Document Lg1NZgbGgoR1EN2wqgzMw4YMd

r L IA24611 A,.. LEAD INDUSTRIES ASSOCIATION tSt MAOIION AVINUI NEW YORK IT. H. V. October 16, 1961 s u bj ec t i mo m miour To Hewers of the toad Industries Associations la a result of tba lmunertbls requests wt have received for inforaetion on tba uaa of lead in tba construction of fallout abaltaro, we haYa prapared tha attached report to answer such in^ilrlas* We hops that tha infcreation it contains will be of assistance to you In answerins slailar inquiries. If you need additional oopiee of this alaeotraphed letter please let us know. Very truly yovirs, David M Eorcina EKBitMt Jp 'ir y"mu s h ^i n!"'>.|","WW,Mii' "ipiwq>r.-.^;w' e^jO^^a^i_yAg.!iMjgCgf'^1 LIA24612 fr' / LEAD INDUSTRIES ASSOCIATION *1 MADISON AVINUI NSW YORK 17, N. V. ~iaai LEAD If F A L L 0 P T SHELTERS Among ths nsny connonly available Materials for o n la tha construc- tloo of fallout shelters, Isad, la torso of weight and apace, provides tho Root offioloot ablold against (uu rays -- tho prine dangerous radiation to bo ax- poctod la fallout. For axaspla, 1-la. thick lead weighing approxlaateV' 60 lb. per aq. ft. la equivalent to 9.7 la. of concrete welching approximately US lb. per aq. ft. or ateel 2.7 la. thick weighing about ilO lb. per aq. ft. Tharttfort, where weight and apace raqulramar.ta are critical, lead la the obvloua choice. How ever, where weight and apace requirements are not critical and coat la the Major consideration, then materials other than lead may be aelected. Lead has a further advantage, uniform density, not alweya enjoyed by concrete or earth. The following table taken from the Atomic &>ergy Comission's Manual entitled "CBC-56.fi1 Indicates the thickness of various Materials required for shielding against penetrating residual radiations, fallouts Approximate Attenuation Factors for Cajna Rays from Fission Products as Function of Shield Thickness for Indicated Materials Shield thickness for indicated Materials, In inches Attenu/- tion facto _ Lead Iron & Steel Concrete (7lTTb "nuns cu ft) cu ft) cu ft) Earth nsrib cu ft) Water TEH; lb cu ft) Wood (Fir) "T3XTT cu ft) 2 0.28 0.7 2.5 It O.fiii 1.8 6.6 10 1.0 2.7 9.7 50 1.6 It.2 lit 100 1.9 it.fi 16 1,000 2.7 6.8 22 10,000 3.5 6.0 27 _ 100,000 U-3 Q 11 32 3.5 6.9 13 0 23 32 39 14 it.fi 13 19 29 33 L5 56 70 9.2 25 36 55 62 88 110 li0 s L- V N 1730.01 mm* m.' s pamnFo gui<iw*uit^ LIA24613 ---------- -------!............ ,, ir-'llf IIIj ------- --- ' t---.>' , I y.f.,---------- -- .r- , .-.a.*-'. -.J ..a-.- --------------- ~--------- - _ . .... . - --^ - 7 * LEAD IK FALLOUT SHELTERS (CONT.) -2- The Office of Civil end Defense ffcbiliiatlon, OCDM, has reccrnended 8 in, of concrete for house fallout basement shelters which added to the protection afforded by the materials in the floors above provide an attenuation factor, see above table, in the neighborhood of 10, ihich la probably adequate for most condi tions. Hcvever, it has been pointed out that an attenuation factor of 1,000 la min^ur 'or those areas subject to heaviest fallout, la to the location of the areas that will be subjected to heaviest fallout, this question may well be re legated to the "How high is upT* category. It is important to note, again referring to the table, that the concrete used in building fallout shelters should have a density of lhlt lb. per cubic foot. Bile means an 8 in. concrete wall will weigh approximately $6 lb. per aq. ft. and a wall 8 ft. high will weigh roughly 770 lb. a running foot. The construction of the concrete walla may not post a serious problem but the ceiling la another matter. The concrete for the celling of a shelt< r 10 x 10 ft. will weigh roughly 10,000 lb. Lead on the other hand will weigh roughly 6,000 lb. and require only 1 in. of head room rather than the 8 in. required if concrete is used. Lead also offers advantages for use in doors, batches, window coverings, atop shallow underground shelters and other critical areas. Copposite materials such as lead and concrete, lead and earth, or lead and steel are other structural possibilities. The necessary thickness of the var ious materials staking up the eotq>oslte is not a straight extrapolation of the figures given In the table and it is therefore ruggested that AS or OCDK be contacted for advice on such construction. Lead for gamma shielding is aveilable in a number of forms, such as sheet, brick, shot or wool. Lead shot can be cold poured Into difficult to pro tect areas or contained in a steel shell for use in doors, hstchss etc. Lead wool ie an ideal caulking material for joints in thatever material or materials are o*J acted for the shelter. Leaded glass, which can contain more than $0% lead by weight is available and can be used for viewing ports there desirable. 1 M *( v