Lyman has published extensively in journals and magazines, testified before Congress and advised other government groups, and been cited in many news stories. He acted as an expert analyst for damage to the Fukushima Daiichi nuclear power plant after the 2011 Tōhoku earthquake and tsunami[2] and co-authored Fukushima: The Story of a Nuclear Disaster (New Press, 2014).[3]
From 1992 to 1995, Lyman did postdoctoral research on science and security policy at Princeton University in the Center for Energy and Environmental Studies (later the Science and Global Security Program). One of the questions he considered was how to deal with post-Cold Warplutonium. He and his colleagues sought ways to turn it into a stable waste form for disposal.[2][3]
From 1995 to 2003, Lyman worked for the Nuclear Control Institute, where he promoted conversion of reactors from highly enriched to low-enriched uranium, which is not directly weapon-usable. He also advised on the protection of nuclear sites from terrorist attacks.
He became president of the Institute in 2001.[2][3]
In 2003, Lyman joined the Union of Concerned Scientists (UCS) as a senior scientist[3] later becoming the Director of Nuclear Power Safety.[1]
Lyman publishes extensively in journals and magazines, and has advised Congress and other government groups on a variety of topics relating to nuclear power, nuclear weapons and safety.[4]
He has recommended that the U.S. Nuclear Regulatory Commission (NRC) implement safety and security upgrades to prevent the possibility of terrorist attacks.[5][6] Given the events of September 11 he describes NRC delays in doing so an "ominous trend".[5]
In 2018, Lyman was awarded the 2018 Leo Szilard Lectureship Award from the American Physical Society "for using his technical expertise and tireless advocacy to maintain and strengthen U.S. policy on nuclear nonproliferation and reactor safety and security."[3][7]
