On Jan. 4, Signal ranked No. 750 in overall U.S. downloads, according to App Annie. The number continued to jump until the app reached No. 1 in overall U.S. downloads on Sunday.

Workers at the Fukushima Daiichi nuclear plant on Wednesday fixed a leak that was allowing radioactive water to spill into the sea, officials from the Tokyo Electric Power Co. said.

A report of a “radioactive box” that prompted authorities to cordon off an area near the Rancho Duarte golf course Thursday afternoon was deemed not to be a threat, authorities said ...

A coin-sized silver capsule containing a radioactive element has disappeared in western Australia. The radioactive element cesium, which is used in mining gauges, cannot be weaponized but can make ...

Plutonium , a radioactive element, is produced when uranium , another radioactive element, absorbs neutrons, and most of it is artificially produced, except for a small amount found in uranium ore.

Signal shared no details of the communication between itself and Facebook. Signal CEO Moxie Marlinspike confirmed on Twitter that Signal's ad account on Instagram was shut down.

CHICAGO (CBS)-- Tissue boxes contaminated with low levels of radioactive material, sold at Bed, Bath and Beyond, pose "no immediate threat" to the public, officials said Friday.

U.S. Iran strikes show no sign of widespread environmental impact So far, any chemical and radioactive contamination seems confined to the nuclear sites hit by U.S. bombs NPR Science ...

In early October, radiation monitors around Europe began detecting a puzzling plume of radioactive particles over the continent. Nearly two months later, no one has claimed responsibility for the ...

French utility EDF discovered a radioactive leak last Wednesday in the primary cooling circuit of its Civaux nuclear plant in southwestern France, the company said, adding there was no safety risk ...

The company that owns the Pilgrim Nuclear Power Station has filed an appeal seeking to discharge radioactive water into Cape Cod Bay after the state denied a permit last month. Holtec ...

Tropical Cyclone Wind Signal No. 2 remains hoisted over two Luzon areas as Tropical Storm Enteng strengthens over the waters off Ilocos Norte.