“Is Nuclear Energy Safe after Fukushima?”
By Dr. Michael Natelson
Ideal Taxes Association, Working Paper #4
Originally delivered as an Osher Lecture
Carnegie Mellon University Lifelong Learning Lecture Series
November 9, 2011
“In the beginning” there was Einstein’s land mark 1905 paper on Special Relativity.
He was primarily concerned with putting the laws of electricity and magnetism on
the same bases as the laws of mechanics. They should be the same in all inertial
frames of reference. (In an inertial reference frame an object at rest stays at rest,
and an object moving with at constant velocity maintains that velocity.) Einstein
succeeded making use of the assertion (resulting from the Michelson-Morley
experiments (1887)) that the speed of light c (300 million meters/second in
vacuum) is the same in all inertial reference frames. The key result in Einstein’s
paper relative to “Nuclear Energy” is E=Mc2 , the most widely known equation to the
educated public. To see how it applies to energy release it is better written as
E=Mc2 , the change in kinetic energy of participants in an inelastic collision (as
apposed to an elastic (billiard ball) collision) is equal to the change in mass of the
participants times the speed of light squared. Given the magnitude of the speed of
light, it is easy to imagine a collision that resulted in a modest loss of mass would
yield a huge increase in kinetic energy of the final constituents. When Einstein
published his papers on this result no such collision (reaction) had been identified,
but this did not inhibit people from imagining such a reaction and its possible
In early 1914, H. G. Wells published his novel The World Set Free. He wrote that in
1932 we would discover a means of controlling the rate of radioactive decay of
heavy elements, thus releasing large quantities of “atomic energy”. This abundant,
and cheep, new energy source would revolutionize the world economy. Not all for
the good, massive unemployment of manual laborers would result. Also, “atomic
bombs” could be constructed, and with economic/social unrest a cataclysmic
“atomic” world war between nation states would take place in the 1950s. As a result
of this terrible war, Wells envisioned that the surviving leaders would see that a
world governing process was an absolute necessity for mankind’s survival, and that
wars between nation state having these weapons would be an anathema.
All Wells’ predictions are not right on the money, but in the large they are
remarkable. Einstein’s “equation” did lead to an abundant (if not “cheap) new
energy source. And, this “energy source” could yield terrible weapons, which having
been used in war once, has led to some international institutions devoted to world
peace and controlling these weapons. Wars between nation states having these
weapons have been avoided. One could assume, as I believe Wells would, that this is
because of mutual recognition of the horrible consequences of their use (by design
It is a remarkable coincidence that Wells chose 1932 for the breakthrough
development of the mechanism of “atomic” energy release. For in fact James
Chadwick discovered the neutron in1932. In 1911 Chadwick’s mentor and colleague
Ernest Rutherford had determined that most of the mass of atoms was concentrated
in a compact positively charged nucleus surrounded by a cloud of much smaller
negatively charged electrons. The make up of the nucleus was not initially
understood, which is easily seen by noting that: The lightest atom (element),
hydrogen, has one electron. It’s positively charged nucleus is called a proton. The
next lightest atom, helium, has two electrons. But it’s nucleus, with twice the
positive charge of a proton, has approximately four times the mass of a proton.
Chadwick’s neutron has no charge and is slightly more massive than the proton.
With a short range, attractive force it can be part of an atomic nucleus, aiding in
holding the protons together (At distances larger than the diameter of an atomic
nucleus positively charged protons repel, but like the neutron at small distances
they also exert an attractive force.). Thus, in the above example, the helium nucleus
(referred to as an alpha particle) has two protons and two neutrons.
Now why is the discovery of the neutron the “breakthrough development”? The
Hungarian physicist and friend of Einstein, Leo Szilard first saw the answer to this
question. A neutral, uncharged, neutron should be able to readily penetrate a
nucleus in an inelastic collision, cause the nucleus to split, fission, with a loss of mass
and a release of much energy and possibly additional neutrons so as to cause more
fissions, i.e. to initiate a chain reaction. Even though fission had not been observed
in the early thirties, Szilard prepared a patent based on this idea for a nuclear
reactor and assigned it the British government in 1936. (Rutherford had speculated
about an energy liberating fission reaction, but with knowledge of only positively
charged protons and alpha particles as initiators, he thought these particles would
need so much kinetic energy to penetrate a positively charged nucleus that the net
energy release would not be of practical use.)
