A pore water study of plutonium in a seasonally anoxic lake

Data are presented here on the distribution of ^239,240Pu in the pore waters of two cores taken from a seasonally anoxic lake. The pore water ^239,240Pu profile exhibits a subsurface activity maximum of 230 ± 30 μBqkg^?1 in the 3–6 cm interval in June, as compared to an activity of 5 ± 3 μBqkg^?1 in the overlying water. The pore water ^239,240Pu profile in June follows the solid phase distribution pattern of ^239,240Pu and also the pore water distributions of Fe and Mn. Under more reducing conditions in August, pore water ^239,240Pu activities drop off to undetectable levels at all depths. This rapid change in the pore water ^239,240Pu activity reflects the dynamic nature of Pu diagenesis in these sediments. Potential diffusional fluxes of ^239,240Pu into the lake's hypolimnion in June are calculated to be on the order of 2·5 μBq cm^?2y^?1. This flux would not be significant in altering the solid phase ^239,240Pu inventory (2·8 × 10⁴μBqcm^?2).     

Cs,Pu and Am in bottom sediments and surface water of Lake Päijänne,Finland

The concentrations and vertical distribution of ^239,240Pu, ²⁴¹Am and ¹³⁷Cs in the bottom sediments and water samples of Lake Päijänne were investigated. This lake is important, since the Päijänne area received a significant deposition from the Chernobyl fallout. Furthermore Lake Päijänne is the raw water source for the Helsinki metropolitan area. In addition no previous data on the distribution of plutonium and americium in the sediment profiles of Lake Päijänne exist. Only data covering the surface layer (0–1 cm) of the sediments are previously available. In the sediments the average total activities were 45 ± 15 Bq/m² and 20 ± 7 Bq/m² for ^239,240Pu and ²⁴¹Am, respectively. The average ²⁴¹Am/^239,240Pu ratio was 0.45 ± 0.14. The ²⁴¹Am/^239,240Pu ratio is lowest in the surface layer of the sediments and increases as a function of depth. The ²³⁸Pu/^239,240Pu ratio of the sediment samples varied between 0.012 ± 0.025 and 0.162 ± 0.079, decreasing as a function of depth. The average activity in water was 4.9 ± 0.9 mBq/m³ and 4.1 ± 0.2 mBq/m³ for ^239,240Pu and ²⁴¹Am, respectively. The ²⁴¹Am/^239,240Pu ratio of water samples was 0.82 ± 0.17. ^239,240Pu originating from the Chernobyl fallout calculated from the average total activities covers approximately 1.95 ± 0.01% of the total ^239,240Pu activity in the bottom sediments. The average total ¹³⁷Cs activity of sediment profiles was 100 ± 15 kBq/m² and 19.3 ± 1.4 Bq/m³ in water samples.     

Sources and distributions of Cs, Pu, Pu radionuclides in the north-western Barents Sea

Sediment deposits are the ultimate sink for anthropogenic radionuclides entering the marine environment. The major sources of anthropogenic radionuclides to the Barents Sea are fallout from nuclear weapons tests, long range transport from other seas, and river and non-point freshwater supplies. In this study we investigated activity concentrations, ratios, and inventories of the anthropogenic radionuclides, ¹³⁷Cs, ²³⁸Pu, ^239,240Pu in dated sediment cores collected along a north-south transect in the northwestern Barents Sea. The data were used to evaluate the influence of different sources on the derived spatial and temporal patterns of anthropogenic radionuclides in seafloor sediment deposits. Activity concentrations of ¹³⁷Cs ranged from <0.1 Bq/kg to 10.5 Bq/kg while ^239,240Pu ranged from <0.01 Bq/kg to 2.74 Bq/kg and ²³⁸Pu activity concentrations ranged from <0.01 Bq/kg to 0.22 Bq/kg. Total inventories of ¹³⁷Cs ranged from 29.5 ± 1.5 Bq/m² to 152.7 ± 5.6 Bq/m² and for ^239,240Pu inventories (6 sediment layers only) ranged from 9.5 ± 0.3 Bq/m² to 29.7 ± 0.4 Bq/m². Source contributions varied among stations and between the investigated radionuclides. The ²³⁸Pu/^239,240Pu ratios up to 0.18 indicate discharges from nuclear fuel reprocessing plants as a main contributor of plutonium. Based on ²³⁸Pu/^239,240Pu ratio, it was calculated that up to 19-27% of plutonium is supplied from sources other than atmospheric global fallout. Taking into account Atlantic current flow trajectories and that both activity concentrations and inventories of plutonium negatively correlate with latitude, Sellafield is a major source for the Barents Sea. Concentrations and inventories of ¹³⁷Cs correlate positively with latitude and negatively with distance from the Svalbard archipelago. The ¹³⁷Cs concentrations are highest in an area of intensive melting of sea ice formed along the Siberian coast. Thus, sea ice and supplies from Svalbard may be important source of ¹³⁷Cs to the Barents Sea seafloor.     

