WorldWideScience

Sample records for high-temperature neutron irradiation

  1. High temperature superconductors for fusion magnets -influence of neutron irradiation

    International Nuclear Information System (INIS)

    Chudy, M.; Eisterer, M.; Weber, H. W.

    2010-01-01

    In this work authors present the results of study of influence of neutron irradiation of high temperature superconductors for fusion magnets. High temperature superconductors (type of YBCO (Yttrium-Barium-Copper-Oxygen)) are strong candidates to be applied in the next step of fusion devices. Defects induced by fast neutrons are effective pinning centres, which can significantly improve critical current densities and reduce J c anisotropy. Due to induced lattice disorder, T c is reduced. Requirements for ITER (DEMO) are partially achieved at 64 K.

  2. An investigation of methods for neutron dose measurement in high temperature irradiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Kosako, Toshisou; Sugiura, Nobuyuki [Tokyo Univ. (Japan); Kudo, Kazuhiko [Kyushu Univ., Fukuoka (Japan)] [and others

    2000-10-01

    The Japan Atomic Energy Research Institute (JAERI) has been conducting the innovative basic research on high temperature since 1994, which is a series of high temperature irradiation studies using the High Temperature Engineering Test Reactor (HTTR). 'The Task Group for Evaluation of Irradiation Dose under High Temperature Radiation' was founded in the HTTR Utilization Research Committee, which is the promoting body of the innovative basic research. The present report is a summary of investigation which has been made by the Task Group on the present status and subjects of research and development of neutron detectors in high temperature irradiation fields, in view of contributing to high temperature irradiation research using the HTTR. Detectors investigated here in the domestic survey are the following five kinds of in-core detectors: 1) small fission counter, 2) small fission chamber, 3) self-powered detector, 4) activation detector, and 5) optical fiber. In addition, the research and development status in Russia has been investigated. The present report will also be useful as nuclear instrumentation of high temperature gas-cooled reactors. (author)

  3. Superconductivity degradation in Gd-containing high temperature superconductors (HTSC) under thermal neutron irradiation

    International Nuclear Information System (INIS)

    Petrov, A.; Kudrenitskis, I.; Makletsov, A.; Arhipov, A.; Karklin, N.

    1999-01-01

    The physical properties of ordered crystals are extremely sensitive to the degree of order in the distribution of the various kinds of atoms over the corresponding sites in the crystal lattice. An increasingly popular means of creating disordered states is to use nuclear radiation. The type of radiation defects which appear and the nature and degree of the structural changes in ordered crystals depend on the kind of radiation and the fluence level, the irradiation temperature, the type of crystal structure, the composition and initial disorder of the material, the character of the interatomic forces, etc. There are many such scientific publications where the effects of fast neutron irradiation on high temperature superconductors (HTSC) have been studied in both polycrystalline and single crystalline superconductors. It is known also that the role of thermal neutrons in structural defects forming is negligible in comparison with fast neutrons because of their small (∼0.025 eV) energy. But it is evident enough that in superconductors containing isotopes with large thermal neutron cross sections the important results concerning the role of point defects could be obtained. Such point defects are creating due to soft displacements of isotopes having interacted with thermal neutrons. Such the possibility of creating point defects in solids including HTSC is investigating by several groups (Austria, USA, China, Latvia) and these investigations have found the support in the person of IAEA. In this review the authors consider the changes brought about by thermal-neutron irradiation (E∼0.025 eV) in the structure, superconducting and magnetic properties of gadolinium containing ordered HTSC with the structure 123, whose extreme electric and magnetic properties continue to attract both research and practical interest. All of the studies reviewed have been done on bulk polycrystalline samples RBa 2 Cu 3 O 7-δ (where R - natural mixture of Gd isotopes, 155 Gd, 157 Gd, 160

  4. Erosion and mass transfer of Mo, W and Nb under neutron irradiation of high temperature materials

    International Nuclear Information System (INIS)

    Berzhatyj, V.I.; Luk'yanov, A.N.; Zavalishin, A.A.; Tkach, V.N.; Fedorenko, A.I.

    1980-01-01

    Studies have been made of the medium composition in thermionic fuel elements of two types during reactor tests; erosion and mass transfer of electrode materials have been investigated in the after-reactor analysis of the tested fuel elements. The studies of electrode material evaporation at the conditions approaching (in environment temperature and composition) those of reactor tests of thermionic fuel elements have shown that the process proceeds in the form of metal oxides. Evaporation rates are determined, the mechanism of evaporation is discussed, and the analytical dependences are obtained for calculating the evaporation rates of Mo and W at certain temperature and gaseous medium composition. It is found that the main contribution to the material transfer off the Mo and Nb surfaces under a high-temperature reactor irradiation comes through the thermal evaporation; in the case of tungsten at the same experimental conditions the rates of mass transfer due to thermal evaporation and neutron sputtering are nearly the same [ru

  5. Fusion neutron irradiation of Ni(Si) alloys at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.S.; Guinan, M.W.; Hahn, P.A.

    1987-09-01

    Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab.

  6. Fusion neutron irradiation of Ni(Si) alloys at high temperature

    International Nuclear Information System (INIS)

    Huang, J.S.; Guinan, M.W.; Hahn, P.A.

    1987-09-01

    Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab

  7. Fusion neutron irradiation of Ni-Si alloys at high temperature*1

    Science.gov (United States)

    Huang, J. S.; Guinan, M. W.; Hahn, P. A.

    1988-07-01

    Two Ni-4% Si alloys, with different cold work levels, have been irradiated with 14-MeV fusion neutrons at 623 K, and their Curie temperatures have been monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2-MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14-MeV fusion neutrons is only 6-7% of that for an identical alloy irradiated by 2-MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6-7% for the fusion neutron irradiated sample.

  8. Effects of high temperature neutron irradiation on the physical, chemical and mechanical properties of fine-grained isotropic graphite

    International Nuclear Information System (INIS)

    Matsuo, H.; Nomura, S.; Imai, H.; Oku, T.; Eto, M.

    1987-01-01

    Effects of neutron irradiation on the dimensional change, coefficient of thermal expansion(CTE), thermal conductivity, corrosion rate, Young's modulus and strengths were studied for the candidate graphite material IG-110 of the experimental very high temperature gas-cooled reactor(VHTR) after irradiation at 585 - 1273 deg C to neutron fluences of up to about 3 x 10 25 n/m 2 (E > 29 fJ) in the JMTR and JRR-2, and to about 7 x 10 25 n/m 2 (E > 29 fJ) in the HFR. The results were compared with the irradiation behaviors of other graphites. Dimensional shrinkage was observed in the whole irradiation temperature range, showing lower value than 2 %. The shrinkage rate showed the minimum in the irradiation temperature of around 850 deg C, followed by the increase for the samples irradiated at higher temperatures. The dimensional stability of the material was clarified to be almost the same with that of H451 graphite. The CTE, thermal resistivity and Young's modulus increased in the early stage of irradiation and then only the CTE decreased while the thermal resistivity and Young's modulus levelled off with further irradiation. The neutron fluence showing the maximum CTE shifted to the lower fluence with increasing irradiation temperature. The increases of both thermal resistivity and Young's modulus were remarkable for the samples irradiated at lower temperatures. Compressive and bending strengths measured at room temperature increased after irradiation as well. The corrosion rate with water-vapor of 0.65 % in helium at high temperatures decreased owing to irradiation and the reduction was independent of irradiation temperature and neutron fluence. The activation energy for the reaction was estimated to be the same before and after irradiation. (author)

  9. Crack initiation behavior of neutron irradiated model and commercial stainless steels in high temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, Kale J., E-mail: kalejs@umich.edu; Was, Gary S.

    2014-01-15

    Highlights: • Environmental constant extension rate tensile tests were performed on neutron irradiated steel. • Percentage of intergranular cracking quantified the cracking susceptibility. • Cracking susceptibility varied with test environment, solute addition, and cold work. • No singular microstructural change could explain increases in cracking susceptibility with irradiation dose. • The increment of yield strength due to irradiation correlated well with cracking susceptibility. -- Abstract: The objective of this study was to isolate key factors affecting the irradiation-assisted stress corrosion cracking (IASCC) susceptibility of eleven neutron-irradiated austenitic stainless steel alloys. Four commercial purity and seven high purity stainless steels were fabricated with specific changes in composition and microstructure, and irradiated in a fast reactor spectrum at 320 °C to doses between 4.4 and 47.5 dpa. Constant extension rate tensile (CERT) tests were performed in normal water chemistry (NWC), hydrogen water chemistry (HWC), or primary water (PW) environments to isolate the effects of environment, elemental solute addition, alloy purity, alloy heat, alloy type, cold work, and irradiation dose. The irradiated alloys showed a wide variation in IASCC susceptibility, as measured by the relative changes in mechanical properties and crack morphology. Cracking susceptibility measured by %IG was enhanced in oxidizing environments, although testing in the lowest potential environment caused an increase in surface crack density. Alloys containing solute addition of Ni or Ni + Cr exhibited no IASCC. Susceptibility was reduced in materials cold worked prior to irradiation, and increased with increasing irradiation dose. Irradiation-induced hardening was accounted for by the dislocation loop microstructure, however no relation between crack initiation and radiation hardening was found.

  10. Fusion neutron irradiation induced ordering and defect production in Cu3Au at high temperatures

    International Nuclear Information System (INIS)

    Huang, J.S.; Guinan, M.W.; Kirk, M.A.; Hahn, P.A.

    1987-08-01

    We irradiate three Cu 3 Au alloys different degrees of initial long-range order at temperatures between 300K and 434K. The resistivity of samples is monitored during irradiation and related to the long-term order parameter by the Muto relation. The results show that the ordering rate, which is proportional to the concentration of freely migrating vacancies, increases at the beginning and then decreases later with fluence. The decrease is a result of the continuous production of sinks in the form of dislocation loops. The effect of sinks on vacancy annihilation in some cases causes a reversed temperature dependence of ordering rate. The free vacancy production rate and the rate of sink production are determined using an ordering kinetics theory. The results of the 14 MeV neutron irradiations are compared to those obtained in other neutron spectra and particle irradiations. The estimated free vacancy production rate is also compared to the primary defect production rate measured at 4.2K in disordered samples

  11. High Temperature Tensile Properties of Unirradiated and Neutron Irradiated 20 Cr-35 Ni Austenitic Steel

    Energy Technology Data Exchange (ETDEWEB)

    Roy, R B; Solly, B

    1966-12-15

    The tensile properties of an unirradiated and neutron irradiated (at 40 deg C) 20 % Cr, 35 % Ni austenitic steel have been studied at 650 deg C, 750 deg C and 820 deg C. The tensile elongation and mode of fracture (transgranular) of unirradiated specimens tested at room temperature and 650 deg C are almost identical. At 750 deg C and 820 deg C the elongation decreases considerably and a large part of the total elongation is non-uniform. Furthermore, the mode of fracture at these temperatures is intergranular and microscopic evidence suggests that fracture is caused by formation and linkup of grain boundary cavities. YS and UTS decrease monotonically with temperature. Irradiated specimens show a further decrease in ductility and an increase in the tendency to grain boundary cracking. Irradiation has no significant effect on the YS, but the UTS are reduced. The embrittlement of the irradiated specimens is attributed to the presence of He and Li atoms produced during irradiation and the possible mechanisms are discussed. Prolonged annealing of irradiated and unirradiated specimens at 650 deg C appears to have no significant effect on tensile properties.

  12. Damage structures in fission-neutron irradiated Ni-based alloys at high temperatures

    Science.gov (United States)

    Yamakawa, K.; Shimomura, Y.

    1999-01-01

    The defects formed in Ni based (Ni-Si, Ni-Cu and Ni-Fe) alloys which were irradiated with fission-neutrons were examined by electron microscopy. Irradiations were carried out at 473 K and 573 K. In the 473 K irradiated specimens, a high density of large interstitial loops and small vacancy clusters with stacking fault tetrahedra (SFT) were observed. The number densities of these two types of defects did not strongly depend on the amount of solute atoms in each alloy. The density of the loops in Ni-Si alloys was much higher than those in Ni-Cu and Ni-Fe alloys, while the density of SFT only slightly depended on the kind of solute. Also, the size of the loops depended on the kinds and amounts of solute. In 573 K irradiated Ni-Cu specimens, a high density of dislocation lines developed during the growth of interstitial loops. In Ni-Si alloys, the number density and size of the interstitial loops changed as a function of the amount of solute. Voids were formed in Ni-Cu alloys but scarcely formed in Ni-Si alloys. The number density of voids was one hundredth of that of SFT observed in 473 K irradiated Ni-Cu alloys. Possible formation processes of interstitial loops, SFT dislocation lines and voids are discussed.

  13. Damage structures in fission-neutron irradiated Ni-based alloys at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, K.; Shimomura, Y. [Hiroshima Univ. (Japan). Faculty of Engineering

    1999-01-01

    The defects formed in Ni based (Ni-Si, Ni-Cu and Ni-Fe) alloys which were irradiated with fission-neutrons were examined by electron microscopy. Irradiations were carried out at 473 K and 573 K. In the 473 K irradiated specimens, a high density of large interstitial loops and small vacancy clusters with stacking fault tetrahedra (SFT) were observed. The number densities of these two types of defects did not strongly depend on the amount of solute atoms in each alloy. The density of the loops in Ni-Si alloys was much higher than those in Ni-Cu and Ni-Fe alloys, while the density of SFT only slightly depended on the kind of solute. Also, the size of the loops depended on the kinds and amounts of solute. In 573 K irradiated Ni-Cu specimens, a high density of dislocation lines developed during the growth of interstitial loops. In Ni-Si alloys, the number density and size of the interstitial loops changed as a function of the amount of solute. Voids were formed in Ni-Cu alloys but scarcely formed in Ni-Si alloys. The number density of voids was one hundredth of that of SFT observed in 473 K irradiated Ni-Cu alloys. Possible formation processes of interstitial loops, SFT, dislocation lines and voids are discussed. (orig.) 8 refs.

  14. Mechanical properties of Mo and TZM alloy neutron-irradiated at high temperatures

    International Nuclear Information System (INIS)

    Ueda, Kazukiyo; Satou, Manabu; Hasegawa, Akira; Abe, Katsunori

    1997-01-01

    This work reports the mechanical properties of irradiated molybdenum (Mo) and its alloy, TZM. Recrystallized and stress-relieved specimens were irradiated at five temperatures between 373 and 800degC in FFTF/MOTA to fluence levels of 6.8 to 34 dpa. Irradiation embrittlement and hardening were evaluated by three-point bend test and Vickers hardness test, respectively. Stress-relieved materials showed the enough ductility even after high fluence irradiation. The role of layered structure of stress-relieved specimen was discussed. (author)

  15. SiC-based neutron detector in quasi-realistic working conditions: efficiency and stability at room and high temperature under fast neutron irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Ferone, Raffaello; Issa, Fatima; Ottaviani, Laurent; Biondo, Stephane; Vervisch, Vanessa [IM2NP, UMR CNRS 7334, Aix-Marseille University, Case 231,13397 Marseille Cedex 20, (France); Szalkai, Dora; Klix, Axel [KIT- Karlsruhe Institute of Technology, Institute of Neutron Physics and Reactor Technology Karlsruhe 76344, (Germany); Vermeeren, Ludo [SCK-CEN, Boeretang 200, B-2400 Mol, (Belgium); Saenger, Richard [Schlumberger, Clamart, (France); Lyoussi, Abadallah [CEA, DEN, Departement d' Etudes des Reacteurs, Service de Physique Experimentale, Laboratoire Dosimetrie Capteurs Instrumentation, 13108 Saint-Paul-lez-Durance, (France)

    2015-07-01

    In the framework of the European I SMART project, we have designed and made new SiC-based nuclear radiation detectors able to operate in harsh environments and to detect both fast and thermal neutrons. In this paper, we report experimental results of fast neutron irradiation campaign at high temperature (106 deg. C) in quasi-realistic working conditions. Our device does not suffer from high temperature, and spectra do show strong stability, preserving features. These experiments, as well as others in progress, show the I SMART SiC-based device skills to operate in harsh environments, whereas other materials would strongly suffer from degradation. Work is still demanded to test our device at higher temperatures and to enhance efficiency in order to make our device fully exploitable from an industrial point of view. (authors)

  16. New fixed-point mini-cell to investigate thermocouple drift in a high-temperature environment under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Laurie, M.; Vlahovic, L.; Rondinella, V.V. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe, (Germany); Sadli, M.; Failleau, G. [Laboratoire Commun de Metrologie, LNE-Cnam, Saint-Denis, (France); Fuetterer, M.; Lapetite, J.M. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten, (Netherlands); Fourrez, S. [Thermocoax, 8 rue du pre neuf, F-61100 St Georges des Groseillers, (France)

    2015-07-01

    Temperature measurements in the nuclear field require a high degree of reliability and accuracy. Despite their sheathed form, thermocouples subjected to nuclear radiations undergo changes due to radiation damage and transmutation that lead to significant EMF drift during long-term fuel irradiation experiment. For the purpose of a High Temperature Reactor fuel irradiation to take place in the High Flux Reactor Petten, a dedicated fixed-point cell was jointly developed by LNE-Cnam and JRC-IET. The developed cell to be housed in the irradiation rig was tailor made to quantify the thermocouple drift during the irradiation (about two year duration) and withstand high temperature (in the range 950 deg. C - 1100 deg. C) in the presence of contaminated helium in a graphite environment. Considering the different levels of temperature achieved in the irradiation facility and the large palette of thermocouple types aimed at surveying the HTR fuel pebble during the qualification test both copper (1084.62 deg. C) and gold (1064.18 deg. C) fixed-point materials were considered. The aim of this paper is to first describe the fixed-point mini-cell designed to be embedded in the reactor rig and to discuss the preliminary results achieved during some out of pile tests as much as some robustness tests representative of the reactor scram scenarios. (authors)

  17. Final report on neutron irradiation at low temperature to investigate plastic instability and at high temperature to study caviation

    DEFF Research Database (Denmark)

    Singh, B.N; Eldrup, Morten Mostgaard; Golubov, D.J.

    2005-01-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties of pure iron and F82H and EUROFER 97 ferritic-martensitic steels have been investigated. Tensile specimens were neutron irradiated to a dose level of 0,23 dpa at333 and 573 K. Electrical resistivity......, based on the production bias model (PBM) were carried out to study the details of evolution of cavitieswith and without helium generation. The phenomena of dislocation decoration and raft formation, which are important for understanding radiation hardening and plastic flow localization, have been...... studied using the Kinetic Monte Carlo (KMC) code during arealistic dynamic irradiation of bcc iron at 300 K. Molecular dynamics (MD) simulations have been carried out to study the stress dependencies of dislocation velocity and drag coefficient for an edge dislocation decorated with small SIA loops...

  18. Final report on neutron irradiation at low temperature to investigate plastic instability and a high temperature to study cavitation

    International Nuclear Information System (INIS)

    Singh, B.N.; Eldrup, M.; Golubov, S.I.; Edwards, D.J.; Jung, P.

    2005-01-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties of pure iron and F82H and EUROFER 97 ferritic-martensitic steels have been investigated. Tensile specimens were neutron irradiated to a dose level of 0,23 dpa at 333 and 573 K. Electrical resistivity and tensile properties were measured both in the unirradiated and irradiated condition. Some additional specimens of pure iron were irradiated at 333 K to doses of 10-3, 10-2 and 10-1 dpa and tensile tested at 333 K. To investigate the effect of helium on cavity nucleation and growth, specimens of pure iron and EUROFER 97 were implanted with different amounts of helium at 323 K and subsequently neutron irradiated to doses of 10-3, 10-2 and 10-1 dpa at 323 K. Defect microstructures were investigated using positron annihilation spectroscopy (PAS) and transmission electron microscopy (TEM). Numerical calculations, based on the production bias model (PBM) were carried out to study the details of evolution of cavities with and without helium generation. The phenomena of dislocation decoration and raft formation, which are important for understanding radiation hardening and plastic flow localization, have been studied using the Kinetic Monte Carlo (KMC) code during a realistic dynamic irradiation of bcc iron at 300 K. Molecular dynamics (MD) simulations have been carried out to study the stress dependencies of dislocation velocity and drag coefficient for an edge dislocation decorated with small SIA loops.The present report describes both experimental procedure and calculational methodology employed in the present work. The main results of all these investigations, both experimental and theoretical, are highlighted with appropriate examples. Finally, a brief summary is given of the main results conclusions. (au)

  19. Neutron irradiation and high temperature effects on amorphous Fe-based nano-coatings on steel - A macroscopic assessment

    Science.gov (United States)

    Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.; Camino, F.; Şavklıyıldız, İ.; Akdoğan, E. K.

    2017-06-01

    The study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ∼2 × 1018 n/cm2. At the higher neutron dose of ∼2 × 1019, macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe2B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.

  20. Neutron irradiation and high temperature effects on amorphous Fe-based nano-coatings on steel – A macroscopic assessment

    International Nuclear Information System (INIS)

    Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.

    2017-01-01

    Here, this study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ~2 x 10 18 n/cm 2 . At the higher neutron dose of ~2 x 10 19 , macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe 2 B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.

  1. Zircaloy behaviour in high temperature irradiated water

    International Nuclear Information System (INIS)

    Urbanic, V.F.

    1982-04-01

    The corrosion and hydriding of Zircaloy during irradiation in high temperature water is strongly dependent on the oxygen concentration of the water. Corrosion tests in the NRX and NRU research reactors using small samples have demonstrated the importance of water chemistry in maintaining Zircaloy corrosion and hydriding within acceptable limits. Zircaloy fuel cladding develops non-uniform, patch-type oxides during irradiation in hich temperature water containing dissolved oxygen. Results from examinations of prototype fuel cladding irradiated in the research reactors are presented to show how local variations in coolant flow, fast neutron flux, metallurgical structure and surface condition can influence the onset of non-uniform corrosion under these conditions. Destructive examinations of CANDU-PHW reactor fuel cladding have emphasized the importance of good chemistry control, especially the dissolved oxygen concentration of the water. When reactor coolants are maintained under normal reducing conditions at high pH (5 to 10 cm 3 D 2 /kg D 2 O; 2 /kg D 2 O; pH > 10 with LiOD), Zircaloy cladding develops non-uniform, patch-type oxides. These patch-type oxides tend to coalesce with time to form a thick, uniform oxide layer after extended exposure. Under reducing coolant conditions, Zircaloy cladding absorbs less than 200 mg D/kg Zr (approximately 2.5 mg/dm 2 equivalent hydrogen) in about 500 days. With oxygen in the coolant, deuterium absorption is considerably less despite the significant increase in corrosion under such conditions

  2. Development of crack growth and crack initiation test units for stress corrosion cracking examinations in high-temperature water environments under neutron irradiation (1) (Contract research)

    International Nuclear Information System (INIS)

    Izumo, Hironobu; Ishida, Takuya; Kawamata, Kazuo; Inoue, Shuichi; Ide, Hiroshi; Saito, Takashi; Ishitsuka, Etsuo; Chimi, Yasuhiro; Ise, Hideo; Miwa, Yukio; Ugachi, Hirokazu; Nakano, Junichi; Kaji, Yoshiyuki; Tsukada, Takashi

    2009-04-01

    To evaluate integrity of irradiation-assisted stress corrosion cracking (IASCC) on in-core structural materials used in light water reactors (LWRs), useful knowledge regarding IASCC has been obtained mainly by post-irradiation examinations (PIEs). In the core of commercial LWRs, however, the actual IASCC occurs under the effects of irradiation on both materials and high-temperature water environment. Therefore, it is necessary to confirm the suitability of the knowledge by PIE with comparison to IASCC behaviors during in-core SCC tests. Fundamental techniques for in-core crack growth and crack initiation tests have been developed already at the Japan Materials Testing Reactor (JMTR) of the Japan Atomic Energy Agency (JAEA). For the in-core crack growth test technique, to evaluate the effects of neutron irradiation on stainless steels irradiated to low neutron fluences, it is indispensable to develop new loading technique which is applicable to compact tension (CT) specimens with thickness of 0.5 inch (0.5T), from the viewpoint of validity based on the fracture mechanics. Based on the present technical investigation for the in-core loading technique, it is expected that a target load of 7.6 kN approximately can apply to a 0.5T-CT specimen by adopting a loading unit of a lever type instead of the previous uni-axial tension type. For the in-core crack initiation test technique, moreover, construction of a loading unit adopting linear variable differential transformers (LVDTs) has been investigated and technical issues have examined. (author)

  3. The behavior of lattice defects produced in Al2O3 irradiated by neutrons at high temperatures

    International Nuclear Information System (INIS)

    Atobe, K.; Koizumi, T.; Okada, M.

    2003-01-01

    Single crystals of α-Al 2 O 3 were irradiated by the two reactors, KUR and JMTR, at three different temperatures. Lattice defects produced by irradiation were studied by esr (electron spin resonance). Three kinds of esr spectram, which are denoted as A, B and C spectram, are observed. The spectram A was observed at three different irradiation temperatures and was ascribed to oxygen vacancies. The spectram B showed no angular dependence for the rotation of external magnetic field to the crystal axis, and the defect density of this spectram decreased with an increase of annealing temperature. When the specimen was annealed at 400 degC after irradiation at 200 degC, the spectram C was observed and was presumed to be due to Al-colloids. (Y. Kazumata)

  4. High temperature ductility of austenitic alloys exposed to thermal neutrons

    International Nuclear Information System (INIS)

    Watanabe, K.; Kondo, T.; Ogawa, Y.

    1982-01-01

    Loss of high temperature ductility due to thermal neutron irradiation was examined by slow strain rate test in vacuum up to 1000 0 C. The results on two heats of Hastelloy alloy X with different boron contents were analyzed with respect to the influence of the temperatures of irradiation and tensile tests, neutron fluence and the associated helium production due to nuclear transmutation reaction. The loss of ductility was enhanced by increasing either temperature or neutron fluence. Simple extrapolations yielded the estimated threshold fluence and the end-of-life ductility values at 900 and 1000 0 C in case where the materials were used in near-core regions of VHTR. The observed relationship between Ni content and the ductility loss has suggested a potential utilization of Fe-based alloys for seathing of the neutron absorber materials

  5. Thermodynamic studies on the ferroelectric phase transition in neutron irradiated (LixK1-x)2SO4 crystals at high temperature

    International Nuclear Information System (INIS)

    Kassem, M.E.; El-Khatib, A.M.; Ammar, E.A.; Denton, M.M.

    1989-05-01

    Thermodynamic studies of (Li x K 1-x ) 2 SO 4 , LKS, mixed crystals have been made in the concentration range (x=0.1,0.2,...,x=0.5). The thermal behavior has been investigated by differential thermal analysis, DTA, and differential scanning calorimeter, DSC, in the vicinity of high temperature phases. Also, the effect of the mixed neutron field of fast and thermal neutrons (10% of the reactor neutron pile is fast neutrons) on the thermal properties of mixed crystals was studied. The results showed a change in the transition temperature Tc, as well as the value of specific heat Cp at transition temperature, due to the change of stoichiometric ratio and radiation doses. The change of enthalpy and entropy of mixed crystals have been estimated numerically. The obtained small values of ΔS/R is characteristic of incommensurate phase transition as previously confirmed by the results of neutron diffraction technique. (author). 16 refs, 5 figs, 1 tab

  6. Irradiation effects of high temperature superconductor of lanthanoid oxides

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Koh-ichi; Kohara, Takao [Himeji Inst. of Tech., Hyogo (Japan)

    1996-04-01

    Neutron irradiation effects on excess oxygen were studied by neutron irradiation on La{sub 2}CuO{sub 4} treated with high pressure oxygen. La{sub 2}CuO{sub 4} was prepared by the usual method and annealed for 10 h under the oxygen pressure of 800-2000 atm. at 600degC. The superconducting transition temperature (Tc) is 27-32K before irradiation (La{sub 2}CuO{sub 4+d}, amount of excess oxygen d=0.03-0.12). Neutron irradiation was carried out by two kinds of experiments. Low irradiation dose test at low temperature (LTL: {approx}20-200K, storage in LN{sub 2}) showed Tc decreased more slowly than that of high temperature range. Experiment at high temperature (Hyd:{approx}80deg{yields}, storage at room temperature) showed -10K/10{sup 18}n/cm{sup 2}, the decrease of Tc was three times larger than that of YBCO type superconductor. (S.Y.)

  7. Development of Environment and Irradiation Effects of High Temperature Materials

    International Nuclear Information System (INIS)

    Ryu, Woo Seog; Kim, D. W.; Kim, S. H.

    2009-11-01

    Proposed materials, Mod.9Cr-1Mo steel (32 mm thickness) and 9Cr-1Mo-1W (100 mm thickness), for the reactor vessel were procured, and welded by the qualified welding technologies. Welding soundness was conformed by NDT, and mechanical testings were done along to weld depth. Two new irradiation capsules for use in the OR test hole of HANARO were designed and fabricated. specimens was irradiated in the OR5 test hole of HANARO with a 30MW thermal power at 390±10 .deg. C up to a fast neutron fluence of 4.4x10 19 (n/cm 2 ) (E>1.0 MeV). The dpa was evaluated to be 0.034∼0.07. Base metals and weldments of both Mod.9Cr-1Mo and 9Cr-1Mo-1W steels were tested tensile and impact properties in order to evaluate the irradiation hardening effects due to neutron irradiation. DBTT of base metal and weldment of Mod.9Cr-1Mo steel were -16 .deg. C and 1 .deg. C, respectively. After neutron irradiation, DBTT of weldment of Mod.9Cr-1Mo steel increased to 25 . deg. C. Alloy 617 and several nickel-base superalloys were studied to evaluate high temperature degradation mechanisms. Helium loop was developed to evaluate the oxidation behaviors of materials in the VHTR environments. In addition, creep behaviors in air and He environments were compared, and oxidation layers formed outer surfaces were measured as a function of applied stress and these results were investigated to the creep life

  8. The behavior of lattice defects produced in Al{sub 2}O{sub 3} irradiated by neutrons at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Atobe, K.; Koizumi, T. [Naruto Univ. of Education, Tokushima (Japan); Okada, M. [Kyoto Univ., Research Reactor Inst., Kumatori, Osaka (Japan)

    2003-01-01

    Single crystals of {alpha}-Al{sub 2}O{sub 3} were irradiated by the two reactors, KUR and JMTR, at three different temperatures. Lattice defects produced by irradiation were studied by esr (electron spin resonance). Three kinds of esr spectram, which are denoted as A, B and C spectram, are observed. The spectram A was observed at three different irradiation temperatures and was ascribed to oxygen vacancies. The spectram B showed no angular dependence for the rotation of external magnetic field to the crystal axis, and the defect density of this spectram decreased with an increase of annealing temperature. When the specimen was annealed at 400 degC after irradiation at 200 degC, the spectram C was observed and was presumed to be due to Al-colloids. (Y. Kazumata)

  9. Neutron analysis of the fuel of high temperature nuclear reactors

    International Nuclear Information System (INIS)

    Bastida O, G. E.; Francois L, J. L.

    2014-10-01

    In this work a neutron analysis of the fuel of some high temperature nuclear reactors is presented, studying its main features, besides some alternatives of compound fuel by uranium and plutonium, and of coolant: sodium and helium. For this study was necessary the use of a code able to carry out a reliable calculation of the main parameters of the fuel. The use of the Monte Carlo method was convenient to simulate the neutrons transport in the reactor core, which is the base of the Serpent code, with which the calculations will be made for the analysis. (Author)

  10. Optimization of the Neutronics of the Advanced High Temperature Reactor

    International Nuclear Information System (INIS)

    Zakova, Jitka; Talamo, Alberto

    2006-01-01

    In these studies, we have investigated the neutronic and safety performance of the Advanced High Temperature Reactor (AHTR) for plutonium and uranium fuels and we extended the analysis to five different coolants. The AHTR is a graphite-moderated and molten salt-cooled high temperature reactor, which takes advantage of the TRISO particles technology for the fuel utilization. The conceptual design of the core, proposed at the Oak Ridge National Laboratory, aims to provide an alternative to helium as coolant of high-temperature reactors for industrial applications like hydrogen production. We evaluated the influence of the radial reflector on the criticality of the core for the uranium and plutonium fuels and we focused on the void coefficient of 5 different molten salts; since the safety of the reactor is enhanced also by the large and negative coefficient of temperature, we completed our investigation by observing the keff changes when the graphite temperature varies from 300 to 1800 K. (authors)

  11. Long duration performance of high temperature irradiation resistant thermocouples

    International Nuclear Information System (INIS)

    Rempe, J.; Knudson, D.; Condie, K.; Cole, J.; Wilkins, S.C.

    2007-01-01

    Many advanced nuclear reactor designs require new fuel, cladding, and structural materials. Data are needed to characterize the performance of these new materials in high temperature, radiation conditions. However, traditional methods for measuring temperature in-pile degrade at temperatures above 1100 C degrees. To address this instrumentation need, the Idaho National Laboratory (INL) developed and evaluated the performance of a high temperature irradiation-resistant thermocouple that contains alloys of molybdenum and niobium. To verify the performance of INL's recommended thermocouple design, a series of high temperature (from 1200 to 1800 C) long duration (up to six months) tests has been initiated. This paper summarizes results from the tests that have been completed. Data are presented from 4000 hour tests conducted at 1200 and 1400 C that demonstrate the stability of this thermocouple (less than 2% drift). In addition, post test metallographic examinations are discussed which confirm the compatibility of thermocouple materials throughout these long duration, high temperature tests. (authors)

  12. High temperature neutron diffraction study of LaPO4

    International Nuclear Information System (INIS)

    Mishra, S.K.; Mittal, R.; Ningthoujam, R.S.; Vatsa, R.K.; Hansen, T.

    2016-01-01

    We report high temperature powder neutron diffractions study in LaPO 4 using high-flux D20 neutron diffractometer in the Institut Laue-Langevin, France. The measurements were carried out in high resolution mode (incident neutron wavelength 1.36 A) at various temperature upto 900°C. CarefuI inspection of temperature dependence of diffraction data showed appearance and disappearance of certain Bragg's reflections above 1273 K. It is a signature of structural phase transition. Rietveld refinement of the powder diffraction data revealed that diffraction patterns at and above 800°C could be indexed using the monoclinic structure with P21/n space group. Detail analysis for identify the water molecules is under investigation. (author)

  13. Levitation apparatus for neutron diffraction investigations on high temperature liquids

    International Nuclear Information System (INIS)

    Hennet, Louis; Pozdnyakova, Irina; Bytchkov, Aleksei; Cristiglio, Viviana; Palleau, Pierre; Fischer, Henry E.; Cuello, Gabriel J.; Johnson, Mark; Melin, Philippe; Zanghi, Didier; Brassamin, Severine; Brun, Jean-Francois; Price, David L.; Saboungi, Marie-Louise

    2006-01-01

    We describe a new high temperature environment based on aerodynamic levitation and laser heating designed for neutron scattering experiments up to 3000 deg. C. The sample is heated to the desired temperature with three CO 2 lasers from different directions in order to obtain a homogeneous temperature distribution. The apparent temperature of the sample is measured with an optical pyrometer, and two video cameras are employed to monitor the sample behavior during heating. The levitation setup is enclosed in a vacuum-tight chamber, enabling a high degree of gas purity and a reproducible sample environment for structural investigations on both oxide and metallic melts. High-quality neutron diffraction data have been obtained on liquid Y 3 Al 5 O 12 and ZrNi alloy for relatively short counting times (1.5 h)

  14. Status for development of a capsule and instruments for high-temperature irradiation in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Man Soon; Choo, Kee Nam; Lee, Chul Yong; Yang, Seong Woo; Shim, Kyue Taek; Chung, Hwan-Sung [Korea Atomic Energy Research Institute, Taejeon (Korea, Republic of)

    2012-03-15

    As the reactors planned in the Gen-IV program will be operated at high temperature and under high neutron flux, the requirements for irradiation of materials at high temperature are recently being gradually increased. The irradiation tests of materials in HANARO up to the present have been performed usually at temperatures below 300degC at which the RPV materials of the commercial reactors are being operated. To overcome the restriction for high-temperature use of Al thermal media of the existing standard capsule, a new capsule with double thermal media composed of two kinds of materials such as Al-Ti and Al-graphite was designed and fabricated as a more advanced capsule than the single thermal media capsule. (author)

  15. LVDT Development for High Temperature Irradiation Test and Application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chul Yong; Ban, Chae Min; Choo, Kee Nam; Jun, Byung Hyuk [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The LVDT (Linear Variable Differential Transformer) is used to measure the elongation and pressure of a nuclear fuel rod, or the creep and fatigue of the material during a reactor irradiation test. This device must be a radiation-resistant LVDT for use in a research reactor. Norway Halden has LVDTs for an irradiation test by the own development and commercialized. But Halden's LVDTs have limited the temperature of the use until to 350 .deg. C. So, KAERI has been developing a new LVDT for high temperature irradiation test. This paper describes the design of a LVDT, the fabrication process of a LVDT, and the result of the performance test. The designed LVDT uses thermocouple cable for coil wire material and one MI cable as signal cable. This LVDT for a high temperature irradiation test can be used until a maximum of 900 .deg. C. Welding is a very important factor for the fabrication of an LVDT. We are using a 150W fiber laser welding system that consists of a welding head, monitoring vision system and rotary index.

  16. A High Temperature-Tolerant and Radiation-Resistant In-Core Neutron Sensor for Advanced Reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Lei [The Ohio State Univ., Columbus, OH (United States); Miller, Don [The Ohio State Univ., Columbus, OH (United States)

    2015-01-23

    The objectives of this project are to develop a small and reliable gallium nitride (GaN) neutron sensor that is capable of withstanding high neutron fluence and high temperature, isolating gamma background, and operating in a wide dynamic range. The first objective will be the understanding of the fundamental materials properties and electronic response of a GaN semiconductor materials and device in an environment of high temperature and intense neutron field. To achieve such goal, an in-situ study of electronic properties of GaN device such as I-V, leakage current, and charge collection efficiency (CCE) in high temperature using an external neutron beam will be designed and implemented. We will also perform in-core irradiation of GaN up to the highest yet fast neutron fluence and an off-line performance evaluation.

  17. A High Temperature-Tolerant and Radiation-Resistant In-Core Neutron Sensor for Advanced Reactors. Final report

    International Nuclear Information System (INIS)

    Cao, Lei; Miller, Don

    2015-01-01

    The objectives of this project are to develop a small and reliable gallium nitride (GaN) neutron sensor that is capable of withstanding high neutron fluence and high temperature, isolating gamma background, and operating in a wide dynamic range. The first objective will be the understanding of the fundamental materials properties and electronic response of a GaN semiconductor materials and device in an environment of high temperature and intense neutron field. To achieve such goal, an in-situ study of electronic properties of GaN device such as I-V, leakage current, and charge collection efficiency (CCE) in high temperature using an external neutron beam will be designed and implemented. We will also perform in-core irradiation of GaN up to the highest yet fast neutron fluence and an off-line performance evaluation.

  18. Applications of neutron irradiation

    International Nuclear Information System (INIS)

    Ito, Yasuo

    1999-01-01

    The present state of art of applications of neutron irradiation is overviewed taking neutron activation analysis, prompt gamma-ray analysis, fission/alpha track methods, boron neutron capture therapy as examples. What is common among them is that the technologies are nearly matured for wide use by non- nuclear scientists. But the environment around research reactors is not prospective. These applications should be encouraged by incorporating in the neutron science society. (author)

  19. Microstructure and hardness evolution of nanochannel W films irradiated by helium at high temperature

    Science.gov (United States)

    Qin, Wenjing; Wang, Yongqiang; Tang, Ming; Ren, Feng; Fu, Qiang; Cai, Guangxu; Dong, Lan; Hu, Lulu; Wei, Guo; Jiang, Changzhong

    2018-04-01

    Plasma facing materials (PFMs) face one of the most serious challenges in fusion reactors, including unprecedented harsh environment such as 14.1 MeV neutron and transmutation gas irradiation at high temperature. Tungsten (W) is considered to be one of the most promising PFM, however, virtually insolubility of helium (He) in W causes new material issues such as He bubbles and W "fuzz" microstructure. In our previous studies, we presented a new strategy using nanochannel structure designed in the W film to increase the releasing of He atoms and thus to minimize the He nucleation and "fuzz" formation behavior. In this work, we report the further study on the diffusion of He atoms in the nanochannel W films irradiated at a high temperature of 600 °C. More specifically, the temperature influences on the formation and growth of He bubbles, the lattice swelling, and the mechanical properties of the nanochannel W films were investigated. Compared with the bulk W, the nanochannel W films possessed smaller bubble size and lower bubble areal density, indicating that noticeable amounts of He atoms have been released out along the nanochannels during the high temperature irradiations. Thus, with lower He concentration in the nanochannel W films, the formation of the bubble superlattice is delayed, which suppresses the lattice swelling and reduces hardening. These aspects indicate the nanochannel W films have better radiation resistance even at high temperature irradiations.

  20. Irradiation effects on C/C composite materials for high temperature nuclear applications

    International Nuclear Information System (INIS)

    Eto, M.; Ugachi, H.; Baba, S.I.; Ishiyama, S.; Ishihara, M.; Hayashi, K.

    2000-01-01

    Excellent characteristics such as high strength and high thermal shock resistance of C/C composite materials have led us to try to apply them to the high temperature components in nuclear facilities. Such components include the armour tile of the first wall and divertor of fusion reactor and the elements of control rod for the use in HTGR. One of the most important aspects to be clarified about C/C composites for nuclear applications is the effect of neutron irradiation on their properties. At the Japan Atomic Energy Research Institute (JAERI), research on the irradiation effects on various properties of C/C composite materials has been carried out using fission reactors (JRR-3, JMTR), accelerators (TANDEM, TIARA) and the Fusion Neutronics Source (FNS). Additionally, strength tests of some neutron-irradiated elements for the control rod were carried out to investigate the feasibility of C/C composites. The paper summarises the R and D activities on the irradiation effects on C/C composites. (authors)

  1. A Study on the High Temperature Irradiation Test Possibility for the HANARO Outer Core Region

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Young Hwan; Cho, M. S.; Choo, K. N.; Shin, Y. T.; Sohn, J. M.; Park, S. J.; Kim, B. G

    2008-01-15

    1. Information on the neutron flux levels and the gamma heat of the concerned test holes, which have been produced from a series of nuclear analysis and tests performed at KAERI since 1993, were collected and analyzed to develop the nuclear data for the concerned test holes of HANARO and to develop the new design concepts of a capsule for the high temperature irradiation devices. 2. From the literature survey and analysis about the system design characteristics of the new concepts of irradiation devices in the ATR and MIT reactor, U.S. and the JHR reactor, France, which are helpful in understanding the key issues for the on-going R and D programmes related to a SFR and a VHTR, the most important parameters for the design of high temperature irradiation devices are identified as the neutron spectrum, the heat generation density, the fuel and cladding temperature, and the coolant chemistry. 3. From the thermal analysis of a capsule by using a finite element program ANSYS, high temperature test possibility at the OR and IP holes of HANARO was investigated based on the data collected from a literature survey. The OR holes are recommended for the tests of the SFR and VHTR nuclear materials. The IP holes could be applicable for an intermediate temperature irradiation of the SWR and LMR materials. 4. A thermal analysis for the development of a capsule with a new configuration was also performed. The size of the center hole, which is located at the thermal media of a capsule, did not cause specimen temperature changes. The temperature differences are found to be less than 2%. The introduction of an additional gap in the thermal media was able to contribute to an increase in the specimen temperature by up to 27-90 %.

  2. Neutron irradiation therapy machine

    International Nuclear Information System (INIS)

    1980-01-01

    Conventional neutron irradiation therapy machines, based on the use of cyclotrons for producing neutron beams, use a superconducting magnet for the cyclotron's magnetic field. This necessitates complex liquid He equipment and presents problems in general hospital use. If conventional magnets are used, the weight of the magnet poles considerably complicates the design of the rotating gantry. Such a therapy machine, gantry and target facilities are described in detail. The use of protons and deuterons to produce the neutron beams is compared and contrasted. (U.K.)

  3. Instrumented indentation for characterization of irradiated metals at room and high temperatures

    International Nuclear Information System (INIS)

    Sacksteder, Irene

    2011-01-01

    The reliability and sustainability of future fusion power plants will highly depend on the aptitude of materials to withstand severe irradiation conditions induced by the burning plasma in reactors. The so-called reduced-activation ferritic-martensitic (RAFM) steels are the current promising candidates for the structural applications considering the reactor's first wall. These steels exhibit irradiation embrittlement and hardening for defined irradiation conditions that are mainly characterized by the irradiation temperature and the irradiation dose. A proper characterization of such irradiated steels implies the use of adapted mechanical testing tools. In the present study, the instrumented indentation technique makes use of a post-processing tool based on neural networks. This technique has been selected for its ability to examine tensile properties by multistage indents on miniaturized irradiated metallic samples. The steel specimens studied in this project have been neutron-irradiated up to a dose of 15 dpa. They have been subsequently tested at room temperature in a Hot Cell by means of an adapted commercial indentation device. The significant irradiation-induced hardening effect present in the range of 250-350 deg C could be observed in the hardness and material's strength parameters. These two material parameters show a similar evolution with increasing irradiation temperatures. Post-irradiation annealing treatments of Eurofer97 have been realized and leads to a partial recovery of the irradiation damage. Considering the demands for characterization in irradiated steels at high temperature and for post-irradiation annealing experiments, the existing instrumented indentation device has been further developed during this work. A conceptual design has been proposed for an indentation testing machine, operating at up to 650 deg C, while remaining the critical temperature limit for tensile strength of the newly developed oxide dispersion strengthening ferritic

  4. Neutronics of a liquid salt cooled - very high temperature reactor

    International Nuclear Information System (INIS)

    Zakova, J.

    2007-01-01

    During last few years, the interest in the innovative, Liquid Salt cooled - Very High Temperature Reactor (LS-VHTR), has been growing. The preconceptual design of the LS-VHTR was suggested in Oak Ridge National Laboratory (ORNL) [1] and nowadays, several research institutions contribute to the development of this concept. The LS-VHTR design utilises a prismatic, High Temperature Reactor (HTR) fuel [2] in combination with liquid salt as a coolant. This connection of high-performance fuel and a coolant with enhanced heat transfer abilities enables efficient and economical operation. Main objective of the LS-VHTR operation may be either an efficient electricity production or a heat supply for a production of hydrogen or, combination of both. The LS-VHTR is moderated by graphite. The graphite matrix of the fuel blocks, as well as the inner and outer core reflectors serve as a thermal buffer in case of an accident, and they provide a strong thermal feedback during normal reactor operation. The high inherent safety of the LS-VHTR meets the strict requirements on future reactor systems, as defined by the Gen IV project. This work, purpose, scope, contribution to the state-of-art: The design, used in the present work is based on the first ORNL suggestion [1]. Recent study is focused on comparison of the neutronic performance of two types of fuel in the LS-VHTR core, whereas, in all previous works, only uranium fuel has been investigated. The first type of fuel, which has been employed in the present analysis, is based on the spent Light Water Reactor (LWR) fuel, whereas the second one consists of enriched uranium oxide. The results of such a comparison bring a valuable knowledge about limits and possibilities of the LS-VHTR concept, when employed as a spent fuel burner. Method:It is used a 3-D drawing of the LS-VHTR core, which contains 324x10 hexagonal fuel blocks. Each fuel block contains 216x10 fuel pins, which consists of TRISO particles incorporated into a graphite

  5. Thermal and irradiation effects on high-temperature mechanical properties of materials for SCWR fuel cladding

    International Nuclear Information System (INIS)

    Kano, F.; Tsuchiya, Y.; Oka, K.

    2009-01-01

    The thermal and irradiation effects on high-temperature mechanical properties are examined for candidate alloys for fuel cladding of supercritical water-cooled reactors (SCRWs). JMTR (Japan Materials Testing Reactor) and Experimental Fast Reactor JOYO were utilized for neutron irradiation tests, considering their fluence and temperature. Irradiation was performed with JMTR at 600degC up to 4x10 24 n/m 2 and with JOYO at 600degC and 700degC up to 6x10 25 n/m 2 . Tensile test, creep test and hardness measurement were carried out for high-temperature mechanical properties. Based on the uniaxial creep test, the extrapolation curves were drawn with time-temperature relationships utilizing the Larson and Miller Parameter. Several candidate alloys are expected to satisfy the design requirement from the estimation of the creep rupture stress for 50000 hours. Comparing the creep strengths under irradiated and unirradiated conditions, it was inferred that creep deformation was dominated by the thermal effect rather than the irradiation at SCWR core condition. The microstructure was examined using transmission electron microscope (TEM) analysis, focusing on void swelling and helium (He) bubble formation. Void formation was observed in the materials irradiated with JOYO at 600degC but not at 700degC. However, its effect on the deformation of components was estimated to be tolerable since their size and density were negligibly small. The manufacturability of the thin-wall, small-diameter tube was confirmed for the potential candidate alloys through the trial tests in the factory where the fuel cladding tube is manufactured. (author)

  6. Hyper-thermal neutron irradiation field for neutron capture therapy

    International Nuclear Information System (INIS)

    Sakurai, Yoshinori; Kobayashi, Tooru; Kanda, Keiji

    1994-01-01

    The utilization of hyper-thermal neutrons, which have an energy spectrum of a Maxwell distribution higher than the room temperature of 300 K, has been studied in order to improve the thermal neutron flux distribution in a living body for a deep-seated tumor in neutron capture therapy (NCT). Simulation calculations using MCNP-V3 were carried out in order to investigate the characteristics of the hyper-thermal neutron irradiation field. From the results of simulation calculations, the following were confirmed: (i) The irradiation field of the hyper-thermal neutrons is feasible by using some scattering materials with high temperature, such as Be, BeO, C, SiC and ZrH 1.7 . Especially, ZrH 1.7 is thought to be the best material because of good characteristics of up-scattering for thermal neutrons. (ii) The ZrH 1.7 of 1200 K yields the hyper-thermal neutrons of a Maxwell-like distribution at about 2000 K and the treatable depth is about 1.5 cm larger comparing with the irradiation of the thermal neutrons of 300 K. (iii) The contamination by the secondary gamma-rays from the scattering materials can be sufficiently eliminated to the tolerance level for NCT through the bismuth layer, without the larger change of the energy spectrum of hyper-thermal neutrons. ((orig.))

  7. Neutron scattering experiments of the ionic crystal deformed plastically with uniaxial compression under high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, Yoshinori; Minakawa, Nobuaki; Aizawa, Kazuya; Ozawa, Kunio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-04-01

    As an aim of huge growth of alkali halide (AH) single crystal, a mosaic structure of small size AH single crystal deformed plastically with uniaxial compression under high temperature was evaluated due to its neutron irradiation experiment. Using TAS-2 installed at JRR-3M guide hole of Japan Atomic Energy Research Institute, locking curve at a representative face factor of the specimen was measured to observe the mosaic structure accompanied with expansion of the crystal due to compression. As a result, though the specimen before compression could be supposed to be divided to some parts already, the locking curve under 10 sec. of compression time showed already some fracture to divisions to suppose finer degradation of the crystal, and division of the locking curve at 600 sec. of compression time could be observed onto its 220 face. And, every compressed specimens showed some changes of crystallization method from standard sample. (G.K.)

  8. High temperature graphite irradiation creep experiment in the Dragon Reactor. Dragon Project report

    Energy Technology Data Exchange (ETDEWEB)

    Manzel, R.; Everett, M. R.; Graham, L. W.

    1971-05-15

    The irradiation induced creep of pressed Gilsocarbon graphite under constant tensile stress has been investigated in an experiment carried out in FE 317 of the OECD High Temperature Gass Cooled Reactor ''Dragon'' at Winfrith (England). The experiment covered a temperature range of 850 dec C to 1240 deg C and reached a maximum fast neutron dose of 1.19 x 1021 n cm-2 NDE (Nickel Dose DIDO Equivalent). Irradiation induced dimensional changes of a string of unrestrained graphite specimens are compared with the dimensional changes of three strings of restrained graphite specimens stressed to 40%, 58%, and 70% of the initial ultimate tensile strength of pressed Gilsocarbon graphite. Total creep strains ranging from 0.18% to 1.25% have been measured and a linear dependence of creep strain on applied stress was observed. Mechanical property measurements carried out before and after irradiation demonstrate that Gilsocarbon graphite can accommodate significant creep strains without failure or structural deterioration. Total creep strains are in excellent agreement with other data, however the results indicate a relatively large temperature dependent primary creep component which at 1200 deg C approaches a value which is three times larger than the normally assumed initial elastic strain. Secondary creep constants derived from the experiment show a temperature dependence and are in fair agreement with data reported elsewhere. A possible determination of the results is given.

  9. Solid State Track Recorder fission rate measurements at high neutron fluence and high temperature

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Roberts, J.H.; Gold, R.

    1985-01-01

    Solid State Track Recorder (SSTR) techniques have been used to measure 239-Pu, 235-U, and 237-Np fission rates for total neutron fluences approaching 5 x 10 17 n/cm 2 at temperatures in the range 680 to 830 0 F. Natural quartz crystal SSTRs were used to withstand the high temperature environment and ultra low-mass fissionable deposits of the three isotopes were required to yield scannable track densities at the high neutron fluences. The results of these high temperature, high neutron fluence measurements are reported

  10. Irradiation performance of AGR-1 high temperature reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Paul A. Demkowicz; John D. Hunn; Robert N. Morris; Charles A. Baldwin; Philip L. Winston; Jason M. Harp; Scott A. Ploger; Tyler Gerczak; Isabella J. van Rooyen; Fred C. Montgomery; Chinthaka M. Silva

    2014-10-01

    The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO-coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.5% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel–including the extent of fission product release and the evolution of kernel and coating microstructures–was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of 110mAg from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocrabon and compact matrix. The capsule-average fractional release from the compacts was 1×10 4 to 5×10 4 for 154Eu and 8×10 7 to 3×10 5 for 90Sr. The average 134Cs release from compacts was <3×10 6 when all particles maintained intact SiC. An estimated four particles out of 2.98×105 experienced partial cesium release due to SiC failure during the irradiation, driving 134Cs release in two capsules to approximately 10 5. Identification and characterization of these particles has provided unprecedented insight into the nature and causes of SiC coating failure in high-quality TRISO fuel. In general, changes in coating morphology were found to be dominated by the behavior of the buffer and inner pyrolytic carbon (IPyC), and infrequently observed SiC layer damage was usually related to cracks in the IPyC. Palladium attack of the SiC layer was relatively minor, except for the particles that released cesium during irradiation, where SiC corrosion was found adjacent to IPyC cracks. Palladium, silver, and uranium were found in the SiC layer of irradiated particles, and characterization

  11. Microstructural evolution under high temperature irradiation: fundamental aspects

    International Nuclear Information System (INIS)

    Martin, G.; Valentin, P.

