Saturday, May 31, 2014

The Truth About Nuclear Power - Part 17

Subtitle: Storing Spent Fuel is Hazardous for Short or Long Term

Nuclear fuel is stored in two ways after removal from a reactor: in a pool of water, or in dry
Nuclear spent fuel pool
image: NRC
casks.  This article explores the current safety hazards of both storage systems.

Previously, articles in the Truth About Nuclear Power (TANP) series discussed economic disadvantages, and safety issues with nuclear power.  The TANP series will have 30 articles, more or less, when complete.  

Previous articles on The Truth About Nuclear Power emphasized the economic aspect by showing that (one) modern nuclear power plants are uneconomic to operate compared to natural gas and wind energy, (two) they produce preposterous pricing if they are the sole power source for a grid, (three) they cost far too much to construct, (four) use far more water for cooling, 4 times as much, than better alternatives, (five) nuclear fuel makes them difficult to shut down and requires very costly safeguards, (six) they are built to huge scale of 1,000 to 1,600 MWe or greater to attempt to reduce costs via economy of scale, (seven) an all-nuclear grid will lose customers to self-generation, (eight) smaller and modular nuclear plants have no benefits due to reverse economy of scale, (nine) large-scale plants have very long construction schedules even without lawsuits that delay construction, (ten) nuclear plants do not reach 50 or 60 years life because they require costly upgrades after 20 to 30 years that do not always perform as designed, (eleven) France has 85 percent of its electricity produced via nuclear power but it is subsidized, is still almost twice as expensive as prices in the US, and is only viable due to exporting power at night rather than throttling back the plants during low demand, (twelve) nuclear plants cannot provide cheap power on small islands, (thirteen) US nuclear plants are heavily subsidized but still cannot compete, (fourteen), projects are cancelled due to unfavorable economics, reactor vendors are desperate for sales, nuclear advocates tout low operating costs and ignore capital costs, nuclear utilities never ask for a rate decrease when building a new nuclear plant, and high nuclear costs are buried in a large customer base, (fifteen) safety regulations are routinely relaxed to allow the plants to continue operating without spending the funds to bring them into compliance, (sixteen) many, many near-misses occur each year in nuclear power, approximately one every 3 weeks, (seventeen) safety issues with short term, and long-term, storage of spent fuel, (eighteen)  safety hazards of spent fuel reprocessing, (nineteen) health effects on people and other living things, (twenty) nuclear disaster at Chernobyl, (twenty-one) nuclear meltdown at Three Mile Island, (twenty-two)  nuclear meltdowns at Fukushima, (twenty-three) near-disaster at San Onofre, (twenty-four) the looming disaster at St. Lucie, (twenty-five)  the inherently unsafe characteristics of nuclear power plants required government shielding from liability, or subsidy, for the costs of a nuclear accident via the Price-Anderson Act, and (twenty-six) the serious public impacts of large-scale population evacuation and relocation after a major incident, or "extraordinary nuclear occurrence" in the language used by the Price-Anderson Act.  Additional articles will include (twenty-seven) the future of nuclear fusion, (twenty-eight) future of thorium reactors, (twenty-nine) future of high-temperature gas nuclear reactors, and (thirty), a concluding chapter with a world-wide economic analysis of nuclear reactors and why countries build them.

Introduction to Storage

Nuclear fuel exists inside reactors in long, thin tubes known as fuel rods.  The fuel rods are bundled together to make a fuel assembly, and the fuel assemblies are inserted into or removed from the reactor as necessary.  After approximately 4-1/2 years in a reactor, each assembly is removed and stored until it is sufficiently cool for safe handling.  As currently practiced in the US, a reactor is shut down for refueling approximately every 18 months.  The refueling requires approximately 30 days.  During refueling, only one-third of the fuel assemblies are removed, and those removed are replaced with fresh fuel assemblies.   A bit of math shows, then, that after 40 years, 26 shutdowns for refueling will have occurred, with one-third of the assemblies removed at each shutdown.   After a 40-year life, which most reactors are designed for, there will be a bit more than 8 full reactor-loads of spent fuel that must be stored.  Adding in the final run, that presents 9 or a bit more reactor-loads that must be stored. 

However, a spent fuel pool is not designed to store 8 or 9 full loads of spent fuel.  The design is for a much shorter period.  This leads to the first safety problem.

Safety Problems

There are at least four safety problems with storing spent fuel in a pool: loss of cooling accident in the pool, overcrowding in the pool, sabotage or other attack, and natural disaster such as an earthquake or flood.   Each of these four issues is discussed below. 

Loss of Cooling Accident

Loss of cooling accident, LOCA, is not confined only to the reactor.  LOCA also applies to the spent fuel pool.  Pumps and cooling water systems are critical to remove residual heat from the hot fuel rod assemblies after being removed from the reactor.  The fuel pellets inside the fuel rods are hot with high temperature caused by radioactive decay of the uranium and other elements.  Some of the radioactive elements decay rapidly, so they no longer produce heat, others decay over thousands of years.   The spent fuel pool typically holds the fuel assemblies for 3 to 5 years, with some being stored longer in the pool.  

