18 Μαρτίου

Δεν ξέρω τι γίνεται, και δεν μπορώ να ξέρω τι γίνεται. Ο φόβος μην "έρθει κάτι κακό σε εμάς" προφανώς έχει πιάσει μερικούς... Μην βιάζεστε, από αύριο το απόγευμα θα αρχίσουν να ανησυχούν στην ...Καλιφόρνια, και η πολλή τηλεόραση συμβάλλει σε λίγη υστερία.

Τα δύο links που έχω δεξιά, (το blog από το Nuclear Science and Engineering του ΜΙΤ, και το Bravenewclimate, δεν είναι ειδησεογραφικά αλλά έχουν εξαιρετικές παρουσιάσεις της κατάστασης. Μην περιμένετε ούτε εφησυχασμούς, ούτε τρομολαγνεία, ούτε "αντιπυρηνική" τοποθέτηση, αλλά έχουν τεχνικές εξηγήσεις σε απλά αγγλικά.

Τα meltdown κλπ είναι εσωτερικά του αντιδραστήρα. Έχουν συμβεί, και είχαν συμβεί και στο Three Mile Island. ΔΕΝ πέρασαν το μεταλλικό κουβούκλιο τότε, και δεν υπάρχουν ενδείξεις ότι θα γίνει τώρα.

Όλη η άσκηση είναι νερό, νερό, νερό. Οι αντιδραστήρες έχουν σβήσει εδώ και μία εβδομάδα, αλλά η αντίδραση σταματάει γρήγορα στην αρχή και εκθετικά όλο και πιο σιγά μετά. Κάθε μέρα που περνάει είναι προς την σταθεροποίηση (αν δεν προκύψει κάτι καινούργιο). Το πρόβλημα με τα αποθηκευμένα τελειωμένα καύσιμα είναι από τα καινούργια που προέκυψαν.

Υποτίθεται ότι παρέχεται νερό με ανορθόδοξες μεθόδους (κανόνια νερού, ελικόπτερα, και πυροσβεστικά) και γράφτηκε ότι προσπαθούν να ηλεκτροδοτήσουν τις αντλίες ψύξης.

Εκλύεται ραδιενέργεια, αλλά χωρίς να είμαι ειδικός, νομίζω ότι μάλλον καταστρέφει τους τεχνικούς και τους πυροσβέστες, όσο και αν είναι ανιχνεύσιμη σε Αμερικανικά αεροδρόμια, ή αν έρθει εδώ την άλλη εβδομάδα. Αυτά που ο κόσμος ταυτίζει με μέγα κίνδυνο και όλεθρο προκύπτουν μόνο σε έκρηξη (και δεν αναφέρομαι στις εκρήξεις υδρογόνου). Οι αναφορές λένε για "σταθερά" επίπεδα ακτινοβολίας.

Το Nikkei λέει ότι δεν έχουν αντλίες ή ρεύμα (και μάλλον μιλάμε για δεκάδες MW) για τις αντλίες που χρειάζονται για το πολλαπλό πρόβλημα όλων των αποθηκών παλιού καυσίμου (και μεταφέρει μάλλον απαισιοδοξία στο θέμα) και ελπίζουν να λύσουν αυτό το πρόβλημα την Παρασκευή. Το BBC είχε αναφέρει νωρίτερα ότι είχαν φέρει γραμμή ηλεκτρικού (αν λειτουργούν ακόμα τα ηλεκτρικά Tepco warned the process of reconnecting power could take up to 15 hours )
Friday, March 18, 2011 http://e.nikkei.com/e/fr/tnks/Nni20110318D18JF224.htm

Radiation Slightly Down Around ReactorTOKYO (Kyodo)--Radiation readings around the troubled reactor of the Fukushima Daiichi nuclear plant fell slightly after the Self-Defense Forces discharged water in an attempt to cool an apparently overheating spent fuel pool, the Nuclear and Industrial Safety Agency said Friday.

The radiation reading came to 279.4 microsievert per hour at the point roughly 1 kilometer west of the No. 2 reactor at 5 a.m. Friday, compared with 292.2 microsievert per hour at 8:40 p.m. Thursday, shortly after the SDF discharged water from fire trucks, according to the agency

U.S. Flights Over Plant Gather Crucial Data http://www.nytimes.com/pages/world/asia/index.htmlBy DAVID E. SANGER and WILLIAM J. BROAD 6:02 PM ET
Readings from American flights over the stricken nuclear plant show that the worst of the contamination has not spewed past the 18-mile range established by Japan

http://au.news.yahoo.com/thewest/a/-/newshome/9032638/crippled-japan-reactor-stable/
Japan's nuclear safety agency says smoke is rising from a building housing a damaged nuclear reactor at a power plant crippled by last week's tsunami.

