Archive for April 2008

Three miles from a 10 kiloton nuke – will I live or die?

April 6, 2008

In the prior post I explained why I’m planning for a bomb size of 10 kilotons. Now I’ll look at the risks from the blast and radiation.

While I believe I have a chance of sustaining no injuries or only minor scathing from the affects of the blast, there are many variables to consider and I’ll return to those risks—from shock, heat, fires and flying debris—at a later time. Ultimately, it may be too difficult to determine risk because of unknown variables. For example, will I be standing next to a window that gets blown out or will I be in an interior room? (The U.S. Dept. of Energy website on the Manhattan Project discusses Hiroshima: “…and the blast wave shattered glass in suburbs twelve miles away.”) In any case, I feel blast affects are secondary to radiation risk, where there is a calculable risk of death.

It’s impossible to know the full risk of radiation without knowing wind direction. If I’m upwind of the blast, the best-case scenario, the risk is from immediate radiation or what’s call “ionizing radiation” (the RAND Corporation report cited below calls it “flash radiation”). I’m having difficulty calculating the precise dose of immediate radiation from 10 kilotons at three miles so, for now, I’ll quote a RAND study, which says the zone of 100% mortality is about a radius of three quarters of a mile: “For a 10-kiloton airburst, everyone will be killed by lethal doses of flash radiation to a distance of 0.7 miles.” This is from the RAND Corporation’s Center for Terrorism Risk Management Policy, page four of a report titled, “Considering the Effects of a Catastrophic Terrorist Attack.”

So, beyond three-quarters of a mile, some live and some die. Even if certain death is unlikely from immediate radiation at three miles, there will be some low level of radiation exposure, which could eventually manifest in health problems. But, at the moment, I feel immediate radiation affects are secondary to “residual radiation,” aka, nuclear fallout. On a bad wind day and sans a fallout shelter, I could be fatally zapped.

Quoting from page six of a report by The Preventive Defense Project, a joint Stanford-Harvard program, titled, “The Day After: Action in the 24 Hours Following a Nuclear Blast in an American City” (the link is a pdf file):

“Further downwind from the detonation point, a plume of radioactive debris would spread. Its shape and size would depend on wind and rain conditions, but the area over which people who did not shelter themselves or flee within hours would receive lethal radiation doses within a day would range from five to ten square miles: the area of Brooklyn for New York, northwest Washington for Washington, DC, or the upper peninsula for San Francisco – but the direction from ground zero depending on the wind.”

(Note: I thought fallout begins to hit the ground within 15 minutes so I’m confused about the above phrase, “flee within hours.” I’ll return to the topic of evacuating versus sheltering in place with better information on how quickly I need to evacuate.)

While immediate radiation creates a circular pattern of radiation exposure, fallout creates an oval pattern that moves downwind from the blast. The Preventive Defense Project’s “The Day After” report has a map of Washington, D.C., with two overlapping ovals placed on top of the map to show the approximate fallout patterns. The smaller, dark oval is the 50% fatality zone, and the longer, lighter oval is the 10% fatality zone. The visual isn’t that important to see (on page eight if you want to follow the link above to the study) but the caption to the illustration tells me what I need to know:

“Over 50% of the population within the dark red oval (approximately 5 miles long) would incur fatal radiation in the course of the first day if they stayed unsheltered in that area. Absent elaborate shelters people should leave as soon as possible.

“Over 10% of the population in the lighter oval (about 8 miles long) would incur severe radiation injury, sometimes fatal, in the first day if they stayed unsheltered in that area. Light shelters could offer significant protection. There and nearby, sheltering offers the better option.”

The bottom line for me is that there’s a 50% mortality risk in an area five miles downwind of the blast. I’m three miles from my target so, depending upon conditions, my location has a high risk of death and, short of death, a high risk of severe radiation exposure. I don’t have access to an “elaborate shelter” so, if my target is nuked, I’ll need to jump into action.

Fortunately, I’m upwind from my target so, on most days, I’m at low risk. I could dig up historical weather information to better define my risk, and I may do that in the future; but I’m not sure if calculating risk based on the weather, reliably unpredictable, is a good use of my time. Also, I’m not sure if I’ll be able to convincingly monitor wind direction in the immediate hours after a blast.

