did not tell them the shape and the components of the weapon detonated?

Mr. CORSEIE. In our opinion, the shape has little to do with it. The effect is important, at a particular location. So if we take a location X feet or X yards from any detonation and say, "At this point you have an overpressure of some stated number, you have a radiation measure in neutrons and gamma radiation of some number," that is information you can use to design protection at that point against those effects.

Mr. HOLIFIELD. In your opening paragraph you say that atomic energy development has placed on the Atomic Energy Commission responsibility for establishing appropriate safeguards for the protection of operating personnel and the general public. That is a general statement.

How far do you feel the Atomic Energy Commission is responsible for the protection of the general public?

Are you referring there to the operations of the Atomic Energy Commission or are you referring further by going into the effects of weapons?

Mr. CORSBIE. My remarks in this statement, Mr. Chairman, were intended to apply primarily to the safeguards and precautions that are set up in connection with our test activities.

Mr. HOLIFIELD. Test activities and the operations of your plants.

Mr. CORSBIE. However, it is recognized there is additional responsibility, but for testimony on that I would prefer to bring in those responsible for other programs.

Mr. HOLIFIELD. As far as you are concerned, you feel that that responsibility in the field of weapon testing is quite broad. In other words, these tests must be conducted whether they are conducted in the continental limits or in the South Pacific, and there is an overriding responsibility on your part to conduct those tests as safely as possible.

Mr. CORSBIE. To conduct them in such a way that they are regarded as safe by the most competent people we can have to look at any possible contingency arising from a detonation.

Mr. HOLIFIELD. And in the setting up of those standards of safety, what degree of protection do you require? If a certain amount of exposure is considered damaging, where do you set the standards to protect the public against that amount of exposure?

Do you allow a latitude of safety there below the amount that you consider to be deleterious?

Mr. CORSBIE. Yes, sir. Let me try to answer, and if it is not satisfactory, I would like for Dr. Harris, a medical doctor of wide experi ence, to give more detail.

We set the criteria at such level as to assure there is no permanent damage. Whether this has to do with the effect of a flash of a bomb on the human eye or whether it is the radiation that is received from fallout on the population or whether it is radiation received by operational people on site. For our operational people we have a higher permissible dose than that off site, but we think that received by the operational people is not beyond normal biological recovery. The body can repair whatever damage it receives from this level of radiation.

Mr. HOLIFIELD. We do not intend to go deeply into this particular phase of the subject, since it is not the purpose of this particular hearing, but could you give us in terms of milliroentgens, or any division of roentgens, what you consider to be the maximum permissible operational dose and relate that to the exposure which is considered safe for the general public? Do you have those figures available? Do you or Dr. Harris or Dr. Tompkins?

Mr. CORSBIE. I would be glad to provide for the record, sir, the amount of radiation in Operation Plumbob. The maximum dose was three roentgens for offsite population. Three thousand m./r., or 3 roentgens.

For the operational people, there was a maximum dose of 3.9 r. for a 13-week period, or 5 r. within the total operational periodI think limited to a year.

Mr. HOLIFIELD. Would you give us an example of what a 3-roentgen or a 3.9-roentgen or a 5-roentgen exposure would be to a body fluoroscopic examination so that we would have some comparison between your criteria and that which a person receives who has a fluoroscopic chest examination, if it is possible to give us that?

Mr. CORSBIE. May I refer this to Dr. Harris?

STATEMENT OF DR. PAYNE S. HARRIS, LOS ALAMOS SCIENTIFIC LABORATORY, AND DIRECTOR, CETG PROJECT 39.7

Dr. HARRIS. Sir, what is actually obtained during a fluoroscopic examination depends to some extent on the type of examination and the type of X-ray equipment used.

Fluoroscopic equipment, in general use, of low peak kilovoltage, poorly filtered, will give amounts of radiation equivalent to or greater than that allowed for total body radiation under operational conditions in the field.

It is possible, and in the medical profession now it is being done, to improve such equipment so that the levels that are obtained in a complete type of examination in which perhaps 40 to 50 percent of the total body volume is radiated, so that the total dose given is in the neighborhood of 100 milliroentgens or less, which is, of course, well below that allowed for operational work in the Commission, both in its laboratories and in field operations.

Mr. HOLIFIELD. Stepping down to the body X-ray which, of course, gives less exposure, what does it ordinarily run? An ordinary body X-ray?

Dr. HARRIS. This again depends upon the machine. The ordinary chest film, that is used in mass survey work for tuberculosis, these particular types of equipment give to a restricted area of the body surface a number of milliroentgens which is perhaps 10 times that given by those types of equipment which take large plates, that are used for detailed examinations and these levels, exact levels that are given in these cases are a number of hundreds of milliroentgens.

