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Comment: Re: Shrug, yawn. Have you read it? (Score 1) 224

by zeigerpuppy (#48957559) Attached to: Nuclear Safety Push To Be Softened After US Objections
Regarding molten salt, I assume you refer to the liquid fluorine molten salt proposals. I looked into this too but it does create a lot more complexity in separation of neutron poisons from the molten stream. I agree that in an accident the design looks better and the fact that it has self regulating qualities is good. However, the molten salt reactors don't get around the largest issue with fission power, expensive to handle waste products. Reprocessing doesn't reduce the volume of waste much (only helps to reuse the plutonium and also reduces mining to some degree). The story of the nuclear fuel cycle was of clean energy but it has left is with quite a number of very polluted sites and a huge bill in dealing with the waste sitting in casks and pools. Perhaps fast neutron burner reactors could help (molten lead looks particularly interesting) but I think that with increasing political instability and the track record of humans being poor managers of super complex systems, nuclear may just not be out friend for a couple more generations. Solar is quite capable of providing is with the energy we need (yes, base load too if we use another type of molten-salt!) and it's not prone to catastrophic failure.

Comment: Re: The real disaster (Score 1) 224

by zeigerpuppy (#48956955) Attached to: Nuclear Safety Push To Be Softened After US Objections

workers who stepped in the water at Fukushima sustained significant radiation burns.

There are safer ways to work around these exposed cores but in some ways Fukushima is worse than Chernobyl. The workers who tunnelled under Chernobyl and laid concrete to stop further core intrusion into ground water avoided the more severe problem that now occurs at Fukushima.

The total exposed core material and the use of MOX also make the total expelled radiation greater at Fukushima, just that most of it has gone into the water rather than into the air.

Comment: Re: Shrug, yawn. Have you read it? (Score 1, Insightful) 224

by zeigerpuppy (#48956899) Attached to: Nuclear Safety Push To Be Softened After US Objections
Actually we learned quite a bit more. When mark 1 reactors lose coolant flow to ultimate heat sink they have at least 3 failure modes that were not previously considered. Loss of ultimate heat sink can happen many ways so this lesson is important for currently operating mark 1 reactors. A flood, drought or any obstruction to intake pumps would have the same effect as loss of pump power. The real lesson was that these reactors do not handle these situations gracefully. Number 1 most likely melted through the control rod holes. Number 2 busted a big hole in its torus and number 3 was most likely a prompt criticality in the spent fuel pool after a melt down and hydrogen explosion. Oh and number 4 fuel pool caught fire. We also learnt that once you have a reactor with a fractured base lying below ground water (which by design these reactors are) it's really hard to stop continued flow of radioactive water into the adjoining river or ocean. These are all relevant to current Mark 1 and other reactors in the US and elsewhere. A rational response would have been to not relicence any of these reactors and move to phased shutdown of the Mk 1 fleet. Issues like embrittlement and small torus cannot be remedied by retrofitting. Also, the spent fuel fire and possible criticality should prompt a hurry up in the program to get fuel out of ponds and into casks.

Comment: Re: I don't know about the US government's stance. (Score 1) 224

by zeigerpuppy (#48956877) Attached to: Nuclear Safety Push To Be Softened After US Objections
The larger problem is regulatory capture by industry. It's a virtual revolving door out there of people moving from paid industry positions tote regulator and back again. The same issue prevented hundreds of breaches at Fukushima being taken seriously. Jail time for CEOs and making the operators responsible for clean up would go a long way however.

Comment: Re: Who has a financial interest in this one then? (Score 1) 224

by zeigerpuppy (#48956857) Attached to: Nuclear Safety Push To Be Softened After US Objections
To answer your question directly. There are more that 20 GE Mk-1 reactors running in the US. They all suffer from the flaws that led to melt throughs and loss of containment at Fukushima. These factors include embrittlement of the primary containment by neutron bombardment. This embrittlement means that cooling has to occur slowly, something that is tricky in an emergency. They also have steam suppression systems that are too small (torus) and valve systems that need to be manually actuated in emergency situations. These flaws were known by GE engineers. These reactors should no longer be licenced as the flaws cannot be fixed by retrofitting. However, shutting down these reactors (which have ha their licenced extended far beyond their engineered lifetimes) would bankrupt the US nuclear industry and scuttle the "nuclear renaissance". It's an ugly truth that the US regulators are gambling with lives to keep the wheels rolling. Prime time to move on to more modern energy sources (large scale solar and wind with flow batteries for load smoothing would be a good start)

Comment: Re: Regulation, more regulation, only lawyers win (Score 1) 224

by zeigerpuppy (#48956805) Attached to: Nuclear Safety Push To Be Softened After US Objections
A prompt criticality is unlikely in a BWR reactor unless you get fractionation of the fuel after it has melted. With MOX fuel it is conceivable that you could accumulate a critical mass of plutonium after a core melt even with boron. Another way in which a prompt criticality can occur is in a spent fuel pool that is packed too tight. Some have suggested this may be the case at unit 3 Fukushima.

Be sociable. Speak to the person next to you in the unemployment line tomorrow.