Chapter II

A NUCLEAR WEAPON OVER DETROIT OR LENINGRAD: A TUTORIAL ON THE EFFECTS OF NUCLEAR WEAPONS
Chapter ll.A NUCLEAR WEAPON OVER DETROIT OR LENINGRAD: A TUTORIAL ON THE EFFECTS OF NUCLEAR WEAPONS
Introduction. 15 General Description of Effects. 15 Blast. 16 Direct Nuclear Radiation. 19 Thermal Radiation. 20 Fires. 21 Electromagnetic Pulse. 22 Fallout. 22 Combined Injuries (Synergism). 26 Detroit and Leningrad. 27 1Mt on the Surface in Detroit. 27 Physical Damage. 27 Infrastructure Status. 33 Radioactive Fallout. 34 Summary. 35 1-Mt Air Burst on Detroit. 35 25-Mt Air Burst on Detroit. 37 Leningrad. 39 l-Mtand 9-Mt Air Bursts on Leningrad. 39 Ten 40-kt Air Bursts on Leningrad. 39 1-kt Terrorist Weapon at Ground Level. 45

TABLES

3. Blast Effects of a 1-Mt Explosion 8,000 ft Above the Earths Surface. 18 4. Casualty Estimates. 31 S. Burn Casualty Estimates. 32 FIGURES
l. Vulnerability of Population in Various Overpressure Zones. 19 2. Main Fallout Pattern Uniform 15 mph Southwest Wind. 24 3. Main Fallout Pattern Uniform 15 mph Northwest Wind. 25 4. Detroit 1-Mt Surface Burst. 29 5. Detroit 1-Mt Air Burst. 36 6. Casualties.,. 37 7. Detroit 25-Mt Air Burst. 38 8. Leningrad Commercial and Residential Sections. 40 9. Leningrad Populated Area. 41 IO. Leningrad l-Mt Air Burst. 42 11. Leningrad 9-Mt Air Burst. 43 12. Leningrad Ten 40-kt Air Burst. 44

INTRODUCTION

This chapter presents a brief description of the major effects of nuclear explosions on the people and structures in urban areas. The details of such effects would vary according to weapons design, the exact geographical layout of the target area, the materials and methods used for construction in the target area, and the weather (especially the amount of moisture in the atmosphere). Thus, the reader should bear in mind that the statements below are essentially generalizations, which are subject to a substantial range of variation and uncertainty. To convey some sense of the actual effects of large nuclear explosions on urban areas, the potential impact of explosions is described in two real citiesDetroit and Leningrad. To show how these effects vary with the size of the weapon, the effects have been calculated in each city for a variety of weapon sizes. The descriptions and analysis assume that there is no damage elsewhere in the country. This may appear unlikely, and in the case of a surface burst it is certainly wrong, since a surface burst would generate fallout that would cause casualties elsewhere. However, isolating the effects on a single city allows the setting forth in clear terms of the direct and immediate effects of nuclear explosions. The result is a kind of tutorial in nuclear effects. Subsequent sections of this report, which deal with the effects of larger attacks, discuss the indirect effects of fallout and of economic and social disruption. Although it is outside the scope of a discussion of nuclear war, there has been considerable public interest in the effects of a nuclear explosion that a terrorist group might succeed in setting off in an urban area. Accordingly, a discussion of this possibility y is added at the end of this chapter.
GENERAL DESCRIPTION OF EFFECTS
The energy of a nuclear explosion is released in a number of different ways:
pulses of electrical and magnetic energy, called electromagnetic pulse (EM P); and the creation of a variety of radioactive particles, which are thrown up into the air by the force of the blast, and are called radioactive fallout when they return to Earth.

an explosive blast, which is qualitatively similar to the blast from ordinary chemical explosions, but which has somewhat different effects because it is typically so much larger; direct nuclear radiation; direct thermal radiation, most of which takes the form of visible Iight;
The distribution of the bombs energy among these effects depends on its size and on
16. The Effects of Nuclear War
the details of its design, but a general description is possible.

