Mr. HOLIFIELD. The committee will stand adjourned to answer the rollcall.

(A brief recess was taken.)

Mr. HOLIFIELD. The committee will be in order.

I believe Dr. Clayton White is the next witness.

Mr. CORSBIE. Mr. Chairman, with your permission we would like to make a change in our order and have Dr. Tompkins testify. This is to accommodate Dr. Tompkins.

Mr. HOLIFIELD. We have a little problem with one of the witnesses from the FCDA who has to be back in Connecticut and then if we put Dr. Tompkins on now we will ask Dr. White to step aside for the time being so we can accommodate Dr. Newmark who has to catch a plane back.

Would you like to have Dr. Tompkins on now?

Mr. CORSBIE. If you please, sir.

FURTHER STATEMENT OF DR. PAUL C. TOMPKINS, SCIENTIFIC DIRECTOR, UNITED STATES NAVAL RADIOLOGICAL DEFENSE LABORATORY, AND DIRECTOR, CETG PROJECT 32

Dr. TOMPKINS. Mr. Chairman and members of the subcommittee, I will be reporting on CETG project 32.3.

Mr. HOLIFIELD. For what year, please?

Dr. TOMPKINS. 1957.

This was originally planned to be an operational evaluation of the radiological defense system proposed by the United States Naval Radiological Defense Laboratory. It was to have involved two shelters, one staging area and a small vital area. About 100 personnel were to be involved in the project. The shot conditions that would make this particular approach worth while did not materialize so the project was scaled down to a study of certain system components associated with the shelter and the staging area, and a study of all the operations within the shelter and from the shelter leading to the establishment of the staging area.

Our major effort was on Shot Diablo, which was approximately a nominal weapon, that is 20-kiloton on a 500-foot tower about 1 mile from the shelter.

(Slide No. 1 was shown.)

SLIDE NO. 1.--Entrance ramp, showing tunnel opening.

The first slide shows the entrance tunnel to the shelter with the. Diablo tower in the background.

(Slide No. 2 was shown.)

The second slide shows the interior of the shelter near the door.. Mr. HOLIFIELD. Is this after the shot?

Dr. TOMPKINS. No, these are pictures before the shot. The shelter is a modified Navy stock ammunition storage magazine, 25 feet by 48. feet. The modification consists of the wooden strongback shown there on the end wall.

An identical structure was tested for blast resistance in another program and another shot and performed very well.

Our concern was with the radiological protection afforded by the shelter when it contained such operational necessities as ventilators, fast-loading entrances and similar openings.

Mr. HOLIFIELD. Now, will you tell us something about the earth coverage on this?

Dr. TOMPKINS. Yes, sir.

25978-58-pt. 1- -6

What you see on this slide is the forward dosimeter tube which is the basic operational radiation detector in the shelter. It consists of a 1-inch steel pipe fitted with a rod that carries the self-reading dosimeter at the upper end. In use, the dosimeter is read, pushed up to an exposed position 3 feet above the ground, withdrawn after a timed interval and read.

The dose accrued during the timed interval is converted to a rate measurement in roentgens per hour.

Shot Diablo gave us a good fallout. (Slide No. 3 was shown.)

SLIDE NO. 3.-Time sequence of the arrival of the fallout.

The next slide shows the time sequence of the arrival of the fallout at the shelter. The left-hand side up there shows the initial gamma. That dropped off at the middle period until the fallout arrived and built up to a peak and dropped off with normal radioactive decay.

Mr. HOLIFIELD. What are the numbers on the bottom?

Dr. TOMPKINS. That is time in minutes. It shows that the peak fallout arrived about 15 minutes after shot time.

Mr. HOLIFIELD. What is the reading on the left?

Dr. TOMPKINS. The reading on the left is in roentgens per hour. The peak was about 100 roentgens per hour which is a dose, a total dose outside of the shelter approximately equal to that which the Rongelap group received after Castle Bravo. This is the reading on the outside.

The group of Rongelap received about 150 to 175 roentgens total dose.

Mr. HOLIFIELD. What has been the history of those people? Have we enough knowledge to predict the physical effect upon them? I saw some of these people personally and interviewed them, and I saw some of the burns which they had and hair slippage and one thing or another, which was minor in degree.

Can you tell how long it took them to restore the blood count to normal and whether there have been any long-range deleterious effects that the doctors can testify to?

Dr. TOMPKINS. I could comment on that, Mr. Chairman, briefly. There certainly were no fatalities. All of the symptoms were cured. I believe that the time for recovery of the normal blood count was something of the order of 3 months and at the present time there are no further indications of injury, or incapacitation. It is too early to tell about the very long, delayed effects. Apparently they are all all right at this point.

Mr. HOLIFIELD. I think it is important to understand that even though you are exposed to a considerable number of roentgens, it does not necessarily mean that death will result. There might be a possible shortening of the days or weeks or years of a person's life as a result of that. There might be a general susceptibility to disease which might take them off, but certainly when we speak of shelter which does not shelter completely but does keep the exposure to a tolerable amount in terms of continuity of life, as contradistinct from outside exposure which would mean death within a few days or weeks, why we are in a field where there is a great area of protection that can be offered if we go about it in the right way, is that not true? Dr. TOMPKINS. I think that is correct; yes.

One might point out that the doses received could not have been much larger without creating casualties. They are certainly on the upper margin of coming out all right.

I would like to pause here in my formal statement and describe briefly for you the actual shelter. The shelter is one of the hemispherical quonset-type huts completely buried in the ground. The shelter entrance was the first slide.

It is completely buried.

Mr. HOLIFIELD. The size of this was 25 by 48?

Dr. TOMPKINS. 25 by 48.

Mr. HOLIFIELD. And it had how much earth over it?

Dr. TOMPKINS. Three feet. It is basically the same as the one Mr. Vortman has talked about. The important thing is to see how much of a lump was raised there. The shelter itself was at ground level. A hole was dug in the top of the shelter at ground level and the earth piled back over it.