The Federal government's national disaster response and planning organization, FEMA, has significantly updated its nuclear disaster plans according to a new bombshell report in Buzzfeed, which describes the new plans as "truly terrifying".

The report is based on an exclusive interview with an unnamed US Federal Emergency Management official. Notably, the official indicated the new FEMA plan includes preparedness for a scenario involving "large nuclear detonations over the 60 largest US cities".

Image source: Life Hacker

The plan was discussed on Thursday at a two day National Academies of Sciences workshop for public health and emergency response officials held on Capitol Hill, and included emergency readiness planning for large scale thermonuclear blasts by state actors, as opposed to a prior emphasis on terror organizations deploying tactical nuclear devices.

FEMA’s head of its chemical, biological, radiological, and nuclear branch, Luis Garcia, told BuzzFeed News, "We are looking at 100 kiloton to 1,000 kiloton detonations".

To put this in perspective the agency's current protocol for disaster relief planners only considers the emergency impact of 1 to 10 kiloton blasts, similar to the power of WWII era atomic bombs.

But according to FEMA conference participants things changed when last year North Korea tested a surprisingly powerful thermonuclear bomb that had a reported blast estimate size of 250 kilotons, capable wiping out a whole US city.

One conference keynote speaker and expert, Cham Dallas, told the conference, “The North Koreans have really changed the calculus,” and concluded, “We really have to look at thermonuclear now.”

According to Buzzfeed's report of the FEMA session:

Dallas presented “speculative” analyses of a nuclear detonations in several cities — including New York and Washington, DC — at the workshop, suggesting that a thermonuclear blast roughly doubles the hundreds of thousands of dead and many more wounded (a 1979 analysis of a 1,000 kiloton blast in Detroit estimated 220,000 deaths, for example) compared to the atomic bomb blasts. They also cause many more burn injuries and larger fallout clouds that travel farther away.

FEMA's updated response plan reportedly includes mass preparations to deal with potential nuclear attack on 60 of America's largest urban centers, and establishing medical services to tend to all the various non-direct impact injuries that result in the aftermath.

Nuclear nightmare scene from Terminator 2: Judgement Day

But the planning doesn't just include direct impact and nuclear fallout as "the agency has also considered scenarios where a nuclear bomb, a cyberattack, a coordinated electromagnetic pulse, and biological weapons all hit the US at the same time," according to the Buzzfeed report.

Thus it appears the "duck and cover" days of the generation that lived through the heart of the Cold War and into the 1980s could be back.