The safety problems occur as anything that can prevent cooling water from flowing into the pool.  These could be electrical issues, mechanical problems with pumps, valves that will not work, leaking pipes, leaking heat exchangers, even leaks in the pool walls and floor.  As seen in a previous article in TANP, see link, such electrical and mechanical issues are regular occurrences at nuclear power plants.  These issues only get worse and more frequent as the plants get older.  Even after the reactor shuts down after 40 years or longer, the spent fuel storage must continue operating far beyond that. 

As happened at Fukushima, spent fuel in a pool that loses water can overheat, cause fires, and lead to radioactive releases.    


Spent fuel pools are overcrowded; they have far more fuel assemblies at closer proximity to each other, than they were designed to handle.  Part of this is due to nuclear plant owners' reluctance to remove fuel assemblies from the pool, and place them in expensive dry cask storage units.  It is an economics issue.  It costs the owner more money to purchase the dry casks and store them per NRC regulations on-site. 

Only this week, the NRC board voted to allow owners to continue storing spent assemblies in the pools, instead of removing them to dry casks.  see link 

The overcrowding increases the severity of a LOCA, as more heat in a smaller space will cause water to boil sooner, and boil more rapidly, thus evaporating the pool and exposing even more fuel to the air.   Overcrowding also has more fuel available to melt, and more mass of radioactive material that can escape into the environment. 

Sabotage or Outside Attack

Nuclear plants have elaborate safeguards against security breaches, but as shown in article 16, see link, several security-related incidents occur each year.  No details are publicly available on security breaches.   It would not take much for sabotage to occur.  Outside attack is a real possibility, as the NRC acknowledged not long ago by requiring all new reactors and plants to be designed and built to withstand an impact from a large passenger aircraft.  The NRC requires the reactor building, spent fuel areas, and cooling systems to withstand such an impact.  Notably, and ominously, this design requirement is not retroactive, it does not apply to the more than 100 operating or shutdown reactors in the US. Such an attack, if successful, could result in LOCA with disastrous results. 

Natural Disaster - Earthquake, Flood, etc.

Natural disasters such as earthquake, floods, tornadoes, hurricanes, volcanic eruptions, tsunamis, etc. are all supposedly accounted for in the nuclear plant's design.  However, even though the nuclear industry repeats the refrain that plants are safe, there is ample evidence that nature can and does surprise humans with events that are beyond our planning.  

Earthquakes are the greatest risk. For example, four reactors in California (two each at San Onofre and Diablo Canyon) are in earthquake zones and are subject to tsunamis.  Each was designed for certain earthquake stresses, and a tsunami of small scale.  However, after being built, it was discovered that additional faults lay offshore from San Onofre.  The tsunami that swamped Fukushima was far larger than was contemplated in its design.   Even inland, other reactors in the US have had earthquakes rattle them, with attendant stresses.  It is sobering to note that metal becomes brittle after long-term exposure to nuclear radiation, and will crack and even fall apart during an earthquake.    Here is a link to an excellent article from Wall Street Journal, 2011, on nuclear plants and earthquakes.  see link.   A short excerpt from the WSJ article:

 " In 1986, a magnitude 5.0 quake struck near the Perry nuclear plant in Ohio, causing minor damage but sparking concern among citizens' groups about potential damage from an even bigger temblor. The plant was shut down at the time, but was scheduled to be loaded with fresh fuel the next day. Small cracks in concrete and leaks in pipes were discovered, none critical.

NRC staffers have been aware of possible gaps in seismic protection in U.S. nuclear plants since at least 2005. That's when utilities, after a long halt in nuclear construction, began planning for new reactors and started filing applications that included environmental reviews for the proposed sites.
NRC staffers say they noticed something in some applications for proposed new plants to be built adjacent to existing reactors: Using updated scientific information, seismic experts hired by the utilities produced "hazard" calculations showing a potential for stronger earthquake-caused ground motion than the original plants were designed to handle.
In other words, the utilities' own experts reckoned there was an increased chance that an existing reactor could be struck by an earthquake that could overwhelm its ability to shut down safely."  [emphasis added]

The Union of Concerned Scientists noted that approximately 30 US nuclear reactors are located where an upstream dam failure would create a flooding hazard. Even if a tsunami does not occur, dam failures can and do occur.  

Hurricanes are routine events along the Gulf Coast and Atlantic coast, however thus far all nuclear plants in their path have survived the winds and waters.  There are multiple plants in Florida, two reactors in Texas at South Texas Nuclear, plus reactors in Louisiana.   Others exist along the Atlantic coast.   The issue, though, is land subsidence in Texas and Louisiana, and levee protections in Louisiana.    

Dry Cask Storage

Storage in dry casks is inherently safer, although curiously the NRC recently stated that
image: NRC
spent fuel pool storage and dry cask storage are equally safe.  One must question that, because a dry cask is simply a large cylinder made of steel and concrete in which the fuel assemblies are placed, then sealed.  The dry casks, as the name implies, use no water for cooling.  Instead, they are stored where air can circulated around them to remove heat.  Clearly, there is no possibility of LOCA, no pumps to go wrong, no electrical systems to fail, no water leaks to occur.   It is true that dry casks require much more real estate for storing, which is more expensive.  Each cask can only hold a few fuel assemblies, and costs increase as more spent fuel is stored in the dry casks.  With the nuclear industry reeling in recent years due to unprofitable operations (as discussed at length in TANP see here and here), it is possible the NRC caved to industry pressure and did not require the industry to invest capital in dry cask storage.

