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Sample records for 144ce dlya blizhajshej

  1. A new 144Ce/144Pr radioisotope generator system

    A miniaturized generator system was developed containing manganese dioxide-coated alumina on which 144Ce is deposited and from which 144Pr is eluted with an aqueous solution of 1% KIO3 in 1 N nitric acid. More than 60% of the 144Pr was recovered with a 99.9% radionuclide purity even after 2000 ml eluant and 1000 1 or air had been passed through the column. (author)

  2. Chromatographic isolation of 144Ce and 144Pr from the wastes of irradiated uranium treatment

    A two-step chromatographic technique was elaborated to isolate 144Ce, 144Pr from a solution of uranium fission products in 6M HNO3. The oxidation to Ce(III) by bromate and selective adsorption of 144Ce(IV) on anion exchange column were used to concentrate and purify 144Ce. Some impurities of uranium, 95Zr, 95Nb, 106Ru remain in 144Ce solution after the first step of its isolation. The final purification is achieved by passing the 6M HNO3 solution of 144Ce(IV) through the HDEHP-coated teflon column. The decontamination factors of 144Ce from main fission products are given. 7.2 mCi of (144Ce+144Pr) are recovered from each gram of irradiated uranium trioxide with the yield greater than 99%. An improvement of known generator was carried out to elute a purer 144Pr from maternal 144Ce(IV) adsorbed on the anion exchange column. (author)

  3. Toxicity of 144Ce inhaled in a relatively insoluble form by immature beagle dogs. VI

    Immature Beagle dogs (approximately equal to 3 months of age at exposure) have been exposed by inhalation to a relatively insoluble form of 144Ce (in fused aluminosilicate particles) to compare the resulting patterns of metabolism, dosimetry and biological effects with those seen in dogs exposed at 12 and 14 months of age and at 8 to 10.5 years of age. Five blocks of longevity animals, each consisting of 10 exposed dogs and one control, are currently on experiment. The initial lung burdens of the 144Ce-exposed dogs range from 0.004 to 140 μCi 144Ce/kg body weight. Three dogs with initial lung burdens of 73 to 120 μCi 144Ce/kg body weight died at 66 to 121 days after exposure with pulmonary injury and congestive heart failure. One dog with an initial lung burden of 140 μCi 144Ce/kg body weight died at 91 days after exposure with severe radiation pneumonitis and minimal pulmonary fibrosis and another dog whose initial lung burden was 70 μCi 144Ce/kg body weight died at 511 days after exposure with pulmonary injury that was mainly fibrotic in nature. Two dogs with initial lung burdens of 52 and 64 μCi 144Ce/kg body weight had primary pulmonary hemangiosarcomas and died at 618 and 689 days, respectively, with cumulative average absorbed beta doses to lung of 23,000 and 29,000 rads. One dog with an initial lung burden of 28 μCi 144Ce/kg body weight was euthanized at 1227 days after exposure with a hemangiosarcoma of the mediastinum, and another dog with an initial lung burden of 12 μCi 144Ce/kg body weight died at 1520 days after exposure from epilepsy. Serial observations are continuing on the surviving 40 exposed and five control dogs

  4. Toxicity of 144Ce inhaled in a relatively insoluble form by immature Beagle dogs. XVII

    Immature Beagle dogs (3-mo old) received a single, brief inhalation exposure to 144Ce in fused aluminosilicate particles as part of a series of studies designed to study the effects of age on dose response relationships for inhaled radionuclides. Forty-nine dogs inhaled graded levels of 144Ce that resulted in initial lung burdens ranging from 0.004-140 μCi/kg 0.15-5200 kBq/kg) body weight. Five control dogs inhaled nonradioactive fused aluminosilicate particles. Forty-one of the 144Ce-exposed dogs have died: 11 with lung tumors 4 with tumors of the tracheobronchial lymph nodes, with a nasal cavity tumor, and 9 with non neoplastic diseases of the respiratory tract. Observations are continuing on the 8 144Ce-exposed dogs that are surviving at this time. (author)

  5. Toxicity of inhaled 144CeCl3 in beagle dogs. VIII

    Studies on the metabolism, dosimetry, and effects of inhaled 144CeCl3 in the Beagle dog are continuing to provide information that will aid in assessing the biological consequences of inhaling 144Ce such as might be released in certain nuclear accidents. Studies on the tissue distribution of inhaled 144CeCl3 have shown that the 144Ce deposited in lung is translocated at a moderately rapid rate to liver and skeleton and that significant radiation doses are accumulated by all three organs. Fifty-five dogs that inhaled 144CeCl3 and 15 control dogs were placed in a longevity study and are being observed for their lifespan. The 144Ce dogs had long-term retained burdens with values ranging from 20 to 2900 μCi. Thirty-one of the dogs exposed to 144CeCl3 have died; 8 at 21 to 44 days after inhalation with signs attributed to severe bone marrow damage and associated pancytopenia; 2 at 138 and 144 days with radiation pneumonitis; 3 at 309 to 874 days with hepatic necrosis; 1 at 510 days with marrow aplasia; 1 at 375 days with pulmonary fibrosis; and 16 at 799 to 3081 days, most with neoplasms or myeloproliferative disorders. In this last group, 1 dog had an osteosarcoma, 3 had squamous cell carcinomas of the maxilla, 2 of the latter also having primary pulmonary neoplasms, 5 had hemangiosarcomas of the liver, 1 had a hemangiosarcoma of the nasal cavity, 2 had myelogenous leukemia, 1 had myelofibrosis with myeloid metaplasia, 1 had spinal cord ependymomas, and 2 did not have neoplasms. One of these had severe myelomalacia and the other diffuse hepatic lipidosis with severe degeneration. Two controls died; 1 with a thyroid carcinoma and 1 with aspiration pneumonia. Serial observations are continuing on the 24 surviving 144CeCl3 dogs and 13 control dogs. (U.S.)

  6. Toxicity of inhaled 144CeCl3 in beagle dogs. XI

    Studies on the metabolism, dosimetry and effects of inhaled 144CeCl3 in Beagle dogs are being conducted to assess the biological consequences of inhaling 144Ce such as might be released in certain nuclear accidents. Studies on the organ distribution of inhaled 144CeCl3 have shown that the 144Ce deposited in the lung is translocated at a moderately rapid rate to liver and skeleton and that significant radiation doses are accumulated by all three organs. Fifty-five dogs that inhaled 144CeCl3 and 15 control dogs are being observed for their life span. The 144Ce dogs have long-term retained burdens with values ranging from 20 to 2900 μCi. Forty-five of the dogs exposed to 144CeCl3 have died; eight from 21 to 44 days after inhalation with severe bone marrow damage and associated pancytopenia; two at 138 and 144 days with radiation pneumonitis; three from 309 to 874 days with hepatic necrosis; one at 510 days with marrow aplasia; one at 375 days with pulmonary fibrosis; and 30 from 799 to 4085 days, most with neoplasms or myeloproliferative disorders. In this last group, one dog had an osteosarcoma, five had squamous cell carcinomas of the nasal cavity (two also having primary pulmonary neoplasms), six had hemangiosarcomas of the liver, one had a hemangiosarcoma of the nasal cavity, two had myelogenous leukemia, one had myelofibrosis with myeloid metaplasia, one had spinal cord ependymomas, one had a malignant melanoma (also an ependymoma) and two had mammary adenocarcinomas. Three dogs had primary pulmonary neoplasms including two with bronchogenic adenocarcinomas and one with an adenoma. Seven did not have malignant neoplasms. Two of these had severe myelomalacia, one had pulmonary edema, three had congestive heart failure and one had diffuse hepatic lipidosis with severe hepatic degeneration

  7. Toxicity of 144Ce inhaled in a relatively insoluble form by immature Beagle dogs. XII

    Immature Beagle dogs (3 months old) were exposed once by inhalation to an aerosol of 144Ce incorporated in fused aluminosilicate particles. The influence of this age on the dose-response relationships is being compared to that of 13-mo-old and 8 to 10.5-yr-old dogs. This study involves 49 dogs that received graded initial lung burdens from 0.004 to 140 μCi 144Ce/kg body weight and five control dogs. To date, 19 of the 144Ce-exposed dogs and one of the controls have died. Dogs with the highest initial lung burdens of 144Ce died during the first 4 months with radiation pneumonitis, pulmonary fibrosis, and congestive heart failure. Pulmonary hemangiosarcoma was the primary finding in dogs that died at 1.5 to 2 years after exposure. Deaths beyond that time have been due primarily to extrapulmonary hemangiosarcomas. Observations are continued on the surviving 30 144Ce-exposed and four control dogs at 7.0 to 11.2 years after exposure

  8. Toxicity of 144Ce inhaled in a relatively insoluble form by aged Beagle dogs. XII

    The toxicity of relatively insoluble 144Ce inhaled by 8- to 10.5-year-old Beagle dogs is being investigated to determine possible age-related differences in long-term biological responses. Forty-two dogs were exposed to aerosols of 144Ce in fused aluminosilicate particles to yield initial lung burdens of 2.2 to 75 μCi 144Ce/kg body weight, and 12 control dogs were exposed to non-radioactive fused aluminosilicate particles. All 144Ce-exposed and control dogs have died or were euthanized between 197 and 2726 days after the inhalation exposure. Prominent findings in the 144Ce-exposed dogs were radiation pneumonitis in 19 of the 23 dogs that died during the first 943 days after exposure, and neoplastic disease in 13 of the 20 dogs that died beyond 904 days after exposure. Pulmonary tumors were found in five of these dogs. In contrast to the study with young adult dogs, in which pulmonary hemangiosarcomas were one of the prominent findings, all of these tumors were carcinomas

  9. Toxicity of inhaled 144Ce in fused aluminosilicate particles in aged beagle dogs. V

    The toxicity of 144Ce in fused aluminosilicate particles inhaled by 8- to 10.5-yr-old dogs is being investigated to provide information on age-related differences in the response of older members of the human population to accidental inhalation of radioactive aerosols. These data on aged dogs will be compared to the results of similar studies of dogs exposed at approximately 3 mo or 12 to 14 mo of age. Six blocks of five female dogs each have been divided into four exposure levels with mean initial lung burdens of 7.2, 14, 28 and 57 μCi 144Ce/kg body weight. Six blocks of four male dogs have been divided into three exposure levels with mean initial lung burdens of 7.2, 14 and 28 μCi 144Ce/kg body weight. Controls in each block were exposed to fused aluminosilicate particles containing stable cerium. Fifteen dogs with initial lung burdens ranging from 20 to 75 μCi 144Ce/kg body weight and cumulative doses to lung of from 22,000 to 74,000 rads have died or were euthanized 197 to 1207 days after exposure with clinicopathologic findings of radiation pneumonitis and pulmonary fibrosis.Pulmonary retention of the inhaled 144Ce was similar to that observed previously in dogs exposed at 18 to 22 mo of age in a radiation dose pattern study. Serial observations are continuing on the 19 surviving 144Ce-exposed and eight control dogs

  10. Toxicity of 144Ce fused clay particles inhaled by aged dogs. III

    The toxicity of 144Ce fused clay particles inhaled by 8- to 10.5-year-old dogs is being investigated to provide information on age-related differences in the response of older members of the human population to accidental inhalation of radioactive aerosols. These data on aged dogs will be compared to the results of similar studies using dogs exposed at approximately 3 months or 12 to 14 months of age. To date, 7 blocks of 5 dogs each, divided into 4 exposure levels with mean initial lung burdens of 7.5, 14, 24, and 57 μCi/kg body weight and control dogs exposed to non-labeled fused clay particles have been entered into a longevity study. Twelve dogs with initial lung burdens ranging from 20 to 75 μCi 144Ce/kg body weight and cumulative doses to lung of from 22,000 to 74,000 rads have died at 197 to 943 days post-inhalation with clinico-pathologic findings of radiation pneumonitis and pulmonary fibrosis. Two of these also had congestive heart failure. In addition, 4 dogs with ILBs of 8 to 14 μCi 144Ce/kg body weight have died of mammary neoplasms or congestive heart failure but without radiation pneumonitis. One dog with an ILB of 9 μCi 144Ce/kg body weight died with a chronic interstitial foreign body pneumonia. Two control dogs have died, one with a mammary carcinoma and one with pyometra. Pulmonary retention of the inhaled 144Ce was similar to that observed previously in dogs exposed at 18 to 22 months of age in a radiation dose pattern study. Serial observations are continuing on the 11 surviving 144Ce-exposed dogs and 5 controls. (U.S.)

  11. Toxicity of 144Ce inhaled in a relatively insoluble form by immature Beagle dogs. VIII

    The influence of age at exposure on the resulting patterns of deposition, retention, dosimetry and biological effects from a single inhalation exposure to a relatively insoluble form of a beta-emitting radionuclide with a relatively long physical half-life is being investigated. Immature Beagle dogs (3 months of age) have been exposed once, by inhalation, to an aerosol of 144Ce incorporated in fused aluminosilicate particles. Eighteen of these dogs were serially sacrificed to study the patterns of deposition, retention and dosimetry and the remaining 49 dogs received graded initial lung burdens that ranged from 0.004 to 140 μCi 144Ce/kg body weight and are being observed over their life span for study of the resulting long-term biological effects. Five control dogs are also included in this study. To date, 13 of the 144Ce-exposed dogs in the longevity study and none of the controls have died. Dogs with the highest initial lung burdens of 144Ce died first (during the first 4 months) with radiation pneumonitis, pulmonary fibrosis and congestive heart failure. Pulmonary hemangiosarcoma was the primary finding in dogs that died at 1.5 to 2 years after exposure. Deaths beyond that time have primarily involved extrapulmonary hemangiosarcomas. One dog, 627B, with an initial lung burden of 24 μCi 144Ce/kg body weight died during the past year at 2341 days after exposure with a widely disseminated hemangiosarcoma showing heavy involvement of the liver and skin. Observations are continuing on the surviving 36 144Ce-exposed and five control dogs

  12. Toxicity of 144Ce inhaled in a relatively insoluble form by aged beagle dogs. VI

    The toxicity of 144Ce inhaled in fused aluminosilicate particles by 8 to 10.5-year-old dogs is being investigated to provide information on age-related differences in the response of older members of the human population to accidental inhalation of radioactive aerosols. These data on aged dogs will be compared to the results of similar studies of dogs exposed at approximately 3 months or 12 to 14 months of age. Six blocks of five female dogs each have been divided into four exposure levels with mean initial lung burdens of 7.2, 14, 28 and 57 μCi 144Ce/kg body weight. Six blocks of four male dogs each have been divided into three exposure levels with mean initial lung burdens of 7.2, 14 and 28 μCi 144Ce/kg body weight. Controls in each block were exposed to fused aluminosilicate particles containing stable cerium. Eighteen dogs with initial lung burdens ranging from 14 to 75 μCi 144Ce/kg body weight and cumulative doses to lung of from 22,000 to 74,000 rads have died or were euthanized 197 to 1207 days after exposure with clinicopathologic findings of radiation pneumonitis and pulmonary fibrosis

  13. Effect of 144Ce inhaled in fused clay particles on the tracheobronchial lymph nodes

    Tracheobronchial lymph node changes and lymphopenia are sequelae to inhalation of relatively insoluble radioactive aerosols by Beagle dogs. To assess the development of these lesions, tracheobronchial lymph nodes from dogs that inhaled 144Ce in fused clay particles were examined at intervals from 2 to 730 days after exposure. Initial lung burdens in the dogs studied ranged from 33 to 63 μCi/kg body weight. The concentration of radioisotope in the tracheobronchial lymph nodes increased during the first year after exposure and exceeded that in the lung about 100 days after exposure. Autoradiographs of the lymph nodes showed that 144Ce particles were present in macrophages in the paracortical zone two days after exposure and that concentrations continued to increase in the paracortical zone and medullary cords. Histologic changes in the nodes included atrophy of the germinal centers and lymphocytic follicles, loss of lymphocytes and accumulation of macrophages in the paracortical zone, accumulation of pigment and isotope-laden macrophages in the medullary cords, occasional infiltrates of neutrophils in the medullary cords and, at later time periods, focal fibrosis of the medullary cords. Tracheobronchial lymph node weights of the dogs exposed to 144Ce in fused clay were not decreased until 512 days after exposure. These findings indicate that tracheobronchial lymph nodes accumulate relatively high burdens of 144Ce after inhalation of 144Ce in a relatively insoluble form and that the pathologic changes resulting from these burdens are basically atrophic in nature. Primary neoplasms in lymph nodes have not been observed in dogs with initial lung burdens from 0.0024 to over 30 μCi/kg body weight followed for up to 2000 days post-exposure. At the higher levels, however, a high incidence of primary pulmonary neoplasia has been observed. (U.S.)

  14. Toxicity of 144Ce inhaled in a relatively insoluble form by immature Beagle dogs. VII

    Immature Beagle dogs (approx. = 3 months of age at exposure) have been exposed by inhalation to a relatively insoluble form of 144Ce (in fused aluminosilicate particles) to compare the resulting patterns of metabolism, dosimetry and biological effects with those seen in dogs exposed at 12 and 14 months of age and at 8 to 10.5 years of age. Five blocks of longevity animals, each consisting of 10 exposed dogs and one control, are currently being studied. The initial lung burdens of the 144Ce-exposed dogs range from 0.004 to 140 μCi 144Ce/kg body weight. Three dogs with initial lung burdens of 73 to 120 μCi 144Ce/kg body weight died at 66 to 121 days after exposure with pulmonary injury and congestive heart failure. One dog with an initial lung burden of 140 μCi 144Ce/kg body weight died at 91 days after exposure with severe radiation pneumonitis and minimal pulmonary fibrosis and another dog whose initial lung burden was 70 μCi 144Ce/kg body weight died at 511 days after exposure with pulmonary injury that was mainly fibrotic in nature. Four dogs with initial lung burdens of 52 to 79 μCi/kg body weight had primary pulmonary hemangiosarcomas and died between 618 and 738 days, with cumulative average absorbed beta doses to lung of 23,000 to 31,000 rads. Two of these dogs, 1027S and 1024D, died within the past year. One dog with an initial lung burden of 28 μCi/kg body weight was euthanized at 1227 days after exposure with an hemangiosarcoma of the mediastinum. Within the past year, Dog 627S, with an initial lung burden of 48 μCi/kg body weight, died 1732 days after exposure with hemangiosarcoma primary in the liver or spleen. A dog with an initial lung burden of 12 μCi/kg body weight died from epilepsy at 1520 days after exposure. Serial observations are continuing on the surviving 37 exposed and five control dogs

  15. Toxicity of inhaled 144Ce fused clay particles in beagle dogs. VII

    The metabolism, dosimetry, and effects of inhaled 144Ce in fused clay particles are being investigated in the Beagle dog to aid in assessing the biological consequences of release of 144Ce in a relatively insoluble form such as might occur in certain types of nuclear accidents. The toxicity of inhaled 144Ce fused clay is also of general interest since it is representative of intermediate-lived beta-emitting radionuclides. Two major studies with young adult dogs (12 to 14 months of age at exposure) are involved: (1) a metabolism and dosimetry study in which 24 dogs were serially sacrificed over an extended period of time, and (2) a longevity study with 2 series of dogs; Series I with 15 dogs exposed to aerosols of 144Ce in fused clay particles to yield initial lung burdens of 11 to 210 μCi/kg body weight and 3 control dogs exposed to nonradioactive fused clay particles and Series II with 96 dogs exposed to aerosols of 144Ce in fused clay particles to yield initial lung burdens of 0.0024 to 66 μCi/kg body weight and 12 control dogs exposed to nonradioactive fused clay particles. Twenty-eight dogs died or were euthanized at 143 to 2396 days after inhalation of 144Ce. The prominent findings were radiation pneumonitis in 17 dogs that died or were euthanized at early time periods and neoplastic disease in 10 of the 11 dogs that died or were euthanized at 750 days or later; 5 with hemangiosarcoma of the lung, 1 with both a hemangiosarcoma and a fibrosarcoma of the lung, 1 with both a bronchiolo-alveolar carcinoma and a hemangiosarcoma of lung, 1 with a hemangiosarcoma of lung, bronchiolo-alveolar carcinoma, and a bronchiogenic adenocarcinoma, and 1 each with a hemangiosarcoma of the mediastinum and of the spleen. The cumulative radiation dose to the lung at time of death has ranged from 22,000 to 140,000 rads. Serial observations are continuing on the 83 survivors and 15 controls. (U.S.)

  16. Extraction of carrier-free 144Ce with acetylacetone and 8-hydroxyquinoline

    The extraction of carrier-free 144Ce with 3.25 to 0.65 M solutions of acetylacetone in carbon tetrachloride and with 1.0 to 0.01 M solutions of 8-hydroxyquinoline in chloroform at a constant as well as variable pH was investigated. On the basis of the analysis of distribution curves it may be presumed that in both extraction systems the oxidation of cerium(III) to cerium(IV) microamounts takes place. The distribution curves of extraction and reextraction in the systems with 8-hydroxyquinoline show a considerable complexity. In the extraction system with acetylacetone constants were found which satisfactorily express the distribution of 144Ce in this system. (author)

  17. Biological effects of repeated exposure of beagle dogs to relatively insoluble aerosols of 144Ce. IV

    This experiment is being conducted to study the behavior and long-term biological effects in Beagle dogs of 144Ce inhaled in fused aluminosilicate particles in repeated inhalation exposures for comparison with similar data from dogs that were exposed only once to a similar aerosol. Four groups of nine dogs each were exposed once every eight weeks for two years (13 exposures) to achieve specified exposure goals. The 144Ce-exposed dogs received increasing or relatively constant beta radiation dose rates in contrast to the steadily decreasing dose rate seen after a single inhalation exposure. Exposures in the first and second groups were planned to yield a cumulative absorbed dose to lung of approximately equal to 35,000 rads and those in the third group approximately equal to 17,000 rads within two years after the first exposure. Singly exposed dogs that had died with pulmonary tumors when this experiment was initiated had cumulative doses to death of 29,000 to 61,000 rads. All 13 exposures have been completed. One dog in the 4.5-μCi 144Ce/kg body weight group died at 771 days after first exposure with emaciation, adrenal cortical degeneration and bone marrow aplasia. One control dog died accidentally during anesthesia. During the past year, two additional dogs have died. One dog in the repeated 2.5-μCi 144Ce/kg body weight group died at 1256 days after the first exposure with radiation pneumonitis and pulmonary fibrosis and a control dog died at 1052 days with autoimmune hemolytic anemia. The remaining 32 dogs appear to be in good physical condition except for a persistent lymphopenia at approximately equal to 4 years after the first exposure. They are being maintained for life span observations

  18. The uptake of 90Sr, 137Cs and 144Ce by leaves of spring wheat and rape

    The distribution and accumulation of 90Sr, 137Cs, 144Ce through the leaf surface into the plant have been studied. The results show that the uptake rate of 137Cs by crop plant is about 53%, while the uptake rate for 90Sr and 144Ce is about 0.4%. However 90Sr is absorbed in significant amount from soil whereas 137Cs is absorbed in negligible amount

  19. Liver tumors in Beagle dogs exposed by inhalation to 144CeCl3

    Primary malignant hepatic neoplasms developed in 9 of 55 Beagle dogs (16 percent) exposed to 144CeCl3 in CsCl aerosol (seven primary hepatic hemangiosarcomas, one hepatocellular carcinoma and one intrahepatic bile duct carcinoma). Cerium-144 was rapidly translocated from the lung to the liver and skeleton; the liver received the highest cumulative beta dose. The latent periods of hepatic hemangiosarcomas appeared to be dose-related; death from hepatic hemangiosarcoma occurred earlier in dogs which received higher beta doses

  20. Biological effects of repeated inhalation exposure of Beagle dogs to relatively insoluble aerosols of 144Ce. V

    The behavior and long-term biological effects in Beagle dogs of 144Ce inhaled in fused aluminosilicate particles in repeated inhalation exposures are being studied for comparison with data from dogs that were exposed only once to a similar aerosol. Four groups of nine dogs each were exposed once every 8 weeks for 2 years (13 exposures) to achieve specified exposure goals. These goals were: to increase the lung burden by 2.5 μCi 144Ce/kg body weight with each exposure in the first group; to reestablish lung burdens of 9 or 4.5 μCi 144Ce/kg body weight in the second and third groups, respectively; and to expose controls (fourth group) to fused aluminosilicate particles containing stable cerium. With these exposure sequences, the 144Ce-exposed dogs received increasing or relatively constant beta radiation dose rates in contrast to the steadily decreasing dose rate seen after a single inhalation exposure. Exposures in the first and second groups were planned to yield a cumulative absorbed dose to lung of approx. = 35,000 rads and those in the third group approx. = 17,000 rads within two years after the first exposure. All 13 exposures have been completed. During the past year, one dog in the 9.0 μCi 144Ce/kg body weight group died at 1558 days after the first exposure with autoimmune hemolytic anemia. The remaining 24 144Ce-exposed and seven control dogs generally appear to be in good physical condition with exception of a persistent lymphopenia at approx. = 5 years after the first exposure. They are continuing to be maintained for life span observations

  1. Effects of inhaled 144Ce on cardiopulmonary function and histopathology of the dog

    Twelve dogs inhaled single doses of relatively insoluble particles containing 144Ce and six dogs inhaled particles containing stable cerium as controls. Pulmonary function, clinical, and radiographic evaluations were performed serially. The dogs developed progressive radiation pneumonitis and pulmonary fibrosis similar to that previously reported for whole-lung irradiation from internal or external sources. Focal histologic changes in bronchioles and alveoli were detected functionally during treadmill and tube-breathing stresses at a time when the dogs' clinical and radiographic appearances were normal. Moderate functional impairment was associated with more severe inflammatory and proliferative changes in airways and alveoli. Severe impairment resulted from progressive fibrosis and scarring. These were several strong correlations between functional indices and histological scores. There was a nonlinear relationship between cumulative radiation dose and effects, and once the functional alterations became clinically evident, the disease progressed with little further increase in dose

  2. Biological effects of repeated inhalation exposure of beagle dogs to aerosols of 144Ce in fused clay particles I

    This experiment was initiated to study the biological behavior and long-term effects of repeated inhalation exposures to 144Ce in fused clay particles compared with those seen in Beagle dogs that received a single exposure as young adults. The 36 dogs, divided into four equal groups, are exposed every 8 weeks to achieve the following: to maintain lung burdens of 9 and 4.5 μCi 144Ce/kg body weight in the first and second groups, respectively; to increase the lung burden by 2.5 μCi 144Ce/kg body weight in the third group with each exposure and to expose controls (fourth group) to fused clay containing stable cerium. With these exposure sequences, the 144Ce-exposed dogs will receive increasing or maintained β dose rates in contrast to the steadily decreasing dose rate seen after a single inhalation exposure. Exposures to the first and third groups will produce a cumulative absorbed dose to lung of approximately equal to 35,000 rads and those to the second group will yield approximately equal to 17,000 rads within 2 yr after the first exposure. Single exposure dogs that had died with pulmonary neoplasia when this experiment was initiated had cumulative doses to death of 29,000 to 61,000 rads. Six of the planned 13 exposures have been completed to date. All exposed dogs are surviving and will be maintained for lifespan observation. (U.S.)

  3. Effect of fasting on the transit time of 144Ce in the mouse gut

    Our work with G.I. absorption of actinide elements indicates greater absorption by fasted animals than by animals on regular diets (Weiss and Walburg, undated). Residence time of a metallic compound in the gut may be an important factor influencing G.I. absorption. Cerium-144 (III) chloride was administered by gavage to fasted mice and to mice on regular feed. The G.I. tract was excised, cut into sections, and the activity of each section determined as a function of time after dosing. Our results indicate rapid transit of 144CeCl3 along the empty mouse gut. One hour after dosing, about half the Ce is in the cecal contents; about 40% remains in stomach contents. Twelve hours after dosing, only about 2% remains in the cecum; by 16 hours, almost the entire dose has been cleared from the intestine. Transit times in mice with stomach and intestines containing food were 12 hours longer than in fasted mice. These results lead to the conclusion that factors other than G.I. residence time determine G.I. absorption of actinides in mice

  4. Effect on canine lymphocyte function of 144Ce inhaled in fused clay particles

    Beagle dogs exposed by inhalation to 144Ce in fused clay particles develop a persistent lymphopenia and the remaining peripheral lymphocytes in these dogs show a depressed in vitro response to plant mitogens. These studies were designed to evaluate the cellular basis for this defect. The survival and growth of lymphocytes from irradiated and control dogs were evaluated through 96 hours of culture. Many irradiated lymphocytes that were viable in vivo died within 24 hours in vitro. The remaining lymphocytes appeared to grow normally indicating that the early in vitro death was responsible for at least a portion of the difference between irradiated and control lymphocyte cultures. A second experiment was designed to determine if any humoral factors in plasma of irradiated dogs were responsible for the poor response of the lymphocytes. Lymphocytes from irradiated and control dogs were grown with plasma from both types of animals. Heterologous plasma had no apparent effect on lymphocyte growth, indicating that humoral factors were not involved. (U.S.)

  5. Biological effects of repeated inhalation exposure of Beagle dogs to relatively insoluble aerosols of 144Ce. VI

    Beagle dogs were exposed repeatedly to a relatively insoluble form of 144Ce (in fused aluminosilicate particles) to study the deposition, retention and long-term biological effects for comparison with data from dogs that were exposed only once to a similar aerosol. Four groups of nine dogs each were exposed once every 8 weeks for 2 years (13 exposures) to achieve specified exposure goals. These goals were: to increase the lung burden by 2.5 μCi 144Ce/kg body weight with each exposure; to reestablish lung burdens of 9 or 4.5 μCi 144Ce/kg body weight and to expose controls to fused aluminosilicate particles containing nonradioactive cerium. With these exposure sequences, the 144Ce-exposed dogs received increasing or relatively constant beta radiation dose rates in contrast to the steadily decreasing dose rate seen after a single inhalation exposure. Following completion of the exposure series, the dogs are being observed for the development of long-term biological effects. To date, 11 dogs have died or were euthanized, nine exposed dogs and two controls. Although pulmonary hemangiosarcomas were a prominent finding in dogs exposed once to the same aerosol at a level that led to cumulative doses to lung similar to these repeatedly exposed dogs, only one has been observed in the repeatedly exposed dogs. Other effects of note to date include three pulmonary carcinomas, two hemangiosarcomas of the tracheobronchial lymph nodes and one splenic hemangiosarcoma. Observations are continuing on the surviving 18 exposed and seven control dogs

  6. Kinetic study of the deposition of 144Ce, 143Pr and 147Nd on a platinum anode

    Investigation of the electrodeposition of radioactive rare earth metal isotopes confirm that, depending on the conditions of electrolysis, they can be deposited on the platinum either cathodically or anodically. The anodic deposition of these isotopes can take place with electrochemical oxidation or electrosorption without electron-transfer, depending on the lanthanide(III-IV) oxidation potentials. The present paper reports the results of the investigation connected with the anodic deposition of 144Ce, 143Pr and 147Nd. (author)

  7. Decontamination of 60Co and 144Ce. low-activity liquid wastes with the Fe3+ /OH- /Ca2+ /PO-4-3- system

    The influence of reaction time, concentrations of Fe3+ and PO-4-3+, temperature and agitation velocity in the efficiency of decontamination of 60Co and 144Ce low-activity liquid wastes using the Fe3+ /OH-/Ca2+ /PO-4-3+ precipitator system was stud ied in this paper. The mathematical models of this process were obtained for 60Co and 144Ce. The best conditions for the decontamination we re calculated using the optimization program

  8. Biological alterations resulting from chronic lung irradiation. I. The pulmonary lipid composition, physiology, and pathology after inhalation by beagle dogs of 144Ce-labeled fused clay aerosols

    Three groups of four beagle dogs inhaled a 144Ce-labeled fused clay aerosol; two additional dogs per group, exposed to a stable cerium-labeled fused clay aerosol, were used as controls. At monthly intervals, one diaphragmatic lobe of each of two dogs exposed to 144Ce and one control animal from each group was lavaged with isotonic saline. The recovered lavage solutions were centrifuged to isolate lung cells (mostly macrophages) and surfactant for lipid analyses. The groups were sacrificed at 2, 4, and 6 mo after exposure, when the lungs of the dogs exposed to 144Ce had average cumulative radiation doses of 23, 36, and 59 krad, respectively. Chronic irradiation of the lung resulted in a progressive radiation pneumonitis which was assessed clinically and pathologically at various intervals. At sacrifice, the lungs were analyzed for 144Ce and the right apical and diaphragmatic lobes were minced and lyophilized and the lipids were extracted. Total lipids from all lung samples were determined gravimetrically and individual compounds were identified, isolated, and quantitated. The quantities of lipid in lung tissue, in pulmonary cells, and in surfactant increased as a function of time and radiation dose. Neutral lipids (sterol esters and triglycerides) accounted for most of the increase. (U.S.)