Mr. HOLIFIELD. When you say milliroentgen, you mean thousandths of a roentgen?

Dr. HARRIS. Yes.

Mr. HOLIFIELD. So the amount you allow offsite of 3 roentgens is quite a bit more than a person receives in either a fluoroscopic or an X-ray body examination?

Dr. HARRIS. Sir, I would like to correct one point, I believe.

Dr. Tompkins, Dr. Vortman, and myself agree that the level offsite for operation is not 3 roentgens. It is much less than that. It is essentially a factor of 10 below 3 roentgens.

Mr. HOLIFIELD. Let us reduce that to milliroentgens.

Dr. HARRIS. That would be 300 milliroentgens.

Mr. HOLIFIELD. Well, this makes quite a difference, you see, in the testimony.

Then your offsite allowable of the exposure does correspond with a fluoroscopic examination?

Dr. HARRIS. Of certain types, yes, sir.

Mr. HOLIFIELD. And in a fluoroscopic examination, I realize the time element enters into it. If it was left on the patient an unusual length of time, it would run higher than the offsite.

Dr. HARRIS. It could, yes, sir.

Mr. HOLIFIELD. And if it was just instantaneous, it would be less. Let us get to some comparison.

Your 13-week allowable is 3.9. Are you in agreement upon that figure?

Dr. HARRIS. Yes, sir.

Mr. HOLIFIELD. And that is accumulated? That is the accumulated exposure?

Dr. HARRIS. Yes, sir.

Mr. HOLIFIELD. And if you had several fluoroscopic or X-ray examinations that would also be cumulative?

Dr. HARRIS. Well, sir, I do not quite understand what you mean by "accumulative."

Mr. HOLIFIELD. I mean the exposure. The radiation.

Dr. HARRIS. The total dose is accumulative, but the response to a dose, the effective response to a dose has some relation to the time over which the dose is given.

Mr. HOLIFIELD. That is true.

Dr. HARRIS. So that the effective level of dose, after a number of X-ray exposures separated in time, in which the total accumulated dose would be equal to or greater than what is allowed for operational purposes, the effective dose in terms of body effect may very well be less than for the single-shot exposure during a field operation.

Mr. HOLIFIELD. That is true, but we are not talking about a single shot; we are talking about a 3.9 roentgen exposure over a 13-week period, which is an accumulative rate, is it not?

Dr. HARRIS. This can be given. The regulations for field operations are such that the 3.9 can be obtained in any time period over this 13 weeks.

Mr. HOLIFIELD. That is true, but if it is contained in the one shot you remove the individual and do not allow him to have any more.

And your 5 roentgens operational dose for 1 year, that is also accumulative and if it is given in 1 dose you remove that individual from further exposure.

Dr. HARRIS. Yes, sir.

Mr. HOLIFIELD. Áre there any further questions?

Mr. CORSBIE. Well, Mr. Chairman, since we were dealing with numbers that I was not prepared to talk about I would like permission to provide for your committee copies of the operational criteria which spells out in detail these numbers that we have been discussing. Mr. HOLIFIELD. All right, if it is provided in laymen's terms so we can understand it, we will accept it.

(The information requested, appears below :)

Hon. CHET HOLIFIELD,

UNITED STATES ATOMIC ENERGY COMMISSION,
Washington, D. C., May 12, 1958.

Chairman, Subcommittee on Military Operations, Committee on Government Operations, House of Representatives.

DEAR MR. HOLIFIELD: In reply to your request of April 30, 1958, the radiological safety criteria for the Nevada test site are given below.

For operational personnel onsite, the maximum exposure to whole body external gamma radiation is 3.0 roentgens for any 13 consecutive weeks and a maximum of 5 roentgens within a period of 1 year.

For the general populace offsite, the Atomic Energy Commission adopted, as an operational guide, 3.9 roentgens whole body external gamma radiation for Operation Plumbbob. A detailed description of the offsite radiological safety criteria is reproduced in the hearings before the Special Subcommittee on Radiation of the Joint Committee on Atomic Energy, May-June 1957, pages 248–258. The radiation exposures onsite are normally accumulated in increments. Although great effort is made to hold the radiation exposures to as low a value as possible, these radiation doses may be deliberately incurred up to the maximum permissible limits, if the requirements of the test operation are imperative. For the offsite general populace, the basic philosophy is to hold the radiation exposures to an absolute minimum. Past experience has shown that because of the very nature of the phenomenology of fallout the higher exposures to communities around the Nevada test site have resulted from a single or very few occasions of fallout. As the tests have progressed close scrutiny has been kept of these exposures in all communities. If any locality showed a significantly higher than average amount of fallout, that area was avoided when planning future detonations.

