Reasonable nuclear policies - written for both anti and pro nuclear positions

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Phil Graham

Honorary PhD
Mar 10, 2011
651
1
18
Atlanta, GA
I am writing this from the realistic position that the nuclear power cat is out of the bag. Perhaps not for future reactors in light of economic considerations, but certainly for all the currently operating plants, as they are not going to be shut down and decomissioned on a short time scale.

In light of this, I wanted to write up some informed, reasonable positions both for people who want to bring the nuclear power era to an end, and for people support the future growth of nuclear energy. In some circumstances people who are on the opposite sides of the issue may/should/will support positions that allow for alignment on common policy.


What to support if you never want another nuclear plant built:
If you fall into the "no nuclear plants" camp, I've got good news for you, at least in the US. The next generation reactors that are waiting to be built seem likely to be economically infeasible, at least for a good while, while the NRC and industry do some serious design review after Japan. I personally give it a 50/50 chance for "traditional" reactor designs to ever re-emerge as economically feasible.

That stated, there is a very good chance that a large fraction of US nuclear reactors will continue operating for a significant fraction of your lifetime, and nuclear physics operates independent of politics, so merely stating "shut them all down today" isn't a reasonable or educated position to make your voting decisions from. I'd like to give you some more detailed points on how to approach your personal and political decisions for winding down the existing facilities:

  • Conserve electrical usage
  • Oppose the renewal of operating licenses for all existing nuclear plants, and especially the weaker designs like the GE BWR Mark 1 and truly awful Russian RBMK.
  • Discourage developing nations from trying to develop their own, potentially highly inferior, nuclear plant designs.
  • Support utilities stockpiling money for their decommissioning costs.
  • Surrender any near term hopes for dealing with climate change.
  • Support the movement of spent nuclear fuel (SNF) to dry storage away from reactors. Our power plants have way too much used fuel in ponds proximate to reactors.
  • Support the reprocessing of SNF instead of a Yucca Mountain-type solution. This will dramatically reduce (90+ %) the amount of nuclear waste that needs to be stored long term.
  • Support centralized, secure dry storage of SNF for reprocessing.
  • Monetarily support R&D, rather than subsidies, to improve the economic situation of renewable energy sources.
  • Tolerate the NIMBY factor of renewable projects. Too many people want it both ways here (especially with wind and large solar installations)
In the US, President Obama has, in my opinion, done a good thing closing Yucca Mountain. The project was a huge waste of money with no meaningful progress towards waste storage. Further, Yucca Mountain would already have been at capacity with the existing SNF existing in the US. Closing Yucca was a great poker move in the push to re-establish reprocessing of fuel in the US. Those against nuclear power should still investigate, and hopefully thereby support, SNF reprocessing, in my opinion.
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What to support if you think nuclear power is our inevitable future:
Realistically, economics is not making the short term nuclear prospects look promising in the US, even as plants have already begun construction. Coal and natural gas are going to look very attractive, at least in the short term. Just like those opposing nuclear power, your position needs to be more informed, and nuanced, than "build more nuclear plants." You will find that your position points share a fair amount of overlap with those for people opposing nuclear energy:

  • Conserve electrical usage
  • Oppose the renewal of operating licenses for the oldest plants (essentially all pre-three mile island plants) and all of the awful Russian RBMK reactors.
  • Discourage developing nations from trying to develop their own, potentially highly inferior, nuclear plant designs.
  • Support utilities stockpiling money for their decommissioning costs.
  • Surrender any near term hopes for dealing with climate change.
  • Support the movement of spent nuclear fuel (SNF) to dry storage away from reactors. Our power plants have way too much used fuel in ponds proximate to reactors.
  • Support the reprocessing of SNF instead of a Yucca Mountain-type solution. This will dramatically reduce (90+ %) the amount of nuclear waste that needs to be stored long term.
  • Support centralized, secure dry storage of SNF for reprocessing.
  • Support the introduction of small reactors and/or "fast-spectrum" reactors that have high degrees of passive safety, and can transmute long-lived radionuclides into much shorter lived fission products. Related links:
  • Support the disassembly of aging nuclear weapons, and transmuting their plutonium into other materials in fast spectrum reactors
  • Push the NRC and reactor design companies to support standardized reactor components, as the US has far too many design iterations in operation today.
It should be clear that I see both sides of the fence as sharing some important ground in regards to the handling of the "back end" of the nuclear fuel cycle. This is also driven by an inertia that places the time frames for all movements, for or against atomic energy, on a multiple year to multiple decade time scale. The desired ends may differ, but in my judgement, many of the practical way points for both sides of the nuclear fence are in enough agreement to allow overall coherent policy.
 