Blast and shock

Thermal radiation and EMP
Most damage to cities from large weapons
(called static overpressure) that can crush objects, and high winds (called dynamic pressure) that can move them suddenly or knock them down. In general, large buildings are destroyed by the overpressure, while people and objects such as trees and utility poles are destoyed by the wind. For example, consider the effects of a 1megaton (Mt) air burst on things 4 miles [6 km]
Initial nuclear radiation
Residual nuclear radiation (fallout)
Effects of a nuclear explosion
Thermonuclear ground burst
Photo credit: U S Department of Energy
Ch. IIA Nuclear Weapon Over Detroit or Leningrad: A Tutorial on the Effects of Nuclear Weapons q 17
away. The overpressure will be in excess of 5 pounds per square inch (psi), which will exert a force of more than 180 tons on the wall of a typical two-story house. At the same place, there would be a wind of 160 mph [255 km]; while 5 psi is not enough to crush a man, a wind of 180 mph would create fatal collisions is ions between people and nearby objects. The magnitude of the blast effect (generally measured in pounds per square inch) diminishes with distance from the center of the explosion. It is related in a more complicated way to the height of the burst above ground level. For any given distance from the center of the explosion, there is an optimum burst height that will produce the greatest overpressure,
and the greater the distance the greater the optimum burst height. As a result, a burst on the surface produces the greatest overpressure at very close ranges (which is why surface bursts are used to attack very hard, very small targets such as missile silos), but less overpressure than an air burst at somewhat longer ranges. Raising the height of the burst reduces the overpressure directly under the bomb, but widens the area at which a given smaller overpressure is produced. Thus, an attack on factories with a l-Mt weapon might use an air burst at an altitude of 8,000 feet [2,400 m], which would maximize the area (about 28 mi2 [7,200 hectares]) that would receive 10 psi or more of overpressure.

Fireball from an air burst in the megaton energy range
Photo credit: U S Air Force
18. The Effects of Nuc/ear War
Photo credit U S Uepartmenf of Defense
The faintly luminous shock front seen just ahead of the fireball soon after breakaway
Table 3 shows the ranges of overpressures and effects from such a blast. When a nuclear weapon is detonated on or near the surface of the Earth, the blast digs out a large crater. Some of the material that used to be in the crater is deposited on the rim of the crater; the rest is carried up into the air and
returns to Earth as fallout. An explosion that is farther above the Earths surface than the radius of the fireball does not dig a crater and produces negligible immediate fallout. For the most part, blast kills people by indirect means rather than by direct pressure. While a human body can withstand up to 30
Table 3.Blast Effects of a 1-Mt Explosion 8,000 ft Above the Earths Surface
Distance from ground zero (stat. miles) (kilometers) 1,3.48 Peak overpressure 20 psi 10 psi Peak wind velocity (mph) Typical blast effects Reinforced concrete structures are leveled. Most factories and commercial buildings are collapsed. Small wood-frame and brick residences destroyed and distributed as debris, Lightly constructed commercial buildings and typical residences are destroyed, heavier construction IS severely damaged Walls of typical steel-frame buildings are blown away: severe damage to residences. Winds sufficient to kill people in the open. Damage to structures, people endangered by flying glass and debris
Ch. IIA Nuclear Weapon Over Detroit or Leningrad: A Tutorial on the Effects of Nuclear Weapons
psi of simple overpressure, the winds associated with as little as 2 to 3 psi could be expected to blow people out of typical modern office buildings. Most blast deaths result from the collapse of occupied buildings, from people being blown into objects, or from buildings or smaller objects being blown onto or into people. Clearly, then, it is impossible to calculate with any precision how many people would be killed by a given blastthe effects would vary from buiIding to buiIding. In order to estimate the number of casualties from any given explosion, it is necessary to make assumptions about the proportion of people who will be killed or injured at any given overpressure. The assumptions used in this chapter are shown in figure 1. They are relatively conservative. For example, weapons tests suggest that a typical residence will be collapsed by an overpressure of about 5 psi. People standing in such a residence have a 50percent chance of being killed by an overpressure of 3.5 psi, but people who are lying down at the moment the blast wave hits have a 50-percent chance of surviving a 7-psi overpressure. The calculations used here assume a mean lethal overpressure of 5 to 6 psi for people in residences, meaning that more than half of those whose houses are blown down on top of them will nevertheless survive. Some studies use a simpler technique: they assume that the number of people who survive in areas receiving more than 5 psi equal the number of peoFigure 1.Vulnerability of Population in Various

