P - Poster Session Exhibit Hall A 18:00 - 19:00
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P.1 Academic Radiation Safety
The Enhancement of a Radiation Safety Research Laboratory Inspection Program at a Large Academic University RM Ranade*, University of Washington, Seattle
; MJ Zittle, University of Washington, Seattle; PG Campbell, University of Washington, Seattle
Abstract: The University of Washington (UW) is a public institution of higher education and is one of the premier academic research institutions in the United States. In addition, UW is a leader in biological research, supporting two major hospitals and a medical school. Therefore, ionizing radiation is extensively used at UW in research and development, education, calibration, and clinical diagnosis and treatment of patients. Ensuring all regulatory requirements are met and cultivating user involvement to maintain compliance are momentous challenges of a radiation safety program. The UW Environmental Health and Safety (EH&S) Radiation Safety (RS) Office has developed an enhanced research laboratory inspection program that meet these challenges for the UW EH&S RS ionizing radiation safety research laboratory program. Since the launch of the enhanced RS research laboratory inspection program in January 2020, there has been improvement in monitoring by the UW EH&S RS Office and the UW Radiation Safety Committee for the UW EH&S RS ionizing research laboratory safety program.
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P.2 Emergency Response
FREE WEB-BASED ASSESSMENT SCIENTIST AND GAMMA SPECTROSCOPY TRAINING PROVIDED BY US DOE AND US EPA TO IMPROVE NUCLEAR INCIDENT RESPONSE S Fournier, Sandia National Laboratories
; M Enghauser, Sandia National Laboratories; A Kalinowski*, Sandia National Laboratories; J Griggs, US Environmental Protection Agency; R Litman, Environmental Management Support, Inc; J Chapman, ) NNSA NA-84 Office of Nuclear Incident Response Nuclear Emergency Support Team; J Gill, FEMA Nuclear Incident Response Team
Abstract: Through a partnership with the Department of Homeland Security Federal Emergency Management Agency Nuclear Incident Response Team (DHS FEMA-NIRT) the US DOE Consequence Management (CM) program and US EPA have developed automated web-based training modules on nuclear emergency assessment science and gamma spectroscopy for CM in an effort to assist Radiological Emergency Preparedness (REP) programs and laboratories across the country build future spectroscopists and assessment scientists. Topics range from basic introductory material to more advanced concepts like performing parent-progeny decay corrections and identifying and correcting for true coincidence summing biases in measurements for laboratory analysis and emergency response dose assessment calculations and operation of the Sandia National Laboratory (SNL) software Turbo FRMAC for assessment scientists. A fully automated, self-paced version of AS-100 “Introduction to Assessment Science” course is now available online for any interested students. This poster will highlight what training is available, how to access it, and open up a discussion with the radiological emergency dose assessment and radiochemistry community on what the needs are for training like this to help bridge the knowledge gaps left behind in this field.
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P.3 Environmental Monitoring
¬¬ Review of radium accumulation and effects in algae: a work-in-progress AK Gonzales*, Clemson University
; SE Donaher, Clemson University; J Wang, Clemson University; BA Powell, Clemson University; NE Martinez, Clemson University
Abstract: In the early 1900s, radium was nearly ubiquitous in popular culture – numerous novelty items were developed, from so-called “cure-alls” to self-luminous dials. This radium boom led to the radium dial painter tragedy and left many locations (now Superfund sites) contaminated. Moreover, the US Navy used radium dials in many of its ships, and now there are sediment sites impacted by trace radioactive materials, i.e., dials and radium paint chips. There is a lack of literature on the effects of low-level radium on marine biota, including microorganisms like algae, which functions a primary producer in numerous marine food webs. Moreover, algae are valuable indicator organisms for ecosystem health as it is very sensitive to its environment. This presentation reviews the current literature available on the sorption and uptake of radium in algae as well as the bioaccumulation and transfer of radium to higher trophic levels in marine food webs. It also discusses the methodology of a work-in-progress investigating accumulation and biological effects of radium exposure on marine algae. Algae will be grown in aquaria, with a minimum of triplicate samples in each exposure group. At the end of the exposure period, some organisms will be sampled for effects monitoring and the remainder will be sampled for determination of radionuclide content. By assessing the impact of radium on health of model marine biota such as algae, the U.S. Navy can develop science-based remediation goals that are both protective of ecological health and cost-effective.