The reason for proposing any radiation exposure number for the general populace is for guidance to the test organization. In their deliberations before each detonation the advisory panel of the test organization make careful estimates of the most probable patterns of fallout. Since such predictions cannot be guaranteed to be precisely correct, estimates are also made of what might be the worst consequences in the unlikely event these predictions prove to be quite incorrect. It is under these worst conditions that it is said that the predicted fallout should not result in an exposure greatly in excess of 3.9 roentgens.

The record for radiological safety for the Nevada test site speaks for itself. The following is quoted from the congressional hearings mentioned above (pp. 180-181).

"*** the highest fallout level noted to date in an inhabited place around the Nevada test site occurred in 1953 at a motor court near Bunkerville, Nev., where about 15 people might have accumulated 7 to 8 roentgens if they had continued to live there indefinitely."

The National Committee on Radiation Protection and Measurement has stated “*** that individual persons not receive more than a total of accumulated dose to the reproductive cells of 50 roentgens up to age 30 years * * * and not more than 50 roentgens additional up to age 40 ***”

Also, on page 181 of the congressional hearings it is stated "*** the average exposure to only those communities around the Nevada test site that experienced the greatest amount of fallout (0.2 roentgens or more) is 0.6 roentgens for the 6 years since the regular nuclear tests were started *** if the area considered around the Nevada test site is enlarged to include 1 million people the average exposure is 0.1 roentgens for the 6 years or at a rate of about onehalf roentgen per 30 years. This is one-twentieth of the recommendation of the National Committee on Radiation Protection and Measurement for maximum exposures."

Operation Plumbbob (spring and summer 1957) did not materially change these values. There were no higher individual exposures offsite and the small fallout that occurred on some communities was balanced by the addition of the 1 year in the calculations, i. e., the rate remains about 0.1 roentgen per year for the communities with the highest exposures (about 100,000 people), and about one-half roentgen for 30 years for the 1 million people nearest to the Nevada test site.

We will be pleased to furnish you with any additional information you may desire.

Sincerely yours,

C. L. DUNHAM, M. D., Director, Division of Biology and Medicine.

Mr. ROBACK. On page 8 and page 9 of Mr. Corsbie's statement, is he in effect making a plea for continued bomb testing?

Mr. CORSBIE. As we have stated, the tests are useful in proof testing or validating laboratory and theoretical work. In general, until there is a proof test of theoretical concepts, there are uncertainties which could possibly be accepted, but utilizing the test is a means of refining information,

Mr. ROBACK. Somebody probably questions the contribution of testmade knowledge. Is this a statement with regard to the beneficial effects in book knowledge as it relates to human life in peacetimeendeavor or is this a question of balancing the risks of knowing how to protect yourself against weapons as against not testing? Mr. CORSBIE. There are some of both elements in it.

I might say with reference to your query that if a bomb or bombs. could be detonated for the express purpose of gaining information on the effects, as contrasted with attempting to get effects information from developmental shots where yields are uncertain and there are many other uncertainties which reduce the probability of getting good information from the test-good effects information-then there is, in my opinion, my personal opinion, a need for tests for the benefits of mankind. If we say that gaining more information on the biomedical effects of radiation, more information on shielding aspects, more information on blast biology and physical damage from blast, are representative criteria with which the tests are undertaken, then they are needed.

Mr. ROBACK. If there was no more bomb testing by international convention or otherwise, then the information would proceed by laboratory and developmental testing. In other words, you would try to learn as much as you could without explosions. Does that follow? Mr. CORSBIE. There would be no other recourse. Insofar as investigations having to do with radiation are concerned, you would have to deal with artificial sources. If it were prompt radiation it would be a matter of sources that would be used in single or multiple locations. If it were a matter of fallout to be investigated, it would be by simulants distributed over an area. Relative to thermal and blast, I think the thermal could be handled fairly well through current laboratory techniques and capabilities, and blasts in a somewhat less satisfactory degree.

Mr. HOLIFIELD. The testing of small bombs in Nevada does give you the opportunity to extrapolate, does it not, on higher pounds per square inch pressure and higher degrees of intensity of radiation?

Mr. CORSBIE. Yes, sir. The one area in which information is especially needed is in a correlation between low yield and high yield bursts or, as you have stated, extrapolating from low yield of kilotons to megatons, or fractional kilotons to megatons.