Photo credit U S Air force
Burn injuries from nuclear blasts

Thermal Radiation

Approximately 35 percent of the energy from a nuclear explosion is an intense burst of thermal radiation, i.e., heat. The effects are roughly analogous to the effect of a 2-second flash from an enormous sunlamp. Since the thermal radiation travels at the speed of light (actually a bit slower, since it is deflected by particles in the atmosphere), the flash of light and heat precedes the blast wave by several seconds, just as lightning is seen before the thunder is heard.
Photo credit U S Department of Defense
The patients skin is burned in a pattern corresponding to the dark portions of a kimono worn at the time of the explosion
The visible light will produce flashblindness in people who are looking in the direction of the explosion. Flashblindness can last for several minutes, after which recovery is total. A l-Mt explosion could cause flashblindness at distances as great as 13 miles [21 km] on a clear day, or 53 miles [85 km] on a clear night. If the flash is focused through the lens of the eye, a permanent retinal burn will result. At Hiroshima and Nagasaki, there were many cases of flashblindness, but only one case of retinal burn, among the survivors. On the other hand, anyone flashblinded while driving a car could easiIy cause permanent injury to himself and to others. Skin burns result from higher intensities of light, and therefore take place closer to the point of explosion. A 1-Mt explosion can cause first-degree burns (equivalent to a bad sunburn) at distances of about 7 miles [11 km], second-degree burns (producing blisters that lead to infection if untreated, and permanent scars) at distances of about 6 miles [10 km], and third-degree burns (which destroy skin tissue) at distances of up to 5 miles [8 km]. Third-degree burns over 24 percent of the body, or second-degree burns over 30 percent of the body, will result in serious shock, and will probably prove fatal unless prompt, specialized medical care is available. The entire United States has facilities to treat 1,000 or 2,000 severe burn cases; a single nuclear weapon could produce more than 10,000. The distance at which burns are dangerous depends heavily on weather conditions. Extensive moisture or a high concentration of particles in the air (smog) absorbs thermal radiation. Thermal radiation behaves like sunlight, so objects create shadows behind which the thermal radiation is indirect (reflected) and less intense. Some conditions, such as ice on the ground or low white clouds over clean air, can increase the range of dangerous thermal radiation.

general, ignitible materials outside the house, such as leaves or newspapers, are not surrounded by enough combustible material to generate a self-sustaining fire. Fires more likely to spread are those caused by thermal radiation passing through windows to ignite beds and overstuffed furniture inside houses. A rather substantial amount of combustible material must burn vigorously for 10 to 20 minutes before the room, or whole house, becomes inflamed. The blast wave, which arrives after most thermal energy has been expended, will have some extinguishing effect on the fires. However, studies and tests of this effect have been very contradictory, so the extent to which blast can be counted on to extinguish fire starts remains quite uncertain. Another possible source of fires, which might be more damaging in urban areas, is indirect. Blast damage to stores, water heaters, furnaces, electrical circuits, or gas lines would ignite fires where fuel is plentiful. The best estimates are that at the 5-psi level about 10 percent of al I buildings would sustain a serious fire, while at 2 psi about 2 percent would have serious fires, usualIy arising from secondary sources such as blast-damaged utilities rather than direct thermal radiation. It is possible that individual fires, whether caused by thermal radiation or by blast damage to utilities, furnaces, etc., would coalesce into a mass fire that would consume alI structures over a large area. This possibility has been intensely studied, but there remains no basis for estimating its probability. Mass fires could be of two kinds: a firestorm, in which violent inrushing winds create extremely high temperatures but prevent the fire from spreading radially outwards, and a conflagration, in which a fire spreads along a front. Hamburg, Tokyo, and Hiroshima experienced firestorms in World War 11; the Great Chicago Fire and the San Francisco Earthquake Fire were conflagrations. A firestorm is likely to kill a high proportion of the people in the area of the fire, through heat and through asphyxiation of those in shelters. A confIagration spreads slowly enough so that people in its path can
The thermal radiation from a nuclear explosion can directly ignite kindling materials. In
22 q The Etffects of Nuclear War
escape, though a conflagration caused by a nuclear attack might take a heavy toll of those too injured to walk. Some believe that firestorms in U.S. or Soviet cities are unlikely because the density of flammable materials (fuel loading) is too lowthe ignition of a firestorm is thought to require a fuel loading of at least 8 lbs/ft2 (Hamburg had 32), compared to fuel loading of 2 lbs/ft 2 in a typical U.S. suburb and 5 lbs/ft2 in a neighborhood of twostory brick rowhouses. The Iikelihood of a conflagration depends on the geography of the area, the speed and direction of the wind, and details of building construction. Another variable is whether people and equipment are available to fight fires before they can coalesce and spread.