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P.4 Environmental Monitoring
Radioactive Potassium-40 in Water Sfoteners B Billa*, Porters Chapel Academy
; M Beitollahi, University of Utah; S Adzanu, Alcorn State University; M Atkins, Alcorn State University; Je Billa
Abstract: Water is one of the essential entities in human lives. In the U.S., citizens living in urban areas completely rely on city water, while a vast majority of rural Americans rely on ground water. Depending on the location, water sources may consist of salts and to remove salts present in water sources, consumers add water softeners prior to using water for various purposes. One of the southern states in the U.S., the state of Mississippi consists of ~52% of rural population and vastly relies on ground based water systems. It is highly possible that citizens in these rural areas tend to use water softeners to reduce salts such as Calcium, Magnesium, and others. One of the prominently used water softeners, Potassium Chloride (KCl), consists of radioactive Potassium-40 and depending on the source of the potassium; water softeners consist of varied amounts of radioactive (K-40). In this context, a pilot study is proposed with a goal of theoretically estimating and experimentally measuring K-40 via the gamma spectroscopic analyses. Based on the obtained results, a statistical comparison of theoretical and experimental K-40 concentrations was performed using a one-tailed t-test at 95% confidence interval.
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P.5 Environmental Monitoring
How safe are Organic Fertilizers- A Radioactivity Assessment Study J Hooker*, Alcorn State University
; J Billa, Alcorn State University; S Adzanu, Alcorn State University; J Adjaye, Alcorn State University
Abstract: Living organisms directly or indirectly rely on soil based resources and therefore there is a possibility of uptake of these NORMs through food, air, and water. Naturally Occurring Radioactive Materials (NORMs) are part of our lives as they naturally exist in the geological environment. Enhanced NORM results from activities such as burning coal, production and usage of fertilizers, oil and gas industries. Lately, there is a great interest in usage of organic fertilizers in farming industry. Typically, organic fertilizers are derived from animal matter, excretes and vegetable matter, and thus they are widely used to feed both soils and plants. Depending on the geological location and presence of human activities near the repository (pit), there is a possibility of presences of NORM and/or man-made radioisotopes even in organic fertilizers. In this approach, a study was performed on locally produced (Mississippi based) organic fertilizers. A set of 20 organic fertilizer samples were analyzed for presence and quantification of NORM and man-made radioisotopic concentrations via the gamma spectrometry. Based on the obtained radioactivity values and considering the fertilization information based on type of crop, the amount of radiation introduced per acre and per crop type is estimated. Results include radioactivity concentration values and amount of radioisotopes introduced into farmland as a result of fertilization.
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P.6 Environmental Monitoring
Radon Levels in Ground Water of Alcorn State University Campus D Jackson*, Alcorn State University
; J Billa, Alcorn State University; S Adzanu, Alcorn State University; J Adjaye, Alcorn State University
Abstract: Located in rural Mississippi in the counties of Claiborne and Jefferson, Alcorn State University serves approximately 5,000 students and 500 staff members. Water supply for ASU is provided by wells (Ground Water) located on the campus. Ground water primarily consists of Radon (Rn-222), a colorless and odorless radioactive gas that is naturally present in soils and is one of the daughters of U-238. Depending on the geography, types of soil, and types of rocky materials in the earth’s crust, the levels of radon significantly varies. According to the EPA, it is recommended that the community water suppliers must provide drinking water to the citizens with Radon levels no higher than 4,000 pCi/L. Per EPA, Claiborne and Jefferson counties are sunder radon zone 3 (Counties with predicted average indoor radon screening levels less than 2 pCi/L). However, there is limited data on the levels of Radon in groundwater within the region of interest. A pilot study is executed to measure Radon concentration levels in water collected from wells that supply water to ASU community using an Alpha Guard Professional Radon Meter. Multiple samples were collected (at least 10 samples for week and for up to 3 months) and analyzed for Radon concentration so that statistically justifiable and reliable results are obtained. The presented data consist of a comparison of measured radon concentration values in drinking water evaluated in this study to the EPA’s recommendations on radon concentration in drinking water.