  9. Suppression of the pulmonary clearance of Staphylococcus aureus in mice that had inhaled either 144CeO2 or 239PuO2

    The rate of pulmonary clearance of inhaled Staphylococcus aureus in mice was determined at intervals after inhalation exposure to either 144CeO2 or 239PuO2. In mice with mean initial lung burdens between 0.6 and 4.7 μCi 144Ce the pulmonary clearance of S. aureus was suppressed up to 12 weeks after inhalation of 144CeO2. In mice with mean initial lung burdens between 1.3 and 29.0 μCi 239Pu the pulmonary clearance of S. aureus was suppressed up to 26 weeks after inhalation of 239PuO2. The suppressed pulmonary clearance of S. aureus appeared to correlate with the radiation dose rate to the lungs at the time of exposure to bacteria but not with the cumulative radiation dose to the lungs. The changes in bacterial clearance did not appear to be correlated with changes in body weight, hematological parameters, or radiation-induced histopathological changes. Altered bacterial clearance may be related to radiation damage to pulmonary macrophages. It was concluded that irradiation of the lung from radionuclides inhaled in relatively insoluble forms may result in increased bacterial invasion of the lungs

  10. CeLAND: search for a 4th light neutrino state with a 3 PBq 144Ce-144Pr electron antineutrino generator in KamLAND

    Gando, A; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Ishikawa, H; Koga, M; Matsuda, R; Matsuda, S; Mitsui, T; Motoki, D; Nakamura, K; Oki, Y; Otani, M; Shimizu, I; Shirai, J; Suekane, F; Suzuki, A; Takemoto, Y; Tamae, K; Ueshima, K; Watanabe, H; Xu, B D; Yamada, S; Yamauchi, Y; Yoshida, H; Cribier, M; Durero, M; Fischer, V; Gaffiot, J; Jonqueres, N; Kouchner, A; Lasserre, T; Leterme, D; Letourneau, A; Lhuillier, D; Mention, G; Rampal, G; Scola, L; Veyssiere, Ch; Vivier, M; Yala, P; Berger, B E; Kozlov, A; Banks, T; Dwyer, D; Fujikawa, B K; Han, K; Kolomensky, Yu G; Mei, Y; O'Donnell, T; Decowski, P; Markoff, D M; Yoshida, S; Kornoukhov, V N; Gelis, T V M; Tikhomirov, G V; Learned, J G; Maricic, J; Matsuno, S; Milincic, R; Karwowski, H J; Efremenko, Y; Detwiler, A; Enomoto, S

    2013-01-01

    The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq (75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the center or next to a large low-background liquid scintillator detector. The antineutrino generator will be produced by the Russian reprocessing plant PA Mayak as early as 2014, transported to Japan, and deployed in the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015. KamLAND's 13 m diameter target volume provides a suitable environment to measure the energy and position dependence of the detected neutrino flux. A characteristic oscillation pattern would be visible for a baseline of about 10 m or less, providing a very clean signal of neutrino disappearance into a yet-unknown, sterile neutrino state. This will provide a comprehensive test of the electron dissaperance neutrino anomalies and could lead to the discovery of a 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.

  11. An experimental study of the time dependence of uptake from soil of 137Cs, 106Ru, 144Ce and 99Tc into green vegetables, wheat and potatoes

    In this study the experimental data were analysed using the CEGB's dynamic foodchain model, and were used to validate the relevant part of the model structure, to produce model-specific input data and to identify possible future improvements to the model structure. The root uptake of the specified radionuclides was studied and the concentration levels measured. The data were analysed using a simplified version of the general model. The compartment system incorporated within the model was shown to be capable of reproducing the data for 137Cs, 106Ru and 144Ce to an extent sufficient to justify its use in ingestion radiological dose assessments, but to be less successful in fitting the 99Tc data. The analysis resulted in the production of a well validated set of model-specific input data relevant to UK conditions and agricultural practice differing significantly from values obtained from global literature surveys. Possible future improvements to the model structure were also identified, aimed at providing improved estimates of crop contamination levels for timescales in excess of those considered in this study. (U.K.)

  12. A Brief Review of Past INL Work Assessing Radionuclide Content in TMI-2 Melted Fuel Debris: The Use of 144Ce as a Surrogate for Pu Accountancy

    D. L. Chichester; S. J. Thompson

    2013-09-01

    This report serves as a literature review of prior work performed at Idaho National Laboratory, and its predecessor organizations Idaho National Engineering Laboratory (INEL) and Idaho National Engineering and Environmental Laboratory (INEEL), studying radionuclide partitioning within the melted fuel debris of the reactor of the Three Mile Island 2 (TMI-2) nuclear power plant. The purpose of this review is to document prior published work that provides supporting evidence of the utility of using 144Ce as a surrogate for plutonium within melted fuel debris. When the TMI-2 accident occurred no quantitative nondestructive analysis (NDA) techniques existed that could assay plutonium in the unconventional wastes from the reactor. However, unpublished work performed at INL by D. W. Akers in the late 1980s through the 1990s demonstrated that passive gamma-ray spectrometry of 144Ce could potentially be used to develop a semi-quantitative correlation for estimating plutonium content in these materials. The fate and transport of radioisotopes in fuel from different regions of the core, including uranium, fission products, and actinides, appear to be well characterized based on the maximum temperature reached by fuel in different parts of the core and the melting point, boiling point, and volatility of those radioisotopes. Also, the chemical interactions between fuel, fuel cladding, control elements, and core structural components appears to have played a large role in determining when and how fuel relocation occurred in the core; perhaps the most important of these reaction appears to be related to the formation of mixed-material alloys, eutectics, in the fuel cladding. Because of its high melting point, low volatility, and similar chemical behavior to plutonium, the element cerium appears to have behaved similarly to plutonium during the evolution of the TMI-2 accident. Anecdotal evidence extrapolated from open-source literature strengthens this logical feasibility for

  13. The study of the effect of gamma radiation on the ionic and collodial solutions of 144Ce/III/ at trace concentration by the method of self-diffusion and centrifugation

    Gamma irradiation of a solution of trace concentration of 144Ce/III/ at pH 3.0 causes an increase in the self-diffusion coefficient of 144Ce/III/ and small decrease in its centrifugable fraction. The significant increase in the self-diffusion coefficient is observed after irradiation at pH 9.0 and 11.0 and on the centrifugation of these solutions an increased susceptibility of particles containing 144Ce/III/ to the coagulation accurs. The measurements were performed by a method of the open end capillary immersed into the excess of inactive solution and the self-diffusion coefficient calculated as described earlier. The solutions were irradiated either directly in the capillaries for the self-diffusion measurment fixed in the glass tubes or in borosilicate Sial glass sample tubes with subsequent pipetting into the capillaries. The dose rate of 60Co γ-radiation was about 0.4 Mrad. hour-1, the time of irradiation was 1.5 to 15 hours. The period between the end of the irradiation and the beginning of the self-diffusion measurement amounted to about 15 to 30 min. (F.G.)

  14. Radiochemical methods used by the IAEA's laboratories at Siebersdorf for the determination of 90Sr, 144Ce and Pu radionuclides in environmental samples collected for the International Chernobyl Project

    During the IAEA's International Chernobyl Project to assess the radiological consequences of the nuclear reactor accident, the Agency's Laboratories at Seibersdorf participated in the collection and analyses of environmental samples from the Soviet Union. Under Task 2 of this effort, the determination of the activity concentrations of 90Sr and the alpha-emitting Pu radionuclides was important for the corroboration of the official USSR environmental contamination maps. The present paper describes in detail the sampling methods and radiochemical procedures used for the 90Sr, 144Ce, 238Pu and 239,240Pu analyses in these samples with emphasis on the grass and soil treatments. (Author)

  15. Appendix to Health and Safety Laboratory environmental quarterly, March 1, 1976--June 1, 1976. [Tabulated data on content of lead in surface air and /sup 7/Be, /sup 95/Zr, /sup 137/Cs, /sup 144/Ce, and /sup 90/Sr in surface air, milk, drinking water, and foods sampled in USA

    Hardy, E.P. Jr.

    1976-07-01

    Tabulated data are presented on: the monthly deposition of /sup 89/Sr and /sup 90/Sr at some 100 world land sites; the content of lead and /sup 7/Be, /sup 95/Zr, /sup 137/Cs, and /sup 144/Ce in samples of surface air from various world sites; and the content of /sup 90/Sr in samples of milk, drinking water, and animal and human diets collected at various locations throughout the USA. (CH)

  16. Yield-Energy Dependence for 147Nd and 144Ce Under Strong Neutron Field

    QIAN; Jing; LIU; Ting-jin; SUN; Zheng-jun; SHU; Neng-chuan

    2012-01-01

    <正>The data of the fission product yield play an important role in the nuclear science technology and nuclear engineering because they are the key data in the calculation of the decay heat, shield design, nuclear verification, radiochemistry reprocessing and nuclear safety, etc. Especially, it is the essential data in fission power estimation for a fission device. It is well known that there exists a consecutive neutron spectrum with the energy from 1 keV to 15 MeV for a fission-fusion device. So in order to estimate the

  17. Gazifikatsiya biomassy i ee perspektivy dlya proizvodstva elektricheskoi energii

    Vosecký, Martin; Skoblia, Sergej; Koutský, B.; Malecha, J.; Punčochář, Miroslav

    Minsk: BGTI, 2005, s. 72-78. ISBN 985-434-554-8. [Mezhudnarodnaya nauchno-tekhnichaskaya konferentsiya "Resursno- i enepgosberegayuschie tekhnologii i oborudovanie, ekologicheski bezopasnye tekhnologii". Minsk (BY), 16.11.2005-18.11.2005] R&D Projects: GA ČR(CZ) GA104/04/0829 Institutional research plan: CEZ:AV0Z40720504 Keywords : biomass * gasification * electricity production Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  18. Behaviour of the radionuclides 125J, 85Sr, 134Cs and 144Ce in three typical sands of Northern Germany under conditions of water-unsaturated flow

    The investigations described in this study help to explain the migration of radionuclides, being in the seepage water, in the upper soil layers. We investigated the behaviour of the radionuclides of the elements J, Sr, Cs and Ce in three types of loose rocks taken from the C-horizon of characteristic soils existing in the surroundings of Gorleben (Lower Saxony). These loose rocks are medium- and fine-grained sands. In the laboratory we performed Batch and column experiments under the conditions of water-unsaturated flow. For these investigations we used an experimental rainwater, which we had prepared on the basis of the analytic mean values obtained for the rainwater of the Gorleben surroundings. (orig./RW)

  19. High-temperature materials for MHD installations. Vysokotemperaturnye materialy dlya MGD-ustanovok

    Rekov, A.I.; Romanov, A.I. (eds.)

    1977-01-01

    The collection of articles was compiled on the basis of papers presented at the All-Union Conference on materials for MHD Installations in 1972. The collection also contains several articles which give results of studies made in 1973--1974. The articles are concerned with the development and investigation of high-temperature non-metallic materials (ceramic oxides, cermets, fire-resistant concrete, etc.) for various thermal units of a MHD installation (channel, combustion chamber, paragenerator, and others). Particular attention was given to the problem of electron and electric-insulation materials of the MHD-generator's channel. An examination is made of the physico-chemical aspects of producing materials and data are presented on studies of their composition and structure, and descriptions are given of the methods and research results from studies on thermo-mechanical strength, thermal and erosion resistance, electroconductivity, thermoemission, thermal conductivity, chemical resistance, and other properties of materials. The behavior of those materials was also tested in various MHD machines (U-02, U-25, and others). The collection is intended for specialists in the area of making and investigating materials for operating at high temperatures and in aggressive media.

  20. Isledovanie nanochastits, prednaznachenykh dlya adresnoy dostavki lekarstv metodami malouglovogo sinkhrotronogo isledovania i raseyaniya neutronov. Vnutrenaya struktura i funktsional'nost'

    Filippov, Sergey K.; Chytil, Petr; Konarev, P.; Papadakis, K. M.; Radulesku, A.; Pleštil, Josef; Štěpánek, Petr; Etrych, Tomáš; Ulbrich, Karel; Svergun, D.

    Gatchina : National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute B. P. Konstantinov, 2014. s. 72. [Meetings and Youth Conference on Neutron Scattering and Synchrotron Radiation in Condesed Matter (NSSR-CM-2014). 27.10.2014-31.10.2014, St. Petersburg] R&D Projects: GA ČR GAP108/12/0640 Institutional support: RVO:61389013 Keywords : nanoparticles * SAXS * SANS Subject RIV: CD - Macromolecular Chemistry

  1. Problems in stabilizing the quality of brown coal fuel for powerful state regional electric power plants. Zadachi stabilizatsii kachestva burougol'nogo topliva dlya moshchykh GRES

    Varshavskiy, A.M.

    1984-01-01

    The change in the structure of the fuel balance of thermal electric power plants over the last decades is examined. The growing role of brown coals for coal dust combustion at the present time is shown. Data are cited which characterize the Kansko Achinskiy fuel and energy complex, the deposit of brown coal and the specifications on the quality of the coal. Characteristic to this are thick, complexly structured coal strata of high strength with substantial fluctuations in ash content, moisture level and heat creating capability. The powerful energy producing units of thermal electric power plants require a quite uniform fuel quality. The existing GOST 11717-78 insufficiently regulates the specifications for the quality of fuel for state regional electric power plants (GRES) which come from the different open pits of the Kansko Achinskiy basin. It is proposed that the coal be averaged and ground within the concentrating plant by means of cutting excavators and that corrections to the GOST be introduced.

  2. An investigation of the effectiveness of blending (averaging) brown coal for state regional electric power plants (GRES). Issledovaniye effektivnosti usredneniya burykh ugley dlya GRES

    Varshavskiy, A.M.

    1985-01-01

    The variability of the ash content of coal effects the specific expenditure of fuel by a state regional electric power plant for producing electric power. The studies were conducted at the Aleksandriyskiy thermal power plant (TeTs) number three and at the Zaporozhye, Yermakovskiy and Nazarovskiy state regional thermal power plants. It is established that a reduction in the mean square deviation of the hourly volumes of coal from 3 to 0.5 leads to a savings of 3.2 to 3.8 percent of coal and 2.4 to 2.9 percent brown coal. Regression equations are acquired. Correlation factors are calculated which do not exceed 0.7 percent of the reliable association between indicators.

  3. On Jackson's theorem for the modulus of smoothness determined by a nonsymmetric generalised shift operator

    Potapov, Mikhail K.; Berisha, Faton M.

    2012-01-01

    In this paper a class of asymmetrical operators of generalised translation is introduced, for each of them generalised moduli of smoothness are introduced, and Jackson's and its converse theorems are proved for those moduli. ----- V eto\\v{i} rabote rassmatrivaetsya klass sesimmetrichnykh operatorov obobshchenogo sdviga, dlya kazhdogo iz nikh vvoditsya obobshchennye moduli gladkosti i dlya nikh dokazybaetsya teorma Dzheksona i teorema, obratnaya e\\v{i}.

  4. The results of using space photographic information to study the geological structure of the Pechora coal basin. Rezultaty primeneniya kosmicheskoy foroinformatsii dlya izucheniya geologicheskogo stroyeniya Pechorskogo ugol'nogo basseyna

    Zhuravlev, A.V.

    1983-01-01

    The possibilities of space structural analysis as applied to the Pechora basin are examined. A number of first order structures are identified directly on the space photographs (the Korotaikhinsk depression, the Chernysheva uplift and the Paykhoyskiy anticlinorium and so on). Ring shaped morphostructures are confined to the uplifts of the basement rock and the cap, to periclinal parts of the depressions and the points of crossing and confluence of linear positive structures. The results are cited of a comparison of the rose diagrams of the lineaments and the fracture faults in the basin as a whole and in its individual structures. Charts of the density of the nodes of intersection, the thickness and density of the lineaments and the tectonic field intensity are built for the northern part of the Chernyshev chain and the Losyu Rogovskiy depression, based on an analysis of which the zones of high concentration of lineaments are identified. A conclusion is drawn about their affinity to positive structures of different regions.

  5. Influence of variations in dose and dose rates on biological effects of inhaled beta-emitting radionuclides

    The biological effects of inhaled β-emitting radionuclides, 90Y, 91Y, 144Ce and 90Sr, are being investigated in beagle dogs that received single acute exposures at 12 to 14 months of age. The aerosols studied have included 91YC13,144CeC13, 90SrC12, and 90Y, 91Y, 144Ce or 90Sr in aluminosilicate particles. Thus, 91YCl3, 144CeCl3 and the aluminosilicate containing radionuclide particles all resulted in significant exposures to lung; 91YC13, 144CeC13 an 90SrC12 resulted in significant exposures to bone; 91YC13 and 144 CeC13 resulted in significant exposures to liver. The higher initial doserate exposures have been more effective than low dose-rate exposures on a per-rad basis in producing early effects. To date (144CeO2, it was observed that, on a μCi initial lung burden per kilogram body weight basis, mice did not develop pulmonary tumours whereas beagle dogs did. To fid out the reason for this observation mice have been repeatedly exposed by inhalation to 144CeO2 to maintain lung burdens of 144Ce that resulted in radiation dose rates similar to that observed in beagle dogs. Several of the repeatedly exposed mice developed malignant pulmonary tumours. Thus, with similar dose rates and cumulative doses to the lung, mice and dogs responded in a similar manner to chronic β radiation

  6. Nasal carcinomas in beagle dogs after inhalatioon of relatively soluble forms of beta-emitting radionuclides

    Beagle dogs were exposed by inhalation to relatively soluble forms of three beta-emitting radionuclides and are being held for life span observation to evaluate hazards associated with nuclear power production. Dogs were exposed to graded activity levels of 91YCl3, 144CeCl3 or 90SrCl2. With 91YCl3 and 144CeCl3, significant radiation dose was delivered to liver, respiratory tract, and skeleton. With 90SrCl2, the dose was essentially to skeleton. Nasal cavity squamous cell carcinomas have been the most frequent neoplasms in the 91Y and one of the most frequent in the 144Ce study while relatively few have been seen after 90Sr exposure. Also one nasal cavity hemangiosarcoma was seen in the 144Ce study. The 90Sr-exposed dogs have survived longer after exposure and have higher skeletal radiation doses than do the dogs exposed to 91Y or 144Ce. The greater incidence of nasal carcinomas can be explained by the finding of high concentrations of the lanthanides, 91Y and 144Ce, associated with the nasal turbinate epithelium

  7. Il personaggio scontornato in Škola dlja Durakov. Dal romanzo di Saša Sokolov agli adattamenti teatrali

    Irina Marchesini

    2012-01-01

    Sokolov’s Shkola dlya Durakov (A School for Fools, 1976) is an extremely complex novel, which “depicts [the] world”, as D. Barton Johnson (1986:640)[1] poignantly observes, “through the eyes, and pure, if eccentric, language, of a schizophrenic youth”. How is it possible to translate such linguistic features and the effects they create into another medium? This question lies at the core of my proposal, which aims to approach the problem of intermedial transla...

  8. On a connection between a generalised modulus of smoothness of order~$r$ and the best approximation by algebraic polynomials

    Potapov, Mikhail K.; Berisha, Faton M.

    2012-01-01

    In this paper an asymmetrical operator of generalised translation is introduced, the generalised modulus of smoothness is defined by its means and the direct and inverse theorems in approximation theory are proved for that modulus. ----- V danno\\v{i} rabote vvoditsya nesimmetrichny\\v{i} operator obobshchennogo sdviga, s ego pomoshchyu opredelyaetsya obobshchenny\\v{i} modul' gladkosti i dlya nego dokazyvaetsya pryamaya i obratnaya teoremy teorii priblizheni\\v{i}.

  9. Elimination of cerium-144 - physical and biological characteristics

    The decontamination efficiency of the preparation pentacyn (CaNa3-DTPA) with regard to radiocerium was evaluated. Investigated were not only physical parameters (radionuclide kinetics, absorbed doses decrease), but also morphological and biochemical indexes. Four groups of male Wistar rats were treated accordingly with 144Ce; 144Ce + pentacyn; external irrradiation + 144Ce; external irradiation + 144Ce + pentacyn. External gamma irradiation was performed with a dose of 260 cGy, 144Ce (1480 kBq/animal) was introduced intratarcheally 1 h after external irradiation. Pentacyn was administred according to the following scheme, ensuring maximal efficiency and minimal toxicity: intratracheally administration 30 min after radionuclide intake by 0.2 ml and subsequent intraperitoneally applications on days 1, 3, 5, 7, 10 and 17 by 0.5 ml. Determined were the following parameters characterizing the development of fibrous process: the quantity of oxyproline in collagen, the quantity of hexosamine in lung tissues, the changes in dry mass and heart camera index. It was concluded that biological criteria are important component of the decontamination efficiency evaluation

  10. Genetic effects induced by radionuclides in the populations of the chlorella and antimutagenic influence of the vitamins C and B12

    Genetic influence of 90Sr, 137Cs and 144Ce on the chlorella populations has been studied, as well as antimutagenic effect of C and B12 vitamins on the influenced by 90Sr and 144Ce chlorella populations. The radionuclides 90Sr, 137Cs and 144Ce have been determined to increase the number of lethal and mutant cells in the chlorella populations. It has been shown that according to the influence of the number of lethally injured cells the radionuclides under study (within the concentration range 3.7X104 - 3.7X106 Bk/l) may be presented by the sequence 144Ce>137Cs≥90Sr, while according to the influence of the number of mutant cells - by the reverse sequence 90Sr>137Cs≥144Ce. Such different effect of the radionuclides on the chlorella populations may, possibly, be explained by different physical-chemical state of these radionuclides in water medium, their different uptake mechanism in plant cells, and different localization in them. A conclusion is drawn that C and B12 vitamins reduce radiosensitivity of water organisms, especially their lethality. B12 vitamin is stornger a mutagen than vitamin C

  11. Physiological and genetic effects induced in the chlorella culture by radionuclides

    Radionulcides 90Sr. 137Cs and 144Ce suppress chlorella populations in 37-10-6-37X10-4 Bk/e copcentration range; they increase the amount of lethally damaged and mutant cells at that. Investigated radionuclides can be presented in the form of 144Ce > 137Cs > 90Sr series with respect to their effect on the intensity of chlorella population photosynthesis and amount of lethally damaged cells. as well as accumulation levels, and in the form of 90Sr 137Ce > 144Ce series with negative sequence with respect to the effect on cell density, especially on the amount of mutant cells. The inverse relationship betWeen the change of photosynthesis intensity and the amount of lethally damaged cells, as well as betWeen the change of cell density and the maount of mutant cells was observed during radionuclide effect on chlorella populations

  12. Combinative effect of medium physical and chemical factors on the penetration and localization of some radionuclides in water plant cells

    As a result of the experiments, carried out with the charophytes algae Nitellopsis obtusa, gathered from lake Drukshyaj (the North-East part of the Lithuanian SSR) in 1985, it has been determined that the 90Sr, 144Ce and 137Cs radionuclides accumulation by water plant cell constituents (wall, protoplasm, vacuole) is substantially influenced by the water temperature, the chemical substances, which change the water structure, as well as the combinative effect of these factors. An identical character of the changes of the accumulation factors of 90Sr and 137Cs, which are found in the water solutions in an ionic form, and slightly different character in the case of 144Ce, which exists by 85% in the form of colloid particles, have been noted. In the case of 144Ce the influence of the physical as well as chamical factors on the cell walls is felt stronger than on the inner cell membranes

  13. Separation of radioactive substances by anodic electrolysis

    In experiments on the electrodeposition of radioisotopes on a platinum anode it was observed that the isotopes could be classified into: (1) those whose cations are deposited as oxides; and (2) those whose cations are only adsorbed on the anode. Under given conditions this difference can be used to separate ions of the two groups. In the present paper, experimental details are given of the separation of 144Ce from 140La. The separation of 144Ce from uranium fission products in the presence of uranyl ion is also discussed. (U.K.)

  14. Toxicity studies of inhaled beta-emitting radionuclides: status report

    The influence of total dose and dose rate on the effects of inhaled beta-emitting radionuclides is being studied in laboratory animals. The radionuclides are inhaled either in a relatively soluble form (90SrCl2, 144CeCl3, 91YCl3 or 137CsCl) or in a relatively insoluble form in fused aluminosilicate particles. The organs affected depend on the solubility and chemical characteristics of the radio isotopes. Studies with young adult dogs are complemented with comparable studies in other species (mice, rats and Syrian hamsters), with animals of different ages and with animals repeatedly exposed to 144Ce

  15. Toxicity studies of inhaled beta-emitting radionuclides - status report

    The influence of total dose and dose rate pattern on the effects of inhaled β-emitting radionuclides is being studied in laboratory animals. The inhaled radionuclides were either in a relatively soluble form (90SrCl2, 144CeCl3, 91YCl3, or 137CsCl), or in a relatively insoluble form in fused aluminosilicate particles. The organs affected depend on the solubility and chemical characteristics of the radionuclides. Studies with young adult dogs are complemented by comparable studies in other species (mice, rats, and Syrian hamsters), with animals of different ages and animals repeatedly exposed to 144Ce. 12 references, 2 figures, 2 tables

  16. Assessment of a cerium---praseodymium-144 inhalation case

    A case involving an acute exposure to a 144Ce-144Pr contaminated atmosphere is presented with a discussion of the treatment and evaluation of data collected out to 800 days post intake. Treatment included irrigation of the upper nasal passages with normal saline, nebulization with normal saline mist and DTPA therapy. Assessment of the deposition and the resulting dose commitment was based on in vivo measurements and excretion data. The initial pulmonary burden, which cleared with three distinct half times, was estimated at 2.1 μCi of 144Ce

  17. Assessment of a cerium-praseodymium-144 inhalation case

    A case involving an acute exposure to a 144Ce-144Pr-contaminated atmosphere is presented with a discussion of the treatment and evaluation of data collected up to 800 days post-intake. Treatment included irrigation of the upper nasal passages with normal saline, nebulization with normal saline mist, and intravenous DTPA therapy. Assessment of the deposition and the resulting dose commitment was based on in vivo measurements and excretion data. The initial pulmonary burden, which cleared with three distinct half-times, was estimated at 2.1 μCi of 144Ce. (author)

  18. Comparison of the effects of inhaled alpha- and beta-emitting radionuclides on pulmonary function in the dog

    Alterations of pulmonary function in representative groups of dogs developing nonneoplastic lung disease, after single inhalation exposures to cerium-144 or plutonium-238 in relatively insoluble particulate forms, were compared. The inhaled particles had similar aerodynamic diameters and effective half-lives of retention in the lung. The mean initial lung burdens of the 144Ce- and 238Pu-exposed groups were 51 and 0.65 μCi/kg of body weight, respectively. Because of the respective ranges of the beta emissions from 144Ce and the alpha emissions from 238Pu, the lungs of the 144Ce-exposed dogs were relatively uniformly irradiated, whereas only approximately 6% of the lung tissue of rates to the 238Pu-exposed dogs was irradiated. The calculated average dose rates to the irradiated tissue were similar for both radionuclides. Pulmonary function was measured serially without sedation. Both groups developed progressive, restrictive lung disease, which ended in death from pulmonary failure. Dogs that inhaled 144Ce had an early reduction of CO diffusing capacity followed by a progressive mechanical and gas-exchange impairment similar to that reported for dogs and men exposed to external irradiation. Dogs that inhaled 238Pu had increased respiratory frequencies which often persisted for months before mechanical and gas-exchange abnormalities became evident

  19. Separation of cerium from high level waste solution of Purex origin

    A simple solvent extraction procedure for the separation of 144Ce from Purex high level waste (HLW) is described. 2-ethylhexyl 2-ethylhexyl phosphonic acid (KSM-17) has been used as extractant. About 10 mCi of cerium was separated from HLW using this technique. This method is amenable for automation and scale up. (author)

  20. Radiation-induced liver lesions in beagle dogs

    The risk for liver disease from internally deposited beta-emitting radionuclides is unknown because there are no human populations exposed to hepatotropic beta-emitting radionuclides available for study. In this report, we discuss the hepatic lesion in dogs exposed to a beta-emitting radionuclide, 144CeCl3, and held for their life spans

  1. Quantitative analysis of fission products by γ spectrography

    The activity of the fission products present in treated solutions of irradiated fuels is given as a function of the time of cooling and of the irradiation time. The variation of the ratio (144Ce + 144Pr activity)/ 137Cs activity) as a function of these same parameters is also given. From these results a method is deduced giving the 'age' of the solution analyzed. By γ-scintillation spectrography it was possible to estimate the following elements individually: 141Ce, 144Ce + 144Pr, 103Ru, 106Ru + 106Rh, 137Cs, 95Zr + 95Nb. Yield curves are given for the case of a single emitter. Of the various existing methods, that of the least squares was used for the quantitative analysis of the afore-mentioned fission products. The accuracy attained varies from 3 to 10%. (author)

  2. Decontamination of a radioactive process waste water by adsorbing colloid flotation

    As a part of a research programme on the treatment of a radioactive process waste water by foam separation techniques, adsorbing colloid flotation was tested to remove 144Ce, 60Co, 65Zn and 89Sr from the waste water. Potassium oleate was used as the collector, and Fe(III) hydroxide, Al(III) hydroxide or Co(II) hydroxide as the coprecipitant. Under the optimal conditions; removals exceeding 99% could be achieved for 65Zn with any of the tested coprecipitants, for 144Ce with Fe(III) and Co(II) hydroxides and for 60Co with only Co(II) hydroxide. For 89Sr removals > 90% could be achieved with only Fe(III) hydroxide. The adsorbing colloid flotation process was compared with both chemical precipitation and ion exchange, and advantages of adsorbing colloid flotation were enumerated. (author)

  3. Decontamination of radioactive process waste water by adsorbing colloid flotation

    Adsorbing colloid flotation was tested to remove 144Ce, 60Co, 65Zn, and 89Sr from radioactive process waste water. Potassium oleate was used as the collector, and Fe(III) hydroxide, Al(III) hydroxide or Co(II) hydroxide as the coprecipitant. Under optimal conditions, removals exceeding 99% could be achieved for 65Zn with any of the tested coprecipitants, for 144Ce with Fe(III) and Co(II) hydroxides and for 60Co with only Co(II) hydroxide. For 89Sr removals of 90% could be achieved only with Fe(III) hydroxide. The adsorbing colloid flotation process was compared with both chemical precipitation and ion exchange. Advantages of adsorbing colloid flotation are discussed. (author)

  4. Separation of plutonium from uranium and fission products in the zirconium pyrophospate column

    Distribution coefficients were of the following ions were determined in the system zirconium pyrophosphate - aqueous solution HNO3 : Pu3+, Pu4+, PuO22+, UO22+, 234Th2+, 95Zr, 95Nb, 106Ru, 144Ce3+, 90Sr2+, 137Cs+, 59Fe3+ and 59Fe2+. According to the distribution coefficients it can be concluded that the separation of some cations is possible. This was proved by using separation columns. The following successful separations were completed: 90Sr2+ from 90I3+, 90Sr2+ from 90I3+ and 1'37Cs+, UO2+ from 234Th4+, Pu4+ from UO22+, 95Zr, 95Nb, 106Ru, 144Ce3+, 90Sr2+, 137Cs+. Decontamination factors of plutonium from the mentioned cations were determined. It was found that the sorption of Cs+ and Sr2+ is based on ion exchange

  5. Accumulation and excretion of radionuclides by alga Chara tomentosa

    It has been found in the course of the study of accumulation and excretion of radionuclides by alga chara tomentosa that 55Fe, 60Co, 91Y are accumulated by living and dead components of alga chara tomentosa to a far greater extent and are stronger retained than 90Sr, 137Cs, 144Ce. The main part of the absorbed quantities of all investigated nuclides (80-92%) is fixed on the surface of the plant in the ''cortex'' layer

  6. Radio-isotope converter

    Due to the surface power density required for thermoelectric and thermionic converters, available radioactive sources are surveyed and listed. Curves of specific minimum diameter versus thermal flux density are given. 210Po and 242Cm appear to be suitable for direct thermionic when alpha emitters such as 238Pu and 244Cm are still suitable for thermoelectric conversion. This mode will also work with beta emitters 170Tm, 90Sr, 144Ce and 137Cs. Some thermoelectric radioisotope heated converters are suggested. (authors)

  7. Electrochemical investigation of rare earth amalgams

    Using the method of filtration of heterogeneous samarium amalgams, containing radioactive isotopes sup(144)Ce and sup(152)Eu, it has been shown that cerium is inserted into the solid phase of samarium amalgam, whereas europium does not cocrystallize with samarium. The solubility of praseodymium, neodymium, and gadolinium in mercury has been determined on the basis of the curves current VS time of decomposition of heterogeneous amalgams of these metals

  8. Comparison of the effects of inhaled alpha- and beta-emitting radionuclides on pulmonary function of the dog

    Pulmonary function changes of representative dogs after inhalation of a relatively insoluble form of 144Ce in fused aluminosilicate particles and 238PuO2 were compared. Both radionuclide forms had approximately the same effective half-life, but the 238PuO2 irradiated 11 percent of the lung while the 144Ce irradiated 100 percent. Both groups developed restrictive lung disease progressing to pulmonary failure but the sequence of functional changes differed. The first change in dogs that inhaled 144Ce was a reduced CO diffusing capacity followed later by changes in breathing pattern, lung compliance and alveolar-capillary O2 exchange. The first change in dogs that inhaled 238PuO2 was an increase in respiratory frequency which persisted for several months before nearly simultaneous changes in diffusing capacity, compliance and gas mixing. An impairment in alveolar-capillary O2 exchange occurred later in dogs that inhaled 238PuO2. Functional alterations of both groups in pulmonary failure were similar. The differences in the pattern of functional changes were thought to be related to differences in dose pattern, but the exact relationships are unknown

  9. Pulmonary carcinogenesis and chronic beta irradiation of lung

    Light water nuclear power reactor fuel cycles at various stages contain substantial quantities of β-emitting radionuclides. Thus, in the event of an accident, there is potential for inhalation exposure of man to various types and forms of β-emitting radionuclides. In order to study the biological effects of such potential exposures, a series of life span studies have been initiated in which beagle dogs have been exposed to inhalation to achieve graded lung burdens of a relatively insoluble fused clay form of β-emitting radionuclides. The specific radionuclides, 90Y, 91Y, 144Ce, or 90Sr, were selected on the basis of physical half-life to produce a variety of radiation-dose patterns to the lung. Early effects have been the development of radiation pneumonitis and progressive pulmonary fibrosis. In general, dogs which receive high- and rapidly-declining dose-rate exposure from 90Y or 91Y die earlier and at lower cumulative doses than dogs exposed to 144Ce or 90Sr. By contrast, the incidence of later-occurring malignant lung tumors and the degree of inflammatory response is greater in dogs which received protracted low dose-rate exposure associated with 144Ce and 90Sr. Of particular note is the nature of the lung tumors thus far observed

  10. High voltage deposition of daughter 144Pr on platinum electrode from chlorbenzene solution of cerium 8-hydroxyquinolinate

    The deposition of 144Pr, carrier-free, on platinum electrode, formed by beta-decay of 144Ce which was in the form of cerium tetrakis (8-hydroxyquinolinate) chelate in chlorobenzene, was studied in dependence on time and intensity of the electric field. The amount of 144Pr deposited on the cathode after 20 min at the intensity of electric field 8 kV cm-1 was 14% of its total equilibrium amount in the solution. The proportion of 144Pr formed in the solution as ions was found by extrapolating the experimental relationships to be 23%. This value was similar to that of the break-up of molecular forms under the formation of simple 144Pr ions expected on the basis of the decay scheme of 144Ce and the mechanism of the energy transfer inside the atoms and molecular systems. On the basis of the mobility of cations found (9.6x10-5 cm2kV-1s-1) it was assumed that deposited ions were probably monotypes. The amount of 144Pr deposited on the anode was about 1% and that of 144Ce on both the cathode and the anode (caused by adsorption) was 0.5 to 1%. (author)

  11. Evolution of gamma artificial radioactivity in coastal sediments of the English Channel during the years 1976, 1977 and 1978

    During 1976-1977, a state of equilibrium was found to prevail for 106Ru and 144Ce, especially in the North-West Cotentin and the Norman-Breton gulf, where reconcentration of both radionuclides was observed with preferential enrichment of the latter over the former. Levels of 125Sb and 137Cs were found to be low but were difficult to interpret, because of the particular physico-chemical behavior of 125Sb and the long half-life of 137Cs. The results obtained for 103Ru, 141Ce, 95Zr may be explained entirely by the contribution of atmospheric fallout. 144Ce and 106Ru levels in the Norman-Breton gulf may be for the most part ascribed to La Hague disposals, radionuclide dispersal from the emissary being characterized by an eastward transfer of the soluble fraction and a westward transfer of the particulate fraction, with transit times which may last up to 2 years. The boundary between the areas submitted respectively to the twofold impact of fallout and industrial waste, and to fallout alone would appear to lie between the mouth of the Trieux river and Morlaix Bay. From a graphic representation of the relationship between radionuclides, empiric distribution laws for 106Ru and 137Cs were established from 144Ce level parameters characteristic of the areas considered (years 1976-1977)

  12. Influence of complex formation on extraction of some fission products by sorption on inorganic sorbents

    Sorption of fission products of radionuclides 137Cs, 89,90Sr, 90,91Y, 86Rb, 133Ba, 95Zr+95Nb, 95Nb, 103,106Ru, 141,144Ce, 115mCd, 113Sn, 125Sb by hydroxides Fe(III), Mn(IV) on the background of 1 mol/l of NaNO3 at the pretense of ions SO42-, C2O42- at a wide ph range (1+14) is studied in present work. Optimal conditions of extraction of each radionuclide by sorption on inorganic sorbents are defined.

