COMMONWEALTH OF AUSTRALIA "147$ ftf^-i
DEPARTMENT OF HUMAN SERVICES AND HEALTH
Particle Sizing of Airborne Radioactivity Field Measurements at Olympic Dam
by
Stephen B Solomon, Myra Wilks, Richard O'Brien and George Ganakas
Australian Radiation Laboratory
Lower Plenty Road, Yallambie, Victoria 3085 Telephone: (03) 433 2211 Facsimile: (03) 432 1835 TR 113 AUSTRALIAN RADIATION LABORATORY
Particle Sizing of Airborne Radioactivity Field Measurements at Olympic Dam
by
Stephen B Solomon, Myra Wilks, Richard O'Brien and George Ganakas
ARL/TR113 LOWER PLENTY ROAD ISSN 0157-1400 YALLAMBIE VIC 3085 December 1993 TELEPHONE: 433 2211 AfiSIBACI
On July 1, 1991 the Australian Radiation Laboratory (ARL) commenced a two year project entitled "Particle sizing of airborne radioactivity", funded by a Mining & Quarrying Occupational Health & Safety Committee (M&QOH&SC) grant (Submission No. 9138). This study set out to measure airborne radioactivity size distributions in an underground uranium mine, in order to provide better estimates of the health risks associated with inhalation of airborne radiation in the work place. During the course of a two week field visit to the underground uranium mine at Olympic Dam, South Australia, a wide range of measurements of airborne radioactivity were carried out in order to characterise typical atmospheric conditions. These measurements included both active and passive measurement of radon gas, continuous and spot sample measurements of radon daughter levels, as well as wire screen diffusion battery measurements of the radon daughter size distributions. Measurement samples were collected at over 50 sites within the mine. The results showed that ;
• the ventilation is relatively uniform within the mine and the radon daughter concentrations are kept to less than 20% of the equilibrium concentration, • the particle size of the radon progeny appears to be affected by the combustion products from the larger ore-handling vehicles, leading to sizes of the order 200 - 300 run, • in areas closer to the ventilation intakes or in sections of the mine without large diesel vehicles, the radon daughter particles were smaller; of the order of 100 - 150 nm, • the radon and radon daughter concentrations showed marked variabil ity with both time and position within the mine, • the average value for the unattached fraction throughout the mine was approximately 3% to 4%, • dose conversion factors (DCF), from WLM exposure to effective dose in mSv, were derived from the measured results using a number of dosimetric models, including the most recent version of the ICRP Respiratory Tract Model (RADEP). The James-Birchall and Jacobi-Eisfeld models gave average DCF values of 10.4 and 8.2 mSv/WLM, respectively. Using a normalisation factor of 2.5, the calculated average DCF value from the ICRP Respiratory Tract Model, computed from RADEP was 8.1 mSv/WLM. The corresponding PAEC-weighted average was 7.3 mSv/WLM. This compares with the value used at present of 10 mSv/WLM, and the ICRP-proposed epidemiologically-based DCF vulue of 5 mSv/WLM. • the sizing of the long-lived radioactive dust was not completed due to a lack of sensitivity for the low flow-rate cascade impactors.
The main conclusion to be drawn from the results of the ARL study at Olympic Dam is that the present radiation protection methods and dose conversion factors used in Australia provide a good estimate of the radiation risk for the inhalation of radon progeny
2 INTRODUCTION
The primary pathway for health detriment associated with airborne radon arises from the inhalation of the short-lived decay products and the resultant alpha particle exposure to the respiratory tract. Epidemiological studies of long-term exposure to uranium mine workers from 222Rn daughters have shown a strong correlation between the integrated potential alpha energy concentration (PAEC) exposure and the increased incidence of lung cancer [eg. Samet 1989]. Current values for the excess relative risk for inhalation of radon daughters are in the range 0.5 to 3 per 100 Working Level Month (WLM) [NRC 1991]. The development of dosimetric models of radiation exposure of the respiratory tract has allowed the study of the dependence of the derived radiation dose on atmospheric and biological factors, as well as the physical characteristics of the radon daughters.
Radon daughters are isotopes of polonium, bismuth and lead; and following their formation these are subject to a variety of interactions with atmospheric gases, airborne particles and surfaces. During the 1970s, detailed measurements were made in underground uranium mines to characterise some of the physical properties of the airborne radon daughters [George and Hinchcliffe 1972, George et al. 1975, Mercer 1975, Bigu and Kirk 1980]. Measurements of the radon daughter activity size distributions showed that the major fraction of daughters was associated with the accumulation mode aerosol, in the size range 0.1 to 0.3 nm. The radon daughters not associated with this accumulation mode, the so-called "unattached fraction", were found to be extremely mobile. More recent studies have shown that these "unattached" daughters can form an ultrafine mode, with particle sizes in the range 0.5 to 15 nm [Holub and Knutson 1987; Hopke 1990].
The dosimetric models for inhalation of radon daughters developed in the early 1980s by Jacobi-Eisfeld [Jacobi and Eisfeld 1980] and James-Birchall [James et al. 1980] showed the derived radiation doses to be weakly dependent on the radon daughter equilibrium ratios (F), moderately dependent on the radon daughter activity median diameter (AMD) and strongly dependent on the unattached fraction of PAEC (fp). A Nuclear Energy Agency (NEA) Group of Experts reviewed these models and categorised the atmospheric conditions in underground uranium mines according to ventilation regimes', low, medium and high, with a separate category for open-pit mines. Typical values for the unattached fraction, drawn from the literature, were assigned to each ventilation regime, to derive corresponding factors for the conversion from WLM
exposure to effective dose equivalent [NEA 1983]. Since most of the measured fp values were less than 5%, and typically less than 2%, the derived dose conversion factors were not increased greatly from earlier estimates and were in the range 5.6 to 13 mSv/WLM (1.6 to 3.7 Sv per J h m'J ).
The dosimetric models developed by the ICRP Task Group on Human Respiratory Tract Models [NRC 1991, James et al. 1991], have incorporated the more recent data on respiratory tract deposition as a function of particle size. This includes recent data on deposition of ultrafine particles in the nose [Cheng et al. 1988, Swift et al. 1992]. The results of this model show that the dose per unit exposure is about a factor of 25 times higher for an ultrafine (unattached) radon progeny with an activity median thermodynamic diameter (AMTD)of ~1 nm than for attached radon progeny, with an AMTD in the range 100 to 300 nm. The peak in the bronchial dose conversion factor (DCF) occurs between 1 and 2 nm, depending on the breathing mode (nose or mouth breathing), with the bronchial DCF by a factor of 3 between 1 and 10 nm.
Appropriate dose conversion factors for a uranium mining operation can be derived from measurements of fp and AMD in the case of the earlier
3 Jacob!-Eisfaid (J-E) and James-Birchall (J-B) models, or from the measured radon daughter particle-size distributions over the range 0.5 to 1000 nm for the new ICRP Lung Model. There is little published data on radon daughter size distributions for particle sizes less than 10 nm, and none covering conditions in Australian uranium mines. This report describes the methods used for the measurement of unattached fraction, the sizing of the radon daughters over the range 0.5 nm to 1000 nm in the underground uranium mine operated by Olympic Dam Operations (ODO) at Olympic Dam, South Australia. The results of measurements carried out in the ODO mine are reported, together with the calculated dose conversion factors derived from the older dosimetric models and from the new ICRP Lung Model using the computer code RADEP (Birchall and James 1993).
METHODS
The Mine
The mine under study is located approximately 600 km north of Adelaide and produces copper, uranium, gold and silver. The uranium and its associated daughter products are the principal sources of the radiological risk within the mine and the worker exposure to external gamma-ray radiation, airborne radon daughters and long-lived radioactive dust is monitored to ensure compliance with the regulatory radiation dose limits for workers, currently 20 mSv per year. Underground development began in 1983 and at the time of the field measurements (July 1992) the length of underground drives exceeded 60 km. A schematic map of the access drives and the mining stopes is shown in Figure 1. This map shows the position of the access decline from the surface, the Whenan shaft used for transporting the ore to the surface, and the relative locations of the mining activities.
4 The method of mining at ODO uses long hole open stopcs. Following its removal at the base of each stope, the ore is transported by large diesel-powered dump trucks to the tipple grizzly for input to the crusher station. Following crushing, the ore is loaded in skips for transfer to the surface for further processing. The ventilation system is designed to reduce the ingrowth time for radon daughters reaching the main work areas. This is achieved by arranging for fresh air to pass through the work areas and access drives before passing into the stopes and out the exhaust shafts. A schematic diagram of a typical long hole stope ventilation system is shown in Figure 2. The size of the mine and the range of mining activities carried out makes the assessment of typical mine atmospheres a difficult task.
Plymre 2. Schematic diagram of a Long-Hole Open Stope showing the access shafts for mining and ventilation.
«
i i
Over the period July 20 to July 30, 1992, extensive field measurements were carried out in the mine at Olympic Dam by six members of the Australian Radiation Laboratory (ARL), with the cooperation and assistance of ODO management and employees. Detailed planning of the sampling sites was carried out at a meeting between members of the ARL field team, ODO staff from the radiation monitoring and ventilation control sections, and the occupational health and safety representatives for the underground workforce. A total of over 50 sites was selected throughout the mine. The position of these sampling sites is shown schematically in Figure 3 and Figure 4. Seven sampling sites with access to mains power were selected for detailed study using the aerosol sizing equipment. One of these sites in the Vent Bag Store at 32LH58 was chosen as the reference point for the study of temporal variability. A further 40
5 Figure 3. Schematic map showing meosurements sites in the vicinity of the Vhenan Shaft
#42
Figure 4. Schematic map showing measurement locations in the vicinity of the Vent Bag Store.
# new working* not
6 Table 1. List of sampling locations vith the mine at Olympic Dam by site ID number, grid location and work activity
ID SITE WORK ACTIVITY COMMENT Reference Sampling Location 1 32LH58 Vent Bag Store Vent bag store Mains-Powered Daily Sampling Sites 6 26F BROWN 34 Slot Raise Bore 18 31MD55 Sub-Station Sub-station 24 32LJ61 Substation Sub-Station 1 32LH58 Vent Bag Store Vent bag store 31 35FBROWN7 Slot 51 41IJ61 Substation 52 A BLOCK Pump Station Rattery-Pnwered Daily Sampling Sites 20 32F PURPLE10 Slot Production Drilling 36 36DC Extraction Site 40 38NB46 SE Drive 56 Underground Store 48 41LJ61 Substation Battery-Powered Gran-Samp!ing Sites 2 26BYELL0W24 SLOT JUMBO #6 Scaling,rock bolting 3 26F BR0WN25 Slot Raise Bore 4 26LJ59 Vent Return Vent return 5 26BYELL0W23 Slot Slot 6 26FBR0WN 34 Slot Raise Bore 7 26FBROWN25 Slot Raise Bore 8 26NB48 Yellow Access Access 9 29DNWRED4 South Jumbo#8 Jumbo rig 10 29DNW RED4 Slot Jumbo Rock bolting 11 29RED4 South Drill Drive Drill 12 29DNWRED4 Development no activity 13 30FBROWN25 Slot 14 30FBR0WN34 Drill Drive Bogging 15 30LG62 NE Perimeter 16 30NB50 SE Incline 17 31MD55 NE Perimeter Roof Bolting No activity 18 31MD55 Sub-Station Sub-station 19 32PURPLE10 Drive 21 32FPURPLE10 Slot Simba Rig Inside 22 32FPURPLE10 Slot Simba Rig Outside 1 32LH58 Vent Bag Store Vent bag store 24 32LJ61 SUBSTATION Sub-Station 23 32F PURPLE10 Drill Drive Simba Rig Drilling 25 33LF62 SE DECLINE Bogging No activity 26 33NB53 South Incline 27 33NC53 STORE Store 28 39 CC 0LIVE3 S'.ope 29 35F BROWN24-2 Drill Drive Development Slot No activity 30 35ME55 NW PERIMETER Development Recent firing 31 35FBROWN7 Slot 32 35LH61 NE PERIMETER Bogging site No activity 33 35ME55 NW PERIMETER 34 36DCGREY1 ST0PE Extraction level No activity 35 36DC Vent Doors 37 36MH54 Crusher Station Ore crushing 38 37DNWGREEN4 STOPE Bogging 39 38A SUB-STATION 41 38NB46 SE DRIVE OnRam 2 Exploration drilling 42 38NG52 RAISE ACCESS JUMBO # Development Drilling 43 38NG52 South Decline 44 39CCOLIVE3 STOPE Bogging Ore extraction 45 40MA59 NW Decline JUMBO #8 Development drive NA 46 41LJ61 NW Drive Jumbo //8 Development Drilling 47 41F SUB-STATION Electrical 49 41LJ61 NW DRIVE Prior to Blasting 50 41LJ61 NW Perimeter 51 41LJ61 SUBSTATION 52 A BL0CKPUMP STATION 53 Crusher Platform 54 Crusher Sub-Station 55 Shift Boss Room 57 WORKSHOP Vehicle repairs
7 sampling sites, with no access to mains power, were selected for the battery powered measurements. A full list of the sampling sites is given in Table 1.
Measurement: Protocols
The main aim of the measurements within the mine was to characterise the airborne radioactivity at representative work locations and for particular work practices. It was necessary to address the likelihood of marked spatial and temporal variability for both the aerosol conditions and the radon and radon daughter levels throughout the mine. In general, mains power was not available in the immediate vicinity of the actual ore handling operations. The measurement protocols were chosen to balance the requirements of the sizing study with the difficulty in carrying out complex measurements in an operational mine. Four separate measurement systems were used, two requiring mains power and two using self-contained battery power. The latter two systems could be operated in close proximity to the ore handling and drilling operations, but the amount of information gained was not as extensive as for the mains-powered systems. The first of the mains-powered measurement systems was designed to provide continuous unattended measurements of radon and radon daughter activity concentration, radon daughter activity size distributions and unattached fractions at the reference site for the full period of the ARL study. The second mains-powered system was designed to obtain grab sample measurements of radon and radon daughter activicy concentrations, radon daughter activity size distributions and radon daughter unattached fraction at representative locations within the mine. The details of the specific equipment are provided in the next section.
Measurement Methods
Radon (1) Two-Filter Tube (TFT) A large two-filter tube of volume 39.5 L was operated at a nominal flow rate of 60 Lpm. After a 15 minute sampling period, the back filter was transferred to a drawer assembly and the alpha-particle activity was measured using a solid state alpha particle detector. The integrated counts were converted to radon concentration using the method of Thomas (1970). The TFT was calibrated in the Radon Test Chamber at ARL prior to the field measurements. The TFT was operated concurrently with the grab-sample graded screen array (GSA) and wire screen parallel diffusion battery (PDB) measurements.
