Saturday, September 10, 2011

Did Seismic Ground Motion Cause a Flux Spike Big Enough to Trip North Anna?

Over the last two weeks there has been considerable discussion over: "What specifically caused the dual unit reactor trips at Dominion's North Anna Station during the Earthquake in Mineral Virginia?" Some of the possible likely causes discussed include:
  • Sensed power imbalance in the unit auxiliary transformers?
  • "Relay chatter" (which is actually caused by the seismic ground motions shaking mechanical relay contacts apart) that gives the appearance of de-energize to trip logic actuating?
On of the more exotic modes hypothesized was that horizontal ground motions that lasted about 3 seconds had caused a neutron power disturbance that generated a reactor trip on high local neutron flux. The New York Times reported the following:

"Because the earthquake moved the water in the reactors, the sensors indicated that the neutron population there was no longer distributed properly, and the system called for the automatic shutdown, Dominion officials say."

This gives the possible impression that shaking a nuclear reactor will make the power spike to the point where the neutron flux goes from its nominal full output power (e.g. 100%) to greater than 110%. It sounds fishy to me based upon basic physics principles. One of the youngster engineers in our engineering department asked me about this and I asked him if he remembers his Reactor Engineering 101 courses from college? Could a nuclear reactor actually physically respond to the ground motions? He didn't remember so I spent a couple of hours the other afternoon with him. [I actually get paid to mentor the young folks - its more enjoyable than going to project meetings...] This is what I walked him through.

A Nuclear Reactor is a heavily damped system which physically behaves according to natural time constants - some of which are a minute or more in magnitude. When you try to change the output power rapidly in won't immediately react because of all those time constants. A very long time ago early nuclear engineers measured the dynamic response of different types of reactors (fast reactors, water cooled reactors, and graphite reactors) and they found that the effective neutron lifetime and delayed neutron precursors played a huge role in controlling the time behavior and safety of reactors. 

The figure below is taken from p.487 of Bell & Glasstone's "Nuclear Reactor Theory"[Reference 1]. It shows a comparison of the Gain and Phase shift to an oscillatory (sine wave-type) disturbance to reactivity - either by control rod motions or any other thing that tries to change the neutron balance in a critical reactor. The frequency scale is in units of Radians/second. To convert to more typical units recall that: 
       1 Cycle/second = 360 Degrees/sec = 2*Pi Radians/sec = 6.283 Radians/sec.
Thus: 1Radian/sec = 0.159 Cycles/sec, 10 Radians/sec = 1.59 Cycles/sec, 100 Radians/sec = 15.9 Cycles/sec.

What the curves show:
  1. The top curve is the Gain (like in a stereo amplifier as a function of frequency).
  2. The second curve shows the phase angle shift. This is a delay in reaching a peak value given that there are 360 degrees in a cycle.
  3. If a very low frequency oscillation in the core reactivity (less than say one cycle every ten seconds) is made the reactor amplifies this. Thus a 1% perturnation in reactivity results in a several percent perturbation in neutron flux.
  4. If the oscillation is about one cycle per second - there is no amplification. Thus a "one-for-one" effect -- a 1% change in core reactivity results in about a 1% change in power
  5. If the oscillation is greater than one cycle per second and higher - there is an attenuation or damping of the neutron flux response because the inherent time constants within the nuclear reactor system are incapable of responding to such fast changing input events.
There are several curves represented for different reactor types. The key difference is the Effective Neutron Lifetime Parameter - larger effective neutron lifetimes (such as for a graphite reactor) are less responsive and thus damp the response even more.

What Kind of Frequency Input Did the Earthquake Present?
I don't have seismograph records for the recent earthquake so I will rely on a recent USGS projection [Reference 2] which shows the likely acceleration magnitude vs. ground motion period for 30km away from an Eastern US fault.

To understand where the greatest acceleration content is one must convert the period (expressed in seconds) to cycles per second. A period of 0.01 seconds equates to 100 Cycles/sec. A period of 0.1 seconds equates to 10 Cycles per second. A period of 1 second would be 1 cycle/sec. Thus one would expect the highest accelerations would be with a frequency of: 10-100 Cycles/sec.

Putting It All Together
I do not have the exact effective neutron lifetime parameter for the reactor cores at North Anna. I do have them for a set of PWRs and they range from 2.53E-5 sec to 3.14E-5 sec. If I overlay the region of earthquake accelerations on top of the Gain curve I get a figure like the one below.
The frequency range of the seismic events occurs in a frequency range that is too fast for the reactor to respond to -- so the reactor core and neutron population effectively ignores the shaking. My conclusion is that a horizontal seismic acceleration which might shake fuel rods and thus cause a reactivity oscillation is not in a frequency range where anything would happen. Ruling this out, more likely causes of a neutron flux trip would more likely be effects of the shaking on excore neutron detectors and their cabling.

1. George I. Bell,  Samuel Glasstone, "Nuclear Reactor Theory", Copyright 1970 Van Nostrand Reinhold.
2. P. Somerville, et al, "Ground Motion Attenuation Relations for the Central and Eastern United States", Final Report to the USGS, Contract 99HQGR0098, June 2001.

Friday, September 2, 2011

No -- We Did Not Almost Lose the North Anna Nuclear Power Plant

Last week in an article in the Los Angeles Times a spokesman for the Union of Concerned Scientists (UCS) stated:

"The North Anna plant is designed to withstand a 5.9 to 6.1 quake. Last week, it came “uncomfortably close” to that maximum, said Edwin Lyman, a senior scientist at the Union of Concerned Scientists, a group that advocates stronger regulation of nuclear power."

This alarming statement implies that if an earthquake approached or exceeded the design basis earthquake level that there was imminent danger to the public. Wrong! I'd like to take a closer look at what a design basis earthquake at a nuclear power plant actually means - and what it doesn't mean.

What is a Design Bases Earthquake - How Does it Relate to Actual Risk?
As a part of the original licensing process of a nuclear power plant the applicant prepares a safety analysis report which identifies and characterizes all the potential hazards (both internal and external) that the proposed facility would be exposed to over it's operational life. This is covered by Title 10 Code of Federal Regulations Part 50, Appendix A - General Design Criteria for Nuclear Power Plants, Criterion 2: "Design Bases for Protection Against Natural Phenomena". It includes: severe weather such as hurricanes, tornadoes, flooding, earthquakes, gas pipeline failures, oil refinery explosions, etc. There are numerous NRC regulatory guides [References1, 2, 3] which identify the preferred methods to establish what level of seismic acceleration should be used for establishing the Design Bases Earthquake. The considerations include: historical records of earthquake locations and magnitudes, geological investigations of the site (digging "bore holes" looking for evidence of ancient fault lines, characterization of the underlying rock strata and the foundations. A value would be established based upon reviews performed by the licensee and typically with some adjustments made by the NRC staff reviewers - before they would "sign-off" on its conservatism.

