At Least 4 Nuke Plants Will Apply for Restart Under the New Safety Regulations to Be Implemented in July

If they are approved, there will be 8 additional reactors, including one with MOX fuel, will be online in Japan, in addition to two reactors at Ooi Nuclear Power Plant.

These plants are:

1. Takahama Nuclear Power Plant: Reactor 3 (MOX), Reactor 4, operated by Kansai Electric Power Company;

2. Ikata Nuclear Power Plant: Reactor 3, operated by Shikoku Electric Power Company;

3. Sendai Nuclear Power Plant: Reactor 1, Reactor 2, operated by Kyushu Electric Power Company; and

4. Tomari Nuclear Power Plant: Reactors 1, 2 and 3, operated by Hokkaido Electric Power Company.

Hokkaido Electric has postponed the plan to use MOX fuel for Reactor 3, but the plan is not abandoned. With local municipalities counting on MOX fuel subsidies to the tune of 6 billion yen, big money for these small municipalities, there will be a strong pressure for Hokkaido Electric, once the plant is back in operation, to pursue MOX fuel.

Shikoku Electric's Ikata Nuclear Power Plant sits near the tail end of the Median Tectonic Line, one of the biggest fault lines in Japan.

NHK News (5/28/2013) says the operators of these plants are going to apply anyway even though the plants may not satisfy the new safety regulations being compiled by the Nuclear Regulatory Authority.

Some of the problems that even NHK seems to recognize are:

津波対策の基準となる最大規模の津波や、新たに求められた火山について評価や安全対策を終えておらず「検討中」としていて、
Risk evaluation and the safety countermeasures for the maximum size of tsunami or for volcanic eruptions that will be newly required haven't been completed, they are "under consideration";

残る２か月足らずで安全性をどこまで確認できるのか具体的な見通しは立っていません。
How much safety can be ascertained in less than two months is not known;

新基準で義務づけられている、事故時の対策拠点となる「緊急時対策所」を別の施設で代用するケース
There are cases [NHK doesn't say which ones] where "emergency headquarters" as mandated by the new standard will be substituted by other facilities;

「防潮堤」を津波の想定が敷地の高さを下回っているので不要だとしているケース
There are cases where the operators says there is no need for "seawalls" because the expected height of tsunami is lower than the site elevation.

Uh... have we heard the last one before?

I think it is a clever ploy by the plant operators to apply at the same time for 4 plants with 9 total reactors, because the Nuclear Regulatory Authority lacks manpower to be able to assess the safety of each as they solidify the new safety regulations that are still evolving.

According to NHK, the operator of Tsuruga Nuclear Power Plant Reactor 2, Japan Atomic Power Company, says it will apply for the restart of that reactor anyway, even though the reactor has been declared by the Nuclear Regulatory Authority's panel of experts to be directly above the active fault line.

And there is TEPCO, who wants to restart Kashiwazaki-Kariwa Nuclear Power Plant with 7 reactors in Niigata Prefecture, even though they too may be sitting on the active fault line.

Fukushima happened, so we're safe for another decade or two at least. That must be the thinking.

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(Anything Goes Series -3) "Danger of Active Faults Is Baseless Rumor", Says Tokyo University Geologist

The others chime in, and say, basically, "Let's coexist with nuclear power plants that sit on top of active faults."

Very interestingly, the pro-nuclear Sankei Shinbun's article echoes the open letter by the US Energy and Commerce Commission to the Nuclear Regulatory Commission, with its curious emphasis on "performance-based" policy.

The article by Sankei Shinbun quotes a physicist, a nuclear engineer, and an marine geologist among others who say the Nuclear Regulatory Authority's new safety regulation proposal is not based on science but is pure fiction.

I'm afraid the entire country of Japan is pure fiction at this point.

Sankei's article starts with a very tricky headline as if it were the NRA who says it is possible (for nuclear power plants) to coexist with active faults. It is not, but unless you actually read the article, Sankei readers wouldn't know that.

