Off-site nuclear emergency preparedness and response plans have conventionally focused on sheltering, stable iodine prophylaxis, and evacuation of residents as the primary short-term protective actions. Among these, the effectiveness of administering stable iodine prophylaxis has been affirmed over the years, by its ability to reduce intake of radioiodine and minimize the incidence of thyroid cancer in the administered population. The hypothesis of this study was that an advance distribution of prophylaxis, also called predistribution, to households during the preparedness stage is justified. To validate this hypothesis, we carried out a systematic literature review of existing studies on this topic. We also used multi-attribute utility theory to select relevant literature as per the criteria specific to this study. A detailed qualitative analysis was carried out to find the evidence that either substantiated or disproved our hypothesis. We found that over the years, there has been a steady increase in the number of articles advocating a predistribution strategy, especially following nuclear accidents. The most commonly held views against predistribution were as follows: (i) it would lead to accidental ingestion or possible overdose, (ii) it would be misplaced and not serve its purpose at the time of emergency, and (iii) it would not be cost-effective to implement such a distribution. The most common arguments supporting the hypothesis were as follows: (i) it offered maximum effectiveness as it could be immediately administered upon declaration of emergency, (ii) it reduces risk to the first responders who may otherwise be involved in distribution, and (iii) it serves as a last mode of radiation protection when consumed immediately and all other protective actions fail. This study found overwhelming evidence in support of the hypothesis, and hence, we suggest that a predistribution strategy for prophylactics is justified on the grounds of effective and timely radiation protection.
{"title":"A qualitative analysis of iodine prophylaxis predistribution as a viable strategy in nuclear emergency preparedness","authors":"Anirudh Chandra, M. Iyengar, Probal Chaudhury","doi":"10.4103/rpe.rpe_50_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_50_20","url":null,"abstract":"Off-site nuclear emergency preparedness and response plans have conventionally focused on sheltering, stable iodine prophylaxis, and evacuation of residents as the primary short-term protective actions. Among these, the effectiveness of administering stable iodine prophylaxis has been affirmed over the years, by its ability to reduce intake of radioiodine and minimize the incidence of thyroid cancer in the administered population. The hypothesis of this study was that an advance distribution of prophylaxis, also called predistribution, to households during the preparedness stage is justified. To validate this hypothesis, we carried out a systematic literature review of existing studies on this topic. We also used multi-attribute utility theory to select relevant literature as per the criteria specific to this study. A detailed qualitative analysis was carried out to find the evidence that either substantiated or disproved our hypothesis. We found that over the years, there has been a steady increase in the number of articles advocating a predistribution strategy, especially following nuclear accidents. The most commonly held views against predistribution were as follows: (i) it would lead to accidental ingestion or possible overdose, (ii) it would be misplaced and not serve its purpose at the time of emergency, and (iii) it would not be cost-effective to implement such a distribution. The most common arguments supporting the hypothesis were as follows: (i) it offered maximum effectiveness as it could be immediately administered upon declaration of emergency, (ii) it reduces risk to the first responders who may otherwise be involved in distribution, and (iii) it serves as a last mode of radiation protection when consumed immediately and all other protective actions fail. This study found overwhelming evidence in support of the hypothesis, and hence, we suggest that a predistribution strategy for prophylactics is justified on the grounds of effective and timely radiation protection.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"123 - 133"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45662956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nonconjugated conductive polymers have unique characteristics for providing protection against nuclear radiation including radioactive iodine (carcinogenic) which remains in vapor phase at and above room temperature and is difficult to contain. When iodine comes in contact with such a polymer, a charge-transfer occurs between the double bond and iodine, and as a consequence, the iodine atoms become bound to the polymer chain. Large films/sheets of these polymers covering nuclear reactors and waste storage facilities will act as effective shields against radioactive iodine since iodine atoms will be captured by these polymers and will not be able to escape to the environment. In addition, apparels made of these polymers will reduce exposure to radioactive iodine for doctors, nurses, attendees, and visitors during and after radioiodine therapy of thyroid patients. Thus, these polymeric shields should protect lives and the environment and reduce or avoid the exposure to humans in case of iodine releases from nuclear reactors: in normal day-to-day operations, due to accidents, and in disasters up to the magnitude of Fukushima Daiichi and Chernobyl.
