Trip Report on Foreign Travel (October 25 - November 15, 1971)

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Los Alamos Scientific Laboratory University of California Los Alamos, New Mexico 87544 Current concern over environmental plutonium contamination generally and contamination of the environs of the Nevada Test Site specifically prompted a trip to Copenhagen, Denmark, and to Palonares, Spain (via Madrid), to hear first-hand from the people primarily involved the sequel to the nuclear weapons accidents at Thule, Greenland (1968), and at Falomares, Spain. (1966). These two incidents attracted international attention because they involved plutonium contamination of the public domain of foreign countries. A brief account of these incidents is given for those who may have forgotten or those who nay not be familiar with them — although it is difficult to The Thule incident occurred on January 21, 1S68. A crew-abandoned SAC B-52 -bomber Carrying four nuclear weapons crashed on the ice of North Star j Bay approximately seven miles from the west end of the Thule runway. The | aircraft and nuclear weapons disintegrated on impact, and the plutonium-239 ! inventory of all four weapons was released to the environment. About 3200 g

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of platoniiEi, largely in the fom of plutoniua oxide particles, was trapped in the fire-blackened area of melted and refrozen snowpack about 500 feet vide and 2100 feet long. About 350 g of plutonium was trapped in the crushed and refrozen ice at the impact point, and the remainder was impinged into the aircraft wreckage, blown beneath the ice, and dispersed as airborne contamina tion in a predominantly southerly direction from the crash site. It was not possible to say how much of the plutonium was deposited as general airborne environmental contamination, but it could not have been more than a few kilo grams. Cleanup of the Thule incident consisted of collection of all parts of the weapons and parts of the aircraft (not blown beneath the ice at point of impact) and removal of the blackened, refrozen snowpack down to the original surface ice. All collected material was returned to the continental United States. The ice (3 to 4 feet thick) at the point of impact was completely broken into chunks that were displaced downward into the water. These pieces floated back to the surface and were fixed in a random orientation by re freezing. Extensive ice core sampling allowed the estimation that about 350 g of plutonium was contained in the ice at impact point. This area, that would have been very difficult to remove, was covered with black, carbonized sand. Heat absorption after the sun began to shine resulted in early melting of the area before general break-up of the bay ice occurred.. Therefore, at least 350 g of plutonium plus that blown beneath the ice at time of impact was released to the waters of North Star Bay. During subsequent months Danish scientists, with U. S* help, conducted an extensive ecological survey and again in 1969 and 1970. The purpose of the trip to Copenhagen was to hear, first-hand the general results and impressions gained from these follow-up stud

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It was with great sadness that I learned of the death froa cancer of Professor Jorgen Koch, a personal friend and head of the Danish scientific team In 1968, only a month prior to my arrival. Because of Professor Koch's death, my visits were confined largely to his widow; Dr. Henry Gj^rup (a xnembe of the 1968 Danish scientific team), Head of the Health Physics Department, Danish Atomic Energy Research Establishment, Riso; and Mr. Per Grande, Directo of the Danish National Health Service, State Institute of Radiation Hygiene (also a member of the 1968 Danish scientific team). The first year an extensive ecological sampling program of the Thule area flora and fauna was conducted, and samples were sent to Riso for plutonium analysis. Their conclusions were that the accident measurably raised the plut nium level in the marine environment as far out as approximately 20 kilometers from the point of impact. The highest concentrations were found in bottom sed iment, bivalves, and Crustacea. The higher animals such as birds, seals, and walrus showed plutonium levels hardly significantly different from the fallout background. Stomach contents of the higher animals were analyzed both with respect to the biota ingested and their plutonium content. Ingesta contained many of the lower life forms that concentrate plutonium; however, plutonium levels were hardly above regional background, indicating that the animals samt had-not been feeding in the higher contamination areas. In principle, analyst of ingesta is an effective method of sampling a contaminated environment in relation to specific species at risk. Fistulated cattle and goats (one a grazing species, the other a browser) would be effective samplers of certain contaminated areas in and near the Nevada Test Site. Plans to conduct such studies are in the formative stages and should be considered as a high-priori

