TRU oxide sample reactivity worths measured in the FCA-IX assemblies with systematically changed neutron energy spectra

Fukushima, Masahiro; Okajima, Shigeaki*; Mukaiyama, Takehiko*

Journal of Nuclear Science and Technology, 20 Pages, 2023/00

https://doi.org/10.1080/00223131.2023.2240872

A series of integral experiments was conducted to evaluate the fission and the capture cross- sections of transuranic (TRU) nuclides at the fast critical facility FCA of the Japan Atomic Energy Agency (JAEA). The experiments were carried out using seven uranium-fueled assemblies of the FCA. The neutron energy spectra of the core regions were adjusted so as to change from an intermediate neutron spectrum to a fast neutron spectrum on an assembly-by-assembly basis. The integral data measured with these experimental configurations provide some neutron energy characteristics: 1) fission rate ratios (FRRs) of Np, Pu, Pu, Am, Am, and Cm relative to Pu by using absolutely calibrated fission chambers, 2) small sample reactivity worths (SRWs) of Np, Pu, Pu, Am, and Am where oxide powders of around 15 to 20 grams were used, 3) criticalities, and 4) spectral indices such as fission rate ratios of U relative to U. In this paper, details of the SRW measurements are reported, and the latest Japanese Evaluated Nuclear Data Library JENDL-5 is tested by using the integral data obtained in systematically varied neutron energy spectra.

Validation of minor actinide cross sections by studying samples irradiated for 492 days at the dounreay prototype fast reactor, 2; Burnup calculations

Tsujimoto, Kazufumi; Kono, Nobuaki; Shinohara, Nobuo; Sakurai, Takeshi; Nakahara, Yoshinori; Mukaiyama, Takehiko; Raman, S.*

Nuclear Science and Engineering, 144(2), p.129 - 141, 2003/06

https://doi.org/10.13182/NSE03-A2348

To evaluate neutron cross-section data of minor actinides, separated actinide samples and dosimetry samples were irradiated at the Dounreay Prototype Fast Reactor for 492 effective full power days. Based on the burnup calculations of major actinide and dosimetry samples, the neutron flux distribution and the flux level were adjusted at the locations where minor actinide samples were irradiated. The burnup calculations were carried out for minor actinides using the determined flux distribution and flux level. This paper discusses the burnup calculations and the validation of minor actinide cross-section data in evaluated nuclear data libraries. We find that we can obtain reliable FIMA (fission per initial metallic atom) values by using the Nd method except that the uncertainties in the FIMA values are large for U, Pu, Am isotopes, and Cm isotopes because the Nd yields are known poorly for these isotopes and are probably overestimated. For these isotopes, measurements to improve the fission-yield data are needed. We also find that, in general, the JENDL-3.2 nuclear data for the minor actinides are adequate for the conceptual design study of transmutation systems. But, there are some nuclides (especially Pu and Pu) for which new measurements are needed particulary if the minor actinides constitute a major part of the nuclear fuel.

Validation of minor actinide cross sections by studying samples irradiated for 492 days at the dounreay prototype fast reactor, 1; Radiochemical analysis

Shinohara, Nobuo; Kono, Nobuaki; Nakahara, Yoshinori; Tsujimoto, Kazufumi; Sakurai, Takeshi; Mukaiyama, Takehiko*; Raman, S.*

Nuclear Science and Engineering, 144(2), p.115 - 128, 2003/06

https://doi.org/10.13182/NSE03-A2347

no abstracts in English

Transmutation of long-lived nuclides

Mukaiyama, Takehiko

Genshikaku Kenkyu, 46(2), p.47 - 73, 2001/06

no abstracts in English

High intensity proton accelerator project and status of accelerator driven nuclear system developments

Mukaiyama, Takehiko

Genshiryoku Shisutemu Nyusu, 11(1), p.5 - 13, 2000/06

no abstracts in English

Present status of research & development on accelerator-driven nuclear systems

Mukaiyama, Takehiko

Genshikaku Kenkyu, 44(6), p.23 - 32, 2000/04

no abstracts in English

The Joint project of neutron science project at JAERI and Japan hadron facility project at KEK

Mukaiyama, Takehiko

RIST News, (28), p.3 - 11, 1999/09

no abstracts in English

Introduction

Mukaiyama, Takehiko

Chuseishi Kagaku; NSA/Commentaries, No.7, p.1 - 2, 1999/06

no abstracts in English

Development of authentication system for the Fast Critical Assembly (FCA) Portal Monitor (P/M) and Penetration Monitor (PN/M) systems of JAERI

Ogawa, Hironobu; Mukaiyama, Takehiko

JAERI-Tech 99-041, 188 Pages, 1999/05

JAERI-Tech-99-041.pdf:10.42MB

no abstracts in English

OMEGA program in Japan and ADS development at JAERI

Mukaiyama, Takehiko

Proceedings of the 3rd International Conference on Accelerator Driven Transmutation Technologies and Applications (CD-ROM), 12 Pages, 1999/00

no abstracts in English