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P.7 Environmental Monitoring
Radium Concentrations in Sludge Samples from Water Treatment Facilities D James*, Alcorn State University
; J Billa, Alcorn State University; S Adzanu, Alcorn State University; J Adjaye, Alcorn State University
Abstract: Water is one of the basic means for survival of living organisms. Prior to supplying water to their citizens, the City and County authorities tend to purify water by following advanced procedures as water is collected from sources such as ground, river, lake etc. Being part of earth’s crust/ surface, water tends to dissolve nutrients and elements that may be present in soils. Levels of these nutrients in water are highly dependent on location, geological formation of ground, and presence of human activities near the water source. In this context, a study is conducted on evaluation of radioactivity levels in sludge samples collected from treatment plants three different cities located in South-West Mississippi. Sludge samples collected from the treatment plants are dried and analyzed for the presence of natural radioactivity (40K, 226Ra, 232Th etc.) as well as possible man-made radioactivity. Sample analyses are performed using a high purity germanium detector with a relative efficiency of 35%. Further, the obtained radioactivity values are compared with the documented values of average 40K, 226Ra, 232Th concentrations in drinking water sludge samples.
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P.8 Environmental Monitoring
Radioactivity in Fish Native to Lower Mississippi Watersheds F Shoulders*, Alcorn State University
; J Billa, Alcorn State University; S Adzanu, Alcorn State University; J Adjaye, Alcorn State University; Je Billa
Abstract: Being part of surface water based resources, fish tend to uptake various elements/pollutants (if present) that may have been naturally or artificially (due to man-made activities) present in soils and water bodies. Levels of these pollutants could be impacted by factors such as size of the fish, naturally present elements in soils and water, and more importantly presence of man-made activities in the vicinity of water bodies. In this context, five different kinds of fish native to lower Mississippi region – Channel catfish (Ictalurus punctatus), Garfish (Belone belone), Small Mouth Buffalo/Gaspagoo (Ictiobus bubalus), Small Mouth Buffalo (Ictiobus bubalus), and Breams (Abramis brama) are collected and analyzed using a 35% efficient solid-state detector for man-made and naturally occurring isotopes. Doses resulted from consumption of these fish is estimated considering the levels of experimental radioactivity values. The overall goal is to assess the dose from consumption of local fish and compare the obtained doses to the Nuclear Regulatory Commission (NRC) recommended safety dose levels for the public.
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P.9 External Dosimetry
Assessment of personal dosimeter response with energy and geometry of exposure for evaluating the reconstruction of organ dose for Korean radiation workers. HY Jeong*, KIRAMS, Han Yang Univ
; YS Chung, Han Yang Univ; JS Kim, KIRAMS; JR Yoo, KIRAMS; SH Park, KIRAMS
Abstract: To assess the health effects induced by occupational radiation exposure, it requires reconstructing the organ-absorbed dose from personal dosimeter, reported of personal dose equivalent (Hp(10)).
In the general organ dose reconstruction process, the organ dose can be calculated using conversion coefficients for Hp(10) to air kerma(Hp(10)/Ka) provided in the ICRP 47 and 51 reports and air kerma to organ dose(DT/Ka) of the ICRP 103 report. However, this organ dose reconstruction process has some bias including geometry in dosimeter calibration and structural difference of phantom. To overcome these limitations, we investigated the practical dosimeter responses (Hp(10)/Ka) based on an actual irradiation experiments reflecting the Korean working condition and various factors such as source energy, exposure geometry, and dosimeter reading algorithms, etc.
The method for the experiment examined the dosimeter response to 1 mGy photon beam (N100, N150, N300 and Cs-137) irradiation in anteroposterior(AP), right lateral(RLAT), and rotational(ROT) geometry for the three different kinds of dosimeter which have been used as a regal dosimeter for radiation workers (thermoluminescence dosimeter(TLD), glass dosimeter, and optically stimulated luminescent dosimeter(OSLD)). A female RANDO Phantom was also used in addition to the slab and male RANDO Phantom for the dose assessment of female workers. To evaluate the effect of dosimeter response on organ-dose, it was applied to representative exposure scenarios by industry. And we compared with the conversion coefficient Hp(10)/Ka calculated by ICRP 74 and 51.
As a result, dosimeter response of the slab phantom is mostly higher than the RANDO phantom and it was lowest in the order of LAT, ROT and AP geometry. In the case of applying exposure scenario, the overall dosimeter response value was evaluated to be lower than conversion coefficient Hp(10)/Ka provided by ICRP. These results can make the organ dose increase. Thus, it might significantly affect the reliability of epidemiological study.
