原発新規制基準 ゼロリスクにとらわれるな

[The Yomiuri Shimbun] April 12, 2013
NRA should not get caught up in myth of completely 'risk-free' reactors
原発新規制基準　ゼロリスクにとらわれるな（4月11日付・読売社説）

The Nuclear Regulation Authority has approved the final draft of new safety standards to be applied to the nation's nuclear power plants.
　原子力規制委員会が、原子力発電所に適用する新たな規制（安全）基準の最終案を決めた。

Taking lessons from the nuclear crisis at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant, the new standards will require operators of nuclear power plants to prepare for earthquakes and tsunami larger than those they had estimated prior to March 11, 2011.
Measures to prevent critical accidents, such as meltdowns of nuclear reactors, were also incorporated in the new standards, including energy supplies from multiple power sources and reinforcing reactor cooling systems.
　東京電力福島第一原発事故を踏まえ、従来の想定より大きな地震や津波への対策を求めた。原子炉が壊れる重大事故を防ぐため、電源や冷却機能の拡充も盛り込んだ。

It is indeed necessary to correct the weaknesses of the old safety standards in place before the nuclear crisis. However, although many people--including those inside the NRA--complained during the deliberation process that the nuclear regulatory body was going too far in seeking to reducing the risk from nuclear power plants to zero, their views were hardly reflected in the final draft.
　事故前の基準の欠陥を改めることは必要だろう。だが、新基準の検討過程で内外から相次いだ「ゼロリスクを求め過ぎだ」との批判はほとんど反映されなかった。

New standards overly strict

It is clear that the final draft has a number of flaws.
　問題をはらむ基準案である。

One of them is the requirements on active faults found under nuclear power plants. In the previous safety standards, faults that were confirmed to have moved within 130,000 years were judged as active faults. However, the final draft will require operators to expand the scope of investigation significantly--movements within the past 400,000 years will be subject to investigation.
　その一つは、原発敷地内の活断層の扱いだ。これまでは１２万～１３万年前以降に動いたものを対象としていたが、最大４０万年前まで遡って調査することを課した。

The nuclear regulatory body has already adopted the new criteria for researching active faults at idle nuclear power plants. While conducting the research, Acting NRA Chairman Kunihiko Shimazaki has repeatedly called on power companies to prove that they are "100 percent sure" that there are no active faults. A clause reflecting Shimazaki's requirements is expected to be included in the new safety standards.
　規制委はすでに、これを先取りして原発敷地内の活断層を調査している。この際、島崎邦彦委員長代理は繰り返し、「活断層が１００％ない」という証明を求めており、新基準にも同様の項目が設けられることになった。

However, it is obvious that Shimazaki's demands are extremely unscientific. Power companies should pursue approaches based on engineering, such as reinforcing the safety equipment at nuclear power plants so the power plants will be able to withstand seismic activity.
　あまりに非科学的な要求だ。むしろ、活断層が動いても大丈夫なよう安全設備の強度を増す工学的な対応を優先すべきである。

Some experts have raised concerns about other measures laid out in the final draft, pointing out their "excessiveness." One example is the requirement of filtered vents, which would help release pressure from nuclear reactors in the case of a serious accident.
　専門家が「過剰」と指摘する項目もある。典型例が、重大事故時に原子炉内の圧力を逃す手段であるフィルター付きベントだ。

The new safety standards will obligate all of the nation's nuclear power plants to install filtered vents. However, last month, the United States concluded it is unnecessary to install the filtered vents in its nuclear reactors for the time being, after hearing expert opinion. It is understandable that a senior official of the U.S. Energy Department raised concerns that Japan's strict standards may affect nuclear power plants in other countries.
　新基準は全原発に設置を義務づけたが、米国は先月、専門家の議論を経て、米国の原発には当面、不要とした。米エネルギー省幹部が「日本の厳しい基準が海外にも影響しかねない」と懸念を示したのは、もっともである。

After collecting public opinion on the final draft, the nuclear regulatory body plans to put the new standards into effect in July, or earlier if possible. Based on the new standards, the NRA will check whether the nation's idled nuclear reactors are suitable for restart.
　規制委は意見公募を経て、７月までに新基準を施行する。これに基づいて、停止中の原発の安全性について審査する。

Restart of N-plants urgent

What is important is to improve the efficiency of inspections. According to the NRA, it will only be able to check three nuclear power plants at a time due to a shortage of officials possessing sufficient expertise. The nuclear regulatory body must reinforce its inspection framework by taking such steps as recruiting talented people.
　重要なのは、審査の効率を上げることだろう。技術に詳しい職員が限られ、同時に審査できるのは３か所の原発だけという。人材確保など体制強化が必要である。

Flexibility is also crucial. Measures should be introduced in accordance with the specific conditions of each nuclear power plant. It is not realistic to demand all nuclear power plants have the same amount of fire extinguishing equipment, for example.
　原発ごとの柔軟な対応も不可欠だ。一律に消火設備などの数を決めるのは現実的ではない。

To pass inspections, nuclear power plants will be required to introduce retrofits reflecting the latest safety measures for nuclear reactors. Improving safety is important, but we are concerned that the plan would lead to higher costs, forcing power companies to shut down some reactors.
　審査では、各炉に最新技術の導入を義務づける「バックフィット制度」を適用する。安全向上は大切だが、費用がかさみ、廃炉を迫られる例も出るのではないか。

The nation's power supply faces a tough situation. The price of electricity has gone up after the price hike for fuel for thermal power plants. It is urgent to restart power plants once their safety is confirmed.
　原発の停止で電力供給は綱渡りだ。火力の燃料費高騰で電気料金も上がっている。安全を確認した原発の再稼働は急務である。

We ask the NRA to judge whether nuclear power plants are eligible for restart, without being swayed by the current public desire for the absolute safety of nuclear power plants.
　規制委は、１００％の安全を求める風潮にとらわれることなく、各原発の再稼働の可否を判断してもらいたい。

(From The Yomiuri Shimbun, April 11, 2013)
（2013年4月11日01時30分  読売新聞）