Even if spent fuel is stored in dry casks, the fuel must be guarded for a very long time.  How long is much debated.  Some of the long-lived transuranics will be spitting radioactivity for thousands of years.  For example, plutonium Pu-239 has a half-life of 24,000 years.   Nuclear power plants today are creating obligations on future generations, for thousands of years.  Those future generations may not thank us for this. 


It can be seen that there are serious safety issues with storage of spend nuclear fuel, whether in pools or dry casks.  One solution, proposed by many, is to simply reprocess the fuel and concentrate the wicked components and recycle the usable parts.  However, in the US we must deal with the law as it stands.  Reprocessing is not allowed here.  

The ever-present danger of LOCA in spent fuel pools is growing greater year after year, as more and more fuel is added, equipment ages and breaks down, and statistically at least, a natural disaster is more likely.

Previous articles in the Truth About Nuclear Power series are found at the following links.  Additional articles will be linked as they are published. 

Roger E. Sowell, Esq. 
Marina del Rey, California


Coal Unmined - Cost Prohibitive

Subtitle: The coal is there but is mining it profitable?

From an article in the Sydney Morning Herald,  ". . .according to a new report by the Institute for Energy Economics and Financial Analysis, sinking coal prices and high development costs would make the [Galilee Basin, Queensland] project prohibitively expensive to supply India’s growing demand for electricity.
“The key point is that retail electricity prices in India are considerably lower than the level required for the profitable generation of imported coal-fired power, particularly when that coal is sourced from isolated deposits with none of the required infrastructure in the middle of Queensland. . .” "

In addition, infrastructure must be built, adding to the project cost:  "[the project requires]  massive infrastructure investment including rail lines and port facilities in environmentally sensitive areas close to the Great Barrier Reef near Townsville and Mackay."

see link

As seen earlier on SLB, see link, the world will soon run out of coal.  Even if coal deposits are already identified, economics will dictate whether the coal is actually mined, transported, and burned in a power plant for electricity.   The above indicates this coal may not be economic at this time.  However, the Indian companies that own the coal lease claim to be pressing forward on the project. 

From the Indian government perspective, economics may not matter.  India is quickly exhausting its domestic coal reserves and has little choice but to import coal to keep the power plants running.  A conference at UCLA discussed the India energy outlook, concluding that domestic coal reserves will be exhausted in less than 20 years (by 2030).  India is desperate for electricity, with approximately one-third of the population having none. 

Roger E. Sowell, Esq.
Marina del Rey, California

Wednesday, May 28, 2014

Exelon Nuclear Plants Fail to Win Bid to Sell Power

Subtitle:  Unable to Compete, Nuclear Seeks Subsidies from Uncle Sam

From The Chicago Tribune, three nuclear power plants that cannot compete in selling power to the market have the powerful Speaker of the House in the Illinois state legislature stand up for them, seeking yet another bail-out from the federal government.   As stated earlier on SLB, nuclear plants in the US cannot compete against natural gas and wind energy.  see link

"Three nuclear plants owned by Chicago-based Exelon Corp. failed to secure contracts to provide power to the electrical grid at an annual auction held last week.
Exelon’s Byron and Quad Cities plants in Illinois were priced out of the auction by competing power providers, the company said Tuesday, placing the future of those assets in question. Its Oyster Creek plant in New Jersey, which is slated to close in 2019, also didn’t clear the auction. . . . But [Illinois] House Speaker Michael Madigan [D - IL] wants to help keep those plants open. They are among the top employers in the towns and counties in which they operate. A resolution sponsored by Madigan was introduced to the House last Friday urging the U.S. Environmental Protection Agency, the Federal Energy Regulatory Commission and the electric grid operators, to adopt policies that are "friendly" to nuclear power. Translation: enact a new rule to curb carbon emissions, which would be a boon to Exelon because its nuclear plants do not release greenhouse gases."
The company also decries the loss of jobs from shutting down the nuclear plants.  It seems (in their view) there would be no jobs created by the companies that step up to build competitive power plants, whether natural gas-fired or renewable.
For perspective, California recently closed the San Onofre Nuclear Generating Station, with two reactors.  Hundreds of jobs were lost.   But, more jobs are created by those who build more power plants to replace the unsafe nuclear power.  
Finally, Exelon argued that nuclear power plants are reliable and provide power even during the recent cold winter.  That may be true, but one wonders exactly how utilities managed to provide reliable power in the almost 100 years (1880-1960) before those oh-so-reliable nuclear plants were on the grids.  Even today, how does a northern state without any nuclear plants provide reliable power in the winter, e.g. Wyoming, Montana, Idaho, North Dakota, and South Dakota?     The desperation is indeed apparent, based on the "we are reliable" argument. 
For more on nuclear power's inability to compete, see this link.
For more on nuclear power enjoying multiple subsidies, see this link

Roger E. Sowell, Esq.
Marina del Rey, California

Tuesday, May 27, 2014

Forecasting the Future - Hubris or Honesty

Subtitle:  Coal Exhaustion Looms - Renewable Energy to the Rescue

"It's hard to make predictions, especially about the future," - attributed to Yogi Berra.

