#Fukushima I Nuke Accident Tellurium-132 Conundrum: Case of Missing Iodine and Cesium

This blog posted on June 3 that the Nuclear and Industrial Safety Agency revealed tellurium-132 had been detected 6 kilometers from the plant on the morning of March 12, before the venting of the Reactor 1.

Well, that Yomiuri Shinbun article in that post was incomplete, to say the least. It turns out that it was not only one location in Namie-machi where radioactive tellurium was detected but also at 3 other locations: one more location in Namie-machi, one location in Okuma-machi, and one location in Minami-Soma City.

Moreover, the same air radiation survey done by Fukushima Prefecture detected more volatile iodine-131 at half as much as tellurium, but it hardly detected any cesium-137 except at one location.

It's not supposed to happen that way, if what we've been told about the circumstance is correct, as a Kyoto University professor says in the article in Tokyo Shinbun, below.

(I'll go look for the information at NISA, and update if I find more data.)

Tokyo Shinbun (6/5/2011; emphasis added) reports the puzzling detection of tellurium-132 on March 12:

　東日本大震災の発生翌日、福島第一原発で爆発が起きる前に福島県が行ったモニタリング調査で、金属性で飛散しにくい放射性のテルルが原発から約七 キロ離れた同県浪江町などで検出されていたことが分かった。拡散しやすい揮発性の放射性ヨウ素より多く検出されており、早い段階で金属性の放射性物質が広 く飛散していた。テルルはレアメタル（希少金属）の一種で、放射性同位体のテルル１３２の半減期は三日余り。主にベータ線を出す。

It has been revealed that radioactive tellurium, a metal that is hard to disperse in the atmosphere, was detected on the next day [March 12] of the earthquake in Namie-machi, 7 kilometers from the plant, and other locations according to the result of the monitoring survey done by Fukushima Prefecture before the explosion at Fukushima I Nuclear Power Plant that day. More tellurium was detected than more volatile radioactive iodine. It shows that metallic radioactive materials [like tellurium] dispersed wide from an early stage [of the accident]. Tellurium is a rare metal, and tellurium-132 has a half-life of about 3 days, emitting beta rays.

　データは保安院が三日夜に公表。三月十二日朝から十三日夜までの大気を調べたもので、大半がこれまで未公表だった。テルル１３２は十二日朝から昼 すぎにかけ、浪江町の二カ所と大熊町、南相馬市で検出。濃度は一立方メートルあたり法定限度の二〇ベクレルを超える一一九～二三ベクレルだった。

The data was revealed on June 3 evening by the Nuclear and Industrial Safety Agency. The monitoring survey of the air was done from March 12 morning till March 13 night, and the most of the data had been withheld until June 3. Tellurium-132 was detected from the morning till the early afternoon on March 12 at 2 locations in Namie-machi, and Okuma-machi and Minami-Soma City. The concentration was between 23 to 119 becquerels per cubic meter, exceeding the safety limit of 20 becquerels per cubic meter.

　当時の原子炉建屋は換気装置が止まり外に空気が出ない状態。蒸気を放出するベント作業は十二日午後に行われ、その直後に水素爆発が起きた。

At that time, there was no air escaping the reactor building as the air exchange system had stopped. The venting to release the steam was done in the afternoon of March 12, and a hydrogen explosion [in the Reactor 1] happened after the venting.

　東京電力は、核燃料の損傷が最も進んでいたとされる１号機が漏出元とみており、「格納容器内の圧力が高まり、接ぎ目から水素とともにテルルが漏れ出したのでは。建屋内の圧力も高まって外に漏れ、風に乗って広がったことが考えられる」と説明している。

TEPCO thinks that tellurium came from the Reactor 1 whose fuel core was most damaged, and explains, "As the pressure inside the Containment Vessel rose, tellurium, along with hydrogen, may have escaped from the joints [on the Containment Vessel]. The pressure inside the reactor building also rose, and then tellurium leaked outside the building and was carried by the wind and spread wide."

　ただ、拡散しやすい揮発性のヨウ素１３１の検出量はテルルの半分程度。テルルと同じ金属性のセシウム１３７は浪江町の一カ所でテルルを上回った以外、微量しか検出されなかった。

However, volatile and therefore more easily dispersed iodine-131 was detected at half the amount of tellurium. Cesium-137 was detected in one location in Namie-machi in the amount exceeding that of tellurium; however, at other locations, it was detected in only minute amount.

