recommendations should not be considered mandatory; in fact, under some circumstances there may be methods of accomplishing the same results which are as good or even better than those specifically recommended by the NCRP. There are other areas in which it is as yet impossible to formulate a single set of detailed recommendations that will be applicable under the diversity of conditions to be found in practice. The important consideration is that in any operation the overall operating procedures shall be controlled to conform as closely as possible with the basic standards of radiation protection.

It is quite likely that firmer scientific bases for fundamental standards of radiation protection will come from laboratory research which contributes to a better understanding of the mechanisms of induction of such diseases as leukemia and cancer rather than from applied research planned to obtain quantitative answers to specific questions. The problems of determining, for example, whether or not there is a threshold for the production of leukemia and of cancer by radiation and of how the incidence of either of these diseases depends upon radiation doses at very low rates of exposure is similar to-and may be identical with-that of discovering how these diseases are produced. Medical science has made encouraging progress over the past several decades in gaining an understanding of the fundamental mechanisms involved, but the many competent scientists engaged in this field of research have so far been unable to give us answers adequate to our needs.

On the other hand, the development of secondary standards depends very largely on obtaining specific quantitative data on the biochemical and physical characteristics of individual radioisotopes in relation to their retention and distribution in the various organs or tissues of the body. Thus, research designed to reduce the uncertainties involved in our standards of radiation protection should strike a balance between the effort expended to obtain answers to specific questions and that for increasing our fundamental knowledge of mechanisms involved in producing the biological effects of radiation. Before leaving this phase of the discussion it should be observed that few if any of the industrial toxins have been subject to such a relentless scrutiny for possible small effects of low concentration on average life span, for the ability to produce small statistical increases in cancer or leukemia, etc., as has ionizing radiation.

LIMITS FOR POPULATION GROUPS

The determination of appropriate limits for the control of exposures of population groups to radiation is more difficult than for the control of occupational exposures for several reasons. Up to the present time, this problem has been met by using for environmental limits a small fraction of occupational limits. The fraction one-tenth, used for this purpose by the Atomic Energy Commission since 1951, was recommended by the ICRP in 1954 and by the NCRP in 1955. In their most recent reports, both the NCRP and the ICRP recommend that exposures to population groups in the neighborhood of atomic energy installations be limited to one-tenth of occupational values.

In addition, the ICRP recommends fractions applicable to the total population. For exposures of genetic significance, the recommended fraction is onehundredth and for other exposures one-thirtieth. Except for the recommendation that the average genetic exposure to the total population from all sources should not exceed a total of 14 rem per generation of 30 years, the NCRP has made no recommendations applicable to the total population.

(Whereupon, the committee recessed at 12:30 p.m., to reconvene at 2 p.m. the same day.)

AFTERNOON SESSION

Chairman ANDERSON. The committee will be in order.

I understand that the first witness this afternoon is Dr. Joseph Lieberman.

Mr. GRAHAM. Yes, sir; we have him here. With your permission we will start him right away.

Chairman ANDERSON. You may proceed.

STATEMENT OF DR. J. A. LIEBERMAN, CHIEF, ENVIRONMENTAL AND SANITARY ENGINEERING BRANCH, DIVISION OF REACTOR DEVELOPMENT, AEC

Dr. LIEBERMAN. As Commissioner Graham said, I propose to skip over parts of my statement and concentrate on the topics of the disposal into the ocean, the burial of wastes on land, and our working relationships with other agencies of the States.

Chairman ANDERSON. We will carry the statement in full.

Dr. LIEBERMAN. Management and disposal of radioactive wastes is a general problem whose thread runs through the entire fabric of all nuclear energy operations. Waste materials in either gaseous, liquid, or solid form are evolved in essentially all operations associated with nuclear energy facilities beginning with the mining and milling of uranium ore, through the production of feed materials, isotope use, reactor operations, and chemical reprocessing of irradiated reactor fuels.