With the discovery of the neutron, the Italian physicist Enrico Fermi began
experiments bombarding naturally occurring heavy elements (e.g. Uranium) with
neutrons to produce new heavy (transuranic) elements. He received a Nobel prize
for this work in 1938. However, the German chemists Hahn and Strassman
determined that Fermi had produced lighter elements. Hahn’s long time associate
Lisa Meitner and her nephew Otto Frish identified Fermi’s process as fission, and
reconciled it with a physics model of a heavy element nucleus absorbing a neutron
and becoming unstable, splitting into high kinetic energy lighter elements (fission
products), additional neutrons (2 or 3) , high energy electromagnetic radiation
(gamma rays) and electrons/anti-electrons (beta particles).
News of Meitner’s work reached the USA in 1939, where Szilard, Einstein and Fermi
had all emigrated to escape Fascism. Einstein was urged to write President
Roosevelt to pursue nuclear research and stockpile Uranium, and so began the
Manhattan Project. Niels Bohr, the eminent Danish physicist, was visiting the USA at
the time, and informed his US colleagues that the most readily fissionable naturally
occurring nucleus would be the minority isotope of Uranium, U235 (92 protons, 143
neutrons, .711 weight % of total U). (Various elements have more than one atomic
weight, i. e. more than one isotope, depending on the number of neutrons in their
The Manhattan Project’s prime objective was to produce nuclear weapons as
quickly as possible, before Germany or Japan. (Both countries had outstanding
physicists.) But, as a key part of this effort nuclear reactors were developed. Fermi
and Szilard led the design and construction of the first, a low power Critical Pile (CP-
1) located under the stands of the University of Chicago’s Stag field.
With a mustering of talent and resources that no technology has ever received, the
Manhattan Project succeeded. The most terrible war was ended, but nuclear energy
was destined to be associated with “the bomb”. The first large reactors were built in
Hanford Washington to produce the transuranic element Plutonium, a key
component of more advanced “bombs”. (The bomb dropped on Hiroshima used
Uranium enriched in the isotope U235). It was not until December of 1953 with
President Eisenhower’s Atoms for Peace speech to the United Nations, that the
development of nuclear reactors for electrical energy production got its big push.
By the end of WWII work was under way on reactor concepts for powering
submarines. This effort was ultimately centered at Westinghouse’s Bettis Atomic
Power Laboratory in Pittsburgh. The design for the first nuclear submarine, USS
Nautilus (commissioned September 1954) was a pressurized water reactor, PWR.
Water at ~ 2000LB/square inch and ~600o F is pumped through the reactor “core”,
made up of fuel elements (some form of Uranium clad in corrosion resistant metal),
the through heat exchangers (steam generators) and back through the core, this is
called the primary loop(s). On what is called the secondary side of the heat
exchangers, water is turned to steam which drives turbines, the steam exhausted
from the turbines enters another heat exchanger (a condenser) where it is cooled to
liquid and pumped back to the ”steam generators”, this is called the secondary loop.
In the condenser “waste” heat is transferred to an ultimate heat sink, in the case of a
submarine, the ocean.
Gwilym Price, the post war president of Westinghouse, met with Captain Hyman
Rickover, the point man on the Navy’s nuclear submarine effort, and agreed to found
and staff the Bettis Lab. (1948). Price saw a future for commercial nuclear energy
and supported Bettis’ work (under Rickover’s direction) in conjunction with the
utility, Duquesne Light, to design and build the nation’s first commercial nuclear
power plant at Shippingport PA (1957). This plant was based on PWR technology.
During the same time period an alternate “water’’ reactor was being developed at
the Argonne National Laboratory. It is referred to as a boiling water reactor, BWR. In
this case there is a single “loop.” Water (at ~1000 lbs/ in2 , ~550 OF ) is pumped
through the core where it boils. The liquid-steam mixture leaves the core and passes
through baffles (separators) which direct the liquid back to the inlet to the care, and
allows the steam to be piped directly to a turbine. As in a PWR the steam exhausted
from the turbine is directed to a condenser and cooled to liquid. In a BWR the cooled
water is pumped back to the inlet of the core. General Electric followed up on the
Argonne work and commercialized BWR technology.
