Proyecto Indalo - Following of the Effects of the Accident at Palomares Spain from 1966

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Covering letter stating inclosure is a submission for continuing asistan ce for the next fiscal year (October 1976 to September 30 1977) TITLE : PROVECTO INDALO. Following of the effects of the accident at V Two nuclear weapons accidentally dropped from a burning B-52 went into one-part disruptive explosion spreading Pu over areas of farm land and houses at Palomares, located close to the sea in the province Joint clean up by United States Air forces and Junta de Energia Nulear was made by removal of most contaminated soil, deep plowed and wetted and fields restored. Wright Langham helped us to set up a surveillance program which had fcbrmalized under the Otero-Hall agreement signed in Madrid in March The agreement covers surveillance and sampling of air, soils, vege- £ tition and the people who lived in Palomares at the time. Lately people wio were not closely affected by the burst have requested and been su pplied with the personal surveillance and monitoring afforded those most The procedures in the Agreement which have been carried out with the support of the A E C include counting equipment, alpha spectrometers,

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whole body and lung counters and miscellaneous special supplies. Be cause of the naturally high alpha background of the area alpha spectrome try is required and the rate of carrying out the chemical and radiometric analyses of samples has been correspondingly slow. The lung counter has not functioned in a reliable manner until recently^ > Mr Phil Dean has been^of.great assistance here. Urine specimens from the 78 people most affected have therefore served for the best estimate of whole body content of Pu . We have hoped to get data from the lung counter the would certify or agree with the urine data and viceversa but this still has not been achieved (see below). For obvious reasons the people have to be brought from Palomares to th counter which is situated on the grounds of the Centro de Energia Nuclear "Juan Vigon" adjacent to the Medical and Health Physics Building. This is the most expensive part of the survei I lance, but estimates of personnel con tamination are the most important in our view. Unfortunaly they have not been obtained definitively as yet. We recognize that counting accurately in the range of less than 16 nanocurie of ,Pu is close to the limit of the technique. With Mr. Dean's help we hope to achieve this real lability. Without the chest counts we have no way of estimating wether the people living as farmers on the low contaminated soil have inhaled resuspended 239 Pu on agricultural dust or otherwise. By other way we should like to note that many of these people show lung counting rates that are of low reliability and we are caught in the logic of selecting the count of one person as beeing reliable and that of another nol when both live under similar circunstances. We wish to be assured of the reliability of their lung counting procedures or else put pur confidence so lely on urinary excretion as the criterion for their internal contamination.

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1. - SUMMARY OF CURRENT RESULTS. A network of aerosoles sampling was set up in order to discover what possibilities there might be of internal contamination of the people who live in the zone and cultivate the fields, as an isolated or related consequence of the ploughing operations on the ground and the climatological characteristics of the zone, especially those related to the low rainfall and pre vailing winds. The airborne sampling was stablished in June 1966. This network consisted of four sampling stations, and two for the study of the speed and direction of the winds. The samples stations were situated in the places nominated S-1, S-2, P and 3-1, which respectively corres pond to the zones where the two fragmented bombs fell, 'and one point at the urban centre of Palomares. Those for measuring the characteristics of the winds were situated at S-1 and P. In each one of these stations, at a height of 1.70 m, continuous 24-hour samples are taken, with a volume of approximately 95 m , every day of the year, on membrane filter paper. The samples are prepared for sending to the laboratories of the Medicine and Protection Division of JEN, where in principle, a minimum of one week after they were taken, a count was made of the total alfa activity due to ra-l dioactive elements with a long half life. In September 1969 the network was reduced to the sampling stations The following conclusions may be drawn from the analysis of the results - The elimination of the radionuclides contaminating the surface layer of soil , and their dilution in tiie subsoil to a depth of 25 cm. , has

