January 19, 2012
Cold Shutdown… or Escape of Hot Fuel?
noted last month in connection with
TEPCO’s announcement of “cold
shutdown” of the Fukushima reactors:
If the reactors are “cold”, it may be because most of the hot
radioactive fuel has leaked out.
The New York Times
pointed out last month:
A former nuclear engineer with three decades of experience at a
major engineering firm… who has worked at all three nuclear power
complexes operated by Tokyo Electric [said] “If the fuel is still
inside the reactor core, that’s one thing”... But if the fuel has
been dispersed more widely, then we are far from any stable
Indeed, if the center of the reactors are in fact relatively “cold”,
it may be because most of the hot radioactive fuel has leaked out of
the containment vessels and escaped into areas where it can do
damage to the environment.
After drilling a hole in the containment vessel of
TEPCO cannot find the fuel.
The steam-blurred photos taken by remote control Thursday found none
of the reactor’s melted fuel...
The photos also showed inner wall of the container heavily
deteriorated after 10 months of exposure to high temperature and
humidity, Matsumoto said.
TEPCO workers inserted the endoscope
- an industrial version of the
kind of endoscope doctors use - through a hole in the beaker-shaped
container at the Fukushima Dai-ichi plant’s No. 2 reactor...
The probe failed to find the water surface, which indicate the water
sits at lower-than-expected levels inside the primary containment
vessel and questions the accuracy of the current water monitors,
And while cold shutdown means that the water inside the reactors is
below the boiling point, CNN
Massive steam and water drops made
it difficult to get a clear vision…
Given that steam forms
when water boils, this is an indication that
the reactor is not in cold shutdown.
points out that reactors 1 and 3 are probably in no better
The fuel inside the Nos. 1 to 3 reactors is believed to have melted
through the pressure vessels and been accumulating in the outer
primary containers after the Fukushima plant lost its key functions
to cool the reactors in the wake of the earthquake and tsunami on
March 11 last year.