The United States provided Greek police and border officials with radiation detection equipment Wednesday to help guard the Athens Olympics against a nuclear or "dirty" bomb.
Recent terrorist attacks have demonstrated that the use of such weapons at the Aug. 13-29 Olympics by terrorist groups could not be ruled out, said Anita Nilsson, director of nuclear security for the International Atomic Energy Agency.
Energy Secretary Spencer Abraham gave Greece the radiation detectors, worth more than $26 million.
"They will supplement the extraordinary security apparatus at the Olympics," Abraham said as he delivered some of the equipment.
Permanent detectors will be installed at 32 airports and seaports and Olympic venues. Portable equipment will be given to police and border guards, customs officers and the coast guard to "help detect, deter and interdict nuclear smuggling," Abraham said.
The equipment will be "deployed to detect radioactive materials that might be used as a weapon by terrorists in a radiological dispersal device, a so-called dirty bomb," the IAEA said in a statement from Vienna, Austria.
A dirty bomb is a conventional explosive designed to spread radioactive material.
"There has been good cooperation with the Greek Atomic Energy Commission and with the other international partners in developing and implementing this work," said Mohamed ElBaradei, IAEA director general. "We are collectively striving for a high measure of security."
The head of the Greek commission, Leonidas Kamarinopoulos, said there was little chance a dirty bomb would be used. Authorities, however, were taking no chances.
This month, Greece increased its Olympic security budget to more than $1.2 billion. About 70,000 police officers and soldiers will patrol Athens and Olympic venues during the games.
In March, a two-week multinational security exercise tested efforts to safeguard the games from a host of possible threats ranging from hijackings to a dirty bomb.
Abraham said the United States had provided similar equipment and training to safeguard the 2002 Winter Olympics in Salt Lake City.
The joint program began last year and aims to protect Greece's sole nuclear reactor and other sites where radioactive materials are stored.
"We are improving protection systems at the Demokritos research reactor, 22 hospitals clinic and at sensitive industrial facilities," Kamarinopoulos said.
The Demokritos research reactor, which uses highly enriched uranium, is located in suburban Halandri — a few miles from the center of Athens.
Greece has held a number of exercises to deal with mass casualties from a nuclear, biological or chemical attack. NATO, which has been asked by Greece to provide aerial surveillance during the games, also has promised to fly in medicine and rescue equipment if such an attack occurs.
"An important part of our security plan has now significantly been reinforced," Public Order Minister Giorgos Voulgarakis said.
His ministry has been hosting a three-day meeting for 350 security experts representing national Olympic committees, sponsors and broadcasters. On the second day, the experts discussed protecting the Athens airport, the Olympic Village, hotels, transport systems, athletes and officials.
CBS News consultant Ret. Army Col. Mitch Mitchell, a terrorism expert, went to Athens as part of a team to help the government of Greece evaluate their security measures against terrorism, the strength of their anti-terror and counterterrorism programs and their resources for consequence management.
He says Athens should be safe for the Olympic games — Greece has put over $1 billion into security — but there are still some things to consider.
"Greece is a crossroads of Mideast traffic and so a lot of people go through that country and they might drop off a few to stay and cause trouble during the Olympics," Mitchell said. "That's what we're trying to prevent."
The United States is sending 550 athletes and a support staff of 300, along with more than 100 federal agents to keep an eye on them, USOC chief security officer Larry Buendorf has said.