"U.S. Sees Array of New Threats at Japan's Nuclear Plant"

"United States government engineers sent to help with the crisis in Japan are warning that the troubled nuclear plant there is facing a wide array of fresh threats that could persist indefinitely, and that in some cases are expected to increase as a result of the very measures being taken to keep the plant stable, according to a confidential assessment prepared by the Nuclear Regulatory Commission.

Among the new threats that were cited in the assessment, dated March 26, are the mounting stresses placed on the containment structures as they fill with radioactive cooling water, making them more vulnerable to rupture in one of the aftershocks rattling the site after the earthquake and tsunami of March 11. The document also cites the possibility of explosions inside the containment structures due to the release of hydrogen and oxygen from seawater pumped into the reactors, and offers new details on how semimolten fuel rods and salt buildup are impeding the flow of fresh water meant to cool the nuclear cores.

In recent days, workers have grappled with several side effects of the emergency measures taken to keep nuclear fuel at the plant from overheating, including leaks of radioactive water at the site and radiation burns to workers who step into the water. The assessment, as well as interviews with officials familiar with it, points to a new panoply of complex challenges that water creates for the safety of workers and the recovery and long-term stability of the reactors. "

James Glanz And William J. Broad report for the New York Times April 5, 2011.

SEE ALSO:

"Japan Nuclear Plant Operator Prepares to Inject Nitrogen" (New York Times)

"Fishermen: Utility's Actions in Japan Nuclear Crisis 'Unforgivable'" (CNN)

"Hitachi President Says To Review Nuclear Target" (Reuters/Kyodo)

"Japan Nuclear Plant Operator Reports Some Success on  Leak" (Los Angeles Times)

"Japanese Nuclear Plant Worker Discusses Choice To Sacrifice His Life" (Yahoo! News)

"Japan Tsunami Survivor Returns To Help Save Nuclear Plant" (AFP)

"Japan PM Tells Nuclear Workers 'You Can't Lose This Battle" (AFP)

"Japan's Radioactive Ocean" (Mother Jones)

"Radiation From Japan's Damaged Nuclear Plant Off the Charts" (ENS)

TEPCO, Japan Lacked Effective Crisis Management (Der Spiegel)

"Tiny Fish Spur Widening Worry" (Wall St. Journal)

"Japan's Farmers Confront Toxins From the Tsunami" (Wall St. Journal)

"FACTBOX - Restrictions on  Japanese Food Imports" (Reuters)

"Screening the Day's Catch for Radiation" (New York Times)