Feb 12, 2014 — Researchers from California's Lawrence Livermore National Laboratory say they've figured out how to get their laser to squeeze hydrogen atoms together to make helium atoms, releasing energy in the process. It's an important step in the decades-long quest for fusion energy.
Feb 25, 2013 — Talks start Tuesday in Kazakhstan. The U.S. and its allies want Iran to give up any ambitions for nuclear weapons. Iran says its nuclear program is for peaceful purposes.
Feb 12, 2013 — Analysts also say North Korea's claim that the device was smaller and lighter than ones it previously tested might be a sign it has moved closer to being able to fit a weapon on to a missile. Leaders around the world are condemning North Korea's actions.
Sep 23, 2012 — A little-known, but longtime nuclear standoff ended this week when U.S. Defense Secretary Leon Panetta lifted a 26-year-old ban that kept New Zealand naval ships from docking at U.S. bases. The ban stems from New Zealand's nuclear-free policy that forbids U.S. nuclear ships into its ports.
May 23, 2012 — The U.S. and other world powers hope to lay out a step by step process that will eventually lead to an end to Iran's nuclear enrichment program. Iran hopes to ease punitive sanctions that are choking its economy.
May 17, 2012 — President Obama has said "all options are on the table." The U.S. ambassador to Israel said this week that military options are ready, if necessary, but that diplomacy is still the preferred solution.
Nov 7, 2011 — The International Atomic Energy Agency believes Iran has "mastered the critical steps needed to build a nuclear weapon," The Washington Post reports. Iran has issued a denial.
Jul 7, 2011 — Abdul Qadeer Khan, the father of Pakistan's nuclear program, says he has documents proving the connection. Meanwhile, fears grow over terrorists' attempts to attack Pakistan's military facilities.
May 24, 2011 — The International Atomic Energy Agency's findings will put renewed focus on the two nations' nuclear ambitions.
Feb 19, 2014 — In 2012, Sister Megan Rice, 84, and two other activists broke into Tennessee's Y-12 National Security Complex, where bomb-grade uranium is stored. Rice had asked the judge to show her "no leniency."