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P.10 External Dosimetry
Further characterization of BeO detectors for applications in external and medical dosimetry E Kara*, Helmholtz Zentrum München, Neuherberg, Germany
; C Woda, Helmholtz Zentrum München, Neuherberg, Germany
Abstract: Beryllium oxide (BeO) shows high potential for use in medical applications as an Optically Stimulated Luminescence (OSL) dosimeter due to its nearly tissue-equivalence, in contrast to the currently more frequently employed Carbon-doped Aliminum Oxide (Al2O3:C) (Bos, 2001; Bulur and Göksu, 1998). However, investigations of BeO dosimeters are still limited (Sommer et al., 2008, 2007), as compared to the plentiful literatures of Al2O3:C in medical dosimetry (Yukihara and McKeever, 2008). This study aims to investigate the suitability of BeO dosimeters for medical dosimetry applications by using the OSL technique and estimating the errors due to the read-out process. BeO dosimeters were characterized in terms of annealing temperature and duration, effect of preheat treatment on short time fading, angular dependence and instrumental errors in laboratory conditions. The uncertainty assessment was carried out to evaluate the achievable precision and accuracy in measurement of absorbed dose for clinical research in more realistic conditions. In summary, BeO dosimeters have potential to be used in clinical applications for dose evaluation but applying an optimized measurement procedure is necessary due to the complex luminescence mechanism of the material.
E.K. is supported by the Program of Selection and Placement of Students for Overseas Postgraduate Education (YLSY) scholarship, awarded by the Ministry of Higher Education of the Republic of Turkey.
References
Bos, A.J.J., 2001. High sensitivity thermoluminescence dosimetry. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 184, 3–28.
Bulur, E., Göksu, H.Y., 1998. OSL from BeO ceramics: New observations from an old material. Radiat. Meas. 29, 639–650.
Sommer, M., Freudenberg, R., Henniger, J., 2007. New aspects of a BeO-based optically stimulated luminescence dosimeter. Radiat. Meas. 42, 617–620.
Sommer, M., Jahn, A., Henniger, J., 2008. Beryllium oxide as optically stimulated luminescence dosimeter. Radiat. Meas. 43, 353–356.
Yukihara, E.G., McKeever, S.W.S., 2008. Optically stimulated luminescence (OSL) dosimetry in medicine. Phys. Med. Biol. 53, R351–R379.
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P.11 Homeland Security
The Gap in NRC Financial Assurance and Insurance Liability for Blood and Research Gamma Irradiators J Kamen*, Mount Sinai
; E Abraham, Mount Sinai; D Perricelli, Healthcare Risk Advisors; S Price, Alliance insurance Services, Inc
Abstract: In 2019, a federal contractor accidently infiltrated a 2,900 curie Cesium-137 sealed source, releasing a few grams of its contents. As a result, thirteen people were contaminated as well as all seven floors of the University of Washington research building which housed the radiation source. Estimates for remediation, clean-up costs and lost revenue exceeded $150 million. The magnitude of this cost has prompted licensees in possession of such radioactive sources to question if their insurance coverage is adequate to cover a large scale incident and if coverage for such exposure even exists.
In this article, we identify potential gaps in the NRC Financial Assurance (FA) regulation and commercially available insurance policies by evaluating several possible radioactive material release scenarios and assessing associated risks, damages, and accountability. While insurance can mitigate the cost or remediation, it is unlikely that sufficient limits would exist to fully protect healthcare institutions from direct financial liability in the event that their radioactive sources are implicated in an NCBR (nuclear, biological, chemical, or radiological) or mass contamination event.
This paper seeks to outline the risks and liability to healthcare institutions can be significantly reduced by removing such gamma irradiators rather than seeking to insure against the cost of remediation in the event of a leak and/or exposure. As such, licensees are encouraged to explore financial incentives offered by U.S. government programs to, not only dispose of their present gamma irradiator sources at no cost, but also provide financial support to replace them with alternative technologies.