In any event, a few articles on SLB have alluded to the future, if not outright predicted the future.  One article made the case for Peak Oil as non-existent, and argued that the US should build several coal-to-liquids plants to help reduce the world price of crude oil see link. Another described future energy supplies, with renewables and regenerables as the primary supplies see link.  Still another described the near-impossibility of having nuclear power plants as the long-term supply of energy  see link.  Another described the outrageous power prices that would result from an all-nuclear-powered grid see link.  

For another quasi-quote:  "A foolish man maintains his opinion no matter what the facts are.  A wise man considers new facts, and modifies his opinions accordingly."  - paraphrased.  

A new fact presented itself to me a few days ago, and after giving it some thought, it is time to modify an opinion.  The new fact is that coal, that mainstay of electric power generation world-wide, is in shorter supply than I had remembered.  In fact, several reputable sources now state that world reserves of coal will be exhausted in roughly 60 to 70 years - and that is if no increase in current consumption occurs.  Yet, growing economies in several countries are increasing their coal consumption year-over-year.  China and India are on that list.   It is entirely conceivable that coal will run out in less than 50 to 60 years.  

What then, are the alternatives?   From Yogi's quote above, it may be futile to make predictions.   It was only 135 years ago when no one had electricity, because the first generators connected to a grid were started in approximately 1880.   Only 70 years ago, the first atomic energy was created - and that was a bomb, not a power plant.   How, then, can one predict the future of energy supplies 100 or 200 years into the future? 

One thing we can do is examine the existing energy mix, and see what will be available in 100 years.  We note that power is generated today by hydroelectricity from water flowing from dams, by burning natural gas in power plants, by burning coal in power plants, a small amount by burning oil in power plants, by nuclear fission in power plants, and a small amount by renewables such as geothermal, wind, and solar.   There are also some very small experimental plants for ocean waves and tides, and river currents.  

However the greatest source of modern electricity is burning coal, at 41 percent of the total in 2011 (source, IEA).  Next is natural gas at 21 percent.   The people who drill for gas are quite good at finding more as the need arises, drilling in new areas or deeper in old areas.  In addition, we know that great stores of methane exist in the cold, deep ocean as methane hydrates.    The same is not true for coal, however.  

Coal is only economic if it can be mined and brought to the surface at fairly low cost.  Indeed, coal must exist in a seam at least 2 feet thick, and at less than 4000 feet depth, or it is stranded, left in place.  CalTech's Professor Rutledge gives an excellent overview of world coal reserves in his 2011 paper.  ("Estimating long-term world coal production with logit and probit transforms,"  International Journal of Coal Geology, 85 (2011) 23-33 ).  He paints a grim picture.  Roughly, there are 500 billion tonnes of mine-able coal left in the world, and the existing consumption rate is 7.8 billion tonnes per year.  This provides approximately 60 to 70 years of coal remaining.   However, a slight positive note is that Rutledge did not include coal deposits near the Arctic, in Alaska North Slope, and Siberia's Lena and Tungus fields.   Whether those fields in the harsh, cold far north can be produced economically is an open question. 

As stated earlier, nuclear fission is not a candidate due to resource limitations, outrageous cost, and serious safety concerns.  The world is in great need, then, dire need actually, of a replacement energy source for coal and nuclear.  Together, that is nearly 55 percent of today's energy production.  

Knowing this, it makes sense to turn to the renewables: wind, solar, and ocean current.  It may also be possible to make the ocean-temperature-difference technology (OTEC) work.  If the technologies still need a subsidy to advance so they can stand alone and provide electricity at reasonable rates, then prudence dictates the subsidies be made.   

Advances in grid-scale energy storage have been made, with underwater storage in the shallow oceans an excellent candidate.  Similar systems can be deployed around the deeper Great Lakes in the US.  

Is this hubris?  Will engineers and planners of the year 2100 read this or similar articles, and get a good laugh?  It could happen.   Until some major technology improvement or discovery occurs, though, this is about the best we can do.  We can alter our grids so that power can flow from onshore turbines in windy areas to storage facilities.  We can install large, economic wind turbines offshore and store the power underwater in hollow spheres for later use.  We can maintain the improvements in solar photo-voltaics, primarily efficiency and cost reduction.  A recent announcement showed that 40 percent efficiency has been achieved in PV (2014).   We can install and test slow-speed ocean current turbines, and tap into the incredible amounts of energy in the ocean currents.   

The problem is made much, much more acute when one considers the effect of population growth, and the increase in energy-per-capita.  A growth rate in electricity consumption of only 2 percent per year will triple electricity demand in only 55 years.  (the STEM majors will run that calculation and verify it as 2.97, close enough to 3.0)   Even more sobering is that number will again triple in another 55 years.  That puts the world needing 9 times the present energy in only 110 years.   That puts Professor Rutledge's 60 to 70 years for coal-exhaustion as an optimistic figure.  We may well run out of coal long before that.  

When various governments decide to continue subsidies for wind, or solar, or fund research into alternative energies, and some decry these as a waste of money, I hope someone points this article to them.   What would the nay-sayers do?  There will be a grim day of reckoning when the coal runs out.   It would be far, far better to have proven, economic means to provide grid-scale electricity at least a decade before the coal-runs-out-day. 

