Gen IV Nuclear Plants - AIChE Presentation

Subtitle: Gen IV Designs Have Too Many Serious Flaws

This article follows the previous article (see link) with my recollections and comments on the nuclear power presentation at the AIChE dinner meeting on 4-11-2019 in Houston, Texas.

The presenter, Dr. Pavel V. Tsvetkov, seemed quite knowledgeable and sincere in his views.  To his credit, he mentioned a few negative points for nuclear energy in general, and specific points to some of the designs he presented.  He did, however, say some things that were either unrealistic, or entirely too optimistic in my view.   And, that is ok; I believe we need optimists in the world, as long as their views are filtered and judged through a sober process that adequately considers safety, costs, and better alternatives. 

The questions in my previous article remained unanswered for the most part, as they were not asked.  A few others in attendance did ask a similar question on the safety, and spent fuel, and plant size or capacity.  But, nothing on subsidies, capacity factor in operation, construction costs, operating costs, or decommissioning costs. 

A few of the presenter's points made me pause and hope that no one ever, ever builds one of these things.  More on that below. 

In no particular order, then, here are some points I recall that seemed true about nuclear energy's drawbacks. 

- The entire fission nuclear process is carbon-free only in the operating reactor portion.  All the other aspects are performed now, and likely in the future, with a large degree of fossil fuel use.   Those other aspects include, but are probably not limited to, uranium mining, uranium ore processing and concentration, uranium fuel preparation and delivery, constructing a plant, decommissioning a plant, and spent fuel cooling, handling and monitoring. 

- Nuclear reactors have some ways to produce electricity other than boiling water or heating a gas, but the engineering challenges are simply too great to spend time on these.  

-  Nuclear plants can be built to follow the grid load, but the costs are greater.  This is a crucial point, because already high costs are increased even more as the plant reduces output to follow the load.  

Next, here are some points the presenter made that are absolutely false, in my experience. 

- Existing nuclear plants will run for 100 years.   No, they won't.  These plants shut down almost always before the 40th year of operation.  The ones that keep running are crying desperately for more government subsidies because they are losing money. 

-  SMR, or small modular reactors of various designs, will be very low-cost.  He stated they will be built in factories just like cars are built.   That is certainly not going to happen, as the need for electrical plants simply is not on the same scale as automobile sales.   Automobile sales are in the millions of units per year.  Power plant sales are in the few hundreds of plants per year.    No economy of production volume will change those economics.   For example, one can calculate that for a 40 year life, replacing only the natural gas and coal-fired plants in the US requires approximately 60 new plants each year.  If these were small enough, say 50 MWe output as envisioned for small modular reactors, we can increase that to 300 plants per year.   That is nowhere close to the millions per year required to achieve economy of scale through increased production volume.  Instead, the economics work against one, as smaller units cost much more per quantity of output. 

- Molten salt reactors, such as molten fluoride with dissolved thorium or uranium, are intrinsically safe.  No, they are not.  He showed a conceptual flow diagram that made me cringe.  The molten, 900 degree C radioactive bath is pumped from the reactor vessel through a heat exchanger, where a heat transfer fluid is heated.   That heat transfer fluid is then pumped through a second heat exchanger, where water is boiled to make steam for a turbine.  The heat transfer fluid is then pumped back around in a loop to the first heat exchanger.   The cringe-worthy aspect is the fact that heat exchangers eventually leak.  There will be heat exchanger fluid flow either into the radioactive molten salt, or the other way round with the molten salt injected into the heat exchanger fluid.  One picks one, or the other by choice of operating pressures in the heat exchanger.  Either way, that is some serious bad news when (not IF) the leaks occur.    As proof, one need only look at the heat exchanger leaks that occur periodically in the existing nuclear reactor fleet; and note soberly that such a leak was what caused the San Onofre Generating Station (SONGS) to shut down permanently.   That was "only" a radioactive steam leak.  

Another serious drawback is the pumping of that radioactive, molten fluoride salt.   Pumps leak, and having that material leak onto the concrete floor is more than a bit troublesome.  There will also be valves in the lines, and valves also leak.  Who wants radioactive, molten fluoride salt dripping from a valve, making a puddle to step in or over?

