@article{oai:repo.qst.go.jp:00046106,
 author = {Nakanishi, Takahiro and Zheng, Jian and Aono, Tatsuo and Yamada, Masatoshi and Kusakabe, Masashi and 中西 貴宏 and 鄭 建 and 青野 辰雄 and 山田 正俊 and 日下部 正志},
 issue = {8},
 journal = {Journal of Environmental Radioactivity},
 month = {Apr},
 note = {Using a sector-field ICP-MS the vertical distributions of the 99Tc concentration and 99Tc/137Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The 99Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m3, no greater than the estimated background level. Relatively high 99Tc/137Cs activity ratios would be caused by the inflow of the high-99Tc/137Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The 99Tc concentration and the 99Tc/137Cs activity ratio in water column showed gradual decreases with depth. Our results implied that 99Tc behaves in a more conservative manner than 137Cs in marine environments.},
 pages = {774--779},
 title = {Vertical distributions of 99Tc and 99Tc/137Cs activity ratio in the coastal water off Aomori, Japan},
 volume = {102},
 year = {2010}
}