Thermal-hydraulic design calculations for JRR-3 cold neutron source with the new moderator cell

Tokunaga, Sho; Horiguchi, Hironori; Nakamura, Takemi

JAEA-Technology 2023-001, 37 Pages, 2023/05

JAEA-Technology-2023-001.pdf:1.39MB

The cold neutron source (CNS) of the research reactor JRR-3 converts thermal neutrons generated in the reactor into low-energy cold neutrons by moderating them with liquid hydrogen stored in the moderator cell. Cold neutrons generated by the CNS are transported to experimental instruments using neutron conduits, and are used for many studies of physical properties, mainly in life science, polymer science, environmental science, etc. Improvement of cold neutron intensity is essential to maintain competitiveness with the world's research reactors in neutron science, and we are developing a new CNS that incorporates new knowledge. The current moderator cell for the CNS of JRR-3 is a stainless-steel container which is a canteen bottle type, and the cold neutron intensity can be improved by changing the material and shape. Therefore, the basic specifications of the new moderator cell were changed to aluminum alloy which has a smaller neutron absorption cross section, and the shape was optimized using a Monte Carlo code MCNP. Since these changes in specifications will result in changes in heat generation and heat transfer conditions, the CNS of JRR-3 was re-evaluated in terms of self-regulating characteristic, heat transport limits, heat resistance and pressure resistance, etc., to confirm its feasibility in thermal-hydraulic design. This report summarizes the results of the thermal-hydraulic design evaluation of the new moderator cell.

Thermal-hydraulic experiments and analyses of coupled moderator vessel for spallation neutron source

Aso, Tomokazu; Sato, Hiroshi; Kaminaga, Masanori; Hino, Ryutaro; Monde, Masanori*

Nihon Kikai Gakkai Kanto Shibu Ibaraki Koenkai (2003) Koen Rombunshu (No.030-3), p.45 - 46, 2003/09

no abstracts in English

Measurement of residual stress in the neutron cold moderator cell for high-intensity proton accelerators

Moriai, Atsushi; Kogawa, Hiroyuki; Yamamoto, Kazuyoshi; Kaminaga, Masanori; Minakawa, Nobuaki; Horiguchi, Yoji

Nihon Zairyo Gakkai Dai-37-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.35 - 37, 2001/00

no abstracts in English

Temperature analysis of solid methane particle and a container for thermal neutron moderator

Aso, Tomokazu; Ishikura, Shuichi*; Teshigawara, Makoto*; Hino, Ryutaro

JAERI-Tech 97-063, 59 Pages, 1997/12

JAERI-Tech-97-063.pdf:1.83MB

no abstracts in English

Conceptual design of high-performance moderator vessel for JRR-3 cold neutron source, 2; Evaluation of optimum geometry by structural analysis

Nakamura, Takemi; Tokunaga, Sho; Kikuchi, Masanobu

no journal, , 

JRR-3 plans to replace the moderator cell of cold neutron source. The purpose of improve the strength of the cold neutron source, a conceptual design was carried out to improve the performance of the moderator cell. Since the optimum shape was determined by nuclear characteristic analysis, the characteristics of the new moderator cell are introduced.