Measurement of neutron dose under criticality accident conditions at TRACY using ebonites

Murazaki, Minoru; Nobuhara, Fumiyoshi*; Iwai, Shohei*; Tonoike, Kotaro; Uchiyama, Gunzo

JAEA-Technology 2009-045, 46 Pages, 2009/09

JAEA-Technology-2009-045.pdf:12.88MB

Neutron doses under criticality accident conditions at TRACY were measured using ebnites, which are hard rubber containing sulfur. To evaluate a neutron dose, beta rays emitted from P induced by S(n,p) reaction are measured with Geiger-Mller (GM) counter. A calibration factor (Gy/cpm), which is pre-determined using a Cf source, is applied to the count rates to obtain neutron doses. Factors to correct for the difference between responses of S(n,p) to the spectrum of Cf source and to spectra of TRACY were calculated and applied to the doses. Ebonites were exposed by TRACY with and without the water reflector. Neutron doses in TRACY without a reflector were evaluated with an uncertainty of less than about 40%. On the other hand, average of neutron doses in TRACY with the water reflector were accurate. By these measurements, it was found that ebonites can be used as a neutron dosimeter for criticality accidents.

2016 Activity Summary on Simple Calculation Code Review WG for radiation shielding, 2; An Issue of the code development and a roadmap towards a new photon point-kernel code with build-up factors

Nobuhara, Fumiyoshi*; Hirao, Yoshihiro*; Matsuda, Norihiro; Sakamoto, Hiroki*; Sakamoto, Yukio*; Iwashita, Mitsushige*; Yoshioka, Kentaro*

no journal, , 

no abstracts in English

The Activity report of review WG for simple radiation shielding in phase 2

Nobuhara, Fumiyoshi*; Hirao, Yoshihiro*; Matsuda, Norihiro; Onishi, Seiki*

no journal, , 

The Working Group for Review of Simplified Shielding Analysis Codes (WG) was established in the Radiation Science and Technology subcommittee of the Atomic Energy Society of Japan (AESJ) to identify and review issues related to existing simplified shielding analysis codes that are widely used such as actual shielding design and safety assessment. In the second phase of the WG activity, we mainly studied the point kernel code and the albedo method for the maze, and the results were summarized in the second phase report. The obtained issues related to the point kernel code will be reflected in the research program started in 2020 adopted in the Radiation Safety Research Program.