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Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

Phil, how do you think our prospects for longer term energy consumption fare when considering controlled nuclear fusion using deuterium and tritium. From my shallow reading of various articles on the web, it sounds like fusion is going to be the final answer to pretty much all of our power concerns: longevity, safety (both short term and long term), geographic diversity. Seems that those of us who favor nuclear power over fossil fuels should be pushing for a rapid expansion of the R&D of fusion power reactors over fission.
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

Justice C. Bigler said:
Phil, how do you think our prospects for longer term energy consumption fare when considering controlled nuclear fusion using deuterium and tritium. From my shallow reading of various articles on the web, it sounds like fusion is going to be the final answer to pretty much all of our power concerns: longevity, safety (both short term and long term), geographic diversity. Seems that those of us who favor nuclear power over fossil fuels should be pushing for a rapid expansion of the R&D of fusion power reactors over fission.
Click to expand...

Justice,

Deuterium based fusion for power generation is fiction. Period. The residual neutron fluxes out of this class of reaction is so high as to cause catastrophic materials failure in short order. You cannot contain neutrons in a plasma because they have no elecric charge. The leaking neutrons damage the crystal structure of the plasma vessel, and can also render it somewhat radioactive.

The only fusion technology with low enough neutron flux to even start to make sense is based on boron and is little more than sketches on blackboards. Even if you solve the problem of neutrons all the heat handling concerns remain.

Fusion makes the energy from fission look tame, and its not going to be even on the table in any form in our lifetimes.

My professional materials scientist opinion.
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

TJ Cornish said:
Any thoughts on Thorium reactors?
Click to expand...

If we are going back to the drawing board completely, I think the thorium fuel cycle has plenty of merit. Less bad stuff, controlled burnup, etc. Bill Gates' people might be able to use thorium rather than depleted uranium (DU) in their Terrapower reactor design.

To me, the most glaringly obvious thing we need to do for nuclear power is change the working fluid away from water to something that does not have a vapor pressure in excess of atmospheric temperature at operating temperatures. This leaves us with liquid metals, metal alloys, and "molten salts."

The second most obvious thing we can do is avoid highly inflammable core materials, like graphite. Obviously everything burns, eventually, but we don't need to compound the problem. This also eliminates most liquid metals as core coolants.

The Russians have had pretty good luck with molten sodium-cooled power generating reactors (BN-800 under construction, BN-600 and BN-350), but the french had lots of problems with the superphenix. The US also had pretty good success with sodium cooled test reactors. The Russians also ran lead bismuth eutectic cooled reactors.

The third obvious thing we can do is move to reactors that shut themselves down by the nature of doppler broadening affecting neutron capture. To the best of my knowledge only fast spectrum reactors exhibit this behavior, and that you cannot play this game with "thermalized neutrons (I am not a nuclear engineer).

Personally, I am a cheerleader for the molten salt team as the most viable working fluid for future nuclear reactors, regardless of fuel cycle. The salts under consideration are chemically stable above 1000C, have low vapor pressures, and good heat transfer.

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My hypothetical reactor of choice is fast spectrum, cooled by molten salt, operating at atmospheric pressure. There is no pressure vessel to keep high pressure radioactive steam in, and no highly inflammable core materials. The building protection can therefore be more specifically focused on keeping the outside world outside.

In the event of a catastrophic natural disaster, my hypothetical reactor shuts down as follows:
1. Instantaneous power spike reduces neutron capture from fueling pins, slowing fission.

2. Loss of power shuts down electromagnets that hold the neutron reflector around the fuel pins, and gravity carries the reflector to the bottom of the reactor salt pool. This effectively ceases all possibility of fission.

3. Natural convection circulates molten salt from the salt pool around the pins, cooling them without pumps. The salt absorbs heat and transfers it to the reactor vessel.

4. A section of the walls of the reactor vessel surrounding the salt pool are hollow, as there are no high pressures to contain. These sections are filled with cooling water of sufficient thermal mass to scrub all waste heat from fuel decay products for a certain amount of time. As the molten salt heats this water, it evaporates, absorbing energy, and exhausts passively through electronic-less pressure valves.

5. A "core-catcher" is in place below the reactor in the event passive effects 1-4 fail.

Obviously this is a gross oversimplification of all the components needed in a reactor, but this is the general idea...
 
