Nuclear Weapons Test Site Research Articles

Speciation of 137Cs, 90Sr, 241Am, and 239+240Pu artificial radionuclides in soils at the Semipalatinsk test site

This paper reports the speciation of 137Cs, 241Am, 90Sr and 239+240Pu in the soil samples of the Experimental Field (EF). The EF is a testing ground of the Semipalatinsk nuclear weapons test site used for surface and atmospheric tests. The study revealed low mobility of artificial radionuclides in the EF site soils.The revealed high radionuclide concentrations in soil mainly exist in tightly bound form. On average, the content of the tightly bound form of 137Cs was revealed to be below 98%, that of 90Sr - 94%, 241Am - 89%, and 239+240Pu - 98%.The radionuclides occurrence forms were analyzed in correlation with the physicochemical parameters of soils. Reliable relationships have been established between the content of carbonates and the content of the exchangeable, acid-soluble and strongly bound 90Sr forms in soils, as well as the content of the water-soluble salts and the content of the strongly bound 239+240Pu form in the soil.Similarly, we compared the distributions of the radionuclides speciation and their stable isotopes with their analogous elements in the soil. Unlike 137Cs and 90Sr, which are in a tightly bound form in the soils of the Experimental Field site, the main content of soil “competitors” of the 137Cs radionuclide – K and Cs is observed in an exchange form, less significantly in an acid-soluble form. The alkaline earth metals (analogous elements for 90Sr) are mainly observed as a composition of the exchangeable and acid-soluble forms. The results allow to conclude that there is no equilibrium distribution of the physicochemical forms of radionuclides introduced into the soil and the natural presence forms of their stable analogs in the soil. Such equilibrium distribution can only be achieved at a complete isotopic exchange in phases and soil components, which under the conditions of the Experimental Field is not possible in the near future.It can be concluded that the behavior of the studied radionuclides in soils is stipulated by the initial form delivered by the fallouts from tests at the EF site.

Commentary: Transparency for nuclear weapons test sites

Commentary: Transparency for nuclear weapons test sites

Comparison of Homogeneous and Particulate Lung Dose Rates For Small Mammals.

Small, highly radioactive fragments of material incorporated into metallic matrices are commonly found at nuclear weapons test and accident sites and can be inhaled by wildlife. Inhaled particles often partition heterogeneously in the lungs, with aggregation occurring in the periphery of the lung, and are tenaciously retained. However, dose rates are typically calculated as if the material were homogeneously distributed throughout the entire organ. Here the authors quantify the variation in dose rates for alpha-, beta-, and gamma-emitting radionuclides with particle sizes from 0.01-150 μm (alpha) and 1-150 μm (beta, gamma) and considering three averaging volumes-the entire lung (64 cm), a 10-cm volume of tissue, and a 1-cm volume of tissue. Dose rates from beta-emitting particles (e.g., Sr) were approximately one order of magnitude higher than those from gamma-emitting radionuclides (e.g., Cs). Self-shielding within the particle, which reduces the dose rate to the surrounding tissue, was negligible for gammas and minor for betas. For alpha-emitting particles (e.g., Pu), self-shielding in larger particles is substantial, with >90% of emissions captured within particles of +20 μm diameter; but for smaller sizes of the respirable range of 0.01 to 5 μm, an average of 85% of the energy escapes the particle and is deposited in the surrounding tissues. These data provide more detail on respirable particles, which may remain lodged deep in the lung where they represent a considerable contribution to long-term lung dose rates. For practical dose rate calculation purposes, a graph of particle size vs. dose rates for plutonium-containing hot particles is provided. This study demonstrates one possible approach to dose assessments for biota in environments contaminated by radioactive particles, which may prove useful for those engaged in environmental radioprotection.

