Intruder configurations in Ne at the transition into the island of inversion; Detailed structure study of Ne

Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.

Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08

https://doi.org/10.1016/j.physletb.2023.138038

Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

Nondestructive inspection using neutron for regenerative cooling combustion chamber

Masuoka, Tadashi*; Sato, Masaki*; Moriya, Shinichi*; Tsuchiya, Yoshinori*; Suzuki, Hiroshi; Iikura, Hiroshi; Matsubayashi, Masahito

Nihon Koku Uchu Gakkai Rombunshu, 58(680), p.254 - 260, 2010/09

https://doi.org/10.2322/jjsass.58.254

The regenerative cooling combustion chamber of a liquid rocket engine is exposed to large temperature difference between the combustion gas and the coolant such as liquid hydrogen. It induces thermal stress, and strain is accumulated over cyclic firing tests in the chamber wall. To evaluate the strain and the deformation of chamber wall is important since the chamber life usually relates to such strain and deformation. The primary objective of the present study is to establish a method to obtain experimental data on strains and deformations for correlation with the numerical data. In this study, residual strains and radiographs of a combustion chamber were obtained by applying neutron diffraction method and neutron radiography. Furthermore, two-dimensional nonlinear finite element method (FEM) analyses were conducted to calculate the residual strain in the chamber wall. From data of strain measurements, the feasibility of neutron diffraction method for a combustion chamber was shown because the data from X-ray diffraction method and FEM analyses qualitatively corresponded with those from neutron diffraction method. Concerning neutron radiography, higher spatial resolution was necessary to observe chamber wall deformation.

Design of operation and maintenance management support system for JOYO

Sato, Masuo*; Fukawa, Naohiro*; Tamaoki, Tetsuo*; Takahashi, Hideji*; Ito, Atsushi*; Yoshida, Megumi*; Sonoda, Yukio*; Yamamoto, Kazuhiko*; Maruyama, Fumi*

PNC TJ9164 89-003, 200 Pages, 1989/03

PNC-TJ9164-89-003.pdf:5.83MB

In nuclear power plant, we need to realize the computerization for the management of the plant operation and maintenance. Especially, in a periodic inspection, lots of works are concentrated. A great deal of man power is required for examining the permission of works, publishing the component isolation tags and making or revising the documents to control the schedules. Recently, in Light Water Reactor, a lot or computerization systems are developed. We design the plant management system in consideration of the characteristics of a Fast Breeder Reactor. We embody the softwear methods and hardwear systems widely to systematize the plant management technology that is accumulated at the experimental reactor JOYO. We can expect an economization and an inprovment of realiability and efficiency of the plant management.

Design of operation guide system with simulator; The preliminary design of "JOYO" operation guide system

*; Sato, Masuo*; Tamaoki, Tetsuo*; Fukawa, Naohiro*; Sano, Kenji*; *

PNC TJ901 85-08, 110 Pages, 1985/02

PNC-TJ901-85-08.pdf:3.83MB

Recently, development work of man-machine interface is being performed in many fields of nuclear power plant operation design from the viewpoint of "Operational Safety". Out of the many man-machine interface works, development of operation guide system for supporting operator's judgement on the plant condition is considered as an important work. The aim of this development work above is to improve cooperation between man and machine in the point of their interface by offering necessary and appropriate information to operator according to the plant condition. In this design, it is intended to ensure man-machine communication positively, and the preliminary design of the following items was performed in relation to operation guide system which aims at improvement of operation property of fast experiment reactor "JOYO". (1)Plant condition supervisory function. (2)Plant condition diagnosis function based on the knowledge data base. (3)Plant condition diagnosis function based on the experience data base. (4)Information display function and conversation function. (5)Hardware system configuration. This operation guide system intends to apply to "JOYO" finally. As the previous step, it is planned to verify with "JOYO" training simulator. And in this design, the interface between simulator and this system, and the items of reconstruction of simulator is also investigated.