Radiation safety management of residual long-lived radioactivity distributed in an inner concrete wall of a medical cyclotron room

Ichiro Yamaguchi, Ken ichi Kimura, Toshioh Fujibuchi, Yasuyuki Takahashi, Kyoko Saito, Hidenori Otake

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The depth distribution of residual long-lived radioactivity in the inner concrete wall of a medical cyclotron room was measured by assaying concrete cores. Seven long-lived radioactive nuclides (46Sc, 60Co, 65Zn, 134Cs, 152Eu, 22Na and 54Mn) were identified by gamma-ray spectrometry of the concrete samples. It was confirmed that the gamma-ray-emitting radionuclides induced by thermal neutrons through the (n, γ) reaction are dominant, and that the activity induced by thermal neutrons is greater at a depth of 10-30 cm, rather than at the surface of the concrete, and decreased exponentially beyond a depth of ~40 cm. Although the specific activity at the surface was greater than the clearance level for radioactive waste indicated in IAEA RS-G-1.7, the mean specific activities in the walls and floor were less than the clearance level.

Original languageEnglish
Article numberncr129
Pages (from-to)167-169
Number of pages3
JournalRadiation Protection Dosimetry
Volume146
Issue number1-3
DOIs
Publication statusPublished - Jul 1 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Radiation
  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Public Health, Environmental and Occupational Health

Fingerprint Dive into the research topics of 'Radiation safety management of residual long-lived radioactivity distributed in an inner concrete wall of a medical cyclotron room'. Together they form a unique fingerprint.

  • Cite this