  13. Life-span health effects of relatively soluble forms of internally deposited beta-emitting radionuclides

    As part of a large research effort to study the lifetime health risks of inhaled radionuclides, Beagle dogs inhaled 90SrCl2 or 144CeCl3 or were injected intravenously with 137CsCl. Because these three compounds were soluble in body fluids, the resulting widely differing patterns of radionuclide distribution and dose reflected tissue affinities of the elements involved. Long-term health effects, predominantly cancers, were seen in the organs receiving the highest doses. Investigations are continuing on the extent to which other less irradiated organs may have also been affected

  14. Radionuclide volatilization during plasmachemical reprocessing of radioactive wastes

    Volatilization of 137Cs, 60Co, 90Sr, 144Ce and α-active radionuclides under high temperature utilization of solid and liquid low- and intermediate level radioactive wastes is studied. Low temperature plasma of arc plasmatroned was used as a heat carrier in the laboratory conditions and on experimental installation with shaft furnace and direct flow plasma-chemical reactor. The lowest radionuclides lost (1-2%) was observed from the shaft furnace due to the presence of radionuclides sorbiting layer of wastes

  15. The dispersion of pollutants in the Romanian rivers Olt, Somes and Danube

    The paper describes the results obtained in three tracer experiments carried out into the Romanian rivers Olt and Somes as well as into the Romanian part of the Danube by using the radioactive tracer 82Br. The possibility of a radioactive discharge to occur from the Cernavoda Nuclear Power Plant bring to focus also knowing of the distribution of fission products between water and solid suspended material. Consequently there were also studied and presented the distribution coefficients of the radionuclides 131I, 99Mo, 144Ce, 137Cs, and 95Zr for clay, loess and the particular alluvium collected from the Danube bed. (author)

  16. Behaviour of solid fission products in the HTGR coated fuel particles

    Results of profile measurements for volume concentrations of 134,137Cs, 144Ce, 155Eu, 106Ru and fissionable material in the HTGR coated fuel particles which have been subjected to standard tests in the temperature range of 1273-2133 K and at burnup up to 17% fima are presented. Values of the effective coefficients of cesium diffusion in kern and protective coating of fuel particles which were subjected to standard in-pile tests in spherical fuel elements at the temperature of 1273 K and the burnup up to 15% fima as well as the value of relative release of solid fission products from the samples studied are given

  17. Migration studies of radionuclides at the WIPP site

    A study was made of the effects on radionuclide migration from the solid TRU waste of inorganic and organic ligands in brine media. Typical organic waste meterials were exposed to synthetic brine at 700 for up to 1 year. Pure brine and brine/organic waste extracts were used to determine actinide and lathanide (153Gd, 144Ce, 152Eu, 243Am) distribution coefficients K/sub d/ between geological media and the brine. Results show that brine containing extract from plywood, etc. reduces considerably the K/sub d/

  18. Proposed Search for a Fourth Neutrino with a PBq Antineutrino Source

    Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV2. We show that this hypothesis can be tested with a PBq (ten kilocurie scale) 144Ce or 106Ru antineutrino beta source deployed at the center of a large low background liquid scintillator detector. In particular, the compact size of such a source could yield an energy-dependent oscillating pattern in event spatial distribution that would unambiguously determine neutrino mass differences and mixing angles.

  19. 1. Quarterly progress report 1984

    This report of the SCPRI exposes an interpretation of the principal results concerning the surveillance of radioactivity in the environment: atmospheric dusts, rainwater, surface water, underground water, sewage water, drinking water, food chain, sea water around nuclear plant sites and other sites. The activities of various radioisotopes are presented in tables (7Be, 54Mn, 58Co, 60Co, 90Sr, 95Nb, 106Ru, 110Ag, 125Sb, 131I, 134Cs, 137Cs, 144Ce, 226Ra, U, K, T and Rn). This report exposes also the state of surveillance and assistance operations on work sites and, the state of incidents along the three months; a bibliographic selection is also presented

  20. Appendix to Health and Safety Laboratory environmental quarterly report. [Fallout radionuclides deposited and in surface air at various world sites; /sup 137/Cs and /sup 90/Sr in milk and drinking water in New York City; and stable Pb in surface air

    Hardy, E.P. Jr.

    1977-07-01

    Tabulated data are presented on the deposition of fallout /sup 89/Sr and /sup 90/Sr at various world land sites through 1976; the ..gamma.. spectra and content of /sup 7/Be, /sup 95/Zr, /sup 137/Cs, /sup 144/Ce, /sup 90/Sr, /sup 210/Pb, /sup 238/Pu, /sup 239/Pu, and stable Pb in samples of surface air collected during 1966 at various world sites; and the content of fallout /sup 137/Cs and /sup 90/Sr in samples of drinking water and milk collected in New York City through 1976. (CH)

  1. Reconstruction of dose on the basis of forest litter activity measurements (case studies)

    In a large scale investigation of Polish forest litter contamination performed in recent years we observed the variety of Chernobyl fallout in Poland. Besides large differences in the radiocaesium contamination levels, we found a non-uniform isotopic composition of the fallout; in the north-eastern part of the country we found enhanced (relative to caesium) amounts of non-volatile radioisotopes. We were still able to detect 144Ce, 154Eu and 155Eu as well as plutonium isotopes of Chernobyl origin. 7 refs

  2. Chelating agents in pharmacology, toxicology and therapeutics

    The proceedings contain 71 abstracts of papers. Fourteen abstracts were inputted in INIS. The topics covered include: the effects of chelating agents on the retention of 63Ni, 109Cd, 203Hg, 144Ce, 95Nb and the excretion of 210Po, 63Ni, 48V, 239Pu, 241Am, 54Mn; the applications of tracer techniques for studies of the efficacy of chelation therapy in patients with heart and brain disorders; and the treatment of metal poisoning with chelating agents. (J.P.)

  3. Dynamics of contents and organic forms of radionuclide compounds in the liquid phase of forest soils in the zone of contamination from the Chernobyl Nuclear Power Plant

    In the profile of forest soils in a 30-km zone around the Chernobyl nuclear power plant (NPP), in areas characterized by different positions in relation to the source of emission, the authors determined the relative contents of long-lived radionuclides 106Ru, 134,137Cs, and 144Ce in soil solutions (as of 1987). On the example of 137Cs, they consider the dynamics (1987-1990) of relative contents and forms in which the radionuclide is found in the liquid phase of soils in the zone of radioactive contamination from the Chernobyl NPP

  4. Silviculture-ecological consequences of forest pollution due to radioactive effluents

    Radioactive contamination effect on the forest areas of Pripyat' Polessie is considered. Radiation processes in damaged pinetree plantations are characterized. Radionuclide migration dependent on soil types and tree stocks is analyzed. The data analysis has shown the evidence of 144Ce, 1'37Cs, 134Cs, 106Ru in 3 years after radioactive contamination in the controlled area. By the end of the third year a significant radionuclide migration had occurred between the forest floor and lower aquifers. refs. 2; figs. 2; tabs. 8

  5. Study of shortening of lifetime and of the occurrence of cancers in situ induced by cerium-144 hydroxide administered locally in various organs

    The authors compare the local action of 144Ce administered to rats in three different ways. Inhalation was chosen with a view to comparing the action of the β-emitter 144Ce with that of α-emitters such as plutonium and americium. Intramuscular injection was used to study the risk incurred through wounds contaminated by fission products, the purpose being to devise a model for the experimental study of osteosarcoma therapy. Oro-facial injection was selected in order to determine the carcinogenic effects of local irradiation in the sinuses and maxillaries. Here, too, it seemed useful to have a reproducible model of facial tumours that could be used for physiopathological and therapeutic studies. Cerium administered in hydroxide form and precipitating on the spot upon contact with living tissue gives local irradiation much greater than the dose delivered to other organs by the very slight fraction that diffuses. For these three modes of application the activities deposited in situ were varied, and for two of the three cases (intramuscular and intrafacial injection) the age of the animals at the moment of contamination was varied, too. The experiments brought out two principal effects: the appearance of local tumours, often cancerous, and a shortening of the animals' lifetime, the degree of the effect in both cases being linked to the dose. The experiments described here suggest that lifetime shortening and the presence of cancers in rats are separate phenomena, apparently independent of each other

  6. Gastrointestinal transit in the pig: measurement using radioactive lanthanides and comparison with sheep

    A technique to characterize the transit time of digesta through the gastrointestinal tract of the sheep has been described by Francois and Compere (1971). In the present paper, the authors present an adaptation of the method to the pig. On the first day of the experiment, each animal was given a diet uniformly labelled with 144Ce as an unabsorbable marker. The feces were collected at 1 or 2-hour intervals at progressively extended periods for the remainder of the collection period. The fecal concentration of the marker rose rapidly to a maximum, then decreased following a simple exponential law. Data were also expressed as a cumulative excretion curve of 144Ce. The mean retention time in the pig digestive tract could be calculated by concentration curves using either the m(t) parameter of Debouche (1974) or the t parameter proposed by Levenspiel (1974) to describe the flow of a fluid in an open vessel. The values obtained were identical to those found by Castle and Castle (1957) for the R parameter. These data are compared to those given by the same technique with the sheep

  7. Deadspace breathing as a screening test for early lung damage

    Breathing through added external deadspace (V/sub Dext/) was found to increase the tidal volume of normal dogs in order to achieve alveolar ventilation adequate for gas exchange. Addition of V/sub Dext/ did not alter alveolar-arterial gas gradients or cardiovascular function. Respiratory patterns during V/sub Dext/ breathing were compared with variables measured during treadmill exercise to investigate deadspace breathing as an indicator of early lung dysfunction caused by radiation pneumonitis in dogs. Dogs were evaluated clinically, radiographically and by pulmonary function tests at rest before and after inhaling 144Ce in fused aluminosilicate particles. By 4 mo after inhalation of 32 to 50 μCi/kg 144Ce, there were increases in respiratory frequency and minute volume during V/sub Dext/ breathing and in minute volume and the ventilatory equivalent for O2 while running. No other significant functional, radiographic or clinical changes were noted. The dogs were sacrificed and scattered foci of inflammation were found in their lungs. Deadspace testing detected early, subclinical lung alterations with a sensitivity and at a time identical to treadmill testing and did not require whole-body exercise or training

  8. Natural sorbents as barriers against migration of radionuclides from radioactive waste repositories

    The sorption properties of Bulgarian inorganic sorbents - clinoptilolite, vermiculite, bentonite, glauconite, celadonite and loess, which can be used as buffer, backfill and sealing materials in radwaste repository are studied. Experimental data about sorption and desorption capacities, radiation and thermal stability of sorbents from different Bulgarian deposits are reported and compared. Clinoptilolite from Beli Plast and its sodium variety from Kostino and Moryantsi is recommended as a barrier against radionuclide migration from radwaste repository due to their high sorption capacity of 137Ce, 90Sr and 60Co. The high selectivity of vermiculite for polyvalent ions (144Ce, 59Fe and 90Sr) gives grounds to include the sorption on vermiculite as a second step in the ion exchange technology for low level laundry waste decontamination. Bentonite is studied as a proposed buffer, backfill and sealing material. Its selectivity for cesium is lower compared to those of clinoptilolite. Thus a tailored-made mixture of bentonite and clinoptilolite will act as a barrier against radionuclides in different oxidation state. Glauconite can be successfully used as a barrier against migration of 144Ce, 90Sr, 54Mn and 65Zn. Loess is also included in the study, as the Kozloduy NPP is sited on loess formation and it is a natural potential site for low and intermediate level waste burial. It is concludes that zeolites and clays of Bulgarian deposits can be used effectively against radionuclide migration from radioactive waste repositories. 59 refs., 5 tabs. (author)

  9. Distribution of fission products in graphite sleeves and blocks of the ninth and tenth OGL-1 fuel assemblies

    Distribution of fission products in graphite sleeves and blocks of the ninth and tenth OGL-1 fuel assemblies was measured by gamma spectrometry with lathe sectioning. The assemblies were loaded with HTGR fuel compacts, which had been produced by a scaled-up facility for the High Temperature Engineering Test Reactor (HTTR) being developed by JAERI; and they were irradiated in an in-pile gas loop, OGL-1. Fission products detected in the sleeves were 137Cs, 134Cs, 155Eu, 154Eu, 144Ce, 125Sb and 110mAg. The last nuclide, however, may have been produced by activation of a stable isotope, 109Ag, contained as impurity. Effective retention capability of the sleeve was observed for 155Eu, 154Eu, 144Ce and 125Sb; while, not for 137Cs and 134Cs. Concentration of 137Cs in the graphite blocks was markedly higher at the downstream side than at the upstream side of the coolant. This was ascribed to migration of the nuclide with the coolant flow and its subsequent sorption on the surface of the block. (author)

  10. Educational laboratory experiments on chemistry in a nuclear engineering school

    An educational laboratory experiment on radiochemistry was investigated by students in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. Most of them are not chemical engineers, but electrical and mechanical engineers. Therefore, the educational experiment was designed for them by introducing a ''word experiment'' in the initial stage and by reducing the chemical procedure as far as possible. It began with calculations on a simple solvent extraction process-the ''word experiment''--followed by the chemical separation of 144Pr from 144Ce with tri-n-butyl phosphate in a nitric acid system and then measurement of the radioactive decay and growth of the separated 144Pr and 144Ce, respectively. The chemical procedure was explained by the phenomenon but not by the mechanism of chelation. Most students thought the experiment was an exercise in solvent extraction or radiochemical separation rather than a radioactive equilibrium experiment. However, a pure chemist considered it as a sort of physical experiment, where the chemical procedure was used only for preparation of measuring samples. Another experiment, where 137Cs was measured after isolation with ammonium phosphomolybdate, was also investigated. The experiment eliminated the need for students who were not chemists to know how to use radioactive tracers. These students appreciated the realization that they could understand the radioactivity in the environmental samples in a chemical frame of reference even though they were not chemists

  11. Evaluation of fission product yields from fission spectrum n+239Pu using a meta analysis of benchmark data

    Chadwick, Mark B.

    2009-10-01

    Los Alamos conducted a dual fission-chamber experiment in the 1970s in the Bigten critical assembly to determine fission product data in a fast (fission neutron spectrum) environment, and this defined the Laboratory's fission basis today. We describe how the data from this experiment are consistent with other benchmark fission product yield measurements for 95,97Zr, 140Ba, 143,144Ce, 137Cs from the NIST-led ILRR fission chamber experiments, and from Maeck's mass-spectrometry data. We perform a new evaluation of the fission product yields that is planned for ENDF/B-VII.1. Because the measurement database for some of the FPs is small—especially for 147Nd and 99Mo—we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data. The %-relative changes compared to ENDF/B-VI are small for some FPs (less than 1% for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (3%) and 147Nd (5%). We suggest an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average energies.

  12. Il personaggio scontornato in Škola dlja Durakov. Dal romanzo di Saša Sokolov agli adattamenti teatrali

    Irina Marchesini

    2012-12-01

    Full Text Available Sokolov’s Shkola dlya Durakov (A School for Fools, 1976 is an extremely complex novel, which “depicts [the] world”, as D. Barton Johnson (1986:640[1] poignantly observes, “through the eyes, and pure, if eccentric, language, of a schizophrenic youth”. How is it possible to translate such linguistic features and the effects they create into another medium? This question lies at the core of my proposal, which aims to approach the problem of intermedial translation from prose to theatre through the presentation of an individual case-study. In fact, A School for Fools has been staged by the director Andrey Moguchy (Formalny Theatre, Saint Petersburg, Russia. With the intention of reproducing Sokolov’s aesthetic construction of illusion, Moguchy introduces a new genre in the theatrical context, the so-called “vizualnaya associaciya” (“visual association”. As the director explained in a recent interview, this original genre recalls the Impressionists’ position in observing and representing nature, in order to obtain the same effect generated by the reading of the novel. To comprehend this process better, special attention is devoted to the construction of unusual, hybrid characters, highlighting their constitutive features both in the novel and in the theatrical adaptation. Moreover, this research seeks to enrich discussion of the work of Sokolov and Moguchy. [1] Johnson, D. Barton (1986 “Sasha Sokolov's Twilight Cosmos: Themes and Motifs”, in: Slavic Review, 45, 4 (Winter 1986, pp. 639-649.

  13. Improved estimate of the cross section for inverse beta decay

    Ankowski, Artur M

    2016-01-01

    The hypothesis of the conserved vector current, relating the vector weak and isovector electromagnetic currents, plays a fundamental role in quantitative description of neutrino interactions. Despite being experimentally confirmed with great precision, it is not fully implemented in existing calculations of the cross section for inverse beta decay, the dominant mechanism of antineutrino scattering at energies below a few tens of MeV. In this article, I estimate the corresponding cross section and its uncertainty, ensuring conservation of the vector current. While converging to previous calculations at energies of several MeV, the obtained result is appreciably lower and predicts more directional positron production near the reaction threshold. These findings suggest that in the current estimate of the flux of geologically produced antineutrinos the 232Th and 238U components may be underestimated by 6.1 and 3.7%, respectively. The proposed search for light sterile neutrinos using a 144Ce--144Pr source is predi...

  14. Radiation-induced mesotheliomas in rats

    Mesotheliomas have been reported in rats that inhaled plutonium, but these tumors have not been extensively studied. To investigate a possible role for inhaled radionuclides in the induction of mesotheliomas, four life-span studies conducted at the Inhalation Toxicology Research Institute are reviewed. A total of 3076 F344 rats were exposed by inhalation to aerosols of 239PuO2, mixed uranium-plutonium oxide, or 144CeO2. Results showed that a low incidence of pleural mesotheliomas was induced by either alpha- or beta-emitting radionuclides deposited and retained in the lung. Chronic alpha irradiation was more effective per unit dose in producing mesotheliomas than chronic beta irradiation of the lung by a factor of 15. 7 refs., 1 tab., 7 figs

  15. Study on measurement of trace radioactivity, (2)

    The method was worked out so as to measure 59Fe, 60Co, 65Zn, 95Zr, and 144Ce successively from the same sample by ion-exchange separation. This method was also applicable to the measurement of 90Sr and 137Cs. It was confirmed that 131I in milk could be measured satisfactorily by the method of US Atomic Energy Commission, when raw milk before processing was preserved in good condition. 3H in natural water can be measured with a gas magnifying counter without isotope concentration when water is transformed into hydrogen gas. It was found that an external heater type reactor is desirable to transform 3H in water into methane gas so far as the repair is concerned. The present reactor needs some improvement, however, to get better yield as the best synthesizing yield for methane gas obtained so far was only 48.8%. (Kobatake, H.)

  16. Specific processes in solvent extractiotn of radionuclide complexes

    The doctoral thesis discusses the consequences of the radioactive beta transformation in systems liquid-liquid and liquid-ion exchanger, and the effect of the chemical composition of liquid-liquid systems on the distribution of radionuclide traces. A model is derived of radiolysis in two-phase liquid-liquid systems used in nuclear chemical technology. The obtained results are used to suggest the processing of radioactive wastes using the Purex process. For solvent extraction the following radionuclides were used: 59Fe, 95Zr-95Nb, 99Mo, sup(99m)Tc, 99Tc, 103Pd, 137Cs, 141Ce, 144Ce-144Pr, 234Th, and 233Pa. Extraction was carried out at laboratory temperature. 60Co was used as the radiation source. Mainly scintillation spectrometry equipment was used for radiometric analysis. (E.S.)

  17. Training of skin decontamination and its results

    In the nuclear power and radioisotope handling facilities, one of the most important problems is a radioactive contamination on skin. Hand skin contamination occurs very often in the operation area and such surface contamination must be removed as soon as possible to prevent an internal contamination. From 1967 to 1975, training courses for skin decontamination had been held with total 536 of trainee based on the radiation protection manual at the Oarai Research Establishment of JAERI. In the training courses, fresh pig skin samples used instead of human skin were contaminated with 137Cs, 131I, 85Sr, 60Co, 144Ce, 88Y, 239Pu, fission products and activated metal corrosion particles, respectively. These samples were washed practically by each trainee with the skin decontamination method recommended in the manual. Results obtained in the training showed that such training itself is a significant work and this skin decontamination method is an excellent first aid. (auth.)

  18. The Chernobyl fallout in Greece and its effects on the dating of archaeological materials

    The effects of the fallout from the nuclear reactor accident at Chernobyl have been monitored at various sites in Greece. Here we present the first estimates of gamma dose rates, an essential parameter in the dating of archaeological materials by thermoluminescence (TL) and ESR methods. The dose rates are derived from the long-lived radionuclides of 137Cs, 134Cs, 106Ru and 144Ce (with t1/2 ≥ 1 yr). The present dose rates vary between 30 and 60 mrad/yr, but maximum values of around 811 mrad/yr have also been recorded, for ground-surface exposures. These dose rate values must be regarded as very significant to TL and ESR dating of samples from now on and a correction factor should be applied. (orig.)

  19. The risk of liver tumors in dogs and man from radioactive aerosols

    Life-span studies in progress using beagle dogs that inhaled relatively soluble or relatively insoluble forms of radionuclides will provide information from which we may project the risk to humans for liver cancer from inhaled radioactive material. Twenty-two liver tumors have been observed in dogs exposed to beta-emitting radionuclides, mainly 144Ce, and one liver tumor in a dog exposed to 238Pu. Two liver cancers were also observed in control dogs. The risk of liver cancer in dogs that inhaled beta-emitting radionuclides was calculated to be 90 liver cancers per million rads. The risk of liver cancers in dogs in our studies and in studies at the University of Utah, when compared to the incidence of liver tumors in humans exposed to Thorotrast, suggest that the risk of liver cancer from an inhaled beta-emitting radionuclide in people is about 30 liver cancers per million person-rads. 19 refs., 3 tabs

  20. Electrodeposition of actinide traces from aqueous alkaline solutions and tributyl phosphate

    The electrodeposition of uranium and trace quantities of 239Pu, 234Th, 144Ce on a stainless steel disk was investigated from 0.5-2.0M NaOH and the two-phase system, extract of actinides in TBP-aqueous solution of NaOH. The electrodeposition yield of the above elements reaches 98-100% in 40 min of electrolysis with current density 0.4-0.5 A/cm2. The presence of 0.5M Na2CO3, 2.0M NaNO3, 2.0M NaNO2, 0.2M NaF in alkaline solutions does not decrease the electrodeposition yield. The electrodeposited films meet all the requirements of α-spectrometry. The uranium oxidation states (V) and (IV) were determined in the electrodeposited films. (author) 9 refs.; 3 figs.; 1 tab

  1. Methodology for the evaluation of decontaminant drugs at in vitro systems

    An experimental system was developed in order to facilitate hte study of the action of decontaminant drugs in hepatic tissue. Three stages are distinguished: 1) The isolation and the hepatocytes culture in the presence of a chelant agent. 2) The obtainment of the soluble cytoplasmic fraction and its chromatographyc analysis. 3) The comparison of the behaviour of the chelant agent in in vivo and in vitro of the mentioned fraction. 144CeCl was employed as a radionuclide and DTPA CaNa3 as a decontaminant agent. The preliminary results of the mechanism of action of the decontaminant obtained by chromatography shows a different distribution of the radionuclide between compounds of high and low molecular weight, in the hepatocytes incubated in the presence of the chelant concerning the controls. (M.E.L.)

  2. Development of a technology and a pilot plant for treatment of small volumes of liquid radioactive waste

    The development of technology for treatment of liquid radioactive waste is described. Waste arisings are estimated. Liquid wastes of concern are mainly low active wastes according to the Bulgarian legislation. The activity is determined by the presence of 134Cs, 137Cs, 60Co, 90Sr, 144Ce, 65Zc, 54Mn, 110mAg. Different precipitation processes are compared. The mixed iron hydroxide - calcium phosphate precipitation is determined as suitable for decontamination of the liquid radioactive waste. Effective decontamination is achieved when precipitation is followed by ion exchange. Additional increase of the decontamination is possible when sorbents are added during the precipitation step. The sorption and desorption of radionuclides on zeolites are studied. Cement solidification and thermal treatment of zeolites are studied for immobilization of radioactive material from precipitation and ion exchange. Both methods produce stable waste forms suitable for containment of the radionuclides. (author). 17 refs, 3 figs, 12 tabs

  3. Measurements of fission product concentrations in surface air at Bombay, India, during the period 1975-1981

    Measurements on airborne fallout radioactivity for the period 1975 up to the middle of 1981 are given. Normally, these measurements are confined to Bombay, but after nuclear tests, some of the other stations where these measurements were carried out in previous years are operated for some time to study the levels of fresh activity. The levels of the long-lived fission products 144Ce, 106Ru and 137Cs, and the short-lived fission products 95Zr and 140Ba, were measured, whenever they could be detected following nuclear tests, and tabulated. The data indicate that the activity varies by large factors from tests of similar yield, depending on the meteorological and other conditions. It was determined that the travel time for the Chinese test debris from Lop Nor, China to the West-coast of India is 14 to 16 days

  4. Preparative electrophoresis of industrial fission product solutions

    The aim of this work is to contribute to the development of the continuous electrophoresis technique while studying its application in the preparative electrophoresis of industrial fission product solutions. The apparatus described is original. It was built for the purposes of the investigation and proved very reliable in operation. The experimental conditions necessary to maintain and supervise the apparatus in a state of equilibrium are examined in detail; their stability is an important factor, indispensable to the correct performance of an experiment. By subjecting an industrial solution of fission products to preparative electrophoresis it is possible, according to the experimental conditions, to prepare carrier-free radioelements of radiochemical purity (from 5 to 7 radioelements): 137Cs, 90Sr, 141+144Ce, 91Y, 95Nb, 95Zr, 103+106Ru. (author)

  5. Game as a bioindicator of the radiocontamination

    Natural and artificially produced radionuclides were determined in meat and bones of deer, boar and wild hare on hunting areas in Vojvodina (Serbia). Seven natural radionuclides and three fission products (235U, 238U, 232Th, 7Be, 144Ce, 40K, 106Ru, 134Cs, 137Cs, 90Sr) were identified in the investigated game samples. The highest contents of the radionuclides were found in bones and meat of boars and the lowes in the bones of fallow-deer. The predominant radionuclides were 40K and 90Sr, for all of the investigated animals and their contents depended strongly upon the game species, organ type and the age of the animal. The examined breeding sites did not appear to have any effect on the radionuclide contents in game, which indicates that the radionuclides were uniformly distributed over the habitat. (author) 5 refs.; 3 tabs

  6. Calculated activities of some isotopes in the RA reactor highly enriched fuel significant for possible environmental contamination - Operational report

    This report contains calculation basis and obtained results of activities for three groups of isotopes in the RA reactor 80% enriched fuel element. The following isotopes are included: 1) 85mKr, 87Kr, 88Kr, 131J, 132J, 133J, 134J, 135J, 133Xe, 138Xe i 138Cs, 2) 89Sr, 90Sr, 91Sr, 92Sr, 95Zr, 97Zr, 103Ru, 105Ru, 106Ru, 129mTe, 134Cs, 137Cs, 140Ba, 144Ce, kao i 3) 238Pu, 239Pu i 240Pu. It was estimated that the fuel is exposed to mean neutron flux. The periodicity of reactor operation is taken into account. Calculation results are given dependent on the time of exposure. These results are to be used as source data for Ra reactor safety analyses

  7. Transuranic elements and strontium-90 in samples from forests in Poland

    Enhanced levels of non-volatile nuclides;141,144Ce, 95Zr, 95Nb, 103,106Ru, 238,239,240,241Pu, 241Am, 242,243,244Cm and 154,155Eu were observed in the samples from north-western Poland. This was considered to be a result of finding in sample ''hot particle''. Investigations conducted in the Institute of Nuclear Physics allowed us to conclude that on this area a non typical isotopic composition of Chernobyl fallout was very common. The enhanced activities (up to 100% above the global fallout value) of 90Sr, 238,239,240Pu and 241Am were observed. The presence of 243,244Cm and 154,155Eu was confirmed. It seems that the quasi-continuous fallout of huge numbers of small 'hot particles' occurred there from the high altitude radioactive cloud, which moved toward Scandinavia on 26-th of April, 1986. (author)

  8. Search for Sterile Neutrinos with a Radioactive Source at Daya Bay

    Dwyer, D A; Littlejohn, B R; Vogel, P

    2011-01-01

    The far site detector complex of the Daya Bay reactor experiment is proposed as a location to search for sterile neutrinos with > eV mass. Antineutrinos from a 500 kCi 144Ce-144Pr beta-decay source (DeltaQ=2.996 MeV) would be detected by four identical 20-ton antineutrino targets. The site layout allows flexible source placement; several specific source locations are discussed. In one year, the 3+1 sterile neutrino hypothesis can be tested at essentially the full suggested range of the parameters Delta m^2_{new} and sin^22theta_{new} (90% C.L.). The backgrounds from six nuclear reactors at >1.6 km distance are shown to be manageable. Advantages of performing the experiment at the Daya Bay far site are described.

  9. Radionuclides in plankton from the South Pacific Basin

    We have initiated an investigation of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review has shown that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 104. We participated in Operations Deepfreeze 1981 and 1982, collecting a total of 48 plankton samples from the USCGC Glacier on its Antarctic cruises. Battelle Pacific Northwest Laboratories sampled air, water, rain, and fallout. We were able to measure concentrations in plankton of the naturally-occurring radionuclides 7Be, 40K, and the U and Th series, and we believe that we have detected low levels of 144Ce and 95Nb in seven samples ranging as far south as 680. Biological identification of the plankton suggests a possible correlation between radionuclide concentration and the protozoa content of the samples. 7 references, 5 figures

  10. Fission product release from ZrC-coated fuel particles during postirradiation heating at 1600 C

    Release behavior of fission products from ZrC-coated UO2 particles was studied by a postirradiation heating test at 1600 C (1873 K) for 4500 h and subsequent postheating examinations. The fission gas release monitoring and the postheating examinations revealed that no pressure vessel failure occurred in the test. Ceramographic observations showed no palladium attack and thermal degradation of ZrC. Fission products of 137Cs, 134Cs, 106Ru, 144Ce, 154Eu and 155Eu were released from the coated particles through the coating layers during the postirradiation heating. Diffusion coefficients of 137Cs and 106Ru in the ZrC coating layer were evaluated from the release curves based on a diffusion model. 137Cs retentiveness of the ZrC coating layer was much better than that of the SiC coating layer. ((orig.))