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In subsequent years the sampling program at Thule has been confined largely to bottom sediments and the bivalves and Crustacea brought up in the sediment sampling. The levels in bivalves and Crustacea are comparable to that in the sediments in which they live, and a major part of the activity is •confined to external surfaces. Activity of the sediment appears to be spread ing out and decreasing exponentially with time. Their continued interest seems to be in using the sediment sampling program to collect useful information on currents and sediment movements in Bylot Sound and on early incorporation of plutonium into a relatively simple food web. They plan to return to Thule during the open period in 1972. Dr. Gj^rup informed me that more participa An unrelated but side issue of considerable interest was revealed by a visit to the State Institute of Radiation Hygiene. Mr. Per Grande's Institute does all radiation hygiene surveillance (except for Riso) for the whole of Denmark with a very modest staff (about 20). Their primary record of exposure is the film badge, which the Institute processes, reads, records, and files. The developed film is matched by eye with a set of standards. Only those show ing a density greater than that corresponding to 10 mrem per week are densitometered and recorded. There seems to be little or no public agitation about the horrors of radiation. Either the Danish public is immune to the radiation hysteria virus, or it has not spread to that part of the world. They are now earnestly-talking about developing nuclear power stations; perhaps introductio: of the virus will be forthcoming.

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The Palonares Incident (Fig. 2) Oa January 17, 1966, a B-52 refueling accident occurred above the Spanish village of Palonares (population about 1000) on the Spanish Mediter ranean coast. Both the bonber and KC-135 tanker were destroyed in the air. Onie of the four nuclear weapons aboard the bomber was recovered intact frcn the Mediterranean about five miles off-shore, and a second was recovered intact from the dry Almanzora riverbed east of the village (impact point No. 1). The main chutes did not open on the other two, and on Impact they underwent high explosive detonation, one in the east edge of the village (impact point No. 3) and the other approximately one mile to the west (impact point No. 2). At the time a 30-knot wind was blowing toward the east. The plutonium-bearing dust cloud from the one toward the west traveled across irrigated fields and the northern edge of the village. The cloud from the one that fell in the eastern edge of the village traveled away from the village but across the prime ir rigated areas for growing tomatoes, beans, and alfalfa. The last tomato crop of the season was just ready for harvest. Corrective measures consisted of removal and shipment back to the U. S. of the vegetation and topsoil froa approximately 5.4 acres.where the surface contamination was above 32 yCi/M and removal of vegetation and plowing of all accessible areas with surface con tamination between 32 yCi/M^ and the lower limit of detection of the portable alpha monitoring instruments in use at the time (less than 0.32 yCi/M^). The total area plowed was approximately 550 acres.. Tha cloud from the detonation west of the village traveled down a small valley, the upper end of which had once been in dry-land farming but long abondoned because of inadequate rainfall

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The lower end of the valley near the village was under irrigation. The princi pal crops here were tonatoes and alfalfa. Because of the rough, rocky terrain, it was not practical to plow the sides of the valley even though contanina— tion levels in spots were greater than 3.2 yCi/M^. In this case attempts were made to work into the ground with pick and shovel all "hot spots" that were greater than this value. Hillside contamination less than that was left untreated except for picking up contaminated aircraft debris. An agreement between the U. S. and Spanish Atomic Energy Commission set up a four-point follow-up program to the Palonares incident. The program was to be strictly under the direction of the Junta de Energia Nuclear’s Division de Kedicine y Proteccion (Dr. Eduardo Ramos) with equipment, technical help, and operational support from the U. S. Atomic Energy Commission. The fourpoint program was as follows: . (1) Collection of information on uptake and retention of plutonium and uranium by representative numbers of a population group potentially exposed to inhalation of a plutonium oxide aerosol. (2) Measurement of temporal and seasonal fluctuations in plutonium air concentrations above a plutonium oxide-contaminated agricultural area . that„has been subjected to the agreed upon decontamination procedures. (3> • Serial measurements of contamination levels (both by plant uptake from the soil and wind dispersal) of agricultural products produced in a contaminated area subsequent to decontamination. <4> Studies of the temporal migration and redistribution of plutonium