Ch, IIA Nuclear Weapon Over Detroit or Leningrad: A Tutorial on the Effects of Nuclear Weapons 23
are unlikely to cause many deaths, because they will fall in areas where most people have already been killed. However, the radioactivity will complicate efforts at rescue or eventual reconstruct ion. The radioactive particles that rise higher will be carried some distance by the wind before returning to Earth, and hence the area and intensity of the fallout is strongly influenced by local weather conditions. Much of the material is simply blown downwind in a long plume, The map shown in figure 2 illustrates the plume expected from a 1-Mt surface burst in Detroit if winds were blowing toward Canada. The illustrated plume assumed that the winds were blowing at a uniform speed of 15 mph [24 km] over the entire region, The plume wouId be longer and thinner if the winds were more intense and shorter and somewhat more broad if the winds were slower. If the winds were from a different direction, the plume would cover a different area. For example, a wind from the northwest would deposit enough fallout on Cleveland to inflict acute radiation sickness on those who did not evacuate or use effective fallout shelters (figure 3). Thus wind direction can make an enormous difference. Rainfal I can also have a significant influence on the ways in which radiation from smalIer weapons is deposited, since rain will carry contaminated particles to the ground. The areas receiving such contaminated rainfall would become hot spots, with greater radiation intensity than their surroundings, When the radiation intensity from fallout is great enough to pose an immediate threat to health, fallout will generally be visible as a thin layer of dust. The amount of radiation produced by fallout materials will decrease with time as the radioactive materials decay. Each material decays at a different rate, Materials that decay rapidly give off intense radiation for a short period of time while long-lived materials radiate less intensely but for longer periods, Immediately after the fallout is deposited in regions surrounding the blast site, radiation intensities will be very high as the short-lived
materials decay. These intense radiations will decrease relatively quickly. The intensity will have fallen by a factor of 10 after 7 hours, a factor of 100 after 49 hours and a factor of 1,000 after 2 weeks. The areas in the plume illustrated in figures 2 and 3 would become safe (by peacetime standards) in 2 to 3 years for the outer ellipse, and in 10 years or so for the inner ellipse. Some radioactive particles will be thrust into the stratosphere, and may not return to Earth for some years. In this case only the particularly long-lived particles pose a threat, and they are dispersed around the world over a range of latitudes, Some fallout from U.S. and Soviet weapons tests in the 1950s and early 1960s can still be detected. There are also some particles in the immediate fallout (notably Strontium 90 and Cesium 137) that remain radioactive for years. Chapter V discusses the likely hazards from these long-lived particles. The biological effects of fallout radiation are substantially the same as those from direct radiation, discussed above, People exposed to enough fallout radiation wiII die, and those exposed to lesser amounts may become ill. Chapter 11 I discusses the theory of fallout sheltering, and chapter IV some of the practical difficulties of escaping fallout from a large counterforce attack. There is some public interest in the question of the consequences if a nuclear weapon destroyed a nuclear powerplant. The core of a power reactor contains large quantities of radioactive material, which tends to decay more slowly (and hence less intensely) than the fallout particles from a nuclear weapon explosion, Consequently, fallout from a destroyed nuclear reactor (whose destruction would, incidently, require a high-accuracy surface burst) would not be much more intense (during the first day) or widespread than ordinary fallout, but would stay radioactive for a considerably longer time. Areas receiving such fallout wouId have to be evacuated or decontaminated; otherwise survivors would have to stay in shelters for months,