(2) Continuous Two Filter Tube (CTFT) A small two-filter •-ube of volume 6 L was operated in a continuous sampling mode, with a flow rate of 1.0 Lpm. The alpha particle activity from radon daughters deposited on the back filter was measured in-situ using a solid state alpha particle detector positioned in front of the filter. The alpha particle decays were integrated over 20 minute count intervals and stored in the memory of a portable electronic data logging system. The monitor was calibrated in the ARL Radon Test Chamber prior to its use in the field.
(3) Electrostatic Two Filter Tube The electrostatic TFT is a variation of the standard TFT in which the radon daughters are electrostatically collected on the front face of a solid-state alpha paiticle detector maintained at ground potential [Kennedy et al. 19P4]. The monitor used for this study comprised an aluminium sphere of 6L volume, maintained at an electrical potential of 4500 V. Filtered, dried air was drawn into the sphere at a continuous sampling rate of 0.5 Lpm. The alpha particle activity from radon daughters collected on the front face of a solid state
R alpha particle tetector during each 20 minute interval was analysed using alpha spectroscopy to determine the radon concentration in the sample air.
(b) Charcoal Cup Passive Monitors Integrated measurements of radon concentration over sampling periods of up to six days were carried out as in", a passive radon monitor based on the adsorption of radon onto activated charcoal [Pojer et al. 1990 ]. At the end of the sampling period the monitors were sealed and returned to AR1. in Melbourne for gamma-ray counting of the radon collected. The average radon concentration was calculated using previously determined calibration factors.
Radon Daughters (1) Graded Screen Array (GSA) Samples Spot samples for radon daughter measurement were collected at multiple sites each day using a serial graded screen array system . The GSA used an open-face filter holder, containing a sequence of 105, 200 and 400 mesh screens and a backup filter, as shown in the left hand portion of Figure 5. Samples were collected at a sampling rate of 4.010.1 Lpm using a small battery-powered pump. Following the end of sampling period, the front face of each screen and the filter were measured for alpha particle activity by placing them in one of four portable alpha particle detectors. The gross alpha particle activity on each screen and the backup filter was measured over three time intervals and the radon daughter concentrations determined using the modified-Tsivoglou technique [Thomas 1972]. Each sample was analysed to determine the individual radon daughter concentrations, the total PAEC, the value of fp as well as the particle size distribution for the ultrafine (unattached) mode.
Figure 5. Schematic diagram of sampling configurations used for the sizing of ultrafine radon daughters using serial graded screen arrays (GSA) methods and accumulation mode radon daughters uses parallel diffusion
Filter Holder Wt^m' Ho,der
Detector
105 200 400 Filter Preamp/Amp. -
Serial Graded Screen Array Diffusion Battery Sampling Head
(2) Continuous 2-stage Diffusion Battery (Cfp) A portable two-stage diffusion battery was used to provide continuous measurement of PAEC and the value of fp. This monitor was small, self-contained and light-weight and could be located in the midst of normal mining activities without the need for mains power. Two sampling heads, with in-situ alpha particle counting capability were operated at a continuous flow rate of 0.75 Lpm for each stage. The Cfp sampling head design was similar to the sampling assembly shown schematically on the right hand portion of Figure 5. The count rate of alpha particle decays from radon daughters deposited on the filter in sampling head #1 was used to derive PAEC. The fp values were determined from the alpha activity emitted by radon daughters deposited onto a 105 mesh wire screen in sampling head #2, assuming that 80X of the activity was on tue front of the screen [Solomon and Ren 1992]. The collection efficiencies for the two sampling heads were calculated using the Fan-Model filtration theory [Cheng and Yeh 1980 ]. The derived curves, plotted on the left hand portion of Figure 6, show that the wire screen had a 50X penetration efficiency (Dp50) of 5 nm.
(3) Continuous 5-Stage Wire Screen Diffusion Battery (CDB) A computer-controlled data acquisition system was used at a single reference location, in this case the Vent Bag Store, 32LH58 to collect data on radon and radon daughters over the full period of the field measurements. Radon levels were measured with the electrostatic-based two-filter tube, using alpha spectroscopic analysis of the activity deposited on the surface of a solid-state alpha particle detector [Kennedy et al. 1980]. The PAEC, the fp and the PAEC activity size distributions were measured using a five-stage wire screen parallel diffusion battery, which was operated with a continuous sampling rate of 1.7 Lpm per stage. The five sampling heads, of the type shown schematically on the right hand portion of Figure 5, used in-situ counting r>f the alpha particles from the radon daughters deposited on each filter. The calculated collection efficiencies for each stage, derived from the fan-filtration theory with corrections for inertial and impaction processesiCheng et al. 1980], are plotted in the middle portion of Figure 6. A single sampling pump was used for the CDB, with the flow split through a manifold to each of the five rotameters connected to each of the five sampling heads. The alpha spectroscopy for the radon monitor and the collection and analysis of the diffusion battery data were carried out by a purpose-written computer programme running on a IBM-PC based computer. For each 20 minute integration period, the set of five integrated alpha counts were converted to PAEC and deconvoluted using both the Twomey and the Expectation Maximisation (EMax) algorithms [Twomey 1975; Maher and Laird 1985] to derive two sets of particle size distributions in 20 logarithmically spaced size intervals between 1 and 1000 nm. These distributions were then analysed to determine the size and position of each peak, and the appropriate dose conversion factors.
10 (4; Parcllel Diffusion Battery and 4-Stage Serial Graded Screen Array (GSA/PDB) The two continuous systems described above do not provide detailed size distribution data below 4 nm, the lower portion of the ultrafine mode. To improve the measurement of the ultrafine mode, grab samples were collected using a combined four-stage serial graded screen array and a five-stage parallel wire screen diffusion battery (GSA/PDB). The GSA used an cpen-face filter holder, containing 105, 200 and 400 mesh screens and a backup filter, as shown in the left hand portion of Figure 5. Samples were collected at a sampling rate of 9.5 ±0.1 Lpm . The wire screen collection efficiencies were derived as a function of particle size [Cheng et al. 1980], with corrections for internal losses in the screens and for the front to total ratio [Solomon and Ren 1992]. The PDB used 5 sets of the ARL sampling assemblies with in-situ alpha counting. Stages #2, #3 and #4 used 1, 6 and 23 sets of 3.7 cm diameter 105 mesh screens, respectively. Stage #5 used 40 sets of 9.5 cm diameter 105 mesh screens. The sampling rate for each stage was set to 1.7 ±0.1 Lpm. The right hand portion of Figure 6 shows the collection efficiency curves for the combined systems. For the PDB, the reduction in the collection efficiency due to increasing contributions from the impaction and interception does not begin until 1200 nm.
Sampling with the GSA and PDB system was carried out concurrently with the TFT. After the end of each 15 minute sample, the screens and the filter from the GSA were transferred to one of four drawer assemblies. The pulse signals from alpha particle decays on the filters in each drawer assembly were connected to the lower four channels of a 10-input computer-controlled counter. The five pulse signals from the PDB sampling heads were connected to the next 5 inputs of the same counter. All nine sets of pulse inputs were counted simultaneously over three count intervals and the alpha particle counts were analysed using the modified-Tsivoglou method to derive activity concentrations of Po, *Pb, 21*Bi and the PAEC for each stage. These activity concentrations were in turn analysed using both the Twomey and EMax algorithms to provide the particle size distributions for each daughter and the PAEC over the size range 0.5 to 1200 nm. As for the CDB, the size distributions were analysed to determine the size and position of each mode in the activity size distribution and the corresponding weighted dose conversion factors for the J-B, the J-E and the new 1CRP Lung models.
Long-lived Radioactive Dust Cascade impactors Three different types of commercial low-pressure cascade impactor were used to collect samples of radioactive dust within the mine. These were;
(a) a Marple Type 290 6-stage personal impactor operated at a flow rate of 4 Lpm,
(b) a Sierra Type 210 10-stage cascade impactor operated at a flow rate of 4 Lpm, and
(c) an Anderson CI-2000 8-stage cascade impactor operated at a flow rate of 27 Lpm.
Samples were collected at each site for 24 hour periods. The long-lived radioactive dust deposited onto filters in each stage of each of the three cascade impactors was to ie measured by alpha spectroscopy at ARL in Melbourne. However, even with low-background solid state alpha particle detectors and extended counting times it was not possible to obtain statistically significant
11 results for any of the impactors. For this reason, no dust sizing measurements were obtained from this field visit.
Dosimetric Models
The dosimetric models developed in the early 1980s by Jacobi-Eisfeld [Jacobi and Eisfeld 1980] and James-Birchall [James et al. 1980], and reviewed by the NEA Group of Experts in 1983 [NEA 1983], investigated the dependence of the derived effective dose equivalent on the radon daughter equilibrium ratios (F), the radon daughter activity median diameter (AMD) and the unattached fraction
(fp). Both models included the observation that many of the induced cancers appeared in the upper portion of the respiratory tract, but used the standard ICRP apportioning of weighting factors for the bronchial and alveolar regions of 0.5 and 0.5. The models showed the derived doses to be weakly dependent on
F, moderately dependent on AMD and strongly dependent on the fp. For the analysis in this report, the tabulated values for the dose conversion factors in the NEA report were fitted to analytic functions in AMD and fp. For the J-B i.iodel the conversion factor from WLM exposure to effective dose was approximated by;
0 C F (J-B ) = 1.55x 10"'*• AMD2 - 0.0855 • AMD + 15.8+ ( -1.5x l(f *'AMD 2 + 0.085 -AMD + 112 ) • 1 fp ••(I) Similarly, the J-E model conversion factor was approximated by;
D C F (J-E ) = B.OOx 10 AMD 0.0630* AMD + If. 5 + (-7.5 x 10 •AMD + 0.0235 «AMD + 23) • I fp (2)
The new ICRP Lung Model [NRC 1991, James et al. 1991] has incorporated the more recent data on respiratory tract deposition as a function of particle size. This includes recent data on deposition of ultrafine (nm) particles in the nose [Cheng et al. 1988, Swift et al. 1992]. Figure 7 shows the conversion factors for occupational exposure calculated using the computer code RADEP, assuming a 3 ~1 breathing rate of 1.2 m h . The curve shown gives the value of the conversion factor from WLM exposure to mSv effective dose. The model values have not been normalised to adjust the risk detriment to the epidemiological-derived value. For a risk detriment of 2.77 x 10 "* per Sv, the normalisation factor is 2.5. Figure 7. Factors for the conversion from radon daughter exposure to effective dose from the new ICRP Lung Model, computed for occupational exposure to an adult male using the computer program RADEP.