Because of the nature and characteristics of the radioactive materials involved, their ability to cause damage to human tissue, their nondetectability by the human senses, and their potential danger as an environmental contaminant, the safe handling and final disposal of nuclear energy wastes are integral and important aspects of these operations. This importance is attested to by the efforts expended in this area in the atomic energy program to date. As was brought out in the waste disposal hearings before this committee earlier this year, plant investment for radioactive waste handling and disposal in the AEC is on the order of $200 million. Annual operating costs for waste disposal are about $6 million. It is believed fair to state that more money probably has been spent and more scientific and technological effort concentrated on facilities, operations, and research and development with regard to nuclear industry wastes than on any other industrial contaminant we have known. The extent and nature of this effort were covered in detail in the waste disposal hearings previously mentioned.

One point that must be strongly emphasized in any discussion of this subject is that, from an engineering and environmental standpoint particularly, the disposal of radioactive wastes cannot be considered as a single problem with a single, best solution. The great variation in the characteristics of the waste products from various processes and operations, including radioactive half-life, concentration, and chemical state, physical characteristics, actual quantities of radioactive materials involved, and the specific location of the nuclear activity are all important in assessing the significance of the potential hazard and in establishing specific engineering design and operational criteria for their safe handling and disposal.

The three major components of waste management are as follows: (1) Determination of the extent to which specific isotopes may be permitted to reach man.

This includes immediately the concept of concentrations of various isotopes in air and water, the ecological implications of biologic concentration of radioactivity by various organisms in our food chain, and other highly important, complex and, in some instances, unknown biological considerations. From an engineering standpoint the idea

of some quantitative standard of permissible or acceptable concentration of radioactivity in air and water is obviously important.

(2) The specific nature of the radioactive waste under consideration. This is a highly variable component and, in order for proper consideration to be given to it, it must be approached in specific, quantitative terms. It must be completely understood that there is littlebasis for comparison of waste management techniques or problems associated with the liquid wastes emanating from a normally operating water-cooled reactor, for example, and those associated with, let us say, the aqueous reprocessing of enriched uranium-aluminum alloy fuels.

(3) The physical, chemical, and biological characteristics of the environment in which the waste is to be considered or handled.

Required here, again in specific, quantitative terms-to the maximum extent possible-is knowledge or data of the atmosphere, the hydrosphere, and the lithosphere, relating to dilution and/or concentration of radioactivity in the environment.

Essentially, then, proper waste management consists of so identifying and quantitatively describing items 2 and 3 and their combined behavior so as to assure conformance to the standards established in item 1.

The two fundamental waste disposal concepts that are applicable to the overall waste problem are characterized by the phrases "concentrate and contain" and "dilute and disperse." The dilute-and-disperseapproach is applicable to wastes that normally contain small concentrations of radioactive materials, or in which the concentration can be reduced to small quantities by treatment; and to environments with adequate dilution capacity. The term "dispersal" is used here to describe the discharge of wastes to the environment in a manner that permits little or no direct control by man over the fate of the wastes following their discharge. The discharge of liquid wastes to surface waterways or gaseous wastes to the atmosphere are examples of dispersal.

The concentrate-and-contain technique must be utilized for wastesthe so-called high-level wastes that contain more radioactive materials than can be assimilated safely by the environment. Systems for final disposal of these wastes must be such that they (a) permit continuing, long-term control by man over the wastes, and/or (b) assure the wastes will be contained essentially at the point of disposal so that man, his environment, and his resources are not adversely affected. The time element involved is literally hundreds of years.

One of the more significant features of the waste disposal problem in its broad sense is the requirement for focusing the competence of many scientific and technical disciplines on the problem. Since considerations involved in waste disposal cut across all activities and operations related to the utilization of nuclear energy, it becomes evident that the chemical, sanitary, and nuclear engineer; the geologist, hydrologist, and meteorologist; the biologist, chemist, and physicist; and still others have interests and concern with various aspects of the problem. This was clearly recognized in the early stages of AEC operations and accounts for the close and continuing day-to-day working relationships with other specialized Federal agencies and

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State and interstate groups having particular competencies and interests related to the control of effluents.

Waste disposal operations can be categorized according to the characteristics of the wastes under consideration and the way in which they are handled. The particular environment involved is also pertinent to such categorization.

The great majority of wastes of all types that are being handled are from AEC operations. For example, at one AEC installation, Hanford, some 52 million gallons of highly radioactive wastes resulting from chemical processing of irradiated fuel are in storage. This waste contains many millions of curies of radioactive materials. In addition, at Hanford, almost 4 billion gallons of intermediate level wastes have been discharged to the ground through special crib structures. Involved in this disposal were some 2.5 million curies of radioactive materials.