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proven effective in reducing the mean values for radionuclide con centration in the air to levels consistently below the permissible During the first years on very few occasions was the daily concen tration of radionuclides in the air higher than the maximun permi ssible value, and on all of those occasions, the wind velocity fluctuated between 17 and 64 km/hr. , The combined action of the weather conditions and farming of the soil have resulted in the resuspension of particles of plutonium and uranium oxides in the air, although the concentration of the-• se radionuclides in the air has consistently remained well below the maximum permissible concentrations for these elements, in the insoluble form in which they are found in the area of the accident. The incidence of the presence of uranium in the air was higher than that plutonium , for 30% of the samples analyzed showed no trace of plutonium , as compared with 30% which contained no In the zone containing the town, the airborne concentrations of plutonium and uranium have remained far below the ones in other areas where larger concentrations of these elements were mixed The values for 1967 were lower than the ones for 1966, with the exception of the concentration of plutonium -239 in area 2-2, which increased significantly in 1967. From 1969 the con centrations were decreasing and in the last years and from time

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to time some samples give results in the order of 10 jjC\/crr>3 Most of the samples are giving results which are under the detection limit, wich is 5 x 10 ; yjCi/cm3. The contamination of the soil surface was not homogeneous . In order to determine the degree of distribution, and what this distribu tion was on the surface, as well as its depth , after the operations of decontamination, and those planned to eliminate surface contami nation in areas required , a study was planned in order to find out which these were and to permit us, as years go by , to discover the dynamics of plutonium-239 in cultivated land, both as regards its dynamics parameters and those introduced by tilling and culti For this purpose, six areas were chosen of 50 m2 each, two from each of the 3 zones into which the total contaminated area was divi ded, corresponding to the two areas where the bombs felt and broke. These areas were chosen in places which had remained most contami nated after the removal of a layer of earth on the areas which had con and 3 comprise areas where total alfa contaminations were found to where the upper layer of earth was also removed during decontamina tion operations. The areas in zone 5 showed contartiinations of the or In order to find the average bacground of total alfa activity on the ground of the zone, two similar areas were chosen, with similar geo logical characteristics and situated at 1.000 m. and 7.000 respectively from the zero line of the contaminated zone.

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In each of the areas, and in accordance with its diagonals, during the first year, 1966, nine samples were taken which were divided into fragments, corresponding to depths of 0-5, 5-15, 15-25, 25-35 and 35-45 cm. Of the homogenised samples corresponding to each fragment, two fractions of 0. 50 gm. were taken, which were submitted to chemical treatment and alfa counting, in order to determine the total alfa activity. Same type of samples have been taking during 1967, 1969, 1971, 1972, 1975 and 1976 at points in the same areas and following a preplanned dis tribution order in order to obtain complete knowledge of the dynamics of the contamination, as well as to deduce the contamination factors of the vegetable products which are cultivated in them. In 1969, 1972, 1973, 1975 and 1976 it has been made a separate sampling of the surface of the In these samples, we are determining the Pu-239 content by radioche mical separation and alpha spectrometry. From the results obtained so far it may be deduced: 1).- In 1966 in zone 2-1 , where a 5 cm. layer of soil was removed, the remaining contamination was nil. During the following years it has beei found Pu-239 surface contamination transported maybe by winds or by 2).- As a result of ploughing and breaking up of the ground, a distribu tion of contaminating elements have been obtained to a depth of 30 cm. Generally highest contamination levels are found in layers between 3).- The maximum average value of Pu-239 concentration found in the area: studied is in the order of 6 x 10 picoCi/gr. /