The resultant Design Bases Earthquake (DBE) amounts to a specified value that an applicant must be able to conservatively demonstrate the reactor can be safely shutdown. Conservatively demonstrate means there are design margins or safety factors between the DBE and the point of actual failure. Typical values for DBEs for central and eastern United States earthquakes were in the range of: 0.10 - 0.17g  (where "g" is the acceleration equivalent to the earth's gravitational acceleration ~32 ft/sec2).

The DBE becomes a design requirement which is used in all design activities for establishing  loads on buildings, required supports, anchorage. A general misconception about engineering  practice is that engineers calculate everything associated with allowable stresses and design limits. This is not exactly correct. They evaluate requirements and apply "standard solutions" which have large safety margins built in. Professional societies such as the American Society of Mechanical Engineers (ASME), and the American Society of Civil Engineers (ASCE) develop standardized conservative solutions to design problems that are widely reviewed and accepted. This simplifies creating the design as all that must be checked is that the specifications were understood and the correct "code solution" applied to the problem. The codes specify the details of : "how thick", "how many reinforcements are needed", "pre-tensioning", "what kind of materials are needed to achieve certain strength". This is effectively what is meant when we say designing it according to the "code" -- anything else is characterized as "sub-standard". These design codes are recognized to have safety margins built into them to account for aging and unexpected loads. It is not uncommon to see safety factors of two or more over the bare minimum of what is required.

Thus there is a standard expectation that when a nuclear power plant has a DBE of 0.15g - that there are significant built-in safety margins. The reality is that there are typically much larger design margins available by factoring in actual earthquake experience (in which objects deform but do not fail) - and the results of qualification tests which demonstrate actual seismic capability of major components (pumps, major valves, circuit breakers) by testing. Testing is often an option for components which because of their geometry are sometimes too difficult to analyze and much easier to test.

What becomes really important is not the DBE which is a licensing and design concept -- but the level of ground acceleration at which the plant actually does fail and release radioactive matrerial. This can only be determined by performing a Seismic Probabilistic Risk Assessment (PRA) which factors in the frequency (per year) of a specific size earthquake and the probability that a combination of seismic induced failure occurs given the earthquake. [Reference 4]

Analysis to produce the probability of seismic induced failures occurs given the earthquake is called a "Fragility Analysis". A typical fragility response curve is shown below and includes a "best-estimate" of failure and the effects of uncertainties  which results in a more conservative projection. The concept displayed in such a curve is that at low acceleration levels there is effectively "0" probability of failure. With higher ground accelerations for a component there is an increasing likelihood of failure and at some acceleration level there is pretty much guaranteed failure of a component.

When specialists do a Seismic PRA what is typically found to be the dominant source of risk is a combination of the following:
  • An earthquake damages incoming power lines by failing the ceramic insulators associated with high voltage power lines.
  • Onsite emergency diesels fail due to provide power (typical causes include anchorage of diesel engine coolers, disruption of fuel oil supplies, etc)
  • Inability to restore power from downed transmission lines or bring in a large portable generator eventually results in loss of battery power, instrumentation, and the ability to cool the reactor.
Typical plant specific fragility curves [Reference 5] for these types of failure modes are shown below:
What these curves show is that failure of offsite power connections is pretty likely. That's bad - but the plant is designed to cope with this. [Last week's Blog covers how a PWR shuts down in a loss of offsite power.] Failure of the emergency diesel generators is not very likely and requires a significantly bigger and thus less likely earthquake. Reading the second curve there is high confidence of less than 5% chance of failure for acceleration levels up to 0.5g which is roughly three times the DBE. There is thus significant safety margin in the design of the diesels against the DBE for the plant in question. If there were a large earthquake the most likely scenario would be an extended loss of offsite power - which the plant is designed for.

So What Has Changed in the Perception of Seismic Risks?
Its not only that an actual earthquake happened in Mineral Virginia and caused the North Anna nuclear power plant to shut down. Joint research efforts by the US Geological Survey (USGS) and the utility-sponsored Electric Power Research Institute (EPRI) have been reviewing the hazard curves for central and eastern US. Preliminary results started becoming publicly available for comment about a year ago. The hazard curves are basically a characterization of frequency of experiencing an earthquake of a particular magnitude. Not surprisingly: small earthquakes are relatively frequent. The larger the earthquake, the less likely its frequency of occurrence. The figure below shows some of the preliminary results (which will not be finalized until December 2011) for a particular site. (NOTE: To get the actual acceleration at a particular site one would need to take the actual fault location and adjust it to address site attenuation and various other ground and structural factors.)
Previously, for this hypothetical site one would expect to see an earthquake exceeding 0.1g about once every 10,000 years (a probability of 1E-4/yr). Newer information from geological surveys and other sources indicates it could occur with a frequency of 9E-4/yr or every 1100 years. That's obviously an increase. For very large and substantially less frequent earthquakes the historical data is harder to find -- a one in a million year earthquake is beyond all human records and thus can only rely upon geological investigations and conservative judgements.

What is the True Risk Significance of Large Eastern Earthquakes?
If I were doing this in "great engineering detail" I'd obviously consider a wider spectrum of failure mode combinations (although these are far less likely and contribute less to the risks). To do it quick and dirty: if I take the new hazard curve (or something like it) and my dominant accident sequence is the loss of offsite power and failure of the diesels at greater than 0.5g, the likelihood of the earthquake with such a ground acceleration is on  the order of once every 100,000 years. It used to be once every 1,000,000 years. I don't know about all my readers out there -- but given the daily risks of just about everything else out there I think I can live with this increased risk. I am guessing that this is why the NRC is concluding that there is need to do some further analysis but that the seismic safety of existing nuclear power plants on the east coast is acceptably safe for the time being. I do expect there will be a lot of safety analysis engineers doing a lot of work to go through this exercise as I have attempted to illustrate -- but obviously in greater detail.

  1. Design Response Spectra for Seismic Design of Nuclear Power Plants, USNRC Regulatory Guide 1.60, Rev 1, December 1973.
  2. Damping Values for Seismic Design of Nuclear Power Plants, USNRC Regulatory Guide 1.61, October 1973
  3. Combining Modal Responses and Spatial Components in Seismic Response Analysis, USNRC Regulatory Guide 1.92 Rev 1, February 1976.
  4. R.P. Kennedy et al, "Probabilistic Seismic Safety Study of an Existing Nuclear Power Plant", Nuclear Engineering and Design, Vol.59, No.2, pp. 315-338. 
  5. D.A. Wesley et al,, "Seismic Fragilities of Structures and Components at the Millstone 3 Nuclear Power Station", Structural Mechanics Associates Report SMA 20601.01-R1-0, March 1984.