    1984-01-01

    In view of the impossibility to propose theoretically established scaling laws for extrapolating microstructural evolutions to unknown irradiation conditions, a full modelization of microstructural evolution at the atomistic level cannot be avoided. We briefly review the main models available for describing: defect balance under irradiation, the nucleation of clusters of various types, the development of each of the components of the microstructure, synergistic effects among the latter. Attention is called on the problems which remain to be solved at each step. In particular, the swelling incubation phenomenon is just being studied from the fundamental viewpoint. A table of available relevant observations thereof is given. The existence of dose-rate thresholds accross which microstructural evolution undergoes a qualitative change is stressed. Such thresholds call for a detailed modelization of microstructural evolution in order to propose safe extrapolation techniques [fr

  12. Irradiation performance of AGR-1 high temperature reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul A., E-mail: paul.demkowicz@inl.gov [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Hunn, John D. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States); Ploger, Scott A. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Morris, Robert N.; Baldwin, Charles A. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States); Harp, Jason M.; Winston, Philip L. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Gerczak, Tyler J. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States); Rooyen, Isabella J. van [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Montgomery, Fred C.; Silva, Chinthaka M. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States)

    2016-09-15

    Highlights: • Post-irradiation examination was performed on AGR-1 coated particle fuel. • Cesium release from the particles was very low in the absence of failed SiC layers. • Silver release was often substantial, and varied considerably with temperature. • Buffer and IPyC layers were found to play a key role in TRISO coating behavior. • Fission products palladium and silver were found in the SiC layer of particles. - Abstract: The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.6% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel including the extent of fission product release and the evolution of kernel and coating microstructures was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of {sup 110m}Ag from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocarbon and compact matrix. The capsule-average fractional release from the compacts was 1 × 10{sup −4} to 5 × 10{sup −4} for {sup 154}Eu and 8 × 10{sup −7} to 3 × 10{sup −5} for {sup 90}Sr. The average {sup 134}Cs fractional release from compacts was <3 × 10{sup −6} when all particles maintained intact SiC. An estimated four particles out of 2.98 × 10{sup 5} in the experiment experienced partial cesium release due to SiC failure during the irradiation, driving {sup 134}Cs fractional release in two capsules to approximately 10{sup −5}. Identification and characterization of these particles has provided unprecedented insight into

  13. Use of TRIGA-pulsed irradiations for high-temperature Doppler measurements

    Energy Technology Data Exchange (ETDEWEB)

    Foell, W K; Cashwell, R J; Bhattacharyya, S K [Argonne National Laboratory, Argonne, IL (United States); Russell, G J [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1974-07-01

    Conventional activation and reactivity measurements of the nuclear Doppler Effect have been limited to temperatures of about 2000{sup o}K because of problems with furnace equipment. There is a need for Doppler data at higher temperatures for design of reactors and analysis of reactor accidents. To fill this need, a novel technique using pulsed-mode operation of a TRIGA reactor has been developed at the University of Wisconsin. This new method, the Pulsed Activation Doppler (PAD) technique, has been used successfully for high temperature Doppler measurements of UO{sub 2} fuel pellets. In the PAD technique, UO{sub 2} test pellets were doped with varying amounts of U-235, with fissile enrichments varying from 0.22% to 12% by weight. The pellets were encapsulated in individual irradiation cells and electrically preheated to predetermined temperatures. Pyrofoam-graphite heaters were used to give preheat temperatures of up to 1720 deg. K. The cells were then positioned in the University of Wisconsin TRIGA reactor core and pulse-irradiated. During the rapid irradiation, adiabatic fission energy deposition occurred in the pellets and very high temperatures (over 3115 deg, K) were attained. Corresponding resonance neutron captures occurred at the elevated temperatures. The Doppler Ratio was deduced from the gamma activities of the Np-239 in the heated and unheated reference pellets. UO{sub 2} pellets of two nominal diameters, 210 mils (a surface-to-mass ratio, s/m = 1.1 cm{sup 2} /gm) and 360 mils (s/m = 0.63 cm{sup 2}/gm), were used for the experiments. For the 210 mil diameter pellets there was very good agreement between experimental results and Doppler ratios predicted both from extrapolations of the Hellstrand low-temperature resonance integral correlations and from GAROL calculations. Significantly, the agreement was good even for those pellets which experienced extensive melting. For the 360 mil diameter pellets the theoretical predictions were 10-15% lower than

  14. Neutron irradiation facility and its characteristics

    International Nuclear Information System (INIS)

    Oyama, Yukio; Noda, Kenji

    1995-01-01

    A neutron irradiation facility utilizing spallation reactions with high energy protons is conceived as one of the facilities in 'Proton Engineering center (PEC)' proposed at JAERI. Characteristics of neutron irradiation field of the facility for material irradiation studies are described in terms of material damage parameters, influence of the pulse irradiation, irradiation environments other than neutronics features, etc., comparing with the other sorts of neutron irradiation facilities. Some perspectives for materials irradiation studies using PEC are presented. (author)

  15. Array-type sensor to determine corrosive conditions in high temperature water under gamma rays irradiation

    International Nuclear Information System (INIS)

    Satoh, T.; Tsukada, T.; Uchida, S.; Katoh, C.

    2010-01-01

    One of the problems to determine electrochemical corrosion potential (ECP) in high temperature water under irradiation is to apply long-lived and reliable reference electrodes. In order to avoid troubles due to the reference electrode, a new concept to determine ECP without the reference electrode has been proposed. Several metal plates are applied as working electrodes and at the same time as the reference electrodes. Potential of the metal plates with stable oxide films on their surfaces show stable values in high temperature water. As a result of the combination of their potential values, ECP of each metal can be determined without any specific reference electrode. Array-type sensors consisting of several metal plates, e.g., Fe, Ni, Cr, Zr, Pt, Pd, Re, Ir, with well developed oxide films on their surface were prepared for ECP measurement in high temperature water under neutron/gamma ray irradiations. In order to confirm the feasibility of this concept, responses of the redox potentials of the pure metals to changes in the simulated BWR reactor water conditions were measured and the ECP was determined by the differences in potentials between a couple of metal plates. Major conclusions of the study are as follows: 1) The redox potentials of the Fe, Pt, Zr, Ir, Pd, and Re electrodes showed the different dependences on the changes in O 2 and H 2 O 2 concentrations. The redox potentials of the electrodes increased as the oxidant concentrations increased except for Zr electrode. The potential of the Zr electrode was kept the very low potential at the wide range of O 2 and H 2 O 2 concentrations differed form the other electrodes. 2) It was estimated that the redox potential of highly soluble metal may be increased, while that of low soluble metal may be decreased by an oxide film. The stable oxide film would cause the stable potential response of the electrode with oxide film. 3) The relationship between the oxidant concentrations and the redox potentials of the

  16. Is uranium dioxide a glass at high temperature: the reason for its irradiation resistance?

    International Nuclear Information System (INIS)

    Desgranges, Lionel

    2008-01-01

    Electronic intrinsic carriers are shown to have some influence on UO 2 high temperature properties. The physical nature of these carriers, called polarons, is discussed and it is proposed that they could correspond to quasi-broken bonds, in a similar way to intrinsic electronic defects in SiO 2 . It is shown that this hypothesis provides an explanation, at least qualitative, for UO 2 specific behavior at high temperature and under irradiation. (author)

  17. An investigation of high-temperature irradiation test program of new ceramic materials

    International Nuclear Information System (INIS)

    Ishino, Shiori; Terai, Takayuki; Oku, Tatsuo

    1999-08-01

    The Japan Atomic Energy Research Institute entrusted the Atomic Energy Society of Japan with an investigation into the trend of irradiation processing/damage research on new ceramic materials. The present report describes the result of the investigation, which was aimed at effective execution of irradiation programs using the High Temperature Engineering Test Reactor (HTTR) by examining preferential research subjects and their concrete research methods. Objects of the investigation were currently on-going preliminary tests of functional materials (high-temperature oxide superconductor and high-temperature semiconductor) and structural materials (carbon/carbon and SiC/SiC composite materials), together with newly proposed subjects of, e.g., radiation effects on ceramics-coated materials and super-plastic ceramic materials as well as microscopic computer simulation of deformation and fracture of ceramics. These works have revealed 1) the background of each research subject, 2) its objective and significance from viewpoints of science and engineering, 3) research methodology in stages from preliminary tests to real HTTR irradiation, and 4) concrete HTTR-irradiation methods which include main specifications of test specimens, irradiation facilities and post-irradiation examination facilities and apparatuses. The present efforts have constructed the important fundamentals in the new ceramic materials field for further planning and execution of the innovative basic research on high-temperature engineering. (author)

  18. Neutrons from Antiproton Irradiation

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael; Petersen, Jørgen B.B.

    the neutron spectrum. Additionally, we used a cylindrical polystyrene loaded with several pairs of thermoluminescent detectors containing Lithium-6 and Lithium-7, which effectively detects thermalized neutrons. The obtained results are compared with FLUKA imulations. Results: The results obtained...... spectrum is very low, and does not pose a problem for radiation therapy. However, the contribution from fast neutrons is much more significant. The dose equivalent contribution from neutrons originate from the patient alone and reaches levels which are found in passive moderated proton therapy. The exact...

  19. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Kulriya, P.K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A.K.; Avasthi, D.K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd 2 Ti 2 O 7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd 2 Ti 2 O 7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd 2 Ti 2 O 7 is readily amorphized at an ion fluence 6 × 10 12 ions/cm 2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 10 13 ions/cm 2 . The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures

  20. Neutron irradiation of seeds 2

    Energy Technology Data Exchange (ETDEWEB)

    1968-10-01

    The irradiation of seeds with the fast neutron of research reactors has been hampered by difficulties in accurately measuring dose and in obtaining repeatable and comparable results. Co-ordinated research under an international program organized by the FAO and IAEA has already resulted in significant improvements in methods of exposing seeds in research reactors and in obtaining accurate dosimetry. This has been accomplished by the development of a standard reactor facility for the neutron irradiation of seeds and standard methods for determining fast-neutron dose and the biological response after irradiation. In this program various divisions of the IAEA and the Joint FAO/IAEA Division co-operate with a number of research institutes and reactor centres throughout the world. Results of the preliminary experiments were reported in Technical Reports Series No. 76, ''Neutron Irradiation of Seeds''. This volume contains the proceedings of a meeting of co-operators in the FAO/IAEA Neutron Seed Irradiation Program and other active scientists in this field. The meeting was held in Vienna from 11 to 15 December 1967. Refs, figs and tabs.

  1. Neutron irradiation of seeds 2

    International Nuclear Information System (INIS)

    1968-01-01

    The irradiation of seeds with the fast neutron of research reactors has been hampered by difficulties in accurately measuring dose and in obtaining repeatable and comparable results. Co-ordinated research under an international program organized by the FAO and IAEA has already resulted in significant improvements in methods of exposing seeds in research reactors and in obtaining accurate dosimetry. This has been accomplished by the development of a standard reactor facility for the neutron irradiation of seeds and standard methods for determining fast-neutron dose and the biological response after irradiation. In this program various divisions of the IAEA and the Joint FAO/IAEA Division co-operate with a number of research institutes and reactor centres throughout the world. Results of the preliminary experiments were reported in Technical Reports Series No. 76, ''Neutron Irradiation of Seeds''. This volume contains the proceedings of a meeting of co-operators in the FAO/IAEA Neutron Seed Irradiation Program and other active scientists in this field. The meeting was held in Vienna from 11 to 15 December 1967. Refs, figs and tabs

  2. Effect of phase instabilities on the correlation of nickel ion and neutron irradiation swelling in solution annealed 316 stainless steel

    International Nuclear Information System (INIS)

    Rowcliffe, A.F.; Lee, E.H.; Sklad, P.S.

    1979-01-01

    Annealed 316 stainless steel specimens were neutron irradiated to establish steady-state microstructures and then subjected to further high temperature irradiations with 4 MeV Ni ions. It is shown that void growth under neutron irradiation is simulated in ion irradiations carried out at approx. 180 0 C above reactor temperature. However, the precipitate microstructure developed during neutron irradiation is unstable during subsequent ion irradiation. As a result, the relative swelling rates at various reactor temperatures are not simulated correctly

  3. Spiral spin state in high-temperature copper-oxide superconductors: Evidence from neutron scattering measurements

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker

    2005-01-01

    An effective spiral spin phase ground state provides a new paradigm for the high-temperature superconducting cuprates. It accounts for the recent neutron scattering observations of spin excitations regarding both the energy dispersion and the intensities, including the "universal" rotation by 45...... model. The form of the exchange interaction function reveals the effects of the Fermi surface, and the unique shape predicts large quantum spin fluctuations in the ground state....

  4. High-temperature irradiation effects on mechnical properties of HTGR graphites

    International Nuclear Information System (INIS)

    Oku, Tatsuo; Eto, Motokuni; Fujisaki, Katsuo

    1978-04-01

    The irradiation effects on stress-strain relation, Young's modulus, tensile strength, bending strength and compressive strength of HTGR graphites were studied in irradiation temperature ranges of 200 - 300 0 C and 800 - 1400 0 C and in neutron fluences up to 7.4 x 10 20 n/cm 2 and 3 x 10 21 n/cm 2 (> 0.18 MeV). Fracture criteria and strain energy to fracture of the unirradiated and the irradiated graphites were also examined. (1) Neutron fluence dependences are similar in Young's modulus, tensile strength and bending strength. (2) The change of compressive strength and of tensile and bending strengths with neutron fluence differ; the former varies with graphite kind. (3) At lower irradiation temperatures the bending fracture strain energy decreases with increasing neutron fluence and at higher irradiation temperatures it increases. (4) The fracture criteria of graphites deviates from the constant strain energy theory (α = 0.5) and the constant strain theory (α = 1), shifting from α asymptotically equals 0.5 to α asymptotically equals 1 with increasing irradiation temperature. (auth.)

  5. Neutron irradiation effects on plasma facing materials

    Science.gov (United States)

    Barabash, V.; Federici, G.; Rödig, M.; Snead, L. L.; Wu, C. H.

    2000-12-01

    This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.

  6. Neutron irradiation effects on plasma facing materials

    International Nuclear Information System (INIS)

    Barabash, V.; Federici, G.; Roedig, M.; Snead, L.L.; Wu, C.H.

    2000-01-01

    This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed

  7. Experimental studies of neutron irradiated uranium dioxide at high temperatures

    International Nuclear Information System (INIS)

    Tanke, R.H.J.

    1990-01-01

    In case of an accident situation, in which the heat of the nuclear fuel can no longer be transferred to coolin water, the temperature of the nuclear fuel ay rise very strongly, so that radioactive fission products may be released, which can ultimately lead to the release of radioactive substances to the environment. In this respect it is important to know more about the release rate of the various fission products and their fuel samples, used in the investigation, were UO-2 spheres of approximately 1 mm. The chemical forms of the particles which are being released from the sphees during evaporation have been determined using a mass spectrometer. At the same time, the activity of the fission products has been measured using a gamma spectrometer. A gamma tomographer has been developed for determining the three-dimensional distribution of the concentration of radioactive fission products in the sphere. With this tomographer the change of this distribution as a function of temperature could be measured. For interpretation of the results two models have been developed: a model of the evaporation of the non-stoichiometric UO-2, and a model of the diffusion of fission products in UO-2. The first model was used to determine the stoichiometry of the sphere while the second has been used to determine the activation energy for the diffusion of the fission products. The main conclusion is that the microstructure of the nuclear fuel has a great effect on both the amount of free oxygen atoms, the release rate and the chemical form of fission products. This microstructure has not been investigated in greater detail so that all other conclusions are of qualitative nature. (author). 111 refs.; 114 figs.; 13 tabs

  8. Hair dosimetry following neutron irradiation.

    Science.gov (United States)

    Lebaron-Jacobs, L; Gaillard-Lecanu, E; Briot, F; Distinguin, S; Boisson, P; Exmelin, L; Racine, Y; Berard, P; Flüry-Herard, A; Miele, A; Fottorino, R

    2007-05-01

    Use of hair as a biological dosimeter of neutron exposure was proposed a few years ago. To date, the (32)S(n,p)(32)P reaction in hair with a threshold of 2.5 MeV is the best choice to determine the fast neutron dose using body activation. This information is essential with regards to the heterogeneity of the neutron transfer to the organism. This is a very important parameter for individual dose reconstruction from the surface to the deeper tissues. This evaluation is essential to the adapted management of irradiated victims by specialized medical staff. Comparison exercises between clinical biochemistry laboratories from French sites (the CEA and COGEMA) and from the IRSN were carried out to validate the measurement of (32)P activity in hair and to improve the techniques used to perform this examination. Hair was placed on a phantom and was irradiated at different doses in the SILENE reactor (Valduc, France). Different parameters were tested: variation of hair type, minimum weight of hair sample, hair wash before measurement, delivery period of results, and different irradiation configurations. The results obtained in these comparison exercises by the different laboratories showed an excellent correlation. This allowed the assessment of a dose-activity relationship and confirmed the feasibility and the interest of (32)P measurement in hair following fast neutron irradiation.

  9. The irradiation behavior of atomized U-Mo alloy fuels at high temperature

    Science.gov (United States)

    Park, Jong-Man; Kim, Ki-Hwan; Kim, Chang-Kyu; Meyer, M. K.; Hofman, G. L.; Strain, R. V.

    2001-04-01

    Post-irradiation examinations of atomized U-10Mo, U-6Mo, and U-6Mo-1.7Os dispersion fuels from the RERTR-3 experiment irradiated in the Advanced Test Reactor (ATR) were carried out in order to investigate the fuel behavior of high uranium loading (8 gU/cc) at a high temperature (higher than 200°C). It was observed after about 40 at% BU that the U-Mo alloy fuels at a high temperature showed similar irradiation bubble morphologies compared to those at a lower temperature found in the RERTR-1 irradiation result, but there was a thick reaction layer with the aluminum matrix which was found to be greatly affected by the irradiation temperature and to a lesser degree by the fuel composition. In addition, the chemical analysis for the irradiated U-Mo fuels using the Electron Probe Micro Analysis (EPMA) method were conducted to investigate the compositional changes during the formation of the reaction product.

  10. Optimizing Neutron Thermal Scattering Effects in very High Temperature Reactors. Final Report

    International Nuclear Information System (INIS)

    Hawari, Ayman

    2014-01-01

    This project aims to develop a holistic understanding of the phenomenon of neutron thermalization in the VHTR. Neutron thermalization is dependent on the type and structure of the moderating material. The fact that the moderator (and reflector) in the VHTR is a solid material will introduce new and interesting considerations that do not apply in other (e.g. light water) reactors. The moderator structure is expected to undergo radiation induced changes as the irradiation (or burnup) history progresses. In this case, the induced changes in structure will have a direct impact on many properties including the neutronic behavior. This can be easily anticipated if one recognizes the dependence of neutron thermalization on the scattering law of the moderator. For the pebble bed reactor, it is anticipated that the moderating behavior can be tailored, e.g. using moderators that consist of composite materials, which could allow improved optimization of the moderator-to-fuel ratio.

  11. Materials irradiation research in neutron science

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Kenji; Oyama, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    Materials irradiation researches are planned in Neutron Science Research Program. A materials irradiation facility has been conceived as one of facilities in the concept of Neutron Science Research Center at JAERI. The neutron irradiation field of the facility is characterized by high flux of spallation neutrons with very wide energy range up to several hundred MeV, good accessibility to the irradiation field, good controllability of irradiation conditions, etc. Extensive use of such a materials irradiation facility is expected for fundamental materials irradiation researches and R and D of nuclear energy systems such as accelerator-driven incineration plant for long-lifetime nuclear waste. In this paper, outline concept of the materials irradiation facility, characteristics of the irradiation field, preliminary technical evaluation of target to generate spallation neutrons, and materials researches expected for Neutron Science Research program are described. (author)

  12. Preparation of the Crosslinked Polyethersulfone Films by High Temperature Electron-Beam Irradiation

    International Nuclear Information System (INIS)

    Li, J.

    2006-01-01

    The aromatic polymers, mainly so called engineering plastics, were famed for the good stability under irradiation. However, high temperature irradiation of the aromatic polymers can result the crosslinked structure, due to the improved molecular mobility. Polyethersulfone (PES) is a wide used engineering plastic because of the high performance and high thermal stability. PES films were irradiated by electron-beam under nitrogen atmosphere above the glass transition temperature and then the covalently crosslinked PES (RX-PES) films were obtained. The irradiations were also performed at ambient temperature for comparison. The network structure formation of the RX-PES films was confirmed by the appearance of the gel, which were measured by soaking the irradiated PES films in the N,N-dimethylformamide (DMF) at room temperature. When the PES films were irradiated to 300 kGy, there was gel appeared. The gel percent increased with the increasing in the absorbed dose, and saturated when the absorbed dose exceeded 1200 kGy. However, there was no gel formed for the PES films irradiated at ambient temperature even to 2250 kGy. The G(S) and G(X) were calculated according to the Y-crosslinking mechanism. The results values are consistent in error range. G(S) of 0.10 and G(X) of 0.23 were obtained. As calculated, almost all the macromolecular radicals produced by chain scission were used for crosslinking. Also, the glass transition temperature of the RX-PES films increased with the increasing in the absorbed doses, while the glass transition temperature of the PES films irradiated at ambient temperature decreased with the increasing in the absorbed doses. The blending films of the PES with FEP or ETFE were prepared and the high temperature irradiation effects were also studies

  13. High-temperature superconductors, as seen through the eyes of neutrons

    Directory of Open Access Journals (Sweden)

    Z. Yamani

    2006-09-01

    Full Text Available   Neutron scattering is proved to be a vital probe in unveiling the magnetic properties of high temperature superconductors (HTSC. Detailed information about the energy and momentum dependence of the magnetic dynamics of HTSC have been obtained directly by this technique. Over the past decade by improving the crystal growth methods, large and high quality single crystals of HTSC, which are essential for a neutron scattering experiment, have become available. The results of neutron scattering measurements on such crystals have considerably enhanced our understanding of the magnetism in HTSC both in the superconducting (SC and normal states. In this review, the neutron scattering results on two main HTSC families, La2-xSrxCuO4 (LSCOx and YBa2CuO3O6+x (YBCO6+x, are considered with an emphasis on the most prominent properties of these materials that are now widely accepted. These include the presence of strong antiferromagnetic (AF fluctuations even in optimally doped region of the phase diagram, neutron resonance peak that scales with SC transition temperature, Tc, incommensurate magnetic fluctuations (stripes, and a pseudogap in the normal state of underdoped materials.

  14. Application of a high-temperature neutron diffraction apparatus to the study of refractory oxides

    International Nuclear Information System (INIS)

    Aldebert, P.; Badie, J.-M.; Buevoz, J.-L.; Roult, G.

    1975-01-01

    A furnace allowing studies of refractory materials by neutron diffraction in situ up to 2500 deg C is described. It is fitted on to a new type of time of flight spectrometer the pulsed source of which is given by a correlation chopper. The advantages of this technique in comparison with fixed-wavelength goniometers are developped. The examination at high temperature of several refractory oxides has been carried out with this experimental device. The thermal expansion curve of α alumina has been established with accuracy up to near the melting point. Several high temperature cristalline forms, X form La 2 O 3 , the tetragonal and cubic ZrO 2 , tetragonal HfO 2 , have been studied. Concerning the latter two, the case of their solid solutions 2MO 2 -M' 2 O 3 (with M=Hf or Zr and M'=La or Y) has also been considered, at room temperature only [fr

  15. Hardness of AISI type 410 martensitic steels after high temperature irradiation via nanoindentation

    Science.gov (United States)

    Waseem, Owais Ahmed; Jeong, Jong-Ryul; Park, Byong-Guk; Maeng, Cheol-Soo; Lee, Myoung-Goo; Ryu, Ho Jin

    2017-11-01

    The hardness of irradiated AISI type 410 martensitic steel, which is utilized in structural and magnetic components of nuclear power plants, is investigated in this study. Proton irradiation of AISI type 410 martensitic steel samples was carried out by exposing the samples to 3 MeV protons up to a 1.0 × 1017 p/cm2 fluence level at a representative nuclear reactor coolant temperature of 350 °C. The assessment of deleterious effects of irradiation on the micro-structure and mechanical behavior of the AISI type 410 martensitic steel samples via transmission electron microscopy-energy dispersive spectroscopy and cross-sectional nano-indentation showed no significant variation in the microscopic or mechanical characteristics. These results ensure the integrity of the structural and magnetic components of nuclear reactors made of AISI type 410 martensitic steel under high-temperature irradiation damage levels up to approximately 5.2 × 10-3 dpa.

  16. New temperature monitoring devices for high-temperature irradiation experiments in the high flux reactor Petten

    Energy Technology Data Exchange (ETDEWEB)

    Laurie, M.; Futterer, M. A.; Lapetite, J. M. [European Commission Joint Research Centre, Institute for Energy, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Fourrez, S. [THERMOCOAX SAS, BP 26, Planquivon, 61438 Flers Cedex (France); Morice, R. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris (France)

    2009-07-01

    Within the European High Temperature Reactor Technology Network (HTR-TN) and related projects a number of HTR fuel irradiations are planned in the High Flux Reactor Petten (HFR), The Netherlands, with the objective to explore the potential of recently produced fuel for even higher temperature and burn-up. Irradiating fuel under defined conditions to extremely high burn-ups will provide a better understanding of fission product release and failure mechanisms if particle failure occurs. After an overview of the irradiation rigs used in the HFR, this paper sums up data collected from previous irradiation tests in terms of thermocouple data. Some research and development work for further improvement of thermocouples and other on-line instrumentation will be outlined. (authors)

  17. Neutron irradiation of bacteriophage λ

    International Nuclear Information System (INIS)

    Bozin, D.; Milosevic, M. . E-mail address of corresponding author: bozinde@vin.bg.ac.yu

    2005-01-01

    Double strand breaks (DSB) are the most dangerous lesions in DNA caused by irradiation, but many other lesions, usually called mutations, have not been clearly identified. These lesions, like DSB, can be the source of serious chromosomal damages and finally - cell death. Growing interest in heavy particles for radiotherapy and radioprotection encourages the search of the molecular basis of their action. In this respect, we chose bacteriophage λ1390 as the model system for the study of consequences of neutron irradiation. This derivative of λ phage possesses an unique ability to reversibly reorganize their genome in response to various selective pressures. The phages were irradiated with 13 Gy of mixed neutrons (7.5 Gy from fast and 5.6 Gy from thermal neutrons) and phages genomes were tested to DSB and mutations. Additionally, the stability of λ capsid proteins were tested. After all tests, we can conclude that, under our conditions, low flux of neutrons does not induce neither DNA strand break or DNA mutation nor the stability of λ capsid proteins. (author)

  18. High temperature deformation behavior, thermal stability and irradiation performance in Grade 92 steel

    Science.gov (United States)

    Alsagabi, Sultan

    The 9Cr-2W ferritic-martensitic steel (i.e. Grade 92 steel) possesses excellent mechanical and thermophysical properties; therefore, it has been considered to suit more challenging applications where high temperature strength and creep-rupture properties are required. The high temperature deformation mechanism was investigated through a set of tensile testing at elevated temperatures. Hence, the threshold stress concept was applied to elucidate the operating high temperature deformation mechanism. It was identified as the high temperature climb of edge dislocations due to the particle-dislocation interactions and the appropriate constitutive equation was developed. In addition, the microstructural evolution at room and elevated temperatures was investigated. For instance, the microstructural evolution under loading was more pronounced and carbide precipitation showed more coarsening tendency. The growth of these carbide precipitates, by removing W and Mo from matrix, significantly deteriorates the solid solution strengthening. The MX type carbonitrides exhibited better coarsening resistance. To better understand the thermal microstructural stability, long tempering schedules up to 1000 hours was conducted at 560, 660 and 760°C after normalizing the steel. Still, the coarsening rate of M23C 6 carbides was higher than the MX-type particles. Moreover, the Laves phase particles were detected after tempering the steel for long periods before they dissolve back into the matrix at high temperature (i.e. 720°C). The influence of the tempering temperature and time was studied for Grade 92 steel via Hollomon-Jaffe parameter. Finally, the irradiation performance of Grade 92 steel was evaluated to examine the feasibility of its eventual reactor use. To that end, Grade 92 steel was irradiated with iron (Fe2+) ions to 10, 50 and 100 dpa at 30 and 500°C. Overall, the irradiated samples showed some irradiation-induced hardening which was more noticeable at 30°C. Additionally

  19. Neutron irradiation effects of iron alloys and ceramics

    International Nuclear Information System (INIS)

    Kuramoto, Eiichi; Takenaka, Minoru; Hasegawa, Masayuki.

    1991-01-01

    Positron annihilation angular correlation measurements have been performed for the neutron irradiated various metals and ceramics in order to obtain the information of the microvoids and positronium formation in them. Positronium (Ps) formation was observed in Nb containing a small amount of oxygen and Fe-15%Cr-16%Ni-0.006%B 10 . In practical steels such as JPCA and JFMS no Ps formation was observed. High temperature deformation might induce microvoids into metals, but the positron annihilation angular correlation measurements could not confirm this. In non-metallic materials neutron irradiated no Ps formation has so far been observed. (author)

  20. High-temperature annealing of proton irradiated beryllium – A dilatometry-based study

    Energy Technology Data Exchange (ETDEWEB)

    Simos, Nikolaos, E-mail: simos@bnl.gov [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Savkliyildiz, Ilyas [Rutgers University (United States)

    2016-08-15

    S−200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 10{sup 20} cm{sup −2} peak fluence and irradiation temperatures in the range of 100–200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation {sup 4}He and {sup 3}H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

  1. Experimental study of pyrolytic boron nitride at high temperature with and without proton and VUV irradiations

    International Nuclear Information System (INIS)

    Balat-Pichelin, M.; Eck, J.; Heurtault, S.; Glénat, H.

    2014-01-01

    Highlights: • New results for the high temperature study of pBN in high vacuum for the heat shield of solar probes. • Physico-chemical behavior of pBN studied up to 1700 K with proton and VUV irradiations. • Rather low effect of synergistic aggressions on the microstructure of pBN material. • The α/ε ratio of pBN coating on C/C measured up to 2200 K is 20% lower than for the C/C itself. - Abstract: In the frame of future exploration missions such as Solar Probe Plus (NASA) and PHOIBOS (ESA), research was carried out to study pyrolytic BN material envisaged as coating for their heat shields. The physico-chemical behavior of CVD pBN at very high temperature with or without hydrogen ions and VUV (Vacuum Ultra-Violet) irradiations was studied in high vacuum together with the in situ measurement of the thermal radiative properties conditioning the thermal equilibrium of the heat shield. Experimental results obtained on massive pBN samples are presented through in situ mass spectrometry and mass loss rate, and post-test microstructural characterization by XRD, SEM, AFM and nano-indentation techniques, some of them leading to mechanical properties. It could be concluded that synergistic effect of high temperature, protons and VUV radiation has an impact on the emission of gaseous species, the mass loss rate and the mechanical properties of the material

  2. Survey report on high temperature irradiation experiment programs for new ceramic materials in the HTTR (High Temperature Engineering Test Reactor). 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    A survey research on status of research activities on new ceramic materials in Japan was carried out under contract between Japan Atomic Energy Research Institute and Atomic Energy Society of Japan. The purpose of the survey is to provide information to prioritize prospective experiments and tests in the HTTR. The HTTR as a high temperature gas cooled reactor has a unique and superior capability to irradiate large-volumed specimen at high temperature up to approximately 800degC. The survey was focused on mainly the activities of functional ceramics and heat resisting ceramics as a kind of structural ceramics. As the result, the report recommends that the irradiation experiment of functional ceramics is feasible to date. (K. Itami)

  3. Neutron diffraction study of high temperature phase of K2SeO4

    International Nuclear Information System (INIS)

    Iwata, Yutaka; Koyano, Nobumitsu; Shibuya, Iwao; Hidaka, Masanori; Okazaki, Atsushi.

    1984-01-01

    The crystal structure of high-temperature phase of K 2 SeO 4 has been determined by means of single crystal neutron diffraction. The space group is P6 3 /mmc of hexagonal system with two formula units per unit cell. The structure is characterized by an averaged dispositions of SeO 4 tetrahedra with one of its Se-O bonds pointing parallel and antiparallel to the hexagonal c-axis in addition to the split distribution of potassium atoms. Heavily distorted distribution of oxygen atoms in SeO 4 is observed in Fourier maps corrersponding to split positions and reorientational motion of tetrahedra. This disordered arrangement is found to have close relation with the room temperature orthorhombic structure. The hexagonal-orthorhombic phase transition of K 2 SeO 4 at 472 0 C is grouped to an order-disorder type. (author)

  4. Development of a neutronic model for the fuel of a high temperature gas reactor type PBMR

    International Nuclear Information System (INIS)

    Oropeza C, I.; Carmona H, R.; Francois L, J. L.

    2008-01-01

    In this work was developed the neutronic model of a fuel sphere of a nuclear reactor of gas of high temperature to modulate of bed of spheres (PBMR), using the Monte Carlo method with the MCNPx code. In order to be able to verify the fuel model constructed in this investigation, it is used a case of reference, based on an international exercise b enchmark . The benchmark report contains the results sent by different international participants for five phases with respect to the high temperature gas reactor (HTR), fed with uranium, plutonium and thorium. In particular, in first stage of benchmark an infinite adjustment of uranium compound fuel spheres is considered unique, with which our results were compared. This first stage considers two cases: cell calculations with spherical external frontier and cell calculations with cubic external frontier. The objective is to identify any increase in the uncertainty, related to the uranium fuel, that is associated with the plutonium and thorium fuels. In order to validate our results, the values of the neutron multiplication factor were taken in account, in cold and in the heat of the moment from the participants who sent their results obtained with Monte Carlo and deterministic calculations. The model of the fuel sphere developed in this work considers a regular distribution of 15000 Triso particles, in a cubic mesh centered within the sphere. For it was necessary to define the step firstly or p itch o f the cubic mesh. Generally, the results obtained by the participants of benchmark and those of this investigation present good agreement, nevertheless, appear some discrepancies, attributed to factors like different libraries of cross sections used, the nature of the solution: Monte Carlo or deterministic, and the difficulty of some participants to model the external frontier condition of reflection. (Author)

  5. Evaluation of Candidate Linear Variable Displacement Transducers for High Temperature Irradiations in the Advanced Test Reactor

    International Nuclear Information System (INIS)

    Knudson, D.L.; Rempe, J.L.; Daw, J.E.

    2009-01-01

    The United States (U.S.) Department of Energy (DOE) designated the Advanced Test Reactor (ATR) as a National Scientific User Facility (NSUF) in April 2007 to promote nuclear science and technology in the U.S. Given this designation, the ATR is supporting new users from universities, laboratories, and industry as they conduct basic and applied nuclear research and development to advance the nation's energy security needs. A fundamental component of the ATR NSUF program is to develop in-pile instrumentation capable of providing real-time measurements of key parameters during irradiation experiments. Dimensional change is a key parameter that must be monitored during irradiation of new materials being considered for fuel, cladding, and structures in next generation and existing nuclear reactors. Such materials can experience significant changes during high temperature irradiation. Currently, dimensional changes are determined by repeatedly irradiating a specimen for a defined period of time in the ATR and then removing it from the reactor for evaluation. The time and labor to remove, examine, and return irradiated samples for each measurement makes this approach very expensive. In addition, such techniques provide limited data (i.e., only characterizing the end state when samples are removed from the reactor) and may disturb the phenomena of interest. To address these issues, the Idaho National Laboratory (INL) recently initiated efforts to evaluate candidate linear variable displacement transducers (LVDTs) for use during high temperature irradiation experiments in typical ATR test locations. Two nuclear grade LVDT vendor designs were identified for consideration - a smaller diameter design qualified for temperatures up to 350 C and a larger design with capabilities to 500 C. Initial evaluation efforts include collecting calibration data as a function of temperature, long duration testing of LVDT response while held at high temperature, and the assessment of changes

  6. Neutron irradiation damage in transition metal carbides

    International Nuclear Information System (INIS)

    Matsui, Hisayuki; Nesaki, Kouji; Kiritani, Michio

    1991-01-01

    Effects of neutron irradiation on the physical properties of light transition metal carbides, TiC x , VC x and NbC x , were examined, emphasizing the characterization of irradiation induced defects in the nonstoichiometric composition. TiC x irradiated with 14 MeV (fusion) neutrons showed higher damage rates with increasing C/Ti (x) ratio. A brief discussion is made on 'cascade damage' in TiC x irradiated with fusion neutrons. Two other carbides (VC x and NbC x ) were irradiated with fission reactor neutrons. The irradiation effects on VC x were not so simple, because of the complex irradiation behavior of 'ordered' phases. For instance, complete disordering was revealed in an ordered phase, 'V 8 C 7 ', after an irradiation dose of 10 25 n/m 2 . (orig.)

  7. Crystal structure and ionic conduction path of solid electrolytic materials by high temperature neutron diffraction method

    International Nuclear Information System (INIS)

    Yashima, Masatomo; Nomura, Katsuhiro

    2005-01-01

    Research of the distribution of oxide ions and the ionic conduction path of bismuth oxide (Bi 2 O 3 ), cerium oxide (CeO 2 ) and lanthanum gallate ((La 0.8 Sr 0.2 )(Ga 0.8 Mg 0.15 Co 0.05 )O 3-δ ) is stated. The high temperature neutron diffraction method, analytical method such as Rietveld method, crystal structure analysis of ionic conductor and MEM (Maximum- Entropy Method) are explained. The nuclear density distribution of oxide ions in bismuth oxide showed so larger distribution in the direction of and than Bi ions that the oxide ions conducted these direction in the crystal. The nuclear density distribution of oxide ions of cerium oxide indicated larger distribution in the direction of than Ce ions and its tendency was remarkable at high temperature. Accordingly, the oxide ions conducted in the direction of and . The oxide ions distribution in lanthanum gallate compound was larger and complicated than positive ions. The oxide ions conducted to by describing an arc between the two stable positions. The nuclear density on the conduction path increased with increasing temperature. This above result corresponded to increase of oxide ion conductivity in the area. (S.Y.)

  8. Accelerator-Based Irradiation Creep of Pyrolytic Carbon Used in TRISO Fuel Particles for the (VHTR) Very High Temperature Reactors

    International Nuclear Information System (INIS)

    Wang, Lumin; Was, Gary

    2010-01-01

    Pyrolytic carbon (PyC) is one of the important structural materials in the TRISO fuel particles which will be used in the next generation of gas-cooled very-high-temperature reactors (VHTR). When the TRISO particles are under irradiation at high temperatures, creep of the PyC layers may cause radial cracking leading to catastrophic particle failure. Therefore, a fundamental understanding of the creep behavior of PyC during irradiation is required to predict the overall fuel performance.

  9. Swelling and fracturing of borides under neutron irradiation

    International Nuclear Information System (INIS)

    Krainy, A.G.; Ogorodnikov, V.V.; Grinik, E.U.; Chirko, L.I.; Shinakov, A.A.

    1994-01-01

    The neutron irradiation of high temperature borides, which are included in boron-containing reactor materials, results in high internal stresses, leading to considerable swelling and micro- and macro-fracturing. Experimental results over a large range of temperature and fluences, show a change of damage mechanism for borides within 400-530 C: the macro-cracking with formation of annular and radial cracks is observed below this temperature zone. The accumulation of micro-fractures and the process of gas swelling take place at irradiation temperatures above 530 C. The effect of the high internal stresses is compared to external pressure. 12 refs., 4 figs

  10. Irradiation-induced creep in fuel compacts for high-temperature reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Veringa, H; Blackstone, R [Stichting Energieonderzoek Centrum Nederland, Petten; Loelgen, R

    1977-01-01

    Restrained shrinkage experiments at neutron fluences up to 3 x 10/sup 21/ n cm/sup -2/ DNE in the temperature range 600 to 1200/sup 0/C were performed on three different dummy coated-particle fuel compacts in the high-flux reactor at Petten. The data were evaluated to obtain the steady-state radiation creep coefficient of the compacts. It was found that, for the materials investigated, the creep coefficient is temperature dependent, but no clear relationship with Young's modulus could be established. Under certain conditions this irradiation-induced plasticity influences the elastic properties, with the concomitant increase of the creep coefficient. This effect coincides with the formation and further opening up of cracks due to stresses caused by irradiation-induced shrinkage of matrix material.

  11. Irradiation-induced creep in fuel compacts for high-temperature reactor applications

    International Nuclear Information System (INIS)

    Veringa, H.; Blackstone, R.; Loelgen, R.

    1977-01-01

    Restrained shrinkage experiments at neutron fluences up to 3 x 10 21 n cm -2 DNE in the temperature range 600 to 1200 0 C were performed on three different dummy coated-particle fuel compacts in the high-flux reactor at Petten. The data were evaluated to obtain the steady-state radiation creep coefficient of the compacts. It was found that, for the materials investigated, the creep coefficient is temperature dependent, but no clear relationship with Young's modulus could be established. Under certain conditions this irradiation-induced plasticity influences the elastic properties, with the concomitant increase of the creep coefficient. This effect coincides with the formation and further opening up of cracks due to stresses caused by irradiation-induced shrinkage of matrix material. (author)

  12. Post irradiation characterization of beryllium and beryllides after high temperature irradiation up to 3000 appm helium production in HIDOBE-01

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, A.V., E-mail: fedorov@nrg.eu [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, Petten, 1755 ZG (Netherlands); Til, S. van; Stijkel, M.P. [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, Petten, 1755 ZG (Netherlands); Nakamichi, M. [Japan Atomic Energy Agency, Rokkasho (Japan); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/ Josep Pla, n° 2, Torres Diagonal Litoral, Edificio B3, Barcelona 08019 (Spain)

    2016-01-15

    Titanium beryllides are considered as advanced candidate material for neutron multiplier for the helium cooled pebble bed (HCPB) and/or the water cooled ceramic breeder (WCCB) breeder blankets. In the HIDOBE-01 (HIgh DOse irradiation of BEryllium) experiment, beryllium and beryllide pellets with 5 at% and 7 at% Ti are irradiated at four different target temperatures (T{sub irr}): 425 °C, 525 °C, 650 °C and 750 °C up to the dose corresponding to 3000 appm He production in beryllium. The pellets were supplied by JAEA. During post irradiation examinations the critical properties of volumetric swelling and tritium retention were studied. Both titanium beryllide grades show significantly less swelling than the beryllium grade, with the difference increasing with the irradiation temperature. The irradiation induced swelling was studied by using direct dimensions. Both beryllide grades showed much less swelling as compare to the reference beryllium grade. Densities of the grades were studied by Archimedean immersion and by He-pycnometry, giving indications of porosity formation. While both beryllide grades show no significant reduction in density at all irradiation temperatures, the beryllium density falls steeply at higher T{sub irr}. Finally, the tritium release and retention were studied by temperature programmed desorption (TPD). Beryllium shows the same strong tritium retention as earlier observed in studies on beryllium pebbles, while the tritium inventory of the beryllides is significantly less, already at the lowest T{sub irr} of 425 °C.

  13. Study on neutron irradiation behavior of beryllium as neutron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    More than 300 tons beryllium is expected to be used as a neutron multiplier in ITER, and study on the neutron irradiation behavior of beryllium as the neutron multiplier with Japan Materials Testing Reactor (JMTR) were performed to get the engineering data for fusion blanket design. This study started as the study on the tritium behavior in beryllium neutron reflector in order to make clear the generation mechanism on tritium of JMTR primary coolant since 1985. These experiences were handed over to beryllium studies for fusion study, and overall studies such as production technology of beryllium pebbles, irradiation behavior evaluation and reprocessing technology have been started since 1990. In this presentation, study on the neutron irradiation behavior of beryllium as the neutron multiplier with JMTR was reviewed from the point of tritium release, thermal properties, mechanical properties and reprocessing technology. (author)

  14. Comparative Analysis of Single and Dual Irradiation Pass of Deep Burn High Temperature Reactor Scenario

    International Nuclear Information System (INIS)

    Jeong, Chang Joon; Jo, Chang Keun; Noh, Jae Man

    2012-01-01

    A concept of a deep-burn (DB) of trans uranic (TRU) elements in a high temperature reactor (HTR) has been proposed and studied with a single irradiation pass. However, there is still a significant amount of TRU after burn in an HTR. Therefore, it is necessary to burn more TRU in a fast reactor (FR) with repeated reprocessing such as a pyro-process. In this study, the fuel cycle calculations are performed and the results are compared for a singlepass DB-HHR scenario and a dual-pass sodium-cooled fast reactor (SFR) scenario. For the analysis, front-end and back-end parameters are compared. The calculations were performed by the DANESS (Dynamic Analysis of Nuclear Energy System Strategies), which is an integrated system dynamic fuel cycle analysis code

  15. Structural properties and neutron irradiation effects of ceramics

    International Nuclear Information System (INIS)

    Yano, Toyohiko

    1994-01-01

    In high temperature gas-cooled reactors and nuclear fusion reactors being developed at present, various ceramics are to be used in the environment of neutron irradiation for undertaking important functions. The change of the characteristics of those materials by neutron irradiation must be exactly forecast, but it has been known that the response of the materials is different respectively. The production method of ceramics and the resulted structures of ceramics which control their characteristics are explained. The features of covalent bond and ionic bond, the synthesis of powder and the phase change by heating, sintering and sintering agent, and grain boundary phase are described. The smelling of ceramics by neutron irradiation is caused by the formation of the clusters of Frenkel defects and minute spot defects. Its restoration by annealing is explained. The defects remaining in materials after irradiation are the physical defects by flipping atoms cut due to the collision with high energy particles and the chemical defects by nuclear transformation. Some physical defects can be restored, but chemical defects are never restored. The mechanical properties of ceramics and the effect of irradiation on them, and the thermal properties of ceramics and the effect of irradiation on them are reported. (K.I.)

  16. Neutronic behavior of thorium fuel cycles in a very high temperature hybrid system

    International Nuclear Information System (INIS)

    Rodriguez Garcia, Lorena; Milian Perez, Daniel; Garcia Hernandez, Carlos; Milian Lorenzo, Daniel; Velasco, Abanades

    2013-01-01

    Nuclear energy needs to guarantee four important issues to be successful as a sustainable energy source: nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. Pebble bed reactors (PBR), which are very high temperature systems together with fuel cycles based in Thorium, they could offer the opportunity to meet the sustainability demands. Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. This paper shows the main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a variety of fuel cycles with Thorium (Th+U 233 , Th+Pu 239 and Th+U). The parameters related to the neutronic behavior like deep burn, nuclear fuel breeding, Minor Actinide stockpile, power density profiles and other are used to compare the fuel cycles using the well-known MCNPX computational code. (author)

  17. Neutronic behavior of thorium fuel cycles in a very high temperature hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Garcia, Lorena; Milian Perez, Daniel; Garcia Hernandez, Carlos; Milian Lorenzo, Daniel, E-mail: dperez@instec.cu, E-mail: cgh@instec.cu, E-mail: dmilian@instec.cu [Higher Institute of Technologies and Applied Sciences, Havana (Cuba); Velasco, Abanades, E-mail: abanades@etsii.upm.es [Department of Simulation of Thermo Energy Systems, Polytechnic University of Madrid (Spain)

    2013-07-01

    Nuclear energy needs to guarantee four important issues to be successful as a sustainable energy source: nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. Pebble bed reactors (PBR), which are very high temperature systems together with fuel cycles based in Thorium, they could offer the opportunity to meet the sustainability demands. Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. This paper shows the main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a variety of fuel cycles with Thorium (Th+U{sup 233}, Th+Pu{sup 239} and Th+U). The parameters related to the neutronic behavior like deep burn, nuclear fuel breeding, Minor Actinide stockpile, power density profiles and other are used to compare the fuel cycles using the well-known MCNPX computational code. (author)

  18. Application of neutron diffraction in characterization of texture evolution during high-temperature creep in magnesium alloys

    International Nuclear Information System (INIS)

    Sediako, A.; Shook, S.; Vogel, S.; Sediako, D.

    2010-01-01

    A good combination of room-temperature and elevated temperature strength and ductility, good salt-spray corrosion resistance and excellent diecastability are frequently among the main considerations in development of a new magnesium alloy for automotive industry. Unfortunately, there has been much lesser effort in development of wrought-stock alloys for high temperature applications. Extrudability and high temperature performance of wrought material become important factors in an effort to develop new wrought alloys and processing technologies. This paper shows some results received in creep testing and studies of in-creep texture evolution for several wrought magnesium alloys developed for use in elevated- temperature applications. Along with others 'traditional' characterization techniques of metals' performance in high- temperature creep, neutron diffraction was employed in this study to analyze evolution of crystallographic texture during creep deformation. The paper compares two methods of texture analysis in neutron diffraction studies: based on monochromatic (reactor-source) beam and white neutron beam (time-of-flight method, synchrotron). The time-of-flight (TOF) spectrometer illuminates the sample with a non-filtered beam of neutrons and captures the readings with an encircled detector array. This provides a very fast and detailed picture of the crystallographic texture for the bulk of the sample. As the white beam retains all neutron wavelengths, it takes much less time to collect statistically-valid dataset for the diffraction pattern. On the other hand, the monochromatic beam setup includes a monochromatic crystal that filters out a specific wavelength. The diffracted beam is then captured by a much simpler neutron detector. This setup is more flexible, allowing for choosing various wavelengths (depending on the sample material) but obviously requiring more time for statistically viable data collection. These studies were performed using E3 neutron

  19. HIGH-TEMPERATURE SAFETY TESTING OF IRRADIATED AGR-1 TRISO FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Stempien, John D.; Demkowicz, Paul A.; Reber, Edward L.; Chrisensen, Cad L.

    2016-11-01

    High-Temperature Safety Testing of Irradiated AGR-1 TRISO Fuel John D. Stempien, Paul A. Demkowicz, Edward L. Reber, and Cad L. Christensen Idaho National Laboratory, P.O. Box 1625 Idaho Falls, ID 83415, USA Corresponding Author: john.stempien@inl.gov, +1-208-526-8410 Two new safety tests of irradiated tristructural isotropic (TRISO) coated particle fuel have been completed in the Fuel Accident Condition Simulator (FACS) furnace at the Idaho National Laboratory (INL). In the first test, three fuel compacts from the first Advanced Gas Reactor irradiation experiment (AGR-1) were simultaneously heated in the FACS furnace. Prior to safety testing, each compact was irradiated in the Advanced Test Reactor to a burnup of approximately 15 % fissions per initial metal atom (FIMA), a fast fluence of 3×1025 n/m2 (E > 0.18 MeV), and a time-average volume-average (TAVA) irradiation temperature of about 1020 °C. In order to simulate a core-conduction cool-down event, a temperature-versus-time profile having a peak temperature of 1700 °C was programmed into the FACS furnace controllers. Gaseous fission products (i.e., Kr-85) were carried to the Fission Gas Monitoring System (FGMS) by a helium sweep gas and captured in cold traps featuring online gamma counting. By the end of the test, a total of 3.9% of an average particle’s inventory of Kr-85 was detected in the FGMS traps. Such a low Kr-85 activity indicates that no TRISO failures (failure of all three TRISO layers) occurred during the test. If released from the compacts, condensable fission products (e.g., Ag-110m, Cs-134, Cs-137, Eu-154, Eu-155, and Sr-90) were collected on condensation plates fitted to the end of the cold finger in the FACS furnace. These condensation plates were then analyzed for fission products. In the second test, five loose UCO fuel kernels, obtained from deconsolidated particles from an irradiated AGR-1 compact, were heated in the FACS furnace to a peak temperature of 1600 °C. This test had two

  20. New facility for post irradiation examination of neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Ishitsuka, Etsuo; Kawamura, Hiroshi

    1995-01-01

    Beryllium is expected as a neutron multiplier and plasma facing materials in the fusion reactor, and the neutron irradiation data on properties of beryllium up to 800 degrees C need for the engineering design. The acquisition of data on the tritium behavior, swelling, thermal and mechanical properties are first priority in ITER design. Facility for the post irradiation examination of neutron irradiated beryllium was constructed in the hot laboratory of Japan Materials Testing Reactor to get the engineering design data mentioned above. This facility consist of the four glove boxes, dry air supplier, tritium monitoring and removal system, storage box of neutron irradiated samples. Beryllium handling are restricted by the amount of tritium;7.4 GBq/day and 60 Co;7.4 MBq/day

  1. Release behavior of fission products from irradiated dispersion fuels at high temperatures

    International Nuclear Information System (INIS)

    Iwai, Takashi; Shimizu, Michio; Nakagawa, Tetsuya

    1990-02-01

    As a framework of reduced enrichment fuel program of JMTR Project, the measurements of fission products release rates at high temperatures (600degC - 1100degC) were performed in order to take the data to use for safety evaluation of LEU fuel. Three type miniplates of dispersion silicide and aluminide fuel, 20% enrichment LEU fuel with 4.8 gU/cc (U 3 Si 2 90 %, USi 10 % and U 3 Si 2 50 %, U 3 Si 50 % dispersed in aluminium) and 45 % enrichment MEU fuel with 1.6 gU/cc, were irradiated in JMTR. The burnups attained by one cycle (22 days) irradiation were within 21.6 % - 22.5 % of initial 235 U. The specimens cut down from miniplates were measured on fission products release rates by means of new apparatus specially designed for this experiment. The specimens were heated up within 600degC - 1100degC in dry air. Then fission products such as 85 Kr, 133 Xe, 131 I, 137 Cs, 103 Ru, 129m Te were collected at each temperature and measured on release rates. In the results of measurement, the release rates of 85 Kr, 133 Xe, 131 I, 129m Te from all specimens were slightly less than that of G.W. Parker's data on U-Al alloy fuel. For 137 Cs and 103 Ru from a silicide specimen (U 3 Si 2 90 %, USi 10 % dispersed in aluminium) and 137 Cs from an aluminide specimen, the release rates were slightly higher than that of G.W. Parker's. (author)

  2. EPR of alanine irradiated by neutrons

    International Nuclear Information System (INIS)

    Pivovarov, S.P.; Seredavina, T.A.; Zhdanov, S.V.; Mul'gin, S.I.; Zhakparov, R.K.

    2001-01-01

    In the work the first results of EPR studies of alanine, irradiated with diverse doses at neutron cyclotron generator different conditions and on the critical reactor stand are presented. A dose linearity dependence of EPR signal is observing, the methods of γ-background contribution separation are discussed. Obtain results is giving the basis to recommendation of alanine as an effective detector irradiation. However it is demanded the farther study on clarification of radiation sensitivity value dependence on the neutron energy spectrum form

  3. Polarizing neutron by light-irradiated graphene

    International Nuclear Information System (INIS)

    Peng, Feng

    2015-01-01

    We study the spin orientation of the neutron scattered by light-irradiated graphene and calculate the average value of spin z-component of the neutron in terms of a generating functional technique. Our calculation results indicate that there is a remarkable neutron polarization effect when a neutron penetrates graphene irradiated by a circularly polarized light. We analyse the dynamical source of generating this effect from the aspect of photon-mediated interaction between the neutron spin and valley pseudospin. By comparing with the polarization induced by a magnetic field, we find that this polarization may be equivalent to the one led by a magnetic field of several hundred Teslas if the photon frequency is in the X-ray frequency range. This provides an approach of polarizing neutrons. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Development of ODS ferritic-martensitic steels for application to high temperature and irradiation environment

    International Nuclear Information System (INIS)

    Lambard, V.

    2000-01-01

    Iron oxide dispersion strengthened alloys are candidate for nuclear fuel cladding. Therefore, it is crucial to control their microstructure in order to optimise their mechanical properties at temperatures up to 700 deg C. The industrial candidates, ODS ferritic alloys, present an anisotropic microstructure which induces a weakening of mechanical properties in transversal direction as well as the precipitation of brittle phases under thermal aging and irradiation. For this purpose, we tried to develop a material with isotropic properties. We studied several 9Cr-1Mo ferritic/martensitic alloys, strengthened or not by oxide dispersion. The mechanical alloying was performed by attribution and powders were consolidated by hot extrusion. In this work, different metallurgical characterisation techniques and modelling were used to optimise a new martensitic ODS alloy. Microstructural and chemical characterization of matrix has been done. The effect of austenitizing and isochronal tempering treatments on microstructure and hardness has been studied. Oxide distribution, size and chemical composition have been studied before and after high temperature thermal treatment. The study of phase transformation upon heating has permitted the extrapolation to the equilibrium temperature formation of austenite. Phase transformation diagrams upon cooling have been determined and the transformation kinetics have been linked to austenite grain size by a simple relation. Fine grain size is unfavourable for the targeted application, so a particular thermal treatment inducing a coarser grain structure has been developed. Finally, tensile properties have been determined for the different microstructures. (author)

  5. Neutron analysis of the fuel of high temperature nuclear reactors; Analisis neutronico del combustible de reactores nucleares de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Bastida O, G. E.; Francois L, J. L., E-mail: gbo729@yahoo.com.mx [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)

    2014-10-15

    In this work a neutron analysis of the fuel of some high temperature nuclear reactors is presented, studying its main features, besides some alternatives of compound fuel by uranium and plutonium, and of coolant: sodium and helium. For this study was necessary the use of a code able to carry out a reliable calculation of the main parameters of the fuel. The use of the Monte Carlo method was convenient to simulate the neutrons transport in the reactor core, which is the base of the Serpent code, with which the calculations will be made for the analysis. (Author)

  6. Positron lifetime study of neutron-irradiated molybdenum

    International Nuclear Information System (INIS)

    Hinode, Kenji; Tanigawa, Shoichiro; Kumakura, Hiroaki; Doyama, Masao; Shiraishi, Kensuke.