- Gen IV nuclear plants can be used to produce fresh water via desalination.   No, they won't.  The economics will not allow such a thing.  Even if desalination is ever necessary, solar thermal plants have a huge economic advantage over the incredibly expensive and dangerous nuclear plants. 

- Molten metal Gen IV nuclear plants will operate at high temperatures, therefore high thermal cycle efficiencies, and will be safe.   No, the same issues exist as described above with pumping molten salts: it is extremely difficult and dangerous to pump hot, molten sodium, and the same for hot, molten lead.   Sodium reacts explosively with contact with humid air, and lead fumes cause all manner of brain damage in humans. 

- Gen IV reactors will be ideal for supplying process heat in refineries and petrochemical plants, also chemical plants.   No, they won't.  The inherent dangers in such process plants simply will not be improved by the presence of a nuclear plant, whether for electricity or process heat production.  Instead, having a nuclear plant on the premises will make emergency responses much, much more hazardous.   Unfortunately, refineries and other process plants sometimes have operating upsets, fires, and explosions that require emergency response personnel to enter and handle the problems.   Who wants to speculate on the incredible situation where the plant is on fire, but the nuclear plant is so close to the fire that a radiation release is not only possible, but very likely.   No, thanks.  


There may be more issues to write about and discuss, but here ends the article for today. 

Roger E. Sowell, Esq.

Houston, Texas

copyright (c) 2019 by Roger Sowell - all rights reserved

Topics and general links:

Nuclear Power Plants.......here

Climate Change................here  and here

Fresh Water......................here

Engineering......................here  and here

Free Speech.................... here

Renewable Energy...........here  

NuScale Small Modular Reactor Begins Safety Certification

The nuclear cheerleaders should be cheering like mad over this one:  see link.  That's a welcome thing in their world, given the recent disastrous news of Westinghouse Electric filing for bankruptcy earlier this week.  see link to SLB article 

NRC To Begin Full Certification Review of NuScale Small Modular Reactor

“The Nuclear Regulatory Commission has docketed for review NuScale Power LLC’s
application to certify the company’s small modular reactor design for use in the United States.

“The company submitted its application Jan. 12 for the design, in which the reactor building holds 12 co-located pressurized-water reactor modules for a total output of 600 MWe. NuScale is the first company to submit a small modular reactor (SMR) design for certification. SMR designs seek to meet NRC safety requirements through smaller reactor cores and passive safety features. The NRC, after completing its acceptance review, has concluded NuScale’s application is complete enough for a full design certification review. The staff soon will provide a review schedule.

“The NRC’s certification process determines whether a reactor design meets U.S. safety
requirements. Companies can then reference a certified design when applying for a Combined License to build and operate a reactor in the United States. The NRC’s Advisory Committee on Reactor Safeguards provides input on design certification reviews. If issued, certifications are valid for 15 years.

“The NRC has most recently certified Westinghouse’s AP1000 and GE-Hitachi’s Economic Simplified Boiling Water Reactor designs.”

Sowell Commentary

The certification process evaluates only the safety aspects and has zero concern over economics, costs to construct, time to construct, costs to operate, reliability or onstream factor, costs to decommission, etc. SMRs have zero chance of producing economically attractive electricity.  An earlier article on SLB see link discussed the economics of SMRs, and concluded they must have very short construction times to have any advantage over conventional, large (1000 MWe or greater) plants.  

Excerpts from that earlier SLB article include:

"The analysis for two 600 MW plants shows construction must be finished within 5.5 years to break even with the costs to build a 1200 MW plant.  Similarly, for SMRs of 300 MW, where four plants would be required to produce 1200 MW of power, and 200 MW, where six plants would be required.  The results are as follows.  The 300 MW plants must be constructed in 4 years to have zero savings, with any savings produced only if construction time is 2 or 3 years.  The 200 MW plants must be constructed in 2.1 years to have zero savings over the cathedral design.    It seems highly unlikely that small, modular plants can be built on such short timescales."  (end excerpt)

The NuScale design purports to have twelve, 50 MWe reactors in the same containment building to produce 600 MW electricity.  From the NRC documents filed by NuScale, 

"A NuScale Power Module (NPM). . . is a collection of systems, sub-systems, and components that together constitute a modularized, movable, nuclear steam supply system (NSSS). The NPM is composed of a reactor core, a pressurizer, and two steam generators integrated within a reactor pressure vessel (RPV) and housed in a compact steel containment vessel.

