Planned releases of wastewater from Fukushima nuke plant deemed "safe"

A panel of technical advisers to the Fukushima prefectural government and two municipalities finalized a report at a meeting in Fukushima city on July 26 confirming the safety of a detailed plan drawn up by Tokyo Electric Power Company Holdings Inc. (TEPCO) to release into the sea treated water from the utility's crippled Fukushima Daiichi nuclear plant. The move followed the Nuclear Regulation Authority's recent approval of the TEPCO plan calling for the discharge into the ocean of wastewater that is treated but still contains tritium, a radioactive substance. The contents of the report were endorsed by the three parties constituting the panel -- the prefecture and the towns of Okuma and Futaba, which the plant straddles. Based on the report, they will decide in August whether to give TEPCO the go-ahead to build relevant facilities, including an undersea tunnel linking the plant's premises and several points where treated water will be released roughly one kilometer offshore. Prefecture, towns to decide in August whether to okay construction TEPCO intends to begin construction work as soon as it receives consent from the prefecture and the two plant-hosting towns, marking a milestone in the process toward releasing wastewater into the sea. But opposition remains strong among local communities and other parties worried about fresh reputational damage, leaving it uncertain if water releases will start next spring as envisioned by the national government and TEPCO. The draft of the report that confirms the safety of the discharge plan was approved first by the prefecture's council for monitoring the safety of the decommissioning of the plant, which is made up of intellectuals and officials from the prefecture as well as the cities, towns and villages concerned. Then the report became final with technical panel approval before the decision was notified to Okuma and Futaba towns later in the day. In examining the report, the technical panel judged that TEPCO's attempts to address issues associated with the plan are appropriate. These include ensuring the definite implementation of re-purification (secondary treatment) and how to respond to cases of technical glitches and natural disasters. The panel also endorsed the detailed designs of the equipment and machinery to be used as well as the maintenance plans for them, in addition to the safety precautions for the construction work and the assessment of radiation effects. Also taking into consideration the fact that the Nuclear Regulation Authority had already approved the release plan, the panel concluded after a comprehensive review that it "will ensure the safety of the neighboring areas." But the panel came up with eight-point demands given that the planned ocean releases are expected to last at least 30 years. Regarding measures to be taken before the start of discharges, it urged TEPCO to give top priority to safety in the construction of facilities, not the schedule. As for long-term measures, the panel called for TEPCO to measure treated water as much as possible in order to confirm the presence of radioactive substances and transmit relevant information in an easy-to-understand manner, among other things. TEPCO submitted a request for advance approval of its wastewater release plan last December to the prefecture and the two towns. After that, the decommissioning safety monitoring council met nine times (including divisional meetings) while the technical panel held seven sessions to examine the plans to ensure safety that the utility came up with in its report. At the July 26 council meeting, one member pointed to the need to reduce the volume of fresh contaminated water arising from the cooling of nuclear fuel debris. Under the TEPCO plan, wastewater will be diluted by seawater to bring down the tritium content to less than one-40th of the standard level set by the national government before it is released into the sea about a kilometer off the damaged plant via pipes stretching through the planned underwater tunnel. The Nuclear Regulation Authority approved the plan at an extraordinary meeting on July 22. Okuma, Futaba mayors say they will check details soon Okuma Mayor Jun Yoshida and Futaba Mayor Shiro Izawa told reporters when they visited the Ministry of Economy, Trade and Industry in Tokyo on July 26 that they would like to make a decision after receiving explanations and reports from the central and prefectural governments. Both mayors did not say when they will decide but indicated they will soon check the details of the monitoring panel's report and related information. The two towns are also expected to hold hearings with local assembly members soon as they seem likely to engage fully and rapidly in their decision-making processes. [Key points of technical panel report] - TEPCO's ocean release plan was confirmed to satisfy the national regulatory standards and the matters for which measures should be taken. The safety of the neighboring areas will be secured by ensuring the implementation of safety precautions. - In enforcing the plan, it is indispensable to take measures for the further improvement of safety precautions and make efforts to send out information in an easy-to-understand manner. In this connection, we have specified eight-point demands. We will monitor how TEPCO responds. [8-point demands to TEPCO] (1) Confirmation of radioactive substances contained in treated water --> In selecting nuclear species to be measured, cover as many more species as possible other than the 62 nuclides and carbon-14 that are currently included, and thus clarify the presence of nuclear species contained in treated water. (2) Appropriate operation and management at the time of circulation and agitation of treated water. --> In circulating and agitating treated water to homogenize measurement samples, take water-insoluble granular radioactive substances into consideration. Properly monitor the effects of residual water and sediment left at the bottom of each tank after discharging. (3) Management of radioactive substances contained in seawater for dilution --> When drawing in seawater for wastewater dilution, take measures to prevent radioactive substances from being mixed in from around an area where seawater is taken for cooling the Nos. 5 and 6 nuclear reactors. Regularly monitor the density of radioactive substances in the seawater taken. (4) Drawing up effective maintenance plan to forestall trouble --> Share the recognition among the quarters concerned that equipment for diluting and discharging wastewater is important. Draw up an effective maintenance plan to fend off any trouble associated with the equipment. (5) Measures to prevent spread of environmental impacts under abnormal circumstances --> In preparation for wastewater leakage, an unintended discharge or other abnormalities, prepare and update a procedure manual that will enable prompt and assured enforcement of flexible responses in order to prevent the spread of environmental impacts. Train constantly and take multifaceted safety precautions in terms of equipment. (6) Safety-first construction work --> In installing equipment and facilities, give top priority to safety rather than to a shortened work schedule. The construction of an undersea tunnel and other offshore work, in particular, are expected to face tough environmental conditions. In preparation for contingency situations, maximize efforts to ensure safety based on risk assessments. (7) Sending out easy-to-understand information on treated water measurement results and other data --> Always disclose the latest information on a website and elsewhere regarding measurement results and the status of equipment operations, among other things. Strive to offer easy-to-understand information by, for instance, making comparisons with safety-related figures. In the event of trouble, swiftly report it to relevant quarters and publicize the impact of radiation and other information precisely and in an easy-to-understand manner. (8) Transmission of easy-to-understand information on evaluation of radiation effects --> Explain evaluation results regarding radiation effects in an easy-to-understand manner by, for instance, comparing them with levels in the natural environment so that they may not arouse anxiety among prefectural residents. Treated wastewater containing radioactive substance tritium: "Contaminated water" arising from the discharge of water onto the debris of melted nuclear fuel at Tokyo Electric Power Company Holdings Inc.'s (TEPCO) Fukushima Daiichi nuclear plant as well as groundwater and rainwater flowing into plant facilities are purified by the Advanced Liquid Processing System (ALPS) to produce treated water. The system removes most of the 62 nuclides, but tritium, similar in nature to water, remains intact in the process. While tritium exists in the natural environment, it is also generated by nuclear fission inside a nuclear reactor. Tritium-containing wastewater is released into the sea after being diluted with seawater at most common types of nuclear plants. (Translated by Kyodo News)

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