhas been prepared for an IRAC code system to calculate product isotopes and induced radioactivity in various radiation environments in the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) facility of Japan Atomic Energy Research Institute (JAERI). The generation scheme of the ACSELA library is presented. Comparisons are shown between the calculated results and experimental data for incident protons and carbon ions as well as evaluations of the Los Alamos 150 MeV library for incident protons.