When Congress passed the 1946 Atomic Energy Act, which estab­lished aec, it gave that organization the responsibility for assuring the safety of atomic energy workers as well as the public at large. The unusual step of vesting this responsibility in a federal agency rather than in the states, was taken for a variety of reasons, among which were the fact that much of the required technical knowledge was then classified; the special­ists who had this knowledge were, for the most part, located in a few large laboratories owned by the federal government; and Congress recognized the basically interstate nature of the risks of this new industry.

Before I begin a more detailed critique of the standards, it seems ap­propriate to summarize the record of the aec to date. There have been no known radiation injuries to any member of the public from any of the ci­vilian activities of aec. Among the approximately 100,000 employees of the aec and its contractors, there have been six fatal accidents owing to nuclear accidents, all of which occurred in the course of experimental re­search. There has been one additional death in a privately operated indus­trial company licensed by the aec. Among this large population of indus­trial workers, I have been unable to find a single record of injury from the cumulative effects of exposure.

During the same period, a total of 276 on-the-job accidental deaths have occurred from all causes — vehicle accidents, falls, and so forth. Thus, the safety record of the aec is very good; its occupational fatality rate is about 25 per cent of the average for all industry, as published by the National Safety Council (aec, 1943-1967). This excellent record of occupational safety is cited simply to illustrate that the aec has demon­strated a high degree of concern with protection of its personnel. It has demonstrated similar concern with public safety.

Because of a technicality in the Atomic Energy Act, responsibility for the health of uranium miners was not preempted by aec, but has con­tinued to reside with the states. The radiation safety record in the mines has been far less satisfactory, and more than 100 deaths from lung cancer have resulted from the cumulative exposure to the radioactivity of the mine atmospheres (Donaldson, 1969). It is regrettable that federal pre­emption of health and safety matters in the atomic energy program did not include the mining industry, because this tragic record might have been avoided had the aec standards of permissible occupational exposure been enforced.

Another governmental agency concerned with radiation protection is the Federal Radiation Council, which consists of representatives of sev­eral federal departments and agencies. It was established by presidential order in 1959 to assure a consistent governmental approach to radiation protection matters. The Council has promulgated a number of radiation protection guides to assist in evaluation of hazards from nuclear weapons testing and, more recently, for control of radiation exposure in uranium mines.

When confronted with such data, one can hardly avoid wondering how long such growth and production rates can be sustained. A powerful method of analysis is that illustrated in Figure 8 (Hubbert, 1956, Fig. 11). For any exhaustible resource, such as coal or petroleum, the curve of the annual rate of production must begin initially at zero. The production rate tends to increase exponentially for a limited period. Next, as the re­source becomes progressively depleted, the production curve must reach one or more maxima and finally decline gradually to zero as the resource becomes exhausted. A mathematical property of this graph is that when the production rate, dQ/dt, is plotted against time on an arithmetic scale, the area under the curve is proportional to the cumulative production. Hence, this area must always be equal to or less than the quantity of the resource initially present. Therefore, if by geological and other means the amount of coal or oil initially present in a given area can be estimated, the production curve analogous to those shown heretofore can be approxi­mated for the future, subject to the stringent condition that the area under the curve must not exceed the estimate of the initial magnitude of the re­source.

What is required, therefore, is an independent estimate of the amount of the resource initially present. For coal, both for the United States and for the major geographical areas of the world, such estimates have recent­ly been published by Paul Averitt (1969) of the United States Geological Survey. With an allowance of a 50 per cent loss of coal in place during mining, these estimates are shown graphically in Figure 9.

Of the world’s initial supply of 7.6 X 1012 metric tons of producible coal, about 65 per cent occurs in Asia (including European Russia), about 27 per cent in North America, about 5 per cent in Europe, and the remaining 2 per cent on the three entire continents of Africa, South America, and Australia. Of the North American initial supply of 2.0 X 1012 metric tons, 1.5 X 1012, or three-quarters, occurred in the United States.

Using these data in conjunction with the previous production histo­ries, and the technique shown in Figure 8, estimates can be made of the fu­ture possible coal production for both the world and the United States. In each instance, two curves are drawn, the first based on Averitt’s total esti­mate, and a second of about half that amount. The lower figures result from eliminating the deeper and thinner coal seams included in Averitt’s estimates.

Western

Europe

South and Central ЩЁ *14*X lO^rnetric tons

^ Ш

For the world production estimate (Fig. 10), the curve based on the higher figure is shown reaching its peak at about the year 2140; the peak of the curve based on the lower figure is shown at a few years earlier — at about 21

Academy of Sciences.) versa. Also shown in Figure 10 is a curve of what the world production rate would be if the growth rate of 3.61 per cent per year which has pre­vailed since the end of World War II should continue for another half cen­tury. In the view of the limitations imposed by the area under the curve, such a continuation is manifestly impossible.

Corresponding curves for the future coal production of the United States (Fig. 11) show the curve based on the higher figure of about 1.5 x 1012 metric tons of initial producible coal peaking at about the year 2220; the lower curve peaks at about 2170. Here again, higher rates of produc­tion than those shown would cause the curves to reach their peaks earlier, whereas lower production rates would delay the peak dates somewhat. However, a conclusion that is consistent with all of the curves shown in Figures 10 and 11, or any likely variation of these curves, is that the maxi­mum length of time that the coal reserves will be sufficient to supply a ma­jor part of the world’s, or of the United States’, energy needs can hardly exceed about three centuries.