A spokesman for Japan's nuclear safety agency said the smoke was seen rising from Unit 2 at the Fukushima plant.

The spokesman says the agency does not know the cause, but an explosion occurred in Unit 2 earlier in the week, possibly damaging a chamber next to the reactor core

http://e.nikkei.com/e/fr/tnks/Nni20110318D18JF302.htm
workers braving the risk of radiation exposure to prevent the problems from developing into a catastrophe
The unprecedented cooling mission, which was launched Thursday by the Self-Defense Forces by spraying tons of water over the plant's No. 3 reactor building, was bolstered on the second day with more pumps, after efforts were focused in the morning to restore power to some of the reactors' cooling systems, the government said
considering dousing a spent nuclear fuel pool at the No. 1 reactor, although it does not pose as imminent a threat as the No. 3 and No. 4 reactors of releasing radioactive materials into the air, to extend all possible means.
The radiation level at 11 a.m. dropped to 265.0 microsievert per hour from 351.4 microsievert per hour at 12:30 a.m. Thursday. It measured 292.2 microsievert per hour at 8:40 p.m. Thursday, shortly after SDF trucks sprayed water at the No. 3 reactor pool as part of efforts to avert any massive emission of radioactive materials into the air from the facility.

Japan battles nuclear, humanitarian crisisShingo Ito, AAP, AAPhttp://au.news.yahoo.com/thewest/a/-/newshome/9032638/japan-battles-nuclear-humanitarian-crisis/
March 18, 2011, 5:00 pm Japanese engineers have conceded that burying a crippled nuclear plant in sand and concrete – the method used to seal huge leakages from Chernobyl in 1986 – may be a last resort to prevent a catastrophic radiation release.

But they still hoped to solve the crisis by fixing a power cable to at least two reactors to restart water pumps needed to cool overheating nuclear fuel rods. Workers also sprayed water on the No.3 reactor, the most critical of the plant’s six.

It was the first time the facility operator had acknowledged burying the sprawling complex was possible, a sign that piecemeal actions such as dumping water from military helicopters or scrambling to restart cooling pumps may not work.

"It is not impossible to encase the reactors in concrete. But our priority right now is to try and cool them down first," an official from the plant operator, Tokyo Electric Power Co, told a news conference

As engineers work to restore power to the stricken plant, the toll of dead and missing from the quake and tsunami reached 16,900.
Half a million people made homeless when the monster waves razed Japan’s northeast coast are suffering in appalling conditions, struggling to stay warm in freezing temperatures and with scant supplies of food and fuel


http://e.nikkei.com/e/fr/tnks/Nni20110318D18JF334.htm
Friday, March 18, 2011

Fukushima Hiked To Same Accident Level As Three Mile IslandTOKYO (Dow Jones)--The Japan Nuclear and Industrial Safety Agency said Friday it raised the accident scale level of the quake-damaged Fukushima Daiichi nuclear-power complex to 5, similar to the level of the accident at Three Mile Island in 1979.

The agency attributed the decision to raise the level from 4 to "serious damage" to fuel at the plant's reactors

News update, 3/18
Posted on March 18, 2011 10:19 am UTC by mitnse http://mitnse.com/
News Brief, 3/18/11, 10 AM EDT
Spraying of spent fuel pools at Units 3 and 4 is still underway. Visual inspection of Unit 4’s pool showed water in the pool, and so efforts have been temporarily focused upon Unit 3. While efforts at using helicopters to dump water onto the pools had been largely unsuccessful , army firetrucks used in putting out aircraft fires have been employed with some success. The elite Tokyo Hyper Rescue component of the Tokyo fire department has arrived on scene and is conducting missions of roughly two hours in length, during which they spray the pools for 7-8 minutes, wait for steam to dissipate, and spray again.

A cable has been laid from a TEPCO power line 1.5 km from the facility, which will be used to supply power to emergency cooling systems of the reactors at Units 1 and 2.

Backup diesel generators have been connected to cool the spent fuel pools at Units 5 and 6. As of 4 PM JST, temperatures in those pools have reached 65.5 and and 62 degrees Celsius.