Saturday, August 27, 2011

A Primer on How A Pressurized Water Reactor Shuts Down

My motivation for this layman's primer is to correct the misstatements of what actually goes on when an operating Pressurized Water Reactor Shuts Down as a result of either a suddenly occurring event such as an earthquake or because of an impending severe storm such as a hurricane. There are two types of shutdowns to be considered: (1) one in which an event such as earthquake or loss of offsite power occurs and the unit automatically trips, and (2) one in which station procedures recognizing a deteriorating weather situation (as an example) takes a slower path to shutdown. I will discuss both of these cases. I will discuss the equivalent case for an operating Boiling Water Reactor in a separate blog.

Safety Considerations
The key difference between a nuclear power plant and a coal fired thermal power plant is that after a unit trip the nuclear heat source continues to produce heat. When a coal fired power plant is tripped: the blower fans and fuel supply is cut off quickly stops generation of new heat. The heat that remains is a result of the hot tubes in the boiler needing to cool down and this is accomplished by continuing to supply feedwater to the boiler. A nuclear power plant on the other hand continues to generate decay heat. This is a well known and well understood phenomenon and is characterized by design standards such: ANSI/ANS Std. 5.1 [Reference 1]. A graph of how decay heat drops off with time (dotted line) is shown in the figure below.

The dotted lines are taken directly from the standard. One second after a reactor trips, the standard assumes the heat is at 8% of the original power output. So if we had a reactor generating 1000MegaWatts of heat at one second after trip it is putting out 80 MegaWatts. At 100 seconds the heat has dropped to ~3.5% (or like 35MegaWatts) and so forth. As in the case of the coal fired boiler - after a unit trip there are is a lot of very hot metal which need to be cooled down as well (e.g. piping, steam turbines, etc). All of this requires continuous addition of water.

Plant Trip from Full Power with Offsite Power Available
When a pressurized water reactor (see figure below) is operating at full power one would find: hot steam is being produced at nominally 900-1000 pounds per square inch or "psi" by boiling water in the steam generators. The source of heat in the steam generators is hotter water, typically 580-600F pumped to the steam generators from the reactor by reactor coolant pumps that take the water from the colder side of the steam generators.

Depending on the size and rating of the reactor plant, water coming into the reactor enters at above 500F and is heated in the reactor and heads for the steam generators. There are two main sources of heat to the water: heat transferred from the reactor (depending on the rating of the unit several hundreds to thousands of MegaWatts) and heat added to the water by the functioning of the reactor coolant pumps (which can be several MegaWatts). When a unit trips from full power, the control rods are inserted in 1-2 seconds and the reactor transitions from heat directly from fissioning to decay heat plus reactor coolant pump heat. The figures below are taken from a actual full power plant trip as recorded by the unit's plant data logging computer..
When the measured neutron "flux" power (scale on the right) abruptly drops - the actual time when the reactor trip occurred - the measured temperatures at the cold and hot sides start to approach each other. The difference between the upper and lower temperature is proportional to the decay heat and heat added by the reactor coolant pumps.

The immediate actions by a well trained crew of operators in the control room would be to announce over the plant address system that the reactor had tripped and then they begin their immediate reviews to confirm that: all control rods have fully inserted, that the turbine has tripped and main generator disconnected, that electrical buses needed to power equipment is energized, and that pressures, water levels and temperatures are trending the way that is expected and that there is no need for operating emergency cooling systems. Equipment operators in the plant will typically walk to their pre-defined post-unit-trip duty stations and make further adjustments on equipment in the turbine building. The normal preferred pathway from this point on would be to continue to generate steam in the steam generators - send it directly to the main condenser - cool the steam and feed it back to the steam generators. After about 10 minutes in this condition, the control room staff would actually hold a meeting to discuss what caused the trip, any out of tolerance conditions observed by the operators, or indications that are not as expected, and where to proceed from this point based upon their written procedures. The options include to continue to remain on steam generator cooling (which we call hot standby) or proceed to cold shutdown - meaning the primary coolant system in further cooled down to temperatures where heat is removed by a special set of heat exchangers called a residual heat removal system.

Plant Trip from Full Power with Loss of Offsite Power
In a plant trip from full power without offsite power (like recently occurred at the North Anna plant following the earthquake in Mineral Virginia last week) the response by the control room operators would essentially be the same. The initial steps are in fact identical. Typically they would experience a momentary dimming of control room lighting while emergency diesel generators kicked in. They would announce a plant trip, confirm the control rods are inserted, that the turbine and main generator have tripped, and evaluate the status of incoming electrical connections.

There are several key differences in what equipment would be used to remove post-trip decay heat. All non-essential electrical buses are de-energized when there is a loss of offsite power. Emergency diesel generators have started and essential pumps, motors and loads such as battery chargers are reloaded automatically to the diesels. The main condenser unit - which is not a safety system and is not powered by emergency diesel generators - and all of its associated pumps and heat exchangers are just sitting there and not available to remove decay heat from the steam generators. Additionally the main reactor coolant pumps which are not safety related de-energize and spin down. While this implies no forced coolant flow -- it also means a rapid elimination of the several MegaWatts of pump heat added to the system - leaving only the decay heat from the reactor. Initially, there is considerable momentum of water circulating in the coolant system to carry away the decay heat from the reactor.

So, after this point: How is the heat transported from the reactor to the steam generators?

The answer is natural circulation. Pressurized Water Reactors (both those with U-tubes, and those with straight tubes) are designed with relatively large vertical elevations in mind that allow hot water to rise - as the coolant flows up through the reactor to the steam generator. As the water cools - via transferring heat in the steam generators through boiling water on the steam side it becomes colder and denser. The denser, heavier water wants to flow downwards to the lowest point in the coolant system -- which in this case is the bottom of the reactor vessel. I show two elevations drawings for common nuclear power plant designs below. The points being highlighted are the "thermal centers" in the steam generator (Hsg) and the reactor (Hrx). The thermal center is the point in the closed loop of the coolant system where the mid-range coolant temperature -- which we call Tavg is physically located.  As long as: Hsg is elevated above Hrx water is naturally circulated to remove decay heat without any moving parts in the primary coolant system.
So - hotter less dense water rises in the reactor core, and colder denser water wants to fall downwards - as long as heat is being removed in the steam generators. I show below a trend plot below from an actual trip with loss of offsite power.
In the first few hundred seconds, what we see is the rapid drop off of forced primary flow provided by the pumps -- but it doesn't go to "zero" because natural circulation kicks in and provides 4-5% normal flow. As the decay heat from the reactor core starts to drop off, the heat added to the water drops off and this naturally slows down the rate of water flow. The figure below shows what the temperature trend looked like over a significantly longer time scale as the plant entered a stable long term natural circulation cooling..

I have previously mentioned that it is important to keep water flowing to the steam generators and steam flowing out of them.

Getting water into the steam generator is accomplished by what we call an auxiliary feedwater (AFW) pump system. Depending on the design, this can be a combination of one (or two) electrically driven AFW pumps and a diverse steam driven AFW pump. Typically only one of these is needed and operators would keep only one feeding the system and shutdown (or secure) the others to keep them in reserve and to prevent them from overfilling the steam generator. The electric driven AFW pump(s) would be powered by a diesel. The steam driven pump is powered by a small portion of the steam generated by the steam generators. This is kind of a "play as you go" operation - the higher the decay heat load the higher the steaming rate - the lower the decay heat to lower the steaming rate. These pumps take suction from a safety related water storage tank (or in many designs several tanks) with enough water to last typically a day. If this tank should become depleted operators have that whole day to align to an alternate water source such as a small diesel fire water pump using well water, river water, or even ocean water.