    1978-01-01

    Annealing behavior of fast-neutron-irradiated molybdenum was studied by means of positron lifetime technique. It was found that Stage III annealing can be mainly identified as the vacancy migration process from the detailed analyses of data. The void growth after successive high temperature annealings was clearly detected through the changes of positron lifetime parameters. An attempt to analyse the size distribution of voids from positron lifetime spectra was presented, and discussions on the evaluation of void concentration from positron data are also given. (author)

  7. An investigation of neutron irradiation test on superplastic zirconia-ceramic materials

    International Nuclear Information System (INIS)

    Shibata, Taiju; Ishihara, Masahiro; Baba, Shinichi; Hayashi, Kimio

    2000-05-01

    A neutron irradiation test on superplastic ceramic materials at high temperature has been proposed as an innovative basic research on high-temperature engineering using the High Temperature Engineering Test Reactor (HTTR). For the effective execution of the test, we reviewed the superplastic deformation mechanism of ceramic materials and discussed neutron irradiation effects on the superplastic deformation process of stabilized Tetragonal Zirconia Polycrystal (TZP), which is a representative superplastic ceramic material. As a result, we pointed out that the decrease in the activation energy for superplastic deformation is expected by the radiation-enhanced diffusion. We selected a fast neutron fluence of 5x10 20 n/cm 2 and an irradiation temperature of about 600degC as test conditions for the first irradiation test on TZP and decided to perform a preliminary irradiation test by the Japan Materials Testing Reactor (JMTR). Moreover, we estimated the radioactivity of irradiated TZP and indicated that it is in the order of 10 10 Bq/g (about 0.3 Ci/g) immediately after irradiation to a thermal neutron fluence of 3x10 20 n/cm 2 and that it decays to about 1/100 in a year. (author)

  8. Proposal of a neutron transmutation doping facility for n-type spherical silicon solar cell at high-temperature engineering test reactor.

    Science.gov (United States)

    Ho, Hai Quan; Honda, Yuki; Motoyama, Mizuki; Hamamoto, Shimpei; Ishii, Toshiaki; Ishitsuka, Etsuo

    2018-05-01

    The p-type spherical silicon solar cell is a candidate for future solar energy with low fabrication cost, however, its conversion efficiency is only about 10%. The conversion efficiency of a silicon solar cell can be increased by using n-type silicon semiconductor as a substrate. This study proposed a new method of neutron transmutation doping silicon (NTD-Si) for producing the n-type spherical solar cell, in which the Si-particles are irradiated directly instead of the cylinder Si-ingot as in the conventional NTD-Si. By using a 'screw', an identical resistivity could be achieved for the Si-particles without a complicated procedure as in the NTD with Si-ingot. Also, the reactivity and neutron flux swing could be kept to a minimum because of the continuous irradiation of the Si-particles. A high temperature engineering test reactor (HTTR), which is located in Japan, was used as a reference reactor in this study. Neutronic calculations showed that the HTTR has a capability to produce about 40t/EFPY of 10Ωcm resistivity Si-particles for fabrication of the n-type spherical solar cell. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Effect of neutron irradiation on vitreous carbon

    International Nuclear Information System (INIS)

    Kurolenkin, E.I.; Virgil'ev, Yu.S.; Chugunova, T.K.

    1989-01-01

    The change in mass (m), volume (V), specific electric resistance (ρ), coefficient of linear thermal expansion (α), dynamic elasticity modulus (E), and limit of bending strength (σ) of vitreous carbon are studied upon neutron irradiation. Samples for study were two forms of vitreous carbon obtained by hardening thermally reactive polymers at 900-1,000 degree K. Phenol-formaldehyde (bakelite lacquer A, Bakelite A) and furfural-phenol-formaldehyde (FM-2) resin were used. They were irradiated in the experimental water - water VVR-M reactor between 360-1,030 degree K. The maximal neutron flux was 1.65·10 21 neut/cm 2 . Neutron irradiation of vitreous carbon led to its shrinkage and accompanied weakening. Shrinkage and weakening of vitreous carbon was decreased with an increase of treatment and irradiation temperatures

  10. A neutron irradiator applied to cancer treatment

    International Nuclear Information System (INIS)

    Campos, Tarcisio P.R.; Andrade, Ana P. de

    2000-01-01

    Cancer and the way of treating it with neutron capture therapy are addressed. This paper discusses also the type of neutron facilities used to treat cancer around the world, as follow: discrete neutron sources, accelerators, and nuclear reactors. The major features of an epithermal neutron irradiation facility applied to BNCT treatment are addressed. The main goal is to give another choice of neutron irradiators to be set in a hospital. The irradiation facility embeds a set of 252 Cf neutron source coupled with a homogeneous mixture of uranium-zirconium hydride alloy containing 8.4 wt % uranium enriched to 20% U 235 . The facility delivers an epithermal neutron beam with low background of fast neutron and gamma rays. The N particle transport code (MCNP-4A) has been used during the simulation in order to achieve the desired configurations and to estimate the multiplication factor, k eff . The present facility loaded with 30 mg of 252 Cf neutron source generates an external beam with an intensity of 10 7 n/cm 2 .s on the spectrum of 4 eV to 40 KeV. The 252 Cf - facility coupled with fissile material was able to amplify the epithermal flux to 10 8 n/cm 2 .s, maintaining the figure-of-merits represented by the ratios of the fast dose and gamma dose in air per epithermal neutron flux closed to those values presented by BMRR, MITR-II and Petten Reactor. The medical irradiation facility loaded with 252 Cf- 235 U can be a choice for BNCT. (author)

  11. Chemical reactions induced by fast neutron irradiation

    International Nuclear Information System (INIS)

    Katsumura, Y.

    1989-01-01

    Here, several studies on fast neutron irradiation effects carried out at the reactor 'YAYOI' are presented. Some indicate a significant difference in the effect from those by γ-ray irradiation but others do not, and the difference changes from subject to subject which we observed. In general, chemical reactions induced by fast neutron irradiation expand in space and time, and there are many aspects. In the time region just after the deposition of neutron energy in the system, intermediates are formed densely and locally reflecting high LET of fast neutrons and, with time, successive reactions proceed parallel to dissipation of localized energy and to diffusion of the intermediates. Finally the reactions are completed in longer time region. If we pick up the effects which reserve the locality of the initial processes, a significant different effect between in fast neutron radiolysis and in γ-ray radiolysis would be derived. If we observe the products generated after dissipation and diffusion in longer time region, a clear difference would not be observed. Therefore, in order to understand the fast neutron irradiation effects, it is necessary to know the fundamental processes of the reactions induced by radiations. (author)

  12. Effect of neutron irradiation on select MAX phases

    International Nuclear Information System (INIS)

    Tallman, Darin J.; Hoffman, Elizabeth N.; Caspi, El’ad N.; Garcia-Diaz, Brenda L.; Kohse, Gordon; Sindelar, Robert L.; Barsoum, Michel W.

    2015-01-01

    Herein we report on the effect of neutron irradiation – of up to 0.1 displacements per atom at 360(20) °C or 695(25) °C – on polycrystalline samples of Ti 3 AlC 2 , Ti 2 AlC, Ti 3 SiC 2 and Ti 2 AlN. Rietveld refinement of X-ray diffraction patterns of the irradiated samples showed irradiation-enhanced dissociation into TiC of the Ti 3 AlC 2 and Ti 3 SiC 2 phases, most prominently in the former. Ti 2 AlN also showed an increase in TiN content, as well as Ti 4 AlN 3 after irradiation. In contrast, Ti 2 AlC was quite stable under these irradiation conditions. Dislocation loops are seen to form in Ti 2 AlC and Ti 3 AlC 2 after irradiation at 360(20) °C. The room temperature electrical resistivity of all samples increased by an order of magnitude after irradiation at 360(20) °C, but only by 25% after 695(25) °C, providing evidence for the MAX phases’ dynamic recovery at temperatures as low at 695(25) °C. Based on these preliminary results, it appears that Ti 2 AlC and Ti 3 SiC 2 are the more promising materials for high-temperature nuclear applications

  13. Analytical and numerical study of graphite IG110 parts in advanced reactor under high temperature and irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jinling, E-mail: Jinling_Gao@yeah.net; Yao, Wenjuan, E-mail: wj_yao@yeah.net; Ma, Yudong

    2016-08-15

    Graphical abstract: An analytical model and a numerical procedure are developed to study the mechanical response of IG-110 graphite bricks in HTGR subjected to high temperature and irradiation. The calculation results show great accordance with each other. Rational suggestions on the calculation and design of the IG-110 graphite structure are proposed based on the sensitivity analyses including temperature, irradiation dimensional change, creep and Poisson’s ratio. - Highlights: • Analytical solution of stress and displacement of IG-110 graphite components in HTGR. • Finite element procedure developed for stress analysis of HTGR graphite component. • Parameters analysis of mechanical response of graphite components during the whole life of the reflector. - Abstract: Structural design of nuclear power plant project is an important sub-discipline of civil engineering. Especially after appearance of the fourth generation advanced high temperature gas cooled reactor, structural mechanics in reactor technology becomes a popular subject in structural engineering. As basic ingredients of reflector in reactor, graphite bricks are subjected to high temperature and irradiation and the stress field of graphite structures determines integrity of reflector and makes a great difference to safety of whole structure. In this paper, based on assumptions of elasticity, side reflector is regarded approximately as a straight cylinder structure and primary creep strain is ignored. An analytical study on stress of IG110 graphite parts is present. Meanwhile, a finite element procedure for calculating stresses in the IG110 graphite structure exposed in the high temperature and irradiation is developed. Subsequently, numerical solution of stress in IG110 graphite structure is obtained. Analytical solution agrees well with numerical solution, which indicates that analytical derivation is accurate. Finally, influence of temperature, irradiation dimensional change, creep and Poisson

  14. A neutron irradiator to perform nuclear activation

    International Nuclear Information System (INIS)

    Zamboni, C. B.; Zahn, G.S.; Figueredo, A. M. G.; Madi, T. F.; Yoriyaz, H.; Lima, R. B.; Shtejer, K.; Dalaqua Jr, L.

    2001-01-01

    The development of appropriate nuclear instrumentation to perform neutron activation analyze (NAA), using thermal and fast neutrons, can be useful to investigate materials outside the reactor premises. Considering this fact, a small size neutron irradiator prototype was developed at IPEN facilities (Instituto de Pesquisas Energeticas e Nucleares - Brazil). Basically, this prototype consists of a cylinder of 1200 mm long and 985 mm diameter (filled with paraffin) with two Am-Be sources (600GBq each) arranged in the longitudinal direction of its geometric center. The material to be irradiated is positioned at a radial direction of the cylinder between the two Am-Be sources. The main advantage of this irradiator is a very stable neutron flux eliminating the use of standard material (measure of the induced activity in the sample by comparative method). This way the process became agile, practical and economic, but quantities at mg levels of samples are necessary to achieve good sensitivity, when the material has a low microscopy neutron cross section. As fast and thermal neutron can be used, the flux distribution, for both, were calculated and the prototype performance is discussed

  15. Irradiation facilities at the advanced neutron source

    International Nuclear Information System (INIS)

    West, C.D.

    1992-01-01

    The Advanced Neutron Source (ANS) is a facility, centered around a new 330MW(f) heavy-water cooled and reflected research reactor, proposed for construction at Oak Ridge. The main scientific justification for the new source is the United States' need for increased capabilities in neutron scattering and other neutron beam research, but the technical objectives of the project also cater for the need to replace the irradiation facilities at the aging High Flux Isotope Reactor and to provide other research capabilities to the scientific community. This document provides a description of the ANS facilities

  16. STATUS OF TRISO FUEL IRRADIATIONS IN THE ADVANCED TEST REACTOR SUPPORTING HIGH-TEMPERATURE GAS-COOLED REACTOR DESIGNS

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, Michael; Petti, D. A.; Palmer, Joe

    2016-11-01

    The United States Department of Energy’s Advanced Reactor Technologies (ART) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is irradiating up to seven low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The experiments will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of several independent capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2) started irradiation in June 2010 and completed in October 2013. The third and fourth experiments have been combined into a single experiment designated (AGR-3/4), which started its irradiation in December 2011 and completed in April 2014. Since the purpose of this experiment was to provide data on fission product migration and retention in the NGNP reactor, the design of this experiment was significantly different from the first two experiments, though the control

  17. Neutron resistant irradiation alloy and usage thereof

    International Nuclear Information System (INIS)

    Okada, Osamu; Nakata, Kiyotomo; Kato, Takahiko.

    1997-01-01

    A neutron irradiation embrittlement-resistant alloy comprising a Ti alloy having an average grain size of 2μm or smaller and containing from 30 to 40wt% of Al is subjected to powder solidification and then to isothermal forging at a forging rate of from 50 to 80% at a temperature range of from 1150 to 1500K. Namely, since the Ti-Al type alloy comprises from 30 to 30wt% of Al, optionally, from 1 to 6% of Mn, from 0.1 to 0.5% of Si, from 4 to 16% of V and the balance of Ti, it has excellent specific strength, high durable temperature and excellent neutron irradiation resistance, and has ductility required as structural materials. Accordingly, if the Ti-Al type alloy excellent in embrittlement resistance to neutron irradiation dimensional stability of materials is applied to constitutional parts of a reactor core of a nuclear reactor and a thermonuclear reactor to be exposed under neutron irradiation, high reliability is provided and the amount of activated materials is reduced by improving the working life of the materials. (N.H.)

  18. Progress report on irradiation experiment on small size specimens in high temperature flux module

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, M.; Jacquet, P.; Chaouadi, R.

    2011-02-15

    This report describes the progress made in IFREC/DEMO Research and Development Program during the year 2010 at SCK/CEN. This task is part of demonstrating the possibility to irradiate small specimens in the HFTM modules that will be used in DEMO. Different small specimens of three candidate materials of DEMO fusion reactor will be irradiated with the objective of validating the specimen geometry and size to reliably characterize the mechanical properties of unirradiated and in future of irradiated materials.

  19. Transmission electron-microscopic studies of structural changes in polycrystalline graphite after high temperature irradiation

    International Nuclear Information System (INIS)

    Platonov, P.A.; Gurovich, B.A.; Shtrombakh, Ya.I.; Karpukhin, V.I.

    1985-01-01

    Transmission electron-microscopic investigation of polycrystalline graphite before and after irradiation is carried out. The direct use of graphite samples after ion thinning, as an inquiry subject is the basic peculiarity of the work. Main structural components of MPG-6 graphite before and after irradiation are revealed, the structural mechanism of the reactor graphite destruction under irradiation is demonstrated. The mean values of L αm and L cm crystallite dimensions are determined. Radiation defects, occuring in some crystallites after irradiation are revealed by the dark-field electron microscopy method

  20. Neutron irradiation induced amorphization of silicon carbide

    International Nuclear Information System (INIS)

    Snead, L.L.; Hay, J.C.

    1998-01-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 x 10 25 n/m 2 . Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (-10.8%), elastic modulus as measured using a nanoindentation technique (-45%), hardness as measured by nanoindentation (-45%), and standard Vickers hardness (-24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C

  1. ATF Neutron Irradiation Program Technical Plan

    Energy Technology Data Exchange (ETDEWEB)

    Geringer, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-03-01

    The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post-irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.

  2. A time-of-flight spectrometer for neutron diffraction under high pressure or at high temperature

    International Nuclear Information System (INIS)

    Roult, G.; Buevoz, J.L.

    1975-01-01

    For high pressure neutron diffraction studies (40 kilobars) the sample is placed in a very thick cell. In order to allow the neutron beam to go through the cell loosing as little intensity as possible, the inner part is kept solid while the external part has some windows facing the incident and reflected beam. The window dimensions are small (a few millimeters wide and a few centimeters long). There are two alternatives: to have the window either in a perpendicular plane or in a plane parallel to the axis. In the first case a fixed wavelength spectrometer can be used but the sample is small and the contribution of the cell to the diffraction pattern is relatively great. In the second case samples can be something like ten times greater and the cell contribution can be eliminated but a fixed wavelength spectrometer cannot be used. Thus the time-of-flight method is very convenient. The second alternative was chosen

  3. Ultra-High Field Magnets for X-Ray and Neutron Scattering using High Temperature Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Winn, Barry L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Broholm, C. [Johns Hopkins Univ., Baltimore, MD (United States); Bird, M. [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab); Breneman, Bruce C. [General Atomics, San Diego, CA (United States); Coffey, Michael [Cryomagnetics, Oak Ridge, TN (United States); Cutler, Roy I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duckworth, Robert C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Erwin, R. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Hahn, Seungyong [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab); Hernandez, Yamali [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Herwig, Kenneth W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holland, Leo D. [General Atomics, San Diego, CA (United States); Lonergan, Kevin M. [Oxford Instruments, Abingdon (United Kingdom); Melhem, Ziad [Oxford Instruments, Abingdon (United Kingdom); Minter, Stephen J. [Cryomagnetics, Oak Ridge, TN (United States); Nelson, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Paranthaman, M. Parans [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pierce, Josh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ruff, Jacob [Cornell Univ., Ithaca, NY (United States); Shen, Tengming [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherline, Todd E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smeibidl, Peter G. [Helmholtz-Zentrum Berlin (HZB), (Germany); Tennant, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); van der Laan, Danko [Advanced Conductor Technologies, LLC, Boulder, CO (United States); Wahle, Robert J. [Helmholtz-Zentrum Berlin (HZB), (Germany); Zhang, Yifei [SuperPower, Inc., Schenectady, NY (United States)

    2017-01-01

    X-ray and neutron scattering techniques are capable of acquiring information about the structure and dynamics of quantum matter. However, the high-field magnet systems currently available at x-ray and neutron scattering facilities in the United States are limited to fields of 16 tesla (T) at maximum, which precludes applications that require and/or study ultra-high field states of matter. This gap in capability—and the need to address it—is a central conclusion of the 2005 National Academy of Sciences report by the Committee on Opportunities in High Magnetic Field Science. To address this gap, we propose a magnet development program that would more than double the field range accessible to scattering experiments. With the development and use of new ultra-high field–magnets, the program would bring into view new worlds of quantum matter with profound impacts on our understanding of advanced electronic materials.

  4. High temperature materials

    International Nuclear Information System (INIS)

    2003-01-01

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  5. Testing of Performance of Optical Fibers Under Irradiation in Intense Radiation Fields, When Subjected to Very High Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Blue, Thomas [The Ohio State Univ., Columbus, OH (United States); Windl, Wolfgang [The Ohio State Univ., Columbus, OH (United States); Dickerson, Bryan [Luna Innovations, Inc. (United States)

    2013-01-03

    The primary objective of this project is to measure and model the performance of optical fibers in intense radiation fields when subjected to very high temperatures. This research will pave the way for fiber optic and optically based sensors under conditions expected in future high-temperature gas-cooled reactors. Sensor life and signal-to-noise ratios are susceptible to attenuation of the light signal due to scattering and absorbance in the fibers. This project will provide an experimental and theoretical study of the darkening of optical fibers in high-radiation and high-temperature environments. Although optical fibers have been studied for moderate radiation fluence and flux levels, the results of irradiation at very high temperatures have not been published for extended in-core exposures. Several previous multi-scale modeling efforts have studied irradiation effects on the mechanical properties of materials. However, model-based prediction of irradiation-induced changes in silica's optical transport properties has only recently started to receive attention due to possible applications as optical transmission components in fusion reactors. Nearly all damage-modeling studies have been performed in the molecular-dynamics domain, limited to very short times and small systems. Extended-time modeling, however, is crucial to predicting the long-term effects of irradiation at high temperatures, since the experimental testing may not encompass the displacement rate that the fibers will encounter if they are deployed in the VHTR. The project team will pursue such extended-time modeling, including the effects of the ambient and recrystallization. The process will be based on kinetic MC modeling using the concept of amorphous material consisting of building blocks of defect-pairs or clusters, which has been successfully applied to kinetic modeling in amorphized and recrystallized silicon. Using this procedure, the team will model compensation for rate effects, and

  6. Testing of Performance of Optical Fibers Under Irradiation in Intense Radiation Fields, When Subjected to High Temperature

    International Nuclear Information System (INIS)

    Blue, Thomas; Windl, Wolfgang; Dickerson, Bryan

    2013-01-01

    The primary objective of this project is to measure and model the performance of optical fibers in intense radiation fields when subjected to very high temperatures. This research will pave the way for fiber optic and optically based sensors under conditions expected in future high-temperature gas-cooled reactors. Sensor life and signal-to-noise ratios are susceptible to attenuation of the light signal due to scattering and absorbance in the fibers. This project will provide an experimental and theoretical study of the darkening of optical fibers in high-radiation and high-temperature environments. Although optical fibers have been studied for moderate radiation fluence and flux levels, the results of irradiation at very high temperatures have not been published for extended in-core exposures. Several previous multi-scale modeling efforts have studied irradiation effects on the mechanical properties of materials. However, model-based prediction of irradiation-induced changes in silica'@@s optical transport properties has only recently started to receive attention due to possible applications as optical transmission components in fusion reactors. Nearly all damage-modeling studies have been performed in the molecular-dynamics domain, limited to very short times and small systems. Extended-time modeling, however, is crucial to predicting the long-term effects of irradiation at high temperatures, since the experimental testing may not encompass the displacement rate that the fibers will encounter if they are deployed in the VHTR. The project team will pursue such extended-time modeling, including the effects of the ambient and recrystallization. The process will be based on kinetic MC modeling using the concept of amorphous material consisting of building blocks of defect-pairs or clusters, which has been successfully applied to kinetic modeling in amorphized and recrystallized silicon. Using this procedure, the team will model compensation for rate effects, and

  7. High-temperature method of rapid separation of In-111 from irradiated silver targets

    International Nuclear Information System (INIS)

    Mazgaj, Z.; Kolaczkowski, A.; Mikulski, J.; Novgorodov, A.F.; Zielinski, A.; Joint Inst. for Nuclear Research, Dubna

    1990-01-01

    A high-temperature method of separation of In-111 from α-particle activated silver targets was developed. The separation is carried out under reduced pressure, in the atmosphere of HCl and H 2 O vapours. Indium-111, adsorbed on a quartz collector, is washed out quantitatively with 0.1 N HCl. The contaminant, Cd-109 (product of decay of In-109), is removed from the preparation by means of ion-exchange chromatography. 4 tabs., 6 refs. (author)

  8. Phase stability of oxide dispersion-strengthened ferritic steels in neutron irradiation

    International Nuclear Information System (INIS)

    Yamashita, S.; Oka, K.; Ohnuki, S.; Akasaka, N.; Ukai, S.

    2002-01-01

    Oxide dispersion-strengthened ferritic steels were irradiated by neutrons up to 21 dpa and studied by microstructural observation and microchemical analysis. The original high dislocation density did not change after neutron irradiation, indicating that the dispersed oxide particles have high stability under neutron irradiation. However, there is potential for recoil resolution of the oxide particles due to ballistic ejection at high dose. From the microchemical analysis, it was implied that some of the complex oxides have a double-layer structure, such that TiO 2 occupied the core region and Y 2 O 3 the outer layer. Such a structure may be more stable than the simple mono-oxides. Under high-temperature irradiation, Laves phase was the predominant precipitate occurring at grain boundaries α phase and χ phase were not observed in this study

  9. Protons in neutron-irradiated and thermochemically reduced MgO crystals doped with lithium impurities

    International Nuclear Information System (INIS)

    Gonzalez, R.; Pareja, R.; Chen, Y.

    1992-01-01

    H - (hydride) ions have been observed in lithium-doped MgO crystals which have been neutron irradiated or thermochemically reduced (TCR). Infrared-absorption measurements have been used to identify the local modes of the H - ions in these crystals. The concentration of the H - ions in the neutron-irradiated crystals is found to be far less than that found in the TCR crystals. The thermal stability of H - and oxygen vacancies in both oxidizing and reducing atmospheres are investigated. The emergence of sharp structures due to OH - ions is attributed to the displacements of substitutional Li + ions, leaving behind unperturbed OH - ions, via a mechanism of rapid radiation-induced diffusion during irradiation in a reactor. Results of neutron-irradiated MgO:Li, which had previously been oxidized at high temperature, are also presented

  10. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Mauro, N. A., E-mail: namauro@noctrl.edu [Department of Physics, North Central College, Naperville, Illinois 60540 (United States); Vogt, A. J. [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Derendorf, K. S. [Mechanical Engineering and Materials Science, Washington University, St. Louis, Missouri 63130 (United States); Johnson, M. L.; Kelton, K. F. [Department of Physics and Institute of Materials Science and Engineering, Washington University, 1 Brookings Drive, St. Louis, Missouri 63130 (United States); Rustan, G. E.; Quirinale, D. G.; Goldman, A. I. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Kreyssig, A. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Division of Materials Sciences and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States); Lokshin, K. A. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Neuefeind, J. C.; An, Ke [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Wang, Xun-Li [Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Ave., Kowloon (Hong Kong); Egami, T. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Physics and Astronomy, Joint Institute for Neutron Sciences, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2016-01-15

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr{sub 64}Ni{sub 36} measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg)

  11. Microscopic neutron investigation of the Abrikosov state of high-temperature superconductors

    International Nuclear Information System (INIS)

    Chang, Johan Juul; Mesot, Joel

    2008-01-01

    Using small angle neutron scattering we have been able to observe for the first time a well-defined vortex lattice (VL) structure both in the hole-doped LSCO and electron-doped NCCO superconductors. Our measurements on optimally doped LSCO reveal the existence of a magnetic field-induced phase transition from a hexagonal to a square coordination of the VL. Various scenarios to explain such phase transition are presented. In NCCO also a clear square VL could be detected, which is unexpectedly kept down to the lowest measurable magnetic fields. (author)

  12. Neutron irradiation of rat embryos in utero

    International Nuclear Information System (INIS)

    Vogel, H.H. Jr.

    1978-01-01

    In the rat radiation is most effective in producing congenital anomalies during the organ-forming period (days 9 to 13), which is approximately equivalent to the 14th to 50th days of human pregnancy. We have exposed female Sprague--Dawley rats on the 18th day of pregnancy to single whole-body doses of fission neutrons (20 to 150 rads). After 20 rads there was a small decrease in body weight which lasted from birth to weaning. During this period 9% of the irradiated rats died compared with 4% of the controls. After 50 rads, 65/275 (23.6%) of the rats died between birth and weaning, and the body-weight loss of the survivors was increased. After 100 rads, 62/133 (47%) died at birth or day 1 and 103/133 (77.4%) died before weaning. A large and significant decrease in body weight persisted in the survivors. After 150 rads of fission neutrons, all 95 rats died within 48 hr of birth. From cross-fostering experiments, we believe this is a direct effect of radiation on the embryos and not an indirect action through the mother or her milk. The LD 50 for the period from birth to weaning is approximately 75 rads of fission neutrons. Studies of organ weight were conducted daily for the first week after birth in an attempt to find the cause of radiation mortality. Body weight of the irradiated animals averaged only about one-half that of the controls. The liver, kidney, brain, and testes of the neutron-irradiated rats weighed significantly less than those of the controls. The weights of the spleen, lungs, duodenum, and stomach were decreased but not significantly. The bone marrow appeared depleted in the irradiated long bones, but the spleen maintained active hematopoiesis 1 to 2 months after neutron exposure

  13. Tritium release from neutron irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik

    1998-01-01

    One of the most important open issues related to beryllium for fusion applications refers to the kinetics of the tritium release as a function of neutron fluence and temperature. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating the beryllium response under neutron irradiation. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from the above mentioned irradiation experiments, trying to elucidate the tritium release controlling processes. In agreement with previous studies it has been found that release starts at about 500-550degC and achieves a maximum at about 700-750degC. The observed release at about 500-550degC is probably due to tritium escaping from chemical traps, while the maximum release at about 700-750degC is due to tritium escaping from physical traps. The consequences of a direct contact between beryllium and ceramics during irradiation, causing tritium implanting in a surface layer of beryllium up to a depth of about 40 mm and leading to an additional inventory which is usually several times larger than the neutron-produced one, are also presented and the effects on the tritium release are discussed. (author)

  14. Lipid and carotenoid production by Rhodotorula glutinis under irradiation/high-temperature and dark/low-temperature cultivation.

    Science.gov (United States)

    Zhang, Zhiping; Zhang, Xu; Tan, Tianwei

    2014-04-01

    The capacity of lipid and carotenoid production by Rhodotorula glutinis was investigated under different irradiation conditions, temperatures and C/N ratios. The results showed that dark/low-temperature could enhance lipid content, while irradiation/high-temperature increased the yields of biomass and carotenoid. The optimum C/N ratio for production was between 80 and 100. A two-stage cultivation strategy was used for lipid and carotenoid production in a 5L fermenter. In the first stage, the maximum biomass reached 28.1g/L under irradiation/high-temperature. Then, the cultivation condition was changed to dark/low-temperature, and C/N ratio was adjusted to 90. After the second stage, the biomass, lipid content and carotenoid reached 86.2g/L, 26.7% and 4.2mg/L, respectively. More significantly, the yields of biomass and lipid were 43.1% and 11.5%, respectively. Lipids contained 79.7% 18C and 16.8% 16C fatty acids by GC analysis. HPLC quantified the main carotenoids were β-carotene (68.4%), torularhodin (21.5%) and torulene (10.1%). Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  15. Six-axis multi-anvil press for high-pressure, high-temperature neutron diffraction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Sano-Furukawa, A., E-mail: sano.asami@jaea.go.jp; Hattori, T. [Quantum Beam Science Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); J-PARC Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Arima, H. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamada, A. [The University of Shiga Prefecture, Shiga 522-8533 (Japan); Tabata, S.; Kondo, M.; Nakamura, A. [Sumitomo Heavy Industries Co., Ltd., Ehime 792-0001 (Japan); Kagi, H.; Yagi, T. [Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

    2014-11-15

    We developed a six-axis multi-anvil press, ATSUHIME, for high-pressure and high-temperature in situ time-of-flight neutron powder diffraction experiments. The press has six orthogonally oriented hydraulic rams that operate individually to compress a cubic sample assembly. Experiments indicate that the press can generate pressures up to 9.3 GPa and temperatures up to 2000 K using a 6-6-type cell assembly, with available sample volume of about 50 mm{sup 3}. Using a 6-8-type cell assembly, the available conditions expand to 16 GPa and 1273 K. Because the six-axis press has no guide blocks, there is sufficient space around the sample to use the aperture for diffraction and place an incident slit, radial collimators, and a neutron imaging camera close to the sample. Combination of the six-axis press and the collimation devices realized high-quality diffraction pattern with no contamination from the heater or the sample container surrounding the sample. This press constitutes a new tool for using neutron diffraction to study the structures of crystals and liquids under high pressures and temperatures.

  16. Fast neutron irradiation and thermal properties of doped nonstoichiometric lithium potassium sulphate crystals

    International Nuclear Information System (INIS)

    Kassem, M.E.; Gomaa, N.G.; El-Khatib, A.M.

    1990-01-01

    The influence of point defects introduced by fast neutron irradiations with neutron fluences up to 1.08 x 10 10 n/cm 2 on the thermal properties of pure and doped Li 1.4 K 0.6 SO 4 single crystals are studied in the vicinity of high temperature phase transition at 705 K. The temperature dependence of specific heat is found to be shifted towards lower temperature with the increase of neutron fluence, and can be affected by the presence of Cu 2+ dopant. The change in the value of the specific heat can be attributed to the presence of internal strain generated inside the crystal. (author)

  17. Thermal Cycling and High Temperature Reverse Bias Testing of Control and Irradiated Gallium Nitride Power Transistors

    Science.gov (United States)

    Patterson, Richard L.; Boomer, Kristen T.; Scheick, Leif; Lauenstein, Jean-Marie; Casey, Megan; Hammoud, Ahmad

    2014-01-01

    The power systems for use in NASA space missions must work reliably under harsh conditions including radiation, thermal cycling, and exposure to extreme temperatures. Gallium nitride semiconductors show great promise, but information pertaining to their performance is scarce. Gallium nitride N-channel enhancement-mode field effect transistors made by EPC Corporation in a 2nd generation of manufacturing were exposed to radiation followed by long-term thermal cycling and testing under high temperature reverse bias conditions in order to address their reliability for use in space missions. Result of the experimental work are presented and discussed.

  18. Hydration of Caffeine at High Temperature by Neutron Scattering and Simulation Studies.

    Science.gov (United States)

    Tavagnacco, L; Brady, J W; Bruni, F; Callear, S; Ricci, M A; Saboungi, M L; Cesàro, A

    2015-10-22

    The solvation of caffeine in water is examined with neutron diffraction experiments at 353 K. The experimental data, obtained by taking advantage of isotopic H/D substitution in water, were analyzed by empirical potential structure refinement (EPSR) in order to extract partial structure factors and site-site radial distribution functions. In parallel, molecular dynamics (MD) simulations were carried out to interpret the data and gain insight into the intermolecular interactions in the solutions and the solvation process. The results obtained with the two approaches evidence differences in the individual radial distribution functions, although both confirm the presence of caffeine stacks at this temperature. The two approaches point to different accessibility of water to the caffeine sites due to different stacking configurations.

  19. High temperature homogenization improves impact toughness of vitamin E-diffused, irradiated UHMWPE.

    Science.gov (United States)

    Oral, Ebru; O'Brien, Caitlin; Doshi, Brinda; Muratoglu, Orhun K

    2017-06-01

    Diffusion of vitamin E into radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) is used to increase stability against oxidation of total joint implant components. The dispersion of vitamin E throughout implant preforms has been optimized by a two-step process of doping and homogenization. Both of these steps are performed below the peak melting point of the cross-linked polymer (homogenization of antioxidant-doped, radiation cross-linked UHMWPE could improve its toughness. We found that homogenization at 300°C for 8 h resulted in an increase in the impact toughness (74 kJ/m 2 compared to 67 kJ/m 2 ), the ultimate tensile strength (50 MPa compared to 43 MPa) and elongation at break (271% compared to 236%). The high temperature treatment did not compromise the wear resistance or the oxidative stability as measured by oxidation induction time. In addition, the desired homogeneity was achieved at a much shorter duration (8 h compared to >240 h) by using high temperature homogenization. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1343-1347, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  20. Study on structural recovery of graphite irradiated with swift heavy ions at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pellemoine, F., E-mail: pellemoi@frib.msu.edu [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Avilov, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Bender, M. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Ewing, R.C. [Dept. of Geological Sciences, Stanford University, Stanford, CA 94305-2115 (United States); Fernandes, S. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Lang, M. [Dept. of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996-2300 (United States); Li, W.X. [Dept. of Geological Sciences, Stanford University, Stanford, CA 94305-2115 (United States); Mittig, W. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Schein, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Severin, D. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Tomut, M. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Laboratory of Magnetism and Superconductivity, National Institute for Materials Physics NIMP, Bucharest (Romania); Trautmann, C. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Dept. of Materials Science, Technische Universität Darmstadt, Darmstadt (Germany); and others

    2015-12-15

    Thin graphite foils bombarded with an intense high-energy (8.6 MeV/u) gold beam reaching fluences up to 1 × 10{sup 15} ions/cm{sup 2} lead to swelling and electrical resistivity changes. As shown earlier, these effects are diminished with increasing irradiation temperature. The work reported here extends the investigation of beam induced changes of these samples by structural analysis using synchrotron X-ray diffraction and transmission electron microscope. A nearly complete recovery from swelling at irradiation temperatures above about 1500 °C is identified.

  1. Radiation damage in stainless steel under varying temperature neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Naoaki [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1998-03-01

    Microstructural evolution of model alloys of 316SS was examined by neutron irradiation at JMTR under cyclic temperature varying condition. In the case of Fe-16Cr-17Ni, formation of interstitial loops and voids are strongly suppressed by varying the temperature from 473K to 673K. By adding Ti as miner element (0.25wt%), however, abnormal accumulation of vacancies (void swelling of 11%dpa at 0.1dpa) was observed. Theoretical analysis standing on the rate theory of defect clustering and simulation irradiation experiments with heavy ions indicates that the vacancy-rich condition which appears temporally during and after changing the temperature from low to high brings these results. It was also shown that only 1 dpa pre-irradiation at low temperature changes swelling behavior at high temperature above several 10 dpa. The understanding of non-steady-state defect processes under temperature varying irradiation is very important to estimate the radiation damage under fusion environment where short-term and long-term temperature variation is expected. (author)

  2. Neutron Spectrum Measurements from Irradiations at NCERC

    Energy Technology Data Exchange (ETDEWEB)

    Jackman, Kevin Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mosby, Michelle A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bredeweg, Todd Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hutchens, Gregory Joe [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); White, Morgan Curtis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-15

    Several irradiations have been conducted on assemblies (COMET/ZEUS and Flattop) at the National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS). Configurations of the assemblies and irradiated materials changed between experiments. Different metallic foils were analyzed using the radioactivation method by gamma-ray spectrometry to understand/characterize the neutron spectra. Results of MCNP calculations are shown. It was concluded that MCNP simulated spectra agree with experimental measurements, with the caveats that some data are limited by statistics at low-energies and some activation foils have low activities.

  3. Molecular weight distribution of electron and γ-ray irradiated PEEK measured by very high temperature GPC

    International Nuclear Information System (INIS)

    Nakahara, H.

    1996-01-01

    Poly(ether ether ketone)(PEEK) films were irradiated with electron beam in air and in helium. Gel fractions of the PEEK samples were determined as the ratio of the weight of insoluble fraction/total weigh by extracting the samples with 1-chloronaphthalene (1-CN) at 260degC. While unirradiated PEEK samples were dissolved in 1-CN completely, PEEK samples highly (10 - 50 MGy) irradiated in air were almost insoluble in the solvent. The weight-average molecular weight M w of soluble fractions of the samples were measured by very high temperature gel permeation chromatography (VHTGPC): it was found that the M w decreases with increasing dose. On the other hand, PEEK samples irradiated in helium gave gel fractions at lower doses (0 - 5 MGy) than in air. The PEEK films were also irradiated with 60 Co γ-rays in the dose range, i.e. from 0 to 5 MGy. The γ-irradiated PEEK samples were completely dissolved in 1-CN at 260degC. Their M w measured by VHTGPC decreases with increasing dose. (author)

  4. Correlation between locally deformed structure and oxide film properties in austenitic stainless steel irradiated with neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Chimi, Yasuhiro, E-mail: chimi.yasuhiro@jaea.go.jp [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kitsunai, Yuji [Nippon Nuclear Fuel Development, 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki 311-1313 (Japan); Kasahara, Shigeki [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chatani, Kazuhiro; Koshiishi, Masato [Nippon Nuclear Fuel Development, 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki 311-1313 (Japan); Nishiyama, Yutaka [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

    2016-07-15

    To elucidate the mechanism of irradiation-assisted stress corrosion cracking (IASCC) in high-temperature water for neutron-irradiated austenitic stainless steels (SSs), the locally deformed structures, the oxide films formed on the deformed areas, and their correlation were investigated. Tensile specimens made of irradiated 316L SSs were strained 0.1%–2% at room temperature or at 563 K, and the surface structures and crystal misorientation among grains were evaluated. The strained specimens were immersed in high-temperature water, and the microstructures of the oxide films on the locally deformed areas were observed. The appearance of visible step structures on the specimens' surface depended on the neutron dose and the applied strain. The surface oxides were observed to be prone to increase in thickness around grain boundaries (GBs) with increasing neutron dose and increasing local strain at the GBs. No penetrative oxidation was observed along GBs or along surface steps. - Highlights: • Visible step structures depend on the neutron dose and the applied strain. • Local strain at grain boundaries was accumulated with the neutron dose. • Oxide thickness increases with neutron dose and local strain at grain boundaries. • No penetrative oxidation was observed along grain boundaries or surface steps.

  5. Neutron irradiation effects in advanced superconductors

    International Nuclear Information System (INIS)

    Yoshida, H.; Kodaka, H.; Miyata, K.; Hayashi, Y.; Atobe, K.

    1988-01-01

    This paper reports the effects of neutron irradiation on superconducting transitions studied by susceptibility and resistivity measurements for A15 type compounds, Laves-phase compounds and oxide superconductors. For A15 superconductors, the transition temperature (T c ) decreased with increasing neutron fluence and showed large drop started at about 5 x 10 18 n/cm 2 (E > 0.1 MeV). Post-irradiation annealing gave recovery of T c , but the behaviors were different for the materials with different composition and microstructure. The Laves-phase compounds showed less degradation than the A15 superconductors. For oxide superconductors very sensitive transition change was observed, including the radiation-induced superconductivity

  6. A standard fission neutron irradiation facility

    International Nuclear Information System (INIS)

    Sahasrabudhe, S.G.; Chakraborty, P.P.; Iyer, M.R.; Kirthi, K.N.; Soman, S.D.

    1979-01-01

    A fission neutron irradiation facility (FISNIF) has been set up at the thermal column of the CIRUS reactor at BARC. The spectrum and the flux have been measured using threshold detectors. The paper describes the setting up of the facility, measurement and application. A concentric cylinder containing UO 2 powder sealed inside surrounds the irradiation point of a pneumatic sample transfer system located in the thermal column of the reactor. Samples are loaded in a standard aluminium capsule with cadmium lining and transported pneumatically. A sample transfer time of 1 s can be achieved in the facility. Typical applications of the facility for studying activation of iron and sodium in fission neutrons are also discussed. (Auth.)

  7. Behaviour of neutron moderator materials at high temperatures in CASTOR registered -casks: qualification and assessment

    International Nuclear Information System (INIS)

    Krietsch, T.; Wolff, D.; Knopp, U.; Brocke, H.D.

    2004-01-01

    The Federal Institute for Materials Research and Testing (BAM) is the responsible German authority for the assessment of mechanical and thermal designs of transport and storage casks for radioactive materials. BAM checks up the proofs of the applicants in their safety reports and assesses the conformity to the Regulations for the Safe Transport of Radioactive Material. One applicant is the Gesellschaft fuer Nuklear-Behaelter mbH (GNB) with a new generation of transport and storage casks of CASTOR registered -design. GNB typically uses ultra high molecular weight Polyethylene (UHMW-PE) for the moderation of free neutrons. Rods made of UHMW-PE are positioned in axial bore holes in the wall of the cask and plates of UHMW-PE are in free spaces between primary and secondary lid and between the bottom of the cask and an outer plate (Figure 1). Because of the heat generated by the radioactive inventory and because of a strained spring at the bottom of every bore hole, UHMW-PE is subjected to permanent thermal and mechanical loads as well as loads from gamma and neutron radiation. UHMW-PE has been used under routine- and normal conditions of transport for maximum temperatures up to 130 C. For new generations of CASTOR registered -design maximum temperatures will be increased up to 160 C. That means a permanent use of UHMW-PE at temperatures within and above the melting region of the crystallites. In this paper, some results of special investigations for the proofs of usability of UHMW-PE at temperatures up to 160 C under real conditions of transport and storage in CASTOR registered -casks are given. For that, investigations on temperature dependent expansion behaviour under laboratory conditions as well as in large scale experiments, especially in the case of multiple heating and cooling, were done. Besides, geometrical creep strength for long-term loading by temperatures and pressures with regard to the chemical and physical stability properties of UHMW-PE above the

  8. Irradiation creep in reactor graphites for HTR applications. [Neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Veringa, H J; Blackstone, R [Stichting Reactor Centrum Nederland, Petten

    1976-01-01

    A series of restrained shrinkage experiments on a number of graphites in the temperature range 400 to 1400/sup 0/C is described. A description is given of the experimental method and method of data evaluation. The results are compared with data from other sources. Analysis of data confirms that the creep coefficient, which is defined as the radiation induced creep strain per unit stress per unit neutron fluence, is inversely proportional to the pre-irradiation value of the Young's modulus of the material. The radiation creep coefficient increases with temperature in the range 400 to 1400/sup 0/C. It can be represented by the sum of two temperature dependent functions, one of which is inversely proportional to the neutron flux density, the other independent of the neutron flux density. When the data are analysed in this way it is found that the graphites investigated in the present work, although made from widely different starting materials and by different processes, show the same dependence of the irradiation creep coefficient on the temperature and the neutron flux density.

  9. Thermal expansion and decomposition of jarosite: a high-temperature neutron diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongwu [Los Alamos National Laboratory; Zhao, Yusheng [Los Alamos National Laboratory; Vogel, Sven C [Los Alamos National Laboratory; Hickmott, Donald D [Los Alamos National Laboratory; Daemen, Luke L [Los Alamos National Laboratory; Hartl, Monika A [Los Alamos National Laboratory

    2009-01-01

    The structure of deuterated jarosite, KFe{sub 3}(SO{sub 4}){sub 2}(OD){sub 6}, was investigated using time-of-flight neutron diffraction up to its dehydroxylation temperature. Rietveld analysis reveals that with increasing temperature, its c dimension expands at a rate {approx}10 times greater than that for a. This anisotropy of thermal expansion is due to rapid increase in the thickness of the (001) sheet of [Fe(O,OH){sub 6}] octahedra and [SO{sub 4}] tetrahedra with increasing temperature. Fitting of the measured cell volumes yields a coefficient of thermal expansion, a = a{sub 0} + a{sub 1} T, where a{sub 0} = 1.01 x 10{sup -4} K{sup -1} and a{sub 1} = -1.15 x 10{sup -7} K{sup -2}. On heating, the hydrogen bonds, O1{hor_ellipsis}D-O3, through which the (001) octahedral-tetrahedral sheets are held together, become weakened, as reflected by an increase in the D{hor_ellipsis}O1 distance and a concomitant decrease in the O3-D distance with increasing temperature. On further heating to 575 K, jarosite starts to decompose into nanocrystalline yavapaiite and hematite (as well as water vapor), a direct result of the breaking of the hydrogen bonds that hold the jarosite structure together.

  10. Random detailed model for probabilistic neutronic calculation in pebble bed Very High Temperature Reactors

    International Nuclear Information System (INIS)

    Perez Curbelo, J.; Rosales, J.; Garcia, L.; Garcia, C.; Brayner, C.

    2013-01-01

    The pebble bed nuclear reactor is one of the main candidates for the next generation of nuclear power plants. In pebble bed type HTRs, the fuel is contained within graphite pebbles in the form of TRISO particles, which form a randomly packed bed inside a graphite-walled cylindrical cavity. Pebble bed reactors (PBR) offer the opportunity to meet the sustainability requirements, such as nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. In order to simulate PBRs correctly, the double heterogeneity of the system must be considered. It consists on randomly located pebbles into the core and TRISO particles into the fuel pebbles. These features are often neglected due to the difficulty to model with MCPN code. The main reason is that there is a limited number of cells and surfaces to be defined. In this study, a computational tool which allows getting a new geometrical model of fuel pebbles for neutronic calculations with MCNPX code, was developed. The heterogeneity of system is considered, and also the randomly located TRISO particles inside the pebble. Four proposed fuel pebble models were compared regarding their effective multiplication factor and energy liberation profiles. Such models are: Homogeneous Pebble, Five Zone Homogeneous Pebble, Detailed Geometry, and Randomly Detailed Geometry. (Author)

  11. High Ni austenite stainless steel resistant to neutron irradiation degradation

    International Nuclear Information System (INIS)

    Yonezawa, Toshio; Iwamura, Toshihiko; Kanasaki, Hiroshi; Fujimoto, Koji; Nakata, Shizuo; Ajiki, Kazuhide; Nakamura, Mitsuhiro.

    1997-01-01

    The composition of the stainless steel of the present invention comprises from 0.005 to 0.08% of C, up to 3% of Mn, up to 0.2% of Si+P+S, from 25 to 40% of Ni, from 25 to 40% of Cr, up to 3% of Mo, up to 0.3% of Nb+Ta, up to 0.3% of Ti, up to 0.001% of B and the balance of Fe. A solid solubilization treatment at a temperature of from 1,000 to 1,150degC is applied to the stainless steel having the composition. The stainless steel is excellent in stress corrosion cracking-resistance at a working circumstance of a LWR type reactor (high temperature and high pressure water at from 270 to 350degC/from 70 to 160 atm even after undergoing neutron irradiation of about 1 x 10 22 n/cm 2 (E>1 MeV) which is a maximum neutron irradiation amount undergone till the final stage of the working life of the LWR-type reactor. In addition, the average thermal expansion coefficient at from room temperature to 400degC ranges from 15x10 -6 - 19x10 -6 /K. (I.N.)

  12. High-Temperature Phase Equilibria of Duplex Stainless Steels Assessed with a Novel In-Situ Neutron Scattering Approach

    Science.gov (United States)

    Pettersson, Niklas; Wessman, Sten; Hertzman, Staffan; Studer, Andrew

    2017-04-01

    Duplex stainless steels are designed to solidify with ferrite as the parent phase, with subsequent austenite formation occurring in the solid state, implying that, thermodynamically, a fully ferritic range should exist at high temperatures. However, computational thermodynamic tools appear currently to overestimate the austenite stability of these systems, and contradictory data exist in the literature. In the present work, the high-temperature phase equilibria of four commercial duplex stainless steel grades, denoted 2304, 2101, 2507, and 3207, with varying alloying levels were assessed by measurements of the austenite-to-ferrite transformation at temperatures approaching 1673 K (1400 °C) using a novel in-situ neutron scattering approach. All grades became fully ferritic at some point during progressive heating. Higher austenite dissolution temperatures were measured for the higher alloyed grades, and for 3207, the temperature range for a single-phase ferritic structure approached zero. The influence of temperatures in the region of austenite dissolution was further evaluated by microstructural characterization using electron backscattered diffraction of isothermally heat-treated and quenched samples. The new experimental data are compared to thermodynamic calculations, and the precision of databases is discussed.

  13. Fission gas release and grain growth in THO2-UO2 fuel irradiated at high temperature

    International Nuclear Information System (INIS)

    Goldberg, I.; Waldman, L.A.; Giovengo, J.F.; Campbell, W.R.

    1979-01-01

    Data are presented on fission gas release and grain growth in ThO 2 -UO 2 fuels irradiated as part of the LWBR fuel element development program. These data for rods that experienced peak linear power outputs ranging from 15 to 22 KW/ft supplement fission gas release data previously reported for 51 rods containing ThO 2 and ThO 2 -UO 2 fuel irradiated at peak linear powers predominantly below 14 KW/ft. Fission gas release was relatively high (up to 15.0 percent) for the rods operated at high power in contrast to the relatively low fission gas release (0.1 to 5.2 percent) measured for the rods operated at lower power. Metallographic examination revealed extensive equiaxed grain growth in the fuel at the high power axial locations of the three rods

  14. Compaction of irradiated fuel can wastes by high temperature melting in cold crucibles

    International Nuclear Information System (INIS)

    Piccinato, R.; Ruty, J.P.; Caraballo, R.; Jacquet-Francillon, N.

    1993-01-01

    The fusion of hull wastes obtained from the reprocessing of various irradiated fuels is an alternative method to the cementation process used for the conditioning of such wastes. This new process, based on the direct fusion of hulls, has been carried out at CEA Marcoule with an inactive industrial prototype and qualified with an active laboratory prototype. The report shows the results obtained with the lab prototype on stainless steel and zircaloy hulls

  15. High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Hamilton, M.L.; Maloy, S.A.

    2003-01-01

    This study examines the effect of tensile test temperatures ranging from 50 to 600 deg. C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 deg. C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 deg. C and then increased for tensile test temperatures up to and including 500 deg. C. At 600 deg. C, the UE was observed to be less than the values at 400 and 500 deg. C. UE of the irradiated material tensile tested at 400-600 deg. C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends

  16. Irradiation behaviour of advanced fuel elements for the helium-cooled high temperature reactor (HTR)

    International Nuclear Information System (INIS)

    Nickel, H.

    1990-05-01

    The design of modern HTRs is based on high quality fuel. A research and development programme has demonstrated the satisfactory performance in fuel manufacturing, irradiation testing and accident condition testing of irradiated fuel elements. This report describes the fuel particles with their low-enriched UO 2 kernels and TRISO coating, i.e. a sequence of pyrocarbon, silicon carbide, and pyrocarbon coating layers, as well as the spherical fuel element. Testing was performed in a generic programme satisfying the requirements of both the HTR-MODUL and the HTR 500. With a coating failure fraction less than 2x10 -5 at the 95% confidence level, the results of the irradiation experiments surpassed the design targets. Maximum accident temperatures in small, modular HTRs remain below 1600deg C, even in the case of unrestricted core heatup after depressurization. Here, it was demonstrated that modern TRISO fuels retain all safety-relevant fission products and that the fuel does not suffer irreversible changes. Isothermal heating tests have been extended to 1800deg C to show performance margins. Ramp tests to 2500deg C demonstrate the limits of present fuel materials. A long-term programm is planned to improve the statistical significance of presently available results and to narrow remaining uncertainty limits. (orig.) [de

  17. Influence of neutron irradiation on etching of SiC in KOH

    Science.gov (United States)

    Mokhov, E. N.; Kazarova, O. P.; Soltamov, V. A.; Nagalyuk, S. S.

    2017-07-01

    The effect of reactor neutron irradiation on the etch rate of SiC in potassium hydroxide has been studied. In the case of high irradiation doses (1019-1021 cm-2), the etch rate of silicon carbide has been shown to drastically rise, especially in the [0001]Si direction. This considerably mitigates the orientation anisotropy of polar face etching. After high-temperature annealing (up to 1200-1400°C), a higher etch rate of irradiated crystals persists. The results have been explained by the high concentration of radiation-induced (partially clustered) defects they contain.

  18. Thermogravimetric analysis of reactor-neutrons-irradiated LEXAN polycarbonate film

    International Nuclear Information System (INIS)

    Kalsi, P.C.

    2000-01-01

    The effects of reactor-neutrons irradiation on the thermogravimetric (TG) analysis of LEXAN polycarbonate film in air were studied. Irradiation enhances the degradation rate and the effect increases further with increasing neutron fluence. The kinetics of the different steps of degradation were also evaluated from the TG curves. The activation energy values calculated for all the degradation stages decrease on irradiation. (author)

  19. The effect of helium generation and irradiation temperature on tritium release from neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Kupriyanov, I.B.; Gorokhov, V.A.; Vlasov, V.V.; Kovalev, A.M.; Chakin, V.P.

    2004-01-01

    The effect of neutron irradiation condition on tritium release from beryllium is described in this paper. Beryllium samples were irradiated in the SM reactor with neutron fluence (E > 0.1 MeV) of (0.37-2.0) x 10 22 cm -2 at 70-100degC and 650-700degC. Mass-spectrometer technique was used in out of tritium release experiments during stepped-temperature anneal within a temperature range from 250 to 1300degC. The total amount of helium accumulated in irradiated beryllium samples varied from 521 appm to 3061 appm. The first signs of tritium release were detected at temperature of 406-553degC. It was shown that irradiation temperature and helium generation level significantly affect the tritium release. A fraction of 44 - 74 % of tritium content in samples irradiated at low temperature (70 - 100degC) is release from beryllium at an annealing temperature below 800degC, whereas for samples after high temperature irradiation (650 - 700 degC) tritium release did not exceed 14 %. Majority of tritium (∼68%) is released within a temperature range from 800 to 920 degC. The increase of helium generation from 521 appm to 3061 appm results in lowering the temperature of maximal tritium release rate and the upper temperature of tritium release from beryllium by 100-130degC and 200-240degC, correspondingly. On the basis of data obtained, the diffusion coefficients of tritium in beryllium were calculated. (author)

  20. Intense neutron irradiation facility for fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Kenji; Oyama, Yukio; Kato, Yoshio; Sugimoto, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    Technical R and D of d-Li stripping type neutron irradiation facilities for development of fusion reactor materials was carried out in Fusion Materials Irradiation Test Facility (FMIT) project and Energy Selective Neutron Irradiation Test Facility (ESNIT) program. Conceptual design activity (CDA) of International Fusion Materials Irradiation Facility (IFMIF), of which concept is an advanced version of FMIT and ESNIT concepts, are being performed. Progress of users` requirements and characteristics of irradiation fields in such neutron irradiation facilities, and outline of baseline conceptual design of IFMIF were described. (author)

  1. Design, Construction, and Modeling of a 252Cf Neutron Irradiator

    Directory of Open Access Journals (Sweden)

    Blake C. Anderson

    2016-01-01

    Full Text Available Neutron production methods are an integral part of research and analysis for an array of applications. This paper examines methods of neutron production, and the advantages of constructing a radioisotopic neutron irradiator assembly using 252Cf. Characteristic neutron behavior and cost-benefit comparative analysis between alternative modes of neutron production are also examined. The irradiator is described from initial conception to the finished design. MCNP modeling shows a total neutron flux of 3 × 105 n/(cm2·s in the irradiation chamber for a 25 μg source. Measurements of the gamma-ray and neutron dose rates near the external surface of the irradiator assembly are 120 μGy/h and 30 μSv/h, respectively, during irradiation. At completion of the project, total material, and labor costs remained below $50,000.