Attention can now be turned more directly toward consideration of safety. It has been pointed out that a considerable portion of the inherent safety of a reactor is associated with the fact that only well-known tech­nologies are involved in its design. However, there are other important as­pects to reactor safety, which are as follows:

Attitudes toward Safety. In the nuclear industry today there is a healthy attitude toward safety. This attitude is shared by the designers who build these reactors with safety a prime consideration and always well within existing regulations, by the governmental regulatory agencies es­tablishing design and operation criteria and conducting reviews of the safety designs, and by the utilities operating these plants.

Reactor Design Inherent Safety. The reactor design of today was se­lected in many aspects by taking advantage of those laws of nature which provide inherent safety features. For instance, proper reactor material se­lection is an important consideration. This serves the objective of limiting the possibility of a reactor accident.

Reactor Applied Safety. In addition to such natural advantages, the reactor designer includes applied safety features such as proper instru­mentation to limit the probability of a reactor accident.

Engineered Safeguards. The designer, as a further step, then assumes failure of such applied safety features and provides additional equipment systems to provide backup or emergency cooling and control even under accident conditions.

Containment, Another Engineered Safeguard. In spite of the inher­ent and additionally applied safety features making any failure extremely remote, a reactor designer nevertheless assumes that there still may be various serious failures of the reactor process system. Thus, nuclear power reactors are provided with containment barriers. Such barriers in addition to the engineered safeguards have the objective of limiting consequences of an accident in the extremely unlikely event that one ever occurs.

Design Features for Normal Operation. Although considerable effort is applied to preventing accidental release of fission products from a power reactor, a similar emphasis is applied to considerations of the release of radioactive material during normal operation. Every effort has been made to keep this release insignificant relative to natural background.

Each of the above important aspects of nuclear reactor safety will be described in detail so that it can be seen that nuclear power plants repre­sent a new high in public safety.

In the consideration of nonoccupational population exposures, it is my view that the genetic risks will control standards except under certain circumstances. The fact that radiation could cause mutations in biological material was established over forty years ago. In a sense, radiation is as close to a universal mutagen as any potential environmental “pollutant.” The effects must be regarded as nonthreshold, although not independent of dose rate as the early work indicated.

Human genetics has grown remarkably in value and in concept in the recent past. The contribution of heredity to human vitality and its counter­part, morbidity, is enormous. The background data are thus detailed and complex. Indeed, the quantitative figures are much too complex for this discussion. On the other hand, the kind of directly related data on man we have for somatic effects of radiation is largely absent. The generations for man are too long and the “experiments,” if they could be done at all, are too costly and too time-consuming for us to have any considerable fund of information on the effects of radiation on genetic processes in man himself. Therefore, we must use data from animals (largely the fruit fly and the mouse) and calculations based on extrapolation from these to man.

Not being a geneticist, I shall not attempt more than a broad outline, using icrp Publication 8 (1966) as the principal summary of useful data. Also, I shall consider the genetic effects of radiation primarily as measured by the so-called genetic death criterion. This is justified because it includes all of the specific changes and is thus the phenomenon of highest fre­quency.

A “genetic death” is defined as the extinction of a gene lineage through the premature death or reduced fertility of an individual carrying that lineage. This is an entirely different concept from those we were deal­ing with in considering somatic changes. Here the decrement is in terms of the lineage. The expression (i. e., the “death”) may range from failure of a fertilized egg to develop beyond the first few divisions to grossly in­capacitating maladies. The first may not even be noticed. The latter is a serious burden on the individual and/or on society. Each is defined as a “genetic death.” The term death in this context pertaining to effects of radiation (or any other mutagen) does not refer to adults or children already born who die as a result of the exposure. The concept of genetic death is much broader. It may take generations to lose some lineages through this process, while the grossly detrimental mutations never go beyond the first generation.

Geneticists have had to make some very arbitrary assumptions con­cerning the effects of mutations in man. In the context of this discussion the primary factor is the assumption that virtually all mutations in man are unconditionally harmful. This is not true unless any change no matter how slight is defined as harmful. Nevertheless, it is the assumption back of most estimates of the effects of radiation on genetic processes. The normal mutation rate in man is such that “genetic deaths” are estimated to occur normally at the rate of about 200,000 per year per million potential off­spring.

Using the assumption of linearity to dose and skipping volumes of intermediary reasoning, data, and assumptions, it can be estimated that about 200 additional genetic deaths would occur in the first generation of offspring from a million parents receiving 1 rad of ionizing radiation. This is about a 0.1 per cent increase over normal incidence; again a purely statistical matter. Frequencies of more specific genetic traits are all con­siderably lower. These appear at the top of the accompanying tabulation, showing the anticipated genetic effects per million offspring from a 1-rad dose received by the general population (gross estimates) modified from icrp Publication 8 (1966). The data for subsequent generations are not strictly comparable to data for the first generation.

Returning to the average population dose of 0.17 rad maximum population exposure in present standards, there would be 36 additional genetic deaths in the first generation if a million individuals received this dose and all had offspring.

The total effect over many generations is of course much larger. We can predict some 19,000 genetic deaths in ten generations from 1 rad to a million parents, some 85,000 at infinity from 1 rad to a million par­ents. The ratio to normal incidences is about the same as in the first generation: (1.9 X 103)/(2.4 X Ю6), about 0.1 per cent.