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P.12 Industrial HP
Characterization of Airborne Particulates Containing Naturally Occurring Radioactive Materials in Welding Rod Manufacturing Industries JH Park*, Kyung Hee University
; BM Lee, Kyung Hee University; SY Lee, Kyung Hee University; MS Kim, Kyung Hee University; KP Kim, Kyung Hee University
Abstract: The welding rod is manufactured by using minerals including Naturally Occurring Radioactive Materials (NORM) such as zircon sand. In manufacturing process, airborne particulates containing NORM are occurred, thus the workers can be subjected to exposure to radiation by inhalation of airborne particulates. The ICRP recommended that inhalation dose assessment should be performed using actual measurement data of particulate properties. The objective of this study was to investigate particulate properties at welding rod manufacturing industries. The particulate size distribution and concentration at various processing area were analyzed with cascade impactor. The mass density of raw material and residue was measured by pycnometer. The shape of particulates was analyzed using SEM. The radioactivity concentration of Ra-226, Ra-228 contained U/Th decay series was analyzed with HPGe. Airborne particulate concentration by size was distributed log-normally with maximum at range 5.8 - 9.0 ?m. Mass densities of zircon sand and dust in workplaces were in range 2.8 - 5.8 g/cm3. Shape of airborne particulates appeared as spherical shape for all sampling area. Accordingly, the shape factor of unity could be assumed. The radioactivity concentrations of zircon sand were 1.6 – 3.5 Bq/g for Ra-226 and 0.3 – 0.8 Bq/g for Ra-228. The radioactivity concentrations of dust in workplace were 0.05 – 0.2 Bq/g for Ra-226 and 0.02 – 0.2 Bq/kg for Ra-228. The level of radioactivity concentrations of dust in workplace were relatively lower than zircon sand. It is because the dilution of the radioactivity concentration occurred during mixing processing with the other material. This study results will be used as database for safety management in NORM industries. *This work was supported through the KoFONS using the financial resource granted by NSSC. (No. 2105035)
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P.13 Instrumentation
Investigation of Unexpected Effluent Peaks on Cyclotron Vault PM-11 Sodium Iodide Detector E Silvestrini, Northwell Health, Manhasset
; CJ North*, Hofstra University, Hempstead
Abstract: BACKGROUND:
A Camberra offline cyclotron effluent monitoring system with a time resolution on the order of 10 minutes was upgraded to a MediSmarts online system by Rotem using a sampling time of 7 seconds. Readings on the order of 0.1 pCi/mL were observed from detectors in the vault effluent duct that corelated with beam on rather than effluent release. Late in 2021, new atypical readings on the order of 1 pCi/mL were observed in the same vault effluent duct with a curve bearing similarity to F-18 decay.
METHOD:
The cyclotron vault is located underground adjacent to the main building. Five floors above, in the machine room, a PM-11 detector inserted in the vault exhaust stack measures the effluent release due to normal cyclotron operation. One floor above, on the roof and past the filter bank, another PM-11 detector monitors the effluent from the hot cells. GM-41 area detectors located in the vault maze were used to compare the graphs of beam-on times versus vault and hot cell releases. Data from the PM-11 detectors were processed and analyzed in IgorPro9.
RESULTS:
Considered sources for the readings correlating with beam-on were skyshine or ionization of vault air. A radiation protection survey was performed above ground over the cyclotron vault and found to agree with the background readings of the radiation protection survey from installation, indicating that skyshine is unlikely. The planning documents for shielding from installation discuss the potential for neutron activation of vault air on comparable levels to those observed. The most likely source was therefore determined to be ionization of vault air. The later readings that display a potential decay curve are likely attributable to F-18 collected on the filter banks located on the roof of the building.
CONCLUSION:
The shielding surrounding the vault reduces the neutron flux to background levels, eliminating the probability of skyshine being produced and detected during normal cyclotron operations. Ionization of vault air is expected from the GE PET Trace cyclotron operating at 17MeV. It is determined that O-15 is being produced in the vault and detected by the PM-11 detectors, correlating with beam-on times due to its 2-minute half-life. As F-18 effluent from the hot cells is trapped on the filter bank, it interferes with detection of the ionized atmosphere in the vault.