It may be possible, someday, to gasify coal in-situ and collect the gasified product at the surface and do all this economically.  There is research into this.  The practical challenges are, however, enormous.  One must essentially start a fire in the coal-bed, deep underground, with sufficient oxygen to maintain the burning.  The economics of oxygen injection make the entire thing questionable.   Also, a patent from 1980 describes injecting methanol and steam into a coal bed to produce methane.  

Roger E. Sowell, Esq. 
Marina del Rey, California

Sunday, May 25, 2014

The Truth About Nuclear Power - Part 16

Subtitle: Near Misses on Meltdowns Occur Every 3 Weeks

This is the second of approximately one dozen articles on nuclear safety, these will (or do) include (1) the relationship between plant operators and the regulatory commission, NRC, and show that safety regulations are routinely relaxed to allow the plants to continue operating without spending the funds to bring them into compliance.  (2) Also, the many, many near-misses each year in nuclear power plants will be discussed.   (3) The safety issues with short term, and long-term, storage of spent fuel will be a topic. (4)  Safety aspects of spent fuel reprocessing will be discussed.  (5) The health effects on people and other living things will be discussed.  The three major nuclear disasters (to date) will be discussed, (6)  Chernobyl, (7) Three Mile Island, and (8)  Fukushima.   (9) The near-disaster at San Onofre will be discussed, and (10) the looming disaster at St. Lucie.  (11)  The inherent unsafe characteristics of nuclear power plants required government shielding from liability, or subsidy, for the costs of a nuclear accident via the Price-Anderson Act.  (12) Finally, the serious public impacts of evacuation and relocation after a major incident, or "extraordinary nuclear occurrence" in the language used by the Price-Anderson Act, will be the topic of an article.   Previous articles showing that nuclear power is not economic are linked at the end of this article. 


[UPDATE - 6/9/2014: The sordid saga of Rancho Seco nuclear plant near Sacramento, California -- see below]

[UPDATE 2 - 5/10/2015:  The results for 2014 are now available; the conclusion remains the same at one near-miss every 3 weeks, on average.  There were nine additional incidents in 2014.]

[UPDATE 3 -3/20/2016:  The results for 2015 are now available; the conclusion remains the same at one near-miss every 3.5 weeks, on average.  There were ten additional incidents in 2015.]

In the four year period 2010-2013, inclusive, the US nuclear reactors had 70 near-misses.  These occurred in 48 of the 103 reactors.  Some, therefore, had multiple near-misses in the same year.  One plant, Columbia, had 3 near-misses in the same year.  Wolf Creek, and Ft. Calhoun each had one near-miss in three of the four years.  On average, that is 17 near-misses per year, or roughly 17 percent of the reactor fleet.  Put another way, every 3 weeks, another near-miss occurs.  The frequency of near-misses is expected to increase over time, as the aging reactors have more equipment degrade and fail, and new systems are installed that are unfamiliar to the operators.

What is common in these incidents are old and degraded equipment that fails due to improper inspection, replacement equipment that either does not work as expected, or operators are improperly trained, and in one notable case, improperly trained workers left critical bolts improperly tightened on the reactor head.   

The most serious incident, in my view, occurred at the Byron Station, Unit 2, in January, 2012, in Illinois.  A complete loss of cooling water at Unit 2 was temporarily replaced with water from Unit 1. Had this been a single-reactor plant, with no operating reactor close at hand, the loss of cooling could have resulted in a partial or full core meltdown, exactly what happened at Fukushima, Japan.  This is completely unacceptable. 

Some, the nuclear proponents, will argue that the safety systems are adequate since no meltdowns occurred.  However, the sheer number of serious incidents shows that eventually, another catastrophe will occur.  The US has been lucky, but that luck is likely running out as the plants grow older and more mishaps occur.  

Information in these incidents are taken from Union of Concerned Scientists' series of annual reports, 2010 - 2013, inclusive.  The commentary is my own.  Links to the four (now five six) reports are:

2010 see link
2011 see link
2012  see link
2013  see link
2014  see link    (link added 5/10/2015)
2015  see link    (link added 3/20/2016)

Incidents in 2013 (Fourteen incidents)

Arkansas Nuclear One, Units 1 and 2, March, 2013

During a routine shutdown for fuel, repairs, and maintenance, a temporary crane moving the generator stator on Unit 1 collapsed. The heavy load fell through the turbine building floor, killing one worker and injuring eight others. The dropped load also caused Unit 1 to be disconnected from the offsite power grid and caused the Unit 2 reactor to automatically shut down from full power.  This incident was categorized as an AIT, or augmented inspection team response.  An AIT is for incidents that have a 100-fold increase in risk of damage to the reactor core.  

Brown’s Ferry Nuclear Plant Units 1, 2, and 3, May, 2013

SIT: Security problems prompted the NRC to conduct a special inspection. Details of the problems, their causes, and their fixes are not publicly available.  The little public information available indicates there may have been tampering on a fuel oil line to an emergency diesel generator.  An SIT is a special inspection team, for incidents that have a 10-fold increase in risk of reactor core damage. 

Columbia Generating Station, First Incident, February, 2013

SIT: Security problems prompted the NRC to conduct a special inspection. Details of the problems, their causes, and their fixes are not publicly available.   There were no violations nor significant findings. 

