scholarly journals 14C Levels in Tree Rings Located Near Qinshan Nuclear Power Plant, China

Radiocarbon ◽  
2012 ◽  
Vol 54 (02) ◽  
pp. 195-202 ◽  
Author(s):  
Zhongtang Wang ◽  
Yuanyi Xiang ◽  
Qiuju Guo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Tree Rings ◽  
Nuclear Power ◽  
Specific Activity ◽  
Background Level ◽  
Relative Increase ◽  
Pine Tree ◽  
Discharge Management ◽  
Excess Value

Specific activities of radiocarbon in annual tree rings corresponding to 1980-2009 are reported for a pine tree located 2 km from the Qinshan Nuclear Power Plant (Qinshan NPP), China. While a negligible enhanced14C activity due to operation of the Qinshan NPP Plant I is evident, a relative increase (1.8–62.6 Bq/kg C) was observed in the specific activity after operation of the Qinshan NPP Plant II in 2002 and Plant III in 2003. The enhanced values were primarily affected by the14C discharged from Plant III (CANDU-type reactor), and a good correlation was found between the14C discharged from Plant III in the growing season and the14C excess value. The excess14C activities peaked in 2005 (at 302.0 Bq/kg C, which is 62.6 Bq/kg C above the “clean air”14C level), and then declined due to the improvement in14C discharge management of Plant III. In 2009, the14C-specific activity was near the background level.

scholarly journals 14C Levels in Tree Rings Located Near Qinshan Nuclear Power Plant, China

Radiocarbon ◽  
2012 ◽  
Vol 54 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Zhongtang Wang ◽  
Yuanyi Xiang ◽  
Qiuju Guo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Tree Rings ◽  
Nuclear Power ◽  
Specific Activity ◽  
Background Level ◽  
Relative Increase ◽  
Pine Tree ◽  
Discharge Management ◽  
Excess Value

Specific activities of radiocarbon in annual tree rings corresponding to 1980-2009 are reported for a pine tree located 2 km from the Qinshan Nuclear Power Plant (Qinshan NPP), China. While a negligible enhanced 14C activity due to operation of the Qinshan NPP Plant I is evident, a relative increase (1.8–62.6 Bq/kg C) was observed in the specific activity after operation of the Qinshan NPP Plant II in 2002 and Plant III in 2003. The enhanced values were primarily affected by the 14C discharged from Plant III (CANDU-type reactor), and a good correlation was found between the 14C discharged from Plant III in the growing season and the 14C excess value. The excess 14C activities peaked in 2005 (at 302.0 Bq/kg C, which is 62.6 Bq/kg C above the “clean air” 14C level), and then declined due to the improvement in 14C discharge management of Plant III. In 2009, the 14C-specific activity was near the background level.

Annual Variations of 14C Concentration in the Tree Rings in the Vicinity of Ignalina Nuclear Power Plant

Radiocarbon ◽  
2018 ◽  
Vol 60 (4) ◽  
pp. 1227-1236 ◽  
Author(s):  
Žilvinas Ežerinskis ◽  
Justina Šapolaitė ◽  
Algirdas Pabedinskas ◽  
Laurynas Juodis ◽  
Andrius Garbaras ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Tree Rings ◽  
Environmental Samples ◽  
Nuclear Power ◽  
Time Span ◽  
Annual Variations ◽  
Pine Tree ◽  
Accelerator Mass Spectrometer ◽  
Concentration Changes

ABSTRACTIn this paper we analyze the radiocarbon (14C) concentration changes over the whole operational period of the Ignalina Nuclear Power Plant (INPP) including the post-shutdown decommissioning. Environmental samples from the vicinity of the INPP and a rural area as background of pine tree rings were analyzed with the single stage accelerator mass spectrometer (SSAMS). The analysis shows the local influence of the INPP from 3 to 7 pMC. The whole time span from 1983 to 2015 is divided into three periods representing the early and late operational and post-shutdown stages of the INPP with different 14C profiles in analyzed samples. The influence of the maintenance of the INPP and radioactive waste management activities are indicated and discussed.

Terrestrial Distribution of 14C in the Vicinity of Qinshan Nuclear Power Plant, China

Radiocarbon ◽  
2013 ◽  
Vol 55 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Zhongtang Wang ◽  
Yuanyi Xiang ◽  
Qiuju Guo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Specific Activity ◽  
Background Level ◽  
Food Samples ◽  
Pine Needles ◽  
Activity Levels ◽  
Heavy Water Reactor ◽  
Rice Samples

We used accelerator mass spectrometry (AMS) to study radiocarbon-specific activity levels in agricultural and botanical samples (moss and pine needles) distributed within a 6.5-km radius of the Qinshan Nuclear Power Plant (NPP). The 14C-specific activity in moss samples (ranging from 265.6 to 223.0 Bq/kg C) decreased with increased distance from the stacks of Plant III (heavy water reactor) and reached the background level (223.8 Bq/kg C) at 6.5 km distance. Compared to the pine needles, the moss was a better indicator for investigating the 14C distribution near Qinshan NPP. The 14C-specific activity distribution in moss samples showed that the diffusion of 14C discharged from the Qinshan NPP was affected by both geographical and meteorological factors. Excess 14C-specific activity in the food samples ranged from 8.5 to 13.0 Bq/kg C (except for rice samples), resulting in a minimal radiation dose of 0.5 μSv per year to the public.

