CIVIL DEFENSE Chapter Lli.– CIVIL DEFENSE
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Chapter III CIVIL DEFENSE Chapter llI.– CIVIL DEFENSE ragem.—. 49 49 49 49 50 51 53 54 54 54 56 59 Chapter Ill CIVIL DEFENSE INTRODUCTION Effective civil defense measures have the potential to reduce drastically casualties and economic damage in the short term, and to speed a nation’s economic recovery in the long term. Civil defense seeks to preserve lives, economic capacity, postattack viability, and preattack institutions, authority, and values. The extent to which specific civil defense measures would succeed in doing so is controversial. Some observers argue that U.S. civil defense promotes deterrence by increasing the credibility of U.S. retaliation and by reducing any Soviet “destructive advantage” in a nuclear war. Others, however, argue that a vigorous civil defense program would induce people to believe that a nuclear war was “survivable” rather than “unthink- able,” and that such a change in attitude would increase the risk of war. CIVIL DEFENSE MEASURES Civil defense seeks to protect the popula- fects such as induced fires). Since blast is tion, protect industry, and improve the quality usually the most difficult effect to protect of postattack life, institutions, and values. This against, such shelters are generally evaluated section considers several measures that sup- on blast resistance, and protection against port these goals. other direct effects is assumed. Since most ur- ban targets can be destroyed by an overpres- sure of 5 to 10 psi, a shelter providing protec- Population Protection tion against an overpressure of about 10 psi is called a blast shelter, although many blast People near potential targets must either shelters offer greater protection. Other shel- seek protective shelter or evacuate from ters provide good protection against fallout, threatened areas to safer surroundings; if not but little resistance to blast–such “fallout at risk from immediate effects, they must still shelters” are disccused in the next section. protect themselves from fallout. Both forms of Blast shelters generally protect against fallout, protection depend on warning, shelter, sup- but best meet this purpose when they contain plies, life-support equipment (e. g., air filtra- adequate Iife-support systems. (For example, a tion, toilets, communication devices), instruc- subway station without special provisions for tion, public health measures, and provision for water and ventiIation wouId make a good blast rescue operations. I n addition, evacuation in- shelter but a poor fallout shelter. ) volves transportation, This section examines each form of protection. Nuclear explosions produce “rings” of var- ious overpressures. If the overpressure at a Blast Shelters given spot is very low, a blast shelter is un- Some structures, particularly those designed necessary; if the overpressure is very high (e. g., for the purpose, offer substantial protection a direct hit with a surface burst), even the best against direct nuclear effects (blast, thermal blast shelters will fail. The “harder” the blast radiation, ionizing radiation, and related ef- shelter (that is, the greater the overpressure it 49 — 50 ● The Effects of Nuclear War can resist), the greater the area in which it Since radiation may remain dangerous for could save its occupants’ lives. Moreover, if periods from a few days to several weeks, each the weapon height of burst (HOB) is chosen to shelter must be equipped to support its occu- maximize the area receiving 5 to 10 psi, only a pants for at least this time. Requirements in- very smalI area (or no area at all) receives more clude adequate stocks of food, water, and nec- than 40 to 50 psi. Hence, to attack blast shel- essary medical supplies, sanitary facilities, and ters of 40 to 50 psi (which is a reasonably at- other appliances. Equipment for controlling tainable hardness), weapons must be deto- tern perature, humidity, and “air quality” nated at a lower altitude, reducing the area standards is also critical. With many people over which buildings, factories, etc., are de- enclosed in an airtight shelter, temperatures, stroyed. humidity, and carbon dioxide content in- crease, oxygen availability decreases, and fetid The costs of blast shelters depend on the materials accumulate. Surface fires, naturally degree of protection afforded and on whether hot or humid weather, or crowded conditions the shelter is detached or is in a building con- may make things worse. If unregulated, slight structed for other purposes. However, a large increases in heat and humidity quickly lead to variation in costs occurs between shelters discomfort; substantial rises in temperature, added to existing buildings and those built as humidity, and carbon dioxide over time could part of new construction. The installation of even cause death. Fires are also a threat to shelters in new construction, or “slanting,” is shelterers because of extreme tern peratures preferable, but it could take as long as 20 years (possibly exceeding 2,000” F) and carbon for