Experience of an Accidental Contamination by Radioactive Materials - Palomares 1966

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US DOE ARCHIVES Junta do Energfa Nuclear, N'adrid, Coain. On 17 January, 19GG an aviation accident hapoened durintf an in-flight refueling operation vhich caused the loss of a B-52 boniber and a tanker of the United States Air Force. The acci dent took place over the village of Paicmares which belongs to the municipality of Cuevas de Almanzora in the Province of Almeria. Bits of the planes were scattered over a wide area co- . rrespending gone rally to Hie area between the municipalities of Cuevas do Almanzora and of Vera, and the edge of the Vedite rranean Eea between Puerto Pey and Villaricos. Paloniares has -about 1200 inhabitants and is situated on the right bank of the A linany.o ra Piver near iP nouth and the beach. The village is not, properly speaking, an urban nucleus but is irregularly dis tributed to the point where there are no streets. Croups of hou ses or isolated hou«-e- are located at random over an extensive ^.one of uneven terrain which P crossed by a road, paths and innumerable ditches for the irrigation of gardens of Peighboring farms. Tree growth ic poor, but in the surrounding valley® and deni’essions irrigation farming is carried on over a vide area. The landscape is deserl-like with broken and sleep n ountains . bet ween which lie the utterly dry beds of torrential streams; likewi se the entire bed of the Almanacra Piver is dry. Vegetation is semitrooical - data pain s, century plants, prickly pears;, holm oaks. Cultivated plants are mainly climbing tomatoes, broad beans, yellow corn, alfalfa, cereals and some orange and lemon groves. On the Vera side of Palomares are wide areas of irrigated lands and orange groves, and toward Garrucha. a semi-desert area. 1 his zone is bound on the northeast by the rfierra de la He rrex'ia and on the north west by Dtis Algarrobinas . The coast oppo site Palomares is flat and shallow; the beach, which is rocky, for ms a slight arc frem Punto do! Pio to south of Garrucha. The cli mate is mild. Winters are warm and sujrners rather hoi but with BEST COPY AVAJEABEE

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soft sea breezes. Annual rainfall averages 200 L/ni2 per year but is extremely irregularly distributed as it falls in only a few days, frequently causing overflowing of the dry beds of the Almanzora Piver and various ravines. Prevailing winds are from the east and southwest. Agriculture is the wealth of the region with tomatoes as the most important crop at present, followed by broad beans and yellow corn. The climate per nits at least two harvest annually. Offshore fishing is plentiful. SVellfish, cephalopods and various fish are the most important species and are in great demand in As a result of the aforementioned accident, four thermonu clear bombs which were being carried by the B-52 were thrown loose. Two fell with their parachutes open and so were found in tact, one in the bed of the Almanzo.ra Piver very near its mouth and one in the sea. The other two devices could not be recupe rated intact as theirparachute did not open and the impact set off the conventional explosive contained in them . The resulting .fragmen tation and oxidation of the uranium and plutonium fponge whiph ma kes up part of the bomb created a cloud of those two elements. This cloud was dispersed and blown toward the sea by the strong prevailing SAV-NE wind, contaminating .an extensive zone as it se tiled out on the ground, plants and buildings. The hottest parts of this zone were the two in:pact centers : one a semi-desert hill 1.500 int-lei s SIV of tlie village on altitude-line 72 of Algarrol.inas Hill; the other in some gardens at the extreme eastern edge of the village, about 200 meters from the nearest houses. In the inmediate area were found scattered about numerous rnettalic bombfragments of varying sizes. A check on the state of these two devices clearly showed a contamination problem, caused by alpha emitters but no apprecia ble beta or gamma contamination. Steps were inmediately taken which would enable us to de termine the existence of a danger of inhalation of a radioactive clo ud which, considering the characteristics of its elements, could ju£ tify evacuating part or all of the population of Palomares . Air sam pies were thus taken in various places in the town md in the fields, especially between the houses near the eastern, impact area and in places where the surrounding atmosphere was most likely to be contaminated by i:ie washing of radioactive elements deposited on the soil and on plants . _ For this purpose the following equipment was used: a) a mobile laboratory of the Medicine and Protection Division, a Volkswagen, type 22, equipped by ” Frieseke and Hoepfner (Er langen-B ruck, Germany)" and provided with, among other things, both a poi'lable collector of dust samples model FH 422 with an

