* Spent fuel rods need to be moved to safety-Wyden
* Urges Japan to accept help, asks US officials to do more
WASHINGTON, April 16 (Reuters) - Japan, with assistance from the U.S. government, needs to do more to move spent fuel rods out of harm's way at the tsunami-stricken Fukushima Daiichi nuclear plant, said U.S. Senator Ron Wyden on Monday.
Wyden, a senior Democratic senator on the Senate Energy committee, toured the ruined Fukushima plant on April 6, and said the damage was far worse than he expected.
"Seeing the extent of the disaster first-hand during my visit conveyed the magnitude of this tragedy and the continuing risks and challenges in a way that news accounts cannot," said Wyden in a letter to Ichiro Fujisaki, Japan's ambassador to the United States.
Last March, an earthquake followed by a tsunami wrecked the Fukushima plant, causing the world's worst nuclear accident in 25 years and prompting global scrutiny of the safety of nuclear power plants.
Wyden said he was most worried about spent fuel rods stored in damaged pools adjacent to the ocean, and urged the Japanese government to accept international help to prevent further release of the radioactive material if another earthquake should happen.
In a statement on his website, Wyden said the only protection for the pools from another tsunami appeared to be "a small, makeshift sea wall erected out of bags of rock."
Wyden said the spent fuel should be moved to safer storage sooner than anticipated under a 10-year clean-up plan from TEPCO, the owner of the nuclear plant.
The lawmaker also wrote to Secretary of State Hillary Clinton, Energy Secretary Steven Chu and top U.S. nuclear regulator Gregory Jaczko to ask them to find ways to help Japan address the problem. (Editing by Cynthia Osterman)