Almost all the people in the Northeast, almost all dwellings there, have basements, 93 percent of the people have ready access to basements in the northeastern section of the United States.

Mr. ROBACK. Mr. Hanunian, is that information based upon the housing census?

Mr. HANUNIAN. This information is not based upon the census taken last year. That information was not available when I made

these estimates and, so far as I know, it still is not.

The number of basements included as part of the basement census is based rather on the Bureau of Labor Statistics work showing the increments to dwellings, the new dwellings built, and their nature.

Those surveys by the Bureau of Labor Statistics were sample surveys. There is a sampling error involved, but I gather from talking to population census people that the overall figure of about 60 percent or 55 percent is in the right ball park.

Mr. ROBACK. Sixty percent; what is the total number of dwelling units, about 60 million?

Mr. HANUNIAN. I do not know that.

Mr. HOLIFIELD. I think the previous hearings showed about 45 million, if I remember correctly.

Mr. ROBACK. I believe the figure is higher, but if I recall the figures, Mr. Chairman, as many as 20 million units would be tenant occupied, in which case there might not be as much incentive to do anything about improving the opportunity for shelter.

However, Mr. Hanunian is not testifying on that point.

Mr. HANUNIAN. Well, because of this uneven distribution of basements, because not everyone, by any means, has basements or ready access to basements, there is some point in considering a case in which those persons who have ready access to basements make use of them while the rest of the population benefits from no more than the incidental protection described earlier.

MORE BASEMENTS IN DENSELY POPULATED AREAS

Mr. HOLIFIELD. Fortunately, the population concentration seems to be in the area where you do have basements.

Mr. HANUNIAN. Yes, that is right. The location of the basements is doubly fortunate, in fact. It is fortunate because basements are common in the most densely populated regions.

It is also fortunate in a different sort of way, in that basements are scarce in those regions where the amount of shelter they provide would probably be inadequate anyway; that is to say, near the densely targeted missile installations.

But to go on, the three degrees of fallout protection I have described so far reflect, at most, only very modest civil defense protection, if any at all. None imposes a requirement for construction of anything more elaborate than a foxhole, and that much is required only when persons who lack access to basements try to achieve equivalent shelter. However, it now seems that the United States is about to begin a more ambitious civil defense program, one involving the creation of special fallout shelters of some sort. To reflect a completed program of this general sort (though certainly not specifically of the kind the officials have in mind—I do not yet know what that is exactly),

but a modest shelter program-to reflect a completed program of that type, there is a fourth shelter case I want to consider.

ASSUMED FALLOUT SHELTER POTENTIAL

In this fourth case the nuclear residual is 2 percent, that is to say, 2 percent of the radiation outside reaches the population which is inside some kind of shelter. And thirds of a population again receive differing fractions: One-third receiving 1 percent; one-third receiving 2 percent, and one-third receiving 4 percent.

At the very least, these residuals imply virtually continuous occupancy of special shelters in basements, something like the sandbag walled and roofed huts I described a moment ago; however, part-time occupancy of fallout shelters that also provide modest blast protection is implicit in the casualty estimate I am going to show you. This next chart summarizes these four types of shelters. (See table NH-1.)

TABLE NH-1.-Levels of residual radiation

1 Radiation received, as a percentage of the ambient dose.

The incidental protection (which is no shelter at all, really, except that incidental to ordinary behavior), in which the population receives about 40 percent of the dose available to them, the ambient dose.

The basement protection case, the one I discussed second, in which they get a median value of 10 percent of the dose; then a mixture of the incidental and basement cases (to take account of the varying availability of basements), in which, of course, the protection mounts and they receive between 10 and 40 percent; and then the special fallout shelter where the median residual is 2 percent.

Before leaving this topic I should point out that it may be important for shelter occupants to remain in their shelters continuously, or nearly so, for much more than a day or so. To be sure, the rate of radiation falls rapidly over time. Two days after detonation it will be down to 1 percent of the rate at 1 hour after detonation; but even a week or more later, the level may still be high enough to be unacceptable.

The damage estimates I am presenting today are based on maximum biological doses. These were computed with attenuation of the radiation assumed to be constant over time. This may be interpreted as meaning either that the behavior of the population does not change (for example the shelters are occupied continuously), or that abandonment of the shelters is accompanied by local decontamination efforts, or that areas that are still dangerous are evacuated when the shelters are abandoned—which of these interpretations it is appropriate to put on it depending upon which kind of shelter you are considering. It certainly is possible for the population to continue "peacetime" behavior indefinitely until it dies, at least in the incidental protection

case.

But in the case of the better quality protection-the best one I have discussed—it would certainly be necessary for the population to decontaminate if they came out of the shelter after a heavy attack, say, 2 weeks following that attack.

Mr. HOLIFIELD. Those figures are figures representing exposure?

Mr. HANUNIAN. Yes. This indicates the amount of exposure, the fraction of the total dose that does get through.

I would like now to go on to the final attack comparison that I want to show.

Earlier, in the course of exploring how fatalities among the general population are affected by changes in the weight of military or urban center attacks, we noted that an attacker intent on destroying large numbers of people may be able to do it very cheaply. We have seen that diverting only a few hundred megatons from military targets to cities will produce perhaps 50 million deaths from prompt effects alone, if the population is unprepared, and that with fallout the total might be as high as 80 million. But we have also seen that far fewer deaths would result from an attack directed solely against military installations.

