By Ayesha Rascoe and Roberta Rampton
WASHINGTON (Reuters) - Japan's Fukushima nuclear plant seems to be in "slow recovery" from damage incurred this month from an earthquake and tsunami, the head of the Energy Department's nuclear program said on Tuesday.
"However, long-term cooling of the reactors and the pools is essential during this period, and has not been adequately restored to date, to the best of my knowledge," Peter Lyons of the department's Office of Nuclear Energy said at a Senate energy committee hearing.
The hearing comes as the U.S. regulator embarks on a safety review of the nation's 104 nuclear plants in the wake of the Japanese accident, the worst the world has seen in 25 years -- and as the Obama administration and lawmakers grapple with how to boost production of energy that does not contribute to global warming.
President Barack Obama will outline a plan for "America's energy security" in a speech on Wednesday.
Senators at the hearing pressed the operations manager of the U.S. nuclear safety regulator about whether changes need to be made in the wake of the disaster.
Bill Borchardt of the Nuclear Regulatory Commission said it's too soon to draw any conclusions, but said the regulator would take any immediate steps it deems necessary to boost safety, and not wait until plants go through the relicensing process.
(Reporting by Ayesha Rascoe and Roberta Rampton; Editing by Lisa Shumaker)