## (6) Monitoring tap water

In response to the accident at the TEPCO Fukushima Daiichi NPS, the index values for radioactive materials in tap water during an emergency were defined based on an index for intake restrictions of food and drink as defined by the Nuclear Safety Commission of Japan, and the index regulated by the Food Sanitation Act, on March 19 and March 21, 2011. Notice was given to prefectural governments of the countermeasures in the event that radioactive materials exceeded the index values. The guidelines for monitoring and starting or stopping intake restrictions based on examination results were released on April 4, 2011 (and were partially revised on June 30, 2011). Thus far, 20 water suppliers have enforced restrictions of water intake, and all restrictions were removed by May 10, 2011. From that time

The Ministry of the Health, Labour and Welfare reached an interim conclusion in June 2011 concluding that the possibility of restrictions on tap water intake was considered to be low unless vast amounts of radioactive materials were to be emitted from the TEPCO Fukushima Daiichi NPS. Based on a new standard for radioactive materials in food, on March 5, 2012 a new target was settled. Notice was given to prefectural governments and water suppliers on the same day regarding monitoring methods, and countermeasures in the event that radioactive materials exceeded the target value (10 Bq/kg for the total of cesium 134 and 137).

## 3 Initiatives to Eliminate Contamination from Radioactive Materials based on the Act on Special Measures Concerning Handling of Radioactive Pollution

## (1) Act on Special Measures Concerning Handling of Radioactive Pollution

Mitigating the impact of radioactive contamination discharged as a result of the NPS accident on health and the living environment is a pressing issue. In response to this situation, Japan enacted the Act on Special Measures

Figure 2-4-2 Outline of Systems based on the Act on Special Measures Concerning Handling of Radioactive Pollution

Formulation of Basic Policy

Minister for the Environment formulates a draft basic policy for taking countermeasures against environmental contamination due to radioactive materials, and then calls for Cabinet approval

on, no water suppliers have enforced restriction on water intake caused by a situation in which radioactive iodine or radioactive cesium in the water exceeded the index values. In addition, from April 2011, almost none of these substances were detected.

Setting criteria

Minister for the Environment defines criteria for handling waste, soil, and other materials contaminated by radioactive materials

Implementation of monitoring and measurement

National government immediately establishes and implements a system for unified monitoring and measurement to understand the status of environmental contamination

Source: Ministry of the Environment

Concerning Environmental Contamination Due to Radioactive Materials Discharged by Accident at Nuclear Power Plants in Association with Tohoku Region Pacific Coast Earthquake on March 11, 2011 (Act No. 110 of 2011). This act will be referred to as the Act on Special Measures Concerning Handling of Radioactive Pollution (Act on SMCHRP) below (Figure 2-4-2).

Furthermore, on November 11, 2011, a basic policy based on the Act on SMCHRP was endorsed by the Cabinet. It outlines concepts such as monitoring and measurement of environmental contamination, disposing of waste contaminated by radioactive materials discharged in the wake of the accident, and soil decontamination. Based on this, initiatives to eliminate contamination from radioactive materials was scheduled to be promoted in order to reduce promptly the effects of radioactive contamination caused by the accident on people's health and living environment.

## (2) Measures including soil decontamination

## A) The framework based on The Act on SMCHRP

The Act on SMCHRP designates specified areas for decontamination and key areas for contamination surveys. For areas specified as Emergency Planning Zone and Evacuation-Prepared Area in Case of Emergency, where special decontamination is necessary, the central

Table 2-4-2 Framework based on the Act on Special Measures Concerning Handling of Radioactive Pollution

Specifying criteria	Decontamination project	Decontamination implemented by
Decontamination by central government (Decontamination specified area)	Areas that have been specified as alert zones or EPZ	Minister of the Environment formulates decontamination projects for special areas	Central government
Decontamination mainly by local municipalities (Decontamination implementation area)	Where additional per-year exposure dose is 1 mSv or more in key area for contamination survey	Local municipal mayors formulate decontamination implementation projects	Central and prefectural governments as well as local municipalities

Materials: Ministry of the Environment

Table 2-4-3 Targets for Measures including Decontamination of Soil

Area	Target	Remarks
Additional exposure dose (per year) 20 mSv or higher	Swiftly and steadily minimize target areas	Areas with particularly high exposure dose require measures that take a long-term perspective
Additional exposure dose (per year) Less than 20 mSv	Long-term target	Additional exposure dose shall be 1 mSv or less per year
Target through August 2013	Achieve 50% reduction in additional exposure dose per year for the general public versus levels at the end of August 2011 (including physical attenuation of radioactive materials)
Achieve 60% reduction in additional exposure dose per year for children versus levels at the end of August 2011 (including physical attenuation of radioactive materials)

Materials: Created by the Ministry of the Environment, based on the Basic Policy for the Act on Special Measures Concerning Handling of Radioactive Pollution (November 11, 2011)

Figure 2-4-3 Schedule for Decontamination in the Specified Decontamination Area

Source: Policy for decontamination in specified decontamination areas (Road Map) (Ministry of the Environment January 26, 2012)

government must implement decontamination programs based on the decontamination plans established by the Minister.

Furthermore, the Minister of the Environment shall designate key areas for contamination surveys where the per-year additional exposure dose is 1 mSv or higher. Specified municipalities shall establish decontamination plans, for areas where there are additional per-year exposure dose levels of 1 mSv or higher within the contamination survey key areas. Based on these plans, the central government, prefectural governments, and local municipalities must implement decontamination programs.

The areas designated as decontamination special areas include 11 municipalities in Fukushima Prefecture. A total of 104 municipalities (in Iwate, Miyagi, Fukushima, Ibaraki, Tochigi, Gunma, Saitama, and Chiba prefectures) are designated as key areas for contamination surveys (as

## of May 2012)

B) The basic policy for decontamination of soil and other targets

The basic policy based on the Act on SMCHRP clearly identifies the priority on establishing decontamination plans from the perspective of public health, especially considering children, and implementing programs according to exposure levels.

## C) Decontamination in specified decontamination areas

The Minister of the Environment shall formulate "Decontamination Plan for Specified Areas", with establishing concepts based on each classification of