200 H" 180 160 140 - > (/) 120 £ 01 100 + oo 0) 80 _> 0 4- 0.1 10 100 1000 10000 Particle Size (nm) 12 That is, the RADEP-derived DCFs should be reduced by a factor of 2.5 to give radiation risk estimates consistent with the ICRF value for risk detriment [James 1993]. RESULTS The measured size distributions from the CDB and the GSA/PDB systems and from the GSA spot samples were used to derive activity-weighted dose conversion factors using the results from the ICRP Lung Model described in the previous section. In the case of measured values for unattached fractions, the dose conversion factors were calculated from Eqn (1). for the James-Birchall and Eqn (2). for the Jacobi-Eisfeld lung models. Reference Sampling Site (Vent Bag Store) The continuous monitor was operated in the Vent Bag Store from July 22 to July 29, 1992. The diffusion battery functioned for the full period, except for short intervals in the morning when the filters in the sampling heads were changed. The electrostatic TFT malfunctioned on the days between July 25 to 26. The data were analysed to determine the radon concentration, the PAEC, the equilibrium ratio (F) and the unattached fraction (fp) at 20 minute intervals. The full results for this location are given in graphical form in Appendix 1 and the daily average values are summarised in Table 2. Table 2. Daily average results for activity concentrations derived from continuous DB and electrostatic TFT measurements at the Vent Bag Store. Equilibrium Interval Radon (Bq m-3) PAEC (mWL) fp <*) Ratio (F) July 22-23 476 ±120 25±2 1.4 ±2.4 0.20 ±0.03 July 23-24 673 ± 96 26 ±2 13.1 6.8 "1.15 ±0.02 July 24-25 891 ± 32 33 ±6 0.5 ±1.2 0.14 ±0.02 July 25-26 29 ±5 5.1 ±3,4 July 26-27 27 ±5 0.8 ±1.9 July 27-28 576 ± 86 24 ±4 11.5 ± 6.0 0.15 ±0.03 July 28-29 680 ± 46 26 ±7 0.5 ±2.4 0.14 ±0.02 The diffusion battery data were deconvoluted to determine the activity size distributions for each 20 minute interval. For each size distribution the fraction and geometric mean of each peak was determined. The fraction of the activity size distribution below 15 nm was used as a measure of the unattached fraction, lne factors for conversion from WLM exposure to effective dose equivalent were calculated for each 20 minute interval using each of the three lung models. The AMD values for the J-B and J-E models were obtained from the geometric mean of the accumulation mode in each activity size distribution. For the ICRP Lung Model (RADEP) the activity fraction in each size bin from both the Emax and Twomey deconvolution analyses was used to derive the weighted dose conversion factor. The temporal variation in the dose conversion factors derived using the J-B, J-E and RADEP (EMax only) models is shown in Figure 8. 13 The full listing of results from both the diffusion battery and the radon monitor is given in Appendix 1. The daily and overall average values from the CDB measurements are summarised in Table 3. Table 3. Daily average results for dose conversion factors derived from continuous DB measurements at Vent Bag Store. Conversion factors to Effective Dose, fp (X) GM1 (nm) GM2 (nm) mSv/VLM Average J-B & RADEP RADEP J-B J-E J-E (Emax) (Tvomey) 22-23 1.4±2.4 1.1±1.7 216 ±26 6.3±2.9 7. 2± 1.1 6.8±2.0 14.5±2.4 14.0±1.9 23-24 13.1±6.8 4.3±2.1 259 ±30 20.5±8.5 9.9±2.4 15.2±5.3 26.0±7.5 25.0±6.5 24-25 0.5±1.2 0.6±0.7 236 ±69 5.6±2.3 6.7±2.1 6. 1± 2.1 11.8±2.0 11.5±1.5 25-26 5.1±3.4 1.5±0.8 220 ±35 11.0±4.1 8.5±1.6 9.8±2.8 18.5±3.2 18.6±3.4 26-27 0.8±1.9 0.4±0.8 239 ±32 5.4±2.3 6.4±0.9 5.9±1.4 14.U2.1 14.3±2.1 27-28 11.5±6.0 1.6±0.8 196 ±29 19.3±6.8 11.8±1.8 15.6±4.2 26.9±3.9 27.4±4.1 28-29 0.5± 2.4 8.1±13.6 257 ±82 5.7±3.0 6.3±1.4 6.0±1.9 17.2±2 .9 17.7±2.7 Total 4.0± 5.8 2.3±6.1 229 ±53 9.8±7.2 8.0±2.5 8.9±4.7 18.0±6.1 18.0±6.1 Figure 8. Time variation of dose conversion factors for the J-B, J-E and the new ICRP Lung Model, from continuous DB measurements at Vent Bag Store. 0 -I 1 —t— 1 1 1 \ 1 4 1 1 24.5 25 25.5 26 26.5 27 27.5 28 28.5 29 29.5 Decimal Day 14 Mains-Powered Daily Sampling Sites A total of 26 samples was collected at 7 different sampling sites (including the Vent Bag Store) using the GSA/PDB measurement system. The measured activity size distributions derived from the EMax analysis of the PAEC results are shown in Figures 9a to 9g. The particle size distributions derived from the Twomey analysis were similar, producing similar values for the size and positions of the peaks in the distribution. The measured activity size distributions were combined with the RADEP conversion factors to derive weighted factors for conversion from WLM exposure to mSv effective dose. The J-B and J-E model dose conversion factors were derived from Eqn 1 and Eqn 2 using a value for the unattached fraction estimated from the portion of each size distribution below 15 nm and a value for the AMD derived from the geometric mean of the upper peak. The derived geometric means for the ultrafine and accumulation mode peaks in the size distribution, together with the calculated conversion factors, are summarised in Table 4 for each of the mains-powered sampling sites. Table 4. Summary of radon daughter sizing and dose conversion factor results derived from GSA/PDB measurements in the Olympic Dam mine. PAEC GM1 GM2 Convers ion factors to Effective Dose Location fp(*> (WLM) (nm) (nm) , mSv/WLM Average J-B J-E RADEP RADEP J-B & J-E Emax Twomey 26 F Brown 1.1 117 0.50 161 7.4 8.9 8.1 19.1 19.1 0.7 107 0.50 207 5.6 7.2 6.4 14.6 13.9 0 109 48 359 5.1 4.2 4.6 15.4 14.7 0 110 228 4.4 6.3 5.3 13 9 12.8 31 MD 55 0.2 128 0.50 227 4.6 6.4 5.5 16.0 14.0 0 145 42 391 6.1 4.1 5.1 17.2 15.6 0 146 43 370 5.4 4.1 4.8 17.2 15.8 0 165 37 464 9.5 4.5 7 17.2 16.3 32 LJ 61 0 14 27 475 10.2 4.6 v -7.°4 34.0 30.9 0.4 16 0.78 250 4.6 5.9 5.3 14.8 14.0 7.2 16 6.5 212 13.4 9.6 11.5 22.3 23.1 32 LH 58 0 35 219 4.6 6.6 5.6 13.3 13.8 2.9 27 1.4 216 8.0 7.7 7.9 16.6 16.2 35F Brown 1.9 46 0.50 272 6.3 6.0 6.2 12.8 13.1 '" 1 A'" 45 0.54"\ 230 7.3 7.4 14.6 14.2 - -4t5-7 7.5 f 6.8 10.9 16.5 15.8 (Bi-modal }~ 1.1 45 0.50 \ 402 V5.9 12 J 13.2 '1.6 47 0.52 \ 303 7.6 10.4 18.1 17.3 13.2 ._.__„._ "41 LjTlVT 5.0 17 4.2 239 8.0 20 75" "1879"" 4.6 17 1.5 128 TO 11.5 12.3 24.9 24.3 14 13.1 11.4 12.9 23.1 '1.2 "0754 ] 147 24.6 14.3 5.1 4.7 J ''5.4 22 0.59 \ 184 40.0 18.7 29.3 48.0 47.3 23 ------A Block 5.3 33 2.4 136 13.5 11.5 12.5 " 24.5 Pump Station 3.7 46 1.3 121 12.2 11.5 11.9 22.8 21.9 3.3 34 0.50 87 13.6 12.9 13.2 26.6 27.8 36 0.51 126 13. 2 . 11-7 12-4 24.5 24.0 1 Average 3.7 61.3 246 10.4 8.2 9.3 20.4 19.6 15 Figure 9. Activity size distributions for each sampling site, derived from the ENax analysis of the PAEC results from the GSA/PDB measurements. Figure 9a Figure 9b 324 61 SUttlotion «H6I SiAStotion | 1231 10:20 t 13:45 12:25 15:00 13:25 «l I4J3 f*uu i ' I «0.4' 0.2- \lf Ut llll [23 U, >»Z | ..&,•,*£* 0, 1 10 100 1000 10 100 Portfcb Sit (nm) Portidt Szt (nm) Figure 9c Figure 9d A 31X855 «8J | p-* -m- | 26rBro»»' (Bow Boft) | /J\_ 0.8 0.8 8:25 11 ?l —•— 0.7 13:06 0.7 ji V\ 9:38 J.0J- 14:09 12:19 i.. 1S:I1 i:; /p\ 13:49 S0.3- i: Til 0.2 0.2 &1- 0.1 If J |24 J* 1112 [ m Pjl |» J* 1**1 1 0 —i i ifliWi •! • ai»^p — .M— 10 100 10 100 Partlcfc Sit* (nm) Partki* Six* (nm) Figure 9e Figure 9f | 35 Bro»n 79ol JUMO 7 | | » Pock Pimp Slolion | 10:19 8J8 1.2' 1201 10 JO 1 -»- 13:20 i' 12:06 -«• 14:23 l»| 13:14 I 04 1" 0.4 I 0.4 0.2 0 2 \l1 Ut llll ^N[21 it, HIT. 0 0.1 10 100 1000 10 100 Porlicte Silt (nm) Portlcl* Sl» (nm) Figure 9g 1.4 Vnl Bog Slort 14:48 1.2 8:02 0.4 0.2 H 28-21 Ul mi »ii 16 Battery-Powered Daily Sampling Sites The Cfp and CTFT monitors were positioned each morning at different sampling sites within the mine. The alpha particle count rates from the two monitors was analysed to derive radon concentration, PAEC and unattached fraction of PAEC values at 20 minute intervals at each site. The equilibrium ratio F was calculated from the ratio of the PAEC to radon concentration. The full results for each site are given in Appendix 2 and the derived average values are summarised in Table 5. The elevation in radon and PAEC levels at 32F PurplelO was due to a short-term failure of ventilation in the vicinity of the sampling site. Tab^e 5. Mean and standard deviation of results from continuous fp and TFT measurements as a function of sample locati.n. Location Date Rn (Bq m-3) PAEC (mVL) fp (X) F 32F Purple 10 22-23/7/92 2110 ± 1560 105 ± 89 1.4 ± 0.9 0.17 ± 0.04 36DC Extraction Site 23-24/7/92 480 ± 170 14.8 ± 3.3 1.7 ± 0.7 0.12 ± 0.06 38 MB 46 SE Drive 24-25/7/92 1215 ± 220 63.2± 9.8 3.4 ± 1.3 0.20 ±0.04 Underground Store 25-27/7/92 470 ± 120 19.0 ± 4.3 4.1 ± 3.7 0.16 ±0.06 41 U 61 Substation 27-28/7/92 685 ± 135 14.1 ± 3.4 8.4 ± 4.4 0.08 ± 0.02 Vent Bag Store 28-29/7/92 590 ± 135 28.7 ± 4.3 1.7 ± 1.4 0.19 ± 0.05 Battery-Powered Grab-Sampling Sites A total of 37 spot samples was collected at a wide range of sites through-out the mine. Since the measurement system was relatively portable, it was possible to carry out measurements in close proximity to the ore handing and mining activities. A charcoal-based passive radon monitor was placed at each sampling site at the beginning of the week of field measurements and these were collected after a 6 day exposure period. These passive monitors were analysed to provide average radon levels at each site over the full 6 day period. A single spot sample was taken at each site with the GSA system. The samples were analysed to derive radon daughter activities on each screen and the back-up filter. The calculated individual radon daughter concentrations and PAEC for the front screen and the back filter are summarised in Table 6. These values are approximately equal to the corresponding values for the unattached and attached radon daughter concentrations, respectively. In analysing the GSA results some problems were experienced with high and variable backgrounds for the detector used to measure the third screen. In general, the activity measurements for this third screen were not used for the deconvolution analysis. In order to calculate DCF values from the GSA results, a number of alternative approaches were investigated. These were ; • to use the