A guide to radiation for the clueless...

JonnyBravo

ninky wrote: »

there is a difference between radiation and radioactive isotopes (e.g. iodine 131 and cesium 137). whilst radiation levels may reduce relatively quickly radiocative isotopes once released get into the food chain and cause longterm health problems. radio active isotopes have now been detected in the food chain (and tap water). this is more of a longterm worry than radiation levels tbh.

Yes of course.
It is isotopes such as these that generate radiation.

If this source is IN you it is much more dangerous. Alpha and beta radiation are relatively poorly penetrating types of radiation. If the source is inside you and being concentrated in your thyroid you are not in a nice situation.

ninky_2

some steps that can be used to offset the impact of radio active isotopes in the food chain....i can see a few people deciding to go vegan......nursing mothers in the area are at particular risk of passing on radio isotopes to their children and could do well to replace with soya products.

http://www.autonopedia.org/survival/Fallout_and_Radiation_in_Food.html

1. Selection of land that is not radioactive.
2. Deep plowing land to turn it over and bring non-radioactive soil up to the surface. (This works well only where there is deep topsoil).
3. Selecting plants to match the soil characteristics, i.e.. that they have no desire for the radioactive minerals that are in the soil.
4. Fertilizing the soil with a mineral that will be taken up in preference to the radioactive mineral. (Oftentimes this is calcium as found in marl.
5. Composting and creating soil that does not have radioactivity in it and then using that soil in a green house, or otherwise protecting it from contamination.
6. Using hydroponics gardening or other similar methods that tightly control the mineral uptake of the plants.
7. Using distilled water on the plants. (Unfortunately this deprives them of the minerals that they need and minerals then need to be added to the water).
8. Removing the radioactivity from the food. See the article on milk processing for example. There are other techniques for other foods.
9. Storing the food until radioactivity decreases. This works well for the radioactive iodine isotope in powdered milk and cheese.
10. Avoiding foods that have high radioactive content. For example, soy milk might be substituted for dairy or mother's milk for children.
11. Eating lower down on the food chain. As explained in an earlier section, radiation is concentrated by living organisms. Each higher level concentrating it more. It is possible to make flour directly out of bacteria. Using non contaminated oil sources from wells or tarsands would then produce pure uncontaminated flour.
12. Avoiding meats and animal products because they are high up the food chain.
13. Classifying foods by radioactive content and using high content foods for feed for animals that will neither produce product nor be eaten - such as dogs. Coincidentally, because of their relatively short life expectancies, in many cases this will not be detrimental to them.
14. Reserving foods with high radioactive content for individuals with short life expectations. Because at some levels it takes twenty years or longer for the radiation to take effect this will not be detrimental to people who are already elderly. Let them have the meat, fresh milk and eggs.
15. This is by no means an exhaustive list and still other strategies will be developed with experience. Food radioactive content can be indicated in packaging, the content can be certified and varieties of foods can be imported from areas that are radioactive free for that particular food. Eat well and prosper.

michaels

Is this confirmed? I assumed the possibility was that without sufficient cooling the rods could melt and form a large enough mass for a reaction to restart but have not seen info that this has happened (yet). Presumably if this did happen with no heat removal there would very quickly be an explosion in the storage pool that would scatter the nuclear material fairly widely locally and also put smaller particles in to the atmosphere - plus the blast would likely destroy any possibility of cooling reactor three and quite possibly the other reactors and might even damage the containment of reactor 3 to the point of failure.

I thought reactor designs were supposed to 'fail-safe' and can not understand how a design that requires ongoing cooling to count as fail-safe?

ninky wrote: »

there is no containment on the (re-criticalised) spent fuel rods. these pose an even bigger threat than chernobyl.

1984ReturnsForReal_2

michaels wrote: »

Have 5 and 6 had seawater pumped in as well then?

Not that I can imagine them wanting to work on the site anyway in the future but didn't some of the other reactors at Chernobyl continue in use for a few years?

The whole site will be written off.

It is not a case of poor engineering. The location of the site is now proven to be unsuitable for earthquake & large waves.

No one in their right mind could believe there is an argument to keep any of the reactors running.

Percy1983

michaels wrote: »

I thought reactor designs were supposed to 'fail-safe' and can not understand how a design that requires ongoing cooling to count as fail-safe?

Its not so much the fact they need constant cooling, its the fact the cooling systems themselves should be more fail-safe, they should be several levels of backup cooling systems.

I would be suprised if anything but concrete wen't to the site when its all sorted.

blueboy43

michaels wrote: »

I thought reactor designs were supposed to 'fail-safe' and can not understand how a design that requires ongoing cooling to count as fail-safe?

Nuclear power is inherently risky.

The cooling ponds are to contain spent fuel, this continues to give off heat for several years (5 years ish). Thus water needs to be circulated to cool this spent fuel.

ninky_2

michaels wrote: »

Is this confirmed? QUOTE]


yes it is. http://www.iaea.org/newscenter/news/tsunamiupdate01.html

Unit 4
All fuel from Unit 4 had been removed from the reactor core for routine maintenance before the earthquake and placed into the spent fuel pool. The building's outer shell was damaged on 14 March, and there have been two reported fires

so that's the spent fuel from an entire reactor recently place in a pool situated in an explosion and fire damaged building. that's a really scary situation.

michaels

But not confirmed to have gone critical with uncontrolled chain reaction - uncontained and possibly overheating to the extent of catching fire but no evidence of having melted and formed a critical mass (yet?) - surely if they had gone critical outside containment the level of radiation would have forced a plant evacuation?

ninky_2

michaels wrote: »

But not confirmed to have gone critical with uncontrolled chain reaction - uncontained and possibly overheating to the extent of catching fire but no evidence of having melted and formed a critical mass (yet?) - surely if they had gone critical outside containment the level of radiation would have forced a plant evacuation?

the existence of radioactive isotopes in the environment is evidence of re-criticality.

blueboy43

ninky wrote: »

the existence of radioactive isotopes in the environment is evidence of re-criticality.

Not necessarily- there would be radioactive isotopes in the planned or unplanned release of steam from the reactors, that has been going on, in addition to the explosions and fires.