See below simple schematics for PWR and BWR electric power plants.
BWR (figure 2) _________________________________________________________________
1. Reactor pressure vessel (RPV) 10. Generator
2. Nuclear fuel element 11. Exciter
3. Control rods 12. Condenser
4. Circulation pumps 13. Coolant
5. Control rod motors 14. Pre-heater
6. Steam 15. Feedwater pump
7. Feedwater 16. Cold water pump
8. High pressure turbine (HPT) 17. Concrete enclosure
9. Low pressure turbine 18. Connection to electricity grid
By 1960 Westinghouse had established a commercial Atomic Power Division and
with their licensees, e.g. Mitsubishi (Japan), Framatone (France), proceeded to build
PWR plants in the US, Europe and Asia. Other industrial corporations, B&W,
Combustion Engineering and Siemens, have also designed and built PWR plants.
General Electric and its licensees, Hitachi and Toshiba, have built BWR plants in the
US and Asia.
It obviously took more than President Eisenhower’s urging to get these corporations
and their utility customers to embark on the risky enterprise of building and
operating new technology plants. Economic gain, profit, was the primary motive,
but contrary to what some critics have claimed, early industry leaders did not
believe that this would be easy. The first Chairman of the US Atomic Energy
Commission has often been quoted as saying that “nuclear power will be too cheap
to meter.” He was in fact referring to an expectation he had for energy from fusion,
not fission. When a young engineer at Foster-Wheeler Corp. (1954), Theodore
Stern, eventually a Westinghouse Senior VP for commercial nuclear power, wrote an
exhaustive report on how difficult the competition with fossil fuels would be for
nuclear power. So what factors provided the optimism to undertake this enterprise?
ENERGY INTENSITY Fission has produced the enormous energy release
envisioned from E=MC2. Note below the comparison (in the favorite energy units of
nuclear physicists, electron volts) between fission of U235 and “combustion” of
There is a factor fifty million, which is reflected in how little fuel is needed for a
nuclear as apposed to a comparable fossil fuel power plant. This is well illustrated
by comparing the yearly fuel requirement for the large power stations near
Mansfield on the left burns six million metric tons of coal per year in its three 835
megawatt electric (MW(e)) plants. The two Beaver Valley nuclear plants (892
MW(e) and 846 MW(e)) add ~39 metric tons Uranium Oxide (in fuel elements) per
year. The elements reside in the reactors for about four and a half years and are
then removed. They still contain Uranium, but also fission products and transuranic
elements (e.g. Plutonium isotopes). These “spent” fuel elements are initially stored
in water filled pools. After a few years as their high radioactivity and attendant
energy release decreases they can be stored in dry shielded canisters.
MINIMUM WASTE DISPOSAL While much is made today about the “problem” of
nuclear waste disposal, the fact is that almost all the spent fuel generated at the US
plants operating today is stored at the plant sites. The technology exists to reprocess
spent fuel, extracting usable materials (Uranium, fission products with medical and
industrial application and Plutonium to be recycled as power reactor fuel) and
reducing the amount of highly radioactive waste that should ultimately be placed in
a geologically isolated repository. Perspective on the magnitude of this “waste” is
provided in the following table.
From this data one can appreciate why the initiators of commercial nuclear power
did not view waste disposal as a significant inhibitor. The handling of highly
radioactive material cannot be taken lightly, but is not a difficult technical challenge.
In the US it has, however, become a political problem, i.e. Yucca Mountain. By law
the Department of Energy (DoE) is to take ownership and dispose of spent fuel from
the Nation’s commercial nuclear power plants. The utilities that own and operate
these plant contribute to a fund to pay for the DoE’s efforts. In the US, spent fuel is
not “reprocessed” (to be discussed below). The DoE had planned to transport spent
fuel elements to Nevada, put them in highly corrosion resistant containers and place
the containers in drifts (tunnels) under Yucca Mountain (a desert geologic
formation). Senator Harry Reid of Nevada has been able to stifle this plan. Reid
withheld DoE funds for completing a licensing review of the Yucca Mountain
repository by the Nuclear Regulatory Commission. At present the DoE is considering
a new study to reconsider the entire issue, but the legality of halting the licensing
review is being decided in the courts.