Thus it is clear that the validity of any forecasts of attack outcome depends on how well those forecasts reflect enemy motivations. Since these are somewhat unpredictable, prudence demands that we develop the implications of alternative motivations.

I have already made a gesture in that direction by considering attacks against cities and against military installations as alternatives between which the attacker may choose. There would be some point to considering variants of both sorts of attack, but variations of military attacks have the more interesting implication for war plans and for strategy, and it is these we shall consider here. Since some of these attacks may be at least as appropriate to a late time period as to an early one, we ought to allow for the possibility that changes will be made in our civil defense program.

Therefore, I shall now expand the variety of the assumed civil defense postures to include, as one alternative, the use of the specially constructed shelters.

Mr. HOLIFIELD. Now, on this last column there, the fallout shelters, are you including in that category shelters in basements which have been adapted to give the maximum protection from fallout and other types of shelter which might be arranged underground; are you? Mr. HANUNIAN. Yes.

What I mean to imply by this assumption about the residual radiation reaching the population is that this may be the result of there being improved basements, carefully improved basements, with extremely careful use being made of those improved basements.

Mr. HOLIFIELD. Do your figures appear just for houses that have basements, or are you including in addition to basements-is this a figure for the whole population providing they have the equivalent of underground protection which could come from an adapted basement?

Mr. HANUNIAN. Let me try to clarify what I have in mind here. The assumption I have made is really that a certain amount, a certain fraction, of the radiation gets through to the population.

This assumption is consistent with alternative interpretations. One such interpretation is that the people are spending their time continuously in well-improved dwelling basements, that is, basement shelters with sandbagged walls.

Mr. HOLIFIELD. During most of the attack, for the period of time necessary for the radiation to decay on the outside?

Mr. HANUNIAN. The blast survivors enter these basements of theirs, where they have specially prepared shelters in the corner of the basement, perhaps with sandbagged walls and with a roof of beams, and sandbags on the top of that.

They spend every minute of the day there for the first couple of days, and virtually no time outside of those areas for the next couple of weeks.

Now, the assumption I have made is also consistent with a shelter which requires less of the population by way of careful behavior, that is to say, it is consistent with a much better quality shelter (a more expensive shelter, to be sure, but a better quality shelter) that gives them a higher degree of protection during the time they are in the shelter, and, therefore, allows them to spend a larger fraction of their time outside the shelter without getting any larger dose than they would have by that very careful behavior in the basement.

Mr. HOLIFIELD. It is evident there are many basements-let us take the tunnels under the Capitol, for instance, and other rooms under the office buildings in the Capitol, that would be much superior to an ordinary small basement in a residential area from the standpoint of protection

Mr. HANUNIAN. That is right.

Mr. HOLIFIELD (continuing). Because they are deeper, they have more over head in the basement and all that sort of thing.

Mr. HANUNIAN. Yes. There are two important variables, really, that determine the amount of effective shielding. One is the quality of the structure sheltering the people; the other is the quality of their behavior-how well they make use of that shielding.

REASONS FOR DIFFERENT ENEMY ATTACKS

It is well known that surface bursts produce many times the amount of local fallout that air bursts produce, weapon for weapon. An attacker will not be strongly motivated to use only surface bursts unless his intent is to maximize the fallout hazard. If he uses surface bursts rather than air bursts, he sacrifices military effectiveness so far as blast damage is concerned. There is, to be sure, some compensatory advantage gained in that the resulting fallout will make more awkward the continued use of any target installations that have escaped physical destruction.

It is only against fairly hard structures, structures vulnerable to nothing less than about 100 pounds per square inch peak overpressures, that surface bursts appear to be advantageous for him; and thus we would not be justified in assuming that an attacker would use surface bursts universally. He might very well use them against hard targets;

he might choose to attack hard targets in that way. But for the rest we cannot say. And we are, therefore, obliged to consider air bursts as well.

There is another basis for differentiation among military attacks: The allocation of attack weight between missile launch sites and other prime military targets.

While contemplating target sets, we noted that these two categories have distinctly different locational patterns, missile sites being in the west, the other military installations being distributed more or less uniformly. We can expect that casualties among the population at large will show some dependence on where the attack emphasis falls. Further, it is not at all clear on which category the Soviets would concentrate the bulk of their attack. We can expect this to change with time and with circumstances. (For example, imagine a Soviet planner pointing out that if their forces failed to achieve surprise in attacking our missiles, our missiles might have flown from the silos, leaving behind them profitless targets. The planner might urge that retargeting be considered for this contingency.)

CASUALTIES FROM VARIOUS 3,000-MEGATON ATTACKS ON MILITARY TARGETS

I want now to consider four combinations of these variations: missile launch sites receiving alternatively one-sixth and five-sixths of the entire attack weight, with surface bursts being used either universally or only where physically hard structures are the targets. Let us now examine the outcome of such attack variants.

Here, once again, fatalities are shown as a percentage of the national population. Now, however, we consider only total deaths, not blast and fallout deaths separately. (See fig. NH-5.)

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