Last updated on March 1, 2013
21:30(CET)/19:30(UTC)/04:30(JST)
Another rather uneventful day. The sodium silicate injection into the pit seems to have succeed in stopping the flow of water, like I mentioned yesterday this is not a permanent solution and eventually the water will find another path into the ocean until the source of the water is plugged. But it is a good development and every day the water is kept from going into the ocean it is another day with decaying I-131 levels.
TEPCO is pumping nitrogen into the containment of the number 1 reactor and is planning to do the same with number 2 and 3. They are afraid of new hydrogen explosions, this time the source of the hydrogen would be radiolysis of water. Simply put, radiation breaks the chains connecting the hydrogen and oxygen in water and creates free hydrogen. One could also suspect further steam and zirconium reactions might have taken place during the temperature peaks in the number one reactor if the flow of water was temporarily not sufficient. Regardless of the source of hydrogen, if the containment is filled with nitrogen it prevents a combustible mixture of oxygen and hydrogen to occur.
The temperature of the feed water nozzle in the number one reactor is creeping downwards. Now it is at 221.6 degrees Celsius, yesterday it was 233.5 and the day before 242.6. The pressure is showing the opposite trend and is slowly rising, hitting 733 kPa today, 720 kPa yesterday and 704 kPa the day before. Like I also mentioned yesterday this isn’t much of an issue because it is just one tenth of normal operating pressure. Only problem I could imagine is that if the pressure climbs to high the temporary pumps they are using might not be able to match it, but flow rate is steady so far. Containment pressure is steady at 150 kPa.
IAEA reports that instrumentation now has power in reactor number 3. I hope it means they will soon be able to give more detailed information about the status of the reactor. Perhaps my pessimism about the drenched switchboard was wrong, we will see!
There has been reports that detected levels of Tellurium-129 hints of re-criticality, due to the short half live of Te-129 (69.6 minutes). But that ignores that a excited state of Te-129 is also created as a fission product, the excited state has a half life of 33.6 days and of course decays into the ground state. So finding Te-129 now is not very strange at all.
Nothing new about the status of fallout in the prefectures around Fukushima.
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Links(English)
Reuters Japan stop nuclear plant leak
Blogs(English)
Atomic Power Review Wednesday early afternoon update
Idaho Samizdat NRC threat assessment of Fukushima risks
NEI Nuclear Notes Wednesday Update
Links(Swedish)
DN Flytande glas har lyckats täta läckan
Blogs(Swedish)
Hög radioaktivitet i fisk
Tellurium 129 tyder på reaktion i Fukushima
Om miljökatastrofer som räddare av ekosystem
“Oberoende” kärnkraftsexperter avlönas av atomindustrin
Vad händer i Fukushima?
Fukushima news and explanations
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Hur kommer det sig att trycket hela tiden stiger när temperaturen sjunker?
De pumpar kontinuerligt in mer vatten i tanken, förmodligen utan att ventilera ut ånga till wetwell. Därför så kommer trycket fortsätta stiga fast temperaturen sjunker eftersom den totala vattenvolymen helt enkelt stiger.
Varför man inte ser samma grej hända med 2an och 3an vet jag inte, de kanske läcker eller så har man lyckats hålla ånghalten väldigt låg där(inga temperaturspikar i de reaktorerna).
Jag trodde att de tömde ut det vattnet i havet igen.
Nej inte avsiktligt, 2ans reaktor verkar läcka på något sätt så att en del av det vatten som pumpas in rinner ut och hamnar i havet. Men 1an och 3an verkar inte läcka nått. Både inneslutningen och reaktortanken på 1an verkar i stort sett vara intakta