From Sankei Shinbun via Yahoo Japan (1/30/2013; part; my comments in square brackets in blue italic):

地震・津波原発の新安全基準骨子案　「活断層との共生可能」

Proposed new safety standard outline for nuclear power plants in the event of earthquake/tsunami "It is possible to coexist with active faults"

科学的根拠失った規制を危惧

Fearful of regulation without scientific basis

原子力規制委員会が２９日に骨子案をまとめた地震・津波に関する原発の新安全基準。活断層の真上に重要施設の設置を禁止したが、全国に約２千本あるといわれる活断層大国の日本では「耐震設計で活断層との共生は可能」との見方も出ている。科学者らは失われた科学技術への信頼回復を目指す一方で、安全を強調するあまり科学的根拠を失った規制がまかり通ることを危惧している。

On January 29, the Nuclear Regulatory Authority announced its outline proposal for new safety standard for nuclear power plants in the event of earthquake and/or tsunami. The new standard would prohibit the installation of important facilities on top of active faults, but there are people who think it is possible to coexist with active fault with anti-seismic design in the country where there are about 2,000 active faults. Scientists are trying to restore the trust in science and technology which was lost [in the wake of the Fukushima I Nuclear Power Plant accident], but at the same time they are worried that with too much emphasis on safety the regulations without scientific basis will go unchallenged.

[Go unchallenged? OK, who are those scientists?]

元文相で物理学者の有馬朗人氏は２５日に都内で開かれたシンポジウムで、東日本大震災でも無事だった東北電力女川（おながわ）原発（宮城県）や東京電力福島第２原発（福島県）を取り上げ、「活断層があってもどうすれば安全が保たれるか研究開発を進めればよい」

In a symposium held in Tokyo on January 25, former Minister of Education and [nuclear] physicist Akito Arima cited Tohoku Electric Power's Onagawa Nuclear Power Plant (in Miyagi Prefecture) and TEPCO's Fukushima II (Daini) Nuclear Power Plant (in Fukushima Prefecture) as having survived the March 11, 2011 earthquake and tsunami, and said, "Even if there is an active fault, all we need to do is do R&D to maintain safety."

[Well said, Dr. Arima, but nuclear physics doesn't address how to construct buildings on top of an active fault, does it?]

東京大の岡本孝司教授（原子炉工学）は「本当に重要なのは活断層かどうかということではなく、放射性物質が漏れるリスクがあるかどうかだ。だが、その議論がない」と指摘。その上で「規制委での議論は科学とはいえず、小説の世界だ」と断じた。

Professor Koji Okamoto of Tokyo University (nuclear reactor engineering) says, "What's more important is not whether it is an active fault, but whether there is a risk of radioactive leak. But there is no discussion [of the latter]." He concluded, "The discussion at the NRA is not science. It is a world of fiction."

[So, a nuclear reactor engineer calling the discussion by the top seismologists and geologists a fiction. That makes sense. Not.]

首都大学東京の山崎晴雄教授（地震地質学）は「活断層が危ないというのは風評で、原発反対運動の口実として使われている」と指摘。

Professor Haruo Yamazaki of Tokyo Metropolitan University (seismogeology) points out, "Danger of active fault is a baseless rumor, and it is used as a pretext in opposing nuclear power plants."

[Baseless rumor.]

This newspaper is incredible for its choice of words like "go unchallenged", as if the NRA trying to be on the conservative side of science were the bullies punishing the industry for no good scientific reason.

The article continues, saying that the definition of active faults has changed over time - from 50,000 year-old faults to 120,000 to 130,000, and now to 400,000-year-old faults - and the new benchmark of "400,000 years" is "meaningless", quoting a marine geologist. (A marine geologist should know very well about land geology, shouldn't he?)

Right on cue, a faction of the ruling Liberal Democratic Parties has started to make noise about the commissioners of Nuclear Regulatory Authority, who have been installed without the consent from the National Diet by then-Prime Minister Yoshihiko Noda. They say they have doubts about these commissioners because of their extremely strict conditions for the restart of a nuclear power plant, and particularly because of their opinion that Tsuruga Nuclear Power Plant (that sits on active faults) has to be decommissioned.

LDP has already bullied Bank of Japan into submission (whatever Governor Shirakawa says now to defend himself as "independent" is ludicrous). Nuclear Regulatory Authority next?

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"Active Fault Right Under the Reactor Building in Tsuruga Nuke Plant", Japan's Nucleaer Regulatory Authority Concluded After 2-Day Field Research

All five experts on the Nuclear Regulatory Authority's panel agree it is highly likely that the fault that runs right beneath the Reactor 2 building at Tsuruga Nuclear Power Plant is an active fault.

Chairman Shunichi Tanaka doesn't think it is even possible at this point to proceed with the safety evaluation to restart the plant.

