Friday, March 18, 2011

Nuclear Reactor Safety .

Nuclear Reactor Safety
Andre Willers
18 Feb 2011

Synopsis :
Coolant systems have been the culprit in all major accidents .
Some simple and fairly low-cost upgrading of older systems are explored.

Discussion :

The design flaw :

Instead of building the reactor around a coolant system , the coolant system was tacked on .
This only matters in severe disasters , as just seen in Japan . A Richter 9 quake , followed by a 10 m tsunami .

The Japanese Reactor Disaster:
The fission reactions were stopped by safety mechanisms .
But , a reactor cannot be switched off like a light . Residual heat still has to be removed . If the mechanism for that has been rendered inactive , and outside intervention made nearly impossible due to difficulty of access (rubble ,etc) , explosions due to hydrogen buildup occur .These scatter radioactive material , and further damage the plant infrastructure .
A slow-moving disaster . Even small interventions in the beginning will prevent major effects later .

The irony is that the coolant systems inside the containment vessel are still mostly intact . The containment vessels worked .
The operators simply cannot get meaningful amounts of coolant into them from the outside , as these have been rendered inoperative inside the 2-3 day timespan allowed .
There are no access points , power , pumps or water .

Optimal preventative option :
There are two stages :

1.Stage One : Multiply redundant , hardened coolant access points .
Add numerous , seriously hardened access points and channels to the existing plants. This can be done fairly easily at not too great a cost .
Use Gamers ("World of War" etc ,etc) to find the optimals . Virtual reality simulations with the most inventive minds on the planet should winkle out weak points .

2. Stage two : Strategic Emergency Depots
Use existing container format .
Placement : there should be one within one day's flying time of any reactor .
The depots should have
1. Self-contained, self-powered pumps in containers , capable of serial hookups and hookups to the reactor coolant systems as in Stage One above .
2. Fueled containers . These must be kept topped up .
3. Containers of coolant (water , usually)
4. Containers of medical supplies (radiation suits)
5. Containers of long-lasting food and water
6. Heavy earthmoving equipment rigged for air-lifting
7. Sufficient helicopters capable of lifting a loaded container .These would be a major expense , but they can be used for civilian purposes as long as a clear disaster protocol exists , and a rapid-reaction reserve is maintained .This will help to keep costs down and equipment up-to-date and immediately available.
8. Tsunami-resistant lifeboats . See point 8 below .

These can be used for any emergency .
This is a reserve for the civilization .
This can be calculated :
See "Infinite Probes: Reserves" Nov 2008

JIT Strategy
Centralized Reserves like these can be used by companies to keep their JIT competitiveness , but still maintain the benefits of substantial reserves .

Some more innovative strategies :
1, Safe water on site . Nano-filters
Using sea-water as coolant in a reactor ruins it .
There are many nanofilters under development that could deliver high-through put filtering of heavily polluted water .

2, Refrigerate the shebang .
If access is possible , just hook up as many containers of air-conditioners as it takes .

3.Containment Penetrators
The containment vessel can be controllably penetrated by variants of military bunker-busting technology , followed by a quick channeling of the vent .
Rather extreme , but comforting to have around .

4. Entropy Containment
The entire thing can be stopped dead at any point by using Negative Kelvin Systems .
See "Negative Kelvin Update" Feb 2011
But this is a laboratory curiosity at the moment . (Like the electric motor was in Maxwell's days .) Enormous potential , though .

6, Tsunami Resistant Lifeboats
Most tsunami victims die of blunt-force trauma by floating debris , then drown after being knocked unconscious .
Even with 30 minutes warning , they could not get to safety in time .

Using present technology , a low-cost , inflatable , self-erecting and rigidizing lifeboat sufficient to protect humans against low-impact debris can be manufactured .
(Issue a competition for the best design)

These are then airdropped (with suitable lurid colours, sirens ,transponders ,etc) by the Rapid Reaction choppers on areas previously determined to be at high risk from a tsunami at any specified location .

They should be kept in airports near danger zones , droppable by chopper or aircraft .

My estimate is that tsunami deaths can be decreased at least ten times .

Unified Disaster Response .
The Act establishing the Reactor Disaster Management and Tsunami disaster Management would necessitate an overarching National Unified Disaster Response .
Good luck with this .
FEMA in the US is nothing to write home about .

Get your act together .
Death is the most critical of audiences .



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