I’m beginning to wonder, what if I’m over-reacting? What if the probability of a nuke attack is infinitesimally small?

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Will I survive a nuke? Estimating what size nuke to plan for

April 5, 2008

I want to know if I’ll survive a nuclear blast just three miles from ground zero. The first step is to estimate the size of the bomb that would most likely be used in an attack.

Disclaimer to Self: If I’m wrong about my conclusion, i.e., if a larger bomb is used, well, I could unexpectedly get nuked.

Nuclear bombs range in size from .25 kilotons to 100,000 kilotons (100 megatons). Hiroshima was 12.5 kilotons and Nagasaki was 22 kilotons. A suitcase nuke is about 1 to 3 kilotons. Given a particular size bomb, there are variables that affect the extent and type of damage such as weather, terrain (including tall buildings) and where, in relation to the ground, the bomb is detonated. A groundburst causes less blast damage to the surroundings but it creates more debris so nuclear fallout is worse. An airburst causes more blast damage but less fallout.

During the Cold War the possibility of state-sponsored nuclear war gave a legitimate fear of large bombs, in the megaton range. Today, with terrorism a greater risk, I think the smaller the bomb, the greater the risk (if anyone can correct me on that, please do). While very small bombs can be hard to make as you need a minimum amount of fissile material for a bomb to work, larger bombs need more enriched uranium, which is hard to get. Also, terrorists would likely deploy a nuke tactically, so the smaller the bomb the easier it is to sneak into place.

I believe 10 kilotons is the size to plan for. A bomb of this size is small and simple so it could be “homemade” and snuck into place. A couple of important studies, one from the Preventive Defense Project, a joint Stanford-Harvard program, and one from the RAND Corporation, a non-profit think tank, both chose 10 kilotons as a likely size. It’s also roughly the size of Hiroshima so we have firsthand information about the actual damage caused by that load. While Hiroshima was an airburst (about 1900 feet), the Preventive Defense Project modeled their results on a bomb at ground level or in a tall building, hundreds of feet in the air.

Planning for 10 kilotons provides a margin of safety because I think there’s a greater probability of something smaller than 10 kilotons, like a suitcase nuke (I keep wondering, where are all the Russian suitcase nukes?). Also, an untested, homemade 10 kiloton bomb by a non-state group may “fizzle” and produce a lower yield, which is what happened to the North Korean underground test in 2006. And bomb much larger than 10 kilotons could fizzle and yield 10 kilotons or less.

The target I live near is on the water so it would not make sense to use a large bomb as half the blast would be wasted over the water. You hear that, you would-be-bombers? Don’t waste your money on big bombs near the water.

Will I survive a nuke? Assessing the risk

April 4, 2008

I live and work near a known terrorist target so I’m anxious to answer the question: Will I survive a nuclear blast just three miles from ground zero?

I’m not a nuclear scientist or a ballistics expert or military strategist, but I’m surfing the web looking for those guys. This exercise is more back-of-the-napkin than doctorial thesis as I don’t think even a room full of Noble laureates could guarantee an answer. I’m simply looking at probabilities to help me define my risk.

In the next post I estimate the most likely bomb size.

In the post that follows the next post I’ll get started on estimating the risk of death and injury from both the blast and the radiation. I’ll come to a partial conclusion but there are many variables to check so I’ll be fleshing out this answer over time.

Eventually, I’ll look into the probability of an attack, weighing the specific risk to my local target, which will help me decide if I should move to safer ground. Even if I can survive a nuke in good health, I have no doubt that the post-apocalyptic quality of life will suck for a long, long time, so that too will affect my decision to stay or split. I’ll also consider the possibility that a nuclear attack anywhere in the U.S. may create a nationwide syndrome of fear of future attacks.

If you live or work near a target and want to assess your risk, sorry to be glib but I believe a nuke is most likely to explode during business hours, 9AM to 5PM. Not only will there be maximum amounts of people near the target, the most likely bombers are media savvy and want good press coverage. Planning for a potential nuke attack needs to consider both work and home, but the emphasis should probably be on where you work.

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