Fire in Spent Fuel Rod Cooling Pool Would Be Worse Than Meltdown
March 15th, 2011Update: Spent Fuel Rods Exposed to Open Air
Via: The Journal:
THE OPERATOR OF the troubled Fukushima I nuclear power plant in Japan has disclosed that an explosion at reactor 4 this morning – the cause of a fire in a storage pool for ‘spent’ fuel this morning – has caused the rods there to be exposed to the open air.
Tokyo Electric Power Company (TEPCO) said that the fire at the reactor this morning had been caused by a hydrogen explosion inside the reactor – which had left two holes in its walls, measuring a combined total of eight square metres in size.
Those holes, TEPCO has now confirmed, have left the pool of nuclear fuel – which has been evaporating away, as a cooling failure meant sufficient cooling water could not be supplied – now exposed to the open air, with rods therefore exposed to the atmosphere outside.
TEPCO did not indicate, however, how much radiation the ‘spent’ (used) material was liable to emit.
The worrying admission came after Tepco had confirmed the level of radiation being emitted from the pool was too high to allow staff go about their normal work in the reactor’s control room.
Coolant was being evaporated within the pool quicker than it could be pumped back in, a government spokesman had earlier said.
—End Update—
Via: New York Times:
Even as workers race to prevent the radioactive cores of the damaged nuclear reactors in Japan from melting down, concerns are growing that nearby pools holding spent fuel rods could pose an even greater danger.
The pools, which sit on the top level of the reactor buildings and keep spent fuel submerged in water, have lost their cooling systems and the Japanese have been unable to take emergency steps because of the multiplying crises.
Experts now fear that the pool containing those rods from the fourth reactor has run dry, allowing the rods to overheat and catch fire. That could spread radioactive materials far and wide in dangerous clouds.
The pools are a worry at the stricken reactors at the Fukushima Daiichi plant because at least two of the three have lost their roofs in explosions, exposing the spent fuel pools to the atmosphere. By contrast, reactors have strong containment vessels that stand a better chance of bottling up radiation from a meltdown of the fuel in the reactor core.
If any of the spent fuel rods in the pools did indeed catch fire, nuclear experts say, the high heat would loft the radiation in clouds that would spread the radioactivity.
“It’s worse than a meltdown,” said David A. Lochbaum, a nuclear engineer at the Union of Concerned Scientists who worked as an instructor on the kinds of General Electric reactors used in Japan. “The reactor is inside thick walls, and the spent fuel of Reactors 1 and 3 is out in the open.”
A spokesman for the Japanese company that runs the stricken reactors said in an interview on Monday that the spent fuel at the Fukushima Daiichi and Daini plants had been left uncooled since shortly after the quake.
The company, Tokyo Electric, has not been able to cool the spent fuel pools because power has been knocked out, said Johei Shiomi, the spokesman. “There may be some heating up,” he said.
this is the issue dermot posted a link about last night:
http://my.firedoglake.com/kirkmurphy/2011/03/14/nuke-engineer-fuel-rod-fire-at-stricken-reactor-would-be-like-chernobyl-on-steroids/
as i said on another thread, this issue is not being given much attention int he Japanese media.
i sit there watching tv, showing pictures of the two reactor units with their roofs and top one-third of their walls blown off, and i am thinking:
“but the spent fuel assemblies are in pools above the reactor vessels. they are exposed to daylight and it doesn’t seem likely anyone is pumping water into these wrecked structures. and no one even hardly comments about these pools? wtf?”
tokyo electric are evil bastards.
this is fast turning into a worst case scenario.
Just ran across this link to MIT’s Nuclear Science & Engineering blog, which is watching this situation closely:
http://mitnse.com/
The quick read is that the analysts at MITNSE are really not that worried about the situation…but agree that the rumors about Unit 2 having a possible ‘containment breach’ are a definite concern.