Terrestrial Distribution of 14C in the Vicinity of Qinshan Nuclear Power Plant, China

Radiocarbon ◽  
2013 ◽  
Vol 55 (01) ◽  
pp. 59-66 ◽  
Author(s):  
Zhongtang Wang ◽  
Yuanyi Xiang ◽  
Qiuju Guo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Specific Activity ◽  
Background Level ◽  
Food Samples ◽  
Pine Needles ◽  
Activity Levels ◽  
Heavy Water Reactor ◽  
Rice Samples

We used accelerator mass spectrometry (AMS) to study radiocarbon-specific activity levels in agricultural and botanical samples (moss and pine needles) distributed within a 6.5-km radius of the Qinshan Nuclear Power Plant (NPP). The14C-specific activity in moss samples (ranging from 265.6 to 223.0 Bq/kg C) decreased with increased distance from the stacks of Plant III (heavy water reactor) and reached the background level (223.8 Bq/kg C) at 6.5 km distance. Compared to the pine needles, the moss was a better indicator for investigating the14C distribution near Qinshan NPP. The14C-specific activity distribution in moss samples showed that the diffusion of14C discharged from the Qinshan NPP was affected by both geographical and meteorological factors. Excess14C-specific activity in the food samples ranged from 8.5 to 13.0 Bq/kg C (except for rice samples), resulting in a minimal radiation dose of 0.5 μSv per year to the public.

Decontamination of the Special Drainage System at NPP A-1

2001 ◽  
Author(s):  
Ján Rezbárik ◽  
Dušan Majerský ◽  
Stanislav Sekely
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Specific Activity ◽  
Drainage System ◽  
Solid Particles ◽  
Technological Systems ◽  
Solid Product ◽  
High Tendency ◽  
First Time

Abstract The first Czecho-slovak nuclear power plant A-1 was shut down after an accident in 1977 and it is now under decommissioning. In spite of that, some technological systems in nuclear power plant must remain in operation. The planned service life of these systems has already been exceeded and their technical design is not suitable for present requirements. These operated technological systems must be repaired and reconstructed. The special drainage system is one of the technological systems that must be in operation during the decommissioning process. After twenty-nine-year’-s of operation it became necessary to carry out the repairs, adaptations and replacements of some parts of this system with the aim to ensure more reliable operation and higher safety. Radioactive sludge from the bottom of the collecting tank and drain pit was pumped out using an ejector and it was caught in drums. The fixed contamination on the inner surface of the collecting tank was removed by the chemical loop decontamination method using an external circulating decontamination device. The surface of the drain pit was decontaminated with evenly spread decontamination gel that disrupted the fixed contamination. The contamination was then washed down using a water jet system with attached rotary brushes. At NPP A-1, an immobilisation method for the treatment of radioactive sludge and solid particles based on the addition of silicates was successfully used by AllDeco for the first time. This sludge is often sticky with the high tendency to settle out the liquid and has a specific activity three orders of magnitude higher than are the limits for the Conditioning Centre (with high content of alpha radionuclides) and because it is not sound and effective to treat it by technologies generally used for another type of wastes. The immobilisation of the sludge was performed at room temperature. The resulting solid product has suitable properties for temporary storage. Procedures for the verification of the treatment of further sludge from NPP A-1 have been started.

scholarly journals The analysis of radioecological monitoring results in the vicinity of the Kursk Nuclear Power Plant

2020 ◽  
Vol 13 (2) ◽  
pp. 19-30 ◽  
Author(s):  
V. K. Kuznetsov ◽  
A. V. Panov ◽  
N. I. Sanzharova ◽  
N. N. Isamov ◽  
N. V. Andreeva ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Specific Activity ◽  
Natural Radionuclides ◽  
Agricultural Products ◽  
Artificial Radionuclides ◽  
Radioecological Monitoring ◽  
The Impact ◽  
Maximum Content