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oxide in soil, decontaminated by deep plowing, as a result of continued cul tivation and weathering. Technical assistance, approximately $250,000 in equipment (including whole-body and lung counter), and annual operating funds to the extent of about $25,000 per year, have been provided by the U. S* Atomic Energy Commis sion to support the effort. Six or so unclassified papers have been prepared relative to the Palonare incident. These are largely general in scope and difficult to find. My recor show the following articles, some of which I have copies: (1) William D. Moss: Report on Bioassay Laboratory in Madrid, Spain, Los Alamos Scientific Laboratory Report H5MR66-1 (September 1966). (2) Eduardo Ramos Rodriguez: Palomares Two Years After, presentaticn at some European conference, publication not known. (3) Emelio Iranzo: First Results from the Programme of Action following the Palomares Accident, Symposium on Radiological Protection of the Public in a Nuclear Disaster (IRPA) , Interlaken, Switzerland (June 1968). (4) E. Iranzo and E. Ramos: Measures to Determine the Risk to which a Population can be Subjected as a Result of a Nuclear Accident Generating Radioactive Aerosols: Environmental Contamination by Radioactive Materials, International Atomic Energy Agency, Vienna, Austria (1969). _(5) C. Alvarez-Ramis and Gregorides de los Santos: Contamination ca Gasteropodes Terresteres Habitat un Biotope a bas Niveau de Contamination Alpha Due Plutonium et a I'Uranium, Actes du Symposium International da r_sdioecologie. Centre d’Etudes Nucleaires de Cadarache du 8 au 12 (September 1P5S). (6) Emelio Iranzo and Sinesio Salvador: Inhalation Risks to People

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Living near a Contaminated Area, Second International Congress of the Inter national Radiation Protection Association, Brighton, England (Hay 1970); not In addition, uncirculated progress summaries of Palomares activities were prepared by Eduardo Ranos of the JEU Division de Medicine y Proteccion in April 1967 and November 1969. In Madrid, I was privileged to see all primary data collected to date relevant to the four-point program. Under point one, 100 of the most likely .exposed residents of Palonares were taken to Madrid and counted in the lung counter. The lower limit of detection of the counter was approximately AO nCi. No positive counts were observed in any of the 100 individuals. The counter was modified by the Spanish to give a minimum detectable limit of about 16 nCi, and a few of the most likely exposed individuals were recounted. Even with the improved sensitivity, no positive counts were observed. Urine samples (24-hour) were collected from the same 100 individuals. Seventy-one percent of the subjects showed no indication of plutonium in the urine. The others showed urine values of less than 0.1 to 0.2 disintegrations per minute per 24-hour sample — not statistically significant. It is my understanding that no further measurements have been made on the Palomares residents. Point two of the agreement (measurement of air concentrations) was initia* with installation of four continuous air-monitoring stations and two mateorolo: ical stations strategically located with respect to the contaminated area. Cn< of the air-monitoring and meteorological stations was located in the center of the village. Continuous air monitoring at all four stations were continued fo approximately two years. Daily samples were counted for gross alpha activity.

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and 10-day sanples were pooled and analyzed for plutoniun using chemical sep aration and alpha spectrometry. Uranium-234 and uranium-235 were determined also in the 1967 air samples. These results were reported in the paper by Iranzo and Salvador (paper No. 6 in the previous listing) at the Brighton Positive air samples were obtained occasionally at all stations, with the highest values coinciding with periods of high' wind velocity (above 35 km/hour). Mean plutonium values in the village for 1966 and 1967 were 0.38 X 10 15 and 0.09 x 10 ^ yCi/cm^, respectively. Only the air sampling station in the center of the village (station P) and the one in the irrigated fields to the east (station 3-2) are currently in operation. The others have been discontinued and salvaged to obtain parts to keep the other two in operation. Judging froa sound, they are about ready to go also. In ray opinion, it is un fortunate that station 2-2, strategically located to sample wind pickup from the untreated hillsides, has been discontinued. ' With regard to point three of the agreement (plutonium in vegetation), periodic sampling has been conducted. Reported measurements to date are in terras of gross alpha activity. They now have alpha spectrometry data on most of the vegetation samples. The Palomares area is perhaps one of the highest natural alpha background areas in Spain. The number of samples to be processe is large, and the Spanish were given only one alpha spectrometer which has given poor service. Counting times for spectral measurements are long, and air samples alone have been taking most of the available instrument time. Alpha spectrometry analysis of all samples (air, vegetation, and soil) will be required before the actual plutonium contamination can be established. The

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gross alpha and plutoniua neasurenents of vegetation are characterized by great variability froa area-to—area and froa saaple-to—sample within the same area. Undoubtedly, this variability is a manifestation of the difficulty of represent tive saopling and the nonunifora particulate nature of the environmental con tamination. Contamination of vegetation appears to be almost entirely surfacedeposited. Leaves and stalks run higher than the plant fruit. This is espe cially true for tomatoes. …