Plasma and Fusion Research

Volume 17, 1405001 (2022)

Regular Articles

Radioactivation Analysis of Concrete Wall in OKTAVIAN Facility
Shingo TAMAKI, Fajar PANUNTUN1), Kazumichi UEDOI, Wang HAIDONG, Sachie KUSAKA, Yuichiro MANABE, Yoko AKIYAMA, Teruya TANAKA2), Fuminobu SATO and Isao MURATA
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
1)
National Nuclear Energy Agency of Indonesia, Jl. Kuningan Barat, Mampang Prapatan Jakarta, 12710, Indonesia
2)
National Institute for Fusion Science, Toki 509-5292, Japan
(Received 15 August 2021 / Accepted 18 November 2021 / Published 21 January 2022)

Abstract

A deuterium-tritium (DT) neutron generator in Osaka University with a continuous intense neutron source emitting 3 × 1012 fusion neutrons per second has been in operation since 1981. However, radioactivation for the parts of the accelerator body is a serious issue. Hence, in this study, we investigated the radioactivation of the intense irradiation room containing the continuous intense neutron source. Core samples of the concrete wall were collected at various positions in the irradiation room and the radionuclides in them were determined by performing gamma-ray spectrometry. Major long-lived radionuclides found were 54Mn, 60Co, and 152Eu. The radioactivity of 152Eu may possibly be consistent with the result obtained using the simulation code. The radioactivities of 54Mn and 60Co were minimal compared with that of 152Eu. The tritium amount in the core sample was measured employing a tritium sampling system and a liquid scintillation detector and was found to be considerably larger than the amount estimated using the simulation code. Tritium diffused from the titanium-tritium target was attached to the wall surface. However, most of it did not penetrate the concrete wall. These results reveal the radioactivity issue of fusion neutron generator facilities and are expected to aid in the maintenance of their operation.

Keywords

OKTAVIAN, fusion neutron, radioactivation, radioactive waste, tritium, 60Co, 152Eu

DOI: 10.1585/pfr.17.1405001

Full Text

PDF format (4.3Mbytes) PDF Download

References

  • [1] M.Z. Youssef and R.W. Conn, Nuclear technology/fusion 3 (3), 361 (1983).
  • [2] S. Fetter et al., Fusion Eng. Des. 6, 123 (1988).
  • [3] E.T. Cheng, Fusion Eng. Des. 10, 231 (1989).
  • [4] Y. Ikeda et al., Fusion Eng. Des. 18, 387 (1991).
  • [5] H. Freiesleben et al., Fusion Eng. Des. 42 (1-4), 337 (1998).
  • [6] M. Ohta et al., Final results of IRDFF benchmark test at JAEA/FNS. No. INDC (NDS)-0731. 2017.
  • [7] M. Martone et al., J. Nucl. Mater. 212, 1661 (1994).
  • [8] S. Fiore et al., 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), 2016, pp. 1-3.
  • [9] K. Sumita et al., Nucl. Sci. Eng. 106 (3), 249 (1990).
  • [10] K. Masumoto et al., Radiation Safety Management 20, 1 (2021).
  • [11] K. Masumoto et al., J. Radioanal. Nucl. Chem. 255 (3), 465 (2003).
  • [12] K. Bessho et al., Nucl. Instrum. Methods Phys. Res. B 259, 702 (2007).
  • [13] Q.B. Wang et al., J. Radioanal. Nucl. Chem. 273 (1), 55 (2007).
  • [14] A. Brusa et al., Med. Phys. 35 (7), 3049 (2008).
  • [15] K. Masumoto et al., J. Radioanal. Nucl. Chem. 278, 449 (2008).
  • [16] L. Ulrici and M. Magistris, Radiat. Prot. Dosim. 137 (1-2), 138 (2009).
  • [17] C. Bungau et al., Phys. Rev. Special Topics - Accelerators and Beams 17, 084701 (2014).
  • [18] E. Waller et al., Health Phys. 113 (3), 227 (2017).
  • [19] S. Vichi et al., Radiat. Phys. Chem. 161, 48 (2019).
  • [20] C. Duchemin et al., Nucl. Instrum. Methods Phys. Res. A 919, 42 (2019).
  • [21] G. Yoshida et al., Radiation Safety Management 20, 1 (2021).
  • [22] H.L. Swami et al., Fusion Eng. Des. 165, 112229 (2021).
  • [23] T. Sato et al., J. Nucl. Sci. Technol. 11 (1), 86 (2012).
  • [24] H. Miyano et al., Monitoring for Compliance with Clearance Level: 2005, (Atomic Energy Society of Japan, Japan) p. 172. (in Japanese).
  • [25] K. Kumagai et al., Fusion Eng. Des. 136, 1269 (2018).
  • [26] K. Kumagai et al., Plasma Fusion Res. 13, 3404071 (2018).
  • [27] K. Kumagai et al., Plasma Fusion Res. 14, 1405044 (2019).
  • [28] J. Duda et al., J. Environ. Radioact. 189, 236 (2018).
  • [29] H. Miyano et al., Monitoring for Compliance with Clearance Level: 2005, (Atomic Energy Society of Japan, Japan) p. 16. (in Japanese).