  11. 4. Quaterly progress report 1983

    This report of the SCPRI exposes an interpretation of the principal results concerning the surveillance of radioactivity in the environment: atmospheric dusts, rainwater, surface water, underground water, sevrage water, drinking water, food chain, sea water around nuclear plant sites and other sites. The activities of various radioisotopes are presented in tables (7Be, 58Co, 60Co, 75Se, 103Ru, sup(110m)Ag, 124Sb, 125Sb, 134Cs, 137Cs, 144Ce, 90Sr, 95Nb, 106Ru, 226Ra, 54Mn, U, K and T). This report exposes also the state of surveillance and assistance operations on work sites and, the state of incidents along the three months; a bibliographic selection is also presented

  12. Lifetime tumor risk coefficients for beagle dogs that inhaled cerium-144 chloride

    Boecker, B.B.; Hahn, F.F.; Griffith, W.C. [and others

    1995-12-01

    Reported here is one of the life-span radionuclide toxicology studies being conducted at ITRI in Beagle dogs. These studies are examining the life-span health risks of inhaled {Beta}-, {gamma}- and {alpha}-emitting radionuclides to expand available knowledge on these risks especially for the many cases for which human data are not available. The outcomes of these studies are providing important information on dosimetry and dose-response relationships for these inhaled radionuclides and the relative importance of a broad range of dose- and effect-modifying factors. A number of these studies are currently coming to completion. Much of the ITRI effort is being directed to final reviews of the dosimetric, clinical, and pathologic results and writing summary manuscripts. Radiation doses and effects in tissues adjacent to bone, specifically those of epithelial or marrow origin, should be considered when determining risks from internally deposited, bone-seeking radionuclides such as {sup 144}Ce.

  13. Identification of levels in neutron-rich 145Ce and 147Ce nuclei

    High-spin structures in the neutron-rich nuclei 145Ce and 147Ce produced in the spontaneous fission of 252Cf have been investigated by prompt γ-ray spectroscopy. A collective band structure in 145Ce is identified. Several sidebands along with the new high-spin states in 147Ce are also identified. Particle-plus-rotor model calculations indicate that the yrast bands in 145Ce and 147Ce most probably originate from coupling of the νi13/2 orbital to the ground states of 144Ce and 146Ce. The ground state configurations of 145,147Ce are (νh9/2+νf7/2) and νh9/2, respectively. (c) 1999 The American Physical Society

  14. Application of the radiochemical - and the direct gamma ray spectrometry method to the burnup determination of irradiated uranium oxide

    The burn up of natural U3O8 that occurs by the action of thermal neutrons was determined, using the radioisotopes 144Ce, 137Cs, 103Ru, 106Ru and 95Zr as monitors. The determination of the burn up was made using both destructive and non-destructive methods. In the non-destructive method, the technique of direct gamma-ray spectrometry was used and the radioisotopes mentioned were simultaneously counted in a Ge-Li detector. In the radiochemical method the same radioisotopes were isolated one from the other and from all other fission products before counting. The solvent extraction technique was used for the radiochemical separation of uranium, cerium, cesium and ruthenium. To separate zirconium and niobium, adsorption in silica-gel was used. The extraction agent employed to isolate cesium was dipycrilamine and for the separation of the other radioisotopes Di-(2-Ethyl Hexyl) Phosphoric acid (HDEHP) was used. (Author)

  15. Fixation of {gamma}-radionuclides by the PVA-PMAA system

    Won, Hui Jun; Ahn, Byung Gil; Jung, Chong Hun; Kim, Gye Nam; Oh, Won Zin [KAERI, Taejon (Korea, Republic of)

    2000-06-01

    A series of laboratory experiments was conducted to investigate the fixation characteristics of poly(vinylalcohol)-poly(methacrylic)(PVA-PMAA) mixed solution on the soluble {gamma}-radionuclides. Using the potentiometric titration technique, it was found out that the PVA and PMAA in a solution form inter macromolecular complex. The mobilized portion of each radionuclide by water from sand surface treated with a fixative was measured by {gamma}-ray spectroscopy. The mobilized portion of minor radionuclides such as {sup 241}Am, {sup 154}Eu, {sup 155}Eu and {sup 144}Ce were higher than those of {sup 134}Cs and {sup 137}Cs. The capability of PVA-PMAA system was better among the candidate solutions for the fixation of total {gamma}-radioactivity. {sup 134,137}Cs which is composed of more than 85 percent of total {gamma}-radioactivity could be fixed effectively by the PVA-PMAA solution. (author)

  16. Fixation of γ-radionuclides by the PVA-PMAA system

    A series of laboratory experiments was conducted to investigate the fixation characteristics of poly(vinylalcohol)-poly(methacrylic)(PVA-PMAA) mixed solution on the soluble γ-radionuclides. Using the potentiometric titration technique, it was found out that the PVA and PMAA in a solution form inter macromolecular complex. The mobilized portion of each radionuclide by water from sand surface treated with a fixative was measured by γ-ray spectroscopy. The mobilized portion of minor radionuclides such as 241Am, 154Eu, 155Eu and 144Ce were higher than those of 134Cs and 137Cs. The capability of PVA-PMAA system was better among the candidate solutions for the fixation of total γ-radioactivity. 134,137Cs which is composed of more than 85 percent of total γ-radioactivity could be fixed effectively by the PVA-PMAA solution. (author)

  17. Measurement by γ spectrometry of specific activities of radioisotopes present in vegetal ashes. Study of variations of the ambient radioactivity level in the Grenoble transverse valley from March 1966 to August 1968

    The first part of this report addresses the dosimetry of γ emitting radio-elements which are present in vegetal samples. The dose measurements were performed by spectrometry and results were processed by using a least square method. The second part reports works performed in the Grenoble transverse valley by using the same techniques. Radioactivity fluctuations of various radio-elements (40K, 54Mn, 95Zr + 95Nb, 103Ru + 106Rh, 137Cs, 137Ba, 140Ba + 140La, 144Ce + 144Pr) in various vegetal species, in water and in sediments have been monitored in seven points of the Isere river banks, upstream and downstream the city of Grenoble, from March 1966 to August 1968. Fluctuations observed for each radio-element are explained by comparison with physiologic, hydrologic and atmospheric climate conditions. The principles of a systematic control of a site for the detection of possible radioactive pollutions are then defined

  18. Influence of the complexones on the ionic transfer through cell membranes and the level of radionuclides-metals accumulation in water plants

    The influence of the complexones diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetraacetic acid (EDTA) and hydroxyethylidenediphosphonic acid (HEDP) with relatively low concentrations (from 0.1 to 50 mg/l) on ionic permeability of cell membranes of Nitellopsis obtusa algae, as well as on the accumulation levels of the radionuclides 144Ce, 106Ru, 90Sr and 137Cs in different species of water plants has been studied. It has been shown that complexones under study (with the concentrations up to 50 mg/l) may reduce accumulation levels of three- and four-valent metals and their radionuclides in water plants. For the plants in natural as well as in artificial nutrient medium, however, the complexones increase the availability of metals, forming with the readibly soluble, mobile complex compounds

  19. Critical pathway studies for selected radionuclides. Part of a coordinated programme on environmental monitoring for radiological protection in Asia and the Far East

    The programme carried out critical pathway studies for selected radionuclides (60Co, 63Ni, 59Fe, 54Mn, sup(110m)Ag, 106Ru and 144Ce) and assessed population exposure in the vicinity of Tarapur Atomic Power Station. The following topics are covered under the programme. (i) Demographic study of dietary habits and consumption data for Tarapur population. (ii) Concentration and accumulation of radionuclides in food products. (iii) Determination of radionuclides in sea water, silt, marine algae and marine organisms at Tarapur Atomic Power Station (TAPS) Site. (iv) Behaviour of radionuclides released to marine environment. (v) Evaluation of critical exposure pathway. (vi) Population exposure in the vicinity of Tarapur Atomic Power Station

  20. Assessment of selected fission products in the Savannah River Site environment

    Most of the radioactivity produced by the operation of a nuclear reactor results from the fission process, during which the nucleus of a fissionable atom (such as 235U) splits into two or more nuclei, which typically are radioactive. The Radionuclide Assessment Program (RAP) has reported on fission products cesium, strontium, iodine, and technetium. Many other radionuclides are produced by the fission process. Releases of several additional fission products that result in dose to the offsite population are discussed in this publication. They are 95Zr, 95Nb, 103Ru, 106Ru, 141Ce, and 144Ce. This document will discuss the production, release, migration, and dose to humans for each of these selected fission products

  1. Sorption of radionuclides from Pb-Bi melt. Report 1

    Results of laboratory investigations of sorption and interfacial distribution of 54Mn, 59Fe, 60Co, 106Ru, 125Sb, 137Cs, 144Ce, 154,155Eu and 235,238U radionuclides in the system Pb-Bi melt - steel surface are analyzed. It is shown that 106Ru and 125Sb are concentrated in Pb-Bi melt and other radionuclides with higher oxygen affinity are sorbed on oxide deposits on structural materials. Temperature dependences of sorption efficiency of radionuclides are studied. It is shown that there is sharp increase of this value for all radionuclides near the temperature range 350-400 deg C. Recommendations are given on the use of 106Ru and 125Sb as a reference for fuel element rupture detection system with radiometric monitoring of coolant melt samples and 137Cs, 134Cs, 134mCs with radiometric monitoring of sorbing samples

  2. A study of radionuclide transfer between invertebrates and their marine sedimentary environment

    Exchanges between sediment and marine organisms were studied in some benthic marine invertebrates, especially Arenicola marina L. (an Annelid). Experiments were carried out on the transfer of 60Co, 137Cs and accessorily 59Fe and 144Ce. Water was the chief vector for benthic marine invertebrates. These invertebrates seemed to act mainly in sedimentary areas on the redistribution of adsorbed radionuclides within the sediment. Radioactive contamination of the invertebrates was affected by various physiological or ecological factors. Benthic marine invertebrates were then studied as links in food chains. The transfer of 60Co was studied in three food chains or fractions of food chains. The procedure allowed interesting observations from the health protection point of view and more fundamental investigations on cobalt metabolism (regulation, excretion) in a mollusc, a crustacea and a teleost

  3. Recent Borexino results and prospects for the near future

    D'Angelo, D; Benziger, J; Bick, D; Bonfini, G; Avanzini, M Buizza; Caccianiga, B; Cadonati, L; Calaprice, F; Cavalcante, P; Chavarria, A; Chepurnov, A; Davini, S; Derbin, A; Empl, A; Etenko, A; von Feilitzsch, F; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Grandi, L; Hagner, C; Hungerford, E; Ianni, Aldo; Ianni, Andrea; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lehnert, B; Lewke, T; Litvinovich, E; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Mosteiro, P; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Otis, K; Pallavicini, M; Papp, L; Perasso, L; Perasso, S; Pocar, A; Ranucci, G; Razeto, A; Re, A; Romani, A; Rossi, N; Saldanha, R; Salvo, C; Schoenert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; Winter, J; Wojcik, M; Wright, A; Wurm, M; Xu, J; Zaimidoroga, O; Zavatarelli, S; Zuber, K; Zuzel, G

    2014-01-01

    The Borexino experiment, located in the Gran Sasso National Laboratory, is an organic liquid scintillator detector conceived for the real time spectroscopy of low energy solar neutrinos. The data taking campaign phase I (2007 - 2010) has allowed the first independent measurements of 7Be, 8B and pep fluxes as well as the first measurement of anti-neutrinos from the earth. After a purification of the scintillator, Borexino is now in phase II since 2011. We review here the recent results achieved during 2013, concerning the seasonal modulation in the 7Be signal, the study of cosmogenic backgrounds and the updated measurement of geo-neutrinos. We also review the upcoming measurements from phase II data (pp, pep, CNO) and the project SOX devoted to the study of sterile neutrinos via the use of a 51Cr neutrino source and a 144Ce-144Pr antineutrino source placed in close proximity of the active material.

  4. Radiation accidents on human in the nuclear installations and their medical emergency procedures, (1)

    Present nuclear installations are one of the safest installations among industrial facilities, being equipped with various safety instruments. Since X-ray was discovered in 1895, however, many radiation injuries of various degrees and kinds occurred. Among dangerous nuclides often observed as radioactivity pollutions in nuclear installations, the exposure to β-ray such as 90Sr, 106Ru, 95Zr, 131I, 144Ce, etc, is considered to be serious problems. When they affect wounds or are inhaled into lungs, only symptomatic treatment is practicable at present, and usually nothing can be depended upon, but spontaneous eliminating ability. As the mass inhalation of α nuclides, especially transuranium nuclides, is quite dangerous, the treatment by lung-irrigation now under development is most effective as the emergency treatment. When trans-uranium nuclides were accidentally observed from wounds, they should be eliminated by the injection of chelating agent. (Kobatake, H.)

  5. Measurement of leached hulls

    Leached hulls are the short lengths of fuel rod cladding and fuel element hardware which constitute a major waste product of a reprocessing plant employing a chop-and-leach head-end process. The small, undissolved fuel residue (0.1 to 1.0% of original fuel content) which is discarded with this waste must be measured for safeguards, material accountability, and process control reasons. This report gives a critical analysis of hull measurement techniques involving the analysis of fission product gamma rays, spontaneous fission neutrons from curium, and delayed neutron activation. Major emphasis is given to the measurement of 2186-keV gamma rays from 144Ce--144Pr. A detailed description of typical leached hull characteristics is presented at the beginning of the report. An extensive review of experience gained from existing hull measurement systems in the United Kingdom, France, Japan, Germany, Italy, and the United States is presented

  6. Batch extraction studies for the recovery of 233U from thoria irradiated in PHWR

    Batch equilibrium studies were carried out to optimise the extraction parameters for the recovery of 233U from thoria irradiated in PHWR. The thorium concentration and the acidity of the feed was adjusted to ca. 100 g/l and 4 M nitric acid respectively. The concentration of uranium was in the range of 1.4 g/L and it contained long lived fission product like 144Ce-144Pr, 134Cs, 137Cs, 106Ru-106Rh, 105Eu, 154Eu, 90Sr-90Y and 125Sb. 3% TBP in dodecane was used as the solvent. Four stages of batch extraction was followed by a single scrub stage of 4 M nitric acid. The scrubbed organic was stripped with 0.01 M HNO3 thrice. The stripped product was concentrated by evaporation and passed through a cation exchanger to remove the residual thorium. The results of the studies are discussed in detail. (author)

  7. Characterization of gaseous and particulate effluents from the nuclear vitrification project

    Samples were taken during the second high-level liquid waste vitrification campaign associated with the NWVP. Sample analysis established the following total average emission levels in the undiluted vitrification off-gas stream: 3H - 1.2 μCi/m3, 14C - 0.2 μCi/m3, 129I - 1 nCi/m3, NO/sub x/ - 0.5%, 99Tc - 1.6 pCi/m3, and γ-emitters - 105(γ/s)/m3. The aerosol size distribution is composed almost entirely of particles exhibiting smaller diameters than the minimum value for which absolute filters are rated, with an empirical geometric mean diameter of 0.13 μm and a particle mass concentration of 84.7 pg/cm3. The particulate matter was composed of 106Ru, 125Sb, /sup 125m/Te, 134Cs, 137Cs, 144Ce, 154155Eu and 241Am. The particulate emission levels in the undiluted process off-gas stream were: 106Ru - 44 nCi/m3, 125Sb - 0.52 nCi/m3, /sup 125m/Te - 1.7 nCi/m3, 134Cs - 7.8 nCi/m3, 137Cs - 52 nCi/m3, 144Ce - 0.8 μCi/m3, 154Eu - 0.3 nCi/m3, 155Eu - 0.18 nCi/m3, and 241Am - 0.19 nCi/m3. All these environmental gaseous and airborne emissions level liquid waste were well within PNL waste management guidelines

  8. Cycling of radionuclides and impact of operational releases in the near-shore ecosystem off the west coast of India

    Radioecology of the near-shore environment was investigated at Bombay and Tarapur on the west coast of India. The major radionuclides released from the processing plant at Bombay were 137Cs, 144Ce and 106Ru and were discharged through a pipeline to Bombay Harbour bay. At Tarapur the major radionuclides discharged were 131I, 134Cs, 137Cs and 60Co. After dilution with condenser-coolant sea water, releases were carried out through open channels along the shoreline to the sea. Studies on radionuclide cycling in clam-bed sediment, the indicator type benthic organism Anadara granosa, and the fish gobiid mudskipper in Bombay Harbour bay showed that the effective half-life of 137Cs is short compared with the physical half-life (30 years). This is attributable to the desorption of 137Cs from sediment and the fact that the benthic organism readily equilibrates with its environment. The dose to the benthic organism was calculated to be about 0.06 to 3μGy/h. Desorption of 144Ce and 106Ru was not observed. Investigations at Tarapur showed the effective distribution of radionuclides in sea water, sediment, seaweed and marine organisms. It was observed that the radionuclides discharged were mainly confined to a region 2 km from the outfall. The highest activity found in these matrices was only 7% of the derived maximum permissible concentration. The highest thyroid dose due to 131I by fresh seafood intake was 3% of the permissible dose and the highest whole-body dose due to other radionuclides was only 1% of the permissible dose. (author)

  9. EML Surface Air Sampling Program, 1990--1993 data

    Measurements of the concentrations of specific atmospheric radionuclides in air filter samples collected for the Environmental Measurements Laboratory's Surface Air Sampling Program (SASP) during 1990--1993, with the exception of April 1993, indicate that anthropogenic radionuclides, in both hemispheres, were at or below the lower limits of detection for the sampling and analytical techniques that were used to collect and measure them. The occasional detection of 137Cs in some air filter samples may have resulted from resuspension of previously deposited debris. Following the April 6, 1993 accident and release of radionuclides into the atmosphere at a reprocessing plant in the Tomsk-7 military nuclear complex located 16 km north of the Siberian city of Tomsk, Russia, weekly air filter samples from Barrow, Alaska; Thule, Greenland and Moosonee, Canada were selected for special analyses. The naturally occurring radioisotopes that the authors measure, 7Be and 210Pb, continue to be detected in most air filter samples. Variations in the annual mean concentrations of 7Be at many of the sites appear to result primarily from changes in the atmospheric production rate of this cosmogenic radionuclide. Short-term variations in the concentrations of 7Be and 210Pb continued to be observed at many sites at which weekly air filter samples were analyzed. The monthly gross gamma-ray activity and the monthly mean surface air concentrations of 7Be, 95Zr, 137Cs, 144Ce, and 210Pb measured at sampling sites in SASP during 1990--1993 are presented. The weekly mean surface air concentrations of 7Be, 95Zr, 137Cs, 144Ce, and 210Pb for samples collected during 1990--1993 are given for 17 sites

  10. Toxicity of inhaled beta-emitting radionuclides: an experimental approach

    An experimental approach to evaluation of the toxicity of inhaled beta-emitting radionuclides in laboratory animals is described. These radionuclides are being studied in both relatively soluble (90SrCl2, 144CeCl3, 91YCl3 or 137CsCl) and relatively insoluble aerosol forms (90Y, 91Y, 144Ce or 90Sr in fused aluminosilicate particles). Initial lung or whole-body radionuclide burdens were selected to result in early deaths due to severe lesions at the highest exposure levels, and more subtle changes, such as neoplasia, at the lower levels. The organs affected vary depending on the solubility and chemical characteristics of the isotope. For radionuclides inhaled in relatively soluble forms, long-term effects have been seen in the liver, skeleton, respiratory tract and other tissues. In contrast, long-term effects seen in the dogs exposed to relatively insoluble forms have been mainly associated with the lung and contiguous tissues. In all experiments, emphasis is placed on an evaluation of the influence of radiation dose rate and total dose on the resulting dose-response relationship. Over the mid-range of exposure levels, it will be possible to compare the radiation dose and biological response relationships for the several radioactive aerosols with their different radiation dose patterns. These studies with young adult dogs are complemented with comparable studies in other species (mice, rats and Syrian hamsters) and with animals of different ages (immature, aged). This basic approach, with emphasis on factors that alter the resulting radiation dose pattern, offers the maximum likelihood of meeting the continuing, and not always predictable, needs for information on the toxicity of inhaled beta-emitting radionuclides that may be encountered in nuclear industry operations

  11. Toxicity of inhaled beta-emitting radionuclides: an experimental approach

    An experimental approach to evaluation of the toxicity of inhaled beta-emitting radionuclides in experimental animals is described. Graded levels of these radionuclides are being studied in both relatively soluble (90SrCl2, 144CeCl3, 91YCl3, 137CsCl) and relatively insoluble forms (90Y, 91Y, 144Ce and 90Sr in fused clay particles). Initial lung or whole-body activity burdens were selected to result in early deaths due to severe lesions at the highest levels, deaths at later times with moderate to marked pathologic changes and more subtle changes such as neoplasia at the lower levels. The organs affected vary depending on the solubility and chemical characteristics of the isotope. For radionuclides inhaled in relatively soluble forms, long-term effects have been seen in the liver, skeleton, and other tissues in addition to some pulmonary effects. In contrast, long-term effects seen in the dogs exposed to relatively insoluble forms have been mainly associated with the lung and contiguous tissues. In the latter experiments, emphasis is placed on an evaluation of the influence of radiation dose rate and total dose on the resulting dose-response relationship. Over the mid-range of the relationship between radiation dose and biological response, it will be possible to compare the relationships for the several radioactive aerosols with their different radiation dose patterns. These studies with young adult dogs are complemented with comparable studies in other species (mice, Syrian hamsters) and with animals of different ages (immature, aged). This basic approach, with emphasis on factors that alter the resulting radiation dose pattern, offers the maximum likelihood of meeting the continuing, and not always predictable, needs for information on the toxicity of inhaled beta-emitting radionuclides that may be encountered in nuclear industry operations. (U.S.)

  12. Studies of the coagulation flotation of bentonite and its application to the removal of Co2+ ions and fission products, Ce and Eu

    The regions of dispersion, coagulation precipitation, coagulation flotation, and redispersion were determined for aqueous bentonite-cationic surfactant and bentonite-cationic surfactant-polyacrylamide(PAA) systems. The region of coagulation flotation was markedly extended by the addition of PAA to both the lower and higher concentration regions of the cationic surfactant, hexadecyldimethylbenzylammonium chloride(HDBAC), and to the lower concentration region of bentonite. The phenomenon of coagulation flotation was investigated in detail and was applied to the removal of Co2+ ions and nuclear fission products, 144Ce and 155Eu, from an aqueous solution. The composition of the reagents for the maximum efficiency of bentonite flotation corresponded to that of the maximum efficiency of Co2+-ion flotation. The effect of the pH on the flotation efficiency was studied in particular. The maximum flotation efficiency of 96% was obtained at pH 11 for Co2+ ions, 86% at pH 9.7 for 144Ce, and 93% at pH 10.5 for 155Eu. These radioactive elements were almost completely adsorbed on the surface of bentonite particles and were floated with them in the pH region of the maximum flotation efficiency. It was confirmed that Co2+ ions could be floated also from an extremely low concentration (10-9 mol/l) of Co2+ ions with nearly the same efficiency of flotation and with the additives in the same condition. Co2+ ions could also be effectively removed by using the step-by-step flotation, showing as high a flotation efficiency as 99.8%. (auth.)

  13. Radiocaesium forms in soil - problems of experimental determination

    A method for determining Cs form in soil is proposed based on the comparison of the experimental data on desorption of Cs radionuclide from the soil contaminated as a result of the Chernobyl accident and from the soil samples on which Cs was absorbed in laboratory (Cs was introduced in ionic form in solution). The data obtained on desorption of Cs from different soils show that Cs radionuclide is present in the soil contaminated as a result of the Chernobyl accident predominantly in an ionic form (sorbed on the different soil fractions). It has also been found that the ratio of 144Ce/137Cs radionuclides is much higher in solution than in the soil. At the same time the data on sorption of Cs and Ce radionuclides on different soils from solution 0.1M HCI + 0.1M KCI + 0.1M FeCI3 show that the sorption ability of Cs is higher than the sorption ability of Ce for all the soil types investigated. Hence, it can be assumed that the mechanism of the radionuclides extraction is desorption rather than dissolution of the matrix particles, since in the letter case extraction value of the radionuclides would not be different. The fact that the ratio of 144Ce/137Cs radionuclides in solution remains higher than in soil independent on the distance from the Chernobyl NPP indicates that the form of the radionuclides does not change with the distance from the reactor. In order to determine what type of molecules Cs radionuclide can be bound to in soil the experiments on sorption of Cs on sandy soil in the presence of humic acid in solution has been carried out. The data obtained show that the presence of humic acids has none or little effect on the sorption of Cs. This indicates that interaction of Cs radionuclides with humic acid is week and these molecules can not be responsible for binding Cs in soil. (author)

  14. Concentration and depuration of some radionuclides present in a chronically exposed population of mussels (Mytilus edulis)

    Factors are described which affect the concentration (p Ci g-1 dry wt) and loss of 241 Am, 239+240Pu, 238Pu, 144Ce, 137Cs, 134Cs, 106Ru, 95Zr and 95Nb in an exposed population of mussels Mytilus edulis L. from Ravenglass on the Esk estuary, Cumbria, UK which receives radioeffluents from the British Nuclear Fuels Ltd. (BNFL) plant at Sellafield, some 10 km to the north. Tidal position and mussel body size have a negligible influence on the concentration of 241Am, 137Cs and 106Ru in the total soft tissue, but variation in soft tissue weight throughout the year has a considerable influence on the apparent concentration and depuration times of these radionuclides. Apart from the clearance (tsub(1/2) biol, 1 to 3 h) of sediment-associated activity from the digestive tract, the depuration rate profiles follow a single component clearance curve with a biological half-life in excess of 200 d for 241 Am, 239+240Pu, 238Pu and 144Ce, and of 40 d for 137Cs. The clearance of 106Ru is more complex and consists of a 3 component depuration profile with biological half-lives of 6 h, 12 d and 260 d. The depuration profiles presented in this work are for chronically ingested isotopes under natural conditions; acute exposure will most likely result in different profiles, especially those derived from laboratory spiking experiments. Isotope ratio data support the hypothesis that the main route of entry into the mussel for the majority of the radionuclides studied is from the water. (orig./WL)

  15. Sediment-seawater distribution coefficient for radionuclides and estimation of radionuclide desorption ratio from soil in seawater

    Soil can migrate to the sea through river systems by weathering; radionuclides sorbed on the soil could migrate together to the sea. In the terrestrial environment, soil is in contact with freshwater; however, after it reaches the sea, large amounts of high-salinity seawater can contact with the soil. Consequently, some radionuclides as well as stable elements would be released from the soil. To estimate the potential extractability of radionuclides from soil, the solid/liquid distribution coefficient, Kd, was used in this study. Since there were no reported Kd values for sediments in Japanese estuarine areas, the published global fallout 60Co, 90Sr, 137Cs and 144Ce activity concentration data in estuarine areas in Japan were collated first. Data suitable for obtaining Kd for sediment-seawater values were identified. The geometric means of the Kd values for 60Co, 90Sr, 137Cs and 144Ce were 1200, 23, 200 and 2000, respectively. Using the Kd differences between the terrestrial and estuarine environments, the extractability of these radionuclides from soil to seawater was estimated. Stable element concentration data for Japanese soil and estuarine sediments were also used for comparisons. It was found that the extraction of Co and Ce from soil would be negligible; however, Sr and Cs would be partially removed from the soil to the seawater. For Cs, a preliminary study on 137Cs extractability from soil in seawater was carried out. The data supported a possible Cs extraction from Cs contaminated soil in estuarine systems, which might affect the biota living in the systems. (author)

  16. EML Surface Air Sampling Program, 1990--1993 data

    Larsen, R.J.; Sanderson, C.G.; Kada, J.

    1995-11-01

    Measurements of the concentrations of specific atmospheric radionuclides in air filter samples collected for the Environmental Measurements Laboratory`s Surface Air Sampling Program (SASP) during 1990--1993, with the exception of April 1993, indicate that anthropogenic radionuclides, in both hemispheres, were at or below the lower limits of detection for the sampling and analytical techniques that were used to collect and measure them. The occasional detection of {sup 137}Cs in some air filter samples may have resulted from resuspension of previously deposited debris. Following the April 6, 1993 accident and release of radionuclides into the atmosphere at a reprocessing plant in the Tomsk-7 military nuclear complex located 16 km north of the Siberian city of Tomsk, Russia, weekly air filter samples from Barrow, Alaska; Thule, Greenland and Moosonee, Canada were selected for special analyses. The naturally occurring radioisotopes that the authors measure, {sup 7}Be and {sup 210}Pb, continue to be detected in most air filter samples. Variations in the annual mean concentrations of {sup 7}Be at many of the sites appear to result primarily from changes in the atmospheric production rate of this cosmogenic radionuclide. Short-term variations in the concentrations of {sup 7}Be and {sup 210}Pb continued to be observed at many sites at which weekly air filter samples were analyzed. The monthly gross gamma-ray activity and the monthly mean surface air concentrations of {sup 7}Be, {sup 95}Zr, {sup 137}Cs, {sup 144}Ce, and {sup 210}Pb measured at sampling sites in SASP during 1990--1993 are presented. The weekly mean surface air concentrations of {sup 7}Be, {sup 95}Zr, {sup 137}Cs, {sup 144}Ce, and {sup 210}Pb for samples collected during 1990--1993 are given for 17 sites.

  17. The accumulation of radionuclides by Dreissena polymorpha molluscs - The Accumulation of Radionuclides from Water and Food in the Dreissena polymorpha Mollusks

    Jefanova, O.; Marciulioniene, D. [Nature Research Centre, Akademijos str. 2, LT-08412 Vilnius, Lietuva (Lithuania)

    2014-07-01

    The specific activity of {sup 137}Cs, {sup 60}Co, {sup 54}Mn, {sup 90}Sr was measured in mollusks Dreissena polymorpha samples from lake Drukshiai that is the cooling pond of the Ignalina NPP. Item the accumulation of {sup 137}Cs, {sup 90}Sr, {sup 144}Ce, {sup 106}Ru in the mollusks from water and from phytoplankton which is a part of their diet was evaluated under laboratory conditions. The data of long-term (1991-2009) studies conducted at six monitoring stations of lake Drukshiai show that in 1991 {sup 137}Cs in mollusks Dreissena polymorpha was found only in that lake's area which was influenced by the effluent that got into lake from the industrial drainage channel of Ignalina NPP. In later periods of the investigation the {sup 137}Cs specific activity was detected in mollusks samples which had been collected at other monitoring stations (the aquatory of lake Drukshiai). Meanwhile {sup 60}Co and {sup 54}Mn in Dreissena polymorpha were detected only in that lake's area which was impacted by the industrial drainage channel. The data of long-term investigation show that the major amount of radionuclides has come into lake Drukshiai through the industrial drainage system of Ignalina NPP. Albeit {sup 137}Cs, {sup 90}Sr, {sup 144}Ce, {sup 106}Ru get into the mollusks through a large amount of the water rather than from the food (phytoplankton), therefore the food can also be the main source of radionuclides in the organism of these mollusks in aquatic environment when there are low levels of specific activities of these radionuclides. (authors)

  18. Studies on influence of biological factors on concentration of radionuclides

    Biological factors influencing the concentration of radionuclides were studied from the points of uptake through digestive tract, food as pathways, and metabolic activities. The uptake of radionuclides by marine fishes through digestive tract was determined by whole body counter. 137Cs, 65Zn, 131I, 54Mn, 60Co, 85Sr, and 144Ce were used as tracers and was given with solid feed. The feed given was excreated 24 to 48 hours later in small of middle sized fishes, and 20 to 48 hours later in large sized fishes. The uptake rate of 137Cs and 65Zn was high absorption of 20 to 80 per cent, that of 131I, 60Co and 54Mn was not remarkable, and that of 85Sr and 144Ce was low absorption. The biological concentration of 137Cs through pathways of food. In fishes taking up radionuclides through contaminated food, concentration factor increased in accordance with contamination level. In addition, radionuclides with small uptake but delayed excretion and those with high concentration rate could be the factors to decide the concentration factors of marine organisms. In order to study the relationship between metabolic activities and concentration, the uptake of one-year old fishes and adult fishes, and fishes fed and those non-fed were compared. One-year fishes took up large amount of 85Sr during short period, however, concentration by metabolism in adult fishes was slow. Comparing feeding group and non-feeding group, the former showed 85Sr concentration factor of 1.5 to 2 times that of the later, and the later showed 137Cs concentration factor of 2 to 4 times that of the former. However, both uptake and excretion were rapid suggesting that taking food activated the metabolism of substances. (Kanao, N.)