LIPID PROFILE AMONG THE POPULATION EXPOSED TO RADIATION FROM SEMIPALATINSK NUCLEAR TEST SITE, KAZAKHSTAN

Many studies have explored associations between radiation exposure and cancer among atomic bomb survivors in Japan, Chernobyl rescue workers, workers of nuclear industry in Germany and in a historical cohort of people who were exposed to the radiation from the Semipalatinsk nuclear weapons test site in Kazakhstan. Non-cancer consequences of radiation exposure have been less studied. We identified a few publications on associations between radiation and cardiovascular diseases, but most of them were conducted in Japan among Hiroshima and Nagasaki survivors and their offspring. In this population-based cross-sectional study (n = 1 755) we assessed associations between equivalent radiation dose and blood lipids among population of East Kazakhstan and Pavlodar regions who permanently live in close proximity to Semipalatinsk nuclear weapons test site. We studied total cholesterol, low- and high density lipoproteins as dependent variables across quartiles of the equivalent radiation dose using multiple linear regression with adjustment for gender, smoking, alcohol consumption, body mass index and region of residence. We observed significant positive association between equivalent dose and total cholesterol and low density lipoproteins, but not high density lipoproteins. Our results contribute to the understanding of the mechanisms between low dose radiation exposure and cardiovascular diseases

236U and 239,240Pu ratios from soils around an Australian nuclear weapons test site

The isotopes 236U, 239Pu and 240Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes potentially constitute artificial tracers of recent soil erosion and sediment movement. Only Accelerator Mass Spectrometry has the requisite sensitivity to measure all three isotopes at these environmental levels. Coupled with its relatively high throughput capabilities, this makes it feasible to conduct studies of erosion across the geographical extent of the Australian continent.In the Australian context, however, global fallout is not the only source of these isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The tests have made a significant contribution to the Pu isotopic abundances present in the region around Maralinga and out to distances ∼1000 km, and impact on the assessment techniques used in the soil and sediment tracer studies. Quantification of the relative fallout contribution derived from detonations at Maralinga is complicated owing to significant contamination around the test site from numerous nuclear weapons safety trials that were also carried out around the site. We show that 236U can provide new information on the component of the fallout that is derived from the local nuclear weapons tests, and highlight the potential of 236U as a new fallout tracer.

Clinical and epidemiological features of chronic liver disease among the East Kazakhstan residents exposed to radiation from the Semipalatinsk nuclear weapons test site

Background The East Kazakhstan is a territory with radioecological distress caused by nuclear weapons tests performed from 1949 to 1989 at the former Semipalatinsk Test Site. The individual effective doses of external exposure in these areas range between 250-500 mSv. The goal of the study is epidemiological assessment of the chronic liver diseases in the region adjacent to the Semipalatinsk Nuclear Test Site. …

Semey cardiovascular disease registry of the population exposed to radiation from Semipalatinsk nuclear weapons test site, East Kazakhstan

Semey cardiovascular disease registry of the population exposed to radiation from Semipalatinsk nuclear weapons test site, East Kazakhstan

First measurements of 236U concentrations and 236U/239Pu isotopic ratios in a Southern Hemisphere soil far from nuclear test or reactor sites

The variation of the 236U and 239Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of 236U and 239Pu as well as the 236U/239Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30′ – 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil sample (∼20 g) within a day. The samples were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both 236U and 239Pu were found at a depth of 2–3 cm. The 236U/239Pu isotopic ratio in fallout at this site, as deduced from the ratio of the 236U and 239Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The 236U inventory of (8.4 ± 0.3) × 1011 at/m2 was more than an order of magnitude lower than values reported for the Northern Hemisphere. The 239Pu activity concentrations are in excellent agreement with a previous study and the 239+240Pu inventory was (13.85 ± 0.29) Bq/m2. The weighted mean 240Pu/239Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0–30°S).

Miscarriages and Congenital Conditions in Offspring of Veterans of the British Nuclear Atmospheric Test Programme

A postal questionnaire case-control study examined miscarriage in wives and congenital conditions in offspring of the 2007 membership of the British Nuclear Test Veterans Association, a group of ex-servicemen who were stationed at atmospheric nuclear weapon test sites between 1952-67. Results were compared with a veteran-selected control group and also with national data. Based on 605 veteran children and 749 grandchildren compared with 311 control children and 408 control grandchildren there were significant excess levels of miscarriages, stillbirths, infant mortality and congenital illnesses in the veterans? children relative both to control children and expected numbers. 105 miscarriages in veteran?s wives compared with 18 in controls OR=2.75 (1.56, 4.91; p=.00016). There were 16 stillbirths; 3 in controls (OR=2.70 (0.73, 11.72; p=0.13). Perinatal mortality OR was 4.3 (1.22, 17.9; p=.01) on 25 deaths in veteran children. 57 veteran children had congenital conditions vs. 3 control children (OR=9.77 (2.92, 39.3); p=0.000003) these rates being also about 8 times those expected on the basis of UK EUROCAT data for 1980?-2000. For grandchildren, similar levels of congenital illness were reported with 46 veteran grandchildren compared with 3 controls OR=8.35 (2.48, 33.8) p=0.000025. There was significantly more cancer in the veteran grandchildren than controls. Whilst caution must be exercised due to structural problems inherent in this study we conclude that the veterans? offspring qualitatively exhibit a prevalence of congenital conditions significantly greater than that of controls and also that of the general population in England. The effect remains highly statistically significant even assuming a high selection bias in the responses and credibility is strengthened by the high rates of miscarriage reported by the veterans compared with controls, a result which could hardly have been due selection effects.