From Jiji Tsushin (12/10/2012):

敦賀原発、活断層の可能性＝田中委員長「再稼働できない」－専門家一致・規制委
It may be an active fault at Tsuruga Nuke Plant, Chairman Tanaka says "Cannot restart", all experts at Nuclear Regulatory Authority agree

日本原子力発電敦賀原発（福井県敦賀市）で、敷地内の岩盤の亀裂（破砕帯）に活断層の疑いが指摘された問題で、原子力規制委員会は１０日、現地調査の結果を検討する評価会合を開いた。２号機原子炉建屋の直下を通る断層について、専門家５人全員が「活断層の可能性が高い」との認識で一致。これを受け田中俊一委員長は、個人的考えと前置きした上で「今のままでは再稼働に向けた安全審査はとてもできないと判断した」と述べた。

Experts have raised doubt that fractured zones inside the Japan Atomic Power Co. Tsuruga Nuclear Power Plant compound (Tsuruga City, Fukui Prefecture) may be active faults. The Nuclear Regulatory Authority held a meeting on December 10 to evaluate the result of the field survey. As to the fault that runs directly beneath the reactor building of Unit 2, all five experts agreed that "it is highly likely to be an active fault". Chairman Shunichi Tanaka, prefacing that his remark is personal, said "In the current condition, we have decided there is no way we can conduct the safety evaluation for the restart of the plant."

規制委は近く会合を開き、評価結果の妥当性を判断するが、再稼働は認められない見通しとなった。運転停止が長期間続けば、廃炉を求める声が強まる可能性がある。原発の断層問題で、専門家調査団が活断層と判断したのは初めて。

NRA will hold a meeting soon to decide the appropriateness of the evaluation, but the prospect is that the restart will not be allowed. If the shutdown of the reactor continues for a long time, it is possible that people will demand decommissioning the reactor. This is the first time in the investigation of faults in nuclear power plants that a panel of experts determined a fault as active.

評価会合では、日本原電が調査のために掘った試掘溝の西側に、２号機原子炉建屋直下を通る「Ｄ－１破砕帯」の一部とみられる活断層が存在する可能性が高いとの認識で一致した。

In the evaluation meeting, the expert agreed that it is highly likely that an active fault, which is considered to be part of the "D-1 fracture zone" right underneath the reactor building of Unit 2, exists on the west side of the trench that Japan Atomic Power Co. dug for the investigation.

座長役の島崎邦彦委員長代理は、根拠として(1)政府の地震調査研究推進本部が活断層の目安とする４０万年前より新しい十数万年前に動いていたと考えられる(2)原発近くを通る活断層「浦底断層」と非常に近い動きをしている－などを挙げた。

Deputy Chairman Kunihiko Shimazaki explained the basis of their conclusion as: (1) The fault is considered to have been moving, as late as 100,000 and several 10,000 years ago, much later than 400,000 years ago which is a criterion for an active fault as defined by the government's Headquarters of Earthquake Research Promotion; (2) The fault is moving closely together with a [known] active fault near the nuclear power plant, "Urazoko Fault".

I caught part of the live press conference that the Nuclear Regulatory Authority held on December 10 to announce their findings. Deputy Chairman Shimazaki and five experts who went to Tsuruga to investigate in early December were there, answering questions from the reporters.

What struck me was two things: 1) Reporters from the mainstream media seemed knowledgeable enough on the subject to ask intelligent questions to the experts to get the facts out; and 2) The experts pretty much gave straight answers, without any seeming vested interest or ego.

(After watching the beginning of the press conference, the first point still stands, but with the exception of the NHK reporter who was clearly designated by the Nuclear Regulatory Agency (secretariat) to ask the first question. His question was too vague and generalized, Dr. Shimazaki was perplexed as to what he was asking.)

There were some very interesting exchanges between the reporters and the experts who were all geologists, particularly Dr. Shimazaki (seismologist by training).

When asked by a reporter from Fukui TV why it was taking months for the operator of the plant to reach any conclusion but the Nuclear Regulatory Authority's experts were able to reach a conclusion (that an active fault runs beneath the reactor building) in two days, Dr. Shimazaki answered:

やはり事業者さんはですね、非常に微妙な立場に、特に調査をされている方がそういう立場におかれているんではないかとわたくしは思います。基本的には、活断層ではないことを証明するために調査を続けられているわけですから、その証明が出来ない限りは、ある意味調査を続けなければいけないという立場になるわけで、それは我々の立場とはぜんぜん違う立場になります。

After all, the plant operator is in a very delicate position, particularly those who actually do the investigation may be placed in a very delicate position, I suspect. Basically, [the operator] continues the investigation in order to prove that it is not an active fault, and as long as it cannot prove that it has to continue the investigation, so to speak. That is a totally different position than ours.