background subtracted counts for the third screen, • use of a count for the third screen equal to the count on the second screen in the GSA, • to set the count for the third screen to zero, • to ignore the third screen completely and carry out the deconvolution analysis for two screens only. On the final day (July 29) concurrent measurements with the GSA and GSA/PDB system were made at the Vent Bag Store site. This allowed a direct comparison 17 of the four approaches outlined above. From examination of the deconvolution and dosimetric model results it was found that the second and third approaches gave the closest fit. Therefore, for the remaining GSA samples the deconvolution analysis was carried out twice, once with the third screen values set to zero and once with the third screen values set to equal those of the second screen. The results of these analyses were then averaged to derive an estimate of the size and position of the ultrafine mode. The derived values for AMD for ultrafine and fp are summarised in Table 7. Table 6. Radon daughter activity concentrations for accumulation and ultrafine modes» as determined from GSA measurements. ID Radon Daughters> on Back Filter) Radon Daughters on Front Screen PAEC(+1SD) 218Po(+lSD) 2uPb(+lSD) 21*Bi(+lSD) 218Po 214Pb 2UBi PAEC (mWL) (Bq m-3) (Bq m-3) (Bq m-3) (Bq m-3) 1 17.5 0.09 91 8 77 1 44 2 0 2.6 1.6 1.07 1 19.0 0.09 158 8 71 1 49 2 5.2 2.8 7.5 0.39 2 36.9 0.12 218 10 137 1 118 2 7.7 3.8 10 1.32 3 32.9 0.11 222 9 139 1 75 2 15 1.2 3.2 0.5 7 35.0 0.12 221 10 134 1 103 2 0 2.0 5.9 0.28 9 29.2 0.10 435 9 103 1 30 2 15 11 5.6 2.47 9 13.6 0.13 238 12 31 1 27 2 48 7.0 1.0 1.93 10 55.6 0.13 764 11 186 1 88 2 17 8.2 2.7 1.47 14 43.8 0.12 533 10 169 1 57 2 0 2.3 9.9 0.45 17 49.1 0.13 239 11 205 1 142 2 40 24 0 3.89 17 130. 0.19 537 16 504 2 456 3 8.5 1.7 13 1.54 21 14.5 0.10 528 10 0 1 7 2 28 6.8 0.1 1.44 22 31.7 0.13 266 13 139 1 278 2 23 6.0 2.3 1.49 23 40.1 0.12 487 10 158 1 48 2 29 5.6 0.9 1.39 25 17.0 0.09 116 8 70 1 42 2 4.6 4.1 1.5 0.53 27 17.2 0.09 191 8 63 1 33 2 3.6 1.0 9.6 0.12 29 18.4 0.09 188 7 72 1 32 2 0 1.6 34 0.08 30 1.36 0.07 0 6 5 1 7 1 1.4 4.8 2.4 0.79 32 23.7 0.09 297 8 87 1 35 2 36 5 0 0.94 33 0.86 0.06 27 5 0 1 3 1 8.1 0 9.8 0.02 34 18.6 0.09 284 7 58 1 27 1 2.3 1.2 6.0 0.15 34 13.6 0.09 184 8 45 1 22 1 9.4 3.3 1.3 0.44 37 7.39 0.08 33 6 32 1 20 1 65 0.6 0.4 0.99 37 5.51 0.08 74 7 12 1 18 1 26 1.5 0.6 0.37 38 5.13 0.07 32 6 0 1 12 1 0 0.1 5.1 0 38 9.80 0.09 159 7 25 1 18 1 0 7.6 15 1.02 39 29.0 0.11 121 9 126 1 83 2 17 0 2.4 0 40 51.8 0.13 328 10 214 1 133 12 20 18 5.3 3.42 42 8.33 0.07 98 6 18 1 31 1 0 0.9 14 0.03 44 12.6 0.08 77 6 53 1 31 1 7.6 1.0 5.2 0.12 45 16.9 0.09 73 7 72 1 50 1 48 34 3.1 4.09 47 9.88 0.09 170 7 29 1 11 1 0 0 4.6 0.06 49 15.3 0.09 133 7 60 1 33 2 76 5.4 0 1.95 49 20.2 0.09 213 7 83 1 28 1 5.6 6.8 6.8 0.93 55 1.03 0.08 8 6 6 1 0 1 0.9 0.2 2.4 o 57 6.65 0.07 20 6 33 1 14 1 21 0 0.7 0.06 57 5.76 0.08 28 6 24 1 17 1 0 1.8 2.71 0 18 Table 7. CSA spot sampling and passive charcoal cup results as a function of site ID D Activity fp GM1 PAEC Radon DCF (mSv/WLM) (X) (nm) (mVL) Bq m"3) J-B J-E RADEP 1 Vent bag 0 19 4.1 5.7 19.8 1 store 0 19 4.1 5.7 21.6 2 Scaling, roof 2.5 1.5 38 199 7.2 6.6 17.3 bolting 3 Raise bore 0 33 237 4.1 5.7 15.8 7 Raise bore 0.6 0.5 35 4.9 6.0 13.9 9 Drilling 8.6 1.6 32 14.7 8.8 26.1 9 5.6 1.5 16 11.1 7.7 21.8 10 Rock 0.8 1.5 56 5.0 6.0 15.3 bolting 14 Bogging 0 44 4.1 5.7 16.1 17 No activity 1.3 1.5 53 5.7 6.2 15.5 17+ 0.4 0.5 132 4.6 5.9 13.9 21 Sircba - in 2.8 1.8 16 7.6 6.7 18.2 22 Simba - out 1.4 2.4 33 5.8 6.2 16.6 23 Drilling 0.8 2.9 41 5.1 6.0 16.3 25* No activity 1.4 2.4 18 8.2 9.5 21.3 27 Store 1.4 1.7 17 5.8 6.2 16.3 29 No activity 0.8 0.5 18 5.1 6.0 13.7 30 After firing 2.2 0.5 2 44 6.8 6.5 14.2 32- No activity 3.1 1.6 25 7.9 6.8 18.4 33 11.4 0.5 1 44 18.2 9.8 17.6 34 No activity 4.2 3.6 19 190 9.3 7.2 21.3 34 1.4 1.5 14 190 5.8 6.2 15.5 37* Crushing 6.9 1.6 8 56 14.8 11.7 28.5 37* 6 56 6.5 8.8 32.2 38- Bogging 2.5 6.5 5 216 7.2 6.6 20.0 38 1 4.6 11 216 4.8 5.9 18.2 39" Sub-station 29 6.5 8.8 17.7 40* 1.7 0.6 55 8.5 9.6 19.6 42 Drilling 2.5 3.6 8 288 7.2 6.6 19.0 44 Bogging 2.6 0.5 13 7.3 6.6 14.6 45 Drilling 1.7 0.5 21 185 6.2 6.3 14.6 47 Sub-station 1.8 3.7 10 6.4 6.4 18.5 49* Pre-blasting 3.3 1.4 17 149 10.4 10.2 22.5 49* 1.9 1.6 21 149 8.7 9.6 21.2 55 Shift Boss 6.4 5.4 1 76 12.0 8.0 24.5 Room 57 Workshop 7.4 2.4 7 76 13.3 8.4 26.4 57 1.4 0.5 6 76 5.8 6.2 14.3 Ventilation wasi turned off when this measur ement was made *"non-diesel" re gion of the mine 19 The GSA system was not able to resolve particle size modes greater than 40 run and the values for the accumulation mode are not reported in Table 7. Comparison with the GSA/PDB results for the Vent Bag Store measurements for the accumulation mode showed that the GSA system alone over-estimated the AMD, producing an average of 400 nm compared with 250 nm determined from the GSA/PDB. Therefore, the dose conversion factors for the J-B and J-E models were calculated using the GSA-derived values of fp, assuming an accumulation mode of 250 nm, (GSD - 2.5) or 150 nm (GSD - 2.5), depending on the location of the sampling site relative the mining operations. For the ICRP Lung Model analysis, the RADEP-derived dose conversion factors were adjusted by an amount equal to the difference in DCF between radon daughters with an AMD - 400 nm and those with an AMD - 250 or 150 nm. This adjustment was typically of the order of 3 to 4 mSv/WLM (un-normalised). The calculated DCF values for the GSA measurements are summarised in the last column of Table 7. DISCUSSTON The results from the continuous monitors positioned at the Vent Bag Store, shown in Tables 2 and 3 and in Figure 8, indicated that the radon concentration varied by up to a factor of two over the week of the measurements, and the unattached fraction ranged from less than IX to over 10%, with an average value of 4.OX. The PAEC and equilibrium ratios showed a smaller range, varying from 24 to 33 mWL and from 0.14 to 0.33, respectively. The CDB results did not show any strong diurnal pattern in the parameters for the airborne radioactivity. The sudden changes in DCF shown in Figure 8, particularly on July 27, are most likely associated with changes in the mine ventilation or systematic measurement errors due to small shifts in the relative flow rate between the first and second stage of the CDB. This later effect is likely to be less than or equal to 4% absolute, since this was the lowest value of fp on that day and it is not possible to have negative values of fp. The measured AMD values for the accumulation mode derived from the CDB were relatively constant, in the range 200 to 260 nm. The calculated effective dose conversion factors from the J-B and J-E dosimetric models varied by a factor of three and two, respectively, over the period of the measurements. The daily averaged values of the un-normalised RADEP-derived effective DCFs were in the range 14.0 to 27.0 mSv/WLM, with a mean value of 18.0 mSv/WLM. This corresponds M a normalised DCF of 7.0 mSv/WLM. The magnitude of the time variation of parameters measured at the Vent Bag Store (32LH58) was smaller than the spatial variation of the spot sample measurements, where the range in radon concentration and PAEC was greater than a factor of 5. The average value for the unattached fraction from the GSA/PDB measurements was 3.7X. Tins compares with an average of 4.0% from the CDB, 3.5% from the GSA and 3.0% from the continuous fp results. It should be noted that the unattached fractions from the Cfp results are determined for a Dp50 value of 5 nm, whereas the CDB, GSA and GSA/PDB fp values are determined for particle sizes less than 15 nm. The GSA/PDB particle sizing results shown in Table 4 and Figure 9 would suggest that, in the areas of the mines where there are large diesel powered vehicles, the AMD of the accumulation mode was in the range 200 to 300 nm. The average values of AMD and GSD for this "diesel" portion of the mine were 250 nm and 2.50, respectively. In those portions of the mine where there were no large vehicles or the ventilation intakes were close by ("non-diesel"), the AMD values were smaller, in the range 90 to 200 nm, with an average of 150 nm. This would suggest that the main sub-micron aerosol in the mine for attachment of radon daughters comes from the unburnt combustion products from the large diesel-powered vehicles. In a number of the activity size distributions shown in Figure 9, there would appear to be two accumulation modes (bi-modal), with one peak at 40 nm and the 20 other near 350 nm. Since many of these bi-modal distributions occurred at the same sites as uni-raodal samples, it is quite probable that the presence of two peaks above 20 nm is an artifact of the analysis, brought about by poor counting statistics or systematic errors in the measurement technique. The sharp peak at 27 nm in Figure 9a is considered to be an artifact brought about by systematic errors in this particular measurement. However, the set of measurements at 31MB55 consistently produced bi-. odal accumulation mode peaks. This location is near the RB3 ventilation outlet, with air coming from a number of sources in the mine, and the measured bi-modal distributions may be indicative of atmospheric processes leading to particle growth and/or clustering, and aerosol sizes different from those in other areas in the mine. However, the results in Table 4 show that the splitting of the accumulation mode has little effect or the derived dose conversion factors. Table 8 summarises the average and PAEC-weighted average DCF values appropriate to the two types of mine atmospheres ("diesel" and "non-diesel") in the 0D0 mine, for each of the three dosimetric models. The CSA/PDB derived values are the more accurate determinations of DCF, while the GSA values are more representative of workplace exposure. However, the results in Table 8 show that the two measurement systems produced similar average values, particularly for the "diesel" section of the mine. The DCF values derived for the GSA/PDB measurements using the J-B and J-E dosimetric models were in the range 4.1 to 