More specific expressions of gene mutations, chromosomal breaks, and other cell abnormalities leading to genetic death occur with lower frequencies. A specific case, autosomal dominants, is shown from the first generation in the tabulation. Whether one considers the total impact of such effects on the race as acceptable or not at any given dosage level becomes a matter for judgment, even a matter of temperament. One can make these numbers seem large by considering the total population of the United States or of the world. Even 0.1 per cent of these is then a very large number although the current rate may seem very small. Remember also that for this calculation to hold, the entire parental population pro­ducing the million offspring had to receive the radiation or the dose aver­aged in the population produced the same effect. The only conceivable mechanism by which this could occur countrywide or worldwide is nuclear war or gross irresponsibility in allowing the activities of man to pollute his environment with radioactive materials. Thus, one must consider “critical segments” of the population. Here the totals are smaller but the likelihood larger.

All of these figures are calculated rates based on data obtained from animal experiments, assuming first that the rates are reasonably com­parable in man and second that the effects are linear to dose as extrapo­lated from the regions of the experiments to the regions of much lower doses delivered over long time periods. The first assumption can be justi­fied by the fact that spontaneous mutation rates in man are not widely different in general from the animals used for the experiments. The second
assumption is justified because it is the conservative one to make and the only prudent course to take without reliable data to the contrary. Thus, the presence of a risk of genetic detriment must be assumed.

In parallel with the development of a fission-power industry is the problem of the safe disposal of nuclear waste products. For each kilogram of fissile material consumed in a reactor, about 999 grams of highly radio­active fission products are produced. Some of these have radioactive half­lives of about 30 years and are biologically dangerous for the order of 1,000 years. Hence, safe disposal of these products involves their being isolated from the biological environment for such a period of time.

These waste products occur principally in three forms: high-level products which are highly concentrated, intermediate — and low-level prod­ucts which occur principally as aqueous solutions or slurries, and gaseous products which are largely vented to the atmosphere.

From 1955 to 1965 I served on a committee of the National Acade­my of Sciences National Research Council, which advised the aec with regard to land disposal of these wastes. This committee formulated the policy that: First, all radioactive materials are dangerous and should be completely isolated from the biologic environment during their period of activity. Second, no practice of waste disposal should be tolerated when the quantities of wastes are small that would not still be valid when the quantities become orders of magnitude larger.

On the whole, satisfactory progress has been made with respect to the disposal of high-level wastes. The handling of low-level and gaseous wastes, however, is much less satisfactory, largely because of a desire to cut costs in achieving nuclear-power production which is competitive in costs with power from other sources.

The principal need at present, it appears, is to establish an independ­ent agency of the government whose duty and authority is to monitor all waste-disposal practices, and to make public its reports of its activities and findings.

For the past six years I have participated in a program whose purpose was the development of a practical ability to predict the distribution with­in the biosphere of each and every radionuclide produced in the explo­sion of a nuclear device. In particular, our program had the goal of estimating the ultimate dosage to man from the release of radionuclides to the biosphere as a result of the peaceful uses of nuclear energy. We now have a capability for estimating a defendable upper limit for the dosage (Burton & Pratt, 1968; Fisher, in preparation; Ng et al., 1968; Ng & Thompson, 1966; Tamplin, 1967; Tamplin et al., 1968). But before dis­cussing it, I shall explain why I believe that our approach or some similar approach should be applied to the effluents from nuclear reactors and fuel processing plants.

In the Code of Federal Regulations, Title 10, pages 134-144, is a table which lists the maximum permissible concentrations of various radionuclides in air and water released to an unrestricted area. The values listed there for 137Cs are 2 x 10~9 мСі/ml of air and 2 x 10-5 /хСі/ml of water. These levels are set so that a whole-body dosage of 0.5 rad/yr would result from breathing such air for one year or drinking some 2 liters of water per day. But more important is what such levels really mean in terms of what could occur as a consequence of such levels in an unre­stricted area.

The 137Cs in the air will be deposited on pasture plants, which will be eaten by cows and secreted in their milk; the milk will subsequently be consumed by children. If the 137Cs concentration in air were maintained at the maximum permissible concentration (mpc) for just one day, a child consuming 1 liter of milk per day would get a whole-body dose of

7 rad as a consequence of just one day’s deposition. If mpc in air were maintained for one year, the dose would be 2,555 rad — 5,110 times higher than the 0.5 guideline of the aec and 15,000 times the radiation pro­tection guideline of the U. S. Federal Radiation Council (frc) (1960).

The above-dose estimate is derived as follows: The mpc for 137Cs in air is 2 x 10-9 ju, Ci/ml. This is equivalent to 2 x 10~3 мСі/m3. If this concentration existed for 24 hr, the integrated air concentration would be 48 X 10~3 juCi-hr/ms. Now the 1STCs would be deposited on forage at a rate of 17 m/hr (Fisher, 1966). The deposition would thus be:

■I48 X 10-3[(/iCi-hr)/m3]}- j 1т/Ы = 0.82(^Ci/m2)

A deposit of 0.12 /лСі/т2 would lead to a whole-body dose of 1 rad to a 10-kg child consuming 1 liter of milk per day (Ng et al., 1968; Ng & Thompson, 1966). Therefore, the 0.82 juCi/m2 would lead to a dose of 7 rad.

