The Long Term Effects of Nuclear Weapons

[Golan2072]

I am designing a specific world IMTU - a border-world between the Solar Triumvirate and the Matriarchate, which suffered from limited nuclear bombardment during the Matriarchate War (about 80-100 years before my campaign's start).

The world is a habitatable water-world, completely covered with water except for a few tiny islands (each no larger than a few square KM) and one large island, a 600 KM long and 75 KM wide strip of land. Before the war, most habitation was located on that large island - including the Class-D Starport, the main city and a large TL8 fission powerplant.

A Matriarchate raiding group targeted both the main city (which had several factories critical to the Triumvirate supply lines) and a large Triumvirate Marine camp on the other end of the island with one tactical nuke each (20 kiloton in yeald each). The starport, the powerplant and several smaller towns were attacked by conventional high-explosive bombs. This resulted in a major breach in the power plant, releasing even more radioactive fallout into the atmosphere.

What I want to know is:
1) What is the physical destructive radious of a 20-kton nuke? How will it look on a 750,000-resident startown?
2) How much fallout does such nuke produce? how much area does it cover?
3) How many of the original 3 million residents would perish from the nukes, radiation and fallout alone? Will fallout shelters be enough to protect those who had time to reach them (and how long do the survivors have to stay in the shelter)?
4) How large and how deadly is the contaminated zone created by the power-plant containment breach?
5) Can a new (semi-submerged) starport and aqua-arcology startown be safely constructed on the other side of the planet in a short time frame (a decade or two) after the attack?
6) How bad will be the contamination on the island now, about 80 years after the attack? Will parts of it be habitatable?

 

[kafka47]

I believe there was a JTAS article and a Dragon magazine based on the Swycaffer novel that dealt with a nuclear exchange.

Plus, it goes without saying that a perfect adaptation would be Twilight 2000 for after effects of a nuclear war.

In the real world, sources abound on the Internet most credible are the bulletins of atomic scientists.

 

[Andrew Boulton]

20kt is only slightly more than than the two bombs we actually have data on...

 

[stofsk]

Originally posted by Employee 2-4601:
What I want to know is:
1) What is the physical destructive radious of a 20-kton nuke? How will it look on a 750,000-resident startown?

Nuclear weapons calculator.

Thermal radiation radius (3rd degree burns): 39.8 kilometres
Air blast radius (widespread destruction): 19.4 kilometres
Air blast radius (near-total fatalities): 7.4 kilometres
Ionizing radiation radius (500 rem): 5.5 kilometres
Fireball duration: 17.3 seconds
Fireball radius (minimum): 1.4 kilometres
Fireball radius (airburst): 1.8 kilometres
Fireball radius (ground-contact airburst): 2.3 kilometres

2) How much fallout does such nuke produce? how much area does it cover?

Fallout is produced by a nuke that is used as a groundburst. Airburst nukes don't produce fallout in any meaningful quantities. Hiroshima and Nagasaki were nuked via airburst, which didn't prevent the Japanese to reconstructuring the cities after the surrender.

3) How many of the original 3 million residents would perish from the nukes, radiation and fallout alone? Will fallout shelters be enough to protect those who had time to reach them (and how long do the survivors have to stay in the shelter)?

If the nukes are set to detonate via airburst, then there shouldn't be any worry from fallout. If you detonate via groundburst you're actually causing fallout.

If you're talking about the nuke reactor, what is it, fission? I think an emergency shutdown would occur the moment the reactor's security is breached. Also, Chernobyl only killed 40 people. Sure, hundreds contracted radiation sickness, but they didn't DIE.

As for how long do people have to stay in the shelters, well Chernobyl irradiated a small stretch of land - ~20 sq. miles IIRC - but I'm not sure if it's healthy to go wandering around in that area unprotected. They could stay in the shelters for as long as required until they get evac-ed. And needless to say, fallout shelters will protect you from fallout.

4) How large and how deadly is the contaminated zone created by the power-plant containment breach?

Depends on how much radioactive material got blaster all over the joint.

5) Can a new (semi-submerged) starport and aqua-arcology startown be safely constructed on the other side of the planet in a short time frame (a decade or two) after the attack?

On the other side of the planet? Yeah sure, why wouldn't it be?

6) How bad will be the contamination on the island now, about 80 years after the attack? Will parts of it be habitatable?

It all depends on how much radioactive material was released and what efforts were made to clean it up.

 

[stofsk]

WHOOPS! Sorry, I used the calculator for 20 MEGATONS, not kilotons.

Ignore the data I posted, it doesn't relate to your question.

