Health Effects or Generating Electricity With Coal and Uranium
By C.J Barton, Sr.
Question: Would you rather live close to a coal-burning power plant or a nuclear power plant? Why? If you said you prefer to live near a coal-burning plant because nuclear power is more dangerous, you would be in agreement with the majority or the American public. A 1980 survey showed that 80% believe that it is more dangerous to generate electricity with a nuclear reactor than by burning coal. I hope to give you a different view or this very important subject, which will be debated in the establishment or our future energy policy.
The comparison that I will present will be in terms or health effects and we will need to think about risk. This is defined as the chance or injury. damage or loss. One way or expressing risk is loss-or-life expectancy (LLE). This is the average amount by which one's life is shortened by the particular risk under consideration. For example, for smoking one pack or cigaffetes per day the LLE is 6.4 years for men and 2.3 years for women. The risk or lung cancer is 17 times greater for smoking two packs per day than for smoking one. Other examples are an LLE or 2.5 years for being 30 pounds overweight and the LLE for all accidents is 435 days. Table I compares a number or common risks with that or living near ~ nuclear power plant.
Loss of Life Expectancy for Various Risks
|Type or Risk||Loss-or-life expectancy|
|Cigarette smoking (1 pack/day)||1600 days|
|Type Working in mines||1100 days|
|Type Cancer||980 days|
|Type All accidents||435 days|
|Type Motor vehicle accidents||200 days|
|Type Drowning||40 days|
|Type Hurricanes, tornadoes||1 day|
|Type Living lifetime near a nuclear power plant||0.4 days [theoretical]|
Now we will start to think about risk from exposure to radiation. Most people do not realize that we are all exposed to radiation every day or our lives. The average U.S. citizen receives 100 millirems per year from natural sources (30 from cosmic rays, 20 from the ground. 20 from walls and 25 internal). Anything less than 10,000 millirem (10 rem) is commonly considered to be low-level radiation.
We tend to think or the potential health effects or electricity generation solely in terms or the exposure to products released from the electricity generating plants. However, the comparison that I am making considers the complete fuel cycle as shown on the screen.
Fuel Cycle-Electricity Generation From Coal
Mining ---------> Transportation --------> Electrical Generation ------>-Disposal of Ash
Fuel Cycle-Nuclear Power Generation
Mining ---------> Conversi on to Fuel ------>Electricity Generation ------->Waste Disposal
You will notice that there are some differences between the two fuel cycles and we need to consider the health effects of each stage in the fuel cycle, as shown in the next table.
Premature Deaths Per Year Associated With the Operation or a 1000-MWe Power Plant (Comar and Sagan-Lowest & Highest Estimates)
[Workers] Coal Oil Gas Nuclear
Mining accident .45 to .99 .06 to .21 .021 to .21 .05 to .2
Mining disease 0 to 3.5 none none .002 to .1
accident .055 to 0.4 .03 to .1 .02 to .024 none
accident .02 to .04 .04 to 1 .006 to 1 .003 to .2
disease none none none .013 to .33
Accident .01-.03 .01 to .037 .01 to .037 .01
Disease none none none .024
Accident .54-1.5 .14 to 1.5 .057 to .28 .065 to .41
Disease 0-3.5 none none .035 to .45
Coal Oil Gas Nuclear
Transportation .55 to 1.3 none none none
Processing 1 to 10 none none none
Generation .067 to 100 none none .11 to 0.16
Here I have separated occupational health effects from those in the general public. You will note that a large fraction or the health effects in the coal cycle come from mining and transportation and in the uranium fuel cycle from mining. In the U.S. about 60 miners lose their lives each year from accidents and others die from exposure to coal dust in the mines (black lung). In mining uranium, the principal risk is from exposure to radon gas in the underground mines. Since about 100 carloads or coal are burned each day in a large coal-burning plant and about 50% or our electricity is generated in such plants, a number or people are killed each yaar by collisions at crossings.
In the uranium fuel cycle, the quantity of fuel burned is so small that we can neglect the transportation steps, but this is replaced by the conversion of ray uranium into fuel (U02 clad with Zirconium, a zirconium allow). The uranium is enriched to contain about 3% U-235. The last step in the fuel cycle, disposal of ash for the coal cycle, about 30 carloads per day, and storage or burial of used fuel in the uranium cycle, about one carload per year, have received less attention in risk evaluation studies than other parts of the fuel cycles but the health effects of these operations are considered to be low.
In comparing the health effects of effluents from coal-burning and nuclear power plants, we find a surprising fact, the effects of exposure to low levels of radiation are better known than the effects of products from burning coal. The bad effects of burning coal have been recognized for centuries. In fact, during the 13th century the King of England banned the burning of coal in London. Fortunately for the forests of England, the ban did not last long but in 1952 a period or bad weather conditions in London resulted in about 4000 excess deaths, primarily from coal combustion products. The reason the effects of low-level exposure to radiation are so yell known is that from the early forties to about 1975, approximately $ 2 billion had been spent on such studies, far more than has been spent on the effects of exposure to coal combustion products. Consequently, the uncertainty in estimating the health effects of effluents from coal burning plants is much greater than for nuclear power plants but the best estimates show an LLE of 13 days for coal plants as compared to 0.025 days for nuclear plants.
In conclusion, I will make a few remarks about the safety of nuclear power plants. The most common type of plant in the U.S. is the pressurized water reactor (PWR). The next figure shows a diagram of such a plant and the final figure shows the barriers against radioactive release from such reactors. At the end of 1990, there were 111 nuclear power plants in the U. S. generating about 20% of our electricity. In spite of all that you may have heard about the accident at Three Mile Island, the worst to date in this country, there has never been a death from radiation exposure in a U. S. nuclear power plant and no one in the vicinity of Three Mile Island received a radiation dose higher than that received [annually] by the average U. S. citizen (100 mrem) from natural sources. The accident at Chernobyl [involved] a much different type of reactor which would not meet U.S. safety standards. Improvements in the safety of nuclear power plants and in the training of plant operators have occurred in recent years. However, the U.S. public seems to be demanding an even greater degree of safety before allowing additional nuclear power plants to be built and it is possible that future plants may be quite different from
those presently operating.
LIST OF HEALTH EFFECTS COMPARISONS
1. C.L. Comar and L.A. Sagan, Annual Review or Energy, Vol 1. 581 (1976).
2. L.B. Lave and L.C. Freeburg, Nuclear Safety Vol 14 (5) 408 (1973) .
3. Nuclear Power-Issues and Choices (Ballinger, 1977).
4. R.L. Gotchy- NUREG-0332 (1877).
5. D.J. Rose, P.W. Walsh and L.L. Leskovjan, American Scientist (Vol. 64, 281 1976 ).
6. H. Fischer et al. , BNL-51481 (Sept., 1981)