(Photo of a steam driven, Terry Turbine, auxiliary feedwater pump with Woodward Governor)

Getting steam out of the steam generators is accomplished by venting the steam to the atmosphere either by manually opening an atmospheric dump valve or letting the steam pressure naturally rise to the point where a steam generator relief valve operates. Venting to the atmosphere is necessary because - recall: the main condenser is unavailable due to lack of power for running pumps. Venting to the atmosphere is simple and straight forward but it results in continuous depletion of water supplies and this is the main reason for large water storage tanks and the ability to make up to those tanks with alternate water sources such as fire water.
 (photo of the pneumatic controls on a steam generator atmospheric dump valve)

Throughout the cool-down (or until offsite power is restored), electrical power would be provided by redundant diesel generators typically rated at 4-5MegaWatts and about the size of a locomotive engine. These units provide all necessary power to run electric AFW pumps (if operators chose to run an electric pump), power other essential cooling water pumps to cool pump bearings, run safety related room cooling, and keep the redundant batteries powered so that the control room instruments remain powered and operable. To keep the diesels running all that is required is fuel oil and some form of engine cooling. Some plants have water cooled diesels others have air cooled diesels. Fuel oil is stored in a smaller quantity for immediate operational needs in what is called a day tank and over longer periods would be replenished by a fuel oil transfer pump from a much larger supply tank.

With the plant temperatures stabilized - typically in about 10-20 minutes - the control room operators would make contact with outside dispatchers to determine the source of the loss of offsite power and when it was likely that offsite power connections would be restored. From this information the crew meeting would be held and following plant procedures, decisions would be made on whether to remain in hot standby or to proceed to cold shutdown.

What is Different if the Plant has Advanced Warning?
A Hurricane like we are experiencing this weekend on the east coast is an example of an external event which has many hours of advanced warning. The typical issues that might warrant a shutdown of the plant before the hurricane reaches the plant could include the likelihood of storm related damage to the main switch-yard or incoming electrical transmission system. High winds and debris (tree branches, etc.) can knock down transmission lines. Hurricanes have been known to transport large amounts of salt on to high voltage electrical insulators causing transmission lines to electrically short-circuit to transmission tower metal and then to ground. Hurricanes have also been known to tear up the seaweed and kelp from the ocean bed and cause clogging of intake structures - and this could result in reduced water flows to the diesel (if it isn't air cooled) or to other heat exchangers needed to support operation of essential systems. Utilities and the people who operate nuclear power plants know of these potential challenges and have specific emergency operating procedures to deal with external events with long lead times. The general idea behind these procedures is to reduce power ahead of time (thus starting off with a lower decay heat level) and making use of their largest single heat removal system available to them -- namely: the main condenser. Because the condenser is relatively large, it is possible to quickly cooldown the steam generators and reactor coolant system while not discharging steam to the atmosphere. This means the water in the storage tanks for the AFW pumps remains at a maximum inventory level for as long as possible. [I would point out that nuclear power plants also have written procedures covering advance warning of tornadoes and high winds. Although these scenarios may have only 10 minutes advance warning these would also be addressed by rapidly reducing power.]

Typical utility procedures in the event on an oncoming hurricane (where there could be an extended loss of offsite power) would include:
  • reducing overall power output levels several hours before the storm arrives
  • topping off the reserve diesel fuel oil tanks
  • securing from any non-essential maintenance activities that might leave the plant vulnerable in a loss of offsite power situation
  • doing a walk-down of plant areas to remove or secure outside equipment or supplies in the plant yards that might become a missile hurled at plant equipment by hurricane force winds
  • installing temporary flooding protection to doorways leading into plant buildings
  • calling in and stationing additional plant equipment operators in specific areas that might need additional monitoring during a hurricane.

It is thus not surprising that given decades of coping with actual hurricanes, tornadoes, earthquakes, continuous operator training (roughly a week every five weeks involving classroom refresher training and simulator drills on what to do), well written procedures and guidance -- that US nuclear power plants know how to cope with severe weather and other natural disasters. When I read in the main street media that nuclear power plant operators don't know how to deal with such situations and that further improvements are urgently needed because a theoretical physicist thinks we just "dodged a bullet"..... I have only one word to say, and that is:

B@!!$'t  "

[1} Decay Heat Power in Light Water Reactors, ANSI/ANS Std. 5.1-2005, issued by the American Nuclear Society.

Friday, August 19, 2011

Recalling the June 24th 1978 Boston Globe "Pro-Seabrook Ad"

In June of 1978 a group of us at Combustion Engineering Nuclear Power Division following extensive news media coverage of the planned demonstrations by the Anti-Nuclear Clamshell Alliance decided we should make a counter statement in the news media. We hit upon the idea of taking out a full page advertisement in the largest circulation newspaper in the Boston - Southern New Hampshire area - the Sunday Boston Globe. It was strange effort. Here we were in Connecticut planning a media event that would mainly benefit a competitor: Westinghouse Electric in Pennsylvannia and a power company in New Hampshire (Public Service of New Hampshire). The text was primarily drafted by Bill Burchill. Uli Decher and I did some minor editing, but Bill was the main author. Then we went to work on collecting money. Within several days (and this was significantly before the internet and "Pay-Pal") we had collected several thousand dollars from over 750 like minded folks. 

The ad below appeared in the Sunday morning June 24th, 1978 edition of the Boston Globe at a time when the majority of the Clamshell Alliance were confined in makeshift jails after being arrested and refusing to make bail.



A Demonstration Against Nuclear Power?
OR A Demonstration Against Established Society?

Have you thought about, truly examined, the benefits of nuclear power? Are these benefits consistent with our structure of society and its values? Does denial of these benefits oppose our structure of society? Do the demonstrators oppose nuclear power, or do they oppose our structure of society? What is the real issue?!?

What are the benefits?
The benefits of nuclear power can be shared by everyone. But, denial of these benefits will most heavily impact the economically disadvantaged people in our society. The benefits for everyone are clearly represented by the following quotations from the NAACP policy on energy issued in December 1977, and reaffirmed in April 1978:

"Since the early 1960's gains have been made toward bringing the nation's Black citizens into the mainstream of American Economic Life. This has occurred largely during a period of expansion in the economy which created new opportunities for jobs. However, a great deal more remains to be done. We still have tremendous unmet social and economic needs....An abundant energy supply will be necessary if we are to have any chance to meet these challenges.....All alternative energy sources should be developed and utilized. Nuclear power, including the breeder, must be vigorously pursued because it will be an essential part of the total fuel mix necessary to sustain an expanding economy.....We recognize that nuclear power does present certain problems. But we think these problems can be solved through the dedicated efforts by government, the scientific community and industry working cooperatively together. Notwithstanding the claims of opponents of this source of energy, the fact is that nuclear power will be required to meet our future needs for electricity. If we do not move ahead now with nuclear energy, the next generation is likely to be sitting around in the dark blaming the utilities for not doing something this generation's officials would not let them do."

