Reading the national report of Ukraine (2): Lessons from Chernobyl to Fukushima

I haven't finished reading the report document yet (totally over 300 pages), but in addition to the zone classification, there are other useful information and pedagogical analyses already in the first several pages.

In page 14, there is a paragraph saying:

The USSR undoubtedly achieved considerable success in developing nuclear science and engineering, especially in military industry. However, this success was too much politicized. At the same time, shortcomings and errors that led to large disasters both at civil and military nuclear facilities were concealed.  ----- All this resulted in the fact that infallibility moods become firmly established in the nuclear engineering. ---- "The Soviet nuclear reactors are the best in the worlds. " This (attitude) was also eloquently seen in response to the accident happened at the American Three Mile Island Nuclear Power Plant in 1979, when the leaders of the USSR nuclear industry announced that "such accident was impossible under socialism". -----

This analysis can be applied literary "exactly" to the Fukushima nuclear disaster, except the "under socialism" part, which should be replaced with "in Japan".

After nearly 30 years since the Chernobyl catastrophe, no Japanese politicians as well as bureaucrats learned the lessens from the Chernobyl. The ancient Romans used to say "Errare Humanum est", but this repetitive mistake by the Japanese government is too much and unacceptable to me.

Reading "National report of Ukraine: Twenty-five years after Chernobyl Accident"

I am reading now a report from Ukraine, "Twenty-five years after Chornobyl accident: Safety for the Future", which can be downloaded from here. (I did not know this until recently:  in Ukrainian, the correct spelling for "Chernobyl" is "Chornobyl". See Wikipedia.)  The reason for my reading of this document is that I wanted to know how the Ukrainian government set the radioactively contaminated zones.  There are four zones in Ukraine: (1) Exclusion zone, (2) Zone of implicit (mandatory) resettlement for more than 5 mSv/year, (3) Zone of guarantee voluntary resettlement for 1 to 5 mSv/year, (4) Zone of enhanced radiation monitoring for 0.5 to 1 mSv/year.

0.5 mSv/year corresponds to 0.06 μSv/h, which is observed everywhere not only in Tokyo, but in many parts in Japan (and maybe in many places in the world).  Usually, 0.06 μSv/h is regarded as a  "low" dose. When this zone classification was reported in NHK (Japan Broadcasting Cooperation), I thought something is wrong: 0.06 μSv/h is too low as a radiation monitoring district. That is why I decided to read the original report by myself.

First of all, I expected that the report is not open to public in the pdf format, so that I thought I might need to go to library to have a copy of the report. But to my surprise, the document can be downloaded in the pdf format! I appreciate those who allowed the download.

Anyway, I read the document, and found that the levels of the "dose" used for the zone classification turned out to be "additional" dose to the natural level. For example, if the natural dose is 0.06 μSv/h, then the No.4 zone (that is, the zone of enhanced radiation monitoring) should show the radiation level from 0.11 to 0.17 μSv/h. I agree that the places in Tokyo and its neighbours showing this level of radiation are surely contaminated by Cs-137, Cs-134, and other radioactive materials from the Fukushima nuclear power plant. My conclusion is that NHK misinterpreted the report issued by the Ukrainian government. As everybody says, it is important to check the original sources or documents so as to obtain correct information and knowledges.

As an example, a place in Chiba (East of Tokyo) shows 0.14μSv/h (with DoseRAE2 dosimeter). This place is near a small lake called "Inba-numa". See pictures and google map, below. The natural radiation level in this place is about 0.03 to 0.05 μSv/h. Therefore, the additional radiation is 0.09 to 0.11μSv/h (0.79 to 0.96 mSv/year), which satisfies the criterion for No.4 Zone.

Left: a view of "Inba-numa"
Right: radiation level measured in the place shown in the left picture.

View Larger Map

 To confirm how much the classification is reasonable, it is useful to measure the radioactivity of the soil in the place. The measurement should be done with the more sophisticated NaI scintillator (of course much more expensive than simple dosimeter such as DoseRAE2 in the above picture). Fortunately, I can access to one of such scintillators (Berthold LB2045), which  measures the radioactivity of soil samples in the unit of Bq (Becquerel, the number of radiation particles per second) . The measured radioactivity of the soil sample taken in Inba-numa is 318.2 Bq/kg (for Cs-137 and Cs-134). The corresponding gamma-ray spectrum is shown in the picture below.

Radioactivity (Caesium 137 and 134) of the soil sample
taken near the Inba-numa lake, Chiba.