As for the concentration in water, the mpc is based upon the calcu­lation that a 150-lb average man consuming 2,200 g of water at the mpc per day would receive a dose of 0.5 rad. To begin with, a 75-lb child drink­ing this much water would get a dosage twice as high. He would be ex­ceeding the guideline dosage, and so would a 100-lb pregnant woman. Man, woman, and child have also been known to eat fish. The concen­tration of 137Cs in fish flesh, caught in a river, would be 1,000 times higher than the concentration in the water (Chapman et al., 1968; Ng et al., 1968). Thus a man eating a pound of fish a week, grown in water at the mpc, would receive a dosage of 15 rad/yr —30 times the aec guideline and 90 times the frc guideline. If he were a 75-lb child, the dosage would be 60 times the aec guideline and 180 times the frc guideline. In other words, most people would exceed the guidelines if they ate only one pound of fish a year.

The milk and fish represent biological concentration mechanisms. They, by themselves, serve to demonstrate quite conclusively that using air and water mpc values without considering food chains is meaning­less. Still another example can be found in a physical process. If the mpc of 137Cs in air were maintained for one year, the resultant deposition on the ground would be 300 ju, Ci/m2. Since 13 ^Ci/m2 is equivalent to an external radiation dose rate of 1 rad per year (Dunning, 1963), the radiation level from these 300 pCi/m2 would be 23 rad per year. In other words, even if the air concentration were a hundredfold less than the mpc, the radiation levels would exceed the frc guideline. The mpc’s are mean­ingless.

Now, it is often stated that the reactor discharges are kept to a small fraction of the mpc’s. The above analysis indicates that they should be kept to a very small fraction of the mpc’s. What fraction the engineers are using as a design criterion is a critical question.

The mpc values in air and water are of no use to the scientific com­munity in assessing the potential hazard to man from nuclear reactors and consequently are of no use to the engineers who are designing re­actors. In fact, the mpc values lead to an unacceptable risk estimate. What is needed for assessing the hazard is the quantity (the number of curies) of each and every radionuclide that is released to the environment. Armed with such information, we can proceed to estimating the distribution of these radionuclides within the biosphere and to estimating the resultant dosage to various organisms and to man. We can then estimate the po­tential damage to the biosphere and to man. I don’t mean that an abso­lute or accurate estimate can be made. There are too many uncertainties for this. Nevertheless, these uncertainties can be treated in a manner that is weighted toward the protection of public health and safety. The risk estimate that evolves from such an analysis is a defendable upper limit of the risk. On a scientifically valid basis, one can state that the risk can be no larger than this defendable upper limit. Any lower risk estimate is a matter of opinion. In this respect, it is important to recognize that scien­tific opinion is generally no more valid than other forms of opinion.

To illustrate how a defendable upper-limit estimate of the risk can be made, I shall describe our estimate of the dosage to and effect on man from the yearly release to a hypothetical stretch of river on an amount of fission products that would be produced in one hour from the operation of a 500-megawatt (thermal) nuclear power reactor. This stretch of river is 200 km (a little over 100 miles) long, 200 m (about 1,000 ft) wide, and 10 m (about 30 ft) deep. It therefore has a volume of 600 million cubic meters. Assume that this water is replaced each day —that is, the water flows at about 5 miles per hour. Assume also that there are 5 gm/cm2 of bottom material in equilibrium with the water. This is about the first inch. Finally, the population of the surrounding countryside exists totally on a diet of aquatic origin that is derived from the river. The details of the calculations are described in Parts IV and V (Ng et al., 1968; Tamplin et al., 1968) of the UCRL-50163 series of reports (Burton & Pratt, 1968; Fisher, in preparation; Ng et al., 1968; Ng & Thompson, 1966; Tamplin, 1967; Tamplin et al., 1968). Here I shall simply show the results and discuss their implication.

The accompanying tabulation presents the dosage estimate for the whole body over the period from conception to 30 years of age under these assumptions; this dosage would be accumulated from a yearly release to the hypothetical river of the fission products produced in 1 hour in a 500-megawatt (thermal) reactor.

Radionuclide rad

шСе…………………………………. 48

106Ru………………………………… 40

^Sb ……………………………………. 8

147Pm…………………………………. 6

“7Cs………………………………….. 1

14SCe…………………………. 6 x lO’15

Total………………………………. 105

The contribution from the most significant radionuclides (half-life >180 days) is included in addition to the total. There are a number of other radionuclides between 1S7Cs and 142Ce; 142Ce indicates the range over which the individual nuclides contribute to the dosage. As you can see, the total dosage estimate is 105 rad. If one assumes that only 1 per cent of the diet comes from the river, the dosage would be lower by a factor of 100 or 1.0 rad. This is one-fifth of the radiation protection guide­line of the FRC.

The dosage estimate shown in the tabulation is dependent upon the assumptions relating to the diet and the hypothetical river. It is also an upper-limit number. When some of the uncertainties in the biological data are resolved, when the appropriate dietary mix is considered, and when the values for an actual river are used, this upper-limit estimate may be lowered by a factor of 1,000. If this happens, the upper-limit dosage estimate would be a factor of 50 less than the present radiation protection guideline.

But even if we achieved this factor of 1,000, we should not be lulled into complacency. The release rate used in these estimates represents only a few hundredths of 1 per cent of the radionuclide inventory at the end of a single year’s operation of one 500-megawatt nuclear power plant (Division of Radiological Health, Public Health Service, 1966). In other words, this dosage estimate results from essentially complete containment (about 99.99 per cent) of the radioactivity within the power plant. If more than one reactor is planned for the river, the margin for error gets smaller. If we are going to live within the radiation protection guidelines with nuclear power plants, we had better take a very hard look at the permissible levels of release to the environment. At this point, it appears that something approaching absolute containment of the radioactivity is required.