Oxygen Isotope Composition of Trinitite Postdetonation Materials

Trinitite is the melt glass produced subsequent the first nuclear bomb test conducted on July 16, 1945, at White Sands Range (Alamagordo, NM). The geological background of the latter consists of arkosic sand that was fused with radioactive debris and anthropogenic materials at ground zero subsequent detonation of the device. Postdetonation materials from historic nuclear weapon test sites provide ideal samples for development of novel forensic methods for attribution and studying the chemical/isotopic effects of the explosion on the natural geological environment. In particular, the latter effects can be evaluated relative to their spatial distribution from ground zero. We report here δ(18)O(‰) values for nonmelted, precursor minerals phases (quartz, feldspar, calcite), "feldspathic-rich" glass, "average" melt glass, and bulk (natural) unmelted sand from the Trinity site. Prior to oxygen isotope analysis, grains/crystals were examined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to determine their corresponding major element composition. δ(18)O values for bulk trinitite samples exhibit a large range (11.2-15.5‰) and do not correlate with activity levels for activation product (152)Eu; the latter levels are a function of their spatial distribution relative to ground zero. Therefore, the slow neutron flux associated with the nuclear explosion did not perturb the (18)O/(16)O isotope systematics. The oxygen isotope values do correlate with the abundances of major elements derived from precursor minerals present within the arkosic sand. Hence, the O isotope ratios documented here for trinitite melt glass can be attributed to a mixture of the respective signatures for precursor minerals at the Trinity site prior to the nuclear explosion.

Plutonium isotopes and 241Am in the atmosphere of Lithuania: A comparison of different source terms

137Cs, 241Am and Pu isotopes collected in aerosol samples during 1994–2011 were analyzed with special emphasis on better understanding of Pu and Am behavior in the atmosphere. The results from long-term measurements of 240Pu/239Pu atom ratios showed a bimodal frequency distribution with median values of 0.195 and 0.253, indicating two main sources contributing to the Pu activities at the Vilnius sampling station. The low Pu atom ratio of 0.141 could be attributed to the weapon-grade plutonium derived from the nuclear weapon test sites. The frequency of air masses arriving from the North-West and North-East correlated with the Pu atom ratio indicating the input from the sources located in these regions (the Novaya Zemlya test site, Siberian nuclear plants), while no correlation with the Chernobyl region was observed. Measurements carried out during the Fukushima accident showed a negligible impact of this source with Pu activities by four orders of magnitude lower as compared to the Chernobyl accident. The activity concentration of actinides measured in the integrated sample collected in March–April, 2011 showed a small contribution of Pu with unusual activity and atom ratios indicating the presence of the spent fuel of different origin than that of the Chernobyl accident.

Plutonium and uranium contamination in soils from former nuclear weapon test sites in Australia

The British government performed a number of nuclear weapon tests on Australian territory from 1952 through to 1963 with the cooperation of the Australian government. Nine fission bombs were detonated in South Australia at Emu Junction and Maralinga, and a further three fission weapons were detonated in the Monte Bello Islands off the coast of Western Australia. A number of soil samples were collected by the Australian Radiation Laboratories in 1972 and 1978 during field surveys at these nuclear weapon test sites. They were analysed by gamma spectrometry and, for a select few samples, by alpha spectrometry to measure the remaining activities of fission products, activation products and weapon materials. We have remeasured a number of these Montebello Islands and Emu Junction soil samples using the ANTARES AMS facility, ANSTO. These samples were analysed for plutonium and uranium isotopic ratios and isotopic concentrations. Very low 240Pu/239Pu ratios were measured at both sites (∼0.05 for Alpha Island and ∼0.02 for Emu Field), substantially below global fallout averages. Well correlated but widely varying 236U and plutonium concentrations were measured across both sites, but 233U did not correlate with these other isotopes and instead showed correlation with distance from ground zero, indicating in situ production in the soils.

