SAN JUAN, Puerto Rico (AP) -- Puerto Rico's government plans to ask the European Union to include a U.S. Navy bombing range on Vieques island in its investigation of the effects of depleted uranium, a senator announced Thursday.

The announcement comes with a debate raging in Europe that depleted uranium, a slightly radioactive heavy metal used in armor-piercing ammunition, could cause cancer. Such weapons were used by NATO-backed forces during fighting in the Balkans.

NATO has maintained that there is no scientific evidence that exposure to weapons containing depleted uranium posed a significant health risk.

A EU study into health risks is to be completed by February.

The Navy has admitted firing 263 depleted uranium-tipped bullets, of which it recovered 57, on the training range on Vieques. But the Navy said it was an accident, noting that it's against federal law to use those armaments on such exercises.

The U.S. Caribbean territory's legislature expects to pass a bill asking to be included in the European investigation in several days, Senate Vice President Velda Gonzalez told a news conference Thursday.

Anti-Navy activists long have blamed the Navy bombing for higher than average cancer rates on Vieques.

The Navy says there is no evidence the bombing damaged anyone's health. And Navy spokesman Jeff Gordon said he resented the comparison of the use of the ammunition in the Balkans to the incident on Vieques.

''In Kosovo, NATO shot 31,000 bullets only meters from people, and here in Vieques there were only 263 that were more than 9 miles away from the population,'' Gordon said.

Gov. Sila Calderon told reporters Thursday that she would welcome the EU investigation. Calderon supports islanders who reject an agreement between President Clinton and former Gov. Pedro Rossello for a referendum on Vieques that would allow islanders to vote this year for the Navy to withdraw, but only in 2003.