  2. Fast and epithermal neutron radiography using neutron irradiator

    International Nuclear Information System (INIS)

    Oliveira, Karol A.M. de; Crispim, Verginia R.; Ferreira, Francisco J.O.

    2013-01-01

    The neutron radiography technique (NR) with neutrons in the energy range fast to epithermal is a powerful tool used in no-destructive inspection of bulky objects of diverse materials, including those rich in hydrogen, oxygen, nitrogen ad carbon. Thus, it can be used to identify, inclusions, voids and thickness differences in materials such as explosive artifacts and narcotics. Aiming at using NR with fast and epithermal neutrons, an Irradiator was constructed by: a 241 Am-Be source, with 5 Ci activity, a collimator with adjustable collimation rate, L/D; and a shield device composed by plates of borated paraffin and iron. The test specimens chosen were a Beam Purity Indicator (BPI) and an Indicator of Visual Resolution (IVR). The neutron radiography images obtained had a resolution of 444.4 μm and 363.6 μm respectively when registered in: 1) the sheet of the nuclear track solid detector, CR-39 type, through X (n,p) Y nuclear reaction; and 2) Kodak Industrex M radiographic film plate in close contact with a boron converter screen, both stored in a Kodak radiographic cassette. (author)

  3. Detection of 14 MeV neutrons in high temperature environment up to 500 deg. C using 4H-SiC based diode detector

    Energy Technology Data Exchange (ETDEWEB)

    Szalkai, D.; Klix, A. [KIT- Karlsruhe Institute of Technology, Institute of Neutron Physics and Reactor Technology Karlsruhe 76344 (Germany); Ferone, R.; Issa, F.; Ottaviani, L.; Vervisch, V. [IM2NP, UMR CNRS 7334, Aix-Marseille University, Case 231 -13397 Marseille Cedex 20 (France); Gehre, D. [Inst. for Nucl.- and Particle-Phys., Dresden University of Technology, Dresden 01069 (Germany); Lyoussi, A. [CEA, DEN, Departement d' Etudes des Reacteurs, Service de Physique Experimentale, Laboratoire Dosimetrie Capteurs Instrumentation, 13108 Saint-Paul-lez-Durance (France)

    2015-07-01

    In reactor technology and industrial applications detection of fast and thermal neutrons plays a crucial role in getting relevant information about the reactor environment and neutron yield. The inevitable elevated temperatures make neutron yield measurements problematic. Out of the currently available semiconductors 4H-SiC seems to be the most suitable neutron detector material under extreme conditions due to its high heat and radiation resistance, large band-gap and lower cost of production than in case of competing diamond detectors. In the framework of the European I-Smart project, optimal {sup 4}H-SiC diode geometries were developed for high temperature neutron detection and have been tested with 14 MeV fast neutrons supplied by a deuterium-tritium neutron generator with an average neutron flux of 10{sup 10}-10{sup 11} n/(s*cm{sup 2}) at Neutron Laboratory of the Technical University of Dresden in Germany from room temperatures up to several hundred degrees Celsius. Based on the results of the diode measurements, detector geometries appear to play a crucial role for high temperature measurements up to 500 deg. C. Experimental set-ups using SiC detectors were constructed to simulate operation in the harsh environmental conditions found in the tritium breeding blanket of the ITER fusion reactor, which is planned to be the location of neutron flux characterization measurements in the near future. (authors)

  4. High-temperature and high-humidity response of the Eberline Model PRS-2 and the Eberline Model NRD neutron detector

    International Nuclear Information System (INIS)

    McAtee, J.L.

    1981-03-01

    The high-humidity and high-temperature response of the Eberline Model PRS-2 portable scaler-ratemeter and the Eberline Model NRD neutron detector was studied in an environmental chamber. The BF 3 probe used in the NRD detector was found to produce count rate surges at temperatures > 50 0 C and at relative humidity > 50%. The PRS-2 scaler-ratemeter was found to be relatively insensitive to high temperatures and high humidity

  5. High-temperature strength of Nb-1%Zr alloy for irradiation-capsules inner-shell

    International Nuclear Information System (INIS)

    Nomura, Yasushi; Nakata, Hirokatsu; Tanaka, Mitsuo; Fukaya, Kiyoshi.

    1978-04-01

    Coated fuel particles in capsules will be irradiated at about 1600 0 C in JMTR. Nb-1%Zr alloy was chosen for inner shell material of the capsules because of its sufficient strength at 1000 0 C and low induced radioactivity. Nb-1%Zr ingot produced by electron beam melting was formed into seamless tubes by hollowing and swaging, followed by annealing. Creep test in helium flow and tensile test in vacuum were made to examine mechanical strength of the Nb-1%Zr tubes at 1000 0 C. Following are the results; 1) 0.2% yield stress at 1000 0 C is about 6 kg/mm 2 . 2) 3000 hr creep rupture stress at 1000 0 C is about 6 kg/mm 2 . (auth.)

  6. Release of fission products from irradiated aluminide fuel at high temperature

    International Nuclear Information System (INIS)

    Shibata, Toshikazu; Kanda, Keiji; Mishima, Kaichiro; Tamai, Tadaharu; Hayashi, Masatoshi; Snelgrove, James L.; Stahl, David; Matos, James E.; Travelli, Armando; Case, F. Neil; Posey, John C.

    1983-01-01

    Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel cladding material. The release of fission products from the fuel plate at temperature below 500 deg. C was found negligible. The first rapid release of fission products was observed with the occurrence of blistering at 561±1 deg. C on the plates. The next release at 585. C might be caused by melting of the cladding material of 6061-Al alloy. The last release of fission product gases was occurred at the eutectic temperature of 640 deg. C of U-Al x . The released material was mostly xenon, but small amounts of iodine and cesium were observed. (author)

  7. Release of fission products from irradiated aluminide fuel at high temperature

    International Nuclear Information System (INIS)

    Shibata, T.; Kanda, K.; Mishima, K.

    1982-01-01

    Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel-cladding material. The release of fission products from the fuel plate at temperature below 500 0 C was found negligible. The firist rapid release of fission products was observed with the occurrence of blistering at 561 +- 1 0 C on the plates. The next release at 585 0 C might be caused by melting of the cladding material of 6061-Al alloy. The last release of fission product gases was occurred at the eutectic temperature of 640 0 C of U-Al/sub x/. The released material was mostly xenon, but small amounts of iodine and cesium were observed

  8. Effect of neutron irradiation on vanadium alloys

    International Nuclear Information System (INIS)

    Braski, D.N.

    1986-01-01

    Neutron-irradiated vanadium alloys were evaluated for their susceptibility to irradiation hardening, helium embrittlement, swelling, and residual radioactivity, and the results were compared with those for the austenitic and ferritic stainless steels. The VANSTAR-7 and V-15Cr-5Ti alloys showed the greatest hardening between 400 and 600 0 C while V-3Ti-1Si and V-20Ti had lower values that were comparable to those of ferritic steels. The V-15Cr-5Ti and VANSTAR-7 alloys were susceptible to helium embrittlement caused by the combination of weakened grain boundaries and irradiation-hardened grain matrices. Specimen fractures were entirely intergranular in the most severe instances of embrittlement. The V-3Ti-1Si and V-20Ti alloys were more resistant to helium embrittlement. Except for VANSTAR-7 irradiated to 40 dpa at 520 0 C, all of the vanadium alloys exhibited low swelling that was similar to the ferritic steels. Swelling was greater in specimens that were preimplanted with helium using the tritium trick. The vanadium alloys clearly exhibit lower residual radioactivity after irradiation than the ferrous alloys

  9. Effect of neutron irradiation on vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Braski, D.N.

    1986-01-01

    Neutron-irradiated vanadium alloys were evaluated for their susceptibility to irradiation hardening, helium embrittlement, swelling, and residual radioactivity, and the results were compared with those for the austenitic and ferritic stainless steels. The VANSTAR-7 and V-15Cr-5Ti alloys showed the greatest hardening between 400 and 600/sup 0/C while V-3Ti-1Si and V-20Ti had lower values that were comparable to those of ferritic steels. The V-15Cr-5Ti and VANSTAR-7 alloys were susceptible to helium embrittlement caused by the combination of weakened grain boundaries and irradiation-hardened grain matrices. Specimen fractures were entirely intergranular in the most severe instances of embrittlement. The V-3Ti-1Si and V-20Ti alloys were more resistant to helium embrittlement. Except for VANSTAR-7 irradiated to 40 dpa at 520/sup 0/C, all of the vanadium alloys exhibited low swelling that was similar to the ferritic steels. Swelling was greater in specimens that were preimplanted with helium using the tritium trick. The vanadium alloys clearly exhibit lower residual radioactivity after irradiation than the ferrous alloys.

  10. Radiation damage of pixelated photon detector by neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Isamu [KEK, 1-1 Oho Tsukuba 305-0801 (Japan)], E-mail: isamu.nakamura@kek.jp

    2009-10-21

    Radiation Damage of Pixelated Photon Detector by neutron irradiation is reported. MPPC, one of PPD or Geiger-mode APD, developed by Hamamatsu Photonics, is planned to be used in many high energy physics experiments. In such experiments radiation damage is a serious issue. A series of neutron irradiation tests is performed at the Reactor YAYOI of the University of Tokyo. MPPCs were irradiated at the reactor up to 10{sup 12}neutron/cm{sup 2}. In this paper, the effect of neutron irradiation on the basic characteristics of PPD including gain, noise rate, photon detection efficiency is presented.

  11. Correlative Microscopy of Alpha Prime Precipitation in Neutron-Irradiated Fe-Cr-Al Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, Samuel A. [Univ. of Wisconsin, Madison, WI (United States)

    2016-12-01

    Fe-Cr-Al alloys are currently being considered for accident tolerant light water reactor fuel cladding applications due to their superior high temperature oxidation and corrosion resistance compared to Zr-based alloys. This work represents the current state-of-the-art on both techniques for analysis of α' precipitate microstructures and the processes and mechanisms governing its formation in neutron-irradiated Fe-Cr-Al alloys.

  12. Thermal neutron converter for irradiations with fission neutrons

    International Nuclear Information System (INIS)

    Wagner, F.M.; Kampfer, S.; Kastenmuller, A.; Waschkowski, W.; Bucherl, Th.; Kampfer, S.

    2007-01-01

    The new research reactor FRM II at Garching started operation in March 2004. The compact core is cooled by light water, and moderated by heavy water. Two fuel plates mounted in the heavy water tank convert thermal to fast neutrons. The fast neutron flux in the connected beam tube is up to 7 centre dot 10 8 s -1 cm -2 (depending on filters and collimation); the mean neutron energy is about 1.6 MeV. There are two irradiation rooms along the beam. The first is mainly used for medical therapy (MEDAPP facility), the second for materials characterization (NECTAR facility). At the former therapy facility RENT at the old research reactor FRM, the same beam quality was available until July 2000. Therefore, only a small program is run for the determination of the biological effectiveness of the new beam. The neutron and gamma dose rates in the medical beam are 0.54 and 0.20 Gy/min, respectively. The therapy facility MEDAPP is still under examination according to European regulations for medical devices. Full medical operation will start in 2007. The radiography and tomography facility NECTAR is in operation and aims at non-destructive inspection of objects up to 400 kg mass and 80 centre dot 80 centre dot 80 cm 3 in size. As for fission neutrons the macroscopic cross section of hydrogen is much higher than for other materials (e. g. Fe and Pb), one special application is the detection of hydrogen-containing materials (e. g. oil) in dense materials

  13. A new disordering mechanism in A15 type compounds submitted to low temperature irradiation or to quenching from high temperatures

    International Nuclear Information System (INIS)

    Fluekiger, R.

    1984-05-01

    A new diffusion mechanism describing the changes of the long range order parameter in A15 type compounds after both quenching from high temperatures or low temperature irradiation with high energy particles is presented. It is based on the occupation of nonequilibrium or 'virtual' sites centered halfway between two neighbouring A atoms on 6c sites, arising from the instability of a single 6c vacancy recently found by Welch and coworkers by pair potential calculations. After low temperature irradiation, the occupation of this interstitial site creates the necessary conditions for A B site exchanges over several interatomic distances by focused replacement collision sequences. Due to the occupation of a certain concentration of virtual sites, atomic 'overlapping' is not only possible between A atoms on the chains or between A and B atoms (due to deviations from perfect ordering),but also between B atoms on BBB sequences. The latter are retained after low temperature irradiation only and are responsible for the observed lattice expansion and static displacement. (orig.) [de

  14. Neutron irradiation effects in pressure vessel steels and weldments

    Energy Technology Data Exchange (ETDEWEB)

    Ianko, L [International Atomic Energy Agency, Vienna (Austria). Div. of Nuclear Power; Davies, L M

    1994-12-31

    This paper deals with the effects of neutron irradiation on the steel and welds used for the pressure vessels which house the reactor cores in light water reactors: irradiation effects on mechanical properties and the shift in ductile-brittle transition temperature, importance of the knowledge of the neutron fluence and of the monitoring and surveillance programmes; empirical and mechanistic modelling of irradiation effects and the necessity of data extension to new operational limits; consequences on the manufacturing and structural design of materials and structures; mitigation of irradiation effects by annealing; international activities and programmes in the field of neutron irradiation effects on PV steels and welds. 37 refs., 22 figs.

  15. High Temperature Deformation Mechanism in Hierarchical and Single Precipitate Strengthened Ferritic Alloys by In Situ Neutron Diffraction Studies.

    Science.gov (United States)

    Song, Gian; Sun, Zhiqian; Li, Lin; Clausen, Bjørn; Zhang, Shu Yan; Gao, Yanfei; Liaw, Peter K

    2017-04-07

    The ferritic Fe-Cr-Ni-Al-Ti alloys strengthened by hierarchical-Ni 2 TiAl/NiAl or single-Ni 2 TiAl precipitates have been developed and received great attentions due to their superior creep resistance, as compared to conventional ferritic steels. Although the significant improvement of the creep resistance is achieved in the hierarchical-precipitate-strengthened ferritic alloy, the in-depth understanding of its high-temperature deformation mechanisms is essential to further optimize the microstructure and mechanical properties, and advance the development of the creep resistant materials. In the present study, in-situ neutron diffraction has been used to investigate the evolution of elastic strain of constitutive phases and their interactions, such as load-transfer/load-relaxation behavior between the precipitate and matrix, during tensile deformation and stress relaxation at 973 K, which provide the key features in understanding the governing deformation mechanisms. Crystal-plasticity finite-element simulations were employed to qualitatively compare the experimental evolution of the elastic strain during tensile deformation at 973 K. It was found that the coherent elastic strain field in the matrix, created by the lattice misfit between the matrix and precipitate phases for the hierarchical-precipitate-strengthened ferritic alloy, is effective in reducing the diffusional relaxation along the interface between the precipitate and matrix phases, which leads to the strong load-transfer capability from the matrix to precipitate.

  16. Conceptual design, neutronic and radioprotection study of a fast neutron irradiation station at SINQ

    International Nuclear Information System (INIS)

    Zanini, L.; Baluc, N.; Simone, A. De; Eichler, R.; Joray, S.; Manfrin, E.; Pouchon, M.; Rabaioli, S.; Schumann, D.; Welte, J.; Zhernosekov, K.

    2011-12-01

    This comprehensive, illustrated report by the Paul Scherrer Institute PSI in Switzerland documents the proposals concerning the conceptual design, neutronic and radioprotection study of a fast neutron irradiation station at the PSI's Swiss Spallation Neutron Source SINQ facility. The need for fast neutron irradiation is discussed and the possibility of using SINQ as a fast neutron irradiation facility is considered. The production of isotopes, tracers and medical isotopes is discussed, as are fission and fusion reactor technologies. The characteristics of the neutron spectrum in SINQ are discussed. The neutronic and radioprotection calculations for an irradiation station at SINQ are looked at in detail and extensive examples of work done and results obtained are presented and discussed. Radioprotection issues are also looked at. Further contributions in the report cover the hot/cold irradiation station in the SINQ target. An appendix provides detailed drawings of the facility's pneumatic delivery system

  17. Phase transformations in neutron-irradiated Zircaloys

    International Nuclear Information System (INIS)

    Chung, H.M.

    1986-04-01

    Microstructural evolution in Zircaloy-2 and -4 spent-fuel cladding specimens after ∼3 years of irradiation in commercial power reactors has been investigated by TEM and HVEM. Two kinds of precipitates induced by the fast-neutron irradiation in the reactors have been identified, i.e., Zr 3 O and cubic-ZrO 2 particles approximately 2 to 10 nm in size. By means of a weak-beam dark-field ''2-1/2D-microscopy'' technique, the bulk nature of the precipitates and the surficial nature of artifact oxide and hydride phases could be discerned. The Zr(Fe/sub x/,Cr/sub 1-x/) 2 and Zr 2 (Fe/sub x/,Ni/sub 1-x/) intermetallic precipitates normally present in the as-fabricated material virtually dissolved in the spent-fuel cladding specimens after a fast-neutron fluence of ∼4 x 10 21 ncm -2 in the power reactors. The observed radiation-induced phase transformations are compared with predictions based on the currently available understanding of the alloy characteristics. 29 refs

  18. Impact of neutron irradiation on thermal helium desorption from iron

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xunxiang, E-mail: hux1@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Field, Kevin G. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Taller, Stephen [University of Michigan, Ann Arbor, MI 48109 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Wirth, Brian D. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); University of Tennessee, Knoxville, TN 37996 (United States)

    2017-06-15

    The synergistic effect of neutron irradiation and transmutant helium production is an important concern for the application of iron-based alloys as structural materials in fission and fusion reactors. In this study, we investigated the impact of neutron irradiation on thermal helium desorption behavior in high purity iron. Single crystalline and polycrystalline iron samples were neutron irradiated in HFIR to 5 dpa at 300 °C and in BOR-60 to 16.6 dpa at 386 °C, respectively. Following neutron irradiation, 10 keV He ion implantation was performed at room temperature on both samples to a fluence of 7 × 10{sup 18} He/m{sup 2}. Thermal desorption spectrometry (TDS) was conducted to assess the helium diffusion and clustering kinetics by analyzing the desorption spectra. The comparison of He desorption spectra between unirradiated and neutron irradiated samples showed that the major He desorption peaks shift to higher temperatures for the neutron-irradiated iron samples, implying that strong trapping sites for He were produced during neutron irradiation, which appeared to be nm-sized cavities through TEM examination. The underlying mechanisms controlling the helium trapping and desorption behavior were deduced by assessing changes in the microstructure, as characterized by TEM, of the neutron irradiated samples before and after TDS measurements.

  19. Post-irradiation examinations and high-temperature tests on undoped large-grain UO{sub 2} discs

    Energy Technology Data Exchange (ETDEWEB)

    Noirot, J., E-mail: jean.noirot@cea.fr [CEA, DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Pontillon, Y. [CEA, DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Yagnik, S. [EPRI, P.O. Box 10412, Palo Alto, CA 94303-0813 (United States); Turnbull, J.A. [Independent Consultant (United Kingdom)

    2015-07-15

    Within the Nuclear Fuel Industry Research (NFIR) programme, several fuel variants –in the form of thin circular discs – were irradiated in the Halden Boiling Water Reactor (HBWR) at burn-ups up to ∼100 GWd/t{sub HM}. The design of the fuel assembly was similar to that used in other HBWR programmes: the assembly contained several rods with fuel discs sandwiched between Mo discs, which limited temperature differences within each fuel disc. One such variant was made of large-grain UO{sub 2} discs (3D grain size = ∼45 μm) which were subjected to three burn-ups: 42, 72 and 96 GWd/t{sub HM}. Detailed characterizations of some of these irradiated large-grain UO{sub 2} discs were performed in the CEA Cadarache LECA-STAR hot laboratory. The techniques used included electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and secondary ion mass spectrometry (SIMS). Comparisons were then carried out with more standard grain size UO{sub 2} discs irradiated under the same conditions. Examination of the high burn-up large-grain UO{sub 2} discs revealed the limited formation of a high burn-up structure (HBS) when compared with the standard-grain UO{sub 2} discs at similar burn-up. High burn-up discs were submitted to temperature transients up to 1200 °C in the heating test device called Merarg at a relatively low temperature ramp rate (0.2 °C/s). In addition to the total gas release during these tests, the release peaks throughout the temperature ramp were monitored. Tests at 1600 °C were also conducted on the 42 GWd/t{sub HM} discs. The fuels were then characterized with the same microanalysis techniques as those used before the tests, to investigate the effects of these tests on the fuel’s microstructure and on the fission gas behaviour. This paper outlines the high resistance of this fuel to gas precipitation at high temperature and to HBS formation at high burn-up. It also shows the similarity of the positions, within the grains, where HBS forms

  20. Thermal conductivity of beryllium under low temperature high dose neutron irradiation

    International Nuclear Information System (INIS)

    Chakin, V.P.; Latypov, R.N.; Suslov, D.N.; Kupriyanov, I.B.

    2004-01-01

    Thermal conductivity of compact beryllium of several Russian grades such as TE-400, TE-56, TE-30, TIP and DIP differing in the production technology, grain size and impurity content has been investigated. The thermal diffusivity of beryllium was measured on the disks in the initial and irradiated conditions using the pulse method in the range from room temperature to 200degC. The thermal conductivity was calculated using the table values for the beryllium thermal capacity. The specimens and beryllium neutron source fragments were irradiation in the SM reactor at 70degC and 200degC to a neutron fluence of (0.5-11.4)·10 22 cm -2 (E>0.1 MeV) and in the BOR-60 reactor at 400degC to 16·10 22 cm -2 (E>0.1MeV), respectively. The low-temperature irradiation leads to the drop decrease of the beryllium thermal conductivity and the effect depends on the irradiation parameters. The paper analyses the effect of irradiation parameters (temperature, neutron fluence), measurement temperature and structural factors on beryllium conductivity. The experiments have revealed that the short time post-irradiation annealing at high temperature results in partial reduction of the thermal conductivity of irradiated beryllium. (author)

  1. Tritium extraction from neutron-irradiated lithium aluminate

    International Nuclear Information System (INIS)

    Garcia H, F.

    1995-01-01

    Lithium aluminate is being strongly considered as a breeder material because of its thermophysical, chemical and mechanical stability at high temperatures and its favorable irradiation behavior. Furthermore, it is compatible with other blanket and structural materials. In this work, the effects of calcination temperature during preparation, extraction temperature and sweep gas composition were observed. Lithium aluminate prepared by four different methods, was neutron irradiated for 30 minutes at a flux of 10 12 -10 13 n/cm 2 s in the TRIGA Mark III reactor at Salazar, Mexico; and the tritium extraction rate was measured. Calcination temperature do not affect the tritium extraction rate. However, using high calcination temperature, gamma lithium aluminate was formed. The tritium extraction at 600 Centigrade degrees was lower than at 800 Centigrade degrees and the tritium amount extracted by distillation of the solid sample was higher. The sweep gas composition showed that tritium extraction was less with Ar plus 0.5 % H 2 that with Ar plus 0.1 % H 2 . This result was contrary to expected, where the tritium extraction rate could be higher when hydrogen is added to the sweep gas. Probably this effect could be attributed to the gas purity. (Author)

  2. Annealing effects on resistivity and Hall coefficient of neutron irradiated silicon

    International Nuclear Information System (INIS)

    Biggeri, U.

    1995-01-01

    High Temperature Annealing (HTA) treatment has been carried out on fast-neutron irradiated silicon samples with temperatures up to 300 C. Fluences of irradiation up to 1x10 14 n/cm 2 were used. Before annealing, samples irradiated with fluences higher than 1x10 13 n/cm 2 suffered the type conductivity inversion from n-type to p-type. The changes in the resisitivity and Hall coefficient during each annealing step have been measured by Hall effect analysis. Results indicate the possible creation of acceptors for low temperature annealing up to 150 C and the phosphorous release by E centres at annealing temperatures among 150 C and 200 C. Heating samples up to 300 C allows the recovering of the sample resistivity to its value before irradiation, with the peculiarity that bulks inverted to p-type after irradiation does not come back to n-type after annealing. (orig.)

  3. Induced defects in neutron irradiated GaN single crystals

    International Nuclear Information System (INIS)

    Park, I. W.; Koh, E. K.; Kim, Y. M.; Choh, S. H.; Park, S. S.; Kim, B. G.; Sohn, J. M.

    2005-01-01

    The local structure of defects in undoped, Si-doped, and neutron irradiated free standing GaN bulk crystals, grown by hydride vapor phase epitaxy, has been investigated by employing Raman scattering and cathodoluminescence. The GaN samples were irradiated to a dose of 2 x 10 17 neutrons in an atomic reactor at Korea Atomic Energy Research Institute. There was no appreciable change in the Raman spectra for undoped GaN samples before and after neutron irradiation. However, a forbidden transition, A 1 (TO) mode, appeared for a neutron irradiated Si-doped GaN crystal. Cathodoluminescence spectrum for the neutron irradiated Si-doped GaN crystal became much more broadened than that for the unirradiated one. The experimental results reveal the generation of defects with locally deformed structure in the wurtzite Si-doped GaN single crystal

  4. Investigation on cause of outage of Wide Range Monitor (WRM) in High Temperature engineering Test Reactor (HTTR). Post Irradiation Examination (PIE) toward investigation of the cause

    International Nuclear Information System (INIS)

    Shinohara, Masanori; Saito, Kenji; Takada, Shoji; Ishimi, Akihiro; Katsuyama, Kozo; Motegi, Toshihiro

    2012-08-01

    An event, in which one of WRMs were disabled to detect the neutron flux in the reactor core, occurred during the period of reactor shut down of HTTR in March, 2010. The actual life time of WRM was unexpectedly shorter than the past developed life time. Investigation of the cause of the outage of WRM toward the recovery of the life time up to the past developed life is one of the issues to develop the technology basis of High Temperature Gas cooled Reactor (HTGR). Then, two experimental investigations were carried out to reveal the cause of the outage by specifying the damaged part causing the event in the WRM. The one is a post irradiation examination using the X-ray computed tomography scanner in Fuels Monitoring Facility (FMF) to specify the damaged part in the WRM. The other is an experiment using a mock-up simulating the WRM fabricated by the fabricator. The characteristic impedance of the damaged WRM was measured by Time Domain Reflectometry, which was compared with that of the mock-up, which could narrow down the damaged part in the WRM. This report summarized the results of the PIE and the experimental investigation using the mock-up to reveal the cause of outage of WRM. (author)

  5. Simulation analysis of radiation fields inside phantoms for neutron irradiation

    International Nuclear Information System (INIS)

    Satoh, Daiki; Takahashi, Fumiaki; Endo, Akira; Ohmachi, Y.; Miyahara, N.

    2007-01-01

    Radiation fields inside phantoms have been calculated for neutron irradiation. Particle and heavy-ion transport code system PHITS was employed for the calculation. Energy and size dependences of neutron dose were analyzed using tissue equivalent spheres of different size. A voxel phantom of mouse was developed based on CT images of an 8-week-old male C3H/HeNs mouse. Deposition energy inside the mouse was calculated for 2- and 10-MeV neutron irradiation. (author)

  6. Damages to gladiolu corm caused by fast neutron irradiation

    International Nuclear Information System (INIS)

    Zhang Zhiwei; Wang Dan; Zhang Dongxue; Zheng Chun

    2007-01-01

    Gladiolus corms were irradiated to 100-500kGy by fast neutrons in the CFBR-II pulsed reactor, Scanning electron microscope images of the irradiated samples revealed significant radiation damages to the gladiolus corms, and the mutagenic effects were studied by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Within the dose range, radiation damage to the corm increased with the dose, with corm epidermis of the samples irradiated in vertical incidence being more serious than those irradiated in side-incidence to the same dose. Biological characters were investigated via field experiments, and the bands of protein subunit were analyzed by SDS-PAGE. The results showed that the fast neutrons irradiation inhibited growth of M1 generation seedling significantly. Protein expression was obviously inhibited by the irradiation. The study indicates that fast neutron induction is an effective way for gladiolus breeding. And the results may lay a foundation for studies on fast neutron mutation breeding. (authors)

  7. Design, Fabrication, Test Report of the Material Capsule(08M-10K) with Double Thermal Media for High-temperature Irradiation

    International Nuclear Information System (INIS)

    Cho, Man Soon; Choo, K. N.; Kang, Y. H.; Sohn, J. M.; Shin, Y. T.; Park, S. J.; Kim, B. G.; Oh, S. Y.

    2010-01-01

    To overcome the restriction of the irradiation test at a high temperature of the existing material capsule with Al thermal media, a capsule suitable for the irradiation at the high temperature was developed and the performance test was undertaken. The 08M-10K capsule was designed and fabricated as that with double thermal media to verify the structural and external integrity in the high-temperature irradiation higher than 500 .deg. C. The thermal performance test was undertaken at the out-pile test facility, and the soundness of the double thermal media was confirmed with the naked eye after disassembling the capsule. Though the temperatures of the specimens reach 500±20 .deg. C as a result maintaining the capsule during 5 hours after setting the specimens temperatures in the target range, the high-temperature thermal media with double structure was confirmed to maintain the soundness. And the specimens and the thermal media were heated to 600 .deg. C for about 3 minutes, but the thermal media were maintained sound. Especially, the Al thermal media were heated for 5 hours in range of 500±20 .deg. C and for 3 minutes at the temperature of 600 .deg. C. However, the thermal media were confirmed to maintain the soundness. Whether a capsule has only Al thermal media or the high-temperature thermal media with double structure, any capsule can be used in the range of 500±20 .deg. C as the result of this experiment maintaining the specimens high-temperature

  8. Neutron Absorbing Ability Variation in Neutron Absorbing Material Caused by the Neutron Irradiation in Spent Fuel Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Hee Dong; Han, Seul Gi; Lee, Sang Dong; Kim, Ki Hong; Ryu, Eag Hyang; Park, Hwa Gyu [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of)

    2014-10-15

    In spent fuel storage facility like high density spent fuel storage racks and dry storage casks, spent fuels are stored with neutron absorbing materials installed as a part of those facilities, and they are used for absorbing neutrons emitted from spent fuels. Usually structural material with neutron absorbing material of racks and casks are located around spent fuels, so it is irradiated by neutrons for long time. Neutron absorbing ability could be changed by the variation of nuclide composition in neutron absorbing material caused by the irradiation of neutrons. So, neutron absorbing materials are continuously faced with spent fuels with boric acid solution or inert gas environment. Major nuclides in neutron absorbing material are Al{sup 27}, C{sup 12}, B{sup 11}, B{sup 10} and they are changed to numerous other ones as radioactive decay or neutron absorption reaction. The B{sup 10} content in neutron absorbing material dominates the neutron absorbing ability, so, the variation of nuclide composition including the decrease of B{sup 10} content is the critical factor on neutron absorbing ability. In this study, neutron flux in spent fuel, the activation of neutron absorbing material and the variation of nuclide composition are calculated. And, the minimum neutron flux causing the decrease of B{sup 10} content is calculated in spent fuel storage facility. Finally, the variation of neutron multiplication factor is identified according to the one of B{sup 10} content in neutron absorbing material. The minimum neutron flux to impact the neutron absorbing ability is 10{sup 10} order, however, usual neutron flux from spent fuel is 10{sup 8} order. Therefore, even though neutron absorbing material is irradiated for over 40 years, B{sup 10} content is little decreased, so, initial neutron absorbing ability could be kept continuously.

  9. Study of supersaturation of defects under neutron irradiation by Zener relaxation

    International Nuclear Information System (INIS)

    Gonzalez, Hector C.; Justus, Francisco J.W.

    2004-01-01

    Vacancy supersaturation in dynamic equilibrium under fast neutron irradiation could be determined by anelastic relaxation. This phenomenon is particularly noticeable in some substitutional binary alloys. Relaxation is due to the reordering of atoms pairs under a stress, being a local reordering at the atomic scale. Relaxation time (τ) is inversely proportional to the vacancy concentration (Cv) and decreases under irradiation because a dynamical equilibrium of vacancy concentration, higher than thermodynamic equilibrium, is established. Theoretical models allow estimating the magnitude of that supersaturation. Determinations of τ at different temperatures, with and without fast neutron irradiations, were made with an 'in situ' device placed in the high temperature loop in the RA1 CAC-CNEA reactor. An alloy Au-30% Ni was used, since it presents an appreciable Zener effect. The measurements were performed in a spring-shaped specimen in order to minimize temperature and flux gradients. An Arrhenius plot of τ was obtained, and it was observed that for temperatures lower than 220 C degrees a vacancy supersaturation exists. The lowest temperature of our experiments was 190 C degrees. A value of τ at this temperature was three times lower under irradiations. A plot of τ vs. fast neutron fluence (φ f t) at the irradiation temperature T= 203 C degrees was obtained. An increase of τ was observed. After an annealing at T = 280 C degrees, the value of τ recovers the value corresponding to the unirradiated case. This fact suggests that the loops produced by irradiation act as defect sinks. (author) [es

  10. Evaluation of neutron irradiation effect on SCC crack growth behaviour of austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    Austenitic stainless steels are widely used as structural materials alloy in reactor pressure vessel internal components because of their high strength, ductility and fracture toughness. However, exposure due to neutron irradiation results in changes in microstructure, mechanical properties and microchemistry of the material. Irradiation assisted stress corrosion cracking (IASCC) caused by the effect of neutron irradiation during long term operation in high temperature water environments in nuclear power plants is considered to take the form of intergranular stress corrosion cracking (IGSCC) and the critical fluence level has been reported to be about 5x10{sup 24}n/m{sup 2} (E>1MeV) for Type 304 SS in BWR environment. JNES had been conducting IASCC project during from JFY 2000 to JFY 2008, and prepared an engineering database on IASCC. However, the data of crack growth rate (CGR) below the critical fluence level are not sufficient. Therefore, evaluation of neutron irradiation effect project (ENI) was initiated to obtain the CGR data below the critical fluence level, and prepare the SCC growth rate diagram for life time evaluation of core shroud. Test specimens have been irradiated in the OECD/Halden reactor, and the post irradiation experiments (PIE) have been conducting during from JFY 2011 to JFY 2013, finally the modified IASCC guide will be prepared in JFY 2013. (author)

  11. Neutron Dosimetry and Irradiation of Solids; Dosimetrie des neutrons et irradiation des solides

    Energy Technology Data Exchange (ETDEWEB)

    Perriot, G; Schmitt, A P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    Results of work at C.E.A. from 1958 to 1960 are reviewed. The possibilities offered by classical dosimetry methods are discussed. The tests which led to the utilization, for fast neutron dosimetry, of resistivity variations induced in solid W by such neutrons are described. Experimental W irradiation results led to a definition of neutron efficiency which describes the relations between neutron energy and their effects on materials. Possibilities offered by detectors which make use of radiation damage and are sensitive to neutrons at keV energies were explored. In other work, the principal French reactors were classified according to their ability to produce damage in materials such as W. (authors) [French] Dans ce rapport on a presente les resultats essentiels de travaux qui ont ete effectues de 1958 a 1980 par des chercheurs du CEA issus de differents services. En meme temps qu'une revue des possibilites offertes a l'epoque par les methodes classiques de dosimetrie (utilisation des detecteurs par activation), on a decrit les essais qui devaient permettre d'utiliser, a la dosimetrie les neutrons rapides, les variations de resistivite qu'ils creent dans un corps solide (tungstene). L'irradiation du tungstene a montre l'importance qu'il y avait a definir 'l'efficacite' des neutrons, c'est-a-dire leur aptitude plus ou moins grande, selon leur energie, a creer des defauts dans les materiaux. L'efficacite d'un emplacement d'irradiation se trouvant liee au spectre neutronique, on a vu les difficultes qu'il y avait a utiliser les detecteurs par activation des qu'on n'avait plus affaire a un spectre en 1/E ou de fission et on a pu entrevoir les possibilites offertes par les detecteurs utilisant la creation des defauts qui repondent a tous les neutrons d'energies, superieures a quelques keV. Enfin, on a classe les principaux types de Piles Francaises selon leur aptitude a creer plus ou moins rapidement des dommages dans des materiaux comme le tungstene. (auteur)

  12. EDX microanalysis of neutron-irradiated alloys

    International Nuclear Information System (INIS)

    Thomas, L.E.

    1981-09-01

    Energy-dispersive X-ray (EDX) spectrometry of 50 nm thick specimens in the scanning transmission electron microscope provides quantitative elemental analyses of selected regions as small as 20 nm in diameter. To analyze highly radioactive neutron-irradiated alloys it is necessary to reduce the high counting deadtimes caused by energetic γ-Compton scattering in the Si(Li) detector, and to account for spurious background contributions from γ-rays and characteristic x-ray emissions. Several simple methods for overcoming effects of specimen radioactivity are described, including use of a tungsten collimator to attenuate γ and x-rays coming from the thick edges of self-supporting disk specimens. These methods allow analyses of Fe-Cr-Ni based alloys with γ-activities up to 1000 μC/sub i/. Techniques used to maintain high spatial resolution and accuracy in quantitatve analysis are also described, and their use is illustrated

  13. Response of neutron-irradiated RPV steels to thermal annealing

    International Nuclear Information System (INIS)

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1997-01-01

    One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels

  14. A new apparatus design for high temperature (up to 950 °C) quasi-elastic neutron scattering in a controlled gaseous environment

    International Nuclear Information System (INIS)

    Al-Wahish, Amal; Armitage, D.; Hill, B.; Mills, R.; Santodonato, L.; Herwig, K. W.; Al-Binni, U.; Jalarvo, N.; Mandrus, D.

    2015-01-01

    A design for a sample cell system suitable for high temperature Quasi-Elastic Neutron Scattering (QENS) experiments is presented. The apparatus was developed at the Spallation Neutron Source in Oak Ridge National Lab where it is currently in use. The design provides a special sample cell environment under controlled humid or dry gas flow over a wide range of temperature up to 950 °C. Using such a cell, chemical, dynamical, and physical changes can be studied in situ under various operating conditions. While the cell combined with portable automated gas environment system is especially useful for in situ studies of microscopic dynamics under operational conditions that are similar to those of solid oxide fuel cells, it can additionally be used to study a wide variety of materials, such as high temperature proton conductors. The cell can also be used in many different neutron experiments when a suitable sample holder material is selected. The sample cell system has recently been used to reveal fast dynamic processes in quasi-elastic neutron scattering experiments, which standard probes (such as electrochemical impedance spectroscopy) could not detect. In this work, we outline the design of the sample cell system and present results demonstrating its abilities in high temperature QENS experiments

  15. A new apparatus design for high temperature (up to 950°C) quasi-elastic neutron scattering in a controlled gaseous environment.

    Science.gov (United States)

    al-Wahish, Amal; Armitage, D; al-Binni, U; Hill, B; Mills, R; Jalarvo, N; Santodonato, L; Herwig, K W; Mandrus, D

    2015-09-01

    A design for a sample cell system suitable for high temperature Quasi-Elastic Neutron Scattering (QENS) experiments is presented. The apparatus was developed at the Spallation Neutron Source in Oak Ridge National Lab where it is currently in use. The design provides a special sample cell environment under controlled humid or dry gas flow over a wide range of temperature up to 950 °C. Using such a cell, chemical, dynamical, and physical changes can be studied in situ under various operating conditions. While the cell combined with portable automated gas environment system is especially useful for in situ studies of microscopic dynamics under operational conditions that are similar to those of solid oxide fuel cells, it can additionally be used to study a wide variety of materials, such as high temperature proton conductors. The cell can also be used in many different neutron experiments when a suitable sample holder material is selected. The sample cell system has recently been used to reveal fast dynamic processes in quasi-elastic neutron scattering experiments, which standard probes (such as electrochemical impedance spectroscopy) could not detect. In this work, we outline the design of the sample cell system and present results demonstrating its abilities in high temperature QENS experiments.

  16. INTERWELD - European project to determine irradiation induced material changes in the heat affected zones of austenitic stainless steel welds that influence the stress corrosion behaviour in high-temperature water

    International Nuclear Information System (INIS)

    Roth, A.; Schaaf, Bob van der; Castano, M.L.; Ohms, C.; Gavillet, D.; Dyck, S. van

    2003-01-01

    PWR and BWR RPV internals have experienced stress corrosion cracking in service. The objective of the INTERWELD project is to determine the radiation induced material changes that promote stress corrosion cracking in the heat affected zone of austenitic stainless steel welds. To achieve this goal, welds in austenitic stainless steel types AISI 304/347 have been fabricated, respectively. Stress-relief annealing was applied optionally. The pre-characterisation of both the as-welded and stress relieved material conditions comprises the examination of the weld residual stresses by the ring-core-technique and neutron diffraction, the degree of sensitisation by EPR, and the stress corrosion behaviour by SSRT testing in high-temperature water. The weldments will be irratiated to 2 neutron fluence levels and a postirradiation examination will determine micromechanical, microchemical and microstructural changes in the materials. In detail, the evolution of the residual stress levels and the stress corrosion behaviour after irradiation will be determined. Neutron diffraction will be utilized for the first time with respect to neutron irradiated material. In this paper, the current state of the project will be described and discussed. (orig.)

  17. Divertor materials for ITER - Tungsten and carbon/carbon composite behavior under coupled ionic irradiation and high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Raunier, S.; Balat-Pichelin, M.; Sans, J.L.; Hernandez, D. [Laboratoire PROMES-CNRS, Laboratoire Procedes, Materiaux et Energie Solaire, 7 rue du Four Solaire, 66120 Font-Romeu Odeillo (France)

    2007-07-01

    Full text of publication follows: In the frame of the International Thermonuclear Experimental Reactor ITER, the physical-chemical characterization of plasma-facing components (divertor and structural materials) is essential because they are subjected to simultaneous high thermal and ionic fluxes. In this paper, an experimental and theoretical study of the physical-chemical behavior of carbon/carbon composite and tungsten (materials for ITER divertor) under extreme conditions is performed. The simulation of the interaction of hydrogen ions with the material, the theoretical study of physical erosion (TRIM and TRIDYN codes) and the chemical erosion (GEMINI code) are carried out. The conditions of nominal or accidental mode that can occur during the operation of the reactor (high temperature 1300 - 2500 K, high vacuum, H{sup +} ionic flux with different energies) are experimentally simulated. In this work, we have studied the material degradation, the mass loss kinetics, the characterization of the emitted neutral and charged species of heated and both heated and irradiated materials, and the determination of the thermo-radiative properties versus time. This study, done in collaboration with CEA Cadarache, is realized using the MEDIASE experimental device (Moyen d'Essai et de Diagnostic en Ambiance Solaire Extreme) located at the focus of the 1000 kW solar furnace of PROMES-CNRS laboratory in Odeillo. Material characterization pre- and post-processing is performed with classical techniques as SEM, XRD and XPS and also by measuring the BRDF (Bidirectional Reflectivity Diffusion Function). (authors)

  18. Divertor materials for ITER - Tungsten and carbon/carbon composite behavior under coupled ionic irradiation and high temperature

    International Nuclear Information System (INIS)

    Raunier, S.; Balat-Pichelin, M.; Sans, J.L.; Hernandez, D.

    2007-01-01

    Full text of publication follows: In the frame of the International Thermonuclear Experimental Reactor ITER, the physical-chemical characterization of plasma-facing components (divertor and structural materials) is essential because they are subjected to simultaneous high thermal and ionic fluxes. In this paper, an experimental and theoretical study of the physical-chemical behavior of carbon/carbon composite and tungsten (materials for ITER divertor) under extreme conditions is performed. The simulation of the interaction of hydrogen ions with the material, the theoretical study of physical erosion (TRIM and TRIDYN codes) and the chemical erosion (GEMINI code) are carried out. The conditions of nominal or accidental mode that can occur during the operation of the reactor (high temperature 1300 - 2500 K, high vacuum, H + ionic flux with different energies) are experimentally simulated. In this work, we have studied the material degradation, the mass loss kinetics, the characterization of the emitted neutral and charged species of heated and both heated and irradiated materials, and the determination of the thermo-radiative properties versus time. This study, done in collaboration with CEA Cadarache, is realized using the MEDIASE experimental device (Moyen d'Essai et de Diagnostic en Ambiance Solaire Extreme) located at the focus of the 1000 kW solar furnace of PROMES-CNRS laboratory in Odeillo. Material characterization pre- and post-processing is performed with classical techniques as SEM, XRD and XPS and also by measuring the BRDF (Bidirectional Reflectivity Diffusion Function). (authors)

  19. Emulation of neutron irradiation effects with protons: validation of principle

    International Nuclear Information System (INIS)

    Was, G.S.; Busby, J.T.; Allen, T.; Kenik, E.A.; Jensson, A.; Bruemmer, S.M.; Gan, J.; Edwards, A.D.; Scott, P.M.; Andreson, P.L.

    2002-01-01

    This paper presents the results of the irradiation, characterization and irradiation assisted stress corrosion cracking (IASCC) behavior of proton- and neutron-irradiated samples of 304SS and 316SS from the same heats. The objective of the study was to determine whether proton irradiation does indeed emulate the full range of effects of in-reactor neutron irradiation: radiation-induced segregation (RIS), irradiated microstructure, radiation hardening and IASCC susceptibility. The work focused on commercial heats of 304 stainless steel (heat B) and 316 stainless steel (heat P). Irradiation with protons was conducted at 360 deg. C to doses between 0.3 and 5.0 dpa to approximate those by neutron irradiation at 275 deg. C over the same dose range. Characterization consisted of grain boundary microchemistry, dislocation loop microstructure, hardness as well as stress corrosion cracking (SCC) susceptibility of both un-irradiated and irradiated samples in oxygenated and de-oxygenated water environments at 288 deg. C. Overall, microchemistry, microstructure, hardening and SCC behavior of proton- and neutron-irradiated samples were in excellent agreement. RIS analysis showed that in both heats and for both irradiating particles, the pre-existing grain boundary Cr enrichment transformed into a 'W' shaped profile at 1.0 dpa and then into a 'V' shaped profile between 3.0 and 5.0 dpa. Grain boundary segregation of Cr, Ni, Si, and Mo all followed the same trends and agreed well in magnitude. The microstructure of both proton- and neutron-irradiated samples was dominated by small, faulted dislocation loops. Loop size distributions were nearly identical in both heats over a range of doses. Saturated loop size following neutron irradiation was about 30% larger than that following proton irradiation. Loop density increased with dose through 5.0 dpa for both particle irradiations and was a factor of 3 greater in neutron-irradiated samples vs. proton-irradiated samples. Grain boundary

  20. Neutron Flux Characterization of Irradiation Holes for Irradiation Test at HANARO

    Directory of Open Access Journals (Sweden)

    Yang Seong Woo

    2016-01-01

    Full Text Available The High flux Advanced Neutron Application ReactOr (HANARO is a unique research reactor in the Republic of Korea, and has been used for irradiation testing since 1998. To conduct irradiation tests for nuclear materials, the irradiation holes of CT and OR5 have been used due to a high fast-neutron flux. Because the neutron flux must be accurately calculated to evaluate the neutron fluence of irradiated material, it was conducted using MCNP. The neutron flux was measured using fluence monitor wires to verify the calculated result. Some evaluations have been conducted, however, more than 20% errors have frequently occurred at the OR irradiation hole, while a good agreement between the calculated and measured data was shown at the CT irradiation hole.

  1. Calculations on neutron irradiation damage in reactor materials

    International Nuclear Information System (INIS)

    Sone, Kazuho; Shiraishi, Kensuke

    1976-01-01

    Neutron irradiation damage calculations were made for Mo, Nb, V, Fe, Ni and Cr. Firstly, damage functions were calculated as a function of neutron energy with neutron cross sections of elastic and inelastic scatterings, and (n,2n) and (n,γ) reactions filed in ENDF/B-III. Secondly, displacement damage expressed in displacements per atom (DPA) was estimated for neutron environments such as fission spectrum, thermal neutron reactor (JMTR), fast breeder reactor (MONJU) and two fusion reactors (The Conceptual Design of Fusion Reactor in JAERI and ORNL-Benchmark). then, damage cross section in units of dpa. barn was defined as a factor to convert a given neutron fluence to the DPA value, and was calculated for the materials in the above neutron environments. Finally, production rates of helium and hydrogen atoms were calculated with (n,α) and (n,p) cross sections in ENDF/B-III for the materials irradiated in the above reactors. (auth.)

  2. Estimate of absorbed dose received by individuals irradiated with neutrons

    International Nuclear Information System (INIS)

    Fonseca, E.S. da; Mauricio, C.L.P.

    1995-01-01

    An innovating methodology is proposed to estimate the absorbed dose received by individuals irradiated with neutrons in an accident, even in the case that the victim is not using any kind of neutron dosemeter. The method combines direct measurements of 24 Na and 32 P activated in the human body. The calculation method was developed using data taken from previously published papers and experimental measurements. Other irradiations results in different neutron spectra prove the validity of the methodology here proposed. Using a whole body counter to measure 24 Na activity, it is possible to evaluate neutron absorbed doses in the order of 140 μGy of very soft (thermal) spectra. For fast neutron fields, the lower limit for neutron dose detection increases, but the present method continues to be very useful in accidents, with higher neutron doses. (author). 5 refs., 1 fig., 4 tabs

  3. Influence of neutron irradiation on ferromagnetic metallic glasses

    International Nuclear Information System (INIS)

    Miglierini, M.; Nasu, Saburo; Sitek, J.

    1992-01-01

    Transmission 57 Fe Moessbauer spectroscopy is used to study effects of neutron irradiation on magnetic properties of Fe-based ferromagnetic metallic glasses. Elastic stress centers are produced during the process of neutron irradiation as a result of atom mixing. Rearrangement of the atoms causes changes in the average value of the hyperfine field distribution and orientation of the net magnetic moment. They are shown to depend on the composition of the investigated samples. Cr-doped metallic glasses depict transformation from ferromagnetic to paramagnetic state at room temperature after neutron irradiation implying changes in the Curie temperature. Presence of Ni in the samples reduces the effects of radiation damage. (orig.)

  4. Review of recent studies on neutron irradiation embrittlement in light water reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Sudo, Akira; Miyazono, Shohachiro

    1983-06-01

    Recent studies in foreign countries (USA, France, FRG and UK) on neutron irradiation embrittlement have been reviewed. These studies are classified into four areas, such as 1) effect of chemical composition on irradiation embrittlement sensitivity, 2) postirradiation heat treatment for embrittlement relief, 3) fracture toughness evaluation of irradiated materials based on fracture mechanics analysis, and 4) effect of irradiation on fatigue crack propagation behavior. The first area mainly includes the studies related to the effects of copper, phosphorus impurities and nickel alloying and synergistic effect of these components, and furthermore, evaluation of Regulatory Guide 1.99 Rev.l. Studies in the second area show the effects of annealing condition (temperature and time) and metallugical condition on embrittlement relief, and evaluation of periodic annealing in the period of irradiation as a promising method for embrittlement control. Studies in the third area show the correlation between fracture toughness and Cv notch ductility changes with neutron irradiation, and J-R curves of irradiated materials based on the elasto-plastic fracture mechanics. In the forth area, most of studies are investigated in air condition but a few studies in reactor-grade water at high temperature and pressure. (author)

  5. Dose dependence of the microstructural evolution in neutron-irradiated austenitic stainless steel

    International Nuclear Information System (INIS)

    Zinkle, S.J.; Maziasz, P.J.; Stoller, R.E.

    1993-01-01

    Microstructural data on the evolution of the dislocation loop, cavity, and precipitate populations in neutron-irradiated austenitic stainless steels are reviewed in order to estimate the displacement damage levels needed to achieve the 'steady state' condition. The microstructural data can be conveniently divided into two temperature regimes. In the low temperature regime (below about 200 degrees C) the microstructure of austenitic stainless steel is dominated by 'black spot' defect clusters and faulted interstitial dislocation loops. The dose needed to approach saturation of the loop and defect cluster densities is generally on the order of 1 displacement per atom (dpa) in this regime. In the high temperature regime (∼300 to 700 degrees C), cavities, precipitates, loops and network dislocations are all produced during irradiation; doses in excess of 10 dpa are generally required to approach a 'steady state' microstructural condition. Due to complex interactions between the various microstructural components that form during irradiation, a secondary transient regime is typically observed in commercial stainless steels during irradiation at elevated temperatures. This slowly evolving secondary transient may extend to damage levels in excess of 50 dpa in typical 300-series stainless steels, and to >100 dpa in radiation-resistant developmental steels. The detailed evolution of any given microstructural component in the high-temperature regime is sensitive to slight variations in numerous experimental variables, including heat-to-heat composition changes and neutron spectrum

  6. Helium release from neutron-irradiated Li{sub 2}O single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yamaki, Daiju; Tanifuji, Takaaki; Noda, Kenji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Helium release behavior in post-irradiation heating tests was investigated for Li{sub 2}O single crystals which had been irradiated with thermal neutrons in JRR-4 and JRR-2, and fast neutrons in FFTF. It is clarified that the helium release curves from JRR-4 and JRR-2 specimens consists of only one broad peak. From the dependence of the peak temperatures on the neutron fluence and the crystal diameter, and the comparison with the results obtained for sintered pellets, it is considered that the helium generated in the specimen is released through the process of bulk diffusion with trapping by irradiation defects such as some defect clusters. For the helium release from FFTF specimens, two broad peaks were observed in the release curves. It is considered to suggest that two different diffusion paths exist for helium migration in the specimen, that is, bulk diffusion and diffusion through the micro-crack due to the heavy irradiation. In addition, helium bubble formation after irradiation due to the high temperature over 800K is suggested. (J.P.N.)

  7. On the studies of thermodynamics properties of fast neutron irradiated (LixK1-x)2SO4 crystals

    Science.gov (United States)

    El-Khatib, A. M.; Kassem, M. E.; Gomaa, N. G.; Mahmoud, S. A.

    The effect of fast neutron irradiation on the thermodynamic properties of (LixK1-x)2SO4, (x = 0.1, 0.2,˙˙˙˙˙˙˙˙0.5) has been studied. The measurements were carried out in the vicinity of phase transition. The study reveals that as the lithium content decreases the first high temperature phase Tc = 705 K disappears, while the second one is shifted to lower temperature. It is observed also that the specific heat, Cp, decreases sharply with neutron integrated fluence φ and increases once more. Both entropy and enthalpy changes increase with the increase of neutron integrated fluence.

  8. Neutron irradiation control in the neutron transmutation doping process in HANARO using SPND

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Gi-Doo; Kim, Myong-Seop [Korea Atomic Energy Research Institute, Yuseong, Daejeon, 305-353, (Korea, Republic of)

    2015-07-01

    The neutron irradiation control method by using self-powered neutron detector (SPND) is developed for the neutron transmutation doping (NTD) application in HANARO. An SPND is installed at a fixed position of the upper part of the sleeve in HANARO NTD hole for real-time monitoring of the neutron irradiation. It is confirmed that the SPND is significantly affected by the in-core condition and surroundings of the facility. Furthermore, the SPND signal changes about 15% throughout a whole cycle according to the change of the control rod position. But, it is also confirmed that the variation of the neutron flux on the silicon ingots inside the irradiation can is not so big while moving of the control rod. Accordingly, the relationship between the ratio of the neutron flux to the SPND signal output and the control rod position is established. In this procedure, the neutron flux measurement by using zirconium foil is utilized. The real NTD irradiation experiments are performed using the established relationship. The irradiated neutron fluence can be controlled within ±1.3% of the target one. The mean value of the irradiation/target ratio of the fluence is 0.9992, and the standard deviation is 0.0071. Thus, it is confirmed that the extremely accurate irradiation would be accomplished. This procedure can be useful for the SPND application installed at the fixed position to the field requiring the extremely high accuracy. (authors)

  9. Needs of in-situ materials testing under neutron irradiation

    International Nuclear Information System (INIS)

    Noda, K.; Hishinuma, A.; Kiuchi, K.