40 mSv/WLM, with average values of 10.4 and 8.2, respectively. The un-normalised results from RADEP were in the range 12.8 to 48.0 mSv/wTM, with a mean of 20.4 and 19.6 for the EMax and Twomey analyses, respectively. Table 8. Summary of average DCF values fmSv/WLM) for two atmospheric types within the mine. Method and Model "Diesel" Areas "Non-diesel" Areas Un-weighted PAEC-veighted Un-weighted PAEC-veighted GSA/PDB average DCF average DCF average DCF average DCF J-B 7.5 7.0 18.2 18.2 J-E 6.1 6.1 12.2 12.2 RADEP 18.0 16.1 26.8 26.8 Un-weighted PAEC-weighted Un-weighted PAEC-weighted GSA average DCF average DCF average DCF average DCF J-B 7.5 6.4 9.1 8.6 J-E 6.7 6.7 9.8 9.8 RADEP 18.0 18.0 22.8 21.4 With a normalisation factor of 2.5, the corresponding values for the mean un-weighted DCF were 8.2 and 7.9 mSv/WLM, respectively. The corresponding PAEC-weighted values were 7.4 and 7.2 mSv/WLM, respectively. This compares with the current value of 10 mSv/WLM recommended in the Australian Code of Practice for Mining and Milling of Radioactive Ores, but is higher than the value of 5 mSv/WLM proposed by the ICRP for occupational exposure. To conform with a 20 mSv/yr dose limit, a DCF value of 8 mSv/WLM would imply a yearly limit for radon daughter exposure of 2.5 WLH, compared with the 4 W1M limit implied by the ICRP factor. The difference in the DCF values may be due to changes in mining and ventilation practices between the uranium mines operated in the 1940s and 1950s and the present day 0D0 mine. 21 ACKNOWLEDGEMENTS This work was supported by a Research Grant from the Mining and Quarrying Occupational Health and Safety Committee. The authors acknowledge the hard work and assistance of John Peggie and Peter Wykes from the Australian Radiation Laboratory in carrying out the field measurements. The cooperation and assistance of Olympic Dam Operations management and employees, in particular Jim Hondros and Steve Jeffers, is gratefully acknowledged. The work would not have been successfully completed without the time spent with the ARL field team by members of the Radiation Monitoring Section in planning and carrying out the measurements underground ; John Uarneke, Jim Hondros, Darren Billingsley, Rose Douglas and Barry Luke. 22 RF.FF.RF.NCF.S Bigu, J. and Kirk, B. 1980. Determination of unattached radon daughter fractions in some uranium mines. Presented at Workshop on the Attachment of Daughters, Measurement Techniques and Related Topics, October 30, 1980, University of Toronto. Birchall, A. and James, A.C. Uncertainty analysis of the effective dose per unit exposure from radon progeny using the new ICRP Lung Model. Rad*at. Protect. Dosim. (In press). Cheug, Y.S. and Yeh, H.C. 1980. Theory of screen type diffusion battery. J. Aerosol Sci. 11:313-319. Cheng, Y.S., Keating,J.A. and Kanapilly.G.K. 1980. Theory and calibration of screen type diffusion battery. J. Aerosol Sci. 11:549-556. 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Washington D.C.: U.S. Department of Energy, Office of Health and Environmental Research International Commission on Radiological Protection (ICRP) 1959. Report of the Committee II on Permissible Dose for Internal Radiation, ICRP Publication 2. Oxford: Pergamon Press. Jacobi, W. and Eisfeld, K. 1980. Dose to tissues and effective dose equivalent by inhalation of radon-222, radon-220 and their short-lived daughters. GSF Report S-626. Munich-Neuhrberg, West Germany: Gesellschaft fur Strhlen und Umweltforschung. James , A.C., Greenhalgh, J.R. and Birchall, A. 1980. A Dosimetric Model for Tissues of the Human Respiratory Tract at Risk from Inhaled radon and Thoron Daughters, in Radiation Protection: A Systematic approach to Safety. Proc. 5th Congress IRPA, Jerusalem, March 1980. Vol. 2. Oxford: Pergamon Press. James, A.C.. Gehr, P., Masse, R., Cuddihy, R.G. Cross,F.T., Birchall, J.S. Durham, J.S. and Briant, J.K. 1991. 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A study of the two-filter tube method for Radon-222. Health Phys. 18:113. Thomas, J.W. 1972. Measurement of radon daughters in air. Health Phys. 23:783. Twomey, S. 1975. Comparison of constrained linear inversion and an iterative algorithm applied to the indirect estimation of the particle size distribution. J. Comp. Phys. 18:188-200. 24 APPEHDIX 1. Summary of results from Continuous Diffusion Battery (CDB) and Electrostatic Two-Filter Tube at location 32LH58 Vent Bag Store Table Al:l Results for daily means and standard deviations of measurements Radon PSEC rp F (Bqm~3» (mWL) X 22-23/7/92 476 25 1.4 0.202 ± 120 1.9 2.4 0.01.3 23-24/7/92 673 26.1 13.1 0.148 ± 96 5.8 6.8 0.024 24-25/7/92 891 33.1 0.5 0.14 ± 32 4.9 1.2 0.02 25-26/7/92 29.1 5.1 ± 3.8 3.4 26-27/7/92 27.1 0.8 ± 2.8 1.9 27-28/7/92 576 23.6 11.5 0.15 ± 86 6.7 6.6 0.03 28-29/7/92 680 25.7 0.5 0.14 ± 46 4.1 2.4 0.02 Appendix 1.1 Vent Bag Store (32LH58): 22-23/7/92 Vent Bag Store (32LH58): 23-24/7/92 i'oof PMC PMC «m *W fTVi !• }l , j 0.1 !• LI P— :0.1 i 23 Vent Bag Store (32LH58): 24-25/7/92 Vent Bag Store (32LH58): 25-26/7/92 ,1000 r lOOr 100 I PMC y^ %«p :0.1 i i 26 26.3 OUtfMrUM Vent Bag Store (32LH58): 26-27/7/92 Vent Bag Store (32LH58): 27-28/7/92 1000 100] I PMC f^^-f^rt* !10 i %• ! 27.3 28.5 •*•>**<•§ Vent Bag Store (32LH58): 28-29/7/92 FIGURES Al:l - Al.7 Summary graphs of radon concentration (Bq m"3), PAEC (mWL), percent unattached fraction (Xfp) and equilibrium ratio (F) as measured with the Continuous Diffusion Battery at the location 32LH58 Vent Bag Store over the period 22 - 29 July 1992. Appendik 1.2 Table Al:2 Results from CDB and Electrostatic TFT : 22 - 23/7/92 Dec PAEC fp GM1 GM2 J-B J-E Av Emax Twomey Day (mWL) X (tun) (run) (mSv/VXM) (mSv/WLM) 22.40 25.7 0 0 186 5.3 7.6 6.4 14.15 14.18 22.41 26.7 8.6 1.3 193 15.6 10.8 13.2 22.54 21.67 22.43 25.9 5.5 1.3 200 11.7 9.3 10.5 19.02 17.27 22.44 24.2 0 1.5 186 5.3 7.5 6.4 13.83 13.86 22.45 24.3 3.9 1.4 178 10.3 9.4 9.8 17.74 15.4 22.47 22.6 1.2 1.3 180 6.9 8.2 7.6 15.27 14.38 22.48 23.7 7 1.1 198 13.6 10.0 11.8 19.32 15.96 22.50 23.3 10.2 1.3 214 17.2 10.7 13.9 22.5 20.83 22.51 21.6 0 0 197 5.0 7.2 6.1 14.27 14.65 22.52 22.3 0.3 1.7 220 4.9 6.6 5.7 13.84 13.84 22.54 22.5 1.9 1.7 212 7.0 7.5 7.2 14.68 13.13 22.55 21.3 0 0 233 4.3 6.2 5.2 12.4 12.46 22.56 23.6 0.3 1.9 208 5.1 7.0 6.0 13.12 12.75 22.58 23.8 0 0 227 4.4 6.3 5.4 12.31 12.15 22.59 24.6 0.8 1.3 227 5.4 6.6 6.0 13.16 12.54 22.61 24.9 5 1.3 263 10.2 7.1 8.7 16.77 14.85 22.62 23.9 0.2 1.6 251 4.4 5.8 5.1 11.98 11.77 22.63 23.3 0 0 220 4.5 6.5 5.5 12.74 12.76 22.65 23.5 0 0 218 4.5 6.6 5.6 13.63 13.65 22.66 23.7 0.5 4.1 241 4.8 6.2 5.5 12.64 12.26 22.68 23.2 0 0 223 4.4 6.4 5.4 12.12 12.19 22.69 24.5 0 0 227 4.4 6.3 5.4 14.77 14.42 22.70 23.5 0 0 231 4.3 6.2 5.3 12.94 13.38 22.72 24.5 0 0 204 4.8 7.0 5.^ 13 12.88 22.73 25.9 4.8 1.6 206 10.7 8.8 9.8 17.84 15.43 22.75 26.2 0.4 1.3 245 4.7 6.0 5.3 12.27 11.9 22.76 27.3 4.2 1.4 266 9.2 6.8 8.0 15.63 12.99 22.77 27.1 0 0 257 4.1 5.6 4.8 12.86 13.38 22.79 27.2 0 0 229 4.3 6.3 5.3 12.79 12.73 22.80 26.6 2.5 1.7 288 7.1 5.7 6.4 13.66 11.95 22.81 27.4 2.8 1.6 239 7.7 7.0 7.3 16.23 15.4 22.83 27.8 5 1.9 226 10.6 8.2 9.4 17.83 15.83 22.84 26.6 0 0 234 4.3 6.2 5.2 13.87 14.23 22.86 27.1 4.3 1.2 276 9.3 6.5 7.9 16.01 14.38 22.87 25.9 0 0 224 4.4 6.4 5.4 12.37 12.59 22.88 26.5 0 0 202 4.8 7.0 5.9 13.57 13.49 22.90 26.9 1 1.9 195 6.2 7.7 6.9 15.05 14.53 22.91 26.1 0 0 187 5.2 7.5 6.4 14.01 14.23 22.93 26.7 0.7 6.7 207 5.6 7.2 6.4 14.07 13.84 22.94 25.7 0 0 206 4.8 6.9 5.8 12.74 12.69 22.95 26.4 0 0 183 5.4 7.7 6.5 14.09 13.95 22.97 26.8 0 1.6 199 4.9 7.1 6.0 12.92 12.8 22.98 26.7 2.5 1.6 209 7.8 7.8 7.8 16.18 14.98 23.00 25.2 0 0 192 5.1 7.4 6.2 13.45 13.51 23.01 25.3 0 0 193 5.1 7.3 6.2 14.05 14.07 23.02 26.9 5.6 1.4 175 12.4 10.2 11.3 19.79 17.88 23.04 25.8 0.4 1.9 183 5.8 7.8 6.8 15.5 15.49 23.05 23.7 0 0 187 5.2 7.5 6.4 14.07 14 23.06 24.4 0.2 8.9 188 5.4 7.6 6.5 13.76 13.52 23.08 24.7 3.1 1.2 196 8.8 8.5 8.7 16.16 13.88 23.09 23.6 0 0 213 4.6 6.7 5.7 13 12.^6 23.11 22.4 0 0 202 4.8 7.0 5.9 13.6 13.72 23.12 23.6 0 0 235 4.3 6.1 5.2 12.72 12.54 23.13 21.5 0 0 254 4.1 5.7 4.9 11.66 11.92 23.15 23.1 0 0 218 4.5 6.6 5.5 12.91 12.88 23.16 22.1 0 0 204 4.8 7.0 5.9 13.71 14.06 23.18 23.0 0 0 205 4.8 6.9 5.9 14.65 15.16 23.19 22.4 0 0 191 5.1 7.4 6.3 14.77 15.42 23.20 23.4 0 0 183 5.4 7.7 6 5 16.33 17.04 23.22 25.3 0 0 196 5.0 7.2 6.1 14.36 14.52 23.23 25.8 0 0 204 4.8 7.0 5.9 12.87 12.85 23.25 26.9 6.8 3.9 258 12.5 7.9 10.2 19.25 15.42 23.26 27.2 0 0 253 4.1 5.7 4.9 11.39 11.32 23.27 26.7 0 0 242 4.2 5.9 5.1 12.73 13.59 23.29 28.8 0.5 7.2 235 4.9 6.3 5.6 13 12.82 23.30 26.8 0 0 216 4.6 6.6 5.6 13.71 14.15 23.31 28.3 0.4 1.5 210 5.2 7.0 6.1 14.03 13.91 Av. 25.0 1.4 216 6.3 7.Z 6.8 14.5 14.0 SD 1.8 2.4 26 2.9 1.1 2.0 2.4 1.8 Appendix 1.3 Table Al:3 Results from CDB and Electrostatic TFT : 23 - 24/7/92 Dec PAEC "5HI 5H2 tt tt—AT- Emax Twomey Day (mWL) X (mSv/WLM) (nm) (nm) (mSv/WLM) 23.35 6.8 15.7 3.7 247 23.6 11.4 17.5 30.19 25.45 23.36 13.1 0 1.1 240 4.2 6.0 5.1 11.78 11.94 23.38 17.6 0 0 294 4.1 4.9 4.5 10.07 13.56 23.39 22.7 16.4 6.9 269 24.4 10.6 17.5 27.83 28.02 23.40 23.6 0 0 257 4.1 5.6 4.8 11.5 11.46 23.42 27.1 21.9 6.4 304 31.3 10.3 20.8 33.1 32.91 23.43 26.8 16.7 4.9 291 24.8 9.6 17.2 29.76 27.73 23.45 27.1 19.7 5.9 297 28.5 10.1 19.3 31.64 30.98 23.46 26.7 17.1 4.3 293 25.3 9.6 17.4 30.72 27.92 23.47 26.2 16.1 6.1 254 24.0 11.2 17.6 28.24 27.48 23.49 24.4 12.8 4.6 277 19.9 9.1 14.5 25.68 23.46 23.50 26.2 13.1 5.4 320 20.5 7.4 13.9 24.91 24.29 23.52 27.4 17.4 3.9 271 25.6 10.8 18.2 31.37 29.34 23.53 29.2 18.7 5.9 289 27.2 10.3 18.7 30.56 29.85 23.54 31.3 20.8 5.7 256 29.8 12.7 21.3 33.85 33.37 23.56 28.5 0 0 215 4.6 6.7 5.6 14.46 14.52 23.57 29.6 12.3 6.5 245 19.4 10.3 14.8 24.27 23.93 23.58 30.0 15 5.5 238 22.8 11.5 17.1 28.02 26.47 23.60 30.6 11.9 3.4 232 19.0 10.6 14.8 25.86 22.88 23.61 29.3 2.9 2 260 7.6 6.5 7.1 16.13 15.4 23.63 30.0 14.8 4 233 22.6 11.7 17.1 29 27.51 23.64 28.6 11.1 7.9 216 18.3 10.9 14.6 23.01 23.67 23.65 30.0 17 4.7 215 25.6 13.3 19.4 31.57 30.18 23.67 29.4 17.1 4.2 229 25.5 12.7 19.1 31.65 30.07 23.68 29.2 20.1 4 229 29.2 13.8 21.5 35.51 32.83 Av. 26.1 13.1 259 20.5 9.9 15.2 26.0 25.0 SD 5.6 6.8 