Who opposes these benefits?
Many of those who demonstrate against nuclear power are disillusioned with American society and distrustful of its institutions. To them nuclear power symbolizes life's frustrations (so big, so complex, it can't be understood) and its elimination is seen as one bridge to their desired social changes. Many leading opponents of nuclear power advocate the requirement for radical social changes.
Many people have an honest and sincere concern over safety and possible proliferation of materials for nuclear weapons. We would be forever judged as totally negligent in our obligation to the preservation of humanity if we did not consider these concerns. More personally, we too have families. HOWEVER,WE HAVE EXAMINED NUCLEAR POWER AND WE HAVE DECIDED IN ITS FAVOR.

What is the demonstrators' real goal?
For many, the real goal is a major change in American society. Nuclear power is not a central issue itself, but rather the clamor against it is a tool, a lever to be applied in creating an upheaval of our social, economic, and political patterns of life. An aspiration for seeking change is stated to be a desire for a more democratic society. However, the large-scale institutions which are a key product of our free enterprise economic structure are somehow excluded from this society. They are to be replaced instead with small-scale, localized technology controlled by neighbors and friends.

What are the consequences?
The consequences are evident from the history of failures of utopian experiments. Mao's "great leap forward" wherein technology was forced toward backyard industries, including even steel smelting, was a notable failure of an enticing dream. Mahatma Ghandi's "cottage industries" are held by many to have retarded progress toward improving the lot of the masses. One of the greatest improvements for the Indian village inhabitants was electrification. This step parallels the dramatic improvements to our standard of living brought about by the Rural Electrification Agency in the United States in the 1930's. Many of today's "nuclear opponents" have no personal knowledge of that period. Neither do they know what can be made available only by using the large-scale institutions which they wish to abolish.

What should they do?
The "nuclear opponents" should be honest with us about their real goals and use the established democratic processes to seek those goals. Rather than seeking referenda against nuclear power, let them ask for votes on the consequences of the unavailability of that power. Convince the over two million American workers laid off due to energy shortages last winter that there is no connection between jobs and energy supply. Convince the poor, the minorities, the working-class that America is so rich that it no longer needs growth because economic needs are no longer the principle concern of its people. Convince the people who are "without" that they don't want washing machines and refrigerators to relieve domestic drudgery, that they don't want cars for freedom on weekends and holidays, that they don't want the comfort of central heat in the winter and air conditioning in the summer.

What should we do?
We should recognize the real social issues even if they are disguised as oppositon to nuclear power. We should insist upon an open and fair evaluation of the consequences of actions both for and against nuclear power. Finally we should realize the true effects which our decisions will have on the future of our society.


So what has changed over the years?

The Seabrook Station Nuclear Power Plant went into commerical service after all the regulatory and licensing delays in 1990 - some thirteen years after recieving a construction permit. One of the last hurdles was when then Gov. Michael Dukakis refused to agree to Massachusetts participating in federally required emergency planning. Seabrook Station today generates 1245MWe. This is enough energy to supply power to over 900,000 homes and businesses. It has a workforce of approximately 1100 employees and contributes ~$20million to the local economy including ~$10million in property taxes. The current owners NextEra Energy (Florida Power & Light) have submitted their applications to operate plant until 2050.

The Chinese and Indians having abandoned the "great leap forward" and cottage industries are building new nuclear power plants and pioneering methods of speedier construction such as modularized portions of buildings being constructed off-site in factories and then shipped for assembly at the site.

Wednesday, August 10, 2011

Radioactivity Release from Natural Gas Production

Imagine if you can a nuclear power plant releasing radioactive materials to the environment at levels hundreds of times greater than Federal Drinking Water Standards - and the responsible federal authority responded that they were unaware of any releases. In the case of our Environmental Protection Agency (EPA) that's exactly what is going on.

I’m not aware of any proven case where the fracking process itself has affected water.”
Statement by EPA Administrator, Lisa Jackson
Responding to questions before the U.S. House Oversight Committee
May 2011 [Reference 1].

I am guessing that with all the ongoing efforts to write new "Clean Water Rules" aimed at shutting down  power plants that have "once through cooling systems" (rather than cooling towers) and discharge warm water that the Obama Adminstration's EPA Head didn't have time to read the New York Times series on "Drilling Down". [Reference 2].

I found the graphic below from the New York Times particularly informative.

Part of Ms. Jackson's deliberate ignorance of what is going on...... is actually a result of Congressional intent at the urging of certain oil and gas interests. The Energy Policy Act of 2005 exempted fracking from EPA regulations under the Safe Drinking Water Act. Its not a new development either. This monkey business has been going on for years.

Congress passed the Resource Conservation and Recovery Act (RCRA) in 1976 as an amendment to the Solid Waste Disposal Act of 1965 in an effort to enact more comprehensive waste disposal standards nationwide. Through RCRA, Congress declared that the “disposal of solid waste . . . without careful planning and management [was] a danger to human health and the environment.” Congress later amended RCRA with the Solid Waste Disposal Act Amendments of 1980. One of the 1980 amendments, the so-called Bentsen and Bevill Amendments, temporarily exempted “drilling fluids, produced waters, and other wastes associated with the exploration, development, or production of crude oil or natural gas” from regulation under RCRA.Under the Bentsen Amendment, Congress directed EPA to conduct a study to determine whether or not drilling and production wastes should be regulated as hazardous wastes under RCRA. The studies continue [Reference 3] and the best option put forth -- to the pleasure of the oil and gas industry is dilution -- by a process called "Landspreading" which is basically spreading the contamination around over large areas of land.

What is the Source of this Radioactive Contamination?
Our earth is naturally radioactive and is already heavily laden with naturally occurring radioactive isotopes of Uranium, Thorium, Radium, Radon. The figure below from the US Geological Survey shows the relative abundance of several of these naturally occurring isotopes.

Far from being rare elements, Uranium and Thorium are as abundant as common Nickel. Theses elements and their decay products can be bound up in the rock for millenia, slowly decaying back to Lead while emitting alpha, beta, and gamma rays. This continuous decay is one of the heat sources of geothermal energy. But, when drilling deep into the earth's crust, it is possible to run into natural deposits of such ores and their radioactive decay products such as Radium and Radon. Drilling for oil and natural gas is accomplished by pulverizing the underlying rock with heavy rotating drills and flushing the materials out of the exploratory well to the surface using drilling mud. So the drilling mud can come to the surface laden with Uranium, Radium, and Thorium.

