Wind effect on currents in a thin surface layer of coastal waters faced open-sea

Nakano, Masanao; Isozaki, Hisaaki; Isozaki, Tokuju; Nemoto, Masashi*; Hasunuma, Keiichi*; Kitamura, Takashi*

Umi No Kenkyu, 18(1), p.37 - 55, 2009/01

https://ci.nii.ac.jp/naid/110007028667

To investigate the relationship between the wind and the current along the coast, the continuous observation of wind and current carried out for two years. The observed area was off shore Tokai-mura in Ibaraki prefecture, where faces open ocean. Considering the existence of strong pycnocline, the observation was carried out at the shallow depth over the pycnocline. The period of wind and current variation for 1 day and over several days was significant. Although the long period variation is caused from the variation of weather and season, the south current is formed by the permanent north wind component. The high correlation factor (0.64) between wind and surface current at 0.5 m was obtained throughout two years. As the result of harmonic analysis, both wind and current variations of 1 day period were appeared as S1 component tide, and it was confirmed to be land and sea breeze, and wind driven current, respectively. The land and sea breeze, which contains solar component except S1, adds the wind driven current except S1 to the corresponding component tide. From these results, it is considered that the land and sea breeze makes the pseudo S1 tidal current to the sea surface in the open coastal sea.

Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY2006

Takeishi, Minoru; Miyagawa, Naoto; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki; Isozaki, Tokuju; Morisawa, Masato; Fujita, Hiroki; Kokubun, Yuji; Kato, Chiaki; et al.

JAEA-Review 2007-044, 155 Pages, 2008/02

JAEA-Review-2007-044.pdf:2.58MB
JAEA-Review-2007-044(errata).pdf:0.13MB

Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of JAEA, Chapter 4; Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged to the atmosphere and the sea during April 2006 to March 2007. Appendices present comprehensive information, such as monitoring program, monitoring methods, monitoring results and its trends, meteorological data and discharged radioactive wastes.

The Relationship between the Surface Current Offshore Tokai and the Wind Field

Nakano, Masanao; Isozaki, Hisaaki; Isozaki, Tokuju; Ao, Hidetoshi*; Nemoto, Masashi*

JNC TN8400 2005-030, 189 Pages, 2005/09

JNC-TN8400-2005-030.pdf:136.62MB

The marine observation has been performed along the coast of JNC Tokai Reprocessing Plant (TRP) that discharges low level radioactive effluent. Recently the underslung electromagnetic flow-meter measured the current field at the very surface layer (depth: 0.5m, 1.0m, 3.0m). Then, the characteristic of the surface current field was analysed with correlation to the wind field that observed at 20m above sea level in Tokai Works. The tidal component is apparently detected by the harmonic analysis since the diel contents (land and sea breeze) is included in the wind that drives the surface seawater. However it is not the tidal current but the wind current. As the result, it made sure that the surface current is induced by the wind. Especially the wind current develops at the thin surface (skin) layer with pycnocline. The effluent from TRP has no salt and relatively high temperature, and it induces pycnocline near the discharge port. Assessing the marine diffusion of the radioactive materials from TRP, it is important to consider wind current especially.

Data Book on the Current of Tokai Reprocessing Plant; From January to December in 2001

Takeishi, Minoru; Naoto, Miyagawa,; Nakano, Masanao; Isozaki, Hisaaki; Isozaki, Tokuju; Ao, Hidetoshi*; Nemoto, Masashi*

JNC TN8450 2004-006, 117 Pages, 2004/06

JNC-TN8450-2004-006.pdf:10.31MB

Current direction, velocity, water temperature, salinity and etc. were observed by the current meters which were set near the outlet (36 26' 51" N, 140 39' 02"E)of the discharge pipe of the reprocessing plant in JNC Tokai Works. Besides, the horizontal (26 points) and vertical (14 points) observation of water temperature and salinity were executed using the monitoring ship (Seikai). The observation region ranged from 36 22' N to 36 30' N and from 140 37' E to 140 42'E. The data, which were observed in 2001, were described in this report.

Annual report on the environmental radiation monitoring around Tokai Reprocessing Plant FY2003

Takeishi, Minoru; Naoto, Miyagawa,; Hitoshi, Watanabe,; Uezu, Yasuhiro; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki

JNC TN8440 2004-002, 149 Pages, 2004/06

JNC-TN8440-2004-002.pdf:3.78MB

Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed since 1975, based on "Safety Regulations for the Tokai Reprocessing Plant, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant during April 2003 to March 2004. Appendices present comprehensive information, such as monitoring program, monitoring results, meteorological data and annual discharges from the plant.