{"title":"Nonconjugated conductive polymers for protection against nuclear radiation including radioactive iodine","authors":"M. Thakur","doi":"10.4103/rpe.rpe_33_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_33_20","url":null,"abstract":"Nonconjugated conductive polymers have unique characteristics for providing protection against nuclear radiation including radioactive iodine (carcinogenic) which remains in vapor phase at and above room temperature and is difficult to contain. When iodine comes in contact with such a polymer, a charge-transfer occurs between the double bond and iodine, and as a consequence, the iodine atoms become bound to the polymer chain. Large films/sheets of these polymers covering nuclear reactors and waste storage facilities will act as effective shields against radioactive iodine since iodine atoms will be captured by these polymers and will not be able to escape to the environment. In addition, apparels made of these polymers will reduce exposure to radioactive iodine for doctors, nurses, attendees, and visitors during and after radioiodine therapy of thyroid patients. Thus, these polymeric shields should protect lives and the environment and reduce or avoid the exposure to humans in case of iodine releases from nuclear reactors: in normal day-to-day operations, due to accidents, and in disasters up to the magnitude of Fukushima Daiichi and Chernobyl.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"148 - 153"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48436411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New nuclear projects: Public perception in general","authors":"D. Rao","doi":"10.4103/rpe.rpe_61_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_61_20","url":null,"abstract":"","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"121 - 122"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45166963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Some information on dirty bomb","authors":"Vijay Manchanda","doi":"10.4103/rpe.rpe_31_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_31_20","url":null,"abstract":"","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"185 - 187"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43684080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we look at radium content in soil samples collected from different locations in Egypt which have been measured using active gamma ray spectrometry with high-purity germanium (HPGe) detector and the passive sealed cup technique with LR-115 nuclear track detectors. Furthermore, the radon exhalation rates (mass and area) were measured using passive technique with LR-115 detectors. This investigation was undertaken to evaluate the possible health risks posed by the elements in question. Radium content values were found to vary from 20.83 to 47.57 Bq/kg with an average value of 32.46 ± 7.75 Bq/kg and 17.30 to 42.70 Bq/kg with an average 29.15 ± 6.75 Bq/kg using HPGe and LR-115 detectors, respectively. Area (surface) exhalation rate values were found to vary from 2.88 × 10-6 to 8.53 × 10-6 Bq/m2/h with an average value of 5.75 × 10-6 Bq /m2/h. Mass exhalation rate values were found to vary from 42.9 × 10-9 to 128 × 10-9 Bq/kg/h with an average value of 78.7 × 10-9 Bq/kg/h. All the results obtained in this particular study were found to be less than their corresponding world limits. Overall, the present results have revealed that radium content and both area and mass exhalation rates in the studied area do not pose a risk to human health. The results were compared nationally and with various other countries.
{"title":"Radium content and radon exhalation rates in Egyptian soil samples using active and passive techniques","authors":"A. Omar","doi":"10.4103/rpe.rpe_39_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_39_20","url":null,"abstract":"In this study, we look at radium content in soil samples collected from different locations in Egypt which have been measured using active gamma ray spectrometry with high-purity germanium (HPGe) detector and the passive sealed cup technique with LR-115 nuclear track detectors. Furthermore, the radon exhalation rates (mass and area) were measured using passive technique with LR-115 detectors. This investigation was undertaken to evaluate the possible health risks posed by the elements in question. Radium content values were found to vary from 20.83 to 47.57 Bq/kg with an average value of 32.46 ± 7.75 Bq/kg and 17.30 to 42.70 Bq/kg with an average 29.15 ± 6.75 Bq/kg using HPGe and LR-115 detectors, respectively. Area (surface) exhalation rate values were found to vary from 2.88 × 10-6 to 8.53 × 10-6 Bq/m2/h with an average value of 5.75 × 10-6 Bq /m2/h. Mass exhalation rate values were found to vary from 42.9 × 10-9 to 128 × 10-9 Bq/kg/h with an average value of 78.7 × 10-9 Bq/kg/h. All the results obtained in this particular study were found to be less than their corresponding world limits. Overall, the present results have revealed that radium content and both area and mass exhalation rates in the studied area do not pose a risk to human health. The results were compared nationally and with various other countries.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"179 - 184"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48415793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dany Saba, O. El Samad, R. Baydoun, R. Khozam, N. Manouchehri, L. Kassir, Amine Kassouf, H. Chébib, P. Cambier, N. Ouaini
Chemical fertilizers, phosphate ore treatments, and phosphogypsum wastes contribute to enhanced levels of natural radionuclides in the environment. A total of 27 soil samples were collected from nine uncultivated sites around a Lebanese fertilizer plant in order to analyze the gamma emitter radionuclides (238U,232Th,226Ra,210Pb,137Cs, and40K) and to assess the radiological impact on the surrounding environment, through the calculation of different radiological index parameters. In addition, a total of 27 Dittrichia viscosa plant samples were gathered including roots, leaves, and stems, and the radionuclide transfer factors were determined. Measurements were conducted using a gamma spectrometer with high-purity germanium detectors. The highest values measured in soil samples were 77 ± 9 Bq/kg, 102 ± 10 Bq/kg, and 143 ± 5 Bq/kg for238U,226Ra, and210Pb, respectively.40K levels were comparable to other Lebanese provinces and about 50% less than the worldwide average value. The results showed the absence of radionuclide transfer between soil and plants, except for40K. The average values of the total absorbed dose rate and the annual effective dose were comparable to the worldwide average values. Therefore, the external exposure index and Radium equivalent were found to be below the international recommended values.
