“Health Phys. Abstracts，Volume 122,Number 3

ASimple,Rapid,ComparativeEvaluationofMultipleProductsforDecontaminationofActinide-contaminatedRatSkinExVivoNina M. Griffiths1, Karine Devilliers1, Pierre Laroche2, Anne Van der Meeren1

(1.Laboratory of RadioToxicology, CEA, Paris-Saclay University, Bruyères le Chtel, France;2.Direction of Health, Security, Environment & Radioprotection, ORANO, Paris, France)

Abstract:Decontamination of skin is an important medical countermeasure in order to limit potential internal contamination by radionuclides such as actinides. Minimizing skin surface contamination will ultimately prevent internal contamination and subsequent committed effective dose as well as contamination spreading. The decontamination agents tested on a rat skin ex vivo model ranged from water to hydrogel wound dressings. A surfactant-containing cleansing gel and calixarene nanoemulsion with chelation properties demonstrated marked decontamination efficacies as compared with water or the chelator DTPA. Based on efficacy to remove different actinide physicochemical forms from skin, the results demonstrate that all products can remove the more soluble forms, but a further component of emulsifying or tensioactive action is required for less soluble forms. This indicates that for practical purposes, successful decontamination will depend on identification of the actinide element, the physicochemical form, and possibly the solvent. This study offers a simple, quick, cheap, reproducible screening method for efficacy evaluation of multiple products for removal of a variety of contaminants.

Keywords: operational topics; actinides; decontamination; skin

Health Phys. 122(3):371-382; 2022

DispersionSimulationsofRadonDischargesbetweenNeighboringBuildingsandTheirSensitivitytoMeteorology,DischargeRate,andBuildingGeometry

Luke Lebel, Aneesh John, Volodymyr Korolevych1

(1.Canadian Nuclear Laboratories, Chalk River, ON, K0J 1J0, Canada)

Abstract:In northern climates, it is common to install the discharges of radon sub-slab depressurization systems near ground level. However, this also elevates the ground level outdoor radon concentrations and raises the possibility of radon re-entrainment into homes. The study aims to assess outdoor radon concentrations near above-ground-level discharges along the surfaces of an emitting building and its close neighbor and identify parameters that most influence the dilution. This study employs a series of computational fluid dynamics calculations to assess concentrations along the exhaust-facing and non-exhaust-facing surfaces of the buildings. Different meteorological, venting, and building geometry parameters are explored. Boundary conditions for the CFD calculations are based on field measurements of the ground-level wind speeds and seasonal air temperatures and atmospheric stabilities. Outdoor concentrations can be as high as 7% of the discharge gas, although these become smaller at greater distances from the vent. The direction of the prevailing wind is a particularly important parameter, as it influences the formation of circulating building cavities and building wakes where radon could accumulate. The wind speed, atmospheric stability, and season (plume buoyancy) also have important influences on the outdoor radon concentrations, as do the velocity of the vent system and the size of the buildings. The study has assessed the dilution of the radon-laden exhaust gas and determined the outdoor concentrations that can be expected under a variety of conditions. These results can be used to inform regulators about the potential for radon re-entrainment into homes.

Keywords: emissions; atmospheric; exposure; population; radioactivity; airborne; radon

Health Phys. 122(3):383-401; 2022

AssessmentofRadiologicalHazardofRadioactiveWasteUsingEffectiveorOrganDoses:HowThisMayAffectFinalWasteDisposal

V.K. Ivanov1,2, S. Yu. Chekin1, A.V. Lopatkin2,3, A.N. Menyajlo1, M.A. Maksioutov1, K.A. Tumanov1, P.V. Kashcheeva1, S.S. Lovachev1

(1.A. Tsyb Medical Radiological Research Center, branch of NMRRC of Ministry of Health, Russian Federation, Obninsk;2. Joint Stock Company PRORYV, Moscow;3. N.A. Dollezhal Scientific Research and Design Institute of Energy Technologies (NIKIET) of Rosatom State Corporation, Moscow)

Abstract:The radiological hazard of spent nuclear fuel and radioactive waste slows down further development of nuclear energy systems. The authors evaluate timescales required to reduce the radiological hazard of accumulated waste to the reference level of natural uranium that had been consumed by the nuclear energy system. The estimate of this time scale depends on the radiological hazard metric used in the calculations. In this study, two metrics are compared: (1) the committed effective dose based on ICRP Publication 72 and (2) the lifetime radiation risk calculated with use of organ doses and recent radiation risk models recommended by ICRP. The effective dose of the waste reaches the reference level 300 y after the accumulation of waste, while lifetime attributable risk of waste converges to natural uranium in 100 y. Thus, the lifetime attributable risk (LAR) metric is more appropriate to estimate the time requirements for radioactive waste storage and disposal. The effective dose metric significantly overestimates this timescale as it is not intended for quantifying radiation-related risks.

Keywords: dose equivalent; effective dose; nuclear fuel cycle; nuclear reactor

Health Phys. 122(3):402-408; 2022

SpatialVariabilityandBehaviorofBackgroundRadonConcentrationsinAmbientAirintheSanMateoBasinoftheGrantsMineralBelt

Arthur S. Rood1, Randy Whicker2

(1.K-Spar Inc., 4835 W. Foxtrail Lane, Idaho Falls, ID 83402;2.Environmental Restoration Group, 8809 Washington Street NE, Albuquerque, NM 87113)