Rapid remobilisation of plutonium from estuarine sediments

Plutonium remobilisation experiments, using contaminated Esk Estuary sediments and uncontaminated River Esk and North Sea waters, have successfully reproduced the observed non-conservative behaviour of dissolved Pu in the Esk Estuary, Cumbria, UK. Remobilisation is greatest at low salinites (<4%) and, under these conditions, Pu(III, IV) and Pu(V, VI) are released into solution in similar absolute amounts. The remobilisation process appears to be associated with a rapid (equilibrium achieved in 15 min) exchange reaction involving competition between Pu species, protons and major cations for the available surface sites. The experimental results show a systematic variation in distribution coefficients (i.e. K_d) for total Pu (7·2 × 10⁴−4·1 × 10⁶), Pu(III, IV) (1·0 × 10⁵−5·8 × 10⁶) and Pu(V, VI) (6·4 × 10³−5·5 × 10⁵).     

Time pattern of off-site plutonium deposition from rocky flats plant by lake sediment analyses

A sediment core from a lake downwind of the Rocky Flats Plant, where nuclear weapons components are produced, was used to reconstruct a time pattern of off-site plutonium deposition. Core sections were dated by analyses of ¹³⁷Cs, ^239,240Pu, ²³⁸Pu, and ²⁴¹Am fallout from nuclear testing and ²³⁸Pu fallout from a satellite failure. A peak in transuranic concentrations occurred in late 1969 which was attributable to the Plant. This was confirmed by mass isotopic analysis of plutonium isotopes in selected core segments where the global fallout and Plant contributions could be differentiated. The 18 nCi ^239,240Pu per m² from the Plant that had accumulated in the sediment is reasonable when compared to soil analyses.     

Anomalous concentrations of atmospheric plutonium-238 over Paris

Analysis of monthly rain samples collected in Paris reveals that ²³⁸Pu/ ^239,240Pu activity ratios, usually about 0·04, the fallout value, rose suddenly to 25 in October 1982. Abnormal ratios continued to be observed during the following months. Excess ²³⁸Pu from atmospheric nuclear tests can be eliminated as a possible cause. No correlation was found either with identified satellite re-entries or with atmospheric radioactive anomalies already detected in Northern Europe prior to the Chernobyl accident. Different potential industrial sources are discussed here, but the authors remain unable to identify the origin of the abnormally high ratio. This study shows that a careful investigation of ²³⁸Pu fallout is needed if environmental processes are to be traced via plutonium activity ratios.     

Characterization of plutonium in deep-sea sediments of the Sulu and South China Seas

Anthropogenic Pu isotopes are important geochemical tracers for sediment studies. Their distributions and sources in the water columns as well as the sediments of the North Pacific have been intensively studied; however, information about Pu in the Southeast Asian seas is limited. To study the isotopic composition of Pu, and thus to identify its sources, we collected sediment core samples in the South China Sea and the Sulu Sea during the KH-96-5 Cruise of the R/V Hakuho Maru. We analysed the activities of ^239+240Pu and the atom ratios of ²⁴⁰Pu/²³⁹Pu using isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The ²⁴⁰Pu/²³⁹Pu atom ratios in the sediments of both areas (inventory weighted mean: 0.251 for the South China Sea and 0.280 for the Sulu Sea) were higher than the global fallout value (0.178 ± 0.019), suggesting the existence of Pu from the Pacific Proving Grounds in the North Pacific. Low inventories of ^239+240Pu in sediments were observed in the South China Sea (3.75 Bq/m²) and the Sulu Sea (1.38 Bq/m²). Most of the Pu input is still present in the water column. Scavenging and benthic mixing processes were considered to be the main processes controlling the distribution of Pu in the deep-sea sediments of both study areas.     