  19. Health risks from radionuclides released into the Clinch River

    The purpose of this work is to estimate off-site radiation doses and health risks (with uncertainties) associated with the release of radionuclides from the X-10 site. Following an initial screening analysis, the exposure pathways of interest included fish ingestion, drinking water ingestion, the ingestion of milk and meat, and external exposure from shoreline sediment. Four representative locations along the Clinch River, from the White Oak Creek Embayment to the city of Kingston, were chosen. The demography of the lower Clinch River supplied information dealing with land use that aided in the determination of sites on which to focus efforts. The locations that proved to be the most significant included Jones Island at Clinch River Mile (CRM) 20.5, Grassy Creek and K-25 (CRM 14), Kingston Steam Plant (CRM 3.5), and the city of Kingston (CRM 0). These areas of interest have historically been and are still primarily agricultural and residential areas. Reference individuals were determined with respect to the pathways involved. The primary radionuclides of interest released from the X-10 facility into the Clinch River via White Oak Creek were identified in the initial screening analysis as 137Cs, 90Sr, 60Co, 106Ru, 144Ce, 131I, 95Zr, and 95Nb. Of these radionuclides, 137Cs, 60Co, 106Ru, 90Sr, 144Ce, 95Zr, and 95Nb were evaluated for their contribution to the external exposure pathway. This study utilized an object-oriented modeling software package that provides an alternative to the spreadsheet, providing graphical influence diagrams to show qualitative structure of models, hierarchical models to organize complicated models into manageable modules, and intelligent arrays with the power to scale up simple models to handle large problems. The doses and risks estimated in this study are not significant enough to cause a detectable increase in health effects in the population. In most cases, the organ does are well below the limits of epidemiological detection (1 to 30

  20. Characteristics of particulate radionuclides in the atmospheric surface layer of the 30-km zone of Chernobyl

    For the inhalation dose assessment, reliable estimations are necessary of the average volume concentration of particle bound radionuclides in the atmosphere specifying the nuclide composition, the activity distribution in the different particle size ranges and the solubility characteristics of the nuclides. For that purpose, the analysis of measurement series is presented of the daily average activity concentrations of 137Cs and 144Ce and their temporal and spatial variability. From 1986 till 1994, samples were taken with high-volume samplers and multicascade impactors; the number concentrations of aerosol particles and the number concentrations of 'hot' particles were determined for different conditions with an Aerosol Particle Sizer and a Rotating Arm Impactor. The data demonstrate a decrease the atmospheric concentrations of 137Cs and 144Ce with time larger than caused by radioactive decay alone. A statistical analysis showed a high level of fluctuations in the concentration of radionuclides in air with maxima exceeding the annual average by 10 to 20 times. The analysis of 88 experimental radioactivity size distributions at Zapolie and Pripyat for winddriven resuspension conditions have shown that the measured distributions are generally very wide and differ from the log-normal distribution in the most cases. At Zapolie, the mean air concentrations of 137Cs, discriminated in four size ranges, showed an increasing part of inhalable particles with time since the accident. In 1993, the inhalable fraction was about 48% of the total concentration. The size distribution of atmospheric 137Cs particulate activity during these periods of enhanced resuspension showed a similar common shape with two maxima, the first in the 2-4 μm range, and the second in the 12-20 μm range. The estimated radioactive loading of particles showed an enrichment of resuspended radionuclides compared with soil particles. The highest enrichment factor was found for large particles, the lowest

  1. Probing new physics with underground accelerators and radioactive sources

    New light, weakly coupled particles can be efficiently produced at existing and future high-intensity accelerators and radioactive sources in deep underground laboratories. Once produced, these particles can scatter or decay in large neutrino detectors (e.g. Super-K and Borexino) housed in the same facilities. We discuss the production of weakly coupled scalars ϕ via nuclear de-excitation of an excited element into the ground state in two viable concrete reactions: the decay of the 0+ excited state of 16O populated via a (p,α) reaction on fluorine and from radioactive 144Ce decay where the scalar is produced in the de-excitation of 144Nd⁎, which occurs along the decay chain. Subsequent scattering on electrons, e(ϕ,γ)e, yields a mono-energetic signal that is observable in neutrino detectors. We show that this proposed experimental setup can cover new territory for masses 250 keV≤mϕ≤2me and couplings to protons and electrons, 10−11≤gegp≤10−7. This parameter space is motivated by explanations of the “proton charge radius puzzle”, thus this strategy adds a viable new physics component to the neutrino and nuclear astrophysics programs at underground facilities

  2. An interspecies comparison of the biological effects of an inhaled, relatively insoluble beta emitter

    Mice, rats, Syrian hamsters, and beagle dogs were exposed by inhalation to graded levels of 144Ce in relatively insoluble forms to demonstrate species similarities and differences regarding patterns of deposition, fate, dosimetry, and dose-response relationships. All animals were serially evaluated to determine lung burdens, held for life-span observation, necropsied at death, and examined histopathologically to characterize the lesions present and to determine the cause of death. The primary malignant lung tumors observed in rodents were predominantly squamous-cell carcinomas and adenocarcinomas, whereas those in dogs at earlier times were primarily hemangiosarcomas and those in dogs that died at later times were pulmonary carcinomas. The relationship between the incidence of lung cancer and absorbed beta dose to the lung differed among species. The results of modeling these data provide a better understanding of how the choice of species can influence the outcome of a life-span study. The data are used to estimate the risk of lung cancer in man from an inhaled beta-emitting radionuclide. 26 refs., 5 figs., 6 tabs

  3. Position of sediments in transfer of radionuclides released into coastal sea to human beings

    A great portion of radionuclides released into coastal sea is adsorbed into marine sediments and the adsorbed radionuclides causes the radioactive contamination of marine organisms and then transferred to human beings who consume them. In order to make a quantitative evaluation of this route, the transfer of 9 kinds of radionuclides from sediments to benthic organisms such as algae, bivalve and worm was observed. Then it was compared with the radioactivity in these organisms from radioactively contaminated sea water (Concentration factor). It was observed that the influence of sea water was larger than that of sediments as it was 104 times larger for 54Mn, 103 times larger for 59Fe, 60Co, 95Zr-95Nb, 106Ru-106Rh and 144Ce-144Pr, 102 times larger for 65Zn and 10-102 times larger for 115mCd and 137Cs. Consequently, sea water can be considered as the main route and sediments as the secondary in the case of quantitative comparison of the effect on the accumulation of radionuclides by marine organisms and in the transfer of radionuclides to human beings

  4. Some analytical aspects of the technologies using molten fluorides

    Analytical activities accompanying the development or a molten fluoride reactor can be divided into 3 groups: (i) Balance analyses of fissile and fertile isotopes and their isotope composition; (ii) Analytical control of the reactor process; and (iii) Special analyses and measurements for physical reactor parameters determination. The first group is formed by the precise determination of U, Pu, Th content and isotope composition. Both destructive and non-destructive methods are recommended. The suitable methods are the following: chemical methods (e.g. titrimetric methods), x-ray fluorescence and IDA with alpha- or mass-spectrometric ending. The mass-spectrometry, ICP-MS and gamma-spectrometry are preferred for the isotope analysis. The analyses important for operating reactor form the second group. There is the determination of important activation and fission products as: 233Pa, 137Cs, 90Sr, 144Ce, rare earth elements, transuranium elements, tritium etc. The methods commonly used are based on gamma-spectrometry, alpha-spectrometry, ICP-MS and LSC. In the last group the analyses used for the determination of reactor parameters or the chemical form of some elements in the melt of fluorides can be included. As an example the mass-spectrometric determination of the capture-to-fission ratio or the use of FTIR spectrometry for the determination of the chemical form of fluoride melt. The paper describes the results of measurements obtained for the systems similar to fluoride melts. The possibility of the methods application is discussed. (author)

  5. Long-lived radionuclides in low-level waste

    In July 1982, the Low-Level Waste Licensing Branch of the NRC, anticipating the impact of the proposed Part 61 to 10 CFR, funded a two-year project by SAI to study the radionuclide contents of LWR generated in low-level waste. The objectives of the study are: (1) to analyze, using verified techniques, 150 archived samples for specified beta- and x-ray-emitting nuclides that had not previously been analyzed; (2) to analyze twenty new samples obtained from operating plants for all relevant nuclides and compare them to previous data to ascertain trends; (3) to develop empirical scaling factors through the use of which concentrations of hard-to-analyze nuclides can be estimated from analyses of the gamma-ray emitting nuclides. The new samples are analyzed and the results are summarized and interpreted. Over fifty archived samples have also been analyzed. We discuss scaling factor development. Factors are presented that relate 63Ni and 59Ni to 60Co for PWRs and to 58Co for BWRs, 90Sr to 137Cs for BWRs and 241Pu, 239Pu, 241Am, and 244Cm to 144Ce for all LWRs. 8 figures, 3 tables

  6. Amchitka Radiobiological Program. Final report, July 1970-December 1979

    The Amchitka Radiobiological Program, to collect biological and environmental samples for radiological analyses, began in 1970 and continued through 1979. The principal objective was to determine the extent of radionuclide contamination from worldwide atmospheric fallout and from the detonation of three underground nuclear tests on Amchitka. Leakage of radionuclides from the underground test sites would be suspected if the amount of contamination was significantly greater than could be attributed to worldwide fallout or if an unexpected assemblage of radionuclides was detected. No radionuclides from the underground sites were detected, except for tritium from the Long Shot test (1965) which produced increased tritium concentrations in surface water and freshwater plants near the test site. This final report compiles all previous data into one report and considers the temporal trends in these data. Two naturally occurring radionuclides, 40K and 7Be, were the most abundantly occurring radionuclides in most samples; in lichen samples either 137Cs or 144Ce had the highest activity. All samples were below applicable Radiation Protection Guides and by 1979 most samples were near or below the statistical detection limits. Increased concentrations of short-lived fallout radionuclides following the Chinese atmospheric tests were found in freshwater and seawater samples and in most indicator organisms

  7. Amchitka Radiobiological Program. Final report, July 1970-December 1979

    Sibley, T.H.; Tornberg, L.D.

    1982-11-01

    The Amchitka Radiobiological Program, to collect biological and environmental samples for radiological analyses, began in 1970 and continued through 1979. The principal objective was to determine the extent of radionuclide contamination from worldwide atmospheric fallout and from the detonation of three underground nuclear tests on Amchitka. Leakage of radionuclides from the underground test sites would be suspected if the amount of contamination was significantly greater than could be attributed to worldwide fallout or if an unexpected assemblage of radionuclides was detected. No radionuclides from the underground sites were detected, except for tritium from the Long Shot test (1965) which produced increased tritium concentrations in surface water and freshwater plants near the test site. This final report compiles all previous data into one report and considers the temporal trends in these data. Two naturally occurring radionuclides, /sup 40/K and /sup 7/Be, were the most abundantly occurring radionuclides in most samples; in lichen samples either /sup 137/Cs or /sup 144/Ce had the highest activity. All samples were below applicable Radiation Protection Guides and by 1979 most samples were near or below the statistical detection limits. Increased concentrations of short-lived fallout radionuclides following the Chinese atmospheric tests were found in freshwater and seawater samples and in most indicator organisms.

  8. Three-dimensional plume dynamics in the vadose zone: PORFLO-3 modeling of a defense waste leak at Hanford

    In 1973, approximately 450 m3 of liquid containing radioactive and chemical wastes leaked from the 241-T-106 single-shell tank into the vadose zone at the US Department of Energy's Hanford Site in south-central Washington State. The extent of the 137Cs, 144Ce, and 106Ru contaminant plumes in the vadose zone was estimated in 1973 and 1978 by gamma spectrometry in monitoring wells. Using site data and the PORFLO-3 computer model, a three-dimensional, transient plume migration model was developed for 106Ru and 137Cs. The model was calibrated to the 1973 measured plumes of 106Ru and 137Cs. The calibrated model was then used to study plume migration up to 1990. The simulated 106Ru distribution for 1978 extended deeper than reported values. The simulated distribution of 137Cs for 1978 approximated the measured distribution; the 1973 and 1978 137Cs distributions are similar because of the long half-life and high sorption coefficient of 137Cs. 8 figs., 15 refs

  9. Measurement of radionuclides in bricks made from refuse ash of sewage sludge

    Since people spend about 80% of their time in buildings, in order to estimate the radiation exposure dose of nation, it is necessary to grasp indoor dose level. It has been known that as for indoor radiation exposure dose, it is different according to the types of buildings, and generally it is low in wooden houses, and high in concrete and brick buildings. This difference is due to the shielding of environmental radiation by building material and the radiation emitted from building materials themselves. In this study, the radionuclides in the bricks made of sewage slude-incinerated ash and red bricks for the reference were investigated. The radiation emitted from the bricks was measured with a thermoluminescence dosimeter (TLD). The sampling and pretreatment, the measuring method, the measurement of the radiation dose on the bricks, and the results are reported. As for the natural radionuclides in the bricks, 7Be was detected in most sludge bricks, and the concentration varied largely according to the data of sampling. It was not detected in red bricks. 40K, 214Bi and 228Ac were detected in all the sludge and red bricks. Artificial radionuclides such as 54Mn, 60Co, 106Ru, 131I, 134Cs and 144Ce were not detected in all the sludge and red bricks. The radiation dose on the sludge and red bricks was 20.5 - 21.7 mR, and constant regardless of the data of sampling. (K.I.)

  10. Application of radiochemical-and direct gamma ray spectrometry methods for the determination of the burnup of irradiated uranium oxide

    The burn-up of U3O8 (natural uranium) samples was determined by using both destructive and non-destructive methods, and comparing the results obtained. The radioisotopes 144Ce, 103Ru, 106Ru, 137Cs and 95Zr were chosen as monitors. In order to isolate the radioisotopes chosen as monitors, a separation scheme has been established in which the solvent extraction technic is used to separate cerium, cesium, and ruthenium one from the other and from uranium. The separation between zirconium and niobium and of both from the others was accomplished by means of adsorption on a silica-gel column. When the non-destructive method was used, the radioactivity of each nuclide of interest was measured in the presence of all others. For this purpose, use was made of gamma-ray spectrometry and a Ge-Li detector. The comparison of burn-up values obtained by both destructive and non-destructive methods was made by means of Student's 't' test, and it has shown that the averages of results obtained in each case are equal. (Author)

  11. Development of a CMPO based extraction process for partitioning of minor actinides and demonstration with genuine fast reactor fuel solution (155 GWd/Te)

    Antony, M.P.; Kumaresan, R.; Suneesh, A.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (IN). Fuel Chemistry Div.] (and others)

    2011-07-01

    A method has been developed for partitioning of minor actinides from fast reactor (FR) fuel solution by a TRUEX solvent composed of 0.2 M n-octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO)-1.2 M tri-n-butylphosphate (TBP) in n-dodecane (n-DD), and subsequently demonstrated with genuine fast reactor dissolver solution (155 GWd/Te) using a novel 16-stage ejector mixer settler in hot cells. Cesium, plutonium and uranium present in the dissolver solution were removed, prior to minor actinide partitioning, by using ammonium molybdophosphate impregnated XAD-7 (AMP-XAD), methylated poly(4-vinylpyridine) (PVP-Me), and macroporous bifunctional phosphinic acid (MPBPA) resins respectively. Extraction of europium(III) and cerium(III) from simulated and real dissolver solution, and their stripping behavior from loaded organic phase was studied in batch method using various citric acid-nitric acid formulations. Based on these results, partitioning of minor actinides from fast reactor dissolver solution was demonstrated in hot cells. The extraction and stripping profiles of {sup 154}Eu, {sup 144}Ce, {sup 106}Ru and {sup 137}Cs, and mass balance of {sup 241}Am(III) achieved in the demonstration run have been reported in this paper. (orig.)

  12. Development of a CMPO based extraction process for partitioning of minor actinides and demonstration with genuine fast reactor fuel solution (155 GWd/Te)

    A method has been developed for partitioning of minor actinides from fast reactor (FR) fuel solution by a TRUEX solvent composed of 0.2 M n-octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO)-1.2 M tri-n-butylphosphate (TBP) in n-dodecane (n-DD), and subsequently demonstrated with genuine fast reactor dissolver solution (155 GWd/Te) using a novel 16-stage ejector mixer settler in hot cells. Cesium, plutonium and uranium present in the dissolver solution were removed, prior to minor actinide partitioning, by using ammonium molybdophosphate impregnated XAD-7 (AMP-XAD), methylated poly(4-vinylpyridine) (PVP-Me), and macroporous bifunctional phosphinic acid (MPBPA) resins respectively. Extraction of europium(III) and cerium(III) from simulated and real dissolver solution, and their stripping behavior from loaded organic phase was studied in batch method using various citric acid-nitric acid formulations. Based on these results, partitioning of minor actinides from fast reactor dissolver solution was demonstrated in hot cells. The extraction and stripping profiles of 154Eu, 144Ce, 106Ru and 137Cs, and mass balance of 241Am(III) achieved in the demonstration run have been reported in this paper. (orig.)

  13. Determination of plutonium americium and curium in soil samples by solvent extraction with trioctylphosphine oxide

    A method of Pu, Am and Cm determination in soil samples, which was developed for analyzing samples from territories subjected to radioactive contamination as a result of the Chernobyl accident is described. After preliminary treatment the samples were leached by solution of 7 mol/l HNO23+0.3 mol/l KBrO3 during heating. Pu was isolated by extraction with 0.05 mol TOPO from 7 mol/l HNO3. 144Ce and partially remaining in water phase isotopes of Zr, U and Th were isolated in an extraction-chromatographic column with TOPO and PbO2. Then Am and Cm were extracted by 0.2 mol/l TOPO from solution 1 mol/l HLact+0.07 mol/l DTPA+1 mol/l Al(NO3)3. Alpha-activity of both extracted products was determined in liquid scintillation counter. Chemical yield of plutonium counted to 85±10%, that of americium and curium -75±10%. 17 refs

  14. Study of the behaviour of transuranics and possible chemical homologues in Lake Michigan water and biota

    Concentration factors for Pu, Am and U in Lake Michigan biota are compared to those of a number of stable trace elements that have short residence times in Lake Michigan water. The relative order of uptake for these nuclides in Lake Michigan biota is Am>Pu much>U. Evidence is summarized which suggests that the predominant oxidation state of 239, 240Pu in Lake Michigan water is 4+. Concentrations of 239, 240Pu in net plankton, filterable particulate matter, sediment trap, and benthic floc samples indicate that sorption by biogenic detritus, and settling of this material, can account for the reduced concentration of 239, 240Pu observed in surface waters during summer stratification, but that deposition into the sediments is primarily non-biological. Concentrations of 7Be, 144Ce and 137Cs in sediment trap samples show the effect of spring convective mixing and demonstrate the resuspension of mineral-rich surficial sediments during the summer months. The effect on the concentration of dissolved plutonium in the water column, of varying degrees of resuspension of sedimentary floc, is described using a simple mass-action model. A radiochemical method for the determination of americium and uranium in Lake Michigan environmental samples is also presented. (author)

  15. Calibration of Ge(Li) semiconductor detector by method using agar volume source

    The Ge(Li) semiconductor detector was calibrated for measurements of environmental samples. The radioisotopes used for standard sources are 22Na, 51Cr, 56Co, 57Co, 133Ba, 137Cs, 144Ce and 241Am. These are mixed with hot agar aqueous solution and fixed uniformly in a cylindrical plastic case in cooling. The agar volume source is advantageous in handling over the fluid aqueous source. The prepared cylindrical standard sources are in diameters 6 and 8 cm and thicknesses 1, 5, 10, 20, 30 and 40 mm (only for 8 cm diameter). The radioactivities of prepared standard sources are between 0.03 μCi and 0.2 μCi. It takes only a week to make the calibration except data processing. The obtained full energy peak efficiency curves include 5 - 10% error due to preparation of agar source, reference radioactivity data of purchased standard solutions, reference data of branching ratio of gamma-ray and sum effect. The efficiency curves, however, are sufficient for quantitative analysis of environmental samples. (author)

  16. Varieties of fuel particles in fallout of the Chernobyl NPP exclusion zone

    Soil in the Chernobyl NPP 30-km zone is known to be contaminated by fine particles of dispersed irradiated fuel. Experimental data obtained by the authors shortly after the accident indicated a significant excess of 95Zr in the particles compared with its calculated amount. This suggested that particles of the U fuel also contain construction material from the core, activated Zr. The authors have isolated particles of radioactive material from the heavy soil fraction in order experimentally to confirm this. Their dimensions varied from 85 to 750 μm; their mass, from 10 to 700 μg. Such characteristics as the microstructure, elemental composition, and the concentration of 144Ce and other radionuclides obtained from electron microscope measurements, microprobe analysis, and γ- and α-spectrometry were used to classify the particles. It was found that two types of highly active particles are characteristic of the Chernobyl NPP exclusion zone (up to 4-5 km) and the western track of the fallout for a distance of 20 km from the destroyed fourth block. The first type are genuine particles of irradiated fuel. The second type are aggregates consisting of U and Zr oxides. The second type predominates in fallout of the exclusion zone and in the western track

  17. Animal metabolism

    Studies on placental transport included the following: clearance of tritiated water as a baseline measurement for transport of materials across perfused placentas; transport of organic and inorganic mercury across the perfused placenta of the guinea pig in late gestation; and transport of cadmium across the perfused placenta of the guinea pig in late gestation. Studies on cadmium absorption and metabolism included the following: intestinal absorption and retention of cadmium in neonatal rats; uptake and distribution of an oral dose of cadmium in postweanling male and female, iron-deficient and normal rats; postnatal viability and growth in rat pups after oral cadmium administration during gestation; and the effect of calcium and phosphorus on the absorption and toxicity of cadmium. Studies on gastrointestinal absorption and mineral metabolism included: uptake and distribution of orally administered plutonium complex compounds in male mice; gastrointestinal absorption of 144Ce in the newborn mouse, rat, and pig; and gastrointestinal absorption of 95Nb by rats of different ages. Studies on iodine metabolism included the following: influence of thyroid status and thiocyanate on iodine metabolism in the bovine; effects of simulated fallout radiation on iodine metabolism in dairy cattle; and effects of feeding iodine binding agents on iodine metabolism in the calf

  18. Waste/Rock Interactions Technology Program. Status report on LWR spent-fuel leach tests

    Spent fuels with burnups of 9000, 28,000 and 54,500 MWd/MTU have been leach tested at 250C. Three leach-test procedures (Paige, IAEA and static) were used. IAEA and static tests were conducted in five different solutions: deionized water, sodium bicarbonate, sodium chloride, calcium chloride and Waste Isolation Pilot Plant B brine solutions. Elemental leach data are reported based on the release of 90Sr+90Y, 106Ru, 137Cs, 144Ce, 154Eu, 239+240Pu, 125Sb, 244Cm, 129I, 99Tc, and total uranium. This is the first report on 129I and 99Tc from spent fuel. Termination of the Paige test showed that the plateout (radionuclide adsorption) on the test apparatus had negligible effect on the leach rate of cesium and plutonium, but a major (up to a factor of 50 times) effect on the curium leach rate. Three-hundred additional days of leach testing by the IAEA procedure, from 467 to 769 d, showed a continuation of the leaching trends observed during the first 467 d. Results from the first two static leach test series, 2 and 8 d, gave the 129I and 99Tc release numbers

  19. Communication of nuclear data progress No. 21 (1999)

    The 21th issue of Communication of Nuclear Data Progress (CNDP) is presented, in which the achievements of last half year in nuclear data field in China are carried.It includes the measurement of differential cross sections for 6Li(n,t)4He reaction at 3.67 and 4.42 MeV, 14 MeV neutron activation cross section for 93Nb (n,2n)92Nb reaction, double differential cross sections for 39K(n,α36Cl reaction at 4.41, 5.46, 6.52 MeV; theoretical calculations of n + 235U, 151,153,154,155Eu, 135-138Ba69,71Ga, 83-86Kr at En = 0.001-20 MeV; evaluations of neutron reaction cross sections for 140,141,142,144Ce, 63,65,NatCu, 115In, 105,108Pd and 103Rh, complete data for 63Cu, and photonuclear reaction for 90,91,92,94,96Zr, nuclear data sheets for A = 195 and thermal-neutron captures data evaluation for A = 1-19; construction of covariance matrix for absolute fission yield data measurement; thermal and fast reactor benchmark testing of ENDF/B-6.4. Also the activities on nuclear data in China are summarized

  20. Hazards to the eye lens and gonads from hard beta rays

    Considerable attention has been paid to the protection against x and γ radiation but comparatively less stress has been given to the possible hazard due to external radiation from high-energy beta rays. In order to evaluate the magnitude of this hazard, central-axis depth doses at different source-to-skin distances for 90Sr-90Y and 32P sources were measured. Isodose curves in a testicular phantom for a 90Sr-90Y source were measured. The data of Haybittle for 144Ce for 10 cm SSD has been included. From the measured data, the eye-lens epithelium dose may be as high as 51%, 21.5%, and 82%, respectively, for the three sources instead of 15% as has been conventionally assumed. The isodose curves obtained in the testicular phantom indicate that an appreciable amount of testicular tissue can be subjected to radiation exposures. The radiation hazards due to high-energy beta rays are not negligible and considerable care should be exercised while using these sources

  1. Extrapolation of experimental data on late effects of low-dose radionuclides in man

    The situation of living of population on radionuclide contamination areas was simulated in the experimental study using white strainless rats of different ages. The significance of age for late stochastic effects of internal radionuclide contamination with low doses of 131I, 137Cs, 144Ce and 106Ru was studied. Some common regularities and differences in late effects formation depending on age were found. Results of the study showed that the number of tumors developed increased in groups of animals exposed at the youngest age. The younger animal at the moment of internal radionuclide contamination, the higher percentage of malignant tumors appeared. It was especially so for tumors of endocrine glands (pituitary, suprarenal,- and thyroid). Differences in late effects formation related to different type of radionuclide distribution within the body were estimated. On the base of extrapolation the conclusion was made that human organism being exposed at early postnatal or pubertal period could be the most radiosensitive (1.5-2.0 or sometimes even 3-5 times higher than adults). Data confirmed the opinion that children are the most critical part of population even in case of low dose radiation exposure. (author)

  2. Assay of long-lived radionuclides in low-level wastes from power reactors

    The 10 CFR Part 61 waste classification system includes several nuclides which are difficult to assay without expensive radiochemical methods. In order for waste generators to classify wastes practically, NRC Staff has recommended the use of correlation factors to scale the difficult-to-measure nuclides with nuclides which can be measured more easily (i.e., gamma emitters such as 60Co or 137Cs). In this study, Science Applications International Corporation (SAIC) performed complete radiochemical assays for all the 10 CFR Part 61 waste classification nuclides on over 100 samples. These data, along with almost 800 other samples in the SAIC data base, were used to assess the validity of correlation factors suggested for use in nuclear power plant wastes. Specific generic correlation factors are recommended with other approaches to correlate nuclides for which generic scaling factors are not defensible. The primary nuclide correlations studied were 14C, 55Fe, 59Ni, 63Ni, and 94Nb, with 60Co; 90Sr, 99Tc, 129I, 135Cs, and /sup 239, 240/Pu with 137Cs; 238Pu, /sup 239, 240/Pu, 241Pu, 241Am, 242Cm, and /sup 243, 244/Cm with 144Ce; and 238Pu, 241Pu, 241Am, 242Cm and /sup 243, 244/Cm with /sup 239, 240/Pu

  3. Fraction of energy absorbed from β-emitting particles in the rat lung

    Forty-four male Fischer-344 rats were exposed, nose only, to a relatively insoluble aerosol of 144Ce-labeled fused aluminosilicate particles. Fractional β energy absorption was measured 7 to 9 days after exposure for 28 rats (ages 12 to 25 weeks and body weights of 183 to 337 g); lung burdens were 13 to 82 nCi. An additional group of 16 rats was exposed when 12 weeks old and maintained for 6 months prior to analysis; body weights and lung burdens 6 months after exposure ranged from 276 to 368 g and 16 to 46 nCi, respectively. Lungs were carefully removed, inflated, and frozen by immersion in liquid nitrogen. The energy spectrum from each lung was measured in a 4π β spectrometer, keeping the lung frozen throughout this procedure. Over the range of lung sizes in this study (0.88 to 1.66 g) the mean fractional energy absorption and standard deviation were 0.23 +- 0.078, respectively. Results agreed well with theory, indicating that calculated values for fractional energy absorption in the lung can be used for a range of lung sizes and β energies. Calculated values for fractional energy absorption as a function of β energy are included for several lung sizes between 0.5 and 10 g

  4. Reconstruction of the composition of the Chernobyl radionuclide fallout and external radiation absorbed doses to the population in areas of Russia

    The results of reconstruction of the radionuclide composition of the Chernobyl fallout in the territories of Russia is presented. Reconstruction has been carried out by means of statistical analysis of the gamma spectrometry data on 2867 soil samples collected in the territories of Ukraine, Byelarus and Russia from 1986 to 1988. To verify the data, aggregated estimates of the fuel composition of the 4th block at the moment of the accident (available from the literature) have been used, as well as the estimates of activity released to the atmosphere. As a result, correlation and regression dependences have been obtained between the activities of the radionuclides most contributing to the dose (137Cs, 134Cs, 131I, 140Ba, 140La, 95Zr, 95Nb, 103Ru, 106Ru, 141Ce, 144Ce, 125Sb). Statistically significant regression relations between different pairs of radionuclides (including analysis of the 'noise' contribution to the data) depending on the distance between the point of sample collection and the power station are presented for the 'north-east track' - the northern part of the 30 km zone and southern part of the Gomel 'district (Byelarus) and the Briansk, Kaluga, Tula and Orel districts (Russia). A methodology is also described for reconstructing space-time characteristics of the contamination of the territories by major dose-forming radionuclides released from the Chernobyl NPP 4th unit. (Author)

  5. A study of the decontamination effect of commercial detergents on the skin

    Titanium dioxide paste is generally used as the radiological skin decontaminant in the radiation control area at Japan Nuclear Cycle Development Institute (JNC) Tokai works. It is a typical and proven skin decontaminant in the nuclear industry, but there is a disadvantage in that it has a short shelf life. Recently, many detergents applicable as skin decontaminants have become available in non-nuclear industries such as cosmetics and sanitation. They are easily acquired and have an advantage in that stimulus to the skin is mild, because these products have been developed for the human body. In this study, the decontamination factor of the commercial detergents for each nuclide was examined using imitation skin. Sheets of raw pig skins were contaminated with a nitric-acid solution containing 144Ce, 137Cs, 106Ru or 60Co, and then washed with various detergents such as a neutral detergent, cleansing cream and orange oil. The nuclide removal rates of some of the commercial detergents examined were nearly equal to that of titanium dioxide, thus proving that they show satisfactory decontamination performance as a skin decontaminant. (author)

  6. TMI-2 Reactor Building source term measurements: surfaces and basement water and sediment

    Presented in this report are the results of radiochemical and elemental analyses performed on samples collected from the Three Mile Island Unit 2 Reactor Building from August 1979 to December 1983. The quantities of fission products and core materials that were measured on the external surfaces in the Reactor Building or in the water and sediment in its basement are summarized. Recent analysis results for access panels removed from the air cooling assembly and for liquid and particulate samples collected from the Reactor Building sump and reactor coolant drain tank are included in the report. Measurements show that 59% of the 3H, 2.7% of the 90Sr, 15% of the 129I, 20% of the 131I, and 42% of the 137Cs originally in the core at the time of the accident could be accounted for outside the core in the Reactor Building. With the exceptions of 90Sr and 144Ce, the vast majority of each radionuclide released was found dispersed in the water and sediment in the basement

  7. Studies of environmental radioactivity in Cumbria

    Five stations collecting samples of atmospheric deposition were set up in north Cumbria along a line running inland from the coast for about 17 km. Sampling was continuous from September 1980 to September 1981. Monthly samples were analysed for 106Ru, 137Cs, 144Ce, 238Pu, sup(239,240)Pu, 241Am, 7Be and stable Na, Cl and Al. The objective of the work was to measure the deposition of radionuclides as a function of distance from the sea. By estimating the contributions to the deposition of nuclear weapon test material and of the atmospheric discharges from the British Nuclear Fuels plc works at Sellafield, the effects of the transfer to air and land of radionuclides in the sea could be established. The marine radionuclides were due to the discharges to sea from the Sellafield works. The measurements showed that the deposition was largely due to the sea-to-land transfer process. The highest depositions observed were at 20 m from high water mark, the annual values (rounded, in Bq m-2) being 106Ru, 500; 137Cs, 650; plutonium, 70; 241Am, 30. The highest concentrations in rainwater for the radionuclides studied were less than 3 per cent of the fresh water limits (drinking only) GDL values. The highest estimated accumulations in soil due to atmospheric deposition were less than 1 per cent of the limits. (author)

  8. The long-term behaviour of cemented research reactor waste under the geological disposal conditions of the Boom Clay Formation: results from leach experiments

    The Belgian Nuclear Research Centre SCK-CEN has carried out a number of studies to evaluate the long-term behaviour of cemented research reactor waste under the geological disposal conditions of the Boom Clay Formation. Static leach experiments in synthetic clay water were performed on active samples of cemented research reactor waste. The leach experiments were carried out under anaerobic conditions at two testing temperatures (23 and 85oC). Leach rates of seven radionuclides (60Co, 90Sr, 134Cs, 137Cs, 144Ce, 154Eu and 241Am) were measured. Most investigated radionuclides are well retained within the cement matrix over a 280 days testing period. Results on the source term of radionuclides were complemented with data on the leaching behaviour of cement matrix constituents as Ca, Si, Al, Na, K, Mg and SO4 as well as with data from performance assessment calculations and in situ tests. Despite limitations inherent to short-term experiments, combined results from these investigations indicate only limited interactions of disposed research reactor waste with the near field of a geological repository in clay. (author)

  9. Reconstruction of radionuclide releases from the Hanford Site, 1944-1972

    Historic releases of key radionuclides were estimated as a first step in determining the radiation doses that results from Hanford Site operations. The Hanford Site was built in southcentral Washington State during World War II to provide plutonium for the U.S. nuclear weapons program. As part of the Hanford Environmental Dose Reconstruction (HERD) Project, releases to the Columbia River of 24Na, 32P, 46Sc, 51Cr, 56Mn, 65Zn, 72Ga, 76As, 90Y, 131I, 239Np, and nonvolatile gross beta activity from operation of eight Hanford single-pass production reactors were estimated. Releases of 90Sr, 103Ru, 106Ru, 131I, 144Ce, and 239Pu to the atmosphere from operation of chemical separation facilities were also estimated. These radionuclides and the atmospheric and Columbia River pathways were selected for study because scoping studies showed them to be the largest contributors to dose from Hanford operations. The highest doses resulted from releases to the atmosphere of 131I from chemical separations plants in the pre-1950 period. Prior to 1950, the technology for limiting iodine releases had not been developed. Hence, a very detailed reconstruction of the hourly 131I release history was achieved for 1944-1949 using Monte Carlo methods. Atmospheric releases of the other radionuclides were estimated on a monthly basis for 1944-1972 using deterministic calculations. Monthly releases to the Columbia River for 1944-1971 were based on Monte Carlo methods

  10. Metaphase chromosome aberrations as markers of radiation exposure and dose

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes ''paints'' to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with 144Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to 60Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness

  11. Studies on treatment of radioactive animal carcass, (2)

    A method of dehydration for the waste treatment of radioactive animal carcass by microwave heating was developed. A heating apparatus was devised by annexing the microwave output controlling circuit to a 600 W commercial microwave oven, and the aqueous vapour from the animal carcass was collected by duplex cold traps. Body weight of the carcass was reduced to 20-30% by dehydration, and a three-year storage test proved that the dehydrated carcass was very hard to decompose. Time needed for dehydration was about 10 min for a 25 g mouse, and about 1 hr for 668 g dog. Violent rupture of the carcass, and/or fuming due to overheating that had often been observed during dehydration were proved to be avoidable by controlling the microwave output during the process. The ratio of radioactivity (60Co, 137Cs, 85Sr, 144Ce) that escaped from the carcass during dehydration was found to be less than 3 x 10-4 by a series of experiment. Some related radiation safety problems were discussed. (author)

  12. Radioactivity in surface air and precipitation in Japan after the Chernobyl accident

    Radioactive plumes from the Chernobyl reactor accident first passed over Japan on 3 May 1986. Measurements of 103Ru, 131I and 137Cs in rainfall and airborne dust collected at Chiba near Tokyo show that, in fact, at least two or more kinds of plume arrived during May. Their altitudes were calculated to be about 1500 m in early May and 6300 m in late May. Radionuclides detected in 33 precipitation samples collected by the network of radiation monitoring stations from 1 to 22 May were 7Be, 89Sr, 90Sr, 95Zr, 95Nb, 103Ru, 106Ru, sup(110m)Ag, 125Sb, sup(129m)Te, 131I, 132Te, 132I, 134Cs, 136Cs, 137Cs, 140Ba, 140La, 141Ce and 144Ce. The radiation was characterized by higher levels of the volatile nuclides, such as 103Ru, 132Te, 131I and 137Cs, than fallout levels in nuclear weapons testing, and by activity ratios of 0.48 and 14 for, respectively, 134Cs/137Cs and 89Sr/90Sr, as on 26 April. the fallout activity was higher in Northwestern Japan, the average depositions of 90Sr and 137Cs in Japan from 1 May (or 30 April) to 22 May being 1.4 Bq m-2 and 95 Bq m-2, inventories which are 14 and 550 times higher than the pre-Chernobyl values. (author)

  13. Tumorigenic responses from single or repeated inhalation exposures to relatively insoluble aerosols of Ce-144

    Human occupational or environmental inhalation exposures may involve repeated or chronic exposures, but most laboratory studies of inhaled radionuclides have involved single exposures. This study was designed to compare the biological effects of repeated inhalation exposures of dogs to a relatively insoluble form of 144Ce with existing data for singly-exposed dogs that had the same cumulative dose to the lungs two years after exposure. To date, the biological effects observed in these repeatedly-exposed dogs have been substantially different from those seen in singly-exposed dogs, particularly during the first 5 years after the initial exposure. Although pulmonary hemangiosarcoma was the prominent biological effect seen in singly-exposed dogs between 2 and 4 years after exposure, no lung tumors were seen during the 5 years after the first of the repeated exposures. This response plus other clinical observations are discussed in relation to the patterns of dose rate and cumulative dose for the different exposure conditions. (H.K.)

