Thursday, April 11, 2019

On Generation IV Nuclear Plants

Subtitle: Safer and Cheaper, or Just Make-Work Projects?

Tonight, 4-11-2019, the South Texas Section of AIChE will have the monthly dinner meeting, at which the presentation will discuss the research and status of Generation IV nuclear power plants.  This topic is the result, most likely, of the mis-guided belief by the current Section leadership that man-made climate change requires non-carbon-based electric power generation.  Therefore, they say, more nuclear plants should be built.  And, since no one can deny that the existing crop of nuclear power plants are far too dangerous and far too costly, they see a need for a new generation of nuclear designs.   This article poses a few questions I would ask, given the opportunity, about these planet-saving Gen IV nuclear power plants. 

What is a Gen IV plant?  These are, according to the NRC, nuclear plant designs that do not use light water as a moderator in the reactor.  At present, the existing plants use boiling water, or high pressure water in the reactor core as neutron moderators.  These have been shown to be far too expensive, as stated above.   The Gen IV plants will use various other things, such as graphite spheres in a high-temperature gas reactor (HTGR), molten fluoride salt in the reactor (MSR), or various molten or liquid metals in the reactor (molten lead, molten sodium, e.g.) .  

The questions, for now, include these:  What is the safety for Gen IV?  Will these plants require subsidies?  What is the on-line  capacity factor, or reliability of Gen IV?  What is the cost to construct?  What is the cost to operate?  What is the cost to decommission?  What are the issues with long-term spent fuel?

Safety

Will Gen IV reactors be safe, so safe that there is no longer an absolute need for the US government to provide damage payments for a catastrophic nuclear incident?  At present, every reactor enjoys such protection under the Price-Anderson Act.  Insurance companies refuse to insure nuclear plants, above a modest amount that is required by federal law.   Will these plants have materials of construction that operate reliably and safely for decade after decade?  We note that molten fluoride salts had serious metal cracking and embrittlement in earlier tests, are there proven alloys today that provide a safe operating system?

Subsidies

Will Gen IV plants require the numerous subsidies that current generation of light water reactors have?  SLB has articles on the numerous subsidies, such as liability for radiation leaks via the Price-Anderson Act, construction loan guarantees, new reactor direct subsidies for the first 10 years of operation, making lawsuits during construction almost impossible, and others.

Capacity Factor

Will Gen IV reactors run at 90 percent output year after year, for 40 years or more?  Will these exotic materials, molten lead, molten sodium, molten fluoride salts, create operating problems that shut the plant down routinely?  Test reactors over the years have had very serious drawbacks with pumping such materials, to name just one. 

Cost to Construct  

Will Gen IV plants be built at a low cost, so they can actually compete in the electricity market?  We see that pressurized water reactors now have an outrageous cost, of $12 billion for a 1000 MWe output.   How can anyone know what the costs to build will be?  The industry has time after time given low-ball initial costs, then see the actual costs balloon to 3, 4, and 5 times that initial cost.   

Cost to Operate

Will Gen IV plants have a low cost to operate, so that they can actually compete in the market?  We see today that plant after plant in the US cannot compete, even on their cash costs.  Current plants are shutting down, or crying to the government for more and more subsidies to keep the plants operating.   

Cost to Decommission

Will Gen IV plants require billions of dollars, and decades of time to decommission when the plants finally close?  Who provides that money?  Will it be a government subsidy, like the light water reactors now enjoy?

 Long-term Issues with Spent Fuel

Will the Gen IV reactors have spent fuel that must be stored, guarded, and cooled for centuries?  What are those radioactive byproducts, and what are the toxicity issues?  What requirements will be made to ensure many generations are safe from deadly radiation from these plants?

These questions will suffice, for now.   I hope to ask a question or two.

UPDATE:  The meeting concluded, my thoughts and comments are on the next post at this link.  end update 4-12-2019


Roger E. Sowell, Esq.
Houston, Texas
copyright (c) 2019 by Roger Sowell - all rights reserved



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Nuclear Power Plants.......here
Climate Change................here  and here
Fresh Water......................here
Engineering......................here  and here
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