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Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

Excellent points. I'll add in a few.
  • Nuclear power is as renewable as solar - the radioactivity of the fuel will be there if we use it or not (processing aside).
  • The biggest issue in the nuclear power industry today is spent fuel. We have laws against recycling it, and no good place to store it. The biggest problem at the Fukushima plant is the spent fuel getting exposed to the air, not the LOCA in the reactors.
  • Large-scale nuclear is the only good drop-in replacement for coal from a power grid point of view, although small-scale distributed nuclear may work better in the "smart grid". If you oppose nuclear, please don't oppose all the alternates as well. (Wind and solar don't work well on the grid unless they're backed by something else, typically NG combined cycle).
  • The current nuclear plants in operation are aging (none have been built since the TMI incident). For those who support nuclear, one of the biggest hurdles to new construction is the regulatory climate for new reactor designs. Let's face it, we've learned quite a bit about reactor design since the work in the 1960s and 1970s. It would be great if those new designs could make it into production and have a chance to prove themselves.
  • For all the press that nuclear gets about the incidents that occur, remember that all other sources of energy also have their safety risks as well. If you are going to enter into the fray of energy policy (pro, con, NIMBY, apathetic...), take the time to educate yourself on the pros and cons of all the major technologies. You might be surprised at what you find out.
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

For another data point, it looks like the new Indian nuclear program is pursuing Thorium as a fuel cycle so maybe they will invest the front end engineering to scale this up to large scale production capacity.

Thorium as fuel is independent of water or molten salt/metal as the cooling fluid so we have multiple independent variables here. India also appears to be pursuing the molten salt/metal working fluid approach.

Perhaps India has enough nuclear weapons to stalemate Pakistan, since thorium is not that attractive for weaponizing, but they probably developed breeder reactors in the first place to make weapons.

JR
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

Hey all,

Stumbled on the following preliminary recommendations today thanks to Google news. I think this professor has provided a good list for changes in regards to improving reactor safety. I find it encouraging that his list mirrors my own. While I suggest a change in working fluid, he suggests a change in fuel composition to reduce the amount of hydrogen production (assuming the continued use of light water as a working fluid).

I have copied his text below:

An abstract by Dr. Akira T. Tokuhiro, Associate Professor of Nuclear Engineering at the University of Idaho, that was submitted to Nuclear Exchange outlines some of the initial lessons learned from the Fukushima Daiichi nuclear power plant crisis. Tokuhiro writes that the abstract is largely based on events of the first three weeks and professional interpretation of publically accessible information. He said that only the “provisionally conclusive lessons learned” are noted.

1) Nuclear R&D institutions must consider alternatives to zirconium-based and zircaloy cladding so that chemical reactions that generate hydrogen is prevented. We (as an industry) need to accelerate development and deployment of non-hydrogren producing cladding materials; that is, assuming that the coolant/ moderator/ reflector remains (light) water.

2) Having multiple (reactor) units at one site, having more than two units on site needs critical review in terms of post-accident response and management. We must consider the energetic events at one unit exacerbating the situation (safe shutdown) at the other.

3) Further, there is a definite need for a backup (shielded) reactor plant control center that is offsite (remote) so that the accidents can be managed with partial to full extent of reactor plant status (P, T, flowrates, valve status, tank fluid levels, radiation levels).

4) There is a need for standby back-up power, via diesel generator and battery power, at a minimal elevation (100feet/31m) above and some distance from the plant (thus remotely located). This is needed to offset loss of off-site power for plants subject to environmental water ingress (foremost tsunami). Spare battery power should also be kept off-site and in a confirmed ‘charged’ state.

5) It is clear that the spent fuel pool (SFP) cannot be in proximity of the reactor core, reactor pressure vessel or containment itself. The SFP, in current form, is essentially an open volume subcritical assembly that is not subject to design requirements generally defining a reactor core. Yet, unless thermohydraulic cooling is maintained, it is subject to the similar consequences as a reactor core without adequate cooling. Therefore, we need new passive designs of the SFP, away from the actual plant’s reactor core.

6) Thus needs to be a re-definition of the spent fuel pool. A new standard and design requirement is needed for the spent fuel pool. It should be ‘reclassified’ as a subcritical assembly with a potential to go critical with no active or passive control (rod or soluble ‘poison’) mechanism. Further it needs to be some distance from the reactor plant.

7) We need to identify key valves for emergency core cooling and require them to be nonelectrically activated. Otherwise these valves need a secondary means of open and closed status that is remotely located.

8) If an ‘in-containment’ SFP is maintained, then the fuel transfer crane system must be designed so that it is available to remove the fuel during a post-accident phase. OR a second means such as a robotic arm needs to be available.

