Okay, I need to create a concise summary of this Japanese document. Let me start by reading through the content carefully.
First, the document mentions that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) has compiled data. The key points are the measurement times, locations, and radiation levels. There are several measurement sites listed with their respective distances from Fukushima Daiichi Nuclear Power Plant and the radiation readings in microsieverts per hour. The data includes sites like 【1】, 【2】, 【3】, etc., each with specific distances and values. The note says that the data in the table is the latest addition, so I should mention that.
Then, there's a section about the measurement results from the Ministry of Education, Culture, Sports, Science and Technology. The locations are listed with their distances from the plant, and the values are given. For example, site 【1】 is 60 km northwest with 5.0 μSv/h, site 【2】 is 55 km northwest with 9.3 μSv/h, and so on. The highest value here is 15.5 μSv/h at site 【36】 which is 30 km south. The note also says that the data is for areas 20 km or more from the plant, so I should clarify that.
Next, the document states that the Ministry of Defense's measurements are still being prepared. That's an important point to include as it indicates that more data is pending.
There's a section on radiation levels and their units. The note explains that the units are microsieverts per hour, and the values are for outdoor measurements unless specified otherwise. The numbers range from 0.7 to 15.5 μSv/h. I need to mention the range and the highest value.
Then, there's a part about the criteria for sheltering indoors or evacuating. The effective dose from external exposure is 10,000 to 50,000 μSv, which would require sheltering. For internal exposure, the equivalent dose is 50,000 μSv or more, leading to evacuation. The document also lists various thresholds for different types of radiation, like iodine-131 for children's thyroid, uranium for bones or lungs, and plutonium for bones or lungs. These thresholds are based on the "Atomic Power 2002" report by the Ministry of Education, Culture, Sports, Science and Technology.
The summary should also include the reference to the atomic power facilities disaster countermeasures guidelines, which were decided by the Atomic Energy Commission in 1995 and revised in 2012. The numbers provided are the annual limits for different groups, such as emergency workers and police/firefighters. The document mentions that after the increase, the upper limit is 250,000 μSv per year for certain roles.
I need to make sure the summary is in English, detailed but concise, and doesn't include any markdown. Start directly with the content. Check for any specific terms that need to be translated accurately, like "GM" (Geiger-Müller tube) and "NaI" (sodium iodide scintillator). Also, note the conversion from Sv to μSv, but the user might not need that unless specified. The key is to highlight the main data points: the MEXT measurements, the locations, the radiation levels, the criteria for sheltering or evacuation, and the reference to the guidelines and the annual limits.
Avoid adding any extra information not present in the original text. Make sure to mention that the data is for areas 20 km or more from the plant, and that the highest value is 15.5 μSv/h at site 【36】. Also, note that the Ministry of Defense's data is still under preparation. The summary should be structured to present the main findings clearly without unnecessary details.
The Ministry of Education, Culture, Sports, Science and Technology (MEXT) reported radiation measurements on March 20, 2011, at various locations around the Fukushima Daiichi Nuclear Power Plant. Outdoor readings (in μSv/h) included: 5.0 at 60 km northwest (site 【1】), 9.3 at 55 km northwest (site 【2】), 11.7 at 45 km northwest (site 【3】), 5.3 at 50 km northwest (site 【4】), 1.2 at 45 km north (site 【5】), 2.5 at 45 km north (site 【6】), 2.0 at 45 km north (site 【7】), 5.2 at 40 km northwest (site 【10】), 5.1 at 40 km northwest (site 【11】), 0.7 at 40 km west (site 【12】), and 2.6 at 45 km northwest (site 【20】). The highest value, 15.5 μSv/h, was recorded at site 【36】 (30 km south) for areas 20 km or more from the plant. Measurements at sites closer than 20 km (e.g., 【36】) were not included. The Ministry of Defense’s data remains under preparation.
Radiation levels were categorized into thresholds for sheltering or evacuation:
- Indoor sheltering is advised if external exposure exceeds 10,000–50,000 μSv.
- Evacuation is required if internal exposure reaches 50,000 μSv or more.
- Specific limits for radioactive materials (e.g., iodine-131, uranium, plutonium) are outlined, with annual exposure limits for workers and emergency personnel ranging from 100 μSv to 250,000 μSv, based on the "Atomic Power 2002" guidelines.
The data reflects outdoor measurements unless specified otherwise, with values varying by location and distance from the plant.
