U.S. Senate approves nuclear bomb study

The U.S. Senate approved a Defense Department research into the feasibility of a "bunker buster" nuclear bomb, officially called the Robust Nuclear Earth Penetrator.

By a vote of 53-43, the Senate refused to block the $4 million in funds to study the "bunker buster", which could penetrate underground targets.

It is now up to the House and Senate negotiators to decide on the fate of the funding bill for the Energy Department's bunker-buster research.

The Pentagon believes that 70 countries are trying to protect their key military assets from aerial strikes by burying them underground.

Supporters of the weapon say that its funding was only for a feasibility research to see whether a new, sufficiently-hardened casing can be developed for existing warheads to determine whether it could penetrate deep into earth and destroy reinforced underground bunkers.

But scientists say that the weapon is not efficient and dangerous.

"A bunker buster cannot penetrate into the Earth deeply enough to avoid massive casualties and the spewing of millions of cubic feet of radioactive materials into the atmosphere," said Sen. Dianne Feinstein, D-Calif.

Critics also say that the development of a new nuclear weapon in the U.S. can send the wrong message to countries such as North Korea and Iran while trying to make them abandon their nuclear programs.

"What moral authority do we have to ask others to give up their nukes if we're determined to develop a new generation of nuclear weapons of our own?" asked Massachusetts Sen. Edward Kennedy, a Democrat.