Plasma and Fusion Research

Volume 11, 1305032 (2016)

Letters

Long-Term Monitoring of Tritium Concentration in Environmental Water Samples Collected at Tono Area, Japan

Naofumi AKATA^1,2), Masahiro TANAKA^1,2), Hiromi KATO¹⁾, Hirokuni YAMANISHI³⁾, Hideki KAKIUCHI⁴⁾, Hiroshi HAYASHI¹⁾, Hitoshi MIYAKE¹⁾ and Kiyohiko NISHIMURA¹⁾

1): National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
2): SOKENDAI (The Graduate University of Advanced Studies), Toki, Gifu 509-5292, Japan
3): Kinki University, Higashi-Osaka, Osaka 577-8502, Japan
4): Institute for Environmental Sciences, Obuchi, Rokkasho, Aomori 039-3212, Japan

(Received 7 October 2015 / Accepted 1 February 2016 / Published 17 March 2016)

Abstract

A deuterium plasma experiment is being planned at the Large Helical Device (LHD) at the National Institute for Fusion Sciences (NIFS). To delineate the regional background tritium concentration level before initiation of the experiment, we evaluated tritium concentrations in environmental water samples (river water, pond water, well water, tap water, and rainwater) collected at Tono area, Japan since 1982. Tritium concentrations in environmental water samples ranged widely from N.D. (below the instrumental detection limit of 0.27 Bq L⁻¹) to a maximum of 4.39 Bq L⁻¹. Tritium concentrations at 9 continuous monitoring locations over the 15 years ranged from N.D. to 1.36 Bq L⁻¹. This regional background concentration range will be used to evaluate environmental assessments after the initiation of the deuterium plasma experiment in LHD.

Keywords

NIFS, LHD, tritium monitoring, environmental water sample, deuterium plasma experiment

DOI: 10.1585/pfr.11.1305032

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