    1989-01-01

    Under neutron irradiation, the component atoms of materials are displaced as primary knock-on atoms, and the energy of the primary knock-on atoms is consumed by electron excitation and nuclear collision. Elementary irradiation defects accumulate to form damage structure including voids and bubbles. In situ test under neutron irradiation is necessary for investigating into the effect of irradiation on creep behavior, the electric properties of ceramics, transport phenomena and so on. The in situ test is also important to investigate into the phenomena related to the chemical reaction with environment during irradiation. Accelerator type high energy neutron sources are preferable to fission reactors. In this paper, the needs and the research items of in situ test under neutron irradiation using a D-Li stripping type high energy neutron source on metallic and ceramic materials are described. Creep behavior is one of the most important mechanical properties, and depends strongly on irradiation environment, also it is closely related to microstructure. Irradiation affects the electric conductibity of ceramics and also their creep behavior. In this way, in situ test is necessary. (K.I.)

  10. The intrinsic gettering in neutron irradiation Czochralski-silicon

    CERN Document Server

    Li Yang Xian; Niu Ping Juan; Liu Cai Chi; Xu Yue Sheng; Yang Deren; Que Duan Lin

    2002-01-01

    The intrinsic gettering in neutron irradiated Czochralski-silicon is studied. The result shows that a denuded zone at the surface of the neutron irradiated Czochralski-silicon wafer may be formed through one-step short-time annealing. The width of the denuded zone is dependent on the annealing temperature and the dose of neutron irradiation, while it is irrelated to the annealing time in case the denuded zone is formed. The authors conclude that the interaction between the defects induced by neutron irradiation and the oxygen in the silicon accelerates the oxygen precipitation in the bulk, and becomes the dominating factor of the quick formation of intrinsic gettering. It makes the effect of thermal history as the secondary factor

  11. Study of damages by neutron irradiation in lithium aluminates

    International Nuclear Information System (INIS)

    Palacios G, O.

    1999-01-01

    Lithium aluminates proposed to the production of tritium in fusion nuclear reactors, due to the thermal stability that they present as well as the behavior of the aluminium to the irradiation. As a neutron flux with profile (≅ 14 Mev) of a fusion reactor is not available. A irradiation experiment was designed in order to know the micro and nano structure damages produced by fast and thermal neutrons in two irradiation positions of the fusion nuclear reactor Triga Mark III: CT (Thermal Column) and SIFCA (System of Irradiation Fixed of Capsules). In this work samples of lithium aluminate were characterized by XRD (X-Ray Diffraction), TEM (Transmission Electron Microscopy) and SEM (Scanning Electron Microscopy). Two samples were prepared by two methods: a) coalition method and b) peroxide method. This characterization comprised original and irradiated samples. The irradiated sample amounted to 4 in total: one for each preparation method and one for each irradiation position. The object of this analysis was to correlate with the received neutron dose the damages suffered by the samples with the neutron irradiation during long periods (440 H), in their micro and nano structure aspects; in order to understand the changes as a function of the irradiation zone (with thermal and fast neutron flux) and the preparation methods of the samples and having as an antecedent the irradiation in SIFCA position by short times (2h). The obtained results are referred to the stability of γ -aluminate phase, under given conditions of irradiation and defined nano structure arrangement. They also refer to the proposals of growth mechanism and nucleation of new phases. The error associated with the measurement of neutron dose is also discussed. (Author)

  12. Alterations in water and electrolyte absorption in the rat colon following neutron irradiation: influence of neutron component and irradiation dose.

    Science.gov (United States)

    Dublineau, I; Ksas, B; Joubert, C; Aigueperse, J; Gourmelon, P; Griffiths, N M

    2002-12-01

    To study the absorptive function of rat colon following whole-body exposure to neutron irradiation, either to the same total dose with varying proportion of neutrons or to the same neutron proportion with an increasing irradiation dose. Different proportions of neutron irradiation were produced from the reactor SILENE using a fissile solution of uranium nitrate (8, 47 and 87% neutron). Water and electrolyte fluxes were measured in the rat in vivo under anaesthesia by insertion into the descending colon of an agarose gel cylinder simulating the faeces. Functional studies were completed by histological analyses. In the first set of experiments, rats received 3.8 Gy with various neutron percentages and were studied from 1 to 14 days after exposure. In the second set of experiments, rats were exposed to increasing doses of irradiation (1-4Gy) with a high neutron percentage (87%n) and were studied at 4 days after exposure. The absorptive capacity of rat colon was diminished by irradiation at 3-5 days, with a nadir at 4 days. The results demonstrate that an increase in the neutron proportion is associated with an amplification of the effects. Furthermore, a delay in the re-establishment of normal absorption was observed with the high neutron proportion (87%n). A dose-dependent reduction of water absorption by rat colon was also observed following neutron irradiation (87%n), with a 50% reduction at 3 Gy. Comparison of this dose-effect curve with the curve obtained following gamma (60)Co-irradiation indicates an RBE of 2.2 for absorptive colonic function in rat calculated at 4 days after exposure.

  13. Anisotropic shift of the irreversibility line by neutron irradiation

    International Nuclear Information System (INIS)

    Sauerzopf, F.M.; Wiesinger, H.P.; Weber, H.W.; Crabtree, G.W.; Frischherz, M.C.; Kirk, M.A.

    1991-09-01

    The irreversibility line of high-T c superconductors is shifted considerably by irradiating the material with fast neutrons. The anisotropic and non-monotonous shift is qualitatively explained by a simple model based on an interaction between three pinning mechanisms, the intrinsic pinning by the ab-planes, the weak pinning by the pre-irradiation defect structure, and strong pinning by neutron induced defect cascades. A correlation between the cascade density and the position of the irreversibility line is observed

  14. F-type centers in neutron-irradiated AIN

    International Nuclear Information System (INIS)

    Atobe, Kozo; Honda, Makoto; Fukuoka, Noboru; Okada, Moritami; Nakagawa, Masuo.

    1990-01-01

    The production of point defects by neutron irradiation and thermal decay in sintered AIN polycrystal are investigated. The absorption band at 370 nm is observed after reactor neutron irradiation to a dose of 10 16 n/cm 2 (E > 0.1 MeV). The defect corresponding to the band is tentatively assigned as an F-type center from the optical absorption and electron spin resonance. (author)

  15. Design of hyper-thermal neutron irradiation fields for neutron capture therapy in KUR-heavy water neutron irradiation facility. Mounting of hyper-thermal neutron converter in therapeutic collimator

    International Nuclear Information System (INIS)

    Sakurai, Y.; Kobayashi, T.

    2001-01-01

    Neutron capture therapy (NCP) using thermal neutron needs to improve of depth dose distribution in a living body. Epi-thermal neutron following moderation of fast neutron is usually used for improving of the depth dose distribution. The moderation method of fast neutron, however, gets mixed some of high energy neutron which give some of serious effects to a living body, and involves the difficulty for collimation of thermal neutron to the diseased part. Hyper-thermal neutrons, which are in an energy range of 0.1-3 eV at high temperature side of thermal neutron, are under consideration for application to the NCP. The hyper-thermal neutrons can be produced by up-scattering of thermal neutron in a high temperature material. Fast neutron components in collimator for the NCP reduce on application of the up-scattering method. Graphite at high temperature (>1000k) is used as a hyper-thermal neutron converter. The hyper-thermal neutron converter is planted to mount on therapeutic collimator which is located at the nearest side of patient for the NCP. Total neutron flux, ratio of hyper-thermal neutron to total neutron, and ratio of gamma-ray dose to neutron flux are calculated as a function of thickness of the graphite converter using monte carlo code MCNP-V4B. (M. Suetake)

  16. Non-destructive diagnostics of irradiated materials using neutron scattering from pulsed neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Korenev, Sergey E-mail: sergey_korenev@steris.com; Sikolenko, Vadim

    2004-10-01

    The advantage of neutron-scattering studies as compared to the standard X-ray technique is the high penetration of neutrons that allow us to study volume effects. The high resolution of instrumentation on the basis neutron scattering allows measurement of the parameters of lattice structure with high precision. We suggest the use of neutron scattering from pulsed neutron sources for analysis of materials irradiated with pulsed high current electron and ion beams. The results of preliminary tests using this method for Ni foils that have been studied by neutron diffraction at the IBR-2 (Pulsed Fast Reactor at Joint Institute for Nuclear Research) are presented.

  17. Non-destructive diagnostics of irradiated materials using neutron scattering from pulsed neutron sources

    Science.gov (United States)

    Korenev, Sergey; Sikolenko, Vadim

    2004-09-01

    The advantage of neutron-scattering studies as compared to the standard X-ray technique is the high penetration of neutrons that allow us to study volume effects. The high resolution of instrumentation on the basis neutron scattering allows measurement of the parameters of lattice structure with high precision. We suggest the use of neutron scattering from pulsed neutron sources for analysis of materials irradiated with pulsed high current electron and ion beams. The results of preliminary tests using this method for Ni foils that have been studied by neutron diffraction at the IBR-2 (Pulsed Fast Reactor at Joint Institute for Nuclear Research) are presented.

  18. Fiscal year 1976 DT fusion neutron irradiations and dosimetry at the LLL rotating target neutron source

    International Nuclear Information System (INIS)

    MacLean, S.C.

    1977-01-01

    The DT fusion neutron irradiation of 319 samples during 19 irradiation periods (beam-on time of more than 1026 hours) is described. Experiments from 24 individuals representing 11 institutions are summarized. The numbers of the UCID dosimetry reports detailing each of the irradiations are given

  19. Comparison of deuterium retention for ion-irradiated and neutron-irradiated tungsten

    International Nuclear Information System (INIS)

    Oya, Yasuhisa; Kobayashi, Makoto; Okuno, Kenji; Shimada, Masashi; Calderoni, Pattrick; Oda, Takuji; Hara, Masanori; Hatano, Yuji; Watanabe, Hideo

    2014-01-01

    The behavior of D retentions for Fe 2+ irradiated tungsten with the damage of 0.025-3 dpa was compared with that for neutron irradiated tungsten with 0.025 dpa. The D 2 TDS spectra for Fe 2+ irradiated tungsten consisted of two desorption stages at 450 K and 550 K although that for neutron irradiated tungsten was composed of three stages and addition desorption stage was found around 750 K. The desorption rate of major desorption stage at 550 K increased as the number of dpa by Fe 2+ irradiation increased. In addition, the first desorption stage at 450 K was only found for the damaged samples, indicating that the second stage would be based on intrinsic defects or vacancy produced by Fe 2+ irradiation and the first stage should be the accumulation of D in mono vacancy leading to the lower activation energy, where the dislocation loop and vacancy was produced. The third one was only found for the neutron irradiation, showing the D trapping by void or vacancy cluster and the diffusion effect is also contributed due to high FWHM of TDS spectrum. It can be said that the D 2 TDS spectra for Fe 2+ -irradiated tungsten could not represent that for neutron-irradiated one, showing that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten has a difference from that for ion-irradiated one. (author)

  20. Refractometry characteristics of α-quartz after neutron irradiation

    International Nuclear Information System (INIS)

    Abdkadyrova, I.Kh.

    1997-01-01

    Lattice structure distortions in irradiated crystalline quartz were studied by refractometry methods. The refractometry constants of α-quartz for the flux of fast neutrons 10 18 - 10 21 neutron/cm 2 were calculated. The critical kinetics of this constants at the phase transformation is observed.(author). 5 refs., 1 fig

  1. Studies of neutron irradiation effects at IPNS-REF

    International Nuclear Information System (INIS)

    Kirk, M.A.

    1983-09-01

    Neutron irradiation effects studies at the Radiation Effects Facility (REF) at the Intense Pulsed Neutron Source (IPNS) located at Argonne National Laboratory (ANL) are reviewed. A brief history of the development of this user facility is followed by an overview of the scientific program. Experiments unique to a spallation neutron source are covered in more detail. Future direction of research at this facility is suggested

  2. Hydriding and neutron irradiation in zircaloy-4

    International Nuclear Information System (INIS)

    Ramos, Ruben Fortunato; Martin, Juan Ezequiel; Orellano, Pablo; Dorao, Carlos; Analia Soldati; Ghilarducci, Ada Albertina; Corso, Hugo Luis; Peretti, Hernan Americo; Bolcich, Juan Carlos

    2003-01-01

    The composition of Zircaloy-4 for nuclear applications is specified by the ASTM B350 Standard, that fixes the amount of alloying elements (Sn, Fe, Cr) and impurities (Ni, Hf, O, N, C, among others) to optimize good corrosion and mechanical behavior.The recycling of zircaloy-4 scrap and chips resulting from cladding tube fabrication is an interesting issue.However, changes in the final composition of the recycled material may occur due to contamination with tool pieces, stainless steel chips, turnings, etc. while scrap is stored and handled. Since the main components of the possible contaminants are Fe, Cr and Ni, it arises the interest in studying up to what limit the Fe, Ni and Cr contents could be exceeded beyond the standard specification without affecting significantly the alloy properties.Zircaloy-4 alloys elaborated with Fe, Cr and Ni additions and others of standard composition in use in nuclear plants are studied by tensile tests, SEM observations and EDS microanalysis.Some samples are tested in the initial condition and others after hydriding treatments and neutron irradiation in the RA6

  3. Combined neutron and synchrotron X-ray diffraction study of Sr/Mg-doped lanthanum gallates up to high temperatures

    Science.gov (United States)

    Guenter, M. M.; Lerch, M.; Boysen, H.; Toebbens, D.; Suard, E.; Baehtz, C.

    2006-08-01

    Combined neutron diffraction and high-resolution synchrotron X-ray powder diffraction methods have been used to examine the crystal structures of two sample sets of Sr/Mg-doped Lanthanum gallate with the compositions La0.9Sr0.1Ga1-yMgyO3-0.5(0.1+y) (y=0, 0.1, 0.2) and La0.8Sr0.2Ga1-yMgyO3-0.5(0.2+y) (y=0.15, 0.2) up to 900 °C. At room temperature all samples of the first series exhibit orthorhombic structures with space group Imma: La0.9Sr0.1GaO2.95: a=5.4904(1)Å, b=7.7757(1)Å, c=5.5229(1)Å; La0.9Sr0.1Ga0.9Mg0.1O2.9: a=5.5100(1)Å, b=7.8080(1)Å, c=5.5411(1)Å; La0.9Sr0.1Ga0.8Mg0.2O2.85: a=5.5269(1)Å, b=7.8318(2)Å, c=5.5459(1)Å. The samples of the second series have the cubic perovskite structure with space group Pm3¯m at room temperature: La0.8Sr0.2Ga0.85Mg0.15O2.825: a=3.9160(1)Å; La0.8Sr0.2Ga0.8Mg0.20O2.80: a=3.9195(1)Å. Samples of the first series transform from the orthorhombic to a rhombohedral (Imma→R3¯c) structure at ˜170 °C for La0.9Sr0.1GaO2.95, at ˜430 °C for La0.9Sr0.1Ga0.9Mg0.1O2.9, and between 600 and 700 °C for La0.9Sr0.1Ga0.8Mg0.2O2.85. Both La0.8Sr0.2Ga0.85Mg0.15O2.825 and La0.8Sr0.2Ga0.8Mg0.2 show no structural deviations from the cubic aristotype over the whole temperature range. The room temperature Imma structures of the first series are justified by a domain model and are rationalized in terms of static disorder increasing with Mg content, thus driving the phase transition temperatures to higher values in agreement with tolerance factor considerations. The distortion of the rhombohedral high-temperature phases (octahedra tilting and compression) and the effect of phase transitions on the ionic conductivity are discussed.

  4. High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Wirth, Brian; Motta, Athur; Morgan, Dane; Kaoumi, Djamel; Hosemann, Peter; Odette, Robert

    2018-04-30

    Project Objective: The objective of this proposal is to demonstrate the capability to predict the evolution of microstructure and properties of structural materials in-reactor and at high doses, using ion irradiation as a surrogate for reactor irradiations. “Properties” includes both physical properties (irradiated microstructure) and the mechanical properties of the material. Demonstration of the capability to predict properties has two components. One is ion irradiation of a set of alloys to yield an irradiated microstructure and corresponding mechanical behavior that are substantially the same as results from neutron exposure in the appropriate reactor environment. Second is the capability to predict the irradiated microstructure and corresponding mechanical behavior on the basis of improved models, validated against both ion and reactor irradiations and verified against ion irradiations. Taken together, achievement of these objectives will yield an enhanced capability for simulating the behavior of materials in reactor irradiations

  5. Specific Heat Capacity of Alloy 690 for Simulating Neutron Irradiation

    International Nuclear Information System (INIS)

    Park, Dae Gyu; Kim, Hee Moon; Song, Woong Sub; Baik, Seung Je; Joo, Young Sun; Ahn, Sang Bok; Park, Jin Seok; Lee, Won Jae; Ryu, Woo Seok

    2011-01-01

    The KAERI(Korea Atomic Energy Research Institute) is developing new type of nuclear reactor, so called 'SMART'(System Integrated Modular Advanced Reactor) which has many features of small power and system integrated modular type. Alloy 690 was selected as the candidate material for the heat exchanger tube of the steam generator of SMART. The SMART R and D is now facing the stage of engineering verification and approval of standard design to apply to DEMO reactors. Therefore, the material performance under the relevant environment is required to be evaluated. The important material performance issues are mechanical properties i.e. (fracture toughness, tensile and hardness) and thermal properties i.e. (thermal diffusivity, specific heat capacity and thermal conductivity) for which the engineering database is necessary to design a steam generator. However, the neutron post irradiation characteristics of the alloy 690 are barely known. As a result, PIE(Post Irradiation Examination) of thermal properties are planed and performed successfully. But specific heat capacity measurement is not performed because of not having proper test system for irradiated materials. Therefore in order to verify the effect of neutron irradiation for alloy 690, simulation method is adopted. In general, high energy neutron bombardment in material bring about lattice defects i.e. void, pore and dislocation. Dominant factor to impact to heat capacity is mainly dislocation in material. Therefore, simulation of neutron irradiation is devised by material rolling method in order to make artificial dislocation in alloy 690 as same effect of neutron irradiation. After preparing test specimens, heat capacity measurements are performed and results are compared with rolled materials and un-rolled materials to verify the effect of neutron irradiation simulation. Main interest of simulation is that heat capacity value is changed by neutron irradiation

  6. EL2-related defects in neutron irradiated GaAs1/sub -x/P/sub x/ alloys

    International Nuclear Information System (INIS)

    Munoz, E.; Garcia, F.; Jimenez, B.; Calleja, E.; Gomez, A.; Alcober, V.

    1985-01-01

    The generation of EL2-related defects in GaAsP alloys by fast neutron irradiation has been studied through deep level transient spectroscopy and photocapacitance techniques. After irradiation p-n junctions were not annealed at high temperatures. In the composition range x>0.4, fast neutrons generate a broad center at E/sub c/-0.7 eV that it is suggested to belong to the EL2 family. The presence of photocapacitance quenching effects has been taken as a preliminary fingerprint to make the above assignment. From computer analysis of the nonexponential transient capacitance waveforms, evidence that neutron irradiation creates a family of midgap levels, EL2-related, is found

  7. Results on Neutron and Gamma Irradiation of Electrolytic Tilmeters

    International Nuclear Information System (INIS)

    Calderon, A.; Calvo, E.; Figueroa, C. F.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Vila, I.; Virto, A. L.; Alberdi, J.; Arce, P.; Barcala, J. M.; Fernando, A.; Fuentes, J.; Josa, M. I.; Luque, J. M.; Molinero, A.; Navarrate, J.; Valdivieso, P.; Fenyvesi, A.; Molnar, J.

    2004-01-01

    We report on irradiation studies done to a sample of high precision electrolytic tiltmeters with gamma-rays, up to a maximum dose of 150 kGy, an neutrons, up to a maximum fluence 1.5x10''14 cm''2. The effect of the irradiation on their performance is discussed. (Author) 19 refs

  8. Results on Neutron and Gamma Irradiation of Electrolytic Tilmeters

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A.; Calvo, E.; Figueroa, C. F.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Vila, I.; Virto, A. L.; Alberdi, J.; Arce, P.; Barcala, J. M.; Fernando, A.; Fuentes, J.; Josa, M. I.; Luque, J. M.; Molinero, A.; Navarrate, J.; Valdivieso, P.; Fenyvesi, A.; Molnar, J.

    2004-07-01

    We report on irradiation studies done to a sample of high precision electrolytic tiltmeters with gamma-rays, up to a maximum dose of 150 kGy, an neutrons, up to a maximum fluence 1.5x10''14 cm''2. The effect of the irradiation on their performance is discussed. (Author) 19 refs.

  9. Tensile and fracture toughness test results of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R.; Moons, F.; Puzzolante, J.L. [Centre d`Etude de l`Energie Nucleaire, Mol (Belgium)

    1998-01-01

    Tensile and fracture toughness test results of four Beryllium grades are reported here. The flow and fracture properties are investigated by using small size tensile and round compact tension specimens. Irradiation was performed at the BR2 material testing reactor which allows various temperature and irradiation conditions. The fast neutron fluence (>1 MeV) ranges between 0.65 and 2.45 10{sup 21} n/cm{sup 2}. In the meantime, un-irradiated specimens were aged at the irradiation temperatures to separate if any the effect of temperature from irradiation damage. Test results are analyzed and discussed, in particular in terms of the effects of material grade, test temperature, thermal ageing and neutron irradiation. (author)

  10. Seed irradiation with continuously increasing doses of thermal neutrons

    International Nuclear Information System (INIS)

    Uhlik, J.; Pfeifer, M.; Pittermann, P.

    1977-01-01

    In the 'Raman' pea cv. the biological activity of thermal neutrons was investigated after irradiation of a 780 mm column of seeds for 3000 and 4167 seconds with a flux of 5.607 x 10 9 n.cm -2 per second. For different fractions of the seed column the average density of the neutron flux was calculated. It was proved that for the described method of seed irradiation it was sufficient to determine only the dose approaching the lethal dose. If a sufficiently high column of seeds is used part of the column of seeds will be irradiated with the optimum range of doses. The advantages of the suggested method of irradiation are not only smaller time and technological requirements resulting from the need for the determination of only the critical lethal dose of radiation by means of inhibition tests performed with seedlings, but also a simpler irradiation procedure. The suggested method of irradiation is at least nine times cheaper. (author)

  11. Defects investigation in neutron irradiated reactor steels by positron annihilation

    International Nuclear Information System (INIS)

    Slugen, V.

    2003-01-01

    Positron annihilation spectroscopy (PAS) based on positron lifetime measurements using the Pulsed Low Energy Positron System (PLEPS) was applied to the investigation of defects of irradiated and thermally treated reactor pressure vessel (RPV) steels. PLEPS results showed that the changes in microstructure of the RPV-steel properties caused by neutron irradiation and post-irradiation heat treatment can be well detected. From the lifetime measurements in the near-surface region (20-550 nm) the defect density in Russian types of RPV-steels was calculated using the diffusion trapping model. The post-irradiation heat treatment studies performed on non-irradiated specimens are also presented. (author)

  12. Proceedings of neutron irradiation technical meeting on BNCT

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    The 'Neutron Irradiation Technical Meeting for Boron Neutron Capture Therapy (BNCT)' was held on March 13, 2000 at Tokai Research Establishment. The Meeting is aimed to introduce the neutron beam facility for medical irradiation at JRR-4 to Japanese researchers widely, as well as providing an opportunity for young researchers, engineers, medical representatives such surgeons and doctors of pharmacology to present their research activities and to exchange valuable information. JAERI researcher presented the performance and the irradiation technology in the JRR-4 neutron beam facility, while external researchers made various and beneficial presentations containing such accelerator-based BNCT, spectrum-shifter, biological effect, pharmacological development and so on. In this meeting, a special lecture titled 'The Dawn of BNCT and Its Development.' was given by MD, Prof. Takashi Minobe, an executive director of Japan Foundation for Emergency Medicine. The 11 of the presented papers are indexed individually. (J.P.N.)

  13. Neutron and gamma irradiation effects on power semiconductor switches

    Science.gov (United States)

    Schwarze, G. E.; Frasca, A. J.

    1990-01-01

    The performance characteristics of high power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

  14. Proceedings of neutron irradiation technical meeting on BNCT

    International Nuclear Information System (INIS)

    2000-10-01

    The 'Neutron Irradiation Technical Meeting for Boron Neutron Capture Therapy (BNCT)' was held on March 13, 2000 at Tokai Research Establishment. The Meeting is aimed to introduce the neutron beam facility for medical irradiation at JRR-4 to Japanese researchers widely, as well as providing an opportunity for young researchers, engineers, medical representatives such surgeons and doctors of pharmacology to present their research activities and to exchange valuable information. JAERI researcher presented the performance and the irradiation technology in the JRR-4 neutron beam facility, while external researchers made various and beneficial presentations containing such accelerator-based BNCT, spectrum-shifter, biological effect, pharmacological development and so on. In this meeting, a special lecture titled 'The Dawn of BNCT and Its Development.' was given by MD, Prof. Takashi Minobe, an executive director of Japan Foundation for Emergency Medicine. The 11 of the presented papers are indexed individually. (J.P.N.)

  15. Neutron and gamma irradiation damage to organic materials.

    Energy Technology Data Exchange (ETDEWEB)

    White, Gregory Von, II; Bernstein, Robert

    2012-04-01

    This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

  16. Monitoring of the Irradiated Neutron Fluence in the Neutron Transmutation Doping Process of Hanaro

    Science.gov (United States)

    Kim, Myong-Seop; Park, Sang-Jun

    2009-08-01

    Neutron transmutation doping (NTD) for silicon is a process of the creation of phosphorus impurities in intrinsic or extrinsic silicon by neutron irradiation to obtain silicon semiconductors with extremely uniform dopant distribution. HANARO has two vertical holes for the NTD, and the irradiation for 5 and 6 inch silicon ingots has been going on at one hole. In order to achieve the accurate neutron fluence corresponding to the target resistivity, the real time neutron flux is monitored by self-powered neutron detectors. After irradiation, the total irradiation fluence is confirmed by measuring the absolute activity of activation detectors. In this work, a neutron fluence monitoring method using zirconium foils with the mass of 10 ~ 50 mg was applied to the NTD process of HANARO. We determined the proportional constant of the relationship between the resistivity of the irradiated silicon and the neutron fluence determined by using zirconium foils. The determined constant for the initially n-type silicon was 3.126 × 1019 n·Ω/cm. It was confirmed that the difference between this empirical value and the theoretical one was only 0.5%. Conclusively, the practical methodology to perform the neutron transmutation doping of silicon was established.

  17. Neutron self-shielding with k0-NAA irradiations

    International Nuclear Information System (INIS)

    Chilian, C.; Chambon, R.; Kennedy, G.

    2010-01-01

    A sample of SMELS Type II reference material was mixed with powdered Cd-nitrate neutron absorber and analysed by k 0 NAA for 10 elements. The thermal neutron self-shielding effect was found to be 34.8%. When flux monitors were irradiated sufficiently far from the absorbing sample, it was found that the self-shielding could be corrected accurately using an analytical formula and an iterative calculation. When the flux monitors were irradiated 2 mm from the absorbing sample, the calculations over-corrected the concentrations by as much as 30%. It is recommended to irradiate flux monitors at least 14 mm from a 10 mm diameter absorbing sample.

  18. Aspects of Low Temperature Irradiation in Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Brune, D.

    1968-08-01

    Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined

  19. Aspects of Low Temperature Irradiation in Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D

    1968-08-15

    Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined.

  20. Investigations on neutron irradiated 3D carbon fibre reinforced carbon composite material

    Science.gov (United States)

    Venugopalan, Ramani; Alur, V. D.; Patra, A. K.; Acharya, R.; Srivastava, D.

    2018-04-01

    As against conventional graphite materials carbon-carbon (C/C) composite materials are now being contemplated as the promising candidate materials for the high temperature and fusion reactor owing to their high thermal conductivity and high thermal resistance, better mechanical/thermal properties and irradiation stability. The current need is for focused research on novel carbon materials for future new generation nuclear reactors. The advantage of carbon-carbon composite is that the microstructure and the properties can be tailor made. The present study encompasses the irradiation of 3D carbon composite prepared by reinforcement using PAN carbon fibers for nuclear application. The carbon fiber reinforced composite was subjected to neutron irradiation in the research reactor DHRUVA. The irradiated samples were characterized by Differential Scanning Calorimetry (DSC), small angle neutron scattering (SANS), XRD and Raman spectroscopy. The DSC scans were taken in argon atmosphere under a linear heating program. The scanning was carried out at temperature range from 30 °C to 700 °C at different heating rates in argon atmosphere along with reference as unirradiated carbon composite. The Wigner energy spectrum of irradiated composite showed two peaks corresponding to 200 °C and 600 °C. The stored energy data for the samples were in the range 110-170 J/g for temperature ranging from 30 °C to 700 °C. The Wigner energy spectrum of irradiated carbon composite did not indicate spontaneous temperature rise during thermal annealing. Small angle neutron scattering (SANS) experiments have been carried out to investigate neutron irradiation induced changes in porosity of the composite samples. SANS data were recorded in the scattering wave vector range of 0.17 nm-1 to 3.5 nm-1. Comparison of SANS profiles of irradiated and unirradiated samples indicates significant change in pore morphology. Pore size distributions of the samples follow power law size distribution with

  1. DAMAGE IN MOLYBDENUM ASSOCIATED WITH NEUTRON IRRADIATION AND SUBSEQUENT POST-IRRADIATION ANNEALING

    Energy Technology Data Exchange (ETDEWEB)

    Mastel, B.

    1963-07-23

    Molybdemum containing carbon was studied in an attempt to establish the combined effect of impurity content and neutron irradiation on the properties and structure of specific metals. Molybdenum foils were punched into discs and heat treated in vacuum. They were then slow-cooled and irradiated. After irradiation and subsequent decay of radioactivity to a low level the foils were subjected to x-ray diffraction measurements. Cold-worked foils with less than 10 ppm carbon showed no change in microstructure due to irradiation. Molybdenum foils that were annealed prior to irradiation showed spot defects. In foils containing up to 500 ppm carbon, it was concluded that the small loops present after irradiation are due to the clustering of point defects at interstitial carbon atoms, followed by collapse to form a dislocation loop. The amount of lattice expansion after irradiation was strongly dependent on impurity content. Neutron irradiation was found to reduce the number of active slip systems. (M.C.G.)

  2. Study of boron carbide evolution under neutron irradiation

    International Nuclear Information System (INIS)

    Simeone, D.

    1999-01-01

    Owing to its high neutron efficiency, boron carbide (B 4 C) is used as a neutron absorber in control rods of nuclear plants. Its behaviour under irradiation has been extensively studied for many years. It now seems clear that brittleness of the material induced by the 10 B(n,α) 7 Li capture reaction is due to penny shaped helium bubbles associated to a high strain field around them. However, no model explains the behaviour of the material under neutron irradiation. In order to build such a model, this work uses different techniques: nuclear microprobe X-ray diffraction profile analysis and Raman and Nuclear Magnetic Resonance Spectroscopy to present an evolution model of B 4 C under neutron irradiation. The use of nuclear reactions produced by a nuclear microprobe such as the 7 Li(p,p'γ) 7 Li reaction, allows to measure lithium profile in B 4 C pellets irradiated either in Pressurised Water Reactors or in Fast Breeder Reactors. Examining such profiles enables us to describe the migration of lithium atoms out of B 4 C materials under neutron irradiation. The analysis of X-ray diffraction profiles of irradiated B 4 C samples allows us to quantify the concentrations of helium bubbles as well as the strain fields around such bubbles.Furthermore Raman spectroscopy studies of different B 4 C samples lead us to propose that under neutron irradiation. the CBC linear chain disappears. Such a vanishing of this CBC chain. validated by NMR analysis, may explain the penny shaped of helium bubbles inside irradiated B 4 C. (author)

  3. Biological Effects of Neutron and Proton Irradiations. Vol. II. Proceedings of the Symposium on Biological Effects of Neutron Irradiations

    International Nuclear Information System (INIS)

    1964-01-01

    During recent years the interest in biological effects caused by neutrons has been increasing steadily as a result of the rapid development of neutron technology and the great number of neutron sources being used. Neutrons, because of their specific physical characteristics and biological effects, form a special type of radiation hazard but, at the same time, are a prospective tool for applied radiobiology. This Symposium, held in Brookhaven at the invitation of the United States Government from 7-11 October 1963, provided an opportunity for scientists to discuss the experimental information at present available on the biological action of neutrons and to evaluate future possibilities. It was a sequel to the Symposium on Neutron Detection, Dosimetry and Standardization, which was organized by the International Atomic Energy Agency in December 1962 at Harwell. The Symposium was attended by 128 participants from 17 countries and 6 international organizations. Fifty-four papers were presented. The following subjects were discussed in various sessions: (1) Dosimetry. Estimation of absorbed dose of neutrons in biological material. (2) Biological effects of high-energy protons. (3) Cellular and genetic effects. (4) Pathology of neutron irradiation, including acute and chronic radiation syndromes (mortality, anatomical and histological changes, biochemical and metabolic disturbances) and delayed consequences. (5) Relative biological effectiveness of neutrons evaluated by different biological tests. A Panel on Biophysical Considerations in Neutron Experimentation, with special emphasis on informal discussions, was organized during the Symposium. The views of the Panel are recorded in Volume II of the Proceedings. Many reports were presented on the important subject of the relative effectiveness of the biological action of neutrons, as well as on the general pathology of neutron irradiation and the cellular and genetic effects related to it. Three survey papers considered

  4. Facility for fast neutron irradiation tests of electronics at the ISIS spallation neutron source

    International Nuclear Information System (INIS)

    Andreani, C.; Pietropaolo, A.; Salsano, A.; Gorini, G.; Tardocchi, M.; Paccagnella, A.; Gerardin, S.; Frost, C. D.; Ansell, S.; Platt, S. P.

    2008-01-01

    The VESUVIO beam line at the ISIS spallation neutron source was set up for neutron irradiation tests in the neutron energy range above 10 MeV. The neutron flux and energy spectrum were shown, in benchmark activation measurements, to provide a neutron spectrum similar to the ambient one at sea level, but with an enhancement in intensity of a factor of 10 7 . Such conditions are suitable for accelerated testing of electronic components, as was demonstrated here by measurements of soft error rates in recent technology field programable gate arrays

  5. Evaluation of neutron irradiation effect on SCC crack growth behaviour for austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Austenitic stainless steels are widely used as structural components in reactor pressure vessel internals because of their high strength, ductility, and fracture toughness. However, exposure to neutron irradiation results in changes in microstructure, mechanical properties and microchemistry of the steels. Irradiation assisted stress corrosion cracking (IASCC) caused by the effect of neutron irradiation during long term plant operation in high temperature water environments is considered to take the form of intergranular stress corrosion cracking (IGSCC) and the critical fluence level has been reported to be about 5x10{sup 24}n/m{sup 2} (E>1MeV) in Type 304 stainless steel in BWR environment. JNES had been conducting IASCC project during the JFY (2000) - JFY (2008) period, and prepared an engineering database on IASCC. However, the data of Crack Growth Rate (CGR) below the critical fluence level are not sufficient. So, this project was initiated to obtain the CGR data below the critical fluence level. Test specimens have been irradiated in the Halden reactor, operating by the OECD Halden Reactor Project, and the post irradiation examination (PIE) will be conducted from JFY (2011) to JFY (2013), finally the modified IASCC guide will be prepared in JFY (2013). (author)

  6. Effect of neutron irradiation on p-type silicon

    International Nuclear Information System (INIS)

    Sopko, B.

    1973-01-01

    The possibilities are discussed of silicon isotope reactions with neutrons of all energies. In the reactions, 30 Si is converted to a stable phosphorus isotope forming n-type impurities in silicon. The above reactions proceed as a result of thermal neutron irradiation. An experiment is reported involving irradiation of two p-type silicon single crystals having a specific resistance of 2000 ohm.cm and 5000 to 20 000 ohm.cm, respectively, which changed as a result of irradiation into n-type silicon with a given specific resistance. The specific resistance may be pre-calculated from the concentration of impurities and the time of irradiation. The effects of irradiation on other silicon parameters and thus on the suitability of silicon for the manufacture of semiconductor elements are discussed. (J.K.)

  7. Tritium release from beryllium pebbles after high temperature irradiation up to 3000 appm He in the HIDOBE-01 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Til, S. van, E-mail: vantil@nrg.eu [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Fedorov, A.V.; Stijkel, M.P.; Cobussen, H.L.; Mutnuru, R.K.; Idsert, P. van der [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Zmitko, M. [The European Joint Undertaking for ITER and The Development of Fusion Energy, c/ Josep Pla, no. 2, Torres Diagonal Litoral, Edificio B3, 08019 Barcelona (Spain)

    2013-11-15

    In the HIDOBE (HIgh DOse irradiation of BEryllium) irradiation program, various grades of constrained and unconstrained beryllium pebbles, beryllium pellets and titanium-beryllide samples are irradiated in the High Flux Reactor (HFR) in Petten at four different temperatures (between 698 K and 1023 K) for 649 days [1]. The first of two HIDOBE irradiation experiments, HIDOBE-01, was completed after achieving a DEMO relevant helium production level of 3000 appm and the samples are retrieved for postirradiation examination (PIE). This work shows preliminary results of the out-of-pile tritium release analysis performed on different grades of irradiated beryllium pebbles (different in size). Relationships between irradiation temperature, tritium inventory and microstructural evolution have been observed by light microscopy and scanning electron microscopy.

  8. A design study on hyper-thermal neutron irradiation field for neutron capture therapy at Kyoto University Reactor

    International Nuclear Information System (INIS)

    Sakurai, Y.; Kobayashi, T.

    2000-01-01

    A study about the installation of a hyper-thermal neutron converter to a clinical collimator was performed, as a series of the design study on a hyper-thermal neutron irradiation field at the Heavy Water Neutron Irradiation Facility of Kyoto University Reactor. From the parametric-surveys by Monte Carlo calculation, it was confirmed that the practical irradiation field of hyper-thermal neutrons would be feasible by the modifications of the clinical collimator and the bismuth-layer structure. (author)

  9. Neutronic Modelling in Support of the Irradiation Programmes

    International Nuclear Information System (INIS)

    Koonen, E.

    2005-01-01

    Irradiation experiments are generally conducted to determine some specific characteristics of the concerned fuels and structural materials under well defined irradiation conditions. For the determination of the latter the BR2 division has an autonomous reactor physics cell and has implemented the required computational tools. The major tool used is a three-dimensional full-scale Monte Carlo model of the BR2 reactor developed under MCNP-4C for the simulation of irradiation conditions. The objectives of work performed by SCK-CEN are to evaluate and adjust irradiation conditions by adjustments of the environment, differential rod positions, axial and azimuthal positioning of the samples, global power level, ...; to deliver reliable, well defined irradiation condition and fluence data during and after irradiation; to assist the designer of new irradiation devices by simulations and neutronic optimisations of design options; to provide computational support to related projects as a way to valorise the capabilities that the BR2 reactor can offer

  10. The effect of fast neutron irradiation on the superconducting properties of REBCO coated conductors with and without artificial pinning centers

    Science.gov (United States)

    Fischer, D. X.; Prokopec, R.; Emhofer, J.; Eisterer, M.

    2018-04-01

    Superconductors are essential components of future fusion power plants. The magnet coils responsible for producing the field required for confining the fusion plasma are exposed to considerable neutron radiation. This makes irradiation studies necessary for understanding the radiation response of the superconductor. High temperature superconductors are promising candidates as magnet coil materials. YBCO and GdBCO tapes of several manufacturers were irradiated to fast neutron fluences of up to 3.9 × 1022 m-2 in the research reactor at the Atominstitut. Low energy neutrons contribute to the fission reactor spectrum but not to the expected spectrum at the fusion magnets. Low energy neutrons have to be shielded in irradiation experiments to avoid their substantial effect on the superconducting properties of tapes containing gadolinium. The critical current (I c) of the tapes in this study was examined at fields of up to 15 T and down to a temperature of 30 K. I c first increases upon irradiation and reaches a maximum at a certain fluence, which depends highly on temperature, being highest at low temperature. I c declines at high fluences and eventually degrades with respect to its initial value. Tapes with artificial pinning centers (APCs) degrade at lower fluences than tapes without them. The n-values decrease in all types of tapes after irradiation even when the critical currents are increased. The field dependence of the volume pinning force differs in pristine tapes with and without APCs but shows the same behavior after irradiation.

  11. Investigation of phase transformations by in-situ neutron diffraction in a Co-Re-based high temperature alloy

    Czech Academy of Sciences Publication Activity Database

    Mukherji, D.; Strunz, Pavel; Gilles, R.; Hofmann, M.; Schmitz, F.; Rösler, J.

    2010-01-01

    Roč. 64, č. 23 (2010), s. 2608-2611 ISSN 0167-577X Institutional research plan: CEZ:AV0Z10480505 Keywords : Superalloy * Carbide * Neutron diffraction Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.120, year: 2010

  12. Effects of electron beam irradiation on mechanical properties at low and high temperature of fiber reinforced composites using PEEK as matrix material

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Seguchi, Tadao; Sakai, Hideo; Odajima, Toshikazu; Nakakura, Toshiyuki; Masutani, Masahiro.

    1987-11-01

    Carbon fiber reinforced composite (PEEK-CF) using polyarylether-ether-ketone (PEEK) as a matrix material was prepared and the electron beam radiation effects on the mechanical properties at low and high temperature and the effects of annealing after irradiation were studied. Cooling down to 77 K, the flexural strength of PEEK-CF increased to about 20 % than that at room temperature. The data of flexural strength for the irradiated specimens showed some scattering, but the strength and modulus at 77 K were changed scarcely up to 120 MGy. The flexural strength and modulus in the unirradiated specimen decreased with increasing of measurement temperature, and the strength at 140 deg C, which is the just below temperature of the glass transition of PEEK, was to 70 % of the value at room temperature. For the irradiated specimens, the strength and modulus increased with dose and the values at 140 deg C for the specimen irradiated with 120 MGy were nearly the same with the unirradiated specimen measured at room temperature. The improvement of mechanical properties at high temperature by irradiation was supported by a viscoelastic measurement in which the glass transition shifted to the higher temperature by the radiation-induced crosslinking. A glass fiber reinforced PEEK composite (PEEK-GF) was prepared and its irradiation effects by electron beam was studied. Unirradiated PEEK-GF showed the same performance with that for GFRP of epoxide resin as matrix material, but by irradiation the flexual strength and modulus decreased with dose. It was revealed that this composite was destroyed by delamination because inter laminar shear strength (ILSS) decreased with dose and analysis of the profile of S-S curve showed typical delamination. Fractoglaphy by electron microscopy supported the delamination which is caused by the lowering of adhesion on interface between the fiber and matrix with increase of dose. (author)

  13. Verification of neutron irradiation on S/G tube materials

    International Nuclear Information System (INIS)

    Kang, Byoung Hwi; Lee, S. K.; Jang, D. Y.; Jo, K. H.

    2010-12-01

    The fluence monitors were fabricated with metal wires of the purity ≥ 99.9%, whose dimensions were 0.1mm diameter, about 3mm length, and around 150-200 μg mass range. Three wire samples (Fe, Ni, Ti) were prepared for one irradiation aluminum capsule. Five capsules were irradiated in the OR5 hole of the HANARO reactor at 30 MW power for about 25 days. The reaction rates were calculated by using the measured radiation activity data, and then neutron fluence were obtained from the reaction rates and the weighted neutron cross section with calculated neutron spectrum at the fluence monitor position. The measured neutron fluences were compared to the calculated ones. (Errors ≤ 35%)

  14. Behavior under irradiation of super-mirror for neutron guides

    International Nuclear Information System (INIS)

    N'Guy-Marechal, K.

    1997-10-01

    The aim of this work is to study the aging of NiCx/Ti super-mirror multilayers used in neutron guides under thermal neutron irradiation. These multilayers allow an increase of the apparent critical angle of total reflection by creating constructive interferences. Neutrons fluxes are thus increased in neutron guides made with a super-mirror coating. Thin films of one and ten bilayers have been deposited on a silicon and a borosilicate glass substrate. We have then studied the evolution of their optical, structural and mechanical properties after irradiation and annealing. After irradiation, a decrease in neutron reflectivity has been observed, due to the interdiffusion of both materials: this phenomenon was particularly important in the coatings deposited on a glass substrate. X-ray diffraction and X-ray absorption spectroscopy have shown that the structural evolutions of both nickel and titanium do not depend on the substrate. Nickel layers remain face-centered cubic after treatment, whereas the initially hexagonal closed-packed titanium becomes face-centered cubic with a texture in the [111] direction. This phase transformation has been attributed to the formation of a TiH compound containing as much as 50% hydrogen. Despite these structural changes, stress relaxation has occurred after irradiation in our layers. On the contrary, the mean stress that we have determined in previous samples, elaborated in another laboratory, has increased after irradiation. Comparison of both results shows that stress evolution is linked to the deposition conditions. As stress remains almost unchanged after annealing, we may conclude that only irradiation defects, and not heating, lead to stress evolution. Our samples being very similar to real neutron guides, we can extend the results we have obtained in this work to real super-mirrors. (author)

  15. Irradiation facilities at the spallation neutron source SINQ

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, E.; Ledermann, J.; Aebersold, H.; Kuehne, G.; Kohlik, K. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Four independent experiments for sample irradiation are under construction and in preparation for operational tests at the spallation source SINQ. Three of them are located inside a thermal beam port with end positions inside or near the moderator tank. The other experiment will be established at the end position of a super mirror lined neutron guide for applications with cold neutrons. (author) 3 figs., 1 tab., 6 refs.

  16. Effect of simultaneous ion irradiation on microstructural change of SiC/SiC composites at high temperature

    International Nuclear Information System (INIS)

    Taguchi, T.; Wakai, E.; Igawa, N.; Nogami, S.; Snead, L.L.; Hasegawa, A.; Jitsukawa, S.

    2002-01-01

    The effect of simultaneous triple ion irradiation of He, H and Si on microstructural evolution of two kinds of SiC/SiC composites (HNS composite (using Hi-Nicalon type S SiC fiber) and TSA composite (using Tyranno SA SiC fiber)) at 1000 deg. C has been investigated. The microstructure observations of SiC/SiC composites irradiated to 10 dpa were examined by transmission electron microscopy. He bubbles were hardly formed in matrix of TSA composite, but many helium bubbles and some cracks were observed at grain boundaries of matrix of HNS composite. He bubbles and cracks were not, on the other hand, observed in the both fiber fabrics of HNS and TSA composites. Debonding between fiber and carbon layer following irradiation region was not observed in the both composites. Under these irradiation conditions, TSA composite showed the better microstructural stability against ion beams irradiation than one of HNS composite

  17. Stability of Y-Ti-O nanoparticles in ODS alloys during heat treatment and high temperature swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A. [FLNR, JINR, Dubna (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation); Dubna State University, Dubna (Russian Federation); Sohatsky, A.S.; Kornieieva, K. [FLNR, JINR, Dubna (Russian Federation); O' Connell, J.H.; Neethling, J.H. [CHRTEM, NMMU, Port Elizabeth (South Africa); Nikitina, A.A.; Ageev, V.S. [JSC VNIINM, Moscow (Russian Federation); Zdorovets, M. [Institute of Nuclear Physics, Astana (Kazakhstan); Ural Federal University, Yekaterinburg (Russian Federation); Volkov, A.D. [Nazarbayev University, Astana (Kazakhstan)

    2016-12-15

    Aim of this report is to compare the morphology of swift (167 and 220 MeV) Xe ion induced latent tracks in Y{sub 2}Ti{sub 2}O{sub 7} nanoparticles during post-irradiation heat treatment and after irradiation at different temperatures in pre-thinned TEM foils and TEM targets prepared from hundreds microns thick irradiated oxide dispersion strengthened (ODS) steel. No difference in track parameters was found in room temperature irradiated nanoparticles in pre-thinned and conventional samples. Microstructural data gathered from pre-thinned foils irradiated in the temperature range 350-650 C or annealed at similar temperatures demonstrate that amorphous latent tracks interact with the surrounding matrix, changing the track and nanoparticle morphology, while such effect is not observed in conventional ODS material treated at the same conditions. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. An Electron Microscope Study of the Thermal Neutron Induced Loss in High Temperature Tensile Ductility of Nb Stabilized Austenitic Steels

    Energy Technology Data Exchange (ETDEWEB)

    Roy, R B

    1965-04-15

    Irradiated {approx}3 x 10{sup 19} n/cm{sup 2} (thermal), <3 x 10{sup 18} n/cm{sup 2} (> 1 MeV) at 40 deg C and the corresponding unirradiated control tensile specimens of a 20 % Cr, 25 % Ni, Nb stabilized steel tested at 650 deg C, 750 deg C and 800 deg C have been examined by transmission electron microscopy. The results indicate that the irradiation induced embrittlement of the tensile specimens at elevated temperatures is preceded by the formation of fine precipitates within the grains. These precipitates may restrict the deformation within the grains such that the stresses are concentrated at the grain boundaries thereby leading to premature failure. It is suggested that the main effect of the irradiation is to promote conditions necessary for the formation of these precipitates, namely, super saturation and fresh nucleation sites within the matrix through the energetic emission of He and Li atoms from boron as an impurity.

  19. An Electron Microscope Study of the Thermal Neutron Induced Loss in High Temperature Tensile Ductility of Nb Stabilized Austenitic Steels

    International Nuclear Information System (INIS)

    Roy, R.B.

    1965-04-01

    Irradiated ∼3 x 10 19 n/cm 2 (thermal), 18 n/cm 2 (> 1 MeV) at 40 deg C and the corresponding unirradiated control tensile specimens of a 20 % Cr, 25 % Ni, Nb stabilized steel tested at 650 deg C, 750 deg C and 800 deg C have been examined by transmission electron microscopy. The results indicate that the irradiation induced embrittlement of the tensile specimens at elevated temperatures is preceded by the formation of fine precipitates within the grains. These precipitates may restrict the deformation within the grains such that the stresses are concentrated at the grain boundaries thereby leading to premature failure. It is suggested that the main effect of the irradiation is to promote conditions necessary for the formation of these precipitates, namely, super saturation and fresh nucleation sites within the matrix through the energetic emission of He and Li atoms from boron as an impurity

  20. Detection and measurement of neutron-irradiated gemstones

    International Nuclear Information System (INIS)

    Bunnak, S.; Jerachanchai, S.; Chinudomsub, K.; Saiyut, K.

    1990-01-01

    Color enhance gemstone, neutron-irradiated topaz, was analyzed by gamma spectrometry for examining characteristic and activity. Topaz was irradiated in the wet-tube facility of the Research Reactor TRR/1 which neutron fluence is 2.52x10 17 neutron per square centimeter. After 100 days of decay, topaz was sampling to the qualitative and quantitative analysis using multichannel analyzer of Nuclear Data Model ND65 and hyper pure germanium detector. Calculation and evaluation were done by microcomputer IBM/PC 640 KB RAM. The qualitative analysis showed that the neutron-irradiated topaz has 2 major isotopes, i.e., Ta-182 and Sc-46. Quantitative activity was compared with reference standard source Eu-152 (NBS) and the results were shown in the table 1. The Health Physics Division, OAEP, inspected on 6240.9 gm of the neutron-irradiated topaz using standard release limit 2 nCi/gm (74 Bq/gm). It was found that only 423.9 gm out of the total amount were over the standard release limit

  1. Neutron irradiation effect of thermally-sensitized stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Hide, Kouitiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1998-03-01

    Intergranular stress corrosion cracking (IGSCC) susceptibility of irradiated thermally-sensitized Type 304 Stainless Steels (SSs) was studied as a function of neutron fluence and correlated with mechanical responses of the materials. Neutron irradiation was carried out to neutron fluences up to 1.1 x 10{sup 24} n/m{sup 2} (E > 1MeV) at the light water reactor temperature in the Japan Material Test Reactor. The irradiated specimens were examined by slow strain rate stress corrosion cracking tests in 290degC pure water of 0.2 ppm dissolved oxygen concentration and microhardness measurements. The IGSCC susceptibility of the irradiated specimens increased with neutron fluence up to 1.1 x 10{sup 24} n/m{sup 2}. From an attempt to correlate the IGSCC susceptibility with the mechanical properties, an excellent correlation was identified between the susceptibility and microhardness increments at the grain boundary relative to the grain center. While intergranular corrosion rate of thermally sensitized SS increased with neutron fluence up to 1.1 x 10{sup 24} n/m{sup 2}, that of solution annealed SS did not change. The incremental grain boundary hardening and degradation of intergranular corrosion resistance may presumably be the major factors affecting IGSCC performance. (author)

  2. The morphology of radiation damage in copper irradiated with neutrons at elevated temperatures

    International Nuclear Information System (INIS)

    Kemm, K.R.

    1977-01-01

    This thesis is an investigation of the radiation damage morphology of high purity copper crystals irradiated with fast neutrons at temperatures in the range of 250 to 400 degrees C. At these high temperatures neutron damage is found to accumulate into large 3-dimensional rafts up to 100 μm in size, and the well known homogeneous distribution of black dot damage which is characteristic of irradiations at low temperatures is not observed. The characteristics and composition of the rafts of damage at different temperatures in the range 250 to 400 degrees C have been compared and found to differ to a large extent. It has also been shown that the background areas between rafts contain a rather low density of damage at all temperatures studied. It is therefore concluded that many of the interstitial atoms formed during irradiation migrate over large distances through the crystal lattice to precipitate at the sites of the dislocations forming the large rafts, and so denuded inter-rafts areas are left behind. It is proposed that these large rafts originate from grown-in dislocations present in the crystal before irradiation

  3. Microstructure and mechanical properties of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, E.; Kawamura, H. [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Terai, T.; Tanaka, S.

    1998-01-01

    Microstructure and mechanical properties of the neutron irradiated beryllium with total fast neutron fluences of 1.3 - 4.3 x 10{sup 21} n/cm{sup 2} (E>1 MeV) at 327 - 616degC were studied. Swelling increased by high irradiation temperature, high fluence, and by the small grain size and high impurity. Obvious decreasing of the fracture stress was observed in the bending test and in small grain specimens which had many helium bubbles on the grain boundary. Decreasing of the fracture stress for small grain specimens was presumably caused by crack propagation on the grain boundaries which weekend by helium bubbles. (author)

  4. Neutron irradiation of RPCs for the CMS experiment

    CERN Document Server

    Abbrescia, M; Belli, G; Bruno, G; Colaleo, A; Guida, R; Iaselli, G; Loddo, F; Maggi, M; Marangelli, B; Natali, S; Nuzzo, S; Pugliese, G; Ranieri, A; Romano, F

    2003-01-01

    All the CMS muon stations will be equipped with Resistive Plate Chambers (RPCs). They will be exposed to high neutron background environment during the LHC running. In order to verify the safe operation of these detectors, an irradiation test has been carried out with two RPCs at high neutron flux (about 10**8 n cm**-**2 s**- **1), integrating values of dose and fluence equivalent to 10 LHC- years. Before and after the irradiation, the performance of the detectors was studied with cosmic muons, showing no relevant aging effects. Moreover, no indication of damage or chemical changes were observed on the electrode surfaces.