Plutonium isotopes in surface air of Prague in 1986–2006

Monitoring of ^239,240Pu in surface air of Prague started in 1986 in connection with the Chernobyl accident. Measurable activities of 10–28 μBq m⁻³ were found from 29 April 1986 to 5 May 1986. In the most of the monitoring periods of 1987–1996, activities of ^239,240Pu in air were not measurable. Positive values for ^239,240Pu and ²³⁸Pu in air could be obtained after installation of an aerosol sampler with higher flow-rate in 1997. Activity concentrations of ^239,240Pu and ²³⁸Pu in Prague air in the most of quarters of 1997–2006 were in the range 0.53–5.06 and <0.16–1.10 nBq m⁻³, respectively. Seasonal fluctuations can be found in content of ^239,240Pu in air. Activity ratios of ²³⁸Pu/^239,240Pu in air are higher than those in top soil, so it can be supposed that ²³⁸Pu is coming to air of Prague also from other sources than resuspension of fallout from atmospheric nuclear tests.     

Experimental studies on the bioaccumulation of plutonium from sea water and a deep-sea sediment by clams and polychaetes

The bioavailability of ²³⁷Pu in the (III + IV) and (V + VI) oxidation states from sea water and a NE Atlantic deep-sea sediment has been studied for clams (Venerupis decussata) and polychaete worms (Hermione hystrix). After 22 days' exposure in sea water transfer factors (TF) had not reached equilibrium, and were 74 ± 5 and 61 ± 1 for clams and 370 ± 10 and 275 ± 11 for polychaetes, for Pu (III + IV) and Pu (V + VI) respectively. Depuration rates after sea water exposure followed a single exponential form ($\text{T}{}_{\mathrm{<mtext>b</mtext><mtext>1</mtext><mtext>2</mtext>}}\text{= 50}\text{days}$) for clams, and for polychaetes at least a two component from with $\text{T}{}_{\mathrm{<mtext>b</mtext><mtext>1</mtext><mtext>2</mtext>}}\text{= 1·3}\text{days}$ and 54 days. TF values for ²³⁷Pu bioaccumulation from sediments were very low, 6 × 10^?3 and 5 × 10^?2 for clams and polychaetes, respectively, after 20 days' exposure.Plotonium appears to be about 50% more bioavailable to the same species than americium as measured by laboratory experiments using a similar deep-sea sediment. Depuration experiments with clams after 40 days' exposure to labelled sediment indicated loss followed a single exponential form with a $\text{T}{}_{\mathrm{<mtext>b</mtext><mtext>1</mtext><mtext>2</mtext>}}\text{= 24}\text{days}$. Significant differences in the behaviour of Pu introduced into the uptake and loss experiments in different oxidation states were not observed in general.     

Depositional behaviors of plutonium and thorium isotopes at Tsukuba and Mt. Haruna in Japan indicate the sources of atmospheric dust

Monthly plutonium and thorium depositions at Tsukuba (28 m asl) and Mt. Haruna (1370 m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly ^239,240Pu depositions ranged from 0.044 to 2.67 mBq m⁻² at Tsukuba and from 0.05 to 0.9 mBq m⁻² at Mt. Haruna during the measurement periods. Monthly ^239,240Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly ^239,240Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. ²³⁰Th/²³²Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total ^239,240Pu and Th deposits are derived from remote sources, especially in spring.     

Fractionation of plutonium in environmental and bio-shielding concrete samples using dynamic sequential extraction

Fractionation of plutonium isotopes (²³⁸Pu, ^239,240Pu) in environmental samples (i.e. soil and sediment) and bio-shielding concrete from decommissioning of nuclear reactor were carried out by dynamic sequential extraction using an on-line sequential injection (SI) system combined with a specially designed extraction column. Plutonium in the fractions from the sequential extraction was separated by ion exchange chromatography and measured using alpha spectrometry. The analytical results show a higher mobility of plutonium in bio-shielding concrete, which means attention should be paid to the treatment and disposal of nuclear waste from decommissioning.     