As noted by the US Geological Survey in Reference 4:

"In 1989 the American Petroleum Institute sponsored a preliminary nationwide reconnaissance of measureable radioactivity at the exterior surfaces of oil-field equipment. The results of this non-statistical sampling indicated that gamma-ray radiation levels exceeded natural background radiation levels at 42% of the sites. Radiation levels greater than five times the median background of all site were found at approximately 10% of the sites. Most of the sites with markedly higher radioactivity were concentrated in specific geographical areas such as the Gulf Coast, northeast Texas, southeast Illinois, and south-central Kansas. Additional surveys by some state agencies identified radioactive oil-field equipment in northern Michigan and eastern Kentucky. Pipe casings, fittings, and tanks that have an extended history of contact with produced water are more likely to contain radioactive deposits than other parts of the plumbing system at oil-field production sites. Soil in the immediate vacinity of production sites may be unusually radioactive."

The problem then becomes: What to do with this contaminated equipment and soil? Its contaminated. Anyone working in or around the mud can become contaminated. At the end of the day, the workers on the drill rigs hop in their pick-up trucks and head to town -- where the material gets further spread around.

Radiological Effects of NORM
This type of radioactive drilling waste material goes by the accronym of "NORM" -or- Naturally Occurring Radioactive Material. NORM is frequently found in settling ponds near drilling sites, inside of fluid tanks, on drills, and drill structures. The magnitude of human exposure depends on the relative Radium and Uranium concentration of the NORM. As a point of comparison: depending on where you live your background radiation dose can be 200 - 500 mR/yr. The figures below taken from Reference 3 show the projected doses one obtains as a function of the activity per gram of contaiminated drilling mud and the increased risk of latent cancer.  From this figure we note that any mud with concentrations above ~100pCi/g are going to result in doses that are significantly above normal background radiation levels -- hence the need to dilute the drilling mud by "Landspreading" it.

What I found interesting in the study was that having a home built over "Landspread" NORM results in higher risks than the risks to the workers who did the Landspreading.

My Take on All of this ?

I work for an electric company that operates nuclear power plants. I just finished my day-long Radiation Worker requalification training. I had to pass a 100 question test on: radiation effects, federal dose limits for workers and the general public, proper use of dosimetry, how to prevent the spread of microscopic quantities of radioactive materials out of the plant, how to use a personal frisker and properly exit the radiation control check point, how to properly use a radiation work permit, how to don Anti-Cs, proper As Low As Reasonably Achievable (ALARA) practices, chemistry controls, costs of low level waste, and why as an industry we focus on everything to minmize the spread of contamination. 

Then I see the oil and gas industry mishandling radioactive materials and pretending there is no radioactive contamination, and thus no need for dosimetry, ignoring worker exposure, transporting contaminated drilling equipment from state to state, and when the drilling at one site is completed their solution to dealing with radioactively contaminated mud is to "Landspread" it. On top of this, we have politicians who protect the oil and gas industry by exempting them from dealing with their radioactive waste disposal by exemptions, and federal regulators in charge of environmental protection pretending nothing is going on.

So much for the clean energy from America's Natural Gas.

[1] Dr. Robert Peltier, PE, "Fracking Problems", Power Magazine, August 1, 2011

[2] "Toxic Contamination from Natural Gas Wells", New York Times, February 27, 2011.

[3] K.P.Smith, D.L.Blunt, J.J. Arnish, "Potential Radiological  Doses Associated with the Disposal of Petroleum Industry NORM via Landspreading", DOE/BC/W-31-109, Final Report, September 1998.

[4] "Naturally Occurring Radioactive Materials (NORM) in Produced Water and Oil-Field Equipment - An Issue for the Energy Industry", US Geological Survey Fact Sheet FS-142-99, issued September 1999.

Thursday, June 30, 2011

So… we should dig up a lot of coal?

(Adapted from an Article in the Colorado Mountain Club's Quarterly: 
"Trails and Timberline" )
I was at my daughter’s homecoming parade at Colorado State University in Fort Collins and an excited gentleman came up to me asking if I would sign his petition to:


So I asked him: “Does this mean you think we should dig up a lot of Coal?” He seemed startled by my question – but did not answer. He only more frantically urged me to sign his petition “…for the sake of your children and your grandchildren!!” I guess the implication being: if I didn’t sign his petition, I don’t care about my children or grandchildren?

This encounter is a good example of the type of risk communication coming from some in the environmental movement. There is an intent to “stop something” based upon some group’s assertion of serious environmental hazard – but without any critical examination of the accuracy of the claims. Anybody challenging the accuracy of statements coming from groups trying to “stop the hazard” - are labeled as “unconcerned about the environment”. As a Colorado Mountain Club member who also just happens to be a nuclear engineer, I am taking this opportunity time to shed some light on the subject of “radiation hazards”. Eliminating uranium mining will not reduce public risk from radioactive materials exposure. Quite the contrary: it would just shift the radiation sources and likely increase it.

First, if we really did stop uranium mining – what would be the outcome of this? Answer: The US would end up needing to burn a lot more coal. Uranium has only one major current use: fueling nuclear power plants – which have been displacing the burning of fossil fuels for generating electricity since the 1960’s.
Is burning more coal really a better choice for the environment? I suppose that depends on one’s point of view about the linkage between excess CO2 buildup in the atmosphere and global warming, and whether we should be adding more CO2 when other sources of electricity are available that do not add any CO2. The public in Colorado seems to accept burning of coal for electricity because it is already here and has been used in our state for many years. I certainly do not think we should be forcing the our coal burning power plants to shut down – but I also think we should be switching over to power sources that do not add even more CO2 to the atmosphere.

Where Does the US Electricity Currently Come From?
From 2009 data: 44.5% of US electricity is generated by burning coal. 23.3% comes from burning natural gas, and 20.2% comes from nuclear power plants that use uranium - like the fellow in Fort Collins thinks we should stop mining. Our local supplier of electricity has a mix of energy sources not unlike the national average.

When you add up the numbers: 69.1% of our current electricity production involves producing CO2 emissions.

How did we get such a mix of energy sources for electricity? This question involves balancing resource availability, costs, and what current environmental policies allow.

It is not likely that there will be construction of new major hydroelectric dams as was done in the 1930’s. Hydroelectric dams which generate no CO2 emissions currently supply 10.4% of the country’s electricity. But, no more large hydroelectric sites are available and it is highly unlikely new major dam sites could be approved – primarily due to environmental impacts. Costs and permitting tend to dictate the rest for the electricity production choices. The figure on the next page shows how total electricity production costs (sum of construction, maintenance, and fuel costs) have averaged over the last ten years and why new large scale electricity production, by choice, would be either: coal or nuclear. Electricity production from natural gas and oil has been subject to very significant price fluctuations – because the fuel costs have been so volatile. Electric production costs for coal and nuclear plants are not as sensitive to fuel costs.