Isn't that the truth. I was rather shocked that Dr. Shimazaki very matter-of-factly stated it.

Then, a reporter from pro-nuke Yomiuri (and probably aligned well with the Nuclear Regulatory Agency) asked again, why the group of experts was able to reach the conclusion so quickly, compared to Ooi. Dr. Shimazaki, showing some heat, said,

今回の結論がもし皆さんが速いと言われるのであれば、わたくしは速いとは思いませんよ。はい。わたくし個人的にはですね、データがそろっていれば皆さんの意見は一致するはずなんで、きちんとしたデータがあれば判断は速いとわたくしは思っていますので、決して二日の調査で簡単に結論を出したな、という風に思われるのは心外だ、と思います。きちんとした調査がされていてきちんとしたデータがあれば、日にちはある意味関係ない、皆さんが一致した結論になる、というのがわたくしの思いであります。

If you think our conclusion this time [as compared to that on Ooi Nuke Plant] was made quickly, well I don't think it was quick. No. Personally, I think the same conclusion is reached if the valid data is there, and the decision can be made quickly if there is enough [valid] data. I am a bit annoyed if you think we made a casual decision with only the 2-day investigation. If the investigation is done properly and there is valid data, the number of days [to make decision] is in a way irrelevant, and the experts will agree on the conclusion, that's what I think.

indicating that unlike Kansai Electric (in Ooi Plant investigation) the operator did have a very good set of data but didn't want to draw any conclusion that they didn't want.

The Nuclear Regulatory Authority, before it was formed, was heavily criticized by many as being run by the "nuclear village residents" - people with strong ties to the nuclear industry in Japan, and as such it would be biased toward the industry and toward the restart of the nuclear power plants.

It must be an unpleasant surprise for the industry, so far.

The nuclear industry can hope for the day, very soon, when LDP's Abe is installed again as the Prime Minister of Japan, and fire these commissioners. Abe will have an excellent pretext of firing anyone who was not formally approved by the Diet (as PM Noda pushed through the appointment without consulting the Diet).

The Nuclear Regulatory Authority's reportｓ are here. In his report at the site, Professor Takahiro Miyauchi of Chiba University Earth Science says Urazoko Fault and its related faults may be capable of generating earthquakes greater than M7.5, and urges the criteria for the evaluation to include not just fractured zones but this long stretch (35 kilometers minimum, as long as 65 kilometers) of faults right next to the plant.

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Fuel Assembly Covers Found Cracked and Discolored in SFP of Tsuruga Nuke Plant Reactor 1

Reactor 1 of Tsuruga Nuclear Power Plant in Tsuruga City, Fukui Prefecture, operated by Japan Atomic Power Company, is the very first light-water reactor (by GE) built in Japan, and the 7th oldest commercial reactor in the world (as of January 2012).

(Fukushima I Nuke Plant's Reactor 1 is the second oldest, after Tsuruga's Reactor 1.)

Reactor 2 of Tsuruga Nuclear Power Plant (pressurized-water reactor by Mitsubishi Heavy Industries) may be sitting on top of an active fault.

Both reactors have been stopped due to scheduled maintenance.

From Yomiuri Shinbun (8/17/2012):

敦賀１号機、燃料集合体金属カバーにひび・変色

Metal covers of fuel assemblies have cracks, discoloration in Tsuruga Nuke Plant Reactor 1

日本原子力発電は１７日、運転停止中の敦賀原子力発電所１号機（福井県敦賀市）の燃料集合体を覆う金属カバー９本にひび割れや変色があったと発表した。

Japan Atomic Power Company announced on August 17 that they found cracks and discoloration in 9 metal covers that cover fuel assemblies in Reactor 1 at Tsuruga Nuclear Power Plant (Tsuruga City, Fukui Prefecture) which has been stopped [for maintenance].

　いずれも軽微で周辺環境に影響はないとしている。

The [cracks and discoloration] are all minor, and there is no effect on the environment, according to the operator.