Because of the assumptions involved in the calculations, the fore­going dosage estimates should not be taken at face value. My purpose here was to demonstrate that it is entirely possible to make such estimates of the dosage and to show that it is absolutely essential that such estimates be made to assure that the radiation protection guidelines are not ex­ceeded.

But even the frc suggests that dosage should be kept as far below this guideline as is possible. How far below the radiation protection guide­lines the dosage should be kept depends upon the risk that the population is willing to accept. The risk depends upon the biological effects of low dosage, low dose rate irradiation. Again, a precise estimate of the risk cannot be made, but it is possible to present a defendable upper limit for the risk. One approach to estimating an upper limit to the effects of radia­tion would be to assume that all of the fetal and infant deaths are a con­sequence of mutations occurring in the population. By this assumption, if the mutation frequency were doubled, these death rates would be doubled. This is not an unreasonable assumption. In the United States some 20 to 25 per cent of the conceptions terminate as fetal or early infant deaths, so it is apparent that this represents the most severe selection process imposed on the population. Exclusive of those deaths that result from chromosomal anomalies, some 15-20 per cent of the conceptions terminate as fetal or early infant deaths. This percentage is close to the mutation frequency estimated for the population (14/100 germ cells/ generation) (United Nations Scientific Committee on the Effects of Atomic Radiation, 1966). Since this number of mutations is being eliminated with each generation, the correspondence of these percentages suggests that the above assumption is not unreasonable.

The United Nations Scientific Committee on the Effects of Atomic Radiation (1966) estimates that 1 rad would increase the natural muta­tion frequency by a factor between.10 and.01. The existing radiation protection guidelines would allow a genetically significant dosage of 5 rad. This could increase the mutation frequency and hence increase the fetal and infant death rates between 5 and 50 per cent. As an upper limit then, the radiation protection guideline dosage could increase the fetal and infant death rates by 50 per cent. However, experiments on mice suggest that radiation delivered at low dose rates might produce only one — fifth as many mutations. As a consequence, the upper-limit estimates could be high by a factor of 5, and this would reduce the estimate to between 1 and 10 per cent. Considering that each year we have some 150,000 late-term fetal and infant deaths combined, even 1 per cent represents considerable human tragedy. Certainly, the dosages should be kept as far below the radiation protection guideline as is possible.

In summary, as a member of the scientific community and as a member of the public at large, I view the burgeoning nuclear power in­

dustry with a great deal of anxiety. My impression is that these power plants should be designed so as to approach absolute containment of the radioactivity. My anxiety is only increased when I consider that the only recorded regulations are a set of numbers called mpc’s for air and water that are tabulated in Title 10 of the Code of Federal Regulations. What is needed is a comprehensive study that takes into account both physical and biological concentrating mechanisms and is based upon quantitative data on each and every radionuclide in the inventory of the total nuclear power industry that is anticipated for the future in each ecological region of the nation. Following this study, it would be possible to determine whether something other than a very close approach to absolute contain­ment of the radioactivity is acceptable.

As the situation stands, aside from the bland reassurances of spokes­men for the Atomic Energy Commission and the nuclear power industry, there is no reason to assume that nuclear reactors will not jeopardize the public health and safety.

Abstract

The effects of heated water on aquatic biota are diverse and vary from the dramatic to the subtle. In general, these may be categorized into direct and indirect effects. Examples of the former would be lethality, reduction in reproduction, and alterations in the number and types of species normally present in a particular environment. Indirect effects could be significant increases in the oxygen demand of a water, increase in disease virulency, or increases in the toxicity of other pollutants. Attempts to improve water quality criteria for temperature have pre­sented several interesting considerations to supplement the anti-degra­dation policy of the Federal Water Pollution Control Administration.

So much for what the law is. The next question is what the law ought to be —that is, whether the federal government or the states, or both, should regulate the nuclear safety areas presently regulated exclusively by the AEC.

The issue is who should be the regulator, not how the regulator should regulate. Let us get that distinction clearly in mind from the be­ginning. Questions such as, “How much radioactivity is ‘safe’?” or “How low should we set our limits for radioactivity releases to the environment?” are pertinent to how regulation should be carried out. They are irrelevant to the issue of who should do the regulating. Contentions that radioactiv­ity releases from nuclear power plants should be “as low as possible” or * Frost v. Wenie, 157 U. S. 46 (1895); United States v. Burroughs, 289 U. S. 159 (1933); Sutherland, Statutory Construction, Vol. 1, pp. 365-367. Sutherland specifi­cally discusses the question of abrogation of state law by federal statutes and the re­vival of state legislation by repeal of federal regulations (Secs. 2026, 2027). The cases cited, however, all concern situations in which the federal statute was expressly repealed or the obstacle to state action removed by express congressional enactment.

“none at all” are pertinent to how the regulators go about their jobs. They have no connection with who — what governmental jurisdiction — should exercise the authority under which the regulators act. Oft-heard state­ments, whether they be true or false or somewhere in between, such as “all radiation exposure, even at quite low levels, is harmful to some degree” or “any unnecessary exposure to ionizing radiation should be avoided,” or “it should be general practice to reduce exposure to radiation,” are con­cepts applicable or inapplicable to the regulatory process. They have noth­ing to do with who — what level of government — should do the regulation. (All expressions in quotations in this paragraph were used in a statement by Dr. E. C. Tsivoglou to the Burlington, Vermont, town meeting on Sep­tember 11,1969.)

People injecting these irrelevancies into a discussion of who should do the regulating obscure the issue rather than clarify it. One’s frustra­tions over how regulation is being carried on are quite different matters from who does the regulating.