 

[mike wightman]

I just googled nuclear weapon effects, here are some good ones. There are plenty more.

http://www.fas.org/nuke/intro/nuke/effects.htm

http://www.cddc.vt.edu/host/atomic/nukeffct/

http://www.nukefix.org/weapon.html

http://www.stardestroyer.net/Empire/Science/Nuke.html

 

[veltyen]

"The combined explosive force of all the 715 Soviet nuclear detonations from 1949 to 1990, is approximately 500 megatons." Over two hundred were surface tests, with a sum total force in the order of 100 megaton. From http://www.bellona.no/en/international/russia/report_1-1994/7568.html

1) 20 kiloton is a smallish nuke. Expect complete devastation within a kilometre or two of the impact site, heat, flash and shockwave effects would extend for some distance further.

For a useful comparisson a 1 Megaton nuke would pretty much annihilate anything within approximately 5kilometres. From http://www.fas.org/nuke/intro/nuke/7906/index.html

The above article has the effects of a nuke strike on a large modern city of several million inhabitants, that should be useful as a guide. For a 20 kiloton nuke expect a fireball zone/annihilation zone of a kilometre, no buildings standing. Out from there and (depending on terrain) as far out as 10 kilometres or so there would be buildings knocked over and large debris damage (for example cars thrown from closer to the detonation point). Everyone with exposed skin or sight within that range would also be burnt or blinded, though the blindness would be temporary towards the edge of the zone. After 10 kilometres things should be relatively "normal". Some of the flimsier buildings would have collapsed from the shockwave/earthquake, and there would be extensive panic, fires, and so on. There could be survivors from as close as 2 kilometres from the impact site. Most beings beyond 10 kilometres would survive the initial blast.

2) Fallout can be minimised in a caring sharing nulear exchange.
Devices set to airburst create little fallout, basically just the residue of the device, as well as neutron contamination of the closest material to the blast.
On the other hand you can build nukes to contaminate and soil an area. What you want is a deivce that penetrates the earth a small amount then detonates. This propels a large amount of contaminated matter over a large area. It also reminds me of the planned "bunker buster" nukes.

As for fallout dispersal that can range an extraordinary distance. Often material can end up thousands of kilometres away. This is good in a way, with few nukes released the fallout affects the entire planet a little bit, rather then making a defined area terribly toxic.

3) As many as a million or so. Depends on the terrain and topography of the population centres involved. At the size of the weapons there should be no real need for fallout shelters, that generation will have a high rate of cancers and other problems, but in 80 years time that should have corrected itself.

4) Chernobyl released somewhat more radioactive material then a ground burst 20kTon nuke. Currently the uninhabitable due to radiation area is kept at 30 kilometres or so. If the nuclear strikes were "nice" then this would be far worse in the long term.

5) No problem. They could build a new starport 50 km down the road shortly after the attack.

6) Most of it should have always been habitable. There would be three rather large contaminated zones (the two nuke strikes and the power plant meltdown) that 100 years down the track could be mostly cleaned up.


For the effects you seem to be fishing for then something more like a small saturation campaign of say 20 or so titan missiles at each target. For the effects of a titan missile see here

 

[parmasson]

I know that the planet in question is a water world but what about a strike on a vacuum world? On a vacuum world there can’t be a shock wave can there? The fireball, radiation and heat still travel but buildings designed to exist in a zero atmosphere environment may do better. I am thinking about built in heat and radiation shielding.

 

[mike wightman]

Make it a ground burst...

 

[SanDragon]

With no atmosphere, will there not be any heat, since there is nothing to conduct it?

 

[mike wightman]

Thermal/IR radiation, soft x-rays, UV...

 

[Whipsnade]

Originally posted by Employee 2-4601:
4) How large and how deadly is the contaminated zone created by the power-plant containment breach?

2-4601,

What sort of fission plant was it? Commie Chernobyl design or Western Three Mile Island design? Both had containment failures with extremely different results.

How does the loss of containment occur? Does the nuc breach containment or does it cause a series of events that leads to a breach? A Western style containment building is surprisingly tough, although a direct 'hit' on it would be nasty.

I'm not entirely familiar with you Star Kingdom setting. I know a mix of jump drives and 'star gates' are used. Does the setting have nuclear dampers? If so, the clean up would be rather easy.

5) Can a new (semi-submerged) starport and aqua-arcology startown be safely constructed on the other side of the planet in a short time frame (a decade or two) after the attack?

You're worried about building on the other side of the planet after the use of three tiny tac-nucs? You can build on each 'ground zero' immediately after the blasts. Look at Hiroshima and Nagasaki. Are they abandoned? Sealed off behind razor wire?