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The unhomogeneous distribution of the contaminating particles, even after the ploughing operations.carried out , is perfectly clear from the values obtained , as might logically have been expected . Even results from different samples from the same point and fragment, after the greatest homogenisation possible in the laboratory, show quite a considerable dispersion. The work carried out with vegetables has tended to determine the possib)i I f ties of their external contamination, as a consequence of their cultivation in contaminated and surrounding areas, and to the study of the plants' absorption capacity, and its settling on fruits and seeds. For the purpose, in each one of the areas previously mentioned, and in the places where the soil samples are taken, samples have been ta ken of the existing crops. Not all the areas has been cultivated every year and for this reason it was not possible to take samples from some areas in some years. In area 2-1 , and given that it was part of an un cultivated plot, of which the upper layer of soil had been carefully 1 removed,making sure not to destroy the existing vegetation, the tomato plant samples were taken from nearby strips of cultivated land where the upper layer of soil had not been removed; the same type of sampling it has been made to get wild plants of the area. From the alpha spectrometry results to determine the Pu-239 con tents the following deductions could be made:

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- The plants cultivated on contaminated soils shows a Pu-239 contamination. - Tomatos, beans, barley and maize are the most cultit/ated vegetation in the area. Most of the contamination by Pu-239 has been in the plant itself and very little in the fruits and seeds. - The greatest degree of contamination found has been in wild plants (aspa ragus, esparto grass and other graminaceous plants) which grow in the proximity of the area 2-1. - The degree of contamination has been decreasing along the years in cultivat and wild plants. The last years the contamination by Pu-239 has been spor die in th^1 cultivated plants. - Tomato plants cultivated in 1976 in the proximity of the point were the bomb n? 2 fell down shows important Pu-239 contamination. The study of the determination of possible internal contamination of the people of Palomares, both in the case of those who went there afterwards, ' and especially those who walked through contaminated areas during the first moments, was planned under the following two aspects: 1 ). - Determination of the Plutonium-239 excreted in urine, in order to deter mine the fraction which could have passed the pulmonary and lymphatic 2).- Determination of the quantity of plutonium-239 present in the lungs.

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To obtain this information, after the analysis of plutonium-239 and total alfa activity in urine had been carried out soon after the accident, on the persons who at that time were considered those most likely to ha ve been internally contaminated, a selection was made from the people of Palomares, with respect to the following considerations: 1) . - Situation nearest to the points of impact of the fractional bombs, ar the areas of greatest contamination1 at the moment when the accident occurred, therefore with the greatest possibilities of inhaling the aerosol created in the conventional explosions. 2) .- Stay in zones of highest contamination during the day of the accident and the following day. BEST AVAILABLE COPY 3) .- Residence, at the time of the accident and the days following it, in houses and areas of the town where a higher contamination had been found, within the lower limits where contamination was produced in the town, as may be seen from the plan of the contaminated area. 4) .- Situation during the accident and following it, in houses and areas of the town where contamination was nil, so that they could serve ast controls, and at the same time we could find out with certainty wheth a mistake had been made in not considering evacuation of the people < that area as necessary in the operations of contamination limit fixing and decontamination. DOE ARCHIVES Taking the above factors into account, a total number of 100 persons re selected, of which 49 were males over 14 years, and 9 were fema

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They were taken to Madrid for the said tests to be carried out in the laboratories of the Division de Proteccion y Medicina de la Junta de Energia Nuclear. They first underwe.nt a complete medical examination, in order to find out their state of health and take it into account in the st dy and subsequent epidemiological control. In order to determine the concentration of plutonium-239 excreted in urine, three complete 24-hour samples of urine were taken from each one of the said persona, on three consecutive days. These samples wen submitted to a chemical treatment in order to determine the content of th rpid e'rrr^ by e.lfa spectrometry, on the final electrodeposit following a separation bv ion exchange resins. The result of this analysis showed that in 71 per cent of cases there was no indication of the existence of plutonium-239, 18 per cent showed in some analyses, contents of less than, 0. 1 disintegrations per minute in the urine of 24 hours, 9 per cent showed contents of between 0. 2 and disintegrations per minute over 24 hours , and finally, 2 per cent show< a content of between 0. 2 and 1 d. p. m. in the urine of 24 hours. Bearing in mind what these values represent on the alfa spectrum corre ponding to the 1000-minute measurements taken, we have taken …