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aspiration capacity of 30 cubic jiieterE per hour, and a proper li onal counter of methane gae flux, iriodel PH 407 A. Power was supplied by generators located in the back of the van. b JStaplex portable air-samplers type TP 1 A with a sampling capacity of approximately 30 cubic motors per hour, powered by A.C. generators. Idecatise of its easy maneuverability, the mobile labora tory was used to collect air samples in various places in the vicinity of Palomares and Villaricos and in -other places in a 6 km. radius of action. The Staplex air-samplers were situa ted in the most strategic parts of Palomares and in the two im pact areas, and 30-minute samplings were taken. The position of the samplers was varied for each test within a 100 meter radius of action for each sampler. The measuring of the alpha activity of the samples ta ken was effected in two parts: the first right away in order to acquire as soon as possible an idea of whether the alpha activity was much higher than the normal radioactivity caused by the descendants of radium and thorium in this zone; the se cond 24 hours later to determine the concentration in the air of emitters with a long half-life. The readings shewed that the concentrations of alphaemitting elements in the surrounding air were not high enough to be considered dangerous or to justify evacuation. Except in places less than 100 meters from the impact areas, in the strong siuary when no special decontamination measures had yet been ^dented, the contamination value in the air were equal to or less than hose considered as the maxinum permissible for plutonium239 by the International Commission on Radiological Protection the abovemenlioned places and special circumstances, this conta mination value was surpassed by only one factor of 100. These first findings showed that: . ^ - there was no problem of external radiation of persons; - the biggest problem was possible internal contamination of the inhabitants of Palomares inmediately after the accident as a result of breathing in of the radioactive cloud; - possible external contamination of the inhabitants of Palomares, on clothes, skin and hair, could cause subse quent internal contamination if not eliminated as quickly as possible. This contamination could come from: a) direct contact with the radioactive cloud: b) direct contact with bomb fragments, bits of the planes, crops, the ground or* any other possibly contaminated objects .

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>- the risk of Inter internal contamination by inhalation could remain constant if wind stirred up contaminated dust and kept it in the air; - since the harvesting Of some crops was in full swing in the contaminated areas, field workers could o’e contami nated internally and externally ; - contamination of the exterior of produce and foods could cause some internal contamination in case of ingestion, although the nature of the existing x'adioactive elements and the consequent, slight intestinal absorption diminished - besides the inhabitants of Palomares and others who we re in the village in the moments immediately after the acei dent, the inhabitants of Villaricos could have been affected, as well as the curious came from other villages in the re gion and who crossed the various places where lay. p'arts of the planes and of the material they were transporting. Many persons picked up small bits and kept them as sou - contamination could be spread beyond the affected zone by contaminated persons, materia.! and vegetable products lea ving the zone. In order to acquire a basic idea of the possibility of conta mination of the persons in Palomares at the time of the accident, external contamination was determined first on these living in the houses nearest impact area number 3 and on those who, while not inhabiting those houses, were in a corresponding area at the time. The checks showed fairly unimportant external contamination values, the maximum being about 2000 D.P.M./lOO cm^ and being located mainly on footwrear, lower parts of the trousers and sweaAt the same time the external checks were being made, par tial samples of urine were being taken from tho same persons in order to determine the quantity of alpha entitlers in general and of plutonium 239 in particular which was excreted. This would give a rapid idea of -the extent of internal contamination, if any. The re suits of those tests and of the ones made 24 hours later on the sa me persons showed us that the quantity of plutonium-23G inhaled represented no imincdiale serious risk since the values obtained were below or only slighly above the minimum which corresponds to the maxim;urn permissible dose as established by the I.C.P.P. (maximum permissible dose" /)4 microcuries for bone as a criti cal organ and. 4 microcuries for the whole organism as a critical organ). Also it. was necessary to take into account that the sam-