Aspects of the uptake of radionuclides by sheep grazing on an estuarine saltmarsh. 2. Radionuclides in sheep tissues

The transfer ¹³⁷Cs, ²³⁸Pu, ^239/240Pu and ²⁴¹Am to sheep which graze a saltmarsh in the Esk estuary, 7 km south of the sellafield reprocessing plant in west Cumbria (UK), has been estimated.The concentrations of gamma-emitting radionuclides and of ²³⁸Pu, ^239/240Pu and ²⁴¹Am were measured in liver, lung, muscle, kidney and bone from saltmarsh ewes and lambs. ¹³⁷Cs concentrations in the soft tissues were similar in liver, lung and muscle but were consistently higher in kidney and much lower in bone. The highest concentration of the transuranics was found in liver.Transfer coefficients and concentration factors were calculated for both ewes and lambs. The concentration of ¹³⁷Cs in the tissues of 5-month old lambs was higher than in those of their mothers. Therefore, a higher transfer coefficient was obtained for lamb muscle (1·8 × 10^?1 d kg^?1) than for ewe muscle (6·4 × 10^?2 d kg^?1). Concentration factors were consistently higher for ¹³⁷Cs than for the transuranics.     

Using sequential extraction techniques to assess the partitioning of plutonium and neptunium-237 from multiple sources in sediments from the Ob River (Siberia)

Sequential extraction techniques have been developed to assess partitioning of anthropogenic radionuclides (²⁴⁰Pu, ²³⁹Pu, and ²³⁷Np), originating from a variety of sources, as identified by using bulk sediment isotopic composition. Sediments were leached sequentially with a series of six chemical treatments designed to approximate different environmental processes that may occur or to selectively extract trace metals contained in different solid phases of the sediments (i.e., exchangeable, reducible, carbonate, organic, acid leachable, and refractory). Results indicate the majority of Pu and Np is similarly distributed within many of the extracted fractions, with the largest percentage (66–97%) of both elements being observed in sediments treated with buffered citrate dithionite (CDB), which targets easily reduced constituents such as Mn and Fe hydrous oxides. While these results do indicate an association of Pu and Np with redox sensitive elements, the environmental implications are unclear given that the CDB treatment is more extreme than naturally occurring conditions. Minor amounts of Np partition differently from Pu in sediments. The NH₄-acetate treatment, which is designed to liberate trace metals that are loosely adsorbed onto the surfaces of sedimentary materials such as hydrated iron oxides and humic substances, or present at exchangeable sites in clay minerals, mobilized ∼12% of the total Np while Pu levels were below detection. The H₂O₂ treatment, which is designed to liberate trace metals bound to organic matter, mobilized ∼8 and ∼1% of Np and Pu, respectively. These results indicate that a minor portion of the total Np may be affected by environmental conditions that have little or no effect on Pu. Between 7 and 24% of the Pu was observed in treatments designed to liberate Pu and Np that are tightly bound to lithogenic phases or refractory silicates. The ²⁴⁰Pu/²³⁹Pu observed in accessible and refractory fractions ranged between 0.11 and 0.18. With the exception of one sample, the ²⁴⁰Pu/²³⁹Pu isotope ratios measured in the refractory fractions are essentially identical having a mean ratio value of 0.123 ± 0.001 (1σ). The ²⁴⁰Pu/²³⁹Pu ratios provide isotopic evidence that suggests a portion of non-fallout contamination has a refractory nature. The presence of similarly low ²⁴⁰Pu/²³⁹Pu ratios in refractory fractions of sediments from the Ob and Irtysh Rivers suggests the existence of a source of refractory Pu which is consistent with refractory “hot particles” derived from surface tests at the Semipalitinsk test site.     

Laboratory studies of the chemical behaviour of plutonium associated with contaminated estuarine sediments