30 8.5 2.4 5.3 7.3 6.5 Appendix lr4 Table Al:4 Results from CDB and Electrostatic TFT : 24 - 25/7/92 Dec PAEC *P ÔM1 ÔM2 J-B J-E Av Ernax Tvomey Day (mtfL) % (nm) (nm) (mSv/VLM) (mSv/WLM) 24.59 11.7 0 0 216 4.6 6.6 5.6 11.53 11.44 24.60 16.7 0 0 215 4.6 6.7 5.6 11.97 12.05 24.62 22.2 0 1.3 199 4.9 7.1 6.0 11.94 11.81 24.63 25.4 0 0 202 4.9 7.1 6.0 11.74 11.73 24.64 28.7 0.1 1.1 197 5.1 7.2 6.2 12.18 11.9 24.66 29.9 0 0 169 5.8 8.1 7.0 13.38 13.22 24.67 32.3 4.6 1 174 11.2 9.9 10.6 16.6 14.4 24.69 31.2 0.3 1.1 180 5.8 7.9 6.8 13.07 12.6 24.70 32.0 2.4 1.1 157 9.1 9.6 9.3 15.56 13.73 24.71 33.3 3.6 1.1 173 10.1 9.5 9.8 16.07 14.23 24.73 32.7 3.1 1.1 195 8.8 8.5 8.7 15.06 13.37 24.74 32.2 0 2.3 186 5.3 7.6 6.4 12.5 12.34 24.76 33.6 5 1.1 187 11.4 9.5 10.4 16.73 15.07 24.77 33.3 0.5 1.1 190 5.8 7.6 6.7 12.97 12.33 24.78 32.0 0 0 186 5.3 7.5 6.4 12.68 12.55 24.80 31.8 0 0 202 4.8 7.0 5.9 12.26 12.19 24.81 31.6 0 1.2 190 5.2 7.4 6.3 12.21 12.07 24.82 31.9 1.5 1 177 7.4 8.5 7.9 13.67 12.4 24.84 32.8 0 2.8 180 5.4 7.7 6.6 12.62 12.49 24.85 32.2 0 0 166 5.9 8.3 7.1 13.34 13.36 24.87 34.0 0 0 175 5.6 7.9 6.8 12.94 12.85 24.88 35.2 4 1.1 193 10.0 9.0 9.5 15.61 13.59 24.89 33.3 0 2 181 5.4 7.7 6.6 12.56 12.44 24.91 33.1 0 1.7 188 5.2 7.5 6.3 12.57 12.34 24.92 31.2 0 0 212 4.6 6.7 5.7 12 11.81 24.94 31.1 0 0 206 4.8 6.9 5.8 12.29 12.09 24.95 31.7 0 0 211 4.7 6.8 5.7 11.49 11.47 24.96 35.2 0 0 1 15.7 16.4 16.1 14.91 12.51 24.98 36.2 0.6 1.1 243 4.9 6.1 5.5 11.4 10.72 24.99 35.7 0 0 247 4.1 5.8 5.0 10.72 10.74 25.01 36.3 0 1.2 271 4.0 5.3 4.7 10.43 10.27 25.02 36.8 0 0 231 4.3 6.2 5.3 11.05 11.13 25.03 36.8 0 0 297 4.1 4.9 4.5 10.4 10.28 25.05 36.6 0 1.1 279 4.0 5.2 4.6 10.19 10.01 25.06 37.5 0 2.1 311 4.2 4.6 4.4 10.22 10.06 25.07 36.7 0 1.1 323 4.4 4.5 4.4 9.45 9.4 25.09 34.6 0 0 326 4.4 4.5 4.4 9.39 9.45 25.10 35.9 0 1.2 335 4.6 4.4 4.5 9.7 9.54 25.12 34.2 0 0 309 4.2 4.7 4.4 9.72 9.76 25.13 34.0 0 0 350 4.9 4.3 4.6 9.33 9.32 25.14 35.6 0 0 325 4.4 4.5 4.4 9.56 9.55 25.16 34.8 0 0 339 4.6 4.3 4.5 9.33 9.34 25.17 35.7 0 0 357 5.0 4.2 4.6 9.61 9.57 25.19 35.7 0 1.6 375 5.5 4.1 4.8 9.47 9.36 25.20 34.1 0 0 333 4.5 4.4 4.5 9.52 9.62 25.21 35.3 0 0 301 4.1 4.8 4.4 10.11 10.06 25.23 35.6 0 0 269 4.0 5.3 4.7 10.42 10.41 25.24 34.4 0 0 281 4.0 5.1 4.6 10.12 10.21 25.26 35.5 0 0 299 4.1 4.8 4.5 9.95 9.94 25.27 35.9 0 0 264 4.0 5.4 4.7 10.54 10.62 25.28 38.1 0 0 254 4.1 5.7 4.9 11 11.02 25.30 40.3 0 0 239 4.2 6.0 5.1 11.42 11.32 25.31 40.7 0 1.3 231 4.3 6.2 5.3 11.31 11.11 Av. 33.1 0.5 236 5.6 6.7 6.1 11.8 11.5 SD 4.9 1.2 69 2.3 2.1 2.1 2.0 1.5 Appendix 1.5 Table Al:5 Results from CDB and Electrostatic TFT : 25 - 26/7/92 Dec PAEC fp GN1 GM2 J-B J-E Av Emax Tvomey Day (mVL) X (run) •»*v-^*ta TABLE Al:6 Results from CDB and Electrostatic TFT : 26 - 27/7/92 Dec PAEC fp GM1 GM2 J-3 J-E Av Emax Twomey Day (mVL) X (nm) (nm) (mSv/WLM) (mSv/WLM) 26.34 29.2 6.8 1.6 259 12.5 7.8 10.2 18.8 18.95 26.35 28.7 3.3 1.5 234 8.4 7.4 7.9 15.62 15.35 26.37 29.6 0 0 179 5.4 7.8 6.6 21.05 20.95 26.38 28.3 4.4 1.9 244 9.6 7.5 8.5 16.93 16.9 26.39 28.3 6 1.5 281 11.5 6.9 9.2 17.49 17.51 26.41 28.0 4.5 1.5 296 9.7 6.1 7.9 15.63 15.44 26.42 29.2 0 0 261 4.0 5.5 4.8 10.95 10.86 26.43 28.4 3.8 1.1 291 8.8 6.0 7.4 13.58 11.71 26.45 28.5 0 0 283 4.0 5.1 4.6 12.2 12.22 26.46 28.0 0.1 1.6 293 4.2 4.9 4.6 10.75 10.53 26.48 28.4 3.5 2.2 287 8.4 6.0 7.2 15.33 15.2 26.49 27.4 0 0 284 4.0 5.1 4.5 12.1 12.25 26.50 27.6 0.1 2.3 250 4.2 5.8 5.0 11.86 11.72 26.52 26.7 0 0 292 4.0 4.9 4.5 12.77 13.06 26.53 27.3 0 0 297 4.1 4.8 4.5 11.56 11.76 "«.55 28.3 0 0 237 4.2 6.1 5.2 15.08 15.26 >6 27.1 0 0 262 4.0 5.5 4.8 12.26 12.39 -•=' _>7 27.9 8.3 1.1 293 14.3 7.2 10.8 18.02 17.18 ^6.59 27.1 0 0 279 4.0 5.1 4.6 10.84 10.8 26.60 27.7 0 0 295 4.1 4.9 4.5 13 13.45 26.62 26.9 0 0 285 4.0 5.0 4.5 10.94 11.08 26.63 27.5 0 0 256 4.1 5.6 4.8 12.75 12.99 26.64 25.9 0 0 287 4.0 5.0 4.5 10.5 10.53 26.66 27.1 0 0 235 4.3 6.1 5.2 15.27 15.4 26.67 27.3 3.8 2.6 256 8.8 6.9 7.9 16.43 16.37 26.68 27.9 4.5 2.1 251 9.7 7.3 8.5 17.12 17.11 26.70 25.8 0 0 217 4.5 6.6 5.6 13.63 14.24 26.71 25.3 1 2.7 253 5.3 6.0 5.7 13.28 13.27 26.73 26.4 0 0 235 4.3 6.1 5.2 13.95 14.26 26.74 25.5 0 0 262 4.0 5.5 4.8 12.58 12.87 26.75 27.1 0 0 263 4.0 5.5 4.8 13.28 13.47 26.77 27.5 0 0 259 4.1 5.6 4.8 12.79 13.01 26.78 27.1 0 0 234 4.3 6.1 5.2 12.14 12.04 26.80 25.1 0 0 248 4.1 5.8 5.0 12.27 12.48 26.81 25.9 0 0 242 4.2 5.9 5.1 13.69 13.92 26.82 26.5 0 0 211 4.7 6.8 5.7 18.39 18.34 26.84 25.1 0 0 222 4.5 6.5 5.5 12.6 12.78 26.85 25.8 3 1.6 251 7.8 6.8 7.3 14.91 14.58 26.87 26.1 0 0 208 4.7 6.8 5.8 13.1 13.22 26.88 26.5 0 0 182 5.4 7.7 6.5 14.38 14.58 26.89 27.1 0 0 205 4.8 6.9 5.9 14.16 14.38 26.91 27.2 0 0 201 4.9 7.1 6.0 14.9 15.31 26.92 27.5 0 2.3 222 4.5 6.5 5.5 11.84 11.61 26.93 27.2 0 0 261 4.0 5.5 4.8 12.89 13.36 26.95 28.0 0 0 243 4.2 5.9 5.0 11.87 11.87 26.96 27.8 0 0 249 4.1 5.8 4.9 14.05 14.76 26.98 29.9 0 0 227 4.4 6.3 5.4 15.07 15.26 26.99 27.8 0 0 261 4.0 5.5 4.8 11.69 11.62 27.00 29.0 0 0 226 4.4 6.4 5.4 14.69 15.03 27.02 27.0 0 0 234 4.3 6.1 5.2 14.04 14.95 27.03 28.6 0 0 211 4.7 6.8 5.7 14.53 14.82 27.05 26.8 0 0 231 4.3 6.2 5.3 12.85 13.42 27.06 29.0 0 0 197 5.0 7.2 6.1 15.63 15.85 27.07 27.6 0 0 244 4.2 5.9 5.0 12.85 13.16 27.09 27.8 0 0 222 4.5 6.4 5.5 13.56 13.99 27.10 28.7 0 0 220 4.5 6.5 5.5 13.95 14.27 27.12 27.9 0 0 229 4.3 6.3 5.3 13.05 13.47 27.13 28.9 0 0 229 4.3 6.3 5.3 14.23 14.94 27.14 28.6 0 0 220 4.5 6.5 5.5 13.74 14.45 27.16 27.9 0 0 235 4.3 6.1 5.2 13.69 14.4 27.17 29.2 0 0 215 4.6 6.7 5.6 15.93 16.37 27.18 29.4 0 0 213 4.6 6.7 5.7 13.95 14.23 27.20 29.8 0 0 222 4.5 6.5 5.5 13.66 13.86 27.21 28.6 0 0 209 4.7 6.8 5.8 15.42 16.19 27.23 29.9 0 0 186 5.3 7.5 6.4 16.81 17.34 27.24 29.0 0 0 211 4.7 6.8 5.7 13.76 14.53 27.25 28.5 0 0 226 4.4 6.4 5.4 12.85 13.37 27.27 29.1 0 0 227 4.4 6.3 5.4 12.83 13.34 27.28 30.0 5.5 1.5 243 11.0 7.9 9.4 17.77 17.82 27.29 24.4 0 0 243 4.2 5.9 5.1 13.64 14.46 27.30 22.8 0 0 195 5.0 7.3 6.1 16.04 16.68 27.31 20.9 0 0 199 4.9 7.1 6.0 16.46 17.15 Av. 27.1 0.8 239 5.4 6.4 5.9 14.1 14.3 SD 2.8 1.9 32 2.3 0.9 1.4 2.1 2.1 TABLE Al:7 Results from CDB and Electrostatic TFT : 27 - 28/7/92 Dec PAEC fp GMl GM2 J-B J-E Av Emax Twomey Day (mWL) X (nm) (nm) (mSv/WLM) (mSv/WLM) 27.40 1.3 0 0 177 5.5 7.9 6.7 19.61 19.58 27.41 3.8 17.1 1.2 191 26.1 14.3 20.2 28.66 29.35 27.42 6.9 13.2 1.1 223 20.7 11.5 16.1 23.58 23.29 27.44 11.4 19.1 1.5 219 28.1 13.9 21.0 32.26 33.43 27.45 12.8 0 0 180 5.4 7.7 6.6 25.14 24.94 27.47 15.2 16.1 2 219 24.4 12.7 18.6 30.3 31.03 27.48 16.7 16.5 2.1 254 24.5 11.3 17.9 30.28 30.86 27.49 17.9 19.4 1.9 238 28.2 13.1 20.7 33.22 34.11 27.51 17.9 11.8 1.9 227 19.0 10.8 14.9 25.55 26.09 27.52 18.7 11.2 1.2 212 18.4 11.1 14.8 23.16 23.54 27.53 19.7 20 2.1 240 29.0 13.2 21.1 34.23 34.97 27.55 19.5 15.4 1.9 231 23.4 11.9 17.7 29.16 29.87 27.56 19.6 17.1 1.7 227 25.5 12.8 19.1 30.82 31.71 27.58 20.6 18.8 1.8 214 27.8 14.0 20.9 32.91 33.91 27.59 20.4 15.2 2 208 23.4 12.8 18.1 29.69 30.43 27.60 21.6 18.8 1.1 204 28.0 14.5 21.2 28.39 28 27.62 20.8 18.4 2 251 26.9 12.1 19.5 32.25 32.97 27.63 20.2 14.1 1.9 200 22.2 12.7 17.5 28.67 29.41 27.65 18.9 16 1.2 246 24.0 11.5 17.7 27.03 27.7 27.66 19.7 0 0 103 8.6 10.8 9.7 28.61 28.38 27.67 20.6 20.2 2 188 30.0 15.7 22.8 35.64 36.59 27.69 20.5 19.1 1.6 196 28.5 14.9 21.7 33.14 34.34 27.70 20.3 18.7 1.4 186 28.2 15.2 21.7 32.25 33.55 27.72 20.7 18.5 1.6 192 27.8 14.9 21.3 32.81 33.98 27.73 20.2 13.1 1.5 180 21.5 13.1 17.3 27.3 28.21 27.74 19.6 11.7 2.2 178 19.8 12.6 16.2 27.23 27.76 27.76 20.0 10.9 1.5 207 18.2 11.2 14.7 24.13 24.77 27.77 19.9 9.9 2.2 225 16.6 10.1 13.4 23.85 24.21 27.78 21.0 15.3 1.4 187 24.0 13.7 18.9 28.85 29.89 27.80 19.9 12.4 2.7 241 19.5 10.4 15.0 26.56 26.8 27.81 19.1 11 1.6 225 18.0 10.5 14.3 24.16 24.74 27.83 19.6 0 0 129 7.4 9.7 8.5 23.67 23.74 27.84 19.4 0 0 145 6.7 9.1 7.9 22.37 22.33 27.85 19.7 15.3 1.2 223 23.3 12.3 17.8 26.42 26.94 27.87 20.3 15 1.2 187 23.6 13.6 18.6 27.38 28.16 27.88 21.0 17.4 1.4 212 26.1 13.6 19.8 30.25 31.35 27.90 24.7 13.8 1.8 206 21.8 12.4 17.1 27.86 28.64 27.91 28.4 17.4 3 216 26.0 13.4 19.7 32.94 33.12 27.92 29.1 11.8 1.4 202 19.4 11.8 15.6 25.04 25.76 27.94 30.6 13.7 2 210 21.6 12.2 16.9 28.09 28.71 27.95 31.2 14.2 2 202 22.3 12.7 17.5 28.84 29.54 27.97 31.8 15.2 2 210 23.4 12.8 18.1 29.78 30.46 27.98 31.5 12.3 1.9 212 19.8 11.5 15.7 26.44 27.04 27.99 30.5 6.8 2.7 175 13.9 10.7 12.3 23.23 23.36 28.01 31.1 11.2 2.8 206 18.6 11.4 15.0 26.26 26.51 28.02 30.6 12 1.6 215 19.4 11.3 15.3 25.32 26 28.03 30.2 8.8 2.1 189 16.0 11.0 13.5 23.51 23.94 28.05 30.3 10.7 2.1 179 18.5 12.2 15.4 25.97 26.52 28.06 30.2 6.4 2.7 183 13.2 10.3 11.7 22.45 22.57 28.08 29.1 0 0 143 6.7 9.1 7.9 22.66 22.6 28.09 30.0 16.2 2.6 198 24.9 13.7 19.3 31.86 32.26 28.10 29.0 0 0 136 7.0 9.4 8.2 26.12 26.02 28.12 28.7 7.2 2.4 172 14.5 11.0 12.7 22.72 23.01 28.13 28.1 0 0 148 6.5 8.9 7.7 24.01 23.93 28.15 28.6 10.7 1.8 211 17.8 11.0 14.4 24.46 25.02 28.16 27.8 13.9 2.9 202 22.0 12.6 17.3 29.39 29.62 28.17 27.7 12.6 1.6 178 20.9 13.0 17.0 27.29 28.14 28.19 26.9 8.7 1.5 185 16.0 11.1 13.5 22.66 23.19 28.20 27.7 14.4 1.2 196 22.7 13.0 17.8 26.78 27.54 28.22 27.4 0 0 157 6.2 8.6 7.4 21.05 21.02 28.23 26.7 0 0 161 6.1 8.4 7.3 16.24 16.54 28.24 29.6 14 1.6 189 22.3 13.1 17.7 28.27 29.16 28.26 28.9 7.8 2.2 188 14.8 10.6 12.7 22.54 22.88 28.27 29.8 0 0 141 6.8 9.2 8.0 24.85 24.69 28.28 29.4 9.1 1.4 213 15.8 10.3 13.1 21.79 22.2 28.30 29.6 11.2 2.9 183 19.1 12.2 15.6 27.05 27.29 28.31 29.9 13.9 2.2 196 22.1 12.8 17.4 29 29.56 28.33 30.0 17.1 1.5 184 26.3 14.6 20.4 31.25 32.41 28.34 28.4 7.4 2.5 167 14.9 11.3 13.1 23.21 23.51 28.35 28.7 6 1.8 171 13.0 10.5 11.8 20.84 21.15 28.37 28.7 12.1 1.5 184 20.1 12.5 16.3 26.02 26.83 28.38 28.6 7.1 2.7 198 13.7 10.0 11.8 21.76 21.95 Av. 23.6 11.5 196 19.3 11.H 15.e 26.9 27.4 SD 6.6 6.0 29 6.8 1.8 4.2 3.9 4.1 ftMtndiii I. 8 TABLE A1.8 Results from CDB and Electrostatic TFT : 28- 29/7/92 Bee PXEC rp CHI GHZ 7^1 J^E Av Emax Twomey Day (mWL) X (ran) (nm) (mSv/WLM) (mSv/WLM) 28.43 6.9 0 0 282 4.0 5.1 4.6 12.8 13.13 28.44 13.1 0 0 262 4.0 5.5 4.8 11.62 11.54 28.46 18.7 0 0 252 4.1 5.7 4.9 13.33 13.6 28.47 23.1 0 0 228 4.4 6.3 5.3 17.81 17.93 28.4o 26.1 0 0 220 4.5 6.5 5.5 16.8 17.04 