En grej då som jag inte riktigt får något grepp om... Lagringsbassängen ligger oskyddad ? inte innesluten i någonting osv, bara skyddad av själva byggnaden?
Vattnet i bassängen har varit lågt (varierande uppgifter ifrån att "fuel rods partly exposed" till att bassängen kokat eller varit torr. Enligt Tepco själva har bränslestavarna varit delvis exponerade.
Helicopters and water cannon trucks have dumped metric tons of water on the reactors, but still the water in the pools is evaporating and the rods are heating up. It is also feared that the quake has smashed the rods into each other, which could cause a nuclear reaction.
http://www.reuters.com/article/2011/03/18/us-japan-chernobyl-idUSTRE72H2QG20110318
-- Reactor No. 4 - Under maintenance when quake struck, no fuel rods in reactor core, temperature in spent-fuel storage pool reached 84 C on Monday, fire Tuesday possibly caused by hydrogen explosion at pool holding spent fuel rods, fire observed Wednesday at building housing reactor, pool water level feared receding, renewed nuclear chain reaction feared, only frame remains of reactor building roof.
http://english.kyodonews.jp/news/2011/03/79463.html
1507: Nuclear fuel rods have been exposed again at the Fukushima plant, Kyodo news is reporting. More on this as we get it.
1513: Water level in reactor 2 at Fukushima has fallen again, AFP now reporting citing Japanese media
1521: Fears of a partial meltdown at the Fukushima plant would appear to be growing, as Kyodo news agency reports that fuel rods in number 2 reactor are again "fully exposed".
https://www.flashback.org/sp29466470
"NISA is reportedly also considering opening a hole in the reactor housing building to release hydrogen generated by the exposed fuel rods."
Källa: The Guardian.
Steam from the spent fuel pool would indicate that water covering the spent fuel is evaporating, which in turn could mean the vapour is carrying off radiation.
The spent fuel pool presents a significant radiation risk if its contents are exposed to the atmosphere. When fuel rods are exposed to the air, zirconium metal on the rods will catch fire, which could release radiation contained in the fuel, said Arnie Gundersen, a 29-year veteran of the nuclear industry who is now chief engineer at Fairwinds Associates Inc.
http://www.reuters.com/article/2011/...2?pageNumber=2
17:31 - Japan has told the U.N. Agency radioactivity was being released "directly" into the atmosphere, the IAEA says.
16:44 - Japan has told the United Nations nuclear watchdog (IAEA) that it has extinguished a fire at the spent fuel storage pond at the power plant, the Vienna-based agency says.
http://www.reuters.com/article/2011/...1?pageNumber=5
TOKYO, March 15, Kyodo
Tokyo Electric Power Co. said Monday fuel rods were fully exposed again in the No. 2 reactor of the Fukushima No. 1 nuclear power plant as of 11 p.m.
TEPCO said a steam vent of the pressure container of the reactor that houses the rods was closed for some reason, leading to a sudden drop in water levels inside the reactor.
==Kyodo
http://english.kyodonews.jp/news/2011/03/77925.html
TOKYO —
Fuel rods at the quake-hit Fukushima No. 1 nuclear power plant’s No. 2 reactor were fully exposed at one point after its cooling functions failed, the plant operator said Monday, indicating the critical situation of the reactor’s core beginning to melt due to overheating.
The rods were exposed as a fire pump to pour seawater into the reactor to cool it down ran out of fuel, Tokyo Electric Power Co said. The firm had reported the loss of cooling functions as an emergency to the government.
TEPCO said water levels later recovered to cover 30 centimeters in the lower parts of the fuel rods.
http://www.japantoday.com/category/n...ar-power-plant
pictures emerged showing overheating fuel rods exposed to the elements through a huge hole in the wall of a reactor building at the destroyed Fukushima nuclear plant.
http://www.dailymail.co.uk/news/arti...#ixzz1GyS40wIN
När dom vattnar borde det inte uppstå radioaktiv vattenånga då? Om lagringspoolerna är heta. Kan det förklara varför radioaktiviteten stiger när man vattnar eller frigörs det mer radioaktiva gaser från poolerna när man vattnar?