"The NuScale advanced small modular reactor plant design is scalable, such that from one (1) to twelve (12) NPMs operate within a single Reactor Building."

So, the question is, can this design result in lower construction costs and operating costs compared to, e.g. AP-1000?   There are orders of magnitude more equipment.  For 1100 MW output, the AP-1000 has one reactor, while the NuScale has 22.  Similarly, the AP-1000 has 2 steam generators, and NuScale has 44.  The amount of piping to connect all that equipment is magnitudes greater for NuScale.  That means many more welds, pipe supports, which greatly increases costs. 

As is the usual case with nuclear, it will be years and years before anyone knows the answers based on an actual, operating plant.  The design certification review will require some years.  Finding a suitable utility to invest will require more time, then fabrication and construction will require more years.  

Only then will we truly know how much SMR-produced electricity costs.   My bet is it will be twice or three times the cost of renewable-based electricity with grid-following storage technology. 

Roger E. Sowell, Esq.

Marina del Rey, California

copyright (c) 2017 by Roger Sowell - all rights reserved

Topics and general links:

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

Renewable Energy...........here  

South Australia Invites Comments on Nuclear Power

Subtitle: Nuclear Power for South Australia Not Justifiable

The state of South Australia, Australia, established recently the Nuclear Fuel Cycle Royal Commission to investigate uranium fuel, its mining, enrichment, power generation, and nuclear waste management and storage. (see link)  Australia is a producer and exporter of uranium.  

The NFCRC "will provide all interested persons with an opportunity to provide information and evidence that will help guide the Royal Commission in its decision making and formulation of the final report.

A Royal Commission, acting on its own, cannot undertake an inquiry into complex social, economic and environmental matters concerning the nuclear fuel cycle without significant external assistance.

As such, we (the Royal Commission) will be seeking cooperation and input from a range of involved stakeholders – including academics, subject matter experts, interest groups, members from industry, non-government organisations, consumer groups and members of the community.

Former Governor of South Australia, Rear Admiral the Honourable Kevin Scarce AC CSC RAN (Rtd), was appointed to the role of Royal Commissioner for the Nuclear Fuel Cycle Royal Commission on 9 February 2015. The Royal Commission is seeking to engage with all sectors of the community in order to bring the widest range of views possible into the research and decision making process.

At the conclusion of its investigation, the Commission will produce a report which will make findings based on evidence obtained by the Commission and will make recommendations.


The report (and its recommendations) are required to be provided to the Governor of South Australia, The Honourable Hieu Van Le AO, no later than 6 May 2016."

The Commission organized the uranium issue into four areas :

1. Uranium mining
2. Uranium enrichment into civilian power fuel
3. Civilian nuclear power plants, and
4. Nuclear waste management and storage.

I have been invited to prepare and submit responses to the questions and issues posed in Paper 3 for Civilian nuclear power plants.  There are 17 questions, shown below.   I plan to formally submit detailed answers to most, if not all, the questions.  

The short, summary answer to the over-arching question of Should South Australia build and operate nuclear power plants, is no.   The basis for that conclusion is the facts and particulars of South Australia's power grid both at present and the foreseeable future.  The grid is small, with 5,000 MWe total installed capacity.  The demand is low, with typical daily maximum 1,500 MWe although demand peaks on hot summer days at approximately 3,000 MWe.  More importantly, minimum demand at night is approximately 700 MWe.   Finally, South Australia has access to abundant coal and natural gas for fuel.  

Given the small grid loads, and small minimum night demand, a nuclear power plant that is operated at baseload to provide maximum efficiency and minimum power price, must be a small size at perhaps 300 MWe.   Small nuclear reactors suffer from reverse economy of scale and are very expensive for the amount of power produced.   Conversely, a larger plant would achieve some economy of scale, but the plant must have its output reduced at night to ensure grid stability.  A larger plant would be more costly to allow load changes, and the sales price for electricity produced must increase accordingly.  (see Truth About Nuclear Power, part 2 for details -- see link)   The usual safety concerns also apply: operating upsets and radiation releases, evacuation plans, spent fuel storage or reprocessing, and sabotage and terrorist attacks, to name a few.