The presence of three peaks in the 503 to 1025 keV energy region indicates that this soil is contaminated by Caesium 137 and 134. A small peak near 1550 keV shows a presence of K-40 (potassium 40, a natural radioactive material). CPS for the vertical coordinate means Count Per Sec. The value for Bq is calculated by integrating the spectrum in the relevant energy region. From this result, the 0.14 μSv/h means surely a contamination by Cs-137 and Cs-134.

A fairly large earthquake

A fairly large earthquake hit east japan this evening (around 5:30 pm).

I was outside, trying to observe Jupiter with a recently purchased big reflection telescope. This type of big telescope would be fantastic to enjoy the detailed surface of planets and subtle colouring of nabulae, etc. if the alignment of the autoguidance was perfectly set. Otherwise, this heavy chunk of metal is totally useless. It is likely to happen especially to most of beginners: the setting of the big telescope is very difficult. Last two days, I have been trying to see Jupiter with this telescope, but no success. Even a glance of Jupiter was not seen so far. Only a darkness...

Today, I followed the manual to set the alignment of the telescope with the help of the attached computer system for the control of the gears of the telescope mount. It was that moment when I felt a subtle shaking of the whole ground... It was just a beginning of another big Earthquake hitting Tokyo for the first time since the March 11, 2011.

The oscillation amplitude became larger and larger in time. I could feel the undulation movement of the asphalt itself. Looking up a building and a chimney tower in front of me, I noticed they were also oscillating slowly. The earthquake continued about a minute or so. Indeed, very long-lasting transverse wave it was! So scary. I run to the security office and asked an officer where the epicentre was. He said "Again in Tohoku. Almost the same area as the last big one happened. A Tsunami alert again along the all coasts in the north east Japan!"

Big earthquake, followed by Tsunami, which strikes Fukushima Nuclear Power station: this is the golden formula to destroy many parts in Japan. And I had a feeling that this could happen again. I try to gather the information about the No.4 reactor in Fukushima 1 nuclear power station. Because the spent-fuel pool placed on the top of the reactor has been tilting since the mega earthquake hit last year. Some scientists and engineers have warned that once the pool falls down to scatter the spent fuels, people in Tokyo need to evacuate from the capital immediately. I was so afraid of this possibility. I called my wife and told her to prepare for a possible evacuation in case.

Fortunately, this time, the spent-fuel pool survived the earthquake. But the Fukushima-2 Nuclear power plant, which survived the mega earthquake last year, underwent a minor emergency situation due to today's earthquake, allegedly to Mainichi Newspaper.  The met office (of Japan) announced that this evening's earthquake is an aftershock of the mega earthquake last year, so that it can happen again soon. I don't want to live with nuclear power stations under this sort of situation for long.

Tunnel collapses can happen again somewhere near the epicentre, I guess.

Tunnel collapse and SUBARU Impreza WRX

As reported (for example, in the Guardian), there was a tunnel collapse in a highway near Tokyo a few days ago. This collapse is not a total collapse of the tunnel, but the concrete ceiling panels fell down to crash several cars running below.  9 people were killed by this accident.

But there could be one more casualty: as mentioned in the article of the Guardian, a journalist working for NHK (Nihon Hoso Kyokai = Japan Broadcasting Cooperation) who happened to drive his SUBARU Impreza WRX under the collapsing tunnel, narrowly escaped the accident.

SUBARU Impreza that escaped the accident.
(Picture taken from here.) 

Many people in Japan believed that this escape was possible because it was Impreza, with high performance for a quick acceleration and good rigidity of the car body. If the car was Prius, then the driver would be dead now...

Mt Fuji seen from Hakone

Autumn in Japan is going away, and winter is approaching. 「紅葉」, which means "coloured leaves", is coming down from high mountains to cities right now. So, visiting high mountains in the end of November is not such a good idea, but there are benefits about it.

The first reason is traffic jams... The best "coloured-leaf" season is limited to about two weeks or so. Everybody rushes into narrow mountain roads only in this period. The result is a long long queue along a mountain road. Only-one restaurant in a rural mountain region is full of sight-seeing people.
Whole atmosphere associated with the colour and beauty of the scenery is surely destroyed by these people.  If you visit in the end of November, colour of tree leaves might slightly remain in the mountains (still enjoyable), and best of all just a few visitors are in sightseeing spots. The atmosphere of the nature is back again.

Secondly, you can enjoy not only the colour but also the whiteness of snow-capped mountains at the same time, especially of Mt. Fuji in the case of Hakone. Today, I went to Hakone with an expectation for such a magnificent picture. Hakone is the region inside a large volcano mouth (called "caldera", or crater), near to Mt Fuji.