Figure 2. Main Fallout Pattern Uniform 15 mph Southwest Wind (1-Mt Surface Burst in Detroit). (Contours for 7-Day Accumulated Dose (Without Shielding) of 3,000,900,300, and 90 Rem.)
Figure 3. Main Fallout Pattern lJniforrn 15 mph Northwest Wind (1-Mt Surface Burst in Detroit). (Contours for 7-Day Accumulated Dose (Without Shielding) of 3,000,900,300, and 90 Rem.)
26. The Effects of Nuclear War
Combined Injuries (Synergism)
So far the discussion of each major effect (blast, nuclear radiation, and thermal radiation) has explained how this effect in isolation causes deaths and injuries to humans. It is customary to calculate the casualties accompanying hypothetical nuclear explosion as follows: for any given range, the effect most likely to kill people is selected and its consequences calculated, while the other effects are ignored. it is obvious that combined injuries are possible, but there are no generally accepted ways of calculating their probability. What data do exist seem to suggest that calculations of single effects are not too inaccurate for immediate deaths, but that deaths occurring some time after the explosion may well be due to combined causes, and hence are omitted from most calculations. Some of the obvious possibilities are: q Nuclear Radiation Combined With Thermal Radiation. Severe burns place considerable stress on the blood system, and often cause anemia. It is clear from experiments with laboratory animals that exposure of a burn victim to more than 100 reins of radiation will impair the bloods ability to support recovery from the thermal burns. Hence a sublethal radiation dose could make it impossible to recover from a burn that, without the radiation, would not cause death.
posed to 300 reins, particularly if treatment is delayed. Blood damage will clearly make a victim more susceptible to blood loss and infection. This has been confirmed in laboratory animals in which a borderline lethal radiation dose was followed a week later by a blast overpressure that alone would have produced a low level of prompt lethality. The number of prompt and delayed (from radiation) deaths both increased over what would be expected from the single effect alone.
Thermal Radiation and Mechanical lniuries. There is no information available about the effects of this combination, beyond the common sense observation that since each can place a great stress on a healthy body, the combination of injuries that are individually tolerable may subject the body to a total stress that it injuries cannot tolerate. Mechanical should be prevalent at about the distance from a nuclear explosion that produces sublethal burns, so this synergism could be an important one.

1 Mt on the Surface in Detroit
Physical Damage Figure 4 shows the metropolitan area of Detroit, with Windsor, Canada, across the river to the southeast and Lake St. Clair directly east. The detonation point selected is the intersection of 1-75 and 1-94, approximately at the civic center and about 3 miles [5 km] from the Detroit-Windsor tunnel entrance. Circles are drawn at the 12-, 5-, 2-, and 1-psi Iimits.
The Effects of Nuclear War
Ch. IIA Nuclear Weapon Over Detroit or Leningrad: A Tutorial on the Effects of Nuclear Weapons. 29

<--

+--~--k

o-1 7-27 27-47 47-74

91 13.1026

400 600

180 150

200 450

depend on both the building heights and how close together they are spaced. Typical depths might range from tens of feet in the downtown area where buildings are 10 to 20 stories high, down to several inches where buildings are lower and streets broader in the sector to the west and north, In this band, blast damage alone will destroy all automobiles, while some heavier commercial vehicles (firetrucks and repair vehicles) will survive near the outer edges. However, few vehicles will have been sufficiently protected from debris to remain useful. The parking lots of both Cobb Field and Tiger Stadium will contain nothing driveable. I n this same ring, which contains a nighttime population of about 250,000, about half will be fatalities, with most of the remainder being injured. Most deaths will occur from collapsing buildings. Although many fires will be started, only a small percentage of the buildings are Iikely to continue to burn after the blast wave passes. The mechanics of fire spread in a heavily damaged and debris strewn area are not well understood. However, it is probable that fire spread would be slow and there would be no firestorm. For unprotected people, the initial nuclear radiation would be lethal out to 1.7 miles [2.7 km], but be insignificant in its prompt effects (50 reins) at 2.0 miles [3.2 km]. Since few people inside a 2-mile ring will survive the blast, and they are very Iikely to be in strong buildings that typically have a 2- to 5protection factor, the additional fatalities and injuries from initial radiation should be small compared to other uncertainties. The number of casualties from thermal burns depends on the time of day, season, and atmospheric visibility. Modest variations in these factors produce huge changes in vulnerability to burns. For example, on a winter night