　カバーは使用済み核燃料プールの中にあり、ひびなどは溶接部で見つかった。

The metal covers are in the Spent Fuel Pool, and the cracks were found at the welded parts.

　東北電力女川原発で金属カバーに欠損が見つかった問題を受け、経済産業省原子力安全・保安院が原電などに調査を指示していた。

As damages were found in the metal covers at Tohoku Electric Power Company's Onagawa Nuclear Power Plant, the Nuclear and Industrial Safety Agency under the Ministry of Economy, Trade and Industry instructed Japan Atomic Power Company and other [nuclear power plant operators] to conduct investigation.

I think what Yomiuri is talking about ("metal covers") is a channel box that houses fuel assemblies. For Onagawa Nuke Plant's channel boxes, apparently damaged by the March 11, 2011 earthquake, read my post from July this year.

Japan Atomic Power Company has a lot to learn from TEPCO (believe it or not) when it comes to timely disclosure of information. At their website, the latest press release is from August 10. NISA or METI is no better; there is no press release on this incident on either of them.

Maybe this kind of news wasn't news at all in pre-Fukushima Japan.

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Monju Fast Breeder Ready to Restart in Fukui Prefecture in Mid July

(The horror, the horror...)

The troubled fast breeder that has cost a fortune just to maintain (sort of) over the past 30 years is now ready to restart, after the IVTM (In-Vessel Transfer Machine) that had fallen into the reactor in August of 2010 was finally removed in June last year after two failed attempts.

Just like Ooi Nuclear Power Plant (and couple of other plants in the same area), Monju is accessible by land by only one road, which ends at Monju. There are faults running under the plant, as the Nuclear and Industry Safety Agency says it will review the faults in and around all the nuclear power plants in Japan.

NISA is on the way out, as the regulation of the nuclear industry will fall on the yet-to-be-created regulatory agency and adjunct commissions of experts and politicians.

Remember also that this reactor uses liquid sodium as coolant, which ignites on contact with air.

From Asahi Shinbun Fukui local version on June 22, 2012:

もんじゅ、来月復旧へ

Monju to be restored next month [July]

相次ぐトラブルで運転停止中の高速増殖原型炉「もんじゅ」（敦賀市）が、７月中旬にも完全復旧する見通しになった。日本原子力研究開発機構は２１日、復旧作業を報道陣に公開。原子炉内への落下事故を起こして新品に交換した装置が正常に動くことを示した。

Fast breeder "Monju" (in Tsuruga City, Fukui Prefecture), whose operation has been suspended due to numerous problems, is expected to be fully restored in mid July. Japan Atomic Energy Agency (JAEA) showed the restoration work to the press on June 21, demonstrating the equipment, newly installed after the accident [of the IVTM dropped inside the reactor], operated normally.

　もんじゅでは２０１０年８月、核燃料の交換に使う「炉内中継装置（ＩＶＴＭ）」が原子炉内に落ち、試験運転を中止。今年３月末までに運転再開予定だったが、復旧が遅れていた。

At Monju, the In-Vessel Transfer Machine that is used to replace nuclear fuel fell inside the reactor in August 2010, and the test operation was halted. The plan was to restart the operation by the end of March this year, but the restoration work has taken longer.

　この日は、同機構とプラントメーカーの作業員らが見守る中、原子力安全基盤機構の職員２人が、５月２８日からの作業で新品に換えたＩＶＴＭの動作確認をした。ほかに、制御棒に取り付けた電磁ブレーキの動作確認作業も進めており、７月中旬にも試験運転を再開できる状態になるという。

On June 21, as the workers at JAEA and the plant manufacturers looked on, two personnel from the Japan Nuclear Energy Safety Organization (JNES) confirmed the newly replaced IVTM worked. They will confirm the operation of the electro-magnetic brakes attached to the control rods, and the test operation is set to resume in mid July.

Monju's operation has been nothing but "test operation" for nearly 20 years (the reactor achieved criticality in April of 1994), and for the most part it has been idle because of seemingly endless problems. The biggest of all was the leak of liquid sodium coolant that resulted in fire at the plant in December of 1995, but what was at issue was not so much of the fire incident itself. The Power Reactor and Nuclear Fuel Development Corporation, who was running the plant at that time, downplayed the accident and hid the information of the accident.