Abstract:A modeling study and analysis of measurement data was conducted in the San Mateo basin near the former Homestake Mining Company of California’s mill site located north of Milan, NM, to understand the spatial variability of background radon and identify a suitable background station. Recent guidance from the US Nuclear Regulatory commission clarifies the requirement that dose assessments of existing facilities be based on environmental measurements at the facility’s unrestricted boundary instead of predictive modeling. Background is important because it is subtracted from radon measured at the boundary for dose calculations. The current background station lies on the slopes above the wash floor. The mill site contains two tailing piles with a total area of 1.03 km2that in 2019 emitted 1,750 mBq m-2s-1from the larger of the piles and 320 mBq m-2s-1from the smaller pile. Atmospheric transport modeling was conducted to facilitate understanding of the movement of radon in the San Mateo wash bottom and surrounding hillsides. The model was validated using emission and measurement data from the nearby Ambrosia Lake mining region. The modeling, in combination with current measurements and previous studies, indicated the wash floor has characteristically higher radon concentrations than the slopes above the wash. This phenomenon was attributed to (1) higher radon soil flux in the alluvial sediments that make up the wash floor, (2) nocturnal drainage flow that results in a pooling of radon on the wash floor, and (3) inversion conditions that trap radon in a shallow air mass on the wash floor during late evening and early morning hours. Using a regression of predicted and observed radon concentrations, a background concentration of 25.7 Bq m-3was derived that was close to that measured at background stations about 4 km north of the tailings pile and on the San Mateo wash floor.

Keywords: mining; uranium; modeling； air; radiation; background; radon

Health Phys. 122(3):409-432; 2022

Radium-223DichlorideinPeritonealDialysateFollowingTreatmentofMetastaticCastration-resistantProstateCancer

Christopher Saganich, Michael Zgaljardic1

(1.Medical Health Physics, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065)

Abstract:Radium-223 dichloride was administrated to a patient with castration-resistant metastatic prostate cancer (mCRPC) undergoing in-home peritoneal dialysis. The peritoneal dialysate and tubing sets were collected following four treatment cycles and analyzed for removable contamination, dose rate, and radioactivity. The purpose of the study was to assess radiation safety concerns and compare data with patients having normal renal function. Sixty-two liters of dialysate in 22 samples were collected over 4 mo. The mean surface dose rate of the dialysate bags was 0.16 μSv h-1(range 0.11-0.23 μSv h-1). The highest measured removable surface activity was 150 dpm per 100 cm2. The mean cumulative percent of administered activity was 1.7% (range 1.4%-1.9%). The mean concentration of223Ra in dialysate was 4.0 kBq L-1(range 0.56-14.1 kBq L-1). There was no association between the measured223Ra activity in dialysate with peritoneal dwell time or the number of exchanges following administration. The measurement of the211Bi and223Ra ratio in the dialysate compared with a standard showed an increase of 23% by 40 h post administration. The data presented suggest that223Ra dialysate can be safely managed in the home without risk of radiation dose or contamination if minimal precautions are taken. Patients with normal renal function have been shown to excrete up to six times more223Ra in urine compared to those undergoing hemodialysis or peritoneal dialysis. A potential consequence may be an increase in223Ra activity transiting GI tract leading to intestinal effects.

Keywords: cancer; health effects; radiation; medical; radium

Health Phys. 122(3):433-439; 2022

AReviewoftheEffectoftheIntermediateFrequencyElectromagneticFieldsonFemaleReproduction

Stephanie Mohammed1

(1.Department of Physics, Faculty of Science and Technology, The University of the West Indies, Trinidad, WI)

Abstract:The use of intermediate frequency (IF) fields in occupational equipment and domestic appliances is increasing dramatically. The World Health Organization consistently points out that there is a lack of scientific evidence to assess the reproductive risk in female species within the exposure limits as stated by the International Commission on Non-Ionizing Radiation Protection. The purpose of this review paper is to review the available literature on the effects of IF EMR on female reproduction in all species and to fully understand these effects. A literature review of experimental, epidemiological, in vivo, and in vitro literature from the 1 800 s to the present was conducted. Very few studies have been conducted on the effects of IF on female reproduction. The study of women in their workplace, laboratory rats and mice, and chicken embryos has yielded conflicting results on the dangers of IF. Some reports consider IF harmful during pregnancy, while other results show an insignificant (p<0.05) correlation between the exposed group and the unexposed groups. The experiments conducted so far restrict several parameters such as field strength, frequency, and modulation to draw definitive conclusions. In two experiments, this frequency range is considered safe for non-invasive treatment of cancerous and noncancerous ovarian cells in the initial phase. Evaluation of the IF range on reproduction should be a priority for research. This review shows that there are few reports in this field, and they all contradict each other on whether the IF field is harmful or not. Nonetheless, IF is used in medicine to treat cancer and is currently being researched for non-cancerous cells. More comprehensive IF studies should be conducted to address the limitations in these summary studies.

Keywords: health effects; pregnancy; radiation; medical; radiation; nonionizing

Health Phys. 122(3):440-444; 2022

ApplyingALARAPrinciplesintheDesignofNewRadiologicalFacilities

Samuel I. Baker, Sunita Kamboj1

(1.Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439)

Abstract:The application of ALARA (as low as reasonably achievable) principles to the design of new radiological facilities at Argonne National Laboratory provides a consistent radiation safety basis for future facility operations. This paper discusses the criteria for controlling radiation exposure and the techniques applied to meet those criteria for two new facilities. Argonne is a US Department of Energy (US DOE) laboratory, and the criteria are specified in the DOE Rule found at 10 CFR 835. The worst case radionuclides and their source strengths are chosen. Local shielding is specified to reduce dose rates to less than 50 μSv h-1at 30 cm from the shielding, thus avoiding the creation of a radiation area. Version 6 of the Los Alamos National Laboratory radiation transport code MCNP is then used to calculate the dose rates elsewhere. Based on the results of the calculations, design modifications are made to meet the design objectives criteria.

Keywords: as low as reasonably achievable (ALARA); radiation protection; safety standards; shielding

Health Phys. 122(3):452-462; 2022