less than 1 percent of the population might be exposed to direct thermal radiation, while on a clear summer weekend afternoon more than 25 percent might be exposed (that is, have no structure between the fireball and the person). When visibility is 10 miles [16 km], a l-Mt explosion produces second-degree burns at a distance of 6 miles [10 km], while under circumstances when visibility is 2 miles [3 km], the range of second-degree burns is only 2.7 miles [4.3 km]. Table 5 shows how this variation could cause deaths from thermal radiation to vary between 1,000 and 190,000, and injuries to vary between 500 and 75,000. In the band from 2.7 to 4.7 miles [4.4 to 7.6 km] (2 psi), large buildings will have lost windows and frames, interior partitions, and, for those with light-walled construction, most of the contents of upper floors will have been blown out into the streets. Load-bearing wall buildings at the University of Detroit will be severely cracked. Low residential buildings will be totally destroyed or severely damaged. Casualties are estimated to be about 50 percent in this region, with the majority of these injured. There wilI stiIl be substantial debris in the streets, but a very significant number of cars and trucks will remain operable. In this zone, damage to heavy industrial plants, such as the Cadillac plant, will be severe, and most planes and hangars at the Detroit City Airport wilI be destroyed. In this ring only 5 percent of the population of about 400,000 will be killed, but nearly half will be injured (table 4). This is the region of the most severe fire hazard, since fire ignition and spread is more likely in partly damaged buildings than in completely flattened areas. Perhaps 5 percent of the buildings would be initially ignited, with fire spread to adjoining
buildings highly likely if their separation is less than 50 feet [15 m]. Fires will continue to spread for 24 hours at least, ultimately destroying about half the buildings. However, these estimates are extremely uncertain, as they are based on poor data and unknown weather conditions. They are also made on the assumption that no effective effort is made by the uninjured half of the population in this region to prevent the ignition or spread of fires. As table 5 shows, there would be between 4,000 and 95,000 additional deaths from thermal radiation in this band, assuming a visibility of 10 miles [16 km]. A 2-mile [3 km] visibility would produce instead between 1,000 and 11,000 severe injuries, and many of these would subsequently die because adequate medical treatment would not be available. In the outermost band (4.7 to 7.4 miles [7.6 to 11.9 km]) there will be only light damage to commercial structures and moderate damage to residences. Casualties are estimated at 25 percent injured and only an insignificant number killed (table 4). Under the range of conditions displayed in table 5, there will be an additional 3,000 to 75,000 burn injuries requiring specialized medical care. Fire ignitions should be comparatively rare (limited to such kindling material as newspaper and dry leaves) and easily control led by the survivors.

Whether fallout comes from the stem or the cap of the mushroom is a major concern in the general vicinity of the detonation because of the time element and its effect on general emergency operations. Fallout from the stem starts building after about 10 minutes, so during the first hour after detonation it represents the prime radiation threat to emergency crews. The affected area would have a radius of about 6.5 miles [10.5 km] (as indicated by the dashed circle on figure 4) with a hot-spot a distance downwind that depends on the wind velocity. If a 15-mph wind from the southwest is assumed, an area of about 1 mi2 [260 hectares]the solid ellipse shown would cause an average exposure of 300 reins in the first hour to people with no fallout protection at all. The larger toned ellipse shows the area of 150 reins in the first hour. But the important feature of short-term (up to 1 hour) fallout is the relatively small area covered by lifethreatening radiation levels compared to the area covered by blast damage. Starting in about an hour, the main fallout from the cloud itself will start to arrive, with some of it adding to the already-deposited local stem fallout, but the bulk being distributed in an elongated downwind ellipse. Figures 2 and 3 show two fallout patterns, differing only in the direction of the wind. The
Table 5.Burn Casualty Estimates (1 Mt on Detroit)
Distance from blast (mi) 0 - 1. 7 - - 4. 7. 47-74. Total (rounded Survivors of blast effects 0 Fatalities (eventual) 2-mile visibility 10-mile visibility Injuries 2-mile visibility 0 10-mile visibility 0
(1 percent of population exposed to line of sight from fireball)

120,000 380,000 600,000

1, 200 3,800 2,600

o 500 0.