　京都大原子炉実験所の山本俊弘准教授（原子炉物理）は「現在分かっている状況では、テルルが遠方に飛散することは考えにくい」と述べた。

Associate Professor Toshihiro Yamamoto of Kyoto University Research Reactor Institute (reactor physics) says "Under the circumstance that we have understood so far, it is hard to believe that tellurium would spread far."

Well it apparently did, Mr. Yamamoto. Now what?

(I guess the answer is "So what?")

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#Fukushima I Nuke Accident: NISA Now Says 1.31 Million Becquerel Iodine-131 Was Detected on March 15, 38 Kilometers from the Plant

It was not just the tellurium-132 data that the Japanese government hid.

The national government and the Fukushima prefectural government had the data that showed 1,230,000 becquerels/kilogram iodine-131 was detected from the grass on March 15 in Kawamata-machi, 38 kilometers from Fukushima I Nuclear Power Plant.

They sat on it. It didn't occur to them to disclose, said NISA's Nishiyama. His subordinate at NISA further commented, as seen in the news clip on NHK Japanese, "It is not clear that the data would have helped at all, even if it had been disclosed."

Tell that to parents in Fukushima and elsewhere.

By the way, Kawamata-machi is where the residents in the areas closer to the plant intially evacuated, including the residents in Iitate-mura and Namie-machi.

From NHK Japanese (4:32AM JST 6/4/2011):

... 公表されていなかったのは、避難や飲食物の摂取制限など、住民の防護対策を決める際の参考にするため、発電所周辺で国や福島県によって行われた「緊急時モ ニタリング」のデータの一部です。

Part of the "emergency monitoring data" collected by the national government and the Fukushima prefectural government around the nuclear plant wasn't disclosed [until June 3]. The data was to be used for protection of the residents, such as evacuation and restriction on food and water consumption.

このうち、大気中のちりなどに含まれる放射性物質の調査では、事故の翌日の３月１２日午前８時半すぎに発電所からおよそ ７キロの浪江町の地点で、核燃料が溶けた際に出るテルルと呼ばれる放射性物質が１立方メートル当たり７３ベクレル検出されていました。

In the survey of radioactive materials in the dust particles in the air, 73 becquerels/kilogram of tellurium was detected at 8:30AM on March 12 at a location 7 kilometers from the power plant in Namie-machi. Tellurium is one of the radioactive materials released when the nuclear fuel melts.

このデータが検出さ れる３時間ほど前、政府は避難区域を発電所の３キロから１０キロ以内に拡大し、住民に避難を呼びかけていましたが、燃料の損傷の説明はなく、その後、昼す ぎに行われた原子力安全・保安院の会見でも、核燃料は壊れていないと説明していました。深刻な事態が進みつつあることを示すデータが早い段階で公表されて いれば、住民の避難のしかたや避難への心構えなどに役立てられた可能性がありますが、原子力安全・保安院は「データがどれだけ住民のために役立てられたか は現時点では分からない」としています。

3 hours before tellurium was detected, the national government expanded the evacuation zone from 3-kilometer radius from the plant to 10-kilometer radius, and was asking the residents to leave. But there was no mention of the damage to the fuel. In the press conference that afternoon, the Nuclear and Industrial Safety Agency said the nuclear fuel was not damaged. If the data had been disclosed at an early stage when a serious situation was developing, the data might have been useful in evacuating the residents or better informing the residents. However, NISA claims "It is not known at this point how useful the information would have been to help the residents."

一方、事故発生の４日後に周辺の市町村で行った放射性物質の調査のうち、原発から３０キロから５０キロの４か所で 採取した雑草などのデータも公表されていませんでした。このうち、原発の北西およそ３８キロの川俣町で採取した雑草からはヨウ素１３１が１キログラム当た り１２３万ベクレルという高い濃度で検出されていました。

Meanwhile, of the survey done in cities, towns, and villages around the nuclear plant 4 days after the start of the accident, the data on the grass taken at 4 locations 30 to 50 kilometers from the plant wasn't disclosed. The withheld data shows a high concentration (1,230,000 becquerels/kilogram) of iodine-131 was detected from the grass in Kawamata-machi, 37 kilometers northwest of the plant.

