Hydrogen blast at Japan's quake-hit Fukushima N-plant

Tokyo, Mar 14 (PTI) Radiation risks mounted in Japan
after a second hydrogen explosion rocked the quake-hit
Fukushima nuclear plant Monday leaving 11 workers injured and
the cooling systems failed at another reactor.
Fears of a meltdown escalated as the fuel rods in the
No.2 reactor were "fully exposed" with air pressure suddenly
rising and the flow of cooling water getting blocked.
Hundreds of bodies were found scattered across the
north-eastern coastline bringing alive the horror of Friday's
massive earthquake of 9.0 magnitude and tsunami in which
10,000 people have been estimated to have perished.
A thick column of smoke billowed from Fukushima
reactor No.3 following the explosion at 11 am but the
container was not damaged, Japan's nuclear safety agency said.
"We judge that the possibility of a large amount of
radioactive materials flying off from there is low," Chief
Cabinet Secretary Yukio Edano told a news conference, adding
that seawater was being injected to cool down the No.3
reactor.
However, fuel rods at the No.2 reactor was "fully
exposed" at one point after its cooling function failed, Kyodo
news agency said, quoting the plant operator Tokyo Electric
Power Company (TEPCO).
The seawater injection operation started at 4:34 pm,
but water levels in the No.2 reactor have since fallen sharply
with only one out of five fire pumps working. The other four
were feared to have been damaged by a blast that occurred in
the morning at the nearby No.3 reactor, the agency said.
Apprehending another explosion, TEPCO is contemplating
drilling a hole in the wall of the building that houses No.2
reactor to release hydrogen.
The emergency measures of flooding the affected
reactors with sea-water are to avert a full meltdown,
officials said.
A meltdown occurs when a severe failure of a
nuclear power plant system prevents proper cooling of the
reactor core, to the extent that the nuclear fuel assemblies
overheat and melt. This can lead to release of large amounts
of harmful radioactive material.
"The reactor building exploded but the primary
containment vessel was not damaged. The control room of unit 3
remains operational," the Vienna-based International Atomic
Energy Agency (IAEA) said.
The blast injured 11 people, including 4 employees and
4 Self-Defence Force members, state broadcaster NHK quoted
TEPCO as saying.
Fears of high radiation levels brought back horrific
memories of the nuclear holocaust in the last days of World
War II.
The Fukushima nuclear plant has been shut down since
Friday. "According to the Fukushima plant chief's assessment,
the container's health has been maintained. The possibility is
low that massive radioactive materials have spattered," Edano
said.