Reprocessing of spent fuel is being done in some countries (e.g. France), but in the
US availability of Uranium at reasonable cost is expected to meet the requirements
of existing plants (104), and those to be built in the next ten years (~6), for decades.
An acceleration of plant construction in the US and in the rest of the world will make
reprocessing economically attractive. But as was evident to the pioneers of nuclear
power, fuel resources should not be limiting to the growth of nuclear power.
RESOURCE ABUNDANCE. Uranium is common in the earth’s crust, see the table
below. As noted previously it has a readily fissionable isotope, U235, referred to as
fissile) and a majority fertile isotope U238 . Fertile, in that if it absorbs a neutron it
has a high probability of transmuting into a fissile isotope. In the case of U238 the
result is the fissile isotope of Plutonium, Pu239. The major isotope of Thorium,
Th232, is also fertile. Here neutron absorption can yield the fissile Uranium isotope
U233. The energy potential of fertile isotopes can be exploited in power reactors. In
today’s PWRs and BWRs ~ a third of the energy produced is from fission of Pu239.
Use of Thorium, which is more plentiful than Uranium, will most likely await the
economic viability of reprocessing.
Table 2 ppm is parts per million. ppb is parts per billion.
The bottom line is that Uranium, and ultimately Thorium, fueling reactors could
supply the bulk of humanity’s electrical energy needs for several thousand years. A
further motivation for pioneers of nuclear power is the fact that Uranium and
Thorium have negligible substitution-value. They have no other significant
economic application. This is not true for other sources of electrical energy.
Obviously, coal, oil and natural gas are excellent chemical feed stocks. It is already
clear that it makes no sense to burn oil to generate electricity. It is much more
valuable as an energy source for transportation.
Burning gas in combined cycle turbine generators with thermal efficiencies of~60%
is attractive at today’s gas prices, but with modern home heating furnaces at better
than 90% efficient this use might be a better choice if we are to burn this finite
resource. One can also think about “substitution-value” as applied to the resources
needed for electrical energy generation from “renewable” sources. The land needed
per Watt for solar, biomass and wind farms could have other uses.
Having reviewed the origins of nuclear power and the motivations for its wide
spread application, 104 plants in the US (20% of electricity generation), 433 plant
total (~13% of electricity generation), we address the “questions” raised by the
tragic events of March 11, 2011 in Japan.
First, how should we view the safety of nuclear energy relative to:
The health and welfare of the public?
Data says that it is “safe” when compared to other major sources of electric power.
Table 4 OECD is the Org. for Economic Cooperation and Development(34 European and
North American Countries, plus Japan),does not include Russia, China and India.
Twy is a measure of electrical energy produced, Tara(1012)Watt year. Watt is a unit of
power(energy per unit time, e.g. Joule/second)
The above table is through 2000, but the Nuclear line would not change if it were
brought up to date. The events at the four damaged Fukushima Daiichi plants have
not resulted in “fatalities” due to radiation exposure. (Two workers at these plants
have died from unrelated health problems.) Long term health effects on plant
workers and evacuated civilians are expected to be limited, difficult to measure (i.e.
a small increase in expected cancer rates). Particularly when compared to the
25,000 fatalities directly attributable to the 3/11/2011 earthquake and tsunami.
The “safety” record of commercial nuclear power is clearly outstanding. Besides the
“data,” this assertion is supported by a review of the major incidents, accidents,
which have occurred since the industry reached large-scale implementation in the
At Three Mile Island near Harrisburg Pennsylvania there are two large PWR plants.