Why Not Renewable Energy – With No Fuel Costs?
Any discussion of electrical energy alternatives and environmental impact inevitably leads to the question: Why aren’t our electric utilities just jumping at the opportunity to install all kinds of renewable energy sources for electricity? After all, the fuel charges would theoretically be “Zero, right? The answer is: that while sources such as wind power and solar are obviously available – the only way to deploy them in significantly large quantities to displace burning of fossil fuels would be: if they could produce electricity that exactly matches the needs of the electrical grid at a given time of day. Unfortunately they don’t.

Wind power and solar can produce electricity – but their output goes up and down daily according to the patterns of Mother Nature and they require either some means of energy storage or a mechanism to back up their output when they are unavailable. As an example of this: the power output of a wind turbine varies as: (wind-speed)3. Thus: a unit that generates 4,000 kW at 20 M.P.H. would drop in output by 87% to 500 kW, if the wind-speed decreased down to 10 M.P.H. Now imagine trying to run several hundred such units and properly balance demand with wind turbine output so that a utility company customer’s computers and homeowner’s TV sets don’t fail due to power fluctuations. One option to get around this is to use wind turbines to pump large quantities of water uphill to large mountain reservoirs[1] and then let it out using a hydroelectric dam to make electricity as needed. But the reality is: people in Colorado do not seem any more interested in creating new large artificial water reservoirs up in the mountains for power production[2] pretty much for the same reasons they don’t want more hydroelectric dams.

In places like northern Germany and Denmark[3] which have large off-shore wind farms but no nearby mountain pumped storage reservoirs: oil and gas fired power plants actually end up being used to make up the difference. They basically stand-by, continue to burn fuel at minimal power output to be able to rapidly pick up the required power production if the wind speed is either too low – or too high (which requires the wind turbine to shut down to avoid failure). Thus, what you find is that “free wind power” in Denmark actually comes with the hidden support requirement of burning fossil fuels in order to be deployed in large quantities.

The other reason wind power is not being deployed that rapidly as originally hoped, is that people have started to realize that large wind power facilities necessitate deployment of many machines over vast areas of mountain ridges and seacoasts. Objection to wind power due to “visual impacts” is now actually a common problem that electric utilities have to deal with. There is not any public health risk from this, but people who spend several million dollars for beach front cottages tend to dislike anything spoiling their view. The photograph below is an artist’s conception of how a large offshore wind turbine farm would look from the seacoast off Cape Cod Massachusetts.

Photo Courtesy of Cape Wind Energy

Backing Ourselves into a Corner?

What I am trying to demonstrate is that some form of environmental opposition has been developed for just about every conceivable type of electricity production imaginable, and the source of such opposition is not always about protecting the public health and safety, or the environment. It frequently is related to one small group trying to protect their “immediate environment”. Some call this the: “Not in My Backyard” or “NIMBY” movement. The NIMBY movement may have legitimate real estate investment and personal property value concerns, but these should not be misconstrued as related to public health and safety, or protection of the environment concerns. That would be a real “smoke screen”.

Getting back to uranium mining: If we really had a campaign that stopped uranium mining, and:
·         There are no more viable hydroelectric sites.
·         Deploying large quantities of wind or solar energy for bulk electricity generation require back-up facilities that are either expensive or have major land-use implications.
·         Oil and gas burning are currently too expensive to consider.
What we are really doing is backing ourselves into a corner leaving us few options but: to dig up, transport, and burn a lot more coal.  After all, this is an accepted, although obviously dirty, way of making electricity. I am now going to talk about the radiation exposure hazards of burning coal.

Photo of a Coal Car staging area in the CSX Railway Yard in Virginia. Think about the last time you hiked or ski toured near Moffat Tunnel which runs from the foothills through the Front Range to Winter Park and  – you probably saw a lot more coal cars passing through than Ski Trains going to Winter Park.

45,500-ton Krupp Earth-mover, mines 76,455 cubic meters coal per day in Germany. German environmental groups are quick to criticize the US for not signing on to the Kyoto Protocol, yet Germany remains one of the world’s largest users of Coal.

If we seriously considered stopping uranium mining, how much coal would we need to replace it? Doing the math based upon 1,000,000 kW of electrical capacity it comes out roughly as follows based upon numbers from the US Government’s Council on Environmental Quality (CEQ) and the World Nuclear Association (WNA):

So, there’s also ‘Radioactive Stuff’ in Coal?
Yes. Uranium, thorium, radon, and radium are all naturally occurring radioactive elements that have been present in the earth’s environment since the dawn of time. These elements are readily found in the rock (granite, gneiss, meta-sedimentary rocks, and limestone) that is all around us, and in coal deposits like we burn for making electricity. The US Geological Survey[4] notes that, on average, coal from the Illinois Basin and Colorado Plateau contains ~4 parts per million (ppm) natural uranium and thorium[5]. Concentrations of 20 ppm are rare in the US, but actually common in China[6]. Fly ash, the residue from burning coal, however, tends to concentrate the natural radioactive elements resulting in concentrations of: 8-20 ppm. Is such background radiation dangerous to us? One of my old college textbooks on radiation protection[7] answered it this way:

All life, including man, has been exposed throughout its period of existence to natural sources of ionizing radiation. At the present time it has not been established whether exposure at the relatively low dose rate of average background radiation is harmful or whether, in fact, it is beneficial to man.”

Obviously all life on earth seems to co-exist with the existing natural levels of background radiation in our environment – but obviously I don’t advocate adding a lot more.

In Colorado we are naturally exposed to the highest background levels of radiation of almost anywhere in the US – but it isn’t caused by uranium mining activities. It’s primarily the rock and soil giving off various forms of radon gas. Approximately 55% of our radiation exposure is due to radon. The figure on the next page shows the EPA’s radon hazard map of the entire state.

On top of this are cosmic radiations (which depend on geographical latitude).

Above Figure taken from: United Nations Scientific Committee on Effects of Atomic Radiations, 2000 Edition, Annex B, p.87.

Figure: Courtesy of the Environmental Protection Agency Office of Radiation Programs

Our other major sources include: the rock we frequently hike or climb on (which contains 5-10 ppm naturally occurring uranium, thorium, and radium), there is also granite in the soil, building materials such as “cinder blocks” (made from the previously mentioned coal fly ash and its 8-20 ppm uranium), naturally occurring radium found in drinking water in areas using deep wells[8], the natural radon gas emitted from rock, and even emissions from our color TV sets.

So, if you truly believe that any exposure to radiation is dangerous, I am certainly not going to argue with you. But if you believe this, what you need to do is clear:
· immediately give up rock climbing and mountaineering (proximity to natural radioactive materials in the rock),
·  forget about that Denali or Himalaya expedition (higher altitude = higher exposure to cosmic radiations),
·   forget about those granite counter tops in the kitchen,
·  get out of the mountains immediately,
· move to sea level at the equator - but don’t fly there (an airplane flight will increase your exposure to extraterrestrial radiation sources),
·   live in a grass shack,
·  get rid of all your polypropylene and fleece clothing (the natural static electricity attracts radon),
·         and: do not watch a color TV.