If you come from a wide Kanto plain where Tokyo is located, the Hakone region is something like a magical land hidden inside the large crater. Getting over the rim of the crater, you will see a different world... A blue lake in the bottom of the crater, and active volcanoes ejecting smokes from mouths are rising from the lake. In addition, the long rim of the crater surrounding these "magical land". Fantastic! Today, beyond the rim, I could see Mt Fuji with a snow cap, too!

Mt Fuji beyond the rim of the crater
surrounding the Hakone region.

Today's morning weather was not so good. From Tokyo, Mt Fuji was covered by thick grey clouds. Before getting over the rim to enter the Hakone region, Mt Fuji was also in clouds, and only the bottom part of the mountain was seen. But on arriving at Owaku-dani, a hot spring in Hakone, the clouds suddenly slided away to show the top of Mt Fuji!

Owaku-dani, a hot spring in Hakone
"Smokes" are water vapors from hot springs.

Hakone was drawn in Ukiyoe. Hiroshige's "Picture of Lake water in Hakone" is the most famous. Today's landscape reminds me of this Ukiyoe.

New formulae I found

I am writing a paper with a colleague of mine, about a new formula we have found recently. Creating a formula is a kind of "dream work" for any theoreticians. So, I am very happy that I have achieved that dream finally.

Interestingly, once you find a new formula, then the threshold for a next formula is lower than the first one. Actually, it happened to me.

I had been struggling for a certain physics problem for years, and in the beginning of the last year, I managed to find a numerical solution for that. I decided to make a presentation in a workshop in Japan, and gave a talk in the workshop in the mid September.

At the evening when I finished the presentation, I had a dinner with a collaborator to celebrate the success of our presentation. After I came back to my hotel, I opened my MacBook Air to check the e-mail box, together with a brief checking  of new preprints posted in the arXiv.org. I normally don't check frequently other people's work because I believed that my work was quite unique and that nobody could follow easily.

To my surprise, though, there were two new papers posted last two weeks, and they claimed that they have found a new formula. One was from Europe, and the other was from the US.

In fact, I did some pre-analysis for brushing up my numerical solution, and noticed that my result can lead to a possible new formula, of my own... When I noticed this possibility several months ago, I was so excited. I thought I was finally given a chance from the heaven that I could make a new formula. But due to busy everyday life, such as giving lectures, attending long-hour academic meetings, etc, I left the work unfinished. But I was not so irritated at this slow progress, because I thought I was the only one in the world to have noticed this possibility so far, and that everybody else was so far away from my level. My optimism is totally against the reality, in fact. Two groups in the world seemed to have noticed "my" finding almost simultaneously.

I was so shocked at these two preprints. It seemed my life as a researcher was completely finished by these two papers. But I noticed that these papers were interested in slightly different things. At least, the ansatz they employed were different from mine. I thought that if I summarize what I had in my mind, the final formula I would derive should be different from theirs. So since that night, I started to engage myself to derive a new formula in my own fashion. After a month, I submitted the manuscript to arXiv and a publisher of a physics journal.

During a waiting period for referees' comments, there was no news about the other two papers. It seemed that they were struggling to publish in a journal. Comments from the referees  returned to me very soon, and my paper was accepted for publication earlier than the others! My formula was admitted as a "new formula" that nobody else have found before. Soon after our publication, the formula found by the other two groups were also published in different journals. Luckily, we have submitted to different publishers, so that the reviewing was done independently.

My first formula was obtained more than 15 years since I took a Ph.D. But the second one came only six months after the first formula! And the third one was only a month later after the second!! The first two fomulae were already published. The paper I am writing at the moment is actually for the third one. I am sure that the latest one will be also published soon.

A textbook I wrote

I wrote a textbook for my lectures, actually this is the first book I have ever written! For two years, I have spent painful days to complete a book writing.

Before writing a sentence for this book, I was pretty confident that I could finish writing a book after six months or so. Theoretically it should be possible, but human brain is not designed to function in a multi-tasking fashion. I understand now that my brain is not an exception in this aspect. If your lecture course starts, your mind will be occupied by the thoughts of lecture preparations. If a physical society meeting nears, your mind will be occupied by the thoughts how to make a good presentation in the meeting. As a result, there is no room in your brain for writing a book during these busy days.

Of course, you can write something anyway in these busy days, but the contents you write might not be very interesting to readers, or even to yourself. There are sometimes cases that you feel bad about what you wrote, say,  a week ago. After a week, you can read back your writing from an objective point of view, and found that your writing is quite dull and non-interesting, although you have believed that your writing must be the best in the world while you were writing sentences.

To avoid such a bitter experience, "slow writing" may be helpful, that is, write, a short break, then read what you wrote, and modifications. If you repeat this sort of painstaking processes, then you may be more satisfied in the end. I would like to try this way of "slow writing" in the next occasion.