The decommissioning of nuclear power plants is in the Slovak Republic an actual issue. In 2015 started the second decommissioning stage of nuclear power plant V1 in Jaslovské Bohunice. This stage involves the dis...The decommissioning of nuclear power plants is in the Slovak Republic an actual issue. In 2015 started the second decommissioning stage of nuclear power plant V1 in Jaslovské Bohunice. This stage involves the dismantling and segmentation of activated (reactor pressure vessel, reactor internals) and contaminated parts (steam generators, pressurizer). From this reason it is necessary to investigate the radiation situation in the vicinity of the component to be cut. The presented results show that during remote dismantling the exposure is small (compared with the fragmentation tasks). Moreover, when the pre-dismantling decontamination with decontamination factor of 100 is applied, the total collective effective dose is below the yearly limit of 20 mSv for workers.展开更多
Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,inge...Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,ingestion,and dermal contact.The current research on inhalation exposure pays limited attention to the particle distribution of PAEs and BPs in air,although particulate-bound pollutants are usually size-dependent.In this study,we discussed the size resolution of PAEs and BPs in air particles from city waste recycling plants.With paired urine samples of the workers,we also compared the internal and external exposure of PAEs and BPs and related potential health risks.The particulatebound PAEs and BPs concentrated mainly on coarse particles(Dp>2.1μm),with a bimodal distribution,and the peak particle size ranged from 9–10 to 4.7–5.85μm,respectively.Model calculation revealed that the deposition fluxes of PAEs in different respiratory regions followed the sequence of head airways(167±92.8 ng/h)>alveolar region(18.9±9.96 ng/h)>tracheobronchial region(9.20±5.22 ng/h),and the similar trends went for BPs.The daily intakes of PAEs and BPs via dust ingestion were higher than those fromrespiratory inhalation and dermal contact,with mean value of 96 and 0.88 ng/(kg-bw day),respectively.For internal exposure,the estimated daily intakes of PAEs for waste recycling workers were higher than those in e-waste dismantling workers,while the exposure levels of bisphenols were comparable.Overall,the potential health risks from inhalation exposure to particulate-bound PAEs and BPs were low.展开更多
Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow com...Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow computational speed.Progress in heterogeneous computing has allowed for substantial acceleration in the computation of mesh-type phantoms by utilizing hardware accelerators.In this study,a GPU-accelerated Monte Carlo method was developed to expedite the dose calculation for mesh-type computational phantoms.This involved designing and implementing the entire procedural flow of a GPUaccelerated Monte Carlo program.We employed acceleration structures to process the mesh-type phantom,optimized the traversal methodology,and achieved a flattened structure to overcome the limitations of GPU stack depths.Particle transport methods were realized within the mesh-type phantom,encompassing particle location and intersection techniques.In response to typical external irradiation scenarios,we utilized Geant4 along with the GPU program and its CPU serial code for dose calculations,assessing both computational accuracy and efficiency.In comparison with the benchmark simulated using Geant4 on the CPU using one thread,the relative differences in the organ dose calculated by the GPU program predominantly lay within a margin of 5%,whereas the computational time was reduced by a factor ranging from 120 to 2700.To the best of our knowledge,this study achieved a GPU-accelerated dose calculation method for mesh-type phantoms for the first time,reducing the computational time from hours to seconds per simulation of ten million particles and offering a swift and precise Monte Carlo method for dose calculation in mesh-type computational phantoms.展开更多
文摘The decommissioning of nuclear power plants is in the Slovak Republic an actual issue. In 2015 started the second decommissioning stage of nuclear power plant V1 in Jaslovské Bohunice. This stage involves the dismantling and segmentation of activated (reactor pressure vessel, reactor internals) and contaminated parts (steam generators, pressurizer). From this reason it is necessary to investigate the radiation situation in the vicinity of the component to be cut. The presented results show that during remote dismantling the exposure is small (compared with the fragmentation tasks). Moreover, when the pre-dismantling decontamination with decontamination factor of 100 is applied, the total collective effective dose is below the yearly limit of 20 mSv for workers.
基金supported by the National Natural Science Foundation of China(No.22176071)the Natural Science Foundation of Guangdong Province,China(No.2023A1515011879).
文摘Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,ingestion,and dermal contact.The current research on inhalation exposure pays limited attention to the particle distribution of PAEs and BPs in air,although particulate-bound pollutants are usually size-dependent.In this study,we discussed the size resolution of PAEs and BPs in air particles from city waste recycling plants.With paired urine samples of the workers,we also compared the internal and external exposure of PAEs and BPs and related potential health risks.The particulatebound PAEs and BPs concentrated mainly on coarse particles(Dp>2.1μm),with a bimodal distribution,and the peak particle size ranged from 9–10 to 4.7–5.85μm,respectively.Model calculation revealed that the deposition fluxes of PAEs in different respiratory regions followed the sequence of head airways(167±92.8 ng/h)>alveolar region(18.9±9.96 ng/h)>tracheobronchial region(9.20±5.22 ng/h),and the similar trends went for BPs.The daily intakes of PAEs and BPs via dust ingestion were higher than those fromrespiratory inhalation and dermal contact,with mean value of 96 and 0.88 ng/(kg-bw day),respectively.For internal exposure,the estimated daily intakes of PAEs for waste recycling workers were higher than those in e-waste dismantling workers,while the exposure levels of bisphenols were comparable.Overall,the potential health risks from inhalation exposure to particulate-bound PAEs and BPs were low.
基金supported by the National Natural Science Foundation of China(Nos.U2167209 and 12375312)Open-end Fund Projects of China Institute for Radiation Protection Scientific Research Platform(CIRP-HYYFZH-2023ZD001).
文摘Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow computational speed.Progress in heterogeneous computing has allowed for substantial acceleration in the computation of mesh-type phantoms by utilizing hardware accelerators.In this study,a GPU-accelerated Monte Carlo method was developed to expedite the dose calculation for mesh-type computational phantoms.This involved designing and implementing the entire procedural flow of a GPUaccelerated Monte Carlo program.We employed acceleration structures to process the mesh-type phantom,optimized the traversal methodology,and achieved a flattened structure to overcome the limitations of GPU stack depths.Particle transport methods were realized within the mesh-type phantom,encompassing particle location and intersection techniques.In response to typical external irradiation scenarios,we utilized Geant4 along with the GPU program and its CPU serial code for dose calculations,assessing both computational accuracy and efficiency.In comparison with the benchmark simulated using Geant4 on the CPU using one thread,the relative differences in the organ dose calculated by the GPU program predominantly lay within a margin of 5%,whereas the computational time was reduced by a factor ranging from 120 to 2700.To the best of our knowledge,this study achieved a GPU-accelerated dose calculation method for mesh-type phantoms for the first time,reducing the computational time from hours to seconds per simulation of ten million particles and offering a swift and precise Monte Carlo method for dose calculation in mesh-type computational phantoms.