Anomalous Plutonium Isotopic Ratios in Sediments of Lake Qinghai from the Qinghai-Tibetan Plateau, China

The vertical profiles of (239+240)Pu and (137)Cs activities and (240)Pu/(239)Pu isotopic ratios are determined for three sediment cores of Lake Qinghai from the Qinghai-Tibetan Plateau, China, and compared with those in sediments of another three lakes (Lakes Bosten, Sugan, and Shuangta), the only existing ones closest to Lop Nor area, China's nuclear weapons test site in the northwestern part of the country. The mean inventory of 47.7 ± 18.7 MBq km(-2) for (239+240)Pu activity in Lake Qinghai is comparable to the average value of global fallout expected at the same latitude, yet the mean inventory of 1112.0 ± 78.0 MBq km(-2) for (137)Cs is slightly lower than that of global fallout. Anomalously low (240)Pu/(239)Pu isotopic ratios (0.038-0.125) were found in the 3-6.5 cm deep sediment layers, indicating the trace Pu input from early nuclear weapons research activities at Atomic City in the lake's watershed during the 1950-60s. Model calculation indicated that the Pu input accounted for approximately 5-16% of the total Pu inventory. The observation of low (240)Pu/(239)Pu ratio in the deep sediment layer provided a new time marker for recent sediment dating in the lake and around the area. The results are of great significance to the further understanding of sources, records, and environmental impacts of global and regional nuclear activities in the environment and provide important chronological information for further studies on the water eutrophication process and climatic change, and reconstruction of pollution history of organic contaminants and heavy metals in the watershed of Lake Qinghai.

The Chinese nuclear tests, 1964–1996

A combination of intellectual rigor, technical sophistication, hard work, and intelligence gathering brought China into the world’s nuclear club in record-shattering time.

Residual radionuclide concentrations and estimated radiation doses at the former French nuclear weapons test sites in Algeria

In order to assess the level of residual radioactivity and evaluate the radiological conditions at the former French nuclear testing sites of Reggane and Taourirt Tan Afella in the south of Algeria, the International Atomic Energy Agency, at the request of the government of Algeria, conducted a field mission to the sites in 1999. At these locations, France conducted a number of nuclear tests in the early 1960s. At the ground zero locality of the ‘‘Gerboise Blanche’’ atmospheric test (Reggane) and in the vicinity of a tunnel where radioactive lava was ejected during a poorly contained explosion (Taourirt Tan Afella), non-negligible levels of radioactive material could still be measured. Using the information collected and using realistic potential exposure scenarios, radiation doses to potential occupants and visitors to the sites were estimated.

Thyroid Disease Associated With Exposure to the Nevada Nuclear Weapons Test Site Radiation

A study was begun in 1965 to 1966 to determine whether children exposed to radioactive iodine from nuclear weapons testing at the Nevada Test Site from 1951 through 1962 were at higher risk of thyroid disease. In 1993, we reported that among those examined in 1985 to 1986 (Phase II) there was an association between radiation from the Nevada Test Site and thyroid neoplasms. We reevaluated the relationship between exposure to Nevada Test Site fallout and thyroid disease using newly corrected dose estimates and disease outcomes from the Phase II study. A prospective cohort of school children 12 to 18 years old living in Utah, Nevada, and Arizona was first examined for thyroid disease in 1965 to 1966 and reexamined in 1985 to 1986. In the Phase II report, 2497 subjects formed the basis for this analysis. Thyroid disease, including thyroid neoplasms and thyroiditis, was expressed as cumulative incidence and risk ratios (RRs) with a dose-response expressed as excess risk ratio (ERR/Gy). The RR between thyroid radiation dose in the highest dose group and thyroid neoplasms increased from 3.4 (in the earlier analysis) to 7.5. The RR for thyroiditis increased from 1.1 to 2.7 with an ERR/Gy of 4.9 (95% confidence interval = 2.0 to 10.0). There were too few malignant thyroid neoplasms to estimate risk. Persons exposed to radioactive iodine as children have an increased risk of thyroid neoplasms and autoimmune thyroiditis up to 30 years after exposure.