The research presents the data of long-term observations of the impact of the Kursk Nuclear Power Plant operation on the radioecological situation in the region of its location. The dynamics of the content of natural and artificial radionuclides in the components of agricultural ecosystems was studied due to the data based on the information from the radioecological monitoring network developed in 2003. Samples of soils, agricultural products and animal feeds were taken at 11 control sites located on arable lands and grasslands in the vicinity of the Kursk Nuclear Power Plant, and, in settlements, locally produced food was sampled. It was shown that for the period of studies of 2003-2019, the average specific activity of 90Sr in the soils of agroecosystems of the 10 km influence zone of the Kursk Nuclear Power Plant varied within 2.7-4.3 Bq/kg, and specific activity of 137Cs was 14.6-40.8 Bq/kg. At the same time, there were found no trends of increase in the content of artificial radionuclides in soil over time and at different distances from the NPP, and the increased specific activity of 137Cs in soil compared to the global background is explained by the Chernobyl fallout. The variability of the average content of natural radionuclides in the soil for 40K was 481-625 Bq/kg, 226Ra – 20.6-29.5 Bq/ kg, 232Th – 28.2-39.2 Bq/kg, which corresponded to all-Russian data. The average specific activity of 90Sr in grain was 0.24-0.43 Bq/kg, and 137Cs – 0.19-0.37 Bq/kg. Even the maximum levels of artificial radionuclides in grain were 44 times for 90Sr and 85 times for 137Cs lower than the current SanPiN standards. The highest specific activity values of 137Cs and 90Sr in potatoes, vegetables, and gourds were 160 times lower than the SanPiN standards. It was noted that the maximum content of 90Sr in milk was more than 540 times lower than the SanPin standard, and for 137Cs this difference was 330 times. The maximum content of 137Cs in beef turned out to be over 850 times lower than the SanPiN standard for this radionuclide. About 70 Bq/a of 90Sr and 200 Bq/a of 137Cs enter the population diet with locally produced food, which is almost 400 times for 137Cs and 200 times for 90Sr lower than the annual limit. Milk (46%), meat (31%), potatoes and vegetables (14%) make the main contribution to the formation of the internal dose from agricultural products containing 137Cs, and contribution to dose from 90Sr is made by milk (14%) and crop products (potatoes, vegetables, bread) – up to 78%. In general, we concluded that over the past 17 years, the operation of the Kursk Nuclear Power Plant did not lead to a deterioration of the radioecological situation in the region of its location, because during the survey period there was no significant increase in the content of artificial radionuclides in agricultural products, foods and environmental components.

scholarly journals Radiocarbon Releases At the Krško Nuclear Power Plant

Radiocarbon ◽  
1997 ◽  
Vol 39 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Barbara Vokal ◽  
Ivan Kobal
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Tree Rings ◽  
Indoor Air ◽  
Nuclear Power ◽  
Monitoring Program ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Water Reactor ◽  
Radioactivity Monitoring

Since 1991, radiocarbon analyses of exhaust air have been part of the regular radioactivity monitoring program at the Krško Nuclear Power Plant (NPP), a Westinghouse 632 MWe pressurized water reactor (PWR). Activity of CO2 and hydrocarbons has been identified; the former contributes ca. 43%. A normalized release of total 14C of 0.219 TBqGWe−1a−1 was obtained. Indoor air 14C concentrations in selected rooms inside the plant have generally been <5 Bq m−3, although rare peaks of >1000 Bq m−3 may be reached. Tree rings have shown slight enhanced 14C activity due to the operation of the plant.

Specific activity of243Am and243Cm in the fuel of the 4th power-generating unit of the Chernobyl nuclear power plant

Atomic Energy ◽  
1999 ◽  
Vol 87 (5) ◽  
pp. 788-790 ◽  
Author(s):  
V. A. Ageev ◽  
S. L. Vyrichek ◽  
A. P. Lashko ◽  
T. N. Lashko ◽  
A. A. Odintsov
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Specific Activity ◽  
Chernobyl Nuclear Power Plant ◽  
Power Generating Unit

Pre- and Post-Accident 14C Activities in tree rings near the Fukushima Dai-Ichi Nuclear Power Plant

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1633-1642
Author(s):  
Tetsuya Matsunaka ◽  
Kimikazu Sasa ◽  
Tsutomu Takahashi ◽  
Masumi Matsumura ◽  
Yukihiko Satou ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Tree Rings ◽  
Nuclear Power ◽  
Japanese Cypress ◽  
Fdnpp Accident ◽  
Before And After ◽  
The Mean ◽  
Area Of Influence

ABSTRACTAreas affected by routine radiocarbon (14C) discharges from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) and accidental releases in March 2011 were investigated by analysis of cores from Japanese cypress and cedar trees growing at sites 9 and 24 km northwest of the plant. 14C concentrations in tree rings from 2008–2014 (before and after the accident) were determined by accelerator mass spectrometry, with 14C activities in the range 231–256 Bq kg−1 C. Activities during the period 2012–2014, after FDNPP shutdown, represent background levels, while the significantly higher levels recorded during 2008–2010, before the accident, indicate uptake of 14C from routine FDNPP operations. The mean excess 14C activity for the pre-accident period at the sites 9 and 24 km northwest of the plant were 21 and 12 Bq kg−1 C, respectively, indicating that the area of influence during routine FDNPP operations extended at least 24 km northwest. The mean excess tree-ring 14C activities in 2011 were 10 and 5.8 Bq kg−1 C at 9 and 24 km northwest, respectively, documenting possible impact of the FDNPP accident on 14C levels in trees.

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