Laboratory experiments, with contaminated Esk Estuary sediment and uncontaminated River Esk and North Sea waters, have provided detailed information on Pu remobilisation behaviour. Of the 977 mBq g⁻¹ Pu (III, IV) associated with the sediment, 2·6% is subject to a rapid reversible exchange reaction. Well-defined distribution coefficients (K_d) have been determined with respect to this labile fraction (e.g. 5 × 10³ litres kg⁻¹ for remobilisation into river water). A low level of Pu (III, IV) remobilisation can be maintained following complete removal of the labile fraction, probably through a rate-limited reaction involving a more strongly bound form of Pu. Plutonium (V, VI) remobilisation occurs both through rapid exchange of a comparable labile component and through a mechanism involving photo-oxidation of Pu (III, IV).A dominant proportion of the remobilised Pu (III, IV) in solution is anionic with a molecular weight1000 daltons, probably in the form of an organic complex. Remobilised Pu (V, VI) is mainly in true solution in variously charged forms. Addition of natural colloidal organic carbon (COC) to river water increased the level of labile Pu (III, IV) remobilisation. The effect can be described by two competing equilibria in which labile Pu (III, IV) (a) is complexed by COC, and (b) is adsorbed by the sediment. The same additions of COC reduced the level of Pu (V, VI) remobilisation, either through its action as a reducing agent or through the indirect effect of associated pH changes. Increasing the carbonate alkalinity (NaHCO₃) in river water decreases the remobilisation of both Pu (III, IV) and Pu (V, VI).     

A modelling study on 137Cs and 239,240Pu behaviour in the Alborán Sea, western Mediterranean

A model for simulating the dispersion processes of 137Cs and 239,240Pu in the Alborán Sea is described. The model consists of two hydrodynamic models: a 2D depth-averaged model and a two-layer model which provide tidal and geostrophic currents, respectively; a sediment transport model which provides suspended particle concentrations and sedimentation rates over the domain; and the radionuclide dispersion model including interactions of dissolved radionuclides with suspended particles and bed sediments. These processes are formulated using kinetic transfer coefficients. The hydrodynamic and sediment models are run and validated in advance, and their results are then used to simulate the dispersion of 137Cs and 239,240Pu, which are introduced from atmospheric fallout. Radionuclide concentrations in the water column and distributions in bed sediments have been compared with measurements in the sea. Both set of data are, in general, in agreement. The model has also been applied to calculate radionuclide fluxes through the Strait of Gibraltar. These computed fluxes have been compared with previous estimations as well.     

Pu/Cs ratios in the water column of the North Pacific: a proxy of biogeochemical processes

Anthropogenic radionuclides in seawater have been used as transient tracers of processes in the marine environment. Especially, plutonium in seawater is considered to be a valuable tracer of biogeochemical processes due to its particle-reactive properties. However, its behavior in the ocean is also affected by physical processes such as advection, mixing and diffusion. Here we introduce Pu/¹³⁷Cs ratio as a proxy of biogeochemical processes and discuss its trends in the water column of the North Pacific Ocean. We observed that the ^239,240Pu/¹³⁷Cs ratio in seawater exponentially increased with increasing depth (depth range: 100–1000 m). This finding suggests that the profiles of the ^239,240Pu/¹³⁷Cs ratios in shallower waters directly reflect biogeochemical processes in the water column. A half-regeneration depth deduced from the curve fitting the observed data, showed latitudinal and longitudinal distributions, also related to biogeochemical processes in the water column.     

14C and 210Pb in NE atlantic sediments: Evidence of biological reworking in the context of radioactive waste disposal

Scavenging by the seabed and by sedimentary particles in the deep ocean may have a significant effect on the removal of artificial radionuclides released to the water column as a result of radioactive waste disposal operations. Biological activity in the upper layers of the sediment column will enhance the rate of removal for those particle-reactive radionuclides with a short half-life relative to the turnover time of the upper mixed layer. For longer-lived radionuclides the rate of sediment accumulation will determine the ultimate rate of removal.The rate of sediment accumulation and extent of biological mixing of deep-sea sediment from three areas of the NE Atlantic Ocean have been investigated using ¹⁴C and ²¹⁰Pb data. Treatment of the radiocarbon with a simple box model provided estimates of sedimentation rate (ω), mixed layer depth (L), mixed layer age (T_ML) and the age of material arriving at the surface (T₀), which were broadly similar to previously published values from other ocean basins. Box cores from the Iberia Abyssal Plain, Madeira Abyssal Plain and from the NEA low-level radioactive waste dumpsite yielded sedimentation rates in the range 0.8 to 2.2 cm ky^?1 over the upper 16–25 cm. Continuous particle mixing appears to be taking place to a depth of 4 to 6 cm below the present sediment-water interface. Closely spaced vertical sampling of core 161-2 for ²¹⁰Pb allowed a biodiffusion coefficient (D_B) to be calculated (4 × 10^?9cm²s^?1), treating bioturbations as a diffusive term and sedimentations as an advective term in a simple mathematical model. In general, values of D_B in deep ocean sediments fall within the range 1–10 × 10^?9cm²s^?1, two orders of magnitude lower than nearshore values. From a review of published data it is concluded that biological mixing takes place extensively in the deep ocean; it appears to be fairly constant on a basin-wide scale and amenable to incorporation in mathematical models of radionuclide behaviour in the water column.     