6) How bad will be the contamination on the island now, about 80 years after the attack? Will parts of it be habitatable?

Again look at Hiroshima, Nagasaki, and Chernobyl. What the contamination will be like is going to depend on many factors. Others have pointed out the ground vs air burst differences, you'll need to determine what sort of fission plant was smacked and how the containment breach occurred. Let me suggest 'best' and 'worse' case scenarios:

Best Case Scenario
- Assumptions: Air burst, bomb is designed to be 'clean', Western style fission plant with containment dome.
- Results: Hiroshima/Nagasaki-type contamination, fission plant shuttered and monitored, slightly elevated cancer and birth defect rates that the setting's medical TL can handle easily, rebuilding on the site begins almost immediately.

Worst Case Scenario
- Assumptions: Ground burst or ground penetrator burst, bomb is designed to be 'dirty', Commie style fission plant.
- Results: Chernobyl-type contamination, tens of square kilometers unusable by humans until decontamination occurs (dampers?), downwind areas experience Hiroshima/Nagasaki-type contamination problems, slightly elevated radiation levels planet wide, more long term health effects that the setting's medical TL can handle, no rebuilding within the exclusion zone, immediate new or re-building within 'downwind' zones.

You do mention that the only significant land mass on the planet is a single long, narrow island, sort of a 75km wide slice of Java. A particularily devious Matriarchate atack would involve a series of ground penetrating nuclear strikes with an eye towards covering the entire island with Chernobyl-style exclusion zones. By either multiplying the number of warheads involved, the size of those warheads, purposely using 'dirty' bombs, or nay combination of the three, those strikes, for all intents and purposes, could render the island unusable by humans for some time. Any rebuilding efforts by the Triumvirate would be limited to the much smaller islands or under the sea. Both of those choices would greatly increase the costs involved.

Of course, if your setting has dampers all of this becomes moot.

Please let us know which it turns out.


Have fun,
Bill

 

[Jeff M. Hopper]

Originally posted by Parmasson:
I know that the planet in question is a water world but what about a strike on a vacuum world? On a vacuum world there can’t be a shock wave can there? The fireball, radiation and heat still travel but buildings designed to exist in a zero atmosphere environment may do better. I am thinking about built in heat and radiation shielding.

I'd say that there would be a shock wave, but the shock wave would propagate through the ground - like an earthquake. Expect broken seals and lots of air leaks on a vacuum world.

 

[Andrew Boulton]

"I'd say that there would be a shock wave, but the shock wave would propagate through the ground - like an earthquake."

Only for groundbursts.

 

[Golan2072]

First and foremost, my setting is the Matriarchate/Triumvirate/Alliance/Consortium one; the Star Kingdom of Swan is the work of another person.

More information:
The Matriarchate wanted to get rid of the military aspects of the planet - that is, ground-based anti-ship lasers (powered by the power plant), marine staging area (nuked, bunker-buster used as it was dug well, so we're looking at a ground burst) and several factories in the city (airbust, this would've caused enough damage to halt production for several years atleast).

The power plant was directly hit by several heavy conventional missiles; while it wasn't a cheap Stalinist ("Commie" in americanese) design by any means (these are rare IMTU, a few low-grade polities in the Coreward Autonomous zone are both ineffecient and low-tech enough to make unsafe nuke plants), it suffered from several large holes in the entire structure - the missiles were designed to breach heavy fortifications.

And no dampners yet - they are TL13+ IMTU, current IMTU maximum TL is 12, Matriarchate war was late TL10/early TL11.

 

[Chaos]

Does the power plant have several reactor blocks - and were all of these breached?

Because, if it had, and they weren´t, you could considered having the surviving reactor block back in operation, to power any rebuilt starport or military structures on the island.

After all, from what I´ve heard, the Chernobyl reactor facility (minues the block that blew up) is still being run - though not under any conditions that would be considered acceptable in most Western nations.

 

[veltyen]

Water world.

A second thought I've been having, why didn't the aggressors drop the nukes in the water and wash the island away? Even relatively small nukes can create fairly large tsunamis. Somewhat less localised damage, but a much greater area of effect, and if they are trying to kill the infrastructure that should do the trick well.

 

[Anthony]

After 80-100 years, with pretty small weapons, you can reasonably say that with the exception of specific contaminated areas (mainly, the remains of the reactor, unless cleaned up or sealed with concrete), fallout can be ignored. It might result in a modest increase in background radiation and cancer rate.