On the other hand, the total radioactivity of isotopes shipped from Oak Ridge from August 1946 to November 1958 was 437,000 curies, of which 98 percent, or some 429,000 curies were fabricated into sealed. sources such as cobalt 60, which are generally not subject to waste disposal. In other words, only about 8,000 curies have been shipped as nonsealed source material primarily for medical use. Most of this material was iodine 131 with an 8-day half life. It is obvious that the only common denominator of the waste problems associated with these two different situations is the word "radioactivity."

Generally speaking, essentially all of the wastes evolved from various phases of the reactor fuel cycle and isotope use, with the major exception of the irradiated fuel reprocessing phase, are of the lowlevel variety. That is, in the liquid form, for example, they generally have concentrations of radioactive material on the order of a small fraction of a microcurie per gallon; i.e., are amenable to the diluteand-disperse approach to disposal. In certain cases and environments prior treatment may be required. From an operational standpoint low-level wastes are disposed by discharge into streams, into the oceans, into pits or seepage basins, into sewerage systems, and by burial on land.

Because of the variability of the nature of wastes and the environments in which they must be considered, it is not practical to establish detailed, quantitative waste disposal system specifications that are generally applicable. Where any significant quantities of wastes are involved, individual, case-by-case analysis and evaluation are essential. This philosophy is reflected in the AEC regulations in this area. They establish standards of allowable concentrations in effluents to unrestricted areas and provide for the routine disposal of small quantities of nuisance wastes by release into sewerage systems and by burial in the ground. Provisions for consideration of alternate systems involving higher levels of radioactive discharge are made on an individual case evaluation basis. In any case, the same basic standards of radiation protection-i.e., maximum allowable concentrations of radioactive materials in air and water-apply.

Examples noting the status of several waste disposal operations and systems are briefly described below.

URANIUM MILLING WASTES

Although individual spot mill effluent samples and stream samples below several mills indicate that the concentrations of radioactive materials in excess of maximum allowable (primarily radium) are being discharged, not enough analytical results are yet available to permit a rational assessment of existing or potential environmental (stream) contamination problems. In cooperation with the Robert A. Taft Sanitary Engineering Center of the U.S. Public Health Service an industrial waste investigation was initiated last year on the Colorado Plateau. This problem has been discussed extensively with the State agencies involved. We hope that by the end of this summer sufficient quantitative data will be available to enable a critical evaluation of these industrial effluents and their effects on receiving streams. Control samples upstream from several miles were obtained during the course of this field study to serve as a basis for comparison and evaluation.

POWER REACTOR WASTES SHIPPINGPORT

Loose terminology and erroneous popular notions have both contributed to the association of highly radioactive fission product wastes with normally operating reactors themselves. Although the fission products are formed in the reactor they do not become a waste component until the fuel is removed from the reactor and reprocessed at à chemical processing plant, of which at this time there are only three-at Hanford, Idaho, and Savannah River. The error of such association of high level wastes with the reactor is strikingly shown by the results of the first year's operation of the PWR. Under terms of an agreement with Pennsylvania it was concluded that it would be safe to continuously discharge radioactive materials at the rate of 0.05 curies of mixed isotopes and 300 curies of tritium per month. However, during the first year, a total of about 0.04 curies of mixed isotopes and about 50 curies of tritium were disposed into the Ohio River.

HIGH LEVEL CHEMICAL REPROCESSING PLANT WASTES

It is believed sufficient for the purposes of this testimony to simply note that at the present time, and at least for the immediate future, these wastes are evolved only at the reprocessing sites previously noted. They are not being disposed, but are stored in specially designed underground tanks. The technical and administrative problems involved in their long term or final disposal are formidable, but not insoluble. It appears rather certain that these wastes must be handled under the "concentrate and contain" concept. The periods of time involved are, as noted previously, measured in terms of hundreds of years.

OCEAN DISPOSAL

The radioactive material involved in sea disposal off the Pacific and Atlantic coasts is of a relatively low or intermediate level compared with highly radioactive wastes produced at AEC production sites such as Hanford or the National Reactor Testing Station. The wastes disposed at sea contain quantities of radioactivity normally associated with laboratory operations rather than production or