Atmospheric Dispersion of Radioactive Gaseous Discharges in the Near Field of Buildings, 2014-2020

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The data files are separated into the following categories. [1] Introduction and Contents Files detail outline requirements for the initial investigations and the PhD project proposal. [2] Calculations and Results Files: 8,161 These files contain: Analysed Site Gamma Monitoring Data. These are the gamma monitoring files for the detectors on the EW building during the construction phase of the East Wing cladding. CERC ADMS Supplied Data. An ADMS receptor points map and doses calculated from the concentration field and gamma-ray dose module of ADMS, these are detailed in the paper reproduced in the thesis. Detectors and layouts. This sub-folder contains details of the detector positions on the EW building and the wind logger calibration test certificate. Experiment #2 Results. This folder contains sub-folders with the results according to the experimental numbering scheme specified in chapter 3 of the PhD thesis. Experiment #3 Results. This folder contains sub-folders with the results according to the experimental numbering scheme specified in chapter 3 of the PhD thesis. Also included are processed results showing the measured velocity flow. field for the cube and EW clad buildings. Data is also included showing the puff release measurements and continuous release measurements. Graphical data is included on the measurement planes with respect to the EW building. Experiment #4 Results. Experiment #4 methods document details the experimental investigations. Results are presented for the cube and EW flow fields. Also, the leading-edge effective distance from the building of the release point is shown. Experiment #5 Results. An experiment series #5 data spreadsheet is given summarizing the results along with the document covering the experimental investigations. Along with this there are graphical results from the flow field for different cases using a plotting program. Spreadsheets are presented that contain the experimental results for various building configurations and downstream distances, X. Paper #1 Results. Various spreadsheets are presented showing the calculations for the initial first paper reproduced in the thesis. Photographs: of smoke releases are shown for the EW full building model. Also, a variety of photographs of the wind tunnel cube experiments. [3] Monte Carlo Results Files: 495 20190301_MC_Data.xlsx: contains physical constants and other data for the set-up of the Monte Carlo calculation runs. The 18 sub-folders contain results from the cases of: CA: Continuous Analysis; AV: active vertical release when shown; A/B: release positions SGP/DGP: single Gaussian plume and dual Gaussian plume modelling methods Building: Cube/EW clad/EW unclad; Angle in degrees of building to flow; Zrh: release height [4] Experiment Results Summary Files: 264 20190729_Experiment_Results_Summary.xlsx. Full data on the plume parameterization used for the MC calculations is given in this file. 20190802 Full Scale Results Summary.xlsx. A summary of the full-scale gamma-ray dose measurements on the EW building is given in this file. 20200723_MC_results_summary.xlsx. The Monte Carlo dose results are selectable via Excel pivot table in this file. Experiment Series#5 Analysed.xlsx. Flow field measurement results are selectable via Excel pivot tables in this file. Experiment Series#5 Building Cases Analysed.xlsx. This file uses Excel pivot tables to present results from the different building configurations tested in the experiments. Puff_Releases_Analysis_all_data.xlsm. This file shows a summary of the puff release results and statistical parameters. The following sub-folders contain more experimental results: Analysed Full Scale Data. All full-scale gamma-ray peaks for the EW measurements are provided here. Continuous_Analysis_Cube. Various Excel results files showing the spread parameters for the range of cube experimental cases with passive horizontal releases into the flow are provided. Continuous_Analysis_Cube_AV. Various Excel results files showing the spread parameters for the range of cube experimental cases with active vertical releases into the flow are provided. EW_Clad. Various Excel files showing the concentration field measurements for the EW clad building analysed using pivot table EW_Unclad. Various Excel files showing the concentration field measurements for the EW unclad building analysed using pivot table. [5] Conclusions and Output Reports Files: 19 The files cover presentations presented at different forums during the course of the PhD work about findings from the project. Also included is a radiological assessment report submitted to the Environment Agency after the initial radiological assessment of the site discharges. There are various power-point presentations made on completion of the PhD work. Another set of files cover the reports submitted by CERC, Cambridge, that were referenced in the first published paper cited in the PhD thesis. The folder includes the final PhD thesis after corrections and award.

This work treats very short-range atmospheric dispersion of radioactive gases emitted from stacks just above the roof level of buildings and develops a methodology that provides realistic radiation dose estimates for that zone. Fluid flow in the rooftop region is complex, and the concentration field resulting from an emission into that flow also exhibits high levels of complexity, beyond the capability of existing operational dispersion models. Extensive Laser Doppler anemometry measurements were made in a meteorological wind tunnel to characterise the flow field in this region. Concentration fields were mapped with fast flame ionisation detectors and related to the associated flow characteristics. Parameters investigated were release position, release height, angle of approach flow and building geometry, the latter to contrast behaviour at a real site with that above a standard cuboid building (as would be used in operational dispersion models); sensitivity to surrounding buildings was also investigated. Methods were developed using Monte Carlo techniques to convert the complex spatial distribution of radioactive pollutant in the roof zone into accurate estimates of radiation doses received by persons in that zone. Effective dose estimates accounted for inhalation, immersion and external gamma-rays from the mixed positron/gamma-ray field – including doses within the radioactive plume at roof level. Short duration releases were covered as well as continuous releases. Novel methods are presented to specify the statistical confidence interval from different duration releases in terms of readily generalisable results. Full-scale measurements of gamma ray dose, wind speed and direction were made for one of the building cases and the results used to support the findings obtained by wind tunnel measurements and Monte Carlo calculations. Results are presented in generalisable form, for example as dimensionless concentrations, so that the methods and results can be applied to other similar types of pollutant release.