Plutonium as a chronomarker in Australian and New Zealand sediments: a comparison with Cs

The construction of high resolution chronologies of sediment profiles corresponding to the last 50-100 years usually entails the measurement of fallout radionuclides ²¹⁰Pb and ¹³⁷Cs. The anthropogenic radionuclide, ¹³⁷Cs, originating from atmospheric nuclear weapons testing can provide an important “first appearance” horizon of known age (1954-1955), providing much-needed validation for the sometimes uncertain interpretations associated with ²¹⁰Pb geochronology. However, while ¹³⁷Cs usually provides a strong signal in sediment in the northern hemisphere, total fallout of ¹³⁷Cs in the southern hemisphere was only 25% that of the north and the low activities of ¹³⁷Cs seen in Australian and New Zealand sediments can make its horizon of first appearance somewhat arguable. Low ¹³⁷Cs fallout also limited the size of the 1963-1964 fallout peak, a peak that is usually seen in northern hemisphere sediment profiles but is often difficult to discern south of the equator.This paper shows examples of the use of nuclear weapons fallout Pu as a chronomarker in sediment cores from Australia (3 sites) and New Zealand (1 site). The Pu profiles of five cores are examined and compared with the corresponding ¹³⁷Cs profiles and ²¹⁰Pb geochronologies. We find that Pu has significant advantages over ¹³⁷Cs, including greater measurement sensitivity using alpha spectrometry and mass spectrometric techniques compared to ¹³⁷Cs measurements by gamma spectrometry. Moreover, Pu provides additional chronomarkers associated with changes in the Pu isotopic composition of fallout during the 1950s and 1960s. In particular, the ²³⁸Pu/^239+240Pu activity ratio shows distinct shifts in the early 1950s and the mid to late 1960s, providing important known-age horizons in southern hemisphere sediments. For estuarine and near-shore sediments Pu sometimes has another significant advantage over ¹³⁷Cs due to its enrichment in bottom sediment relative to ¹³⁷Cs resulting from the more efficient scavenging of dissolved Pu in seawater by sediment particles.     

Radioactive contamination in the marine environment adjacent to the outfall of the radioactive waste treatment plant at ATOMFLOT,northern Russia

RTP "ATOMFLOT" is a civilian nuclear icebreaker base located on the Kola Bay of northwest Russia. The objectives of this study were to determine the distributions of man-made radionuclides in the marine environment adjacent to the base, to explain the form of the distributions in sediments and to derive information concerning the fate of radionuclides discharged from ATOMFLOT. Mean activity concentrations (d.w.) for surface sediment, of 63 Bq kg(-1 137Cs, 5.8 Bq kg(-1) 90Sr and 0.45 Bq kg(-1 239,240)Pu were measured. Filtered seawater activity levels were in the range of 3--6.9 Bq m(-3) 137Cs, 2.0-11.2 Bq m(-3) 90Sr, and 16-40 m Bq m(-3), 239,240Pu. Short-lived radionuclides were present at sediment depths in excess of 10cm indicating a high degree of sediment mixing. Correlations of radionuclide activity concentrations with grain-size appear to be absent; instead, the presence of relatively contaminated sediment appears to be related to the existence of radioactive particles.     

The mass spectrometric determination of fallout 239Pu and 240Pu in marine samples

A thermal ionization mass spectrometric technique is presented for the detection of ²³⁹Pu and ²⁴⁰Pu in sea water, pore water, ocean sediments, sediment trap samples and coral samples. Both sample preparation and purification procedures, as well as the procedure used to detect Pu by mass spectrometry (m.s.), are presented. The m.s. technique proves to be over an order-of-magnitude more sensitive than traditional alpha-counting techniques for the detection of Pu in environmental samples. Also, the ratio of ²⁴⁰Pu/²³⁹Pu is obtained with this technique.