9) There needs to be a volumetric guidance analysis for ultimate (decay heat) cooling contingency plans so that not only limitations on volume are understood but also transfer of liquids from one volume to another. Spare tanks and water-filled tanks need to be kept on site as uptake tanks for ‘runoff’ in case of addition of cooling during accident management phases. Spare means to produce boric acid needs to be available off-site. Earthquake-proof diesel generator housing also need to be water-proof. Remote diesel generators are also needed with access to equally remote diesel fuel tanks (also see 4).

10) For nuclear power plants located in or near earthquake zones, we cannot expect structural volumes and ‘channels’ to maintain structural integrity. We should also expect the immediate ground underneath these structures to be porous (earth). Thus design of these volumes and channels should be such that they minimize connections to other (adjacent) volumes from which contaminated (liquid) effluents can flow.

11) Color-code major components so that in case of an accident such as the Fukushima NPP accident, we will be able to quickly identify the major components from digital images.

12)An international alliance of nuclear reactor accident first responders and thereafter, a crisis management team is needed. This does not seem to be available at any significant level at this time. We (the global nuclear industry) cannot wait 3 weeks for international participation.

13)We should consider and work toward international agreement on standards for regulated levels of radiation (activity) and radiation exposure to the general public and separately, those under emergency and extended ‘recovery’ phases. We should also be consistent in definition and practice of evacuation zoning. We should also strongly encourage acceptance and use of SI unit for activity and exposure and not use culturally-based numbering customs (in Japan, one counts in orders of {‘man’}104, {‘oku’}108, 1012 etc.)

14)Under emergency and crisis management, wider access roads are needed to and from NPPs. The access roads need to be clear of debris and of such width to accommodate large-scale trucks needed as first response and thereafter. A means to access the plant via water, such as ocean, calls for infrastructure (boats, water-containing barge, jet-skis etc) is needed as part of a contingency plan for those plants located near bodies.​
 
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Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

Also, while I can't say this with any certainty, I suspect that the ubiquity of the TRIGA reactor has shaped the way spent nuclear fuel (SNF) has been stored, and therefore the TRIGA is something worth reading about.

Also, the Russians had a major accident in 1957 at a fuel processing facility that resulted from a cooling failure.
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

As usual thanks Phil.

A lot of this in hind sight seems like common sense, but the elephant in the room that seems to be missing from these discussions is waste disposal. If we had an effective system for disposing of waste fuel, there wouldn't be need for so much storage, and NIMBY political expedients is what drives the storage occurring proximate to the reactors (one group of concerned neighbors is easier to manage than two, even though two could be safer).

I wholly expect nuclear power to become obsolete, in maybe 100 years, but in the meanwhile we can and should make lots o' steam, safely.

Clearly reactor designs that create less waste, and are less inclined to run away make a lot of sense, if we can get from here to there. At the snails pace they develop new designs, my 100 years could be up before, somebody else knows it.

JR
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

What makes new designs emerge so slowly (on the whole installed units count)?
I guess it has something to do with money. I find it extremely difficult to have security and waste efficiency issues opposed to profit most of the time.

On the other hand in Germany spent fuel is stored in dry storage with passive cooling, after 5 years.

NIMBY is a big problem for finding a solution for spent fuel. I am promoting the thought, that all residents of Germany have to support a permanent spent fuel storage solution, pro or contra nuklear.
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

When trying to win approvals from bureaucrats I suspect old known technology has attractions vs. new unknown.

I am still interested in seeing whether India has success with next generation technology, which can serve as proof of concept that even bureaucrats can't dispute, while I suspect the events in japan will also slow India's liability negotiations.

WRT spent fuel, I hope somebody is capturing and using whatever heat that throws off, while perhaps too low head to be efficiently converted. .

JR
 
Re: Reasonable nuclear policies - written for both anti and pro nuclear positions

John Roberts said:
When trying to win approvals from bureaucrats I suspect old known technology has attractions vs. new unknown.

I am still interested in seeing whether India has success with next generation technology, which can serve as proof of concept that even bureaucrats can't dispute, while I suspect the events in japan will also slow India's liability negotiations.

WRT spent fuel, I hope somebody is capturing and using whatever heat that throws off, while perhaps too low head to be efficiently converted. .

JR
Click to expand...

It seems to me, new technology is emerging painfully slow, due to what you describe and due to older designs still in service. Upgrades are near to impossible, so new, improved designs emerge only when new units are built.

You could, in fact, use heat generated in spent fuel pools, which is not a lot, compared to the reactor itself, but still, for heating control rooms and such. Not so much for real electricity production. But it's better than just letting the heat go into the air or water.
 
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