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P.14 Internal Dosimetry
Determination of time-dependent counting efficiency to consider the exposure scenario using the transportable radiation detection instruments M Park*, Korea Institute of Radiological and Medical Sciences
; J Yoo, Korea Institute of Radiological and Medical Sciences; HS Kim, Korea Institute of Radiological and Medical Sciences; S Lee, Korea Institute of Radiological and Medical Sciences
Abstract: Radiological release into environment due to the nuclear or radiological accidents cause the internal contamination in unmanageable number of individuals potentially contaminated. In that case, there would be a need to monitor these individuals rapidly to mitigate the associated health risks and to assign the priorities of medical resources in the accident area. Transportable radiation detection instruments, including handheld survey meter and portal monitor, are widely available to assess the internal contamination in the initial phase of accident. The internal distribution of intake radionuclide is varied depending on the exposure scenario, including the intake time, radionuclide, route and the biodistribution can be calculated using the biokinetic model. Therefore, this study aims to estimate the time-dependent counting efficiency by taking into account the biokinetic model of intake radionuclide, employing Monte Carlo simulation. Two commercial transportable radiation detection instruments were used in this study: NaI(Tl) based survey meter and plastic-scintillator based portal monitor. The counting efficiencies were obtained using adult mesh type reference computational phantoms, and those phantoms were used to simulate individuals with inhaled and ingested radionuclides. The relationship between the counting efficiencies and time since intake were derived to calculate the time-dependent counting efficiencies of both instruments. In the initial phase of accident, the counting efficiencies were fluctuated because the intake radioactivity rapidly transferred to other organs. After 15 days, the counting efficiencies were stabilized due to the uniform biodistribution of intake radionuclide. The time-dependent counting efficiencies could be practically used in the radiation emergency and help to provide more accurate measurements for radiological triage.
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P.16 Risk Assessment
A Risk Comparison between Lifestyle, Socioeconomic Status, and Radiation among Japanese Nuclear Workers (J-EPISODE) S Kudo*, Radiation Effects Association
; H Furuta, Radiation Effects Association; S Saigusa, Radiation Effects Association
Abstract: The Radiation Effects Association of Japan (REA) has been conducting epidemiological studies to investigate on the health effects of low-dose radiation using a cohort of nuclear workers since 1990. The aim of this study is to conduct a comparison of the cancer risk of mortality between lifestyle habits such as smoking, and socioeconomic status such as years of education, and radiation among Japanese nuclear workers.
The cohort was consisted by male nuclear workers in Japan who answered a lifestyle questionnaire survey conducted during 2003–2004. Workers’ vital statuses were ascertained by workers’ residence registration cards issued by local government offices. Causes of death were identified by data linkage with death records approved for use and provided by the Ministry of Health, Labor and Welfare. The dose records were supplied by Radiation Dose Registry Center within the REA. Personal dose equivalent Hp(10), which is the operational quantity of effective dose obtained from dosimeter readings, was used in the analysis. To exclude systematic errors caused by missing values of questionnaire (from 1 to 12% by questions), multiple imputation was used to impute the missing values. Poisson regression was used to estimate relative risks and confidence intervals for smoking (pack-years), alcohol consumption (ethanol/day), health consciousness, frequency of medical examination, breakfast intake, sleep, body mass index, job category, position, years of education, and cumulative radiation dose.
The number of cohort member was 41,742. The mean age and 10-year-lagged cumulative dose were 54.9 y and 24.8 mSv, respectively. Significantly high relative risks were determined for smoking, alcohol consumption, frequency of medical examination, breakfast intake, sleep, and body mass index. Significantly high relative risks of radiation were not shown except for lung cancer and smoking related cancers of 5- and 50- mSv categories. Their point estimates were smaller than the RR for smoking—especially significantly lower than that for the 40 pack-year and over. The comparison of radiation and smoking risk is unit-dependent, but these results suggest that the low dose radiation risk, if any, is less than smoking and probably less than other lifestyle factors. This study was funded by Nuclear Regulation Authority, Japan.