  5. Neutron irradiation of RPCs for the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G. E-mail: gabriella.pugliese@ba.infn.it; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Guida, R.; Ratti, S.P.; Riccardi, C.; Torre, P.; Vitulo, P

    2003-08-01

    All the CMS muon stations will be equipped with Resistive Plate Chambers (RPCs). They will be exposed to high neutron background environment during the LHC running. In order to verify the safe operation of these detectors, an irradiation test has been carried out with two RPCs at high neutron flux (about 10{sup 8} n cm{sup -2} s{sup -1}), integrating values of dose and fluence equivalent to 10 LHC-years. Before and after the irradiation, the performance of the detectors was studied with cosmic muons, showing no relevant aging effects. Moreover, no indication of damage or chemical changes were observed on the electrode surfaces.

  6. Behavior of fluorine 18 in neutron irradiated zeolites

    International Nuclear Information System (INIS)

    Estevez Lopez, D.R.

    1992-01-01

    The transformation of Li-exchanged H-Y zeolite has been investigated at 300, 550, 850 and 1050 Centigrade degree, formation of quartz structure in addition to an amorphous phase, was nited. The Li-aluminosilicate obtained was neutron irradiated and the chemical behavior of 18 F produced by the reaction sequence 6 Li (n, α) 3 H, 16 O ( 3 H, n) 18 F, was studied. The neutron irradiated material was purged with argon-hydron gas streams. It was found that the amount of released 18 F depends on the temperature used (Author)

  7. Microstructural evolution in neutron irradiated reactor pressure vessel steels

    International Nuclear Information System (INIS)

    English, C.A.; Phythian, W.J.

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. The microstructural evolution in neutron irradiated reactor pressure vessel steels is described. The damage mechanisms are elaborated and techniques for examining the microstructure are suggested. The importance of the initial damage event is analysed, and the microstructural evolution in RPV steels is examined

  8. Focusing mirrors for enhanced neutron radiography with thermal neutrons and application for irradiated nuclear fuel

    Science.gov (United States)

    Rai, Durgesh K.; Abir, Muhammad; Wu, Huarui; Khaykovich, Boris; Moncton, David E.

    2018-01-01

    Neutron radiography is a powerful method of probing the structure of materials based on attenuation of neutrons. This method is most suitable for materials containing heavy metals, which are not transparent to X-rays, for example irradiated nuclear fuel and other nuclear materials. Neutron radiography is one of the first non-distractive post-irradiated examination methods, which is applied to gain an overview of the integrity of irradiated nuclear fuel and other nuclear materials. However, very powerful gamma radiation emitted by the samples is damaging to the electronics of digital imaging detectors and has so far precluded the use of modern detectors. Here we describe a design of a neutron microscope based on focusing mirrors suitable for thermal neutrons. As in optical microscopes, the sample is separated from the detector, decreasing the effect of gamma radiation. In addition, the application of mirrors would result in a thirty-fold gain in flux and a resolution of better than 40 μm for a field-of-view of about 2.5 cm. Such a thermal neutron microscope can be useful for other applications of neutron radiography, where thermal neutrons are advantageous.

  9. Materials for cold neutron sources: Cryogenic and irradiation effects

    International Nuclear Information System (INIS)

    Alexander, D.J.

    1990-01-01

    Materials for the construction of cold neutron sources must satisfy a range of demands. The cryogenic temperature and irradiation create a severe environment. Candidate materials are identified and existing cold sources are briefly surveyed to determine which materials may be used. Aluminum- and magnesium-based alloys are the preferred materials. Existing data for the effects of cryogenic temperature and near-ambient irradiation on the mechanical properties of these alloys are briefly reviewed, and the very limited information on the effects of cryogenic irradiation are outlined. Generating mechanical property data under cold source operating conditions is a daunting prospect. It is clear that the cold source material will be degraded by neutron irradiation, and so the cold source must be designed as a brittle vessel. The continued effective operation of many different cold sources at a number of reactors makes it clear that this can be accomplished. 46 refs., 8 figs., 2 tab

  10. Examination of the creep behaviour of ceramic fuel elements under neutron irradiation

    International Nuclear Information System (INIS)

    Brucklacher, D.

    1978-01-01

    This paper examines the creeping of UO 2 , UO 2 -PuO 2 and UN under neutron irradiation. It starts with the experimental results about the relation between the thermal creep rate and the load, the temperature, as well as characteristic material values, stoichiometry, grain size and porosity. These correlation are first qualitatively discussed and then compared with the statements of actual quantitative equations. From the models and theories on which these equations are based a modified Nabarro-Heering-equation results for the correlation between the creep rate of ceramic fuels, stress, temperature and the fission rate. In the experimental part of the examination, length-changes of creep samples of UO 2 , (U,Pu)O 2 and UN were measured in specially developed irradiation creep casings in different reactors. The measuring data were corrected and evaluated considering the thermal expansion effects, irregular temperature distribution and swelling effects in such a way that the dependences of the creep rate of UO 2 , UO 2 -PuO 2 and UN under irradiation on stress, temperature, fission rate, burn-up and porosity is obtained. It shows that creeping of fuels under irradiation at high temperatures is equivalent to thermally activated creeping, while at low temperature the creep rate induced by irradiation is much higher than the condition without irradiation. The increment of oxidic nuclear fuels is greater than in UN, the stress dependence on low burn-up is proportional in both cases, and the influence of temperature is quite small. (orig.) [de

  11. Trapping of hydrogen isotopes in radiation defects formed in tungsten by neutron and ion irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, Y., E-mail: hatano@ctg.u-toyama.ac.jp [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Shimada, M. [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Alimov, V.Kh.; Shi, J.; Hara, M.; Nozaki, T. [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Oya, Y.; Kobayashi, M.; Okuno, K. [Faculty of Science, Shizuoka University, Shizuoka 422-8529 (Japan); Oda, T. [Department of Nuclear Engineering and Management, The University of Tokyo, Tokyo 113-8656 (Japan); Cao, G. [Department of Engineering Physics, The University of Wisconsin, Madison, WI 53706 (United States); Yoshida, N.; Futagami, N. [Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580 (Japan); Sugiyama, K.; Roth, J.; Tyburska-Püschel, B.; Dorner, J. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Takagi, I. [Department of Nuclear Engineering, Kyoto University, Kyoto 606-8501 (Japan); Hatakeyama, M.; Kurishita, H. [Institute for Materials Research, Tohoku University, Oarai 311-1313 (Japan); and others

    2013-07-15

    Retention of D in neutron-irradiated W and desorption were examined after plasma exposure at 773 K. Deuterium was accumulated at a relatively high concentration up to a large depth of 50–100 μm due to the trapping effects of defects uniformly induced in the bulk. A significant D release in a vacuum continued to temperatures ⩾1173 K because of the small effective diffusion coefficient and the long diffusion distance. Exposure of ion-irradiated W to D{sub 2} gas showed a clear correlation between concentrations of trapped and solute D as determined by the trapping–detrapping equilibrium. These observations indicated that the accumulation of tritium in high concentrations is possible even at high temperatures if the concentration of solute tritium is high, and baking at moderate temperatures is ineffective for removal of tritium deeply penetrating into the bulk. Nevertheless, clear enhancement of D release was observed under the presence of solute H.

  12. First results of laser welding of neutron irradiated stainless steel

    International Nuclear Information System (INIS)

    Osch, E.V. van; Hulst, D.S. d'; Laan, J.G. van der.

    1994-10-01

    First results of experimental investigations on the laser reweldability of neutron irradiated material are reported. These experiments include the manufacture of 'heterogeneous' joints, which means joining of irradiated stainless steel of type AISI 316L-SPH to 'fresh' unirradiated material. The newly developed laser welding facility in the ECN Hot Cell Laboratory and experimental procedures are described. Visual inspections of welded joints are reported as well as results of electron microscopy and preliminary metallographic examinations. (orig.)

  13. Irradiation hardening and localized deformation of neutron-irradiated α-iron single crystals

    International Nuclear Information System (INIS)

    Mughrabi, H.; Stroehle, D.; Wilkens, M.

    1981-01-01

    The early yielding behaviour of neutron-irradiated α iron single crystals orientated for single slip was investigated as a function of neutron dose. In the range of neutron doses between approx. equal to 10 18 and approx. equal to 10 19 n/cm 2 , the irradiation hardening increment was found to be almost constant. Qualitative modifications of this behaviour were observed in the case of predeformed specimens. The localized deformation of the neutron-irradiated specimens by dislocation channelling was investigated by slip-line observations, transmission electron microscopy and X-ray topography. A model of localized deformation is proposed in order to explain the development of the observed asymmetric dislocation double layers which bound the channels and transmit characteristic misorientations. (orig.)

  14. Deformation and Fracture Properties in Neutron Irradiated Pure Mo and Mo Alloys

    International Nuclear Information System (INIS)

    Byun, T.S.; Snead, L.; Li, M.; Cockeram, B.V.

    2007-01-01

    Full text of publication follows: The evolution in microstructural and mechanical properties was investigated for molybdenum and molybdenum alloys after high temperature neutron irradiation. Test materials include oxide dispersion-strengthened (ODS) molybdenum alloy, molybdenum- 0.5% titanium-0.1% zirconium (TZM) alloy, and low carbon arc-cast (LCAC) molybdenum. Tensile specimens were irradiated in high flux isotope reactor (HFIR) at temperatures in the range ∼300 - 1000 deg. C to neutron fluences of 2.28 - 24.7 x 10 25 n/m 2 (E>0.1 MeV) or 1.2-13.1 dpa. Tensile tests were performed at temperatures ranging from -150 deg. C to 1000 deg. C. To evaluate irradiation effects, true stress parameters (yield stress, plastic instability stress, and true fracture stress) and ductility parameters (uniform strain, fracture strain, and reduction area) were compared for both irradiated and non-irradiated materials. Fracture toughness was also evaluated from the fracture stress and fracture strain data using a fracture strain model. The fracture strain was used to determine the ductile-to-brittle transition temperature (DBTT). Results indicate that irradiation in the temperature range of 600 - 800 deg. C hardened the materials by up to 70%, while the irradiation hardening outside this temperature range was much lower (<40%). The plastic instability stress was strongly dependent on test temperature; however, it was nearly independent of irradiation dose and temperature. It was also found that the true fracture stress was dependent on test temperature. The true fracture stress was not significantly influenced by irradiation at elevated and high test temperatures; however, it was decreased significantly at sub-zero temperatures after irradiation due to material embrittlement. The DBTT for 600 deg. C irradiated ODS molybdenum alloy was found to be about room temperature or lower, and among the test materials the ODS alloy showed the highest resistance to irradiation embrittlement

  15. Neutron irradiation creep in stainless steel alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schuele, Wolfgang (Commission of the European Union, Institute for Advanced Materials, I-21020 Ispra (Vatican City State, Holy See) (Italy)); Hausen, Hermann (Commission of the European Union, Institute for Advanced Materials, I-21020 Ispra (Vatican City State, Holy See) (Italy))

    1994-09-01

    Irradiation creep elongations were measured in the HFR at Petten on AMCR steels, on 316 CE-reference steels, and on US-316 and US-PCA steels varying the irradiation temperature between 300 C and 500 C and the stress between 25 and 300 MPa. At the beginning of an irradiation a type of primary'' creep stage is observed for doses up to 3-5 dpa after which dose the secondary'' creep stage begins. The primary'' creep strain decreases in cold-worked steel materials with decreasing stress and decreasing irradiation temperature achieving also negative creep strains depending also on the pre-treatment of the materials. These primary'' creep strains are mainly attributed to volume changes due to the formation of radiation-induced phases, e.g. to the formation of [alpha]-ferrite below about 400 C and of carbides below about 700 C, and not to irradiation creep. The secondary'' creep stage is found for doses larger than 3 to 5 dpa and is attributed mainly to irradiation creep. The irradiation creep rate is almost independent of the irradiation temperature (Q[sub irr]=0.132 eV) and linearly dependent on the stress. The total creep elongations normalized to about 8 dpa are equal for almost every type of steel irradiated in the HFR at Petten or in ORR or in EBR II. The negative creep elongations are more pronounced in PCA- and in AMCR-steels and for this reason the total creep elongation is slightly smaller at 8 dpa for these two steels than for the other steels. ((orig.))

  16. Dosimetry in Thermal Neutron Irradiation Facility at BMRR

    Directory of Open Access Journals (Sweden)

    Hu J.-P.

    2016-01-01

    Full Text Available Radiation dosimetry for Neutron Capture Therapy (NCT has been performed since 1959 at Thermal Neutron Irradiation Facility (TNIF of the three-megawatt light-water cooled Brookhaven Medical Research Reactor (BMRR. In the early 1990s when more effective drug carriers were developed for NCT, in which the eye melanoma and brain tumors in rats were irradiated in situ, extensive clinical trials of small animals began using a focused thermal neutron beam. To improve the dosimetry at irradiation facility, a series of innovative designs and major modifications made to enhance the beam intensity and to ease the experimental sampling at BMRR were performed; including (1 in-core fuel addition to increase source strength and balance flux of neutrons towards two ports, (2 out of core moderator remodeling, done by replacing thicker D2O tanks at graphite-shutter interfacial areas, to expedite neutron thermalization, (3 beam shutter upgrade to reduce strayed neutrons and gamma dose, (4 beam collimator redesign to optimize the beam flux versus dose for animal treatment, (5 beam port shielding installation around the shutter opening area (lithium-6 enriched polyester-resin in boxes, attached with polyethylene plates to reduce prompt gamma and fast neutron doses, (6 sample holder repositioning to optimize angle versus distance for a single organ or whole body irradiation, and (7 holder wall buildup with neutron reflector materials to increase dose and dose rate from scattered thermal neutrons. During the facility upgrade, reactor dosimetry was conducted using thermoluminescent dosimeters TLD for gamma dose estimate, using ion chambers to confirm fast neutron and gamma dose rate, and by the activation of gold-foils with and without cadmium-covers, for fast and thermal neutron flux determination. Based on the combined effect from the size and depth of tumor cells and the location and geometry of dosimeters, the measured flux from cadmium-difference method was 4–7

  17. Dosimetry in Thermal Neutron Irradiation Facility at BMRR

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J. P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Holden, N. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Reciniello, R. N.

    2014-05-23

    Radiation dosimetry for Neutron Capture Therapy (NCT) has been performed since 1959 at Thermal Neutron Irradiation Facility (TNIF) of the three-megawatt light-water cooled Brookhaven Medical Research Reactor (BMRR). In the early 1990s when more effective drug carriers were developed for NCT, in which the eye melanoma and brain tumors in rats were irradiated in situ, extensive clinical trials of small animals began using a focused thermal neutron beam. To improve the dosimetry at irradiation facility, a series of innovative designs and major modifications made to enhance the beam intensity and to ease the experimental sampling at BMRR were performed; including (1) in-core fuel addition to increase source strength and balance flux of neutrons towards two ports, (2) out of core moderator remodeling, done by replacing thicker D2O tanks at graphite-shutter interfacial areas, to expedite neutron thermalization, (3) beam shutter upgrade to reduce strayed neutrons and gamma dose, (4) beam collimator redesign to optimize the beam flux versus dose for animal treatment, (5) beam port shielding installation around the shutter opening area (lithium-6 enriched polyester-resin in boxes, attached with polyethylene plates) to reduce prompt gamma and fast neutron doses, (6) sample holder repositioning to optimize angle versus distance for a single organ or whole body irradiation, and (7) holder wall buildup with neutron reflector materials to increase dose and dose rate from scattered thermal neutrons. During the facility upgrade, reactor dosimetry was conducted using thermoluminescent dosimeters TLD for gamma dose estimate, using ion chambers to confirm fast neutron and gamma dose rate, and by the activation of gold-foils with and without cadmium-covers, for fast and thermal neutron flux determination. Based on the combined effect from the size and depth of tumor cells and the location and geometry of dosimeters, the measured flux from cadmium-difference method was 4 - 7

  18. Irradiation system for neutron capture therapy using the small accelerator

    International Nuclear Information System (INIS)

    Kobayashi, Tooru; Hoshi, Masaharu

    2002-01-01

    Neutron capture therapy (NCT) is to kill tumor cells that previously incorporated the stable isotope which generates heavy charged particles with a short range and a high linear energy transfer (LET) on neutron irradiation. Boron-10 is ordinarily used as such an isotope. The tumor tissue is neutron-irradiated at craniotomy after preceding craniotomy for tumor extraction: therefore two surgeries are required for the present NCT in Japan. The reactions 10 B(n, αγ) 7 Li and 7 Li (p, n) 7 Be are thought preferential for patients and doctors if a convenient small accelerator, not the reactor used at present, is available in the hospital because only one craniotomy is sufficient. Authors' examinations of the system for NCT using the small accelerator involve irradiation conditions, desirable energy spectrum of neutron, characterization of thermal and epi-thermal neutrons, social, practical and technical comparison of the reactor and accelerator, and usefulness of the reaction 7 Li (p, n) 7 Be. The system devoted to the NCT is awaited in future. (K.H.)

  19. Neutron irradiation effect on thermomechanical properties of shape memory alloys

    International Nuclear Information System (INIS)

    Abramov, V.Ya.; Ionajtis, R.R.; Kotov, V.V.; Loguntsev, E.N.; Ushakov, V.P.

    1996-01-01

    Alloys of Ti-Ni, Ti-Ni-Pd, Fe-Mn-Si, Mn-Cu-Cr, Mn-Cu, Cu-Al-Mn, Cu-Al-Ni systems are investigated after irradiation in IVV-2M reactor at various temperatures with neutron fluence of 10 19 - 10 20 cm -2 . The degradation of shape memory effect in titanium nickelide base alloys is revealed after irradiation. Mn-Cu and Mn-Cu-Cr alloys show the best results. Trends in shape memory alloy behaviour depending on irradiation temperature are found. A consideration is given to the possibility of using these alloys for components of power reactor control and protection systems [ru

  20. Mechanical behaviour of neutron irradiated Nb monocrystalline

    International Nuclear Information System (INIS)

    Otero, M.P.; Lucki, G.

    1986-01-01

    Nb [941] - oriented single crystal was irradiated to a fluence of 1,1 x 10 19 n/cm 2 in the IEA-R1 reactor at IPEN-CNEN/SP. Tensile-Stress experiments showed an irradiation induced hardening, characterized by an increase in the yield stress of about 16%. This result was interpreted using the 'lattice hardening' model. The observed slip systems are attributed to the gliding of the anomalous slip planes. (Author) [pt

  1. Gamma and Neutron Irradiation of Semitransparent Amorphous Silicon Sensors

    International Nuclear Information System (INIS)

    Carabe, J.; Fernandez, M. G.; Ferrando, A.; Fuentes, J.; Gandia, J.; Josa, M. I.; Molinero, A.; Oller, J. C.; Arce, P.; Calvo, E.; Figueroa, C. F.; Garcia, N.; Matorras, F.; Rodrigo, T.; Vila, I.; Virto, A. L.; Fenyvesi, A.; Molnar, J.; Sohler, D.

    1999-12-01

    Semitransparent amorphous silicon sensors are key elements for laser light 2D position reconstruction in the CMS multipoint alignment link system. Some of the sensors have to work in very hard radiation environment. We have irradiated with gammas, up to 10 Mrad, and neutrons, up to 10 ''14 cm''-2, two different type of sensors and measured their change in performance. (Author) 10 refs

  2. Comparison of initial damage rates using neutron and electron irradiations

    International Nuclear Information System (INIS)

    Goldstone, J.A.R.

    1978-08-01

    The purpose of this experiment was twofold: (1) The number of interstitials that pin dislocations was studied as a function of neutron energy. (2) By comparison with electron irradiations on the sample, a correlation between the predicted and measured numbers of defects was found. All irradiations were performed on the same high purity copper sample. The sample was machined in the form of a cantilever beam with a flexural resonant frequency of 770 Hz. Changes in Young's modulus at constant strain amplitude were monitored continuously through changes in the resonant frequency of the sample. These changes in the modulus can be related to the number of pinning points added to dislocation lines, which are in turn related to the number of free interstitials produced. Neutron energy dependence experiments were done from 2 to 24 MeV on the copper sample and at 14 MeV on a gold sample. By equating pinning rates from electron and neutron irradiations and using the free interstitial production rate obtained from electron irradiations, an estimate of the free interstitial production cross section for neutrons of 2 to 24 MeV was made

  3. DT fusion neutron irradiation of BNL--LASL superconductor wires

    International Nuclear Information System (INIS)

    MacLean, S.C.

    1976-01-01

    The following samples were irradiated with the LLL rotating target neutron source: 19-core Nb 3 Sn multifilament wires, Nb 3 Sn single core, V 3 Ga single core, NbTi Supercon 402, and NbTi cupronickel jacketed. No test results are given

  4. Comparison of gamma, neutron and proton irradiations of multimode fibers

    International Nuclear Information System (INIS)

    Gingerich, M.E.; Dorsey, K.L.; Askins, C.G.; Friebele, E.J.

    1987-01-01

    The effects of pure gamma, pure proton, and mixed neutron-gamma irradiation fields on a set of both pure and doped silica core multimode fibers have been investigated. Only slight differences are found in the radiation response of pure and doped silica core fibers exposed to gamma or mixed neutron-gamma fields, indicating that Co-60 sources can be used to simulate the effects of the mixed field (except in the case of a pure neutron environment). Although it is noted that neither mix field nor gamma sources adequately simulate the effects of proton irradiation of doped silica core fibers, a good correspondence is found in the case of the pure silica core waveguide. 13 references

  5. Neutronics and Thermal Hydraulics Analysis of a Conceptual Ultra-High Temperature MHD Cermet Fuel Core for Nuclear Electric Propulsion

    Directory of Open Access Journals (Sweden)

    Jian Song

    2018-04-01

    Full Text Available Nuclear electric propulsion (NEP offers unique advantages for the interplanetary exploration. The extremely high conversion efficiency of magnetohydrodynamics (MHD conversion nuclear reactor makes it a highly potential space power source in the future, especially for NEP systems. Research on ultra-high temperature reactor suitable for MHD power conversion is performed in this paper. Cermet is chosen as the reactor fuel after a detailed comparison with the (U,ZrC graphite-based fuel and mixed carbide fuel. A reactor design is carried out as well as the analysis of the reactor physics and thermal-hydraulics. The specific design involves fuel element, reactor core, and radiation shield. Two coolant channel configurations of fuel elements are considered and both of them can meet the demands. The 91 channel configuration is chosen due to its greater heat transfer performance. Besides, preliminary calculation of nuclear criticality safety during launch crash accident is also presented. The calculation results show that the current design can meet the safety requirements well.

  6. Property change of advanced tungsten alloys due to neutron irradiation

    International Nuclear Information System (INIS)

    Fukuda, Makoto; Hasegawa, Akira; Tanno, Takashi; Nogami, Shuhei; Kurishita, Hiroaki

    2013-01-01

    This study investigates the effect of neutron irradiation on the functional properties of pure tungsten (W) and advanced tungsten alloys (e.g., lanthanum (La)-doped W, potassium (K)-doped W, and ultra-fine-grained (UFG) W–TiC alloys) tested in the Japan Materials Testing Reactor (JMTR) or experimental fast reactor Joyo. The irradiation temperature and damage were in the range 804–1073 K and 0.15–0.47 dpa, respectively. TEM images of all samples after 0.42 dpa irradiation at 1023 K showed voids, black dots, and dislocation loops, indicating that similar damage structures were formed in pure W, La-doped W, K-doped W, and UFG W–0.5 wt% TiC. The electrical resistivity of all specimens increased following neutron irradiation. Nearly identical electrical resistivity and irradiation hardening were observed in pure W, La-doped W, and K-doped W. The electrical resistivity of UFG W–TiC was higher than that of other specimens before and after irradiation, which may be attributed to its ultra-fine-grain structure, as well as the presence of impurities introduced during the alloying process. Compared to the other specimens, the UFG W–TiC was more resistant to irradiation hardening

  7. Results of neutronic benchmark analysis for a high temperature reactor of the GT-MHR type - HTR2008-58107

    International Nuclear Information System (INIS)

    Boyarinov, V. F.; Bryzgalov, V. I.; Davidenko, V. D.; Fomichenko, P. A.; Glushkov, E. S.; Gomin, E. A.; Gurevich, M. I.; Kodochigov, N. G.; Marova, E. V.; Mitenkova, E. F.; Novikov, N. V.; Osipov, S. L.; Sukharev, Y. P.; Tsibulsky, V. F.; Yudkevich, M. S.

    2008-01-01

    The paper presents a description of benchmark cases, achieved results, analysis of possible reasons of differences of calculation results obtained by various neutronic codes. The comparative analysis is presented showing the benchmark-results obtained with reference and design codes by Russian specialists (WIMS-D, JAR-HTGR, UNK, MCU, MCNP5-MONTEBURNS1.0-ORIGEN2.0), by French specialists (AP0LL02, TRIP0LI4 codes), and by Korean specialists (HELIOS, MASTER, MCNP5 codes). The analysis of possible reasons for deviations was carried out, which was aimed at the decrease of uncertainties in calculated characteristics. This additional investigation was conducted with the use of 2D models of a fuel assembly cell and a reactor plane section. (authors)

  8. Swelling and tensile properties of neutron-irradiated vanadium alloys

    International Nuclear Information System (INIS)

    Loomis, B.A.; Smith, D.L.

    1990-07-01

    Vanadium-base alloys are candidates for use as structural material in magnetic fusion reactors. In comparison to other candidate structural materials (e.g., Type 316 stainless and HT-9 ferritic steels), vanadium-base alloys such as V-15Cr-5Ti and V-20Ti have intrinsically lower long-term neutron activation, neutron irradiation after-heat, biological hazard potential, and neutron-induced helium and hydrogen transmutation rates. Moreover, vanadium-base alloys can withstand a higher surface-heat, flux than steels because of their lower thermal stress factor. In addition to having these favorable neutronic and physical properties, a candidate alloy for use as structural material in a fusion reactor must have dimensional stability, i.e., swelling resistance, and resistance to embrittlement during the reactor lifetime at a level of structural strength commensurate with the reactor operating temperature and structural loads. In this paper, we present experimental results on the swelling and tensile properties of several vanadium-base alloys after irradiation at 420, 520, and 600 degree C to neutron fluences ranging from 0.3 to 1.9 x 10 27 neutrons/m 2 (17 to 114 atom displacements per atom [dpa])

  9. Effect of neutron irradiation on mechanical properties of ferritic steels

    International Nuclear Information System (INIS)

    Kass, S.B.; Murty, K.L.

    1995-01-01

    Effect of neutron radiation exposure was investigated in various ferritic steels with the main emphasis being the effects of thermal neutrons on radiation hardening. Pure iron of varied grain sizes was also used for characterizing the grain size effects on the source hardening before and after neutron irradiation. While many steels are considered in the overall study, the results on 1020, A516 and A588 steels are emphasized. Radiation hardening due to fast neutrons was seen to be sensitive to the composition of the steels with A354 being the least resistant and A490 the least sensitive. Majority of the radiation hardening stems from friction hardening, and source hardening term decreased with exposure to neutron radiation apparently due to the interaction of interstitial impurities with radiation produced defects. Inclusion of thermal neutrons along with fast resulted in further decrease in the source hardening with a slight increase in the friction hardening which revealed a critical grain size below which exposure to total (fast and thermal) neutron spectrum resulted in a slight reduction in the yield stress compared to the exposure to only fast neutrons. This is the first time such a grain size effect is reported and this is shown to be consistent with known radiation effects on friction and source hardening terms along with the observation that low energy neutrons have a nonnegligible effect on the mechanical properties of steels. In ferritic steels, however, despite their small grain size, exposure to total neutron spectrum yielded higher strengths than exposure to only fast neutrons. This behavior is consistent with the fact that the source hardening is small in these alloys and radiation effect is due only to friction stress

  10. Analytical electron microscopy of neutron-irradiated reactor alloys

    International Nuclear Information System (INIS)

    Thomas, L.E.

    1982-01-01

    Exposure to the high neutron fluxes and temperatures from 400 to 650 0 C in the core region of a fast breeder reactor profoundly alters the microstructure and properties of structural steels and superalloys. The development of irradiation-induced voids, dislocations and precipitates, as well as segregation of alloying elements on a microscopic scale has been related to macroscopic swelling, creep, hardening and embrittlement which occur during prolonged exposures in reactor. Microanalytical studies using TEM/STEM methods, primarily energy dispersive x-ray (EDX) microanalysis, have greatly aided understanding of alloy behavior under irradiation. The main uses of analytical electron microscopy in studying irradiated alloys have been the identification of irradiation-induced precipitates and determination of the changes in local composition due to irradiation-induced solute segregation

  11. Microstructural defects in EUROFER 97 after different neutron irradiation conditions

    Directory of Open Access Journals (Sweden)

    Christian Dethloff

    2016-12-01

    Full Text Available Characterization of irradiation induced microstructural evolution is essential for assessing the applicability of structural steels like the Reduced Activation Ferritic/Martensitic steel EUROFER 97 in upcoming fusion reactors. In this work Transmission Electron Microscopy (TEM is used to determine the defect microstructure after different neutron irradiation conditions. In particular dislocation loops, voids and precipitates are analyzed concerning defect nature, density and size distribution after irradiation to 15 dpa at 300 °C in the mixed spectrum High Flux Reactor (HFR. New results are combined with previously obtained data from irradiation in the fast spectrum BOR-60 reactor (15 and 32 dpa, 330 °C, which allows for assessment of dose and dose rate effects on the aforementioned irradiation induced defects and microstructural characteristics.

  12. Electrical properties of gallium arsenide irradiated with electrons and neutrons

    International Nuclear Information System (INIS)

    Kol'chenko, T.I.; Lomako, V.M.

    1975-01-01

    A study was made of changes in the electrical properties of GaAs doped with Te, S, Se, Si, Ge, Sn (n 0 approximately 10 16 -10 18 cm -3 ) and irradiated either with 2.5-28 MeV electrons or with fast reactor neutrons. An analysis of changes in the electron density indicated that the rate of carrier removal by electron bombardment was independent of the dopant but was governed by isolated radiation defects. The change in the mobility due to irradiation with 2.5-10 MeV electrons was also governed by isolated defects. When the electron energy was increased to 28 MeV the main contribution to the change in the mobility was made by defect clusters. In the neutron-irradiation case the changes in the carrier density and mobility were mainly due to defect clusters and the nature of changes in the electrical properties was again independent of the dopant

  13. Effect of neutron and gamma irradiation on magnetic bubble memories

    International Nuclear Information System (INIS)

    Cambou, B.

    1981-06-01

    Many years of research preceeded the introduction of magnetic bubble memories (M.B.M.) into the memory components market. They are used as bulk storage memories principally for their non volatile characteristics under irradiation. A physical and technological description of MBM is given in the first part of the text together with the results of work on their vulnerability when subjected to irradiation. Permanent damage caused by neutrons and gamma radiation on thin magnetic layers is then studied. A theoretical analysis on the stability of bubbles based on the results of pulsed laser experiments is given. The stability of the information stored in a commercially available MBM subjected to neutron and gamma irradiation (MBM - TIB 203 of 92 kBits, Texas) is described in the last part of the text. The vulnerability thresholds determined for the MBM are too high for them to be used in a radioactive environment with an improved electronic control system [fr

  14. Effects of neutron irradiation and fatigue on ductility of stainless steel DIN 1.4948

    International Nuclear Information System (INIS)

    Vries, M.I. de; Schaaf, B. van der; Staal, H.U.; Elen, J.D.

    1978-10-01

    Test specimens of stainless steel DIN 1.4948, which is similar to AISI type 304, have been irradiated at 723 K and 823 K up to fluences of 1.10 23 neutrons (n).m -2 and 5.10 24 n.m -2 (E > 0.1 MeV). These are representative conditions for the SNR-300 reactor vessel and inner components after 16 years of operation. High temperature (723 K to 1023 K) tensile tests at strain rates (depsilon/dt) from 10 -7 s -1 to 10 s -1 show a considerable decrease of tensile ductility. The extent depends on helium content, test temperature and strain rate. The atomic helium fractions of 3.10 -7 and 7.10 -6 result from the reactions of thermal neutrons with the 14 ppm boron, present in the steel. Helium embrittlement sets in at strain rates below 1 s -1 to 10 s -1 (the range of interest for Bethe-Tait accident analyses). A minimum total elongation value of 6% is shown at 923 K. The post-irradiation fatigue life is reduced by up to about 50% due to intergranular cracking. The combination of irradiation and fatigue causes a decrease of ductility after a smaller number of prior fatigue cycles than in the case of unirradiated material. (Auth.)

  15. Flux effect on neutron irradiation embrittlement of reactor pressure vessel steels irradiated to high fluences

    International Nuclear Information System (INIS)

    Soneda, N.; Dohi, K.; Nishida, K.; Nomoto, A.; Iwasaki, M.; Tsuno, S.; Akiyama, T.; Watanabe, S.; Ohta, T.

    2011-01-01

    Neutron irradiation embrittlement of reactor pressure vessel (RPV) steels is of great concern for the long term operation of light water reactors. In particular, the embrittlement of the RPV steels of pressurized water reactors (PWRs) at very high fluences beyond 6*10 19 n/cm 2 , E > 1 MeV, needs to be understood in more depth because materials irradiated in material test reactors (MTRs) to such high fluences show larger shifts than predicted by current embrittlement correlation equations available worldwide. The primary difference between the irradiation conditions of MTRs and surveillance capsules is the neutron flux. The neutron flux of MTR is typically more than one order of magnitude higher than that of surveillance capsule, but it is not necessarily clear if this difference in neutron flux causes difference in mechanical properties of RPV. In this paper, we perform direct comparison, in terms of mechanical property and microstructure, between the materials irradiated in surveillance capsules and MTRs to clarify the effect of flux at very high fluences and fluxes. We irradiate the archive materials of some of the commercial reactors in Japan in the MTR, LVR-15, of NRI Rez, Czech Republic. Charpy impact test results of the MTR-irradiated materials are compared with the data from surveillance tests. The comparison of the results of microstructural analyses by means of atom probe tomography is also described to demonstrate the similarity / differences in surveillance and MTR-irradiated materials in terms of solute atom behavior. It appears that high Cu material irradiated in a MTR presents larger shifts than those of surveillance data, while low Cu materials present similar embrittlement. The microstructural changes caused by MTR irradiation and surveillance irradiation are clearly different

  16. Effects of pre-irradiation annealing at high temperature on optical absorption and electron paramagnetic resonance of natural pumpellyite mineral

    International Nuclear Information System (INIS)

    Javier-Ccallata, Henry; Filho, Luiz Tomaz; Sartorelli, Maria L.; Watanabe, Shigueo

    2013-01-01

    Highlights: •Natural pumpellyite mineral presents superposition bands around 900 and 1060 nm due Fe 2+ and Fe 3+ . •High temperature annealing influences the EPR and OA spectra. •The behavior of EPR line for 800 and 900 °C can be attributed to forbidden dd transitions due the Fe 3+ . -- Abstract: Natural silicate mineral of pumpellyite, Ca 2 MgAl 2 (SiO 4 )(Si 2 O 7 )(OH) 2 ·(H 2 O), point group A2/m, has been studied concerning high temperature annealing and γ-radiation effects on Optical Absorption (OA) and Electron Paramagnetic Resonance (EPR) properties. Chemical analysis revealed that besides Si, Al, Ca and Mg, other oxides i.e., Fe, Mn, Na, K, Ti and P are present in the structure as impurities. OA measurements of natural and annealed pumpellyite revealed several bands in the visible region due to spin forbidden transitions of Fe 2+ and Fe 3+ . The behaviour of bands around 900 and 1060 nm, with pre-annealing and γ radiation dose, indicating a transition Fe 2+ → e − + Fe 3+ . On the other hand, EPR measurements reveal six lines of Mn 2+ , and satellites due to hyperfine interaction, superimposed on the signal of Fe 3+ around of g = 2. For heat treatment from 800 °C the signal grows significantly and for 900 °C a strong signal of Fe 3+ hides all Mn 2+ lines. The strong growth of this signal indicates that the transitions are due to Fe 3+ dipole–dipole interactions

  17. Effects of pre-irradiation annealing at high temperature on optical absorption and electron paramagnetic resonance of natural pumpellyite mineral

    Energy Technology Data Exchange (ETDEWEB)

    Javier-Ccallata, Henry, E-mail: henrysjc@gmail.com [Escuela de Ingeniería Electrónica y Telecomunicaciones, Universidad Alas Peruanas Filial Arequipa, Urb. D. A. Carrión G-14, J. L. Bustamante y Rivero, Arequipa (Peru); Laboratório de Sistemas Nanoestruturados, Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina (Brazil); Filho, Luiz Tomaz [Departamento de Física Nuclear, Instituto de Física, Universidade de São Paulo, Rua do Matão, travessa R, 187, CEP 05508-900 São Paulo, SP (Brazil); Faculdade de Tecnologia e Ciências Exatas, Universidade São Judas Tadeu, Rua Taquari 546, São Paulo, SP (Brazil); Sartorelli, Maria L. [Laboratório de Sistemas Nanoestruturados, Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina (Brazil); Watanabe, Shigueo [Departamento de Física Nuclear, Instituto de Física, Universidade de São Paulo, Rua do Matão, travessa R, 187, CEP 05508-900 São Paulo, SP (Brazil)

    2013-09-15

    Highlights: •Natural pumpellyite mineral presents superposition bands around 900 and 1060 nm due Fe{sup 2+}and Fe{sup 3+}. •High temperature annealing influences the EPR and OA spectra. •The behavior of EPR line for 800 and 900 °C can be attributed to forbidden dd transitions due the Fe{sup 3+}. -- Abstract: Natural silicate mineral of pumpellyite, Ca{sub 2}MgAl{sub 2}(SiO{sub 4})(Si{sub 2}O{sub 7})(OH){sub 2}·(H{sub 2}O), point group A2/m, has been studied concerning high temperature annealing and γ-radiation effects on Optical Absorption (OA) and Electron Paramagnetic Resonance (EPR) properties. Chemical analysis revealed that besides Si, Al, Ca and Mg, other oxides i.e., Fe, Mn, Na, K, Ti and P are present in the structure as impurities. OA measurements of natural and annealed pumpellyite revealed several bands in the visible region due to spin forbidden transitions of Fe{sup 2+} and Fe{sup 3+}. The behaviour of bands around 900 and 1060 nm, with pre-annealing and γ radiation dose, indicating a transition Fe{sup 2+} → e{sup −} + Fe{sup 3+}. On the other hand, EPR measurements reveal six lines of Mn{sup 2+}, and satellites due to hyperfine interaction, superimposed on the signal of Fe{sup 3+} around of g = 2. For heat treatment from 800 °C the signal grows significantly and for 900 °C a strong signal of Fe{sup 3+} hides all Mn{sup 2+} lines. The strong growth of this signal indicates that the transitions are due to Fe{sup 3+} dipole–dipole interactions.

  18. Synergistic effects of neutron and gamma ray irradiation of a commercial CHMOS microcontroller

    International Nuclear Information System (INIS)

    Xiao-Ming, Jin; Ru-Yu, Fan; Wei, Chen; Dong-Sheng, Lin; Shan-Chao, Yang; Xiao-Yan, Bai; Yan, Liu; Xiao-Qiang, Guo; Gui-Zhen, Wang

    2010-01-01

    This paper presents the experimental results of a combined irradiation environment of neutron and gamma rays on 80C196KC20, which is a 16-bit high performance member of the MCS96 microcontroller family. The electrical and functional tests were made in three irradiation environments: neutron, gamma rays, combined irradiation of neutron and gamma rays. The experimental results show that the neutron irradiation can affect the total ionizing dose behaviour. Compared with the single radiation environment, the microcontroller exhibits considerably more severe degradation in neutron and gamma ray synergistic irradiation. This phenomenon may cause a significant hardness assurance problem. (condensed matter: structure, thermal and mechanical properties)

  19. Real-time measurements of temperature, pressure and moisture profiles in High-Performance Concrete exposed to high temperatures during neutron radiography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toropovs, N., E-mail: nikolajs.toropovs@rtu.lv [Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf (Switzerland); Riga Technical University, Institute of Materials and Structures, Riga (Latvia); Lo Monte, F. [Politecnico di Milano, Department of Civil and Environmental Engineering, Milan (Italy); Wyrzykowski, M. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf (Switzerland); Lodz University of Technology, Department of Building Physics and Building Materials, Lodz (Poland); Weber, B. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf (Switzerland); Sahmenko, G. [Riga Technical University, Institute of Materials and Structures, Riga (Latvia); Vontobel, P. [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Felicetti, R. [Politecnico di Milano, Department of Civil and Environmental Engineering, Milan (Italy); Lura, P. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf (Switzerland); ETH Zürich, Institute for Building Materials (IfB), Zürich (Switzerland)

    2015-02-15

    High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high temperature. Although the exact causes that lead to spalling are still being debated, moisture transport during heating plays an important role in all proposed mechanisms. In this study, slabs made of high-performance, low water-to-binder ratio mortars with addition of superabsorbent polymers (SAP) and polypropylene fibers (PP) were heated from one side on a temperature-controlled plate up to 550 °C. A combination of measurements was performed simultaneously on the same sample: moisture profiles via neutron radiography, temperature profiles with embedded thermocouples and pore pressure evolution with embedded pressure sensors. Spalling occurred in the sample with SAP, where sharp profiles of moisture and temperature were observed. No spalling occurred when PP-fibers were introduced in addition to SAP. The experimental procedure described here is essential for developing and verifying numerical models and studying measures against fire spalling risk in HPC.

  20. Neutron Focusing Mirrors for Neutron Radiography of Irradiated Nuclear Fuel at Idaho National Laboratory

    Science.gov (United States)

    Rai, Durgesh K.; Wu, Huarui; Abir, Muhammad; Giglio, Jeffrey; Khaykovich, Boris

    Post irradiation examination (PIE) of samples irradiated in nuclear reactors is a challenging but necessary task for the development on novel nuclear power reactors. Idaho National Laboratory (INL) has neutron radiography capabilities, which are especially useful for the PIE of irradiated nuclear fuel. These capabilities are limited due to the extremely high gamma-ray radiation from the irradiated fuel, which precludes the use of standard digital detectors, in turn limiting the ability to do tomography and driving the cost of the measurements. In addition, the small 250 kW Neutron Radiography Reactor (NRAD) provides a relatively weak neutron flux, which leads to low signal-to-noise ratio. In this work, we develop neutron focusing optics suitable for the installation at NRAD. The optics would separate the sample and the detector, potentially allowing for the use of digital radiography detectors, and would provide significant intensity enhancement as well. The optics consist of several coaxial nested Wolter mirrors and is suited for polychromatic thermal neutron radiation. Laboratory Directed Research and Development program of Idaho National Laboratory.

  1. Radioisotopes produced by neutron irradiation of food.

    Science.gov (United States)

    Albright, S; Seviour, R

    2016-04-01

    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of (24)Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that (24)Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Neutron irradiation damage of a stress relieved TZM alloy

    International Nuclear Information System (INIS)

    Abe, K.; Masuyama, T.; Satou, M.; Hamilton, M.L.

    1992-01-01

    The objective of this work is to study defect microstructures and irradiation hardening in a stress relieved TZM alloy after irradiation in the Fast Flux Test Facility (FFTF) using the Materials Open Test Assembly (MOTA). Disk specimens of the molybdenum alloy TZM that had been stress relieved at 1199 K (929 C) for 0.9 ks (15 min.) were irradiated in the FFTF/MOTA 1F at 679, 793 and 873 K (406, 520, and 600 C) to a fast fluence of ∼9.6 x 10 22 n/cm 2 . Microstructures were observed in a transmission electron microscope (TEM). Dislocation structures consisted of isolated loops, aggregated loops (rafts) and elongated dislocations. The size of the loops increased with the irradiation temperature. Void swelling was about 1 and 2% at 793 and 873 K (520 and 600 C), respectively. A void lattice was developed in the body centered cubic (bcc) structure with a spacing of 26 - 28 nm. The fine grain size (0.5 - 2 μm) was retained following high temperature irradiation, indicating that the stress relief heat treatment may extend the material's resistance to radiation damage up to high fluence levels. Microhardness measurements indicated that irradiation hardening increased with irradiation temperature. The relationship between the microstructure and the observed hardening was determined

  3. Radioisotopes produced by neutron irradiation of food

    International Nuclear Information System (INIS)

    Albright, S.; Seviour, R.

    2016-01-01

    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of "2"4Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that "2"4Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. - Highlights: • We show that neutron interrogation of food can produce many radioisotopes. • We show a strong dependance between food and certain radioisotopes. • Some isotopes are shown to have an energy dependence. • Previous claims that 24Na is the main threat is shown to only apply in special cases.

  4. Swelling and microstructure of neutrons irradiated 316 Ti SS

    International Nuclear Information System (INIS)

    Seran, J.L.; Le Naour, L.; Grosjean, P.; Hugon, M.P.; Carteret, Y.; Maillard, A.

    1984-06-01

    The analysis of the behaviour of fuel pins irradiated in the same RAPSODIE subassembly, shows that titanium has a marked beneficial effect on the swelling resistance of CW 316 SS in a large range of temperature. This effect is particularly visible at high temperature since CW 316 Ti SS does not swell above 550 0 C up to a dose of 100 French dpa. The results obtained on samples irradiated in a RAPSODIE experimental rig give us confirmation of the good behaviour of CW 316 Ti SS which swells less and at smaller temperature than the other steels of the 316 series such as SA 316 Ti or aged SA 316 Ti. The swelling differences between some of these materials can be associated to different microstructures which are also very different from the ones obtained on the irradiated steels aged in the same time and temperature conditions

  5. Design of a permanent Cd-shielded epithermal neutron irradiation site in the Syrian Miniature Neutron Source Reactor

    International Nuclear Information System (INIS)

    Khattab, K.; Haddad, Kh.; Haj-Hassan, H.

    2008-01-01

    A Cd-shield (cylindrical shell 1 mm in thickness, 34 mm in diameter and 180 mm in length) was used to design a permanent epithermal neutron irradiation site for epithermal neutron activation analysis (ENAA) in the Syrian Miniature Neutron Source Reactor (MNSR). This site was achieved by shielding the surface of the aluminum tube of one of the outer irradiation sites. The calculated depression ratio of thermal neutron flux was 1/10. Homogeneity of the neutron flux in the first outer irradiation site has been found numerically using the WIMSD4 and CITATION codes and experimentally by irradiating five short copper wires using the outer irradiation capsule. Good agreement was obtained between the calculated and the measured results of the neutron flux distributions. (author)

  6. Design of a permanent Cd-shielded epithermal neutron irradiation site in the Syrian Miniature Neutron Source Reactor

    International Nuclear Information System (INIS)

    Khattab, K.; Haddad, Kh.; Haj-Hassan, H.

    2009-01-01

    A Cd-shield (cylindrical shell 1 mm in thickness, 34 mm in diameter and 180 mm in length) was used to design a permanent epithermal neutron irradiation site for epithermal neutron activation analysis (ENAA) in the Syrian Miniature Neutron Source Reactor (MNSR). This site was achieved by shielding the surface of the aluminum tube of one of the outer irradiation sites. The calculated depression ratio of thermal neutron flux was 1/10. Homogeneity of the neutron flux in the first outer irradiation site has been found numerically using the WIMSD4 and CITATION codes and experimentally by irradiating five short copper wires using the outer irradiation capsule. Good agreement was obtained between the calculated and the measured results of the neutron flux distributions. (author)

  7. Morphological profiles of neutron and X-irradiated small intestine

    International Nuclear Information System (INIS)

    Carr, K.E.; O'Shea, O.; Hazzard, R.A.; McCullough, J.S.; Hume, S.P.; Nelson, A.C.

    1996-01-01

    This paper describes the response of mouse small intestine, at several time points after treatment with neutron or X-irradiation, using doses expected to give similar effects in terms of crypt/microcolony survival. Using resin histology, the effects of radiation on the numbers of duodenal cell types and measurements of tissue areas were assessed. The results for individual parameters and for an estimate of overall damage are given in a data display, which summarises the morphological profile of the organ after both types of radiation. Damage and recovery were seen for many of the parameters studied but there was no standard response pattern applicable for all parameters. In particular, the response of individual crypt cell types could not be predicted from knowledge of the change in crypt numbers. With regard to the holistic response of the gut, neutron irradiation appeared to have caused more damage and produced more early effects than the X-irradiation. More specifically, neutron treatment led to more damage to the neuromuscular components of the wall, while X-irradiation produced early vascular changes. (author)

  8. Characterization of neutron-irradiated HT-UPS steel by high-energy X-ray diffraction microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuan, E-mail: xuanzhang@anl.gov [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Park, Jun-Sang; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Li, Meimei [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60439 (United States)

    2016-04-01

    This paper presents the first measurement of neutron-irradiated microstructure using far-field high-energy X-ray diffraction microscopy (FF-HEDM) in a high-temperature ultrafine-precipitate-strengthened (HT-UPS) austenitic stainless steel. Grain center of mass, grain size distribution, crystallographic orientation (texture), diffraction spot broadening and lattice constant distributions of individual grains were obtained for samples in three different conditions: non-irradiated, neutron-irradiated (3dpa/500 °C), and irradiated + annealed (3dpa/500 °C + 600 °C/1 h). It was found that irradiation caused significant increase in grain-level diffraction spot broadening, modified the texture, reduced the grain-averaged lattice constant, but had nearly no effect on the average grain size and grain size distribution, as well as the grain size-dependent lattice constant variations. Post-irradiation annealing largely reversed the irradiation effects on texture and average lattice constant, but inadequately restored the microstrain.

  9. Swelling in neutron-irradiated titanium alloys

    International Nuclear Information System (INIS)

    Peterson, D.T.

    1982-04-01

    Immersion density measurements have been performed on a series of titanium alloys irradiated in EBR-II to a fluence of 5 x 10 22 n/cm 2 (E > 0.1 MeV) at 450 and 550 0 C. The materials irradiated were the near-alpha alloys Ti-6242S and Ti-5621S, the alpha-beta alloy Ti-64, and the beta alloy Ti-38644. Swelling was observed in all alloys with the greater swelling being observed at 550 0 C. Microstructural examination revealed the presence of voids in all alloys. Ti-38644 was found to be the most radiation resistant. Ti-6242S and Ti-5621S also displayed good radiation resistance, whereas considerable swelling and precipitation were observed in Ti-64 at 550 0 C

  10. Nuclear graphite for high temperature reactors

    International Nuclear Information System (INIS)

    Marsden, B.J.

    2001-01-01

    The cores and reflectors in modern High Temperature Gas Cooled Reactors (HTRs) are constructed from graphite components. There are two main designs; the Pebble Bed design and the Prism design. In both of these designs the graphite not only acts as a moderator, but is also a major structural component that may provide channels for the fuel and coolant gas, channels for control and safety shut off devices and provide thermal and neutron shielding. In addition, graphite components may act as a heat sink or conduction path during reactor trips and transients. During reactor operation, many of the graphite component physical properties are significantly changed by irradiation. These changes lead to the generation of significant internal shrinkage stresses and thermal shut down stresses that could lead to component failure. In addition, if the graphite is irradiated to a very high irradiation dose, irradiation swelling can lead to a rapid reduction in modulus and strength, making the component friable.The irradiation behaviour of graphite is strongly dependent on its virgin microstructure, which is determined by the manufacturing route. Nevertheless, there are available, irradiation data on many obsolete graphites of known microstructures. There is also a well-developed physical understanding of the process of irradiation damage in graphite. This paper proposes a specification for graphite suitable for modern HTRs. (author)

  11. CORTAP: a coupled neutron kinetics-heat transfer digital computer program for the dynamic simulation of the high temperature gas cooled reactor core

    International Nuclear Information System (INIS)

    Cleveland, J.C.

    1977-01-01

    CORTAP (Core Transient Analysis Program) was developed to predict the dynamic behavior of the High Temperature Gas Cooled Reactor (HTGR) core under normal operational transients and postulated accident conditions. CORTAP is used both as a stand-alone component simulation and as part of the HTGR nuclear steam supply (NSS) system simulation code ORTAP. The core thermal neutronic response is determined by solving the heat transfer equations for the fuel, moderator and coolant in an average powered region of the reactor core. The space independent neutron kinetics equations are coupled to the heat transfer equations through a rapidly converging iterative technique. The code has the capability to determine conservative fuel, moderator, and coolant temperatures in the ''hot'' fuel region. For transients involving a reactor trip, the core heat generation rate is determined from an expression for decay heat following a scram. Nonlinear effects introduced by temperature dependent fuel, moderator, and coolant properties are included in the model. CORTAP predictions will be compared with dynamic test results obtained from the Fort St. Vrain reactor owned by Public Service of Colorado, and, based on these comparisons, appropriate improvements will be made in CORTAP

  12. High-temperature irradiation of niobium-1 w/o zirconium-clad UO/sub 2/. [Compatibility with lithium

    Energy Technology Data Exchange (ETDEWEB)

    Kangilaski, M.; Fromm, E.O.; Lozier, D.H.; Storhok, V.W.; Gates, J.E.

    1965-06-28

    Twenty-four 0.225-in.-diameter and six 0.290-in.-diameter UO/sub 2/ specimens clad with 80 mils of niobium-1 w/o zirconium were irradiated to burnups of 1.4 to 6.0 at. % of uranium at surface temperatures of 900 to 1400/sup 0/C. UO/sub 2/ and lithium were found to be incompatible at these temperatures, and the thick cladding was used primarily to minimize the chances of contact of UO/sub 2/ and the lithium coolant. The thickly clad specimens did not undergo any dimensional changes as a result of irradiation, although it was found that movement of UO/sub 2/ took place in the axial direction by a vaporization-redeposition mechanism. It was found that 32 to 87% of the fission gases was released from the fuel, depending on the temperature of the specimen. Metallographic examination of longitudinal and transverse sections of the specimens indicated the usual UO/sub 2/ microstructure with columnar grains. Grain-boundary thickening was observed in the UO/sub 2/ at higher burnups. The oxygen/uranium ratio of UO/sub 2/ increased with increasing burnup.

  13. In-reactor behaviour of centrifugally atomized U3Si dispersion fuel irradiated at high temperature in HANARO

    International Nuclear Information System (INIS)

    Kim, Ki Hwan; Park, Jong Man; Yoo, Byeong Ok; Park, Dae Kyu; Lee, Choong Sung; Kim, Chang Kyu

    2002-01-01

    The irradiation test on full-size U 3 Si dispersion fuel elements, prepared by centrifugal atomization and conventional comminution method, has been performed up to about 77 at.% U-235 in maximum burn-up at CT hole position having the highest power condition in the HANARO reactor, in order to examine the irradiation performance of the atomized U 3 Si for the driver fuels of HANARO. The in-reactor interaction of the atomized U 3 Si dispersion fuel meats is generally assumed to be acceptable with the range of 5-15 μm in average thickness. The atomized spherical particles have more uniform and thinner reaction layer than the comminuted irregular particles. The U 3 Si particles have relatively fine and uniform size distribution of fission gas bubbles, irrespective of the powdering method. The bubble population in the atomized particles appears to be finer and more homogeneous with the characteristics of narrower bubble size distribution than that of the comminuted fuel. The atomized U 3 Si dispersion fuel elements exhibit sound swelling behaviours of 5 % in ΔV/V m even at ∼77 at.% U-235 burn-up, which meets with the safety criterion of the fuel rod, 20vol.% for HANARO. The atomized U3Si dispersion fuel elements show smaller swelling than the comminuted fuel elements

  14. Method of measuring neutron spectra in JMTR exclusively used for irradiation and their evaluation

    International Nuclear Information System (INIS)

    Sakurai, Kiyoshi

    1983-01-01

    In the core of the Japan Materials Testing Reactor, about 60 capsules are irradiated. These are the material capsules for irradiating reactor materials, the fuel capsules for irradiating reactor fuel, the RI capsules for producing radioisotopes and so on. In the irradiation experiment using a reactor, the information on the neutron fluence is indispensable, and the neutron fluence in the irradiated specimen part is evaluated with a dosimeter or the nuclear calculation for the core of the JMTR. At the time of irradiating reactor materials, the dosimeter Fe-54 (n,p) Mn-54 is generally used for evaluating the neutron fluence more than 1 MeV. In the case of fuel irradiation, the thermal neutron fluence is evaluated with the dosimeter Co-59 (n,γ) Co-60. It is important to examine in detail neutron spectra by both calculation and experiment in the reactors exclusively used for irradiation such as the JMTR. The neutron irradiation field in the JMTR, neutron spectrum measuring experiment, the neutron flux monitors for standardizing data, the measurement of X-ray and gamma ray, neutron guess spectrum, the compilation of neutron cross section for SAND 2, and the unfolding of neutron spectra are reported. The degree of agreement of the neutron fluence more than 1 MeV by measurement and calculation was +- 10 to 20 %. (Kako, I.)