One suffered a small leak of coolant from its primary loop. Operators had difficulty
finding the leak, and while the reactor “shut down” (the chain reaction and thus
fission energy generation ceased), they did not properly continue to cool the
collection of fuel elements, which made up the core of the reactor. As noted
previously radioactive decay of fission products and transuranics in spent fuel
continue to generate heat after fission ceases. Immediately after a reactor that has
been operating continuously at full power shuts down, it still generates ~7% of its
rated power. This decay heat falls off rapidly initially, to ~4% after a minute, then
~.4% in a day, and then slowly, to ~.04% after a year. The Three Mile Island plant
was equipped to deal with “decay heat”, but the operators initially failed to carry out
proper actions and the core was greatly damaged. However, the reinforced concrete
containment structure that enclosed the primary plant (see PWR diagram above)
performed as expected and there was negligible release of radioactivity to the
atmosphere. There were no fatalities or injuries, but poor communications led to
much consternation of local residents and the public in general. At significant cost to
the nuclear utility insurance program and the government, this plant was
decommissioned. (The damaged fuel was removed and shipped to the DOE’s Idaho
National Laboratory for study and storage.)
The nuclear power industry learned a great deal from Three Mile Island (TMI), and
many actions, which have proved to be positive, have been taken.
Most of the points above are self-explanatory. Two require further discussion:
As part of the licensing process for a nuclear power plant, analyses to demonstrate
safety (of the plant itself and to the public) under a range of abnormal operating
conditions and accidents must be preformed. Before TMI major emphases in safety
analysis was placed on catastrophic events e.g. shearing of a large primary loop
pipe. After TMI the wider range of possible events received systematic attention. A
new discipline of risk informed safety analysis has been developed.
Through wide US Utility support the Electric Power Research Institute (EPRI) was
founded in 1973 to perform research and development for electricity generation (all
kinds), distribution and use. After TMI, based on the success of the EPRI model, the
Institute of Nuclear Power Operations (INPO) was founded (12/79) with the
support US Nuclear Utilities. They independently inspect plants, certify training and
promote information exchange to improve safety and operational effectiveness.
EPRI and INPO have cooperative arrangements with nuclear power industry world
wide. An indicator of the effectiveness of INPO is the improvement in the yearly
average capacity factor of US nuclear power plants, about 60% in the late 70s to
better than 90% in the last decade. (Capacity factor is the ratio of actual energy
production over the theoretical maximum.; 100% can not be achieved for PWRs and
BWRs as they must be periodically refueled, every 18 months for most plants.)
The explosion and fire in the #4 High Power Channel Reactor (RBMK) at Chernobyl
in the Soviet Union (the Ukraine) resulted in the fatalities (34 rescue and
remediation workers) listed in Table 4 above. This reactor was of a design unique to
the Soviet Union. The accident was initiated through human error. An “experiment”
was conducted without proper planning or operator understanding of the reactor
characteristics. But when the reactor did not behave as expected, design flaws led to
Unlike western PWR and BWR, the RBMK had a positive power feedback
mechanism. If the coolant (water) for the fuel elements lost density (e.g. boiled) the
chain reaction in the core could accelerate, power could increase. In the Chernobyl
experiment this “feedback” caused a runaway power excursion. And, as the RBMK
did not have a containment structure, a massive release of radioactive gases and
debris could not be prevented.
Thus the wisdom of requiring containment for western PWR and BWR power plant
designs was confirmed. Soviet PWR designs at that time did not have containment.
After the accident, modifications were made to the RBMK design, but it was not
adopted outside the Soviet Union. Today, eleven modified plants still operate in
The response of workers in dealing with the severely damaged reactor was heroic,
but protection of the public was poor. The world was made aware of the accident
through the detection of fission products in Sweden. A thirty mile radius evacuation
zone was eventually established, and people have been monitored for subsequent
The 34 deaths from high radiation dose happened quickly. An increase in childhood
thyroid cancer (~5000 cases) has been detected. This was caused by ingestion of the
fission product isotope of Iodine (I131). Fortunately, thyroid cancer is curable and
few fatalities are attributable to this increase (some sources indicate 2 fatalities).
The half-life of I131 is eight days so the increase was seen for only a few years after
A 2006 World Health Organization report on Chernobyl indicates that no elevated
cancer rates have been observed in the 240,000 remediation workers that received
above-background level radiation dose while working at the site. The long-term
study of health effect from Chernobyl will provide a better understanding of the
risks of radiation exposure.