Columbia Generating Station, Second Incident, September, 2013

SIT: Security problems prompted the NRC to conduct a special inspection. Details of the problems, their causes, and their fixes are not publicly available. There were no violations nor significant findings. 

Columbia Generating Station, Third Incident, May, 2013

SIT: Workers discovered that the air conditioning unit for a room containing essential electrical equipment had become degraded to the point it might not have been able to prevent the equipment from overheating and failing.  Five violations were issued.  This problem had existed for years.

Sowell commentary: failure to identify such an issue over several years is a gross breach of duty.  Nuclear power plants have safety systems and support in place that must be available if and when needed.  Overheated electrical components that fail to work cannot be tolerated in a nuclear power plant.  Routine inspections should have identified the filter roll was installed improperly.  This incident only increases the perception that nuclear safety is not taken seriously by those who operate the plants.  

Fort Calhoun, December, 2012

SIT: The methods used to install anchor bolts for the raw water pumps deviated from the approved design and would not properly support the pumps from forces during an earthquake, or a barge collision on the Missouri River at the raw water intake point.  Seven violations were issued.   This and similar problems had existed for many years. 

Sowell commentary: as with the previous incident, improperly installed equipment was not identified during many inspections over several years.  This is unacceptable in a nuclear power plant.  

LaSalle County Station, Units 1 and 2, April 2013

SIT:  A lightning strike caused an electrical disturbance that resulted in both reactors automatically shutting down.  After the reactors shut down, the operators declared some emergency systems on both units inoperable.  This was a case of designers not foreseeing a potential problem.  It was considered impossible for a lightning strike to result in shutdown of both reactors.  Investigation showed that poor workmanship during the original construction of the 138,000-volt switchyard facilitated degradation of the grounding system protecting a bank of batteries that were designed to operate switches on the high-voltage systems.  However, the faulty grounding system caused several switches to open that should have remained closed.   This triggered both reactor shutdowns and startup of the five emergency diesel-powered generators.   Operators struggled with several safety systems, including the reactor’s residual heat removal pump.   NRC found the operators had inadequate training.  

Sowell commentary:  This incident illustrates that complex nuclear power plants and their numerous safety systems can be analyzed properly for “what if” scenarios, but that analysis yields a false sense of safety when systems are improperly installed.  In this case, the battery grounding system was improperly installed, so it did not function as analysts and operators expected it to function.  In nuclear power plants, this is simply unacceptable.  The risks of core meltdown and radiation release is simply too great.  This was compounded by inadequate operator training. 

Oyster Creek, October, 2012

SIT: Hurricane Sandy caused an abnormally high water level and caused the site to lose its supply of electricity from the offsite power grid.  The water rose to within 28 inches of critical water pumps and their electric motors.  The motors will not work if water enters them.  A violation was issued but only for the plant operators giving the opposite wind direction to emergency authorities.  Had a radiation release occurred, authorities would have been evacuating people in the wrong area.   NRC is requiring plants with similar vulnerabilities to rising water to take appropriate measures, but only by the end of 2016.  

Sowell commentary: One hopes nothing happens in the interim.  For example, nuclear power plants in hurricane-prone areas include South Texas Nuclear Project only seven miles from the Gulf of Mexico at the mouth of the Colorado River, several plants in Louisiana, several more in Florida, and even more in South Carolina, North Carolina, and further north along the East Coast.  Along the Gulf Coast, the land is subsiding each year.  The safety margin in having critical pumps and their motors on elevated foundations is decreasing as the land subsides. 

Shearon Harris, May, 2013

SIT: Workers reviewing results from inspections conducted in spring 2012 of metal tubes passing through the head of the reactor vessel identified degradation, a cracked weld, which should have been fixed but was not.  Almost one year later, workers again identified the cracked tube, then the reactor was shut down for three weeks for safety reasons while the tube was repaired.  The plant had been operating for nearly one year because plant operators mis-identified the crack in the tube weld. 

Susquehanna Unit 2, December, 2012

SIT: A reactor feedwater valve stuck in the closed position.  Operators opened the circuit breaker to the valve’s control motor so they could manually open the valve.  The open circuit breaker caused the feedwater control system, a new digital system that replaced the aging analog system, to close all the reactor feedwater valves.  The reactor quickly began losing water level, potentially causing a loss-of-cooling-accident.  The reactor control system automatically shut down the reactor.  NRC issued three violations, including failure to have a procedure for a stuck valve, and failure to train the operators on using the new digital feedwater control system. 

Sowell commentary: the lack of a proper procedure to deal with a sticking valve is troubling.  Valves are known to stick, sometimes closed, sometimes open, and sometimes in between.  In nuclear power plants, there is no room for “winging it.”  The failure to properly train operators on a new control system is inexcusable.  

Incidents During 2012 (18 incidents)

Brunswick Unit 2, November 2011

SIT: Workers failed to tighten properly several bolts that hold the reactor head in place.  At 100 percent rate, radioactive water poured out of the reactor head joint at more than 10 times the allowable rate.  Workers shut down the reactor.  The bolts were found to be loose enough to be turned by hand.  Investigation showed that workers assigned to tighten the bolts during the previous shutdown had mis-read the torque wrench, applying only one-tenth the specified torque.  The same workers had mis-read the bolt tension-elongation gauge.  Faulty training was the reason.   The plant’s owner had discontinued training on this procedure in 2004.  No citation was issued by NRC. 

