Page 28 - ARUBA TODAY

A28 SCIENCE
Friday 21 July 2017

Swimming robot probes Fukushima reactor to find melted fuel

By MARI YAMAGUCHI
Associated Press
TOKYO (AP) — An under-
water robot entered a
badly damaged reac-
tor at Japan’s crippled
Fukushima nuclear plant
Wednesday, capturing im-
ages of the harsh impact
of its meltdown, including
key structures that were
torn and knocked out of
place.
Plant operator Tokyo Elec-
tric Power Co. said the
robot, nicknamed “the
Little Sunfish,” successfully
completed the day’s work
inside the primary contain-
ment vessel of the Unit
3 reactor at Fukushima,
which was destroyed by a
massive March 2011 earth-
quake and tsunami.
TEPCO spokesman Taka-
hiro Kimoto praised the
work, saying the robot
captured views of the un-
derwater damage that In this June 15, 2017, file photo, newly developed robot for underwater investigation at the Fukushima’s damaged reactor, moves
had not been previously in the water at a Toshiba Corp. test facility in Yokosuka, near Tokyo.
seen. However, the images Associated Press
contained no obvious sign
of the melted nuclear fuel ended its exploration ear- search Institute for Nuclear posed to be below the re- probes at two other reac-
that researchers hope to lier in the day. Decommissioning, a gov- actor core was missing and tors at the plant.
locate, he said. The robot, about the size of ernment-funded consor- apparently was knocked Japanese officials say they
The robot was left inside a loaf of bread, is equipped tium. down by melted fuel and want to determine prelimi-
the reactor near a struc- with lights, maneuvers with It was on a mission to study other materials that fell nary methods for removing
ture called the pedestal, five propellers and collects the damage and find the from above, and that parts the melted nuclear fuel this
and is expected to go data with two cameras fuel that experts say has of a safety system called a summer and start work in
deeper inside for a fuller in- and a dosimeter. It is con- melted, breached the core control rod drive were also 2021.
vestigation Friday in hopes trolled remotely by a group and mostly fallen to the missing. Scientists need to know the
of finding the melted fuel. of four operators. bottom of the primary con- Remote-controlled robots fuel’s exact location and
“The damage to the struc- The robot was co-devel- tainment chamber, where are key to the decades- understand the structural
tures was caused by the oped by Toshiba Corp., it has been submerged by long decommissioning of damage in each of the
melted fuel or its heat,” the electronics and energy highly radioactive water as the damaged plant, but three wrecked reactors to
Kimoto told a late-night company charged with deep as 6 meters (20 feet). super-high levels of radia- work out the safest and
news conference held helping clean up the plant, The robot discovered that tion and structural damage most efficient ways to re-
nine hours after the probe and the International Re- a grate platform that is sup- have hampered earlier move the fuel.q