  14. Assessment of a Compton-event suppression γ-spectrometer for the detection of fission products at trace levels

    The improvement in detection limits for low and high activity samples measured with the Compton-suppression γ-spectrometer installed at the Institute for Transuranium Elements (ITU) for environmental monitoring of radioactivity, as well as nuclear safeguards, is discussed. The advantage of using two parallel acquisition lines for simultaneous measurement with and without Compton-event suppression is outlined with respect to cascade and non-cascade γ-emitters. The background reduction by Compton-event suppression made it possible to detect small peaks, which otherwise would not have been found in a conventional spectrum. In Compton-event suppression mode, the detection limit for 137Cs was improved by a factor of about 3, for 241Am we found a factor of 1.2 both in high and low active samples. The measurements of environmental reference samples showed good agreement with certified values in both acquisition modes. The application of this instrument for the determination of fission products in smear samples is described. In particular, for nuclides like 54Mn, 125Sb and 144Ce, an improvement in the detection limits by a factor of 1.6-2.4 was obtained

  15. Development of removal methods of radioactive ruthenium by using the column packed with cell materials

    Ruthenium is an element of various valencies and present in many chemical species of nitro-nitrosyl complexes in nitric acid or in solutions containing nitrates. Since radioactive ruthenium (103Ru, 106Ru) of those chamical species is contained in the wastes occurred on the fuel reprocessing by Purex method and others, it is one of the nuclides which are most difficult to be removed by the conventional methods of the radioactive waste treatments. It was found that this nuclide was effectively removed by passing the waste solution through a column packed with the mixture of powder of anode and cathode materials and depolarizers used in the electric cells. The typical mixtures were zinc-charcoal, zinc.palladium-charcoal, zinc-manganese dioxide.charcoal and zinc-carbon fluoride.charcoal. These column methods showed a surpassing removel efficiency for 106Ru complexes and fisson products. The decontamination factors of radioactive ruthenium were 104 for all kinds of ruthenium complexes and 102 for the species not easily removed by the conventional methods. It was also found that the concentrations of 239Pu, U, 144ce, 155Eu, and 125Sb in the waste could be decreased to that below the limits of detection by the cell material columns. Because 106Ru of chemical species which was difficult to be removed by conventional methods could be efficiently separated from the waste solutions, it was concluded that the columns packed with cell materials are valuable tools in the radioactive waste treatments. (author)

  16. Marine plankton as an indicator of low-level radionuclide contamination in the Southern Ocean

    Marsh, K.V.; Buddemeier, R.W.

    1984-07-01

    We have initiated an investigation of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review shows that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 10/sup 4/. In the years 1956-1958, considerable work was done on the accumulation and distribution of a variety of fission and activation products produced by the nuclear tests in the Marshall Islands. Since then, studies have largely been confined to a few selected radionuclides, and by far most of this work has been done in the northern hemisphere. We participated in Operation Deepfreeze 1981, collecting 32 plankton samples from the U.S. Coast Guard Cutter Glacier on its Antarctic cruise, while Battelle Pacific Northwest Laboratories concurrently sampled air, water, rain and fallout. We were able to measure concentrations of the naturally occurring radionuclides /sup 7/Be, /sup 40/K and the U and th series, and we believe that we have detected low levels of /sup 144/Ce and /sup 95/Nb in seven samples ranging as far south as 68/sup 0/. There is a definite association between the radionuclide content of plankton and air filters, suggesting that aerosol resuspension of marine radioactivity may be occurring. Biological identification of the plankton suggests a possible correlation between radionuclide concentration and foraminifera content of the samples. 38 references, 7 figures, 3 tables.

  17. Benefits and risks of bronchopulmonary lavage: a review

    Studies were conducted in beagle dogs and baboons over a period of 20 years to determine the efficiency of treatment by lung lavage after inhalation of insoluble radioactive particles. The radionuclides tested were 144Ce in fused clay, 238Pu, 239Pu, 241Am, Pu-TBP, Pu02, UO2, and (Pu,U)02. After inhalation of any of these radionuclides, a single lavage of the two lungs removed almost a quarter of the intitial lung burden (ILB) in the two species. When lavage was repeated five times, it removed up to half of the ILB. However, the individual variation was large. For the same radionuclide, lavage efficiency was independent of the ILB. Particle removal was better and continued longer for particles with a long retention half-time. The use of lavage can be combined with that of chelating agents like DTPA. The removal of radioactive particles lenghtened survival time and reduced the severity of pathology. The lavage in itself is safe, and does not induce permanent or progressive pathology. The biomedical risk of the lavage mainly depends on the risks inherent in anaesthesia and the health status of the patient. (author)

  18. Release behavior of metallic fission products from pyrocarbon-coated uranium-dioxide particles at extremely high temperatures

    Hayashi, Kimio; Fukuda, Kousaku (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

    1990-04-01

    Uranium-dioxide particles coated by pyrocarbon (BISO), which were irradiated at 1,300 {approx} 1,400degC to burnups of ca. 1% FIMA, were heated isochronally and isothermally at temperatures between 1,600 and 2,300degC. Release fractions of {sup 137}Cs, {sup 155}Eu and {sup 106}Ru were larger than 10{sup -2} after heating at 2,000degC for 2 h; the results were in contrast to much smaller release fractions from TRISO particles with intact silicon-carbide (SiC) coating. The release of {sup 137}Cs and {sup 144}Ce from the BISO particle was controlled by diffusion in the dense pyrocarbon layer at temperatures between 1,600 and 2,300degC, while that of {sup 155}Eu and {sup 106}Ru was controlled by diffusion in the fuel kernel above 1,800degC. These results can be used as reference data on release behavior of the fission products from TRISO particles with defective SiC layers. (author).

  19. Release behavior of metallic fission products from pyrocarbon-coated uranium-dioxide particles at extremely high temperatures

    Uranium-dioxide particles coated by pyrocarbon (BISO), which were irradiated at 1,300 ∼ 1,400degC to burnups of ca. 1% FIMA, were heated isochronally and isothermally at temperatures between 1,600 and 2,300degC. Release fractions of 137Cs, 155Eu and 106Ru were larger than 10-2 after heating at 2,000degC for 2 h; the results were in contrast to much smaller release fractions from TRISO particles with intact silicon-carbide (SiC) coating. The release of 137Cs and 144Ce from the BISO particle was controlled by diffusion in the dense pyrocarbon layer at temperatures between 1,600 and 2,300degC, while that of 155Eu and 106Ru was controlled by diffusion in the fuel kernel above 1,800degC. These results can be used as reference data on release behavior of the fission products from TRISO particles with defective SiC layers. (author)

  20. Interaction of radionuclides with geomedia associated with the Waste Isolation Pilot Plant (WIPP) site in New Mexico

    A survey of the potential of geological media from the vicinity of the Waste Isolation Pilot Plant site in Southeastern New Mexico for retardation of radionuclide migration in an aqueous carrier was conducted. The survey included the measurement of sorption coefficients (Kd) for twelve radionuclides between three natural water simulants and ten samples from various geological strata. The nuclides included 137Cs, 85Sr, 131I, 99Tc, 125Sb, 144Ce, 152Eu, 153Gd, 106Ru, 243Am, 244Cm, and 238Pu. The compositions of the simulant solutions were those expected of water in contact with potash minerals or halite deposits in the area and in a typical groundwater found in the Delaware Basin. The geological samples were obtained from potential aquifers above and below the proposed repository horizons and from bedded salt deposits in the repository horizons. In brine solutions, Tc and I were not significantly adsorbed by any of the minerals and Cs and Sr showed minimal adsorption (Kd's 103 and Ru and Sb Kd's varied in the range of 25 to > 103. In the groundwater simulant, Tc and I showed the same behavior, but the Kd's of the other nuclides were generally higher. Some initial parametric studies involving pH, trace organic constituents in the simulant solutions, and radionuclide concentrations were carried out. Significant differences in the observed Kd's can result from varying one or more of these solution parameters

  1. Classification of hot particles from the Chernobyl accident and nuclear weapons detonations by non-destructive methods

    Both after the Chernobyl accident and nuclear weapon detonations, agglomerates of radioactive material, so-called hot particles, were released or formed which show a behaviour in the environment quite different from the activity released in gaseous or aerosol form. The differences in their characteristic properties, in the radionuclide composition and the uranium and actinide contents are described in detail for these particles. While nuclear bomb hot particles (both from fission and fusion bombs) incorporate well detectable trace amounts of 60Co and 152Eu, these radionuclides are absent in Chernobyl hot particles. In contrast, Chernobyl hot particles contain 125Sb and 144Ce which are absent in atomic bomb HPs. Obvious differences are also observable between fusion and fission bombs' hot particles (significant differences in 152Eu/155Eu, 154Eu/155Eu and 238Pu/239Pu ratios) which facilitate the identification of HPs of unknown provensence. The ratio of 239Pu/240Pu in Chernobyl hot particles could be determined by a non-destructive method at 1:1.5. A non-destructive method to determine the content of non-radioactive elements by Kα-emission measurements was developed by which inactive Zr, Nb, Fe and Ni could be verified in the particles

  2. Innovative separation method for advanced spent fuel reprocessing based on tertiary pyridine resin

    Radiochemical separation experiments have been performed in order to realize a novel reprocessing method based on chromatography techniques using a novel pyridine resin. The newly synthesized tertiary pyridine resin with two functions of ion exchanger and soft-donor was dedicated to the experiments, where highly irradiated mixed oxide fuel from the experimental fast reactor JOYO was used as a reference spent fuel. With a 3-step separation, pure Am and Cm were individually obtained as minor actinide products, and 106Ru group, lanthanides with 137Cs group and Pu group were fractionated, respectively. The decontamination factor of 137Cs and trivalent lanthanides (155Eu, 144Ce) against the Am product exceeded 3.9 x 104 and 1.0 x 105, respectively. The decontamination factor as the mutual separation of 243Cm was larger than 2.2 x 103 against the Am product. Moreover, the content of 137Cs, trivalent lanthanides and 243Cm in Am product did not exceed 2 ppm. The tertiary pyridine resin method is a candidate separation system for an 'advanced ORIENT process', where enhanced separation, transmutation and utilization of actinides, long-lived fission products and rare metal fission product would be oriented. (author)

  3. Chemical and physical considerations of the use of nuclear fuel spikants for deterrence

    Selle, J. E.

    1978-10-01

    One proposed method of inhibiting the diversion of nuclear fuel for clandestine purposes is to add to the fuel a highly gamma-active material of such intensity that remote handling equipment is necessary in all stages of handling and reprocessing. This is called spiking for deterrence. The present work sought to identify candidate spikants and identify potential materials problems that might occur as the result of incorporation of these spikants with the fuel. Potential spikants were identified and thermodynamic analysis was performed to determine their chemical and physical states. Phase relationships between spikants (and their decay products) and the fuel constituents were surveyed. According to criteria defined in this report, /sup 60/Co, /sup 106/Ru, and /sup 144/Ce appear to have the greatest potential as spikants. Cerium should be present as the oxide, soluble in the fuel, while cobalt and ruthenium should be present in the metallic state with very low solubility in the fuel. Experimental work on the distribution of fission products and their interactions with cladding was also surveyed to provide information on the distribution of spikants in the fuel and describe the probable effects of spikants on the fuel. Cobalt, ruthenium, and cerium should not present any problems due to reaction with stainless steel cladding.

  4. Results of gamma-scanning measurements on Windscale AGR stringer Mk4/S46 and implications for civil AGRs

    Axial rating distributions in a WAGR fuel stringer were determined retrospectively using the measured gamma count rates from five fission products after cooling times of 70 to 100 days. The results from all five isotopes were in general agreement with predictions using the Windscale code CAMPARI, but revealed mutually consistent discrepancies with prediction near the top axial reflector. The measurements were conducted to test the gamma-scanning apparatus and methods of analysis in preparation for the post irradiation examination of CAGR fuel. It was concluded from the results that accuracies of +- 2% to +- 3% (1 sigma) should be attainable in the determination of relative ratings using the measured gamma count rates from the isotopes 140Ba, 103Ru, 95Zr, 144Ce and 137Cs. The accuracies will, however, depend on the type of fuel being examined and the fission product used. In particular, care must be taken when using 137Cs since it may migrate from its point of formation, and cooling times of less than 110 days must be achieved to measure relative concentrations of the short-lived isotope 140Ba with sufficient accuracy. (author)

  5. Practical aspects of sea and fresh-water algae utilization

    Regularities of sea and fresh-water microalgae cultivation, revealed during the operation of industrial plants, are presented in detail. The study of the Platymonas viridis cultivation mechanisms has shown the possibility of active intervention into the cycle of intense reproduction of the biomass. Among physical factors of the medium, which influence the reproduction of the industrial strain of Platymonas viridis, the effect of the red light, ultraviolet radiation, ultrahigh frequency fields and gamma radiation upon the cell division of these microalgae has been investigated. It has been shown that the effect of gamma radiation on the cell division of Platymonas viridis, other bacteria and protozoans is inhibiting. In the experiments using the radionuclides strontium-90 and cerium-144 as indicators of metabolism the dependence of the radionuclide accumulation factor on the quantity of stable lead as well as the effect of the temperature on the accumulation process have been studied. The coefficients of 90Sr and 144Ce accumulation by Nitellopsis obtusa cell compartments depending on stable lead and temperature are presented. 200 refs.; 21 figs.; 54 tabs

  6. Transfer factors of trace elements and radionuclides in the marine environment of India

    The document presents the data base on Bioaccumulation Factor, Bp and Distribution Coefficient, Kd values generated in the eastern and western coastal marine waters of India with a view to develop site-specific or species-specific values. Comparison with the IAEA default values from Safety Series No. 57 and Technical Report Series No. 247 values is made. Generally, the Bp values for trace elements do not vary by more than a factor of 3 except for some specific cases like Fe in molluscs, crustaceans and fish, Ni in molluscs and Zn in sea weeds and molluscs. The same is true for the Bp values of fission nuclides viz.,137Cs and 90Sr in molluscs, crustaceans and sea weeds except for the Bp of 137Cs in fish which is significantly lower in the Indian context. The fission nuclide 144Ce shows distinctly higher accumulation factors in all organisms. The Bp values of natural radionuclides such as 210Pb ,210Po, Ra and U are close to the IAEA default values except for the high value of U in fish. Similarly, Bp values of Pu in fish and crustaceans are significantly higher than that of the IAEA default values. The report presents Bp values for Cu and Cd in different marine organisms and Kd values in marine sediments. Kd values for suspended particles are also presented. Bp values for plankton and porifera are also given. (author)

  7. Monte Carlo modeling of beta-radiometer device used to measure milk contaminated as a result of the Chernobyl accident

    This paper presents results of Monte Carlo modeling of the beta-radiometer device with Geiger-Mueller detector used in Belarus and Russia to measure the radioactive contamination of milk after the Chernobyl accident. This type of detector, which is not energy selective, measured the total beta-activity of the radionuclide mix. A mathematical model of the beta-radiometer device, namely DP-100, was developed, and the calibration factors for the different radionuclides that might contribute to the milk contamination were calculated. The estimated calibration factors for 131I, 137Cs, 134Cs, 90Sr, 144Ce, and 106Ru reasonably agree with calibration factors determined experimentally. The calculated calibration factors for 132Te, 132I, 133I, 136Cs, 89Sr, 103Ru, 140Ba, 140La, and 141Ce had not been previously determined experimentally. The obtained results allow to derive the activity of specific radionuclides, in particular 131I, from the results of the total beta-activity measurements in milk. Results of this study are important for the purposes of retrospective dosimetry that uses measurements of radioactivity in environmental samples performed with beta-radiometer devices.

  8. Neutron cross sections of 28 fission product nuclides adopted in JENDL-1

    This is the final report concerning the evaluated neutron cross sections of 28 fission product nuclides adopted in the first version of Japanese Evaluated Nuclear Data Library (JENDL-1). These 28 nuclides were selected as being most important for fast reactor calculations, and are 90Sr, 93Zr, 95Mo, 97Mo, 99Tc, 101Ru, 102Ru, 103Rh, 104Ru, 105Pd, 106Ru, 107Pd, 109Ag, 129I, 131Xe, 133Cs, 135Cs, 137Cs, 143Nd, 144Ce, 144Nd, 145Nd, 147Pm, 147Sm, 149Sm, 151Sm, 153Eu and 155Eu. The status of the experimental data was reviewed over the whole energy range. The present evaluation was performed on the basis of the measured data with the aid of theoretical calculations. The optical and statical models were used for evaluation of the smooth cross sections. An improved method was developed in treating the multilevel Breit-Wigner formula for the resonance region. Various physical parameters and the level schemes, adopted in the present work are discussed by comparing with those used in the other evaluations such as ENDF/B-IV, CEA, CNEN-2 and RCN-2. Furthermore, the evaluation method and results are described in detail for each nuclide. The evaluated total, capture and inelastic scattering cross sections are compared with the other evaluated data and some recent measured data. Some problems of the present work are pointed out and ways of their improvement are suggested. (author)

  9. Gamma spectrometrical analyses of annual deposition samples collected in Romania in 1987-1989

    The dynamics of artificial radionuclide concentrations in deposition samples in the years 1987-1989 is presented in this paper. High resolution gamma spectrometrical analyses have been performed on wet and dry deposition samples from the following stations of the National Environmental Radioactivity Surveillance Network: Cluj-Napoca, Satu-Mare, Constanta, Ceahlau-Tosca, lasi and Craiova. In order to determine small concentrations of low level artificial radionuclides (having an appropriate half life) yearly samples obtained by cumulating daily samples were measured. The following gamma emitting radionuclides were identified in these samples: 106Ru, 110mAg, 125Sb, 134Cs, 137Cs, 144Ce. It can be seen that the level of radionuclide activities in deposition samples at any time is dependent on the 'initial' deposition of May 1986. An environmental half life of 137Cs in deposition can be assessed. For a particular case the evolution during 1987-1989 of 137Cs and 7Be specific activities in monthly samples is also presented. (author)

  10. Linear free energy correlations for fission product release from the Fukushima-Daiichi nuclear accident.

    Abrecht, David G; Schwantes, Jon M

    2015-03-01

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the initial source of the radionuclides to the environment to be from active reactors rather than the spent fuel pool. Linear correlations of the form In χ = −α ((ΔGrxn°(TC))/(RTC)) + β were obtained between the deposited concentrations, and the reduction potentials of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn (TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2015 and 2060 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, and 151Sm through atmospheric venting during the first month following the accident were obtained, indicating that large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores. PMID:25675358

  11. Biological effects of radiation: The induction of malignant transformation and programmed cell death

    In the Chernobyl explosions and fire, powderized nuclear fuel was released from the reactor core, causing an unexpected fallout. X-ray analysis and scanning electron microscopy showed that the isolated single particles were essentially pure uranium. These uranium aerosols contained all of the nonvolatile fission products, including the b-emitters, 95Zr, 103Ru, 106Ru, 141Ce, and 144Ce. The hot particles are extremely effective in inducing malignant transformation in mouse fibroblast cells in vitro. The major factor responsible for this effect is focus promotion caused by a wound-mediated permanent increase in cell proliferation (mitogenesis associated with mutagenesis). Transformed foci were analysed for the activation of c-abl, c-erb-A, c-erb-B, c-fms, c-fos, c-myb, c-myc, c-Ha-ras, c-Ki-ras, c-sis, and c-raf oncogenes at the transcriptional level. The pattern of oncogene activation was found to vary from focus to focus. Long interspersed repeated DNA (L1 or LINE makes up a class of mobile genetic elements which can amplify in the cell genome by retroposition. This element is spontaneously transcriptionally activated at a critical population density and later amplified in rat chloroleukaemia cells. UV light and ionizing radiation induce this activation prematurely, and the activation is followed by programmed cell death (apoptosis) in a sequence of events identical to that seen in LIRn activation occurring spontaneously

  12. Chernobyl radionuclides in a Black Sea sediment trap.

    Buesseler, K O; Livingston, H D; Honjo, S; Hay, B J; Manganini, S J; Degens, E; Ittekkot, V; Izdar, E; Konuk, T

    The Chernobyl nuclear power station accident released large quantities of vaporized radionuclides, and, to a lesser extent, mechanically released small (less than 1-10 micron) aerosol particles. The total release of radioactivity is estimated to be out of the order of 1-2 x 10(18) Bq (3-5 x 10(7) Ci) not allowing for releases of the xenon and krypton gases. The 137Cs releases of 3.8 x 10(16) Bq from Chernobyl can be compared to 1.3 x 10(18) Bq 137Cs released due to atmospheric nuclear weapons testing. Chernobyl-derived radionuclides can be used as transient tracers to study physical and biogeochemical processes. Initial measurements of fallout Chernobyl radionuclides from a time-series sediment trap at 1,071 m during June-September 1986 in the southern Black Sea are presented. The specific activities of 137Cs, 144Ce and 106Ru in the trap samples (0.5-2, 4-12 and 6-13 Bq g-1) are independent of the particle flux while their relative activities reflect their rates of scavenging in the order Ce greater than Ru greater than Cs. PMID:3670387

  13. A probable radiation-induced epidermal carcinoma in a sheep

    The sheep discussed in this report was one of 12 wether lambs given daily doses of 144Ce-144Pr to investigate the effect of radionuclides on the alimentary tract. The sheep received 20 mCi daily over a 16 day period when treatment was discontinued due to the development of sever diarrhea and later anorexia. Changes in the sheep reported (alopecia, ulceration, disappearance of adnexa, and fibrous replacement of the dermal collagen) indicate a radiation dose in excess of that used in previous experiments. About 4.5 yr after dosing, a firm enlargement was noticed in the right ventrolateral coccygeal region. As the enlargement increased in size, ulceration and bacterial infection occurred. The sheep was killed 59 months after initial treatment and a necropsy performed. The findings were consistent with the diagnosis of locally invasive squamouscell carcinoma. The authors feel that the relative rarity of epidermal carcinomas in sheep, exposure of the coccygeal area to large doses of irradiation, and the carcinogenic effect of radiation indicates a probable cause-and-effect relationship of radiation and tumour development. (U.K.)

  14. Radionuclide migration experiments in a natural fracture in a quarried block of granite

    A radionuclide migration experiment was performed over a distance of 1 m in a natural fracture in a quarried block of granite. The fracture in the block was characterized hydraulically by measuring the pressure drop in borehole-to-borehole pump tests. The effective fracture volume in the block was ∼100 mL. A silicone coating was applied to the exterior, and the block was immersed in a tank of water to which hydrazine was added to provide a chemically reducing barrier. Migration experiments were performed at a flow rate of 2.2 mL h-1 using 85Sr, 131I,137Cs, 144Ce, 152Eu, 237Np and 238Pu. A total of 9.5 L of groundwater was pumped through the fracture, corresponding to ∼95 fracture volumes. Only 85Sr, 131I, 137Cs, 237Np and 238Pu were observed in the eluent. Scanning of the fracture surface at the end of the migration experiment showed limited mobility of α-emitting radionuclides and of the rare-earth elements, consistent with static sorption data obtained on representative fracture surface material. The mobility of 137Cs was higher than that of the rare-earth elements, but it was lower than that of 85Sr. When samples of fracture-coating material were separated into fractions with different specific gravity, there was a clear indication of radionuclide association with mineral groups. (author)

  15. Radionuclide migration experiments in a natural fracture in a quarried block of granite

    Vandergraaf, Tjalle T.; Drew, Douglas J.; Masuda, Sumio

    1996-02-01

    A radionuclide migration experiment was performed over a distance of 1 m in a natural fracture in a quarried block of granite. The fracture in the block was characterized hydraulically by measuring the pressure drop in borehole-to-borehole pump tests. The effective fracture volume in the block was ˜ 100 mL. A silicone coating was applied to the exterior, and the block was immersed in a tank of water to which hydrazine was added to provide a chemically reducing barrier. Migration experiments were performed at a flow rate of 2.2 mL h -1 using 85Sr, 131I, 137Cs, 144Ce, 152Eu, 237Np and 238Pu. A total of 9.5 L of groundwater was pumped through the fracture, corresponding to ˜95 fracture volumes. Only 85Sr, 131I, 137Cs, 237Np and 238Pu were observed in the eluent. Scanning of the fracture surface at the end of the migration experiment showed limited mobility of α-emitting radionuclides and of the rare-earth elements, consistent with static sorption data obtained on representative fracture surface material. The mobility of 137Cs was higher than that of the rare-earth elements, but it was lower than that of 85Sr. When samples of fracture-coating material were separated into fractions with different specific gravity, there was a clear indication of radionuclide association with mineral groups.

  16. Marine plankton as an indicator of low-level radionuclide contamination in the Southern Ocean

    We have initiated an investigation of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review shows that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 104. In the years 1956-1958, considerable work was done on the accumulation and distribution of a variety of fission and activation products produced by the nuclear tests in the Marshall Islands. Since then, studies have largely been confined to a few selected radionuclides, and by far most of this work has been done in the northern hemisphere. We participated in Operation Deepfreeze 1981, collecting 32 plankton samples from the U.S. Coast Guard Cutter Glacier on its Antarctic cruise, while Battelle Pacific Northwest Laboratories concurrently sampled air, water, rain and fallout. We were able to measure concentrations of the naturally occurring radionuclides 7Be, 40K and the U and th series, and we believe that we have detected low levels of 144Ce and 95Nb in seven samples ranging as far south as 680. There is a definite association between the radionuclide content of plankton and air filters, suggesting that aerosol resuspension of marine radioactivity may be occurring. Biological identification of the plankton suggests a possible correlation between radionuclide concentration and foraminifera content of the samples. 38 references, 7 figures, 3 tables

  17. Burn-up determination of irradiated uranium oxide by means of direct gama spectrometry and by radiochemical method

    The burn-up of thermal neutrons irradiated U3O8 (natural uranium) samples has been determined by using both direct gamma spectrometry and radiochemical methods and the results obtained were compared. The fission products 144Ce, 103Ru, 106Ru, 137Cs and 95Zr were chosen as burn-up monitors. In order to isolate the radioisotopes chosen as monitors, a radiochemical separation procedure has been established, in which the solvent extraction technique was used to separate cerium, cesium and ruthenium one from the other and all of them from uranium. The separation between zirconium and niobium and of both elements from the other radioisotopes and uranium was accomplished by means of adsorption on a silica-gel column, followed by selective elution of zirconium and of niobium. When use was made of the direct gamma-ray spectrometry method, the radioactivity of each nuclide of interest was measured in presence of all others. For this purpose use was made of gamma-ray spectrometry and of a Ge-Li detector. Comparison of burn-up values obtained by both methods was made by means of Student's 't' test, and this showed that results obtained in each case are statistically equal. (Author)

  18. Fission-Product Development Laboratory cell-decommissioning project plan

    The Fission Product Development Laboratory (FPDL) at Oak Ridge National Laboratory (ORNL) was a full-scale processing facility for separating megacurie quantities of 90Sr, 137Cs, and 144Ce for a variety of source applications, operating at full capacity from 1958 to 1975. Since facility shutdown, the inactive portions of the FPDL have been maintained in a protective storage mode as part of the ORNL Surplus Facilities Management Program (SFMP). Due to the significant radio-nuclide inventory remaining in the facility, the high surveillance and maintenance costs necessary to assure radionuclide containment, and the potential for reuse of the facility by other programs, the decommissioning of the inactive portions of the FPDL has been given a high priority by the SFMP. In response to this program direction, plans are being made for initiation of these activities in late FY 1983. This project plan has been prepared to satisfy the program documentation requirements for SFMP project planning. The plan outlines the scope of the proposed effort, describes the proposed methods of project accomplishment, and provides estimates of the project resource needs and schedule

  19. The passage of lanthanides (Cd-144, Nd-147, Sm-153, Eu-155 and Tb-160) into fetus and newborn after intravenous contamination of rats and estimation of absorbed dose in whole body and gastrointestinal tract

    The purpose of the study was the determination of the passage of certain lanthanum elements (147Nd, 153Sm, 155Eu and 160Tb) from maternal blood through the placenta to the fetus in the second and third weeks of pregnancy and also estimation of absorbed dose in gastrointestinal tract in newborn rats contaminated with 147Nd, 153Sm, 155Eu and 160Tb. The study demonstrated that the lanthanum elements passed across the placental barrier. Placental retention was several times higher in late pregnancy (in the case of 160Tb it was even 16 - fold greater). In the last period of pregnancy this passage increased with increasing mass number of the elements (Nd160Tb (17%) and decreased with the drop of molecular weight of radionuclides. For all lanthanides tested, the dose of γ-radiation absorbed by newborns could be neglected since it comprised only 0.5% of β-radiation. The absorbed dose of β-radiation during the first week of life of new newborns fed by mother injected with 37 kBq of radionuclides ranged from 204 mGy for 160Tb to 0.23 mGy for 144Ce. (author). 15 refs., 5 figs., 4 tabs

  20. Standard test method for gamma energy emission from fission products in uranium hexafluoride and uranyl nitrate solution

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the measurement of gamma energy emitted from fission products in uranium hexafluoride (UF6) and uranyl nitrate solution. It is intended to provide a method for demonstrating compliance with UF6 specifications C 787 and C 996 and uranyl nitrate specification C 788. 1.2 The lower limit of detection is 5000 MeV Bq/kg (MeV/kg per second) of uranium and is the square root of the sum of the squares of the individual reporting limits of the nuclides to be measured. The limit of detection was determined on a pure, aged natural uranium (ANU) solution. The value is dependent upon detector efficiency and background. 1.3 The nuclides to be measured are106Ru/ 106Rh, 103Ru,137Cs, 144Ce, 144Pr, 141Ce, 95Zr, 95Nb, and 125Sb. Other gamma energy-emitting fission nuclides present in the spectrum at detectable levels should be identified and quantified as required by the data quality objectives. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its us...

  1. TMI-2 Reactor Building source term measurements: surfaces and basement water and sediment

    McIsaac, C V; Keefer, D G

    1984-10-01

    Presented in this report are the results of radiochemical and elemental analyses performed on samples collected from the Three Mile Island Unit 2 Reactor Building from August 1979 to December 1983. The quantities of fission products and core materials that were measured on the external surfaces in the Reactor Building or in the water and sediment in its basement are summarized. Recent analysis results for access panels removed from the air cooling assembly and for liquid and particulate samples collected from the Reactor Building sump and reactor coolant drain tank are included in the report. Measurements show that 59% of the /sup 3/H, 2.7% of the /sup 90/Sr, 15% of the /sup 129/I, 20% of the /sup 131/I, and 42% of the /sup 137/Cs originally in the core at the time of the accident could be accounted for outside the core in the Reactor Building. With the exceptions of /sup 90/Sr and /sup 144/Ce, the vast majority of each radionuclide released was found dispersed in the water and sediment in the basement.