Today the conservative approach is to assume a linearly increasing risk starting
from zero at zero exposure. Many scientists, however, believe that there is radiation
hormesis effect. Hormesis implies that below some dose level there is a positive
effect on health. This has been supported for some substances (e.g. certain heavy
A recent PBS Nature program Radioactive Wolves (10/20/2011) reports on the
study of flora and fauna in the Chernobyl exclusion zone. Everything, particularly
the wolves, seems to be thriving. These are important results for work on the
radiation hormesis hypothesis. If the hypothesis becomes theory, recovery from
radioactivity contamination incidents would be more technically sound and
All nuclear power plants are designed to withstand severe environmental events,
e.g. earthquakes, hurricanes/typhoons, tsunamis, plane crashes. For a particular
location, “design events” are selected. For example, the historically largest earth
quake in the area, plus an added margin.
The “design event “ approach to safety posture has been successful up to the March
2011 tsunami strike on the Fukushima Daiichi plants. Four of six BWR plants at the
site were damaged. Various plants through out the world have survived
earthquakes including the massive quake which caused the March 2011 tsunami.
The twin PWR plants at Turkey Point in Florida successfully withstood the force of
Hurricane Andrew (Category 5) in 1992. The full explanation of what happened on
the east coast of Japan is still being determined. From the figure below one can see
that there are plants at four east coast locations near the quake epicenter.
Sea walls were built to protect these sites from “design event” tsunami waves. The
figure below compares the sea wall designs with what actually took place at Daiichi
and Fukushima Daini, just south of Daiichi.
The underestimation of the wave height may have been due to not accounting for a
sinking of the coastline caused by the initiating earthquake. The “sinking” has been
reported to be as much as four feet.
In any case this extraordinary tsunami disabled the emergency diesel-electric
system at the Daiichi site. Per design, all the reactors at power which felt the
earthquake automatically “shut down” (the chain reaction was terminated), and the
process of removing “decay heat” from the reactor cores was initiated.
If no electric power is available from the grid (other unaffected power plants) then
emergency diesels are started to provide power to pumps that circulate coolant to
remove the decay heat. Daiichi three plants were at power when the earthquake
struck. The other three were in a shutdown condition for refueling and
maintenance. The diesel generators supporting plants 1 through 4 started up, but
were put out of commission when the Tsunami hit 35 minutes after the quake.
There is a back-up system with small steam driven turbines that drive coolant
circulation pumps. This works for a while, but it depends on battery controlled
valves. The batteries are drained after about eight hours. The final option was to use
the pumping capability of fire engines at the site to inject water (ultimately sea
water). But by the time these were hooked up the pressure of their pumps was not
great enough to overcome the pressure that developed in the reactors, the pressure
vessels that contain the cores of these three BWRs (see the BWR schematic above),
as decay heat raised the reactor’s coolant temperature and pressure. This pressure
had to be relieved. Valves were opened allowing coolant into the containment
volume. (In these old GE BWR designs containment is a steel structure surrounding
the reactor pressure vessel; see the figure below.)
figure 4 Note the cavities in the Reactor Service Floor on two sides of the Pressure Vessel.
These are spent fuel storage pools.
The problem with this process is that it allowed the cores to be partially uncovered
of liquid. Temperatures of the upper portions of the fuel elements then rose to the
point where the cladding (sealed tubes, containing UO2 pellets, made of a corrosion
resistant alloy of Zirconium) failed releasing fission products (some of which are
gasses). In addition, at these elevated temperatures the cladding undergoes an
exothermic reaction with water, which yields Hydrogen.
Eventually the containment structures became over pressurized and had to be
vented to prevent catastrophic failure. The valve system for this venting did not
work properly (it may have been damaged by the earthquake). Gases should have
been directed to stacks out side the reactor buildings. The gases, however,
accumulated in the upper floor of the unit 1, 2 and 3 buildings, and eventually
Hydrogen explosions blew off the roofs of these buildings.
The explosions did not damage the containment structures, but did allow spent fuel
storage pools to be exposed to the atmosphere and disrupted the monitoring and
cooling of these pools. The failure of fuel elements in the cores and venting of
containment structures meant that fission products were being released to the
environment. The public had to be evacuated from locations within twelve miles of
the Daiichi plants. The exposed spent fuel pools were an additional concern that had
to be addressed by the plant operators and emergency staff. Most airborne fission
product blew out to sea and workers could safely proceed with putting the plants in
a cooled down stable condition (which nine months later has been achieved).