a national policy of slanting to provide ade- monoxide and other noxious gases. A large fire quate protection in cities. might draw oxygen out of a shelter, suffocat- An inexpensive way to protect population ing shelterers. World War I I experience indi- from blast is to use existing underground facil- cates that rubble heated by a firestorm may re- ities such as subways, where people can be main intolerably hot for several days after the located for short periods for protection. If peo- fire is put out. ple must remain in shelters to escape fallout, then life-support measures requiring special Fallout Shelters preparation are needed. In the United States, fallout shelters have Other lethal nuclear effects cannot be over- been identified predominantly in urban areas looked. Although, as noted above, blast shel- (by the Defense Civil Preparedness Agency ters usually protect against prompt radiation, (DCPA) shelter survey), to protect against fall- the shelters must be designed to ensure that out from distant explosions, e.g., a Soviet at- this is the case. tack on U.S. intercontinental ballistic missiles (ICBMs). On the other hand, Soviet fallout Another problem is protection against fall- shelters are primarily intended for the rural out. If a sheltered population is to survive fall- population and an evacuated urban popula- out, two things must be done. First, fallout tion. must be prevented from infiltrating shelters through doors, ventilation, and other conduits. Fallout protection is relatively easy to Other measures to prevent fallout from being achieve. Any shielding material reduces the tracked or carried into a shelter must also be radiation intensity. Different materials reduce taken. More important, the shelter must enable the intensity by differing amounts. For exam- its occupants to stay inside as long as outside ple, the thickness (in inches) of various sub- radiation remains dangerous; radiation doses stances needed to reduce gamma radiation by are cumulative and a few brief exposures to a factor of 10 is: steel, 3.7; concrete, 12; earth, outside fallout may be far more hazardous 18; water, 26; wood, 50. Consider an average than constant exposure to a low level of radia- home basement that provides a protection fac- tion that might penetrate into a shelter. tor (PF) of 10 (reduces the inside level of radia- Ch. ///—Civi/ Defense . 51 tion to one-tenth of that outside). Without ad- ditional protection, a family sheltered here could still be exposed to dangerous levels of radiation over time. For example, after 7 days an accumulated dose of almost 400 reins in- side the basement would occur if the radiation outside totaled 4,000 roentgens. This could be attenuated to a relatively safe accumulation of 40 reins, if about 18 inches of dirt could be piled against windows and exposed walls be- fore the fallout begins. Thirty-six inches of dirt would reduce the dose to a negligible level of 4 reins (400 - 100). Thus, as DCPA notes, “fallout protection is as cheap as dirt. ” Moving dry, unfrozen earth to increase the protection 5 in a fallout shelter requires considerable time and effort, if done by hand. A cubic foot of earth weighs about 100 lbs; a cubic yard about 2,700 Ibs. Given time, adequate instructions, and the required materials, unskilled people can convert home basements into effective ever, few homes in the South and West have fallout shelters. basements. The overall effectiveness of fallout shelters, With adequate time, instructions, and mate- therefore, depends on: (a) having an adequate rials, an “expedient” shelter offering rea- shelter—or enough time, information, and sonable radiation protection can be con- materials to build or improve an expedient structed. This is a buried or semi buried struc- shelter; (b) having sufficient food, water, and ture, shielded from radiation by dirt and other other supplies to enable shelterers to stay shel- common materials. Expedient shelter construc- tered until the outside fallout decays to a safe tion figures prominently in Soviet civil defense level (they may need to remain in shelters for planning. periods ranging from a few days to over 1 month, depending on fallout intensity); and (c) Evacuation entering the shelter promptly before absorbing much radiation. (An individual caught by fall- Evacuation is conceptually simple: people out before reaching shelter could have diffi- move from high-risk to low-risk areas. I n effect, culty entering a shelter without contaminating evacuation (or crisis relocation) uses safe it. ) distances for protection from immediate nu- clear effects. The effectiveness of crisis reloca- Over the years, home fallout shelters have tion is highly scenario-dependent. If relocated received considerable attention, with the Gov- people have time to find or build shelters, if ernment distributing plans that could be used the areas into which people evacuate do not to make home basements better shelters. Such become new targets, and if evacuated targets plans typically involve piling dirt against win- are attacked, evacuation will save many Iives.