Royal Commission's 17 Questions on Civilian Nuclear Power Plants

3.1  Are there suitable areas in South Australia for the establishment of a nuclear reactor for generating electricity? What is the basis for that assessment?

3.2  Are there commercial reactor technologies (or emerging technologies which may be commercially available in the next two decades) that can be installed and connected to the NEM (National Electricity Market)? If so, what are those technologies, and what are the characteristics that make them technically suitable? What are the characteristics of the NEM that determine the suitability of a reactor for connection? 

3.3  Are there commercial reactor technologies (or emerging technologies which may be commercially available in the next two decades) that can be installed and connected in an off-grid setting? If so, what are those technologies, and what are the characteristics that make them technically suitable? What are the characteristics of any particular off-grid setting that determine the suitability of a reactor for connection?

3.4  What factors affect the assessment of viability for installing any facility to generate electricity in the NEM? How might those factors be quantified and assessed? What are the factors in an off-grid setting exclusively? How might they be quantified and assessed? 

3.5  What are the conditions that would be necessary for new nuclear generation capacity to be viable in the NEM? Would there be a need, for example, for new infrastructure such as transmission lines to be constructed, or changes to how the generator is scheduled or paid? How do those conditions differ between the NEM and an off-grid setting, and why? 

3.6  What are the specific models and case studies that demonstrate the best practice for the establishment and operation of new facilities for the generation of electricity from nuclear fuels? What are the less successful examples? Where have they been implemented in practice? What relevant lessons can be drawn from them if such facilities were established in South Australia? 

3.7  What place is there in the generation market, if any, for electricity generated from nuclear fuels to play in the medium or long term? Why? What is the basis for that prediction including the relevant demand scenarios?

3.8 What issues should be considered in a comparative analysis of the advantages and disadvantages of the generation of electricity from nuclear fuels as opposed to other sources? What are the most important issues? Why? How should they be analysed?  

3.9 What are the lessons to be learned from accidents, such as that at Fukushima (Japan), in relation to the possible establishment of any proposed nuclear facility to generate electricity in South Australia? Have those demonstrated risks and other known safety risks associated with the operation of nuclear plants been addressed? How and by what means? What are the processes that would need to be undertaken to build confidence in the community generally, or specific communities, in the design, establishment and operation of such facilities?

3.10 If a facility to generate electricity from nuclear fuels was established in South Australia, what regulatory regime to address safety would need to be established? What are the best examples of those regimes? What can be drawn from them?

3.11 How might a comparison of the emission of greenhouse gases from generating electricity in South Australia from nuclear fuels as opposed to other sources be quantified, assessed or modelled? What information, including that drawn from relevant operational experience should be used in that comparative assessment? What general considerations are relevant in conducting those assessments or developing these models?

3.12 What are the wastes (other than greenhouse gases) produced in generating electricity from nuclear and other fuels and technologies? What is the evidence of the impacts of those wastes on the community and the environment? Is there any accepted means by which those impacts can be compared? Have such assessments making those comparisons been undertaken, and if so, what are the results? Can those results be adapted so as to be relevant to an analysis of the generation of electricity in South Australia?

3.13 What risks for health and safety would be created by establishing facilities for the generation of electricity from nuclear fuels? What needs to be done to ensure that risks do not exceed safe levels?

3.14 What safeguards issues are created by the establishment of a facility for the generation of electricity from nuclear fuels? Can those implications be addressed adequately? If so, by what means?

3.15 What impact might the establishment of a facility to generate electricity from nuclear fuels have on the electricity market and existing generation sources? What is the evidence from other existing markets internationally in which nuclear energy is generated? Would it complement other sources and in what circumstances? What sources might it be a substitute for, and in what circumstances?

3.16 How might a comparison of the unit costs in generating electricity in South Australia from nuclear fuels as opposed to other sources be quantified, assessed or modelled? What information, including that drawn from relevant operational experience, should be used in that comparative assessment? What general considerations should be borne in mind in conducting those assessments or models?

3.17 Would the establishment of such facilities give rise to impacts on other sectors of the economy? How should they be estimated and using what information? Have such impacts been demonstrated in other economies similar to Australia?


END OF ROYAL COMMISSION QUESTIONS.

Roger E. Sowell, Esq. 
Marina del Rey, California
copyright (c) 2015 by Roger Sowell.  All rights reserved.