  2. Probing New Physics with Underground Accelerators and Radioactive Sources

    Izaguirre, Eder; Pospelov, Maxim

    2014-01-01

    New light, weakly coupled particles can be efficiently produced at existing and future high-intensity accelerators and radioactive sources in deep underground laboratories. Once produced, these particles can scatter or decay in large neutrino detectors (e.g Super-K and Borexino) housed in the same facilities. We discuss the production of weakly coupled scalars $\\phi$ via nuclear de-excitation of an excited element into the ground state in two viable concrete reactions: the decay of the $0^+$ excited state of $^{16}$O populated via a $(p,\\alpha)$ reaction on fluorine and from radioactive $^{144}$Ce decay where the scalar is produced in the de-excitation of $^{144}$Nd$^*$, which occurs along the decay chain. Subsequent scattering on electrons, $e(\\phi,\\gamma)e$, yields a mono-energetic signal that is observable in neutrino detectors. We show that this proposed experimental set-up can cover new territory for masses $250\\, {\\rm keV}\\leq m_\\phi \\leq 2 m_e$ and couplings to protons and electrons, $10^{-11} < g_e...

  3. Radioecological synthesis of the various compartments of La Hague (Cotentin) marine environment

    Permits for low level radioactive liquid waste releases by the LA HAGUE (Cotentin, France) fuel reprocessing plant are based on an accurate radioecological study of the marine environment. Since 1967, the monitoring of indicators such as seawater, sediments and marine organisms (Fucus serratus, Laminaria sp., Mytilus sp., ...) have made it possible to create an important environmental data base. A statistical treatment has been used to quantify the spatio-temporal (daily, seasonal, local and regional) variabilities of these indicators from 1975 up to now. It has demonstrated the interest of F. serratus seaweed as bioindicators of radioactivity. Moreover it appears that seawater-soluble radionuclides such as 125Sb and 137Cs are monitored through longer distance from the outlet than those bound to particles such as 144Ce. A study of the sestonic load by satellite images suggested a number of geographical sites of potential accumulation through particle transport, some of which were verified by radioactivity measurements of sediments. However, such accumulation was not confirmed by the particle size distribution at the level of the Cap de LA HAGUE associated with radioactive measurements of seawater. A spectral analysis of biota radioactive levels vs radioactive waste releases showed a time delay of 2 - 4 months for F. serratus and Mytilus sp. collected in the local area of LA HAGUE after either an increase or a decrease of the releases. Modeling of marine currents fields associated with a transfer model can now be used to predict, at small time scales, the radioactivity levels inthe various Cotentin marine compartments from the liquid waste releases

  4. Passive gamma analysis of the boiling-water-reactor assemblies

    Vo, D.; Favalli, A.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S.; Trellue, H.; Vaccaro, S.

    2016-09-01

    This research focused on the analysis of a set of stationary passive gamma measurements taken on the spent nuclear fuel assemblies from a boiling water reactor (BWR) using pulse height analysis data acquisition. The measurements were performed on 25 different BWR assemblies in 2014 at Sweden's Central Interim Storage Facility for Spent Nuclear Fuel (Clab). This study was performed as part of the Next Generation of Safeguards Initiative-Spent Fuel project to research the application of nondestructive assay (NDA) to spent fuel assemblies. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay (NDA) measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The final objective of this project is to quantify the capability of several integrated NDA instruments to meet the aforementioned goals using the combined signatures of neutrons, gamma rays, and heat. This report presents a selection of the measured data and summarizes an analysis of the results. Specifically, trends in the count rates measured for spectral lines from the following isotopes were analyzed as a function of the declared burnup and cooling time: 137Cs, 154Eu, 134Cs, and to a lesser extent, 106Ru and 144Ce. From these measured count rates, predictive algorithms were developed to enable the estimation of the burnup and cooling time. Furthermore, these algorithms were benchmarked on a set of assemblies not included in the standard assemblies set used by this research team.

  5. Status report on LWR spent fuel IAEA leach tests

    Spent light-water-reactor (LWR) fuel with an average burnup of 28,000 MWd/MTU was leach-tested at 250C using a modified version of the International Atomic Energy Agency procedure. Leach rates were determined from tests conducted in five different solutions: deionized water, sodium chloride (NaCl), sodium bicarbonate (NaHCO3), calcium chloride (CaCl2) and Waste Isolation Pilot Plant B brine solutions. Elemental leach rates are reported based on the release of 90Sr + 90Y, 106Ru, 137Cs, 144Ce, 154Eu, /sup 239 + 240/Pu, 244Cm and total uranium. After 467 days of cumulative leaching, the elemental leach rates are highest in deionized water. The elemental leach rates uin the different solutions generally decreased from deionized water to the 0.03M NaCl solution to the WIPP B brine solution to the 0.03M NaHCO3 solution and was a factor of 20 lower in 0.015M CaCl2 solution than in deionized water. The leach rates of spent fuel and borosilicate waste-glass were also compared. In sodium bicarbonate solution, the leach rates of the two waste forms were nearly equal, but the glass was increasingly more resistant than spent fuel in calcium chloride solution, followed by sodium chloride solution, WIPP B brine solution and deionized water. In deionized water the glass, based on the elemental release of plutonium and curium, was 50 to 400 times more leach resistant than spent fuel

  6. Particle size distribution of radioactive aerosols after the Fukushima and the Chernobyl accidents

    Following the Fukushima accident, a series of aerosol samples were taken between 24th March and 13th April 2011 by cascade impactors in the Czech Republic to obtain the size distribution of 131I, 134Cs, 137Cs, and 7Be aerosols. All distributions could be considered monomodal. The arithmetic means of the activity median aerodynamic diameters (AMADs) for artificial radionuclides and for 7Be were 0.43 and 0.41 μm with GDSs 3.6 and 3.0, respectively. The time course of the AMADs of 134Cs, 137Cs and 7Be in the sampled period showed a slight decrease at a significance level of 0.05, whereas the AMAD pertaining to 131I increased at a significance level of 0.1. Results obtained after the Fukushima accident were compared with results obtained after the Chernobyl accident. The radionuclides released during the Chernobyl accident for which we determined the AMAD fell into two categories: refractory radionuclides (140Ba, 140La 141Ce, 144Ce, 95Zr and 95Nb) and volatile radionuclides (134Cs, 137Cs, 103Ru, 106Ru, 131I, and 132Te). The AMAD of the refractory radionuclides was approximately 3 times higher than the AMAD of the volatile radionuclides; nevertheless, the size distributions for volatile radionuclides having a mean AMAD value of 0.51 μm were very close to the distributions after the Fukushima accident. -- Highlights: • AMADs after the Fukushima and Chernobyl accidents in the Czech Rep. were determined. • The mean value of AMADs of the monitored nuclides from the NPP Fukushima was 0.43 μm. • Nuclides from the NPP Chernobyl fell into two categories – refractory and volatile. • The mean value of AMADs of volatile nuclides from the NPP Chernobyl was 0.51 μm. • AMADs of volatile nucl. from the NPP Chernobyl were 3× smaller than of the refractory radionuclides

  7. The behaviour of hot particles in the organism of cattle

    Radionuclide deposition in various organs of lactating cattle and their physiological effect has been studied. Model hot particles similar to those from Chernobyl accident are used. Two types of particles (washed and unwashed condensed phase) have been introduced in gastrointestinal tract (GIT) of the cattle. Particle dynamics in the GIT, radionuclide transfer to animal organism and possible biological consequences have been studied in 9-day-experiment (from the introduction of the hot particles to the slaughter). Distribution of 11 isotopes of Sr, Ru, Cs, Eu and Pu have been traced in different organs. A very small amount of radionuclides have been found in the internal organs after the slaughter: in GIT the percentage of nuclides from the amount introduced is the following: for 137Cs: 0.14 (I group) and 0.19 (II group); for 134Cs - 0.16 and 0.22; for 144Ce - 0.14 and 0.05 respectively. The removal goes mainly with faeces and much less with urine and milk. The peak of cesium concentration in milk is observed in the early period after introduction in GIT (44-68 hours). For the whole period the removed quantities are: I group - 0.173% of 134Cs and 0.166% of 137Cs; II group - 0.106% and 0.104% respectively. The percentage of cesium transfered to cows' organism is the following: I group - 1.61% of 137Cs and 1.65% for 134Cs; II group - 1.04% and 1.11%, respectively. Haematological analysis show an increased amount of leucoytes and neutrophiles. An efficient filtering of nuclides in organs and tissues have been observed. A significant difference in distribution of nuclides from hot particles compared to single introduction of radionuclides is found. Small deviations in haematological parameters have been observed and no local effects in GIT have been found. (author)

  8. Environmental and health consequences in Japan due to the accident at Chernobyl nuclear reactor plant

    A comprehensive review was made on the results of national monitoring program for environmental radioactivity in Japan resulting from the accident at the Chernobyl nuclear power plant in USSR. Period of monitoring efforts covered by the present review is from 30th of April 1986 to 31st of May 1987. A radioactive cloud released from the Chernobyl nuclear reactor initially arrived in Japan on 30th of April 1986 as indicated by the elevated level of 131I, 137Cs and 134Cs activity in the total deposition on 30th of April and also by the increased 137Cs body burden noted on 1st of May. Almost all the radioactive nuclides detected in the European countries were also identified in Japan. For example, the observed nuclides were: 95Zr, 95Nb, 99mTc, 103Ru, 106Ru, 110mAg, 111Ag, 125Sb, 127Sb, 129mTe, 131I, 132Te, 132I, 133I, 134Cs, 136Cs, 137Cs, 140Ba, 140La, 141Ce and 144Ce. Among the above radionuclides, the country average concentration was determined for 131I, 137Cs and 134Cs in various environmental materials such as air, fresh water, soil, milk, leafy and root vegetables, cereals, marine products and other foodstuffs. In contrast to the sharp decline of 131I which was negligible after a few months, 137Cs showed a tendency to maintain its activity in foodstuffs at an appreciable level one year later. Collective effective dose equivalent and dose equivalent to thyroid in Japanese population due to 137Cs, 134Cs and 131I were estimated to be around 590 man Sv and 4760 man Sv, respectively. Corresponding values for the per caput dose equivalent are 5 μSv for whole body and 40 μSv for thyroid, respectively. (author)

  9. RESULTS FOR THE SECOND QUARTER 2010 TANK 50 WAC SLURRY SAMPLE: CHEMICAL AND RADIONUCLIDE CONTAMINANT RESULTS

    Reigel, M.; Bibler, N.

    2010-08-04

    This report details the chemical and radionuclide contaminant results for the characterization of the 2010 Second Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC).1 Information from this characterization will be used by Liquid Waste Operations (LWO) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System. The following conclusions are drawn from the analytical results provided in this report: (1) The concentrations of the reported chemical and radioactive contaminants were less than their respective WAC targets or limits unless noted in this section. (2) The reported detection limits for {sup 94}Nb and {sup 144}Ce are above both the established and requested limits from References 4 and 6. (3) The reported detection limits for {sup 247}Cm and {sup 249}Cf are above the requested limits from Reference 4. However, they are below the limits established in Reference 6. (4) The reported detection limit for Isopar L is greater than the limit from Table 3 of the WAC. (5) A measurable concentration of Norpar 13 is present in the sample. The reported concentration is greater than the requested limit from Table 4 and Attachment 8.2 of the WAC. (6) Isopar L and Norpar 13 have limited solubility in aqueous solutions making it difficult to obtain consistent and reliable sub-samples. The values reported in this memo are the concentrations in the sub-sample as detected by the GC/MS; however, the results may not accurately represent the concentrations of the analytes in Tank 50. (7) The detection limit for isopropanol has been lowered from 0.5 mg/L to 0.25 mg/L{sup 7}. This revised limit now satisfies the limit in Table 4 of the WAC.

  10. Transfer of nuclides from the water phase to the sediments during normal and extraordinary hydrological cycles

    Atucha I and Atucha II nuclear power plants are located on the right margin of the Parana de las Palmas river. This river belongs to the Cuenca del Plata, whose 1982-1983 hydrologic cycle registered the greatest freshets of the century. Works and studies previously fixed had to be altered and investigations were adapted to the possibilities and the particular hydric conditions verified. Considerations on the transfer of nuclides between water and sediments are presented. The floods reduce the water-sediments contact time on the bed of the river. In outer areas, the waters labelled by the nuclear power plant effluent discharge favor the infiltration in alluvial soils, as well as the exchange with the sediments. The investigations carried out for the phase near to the discharge of liquid effluents (related to the critical group) made possible to prove the characteristics of the path of the liquid wastes released, the distribution coefficient and the fixation or penetrability of some nuclides in soils of the floody valley. In this manner, a balance of radioactive nuclides incorporated to soils and sediments from the neighbourhood of Atucha and the water-course of Parana de las Palmas river is obtained. The presence of 60Co and 137Cs in the floody soils on the right margin of this river was detected and measured during the greatest flood of the century. On the other hand, 144Ce, 51Cr, 106Ru and 90Sr have not been detected. The detection of artificial radioisotopes turns out to be impossible in normal hydrological years, even in the sorroundings of the nuclear power plant or the critical group (from the point of view of the surface waters, The Fishing Club, 3 km down stream). (M.E.L.)

  11. Estimation of 90Sr activity in reprocessed uranium from the PUREX process

    90Sr estimation in reprocessed uranium was carried out by a series of solvent extraction and carrier precipitation techniques using strontium and lanthanum carriers. Fuming with HClO4 was used to remove 106Ru as RuO4. Three step solvent extraction with 50% tri-n-butyl phosphate in xylene in presence of small amounts of dibutyl phosphate and thenoyl trifluoro acetone was carried out to eliminate uranium, plutonium, thorium and protactinium impurities. Lanthanum oxalate precipitation in acid medium was employed to scavenge the remaining multivalent ions. Strontium was precipitated as strontium oxalate in alkaline pH and 137Cs was removed by washing the precipitate with water. A strontium recovery well above 70% was obtained. Final estimation was carried out by radiometry using end window GM counter after drying the precipitate under an infra red lamp. The same procedure was extended to the estimation of 90Sr in a diluted sample of the actual spent fuel solution. An additional lanthanum oxalate precipitation step was required to remove the entire 144Ce impurity from this sample. This modified procedure was employed in the determination of 90Sr in a number of reprocessed uranium samples and the over all precision of the method was found to be well within ±10%. An additional barium chromate precipitation step was necessary for the analysis of reprocessed uranium samples from high burnup fuels to eliminate trace amounts of short lived 224Ra produced during the decay of 232U and its daughters as they interfere in the estimation of 90Sr. (author)

  12. Lichen (sp. Cladonia) as a deposition indicator for transuranium elements investigated with the Chernobyl fallout

    Paatero, Jussi; Jaakkola, Timo; Kulmala, Seija [Helsinki Univ., Radiochemistry Lab., Helsinki (Finland)

    1998-06-01

    The feasibility of employing carpet-forming lichens (sp. Cladonia) as a measure for the deposition of transuranium elements was investigated with the Chernobyl fallout. In Finland, the deposition of these elements after the accident was very uneven. The highest deposition values for {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 242}Cm and {sup 243,244}Cm were 5.7, 3.0, 1.3, 98 and 0.025 Bq m{sup -2}, respectively. The amount of deposited {sup 239,240}Pu was, however, only some percent of the fallout of the nuclear test explosions of the 1950s and the 1960s. Instead, practically no {sup 242}Cm was released into the environment during the weapons` testing. The correlation between the refractory nuclides {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 242}Cm, {sup 95}Zr and {sup 144}Ce in lichen was high (r = 0.709-0.979), but the correlation between the transuranium elements and volatile {sup 137}Cs was much lower (r = 0.227-0.276). The calculated biological half-lives of Pu and Am in lichen were 730 and 320 days, respectively. The {sup 238}Pu/{sup 239,240}Pu activity ratio in the top parts of lichen samples was 0.54 ``+`` 0.02 corresponding to a burn-up value of 12 MWd kg{sup -1}. The {sup 238}Pu/{sup 239,240}Pu activity ratios of 0.43 and 0.69 measured from two isolated hot particles correspond to burn-up values of 10 and 14 MWd kg{sup -1}, respectively. (author).

  13. Lovelace ITRI studies on the toxicity of inhaled radionuclides in beagle dogs

    This paper reviews 19 studies conducted by the Lovelace ITRI on the toxicity of inhaled radionuclides in beagle dogs. These studies provide information to estimate potential health effects in accidentally exposed people. Specific radionuclides (90Sr, 90Y, 91Y, 137Cs, 144Ce, 238Pu, and 239Pu), chemical forms, and particle sizes were selected for study because they are abundant in nuclear operations and deliver a wide range of radiation dose patterns. Depending upon the aerosol, one or more of the following organs or tissues received the significant irradiation: lung, nasal cavity, lung-associated lymph nodes, whole body, liver, or skeleton, with the radiation dose delivered over durations of time ranging from a few days to several years. In eight studies monodisperse particles of either 238PuO2 or 239PuO2 were used to evaluate the influence of particle number and total dose on lung cancer induction. Most studies involved single, brief exposures of young adult dogs, but two studies used immature dogs, two used aged dogs, and two studies involved repeated brief exposures. For each aerosol two types of studies were conducted. One was used to evaluate the time course of retention of radioactivity in various tissues of the body for calculating radiation doses. The second was used to determine health effects in animals exposed to achieve different initial lung burdens and observed for the remainder of their life spans. Initial lung burdens were selected to produce early morbidity and mortality at the highest levels and an excess of late-occurring diseases such as cancer at the lowest levels. The latter dogs have had an excess incidence of cancer, especially of the lung, lung-associated lymph nodes, nasal cavity, skeleton, and liver. Relationships between radiation doses to various tissues and effects have been evaluated for individual studies

  14. Impacts to nuclear utilities of 10CFR61

    The disposal of low-level waste from nuclear utilities is regulated by 10CFR61. The basic requirements are that the radionuclide content be quantified and identified and that the waste itself meet certain chemical and physical criteria. Waste packaging protocols are also delineated. In order to meet these requirements, on-site instrumental measurements and radiochemical analysis are required for each waste stream. Complex calculations, often performed by vendor computer programs, are employed to incorporate assay information into shipping manifests acceptable to low-level waste sites. Aside from the continuing increase in low-level waste site charges, 10CFR61 also added to the cost of utility waste disposal. The methodology most applicable to power plants involves scaling difficult to measure nuclides (i.e. nuclides which do not emit easily measured gamma rays) to those which are both easy to measure and possess similar chemical and physical properties. This methodology has been in use for several years in determining the transuranic content of waste based on the 144Ce concentration. The NRC has accepted this technique and has, in fact, suggested its extension to the problem nuclides listed in 10CFR61. These scaling factors are being based on the existing limited data base, engineering judgement, an preliminary data from on-going work. Important differences exist between Boiling Water Reactors (BWRs and Pressurized Water Reactors (PWRs) which preclude the use of common scaling factors. In fact, important differences between substantially similar plant types may prevent generically categorized scaling factors from being used. Uncertainties in this regard will force every nuclear plant to develop a plant specifi program for compliance with 10CFR61. requirements of this new rule

  15. Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    Favalli, A.; Vo, D.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S. J.; Trellue, H.; Vaccaro, S.

    2016-06-01

    The purpose of the Next Generation Safeguards Initiative (NGSI)-Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity's behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

  16. Fallout radionuclides and natural radioactivity in tissues of deers from different regions in Austria

    The concentration of fallout radionuclides in bone and liver samples of deers from different regions in Austria have been investigated. The results indicate that these concentrations are correlated with the altitude and the mean annual rainfall of the region, where the animals lived. About 20 years after the Test Ban Treaty comes into force, 90-Sr and 137-Cs contaminations still can be shown in such tissue samples. In bone 0,5 - 20 pCi 90-Sr and generally less than 0,2 pCi 137-Cs have been found per g fresh weight. Related to the calcium and potassium content of this tissue, maximal values of 95 pCi 90-Sr/g Ca and 730 pCi 137-Cs/g K have been reached. Additionally small amounts of 144-Ce, 60-Co and 54-Mn have been seen, which obviously resulted from the Chinese weapon tests during the last years. In liver samples 90-Sr is below our detection level (i. e. smaller than 0,2 pCi 90-Sr/sample), 137-Cs in the range of 0,1 - 1,7 pCi/g fresh weight. Related to the potassium content of the liver, a maximal value of 190 pCi 137-Cs/g K is observed. Comparing a period of 10 years 137-Cs contaminations remained nearly the same. Also the amount of natural radioactivities like 40-K, 226-Ra, 228-Ac and 212-Pb have been determined in these samples. The results show that the radiation dose to the animals delivered from incorporated natural radioactivities is about one order of magnitude higher than those which has to be expected from fallout contaminations. (Author)

  17. Radionuclide accumulation by aquatic biota exposed to contaminated water in artificial ecosystems before and after its passage through the ground

    This study was designed to investigate the comparative accumulation of radionuclides from contaminated water in artificial ecosystems before and after the water's passage through the ground. Fish, clams, algae, and an emergent vascular plant were experimentally exposed to mixtures of radionuclides in three aqueous streams. Two streams consisted of industrial water discharged directly into a leaching trench, and the same water after it had migrated through the ground for a distance of 260 meters. The third stream was river water, which served as a background or control. Biota exposed to river water in the control stream had very low concentrations of 60Co, less than 3 pCi per gram dry weight (pCi/g DW). Other radionuclides were essentially unmeasurable. Biota exposed to trench water accumulated very high relative concentrations of 60Co. Biota exposed to trench water also had measurable concentrations of 155Eu, 144Ce, 141Ce, 125Sb, 124Sb, 103Ru, 106Ru, 137Cs, 95Zr, 95Nb, 58Co, 54Mn, 59Fe, 65Zn, 90Sr, /sup 239,240/Pu, and 238Pu. Biota exposed to ground water had concentrations of 60Co that ranged between 50 and 1200 pCi/g DW. Fish flesh had the lowest concentration of 60Co and algae the highest. Strontium-90 was measured in the tissues of aquatic biota at concentrations ranging between 360 pCi/g DW in clam flesh to 3400 pCi/g DW in leaves and stems of Veronica. Leaves and fruits of tomato plants rooted in the ground water accumulated 90Sr at concentrations of 160 pCi in fruits and 4200 pCi in leaves. Data indicate that 60Co and 90Sr migrated through the ground along with ground-water flow and were available to all classes of aquatic biota and tomato plants rooted in the water via root uptake, sorption, and food chain transfers. 8 refs., 4 figs., 6 tabs

  18. Mobility of radionuclides in undisturbed and cultivated soils in Ukraine, Belarus and Russia six years after the Chernobyl fallout

    Six years after the accident at the Chernobyl Nuclear Power Plant, the behaviour of radionuclides in soils in rural areas of Ukraine, Belarus and Russia has been studied. Measurements were made to determine the total radioactive contamination, the fuel particle contribution, and the distribution and extractability of the radionuclides 137Cs and 90Sr. Inside the 30 km restriction zone around the plant, particles of highly irradiated fuel accounted for most of the radioactive contamination. The radioactivity in the soil, in decreasing order, was due to 137Cs>90Sr> 144Ce≥ 134Cs> 241Am> 125Sb> 154Eu> 155Eu. Outside the 30 km zone, condensed radionuclides were dominant and here the radionuclide content of the soil was 137Cs> 134Cs> 125Sb> 90Sr. The mobility of 137Cs in the soil increased with increasing distance from the reactor: this was in line with the fact that the 137Cs in condensed form, relative to that in fuel particles, also increased with increasing distance from the reactor. There was greater migration of the γ-emitting radionuclides 125Sb, 137Cs and 144Ce in peaty soils than in soddy podsolic, sandy and loamy soils. In undisturbed soddy podsolic sandy soils, more than 95% of the 137Cs was found in the top 6 cm layer. Not surprisingly, in the cultivated soils, the radionuclides were found more or less homogeneously distributed in the 0-25 cm layer. In the undisturbed soils, the γ-emitters had all migrated down to about the same depth except for the 125Sb which had moved rather deeper. (Author)

  19. Destructive radiochemical analysis of uraniumsilicide fuel for burnup determination

    Gysemans, M.; Bocxstaele, M. van; Bree, P. van; Vandevelde, L.; Koonen, E.; Sannen, L. [SCK-CEN, Boeretang, Mol (Belgium); Guigon, B. [CEA, Centre de Cadarache, Saint Paul lez Durance (France)

    2004-07-01

    During the design phase of the French research reactor Jules Horowitz (RJH) several types of low enriched uranium fuels (LEU), i.e. <20% {sup 235}U enrichment, are studied as possible candidate fuel elements for the reactor core. One of the LEU fuels that is taken into consideration is an uraniumsilicide based fuel with U{sub 3}Si{sub 2} dispersed in an aluminium matrix. The development and evaluation of such a new fuel for a research reactor requires an extensive testing and qualification program, which includes destructive radiochemical analysis to determine the burnup of irradiated fuel with a high accuracy. In radiochemistry burnup is expressed as atom percent burnup and is a measure for the number of fissions that have occurred per initial 100 heavy element atoms (%FIMA). It is determined by measuring the number of heavy element atoms in the fuel and the number of atoms of selected key fission products that are proportional to the number of fissions that occurred during irradiation. From the few fission products that are suitable as fission product monitor, the stable Nd-isotopes {sup 143}Nd, {sup 144}Nd, {sup 145}Nd, {sup 146}Nd, {sup 148Nd}, {sup 150}Nd and the gamma-emitters {sup 137}Cs and {sup 144}Ce are selected for analysis. Samples form two curved U{sub 3}Si{sub 2} plates, with a fuel core density of 5.1 and 6.1 g U/cm{sup 3} (35% {sup 235}U) and being irradiated in the BR2 reactor of SCK x CEN{sup [1]}, were analyzed. (orig.)

  20. Radiation and migration characteristics of the Chernobyl radionuclides causing environmental contamination in various provinces in the European sector of the USSR

    The radionuclide composition of the Chernobyl fallout has been studied over practically the whole European sector of the Union of Soviet Socialist Republics using soil sampling methods, the upper turf layer of the soil being treated as a natural planchet. Regular observation of the migration of radionuclides in the soil-plant system has been in progress since July 1986 at a stationary network of landscape-geochemical testing sites and sampling grounds; two types of natural ecosystem have been looked at - meadowland and forest. The behaviour of individual radionuclides is evaluated using the coefficient of fractionation in relation to 95Zr or 144Ce. The migration characteristics of individual radionuclides were revealed to depend both on soil conditions and on the type of radionuclide composition. The main features of the vertical profile of radionuclide concentrations in soils were clear 2-3 months after the contamination occurred. During subsequent years the migrational profiles changed depending on the individual characteristics of the radionuclides and soil conditions. Information on the radionuclide composition and evolution of the vertical distribution of radionuclides in soils was used to calculate and predict exposure gamma radiation dose from the Chernobyl fallout in various provinces in the European sector of the Soviet Union. When monitoring forest sampling grounds, samples were taken of the soil (litter, humus, mineral layer), the phytomasses of ligneous species (pine needles, leaves, bark, wood), moss and lichens. The main aim of monitoring surveys from 1986 to 1989 was to evaluate the distribution of Chernobyl radionuclides in the compartments of the forest ecosystem. In particular, 60-80% of the total amount of 137Cs was bound with the humus layer of the forest soil. 4 refs, 6 figs, 3 tabs

  1. Feasibility study of passive gamma spectrometry of molten core material from Fukushima Daiichi Nuclear Power Station unit 1, 2, and 3 cores for special nuclear material accountancy - low-volatile FP and special nuclear material inventory analysis and fundamental characteristics of gamma-rays from fuel debris

    The technologies applied to the analysis of the Three Mile Island accident were examined in a feasibility study of gamma spectrometry of molten core material from the Fukushima Daiichi Nuclear Power Station unit 1, 2, and 3 cores for special nuclear material accountancy. The focus is on low-volatile fission products and heavy metal inventory analysis, and the fundamental characteristics of gamma-rays from fuel debris with respect to passive measurements. The inventory ratios of the low-volatile lanthanides, 154Eu and 144Ce, to special nuclear materials were evaluated by the entire core inventories in units 1, 2, and 3 with an estimated uncertainty of 9%-13% at the 1σ level for homogenized molten fuel material. The uncertainty is expected to be larger locally owing to the use of the irradiation cycle averaging approach. The ratios were also evaluated as a function of burnup for specific fuel debris with an estimated uncertainty of 13%-25% at the 1σ level for units 1 and 2, and most of the fuels in unit 3, although the uncertainty regarding the separated mixed oxide fuel in unit 3 would be significantly higher owing to the burnup dependence approach. Source photon spectra were also examined and cooling-time-dependent data sets were prepared. The fundamental characteristics of high-energy gamma-rays from fuel debris were investigated by a bare-sphere model transport calculation. Mass attenuation coefficients of fuel debris were evaluated to be insensitive to its possible composition in a high-energy region. The leakage photon ratio was evaluated using a variety of parameters, and a significant impact was confirmed for a certain size of fuel debris. Its correlation was summarized with respect to the leakage photopeak ratio of source 154Eu. Finally, a preliminary study using a hypothetical canister model of fuel debris based on the experience at Three Mile Island was presented, and future plans were introduced. (author)

  2. Radioactive contamination of bottom sediments in the upper reaches of the Techa river: analysis of the data obtained in 1950 and 1951.

    Mokrov, Yury G

    2003-10-01

    A stationary sorption model has been developed for re-evaluating and analysing archive data from 1950-1951 on the radioactive contamination of Techa river bottom sediments close to the site of liquid radioactive waste discharge. In general, good agreement was obtained between calculations and measurements, which substantiates further the assumptions and conclusions in two preceding articles, on the radionuclide composition of discharged liquid radioactive waste. Estimates on the effective liquid radioactive waste discharges given here are significantly different from those deduced in the 1950s, i.e. in summer 1950 and October 1951. The results are discussed in relation to the Techa River Dosimetry System 2000 (TRDS-2000) that has recently been presented to serve as a means for estimating doses to the Techa river residents. Parameter values describing the exponential decrease of bottom sediment contamination along the river due to short-lived radionuclides, such as (106)Ru, and (144)Ce, agree reasonably with those used in TRDS-2000. However, for other radionuclides, such as (95)Zr, (95)Nb, (91)Y, (90)Sr and (137)Cs, substantial differences are found. It is demonstrated that water flow rate, width of the river, and surface area of bottom sediments are important parameters which were not adequately taken into account in TRDS-2000. Also, the stirring-up of contaminated bottom sediments and their subsequent transport by the water flow are seen to be an important mechanism that governs the radionuclide transport downstream. This mechanism was not included in the TRDS-2000 model. It is concluded that the sorption model used in TRDS-2000 for the reconstruction of radioactive contamination of water and bottom sediments of the Techa river in 1949-1951, is subject to considerable errors. While the present paper is focussed on details of the dosimetric modelling, the implications for the Techa river dosimetry are major. They will be further elucidated in a forthcoming paper

  3. Dose assessment for the Metlino and Muslyumovo populations who lived along the Techa river from 1949 to 1954.

    Mokrov, Yuri G

    2004-09-01

    In the period from 1949 to 1956, liquid radioactive waste was routinely and accidentally discharged by the Mayak Production Association, Southern Urals, Russia, into the Techa river. Based on a novel approach, the contamination of the Techa river water, the bottom sediments and the adjacent flood plains was modelled, and internal and external doses were estimated for two villages located downstream of the site of liquid radioactive waste release. Altogether, 11 radionuclides that occurred in the liquid radioactive waste were included in the calculations. The results suggest significantly higher doses than previously assumed, with the major contribution in the year 1951. Radionuclides with half-lives of less than 1 year, such as 89Sr, 131I, 95Zr+95Nb, 103Ru+103mRh, 140Ba+140La, and 144Ce+144Pr, represent the major sources and, in contrast, long-lived radionuclides, such as 90Sr and 137Cs that have so far been assumed to be most important, did not dominate the doses. For adults from the village Metlino, located 7 km downstream of the site of liquid radioactive waste discharge, the committed effective doses due to intake of radionuclides were calculated to be about 2.3 Sv, while the external doses were between about 1.2 Sv and 6.9 Sv. On the other hand, for adults from Muslyumovo, located 75 km downstream, the committed effective doses due to intake of radionuclides were calculated to be about 0.5 Sv, while the external doses were between 0.5 Sv and 2.0 Sv. The values for the skin doses to the Metlino and Muslyumovo populations were about 7.1 Sv and 1.3 Sv, respectively. It is concluded that the current dose estimates for the residents of the Techa river need, therefore, reevaluation. PMID:15378312

  4. Study on separation of 137Cs from 235U fission process waste - utilization of silica gel-supported ferrocyanide complex salt for 137Cs picking

    In connection with the potential domestic demand especially in the fields of industry and nuclear medicine, the separation of 137Cs from 235U fission process waste is to be of interest although its economic value could be a polemic. A preliminary study on the separation of 137Cs from the 235U fission process waste generated in the production of 99Mo in P.T. BATAN Teknologi, Serpong, was performed through experiments on 137Cs picking from sample solution of the radioactive fission waste (RFW). The presented study is aimed to gain experimental data supporting utilization of the matrix of silica gel-supported ferrocyanide complex salt for the separation of 137Cs from RFW. Subsequent step would be the recovery and purification of 137Cs as part of production technology of 137Cs. The RFW sample was batch-treated with the matrix of silica gel-supported ferrocyanide complex salt which was synthesized from silica gel, potassium hexacyanoferrate(II) and copper(II) chloride. The binding of radioisotopes in RFW on the matrix was observed by γ-spectrometry of the RFW solution before and during the treatment. The results showed that approximately 85% of 137Cs could be picked from the RFW sample into the matrix. Less amount of 95Zr and 95Nb was bound into the matrix. 103Ru was slightly bound into the matrix whereas 141/144Ce and 129mTe were not. It was observed that by using 0.2 and 0.4 g of matrix for 10 ml of RFW, the amount of matrix influenced the binding quantity of 95Zr and 95Nb but not that of 137Cs. (author)

  5. Results For The Second Quarter 2010 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminant Results

    This report details the chemical and radionuclide contaminant results for the characterization of the 2010 Second Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC).1 Information from this characterization will be used by Liquid Waste Operations (LWO) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System. The following conclusions are drawn from the analytical results provided in this report: (1) The concentrations of the reported chemical and radioactive contaminants were less than their respective WAC targets or limits unless noted in this section. (2) The reported detection limits for 94Nb and 144Ce are above both the established and requested limits from References 4 and 6. (3) The reported detection limits for 247Cm and 249Cf are above the requested limits from Reference 4. However, they are below the limits established in Reference 6. (4) The reported detection limit for Isopar L is greater than the limit from Table 3 of the WAC. (5) A measurable concentration of Norpar 13 is present in the sample. The reported concentration is greater than the requested limit from Table 4 and Attachment 8.2 of the WAC. (6) Isopar L and Norpar 13 have limited solubility in aqueous solutions making it difficult to obtain consistent and reliable sub-samples. The values reported in this memo are the concentrations in the sub-sample as detected by the GC/MS; however, the results may not accurately represent the concentrations of the analytes in Tank 50. (7) The detection limit for isopropanol has been lowered from 0.5 mg/L to 0.25 mg/L7. This revised limit now satisfies the limit in Table 4 of the WAC.

