te % water supplies are contuminaton:and the fasion products from underground nuclear detonations largely become fixed at und . near the site of the explosion.<: Whereas, theoretical caleula- is bused on the assumption thatall of the water drunk through- ae maps» wage sence a kip -. meg pean. Mn Saget eiiia Fak ee beh a < tions suggest that concentrations of tritiumin thewater may be ubove acceptable limits for: some underground nuciear detonations,"* this refers coly.to the water immedjately around vround zero. Some dilution js‘to be expected if it noves off site and, more importantly, thecriterion of°‘acceptable limits” bog Lames Huai ial sur tS ea Ct me a met no Spl ee a 2 -- me aa 1 anh ae : car wid at OEJ ae hey Uk oa f iM: Ny ay . of “b te. cae A ‘EMCTION Web OTHERASPECTS ¥ BLAST—DIRECT ANDRSHECTED eee et . . ett ae, — u "he : pesPOON a tA be oe catenin sor5Fae meen at a aa cha ‘er. Tree Oy%. earth‘and thus create’ higher air prapsures thon would:she ee eS “exception of certain situations: noted above: a oe ea EoAY Beckgreund information } Wt Direct blust waves that are potentially damaging are eon: fined “to the immediate ztesting site-arvas. Under certaln, meteorological condition,” however, blast waves may be. ree eee a pte,ae 24 RERReitpace a LA, . vets the material bas been depositedon the ground with the possible a re . out a lifetime will contain thesame concentration of tritiumas set by the limits. The quantity of water initially contaminated to theae limits by an underground nuclear explosior is relatively smail and would not constitute the sule supply for lifetime. - Further,‘tritium decays, with a haif- life of. about W ‘ years. 1 Piers ‘Much’ less radioactive fallout debris enters the body by in- , ‘palation than by ingestion. 2 While the debris is in the air out- «: ‘side the body the radiation exposure is much less'than after oe fracted (bent) trum an upper almvapheric feve! back te ‘the: expected ut those distances. One.layer in which this'may happen:‘ig between 26,000 wud: 50,000 feet altitude where winds may: cause a focusing effeci, at some ¥0-50 miles from ‘the point of detonation. In turn. the blast wave may be repeatedly reflected from the gegund. and bent back from theatmosphere creating a evries of raguiat spaced puints uf focus.atthe carth's surface wilh intervening: “silent” spaces. Such'an effect hag resulted in minor struc: tural ‘damage, such ag-breakingof windows, 75 tv 100- miles: fromthe point of detonation at the Nevada Test Site ™ (fig.7. Asimilar effect is obtained when blast waves ure bent.from a layer of relatively warm ir, called’the ozononphere,‘ag: ¢ height of 90 to 30 miles, ‘The pointoffirst return lo the earn in this case is 70 to 150miles from the burst. Thore may be a return of sound waves from an nititusta above 60 miles (lonosphere), Most of this blast cnergy is al sorbed, however, resulting in no recorded structural damage in some cases audible sharp cracks and pops have beon hear; Procedures and equipment have now been duveloped: i predict with greater accuracy the magnitude arid daregtion these refracted blast Waves. a, The Dete ! Although the blast wave decreases jn energy with each eur ceeding refraction back to the earth’s surface, there has bec; breakage of windows on a second “strike” at 245 miles fru: only a 17 thousnnd ton (TNT equivalent) nuclear expiasion. (All together about $650,000 has heen paid for structural Jama; claime from all tests at the Nevada Test Sit:.) There be 8 a