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P.17 Risk Assessment
Review of Computer Programs for Risk Assessment of Radioactive Waste Overland and Maritime Transportation GW Ryu*, Kyung Hee University
; HW Nam, Kyung Hee University; JB Heo, Kyung Hee University; MW Kwak, Kyung Hee University; KP Kim, Kyung Hee University
Abstract: Low and intermediate level radioactive waste and spent nuclear fuel have been generated due to the operation of nuclear facilities in Korea. As the amount of radioactive waste increases, evaluation of transportation risk has become important. Computer programs for risk assessment of radioactive waste overland and maritime transportation were reviewed prior to evaluate risk of radioactive waste transportation. RADTRAN, RISKIND, and INTERTRAN codes were reviewed for overland transportation. MARINRAD, POSEIDON, and LAMER codes were reviewed for maritime transportation. Exposure scenario, pathway, and consequence of codes were mainly analyzed. Overland transportation risk assessment codes evaluate risk of incident-free transportation and transportation accident. In the case of incident-free transportation, there is no damage to container during transportation, only external radiation doses to workers and the general public are considered. In the case of accident, there is a possibility of dispersion of radioactive material as the container is damaged. Therefore, external and internal radiation doses to the general public are considered. RADTRAN and INTERTRAN are mainly used to evaluate collective dose, RISKIND is mainly used to evaluate individual dose. Maritime transportation risk assessment codes evaluate risk of transportation accident because there is little effect on the general public at incident-free transportation. These codes generally evaluate risk by calculating concentrations of radionuclides in the ocean, concentrations of radionuclides in marine organisms, and sum of radiation doses by exposure pathway. External exposure, inhalation, and ingestion pathways are considered in MARINRAD and POSEIDON. However, only ingestion exposure pathway is considered in LAMER. This study results will be used as a basis for evaluating overland and maritime transportation risk of radioactive waste in the future. This work was supported through the KoFONS using the financial resource granted by NSSC. (No. 2106041)
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P.18 Risk Assessment
Derivation of Dose Constraints of PWR Type Reactor for General Public YH Jin*, Kyung Hee University
; HS Seo, Kyung Hee University; KH Kim, Kyung Hee University; JW Kim, Kyung Hee University; KP Kim, Kyung Hee University
Abstract: International Commission on Radiological Protection (ICRP) proposed fundamental principles of radiological protection as justification, optimization, and dose limits. ICRP 103 recommendation emphasized the key role of principle of optimization. International organizations have recommended setting dose constraints as a quantitative criterion for optimization. However, there are insufficient cases of setting dose constraints in Korea. The objective of this study is to derive dose constraint of PWR type reactor for the general public in Korea. International Atomic Energy Agency (IAEA) and Nuclear Energy Agency (NEA) recommended deriving dose constraint using distribution of radiation doses to the representative person. In addition, In Canada, dose constraint was derived based on 99.99 percentile values in the dose distribution of the general public. Therefore, in this study, dose constraints were derived based on dose distribution to the general public with 99.99, 95, and 75 percentiles. Those percentiles are generally used for dose assessment or optimization of radiation protection. The derived radiation doses based on 99.99, 95, 75 percentiles were relatively low, 0.07, 0.06, and 0.04 mSv/year, respectively. All the derived radiation doses based on the given percentiles were below 0.1 mSv/year, which is the lowest value of the dose constraint levels recommended by the ICRP. Therefore, in this study, the dose constraint of 0.1 mSv/year was proposed when the dose constraint concept is accepted in radiological safety regulation in the future in Korea. The dose constraint will be set through the involvement of stakeholders such as regulatory body and licensees. The study results can be used as a base data for the introduction of the dose constraint concept recommended by ICRP 103 in Korea in the future. * This work was supported by the KoFONS using the financial resource granted by the NSSC of the Republic of Korea (No.1805016).
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P.19 Risk Assessment
Radiation safety investigation of non-medical planned exposure radiation practices in Taiwan FY Hsu, National Tsing Hua University
; LY Chen*, Louisiana State University
Abstract: This study focuses on the radiation safety investigation of the facility operators who use the non-medical planned exposure radiation sources equipment capable of producing ionizing radiation (such as open beam/mobile X-ray detectors, X-ray tube static eliminators, ion implanters, cabinet-type X-rays) and Radioactive material in Taiwan. The competent authority (Atomic Energy Council in Taiwan) provides equipment rosters for sampling and the investigated objects were randomly selected. During the two-year period from 2020 to 2021, a total of 824 radiation sources (including 484 Equipment capable of producing ionizing radiation and 340 sealed radioactive material) were subjected to on-site radiation safety investigations. This paper conducts a statistical analysis of the investigation results, evaluates the radiation dose and risk according to the type and use of radiation operations, and proposes dose constraint practices and suggestions for relevant operators to follow, so as to improve the control efficiency of radiation safety.
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