  6. Oceanographic Survey. 3. Radiological survey of marine environment in Ibaraki Prefecture: marine sediment survey

    Radioactivity in marine environment of Ibaraki Prefecture has been monitored since 1965. This report briefly describes the radiological survey data of marine sediments. The concentrations of radionuclides in marine water were determined yearly 4 times for 3H and twice for 54Mn, 60Co, 90Sr, 95Zr, 95Nb, 106Ru, 137Cs and 144Ce. The concentrations of 90Sr, 137Cs and 239+240Pu were hardly changed and those of 90Sr and 137Cs were near the limit of identification. The annual excretion of radionuclides from major nuclear plants in Ibaraki Prefecture including JAERI (Tokai and Oarai), Japan Atomic Power Co., etc. were determined for 3H, 14C, 90Sr, 137Cs, 60Co, 129I and 239+240Pu. Based on the results, dose equivalent for the intake of marine animals and algae was estimated to be as low as 0-4.4 μSv. This level was extremely lower than the limit of annual dose equivalent; 1000 μSv and it was kept nearly constant if the operators of those facilities were not discontinued for a long. To elucidate the factors related to the transfer of radionuclides into marine sediments, the depth dose distribution in marine sediments were investigated as well as the relation between radionuclide level and granular size. An elevation of 137Cs level was found for the sediments composed of fine granules, which were rich in the sediments of offshore region. The 239+240Pu level was positively correlated to the content of organic compounds in the sea. (M.N.)

  7. Selection of polymer solid supports for supported liquid membrane applications

    The role of polymer support selection upon the performance and stability of a supported liquid membrane(SLM) has been evaluated in detail. Permeation experiments are carried out batch wise in a simple twin stirred cells. Several solid supports such as polytetrafluroethylene (TE-35, TE-36, TE-37), polypropylene (HF-PP), cellulose nitrate (BA-S-83) of different pore sizes and varying thickness are tested. Dicyclohexano-18-crown-6 (DC18C6) in toluene has been employed as mobile carrier in permeation of plutonium (IV) nitrate across SLM. Selectivity of plutonium transport from fission product contaminants such as 137Cs. 103Ru and 144Ce is found to be lesser with large pore size (0.45 μm) support. Chemical stability of these hydrophobic polymer membranes against organic solvents and nitric acid is evaluated. Polytetrafluroethylene supports like TE-35, TE-36, TE-37 and polypropylene HF-PP membranes have not shown any marked deterioration but cellulose nitrate membrane such as BA-S-83 is attacked by organic solvent. Such deleterious effects have been confirmed by the scanning electron microscopy which revealed that pore structure becomes completely blocked. Radiolytic stability of these polymers is also tested by irradiating them up to 3 Mrads using 60Co irradiator. No serious damage due to radiation is observed as micrographs have shown undisturbed network of polymer structure even after the irradiation. Of the different polymer supports tested, both TE-35 and HF-PP thin-film solid membranes prove to be quite suitable for SLM purposes as their optimum pore size, good physical and chemical stability including radiation stability render them relatively more useful for varied applications in liquid membranes. (author). 5 refs., 3 figs., 3 tabs

  8. Forage: A sensitive indicator for airborne radioactivity

    As a part of the radiological environmental monitoring program at the Joseph M. Parley Nuclear Plant to meet the requirements of NRC Regulations 10 CRF 50, Appendix I, routine sampling of forage was implemented. Indicator plots of forage (grass) were established at the plant site boundary in the two Meteorological sectors having the highest X/Q values for ground-level dispersion of airborne radioactivity. Likewise, a control plot was established in a sector having a significantly lower X/Q value at a distance of 18 miles. Procedures for maintenance of the grass plots, sampling of forage, and sample preparation for measurement of gamma radioactivity with a Ge (Li) detector were developed during the reported three year measurement period. Three atmospheric nuclear tests by the Peoples Republic of China in 1976 and 1977 has proven forage sampling to be convenient, sensitive, and in the judgement of the authors gives results which are superior to most other media sampled for airborne radioactivity. Typical measured levels of radioactivity from 150 to greater than 10,000 pCi/kg (dry weight) were obtained for the principal fission products in the Chinese bomb fallout, which included 95Zr-95Nb, 103Ru, 131I, 140Ba-140La, 141Ce, and 144Ce. On a unit weight basis the level of radioactivity measured was consistently higher for forage than for green leafy vegetables. This was attributed to the higher surface area for the forage. For comparison, plots of airborne concentrations for gross beta and particulate gamma emitters are shown during the time periods that include the Chinese nuclear tests. (author)

  9. Pollution of atmospheric air with toxic and radioactive particulate matter investigated by means of nuclear techniques

    The application of spectrometric methods of nuclear techniques to the investigations of atmospheric air pollution by toxic and radioactive elements and results of these investigations conducted in the highly industrialized and urbanized regions of Poland have been presented. The method of precipitation of the samples, the measurements and analysis of radiation spectra of alpha and gamma radiation emitted by isotopes present in the samples have been described. The concentrations of toxic metal dust in the air have been evaluated by neutron activation and X-ray fluorescence analysis. Appropriate methods of measurement, calibration of instrument and the discussion of results have been presented. The work presents the results of investigations performed in Siersza within the years 1973-1974 and in Warsaw in the period of 1975-1977, which have permitted to estimate the mean monthly values of concentration in the atmospheric air of the following radioisotopes: 7Be, 54Mn, 95Zr, 103Ru, 106Ru, 125Sb, 131I, 137Cs, 140Ba, 141Ce, 144Ce, 226Ra, Th-nat, U-nat and the following stable elements: Sc, Cr, Fe, Co, Zn, As, Se, Sb, W, Pb. The analysis of changes in concentration of each particular artificial radioisotope in the air for the region of Poland in connection with Chinese nuclear explosions have been given. On the basis of the performed environmental investigations the method of analysis of relations between the concentrations of particular elements present in the dust has been discussed. The applications of this method have been presented. The hazard to the population and the environment caused by the radioactive and toxic dust present in the atmospheric air has been estimated. (author)

  10. Assessment of doses to biota in the river system

    Doses to aquatic biota in the hydrological system Techa - Ob are estimated.The following water bodies with different levels of radioactive contamination are considered: industrial reservoirs, Techa, Iset, Tobol and Irtysh Rivers. Doses to biota are calculated using the observed data on the content of radionuclides in various environmental components, with consideration for geometric characteristics of the organisms and the exposure sources. The following groups of the river biota are considered: aquatic plants, mollusks and fish. Simplified geometric models (ellipsoids) are used in the internal dose calculations for fish and mollusks. Aquatic plants are approximated either with spheres or with a layer of finite depth. For the external doses assessment the water was considered as an infinite source with the uniform distribution of radionuclides. Sediments were represented as a source with the uniformly distributed activity. Concentration factor of scattered radiation was taken into account for gamma emitters. Sources and levels of radioactive contamination of the Techa - Ob system are analyzed. Data on the activity concentration of radionuclides in water, bottom sediments and aquatic biota are used for the dose assessment. Assessment of doses to biota in the Techa -Ob river system in the period from 1949 to the present time are performed.The highest doses (over 0.01 Gy/day) were received by aquatic organisms in the upper reaches of the Techa River in the period of maximum discharges of radionuclides (1950-1951). In that period, a major contribution to the dose to aquatic organisms was due to the incorporated radionuclides: 89 Sr, 90 Sr, 106 Ru,137 Cs, 144 Ce and others. During 1950-1951, the doses to aquatic organisms were estimated, on average, at 0.003-0.1 Gy/day. After the cessation of intensive radioactive discharges and the construction of a system of protective water bodies, the doses to aquatic biota noticeably decreased. Current levels of exposure to fish in

  11. Organization of radio-ecological monitoring of the areas of the Russian Federation contaminated due to the accident at the Chernobyl NPP (on example of the Bryansk region)

    Linnik, Vitaly; Korobova, Elena; Vakulovsky, Sergey

    2013-04-01

    A severe accident at the Chernobyl NPP on April 26th, 1986 has led to radioactive contamination of many regions of the former USSR, now belonging to the Ukraine, the Republic of Belarus and the Russian Federation. Both natural and arable ecosystems have been subjected to fallout of radioactive isotopes. However both the distribution of radionuclides that define radioecological situation has depended not only on the initial contamination density but also on the landscape geochemical features of the areas controlling biogenic and abiogenic factors of radionuclide migration. To study and monitor peculiarities of migration of the most radioecologically significant radionuclides of Cs-137 and Sr-90 in different natural landscapes the Russian Scientific and Practical Experimental Center of the former State Chernobyl Committee has organized in 1992 a network of experimental plots in the most contaminated western part of the Bryansk region. It included 19 plots 100 m x 100 m in size which characterized 8 meadow and 11 forested catenas in the basin of the Iput' river. Cs-137 contamination level of the plots varied in 1992 from 740 kBq/m2 to 1850 kBq/m2. Although the study site has been located in the remote zone and the contamination was of condensation type the sampling performed at 11 plots registered some refractory radionuclides (144Ce, 154Eu, 238,239,240Pu and 90Sr) that proved the presence of fuel particles in fallout as far as 200 km from the damaged reactors. The sampling and monitoring scheme was organized to determine: the isotopic composition and contamination density of the plots; 2) estimation of radionuclide vertical and lateral migration; 3) evaluation of radionuclide inventories in different soil horizons; 4) calculation of radionuclide transfer in soil-plant system. Radiation measurements included field gamma-spectrometry using collimated gamma spectrometer "Corad" developed in the Kurchatov Institute and laboratory spectrometry the soil and plant samples

  12. Radionuclides contamination of fungi after accident on the Chernobyl NPP

    Zarubina, Nataliia E.; Zarubin, Oleg L. [Institute for Nuclear Research of National Academy of Sciense, 03680, pr-t Nauki, 47, Kiev (Ukraine)

    2014-07-01

    Accumulation of radionuclides by the higher fungi (macromycetes) after the accident on the Chernobyl atomic power plant in 1986 has been studied. Researches were spent in territory of the Chernobyl alienation zone and the Kiev region. Our research has shown that macromycetes accumulate almost all types of radionuclides originating from the accident ({sup 131}I, {sup 140}Ba /{sup 140}La, {sup 103}Ru, {sup 106}Ru, {sup 141}Ce, {sup 144}Ce, {sup 95}Nb, {sup 95}Zr, {sup 137}Cs and {sup 134}Cs). They accumulate the long-living {sup 90}Sr in much smaller (to 3 - 4 orders) quantities than {sup 137}Cs. We have established existence of two stages in accumulation of {sup 137}Cs by higher fungi after the accident on the Chernobyl NPP: the first stage resides in the growth of the concentration, the second - in gradual decrease of levels of specific activity of this radionuclide. Despite reduction of {sup 137}Cs specific activity level, the content of this radionuclide at testing areas of the 5-km zone around the Chernobyl NPP reaches 1,100,000 Bq/kg of fresh weight in 2013. We investigated dynamics of accumulation of Cs-137 in higher fungi of different ecological groups. One of the major factors that influence levels of accumulation of {sup 137}Cs by fungi is their nutritional type (ecological group). Fungi that belong to ecological groups of saprotrophes and xylotrophes accumulate this radionuclide in much smaller quantities than symbio-trophic fungi. As a result of the conducted research it has been established that symbio-trophic fungi store more {sup 137}Cs than any other biological objects in forest ecosystems. Among the symbio-trophic fungi species, species showing the highest level of {sup 137}Cs contamination vary in different periods of time after the deposition. It is connected with variability of quantities of these radio nuclides accessible for absorption at the depth of localization of the main part of mycelium of each species in a soil profile. Soil contamination

  13. Expeditious method to determine uranium in the process control samples of chemical plant separating (233)U from thoria irradiated in power reactors.

    Kedari, C S; Kharwandikar, B K; Banerjee, K

    2016-11-01

    Analysis of U in the samples containing a significant proportion of (232)U and high concentration of Th is of great concern. Transmutation of Th in the nuclear power reactor produces a notable quantity of (232)U (half life 68.9 years) along with fissile isotope (233)U. The decay series of (232)U is initiated with (228)Th (half life 1.9 year) and it is followed by several short lived α emitting progenies, (224)Ra, (220)Rn, (216)Po, (212)Bi and (212)Po. Even at the smallest contamination of (228)Th in the sample, a very high pulse rate of α emission is obtained, which is to be counted for the radiometric determination of [U]. A commercially available anionic type of extractant Alamine®336 is used to obtain the selective extraction of U from other alpha active elements and fission products present in the sample. Experimental conditions of liquid-liquid extraction (LLE) are optimized for obtaining maximum decontamination and recovery of U in the organic phase. The effect of some interfering ionic impurities in the sample on the process of separation is investigated. Depending on the level of the concentration of U in the samples, spectrophotometry or radiometry methods are adopted for its determination after separation by LLE. Under optimized experimental conditions, i.e. 5.5M HCl in the aqueous phase and 0.27M Alamin®336 in the organic phase, the recovery of U is about 100%, the decontamination factor with respect to Th is >2000 and the extraction of fission products like (90)Sr, (144)Ce and (134,137)Cs is negligible. The detection limit for [U] using α radiometry is 10mg/L, even in presence of >100g/L of Th in the sample. Accuracy and precision for the determination of U is also assessed. Reproducibility of results is within 5%. This method shows very good agreement with the results obtained by mass spectrometry. PMID:27591623

  14. [Comparative analysis of the radionuclide composition in fallout after the Chernobyl and the Fukushima accidents].

    Kotenko, K V; Shinkarev, S M; Abramov, Iu V; Granovskaia, E O; Iatsenko, V N; Gavrilin, Iu I; Margulis, U Ia; Garetskaia, O S; Imanaka, T; Khoshi, M

    2012-01-01

    The nuclear accident occurred at Fukushima Dai-ichi Nuclear Power Plant (NPP) (March 11, 2011) similarly to the accident at the Chernobyl NPP (April 26, 1986) is related to the level 7 of the INES. It is of interest to make an analysis of the radionuclide composition of the fallout following the both accidents. The results of the spectrometric measurements were used in that comparative analysis. Two areas following the Chernobyl accident were considered: (1) the near zone of the fallout - the Belarusian part of the central spot extended up to 60 km around the Chernobyl NPS and (2) the far zone of the fallout--the "Gomel-Mogilev" spot centered 200 km to the north-northeast of the damaged reactor. In the case of Fukushima accident the near zone up to about 60 km considered. The comparative analysis has been done with respect to refractory radionuclides (95Zr, 95Nb, 141Ce, 144Ce), as well as to the intermediate and volatile radionuclides 103Ru, 106Ru, 131I, 134Cs, 137Cs, 140La, 140Ba and the results of such a comparison have been discussed. With respect to exposure to the public the most important radionuclides are 131I and 137Cs. For the both accidents the ratios of 131I/137Cs in the considered soil samples are in the similar ranges: (3-50) for the Chernobyl samples and (5-70) for the Fukushima samples. Similarly to the Chernobyl accident a clear tendency that the ratio of 131I/137Cs in the fallout decreases with the increase of the ground deposition density of 137Cs within the trace related to a radioactive cloud has been identified for the Fukushima accident. It looks like this is a universal tendency for the ratio of 131I/137Cs versus the 137Cs ground deposition density in the fallout along the trace of a radioactive cloud as a result of a heavy accident at the NPP with radionuclides releases into the environment. This tendency is important for an objective reconstruction of 131I fallout based on the results of 137Cs measurements of soil samples carried out at

  15. Solid phase extraction of actinides using polymeric beads impregnated with TODGA

    137Cs is one of the major radionuclides contributing to the activity of the high level waste (HLW) and its separation facilitates the safe disposal of the latter in deep geological repository as vitrified mass. The global inventory of 137Cs was estimated to be around 3.7x1014 kBq in 2010. Due to its long half-life and reasonable gamma energy (661 keV), 137Cs it has potential application as a radiation source in gamma irradiators in the environmental pollution control, food preservation and sterilization of medical accessories. It is, therefore, required to develop efficient separation methods for its recovery from HLW. We have recently reported that solvent system containing calix(4)arene-crown-6 ligands in FS-13 have yielded much improved extraction of radio-cesium as compared to analogous solvent systems containing nitrobenzene as the diluents. Our studies involving four different calix-bis-crown-6 and calix-mono-crown-6 ligands have indicated that calix(4)arene-dibenzo-bis-crown-6 (CBC) ligands were better suited due to more favourable extraction of Cs(I) and radiolytic stability of the ligand. In the present study, we have tried use the developed solvent system for the recovery of radio-cesium (137Cs and 134Cs) from actual high level waste (HLW). The HLW, containing a total activity of 100 Ci/L also contained 3.85 g/L U and 7.09 mg/L Pu which were removed by contacting the waste solution twice with 30% TBP in n-dodecane in a hot-cell facility. The raffinate from the TBP extraction step contained negligible amounts of the actinides and was subsequently contacted four times with 1.0x10-3 M CBC in FS-13 (each time with fresh organic phase) in the hot-cell facility and the extraction results indicated 137Cs to remain in the raffinate out of 15.88 Ci/L suggesting ∼ 97% extraction in 4 stages. Quantitative extraction can be done by increasing the number of stages. It was interesting to note that none of the other radionuclides, such as 144Ce, 106Ru, 95Zr, 95Nb, 90Y

  16. Fission Product Yields from Fission Spectrum n+239Pu for ENDF/B-VII.1

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small - especially for 99Mo - we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (4%-relative) and 147Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on the

  17. Reconstruction of radionuclide contamination of the Techa River caused by liquid waste discharge from radiochemical production at the Mayak Production Association

    , rather than relying on a more uncertain reconstruction of quantities released at the point of discharge. Radionuclides considered include 90Sr, 106Ru, 137Cs, and 144Ce. Estimated concentrations of selected radionuclides at various times are presented

  18. Reconstruction of radionuclide contamination of the Techa River caused by liquid waste discharge from radiochemical production at the Mayak Production Association

    Mokrov, Y.; Glagolenko, Y.; Napier, B.

    2000-07-01

    river, rather than relying on a more uncertain reconstruction of quantities released at the point of discharge. Radionuclides considered include {sup 90}Sr, {sup 106}Ru, {sup 137}Cs, and {sup 144}Ce. Estimated concentrations of selected radionuclides at various times are presented.

  19. Reconstruction of radionuclide contamination of the Techa River caused by liquid waste discharge from radiochemical production at the Mayak Production Association.

    Mokrov, Y; Glagolenko, Y; Napier, B

    2000-07-01

    than relying on a more uncertain reconstruction of quantities released at the point of discharge. Radionuclides considered include 90Sr, 106Ru, 137Cs, and 144Ce. Estimated concentrations of selected radionuclides at various times are presented. PMID:10855774

  20. Results For The Third Quarter 2009 Tank 50 WAC Slurry Sample: Chemical And Radionuclide Contaminant Results

    This report details the chemical and radionuclide contaminant results for the characterization of the 2009 Third Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC). Information from this characterization will be used by Liquid Waste Operations (LWO) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System. Recently, a review of the radionuclide inventory in Saltstone Vaults 1 and 4 identified several additional radionuclides, not currently in the WAC, which require quantification (40K, 108mAg, 133Ba, 207Bi, 227Ac, 228Ra, 228Th, 231Pa, 247Cm, 249Cf, 251Cf). In addition, several of the radionuclides previously reported with minimum detection limits below the requirements listed in the WAC required analysis with reduced detection limits to support future inventory reporting requirements (22Na, 26Al, 59Ni, 94Nb, 106Ru, 144Ce, 152Eu, 155Eu, 226Ra). This added scope was formally requested in a revision to the standing Technical Task Request for CY2009 Saltstone support and is further discussed in several supporting documents. The following conclusions are drawn from the analytical results provided in this report: (1) The concentrations of the reported chemical and radioactive contaminants are less than their respective WAC targets or limits unless noted in this section. (2) The reported detection limits for 59Ni, 94Nb, 247Cm, and 249Cf are above the limits requested by LWO; however, they are below the achievable limits established by Analytical Development (AD). (3) The reported detection limit of isopropanol is lower than its WAC Limit for accident analysis in Appendix 8.1, but higher than its WAC concentration given in Table 4 for vault flammability. The higher detection limit is expected based on current analytical capabilities and is documented in the Task

  1. Leaching study of nuclear melt glass: Part I

    Ground samples of three nuclear melt glasses from underground nuclear explosions at the Nevada Test Site (NTS) were leached at 250C with natural ground water from NTS. Using our dynamic single-pass flow-through leaching system we monitored the release of radionuclides from the glasses during 420 days of leaching. We continually flowed the ground water over the melt glass at flow rates of 185 ml/day for half of the samples and 34 ml/day for the rest. Leachate solutions were collected continuously, and composite samples, collected on days 1, 2, 3, 6, 11, 32, 38, 70, 120, 230 and 420, were analyzed using low-background Ge(Li) gamma spectrometers. For most of the radionuclides the leach rate decreased smoothly throughout the experiment. Except for 95Zr, 144Ce, and 155Eu, there was no difference between the fast (185 ml/day) and slow (34 ml/day) flow-rate leach rates. The measurable leach rates ranged from a high of 1 x 10-2 g-glass/m2 day for 22Na (slow flow-rate, day 1 in glass No. 2) to a low of 1 x 6-6 g-glass/m2 day for 54Mn (slow flow-rate, day 420 in glass No. 2). Most of the leach-rate values were about 5 x 10-4 g-glass/m2 day initially, decreasing to 5 x 10-6 g-glass/m2 day after 420 days of leaching. The leach rates had not leveled off by the end of the experiment and were, in general, continuing to decrease. From the activities in the leachate solutions, we determined the percent of the pre-leach activity leached from the melt glasses during the experiment. Only 124Sb, in one fast flow-rate channel of glass No. 2, exceeded 3% of the initial activity leached. The majority of the samples released less than 1% of the pre-leach activity for a given radionuclide. The percent activity released from the samples leached at the fast and slow flow rates were nearly equal

  2. Radionuclides contamination of fungi after accident on the Chernobyl NPP

    Accumulation of radionuclides by the higher fungi (macromycetes) after the accident on the Chernobyl atomic power plant in 1986 has been studied. Researches were spent in territory of the Chernobyl alienation zone and the Kiev region. Our research has shown that macromycetes accumulate almost all types of radionuclides originating from the accident (131I, 140Ba /140La, 103Ru, 106Ru, 141Ce, 144Ce, 95Nb, 95Zr, 137Cs and 134Cs). They accumulate the long-living 90Sr in much smaller (to 3 - 4 orders) quantities than 137Cs. We have established existence of two stages in accumulation of 137Cs by higher fungi after the accident on the Chernobyl NPP: the first stage resides in the growth of the concentration, the second - in gradual decrease of levels of specific activity of this radionuclide. Despite reduction of 137Cs specific activity level, the content of this radionuclide at testing areas of the 5-km zone around the Chernobyl NPP reaches 1,100,000 Bq/kg of fresh weight in 2013. We investigated dynamics of accumulation of Cs-137 in higher fungi of different ecological groups. One of the major factors that influence levels of accumulation of 137Cs by fungi is their nutritional type (ecological group). Fungi that belong to ecological groups of saprotrophes and xylotrophes accumulate this radionuclide in much smaller quantities than symbio-trophic fungi. As a result of the conducted research it has been established that symbio-trophic fungi store more 137Cs than any other biological objects in forest ecosystems. Among the symbio-trophic fungi species, species showing the highest level of 137Cs contamination vary in different periods of time after the deposition. It is connected with variability of quantities of these radio nuclides accessible for absorption at the depth of localization of the main part of mycelium of each species in a soil profile. Soil contamination by 137Cs is one of the principal abiotic influences on the accumulation of this radionuclide by fungi

  3. Accumulation of transuranic elements in the aquatic biota of the Belarusian sector of contaminated area near the Chernobyl nuclear power plant - Accumulation of transuranic elements in aquatic biota of Belarusian sector of contaminated area of Chernobyl nuclear power plant

    Golubev, Alexander; Mironov, Vladislav [International Sakharov Environmental University. Box 220070, 23 Dolgobrodskaya Street, Minsk, 220070 (Belarus)

    2014-07-01

    The evolution of nuclear contamination of Belarus territory after Chernobyl accident includes the four stages: 1. Iodine-neptunium stage, caused mainly by short-lived radionuclides {sup 131}I, {sup 239}Np and others with a half-life period of several weeks; II. Intermediate stage, caused by radionuclides with a half-life period of a year ({sup 144}Ce, {sup 106}Ru, {sup 134}Cs, etc.); III. Strontium-cesium stage, caused by {sup 90}Sr and {sup 137}Cs with a half-life period of about 30 years; IV. Plutonium-americium, caused by long-lived α-emitting radionuclides {sup 241}Am (period of half-life of 432 years) and {sup 239+240}Pu, having high radio and chemo-toxicity. According to forecasts, activity of {sup 241}Am to 2050 year will increase by 2.5 times and it will be the most important dose-related factor for the aquatic biota within the Chernobyl accident zone. In 2002 - 2008 years we have studied the accumulation of trans-uranic elements (TUE, {sup 241}Am, {sup 239+240}Pu) in basic components of water body ecosystems within the Chernobyl zone - non-flowing Perstok Lake, weak-flowing Borschevka flooding and small Braginka River. Among investigated components are water, bottom sediments, submerged macrophytes (Ceratophyllum submersum, Hydrocharis morsus-ranae, Lemna minor, Nuphar lutea, Stratiotes aloides), emergent macrophytes (Typha spp.), shellfish and fish. In the soil cover in the vicinity of the Perstok Lake activity of {sup 241}Am at present is equivalent to 300 - 600 Bq.kg{sup -1}, that is the basic source of its income to the lake. Radionuclides mobility in the water environment is higher than in the soil, that facilitates the rapid incorporation of {sup 241}Am to the trophic nets of water bodies and its removal by near-water animals in the terrestrial biotopes, including outside Chernobyl zone. Thus, the activity of {sup 241}Am in bottom sediments in the Perstok Lake and Borschevka flooding in 2008 year reach respectively 324 and 131 Bq.kg{sup -1}, and the

  4. Accumulation of transuranic elements in the aquatic biota of the Belarusian sector of contaminated area near the Chernobyl nuclear power plant - Accumulation of transuranic elements in aquatic biota of Belarusian sector of contaminated area of Chernobyl nuclear power plant

    The evolution of nuclear contamination of Belarus territory after Chernobyl accident includes the four stages: 1. Iodine-neptunium stage, caused mainly by short-lived radionuclides 131I, 239Np and others with a half-life period of several weeks; II. Intermediate stage, caused by radionuclides with a half-life period of a year (144Ce, 106Ru, 134Cs, etc.); III. Strontium-cesium stage, caused by 90Sr and 137Cs with a half-life period of about 30 years; IV. Plutonium-americium, caused by long-lived α-emitting radionuclides 241Am (period of half-life of 432 years) and 239+240Pu, having high radio and chemo-toxicity. According to forecasts, activity of 241Am to 2050 year will increase by 2.5 times and it will be the most important dose-related factor for the aquatic biota within the Chernobyl accident zone. In 2002 - 2008 years we have studied the accumulation of trans-uranic elements (TUE, 241Am, 239+240Pu) in basic components of water body ecosystems within the Chernobyl zone - non-flowing Perstok Lake, weak-flowing Borschevka flooding and small Braginka River. Among investigated components are water, bottom sediments, submerged macrophytes (Ceratophyllum submersum, Hydrocharis morsus-ranae, Lemna minor, Nuphar lutea, Stratiotes aloides), emergent macrophytes (Typha spp.), shellfish and fish. In the soil cover in the vicinity of the Perstok Lake activity of 241Am at present is equivalent to 300 - 600 Bq.kg-1, that is the basic source of its income to the lake. Radionuclides mobility in the water environment is higher than in the soil, that facilitates the rapid incorporation of 241Am to the trophic nets of water bodies and its removal by near-water animals in the terrestrial biotopes, including outside Chernobyl zone. Thus, the activity of 241Am in bottom sediments in the Perstok Lake and Borschevka flooding in 2008 year reach respectively 324 and 131 Bq.kg-1, and the activity of 241Am in macrophytes of the Perstok Lake at the same year was 1,0 - 3,7 Bq.kg-1. In

  5. Patterns of Cs-137 and Sr-90 distribution in conjugated landscape systems

    Korobova, E.

    2012-04-01

    The main goal of the study was to reveal spatial patterns of 137Cs and 90Sr distribution in soils and plants of conjugated landscapes and to use 137Cs as a tracer for natural migration and accumulation processes in the environment. The studies were based on presumptions that: 1) the environment consisted of interrelated bio- and geochemical fields of hierarchical structure depending on the level and age of factors responsible for spatial distribution of chemical elements; 2)distribution of technogenic radionuclides in natural landscapes depended upon the location and type of the initial source and radionuclide involvement in natural pathways controlled by the state and mobility of the typomorphic elements and water migration. Case studies were undertaken in areas subjected to contamination after the Chernobyl accident and in the estuary zones of the Yenisey and Pechora rivers. First observations in the Chernobyl remote zone in 1987-1989 demonstrated relation between the dose rate, 137Cs, 134Cs, 144Ce, 106Ru, 125Sb in soil cover and the location of the measured plot in landscape toposequence. Later study of 137Cs and 90Sr concentration and speciation confirmed different patterns of their distribution dependent upon the radioisotope, soil features and vegetation cover corresponding to the local landscape and landuse structure. Certain patterns in distribution and migration of 137Cs and 90Sr in soils and local food chain were followed in private farms situated in different landscape position [1]. Detailed study of 137Cs activity in forested site with a pronounced relief 20 and 25 years after the Chernobyl accident showed its stable polycentric structure in soils, mosses and litter which was sensitive to meso- and micro-relief features [2]. Radionuclide contamination of the lower Yenisey and Pechora studied along meridian landscape transects proved both areas be subjected to global 137Cs pollution while the Yenisey floodplain received additional regional contamination

  6. Fission Product Yields from Fission Spectrum n+ 239Pu for ENDF/B-VII.1

    Chadwick, M. B.; Kawano, T.; Barr, D. W.; Mac Innes, M. R.; Kahler, A. C.; Graves, T.; Selby, H.; Burns, C. J.; Inkret, W. C.; Keksis, A. L.; Lestone, J. P.; Sierk, A. J.; Talou, P.

    2010-12-01

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small — especially for 99Mo — we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (4%-relative) and 147Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on

  7. Application of LiF for determining the gamma-radiation characteristics of the shut-down reactor

    Full text: The power of 60Co ∼1.25 MeV gamma-radiation source at the INP AS RUz is limited by 8 Gy/s, which does not satisfy several tasks of material science now. Therefore, we were first to suggest the irradiation of materials with gamma-rays of 0.1-7 MeV, which are emitted by the uranium fission products (41Ar, 135Xe, 125Xe, 125I,137Cs, 134Cs, 144Ce, 95Zr, 140Ba, 140La, 99Mo, 60Co) and l6N, 24Na, 28Al radio-nuclides in water during prophylactic shut-downs of our nuclear reactor WWR-SM. The gamma-dose rate kinetics was monitored with the ion current in ionization chambers KNK-53M fixed outside the reactor core from the stop-moment. The current kinetics comprised 4 steps with a high reproducibility at 2 and 0.5 μA, then 50 and 10 nA, each lasting for 1,10, 40 and up to 200 hours, according to the isotope life-times. LiF crystal is known as a thermal luminescence dosimeter of mixed radiations up to 100 Gy. Yet in this work the absorbed gamma-energy dose Dγ was determined by accumulation of the known stable structure defects in thin cleaved LiF crystals: by induced optical absorption and luminescence of F- and M-centers. The samples were irradiated in Al-containers filled with water to keep the temperature of ∼40 deg. C in the time range from 30 minutes to 150 hours. Optical absorption spectra were registered at spectrometer Specord M-40. Then the induced color center concentration was calculated by the Smakula relation, which is proportional to the absorbed dose Dγ. For a better reliability the photoluminescence center content was also determined. Selecting comparable close intensities of the induced absorption and luminescence bands obtained after irradiations of LiF references in the certified 60Co gamma-sources of the known gamma fluxes 0.7 and 7.5 Gy/s, the gamma-radiation intensity of the shut-down reactor was estimated in correlation with the ion current as 10 nA = 15 Gy/s. At short times of irradiation the linear dose dependence occurred for the