| 1. |
- Hallstadius, L., et al.
(författare)
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Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones
- 1986
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Ingår i: Journal of Environmental Radioactivity. - 0265-931X. ; 4:1, s. 11-30
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Tidskriftsartikel (refereegranskat)abstract
- Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were collected from the Irish coast in 1983. Fallout is found to dominate as a source of 239+240Pu north of latitude 65°N, while for 238Pu a substantial fraction originates from European nuclear fuel reprocessing facilities. The 238Pu/239+240Pu isotope ratio provides clear evidence of the transport of effluent plutonium from the latter to Spitsbergen waters. Fallout plutonium in Arctic waters has a residence time of the order of several years, while for Pu from Sellafield we estimate mean residence times of 11-15 months in Scottish waters and, tentatively, 1·5-3 y during transport from the North Channel (north of the Irish Sea) to Spitsbergen. 241Am found in Arctic waters probably originates from the decay of fallout 241Pu and, like Pu, tentatively has a residence time of the order of several years. Americium from Sellafield has an estimated mean residence time of 4-6 months in Scottish waters.
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| 2. |
- Samuelsson, Christer, et al.
(författare)
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222Rn and 210Pb in the Arctic summer air
- 1986
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Ingår i: Journal of Environmental Radioactivity. - 0265-931X. ; 3:1, s. 35-54
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Tidskriftsartikel (refereegranskat)abstract
- As part of an extensive air chemistry programme, during summer 1980, on board the Swedish ice-breaker 'Ymer', levels of 222Rn (radon) and its long-lived daughters 210Pb and 210Po were measured. The radon was trapped on charcoal and the long-lived daugther products sampled on filters on a daily basis. In addition, short-lived progenies were followed continuously on the filters in order to achieve a time resolution of about one hour. The concentrations of radon and 210Pb in the Arctic summer air north of latitude 75° N averaged 75 ± 21 (1 sd) and 0·075 ± 0·028 mBqm-3, r respectively. During a two week period of persistent polar winds, the mean radon concentration was 19 ±5 mBq m-3. During such 'Arctic background' conditions, radon exhalation from the sea may contribute significantly to the measured radon-in-air concentration. It is shown that steady-state equilibrium models, applied to an air mass over the sea, overstimate the aerosol residence-time calculated from activity ratios. Time-dependent calculations indicate a mean aerosol residence time of 4 to 7 d in Arctic air. Good agreement is observed between radon levels and the time since the air mass left larger areas. Both the 222Rn and the long-lived daughter measurements are insensitive to contamination from ship and local settlement.
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| 3. |
- Abrahamsson, Otto, et al.
(författare)
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Presentation and analysis of a model simulating the response of potash treatment of lakes
- 1997
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Ingår i: Journal of Environmental Radioactivity. - 0265-931X .- 1879-1700. ; 37:3, s. 287-306
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Tidskriftsartikel (refereegranskat)abstract
- The potassium concentration in a lake may influence the caesium levels in lake biota. The biouptake and potential ecosystem effects of a caesium fall-out can be limited by addition of potassium, for example, by a potash treatment. This work presents for the first time a simple and practically useful model to facilitate the planning and to predict the outcome of potash treatments by simulating the processes that regulate the water chemical response of such a treatment. The model is a mixed model in the sense that it contains both statistical regressions and dynamic interactions within a lake ecosystem. This paper focuses on the dynamic processes and gives both calibrations and extensive validations of the model. A few examples on the practical use of the model are presented. The results indicate that the model, using only easily accessible input data, can, in fact, give good predictions on the increase and duration in potassium concentration following a potash treatment.
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| 4. |
- Isaksson, Mats, 1961, et al.
(författare)
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A 10-year study of the 137Cs distribution in soil and a comparison of Cs soil inventory with precipitation-determined deposition
- 2001
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Ingår i: Journal of Environmental Radioactivity. - 0265-931X. ; 55, s. 47-59
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Tidskriftsartikel (refereegranskat)abstract
- During a 10-year period, 1988-1998, surface soil samples have been collected at Blentarp in southern Sweden and analysed for 137Cs from the Chernobyl accident and from the nuclear weapons tests. The distance between the sampling plots on the different sampling occasions has been no more than 3m. The results show that the depth distribution of 137Cs is very similar for each of the sampling occasions, indicating that the caesium migration at this site is very small. The total activity measured in the soil cores is in agreement with the calculated activity of 137Cs deposited at the site after nuclear weapons tests and the Chernobyl accident, based on air activity concentration and the amount of precipitation. The calculated deposition of 137Cs originating from the bomb tests amounts to 1.41kBqm-2 for the period 1962-1986, which is in agreement with the activity of nuclear weapons fallout measured in the soil samples (1.60kBqm-2 as a mean value of the first four years of sampling). The calculated activity of 137Cs of Chernobyl origin was 0.79kBqm-2, which agrees well with the value of 0.79kBqm-2 measured in the soil samples in 1988. Copyright © 2001 Elsevier Science Ltd.
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| 5. |
- Isaksson, Mats, 1961, et al.