As with TMI, the commercial nuclear power industry will learn a great deal from
this admittedly unusual event that befell Japan’s east coast.
In terms of strictly dollars and cents the recovery at Fukushima Daiichi, scraping
units 1, 2 and 3, improving protection and making repairs for units 4, 5 and 6, and
decontaminating the site and evacuation area, will be large, but not in comparison to
Japan’s total recovery cost. The latest estimate is $309 billion.
As at TMI the utility, Tokyo Electric Power Company, is insured (by the Japanese
government for natural disasters, by private insurance companies for utility error).
More important, however, for the future of the commercial nuclear power industry
is the psychological impact of Daiichi. This is already evident in the decisions by
Governments (e.g. Germany and Switzerland) to phase out nuclear power even
though they express concern about global warming (CO2 emission) and are in no
danger of tsunamis. This psychological impact will continue for many years
(decades) as the “recovery” progresses.
Note that things nuclear always get press. Any Daiichi news is on TV and in the front
sections of newspapers. Outside of Japan, the 25,000 deaths and massive coastal
recovery effort have already faded from view. Given the history of nuclear energy,
the bomb, the cold war’s mutually assured destruction and the three nuclear power
accidents/events described here, it is not surprising that the risk associated with
commercial nuclear electric power will be viewed differently (greater in spite of
data) than that of other technologies, e.g. automobile and air transportation. This
assertion naturally leads to the second question to be addressed in this talk: given
Fukushima Daiichi, how “safe” is nuclear power as an
Investment by Utilities, Banks and Governments.
First, taking a parochial view, that of US nuclear utilities, their financial out-look is
good. Their 104 plants (69 PWRs, 35 BWRs) are operating at high capacity ( ~90%)
and at low cost.
Nuclear power plants have high initial capital cost (also called over night cost). But
as today’s US plants came online mostly in the late 1970s through mid 80s these
costs have been depreciated. There have been, and continue to be, additional capital
investments to upgrade these plants: improve safety posture, raise power output
and extend lifetime. US plants are initially licensed for 40 years of operation.
Seventy-one US plants have had their licenses extended for an additional 20 years.
Almost all the rest are applying (to the NRC) for such extensions. These “additional
capital investments” are included in the power production costs shown in the above
Looking ahead US utilities are planning to add nuclear power capacity. Site
preparation and early construction is underway for four Westinghouse AP1000
PWRs, two in Georgia and two in South Carolina. The Tennessee Valley Authority
(TVA) is completing two plants on which construction was halted decades ago. Plans
for 16 additional plants have been announced. How these “plans” progress will
depend on economic and environmental factors.
The principal economic factors are; the cost of money, demand for electric power,
speed and cost of new plant construction, and the cost of alternate power sources,
particularly natural gas.
Today interest rates are low and government loan guarantees may be possible, but
the perceived “risk” of nuclear power can put a premium on a construction loan. The
following two tables show the variation in projected nuclear power cost, depending
on interest rate (and other) assumptions. (They also provide cost comparisons with
other power sources.)
See: nuclearfissionary.com by Jason Morgan for an explanation of various
This table is from the 2009 Update of the 2003 MIT Future of Nuclear
The radical change in the growth of demand for electric power that followed the
1973 Yom Kippur War (and the OPEC oil embargo) brought an end to the ordering
of new nuclear and coal power plants in the US for decades. Many nuclear plants, for
which heavy equipment had been ordered and site preparation started, were
eventually completed, see figure 6 below. US electric power consumption (demand)
was growing 7% per year in 1973. This rate dropped to ~3% in a few years, and is
down ~1% today.
figure 6 US capacity addition
Even with the slowed increase in electric power demand in the USA there is
opportunity for new nuclear construction, particularly as continued operation of
many aging coal plants may not be economically justified given more stringent
environmental regulations. An open question, however, is the time span and
construction cost of new plants. New plant designs (e.g. the Westinghouse AP1000)
are to increase safety and simplify construction and maintenance. But, as it has been
many years since new construction was undertaken in the US. One will have to
await the completion of a few plants to get a definitive answer to the time span and
total initial cost question. Some insight will be gained from construction presently
under way in other countries, particularly the four AP1000s in China.
