The JNC-OEC/JAERI-Oarai area is a radiation controlled area. By law, the radiation level attributed to facility activites must not exceed 1 milliSievert per year outside the boundary of this area. To ensure public safety and prove legal compliance, JNC and JAERI conduct environmental airborne radiation monitoring by collecting and analyzing data acquired from monitoring posts and other instrumentation located along the perimeter and within the radiation control area (see inset in Figure 1).  In total there are 14 monitoring posts used to acquire data from this radiation control area. Six posts, posts 11 –16 are used by JNC-OEC; eight posts, posts 1 – 8, are used by JAERI-Oarai.

Meteorological Measurements
 

Located on JAERI-Oarai property, near the boundary of the JNC-OEC and JAERI-Oarai is a 90 meter meteorological observation tower pictured in Figure 8. From this tower, measurements are collected including wind direction, wind speed, and air temperature.  To measure wind direction and speed there are five propeller type anemometers located on the tower: two at 80 meters, two at 40 meters, and one at 10 meters. To measure air temperature, instruments are located at 90 meters, 40 meters, 10 meters, 1.5 meters. Background solar radiation, as well as incoming and outgoing radiation, are measured using constantan thermocouples at 1.5 meters above ground.

Internet Data Releases for the General Public

JNC-Oarai and JNC-Tokai publish environmental data on their web-sites.  Oarai data is available in both Japanese and English language versions.
These web-sites present the data in several layers:

• A site map with the most recent hourly average airborne radiation and wind speeds
• Tabular displays of hourly radiation and meteorological data
• Graphical displays of hourly radiation and meteorological data, in 24 hour, 48 hour and 7 day histories
• Explanation of the measurement systems

• Radiation Data at O-arai (Japanese)
• Radiation Data at O-arai (English)
• Radiation Data at O-arai (screen capture)
• Radiation Data at Tokai

Data Release Via the Internal JNC Net
 

Airborne radiation data and meteorological data is already being released by JNC-Tokai via the intranet. These figures are screen captures of near real-time data obtained from the JNC intranet. Formal Publications In addition to the time series radiation and meteorological data being electronically transmitted to various locations, the environmental measurements which are obtained through laboratory sampling and analysis, e.g., radiation data on water, soil, and vegetation, are formally recorded and published. On a regular basis.the Ibaraki Prefecture Tokai Area Environmental Radiation Monitoring Committee evaluates and reports the data. Committee members include the Ibaraki prefecture Vice Governor, the leaders of relevant cities, towns, and villages, Ibaraki prefecture assembly members, and members of the academic community experienced in environmental radiation monitoring. The secretary of the committee is the Ibaraki prefecture. Official announcements of the environmental radiation monitoring seasonal report are published quarterly. The reports are available at appropriate city, town, and village locations such as libraries.