{"title":"Radiological impact on uncultivated soil and Dittrichia viscosa plants around a Lebanese coastal fertilizer industry","authors":"Dany Saba, O. El Samad, R. Baydoun, R. Khozam, N. Manouchehri, L. Kassir, Amine Kassouf, H. Chébib, P. Cambier, N. Ouaini","doi":"10.4103/rpe.rpe_15_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_15_20","url":null,"abstract":"Chemical fertilizers, phosphate ore treatments, and phosphogypsum wastes contribute to enhanced levels of natural radionuclides in the environment. A total of 27 soil samples were collected from nine uncultivated sites around a Lebanese fertilizer plant in order to analyze the gamma emitter radionuclides (238U,232Th,226Ra,210Pb,137Cs, and40K) and to assess the radiological impact on the surrounding environment, through the calculation of different radiological index parameters. In addition, a total of 27 Dittrichia viscosa plant samples were gathered including roots, leaves, and stems, and the radionuclide transfer factors were determined. Measurements were conducted using a gamma spectrometer with high-purity germanium detectors. The highest values measured in soil samples were 77 ± 9 Bq/kg, 102 ± 10 Bq/kg, and 143 ± 5 Bq/kg for238U,226Ra, and210Pb, respectively.40K levels were comparable to other Lebanese provinces and about 50% less than the worldwide average value. The results showed the absence of radionuclide transfer between soil and plants, except for40K. The average values of the total absorbed dose rate and the annual effective dose were comparable to the worldwide average values. Therefore, the external exposure index and Radium equivalent were found to be below the international recommended values.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"61 - 69"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47118528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermoluminescent dosimeter (TLD) is still in use for many applications such as radiation protection, medical dosimetry, environmental research, and personnel dosimetry, with the overall aim of estimating radiation dose within a given medium or material. The aim of this study was to determine the coefficient of variation (CV) for thermoluminescent (TL) element within the same bar-coded slide and to establish calibration factors (CFs) at dose equivalent of 0.07 mm depth in tissue (Hp [0.07]) and dose equivalent of 10 mm depth in tissue (Hp [10]) for newly purchased TL elements alongside a new RadPro TLD manual reader and annealing oven. Annealed TL elements were taken to a Secondary Standard Dosimetry Laboratory (SSDL) for irradiation using a cesium-137 source at known doses (0.2–2 mGy). A RadPro Cube 400 manual TLD Reader was used to determine corresponding TL signal. The CV between two identical TL element within a bar-coded slide for (Hp [10]) and (Hp [0.07]) was determined and a graph of dose (mGy) against TL signal (Coulomb) was plotted to determine the elements CF. CVs from the raw data for 40 TL elements for Hp (10) and Hp (0.07) were 14.6% and 15.02%, respectively. Further selection of sensitive TL elements reduced the CVs of Hp (10) and Hp (0.07) to 3.73% and 3.21%, respectively, which was seen to be within ±10% accepted limit. The maximum percentage deviation for the calculated and actual dose for Hp (10) and Hp (0.07) was 16.7% and 14.3%, respectively. The CFs were power of 10 − 6 and the Coefficient of determination (R2) for Hp (10) and Hp (0.07) was 0.9998 and 0.9981, respectively, after adjustments were made on the initial graphs. Although large deviations were observed at low doses from the results of the raw data. Re-selected “golden Chips” had R2 close to unity and CV was within recommended standards.