The final “economic factor” determining the future role of nuclear power is
competition with other sources. While solar and wind are receiving large subsidies
in many countries based on environmental concerns (to be discussed below), they
are unlikely to compete on economics. Their capacity factors are low. Thus, energy
storage and/or supplemental sources must be provided. Wind technology (blades
and generators) is highly developed. Except for economy of scale, cost improvement
should not be expected. Solar to electrical energy conversion efficiency, less than
20% at present, is a challenging problem that has received much attention in the last
thirty years. Given that cost as well as efficiency must be improved it is unlikely that
solar will compete successfully with nuclear.
Coal and nuclear power are both mature technologies and in most cases are
comparable economically. A mine-mouth coal plant obviously has an advantage. If
quality coal (high energy content, low sulfur) is not readily available or if coal
transport costs are high the economic advantages fall to nuclear. Future utility
decisions here and abroad will likely be based on environmental considerations.
Natural gas, burned in modular, high efficiency, combined cycle (jet engine – steam
boiler) electric power plants, has often, in recent years, been the solution to
incremental increases in electricity demand for utilities in the US (see figure 6) and
abroad. The key economic factor in utility decision making is the price of natural
gas. There has been considerable volatility in this price (see figure 7).
In the US today the price has fallen to about $3 per million British thermal
units(Btu) with burgeoning of drilling (with fracking technology) in the Marcellus
shale field of the northeast. Today supply is exceeding demand and drilling activity
is being delayed. However, new chemical plants and pipelines are planned. One
should note that home heating is done with oil in much of New England. Ultimately
gas from Marcellus shale will be a much cheaper alternative. Environmental
regulation of fracking is not a settled issue. It will be a few years before the price of
natural gas reaches something of a steady state condition and its role in electrical
energy production, based on economic considerations, is clarified.
There are three primary “environmental factors” which will influence the future use
of nuclear energy:
First is nuclear waste disposal. As discussed previously the amount is small, the
technology for dealing with it is known, but, particularly in the US, it is a political
problem, which ultimately must be dealt with.
Second is the direct health effect of burning coal. Coal is cheap and abundant and
much has been done to clean the exhaust of its power plant stacks. But, there are
practical limits to what can be achieved. As noted previously, new US regulations on
mercury and other heavy metal emissions, if left in place, may cause many existing
plants to be shut down and will increase the cost of new plants. An even more
difficult problem is fine particulate emissions, particles of ash less than .1 micron
(one-millionth of a meter) in diameter. These are presently not regulated in the US
but are known to have serious health consequences (e.g. asthma).
Finally, there is the question of what if anything is to be done concerning greenhouse
gases, e.g. carbon dioxide, water vapor (clouds) and methane. Modeling the earth’s
climate with predictive computer simulations is a daunting task. (There are no
fundamental solutions to fluid mechanics problems with turbulence, let alone
including multiple fluid phases, e.g. liquid, gas, droplet dispersions.)
Measurements of conditions on land-masses, in the oceans and the atmosphere are
improving, and will aid in qualifying climate models. But, while many atmospheric
scientists believe man’s production of carbon dioxide is a prime driver to global
warming, and that global warming will have grave consequences in the next ~50-
100 years, there are doubters in the scientific community. And, politicians, most of
whom can not understand the science, are of necessity responsible for what actions
are to be taken. If carbon dioxide emissions are to be restrained, clearly nuclear
energy can play a major role.
The damaging of the four plants at the Fukushima Daiichi site has raised questions
about the future viability of nuclear energy as a source of electrical power. I believe
that as recovery proceeds and lessons are learned, the sound safety posture of
nuclear power relative to public health will be verified. Resolution of economic
issues will await performance in building the new generation nuclear plants, the
price of other energy sources (e.g. natural gas) and carbon dioxide emission
The motivation for implementing nuclear power will continue to be based on the
vision of its initiators; Uranium and Thorium represent an effectively inexhaustible
source of energy with minimal environmental impact, and having no substitution
value, their use preserves fossil resources as the chemical feedstock for future