28.50 28.7 0 0 207 4.7 6.9 5.8 20.92 20.76 28.51 29.9 0 0 188 5.2 7.5 6.4 19.65 19.78 28.52 30.3 0 0 189 5.2 7.4 6.3 19.09 19.28 28.54 29.5 0 0 204 4.8 7.0 5.9 14.82 15.44 28.55 30.4 0 0 207 4.7 6.9 5.8 17.15 17.52 28.57 29.7 0 0 203 4.8 7.0 5.9 17.37 17.66 28.58 30.6 0 0 194 5.0 7.3 6.2 16.26 16.59 28.59 29.6 0 0 204 4.8 7.0 5.9 18.99 19.04 28.61 32.8 16.7 3.4 251 24.8 11.5 18.2 31.48 31.48 28.62 30.6 0 0 196 5.0 7.2 6.1 18.58 18.55 28.64 30.6 0 0 180 5.4 7.7 6.6 19.32 19.37 28.65 29.8 0 0 222 4.5 6.5 5.5 18.45 18.54 28.66 28.9 0 0 207 4.7 6.9 5.8 14.76 15.21 28.68 28.8 0 0 215 4.6 6.7 5.6 15.55 15.88 28.69 29.0 0 0 216 4.6 6.6 5.6 16.43 17.11 28.71 29.9 0 0 232 4.3 6.2 5.3 14.18 14.45 28.72 29.1 0 32.5 325 4.4 4.5 4.4 15.R3 16.75 28.73 29.2 0 0 233 4.3 6.2 5.2 14.63 14.99 28.75 29.6 0 0 265 4.0 5.4 4.7 15.4 15.75 28.76 29.2 0 0 256 4.1 5.6 4.8 15.33 15.65 28.77 27.5 0 39 404 6.5 4.1 5.3 15.04 16.54 28.79 29.5 10.8 2.7 279 17.4 8.4 12.9 23.93 24.09 28.80 28.3 0 21.4 403 6.5 4.1 5.3 19.27 19.46 28.82 27.6 0 27.8 439 8.1 4.3 6.2 18.75 19.28 28.83 27.8 0 22.4 480 10.5 4.7 7.6 20.23 20.47 28.84 28.2 0 22.5 397 6.3 4.1 5.2 18.67 18.93 28.86 28.7 0 30.5 381 5.7 4.1 4.9 19.86 20.29 28.87 28.0 0 22.7 394 6.2 4.1 5.1 19.87 20.14 28.89 27.6 0 23.9 372 5.4 4.1 4.8 18.46 18.75 28.90 26.3 0 27.7 356 5.0 4.2 4.6 16.45 16.95 28.91 26.4 0 0 219 4.5 6.5 5.5 15.48 16.68 28.93 27.8 0 0 185 5.3 7.6 6.4 22.3 22.11 28.94 26.3 0 0 221 4.5 6.5 5.5 14.4 15.12 28.96 26.6 0 0 205 4.8 7.0 5.9 16.01 16.9 28.97 24.7 0 0 199 4.9 7.1 6.0 15.03 15.46 28.98 23.9 0 28.1 316 4.3 4.6 4.4 18.67 19.14 29.00 22.9 0 0 179 5.5 7.8 6.6 18.56 18.93 29.01 21.7 0 0 186 5.3 7 6 6.4 16.53 17.95 29.02 21.9 0 0 171 5.7 8.1 6.9 15.71 16.45 29.04 23.1 0 0 178 5.5 7.8 6.6 18.85 19.18 29.05 23.4 3.6 2.4 220 8.9 7.9 8.4 17.04 17.01 29.07 23.4 0 0 187 5.2 7.5 6.4 14.8 15.64 29.08 22.6 0 33.3 295 4.1 4.9 4.5 17.04 17.99 29.09 23.0 0 0 232 4.3 6.2 5.3 17.51 17.76 29.11 22.1 0 38.4 392 6.1 4.1 5.1 16.26 17.8 29.12 22.4 0 29.5 464 9.5 4.5 7.0 17.45 18.47 29.14 21.6 0 0 255 4.1 5.6 4.9 13 14.29 29.15 24.0 0 0 218 4.5 6.6 5.5 18.85 18.96 29.16 24.7 0 25.3 442 8.3 4.3 6.3 21.61 21.98 29.18 23.9 0 0 196 5.0 7.2 6.1 15.11 15.59 29.19 24.3 0 0 205 4.8 7.0 5.9 16.14 16.51 29.21 24.4 0 0 211 4.7 6.8 5.7 15.63 16.19 29.22 24.3 0 0 212 4.6 6.7 5.7 13.31 13.87 29.23 26.2 0 0 200 4.9 7.1 6.0 16.94 17.36 29.25 24.8 0 0 214 4.6 6.7 5.6 15.18 15.81 29.26 25.5 0 39.1 322 4.3 4.5 4.4 18.42 19.22 29.27 25.3 0 37.4 354 5.0 4.2 4.6 17.83 18.72 29.29 23.9 0 0 193 5.1 7.3 6.2 15.73 16.69 29.30 23.0 0 0 196 5.0 7.2 6.1 17.08 17.95 29.32 22.0 0 40.5 327 4.4 4.5 4.4 17.92 19 29.33 21.7 0 0 172 5.7 8.0 6.9 16.13 17.25 29.34 21.6 0 0 184 5.3 7.6 6.5 17.38 18.29 29.36 22.9 0 0 215 4.6 6.7 5.6 15.76 16.73 Av. 25.7 0.5 257 5.7 6.3 6.0 17.2 17.7 SD 4.2 2.4 82 3.0 1.4 1.9 2.9 2.7 APPENDIX 2. Summary of results from Battery-powered sampling sites: Continuous TFT and Continuous fp. TABLE A2:l Results for dally mean and standard deviations of measurements at each site. Radon PAEC Tp- 3 (Bq.m ) (mVL) X Day 1 : 22 - 23/7/92 : 32F Purple 10 SIMBA Rig Average 2107.7 104.7 1.44 0.174 1557.6 88.7 0.87 0.038 Day 2 : 23 - 24/7/92 36DC Extraction Site Average 481.0 14.8 1.73 0.124 ± 167.2 3.3 0.71 0.057 Day 3 : 24 - 25/7/92 38NB46. RAN DRIVE Average 1214.3 63.1 3.37 0.197 ± 221.9 9.8 1.33 0.042 Day 4 : 25 - 27/7/92 Underground Store Average 473.1 18.9 4.10 0.159 ± 122.9 4.2 3.72 0.055 Day 5 : 27 - 28/7/92 41LJ61 Substation Average 685.0 14.1 8.37 0.078 ± 133.0 3.4 4.40 0.019 Day 6 : 28 - 29/7/92 32LH58 Vent Bag Store Average 587 28.6 1.70 0.191 ± 134 4.3 1.42 0.053 J^BBAfifUjk^M^ 32F Purple 10 (Siraba Rig) : 22-23/7/92 36DC Extraction Site: 23-24/7/93 IMOOr TI0000 t'0000 ;I000 5 ^*'v-vYv»vA^n\ [100 1 PAEC jt^t^^H u^i^N^ 255 24 25 38NB46 RAM Drive: 24-25/7/92 Underground Store: 25-27/7/92 • OuOO '1000 I itOOb f T ~KW* ^fv* ^yj /y/v 100 I rlQO PABC %m •A -[0.1 0 0.01 25 •VOJMtriW 41LJ61 Substation: 27-28/7/92 32LH58 (Vent Bag Store): 28-29/7/92 10000 1000 v it 000 1000 j>'W7^iw«v Raton A VHV/WVIAA \^VW/JV I 100 !" PAK PACC I : ;10 *«W i v**"**m t ^o^l /y/^v^V-^W^A 0.1 j- J 0.01 V 27.5 28 28.J 29 OwOUMtUB FIGURE A2:1 - A2:6 Summary graphs of radon concentration (Bq m-3) , PAEC (mWL) , percent unattached fraction (Xfp) and equilibrium ratio (F) as measured at each of the battery-powered sampling sites, during the period 22 - 29 July 1993. Table A2:2 Results from Continuous TFT and Continuous fp: 22-23/7/92 SITE : 32F Purple 10 Simba Rig Dec. Radon PAEC Xfp ', Day (Bq m-3) (mWL) 22.46 821.3 27.574 7.907 0.124 22.47 916.8 45.182 1.471 0.182 22.49 1413.4 63.553 1.699 0.166 22.50 1699.9 74.450 0.976 0.162 22.52 1890.9 83.221 1.622 0.163 22.53 1871.8 89.367 1.487 0.177 22.54 2101 93.038 1.361 0.164 22.56 1394.3 76.576 1.437 0.203 22.57 1508.9 64.019 1.589 0.157 22.58 1069.6 52.042 1.317 0.180 22.60 1222.4 43.903 2.223 0.133 22.61 974.1 38.504 1.456 0.146 22.63 1050.5 38.056 1.801 0.134 22.64 840.4 38.222 0.924 0.168 22.65 1031.4 35.149 1.831 0.126 22.67 764 37.591 1.270 0.182 22.68 1031.4 34.634 1.499 0.124 22.70 1088.7 33.986 1.161 0.116 22.71 1107.8 34.916 1.249 0.117 22.72 916.8 34.800 1.492 0.140 22.74 1203.3 34.484 1.686 0.106 22.75 1757.2 41.411 1.354 0.087 22.77 1699.9 55.564 1.196 0.121 22.78 2674 80.845 1.181 0.112 22.79 2884.1 116.193 1.340 0.149 22.81 3075.1 152.987 0.882 0.184 22.82 4049.2 178.053 0.945 0.163 22.83 3762.7 194.663 0.843 0.191 22.85 4278.4 210.776 1.143 0.182 22.86 4564.9 212.454 1.153 0.172 22.88 4641.3 228.417 1.091 0.182 22.89 4679.5 236.888 1.096 0.187 22.90 4316.6 248.300 1.187 0.213 22.92 3991.9 252.287 1.210 0.234 22.93 4354.8 248.034 1.080 0.211 22.95 4507.6 249.479 1.198 0.205 22.96 5042.4 252.237 1.202 0.185 22.97 5080.6 253.881 0.941 0.185 22.99 4794.1 261.074 0.931 0.201 23.00 5023.3 263.549 0.867 0.194 23.02 4393 268.084 1.022 0.226 23.03 4736.8 265.110 1.237 0.207 23.04 4775 267.868 1.077 0.208 23.06 3800.9 246.622 1.212 0.240 23.07 2788.6 192.737 0.926 0.256 23.08 2120.1 140.811 1.180 0.246 23.10 1871.8 112.655 1.253 0.223 23.11 2196.5 86.626 1.486 0.146 23.13 1298.8 64.832 0.737 0.185 23.14 974.1 51.261 1.053 0.195 23.15 974.1 46.527 1.071 0.177 23.17 916.8 36.993 1.403 0.149 23.18 725.8 34.983 1.662 0.178 23.20 783.1 32.591 0.956 0.154 23.21 725.8 32.607 1.465 0.166 23.22 840.4 31.046 2.274 0.137 23.24 534.8 31.029 1.539 0.215 23.25 859.5 30.182 1.582 0.130 23.27 630.3 32.640 1.781 0.192 23.28 706.7 32.790 1.520 0.172 23.29 553.9 32.956 1.323 0.220 23.31 496.6 36.162 0.976 0.269 23.32 725.8 35.713 0.988 0.182 23.33 592.1 33.770 1.660 0.211 23.35 649.4 34.518 1.504 0.197 23.36 878.6 31.910 2.343 0.134 23.38 974.1 34.069 2.133 0.129 23.39 706.7 36.843 2.367 0.193 ^rmtmm^^T^ TABLE A2:3 Results from Continuous TFT and Continuous fp: 23-24/7/92 — r i - r - — SITE : 36DC Extraction Site Dec Radon PAEC Up F Day ( Bq.BT3) ( mVL) 23.38 534.8 13.372 1.553 0.093 23.60 382.0 14.834 1.820 0.144 23.62 534.8 14.501 1.145 0.100 23.63 496.6 13.089 2.379 0.098 23.64 439.3 12.541 0.993 0.106 23.66 515.7 13.106 1.901 0.094 23.67 439.3 13.754 1.057 0.116 23.68 496.6 13.920 2.088 0.104 23.70 458.4 11.777 2.468 0.O95 23.71 248.3 12.325 2.022 0.184 23.73 515.7 13.488 1.078 0.097 23.74 362.9 13.073 2.065 0.133 23.75 439.3 13.256 2.976 0.112 23.77 611.2 12.658 2.133 0.O77 23.78 439.3 11.860 3.501 0.100 23.80 611.2 13.089 0.793 0.079 23.81 305.6 ?2.242 3.053 0.148 23.82 477.5 15.033 1.796 0.116 23.84 210.1 12.458 1.667 0.219 23.85 611.2 13.056 2.704 0.079 23.87 477.5 11.794 2.113 0.091 23.88 458.4 13.870 1.946 23.89 630.3 13.754 1.057 0.112 23.91 687.6 12.741 2.771 0.081 23.92 496.6 12.375 2.013 0.O69 23.93 496.6 13.073 0.953 0.092 23.95 496.6 11.727 2.125 0.097 23.96 477.5 13.256 0.627 0.087 23.98 420.2 13.189 1.102 0.103 23.99 401.1 14.136 0.734 0.116 24.00 458.4 14.418 2.016 0.130 24.02 286.5 14.086 1.474 0.116 24.03 401.1 13.521 1.689 0.182 24.05 401.1 13.588 1.222 0.125 24.06 343.8 11.927 1.567 0.125 24.07 286.5 13.372 1.553 0.128 2i.09 229.2 13.388 3.567 0.173 24.10 458.4 12.641 0.986 0.216 24.12 649.4 13.920 1.641 0.102 24.13 267.4 14.784 1.124 0.079 24.14 324.7 15.332 1.761 0.205 24.16 343.8 13.970 1.486 0.175 24.17 458.4 14.850 0.979 0.150 24.18 382.0 15.166 2.875 0.120 24.20 649.4 16.727 1.117 0.147 24.21 515.7 18.621 0.781 0.095 24.23 477.5 18.189 2.626 0.134 24.24 725.8 19.966 1.872 0.141 24.25 687.6 20.664 1.206 0.102 24.27 630.3 21.212 1.664 0.111 24.28 764.0 23.604 1.056 0.125 24.30 534.8 22.591 1.287 0.114 24.31 382.0 22.790 1.184 0.156 24.32 477.5 21.279 2.537 0.221 24.34 191.0 22.574 1.472 0.165 Average 481.0 14.846 1.734 0.124 t 167.2 3.316 0.713 0.057 TABLE A2:» Results froa Continuous TFT and Continuous fp: 24-25/7/92 SITE : 38NB 46 RAM DRIVE Dec Radon PAEC Xfp F Day IBq *f3] mWL 24.342 764.0 11.794 8.099 0.057 24.356 840.4 29.601 4.349 0.130 24.369 496.6 42.939 2.563 0.320 24.383 553.9 49.002 3.390 0.327 24.397 706.7 56.261 2.989 0.295 24.411 955.0 59.766 2.640 0.232 24.425 974.1 59.916 2.149 0.228 24.439 1050.5 59.799 3.542 0.21i 24.453 1012.3 62.440 3.159 0.228 24.467 1012.3 60.198 2.449 0.220 24.481 916.8 60.464 2.370 0.244 24.494 1146.0 61.029 2.960 0.197 24.508 1126.9 62.540 2.424 0.205 24.522 1203.3 59.152 2.843 0.18? 