{"title":"Calibration of MTS-N (LiF: Mg, Ti) chips using cesium-137 source at low doses for personnel dosimetry in diagnostic radiology","authors":"A. Omojola, M. Akpochafor, S. Adeneye, M. Aweda","doi":"10.4103/rpe.rpe_6_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_6_20","url":null,"abstract":"Thermoluminescent dosimeter (TLD) is still in use for many applications such as radiation protection, medical dosimetry, environmental research, and personnel dosimetry, with the overall aim of estimating radiation dose within a given medium or material. The aim of this study was to determine the coefficient of variation (CV) for thermoluminescent (TL) element within the same bar-coded slide and to establish calibration factors (CFs) at dose equivalent of 0.07 mm depth in tissue (Hp [0.07]) and dose equivalent of 10 mm depth in tissue (Hp [10]) for newly purchased TL elements alongside a new RadPro TLD manual reader and annealing oven. Annealed TL elements were taken to a Secondary Standard Dosimetry Laboratory (SSDL) for irradiation using a cesium-137 source at known doses (0.2–2 mGy). A RadPro Cube 400 manual TLD Reader was used to determine corresponding TL signal. The CV between two identical TL element within a bar-coded slide for (Hp [10]) and (Hp [0.07]) was determined and a graph of dose (mGy) against TL signal (Coulomb) was plotted to determine the elements CF. CVs from the raw data for 40 TL elements for Hp (10) and Hp (0.07) were 14.6% and 15.02%, respectively. Further selection of sensitive TL elements reduced the CVs of Hp (10) and Hp (0.07) to 3.73% and 3.21%, respectively, which was seen to be within ±10% accepted limit. The maximum percentage deviation for the calculated and actual dose for Hp (10) and Hp (0.07) was 16.7% and 14.3%, respectively. The CFs were power of 10 − 6 and the Coefficient of determination (R2) for Hp (10) and Hp (0.07) was 0.9998 and 0.9981, respectively, after adjustments were made on the initial graphs. Although large deviations were observed at low doses from the results of the raw data. Re-selected “golden Chips” had R2 close to unity and CV was within recommended standards.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"108 - 114"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42425540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amal Jose, A. Kumar, K. Govindarajan, P. Manimaran
The objective of the present study is to propose a set of regional diagnostic reference levels (DRLs) for pediatric intraoral (IO) radiography procedures classified by IO examinations in Tamil Nadu, India. Of the 120 total units, 60 were digital and the remaining 60 units used film as image receptors. The third quartile values obtained for the selected IO examinations ranged from 1.05 mGy for the mandibular incisors to 1.48 mGy for the maxillary molars. The DRLs of the present study compare well with other International published DRLs. Following this primary study, DRLs will be proposed for other regions of the country, to arrive at national DRLs for pediatric IO dentistry.
{"title":"Establishment of pediatric local diagnostic reference levels for intraoral radiography","authors":"Amal Jose, A. Kumar, K. Govindarajan, P. Manimaran","doi":"10.4103/rpe.rpe_9_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_9_20","url":null,"abstract":"The objective of the present study is to propose a set of regional diagnostic reference levels (DRLs) for pediatric intraoral (IO) radiography procedures classified by IO examinations in Tamil Nadu, India. Of the 120 total units, 60 were digital and the remaining 60 units used film as image receptors. The third quartile values obtained for the selected IO examinations ranged from 1.05 mGy for the mandibular incisors to 1.48 mGy for the maxillary molars. The DRLs of the present study compare well with other International published DRLs. Following this primary study, DRLs will be proposed for other regions of the country, to arrive at national DRLs for pediatric IO dentistry.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"77 - 81"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47796534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A study to ascertain the radioactivity levels of various radionuclides from soil samples collected in Chad using a high-resolution gamma ray spectrometry system is presented in this article. The activity concentrations are determined for the radionuclides:226Ra,214Pb,214Bi and228Ac,208Tl,212Pb following the decay of238U and232Th as well as40K,235U, and137Cs. The values of activity concentrations of238U,232Th, and40K in the soil samples ranged from 2 to 245, 2–40, and 20–454 Bq/kg, whereas235U and137Cs ranged from 0.8 to 21.7 and 0.3–3.8 (Bq/kg), respectively. In order to evaluate the radiological exposure of the natural radioactivity, the radium equivalent activity, external exposure index, internal exposure index, and annual effective-dose equivalent have been calculated which ranged from 27 to 465 (Bq/kg), 0.09–1.25, 0.13–2.38, and 0.09–1.65 (mSv/y), respectively. Correlation between238U versus232Th,40K versus238U, and40K versus232Th was investigated; the results showed good correlation for238U versus232Th and40K versus238U while40K versus232Th gives poor correlation. For the 20 samples collected and analyzed for this study, the results showed that average activity concentration of238U is relatively higher than the world average, while for both232Th and40K, it was relatively lower.