Radiation Protection Guides. In expressing these frustrations, it is well to recall a sign posted in the Leadvffle Saloon which read: “Please Do Not Shoot the Pianist — He Is Doing His Best.” For, regardless of who regulates nuclear power plants or how they are regulated, attention must be paid to the established radiation protection guides, which are those is­sued by:

a. The International Commission on Radiation Protection (icrp). The icrp was established in 1928 by the International Congress of Ra­diology to provide radiation protection guidance. It is looked to by na­tional governments and by such international agencies as the World Health Organization, the Food and Agriculture Organization, and the Interna­tional Labor Organization, all of which maintain liaison with the icrp, for basic guidance in all areas of protection against ionizing radiation.

b. The National Council on Radiation Protection and Measurements (ncrp) . The ncrp was formed in 1929 under the auspices of the National Bureau of Standards of the United States. It was incorporated by Act of Congress in 1964. The membership consists of some 65 recognized ex­perts in the field of radiation protection.

c. The Federal Radiation Council (frc). The frc was created by Executive Order 10831 on August 14, 1959, and made statutory in Sep­tember 1959 by an amendment to the Atomic Energy Act of 1954. It ad­vises the President on radiation matters affecting health, including guid­ance for all federal agencies in the formulation of radiation standards and in the establishment and execution of programs of cooperation with the states. Its membership consists of the secretaries of Health, Education, and Welfare; Defense; Agriculture; Interior; Commerce; Labor; and the chairman of the aec. The frc uses the best technical expertise in the field and takes into account the recommendations of ncrp and icrp.

In the case of civilian nuclear power reactors, the purposes of the guides and the regulatory process are to assure radiological safety with respect to the following areas of possible hazard: any possible reactor ac­cident, from the least significant up to and including the unlikely occur­rence of a postulated maximum credible accident; possible exposure of persons within any area where radiation background levels might be in­creased by even the slightest amount owing to routine reactor operations; and, possible exposure of persons from any accumulation of radioactive isotopes in the food chain.

The aec and the nuclear industry have long been heavily committed to research and development work on a broad front — radiation effects, thermal effects, and ecology —so as to obtain a better understanding of the interaction of nuclear plants with the environment. The aec is cur­rently spending about $70 million annually on environmental research and development.

A few examples can be cited to illustrate the scope of the aec’s re­search in environmental science. Since 1944, millions of dollars have been spent in studying the effects of radionuclides and thermal releases in the Columbia River system. A computer program developed in the study of thermal effects has been applied to other rivers in the country, including the Upper Mississippi. Another example is a study aec is sponsoring on the environmental aspects associated with siting power plants on Lake Michigan. The Argonne National Laboratory will have primary respon­sibility for the planning and conduct of this study. It will be coordinated with appropriate government bodies, educational institutions, and indus­trial organizations in the Lake Michigan area. In this important study, principal attention will be given to observing any differences in the ecology at locations where heated water is currently being released to the lake and to characterizing the ecology at undisturbed locations and at proposed power plant sites.

The recommendations of icrp and ncrp were originally intended for protection of workers exposed to ionizing radiation. Before World War II, there was so little use of radiation that the need for standards to protect the public did not yet arise.

The early students of radiation protection did not have the benefits of the generous governmental grants that exist today, nor did they have the sophisticated laboratory equipment of present-day research. However, they did have an all too ample research resource arising out of the tragic misuses of ionizing radiations. Although before World War II there were relatively few X-ray machines, and the radioactive substances to which people were exposed were limited to about two pounds of radium that had been extracted by then from the earth’s crust, hundreds of deaths and many injuries resulted from an inadequate understanding of the principles of radiation hygiene. Fortunately, the effects of the misuses of these sources of ionizing radiation were studied with such extraordinary dili­gence and perception by the experts of a generation ago, that much of the basic information needed to protect the employees of the atomic energy program was already on hand by the time it was initiated during World War II. Two basic recommendations were already available, pertaining to the upper limit of permissible exposure to external X and gamma radia­tion, and to the maximum permissible body burden of radium.

The recommendation that the permissible body burden of 22eRa be limited to 0.1 pCi has not been changed since it was first established early in World War II. This yardstick had been a strong influence in setting the permissible body burdens of other bone-seeking radionuclides.

The maximum permissible dose of external radiation exposure per­mitted during World War II was 0.1 r/day, based on the scanty informa­tion that was available up to that time; this was equivalent to 20 r/yr. If we allow for the difference between roentgens and rads, and for the fact that the radiations now encountered in the atomic energy program are more penetrating than the 75-125-kv X rays that were the principal source of radiation before World War II, we find that the permissible dose for occupational exposure that was recommended by ncrp as much as 30 years ago is within a factor or two of 5 rem/yr permitted today for occu­pational exposure.

The problem of setting standards for protection of the general public is much more complex for several reasons. Because radiation workers are a relatively small fraction of the total population and because the genetic effects are related to the per capita gonadal dose of the population, genetic effects are less important than somatic effects insofar as occupational ex­posure is concerned. The probability of somatic injury at a given level of exposure in the general population is increased by the fact that children and fetuses are involved. Additionally, one becomes more conservative as the size of the exposed population increases, and in this country the gen­eral population is about one thousand times the size of the population in­dustrially exposed.

Leukemia and genetic mutations are the potential effects of ionizing radiation exposure that are of greatest concern insofar as the general population is concerned, and our discussion of the aec standards will fo­cus on these.

