Every single container coming into a U.S. port could be passing through a radiation detector by the end of this year.

During an event at Jersey City, NJ, attended by Robert C. Bonner, commissioner of U.S. Customs And Border Protection, customs officials displayed the agency’s new radiation portal monitors, which sniff out the components of either nuclear bombs or so-called “dirty bombs,” the agency said in a statement.

The devices – described in an Associated Press report as 20-foot tall gateways that look like a football goal – are designed to detect nuclear material smuggled through ports by terrorists. One customs official told AP the portals are “like a giant Geiger counter."

More than 240 of the portals are already in use at Canadian and Mexican border crossings, the news service said. Eventually, customs said it plans to install the radiation portal monitors at all U.S. ports.

“The best way to prevent a terrorist attack is by preventing terrorists or terrorist weapons from entering our country in the first instance,” Bonner said in a prepared statement. “The recent terrorist attacks in Madrid drive home the increased need to secure our borders against terrorist penetration.

“The new highly sophisticated radiation detection devices U.S. Customs and Border Protection is deploying in our seaports are a major step in ensuring that our border and our country are more secure.”

Other devices that serve similar functions are already in use. Customs has deployed more than 300 radiation isotope identifier devices – hand-held radiation detection devices – at every major seaport and land border crossing in the United States. Also, the agency has dispensed 9,400 personal radiation detection devices, which are worn by all customs inspectors.

In addition to the portals, customs officials in New Jersey also planned to demonstrate other new port security technology, such as X-ray type machines that can scan an entire sea container within two to three minutes.