(25 percent of population exposed to line of sight from fireball) 0 - 1 7. - , 2. 7 - 4 , 7 - 7 4. Total (rounded) o 120,000 380.000 600,000

30,000 0

30,000
30,000 95,000 66,000 190.000

11,000

75,000

11.000

Ch. IIA Nuclear Weapon Over Detroit or Leningrad: A Tutorial on the Effects of Nuclear Weapons 33
contours marked are the number of reins received in the week following the arrival of the cloud fat lout, again assuming no fallout protection whatever. Realistic patterns, which will reflect wind shear, 2 wider crosswind distribution, and other atmospheric vari ~bilities, will be much more complex than this i lustration.
centers, with probably 1,000 to 2,000 beds, in the entire United States. The total loss of all utilities in areas where there has been significant physical damage to the basic structure of buildings is inevitable. The electric power grid will show both the inherent strength and weakness of its complex network. The CO I lapse of buiIdings and the toppling of trees and utility poles, along with the injection of tens of thousands of volts of EMP into wires, will cause the immediate loss of power in a major sector of the total U.S. power grid. Main electrical powerplants (near Grosse Point Park to the east, and Zug Island to the south) are both in the l-psi ring and should suffer only superficial damage. Within a day the major area grid should be restored, bringing power back to facilities located as close to the blast as the l-psi ring. Large numbers of powerIine workers and their equipment brought in from the surrounding States will be able to gradually restore service to surviving structures in the 1- to 2-psi ring over a period of days. The water distribution system will remain mostly intact since, with the exception of one booster pumping station at 2 psi (which will suffer only minor damage), its facilities are outside the damaged area. However, the loss of electric power to the pumps and the breaking of many service connections to destroyed buildings will immediately cause the loss of all water pressure. Service to the whole area will be restored only when the regional power grid is restored, and to the areas of Iight and intermediate damage only as valves to broken pipes can be located and shut off over a period of days. There will be only sporadic damage to buried mains in the 2- to 5-psi region, but with increasing frequency in the 5- to 12-psi region. Damaged sections near the explosion center wiII have to be closed off. The gas distribution system will receive similar damage: loss of pressure from numerous broken service connections, some broken mains, particularly in the 5- to 12-psi ring, and

dustry depends heavily on rail transportation, but rail equipment and lines will usually survive wherever the facilities they support survive. Most gasoline fuel oil tanks are located out beyond Dearborn and Lincoln Park and, at 16 miles from the detonation, will have suffered no damage. Arrival of fuel should not be impeded, but its distribution will be totally dependent on cleanup of streets and highways. The civil defense control center, located just beyond the Highland Park area in the 1- to 2psi ring, should be able to function without impairment. Commercial communications systems (television and base radio transmitters) will be inoperable both from the loss of commercial power in the area and, for those facilities in the blast area, from EMP. Those not blast damaged should be restored in several days. In the meantime, mobile radio systems will provide the primary means of communicating into the heavily damaged areas. The telephone system will probably remain largely functional in those areas where the lines have survived structural damage in collapsing buildings, or street damage in areas where they are not buried. Radioactive Fallout The extent and location of radioactive fallout will depend on weather conditions, especially the speed and direction of the wind. Figures 2 and 3 show how a uniform wind velocity of 15 mph could distribute fallout either over sparsely popuIated farming areas in Canada if the wind is from the southwest, or over Cleveland and Youngstown, Ohio, and Pittsburgh, Pa., if the wind is from the northwest. It should not be forgotten that these fallout patterns are idealizedsuch neat elipses would occur in reality only with an absolutely constant wind and no rain. No effort was made to calculate the deaths, injuries, or economic losses that might result from such fallout patterns. However, the possibilities are instructive:. The onset of fallout would depend on wind velocity and distance from the ex-
plosion and it would be most dangerous during the first few days. In the case of an attack on a single city (using a surface burst, as our example does), people living downwind would probably evacuate. Those who neither evacuated nor found adequate fallout shelters would be subjected to dangerous levels of radiation: people in the inner contour would receive a fatal dose within the first week; people in the next contour out would contract very severe radiation sickness if they stayed indoors and would probably receive a fatal dose if they spent much time outdoors; people in the next contour out would contract generally nonfatal radiation sickness, with increased hazards of deaths from other diseases. People in the outer contour (9o roentgens in the first week) would suffer few visible effects, but their life expectancy would drop as a result of an increased risk of eventual cancer. q As time passes, the continuing decay of fallout radiation could be accelerated by decontamination. Some decontamination takes place naturally, as rain washes radioactive particles away, and as they are leached into the soil which attenuates the radiation. It is also possible to take specific measures to speed decontamination. Presumably evacuees would not move back into a contaminated area until the effects of time and decontamination had made it safe. q A Iimiting case is one in which no significant decontamination takes place, and areas receiving fallout become safe only when the radioactive particles have decayed to safe levels. Decay to a level of 500 millirems per year would require 8 to 10 years for the inner contour (3,000 roentgens in the first week); 6 years or so for the next contour (900 roentgens in the first week); 3 to 4 years for the next contour (300 roentgens in the first week); and about 3 years for the outer contour (90 roentgens in the first week). q Natural processes could concentrate some radioactive particles, and those that