Some of us, however, are probably not ready to do all of this.

With all the Natural Radiation Sources, why is Uranium mining - now becoming an Issue?
There is increased uranium mining throughout the world because in addition to the 440 operating nuclear power plants, there are additional nuclear power plants being constructed in China, Finland, France, the Middle East, and now in the US. Our electricity in Colorado comes from Xcel Energy – which owns 3 nuclear power plants in Minnesota. This is occurring because there is widespread recognition that if society needs the electricity, nuclear power plants are a significantly more benign way to generate that electricity than burning fossil fuels – which also emit radiations. That would seem to be a “no-brainer”. But to use the uranium, it needs to be mined and then milled to concentrate the uranium.

The natural occurring uranium in the earth in many locations built up in geological concentrations that are higher than average in the earth’s crust. Some of those locations of natural geologic concentration just happen to be in: Colorado, Wyoming, Utah, and New Mexico. The background radiation doses in these areas, not surprisingly, is already higher than average. The natural concentrations of radioactive elements in drinking water from deep water wells in these areas would also be, higher than average, before there was any mining. The key environmental safety issue in uranium mining is whether: activities associated with mining result in dramatically increased transport of uranium (and its associated radiation exposure of the public) to levels which are above and beyond natural exposure levels - and that would not have occurred had the uranium simply been left buried in the ground.

Isolating radioactive materials deep in the ground is recognized as a good way to shield people on the surface from excess radiation hazards. Uranium mining in the 1950’s and 1960’s was not done with the current attention to environmental protection and there were major issues throughout the western states involving improper surface disposal of radioactive mine tailings piles. These mine tailings brought materials to the surface that had higher than background level radiation sources. The tailings were disposed of the same way the mining industry had historically disposed of all other mine and mill tailings from mines that we see around Colorado: they were just piled up on the surface not too far from where they were taken out of the ground, or milled. Our old abandoned gold and silver mines and mills are a good example of this.

To address these types of mining concerns, the Environmental Protection Agency (EPA) set standards in the 1970’s on doses which future mine operators must control their operations in order to be able to operate. The EPA standards do not require “Zero-radiation-doses”, not because the EPA likes the mining companies – but as noted earlier: Mother Nature did not present us with a Zero radiation dose environment to begin with. It is these standards that any proposed uranium mining activity in Colorado would be regulated against. The State of Colorado’s Division of Reclamation, Mining, and Safety indicates that as of 2009, there are ~1,700 active mines of all types in our state, including: 35 uranium mines which hold permits, and 28 uranium prospecting permits. To obtain a permit requires demonstration that appropriate state and federal guidelines are complied with - and the posting of a surety bond. The purpose of the surety bond is to assure the availability of funds to clean up a site should the mining operation go bankrupt. The state of Colorado currently holds over $400 Million in such bonds and sureties for mines within Colorado to assure mine operators meet their obligations to reclaim their sites when mining activities are ended.

What has become a recent development is the concept of “in-situ leach mining” of uranium which does not necessitate large surface mines and dealing with accumulated mine debris materials on the surface – which was clearly an issue with many of the older uranium mines throughout the west. About 20% of all world uranium mining is now done in this manner. The process works by injecting a solution containing a combination of sodium bicarbonate and lots of dissolved oxygen into wells drilled on the periphery of a known uranium deposit and taking suction from a well drilled in the center. The combination increases the ability to dissolve and leach portions of the underground uranium allowing it to flow towards the well taking suction from the deposit. The process has been evaluated by the Nuclear Regulatory Commission (NRC) and Environmental Protection Agency (EPA) and found to be acceptably safe under appropriate geology and hydrology conditions.  This means that the doses to the public would not be dramatically increased above what we are already exposed to here in Colorado.

My Personal Take on all of this?
Professional societies such as the International Council on Radiological Protection (ICRP) have established dose limit guidelines for protecting the public health and safety that are used throughout the world. These guidelines are incorporated in regulations used by health and safety regulators such as EPA, and the Colorado Division of Reclamation, Mining and Safety. If private companies desire to mine uranium they will need to comply with these guidelines. If people living in a county near a proposed uranium mine object to the activity, they should at least be honest and admit it is more due to their own desires to control “their personal environment”. What I object to is the false alarmist statements that any additional radiation doses are a health concern and by eliminating uranium mining it would reduce public exposure and thus public risk. It won’t. Amid the already very large natural background radiation present in Colorado, it will only shift the very small radiation doses from uranium mining to the very small radioactive doses from coal burning and coal ash disposal. I’m just not convinced burning that much more coal is such a good idea.

Author Profile:
John Bickel is a 1972 graduate of the University of Vermont and received an MS in Physics in 1974, an MS and subsequently PhD in Nuclear Engineering from Rensselaer Polytechnic Institute in 1980. He has 36 years of professional experience working in nuclear power plants in the US, Europe and Asia. He has been a consultant to the US State Department, the Lithuanian and Czech Nuclear Regulatory Authorities, the Korean Peninsula Energy Development Organization (KEDO), and the International Atomic Energy Agency (IAEA) in Vienna. He has been a member of the Colorado Mountain Club since moving to Evergreen Colorado in 2000, and served as Co-Director of the Ski Mountaineering School and Director of the Avalanche Safety Schools. He was elected to the Denver Group Council in 2004 and served as Chairman of the 4,500 member Denver Group in 2007-2008.

[1] There are large pumped storage hydroelectric facilities in both the French and Austrian Alps. Any Club members who have ski toured in the Alps have likely seen either the Lac de Dix in Switzerland or the Gross Glockner hydroelectric projects in Austria.
[2] A US utility tried to build a major pumped storage facility at Storm King Mountain outside of New York City more than 40 years ago but was stopped by an Environmental Group Called “Scenic Hudson”.
[3] Denmark has an installed wind generating capacity of approximately 6,000 separate wind turbines in the North Sea which generate over 2000 Megawatts or about 15% of their electrical grid requirements.
[4] “Radioactive Elements in Coal and Fly Ash”, USGS Fact Sheet 163-97.
[5]This is one of the reasons the radioactive emissions from a coal fired power plants typically exceed those of a nuclear power plant which retain the radioactive materials in the fuel. Currently, coal ash is gathered and used for making cinder blocks which can be found in virtually any residential or commercial construction effort in the US – along with its naturally occurring uranium and thorium.
[6]As one the unusual outcomes of this rise in uranium prices, it is approaching economic viability for actual recovery of uranium out of the ash generated from coal fired power plants. This has recently been demonstrated on a laboratory scale in China.
[7] K. Z. Morgan and J.E. Turner, “Principles of Radiation Protection”, Copyright 1967 John Wiley & Sons.
[8] It is worth noting that there are many areas in Illinois, Wisconsin, and the Carolinas where there is no mining yet unacceptably high radium concentrations in drinking water supplies. As an example: the radium content in Lockport, Illinois is 500 times that found in Lake Michigan water.