The incidence of leukemia has increased among several groups of humans exposed to relatively high doses of ionizing radiation (United Na­tions Scientific Committee on the Effects of Atomic Radiation, 1964). These include Japanese survivors of the atomic bombings of Hiroshima and Nagasaki, patients irradiated for ankylosing spondylitis, radiologists exposed to ionizing radiation in the course of their work, and children ir­radiated in utero in the course of pelvic X-ray examinations. The Japa­nese received a single dose which is estimated to have varied from 100 to 900 rads. The ankylosing spondylitis patients received fractionated doses of 100-300 rads over a one-month period. The cumulative doses received from day to day by the radiologists in the course of their practice is not known but is believed to be considerably in excess of 100 rads. The fetal dose in pelvic examinations is not known but probably was about 3 rads.

Thus, epidemiological experience involves mainly single or multiple exposures at high dose rates compared with those permitted by existing standards, as we shall see below. To estimate the expected effect of doses of a fraction of a rad delivered in small bits, one must extrapolate from these epidemiological data; in the interest of maximum safety, this is done by assuming that there is no threshold and that the biological response is proportional to the dose, and independent of the dose rate. Both the United Nations Scientific Committee on the Effects of Radiation (1964) and the icrp (1966) have emphasized that the estimates made in this way represent an upper limit of risk and that the actual risk may in fact be very much less.

Subject to these conservative assumptions, the epidemiological evi­dence suggests that a dose of 1 rad delivered to a million people (that is, 106 man rads) may produce a maximum of about 20 cases of leukemia during the lifetime of the population. The incidence of leukemia in the normal population is about 70 cases per million per year.

Insofar as genetic effects are concerned, we have no epidemiological information upon which to draw. However, we do have extensive research with lower animals which suggests there is no threshold for genetic effects and that the frequency of mutations is proportional to dose, but is not independent of dose rate (United Nations Scientific Committee on the Ef­fects of Atomic Radiation, 1966). According to these data, a per capita dose of about 10 rads per generation, delivered to successive generations, will eventually cause the spontaneous mutation rate to double. It has re­cently been shown however, that when the dose is fractionated, the genetic effect is somewhat less, by a factor of 6 (Russell, 1968). Thus, for con­tinuous exposure, a dose of 60 rads per generation delivered to many suc­cessive generations would eventually cause the spontaneous mutation rate to double. For a generation of 30 years, the doubling dose would thus be about 2 rad/yr.

We now come to the point where it is necessary to connect the thread of epidemiological and experimental evidence to the apparatus of public health regulation. Public health regulation is not a science but an art. The public health administrator, as an artisan, must start with a mix of scien­tific information of various grades of quality which he must evaluate according to certain philosophical concepts of permissible risk. He must then fabricate a system of regulation that is understandable, that is prac­tical, and above all, that protects the public health. Whether one is regu­lating radioactive, chemical, or biological contaminants of the environ­ment, the same approach must be taken, and the same questions inevitably arise. Thus, we regulate the biological quality of drinking water by making

assays for an innocuous group of coliform organisms because we are basically interested in certain pathogenic organisms that originate in fecal pollution, for which the coliform organisms are a useful indicator. This system of control does not provide absolute safety, but in most cases it provides more safety than is needed. In any case, for many decades this has been a practical system of control which has lent itself to practical systems of enforcement. Other regulatory mechanisms could be designed which would provide more safety, but they might not be so practical to administer or to enforce. The aec standards, for all their defects and in­consistencies, have served well to protect the public health (Environ­mental Radioactivity Exposure Advisory Committee, 1968).

To illustrate the quality of aec standards for protection of its em­ployees, there is the fact that, after about a quarter century of aec ex­perience, there is no known case of radiation injury among atomic energy workers from chronic exposure to ionizing radiation exposure. This is an excellent record, considering the great size of the program, the long period of time, and the enormous quantities of radioactive materials, compared with the disastrous experience with the relatively limited op­portunities for exposure that existed before World War II.

The basic criteria for the upper limit of permissible occupational exposure is that an employee should not accumulate more than 5 {N —18) rads, where N is the employee’s age in years (10CFR20). Stated another way, the employee should not work with ionizing radiation until he is 18 years old and then should not be exposed to more than an average of 5 rad/yr.

When internal radiation exposure is involved, the icrp methodology introduces the concept of the “critical organ,” the organ in which a given radionuclide tends to accumulate (International Commission on Radio­logical Protection, 1959). For example, the critical organ for iodine 131 is the thyroid and for strontium 90, the skeleton. With a few exceptions, exposure to internal emitters is controlled by limiting the quantities of radionuclides that may be absorbed by ingestion or inhalation to that amount which will result in exposure of the critical organ to less than 5 rad/yr.

The maximum permissible dose for exposure of the public, according to aec regulations, is one-thirtieth of the permissible occupational dose. The regulations assume that this average will not be exceeded if the most- exposed individual of a given population receives no more than one-tenth of the permissible occupational dose. In short, the mean exposure of a given population should not exceed 0.17 rad, and the maximum exposure of any individual in that population should not exceed 0.5 rad.

The problem of estimating the initial quantities of oil and gas in any region is much more difficult than that for coal, because oil and gas accu­mulations occupy limited regions of underground space in sedimentary basins at depths up to several miles, whereas coal occurs in stratified beds of large areal extent, and often crops out at the surface. However, in high­ly developed petroleum-bearing areas such as the United States, the com­bination of surface geology and subsurface geology determined by thou­sands of wells and miles of geophysical surveys all combine to yield pro­gressively more accurate estimates of the amount of oil and gas which still remains to be discovered. These estimates, plus the amount of oil and gas discovered already, provide estimates for the ultimate amounts to be pro­duced.

