Monday, June 6, 2011

#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.


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.


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."


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.


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?")


Anonymous said...

Robbie001 sez:

According to the The Nuclear Engineering Department At UC Berkeley Radiological Air and Water Monitoring Forum they detected Te-132
back in March.

"We do see Te-132 and the decay daughter of I-132 along with I-131, Cs-134, and Cs-137 in trace amounts. Just because we see Te-132, does not necessarily mean a core meltdown, but it does indicate a significant release of fission products from the fuel. Te-132 has a half life of about 3 days and therefore we know this is from one of the three operating reactors that were shutdown at the earthquake as opposed to the spent fuel pools which had been shutdown for greater than 100 days. When a reactor shuts down, the production of these nuclides cease and this kind of starts a clock where after a certain amount of time, certain nuclides decay away. Te-132 is one of these and so it gives us some indication of where the release came from. No data from our measurements point to a meltdown, however, I think the accepted assumption is that all three units at Fukushima have some sort of core damage. The extent of this damage is still unknown."

Anonymous said...

Robbie001 sez:

According to this site there were 48 Te-132 alerts in 18 cities monitored by the EPA radnet.

arevamirpal::laprimavera said...

@Robbie, well Berkeley was also wrong, and it was a complete meltdown. Oh well. No one seems to care anywhere. BTW, do you know any place that I could get this radiation detector? It would be for my acquaintance in Japan. Lead time there is 9 months, if at all.

Anonymous said...

those liars need to commit suicide.
there is no honor left in japan.

Anonymous said...

mount fuji awaits your long walk, you ought to go with other liars and all commit suicide at the same time.

Anonymous said...

Robbie001 sez:

@ Areva

Berkeley was wrong but my point was they detected Te-132 back in March.

As for the Radiation Alert INSPECTOR that's a good meter my Radiation Alert MONITOR 5 has served me well for over 12 years. Unfortunately at this stage in the game good equipment is impossible to find. I've had people making ridiculous offers for my equipment and I'm not trying to sell it.

Grainger looks like they may have it in stock but they want almost $800 for it.

This is where you'll want to look in the coming weeks for information on new stock if Grainger has no joy they are the manufacturer of "Radiation Alert" products. I'm pretty sure they are loosely connected to the Oak Ridge National Laboratory. A lot of their employees used to work there and I think their calibration service is done at ORNL at least it used to.

Anonymous said...

Robbie001 sez:

If you manage to find your friend a detector here are some Geiger counter tips for nubies.

1) Geiger counter with mica windows can detect Gamma, X-ray, Beta and Alpha radiation but the sensitivity falls off in the same order. Alpha sensitivity could be 10% or less of the Gamma. Using various probe shields it is possible to determine rough estimates of the Gamma Beta ratio. Alpha detection runs the risk of probe contamination because the probe must be unshielded and close to the source.

2) Avoid contaminating your meter you'll notice when they screen someone on TV the detector is wrapped in plastic this is to keep the detector from becoming contaminated. When in a contamination zone always keep your meter in a sealed plastic bag and wash your hands thoroughly before you handle it outside the bag. Most manufacturers won't accept contaminated equipment for repair and third party shops are very expensive (if they are competent).

3) Most used meters aren't properly calibrated or maintained so they can be inaccurate right out of the box. Professional calibration costs about $75 and should be done every couple of years pre-Fukushima turn around times were a week or two. Computer controlled Geiger counters generally don't need calibration because they run a calibrate routine every time they are turned on.

4) Geiger counters don't detect every energy level with the same sensitivity. Most Geiger counters are tuned to fairly accurately detect the energy spectra of Cs-137 or Co-60 but isotopes that fall outside that spectra are detected at lower sensitivity if at all. For example most forms of Radium, Plutonium, Uranium, Thorium are detected relatively well along with Cs-137, Te-99, Co-60, Sr-90 and P-32. But Tritium beta activity is so low it requires specialized equipment to detect and quantify it. Americium-241 Alpha emissions are so energetic it can overexcite the Geiger–Müller tube and give a false high reading. So remember a Geiger counter doesn't give out hard numbers it is just an approximation of the actual number.

5) Detecting radiation in food isn't always as easy as waving a Geiger counter around the item in question. Generally very specialized detection equipment and protocols are used. Some assay methods used dried and powered samples because water and cell structure masks emissions. I'm not saying surface detection isn't useful I'm just saying it may not represent the actual contamination levels of soil, food and water.

As for used equipment most Geiger counters sold on Ebay aren't worth anything especially old civil defense 7xx series equipment. The "survey" meters are useless because they read in multiples of R/hr at that level you'd be dead in short order. The model 700's are a useful range but most don't work and even fewer are calibrated. The old civil defense meters are great conversation pieces but they are past their useful life unless they are totally refurbished. Even if you get one that works the transformer will fail in short order and there are no replacements available. There are some old timers who were refurbishing some of this equipment but they are few and far between and their refurb's are pricey because they have to gut the machine. I had a few cheap ($15 now $50) Russian counters but I gave them away to local science clubs. All the Russian models used to be cheap but now their prices have soared and the quality is hit or miss so I don't know if I'd recommend one but then again something is better that nothing.

Anonymous said...

@ Robbie001,

Thank you for the info, you and the blog owner are the Man.

btw, is arevamirpal the blog owner?

Anonymous said...

Robbie001 sez:

@Anon 2:34

Thanks, and yes arevamirpal is the owner I just have a big mouth. (^^)

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