Nuclear Bomb: Advanced Simulation Shows Effects of a Nuke Going Off in Washington D.C

How would officials respond if a nuclear bomb exploded in Washington D.C.?

While such an event is unlikely, authorities have to be prepared for the unthinkable, especially with the growing threat of conflict between North Korea and the U.S..

Since the 1950s emergency managers have been using something known as the National Planning Scenario 1 (NPS1) in order to help figure out what their response should be. These scenarios once resembled table-top role-playing games where officials predicted the actions of citizens using statistics. Then, with the advent of computers, these simulations became more complex.

Now computer scientists at Virginia Tech's Biocomplexity Institute, under direction from the U.S. Defense Threat Reduction Agency, have created an advanced new version of NPS1 that simulates the U.S. capital being nuked, Science reports.

The latest model digitally recreates the city complete with buildings, roads, power lines, hospitals cell towers and, most importantly, a virtual population of around 730,000 citizens. In this setting, the researchers are able to simulate a 10-kiloton bomb exploding just north of the White House.

Using the model, researchers can estimate the damage to infrastructure from the initial bomb blast as well as the likely number of casualties. Furthermore, weather data is also included, enabling them to understand how radioactive fallout would spread across the city.

The projections show that the devastation would be catastrophic: hundreds of thousands killed, power lines and communications systems severed, buildings and streets filled with jagged slabs of concrete, clouds of radioactive fallout.

But what really makes the new model stand out is the complexity of its virtual citizens, known as agents, which are autonomous, and can react to situations individually.

These agents—which are statistically identical to the real population in the affected area in terms of sex, age and occupation—are programmed to go about their daily routines. But when the bomb strikes they spontaneously respond in human-like ways to the unfolding disaster.

This simulation graphic demonstrates the area affected by the plume of an Improvised Nuclear Device (IND) in Washington, D.C. Virginia Tech

For example, those who are not killed immediately may decide to flee the vicinity of the blast in panic or jump in a car to desperately search for missing loved ones. Others could become paralyzed with fear and not move at all, taking shelter instead.

The model allows emergency planners to simulate all these movements across the entire population, enabling them to create effective city-wide response strategies.

"Thanks in large part to the information generated by devices like smartphones, we now have a much more detailed understanding of how a city's population behaves day-to-day—when and where people are driving, working at the office, shopping, eating, picking kids up from school, and so on," Chris Barrett, executive director of the Biocomplexity Institute, said in a statement.

"Using this information, we can create very detailed simulations of exactly where people are likely to be in relation to a particular destructive point-in-time event, such as an improvised nuclear device; what resources they'd have access to; and examine how their chances of survival can be increased by the full variety of possible responses."

The inclusion of cell towers and power grids in the simulation reflects the role that mobile communications play in how people respond to disasters today.

For example, the model shows that if responders act quickly to restore downed communications then people can verify if their loved ones are safe, meaning they are more likely to stay where they are.

The complexity of the simulation has a downside, however. Each run took a day and a half to complete using 500-microprocessor computer cluster. Nevertheless, it promises to be a useful tool for emergency planners.