Space here does not permit the reviewing of these methods of estima­tion. However, several lines of evidence (Hubbert, 1967; 1969) converge to indicate that the United States, exclusive of Alaska, is now very near the peak in its rate of production of crude oil, with an estimated ultimate production, using present extractive technology, of about 165 billion bar­rels. Then, allowing an estimate of 25 billion barrels for Alaska (which could be too low by a factor of as much as 2), an estimate of 190 billion barrels is obtained for the whole United States.

In addition to crude oil, it is estimated that the United States, exclu­sive of Alaska, will also ultimately produce about 36 billion barrels of natural-gas liquids. When this is added to the 165 billion barrels for crude oil, 201 billion barrels (or roundly 200) is estimated ultimate production of petroleum liquids.

Similar estimates for the ultimate United States, exclusive of Alaska, production of natural gas range from about 1,050 (Hubbert, 1969) to 1,290 trillion cubic feet (Potential Gas Committee, 1967). Within recent months, the Potential Gas Committee (1969) has revised its estimate for ultimate gas production by the whole United States to 1,859 trillion cubic feet by including Alaska and additional offshore areas to a depth of 1,500 feet. Of this, however, 632 trillion cubic feet were classed as “specula­tive.” The estimates by the present author are considerably lower, about 1,200 trillion cubic feet.

Corresponding figures for the entire world are even more uncertain. However, recent estimates for the ultimate world production of crude oil range from about 1,350 to 2,100 billion barrels. Based on these two fig­ures for crude oil, the ultimate world production of natural-gas liquids and of natural gas can be estimated. These are given in the accompanying tab­ulation, which shows a range for total petroleum liquids from 1,620 to 2,520 billion barrels, and for natural gas from 8,000 to 12,000 trillion cu­bic feet.

Fossil Fuel Ultimate Production

Crude oil………………………………………. 1,350-2,100 KPbbl

Natural gas liquids…………………….. 270-420 10°bbl

Petroleum liquids…………………………… 1,620-2,520 lO’bbl

Natural gas………………………………….. 8,000-12,000 1013 ft3

Combining these approximate estimates for both the United States and the world with the corresponding production data, and then using the technique indicated in Figure 8, we can gain a good idea of about how long the resources of oil and gas can continue to supply a major part of the country’s or the world’s energy requirements.

The crude oil production of the United States, exclusive of Alaska, is shown in Figure 12; total petroleum liquids, in Figure 13; and natural gas, in Figure 14. In each, the left-hand shaded area represents the cumulative production up to the end of 1967. The right-hand shaded area represents the additional oil or gas still to be produced from fields already discov­ered, and the final unshaded area, the estimate of future discoveries. The shaded grid rectangle in the upper right-hand corner is an area scale showing the amount of fluid corresponding to each grid rectangle under the production curve.

Two other features of each of these figures may also be noted. The dashed curve at the top represents what the annual production would be if

recent rates of growth should be continued for a few more decades. The two vertical lines showing a horizontal separation of 80 per cent, show the time required to consume the middle 80 per cent of the ultimate produc­tion. Cumulative production up to the time of the first line represents the first 10 per cent of the ultimate production; that to the right of the second line, the last 10 per cent.

The significance of this is that in considering about how long a given fuel can supply a major fraction of energy requirements, the comparative­ly long periods required for the first and last 10 percentiles can largely be disregarded and attention focused upon the time required for the middle 80 per cent.

From Figure 12, which shows the crude oil production of the conter­minous United States based on an ultimate production of 165 billion bar­rels, it will be seen that the peak rate should occur near the present time. The time required to produce the first 10 per cent of the ultimate cumula­tive production was from 1860 to 1934; that for the last 10 per cent, the time after 1999; but the time required for the middle 80 per cent is only the 65-year period from 1934 to 1999. The figure also indicates that of the 165 billion barrels ultimately to be produced, about 134 billion barrels (80 per cent) has probably been discovered already.

Figure 13 is in all respects similar to Figure 12 except that it pertains to the production of total petroleum liquids in the United States. Here, also, the date of the peak rate of production is near the present, and the time required to produce the middle 80 per cent is about 64 years.

The corresponding curve for natural gas production in the conter­minous United States is shown in Figure 14. In this case, the figure indi­cates that the production of natural gas will reach its peak at about the year 1980 — or about 10 years later than that for crude oil — and that the time required to produce the middle 80 per cent will be the 65-year period from about 1950 to 2015.

It may also be pertinent to remark that since World War II, the natu­ral gas industry in the United States has been building pipelines on the as­sumption of much larger amounts of gas being available than that shown in Figure 14. As a result, the recent slowing down in the rates of discovery and of production of natural gas with respect to the requirements for these pipelines has become a source of acute stress and of some alarm within the industry.

World crude oil production is shown in Figure 15 for both a low fig-

ure of 1,350 billion barrels and a high figure of 2,100 of ultimate produc­tion. For the lower figure, the peak in the production rate is estimated to occur about the year 1990, with the middle 80 per cent of production oc­curring during the 58-year period from about 1961 to 2019. For the higher figure, the peak date is delayed only about 10 years to the year 2000, and the time span required for the middle 80 per cent is increased to only 64 years.

From these considerations it appears, therefore, that although the total span of time during which some oil and gas will be produced will probably be several centuries, the period during which the preponderance of this production will occur will be only about one human lifetime.