Sowell commentary: this is elementary, the tightening of bolts to the proper torque.  That the NRC did not issue a citation is highly questionable.  One wonders how many other bolts in the plant are also not properly tightened.  

Byron Station, Unit 2, January, 2012

SIT: Unit 2 reactor automatically shut down from full power because of an electrical fault in the plant’s switchyard.  An undetected design deficiency prevented the electrical protection system from isolating the fault as intended. Consequently, the fault propagated to cause all the emergency equipment for the unit to be de-energized. The operators took steps to isolate the fault eight minutes later and to restore power to vital equipment from the emergency diesel generators.  No sanctions or violations issued by NRC. 

Sowell commentary:  This points up the problem of undetected design deficiencies.  The Unit 2 reactor was started up in 1987 – this problem had lain dormant for 24 years.  The electrical issues caused Unit 2 to have zero cooling water available – no power to motors for pumps, therefore no flow.  Operators avoided a meltdown only because the second reactor, Unit 1, was operating normally.  Cooling water from that reactor was routed to Unit 2 while the electrical issues were being sorted out.  The report states that full, normal operation was restored 10 hours after the initial problem.  This is completely unacceptable for a nuclear power plant.  Had this been a single-reactor plant, the loss of cooling could have resulted in a partial or full core meltdown, exactly what happened at Fukushima, Japan.  (so much for redundant safety systems). 

A second point: per the UCS report, “Shortly after 10:00 am on January 30, 2012, a portion of the “C” phase power line for the Unit 2 station auxiliary transformer (SAT) in the 345,000-volt switchyard broke and fell to the ground causing an electrical fault.”  In English, this means that a high-voltage power line (the “C” phase, where alternating power is conducted in three phases: A, B, and C), somehow fell apart, broke, and fell to the ground.   The question to be asked is, Why?  Was the line corroded, or did something heavy fall on it, or did some other problem cause the line to break?  Are inspections performed on such lines, and if not, why not?  This line, like the rest of the plant, was presumably only 24 years old.   If the nuclear power plants have issues such as this, with power lines breaking and falling to the ground without warning, this is a serious problem.  

Catawba, Unit 1, April 2012

SIT:  Three unrelated electrical problems caused the Unit 1 reactor to shut down automatically from full power, both reactor units to be disconnected from the offsite power grid, and an emergency diesel generator to fail.   Age-related degradation of the insulation for a power cable to one (of four) reactor coolant pumps on Unit 1 caused an electrical fault that stopped the pump.  That resulted in the automatic shutdown of Unit 1.  Subsequent chain-reaction of electrical issues caused the entire plant to be isolated from the grid, although isolation from the grid was not supposed to happen, if the design was proper.   Fortunately, four emergency diesel-powered generators started as designed to supply emergency power to the plant.   The cause of the isolation from the grid was improperly specified replacement relays for that part of the electrical system.  The original system had proper design and would not have isolated the plant.   NRC issued two violations. 

Sowell commentary: again, we see old and degraded equipment (in this case, wiring insulation) caused the initial problem.  The question is, who does the inspections of the wiring and insulation?  Was the problem inaccessibility?  Or, did nobody think to check the wiring?   Secondly, as NRC noted, it is improper to specify different parts for equipment replacement.   Parts must be like-for-like, else they can (and in this case, did) compromise safety.  

Farley, Units 1 and 2

SIT: a security-related incident for which no public details are available.  

Fort Calhoun, June, 2011 (first incident)

SIT: A replacement electrical breaker overheated, caught fire, and a series of cascading events stopped one of the spent fuel pool cooling pumps.  A second spent fuel cooling pump also lost power as the operators tried to remedy the electrical system.  The spent fuel pool was without circulating cooling water for 90 minutes before a pump could be restarted.  The water in the pool increased 3 degrees F in temperature.  Workers had noticed and reported an acrid smell (electrical smoke) three days earlier, but did not follow up to measure temperatures on the electrical equipment.   From the report:

“The failed electrical breaker was among 12 breakers replaced in November 2009. The replacement breakers were of a different size and material than the original breakers. These design differences created the potential for the breakers to experience higher temperatures during operation due to increased resistance to electrical current flow. The higher temperature exacerbated the situation by increasing the oxidation rate of internal parts, adding even more resistance to current flow. 

During installation, the replacement breakers did not align properly in the breaker compartments so workers made unapproved on-the-spot changes to make them fit. Following installation, workers used a hand-held mirror to visually determine if the pieces seemed to fit together properly. They did not measure the incoming and outgoing electricity to confirm consistency with characteristics of the original breakers.”

The NRC issued three violations. 

Sowell commentary: Again, replacement parts are at the root of an incident at a nuclear power plant.  In this case it affected the spent fuel cooling pool.  The replacement breakers were not like-for-like compared to the approved, original design breakers.   In addition, workers wasted valuable time trying to close a breaker from the control room because they did not know that that breaker required on-site, local manual re-setting.   It is not clear from the report if the breaker that would not close automatically was one that was recently replaced, or was original equipment.  Either way, the operators must be properly trained on all equipment in a nuclear power plant.  As the plants continue to age, this type of problem is more and more likely. 

Fort Calhoun, (second incident)

SIT: a security-related incident for which no public details are available.  