{"title":"Assessment of environmental radiation exposure from soil radioactivity around the Southern area of Chad","authors":"M. Ajani, P. Maleka, I. Usman, S. Penabei","doi":"10.4103/rpe.rpe_25_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_25_20","url":null,"abstract":"A study to ascertain the radioactivity levels of various radionuclides from soil samples collected in Chad using a high-resolution gamma ray spectrometry system is presented in this article. The activity concentrations are determined for the radionuclides:226Ra,214Pb,214Bi and228Ac,208Tl,212Pb following the decay of238U and232Th as well as40K,235U, and137Cs. The values of activity concentrations of238U,232Th, and40K in the soil samples ranged from 2 to 245, 2–40, and 20–454 Bq/kg, whereas235U and137Cs ranged from 0.8 to 21.7 and 0.3–3.8 (Bq/kg), respectively. In order to evaluate the radiological exposure of the natural radioactivity, the radium equivalent activity, external exposure index, internal exposure index, and annual effective-dose equivalent have been calculated which ranged from 27 to 465 (Bq/kg), 0.09–1.25, 0.13–2.38, and 0.09–1.65 (mSv/y), respectively. Correlation between238U versus232Th,40K versus238U, and40K versus232Th was investigated; the results showed good correlation for238U versus232Th and40K versus238U while40K versus232Th gives poor correlation. For the 20 samples collected and analyzed for this study, the results showed that average activity concentration of238U is relatively higher than the world average, while for both232Th and40K, it was relatively lower.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"70 - 76"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42609565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reverse osmosis (RO) is a water purification process that uses a semi-permeable membrane to remove ions from potable water. It has high rejection throughput, low energy consumption, and negligible pollution load when compared to conventional treatment methods. Comparative percentage salt rejection (SR) efficiency for surrogates of cesium and molybdenum was performed using commercially available membranes. Polyamide, polysulfone, polyamide–polysulfone composite, and cellulose acetate were subjected to various operating conditions in a domestically developed high-pressure membrane test cell. Five different concentrations of surrogate salts ranging from 100 to 500 ppm and varied pressures of 15–17 kg/cm2 combined with varying temperatures of the feed solution from 25°C to 45°C were used in this experimental work. It was found that the %SR efficiency of these membranes increased with the increase in salt concentration and feed temperature. However, a significant decrease in SR was observed with increasing pressure. A comparative study of these commercially available RO membranes was also performed against short-lived radioisotope Technetium-99m, and was determined by activity counts of feed and filtered samples using a well counter. The results suggest that the rejection efficiency was found to be highest in the case of polyamide–polysulfone composite, followed by polysulfone, polyamide, and cellulose acetate.
{"title":"Comparative evaluation of the radioactivity removal efficiency of different commercially available reverse osmosis membranes","authors":"Vinod Kumar, S. Nayak, Deeksha Katyal","doi":"10.4103/rpe.rpe_20_20","DOIUrl":"https://doi.org/10.4103/rpe.rpe_20_20","url":null,"abstract":"Reverse osmosis (RO) is a water purification process that uses a semi-permeable membrane to remove ions from potable water. It has high rejection throughput, low energy consumption, and negligible pollution load when compared to conventional treatment methods. Comparative percentage salt rejection (SR) efficiency for surrogates of cesium and molybdenum was performed using commercially available membranes. Polyamide, polysulfone, polyamide–polysulfone composite, and cellulose acetate were subjected to various operating conditions in a domestically developed high-pressure membrane test cell. Five different concentrations of surrogate salts ranging from 100 to 500 ppm and varied pressures of 15–17 kg/cm2 combined with varying temperatures of the feed solution from 25°C to 45°C were used in this experimental work. It was found that the %SR efficiency of these membranes increased with the increase in salt concentration and feed temperature. However, a significant decrease in SR was observed with increasing pressure. A comparative study of these commercially available RO membranes was also performed against short-lived radioisotope Technetium-99m, and was determined by activity counts of feed and filtered samples using a well counter. The results suggest that the rejection efficiency was found to be highest in the case of polyamide–polysulfone composite, followed by polysulfone, polyamide, and cellulose acetate.","PeriodicalId":32488,"journal":{"name":"Radiation Protection and Environment","volume":"43 1","pages":"100 - 107"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48796606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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