TOKYO, April 7 (UPI) -- Millions of gallons of water sprayed on damaged reactors in Japan's quake-hit nuclear plant are now contaminated, raising questions about safe disposal.
The water spraying, an emergency step to prevent a meltdown, has been underway since the March 11 9-magnitude earthquake and tsunami knocked out the plant's power supply and the systems that keep the reactors' spent fuel rod pools from overheating and setting off a dangerous chain reaction.
However, the water collecting in the reactors has become highly radioactive and is leaking through fissures inside the plant into the basements, the Los Angeles Times reported.
The report said no one seems to know how that water can be disposed off safely. Later, Japan also would need to figure out how and where to bury the nuclear waste.
"There is nothing like this, on this scale, that we have ever attempted to do before," Robert Alvarez, former U.S. Energy Department assistant secretary, told the newspaper.
The report said Japanese officials estimate about 15 million gallons of contaminated water have accumulated, with hundreds of thousands more gallons being sprayed each day.
The immediate task is to find a permanent solution to store the high-level radioactive substances in the water, where they will be processed and solidified. Dumping them in the ocean is not an option.
Experts told the Times that the work can be handled only in a specially designed industrial complex but the process of cleaning up the water could take years with costs in the tens of billions of dollars.
Former U.S. Nuclear Regulatory Commission member Victor Gilinsky said the Japanese crisis seems far tougher than the Hanford Nuclear Reservation in Washington State, regarded as the most highly contaminated nuclear weapons site in the United States. At Hanford, the Energy Department reportedly plans to decommission eight reactors and process about 58 million gallons of radioactive sludge now in leaky underground tanks at a cost estimated up to $130 billion.
The work at Hanford can be done without exposure to high radioactivity levels unlike at Fukushima, the report said.
One expert said for now the Fukushima contaminated water needs to be quickly channeled into a concrete-lined holding pond where natural evaporation would at least help reduce its volume.