Harris, April, 2012

SIT:  During a shutdown, one of the three main steam isolation valves took 37 minutes to close, and a second took 4 hours and 7 minutes to close during testing. All three valves are supposed to close within 5 seconds during an accident to limit how much radioactivity is released to the atmosphere. Workers disassembled the valves to learn why they did not close properly.  The found that corrosion caused internal components to swell, effectively preventing the spring inside from closing the valve.  The valves had been in service since the plant was built, more than 25 years.  Since 2000, the plant had not tested these valves at all.    The main steam isolation valves serve to block the steam line from the steam generator to the steam turbine in the event of an incident that could release radioactive steam into the atmosphere.  These are critical valves and are designed to close within 5 seconds.  

Sowell commentary: once again, old and aging plant equipment is not performing as designed.  These valves were known to be critical, but were not tested at all for 12 years.  They would not have functioned properly in an emergency.  This is completely unacceptable in nuclear power plants.  

Palisades, April 2012

SIT: Workers shut down the reactor because of a leak of about 18 gallons per hour of cooling water determined to be through the reactor coolant pressure boundary. The plant’s operating license does not permit the reactor to operate for more than six hours with such leakage; however, the reactor operated for nearly a month under those conditions.  The leak was via a crack in one of the control rod drive mechanisms.  This type of leakage requires immediate reactor shut down, however, the reactor had been recently started up and had run for one month with this condition.  

Palo Verde, Units 1, 2, and 3 (no date and no data available)

SIT: a security-related incident for which no public details are available.  

Perry, January 2012

SIT: The plant owner reported failures to prevent unauthorized individuals from entering secure areas. Details are not available.  However, it is significant that this event occurred more than a decade after the 9/11 attacks.  NRC issued one violation. 

Sowell commentary:  how can a nuclear power plant have deficient security measures at this point, fully a decade or more after 9/11?  

River Bend, May, 2012

AIT: A trip of the reactor due to loss of a single feedwater pump—cascaded into loss of the normal heat sink and loss of cooling water to emergency and non-emergency equipment, because of problems in the in-plant electrical distribution system.   A 13.8 kV power cable failed, and started a fire.  The loss of electricity due to the failed power cable stopped two of the four cooling water circulating pumps, leading to reactor shutdown.  The workers put out the fire, then closed a switch to connect the functioning power to all four pumps.  The reactor was started back up, but a second electric power cable failed.  This led to the loss of all pump power, and shutting down the reactor again.  Workers started up emergency cooling systems and eventually cooled the water in the reactor to below 212 degrees, which is considered a safe temperature.   NRC issued 8 violations due to this event.  Essentially, the workers violated several industry practices, they cut corners. 

Sowell commentary: Again, electrical cables failed that caused a reactor shutdown.  Electrical switches also failed and had not been tested per manufacturer’s requirements.   Electrical cables had not been properly tested, either.  

San Onofre Units 2 and 3, January, 2012

AIT: Unexpected degradation was identified for the tubes within the recently replaced steam generators on Units 2 and 3, causing a release of radioactive steam to the atmosphere.   The new steam generators failed much sooner than expected, and inspection showed a new form of tube erosion.  NRC required the plant owner to identify the cause of the eroded tubes before startup would be allowed.  The plant owner instead decided to shut down both reactors permanently. 

Sowell commentary:  the replacement steam generators were not like-for-like compared to the original equipment, and the tubes failed much more quickly.  The records indicate the new steam generators had more tubes but with a smaller inside diameter.   The experts concluded the tubes banged against each other during operation, from excess vibration.  The banging tubes led to erosion and leaks.   As more and more reactors reach the stage where steam generator replacement is required, we can expect more of this.  In the San Onofre case, the owner chose to shut down permanently rather than spend the time to identify the exact cause as NRC required.    A cascade of events followed the decision to shut down.  More gas-fired power plants are now operated, and some customers’ bills have increased.  The local public utility commission is trying to decide how much of the costs related to replacement power to allocate to customers, and how much to the utility.   Also, new power plants are now approved for construction to replace the generating capacity, with at least 75 MW of that being grid-scale storage.  

Wolf Creek, September 2011 (first incident)

SIT:  One emergency diesel generator experienced load swings of up to 500 kilowatts when loaded to 5,800 kilowatts during a test run on September 1, 2011. The cause was determined to be an improper adjustment to the control system in May 2011 during an attempt to resolve another problem.  NRC issued two violations for improper testing and improper procedures. 

Wolf Creek, January, 2012 (second incident)

AIT:  Two separate, unrelated electrical faults resulted in loss of the plant’s normal sources of electricity. While both emergency diesel generators automatically started and supplied power to essential equipment, other equipment problems complicated the operators’ response to the event.  NRC issued no violations from this event.

Incidents in 2011 and 2010 had similar issues. 

[UPDATE-6/9/2014: The short-lived Rancho Seco nuclear plant near Sacramento, California.  The plant was shut down permanently after only 18 years of operation (1971 - 1989) due to an incredible number of leaks, radiation emissions, fires, mechanical breakdowns, the list is very long.  see link    -  end update]

Previous articles in the Truth About Nuclear Power series are found at the following links.  Additional articles will be linked as they are published. 

Roger E. Sowell, Esq. 
Marina del Rey, California