  15. High temperature in combination with UV irradiation enhances horizontal transfer of stx2 gene from E. coli O157:H7 to non-pathogenic E. coli.

    Directory of Open Access Journals (Sweden)

    Wan-Fu Yue

    Full Text Available Shiga toxin (stx genes have been transferred to numerous bacteria, one of which is E. coli O157:H7. It is a common belief that stx gene is transferred by bacteriophages, because stx genes are located on lambdoid prophages in the E. coli O157:H7 genome. Both E. coli O157:H7 and non-pathogenic E. coli are highly enriched in cattle feedlots. We hypothesized that strong UV radiation in combination with high temperature accelerates stx gene transfer into non-pathogenic E. coli in feedlots.E. coli O157:H7 EDL933 strain were subjected to different UV irradiation (0 or 0.5 kJ/m(2 combination with different temperature (22, 28, 30, 32, and 37 °C treatments, and the activation of lambdoid prophages was analyzed by plaque forming unit while induction of Stx2 prophages was quantified by quantitative real-time PCR. Data showed that lambdoid prophages in E. coli O157:H7, including phages carrying stx2, were activated under UV radiation, a process enhanced by elevated temperature. Consistently, western blotting analysis indicated that the production of Shiga toxin 2 was also dramatically increased by UV irradiation and high temperature. In situ colony hybridization screening indicated that these activated Stx2 prophages were capable of converting laboratory strain of E. coli K12 into new Shiga toxigenic E. coli, which were further confirmed by PCR and ELISA analysis.These data implicate that high environmental temperature in combination with UV irradiation accelerates the spread of stx genes through enhancing Stx prophage induction and Stx phage mediated gene transfer. Cattle feedlot sludge are teemed with E. coli O157:H7 and non-pathogenic E. coli, and is frequently exposed to UV radiation via sunlight, which may contribute to the rapid spread of stx gene to non-pathogenic E. coli and diversity of shiga toxin producing E. coli.

  16. Isotropic nuclear graphites; the effect of neutron irradiation

    International Nuclear Information System (INIS)

    Lore, J.; Buscaillon, A.; Mottet, P.; Micaud, G.

    1977-01-01

    Several isotropic graphites have been manufactured using different forming processes and fillers such as needle coke, regular coke, or pitch coke. Their properties are described in this paper. Specimens of these products have been irradiated in the fast reactor Rapsodie between 400 to 1400 0 C, at fluences up to 1,7.10 21 n.cm -2 PHI.FG. The results show an isotropic behavior under neutron irradiation, but the induced dimensional changes are higher than those of isotropic coke graphites although they are lower than those of conventional extruded graphites made with the same coke

  17. Radiation defects produced by neutron irradiation in germanium single crystals

    International Nuclear Information System (INIS)

    Fukuoka, Noboru; Honda, Makoto; Atobe, Kozo; Yamaji, Hiromichi; Ide, Mutsutoshi; Okada, Moritami.

    1992-01-01

    The nature of defects produced in germanium single crystals by neutron irradiation at 25 K was studied by measuring the electrical resistivity. It was found that two levels located at E c -0.06 eV and E c -0.13 eV were introduced in an arsenic-doped sample. Electron traps at E c -0.10eV were observed in an indium-doped sample. The change in electrical resistivity during irradiation was also studied. (author)

  18. Effects of neutron irradiation on a superconducting metallic glass

    International Nuclear Information System (INIS)

    Kramer, E.A.; Johnson, W.L.; Cline, C.

    1979-06-01

    The effects of fast neutron irradiation on a superconducting metallic glass (Mo 6 Ru 4 ) 82 B 18 have been studied. Following irradiation to a total fluence of 10 19 n/cm 2 , T/sub c/ increases from 6.05 K to 6.19 K, and the width of the transition decreases sharply. The density of the material decreases by 1.5%, and the x-ray scattering intensity maxima are broadened. An improvement in the ductility of the samples is observed which together with the other observations suggests the production of defects having atomic scale dimensions and characterized by excess volume

  19. In vitro antileishmanial properties of neutron-irradiated meglumine antimoniate

    Energy Technology Data Exchange (ETDEWEB)

    Borborema, Samanta Etel Treiger; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Lab. de Biologia Molecular]. E-mail: samanta@usp.br; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Centro de Radiofarmacia]. E-mail: jaosso@ipen.br; Andrade Junior, Heitor Franco de [Instituto de Medicina Tropical de Sao Paulo (IMT-SP), SP (Brazil). Lab. de Protozoologia]. E-mail:hfandrad@usp.br

    2005-10-15

    Pentavalent antimony, as meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam), is the main treatment for leishmaniasis, a complex of diseases caused by the protozoan Leishmania, and an endemic and neglected threat in Brazil. Despite over half a century of clinical use, their mechanism of action, toxicity and pharmacokinetic data remain unknown. The analytical methods for determination of antimony in biological systems remain complex and have low sensitivity. Radiotracer studies have a potential in pharmaceutical development. The aim of this study was to obtain a radiotracer for antimony, with suitable physical and biological properties. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes {sup 122} Sb and {sup 124} Sb, with high radionuclidic purity and good specific activity. This compound showed the same antileishmanial activity as the native compound. The use of the radiotracers, easily created by neutron irradiation, could be an interesting tool to solve important questions in antimonial pharmacology. (author)

  20. Investigation of radiation damage effects in neutron irradiated CCD

    International Nuclear Information System (INIS)

    Brau, James E.; Igonkina, Olga; Potter, Chris T.; Sinev, Nikolai B.

    2005-01-01

    A Charge Coupled Devices (CCD)-based vertex detector is a leading option for vertex detection at the future linear collider. A major issue for this application is the radiation hardness of such devices. Tests of radiation hardness of CCDs used in the SLD vertex detector, VXD3, have been reported earlier. The first measurements of 1998 involved a spare VXD3 CCD that was irradiated with neutrons from a radioactive source (Pu-Be), and from a nuclear reactor. In 2003, we had the opportunity to disassemble the VXD3 detector and study the nature of the radiation damage it incurred during 3 years of operation at SLC. In the preparation for this study, additional experiments with the spare VXD3 CCD were performed. These included measurements of trapping times in neutron irradiated CCDs. Results, reported here, will help us better understand the mechanism of radiation damage effects and develop techniques to minimize performance degradation due to radiation damage

  1. Microstructural evolution in reactor pressure vessel steel under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Katsumi; Fukuya, Koji [Institute of Nuclear Safety System Inc., Seika, Kyoto (Japan)

    2000-09-01

    Understanding microstructural changes in reactor pressure vessel steels is important in order to evaluate radiation-induced embrittlement, one of the major aging phenomena affecting the extension of plant life. In this study, actual surveillance test specimens and samples of rector vessel low-alloy steel (A533B steel) irradiated in a research reactor were examined using state-of-the-art techniques to clarify the neutron flux effect on the microstructural changes. These techniques included small angle neutron scattering and atom probes. Microstructural changes which are considered to be the main factors affecting embrittlement, including the production of copper-rich precipitates and the segregation of impurity elements, were confirmed by the results of the study. In addition, the mechanical properties were predicted based on the obtained quantitative data such as the diameters of precipitates. Consequently, the hardening due to irradiation was almost simulated. (author)

  2. A Study on the Thermal Neutron Filter for the Irradiation of Electronic Materials at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seong Woo; Kim, Sung Ryul; Park, Seung Jae; Shin, Yoon Taeg; Cho, Man Soon; Cho, Kee Nam [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The representative example is a technique of making the semiconductor with the transmutation using the pure Si. This NTD (Neutron Transmutation Doping) Si is used as a high-quality semiconductor because it has a uniform resistance. Likewise, the electronic materials are being investigated to improve the performance of material using the neutron irradiation method. The mechanism for reaction between the electronic materials and the neutrons depends on the energy of the neutron. Capturing reaction by thermal neutrons causes the transmutation and a lot of defects are made by fast neutrons. The study for the effect by such neutron energy is necessary to understand the performance improvement of the irradiated electronic materials. The thermal neutron filter was investigated to be used for the irradiation of electronic materials at HANARO. IP irradiation hole was selected and the irradiation device was designed. The analysis was conducted considering four candidate materials.

  3. The proposed cold neutron irradiation facility at the Breazeale reactor

    International Nuclear Information System (INIS)

    Dimeo, R. M.; Sokol, P. E.; Carpenter, J. M.

    1997-01-01

    We discuss the design considerations of a Cold Neutron Irradiation Facility (CNIF) originally to have been installed at the Penn State Breazeale Reactor (PSBR). The goal of this project was to study the effects of radiation-induced damage to cryogenic moderators and, in particular, solid methane. This work evolved through the design stage undergoing a full safety analysis and received tentative approval from the PSBR Safeguards Committee but was discontinued due to budgetary constraints. (auth)

  4. Separation of Protactinium from Neutron Irradiated Thorium Oxide

    International Nuclear Information System (INIS)

    Dominguez, G.; Gutierrez, L.; Ropero, M.

    1983-01-01

    The chemical separation of thorium and protactinium can be carried out by leaching most of the last one, about 95%, with aqueous HF from neutron irradiated thorium oxide. This leaching reaction la highly favored by the transformation reaction of the ThO 2 material into ThF 4 . For both reactions, leaching and transformation, the reagents concentration, agitation speed and temperature influences were studied and the activation energies were found. (Author) 18 refs

  5. Neutron irradiation effects on high Nicalon silicon carbide fibers

    International Nuclear Information System (INIS)

    Osborne, M.C.; Steiner, D.; Snead, L.L.

    1996-01-01

    The effects of neutron irradiation on the mechanical properties and microstructure of SiC and SiC-based fibers is a current focal point for the development of radiation damage resistant SiC/SiC composites. This report discusses the radiation effects on the Nippon Carbon Hi-Nicalon trademark fiber system and also discusses an erratum on earlier results published by the authors on this material. The radiation matrix currently under study is also summarized

  6. National Low-Temperature Neutron-Irradiation Facility

    International Nuclear Information System (INIS)

    Coltman, R.R. Jr.; Klabunde, C.E.; Young, F.W. Jr.

    1983-08-01

    The Materials Sciences Division of the United States Department of Energy will establish a National Low Temperature Neutron Irradiation Facility (NLTNIF) which will utilize the Bulk Shielding Reactor (BSR) located at Oak Ridge National Laboratory. The facility will provide high radiation intensities and special environmental and testing conditions for qualified experiments at no cost to users. This report describes the planned experimental capabilities of the new facility

  7. Neutron irradiation effects on high Nicalon silicon carbide fibers

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, M.C.; Steiner, D.; Snead, L.L. [Oak Ridge National Laboratory, TN (United States)

    1996-10-01

    The effects of neutron irradiation on the mechanical properties and microstructure of SiC and SiC-based fibers is a current focal point for the development of radiation damage resistant SiC/SiC composites. This report discusses the radiation effects on the Nippon Carbon Hi-Nicalon{trademark} fiber system and also discusses an erratum on earlier results published by the authors on this material. The radiation matrix currently under study is also summarized.

  8. Neutron irradiation facilities for fission and fusion reactor materials studies

    International Nuclear Information System (INIS)

    Rowcliffe, A.F.

    1985-01-01

    The successful development of energy-conversion machines based upon nuclear fission or fusion reactors is critically dependent upon the behavior of the engineering materials used to construct the full containment and primary heat extraction systems. The development of radiation damage-resistant materials requires irradiation testing facilities which reproduce, as closely as possible, the thermal and neutronic environment expected in a power-producing reactor. The Oak Ridge National Laboratory (ORNL) reference core design for the Center for Neutron Research (CNR) reactor provides for instrumented facilities in regions of both hard and mixed neutron spectra, with substantially higher fluxes than are currently available. The benefits of these new facilities to the development of radiation damage resistant materials are discussed in terms of the major US fission and fusion reactor programs

  9. Neutron and gamma irradiation effects on power semiconductor switches

    International Nuclear Information System (INIS)

    Schwarze, G.E.; Frasca, A.J.

    1990-01-01

    The performance characteristics of high power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN bipolar junction transistors (BJTs), and metal-oxide-semiconductor field effect transistors (MOSFETs)

  10. Effects of the neutronic irradiation on the impact tests

    International Nuclear Information System (INIS)

    Lapena, J.; Perosanz, F.J.; Hernandez, M.T.

    1993-01-01

    The changes that the Charpy curves suffer when steel is exposed to neutronic fluence are studied. Three steels with different chemical composition were chosen, two of them (JPF and JPJ) being treated at only one neutronic fluence, while the last one (JRQ) was irradiated at three fluences. In this way, it was possible to compare the effect of increasing the neutronic dose, and to study the experimental results as a function of the steel chemical composition. Two characteristic facts have been observed: the displacement of the curve at higher temperatures, and decrease of the upper shelf energy (USE). The mechanical recovery of the materials after two different thermal treatments is also described, and a comparation between the experimental results obtained and the damage prediction formulas given by different regulatory international organisms in the nuclear field is established. Author. 11 refs

  11. Germanium-doped gallium phosphide obtained by neutron irradiation

    Science.gov (United States)

    Goldys, E. M.; Barczynska, J.; Godlewski, M.; Sienkiewicz, A.; Heijmink Liesert, B. J.

    1993-08-01

    Results of electrical, optical, electron spin resonance and optically detected magnetic resonance studies of thermal neutron irradiated and annealed at 800 °C n-type GaP are presented. Evidence is found to support the view that the main dopant introduced via transmutation of GaP, germanium, occupies cation sites and forms neutral donors. This confirms the possibility of neutron transmutation doping of GaP. Simultaneously, it is shown that germanium is absent at cation sites. Presence of other forms of Ge-related defects is deduced from luminescence and absorption data. Some of them are tentatively identified as VGa-GeGa acceptors leading to the self-compensation process. This observation means that the neutron transmutation as a doping method in application to GaP is not as efficient as for Si.

  12. Irradiation of oxyhemoglobin and carboxyhemoglobin by fast neutrons

    International Nuclear Information System (INIS)

    AbdelBaset, M.S.; Salama, A.A.

    1991-01-01

    Oxyhemoglobin (Hbo 2 ) and carboxyhemoglobin (HbCO) (2.6x10 - 5 M) were subjected to Cf neutron fluences in the range of 10 - 10 n/cm . Irradiation caused partial conversion of oxyhemoglobin to methemoglobin according to the exposure doses. Also, the results indicated that the exposure of HbCO to neutrons leads to the cleavage of iron porphyrin-CO to free CO. After cleavage of 100% CO, the effect of neutrons is devoted to the oxidation of hemoglobin to methemoglobin. From the results presented in this study, it is concluded that HbCO is more radioresistant than HbO 2 . The main target in the case of HbCO is the iron-porphyrin-CO.2 tab.3 fig

  13. Determination of neutron flux distribution in an Am-Be irradiator using the MCNP.

    Science.gov (United States)

    Shtejer-Diaz, K; Zamboni, C B; Zahn, G S; Zevallos-Chávez, J Y

    2003-10-01

    A neutron irradiator has been assembled at IPEN facilities to perform qualitative-quantitative analysis of many materials using thermal and fast neutrons outside the nuclear reactor premises. To establish the prototype specifications, the neutron flux distribution and the absorbed dose rates were calculated using the MCNP computer code. These theoretical predictions then allow one to discuss the optimum irradiator design and its performance.

  14. Cavity nucleation and growth during helium implantation and neutron irradiation of Fe and steel

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Singh, Bachu Narain

    In order to investigate the role of He in cavity nucleation in neutron irradiated iron and steel, pure iron and Eurofer-97 steel have been He implanted and neutron irradiated in a systematic way at different temperatures, to different He and neutron doses and with different He implantation rates....

  15. Commercial Applications at FRM II Based on Neutron Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Gerstenberg, H.; Draack, A.; Kastenmuller, A. [Technische Universitaet Muenchen, Munchen (Germany)

    2013-07-01

    Due to its design as a heavy water moderated reactor with a very compact core FRM II, Germany's most modern and most powerful research reactor, offers excellent conditions for basic research using beam tubes. On the other hand it is equipped with various irradiation facilities to be used mainly for industrial purposes. From the very beginning of reactor operation a dedicated department had been implemented in order to provide a neutron irradiation service to interested parties on a commercial basis. As of today the most widely used application is Si doping. The semiautomatic doping facility accepts ingots with diameters between 125 mm and 200 mm and a maximum height of 500 mm. The irradiation channel is located deep in the heavy water tank and exhibits a ratio of thermal/fast neutron flux density of > 1000. This value allows the doping of Si to a target resistivity as high as 1100 Ωcm within the tight limits regarding accuracy and homogeneity specified by the customer. Typically the throughput of Si doped in FRM II sums up to about 15 t/year. Another topic of growing importance is the use of FRM II aiming the production of radioisotopes mainly for the radiopharmaceutical industry. The maybe most challenging example is the production of Lu-177 n. c. a. based on the irradiation of Yb{sub 2}O{sub 3} to a high fluence of thermal neutrons of typically 1.5E20 cm{sup -2}. The Lu-177 activity delivered to the customer is in the range of 750 GBq. With respect to further processing it turned out to be a highly advantageous to have the laboratories of ITG, the company extracting the Lu-177 from the freshly irradiated Yb{sub 2}O{sub 3} on site FRM II. Further irradiation facilities are available at FRM II in order to allow the activation of samples for analytical purposes or to irradiate samples for geochronological investigations using the fission track technique. Finally a project on the future installation of a facility dedicated to the irradiation of U-targets for

  16. Influence of neutron irradiation on the tritium retention in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Rolli, R.; Ruebel, S.; Werle, H. [Forschungszentrum Karlsruhe, Inst. fuer Neutronenphysik und Reaktortechnik, Karlsruhe (Germany); Wu, C.H.

    1998-01-01

    Carbon-based materials and beryllium are the candidates for protective layers on the components of fusion reactors facing plasma. In contact with D-T plasma, these materials absorb tritium, and it is anticipated that tritium retention increases with the neutron damage due to neutron-induced traps. Because of the poor data base for beryllium, the work was concentrated on it. Tritium was loaded into the samples from stagnant T{sub 2}/H{sub 2} atmosphere, and afterwards, the quantity of the loaded tritium was determined by purged thermal annealing. The specification of the samples is shown. The samples were analyzed by SEM before and after irradiation. The loading and the annealing equipments are contained in two different glove boxes with N{sub 2} inert atmosphere. The methods of loading and annealing are explained. The separation of neutron-produced and loaded tritium and the determination of loaded tritium in irradiated samples are reported. Also the determination of loaded tritium in unirradiated samples is reported. It is evident that irradiated samples contained much more loaded tritium than unirradiated samples. The main results of this investigation are summarized in the table. (K.I.)

  17. Cation disorder in high-dose, neutron-irradiated spinel

    International Nuclear Information System (INIS)

    Sickafus, K.E.; Larson, A.C.; Yu, N.; Nastasi, M.; Hollenberg, G.W.; Garner, F.A.; Bradt, R.C.

    1994-08-01

    The objective of this effort is to determine whether MgAl 2 O 4 spinel is a suitable ceramic for fusion applications. Here, the crystal structures of MgAl 2 O 4 spinel single crystals irradiated to high neutron fluences [>5·10 26 n/m 2 (E n > 0.1 MeV)] were examined by neutron diffraction. Crystal structure refinement of the highest dose sample indicated that the average scattering strength of the tetrahedral crystal sites decreased by ∼ 20% while increasing by ∼ 8% on octahedral sites. Since the neutron scattering length for Mg is considerably larger than for Al, this results is consistent with site exchange between Mg 2+ ions on tetrahedral sites and Al 3+ ions on octahedral sites. Least-squares refinements also indicated that, in all irradiated samples, at least 35% of Mg 2+ and Al 3+ ions in the crystal experienced disordering replacements. This retained dpa on the cation sublattices is the largest retained damage ever measured in an irradiated spinel material

  18. Stability of the Hall sensors performance under neutron irradiation

    International Nuclear Information System (INIS)

    Duran, I.; Hron, M.; Stockel, J.; Viererbl, L.; Vsolak, R.; Cerva, V.; Bolshakova, I.; Holyaka, R.; Vayakis, G.

    2004-01-01

    A principally new diagnostic method must be developed for magnetic measurements in steady state regime of operation of fusion reactor. One of the options is the use of transducers based on Hall effect. The use of Hall sensors in ITER is presently limited by their questionable radiation and thermal stability. Issues of reliable operation in ITER like radiation and thermal environment are addressed in the paper. The results of irradiation tests of candidate Hall sensors in LVR-15 and IBR-2 experimental fission reactors are presented. Stable operation (deterioration of sensitivity below one percent) of the specially prepared sensors was demonstrated during irradiation by the total fluence of 3.10 16 n/cm 2 in IBR-2 reactor. Increasing the total neutron fluence up to 3.10 17 n/cm 2 resulted in deterioration of the best sensor's output still below 10% as demonstrated during irradiation in LVR-15 fission reactor. This level of neutron is already higher than the expected ITER life time neutron fluence for a sensor location just outside the ITER vessel. (authors)

  19. ANITA-2000, Isotope Inventories from Neutron Irradiation, for Fusion Applications

    International Nuclear Information System (INIS)

    Cepraga, Dan-Gabriel

    2000-01-01

    1 - Description of program or function: ANITA-2000 is a code package for the activation characterisation of materials exposed to neutrons in fusion machines. The main component of the package is the activation code ANITA-4M that computes the radioactive inventory of a material exposed to neutron irradiation, continuous or stepwise. It provides activity, atomic density, decay heat, biological hazard, clearance index and gamma-ray source spectra at shut down and for different cooling times. An interactive utility module, MODBIN, to produce the neutron activation cross sections libraries in the required binary ANITA-4M Format, is also included. The GRANITA interactive module may plot activation parameters as a function of the cooling time. The main improvements include: -the number of irradiation time intervals has been increased to 2000; -different neutron wall loading can be used for each burn time interval; -the photon source calculation in the 18 energy group Scale structure has been added; -the clearance index can be calculated. In addition the code language has been standardized to Fortran '95 - by maintaining the backward compatibility (except for the time/date routines) - so as the same code package can be compiled and run on Unix environment and on PC, both under DOS-Windows and under Linux. 2 - Methods: The mathematical solution of the problem is given in analytical form using recurrence relations. Double precision arithmetic is used

  20. High temperature annealing of minority carrier traps in irradiated MOCVD n(+)p InP solar cell junctions

    Science.gov (United States)

    Messenger, S. R.; Walters, R. J.; Summers, G. P.

    1993-01-01

    Deep level transient spectroscopy was used to monitor thermal annealing of trapping centers in electron irradiated n(+)p InP junctions grown by metalorganic chemical vapor deposition, at temperatures ranging from 500 up to 650K. Special emphasis is given to the behavior of the minority carrier (electron) traps EA (0.24 eV), EC (0.12 eV), and ED (0.31 eV) which have received considerably less attention than the majority carrier (hole) traps H3, H4, and H5, although this work does extend the annealing behavior of the hole traps to higher temperatures than previously reported. It is found that H5 begins to anneal above 500K and is completely removed by 630K. The electron traps begin to anneal above 540K and are reduced to about half intensity by 630K. Although they each have slightly different annealing temperatures, EA, EC, and ED are all removed by 650K. A new hole trap called H3'(0.33 eV) grows as the other traps anneal and is the only trap remaining at 650K. This annealing behavior is much different than that reported for diffused junctions.

  1. Irradiation test HT-31: high-temperature irradiation behavior of LASL-made extruded fuel rods and LASL-made coated particles

    International Nuclear Information System (INIS)

    Wagner, P.; Reiswig, R.D.; Hollabaugh, C.M.; White, R.W.; Davidson, K.V.; Schell, D.H.

    1977-04-01

    Three LASL-made extruded graphite and coated particle fuel rods have been irradiated in the Oak Ridge National Laboratory High Fluence Isotope Reactor test HT-31. Test conditions were about 9 x 10 21 nvt(E > .18 MeV) at 1250 0 C. The graphite matrix showed little or no effect of the irradiation. LASL-made ZrC containing coated particles with ZrC coats and ZrC-doped pyrolytic carbon coats showed no observable effects of the irradiation

  2. Effects of neutron irradiation and fatigue on ductility of stainless steel DIN-1-4948

    International Nuclear Information System (INIS)

    de Vries, M.I.; van der Schaaf, B.; Staal, H.U.; Elen, J.D.

    1978-01-01

    Test specimens of stainless steel DIN 1.4948, which is similar to AISI Type 304, have been irradiated at 723 and 823 K up to fluences of 1*10$sup 23$ neutrons (n)*m$sup -2$ and 5*10$sup 24$ n*m$sup -2$ (E>0.1 MeV). These are representative conditions for the reactor vessel and inner components of the liquid metal fast breeder reactor SNR-300 after 16 years of operation. High-temperature (723 to 1023 K) tension tests at strain rates ($epsilon$) from 10$sup -7$ to 10 s$sup -1$ show a considerable decrease of tensile ductility. The extent depends on helium content, test temperature, and strain rate. The atomic helium fractions of 3*10$sup -7$ and 7*10$sup -6$ result from the reactions of thermal neutrons with the 14 ppm boron present in the steel. Helium embrittlement sets in at strain rates below 1 to 10 s$sup -1$ (the range of interest for Bethe-Tait accident analyses). A minimum total elongation value of 6 percent is shown at 923 K. The postirradiation fatigue life is reduced by up to about 50 percent due to intergranular cracking. The combination of irradiation and fatigue causes a decrease of ductility after a smaller number of prior fatigue cycles than in the case of unirradiated material. 8 refs

  3. Neutron irradiation behavior of ITER candidate beryllium grades

    Energy Technology Data Exchange (ETDEWEB)

    Kupriyanov, I.B.; Gorokhov, V.A.; Nikolaev, G.N. [A.A.Bochvar All-Russia Scientific Research Inst. of Inorganic Materials (VNIINM), Moscow (Russian Federation); Melder, R.R.; Ostrovsky, Z.E.

    1998-01-01

    Beryllium is one of the main candidate materials both for the neutron multiplier in a solid breeding blanket and for the plasma facing components. That is why its behaviour under the typical for fusion reactor loading, in particular, under the neutron irradiation is of a great importance. This paper presents mechanical properties, swelling and microstructure of six beryllium grades (DshG-200, TR-30, TshG-56, TRR, TE-30, TIP-30) fabricated by VNIINM, Russia and also one - (S-65) fabricated by Brush Wellman, USA. The average grain size of the beryllium grades varied from 8 to 25 {mu}m, beryllium oxide content was 0.8-3.2 wt. %, initial tensile strength was 250-680 MPa. All the samples were irradiated in active zone of SM-3 reactor up to the fast neutron fluence (5.5-6.2) {center_dot} 10{sup 21} cm{sup -2} (2.7-3.0 dpa, helium content up to 1150 appm), E > 0.1 MeV at two temperature ranges: T{sub 1} = 130-180degC and T{sub 2} = 650-700degC. After irradiation at 130-180degC no changes in samples dimensions were revealed. After irradiation at 650-700degC swelling of the materials was found to be in the range 0.1-2.1 %. Beryllium grades TR-30 and TRR, having the smallest grain size and highest beryllium oxide content, demonstrated minimal swelling, which was no more than 0.1 % at 650-700degC and fluence 5.5 {center_dot} 10{sup 21} cm{sup -2}. Tensile and compression test results and microstructure parameters measured before and after irradiation are also presented. (author)

  4. Characterization of hybrid self-powered neutron detector under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakamichi, M. E-mail: masaru@oarai.jaeri.go.jp; Nagao, Y.; Yamamura, C.; Nakazawa, M.; Kawamura, H

    2000-11-01

    To evaluate the irradiation behaviour of a blanket mock-up on in-pile functional test, it is necessary to measure the neutron flux change in the in-pile mock-up by a neutron detector, such as the self-powered neutron detector (SPND). With its small-sized emitter, which has high sensitivity and fast response time, SPND is an indispensable tool in order to measure the local neutron flux change. In the case of an in-pile functional test, it is necessary that response time is less than 1s and ratio of SPND output current is more than 0.3 of output current of SPND with Rh emitter. Therefore, a hybrid SPND with high sensitivity and fast response time was developed. This hybrid SPND used a hybrid emitter, i.e. Co cladded Pt-13%R000.

  5. Characterization of hybrid self-powered neutron detector under neutron irradiation

    CERN Document Server

    Nakamichi, M; Yamamura, C; Nakazawa, M; Kawamura, H

    2000-01-01

    To evaluate the irradiation behaviour of a blanket mock-up on in-pile functional test, it is necessary to measure the neutron flux change in the in-pile mock-up by a neutron detector, such as the self-powered neutron detector (SPND). With its small-sized emitter, which has high sensitivity and fast response time, SPND is an indispensable tool in order to measure the local neutron flux change. In the case of an in-pile functional test, it is necessary that response time is less than 1s and ratio of SPND output current is more than 0.3 of output current of SPND with Rh emitter. Therefore, a hybrid SPND with high sensitivity and fast response time was developed. This hybrid SPND used a hybrid emitter, i.e. Co cladded Pt-13%Rh.

  6. Characteristics of neutron irradiation facility and dose estimation method for neutron capture therapy at Kyoto University research reactor institute

    International Nuclear Information System (INIS)

    Kobayashi, T.; Sakurai, Y.; Kanda, K.

    2001-01-01

    The neutron irradiation characteristics of the Heavy Water Neutron Irradiation Facility (HWNIF) at the Kyoto University Research Reactor Institute (KIJRRI) for boron neutron capture therapy (BNCT), is described. The present method of dose measurement and its evaluation at the KURRI, is explained. Especially, the special feature and noticeable matters were expounded for the BNCT with craniotomy, which has been applied at present only in Japan. (author)

  7. A comparison of microstructures in copper irradiated with fission, fusion, and spallation neutrons

    International Nuclear Information System (INIS)

    Muroga, T.; Heinisch, H.L.; Sommer, W.F.; Ferguson, P.D.

    1992-01-01

    The objective of this work is to investigate the effects of the neutron energy spectrum in low dose irradiations on the microstructure and mechanical properties of metals. The microstructures of pure copper irradiated to low doses at 36-90 C with spallation neutrons, fusion neutrons and fission neutrons are compared. The defect cluster densities for the spallation and fusion neutrons are very similar when compared on the basis of displacements per atom (dpa). In both cases, the density increases in proportion to the square root of the dpa. The difference in defect density between fusion neutrons and fission neutrons corresponds with differences observed in data on yield stress changes

  8. Positron annihilation and Moessbauer studies of neutron irradiated reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Brauer, G.; Matz, W.; Liszkay, L.; Molnar, B.

    1990-11-01

    Positron annihilation (lifetime, Doppler broadening) and Moessbauer studies on unirradiated, neutron irradiated and neutron irradiated plus annealed reactor pressure vessel steels (Soviet type 15Kh2NMFA) are presented. The role of microstructural properties and the formation of irradiation-induced precipitates is discussed. (orig.) [de

  9. Theoretical description of the influence of neutron irradiation on viscoplastic properties of mild steel

    International Nuclear Information System (INIS)

    Pecherski, R.

    1978-01-01

    The physical bases of plastic deformation of mild steel are described. The influence of neutron irradiation on the change of mechanisms of plastic deformation is discussed in detail. Constitutive equations of viscoplasticity for irradiated mild steel are given. The problem of thickwalled viscoplastic spherical tank irradiated by neutrons is studied. (Z.R.)

  10. Neutron irradiation test of depleted CMOS pixel detector prototypes

    International Nuclear Information System (INIS)

    Mandić, I.; Cindro, V.; Gorišek, A.; Hiti, B.; Kramberger, G.; Mikuž, M.; Zavrtanik, M.; Hemperek, T.; Daas, M.; Hügging, F.; Krüger, H.; Pohl, D.-L.; Wermes, N.; Gonella, L.

    2017-01-01

    Charge collection properties of depleted CMOS pixel detector prototypes produced on p-type substrate of 2 kΩ cm initial resistivity (by LFoundry 150 nm process) were studied using Edge-TCT method before and after neutron irradiation. The test structures were produced for investigation of CMOS technology in tracking detectors for experiments at HL-LHC upgrade. Measurements were made with passive detector structures in which current pulses induced on charge collecting electrodes could be directly observed. Thickness of depleted layer was estimated and studied as function of neutron irradiation fluence. An increase of depletion thickness was observed after first two irradiation steps to 1 · 10 13 n/cm 2 and 5 · 10 13 n/cm 2 and attributed to initial acceptor removal. At higher fluences the depletion thickness at given voltage decreases with increasing fluence because of radiation induced defects contributing to the effective space charge concentration. The behaviour is consistent with that of high resistivity silicon used for standard particle detectors. The measured thickness of the depleted layer after irradiation with 1 · 10 15 n/cm 2 is more than 50 μm at 100 V bias. This is sufficient to guarantee satisfactory signal/noise performance on outer layers of pixel trackers in HL-LHC experiments.

  11. High dose neutron irradiation damage in beryllium as blanket material

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V.P. E-mail: fae@niiar.ru; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B. E-mail: vniinm.400@g23.relkom.ru

    2001-11-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10{sup 22} and 8.0x10{sup 22} cm{sup -2} (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10{sup 22} cm{sup -2} (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10{sup 22} cm{sup -2} (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket.

  12. High dose neutron irradiation damage in beryllium as blanket material

    International Nuclear Information System (INIS)

    Chakin, V.P.; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B.

    2001-01-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10 22 and 8.0x10 22 cm -2 (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10 22 cm -2 (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10 22 cm -2 (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket

  13. Ruthenium release at high temperature from irradiated PWR fuels in various oxidising conditions. Main findings from the VERCORS program

    International Nuclear Information System (INIS)

    Ducros, G.; Pontillon, Y.; Malgouyres, P.P.; Taylor, P.; Dutheillet, Y.

    2005-01-01

    Fission product release and transport in case of PWR severe accident is a major topic in reactor safety assessment due to the potential radiological consequences for surrounding populations and the environment. In this context, the Institute for Radiological Protection and Safety (IRSN) and Electricite de France (EDF) have supported the VERCORS analytical test program which was performed by the ''Commissariat a l'Energie Atomique'' (CEA). It is usually considered as complementary to the PHEBUS FP in-pile integral experimental program. 25 annealing tests were performed between 1983 and 2002 on irradiated PWR fuels under various conditions of temperature and atmospheres (oxidising or reducing conditions).The influence of the nature of the fuel (UO 2 versus MOX, burn-up) and the fuel morphology (initially intact or fragmented fuels) have also been investigated. These led to an extended data base allowing on the one hand to study mechanisms which promote fission products release, and on the other hand to enhance models implemented in severe accident codes. Among all the fission products investigated, ruthenium is of specific concern because of its high radiological effects due essentially to the combination of both its short and long half-life isotopes (i.e. 103 Ru and 106 Ru respectively), but also by its ability to generate volatile gaseous oxides (RuO 3 , RuO 4 ) in very oxidising conditions, in particular in the case of air ingress accidents. Important uncertainties still remain on the release and transport of this element in such situations, and investigations on this open issue are notably carried out in the SARNET European framework. The present communication gives a general overview of the VERCORS program and presents more deeply the main findings concerning the ruthenium release. Its global behaviour is analysed on the basis of several comparative tests: same UO 2 sample (35 and 50 GWd/t) under hydrogen or steam conditions, similar MOX sample (40 GWd/t) under

  14. Electrical properties of indium arsenide irradiated with fast neutrons

    International Nuclear Information System (INIS)

    Kolin, N.G.; Osvenskii, V.B.; Rytova, N.S.; Yurova, E.S.

    1987-01-01

    A study was made of the influence of irradiation with fast reactor neutrons on electrical properties of indium arsenide samples with different dopant concentrations. The laws governing the formation and annealing of radiation defects in indium arsenide were found to be governed by the donor-acceptor interaction. Depending on the density of free carriers in the original crystal, irradiation could produce charged defects of predominantly donor or acceptor types. Donor defects in irradiated InAs samples were annealed practically completely, whereas a considerable fraction of residual acceptor defects was retained even after heat treatment at 900 degree C. The concentration of these residual acceptors depended on the electron density at the annealing temperature

  15. Study of natural diamond detector spectrometric properties under neutron irradiation

    CERN Document Server

    Alekseyev, A B; Kaschuck, Y; Krasilnikov, A; Portnov, D; Tugarinov, S

    2002-01-01

    Natural diamond detector (NDD) performance was studied up to a neutron fluence of 10 sup 1 sup 5 neutron/cm sup 2. The variations of the NDD spectrometric response to incident alpha-particles from sup 2 sup 4 sup 1 Am source after exposure to fast neutron fluences up to 3x10 sup 1 sup 6 n/cm sup 2 were examined. No significant variations up to the level of 10 sup 1 sup 4 n/cm sup 2 were observed. Degradation of charge collection efficiency at higher fluences is reported. No remarkable increase of the NDD leakage current and count rate change had been observed up to a neutron fluence of 3x10 sup 1 sup 6 n/cm sup 2. The charge collection efficiency variations of neutron irradiated diamond spectrometer were studied ex situ under gamma-rays, beta-radiation and visible light excitation. Charge collection efficiency restoration up to 75% level and the NDD performance stabilization by extrinsic low-intensity visible light (550 nm

  16. Features of the structural states of KNbO{sub 3} single crystals before and after fast-neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Stash, A. I., E-mail: astas@yandex.ru; Ivanov, S. A.; Stefanovich, S. Yu.; Mosunov, A. V.; Boyko, V. M.; Ermakov, V. S.; Korulin, A. V.; Kalyukanov, A. I. [State Scientific Center of the Russian Federation Karpov Institute of Physical Chemistry (Russian Federation)

    2017-01-15

    Neutron irradiation is a unique tool for forming new structural states of ferroelectrics, which cannot be obtained by conventional methods. The inf luence of the irradiation by two doses of fast neutrons (F = 1 × 10{sup 17} and 3 × 10{sup 17} cm{sup –2}) on the structure and properties of KNbO{sub 3} single crystals has been considered for the first time. The developed method for taking into account the experimental correction to the diffuse scattering has been used to analyze the structural changes occurring in KNbO{sub 3} samples at T = 295 K and their correlations with the behavior of dielectric and nonlinear optical characteristics. The irradiation to the aforementioned doses retains the KNbO{sub 3} polar structure, shifting Т{sub Ð}¡ to lower temperatures and significantly affecting only the thermal parameters and microstructure of single crystals. Neutron irradiation with small atomic displacements provides a structure similar to the high-temperature modification of an unirradiated KNbO{sub 3} crystal.

  17. Metal ion protection of DNA to fast neutron irradiation

    International Nuclear Information System (INIS)

    Constantinescu, B.; Bugoi, R.; Radulescu, I.; Radu, L.

    1998-01-01

    The most important effects of the ionising radiation are the single and double strand breaks (SSB and DBS), modifications of the DNA bases and deoxyribose, as well as the occurrence of alkali and heat labile sites (revealed as strand breaks after alkaline or thermic treatment of irradiated DNA). The ionising particles can have either direct effects on the DNA constituents or indirect effects, mediated by the OH - radicals, produced by water radiolysis. The occurrence of SSB and DSB in the chromatin DNA strands is supposed to hinder the DNA-dye complex formation. Usually, the dyes present different fluorescence parameters in the two possible states, so one can correlate the lifetime or the quantum yield with the extent of the damage. We took into account the protective effect offered both by histones, which behave as 'scavenger molecules' for OH - radicals and by the high compactness of DNA chromatin. Similar protective effects might be the results of the metallic ion addition which triggers some conformational transitions of the chromatin DNA towards a highly compacted structure. In this paper we present a study of the complexes of fast neutron irradiated chromatin with proflavine. Fluorimetric and time resolved spectroscopic determinations (single photon counting method) of chromatin-Pr complexes were realised. Information regarding the chromatin protein damage were obtained by monitoring the fluorescence of Trp. The chromatin was irradiated (20-100 Gy) with fast neutrons, obtained by the reaction of 13.5 MeV deuterons on a thick beryllium target at the IFIN-HH U-120 Cyclotron. The dose mean lineal energy in water at the point of interest was 50 keV/m and the mean dose rate was 1.5 Gy/min. By fluorescence determinations, changes of the Pr intercalation parameters in fast neutron irradiated chromatin DNA have been observed. Fluorescence techniques provide valuable information on the binding equilibrium by considering the radiation deexcitation of the complex. The

  18. Neutron irradiation effects on magnetic properties of some Heusler alloys

    International Nuclear Information System (INIS)

    Onodera, Hideya; Shinohara, Takeshi; Yamamoto, Hisao; Watanabe, Hiroshi

    1975-01-01

    The neutron irradiation effects were studied with measurements of temperature dependence of magnetization in ordered and disordered Heusler alloys. The irradiation was carried out in JMTR with a total flux of fast neutrons of 10 20 nvt. Fully ordered Cu 2 MnIn, partially ordered Cu 2 MnAl and completely disordered Cu 2 MnSn were prepared with various temperature treatments. The magnetization-temperature curves of each specimen were measured before and after irradiation. In the irradiated Cu 2 MnIn, the disordering by the irradiation gave rise to a decrease of magnetization, and the temperature dependence of magnetization showed that the disordered region contained various regions with different degrees of disorder. For the distribution of the disordered region, the calculation based on the theory of temperature spike by Seitz and Koekler gave a feasible result that a disordered region comprised a central core with a radius of 5.4 A which was completely disordered and a periphery of 3.3 A thickness which was partially disordered. From the magnetization-temperature curves of Cu 2 MnAl, it was considered that the disordered regions induced by the irradiation had different properties from those induced by the heat treatment. The former were the localized and comprised regions corresponding to various degrees of disorder, while the latter spread spatially in a wide range with a certain degree of disorder. The ordering by enhanced diffusion occurred simultaneously to an extent comparable to the disordering, and so it played an important role in the magnetization in the partially disordered Cu 2 MnAl. In the disordered Cu 2 MnSn, however, the ordering effect was very small. It is supposed to be difficult for the A2 structure to transform into the L2 1 structure by the enhanced diffusion. (auth.)

  19. DT fusion neutron irradiation of ORNL magnesium oxide crystals and BNL--LASL superconductor wires

    International Nuclear Information System (INIS)

    MacLean, S.C.

    1978-01-01

    The DT fusion neutron irradiation of two ORNL magnesium oxide crystals and eleven BNL-LASL superconductor wires is described. The sample position and neutron dose record are given. The maximum neutron fluence on any sample was 2.16 x 10 16 neutrons/cm 2

  20. Microstructure-tensile property correlation of 316SS in low dose neutron irradiations

    International Nuclear Information System (INIS)

    Yoshida, N.; Muroga, T.; Araki, K.; Heinisch, H.L.; Kiritani, M.

    1990-05-01

    The objective of this work is to determine the effects of the neutron spectrum on radiation-induced changes in mechanical properties for metals irradiated with fission and fusion neutrons. 10 refs., 6 figs

  1. Irradiation test OF-2: high-temperature irradiation behavior of LASL-made fuel rods and LASL-made coated particles

    International Nuclear Information System (INIS)

    Wagner, P.; Reiswig, R.D.; Hollabaugh, C.M.; White, R.W.; O'Rourke, J.A.; Davidson, K.V.; Schell, D.H.

    1977-10-01

    Three LASL-made, substoichiometric ZrC-coated particles with inert kernels, and two high-density molded graphite fuel rods that contained LASL-made, ZrC-coated fissile particles were irradiated in the Oak Ridge Research Reactor test OF-2. The severest test conditions were 8.36 x 10 21 nvt (E greater than 0.18 MeV) at 1350 0 C. The graphite matrix showed no effect of the irradiation. There was no interaction between the matrix and any of the particle coats. The loose ZrC coated particles with inert kernels showed no irradiation effects. The graded ZrC-C coats on the fissile particles were cracked. It is postulated that the cracking is associated with the low LTI deposition rate and is not related to the ZrC

  2. Ion irradiation to simulate neutron irradiation in model graphites: Consequences for nuclear graphite

    Science.gov (United States)

    Galy, N.; Toulhoat, N.; Moncoffre, N.; Pipon, Y.; Bérerd, N.; Ammar, M. R.; Simon, P.; Deldicque, D.; Sainsot, P.

    2017-10-01

    Due to its excellent moderator and reflector qualities, graphite was used in CO2-cooled nuclear reactors such as UNGG (Uranium Naturel-Graphite-Gaz). Neutron irradiation of graphite resulted in the production of 14C which is a key issue radionuclide for the management of the irradiated graphite waste. In order to elucidate the impact of neutron irradiation on 14C behavior, we carried out a systematic investigation of irradiation and its synergistic effects with temperature in Highly Oriented Pyrolitic Graphite (HOPG) model graphite used to simulate the coke grains of nuclear graphite. We used 13C implantation in order to simulate 14C displaced from its original structural site through recoil. The collision of the impinging neutrons with the graphite matrix carbon atoms induces mainly ballistic damage. However, a part of the recoil carbon atom energy is also transferred to the graphite lattice through electronic excitation. The effects of the different irradiation regimes in synergy with temperature were simulated using ion irradiation by varying Sn(nuclear)/Se(electronic) stopping power. Thus, the samples were irradiated with different ions of different energies. The structure modifications were followed by High Resolution Transmission Electron Microscopy (HRTEM) and Raman microspectrometry. The results show that temperature generally counteracts the disordering effects of irradiation but the achieved reordering level strongly depends on the initial structural state of the graphite matrix. Thus, extrapolating to reactor conditions, for an initially highly disordered structure, irradiation at reactor temperatures (200 - 500 °C) should induce almost no change of the initial structure. On the contrary, when the structure is initially less disordered, there should be a "zoning" of the reordering: In "cold" high flux irradiated zones where the ballistic damage is important, the structure should be poorly reordered; In "hot" low flux irradiated zones where the ballistic

  3. Development of an on-line high-temperature ion source for neutron-rich fission products at TRIGA-SPEC

    Energy Technology Data Exchange (ETDEWEB)

    Renisch, Dennis [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet Mainz (Germany); Collaboration: TRIGA-SPEC-Collaboration

    2012-07-01

    The TRIGA-SPEC experiment at the TRIGA Mainz research reactor aims to determine ground-state properties of exotic nuclides. It includes the Penning-trap mass spectrometer TRIGA-TRAP and the collinear laser spectroscopy setup TRIGA-LASER. Nuclides of interest are produced in the neutron-induced fission of suitable actinide isotopes, thermalized in a gas-filled volume and transported to an on-line ion source with a gas-jet. The ion source being constructed has two operation modes: a high-temperature surface ionization mode and a hollow cathode plasma mode. It is expected that the surface mode will yield a high ionization efficiency for certain elements, in the order of at least several percent, whereas the plasma mode has the advantage, that more elements can be ionized but with lower efficiency compared to the surface ionization mode. The current status of the TRIGA-SPEC experiments and the present performance of the on-line ion source are presented.

  4. TORT-TD/ATTICA3D: a coupled neutron transport and thermal hydraulics code system for 3-D transient analysis of gas cooled high temperature reactors

    International Nuclear Information System (INIS)

    Lapins, J.; Seubert, A.; Buck, M.; Bader, J.; Laurien, E.

    2011-01-01

    Comprehensive safety studies of high temperature gas cooled reactors (HTR) require full three dimensional coupled treatments of both neutron kinetics and thermal-hydraulics. In a common effort, GRS and IKE developed the coupled code system TORT-TD/ATTICA3D for pebble bed type HTR that connects the 3-D transient discrete-ordinates transport code TORT-TD with the 3-D porous medium thermal-hydraulics code ATTICA3D. In this paper, the physical models and calculation capabilities of TORT-TD and ATTICA3D are presented, focusing on model improvements in ATTICA3D and extensions made in TORT-TD related to HTR application. For first applications, the OECD/NEA/NSC PBMR-400 benchmark has been chosen. Results obtained with TORT-TD/ATTICA3D will be shown for transient exercises, e.g. control rod withdrawal and a control rod ejection. Results are compared to other benchmark participants' solutions with special focus on fuel temperature modelling features of ATTICA3D. The provided “grey-curtain” nuclear cross section libraries have been used. First results on 3-D effects during a control rod withdrawal transient will be presented. (author)

  5. Development of the prediction technology of cable disconnection of in-core neutron detector for the future high-temperature gas cooled reactors

    International Nuclear Information System (INIS)

    Shimazaki, Yosuke; Sawahata, Hiroaki; Kawamoto, Taiki; Suzuki, Hisashi; Shinohara, Masanori; Honda, Yuki; Katsuyama, Kozo; Takada, Shoji; Sawa, Kazuhiro

    2015-01-01

    Maintenance technologies for the reactor system have been developed by using the high-temperature engineering test reactor (HTTR). One of the important purposes of development is to accumulate the experiences and data to satisfy the availability of operation up to 90% by shortening the duration of the periodical maintenance for the future HTGRs by shifting from the time-based maintenance to condition-based maintenance. The technical issue of the maintenance of in-core neutron detector, wide range monitor (WRM), is to predict the malfunction caused by cable disconnection to plan the replacement schedule. This is because that it is difficult to observe directly inside of the WRM in detail. The electrical inspection method was proposed to detect and predict the cable disconnection of the WRM by remote monitoring from outside of the reactor by using the time domain reflectometry and so on. The disconnection position, which was specified by the electrical method, was identified by non-destructive and destructive inspection. The accumulated data is expected to be contributed for advanced maintenance of future HTGRs. (author)

  6. Analysis of irradiation-induced stresses in coating layers of coated fuel particles for the High Temperature Engineering Test Reactor (HTTR)

    International Nuclear Information System (INIS)

    Hayashi, Kimio; Kikuchi, Teruo; Fukuda, Kousaku; Sato, Sadao; Toyota, Junji; Shiozawa, Shusaku; Sawa, Kazuhiro; Kashimura, Satoru.

    1991-07-01

    Irradiation-induced stresses in coating layers of coated fuel particles were analyzed by the MICROS-2 code for the fuels of the High Temperature Engineering Test Reactor (HTTR) under its operating conditions. The analyses were made on the standard core fuel (A-type) and the test fuels comprising the advanced SiC-coated particle fuel (B-1 type) and the ZrC-coated particle fuel (B-2 type). For the B-1 type fuel, the stresses were relieved due to the thicker buffer and SiC layers than for the A type fuel. The slightly decreased thickness of the fourth layer for the B-1 type than for the A type fuel had no significant effect on the stresses. As for the B-2 type fuel, almost the same results as for the B-1 type were obtained under an assumption that the ZrC layer as well as the SiC layer undergoes negligible dimension change within the analysis conditions. The obtained results indicated that the B-1 and B-2 type fuels are better than the A type fuel in terms of integrity against the irradiation-induced stresses. Finally, research subjects for development of the analysis code on the fuel behavior are discussed. (author)

  7. Measurement and evaluation of fast neutron flux of CT and OR5 irradiation hole in HANARO

    International Nuclear Information System (INIS)

    Yang, Seong Woo; Choo, Kee Nam; Lee, Seung-Kyu; Kim, Yong Kyun

    2012-01-01

    The irradiation test has been conducted to evaluate the irradiation performance of many materials by a material capsule at HANARO. Since the fast neutron fluence above 1 MeV is important for the irradiation test of material, it must be measured and evaluated exactly at each irradiation hole. Therefore, a fast neutron flux was measured and evaluated by a 09M-02K capsule irradiated in an OR5 irradiation hole and a 10M-01K capsule irradiated in a CT irradiation hole. Fe, Ni, and Ti wires as the fluence monitor were used for the detection of fast neutron flux. Before the irradiation test, the neutron flux and spectrum was calculated for each irradiation hole using an MCNP code. After the irradiation test, the activity of the fluence monitor was measured by an HPGe detector and the reaction rate was calculated. For the OR5 irradiation hole, the radial difference of the fast neutron flux was observed from a calculated data due to the OR5 irradiation hole being located outside the core. Furthermore, a control absorber rod was withdrawn from the core as the increase of the irradiation time at the same irradiation cycle, so the distribution of neutron flux was changed from the beginning to the end of the cycle. These effects were considered to evaluate the fast neutron flux. Neutron spectrums of the CT and OR5 irradiation hole were adjusted by the measured data. The fluxes of a fast neutron above 1 MeV were compared with calculated and measured value. Although the maximum difference was shown at 18.48%, most of the results showed good agreement. (author)

  8. Results of neutron irradiation of liquid lithium saturated with deuterium

    International Nuclear Information System (INIS)

    Tazhibayeva, Irina; Ponkratov, Yuriy; Kulsartov, Timur; Gordienko, Yuriy; Skakov, Mazhyn; Zaurbekova, Zhanna; Lyublinski, Igor; Vertkov, Alexey; Mazzitelli, Giuseppe

    2017-01-01

    Highlights: • The results on neutron irradiation of liquid lithium saturated with deuterium at the IVG.1M research reactor are described. • At temperatures below 573 K the efficiency coefficient of tritium release is well described by the expression K = 0.015 exp(−14/RT), and above 623 K − K = 10 9 exp(−144/RT). • The T 2 molecules contribution into the overall tritium release becomes apparent at temperatures higher than 673 K and increases with the temperature rise. - Abstract: This paper describes the results on neutron irradiation of liquid lithium saturated with deuterium at the IVG.1 M research reactor. The neutron flux at the reactor core center at 2 MW was 5 10 −13 cm −2 s −1 . The efficiency coefficients of helium and tritium release from lithium saturated with deuterium were calculated. The tritium interaction with lithium atoms (formation and dissociation of lithium tritide) has an effect on tritium release. An increment of sample’s temperature results in tritium release acceleration due to rising of the dissociation rate of lithium tritide. At temperatures below 573 K the efficiency coefficient of tritium release is well described by the expression K = 0.015 exp(−14/RT), and above 623 K − K = 10 9 exp(-144/RT). The T 2 molecules contribution into the overall tritium release becomes apparent at temperatures higher than 673 K and increases with the temperature rise.

  9. High temperature materials; Materiaux a hautes temperatures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  10. Recovery characteristics of neutron-irradiated V-Ti alloys

    International Nuclear Information System (INIS)

    Leguey, T.; Pareja, R.

    2000-01-01

    The recovery characteristics of neutron-irradiated pure V and V-Ti alloys with 1.0 and 4.5 at.% Ti have been investigated by positron annihilation spectroscopy. Microvoid formation during irradiation at 320 K is produced in pure V and V-1Ti but not in V-4.5Ti. The results are consistent with a model of swelling inhibition induced by vacancy trapping by solute Ti during irradiation. The temperature dependencies of the parameter S in the range 8-300 K indicate a large dislocation bias for vacancies and solute Ti. This dislocation bias prevents the microvoid nucleation in V-4.5Ti, and the microvoid growth in V-1Ti, when vacancies become mobile during post-irradiation annealing treatments. A characteristic increase of the positron lifetime is found during recovery induced by isochronal annealing. It is attributed to a vacancy accumulation into the lattice of Ti oxides precipitated during cooling down, or at their matrix/precipitate interfaces. These precipitates could be produced by the decomposition of metastable phases of Ti oxides formed during post-irradiation annealing above 1000 K

  11. Neutron-irradiation facilities at the Intense Pulsed Neutron Source-I for fusion magnet materials studies

    International Nuclear Information System (INIS)

    Brown, B.S.; Blewitt, T.H.

