Is it possible to have "Radiation 1K times normal " without core damage?

[Junkdrawer]

Radiation 1K times normal at one Japan nuke plant; pressure release ordered

Update at 6:25 p.m. ET: Japan's nuclear safety agency is preparing to issue what Kyodo News called "an unprecedented order" directing the Tokyo Electric Power Co. to open a valve at the earthquake-crippled Fukushima No. 1 nuclear power plant to release pressure from a reactor that is in danger of overheating.

Original post: Radiation 1,000 times normal has been detected inside a crippled nuclear plant in northeastern Japan where utility managers have released potentially radioactive steam to reduce mounting reactor pressure, the Kyodo News service is reporting, citing the government's safety agency.

That suggests radioactivity could spread around Tokyo Electric Power's Fukushima No. 1 plant, where thousands of residents within a 6-miles were ordered to leave before dawn Saturday.



....

http://content.usatoday.com/communities/ondeadline/post/2011/03/radiation-1000-times-normal-detected-around-crippled-japanese-plant/1

Doesn't this mean there's been at least some rupture of the nuclear fuel cladding and possibly a partial meltdown?

[k2qb3]

1. Yes it's possible....

It means they had to let steam out of containment. The steam would contain tritium which is a mildly radioactive isotope.

1000 times normal sounds like a lot more than it is, Normal is an extremely small number. The reading was 240Rem, which is enough to reach the US/OSHA annual "safe" exposure limit in about two months.

[wtmusic]

2. Thanks for info

and welcome to DU

:bounce: :toast: :bounce:

[livetohike]

4. Welcome to DU!

:hi: Thanks for the good explanation (my husband worked at a nuke plant in the mid 70's).

[Codeine]

5. Actual numbers help put this into perspective.

I'm growing weary of the hysteria.

[backscatter712]

8. Good info

Sounds like an incident that might be something like Three Mile Island if the engineers don't find a way to get the main cooling system back online. There's a secondary system running, but that's not enough to keep the core from overheating. Any nuclear reactor is essentially a giant teakettle, with the heat provided by the nuclear core. When it gets too hot, pressure builds, until the only option is to let some radioactive steam out to keep the whole kettle from going kablooie.

If cooling fails entirely, the result is China Syndrome, where the core melts, then a giant pile of lava-hot molten radioactive uranium melts its way through the bottom of the reactor, the containment vessel, the building's foundation, and down into the ground until it hits the water table, flashes the water to steam and KABLOOIE!

Needless to say, that would be Chernobyl Bad...

[Sirveri]

10. The can keep it lower than TMI using feed and bleed.

Which is probably what they're doing right now, and is probably the reason that they have elevated emission levels on site.

[backscatter712]

11. I'm guessing that's...

Venting radioactive steam when the pressure gets too high, then pumping in fresh water to keep the system from going dry?

[JVS]

3. yes

[PhillySane]

6. All the hens

come home to roost.

[somone]

7. Radioactivity has nothing to do with temperature

and vice versa

That is, nuclei do not decay any faster with increasing temperature.

[Cetacea]

9. "Crippled". So..human. Hows about "potentially deadly"?