24.536 1184.2 61.726 2.927 0.193 24.550 1069.6 61.145 3.871 0.2i;: 24.564 1012.3 61.726 2.994 0.226 24.578 1337.0 62.357 2.964 0.173 24.592 1337.0 61.809 3.460 0.171 24.606 1317.9 59.451 3.213 0.167 24.619 1146.0 64.882 1.952 0.209 24.633 1279.7 68.404 2.580 0.198 24.647 1222.4 69.301 1.708 0.210 24.661 1642.6 71.975 2.048 0.162 24.675 1432.5 68.653 1.421 0.177 24.689 1184.2 69.816 1.784 0.218 24.703 1489.8 70.397 1.622 0.175 24.717 1146.0 71.776 1.620 0.232 24.731 1260.6 71.028 1.462 0.208 24.744 1241.5 73.852 1.265 0.220 24.758 1547.1 71.726 1.418 0.172 24.772 1165.1 73.902 1.461 0.235 24.786 1413.4 78.553 1.163 0.206 24.800 1298.8 75.912 1.286 0.216 24.814 1184.2 76.228 1.280 0.238 24.828 1184.2 75.480 1.485 0.236 24.842 1241.5 73.885 1.911 0.220 24.856 1413.4 70.763 2.465 0.185 24.869 1031.4 74.583 2.561 0.268 24.883 1298.8 68.055 3.692 0.194 24.897 1241.5 65.447 3.141 0.195 24.911 1337.0 58.819 4.307 0.163 24.925 1623.5 61.527 4.725 0.140 24.939 1566.2 60.148 4.246 0.142 24.953 1413.4 60.464 4.361 0.158 24.967 955.0 61.793 4.133 0.239 24.981 1184.2 63.803 3.808 0.199 24.994 1031.4 62.141 5.146 0.223 25.008 1241.5 57.872 4.234 0.172 25.022 1528.0 53.720 5.295 0.130 25.036 1279.7 57.889 5.273 0.167 25.078 1317.9 51.062 5.652 0.143 25.092 1375.2 53.786 4.941 0.145 25.106 1069.6 56.577 3.817 0.196 25.119 1508.9 62.357 4.562 0.153 25.133 1298.8 67.440 2.925 0.192 25.147 1069.6 63.155 3.880 0.218 25.161 1432.5 63.803 3.059 0.165 25.175 1241.5 63.603 4.701 0.190 25.189 1394.3 60.414 4.984 0.160 25.203 1317.9 61.676 4.242 0.173 25.217 1394.3 62.906 4.555 0.167 25.231 1337.0 65.082 3.318 0.180 25.244 1375.2 66.743 4.138 0.180 25.272 1146.0 68.686 3.507 0.222 25.286 1165.1 66.560 3.743 0.211 25.300 1107.8 68.171 3.289 0.228 25.314 1298.8 65.979 4.091 0.188 25.328 1547.1 68.321 3.860 0.163 25.3A2 1317.9 67.175 4.142 0.189 25.356 1489.8 68.404 3.976 0.170 Average 1214.3 63.194 3.376 0.197 1 221.9 9.847 1.329 0.042 TABLE A2:5 Results fro« Continuous TFT and Continuous fp: 25 - 26/7/92 SITE : Underground Store ______Dec Radon PAEC Xîp F Psy (Bq n-3) mML 25.45 974.1 25.46 668.5 25.48 611.2 25.49 649.4 25.50 553.9 3.073 38.514 0.021 25.51 496.6 7.093 19.321 0.053 25.53 611.2 10.299 8.266 0.062 25.54 573 10.814 9.985 0.070 25.56 477.5 12.973 7.522 0.101 25.57 534.8 14.751 7.883 0.102 25.58 477.5 17.292 6.484 0.134 25.60 515.7 16.644 6.487 0.119 25.61 592.1 19.053 5.558 0.119 25.63 496.6 15.299 5.429 0.114 25.64 515.7 16.927 5 888 0.121 25.65 611.2 16.063 5.041 0.097 25.67 592.1 17.724 5.858 0.111 25.68 343.8 15 847 5.110 0.171 25.70 553.9 16.279 5.867 0.109 25.71 649.4 16.578 5.762 0.094 25.72 611.2 15.681 4.899 0.095 25.74 496.6 15.000 5.537 0.112 25.75 496.6 15.946 4.036 0.119 25.76 343.8 16.594 4.755 0.179 25.78 401.1 14.917 5.290 0.138 25.79 439.3 14.667 4.105 0.124 25.81 305.6 15.432 4.306 0.187 25.82 515.7 15.398 4.450 0.110 25.83 458.4 15.182 4.376 0.123 25.85 420.2 15.598 4.393 0.137 25.86 496.6 15.049 3.449 0.112 25.88 324.7 15.814 4.202 0.180 25.89 496.6 15.647 5.573 0.117 25 90 592.1 15.448 3.495 0.097 25.92 477.5 17.790 3.035 0.138 25.93 477.5 18.704 4.663 0.145 25.95 420.2 18.438 5.293 0.162 25.96 458.4 19.252 3.451 0.135 25.97 401.1 17.907 4.174 0.165 25.99 553.9 17.890 3.830 0.120 26.00 420.2 18.255 5.460 0.161 26.01 725.8 16.860 4.557 0.086 26.03 553.9 18.023 4.378 0.120 26.04 458.4 18.289 2.498 0.148 26.06 496.6 18.621 3.568 0.139 26.07 458.4 18.222 2.621 0.147 26.08 534.8 18.687 4.667 0.129 26.10 649.4 18.272 3.523 0.104 26.11 248.3 20.265 3.484 0.302 26.13 687.6 18.554 5.148 0.100 26.14 611.2 17.574 4.135 0.^06 26.15 553.9 14.601 9.670 0.098 26.17 458.4 17.010 6.226 0.137 26.18 573 15.697 6.878 0.101 26.20 573 17.043 4.386 0.110 26.21 630.3 16.312 4.073 0.096 26.22 458.4 16.777 4.208 0.135 26.24 477.5 16.245 4.090 0.126 26.25 496.6 15.647 7.033 0.117 26.26 267.4 15.265 6.393 0.211 26.28 305.6 15.564 5.603 0.188 26.29 458.4 16.162 5.267 0.130 26.31 324.7 15.000 5.952 0.171 26.32 362.9 14.800 5.892 0.151 26.33 458.4 15.398 6.742 0.124 26.35 420.2 15.614 4.654 0.137 26.36 362.9 15.249 2.859 0.155 26.38 382 16.113 3.351 0.156 26.39 362.9 13.903 3.584 0.142 26.40 343.8 15.448 5.242 0.166 Appendix 2.6 Tabl* A2:5 (Cont.) Results from Continuous TFT and Continuous fp: 26-27/7/92 SITE : Underground Store (cont ) "Bee Radon PAEC «P P Day (Bq m-3) mVL 26.42 362.9 18.505 3.030 0.189 26.43 401.1 19.086 3.372 0.176 26.45 515.7 21.428 2.229 0.154 26.46 362.9 20.897 2.683 0.213 26.47 439.3 20.299 2.864 0.171 26.49 401.1 19.086 3.916 0.176 26.50 362.9 19.269 3.556 0.196 26.51 477.5 18.222 3.874 0.141 26.53 343.8 17.824 2.912 0.192 26.54 382 17.176 3.385 0.166 26.56 362.9 16.744 3.720 0.171 26.57 477.5 15.863 3.927 0.123 26.58 725.8 17.059 2.069 0.087 26.60 687.6 21.328 2.434 0.115 26.61 324.7 23.106 1.797 0.263 26.63 439.3 24.684 3.785 0.208 26.64 496.6 24.867 2.422 0.185 26.65 573 22.342 2.788 0.144 26.67 477.5 21.744 2.578 0.168 26.68 305.6 20.199 3.289 0.245 26.70 458.4 23.720 2.714 0.191 26.71 420.2 20.282 1.331 0.179 26.72 439.3 19.335 2.792 0.163 26.74 668.5 22.358 3.622 0.124 26.75 592.1 22.940 2.263 0.143 26.76 382 22.441 2.498 0.217 26.78 362.9 21.328 3.505 0.217 26.79 534.8 19.136 3.364 0.132 26.81 382 21.029 2.567 0.204 26.82 362.9 20.797 2.496 0.212 26.83 477.5 19.767 2.101 0.153 26.85 191 20.232 2.258 0.392 26.86 382 19.501 2.662 0.189 26.88 324.7 19.966 1.976 0.228 26.89 324.7 18.172 3.656 0.207 26.90 305.6 20.315 1.431 0.246 26.92 458.4 19.053 4.032 0.154 26.93 324.7 19.750 3.259 0.225 26.95 305.6 19.601 4.131 0.237 26.96 324.7 20.049 2.796 0.228 26.97 305.6 18.338 2.944 0.222 26.99 458.4 19.269 3.233 0.156 27.00 592.1 19.933 3.958 0.125 27.01 401.1 19.800 2.622 0.183 27.03 343.8 20.431 3.354 0.220 27.04 496.6 19.867 4.181 0.148 27.06 687.6 11.096 2.559 0.114 27.07 477.5 21.943 3.123 0.170 27.08 248.3 20.249 3.486 0.302 27.10 534.8 20.714 2.907 0.143 27.11 362.9 19.966 2.704 0.204 27.13 496.6 22.093 1.034 0.165 27.14 324.7 22.308 1.303 0.254 27.15 649.4 19.750 1.367 0.113 27.17 477.5 22.973 2.169 0.178 27.18 630.3 22.8u/ 1.457 0.134 27.20 362.9 26.827 1.238 0.274 27.21 343.8 27.757 0.673 0.299 27.22 324.7 26.428 1.021 0.301 27.24 573 27.358 1.214 0.177 27.25 592.1 27.425 1.136 0.171 27.26 592.1 25.016 1.245 0.156 27.28 515.7 25.797 1.449 0.185 27.29 611.2 27.092 0.996 0.164 27.31 592.1 27.342 0.987 0.171 27.32 611.2 27.591 1.430 0.167 27.33 31.262 0.863 27.35 30.116 1.448 27.36 28.554 1.018 27.38 28.621 1.524 Average 473.1 18.9 4.09 0.159 ± 122.8 4.264 3.72 0.055 Appendix 2.7 TABLE A2:6 Results from Continuous TFT and Continuous fp: 27-28/7/92 SITE : 41LJ61 Substation Bee Räaön JSEC ïlp 1 Da^ (Bq m-3) mVL 27.357 382 3.056 14.946 0.030 27.371 592 6.362 9.138 0.040 27.385 516 10.648 2.925 0.076 27.399 573 11.810 2.461 0.076 27.413 516 12.691 3.599 0.091 27.426 573 15.531 3.342 0.100 27.440 745 14.800 1.824 0.074 27.454 802 15.382 2.295 0.071 27.468 649 16.810 1.853 0.096 27.482 745 18.289 2.498 0.091 27.496 745 18.721 1.886 0.093 27.510 840 20.448 3.148 0.090 27.524 1070 20.913 2.681 0.072 27.538 783 19.418 2.352 0.092 27.551 611 21.810 2.380 0.132 27.565 649 20.697 2.508 0.118 27.579 917 19.485 3.303 0.079 27.593 649 19.368 4.288 0.110 27.607 573 19.551 4.036 0.126 27.635 1012 15.149 7.127 0.055 27.649 688 16.378 6.719 0.088 27.663 993 17.425 4.886 0.065 27.676 688 14.883 8.650 0.080 27.690 669. 13.820 9.165 0.076 27.704 497 12.907 10.779 0.096 27.718 611 12.076 14.615 0.073 27.732 783 12.076 13.239 0.057 27.746 669 13.256 11.905 0.073 27.760 821 13.837 8.253 0.062 27.774 821 14.136 8.373 0.064 27.788 936 12.508 11.620 0.049 27.801 898 12.907 7.561 0.053 27.815 802 11.976 10.229 0.055 27.829 669 11.428 12.355 0.063 27.843 669 10.980 11.157 0.061 27.857 516 10.432 14.132 0.075 27.871 688 11.511 13.889 0.062 27.885 649 10.531 15.773 0.060 27.899 649 10.349 17.055 0.059 27.913 783 9.668 18.471 0.046 27.926 611 10.315 14.291 0.062 27.940 554 10.066 14.439 0.067 27.954 649 10.963 12.121 0.062 27.968 649 11.229 12.389 0.064 27.982 821 11.412 10.007 0.051 27.996 458 11.761 13.418 0.095 28.010 611 11.794 10.387 0.071 28.024 745 12.508 11.786 0.062 28.038 535 13.023 9.247 0.090 28.051 707 13.521 7.525 0.071 28.065 726 11.860 7.178 0.060 28.079 535 14.269 7.858 0.099 28.093 707 13.704 10.909 0.072 28.107 554 12.940 13.318 0.086 28.121 535 12.691 11.453 0.088 28.135 726 10.648 13.846 0.054 28.149 745 11.927 15.494 0.059 28.163 478 12.873 10.645 0.100 28.176 707 12.973 11.68* 0.068 28.190 497 13.787 6.777 0.103 28.204 630 14.136 9.988 0.083 28.218 649 14.468 7.319 0.082 28.232 573 16.129 6.179 0.104 28.246 649 17.076 7.174 0.097 28.260 707 16.860 7.266 0.088 28.274 745 16.860 5.911 0.084 28.288 860 16.628 7.742 0.072 28.301 611 15.066 7.993 0.091 28.329 649 16.378 6.719 0.093 28.343 726 16.345 4.700 0.083 28.357 783 17.591 3.895 0.083 28.371 821 17.840 3.142 0.080 Average 685 14.145 8.374 C.078 ± 133 3.439 4.404 0.019 Appendix 2.8 TABLE A2:7 Results from Continuous TFT and Continuous fp: 28 - 29/7/92 SITE : 32LHS8 Vent Bag Store Dec Radon PAEC Xfp P Day (Bq m-3) mVL 28.410 554 28.451 764 28.465 592 4.547 12.842 0.028 28.479 630 12.505 2.958 0.073 28.493 688 18.251 1.493 0.098 28.507 764 22.970 2.458 0.111 28.521 688 26.645 2.265 0.143 28.535 458 26.738 2.257 0.216 28.549 669 29.370 1.458 0.163 28.563 955 28.810 1.081 0.112 28.576 688 31.005 1.821 0.167 28.590 611 30.320 1.733 0.184 28.604 707 32.158 1.029 0.168 28.618 630 29.323 1.261 0.172 28.632 840 31.628 0.985 0.139 28.646 497 33.622 1.158 0.251 28.660 592 30.476 1.150 0.190 28.674 688 31.395 1.054 0.169 28.688 497 30.974 1.383 0.231 28.701 497 30.382 1.153 0.226 28.715 458 30.055 1.360 0.243 28.729 611 31.924 1.037 0.193 28.743 707 30.429 2.047 0.159 28.757 554 31.036 0.878 0.207 28.771 630 30.803 1.769 0.181 23.785 535 30.305 0.899 0.210 28.799 630 33.917 1.664 0.199 28.813 707 30.881 1.135 0.162 28.826 458 31.706 1.535 0.256 28.840 611 30.351 1.154 0.184 28.854 516 29.884 1.954 0.214 28.868 669 30.087 1.812 0.167 28.882 497 31.877 1.404 0.238 28.896 458 32.485 1.318 0.262 28.910 707 29.666 1.509 0.155 28.924 860 32.298 1.507 0.139 28.938 497 30.320 1.220 0.226 28.951 439 31.348 1.056 0.264 28.965 592 31.083 1.816 0.194 28.979 478 29.946 1.170 0.232 28.993 630 30.149 1.162 0.177 29.007 669 29.105 1.672 0.161 29.021 611 28.996 1.477 0.176 29.035 458 26.847 2.320 0.217 29.049 630 25.337 1.383 0.149 29.063 267 25.851 1.883 0.358 29.076 420 27.003 1.514 0.238 29.090 497 27.019 2.017 0.201 29.104 439 27.408 1.847 0.231 29.118 420 26.520 1.321 0.234 29.132 649 26.240 0.964 0.150 29.146 420 28.000 1.460 0.247 29.160 669 25.633 1.443 0.142 29.174 554 27.548 1.201 0.184 29.188 420 28.218 1.173 0.248 29.201 649 29.682 1.443 0.169 29.215 630 29.277 1.729 0.172 29.229 535 30.180 0.774 0.209 29.243 458 30.055 1.749 0.243 29.257 516 31.099 1.314 0.223 29.271 420 29.557 1.120 0.260 29.285 401 30.927 1.133 0.285 29.299 592 30.242 1.223 0.189 29.313 554 31.971 1.340 0.214 29.326 516 28.685 1.561 0.206 29.340 439 28.451 2.326 0.240 29.354 936 28.000 1.738 0.111 29.368 764 29.728 1.964 0.144 29.382 458 29.432 2.183 0.238 29.396 611 26.785 2.108 0.162 29.410 898 27.392 1.421 0.113 29.437 26.427 2.873 Average 587 28.65 1.702 0.191 ± 134 4.320 1.419 0.053 Appendix ?.9