More than anything else, the loss of credibility was what stopped Monju operation until March 2010, when the NISA deemed the reactor was "appropriately safe". The governor of Fukui set about restarting the plant. It reached the criticality in May 2010, only to have the IVTM dropped into the reactor 3 months later.

Here's the Google map of Monju location. Scroll to the northeast direction, you see Tsuruga Nuclear Power Plant which has Japan's oldest boiling water reactor and pressurized water reactor. A known active fault runs through the middle of that plant, and Reactor 2 may be sitting right on top of yet another potentially active fault. You also see a landfill over the mountain from Tsuruga Nuke Plant. That's where they are building Reactor 3 and 4. (You have to admire the dare.)

View Larger Map

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Tsuruga Nuke Plant Reactor 2 May Have Been Sitting on Top of Active Fault All These Years

As the mayor of Tsuruga City was strongly promoting nuclear power generation in the county in China that has a nuclear power plant with 6 operating reactors and 4 under construction, the Nuclear and Industrial Safety Agency warned the operator of Tsuruga Nuclear Power Plant that Reactor 2 of the plant may be sitting on an active fault.

Even in Japan, the national guideline is not expecting a reactor to be built on top of an active fault.

Reactor 2 of Tsuruga Nuclear Power Plant is a pressurized water reactor made by Mitsubishi Heavy Industries. Reactor 1 is a light water reactor by GE. Tsuruga's Reactor 2 was considered to be one of the better made PWRs in Japan. Both reactors have been shut down for regular maintenance.

Construction of Reactor 2 started in 1982, and the reactor started operation in 1987.

Two more reactors are being built at Tsuruga Nuke Plant. The reactors will be Advanced Pressurized Water Reactors (APWR) by Mitsubishi Heavy Industries. If they proceed with the construction, that is.

From NHK News (4/25/2012):

敦賀原発“活断層”で再調査へ

"An active fault" at Tsuruga Nuclear Power Plant to be studied again

福井県にある敦賀原子力発電所の地下を走る亀裂が活断層の可能性があると専門家が指摘したことを受けて、日本原子力発電は改めて現地調査を行うなどして対応を検討することにしています。

An expert has pointed out the possibility that cracks that run under Tsuruga Nuclear Power Plant in Fukui Prefecture are active faults. The Japan Atomic Power Company (JAPC) is going to do the survey again and come up with the plan.

福井県敦賀市にある日本原子力発電の敦賀原発では、２４日、活断層の専門家や原子力安全・保安院の担当者らが敷地内の地層が露出している地点を調査し、地中にある「破砕帯」と呼ばれる亀裂の状態を調べました。

On April 24, an expert in active faults and officials from the Nuclear and Industrial Safety Agency (NISA) studied the area where the strata are exposed at JAPC's Tsuruga Nuclear Power Plant in Tsuruga City in Fukui Prefecture. They particularly looked at the crack called "fracture zone".

その結果、専門家は２号機から西に１５０メートルほど離れた地中を走る亀裂について、「活断層の可能性があり、敷地内を走る浦底断層という活断層と連動して、地震の揺れが想定より大きくなる可能性がある」と指摘しました。

As the result, the expert pointed out that the crack that runs underground at about 150 meters west of Reactor 2 "may be an active fault, and it may move together with the active fault called Urazoko Fault that runs through the compound, making the shaking from an earthquake bigger than anticipated".

また、２号機の真下を走る別の亀裂についても活断層の可能性があるかどうか調べる必要があるとして、保安院は日本原電に対し、再調査を行うよう指示しました。

There is another crack that runs right beneath Reactor 2. It needs to be studied to determine if it is also an active fault. NISA has instructed JAPC to do the survey again.

国の耐震設計の指針では活断層の真上に原発の重要な設備を設置することは想定されておらず、２号機の真下の亀裂が活断層であった場合、２号機は運転が再開できなくなる可能性が出てきます。

The guideline for seismic design by the national government does not expect having an important facility of a nuclear power plant right above an active fault. If the crack beneath Reactor 2 turns out to be an active fault, there is a possibility that JAPC cannot restart the reactor.

これを受けて、日本原電は、近く国の原子力安全・保安院に調査の計画を報告したうえで、改めて現地で地層などの調査を行うなどして今後の対応を検討することにしています。

JAPC will report to NISA shortly with the plan for the survey, and will study the strata to decide what to do.