原発周辺の雑草については、この調査から９日後になって初めて飯舘村で１キログラム当たり２５２ 万ベクレルの放射性ヨウ素が検出されたと発表されていました。

About the grass in the area around the plant, it was announced [on March 24] that 2,520,000 becquerels/kilogram of radioactive iodine was detected in Iitate-mura, 9 days after [the data in Kawamata-machi was taken].

これについて、環境中の放射性物質に詳しい学習院大学の村松康行教授は「放射性ヨウ素は子ど もへの影響が大きく最も注意が必要な物質だ。早い段階で遠くまで放射性ヨウ素の汚染が広がっていることが公表されていればより早く何らかの対応ができた可 能性がある。当時の対応を検証する必要がある」と指摘しています。

Professor Yasuyuki Muramatsu of Gakushuin University, an expert in environmental radiation, points out, "Radioactive iodine affects children the most and we should monitor it very carefully. If the extent of contamination of radioactive iodine in places far away from the plant was disclosed early on, we could have done something about it. We need to examine the government response at that time."

データの公表が遅れたことについて、原子力安全・保安院は「対策本部を現地から福島県庁 に移す際に混乱したため、データがあることは把握していたが、公表しようという考えに至らなかった。深く反省している」と話しています。

About the delay in disclosing the data, NISA says, "There was a confusion when we moved the headquarters [to deal with the accident] from the plant to the Fukushima prefectural government hall. We knew there was such data, but it never occurred to us to disclose it. We deeply regret."

"Delay" is an understatement. And it is clear that it was a selective amnesia; they picked the worst data and hid it.

The government also "forgot" to disclose the simulation data that were created in case of an accident at Fukushima II Nuclear Power Plant, according to NHK.

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#Fukushima I Accident: Tellurium-132 Was Detected on March 12 Morning, 6 Kilometers from the Plant, NISA Now Admits

Telluriuim-132 was detected 6 kilometers northwest of Fukushima I Nuke Plant in Namie-machi in the morning of March 12.

That's before the Reactor 1's reactor building blew up (March 12 late afternoon), and even before TEPCO managed to do the venting (March 12 early afternoon) for the Reactor 1.

Nuclear and Industrial Safety Agency, regulator for the nuclear industry, decided to sit on the data for 2 months and 3 weeks. Agency spokesman Nishiyama's excuse? "It never occurred to us to disclose the data."

The Japanese government is doing "one heck of a job" indeed, as IAEA's over-the-top praise indicates (from IAEA's preliminary report):

"The Japanese government's longer term response to protect the public, including evacuation, has been impressive and extremely well organized."

Yomiuri Shinbun (11:09PM JST 6/3/2011; emphasis is mine):

東京電力福島第一原子力発電所から約６キロ離れた福島県浪江町で３月１２日朝、核燃料が１０００度以上の高温になったことを示す放射性物質が検出されていたことが分かった。

It was disclosed that the radionuclide that would indicate the nuclear fuel temperature exceeded 1,000 degrees Celsius was detected in the morning of March 12 in Namie-machi in Fukushima Prefecture, about 6 kilometers [north] from Fukushima I Nuclear Power Plant.

　経済産業省原子力安全・保安院が３日、発表した。事故発生から２か月以上も経過してからの公表で、保安院の西山英彦審議官は「隠そうという意図はなかったが、国民に示すという発想がなかった。反省したい」と釈明した。政府の事故調査・検証委員会の検証対象になりそうだ。

The Nuclear and Industrial Safety Agency (NISA) of the Ministry of Economy, Trade and Industry (METI) announced on June 3. Asked about the disclosure after more than 2 months after the accident started, Agency spokesman Hidehiko Nishiyama defended his agency by saying "We didn't intend to hide the information, but it never occurred to us to disclose it to the public. We are sorry." The government's commission on the Fukushima I accident may investigate the incident further.

　検出された物質は「テルル１３２」で、大気中のちりに含まれていた。測定時間は、１号機で放射性物質の混じった蒸気が放出された「ベント」の前だった。

The radionuclide detected was "tellurium-132", and it was found in the dust particles in the air. It was detected before the venting of the Reactor 1, which released radioactive steam.

By the way, University of California Berkeley was detecting tellurium-132 in the air from March 18 to March 29. Is it any wonder that it was detected at a location 6 kilometers from the plant, when it was detected across the Pacific Ocean?

Tellurium-132's half-life is 3.2 days.

That seems to me to indicate that fission was ongoing long after the SCRAM (March 11). I'm still patiently waiting for NISA and the government to admit recriticality had occurred.

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