Atomic intelligence in Norway during the Cold War

Thanks to its geographical location and close military ties to the US and Britain, Norway took substantial part in the Western intelligence effort against the Soviet nuclear weapons programme during the Cold War. Norway's relative proximity to the nuclear weapons test sites on Novaya Zemlya and the nuclear submarine bases on the Kola Peninsula was of particular importance in this regard. Whereas the tasks of surveying the development, deployment and possible employment of Soviet nuclear forces always had first priority, Western atomic intelligence conducted from Norwegian soil and waters was occasionally aimed even at gathering information about the geophysical and possible long-term medical and environmental implications of high-yield nuclear explosions in the atmosphere.

Shot in the dark [nuclear weapon testing

This paper discusses the future of the National Ignition Facility (NIF) located in Livermore, CA, amid criticisms about whether it can achieve its stated scientific goals and whether such a money-draining project was really necessary in the first place. Envisioned as an ideal site for nuclear weapons testing, the NIF could produce fusion in controlled conditions that would allow weapons specialists to simulate the detonation of different types of bombs to help them assess the status of aging atomic stockpiles without conducting risky test explosions that international law is trying to ban. A major source of concern among critics is the question of whether a fusion reaction that occurs inside a capsule smaller than a fingernail can provide an accurate indication of how a full-size nuclear weapon would detonate. NIF scientists are confident, however, that applying computer-generated formulas to their experimental data can account for such scale differences.

Determination of plutonium in environmental samples by AMS and alpha spectrometry

Environmental samples from nuclear weapons test sites at the atolls of Mururoa and Fangataufa (French Polynesia, south Pacific) have been analyzed for their content of plutonium isotopes by applying the independent techniques of decay counting (Alpha Spectrometry) and accelerator mass spectrometry (AMS). Here, we propose the combination of both techniques which results in a maximum of information on the isotopic signature of Pu in environmental samples. Plutonium was chemically separated from the bulk material by anion exchange. 242Pu was used as an internal standard for both AMS and alpha spectrometry. The samples for alpha spectrometry were prepared by micro-precipitation with NdF 3. After alpha spectrometry, the samples were reprocessed for AMS. Pu was co-precipitated with Fe(OH) 3 and finally, solid samples were prepared. At the VERA (Vienna Environmental Research Accelerator) facility, the various Pu isotopes were separated by their isotopic masses and quantified by the AMS technique. A good agreement of the results obtained from the AMS measurements was found with those obtained from Alpha Spectrometry. Overall, the data agree on average within 10% of each other. Isotope ratios for 238Pu, 239Pu and 240Pu can be extracted from our investigations. Alpha spectrometry delivers data for the 238Pu and the combination of (239+240)Pu concentrations in those samples. In addition, the AMS technique provides information on the individual concentrations of 240Pu and 239Pu.

90Sr, 137Cs and 239,240Pu concentration surface water time series in the Pacific and Indian Oceans – WOMARS results

Under an IAEA's Co-ordinated Research Project “Worldwide Marine Radioactivity Studies (WOMARS)” 90Sr, 137Cs and 239,240Pu concentration surface water time series in the Pacific and Indian Oceans have been investigated. The Pacific and Indian Oceans were divided into 17 latitudinal boxes according to ocean circulation, global fallout patterns and the location of nuclear weapons test sites. The present levels and time trends in radionuclide concentrations in surface water for each box were studied and the corresponding effective half-lives were estimated. For the year 2000, the estimated average 90Sr, 137Cs and 239,240Pu concentrations in surface waters of the Pacific and Indian Oceans varied from 0.1 to 1.5 mBq/L, 0.1 to 2.8 mBq/L, and 0.1 to 5.2 μBq/L, respectively. The mean effective half-lives for 90Sr and 137Cs in surface water were 12 ± 1 years for the North, 20 ± 1 years for the South and 21 ± 2 years for the Equatorial Pacific. For 239,240Pu the corresponding mean effective half-lives were 7 ± 1 years for the North, 12 ± 4 years for the South and 10 ± 2 years for the Equatorial Pacific. For the Indian Ocean the mean effective half-lives of 137Cs and 239,240Pu were 21 ± 2 years and 9 ± 1 years, respectively. There is evidence that fallout removal rates before 1970 were faster than those observed during recent decades. The estimated surface water concentrations of 90Sr, 137Cs and 239,240Pu in latitudinal belts of the Pacific and Indian Oceans for the year 2000 may be used as the average levels so that any new contribution from nuclear facilities, nuclear weapons test sites, radioactive waste dumping sites and from possible nuclear accidents can be identified.