日本原電は「調査の結果によっては想定している最大の地震の揺れや原発の耐震性など、さまざまなことに影響するので慎重に調べたい」と話しています。

JAPC says, "The result of the survey may affect various issues such as expected maximum earthquake and seismic stability of the plant. We would like to proceed very cautiously."

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Tsuruga Nuke Plant to Stop the Reactor No.2 on May 7

After the highly elevated levels of radioactive xenon-133 and iodine-133 were detected in the cooling water from the Reactor Pressure Vessel of the Reactor 2 on May 2 (see my post on May 2), Japan Atomic Power Company (JAPC) has decided to shut down the Reactor 2 at Tsuruga Nuclear Power Plant in Fukui Prefecture in order to identify which fuel rods are leaking the radioactive materials.

JAPC's latest press release on May 6 shows that the level of xenon-133 has gone up further since May 2. Though the level of iodine-133 dropped to the pre-May 2 level, the level of iodine-131 has since gone up. The level of iodine-131 didn't show any increase on May 2.

JAPC will shut down the Reactor 2 on May 7 by first reducing the power output at 9:00AM, stopping the power generation at 5:00PM, bringing the reactor to a complete stop at 7:ooPM.

Tsuruga Nuke Plant's Reactor 1 is shut down for maintenance (link in Japanese) since January 26, 2011, and won't be back online until March 2012.

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Radioactive Materials Leak in Cooling Water in RPV at Tsuruga Nuclear Power Plant

High concentration of radioactive materials with very short half-life, iodine-133 (half-life 21 hours) and xenon-133 (half-life 5.2475 days), was detected in the cooling water inside the Reactor Pressure Vessel (RPV) of the Reactor 2 at Tsuruga Nuclear Power Plant run by Japan Atomic Power Company (JAPC).

The amount of iodine-133 doubled from a week ago, and the amount of xenon-133 was 750 times as much as a week ago.

JAPC suspects there are minute holes in the cladding, through which the radioactive materials are leaking.

Tsuruga Nuclear Power Plant is part of what is dubbed as "Nuke Power Ginza" in Fukui Prefecture. There are 5 nuclear power plants in the region with total 14 reactors.

From the company's press release on May 2:

"The Reactor No.2 at Tsuruga Nuclear Power Plant (PWR, 1,160,000 kilowatt) was tested for iodine and noble gas during the regular operation on May 2, 2011 in the cooling water that circulates around the fuel rod clusters; xenon-133 and iodine-133 were found to be exceeding the previous test result of April 26 as follows:

"Xenon-133:
5.2 Bq/cm3 (cubic centimeter) (April 26) to 3,900 Bq/cm3 (May 2)

"Iodine-133:
2.1 Bq/cm3 (April 26) to 4.2 Bq/cm3 (May 2)

"Based on this result, we have determined that there is a possibility of a leak of radioactive materials from the fuel rod clusters, and we have decided to monitor the radiation level of the cooling water [by monitoring it every day, instead of once a week - the footnote No. 2 in the original document].

"Further, in order to identify the leaking fuel rods, we may shut down the reactor.

"There is no leak of radiation in the environment as the result of this event."

敦賀発電所２号機（加圧水型軽水炉：定格電気出力１１６万キロワット）は、定
格熱出力一定運転中の平成２３年５月２日、定例の原子炉容器内にある燃料集合体
の周りを循環している１次冷却材中のヨウ素濃度および希ガス濃度の測定※１の結
果、希ガス（Ｘｅ－１３３）とヨウ素（Ｉ－１３３）が前回の測定値（４月２６日
測定：５．２Ｂｑ／ｃｍ３（Ｘｅ－１３３）、２．１Ｂｑ／ｃｍ３（Ｉ－１３３））
を上回る値（３，９００Ｂｑ／ｃｍ３（Ｘｅ－１３３）、４．２Ｂｑ／ｃｍ３（Ｉ－
１３３））であることが確認されました。
このため、燃料集合体から漏えいが発生した疑いがあると判断し、１次冷却材中
の放射能濃度の監視を強化※２しました。
今後、漏えい燃料の特定調査を行うため、計画的に原子炉を停止することを検討
します。
なお、本事象による周辺環境への放射能の影響はありません。

Looking at the chart attached to the company's press release, the amount of iodine-131 remained constant, while xenon-133 and iodine-133 spiked.

The Reactor 2 at Tsuruga Plant is in its 18th Cycle (of power generation) that started on July 12, 2010.

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