 

[Whipsnade]

Originally posted by Employee 2-4601:
First and foremost, my setting is the Matriarchate/Triumvirate/Alliance/Consortium one; the Star Kingdom of Swan is the work of another person.

2-4601,

Mea culpa. You have my apologies. I got my fan settings mixed up. Sorry.

... marine staging area (nuked, bunker-buster used as it was dug well, so we're looking at a ground burst).

Okay, that's the one you need to worry about. Where is it located with respect to the cities on your 75 by 600 km island? Upwind? Downwind? Close to the sea? Center of the island? Figure out the fallout pattern/plume and you can write off the region under the pattern/plume for a few decades.

The power plant was directly hit by several heavy conventional missiles; while it wasn't a cheap Stalinist ("Commie" in americanese) design by any means (these are rare IMTU, a few low-grade polities in the Coreward Autonomous zone are both ineffecient and low-tech enough to make unsafe nuke plants), it suffered from several large holes in the entire structure - the missiles were designed to breach heavy fortifications.

So what? They breached the containment dome, what happened next? Was the reactor vessel deamged? Was the shielding around it damaged? Was the core uncovered? Were the fuel bundles breached? You don't smash the dome and automatically release uranium. There is plenty of other stuff your conventional missiles need to damage/destroy/breach in addition to the dome. I think we've seen that even pin point accuracy and smart bombs don't get every job done.

How about a real world example? You're Israeli if I recall correctly. When your air force destroyed that Iraqi reactor (thank you) was there any radiation released? Yes, I know the raid was planned before the reactor was fueled, but you simply smashed machinery and barely damaged the reactor vessel.

To get to the fuel, the Matriarchate will have to breach the containment dome, then breach the machinery, then breach the shielding, then breach the reactor vessel, then breach the fuel bundles, and finally breach the cladding. Once the fule is reached, they'll then have to disperse it. Throw enough missiles at it and you'll simply collapse the entire structure on top of the fuel. Then how will you disperse it?

They've got quite a bit of work ahead of them to get anything resembling a Chernobyl-type release. Remember, Chernobyl's idiotic graphite shielding burned which melted the fuel bundles and allowed the release to be as massive as it was thanks to the smoke plumes and the molten flow.

And no dampners yet - they are TL13+ IMTU, current IMTU maximum TL is 12, Matriarchate war was late TL10/early TL11.

Without dampers, I'd go for a series of ground bursts specifically targetted to 'crap up'(1) as much of the island as possible.


Have fun,
Bill

1 - Believe it or not, 'crap up' is an actual radiological controls term.

2 - I'm lookig at this through the eyes of a nuclear engineer because I am one and because you wanted some answers. If you as a GM need the missile strike on the reactor to go 'Chernobyl', simply do it. I'm sure no one in your group will complain, it's a game setting after all.

 

[Golan2072]

Originally posted by Bill Cameron:
Mea culpa. You have my apologies. I got my fan settings mixed up. Sorry.

This is not the first time someone is confused about my setting. I've gotta build a web site for it and put it in my signature...

Okay, that's the one you need to worry about. Where is it located with respect to the cities on your 75 by 600 km island? Upwind? Downwind? Close to the sea? Center of the island? Figure out the fallout pattern/plume and you can write off the region under the pattern/plume for a few decades.

Middle of the island, western shore; the wind usually goes from west to the east, but there are some low mountains in the middle of the island. The base also dealt with wet navy activities (a major factor on such a world).

[/qb]So what? They breached the containment dome, what happened next? Was the reactor vessel deamged? Was the shielding around it damaged? Was the core uncovered? Were the fuel bundles breached? You don't smash the dome and automatically release uranium. There is plenty of other stuff your conventional missiles need to damage/destroy/breach in addition to the dome. I think we've seen that even pin point accuracy and smart bombs don't get every job done.

The Matriarchate wanted that power plant offline for atleast several years; they should\ve done whatever needed to do so, and my setting assumes that they've hit it well enough to do this job - what needs to be destroyed for this is probably your call as you are the professional here

.

[qb]2 - I'm lookig at this through the eyes of a nuclear engineer because I am one and because you wanted some answers.

That's one reason I am so thankful for your advice - I am an ecology student; I know well enough about radiation damage (I even had a specific radiobiology course, including a visit to the (antiquated) Nahal Soreq semi-civilian reactor, which was IIRC Israel's first one), about how a living body tries to repair it (or to resist it - some bacteria 'pack' their DNA so tight that they are very resistant to ionizing radiation) and about mutations and their RL effect, but I don't know much about the human-made devices that can create this radiation (nukes, dirty bombs, nuclear waste and faulty reactors).