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pies of urine could easily bo contaminated from the immediate external surroundings, giving a higher or erroneous evaluation of the internal contamination of the persons in question. This was verified by new tests perform.ed on "persons who remained under a rigid check in a completely contan.inalion-free pla ce after having been completely decontaminated externally. In one case in which the person was n.oved to Madrid ' ecause of a high contamination value and placed under daily checks for ten consecutive days, it was possible to ascertain that his' dose could not be over 80% of the maximum permissible dose, considering bone as a critical organ, and that consequently and considering his age (76), there was no reason for serious Once the external contamination checks wer finished on those persons who could be considered most affected, external contamination checks were started and carried on almost conti nuously for approsin.ately 16 hours a day on the Civil Guards who had helped in the contaminated zones and on all the neigh bors from' Palomares, Villaiicos and the villages of the region who had visited the scene of me accident soon after it took These examinations w'ere made for three main reasons: a) for the tranquilizing psychological effect on the population when shown there was no external contam ination.-Unjustified collective panic could have begun vithoul any real basis since completely erroneous information was given out for various reasons during the first days which created a certain uneasiness among the sin; pie people of the village. b) to delect contamination of clothing, skin and hair in order to set adequate norms of decontamination, if positive, or to collect the contaminated articles, if high. c) to detect the existence and amount of external contamiination on persons in order to determine which ones, even though they we re not in a place where they might logically have breathed in the radioactive cloud, might have breathed in radiation later as a result of direct contact with the ground, vegetable products or contaminated material and so should be tested immediately #or later for internal contamination. * DOE ARCHIVI The first measurings of external contamination were taken on the spot with portable alpha activity detectors, model. 2672, from the Nuclec\r Chicago Corporation. On the second day two fixed detection units, type Integratcur Porlaiif Alpha 13eta I.P.A. ters in the village and manned by two t< ams of two technicians each from* the Medicine and Protection Division of the Nuclear Id-

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The results showed no apprecictble conlan ination on the 1950 nersons tested; only a sanal! number shoved conta mination values of 2000 DP\ /lOO cm and an even smaller number of 20.000 DPV/lOO cn.^ on certain parts of their clothing, this group being the military nersonnel (C-ivil Guard) on guard duly in the most exposed zones. The folloving measures vere taken to avoid possible nev external contamination, reduce the danger of inhalation from staying in contaminated places and prevent the spread of conta mination to area avay from those of the accident: a) People vere forbidden to enter the cultivated areas of Palomares as long as the contaminated zones vere not marked off. b) Interdiction to approach and look around the remains of the planes until they vei'e proven not contam inated. c) Blocking of the center of Palomares to curious outsiders until a lov degree of contamination or the absence of it had been determined, etc. d) The picking of tomaioes and broad beans, vhieh vas in full sving, vas stopped until it vas ascertained vhich ones could be picked vithout danger to the picker and the consumer. e) It vas forbidden to send to outside markets the tomatoes in stock and vhich had been picked after January 17th until they , vere proven not contaminated. f) The foods slocked in the village vere cheched for contamina g)Vehicules entering and leaving the zone vere cheched. As soon as the remains of the tvo thermonuclear bombs vere located, work began to determine the extension and degree of conlam.ination in the soil, cultivated and vild plants, vater re servoirs and houses in the village. For that purpose, once the geographical situation of the tvo impact areas and the distribution of bits of the planes vere studied, a rapid field inspection vas started to measure insolated alpha activity in the soil in order to get a general idea of the problem: and organize the vork of deli miting all contaminated areas. Consequently, the Palomares area vas divided into three zones, tvo corresponding to the impact areas and which we shall call zones tvo and three, and the ♦bird, called zone five, corresponding to the town, vhich vas^^ between the impact areas, and vhich ve predicted would b*.- fairly veil protected because of the wind direction at the moment of the accident. In areas tvo and three, measuring of superficial radiation vas botrun at the zero points of im.pact and covered ?60 degrees of the surrounding land. The measu rings; wore taken along radial axes 15 degrees apart, and soil

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and vegetation were tested every 25 meters until about 100 meters beyond the point where the reading was zero. Thus to facilite quick and easy general …