People live close to where they work. In general, there is no daily cross-city movement. Buildings (except in the old part of the city) are unlikely to burn. Apartment building spacing is so great as to make fire spread unlikely, even though a few buiIdings wouId burn down. There will be much less debris preventing access to damaged areas. Transportation is by rail to the outlying areas, and by an excellent metro system within the city. There is only one television station in the middle of the city so mass communications would be interrupted until other broadcasting equipment was brought in and set up.
Ten 40-kt Air Bursts on Leningrad
Figure 12 shows one possible selection of burst points, set to have the 5-psi circles
40 The Effects of Nuclear War
Figure 8. LeningradCommercial and Residential Sections
Ch, IIA Nuclear Weapon Over Detroit or Leningrad: A Tutorial on the Effects of Nuclear Weapons. 41
Figure 9.LeningradPopulated Area
42. The Effects of Nuclear War
Figure 10. Leningrad 1Mt Air Burst
Figure 11.Leningrad 9-Mt Air Burst

LENINGRAD

Effects of Nuclear War
touching, and with only the envelope of the 2and l-psi rings shown, Since this is an effects discussion only, it is assumed that this precise pattern can be achieved. The errors arising from neglecting the overlap of the 2- to 5-psi bands will be negligible compared to uncertainties in population distribution and structural design. Casualty estimates are shown in the right hand column of figure 6 (p. 37). Note
that fatalities are only slightly greater than for the l-Mt case, which corresponds well to the equivalent megatonage (1.17 Mt) of the ten 40kiloton (kt) weapons. However, the number of injured are considerably smaller because they primarily occur in the 2- to 5-psi band, which is much smalIer for the 40-kt pattern than for the single 1-Mt case.
1-KT TERRORIST WEAPON AT GROUND LEVEL
To this point this chapter has addressed nuclear effects from current strategic weapon systems. Another nuclear weapon of concern is one constructed by terrorists and detonated in a major city, * A terrorist group using stolen or diverted fission material, having general technical competence but lacking direct weapon design experience, could probably build a weapon up to several kilotons. This weapon would be large and heavy, certainly not the often-discussed suitcase bomb, so is Iikely to be transported in a van or small truck, with threatened detonation either in the street or the parking garage of a building. Because of the locations and yield of this weapon, its effects will be much less devasting than those of high-yield, strategic weapons. The range and magnitude of all the nuclear effects will be greatly reduced by the low yields; in addition, the relative range of lethal effects will be changed. At high yields, blast and thermal burn reach out to greater distances than does the initial nuclear radiation. At 1 kt the reverse is true; for example, 5-psi overpressure occurs at 1,450 feet [442 m], while 600 reins of initial radiation reaches out to 2,650 feet [808 m], For the 1-Mt surface burst, 5 psi occurred at 2.7 miles and 600 reins at 1.7 miles. In addition to these changes in range, the highly built-up urban structure in which the weapon is placed wilI significantly modify the resulting nuclear environment. This occurs

In summary, the ranges of nuclear effects from a low-yield explosion in the confined space of an urban environment will differ significantly from large yield effects, but in ways that are very difficult to estimate. Thus the numbers of people and areas of buildings affected are very uncertain. However, it appears that, with the exception of streets directly exposed to the weapon, lethal ranges to people will be smaller than anticipated and dominated by the blast-induced CO I lapse of nearby buiIdings.