(författare)
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Calculations of the deposition of 137Cs from nuclear bomb tests and from the Chernobyl accident over the province of Skane in the southern part of Sweden based on precipitation
- 2000
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Ingår i: Journal of Environmental Radioactivity. - 0265-931X .- 1879-1700. ; 49, s. 97-112
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Tidskriftsartikel (refereegranskat)abstract
- The deposition of 137Cs over the province of Skane (an area of about 100x100km2) in the southern part of Sweden has been investigated. The origin of the deposition of 137Cs is, in about equal parts, from nuclear weapons tests and from the Chernobyl nuclear accident and amounts to about 1-3kBq/m2. The activity concentrations of 134Cs and 137Cs in soil samples from 16 sites distributed in a grid pattern over the investigated area have been measured and the depositions from the nuclear weapons tests and from the Chernobyl accident have been separated. These pre- and post-Chernobyl activities have been compared with depositions calculated from measurements of the activity concentrations of 134Cs and 137Cs in precipitation at two places and from measurements of the precipitation from a network of between 113 and 143 precipitation stations. Comparisons with in situ measurements and with aerial survey measurements have also been made. The agreement is good gain and it has been possible to gain a good and detailed knowledge in retrospect of the deposition from measurements of the deposition per mm of precipitation from just a few stations, and of the precipitation from a network of stations. Copyright (C) 2000 Elsevier Science Ltd.
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| 6. |
- Salih, Isam, et al.
(författare)
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Determination of 222Rn and 226Ra in water using a large volume ionisation chamber
- 2000
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Ingår i: Journal of Environmental Radioactivity. - 0265-931X. ; 48:2, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- A new method for measuring 222Rn and 226Ra in water has been devised. It is based on exhaling radon to a void volume by continuous bubbling of air through the water. The exhaled radon is then transferred in a closed circuit to a modified radon gas pulse ionisation chamber for alpha-spectrometric measurements. About 86% of the radon in water is transferred from 0.75 l of water to the void volume (3.2 l). The set-up offers direct and specific 222Rn measurements for a wide range of concentrations and shows a low detection limit (LLD=45 mBq l−1 for 8 h counting time). Radium in water is measured, via radon, after sample storage for a month. The method was compared with gamma ray spectrometry for radon and for radium, the latter after pre-concentration by co-precipitation with MnO2 from 10 l water samples. An excellent agreement between the two techniques was obtained. As a part of a radon survey, the method was employed for analysis of drinking water from bedrock wells.
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| 7. |
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| 8. |
- Adliene, Diana, et al.
(författare)
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Assessment of the environmental contamination with long-lived radionuclides around an operating RBMK reactor station
- 2006
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Ingår i: Journal of Environmental Radioactivity. - : Elsevier BV. - 1879-1700 .- 0265-931X. ; 90:1, s. 68-77
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Tidskriftsartikel (refereegranskat)abstract
- The presence of man-made gamma emitting radionuclides in the region within 32 km radius of the Ignalina NPP/Lithuania has been investigated during the period 2001-2004, prior to the closure of the first 4 the two operating RBMK 1500-type reactors. Gamma spectrometric measurements of various terrestrial and aquatic plants as well as of soil samples showed moderate environmental contamination with the fission product Cs-137 and with the neutron activation products Co-60 and Mn-54. Traces of the activation products Zn-65 and Ag-110m were found in the nearest vicinity of the NPP. Activity concentrations were inhomogeneously distributed in the area of interest. Moss and algae samples showed the highest uptake of radionuclides. In addition to the gamma spectrometric measurements, the levels of C-14 were determined in the same bio-indicator samples using accelerator mass spectrometry. (c) 2006 Elsevier Ltd. All rights reserved.
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| 9. |
- Akbari, Keramatollah, 1961-, et al.
(författare)
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Influence of indoor air conditions on radon concentration in a detached house
- 2013
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Ingår i: Journal of Environmental Radioactivity. - Elsevier : Elsevier BV. - 0265-931X .- 1879-1700. ; 116, s. 166-173
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Tidskriftsartikel (refereegranskat)abstract
- Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden.In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach.The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50-60%
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| 10. |
- Almgren, Sara, 1979, et al.
(författare)
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Gamma radiation doses to people living in Western Sweden.
- 2008
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Ingår i: Journal of environmental radioactivity. - : Elsevier BV. - 0265-931X. ; 99:2, s. 394-403
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Tidskriftsartikel (refereegranskat)abstract
- Indoor environments contribute to gamma radiation in the general population. The aims of the present study were to investigate average gamma radiation doses in a rural and an urban area of Sweden, compare indoor dose rates with personal exposure, and study the effects of building characteristics on radiation levels. Radiation was measured with thermoluminescence dosimeters (TLDs). Repeated measurements were performed with TLDs worn by participants (n=46) and placed in their dwellings. Personal dose rates were 0.092microSv/h (rural) and 0.096microSv/h (urban). The mean effective gamma dose rates in dwellings were 0.091microSv/h (rural) and 0.11microSv/h (urban), which are higher than the world average. Dose rates in apartments were higher than in detached houses and higher for concrete than wooden dwellings. Personal dose rates were strongly associated with dwelling dose rates (r(p)=0.68, p<0.01) and could be modelled. Within-participant variability was low.
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