    1982-01-01

    The decommissioning of reactor-based neutron sources in the USA has led to the development of a new generation of neutron sources that employ high-energy accelerators. Among the accelerator-based neutron sources presently in operation, the highest-flux source is the Intense Pulsed Neutron Source (IPNS), a user facility at Argonne National Laboratory. Neutrons in this source are produced by the interaction of 400 to 500 MeV protons with either of two 238 U target systems. In the Radiation Effects Facility (REF), the 238 U target is surrounded by Pb for neutron generatjion and reflection. The REF has three separate irradiation thimbles. Two thimbles provide irradiation temperatures between that of liquid He and several hundred degrees centigrade. The third thimble operates at ambient temperature. The large irradiation volume, the neutron spectrum and flux, the ability to transfer samples without warm up, and the dedication of the facilities during the irradiation make this ideally suited for radiation damage studies on components for superconducting fusion magnets. Possible experiments for fusion magnet materials are discussed on cyclic irradiation and annealing of stabilizers in a high magnetic field, mechanical tests on organic insulation irradiated at 4 K, and superconductors measured in high fields after irradiation

  12. Impurities effect on the swelling of neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Donne, M.D.; Scaffidi-Argentina, F.

    1995-01-01

    An important factor controlling the swelling behaviour of fast neutron irradiated beryllium is the impurity content which can strongly affect both the surface tension and the creep strength of this material. Being the volume swelling of the old beryllium (early sixties) systematically higher than that of the more modem one (end of the seventies), a sensitivity analysis with the aid of the computer code ANFIBE (ANalysis of Fusion Irradiated BEryllium) to investigate the effect of these material properties on the swelling behaviour of neutron irradiated beryllium has been performed. Two sets of experimental data have been selected: the first one named Western refers to quite recently produced Western beryllium, whilst the second one, named Russian refers to relatively old (early sixties) Russian beryllium containing a higher impurity rate than the Western one. The results obtained with the ANFIBE Code were assessed by comparison with experimental data and the used material properties were compared with the data available in the literature. Good agreement between calculated and measured values has been found

  13. Neutron Irradiation Tests of Calibrated Cryogenic Sensors at Low Temperatures

    CERN Document Server

    Junquera, T; Thermeau, J P; Casas-Cubillos, J

    1998-01-01

    This paper presents the advancement of a program being carried out in view of selecting the cryogenic temperature sensors to be used in the LHC accelerator. About 10,000 sensors will be installed around the 26.6 km LHC ring, and most of them will be exposed to high radiation doses during the accelerator lifetime. The following thermometric sensors : carbon resistors, thin films, and platinum resistors, have been exposed to high neutron fluences (>10$^15$ n/cm$^2$) at the ISN (Grenoble, France) Cryogenic Irradiation Test Facility. A cryostat is placed in a shielded irradiation vault where a 20 MeV deuteron beam hits a Be target, resulting in a well collimated and intense neutron beam. The cryostat, the on-line acquisition system, the temperature references and the main characteristics of the irradiation facility are described. The main interest of this set-up is its ability to monitor online the evolution of the sensors by comparing its readout with temperature references that are in principle insensitive to t...

  14. High-light damage in air-dry thalli of the old forest lichen Lobaria pulmonaria - interactions of irradiance, exposure duration and high temperature

    International Nuclear Information System (INIS)

    Gauslaa, Y.; Solhaug, K.A.

    1999-01-01

    High-light damage in air-dry thalli of Lobaria pulmonaria were measured in the laboratory as reductions in maximal PSII efficiency (FV/FM) after a 48 h recovery in a hydrated state at low light to account for permanent damage. Thalli treated with the lowest light dose (90 mol photons m −2 ) recovered normal FV/FM-values with increasing irradiances (400–700 nm) up to 1000 µmol photons m −2 s −1 . Doubling this dose lowered the threshold level for damage from 1000 to 320 µmol photons m −2 s −1 , and reduced FV/FM at 1000 µmol photons m −2 s −1 by more than 50%. A second doubling of the dose to 360 mol photons m −2 caused damage at 200 µmol photons m −2 s −1 , and a nearly complete cessation of PSII efficiency occurred at 1000 µmol photons m −2 s −1 . No reciprocity of irradiance and duration of illumination for PSII function was found. The measured time-dependent decrease in FV/FM was remarkably similar for the naturally coupled, but artificially separated, light and temperature factors. Therefore, the damage of high light on desiccated L. pulmonaria seemed to be an additive effect of high irradiance and high temperatures. Air-dry thalli were highly heat susceptible, being affected already at temperatures around 40 °C. Logging operations in forests are likely to raise the solar radiation at remaining lichen sites to destructive levels. (author)

  15. Decommissioning of an Irradiator MPX-γ - 25M and a neutron Irradiator

    International Nuclear Information System (INIS)

    Soguero, Dania; Guerra, Mercedes; Prieto, Enrique; Desdin, Luis

    2013-01-01

    In this paper a technology is developed with its procedures in radiation protection to ensure the safety of the process of decommissioning of two irradiators. Both processes are described, the process of decommissioning of a neutron Irradiator 4. 44·10 11 Bq, employed in the vegetal radio mutagenesis, and disassembling of an installation of gamma irradiation of 3.33 * 10 12 Bq, self-shielded of category I, model MPX - γ - 25 M. The specific objectives are: a) identify aspects of the contractual assurance, of human and technical resources, b) to evaluate the radiological situation of the process and c) analyze the potential radiological extraordinary events in each of the steps of the process, ensuring the right answers. Evaluation of radiological successful events described can be considered as reference to address the process of disassembling of other similar irradiators

  16. Spectroscopic study of fast-neutron-irradiated chromatin

    International Nuclear Information System (INIS)

    Radu, L.; Gazdaru, D.; Constantinescu, B.

    2004-01-01

    The effects produced by fast neutrons (0-100 Gy) on chromatin structure were analyzed by (i) [ 1 H]-NMR spectroscopy, (ii) time resolved spectroscopy, and (iii) fluorescence resonance energy transfer (FRET). Two types of chromatin were tested: (i) a chromatin from a normal tissue (liver of Wistar rats) and (ii) a chromatin from a tumoral tissue (Guerin limphotrope epithelioma, a rat solid tumor). The fast-neutron action on chromatin determines greater values of the [ 1 H]-NMR transverse relaxation time, indicating a more injured structure. Time-resolved fluorescence measurements show that the relative contribution of the excited state lifetime of bound ethidium bromide to chromatin DNA diminishes with increasing irradiation doses. This reflects the damage that occurs in DNA structure: production of single- and double-strand breaks due to sugar and base modifications. By the FRET method, the distance between dansyl chloride and acridine orange coupled at chromatin was determined. This distance increases upon fast-neutron action. The radiosensitivity of the tumor tissue chromatin seems higher than that of the normal tissue chromatin, probably because of its higher (loose) euchromatin/(compact) heterochromatin ratio. As the values of the physical parameters analyzed are specific for a determined dose, the establishment of these parameters may constitute a criterion for the microdosimetry of chromatin radiolesions produced by fast neutrons. (author)

  17. Spectroscopic study of fast-neutron-irradiated chromatin

    Energy Technology Data Exchange (ETDEWEB)

    Radu, L. [V. Babes National Inst., Dept. of Molecular Genetics, Bucharest (Romania)]. E-mail: serbanradu@pcnet.ro; Gazdaru, D. [Bucharest Univ., Dept. of Biophysics, Physics Faculty, Bucharest (Romania); Constantinescu, B. [H. Hulubei National Inst., Dept. of Cyclotron, Bucharest (Romania)

    2004-02-01

    The effects produced by fast neutrons (0-100 Gy) on chromatin structure were analyzed by (i) [{sup 1}H]-NMR spectroscopy, (ii) time resolved spectroscopy, and (iii) fluorescence resonance energy transfer (FRET). Two types of chromatin were tested: (i) a chromatin from a normal tissue (liver of Wistar rats) and (ii) a chromatin from a tumoral tissue (Guerin limphotrope epithelioma, a rat solid tumor). The fast-neutron action on chromatin determines greater values of the [{sup 1}H]-NMR transverse relaxation time, indicating a more injured structure. Time-resolved fluorescence measurements show that the relative contribution of the excited state lifetime of bound ethidium bromide to chromatin DNA diminishes with increasing irradiation doses. This reflects the damage that occurs in DNA structure: production of single- and double-strand breaks due to sugar and base modifications. By the FRET method, the distance between dansyl chloride and acridine orange coupled at chromatin was determined. This distance increases upon fast-neutron action. The radiosensitivity of the tumor tissue chromatin seems higher than that of the normal tissue chromatin, probably because of its higher (loose) euchromatin/(compact) heterochromatin ratio. As the values of the physical parameters analyzed are specific for a determined dose, the establishment of these parameters may constitute a criterion for the microdosimetry of chromatin radiolesions produced by fast neutrons. (author)

  18. Neutron energy spectrum influence on irradiation hardening and microstructural development of tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Makoto, E-mail: makoto.fukuda@qse.tohoku.ac.jp [Tohoku University, Sendai, 980-8579 (Japan); Kiran Kumar, N.A.P.; Koyanagi, Takaaki; Garrison, Lauren M. [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Snead, Lance L. [Massachusetts Institute of Technology, Cambridge, MA, 02139 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Hasegawa, Akira [Tohoku University, Sendai, 980-8579 (Japan)

    2016-10-15

    Neutron irradiation to single crystal pure tungsten was performed in the mixed spectrum High Flux Isotope Reactor (HFIR). To investigate the influences of neutron energy spectrum, the microstructure and irradiation hardening were compared with previous data obtained from the irradiation campaigns in the mixed spectrum Japan Material Testing Reactor (JMTR) and the sodium-cooled fast reactor Joyo. The irradiation temperatures were in the range of ∼90–∼800 °C and fast neutron fluences were 0.02–9.00 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV). Post irradiation evaluation included Vickers hardness measurements and transmission electron microscopy. The hardness and microstructure changes exhibited a clear dependence on the neutron energy spectrum. The hardness appeared to increase with increasing thermal neutron flux when fast fluence exceeds 1 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV). Irradiation induced precipitates considered to be χ- and σ-phases were observed in samples irradiated to >1 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV), which were pronounced at high dose and due to the very high thermal neutron flux of HFIR. Although the irradiation hardening mainly caused by defects clusters in a low dose regime, the transmutation-induced precipitation appeared to impose additional significant hardening of the tungsten. - Highlights: • The microstructure and irradiation hardening of single crystal pure W irradiated in HFIR was investigated. • The neutron energy spectrum influence was evaluated by comparing the HFIR results with previous work in Joyo and JMTR. • In the dose range up to ∼1 dpa, the neutron energy spectrum influence of irradiation hardening was not clear. • In the dose range above 1 dpa, the neutron energy influence on irradiation hardening and microstructural development was clearly observed. • The irradiation induced precipitates caused significant irradiation hardening of pure W irradiated in HFIR.

  19. Chemical transformations associated with neutronic irradiation of telluric acid

    International Nuclear Information System (INIS)

    Bertet, M.

    1963-01-01

    The chemical transformations which arise from irradiation of telluric acid with neutrons have been studied under several experimental conditions. The effects of the reaction (n, γ ) on Te VI and of the isomeric transitions 131m Te VI → 131 Te and 129m Te VI → 129 Te, and the oxidation states of 131 I formed by β decay of 131 Te have been investigated in detail. The Szilard-Chalmers effect has been put in evidence. Retention (R) depends on the isomeric state of Rd-Te and is higher for the metastable isotopes. R increases with the time of irradiation. R seems to be independent of the medium which is used for dissolving telluric acid irradiated in the solid state. Higher values of R are found if the acid is irradiated in neutral or alkaline solution; irradiation in acid solution leads to lower values for R. Retention for 131 Te VI and 129 Te VI formed by isomeric transition depends on the pH of the solution where this disintegration occurs. For instance, with 129 Te, R is greater in 6 M NaOH (80 per cent) than in 3 M HCI (40 per cent). The relative amounts of the oxidation states of 131 I (reduced fraction (I - , IO - , I 2 ), iodate and periodate) depend on the medium, both if the acid is irradiated in the solid state and it is irradiated in solution. In the first case, the reduced fraction increases from 12 to 89 per cent when the dissolving medium is changed from neutral to 0.8 M HNO 3 . In the second case, the reduced fraction is 90 per cent in neutral or acid solution and 64 per cent in 0.5 M KOH. It has been shown, furthermore, that microamounts of Te VI are formed in certain cases. (author) [fr

  20. Fast neutron irradiation for locally advanced pancreatic cancer

    International Nuclear Information System (INIS)

    Smith, F.P.; Schein, P.S.; MacDonald, J.S.; Woolley, P.V.; Ornitz, R.; Rogers, C.

    1981-01-01

    Nineteen patients with locally advanced pancreatic cancer and one patient with islet cell cancer were treated with 1700-1500 neutron rad alone or in combination with 5-fluorouracil to exploit the theoretic advantages of higher linear energy of transfer, and lower oxygen enhancement ratio of neutrons. Only 5 of 14 (36%) obtained partial tumor regression. The median survival for all patients with pancreatic cancer was 6 months, which is less than that reported with 5-fluorouracil and conventional photon irradiation. Gastrointestinal toxicity was considerable; hemorhagic gastritis in five patients, colitis in two and esophagitis in one. One patient developed radiation myelitis. We therefore, caution any enthusiasm for this modality of therapy until clear evidence of a therapeutic advantage over photon therapy is demonstrated in controlled clinical trials

  1. Fast neutron irradiation for locally advanced pancreatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Smith, F.P. (Georgetown Univ. Medical Center, Washington, DC); Schein, P.S.; MacDonald, J.S.; Woolley, P.V.; Ornitz, R.; Rogers, C.

    1981-11-01

    Nineteen patients with locally advanced pancreatic cancer and one patient with islet cell cancer were treated with 1700-1500 neutron rad alone or in combination with 5-fluorouracil to exploit the theoretic advantages of higher linear energy of transfer, and lower oxygen enhancement ratio of neutrons. Only 5 of 14 (36%) obtained partial tumor regression. The median survival for all patients with pancreatic cancer was 6 months, which is less than that reported with 5-fluorouracil and conventional photon irradiation. Gastrointestinal toxicity was considerable; hemorhagic gastritis in five patients, colitis in two and esophagitis in one. One patient developed radiation myelitis. We therefore, caution any enthusiasm for this modality of therapy until clear evidence of a therapeutic advantage over photon therapy is demonstrated in controlled clinical trials.

  2. Effect of neutron irradiation on single crystal V3Si

    International Nuclear Information System (INIS)

    Viswanathan, R.; Caton, R.; Cox, D.E.; Guha, A.; Sarachik, M.P.; Smith, F.W.; Testardi, L.R.

    1977-01-01

    We We have investigated the effect of successive neutron irradiation up to a fluence of approximately 2 x 10 19 n/cm 2 , by measurements of heat capacity, susceptibility, resistivity, acoustic velocity and neutron diffraction in a single crystal V 3 Si. We find that for low level doses (phi t greater than or equal to 3.5 x 10 18 n/cm 2 ) (a) the structural transformation is very sensitive, whereas the suerconducting transition temperature, T/sub c/, is hardly affected, and (b) except for low temperature heat capacity, most of the other measurements show very little change. For the highest fluence of 2 x 10 19 n/cm 2 used to date, the T/sub c/ dropped to 7.5 K with large changes in the linear heat capacity coefficient, magnetic susceptibility and sound velocity. These results are discussed briefly in this paper

  3. High-energy neutron irradiation of superconducting compounds

    International Nuclear Information System (INIS)

    Sweedler, A.R.; Snead, C.L.; Newkirk, L.; Valencia, F.; Geballe, T.H.; Schwall, R.H.; Matthias, B.T.; Corenswit, E.

    1975-01-01

    The effect of high-energy neutron irradiation (E greater than 1 MeV) at ambient reactor temperatures on the superconducting properties of a variety of superconducting compounds is reported. The materials studied include the A-15 compounds Nb 3 Sn, Nb 3 Al, Nb 3 Ga, Nb 3 Ge and V 3 Si, the C-15 Laves phase HfV 2 , the ternary molybdenum sulfide Mo 3 Pb 0 . 5 S 4 and the layered dichalcogenide NbSe 2 . The superconducting transition temperature has been measured for all of the above materials for neutron fluences up to 5 x 10 19 n/cm 2 . The critical current for multifilamentary Nb 3 Sn has also been determined for fields up to 16 T and fluences between 3 x 10 17 n/cm 2 and 1.1 x 10 19 n/cm 2

  4. Point defects in cubic boron nitride after neutron irradiation

    International Nuclear Information System (INIS)

    Atobe, Kozo; Honda, Makoto; Ide, Munetoshi; Yamaji, Hiromichi; Matsukawa, Tokuo; Fukuoka, Noboru; Okada, Moritami; Nakagawa, Masuo.

    1993-01-01

    The production of point defects induced by reactor neutrons and the thermal behavior of defects in sintered cubic boron nitride are investigated using the optical absorption and electron spin resonance (ESR) methods. A strong structureless absorption over the visible region was observed after fast neutron irradiation to a dose of 5.3 x 10 16 n/cm 2 (E > 0.1 MeV) at 25 K. This specimen also shows an ESR signal with g-value 2.006 ± 0.001, which can be tentatively identified as an electron trapped in a nitrogen vacancy. On examination of the thermal decay of the signal, the activation energy for recovery of the defects was determined to be about 1.79 eV. (author)

  5. Crystallographic changes in lead zirconate titanate due to neutron irradiation

    Directory of Open Access Journals (Sweden)

    Alexandra Henriques

    2014-11-01

    Full Text Available Piezoelectric and ferroelectric materials are useful as the active element in non-destructive monitoring devices for high-radiation areas. Here, crystallographic structural refinement (i.e., the Rietveld method is used to quantify the type and extent of structural changes in PbZr0.5Ti0.5O3 after exposure to a 1 MeV equivalent neutron fluence of 1.7 × 1015 neutrons/cm2. The results show a measurable decrease in the occupancy of Pb and O due to irradiation, with O vacancies in the tetragonal phase being created preferentially on one of the two O sites. The results demonstrate a method by which the effects of radiation on crystallographic structure may be investigated.

  6. Annealing of dislocation loops in neutron-irradiated copper investigated by positron annihilation

    International Nuclear Information System (INIS)

    Gauster, W.B.; Mantl, S.; Schober, T.; Triftshauser, W.

    1975-01-01

    Positron annihilation angular correlation measurements were carried out on neutron-irradiated copper as a function of annealing temperature. Two types of specimens were used: single crystals irradiated with fast neutrons, and 10 B-doped polycrystalline samples irradiated with thermal neutrons. All irradiations were at approximately 320 0 K. A structure in the annealing curve, not previously observed by other techniques, indicates that between 460 and 600 0 K the dislocation loops present after irradiation dissociate and more effective positron trapping sites are formed. (auth)

  7. Swelling in neutron irradiated nickel-base alloys

    International Nuclear Information System (INIS)

    Brager, H.R.; Bell, W.L.

    1972-01-01

    Inconel 625, Incoloy 800 and Hastelloy X were neutron irradiated at 500 to 700 0 C. It was found that of the three alloys investigated, Inconel 625 offers the greatest swelling resistance. The superior swelling resistance of Inconel 625 relative to that of Hastelloy-X is probably related to differences in the concentrations of the minor rather than major alloy constituents, and can involve (a) enhanced recombination of defects in the Inconel 625 and (b) preferential attraction of vacancies to incoherent precipitates. (U.S.)

  8. Ultrasonic attenuation measurements and 'glassy' behaviour of neutron irradiated quartz

    International Nuclear Information System (INIS)

    Laermans, C.; Esteves, V.; Vanelstraete, A.

    1986-01-01

    The ultrasonic attenuation of longitudinal acoustic waves in slightly disordered crystalline quartz has been measured over a temperature range from 1.3 to 300 K, using the pulse-echo technique. Neutron irradiation is demonstrated to increase the ultrasonic attenuation at low temperatures indicating the presence of two-level tunneling systems similar to those of glasses. The present low-temperature acoustic results agree with a frequency independence and a T 3 behaviour for the relaxation process predicted by the two-level tunneling TLS-model where the regime ωT 1 >> 1 holds. (author)

  9. Gamma and neutron irradiation tests on commercial IC op amps

    International Nuclear Information System (INIS)

    Kennedy, E.J.; Morris, A.C. Jr.; Su, D.K.

    1985-01-01

    Experimental results of gamma and neutron irradiation tests on 30 types of integrated-circuit operational amplifiers from 11 manufacturers are presented. All units were low-cost, commercial-grade devices. Op amps were evaluated for changes in offset voltage, input bias current, power supply current, open-loop gain, gain-bandwidth product, slew rate, power-supply and common-mode rejection ratios. Bipolar transistor op amps with resistive collector load resistors for the input stage indicated the best radiation hardness

  10. Irradiation temperature dependence of defect formation of nitrides (A1N and c-BN) during neutron irradiations

    International Nuclear Information System (INIS)

    Atobe, Kozo.; Okada, Moritami; Nakagawa, Masuo

    2000-01-01

    The nitrogen vacancy concentration in the more refractory nitrides (A1N and c-BN) is determined as a function of reactor fluence up to 5.2x10 17 thermal neutrons/cm 2 and a function of the irradiation temperature at 25, 50, 100, 150, 200, 250 K. It is found that there is no remarkable dependence of the defect formation in nitrides on the irradiation temperature. The production of damage in the nitrides is considerably different from that in oxides. From the irradiation experiments using thermal neutron irradiation field, it is suggested in reactor irradiation that the atomic displacements in the nitrides occur predominately from energetic particles of the nuclear reactions with thermal neutrons in addition to the elastic collisions by fast neutron

  11. Indium antimonide crystal defects formed by fast neutron irradiation

    International Nuclear Information System (INIS)

    Vitovskij, N.A.; Dolgolenko, A.P.; Mashovets, T.V.; Oganesyan, O.V.

    1979-01-01

    It is shown, that indium antimonide irradiation with fast neutrons of reactor results in the formation of disorded regions with a mean radius of approximately 130 A surrounded with space charge regions forming barriers for main carriers. But the found values of defect cluster depolarization coefficient (Lsub(x)sup(n)=0.18 and Lsub(x)sup(p)=0.29) show, that the clusters have marked conductivity for main charge carriers. The found position of the Fermi level in the disorded regions Esub(F)=Esub(c)-0.085 eV does not depend on the impurity type and its concentration in an initial material. The disorded regions play the main part in charge carrier scattering at low temperatures and markedly contribute to the change of mobility at 80 K. It is found, that irradiation temperature change in the range from 77 to 300 K does not effect practically on the disorded region parameters

  12. Phase transformations in lithium aluminates irradiated with neutrons

    International Nuclear Information System (INIS)

    Carrera, L.M.; Delfin L, A.; Urena N, F.; Basurto, R.; Bosch, P.

    2003-01-01

    The lithium aluminate like candidate to be used in the coverings producers of tritium in the fusion nuclear reactors, presents high resistance to the corrosion to the one to be stuck to structural materials as special steels. However, the crystallographic changes that take place in the cover that is continually subjected to irradiation with neutrons, can alter its resistance to the corrosion. In this work the changes of crystalline structure are shown that they present two types of nano structures of lithium aluminates, subjected to an average total dose 7.81 x 10 8 Gy in the fixed irradiation system of capsules of the one TRIGA Mark lll nuclear reactor of the Nuclear Center of Mexico. The studied nano structures presented only phase transformations without formation of amorphous material. (Author)

  13. Preparation of 227Ac by neutron irradiation of 226Ra

    International Nuclear Information System (INIS)

    Kukleva, E.; Kozempel, J.; Vlk, M.; Micolova, P.; Vopalka, D.

    2015-01-01

    Radium-223 is prospective alpha-emitting therapeutic radionuclide for targeted radionuclide therapy. Although 223 Ra is formed naturally by the decay of 235 U, for practical reasons its preparation involves neutron irradiation of 226 Ra. The α-decay of the 227 Ra (T 12 = 43 min.) produced via 226 Ra(n,γ) 227 Ra reaction leads to 227 Ac, a mother nuclide of 227 Th and 223 Ra subsequently. Irradiation target radium material is generally available in multi-gram quantities from historical stock. Main aim of this study was to experimentally and theoretically evaluate and verify available literature data on production of 223 Ra. According to data obtained from γ-spectra, the approximate yield values were determined and effective cross-section for the 223 Ra production was calculated. (authors)

  14. Dielectric changes in neutron-irradiated rf window materials

    International Nuclear Information System (INIS)

    Frost, H.M.; Clinard, F.W. Jr.

    1987-01-01

    Ceramics used for windows in ECRH heating systems for magnetically-confined fusion reactors must retain adequate properties during and after intense neutron irradiation. Of particular concern is a decrease in transmissivity, a parameter inversely related to the product of dielectric constant K and loss tangent tanδ. Samples of polycrystalline Al 2 O 3 and BeO were irradiated to 1 x 10 26 n/m 2 at 660K in the EBR-II fission reactor, and the above properties subsequently measured at 95 GHz. It was found that ktanδ for both materials doubled, implying a doubling of thermal stresses and a consequent reduction of time-to-failure from an assumed one year to 20 min for beryllia and 2 s for alumina. In the case of BeO, a large increase in reflectance of the incident millimeter-wave power results from dielectrically uncompensated swelling. This phenomenon could significantly degrade source performance

  15. Hydrides formation In Zircaloy-4 irradiated with neutrons

    International Nuclear Information System (INIS)

    Vizcaino, P; Flores, A V; Vicente Alvarez, M A; Banchik, A.D; Tolley, A; Condo, A; Santisteban, J R

    2012-01-01

    Under reactor operating conditions zirconium components go through transformations which affect their original properties. Two phenomena of significant consequences for the integrity of the components are hydrogen uptake and radiation damage, since both contribute to the material fragilization. In the case of the Atucha I nuclear power reactor, the cooling channels, Zircaloy-4 tubular structural components about 6 meters long, were designed to withstand the entire lifetime of the reactor. Inside them, fuel elements 5.3 meters long are located. The fuel elements are cooled by a heavy water flow which circulates from the bottom (250 o ) to the top of the reactor (305 o C). The channels are affected by a fast neutron flux (En>1 Mev), increasing from a nominal value of 1.35 x 10 13 neutrons/cm 2 sec at the bottom to 1.69 x 10 13 neutrons/cm 2 sec at the top, reaching a maximum value of 3.76 x 10 13 neutrons/cm 2 sec at the center of the channels. However, due to the reactor operating conditions, they are replaced after about 10 effective full power years, time at which they reach 10 22 neutrons/cm 2 at the most neutronically active regions of the reactor. Studies on cooling channels are meaningful from many points of view. The channels are structural components which do not work under internal pressure or any other type of structural stress. The typical temperature of the cladding tubes in the reactor is about 350 o C, at which many types of irradiation defects are annealed [1]. The temperature range of the cooling channels lies between 200 o C-235 o C (outer foil of the channels) and 260 o C-300 o C (internal tube), a difference which makes the defect recovery kinetics slower. In the present context, following the program developed in the research contract 15810, we continue with the work started on the effects of the radiation on the hydride formation focusing on the dislocation loops in the zirconium matrix and its possible role as preferential sites for hydride

  16. Fracture mechanics behaviour of neutron irradiated Alloy A-286

    International Nuclear Information System (INIS)

    Mills, W.J.; James, L.A.

    The effect of fast-neutron irradiation on the fatigue-crack propagation and fracture toughness behaviour of Alloy A-286 was characterized using fracture mechanics techniques. The fracture toughness was found to decrease continuously with increasing irradiation damage at both 24 deg. C and 427 deg. C. In the unirradiated and low fluence conditions, specimens displayed appreciable plasticity prior to fracture, and equivalent Ksub(Ic) values were determined from Jsub(Ic) fracture toughness results. At high irradiation exposure levels, specimens exhibited a brittle Ksub(Ic) fracture mode. The 427 deg. C fracture toughness fell from 129 MPa√m in the unirradiated condition to 35 MPa√m at an exposure of 16.2 dpa (total fluence of 5.2x10 22 n/cm 2 ). Room temperature fracture toughness values were consistently 40 to 60 percent higher than the 427 deg. C values. Electron fractography revealed that the reduction in fracture resistance was attributed to a fracture mechanism transition from ductile microvoid coalescence to channel fracture. Fatigue-crack propagation tests were conducted at 427 deg. C on specimens irradiated at 2.4 dpa and 16.2 dpa. Crack growth rates at the lower exposure level were comparable to those in unirradiated material, while those at the higher exposure were slightly higher than in unirradiated material. (author)

  17. Positron lifetime study of copper irradiated by energetic protons or energetic neutrons

    International Nuclear Information System (INIS)

    Howell, R.H.

    1979-03-01

    Positron lifetime measurements of pure copper damaged by irradiation with energetic protons and neutrons are presented. Lifetime determinations of the bulk material and various traps were made, and the dependence of the trapping rate on dose and irradiation energy were investigated. The results from the neutron- and proton-irradiated samples point to the existence of traps with similar but distinct lifetime parameters, not varying greatly from values reported in deformation studies. Also, a trap with long lifetime is seen for some proton irradiations, but is never seen for the neutron irradiations. The trapping rate of the short-lifetime trap is a linear function of dose for proton-irradiated samples and nearly so for the neutron irradiation. 1 figure

  18. The effect of neutron irradiation on silicon carbide fibers

    International Nuclear Information System (INIS)

    Newsome, G.A.

    1997-01-01

    Nine types of SiC fiber have been exposed to neutron radiation in the Advanced Test Reactor at 250 C for various lengths of time ranging from 83 to 128 days. The effects of these exposures have been initially determined using scanning electron microscopy. The fibers tested were Nicalon trademark CG, Tyranno, Hi-Nicalon trademark, Dow Corning SiC, Carborundum SiC, Textron SCS-6, polymethysilane (PMS) derived SiC from the University of Michigan, and two types of MER SiC fiber. This covers a range of fibers from widely used commercial fibers to developmental fibers. Consistent with previous radiation experiments, Nicalon fiber was severely degraded by the neutron irradiation. Similarly, Tyranno suffered severe degradation. The more advanced fibers which approach the composition and properties of SiC performed well under irradiation. Of these, the Carborundum SiC fiber appeared to perform the best. The Hi-Nicalon and Dow Corning Fibers exhibited good general stability, but also appear to have some surface roughening. The MER fibers and the Textron SCS-6 fibers both had carbon cores which adversely influenced the overall stability of the fibers

  19. In vitro neutron irradiation of glioma and endothelial cultured cells

    Energy Technology Data Exchange (ETDEWEB)

    Menichetti, L. [Department of PET and Radiopharmaceutical Chemistry, C.N.R. Institute of Clinical Physiology, Pisa (Italy)], E-mail: luca.menichetti@ifc.cnr.it; Gaetano, L. [University Scuola Superiore Sant' Anna, Pisa (Italy); Zampolli, A.; Del Turco, S. [Department of PET and Radiopharmaceutical Chemistry, C.N.R. Institute of Clinical Physiology, Pisa (Italy); Ferrari, C. [University of Pavia, Department of Surgery, Laboratory of experimental Surgery, Pavia (Italy); Bortolussi, S.; Stella, S.; Altieri, S. [University of Pavia, Department of Nuclear Physics, Pavia (Italy); National Institute for Nuclear Physics (INFN), Section of Pavia (Italy); Salvadori, P.A. [Department of PET and Radiopharmaceutical Chemistry, C.N.R. Institute of Clinical Physiology, Pisa (Italy); Cionini, L. [Unit of Radiotherapy, AOUP-University Hospital, Pisa (Italy)

    2009-07-15

    To fully develop its potential boron neutron capture therapy (BNCT) requires the combination of a suitable thermal/epithermal neutron flux together with a selective intake of {sup 10}B-boron nuclei in the target tissue. The latter condition is the most critical to be realized as none of the boron carriers used for experimental or clinical purposes proved at the moment an optimal selectivity for cancer cells compared to normal cells. In addition to complex physical factors, the assessment of the intracellular concentration of boron represent a crucial parameter to predict the dose delivered to the cancer cells during the treatment. Nowadays the dosimetry calculation and then the prediction of the treatment effectiveness are made using Monte Carlo simulations, but some of the model assumption are still uncertain: the radiobiological dose efficacy and the probability of tumour cell survival are crucial parameters that needs a more reliable experimental approach. The aim of this work was to evaluate the differential ability of two cell lines to selectively concentrate the boron-10 administered as di-hydroxyboryl-phenylalanine (BPA)-fructose adduct, and the effect of the differential boron intake on the damage produced by the irradiation with thermal neutrons; the two cell lines were selected to be representative one of normal tissues involved in the active/passive transport of boron carriers, and one of the tumour. Recent in vitro studies demonstrated how BPA is taken by proliferating cells, however the mechanism of BPA uptake and the parameters driving the kinetics of influx and the elimination of BPA are still not clarified. In these preliminary studies we analysed the survival of F98 and human umbilical vein endothelial cells (HUVEC) cells line after irradiation, using different thermal fluencies at the same level of density population and boron concentration in the growing medium prior the irradiation. This is first study performed on endothelium model obtained by

  20. Impurity effects in neutron-irradiated simple oxides: Implications for fusion devices

    International Nuclear Information System (INIS)

    Gonzalez, R.; Chen, Y.; Caceres, D.; Vergara, I.

    2006-01-01

    Radiation damage induced by neutron irradiation was studied in undoped MgO crystals and in MgO doped with either iron, hydrogen or lithium impurities. The oxygen-vacancy concentration produced by irradiation increases with neutron fluence. The net production rates resulting from irradiations with 14.8 MeV neutrons are about twice those produced by fission neutrons. In nominally pure crystals, the oxygen-vacancy concentration incurred by the fission-neutron irradiation is higher in crystals with a larger number of inherent impurities (such as iron) due to trapping of interstitials by impurities. Suppression of these defects is observed in MgO:H crystals and attributed to migration of oxygen vacancies to microcavities filled with H 2 gas. In MgO:Li crystals irradiated with neutron fluences below 10 18 n/cm 2 , most of the oxygen vacancies are camouflaged as hydride ions. Nanoindentation experiments show that hardness increases with neutron fluence and is independent of the presence of lithium in the crystal. Comparison between a neutron-irradiated and a thermochemically reduced crystal containing similar concentrations of oxygen vacancies shows that 70% of the neutron-irradiation hardening is produced by interstitials, 30% by oxygen vacancies and a negligible amount by higher-order point defects

  1. Genes involved in yeast survival after irradiation with fast neutrons

    International Nuclear Information System (INIS)

    Bozin, D.; Milosevic, M.J.

    2001-01-01

    Life on the Earth has evolved against a continuous background of ionizing radiation. It would be expected, therefore, that all possible mutations have been produced at some time or another; man-made radiation from medical or industrial sources will not result in any new types of mutation but will simply increase the whole spectrum of mutations that occur spontaneously. Any such lesion can be mutagenic and, in principle, lethal. To counteract the consequences of DNA damage, evolution has equipped all living cells with an intricate network of defense and repair systems. Together, these systems act as a kind of nuclear 'immune system' that is able to recognize and eliminate many types of DNA lesions. In the case of the yeast Saccharomyces cerevisiae, in these processes over 30 RAD genes participate. We tested the survival of haploid and diploid rad1 yeast mutant strains at a dose of 15 Gy of γ or fast neutron radiation. We demonstrated that the lethality of rad1 mutants both haploid and diploid are significantly higher after fast neutron irradiation. The results indicate to the role and position of these genes in the DNA repair of damages specifically induced by fast neutrons. (authors)

  2. Scanning tunneling spectroscopy on neutron irradiated MgB2 thin films

    International Nuclear Information System (INIS)

    Di Capua, Roberto; Salluzzo, Marco; Vaglio, Ruggero; Ferdeghini, Carlo; Ferrando, Valeria; Putti, Marina; Xi Xiaoxing; Aebersold, Hans U.

    2007-01-01

    Neutron irradiation was performed on MgB 2 thin films grown by hybrid physical chemical vapor deposition. Samples irradiated with different neutron fluences, having different critical temperatures, were studied by scanning tunneling spectroscopy in order to investigate the effect of the introduced disorder on the superconducting and spectroscopic properties. A monotonic increase of the π gap with increasing disorder was found

  3. Scanning tunneling spectroscopy on neutron irradiated MgB{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Di Capua, Roberto [University of Napoli and CNR-INFM/Coherentia, Via Cinthia, Naples I-80126 (Italy)], E-mail: rdicapua@na.infn.it; Salluzzo, Marco; Vaglio, Ruggero [University of Napoli and CNR-INFM/Coherentia, Via Cinthia, Naples I-80126 (Italy); Ferdeghini, Carlo [CNR-INFM/LAMIA, Via Dodecaneso 33, Genova I-16146 (Italy); Ferrando, Valeria [CNR-INFM/LAMIA, Via Dodecaneso 33, Genova I-16146 (Italy); Pennsylvania State University, University Park, PA 16802 (United States); Putti, Marina [CNR-INFM/LAMIA, Via Dodecaneso 33, Genova I-16146 (Italy); Xi Xiaoxing [Pennsylvania State University, University Park, PA 16802 (United States); Aebersold, Hans U. [Paul Scherrer Institut, Villigen CH-5232 (Switzerland)

    2007-09-01

    Neutron irradiation was performed on MgB{sub 2} thin films grown by hybrid physical chemical vapor deposition. Samples irradiated with different neutron fluences, having different critical temperatures, were studied by scanning tunneling spectroscopy in order to investigate the effect of the introduced disorder on the superconducting and spectroscopic properties. A monotonic increase of the {pi} gap with increasing disorder was found.

  4. Hematologic status of mice submitted to sublethal total body irradiation with mixed neutron-gamma radiation

    International Nuclear Information System (INIS)

    Herodin, F.; Court, L.

    1989-01-01

    The hematologic status of mice exposed to sublethal whole body irradiation with mixed neutron-gamma radiation (mainly neutrons) is studied. A slight decrease of the blood cell count is still observed below 1 Gy. The recovery of bone marrow granulocyte-macrophage progenitors seems to require more time than after pure gamma irradiation [fr

  5. Characterization of the fast neutron irradiation facility of the Portuguese Research Reactor after core conversion

    International Nuclear Information System (INIS)

    Marques, J.G.; Sousa, M.; Santos, J.P.; Fernandes, A.C.

    2011-01-01

    The fast neutron irradiation facility of the Portuguese Research Reactor was characterized after the reduction in uranium enrichment and rearrangement of the core configuration. In this work we report on the determination of the hardness parameter and the 1 MeV equivalent neutron flux along the facility, in the new irradiation conditions, following ASTM E722 standard.

  6. First results on irradiation of ceramic parallel plate chambers with gammas and neutrons

    International Nuclear Information System (INIS)

    Arefiev, A.; Bencze, Gy.L.; Bizzeti, A.; Choumilov, E.; Civinini, C.; Dajko, G.; D'Alessandro, R.; Fenyvesi, A.; Ferrando, A.; Fouz, M.C.; Iglesias, A.; Ivochkin, V.; Josa, M.I.; Malinin, A.; Meschini, M.; Molnar, J.; Pojidaev, V.; Salicio, J.M.; Tanko, L.; Vesztergombi, G.

    1996-01-01

    Ceramic parallel plate chambers were irradiated with gamma rays and neutrons. Results on radiation resistance are presented after 60 Mrad gamma and 0.5.10 16 neutrons per cm 2 irradiation of the detector surface. Results of activation analysis of chambers made of two different ceramic materials are also presented. (orig.)

  7. Fast neutron irradiation effects on liver chromatin structure

    International Nuclear Information System (INIS)

    Constantinescu, B.; Radu, L.

    1996-01-01

    The growing interest in neutron therapy requires complex studies on the mechanisms of neutron action on biological systems, especially on chromatin. The chromatin was extracted from a normal tissue-livers of Wistar rats - and from a tumoral tissue - Walker tumour maintained on Wistar rats. Irradiation doses from 5 Gy to 100 Gy by fast neutron intense beams produced via d(13.5 MeV) +Be (thick target) reaction at Bucharest U-120 Classical Cyclotron were used. To study the post-irradiation effects, various methods were employed. So, the variation in the 260 nm absorbency in chromatin thermal transition was pursuit. The chromatin-ethidium bromide complexes fluorescence with λ ex =480 nm and λ em =600 nm was analyzed. To determine chromatin DNA strand breaks a fluorimetric method, with cells' suspensions as starting material was used. This method requires a partial treatment with alkali producing three components: T-estimating the total fluorescence of DNA double helix, P-assigning the untwisting rate and B-the blank, where DNA is completely unfolded The percentsge of DNA double strand,-D-, remaining after this treatment, is: %D=100x(P-B)/(T-B). The intrinsic chromatin fluorescence was determined for tyrosine (λ ex =280 nm, λ em =305 nm), specific for badic chromatin prooteins, and for tryptophane (λ ex =290 nm, λ em =345 nm) specific for acid chromatin proteins. Polyacrylamide gel electrophoresis was performed: The double fluorescent labelling of chromatin was realized with acridine orange for DNA and with dansyl chloride for chromatin proteins. Fluorescence intensity determinations were done with λ ex =505 nm, λ em =530 nm for acridine orange and with λ ex =323 nm, λ em =505 nm for dansyl chloride. A Pye Unicam SP 1800 spectrophotometer and a Aminco SPF 500 spectrofluorimeter were employed. (author)

  8. Results of neutron irradiation of liquid lithium saturated with deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Tazhibayeva, Irina, E-mail: tazhibayeva@ntsc.kz [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Ponkratov, Yuriy; Kulsartov, Timur; Gordienko, Yuriy; Skakov, Mazhyn; Zaurbekova, Zhanna [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Lyublinski, Igor [JSC «Red Star», Moscow (Russian Federation); NRNU «MEPhI», Moscow (Russian Federation); Vertkov, Alexey [JSC «Red Star», Moscow (Russian Federation); Mazzitelli, Giuseppe [ENEA, RC Frascati, Frascati (Italy)

    2017-04-15

    Highlights: • The results on neutron irradiation of liquid lithium saturated with deuterium at the IVG.1M research reactor are described. • At temperatures below 573 K the efficiency coefficient of tritium release is well described by the expression K = 0.015 exp(−14/RT), and above 623 K − K = 10{sup 9} exp(−144/RT). • The T{sub 2} molecules contribution into the overall tritium release becomes apparent at temperatures higher than 673 K and increases with the temperature rise. - Abstract: This paper describes the results on neutron irradiation of liquid lithium saturated with deuterium at the IVG.1 M research reactor. The neutron flux at the reactor core center at 2 MW was 5 10{sup −13} cm{sup −2} s{sup −1}. The efficiency coefficients of helium and tritium release from lithium saturated with deuterium were calculated. The tritium interaction with lithium atoms (formation and dissociation of lithium tritide) has an effect on tritium release. An increment of sample’s temperature results in tritium release acceleration due to rising of the dissociation rate of lithium tritide. At temperatures below 573 K the efficiency coefficient of tritium release is well described by the expression K = 0.015 exp(−14/RT), and above 623 K − K = 10{sup 9} exp(-144/RT). The T{sub 2} molecules contribution into the overall tritium release becomes apparent at temperatures higher than 673 K and increases with the temperature rise.

  9. Irradiation temperature dependence of production efficiency of lattice defects in some neutron-irradiated oxides

    International Nuclear Information System (INIS)

    Okada, Moritami; Atobe, Kozo; Nakagawa, Masuo

    2004-01-01

    Temperature dependence of production efficiency of irradiation-induced defects in neutron-irradiated oxides has been investigated. Some oxide single crystals, MgO, α-Al 2 O 3 (sapphire) and TiO 2 (rutile), were irradiated at several controlled temperatures, 10, 20, 50, 100, 150 and 200 K, using the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL), and at ambient temperature (∼370 K) in the same facility. Irradiation temperature dependence of production efficiency of a 1 μm band in TiO 2 differs greatly from that of anion vacancy (F-type centers) in MgO and α-Al 2 O 3 . Results for MgO and α-Al 2 O 3 show steep negative gradients from 10 to 370 K, whereas that for TiO 2 includes a valley between 40 and 60 K and a hump at about 130 K, and then disappear at about 200 K. In MgO and α-Al 2 O 3 , this behavior can be explained by the recombination of Frenkel pairs, which is activated at higher temperature. In TiO 2 , in addition to the recombination mechanism, a covalent bonding property is thought to be exerted strong influence, and it is suggested that a disappearance of the 1 μm band at above 200 K is due to the recombination process of Frenkel pairs which is caused by the irradiation-induced crystallization

  10. Shielding of a neutron irradiator with {sup 241}Am-Be source

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, K.A.M. de; Crispim, V.R.; Silva, A.X., E-mail: koliveira@con.ufrj.b, E-mail: verginia@con.ufrj.b, E-mail: ademir@con.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear; Fonseca, E.S., E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    The equivalent dose rates at 1.0 cm from the outer surface of the shielding of a neutron irradiation system that uses {sup 241}Am-Be source with activity of 185 GBq (5 Ci) were determined. A theoretical-experimental approach including case studies, through computer simulations with MCNP code was employed to calculate the best shielding thickness. Following the construction of the neutron irradiator, dose measurements were conducted in order to validate data obtained from simulation. The neutron irradiator shielding was designed in such a way to allow transport of the neutron radiography system for in loco inspections ensuring workers' radiologic safety. (author)

  11. Using TRIGA Mark II research reactor for irradiation with thermal neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kolšek, Aljaž, E-mail: aljaz.kolsek@gmail.com; Radulović, Vladimir, E-mail: vladimir.radulovic@ijs.si; Trkov, Andrej, E-mail: andrej.trkov@ijs.si; Snoj, Luka, E-mail: luka.snoj@ijs.si

    2015-03-15

    Highlights: • Monte Carlo N-Particle Transport Code was used to design and perform calculations. • Characterization of the TRIGA Mark II ex-core irradiation facilities was performed. • The irradiation device was designed in the TRIGA irradiation channel. • The use of the device improves the fraction of thermal neutron flux by 390%. - Abstract: Recently a series of test irradiations was performed at the JSI TRIGA Mark II reactor for the Fission Track-Thermoionization Mass Spectrometry (FT-TIMS) method, which requires a well thermalized neutron spectrum for sample irradiation. For this purpose the Monte Carlo N-Particle Transport Code (MCNP5) was used to computationally support the design of an irradiation device inside the TRIGA model and to support the actual measurements by calculating the neutron fluxes inside the major ex-core irradiation facilities. The irradiation device, filled with heavy water, was designed and optimized inside the Thermal Column and the additional moderation was placed inside the Elevated Piercing Port. The use of the device improves the ratio of thermal neutron flux to the sum of epithermal and fast neutron flux inside the Thermal Column Port by 390% and achieves the desired thermal neutron fluence of 10{sup 15} neutrons/cm{sup 2} in irradiation time of 20 h.

  12. DNA-repair after irradiation of cells with gamma-rays and neutrons

    International Nuclear Information System (INIS)

    Altmann, H.

    1975-11-01

    The structural alterations of calf thymus DNA produced by neutron or gamma irradiation were observed by absorption spectra, sedimentation rate and viscosity measurements. Mixed neutron-gamma irradiation produced fewer single and double strand breaks compared with pure gamma irradiation. RBE-values for mixed neutron-gamma radiation were less than 1, and DNA damage decreased with increasing neutron dose rate. Repair processes of DNA occuring after irradiation were measured in mouse spleen suspensions and human lymphocytes using autoradiographic methods and gradient centrifugations. The number of labelled cells was smaller after mixed neutron-gamma irradiation than after gamma irradiation. The rejoining of strand breaks in alkaline and neutral sucrose was more efficient after gamma irradiation than after mixed neutron-gamma irradiation. Finally, the effect of detergents Tween 80 and Nonident P40 on unscheduled DNA synthesis was studied by autoradiography after mixed neutron-gamma irradiation (Dn=5 krad). The results showed that the DNA synthesis was inhibited by detergent solutions of 0.002%

  13. Performance of silicon pad detectors after mixed irradiations with neutrons and fast charged hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Kramberger, G. [Jozef Stefan Institute, Department of Physics, University of Ljubljana, Jamova 39, SI-1000 Ljubljana (Slovenia)], E-mail: Gregor.Kramberger@ijs.si; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M. [Jozef Stefan Institute, Department of Physics, University of Ljubljana, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2009-10-11

    A large set of silicon pad detectors produced on MCz and FZ wafer of p- and n-type was irradiated in two steps, first by fast charged hadrons followed by reactor neutrons. In this way the irradiations resemble the real irradiation fields at LHC. After irradiations controlled annealing started in steps during which the evolution of full depletion voltage, leakage current and charge collection efficiency was monitored. The damage introduced by different irradiation particles was found to be additive. The most striking consequence of that is a decrease of the full depletion voltage for n-type MCz detectors after additional neutron irradiation. This confirms that effective donors introduced by charged hadron irradiation are compensated by acceptors from neutron irradiation.

  14. Performance of silicon pad detectors after mixed irradiations with neutrons and fast charged hadrons

    International Nuclear Information System (INIS)

    Kramberger, G.; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

    2009-01-01

    A large set of silicon pad detectors produced on MCz and FZ wafer of p- and n-type was irradiated in two steps, first by fast charged hadrons followed by reactor neutrons. In this way the irradiations resemble the real irradiation fields at LHC. After irradiations controlled annealing started in steps during which the evolution of full depletion voltage, leakage current and charge collection efficiency was monitored. The damage introduced by different irradiation particles was found to be additive. The most striking consequence of that is a decrease of the full depletion voltage for n-type MCz detectors after additional neutron irradiation. This confirms that effective donors introduced by charged hadron irradiation are compensated by acceptors from neutron irradiation.

  15. Neutron Field Characterization of Irradiation Locations Applied to the Slovenian TRIGA Reactor

    International Nuclear Information System (INIS)

    Barbot, Loic; Domergue, Christophe; Breaud, Stephane; Destouches, Christophe; Villard, Jean-Francois; Snoj, Luka; Stancar, Ziga; Radulovic, Vladimir; Trkov, Andrej

    2013-06-01

    This work deals with several neutron flux measurement instruments and particle transport calculations combined in a method to assess the neutron field in experimental locations in nuclear reactor core or reflector. First test of this method in the TRIGA Mark II of Slovenia led to the assessment of three energy groups neutron fluxes in central irradiation locations within reactor core. (authors)

  16. DT fusion neutron irradiation of BPNL niobium nickel and 316 stainless steel at 1750C

    International Nuclear Information System (INIS)

    MacLean, S.C.

    1977-01-01

    The DT fusion neutron irradiation at 175 0 C of 17 niobium wires, one niobium foil, 14 316 stainless steel wires, one 316 stainless steel foil, nine nickel wires, and two nickel foils from BPNL is described. The sample position, beam-on time, neutron dose record, and neutron fluence are given

  17. Microstructural evolution of neutron-irradiated Ni-Si and Ni-Al alloys

    Science.gov (United States)

    Takahashi, H.; Garner, F. A.

    1992-10-01

    Additions of silicon and aluminum suppress the neutron-induced swelling of pure nickel but to different degrees. Silicon is much more effective initially when compared to aluminum on a per atom basis but silicon exhibits a nonmonotonic influence on swelling with increasing concentration. Silicon tends to segregate toward grain boundaries while aluminum segregates away from these boundaries. Whereas the formation of the Ni 3Si phase is frequently observed in charged particle irradiation experiments conducted at much higher displacement rates, it did not occur during neutron irradiation in this study. Precipitation also did not occur in Ni-5Al during neutron irradiation, nor has it been reported to occur during ion irradiation.

  18. Surface damage in the small intestine of the mouse after X - or neutron irradiation

    International Nuclear Information System (INIS)

    Hamlet, R.; Carr, K.E.; Nias, A.H.; Watt, C.

    1981-01-01

    Damage after X-irradiation includes lateral villous collapse, progressing after 3 - 5 days to villi which sometimes show signs of vertical collapse. After neutron irradiation vertical villous collapse is established earlier, with less swelling of villous tips. It seems, therefore, that at radiobiologically equivalent doses, neutron and X-irradiation produce different levels of surface damage, with neutron irradiation being the more destructive. Early villous tip damage may perhaps be due to disruption of susceptible cells already at the extrusion zone, or to stromal damage

  19. Research on measurement of neutron flux in irradiation channels of research reactor

    International Nuclear Information System (INIS)

    Yin Zhitao; Lv Zheng; Wang Yulin; Zheng Wuqin

    2014-01-01

    Relative distribution of thermal neutron flux in the irradiation channel is measured by classical activation foil method. After that, on a representative point in the irradiation channel, neutron temperature and absolute neutron flux are also measured. Cadmium ratio correction method is used to check the experiment result in the end. Comparative analysis shows that the results from two different methods are agreed pretty well, which adds the credibility of experiment results. (authors)

  20. Inhomogeneous strain induced by fast neutron irradiation in NaKSO/sub 4/ crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, S.H.; Kassem, M.E.; El-Khatib, A.; El-Gamal, M.A.; El-Wahidy, E.F.

    1987-11-01

    The paper reports the effect of fast neutron irradiation on the thermal properties of NaKSO/sub 4/ crystals in the temperature range 400-475 K. Results are presented for the thermal expansion, tensile strain and specific heat of NaKSO/sub 4/, as a function of neutron irradiation dose. All these results revealed an inhomogeneous strain induced by the radiation. It is suggested that this induced inhomogeneous strain could be used to detect neutron exposure doses.

  1. Inhomogeneous strain induced by fast neutron irradiation in NaKSO4 crystals

    International Nuclear Information System (INIS)

    Kandil, S.H.; Kassem, M.E.; El-Khatib, A.; El-Gamal, M.A.; El-Wahidy, E.F.

    1987-01-01

    The paper reports the effect of fast neutron irradiation on the thermal properties of NaKSO 4 crystals in the temperature range 400-475 K. Results are presented for the thermal expansion, tensile strain and specific heat of NaKSO 4 , as a function of neutron irradiation dose. All these results revealed an inhomogeneous strain induced by the radiation. It is suggested that this induced inhomogeneous strain could be used to detect neutron exposure doses. (UK)

  2. Study on changes of sperm count and testis tissue in black mouse after neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Ki Jung; Seo, Won Sook [KAERI, Daejeon (Korea, Republic of); Son, Hwa Young [Chungnam National Univ., Daejeon (Korea, Republic of)

    2006-03-15

    For the purpose of the biological effect in black mouse by neutron irradiation, mice were irradiated with 16 or 32 Gy neutron (flux: 1.036739E+09) by lying flat pose at BNCT facility on HANARO Reactors. And 90 days later of irradiation, physical changes of testis and testis tissue were examined. There were no weight changes but a little bit volume changes and sperm counts in the tests. Atrophy of seminiferous tubules irradiated with 32 Gy neutron is increased in number and severity and those in stage VI showed depletion of spermatogonia and pachytene spermatocytes compared to the non-irradiated control group. Testis damage of black mouse was not recovered after long time by 32 Gy neutron irradiation.

  3. Study on changes of sperm count and testis tissue in black mouse after neutron irradiation

    International Nuclear Information System (INIS)

    Chun, Ki Jung; Seo, Won Sook; Son, Hwa Young

    2006-01-01

    For the purpose of the biological effect in black mouse by neutron irradiation, mice were irradiated with 16 or 32 Gy neutron (flux: 1.036739E+09) by lying flat pose at BNCT facility on HANARO Reactors. And 90 days later of irradiation, physical changes of testis and testis tissue were examined. There were no weight changes but a little bit volume changes and sperm counts in the tests. Atrophy of seminiferous tubules irradiated with 32 Gy neutron is increased in number and severity and those in stage VI showed depletion of spermatogonia and pachytene spermatocytes compared to the non-irradiated control group. Testis damage of black mouse was not recovered after long time by 32 Gy neutron irradiation

  4. Uranium doping and neutron irradiation of Bi-2223 superconduction tapes for improved critical current density

    International Nuclear Information System (INIS)

    Moss, S.D.; Wang, W.G.; Dou, S.X.; Weinstein, R.

    1998-01-01

    It is demonstrated that a combination of neutron irradiation with uranium doping introduce fission tracks through a Bi-2223 tape which act as effective pinning centres, leading to a substantial increase in critical current. Preliminary data suggests that the combination of uranium doping and neutron irradiation produces improved flux pinning in Bi-2223 tapes over neutron irradiation alone. Before irradiation, SEM, DTA and XRD analyses were performed on the tapes. Both before and after irradiation the trapped maximum magnetic flux was measured at 77K. Before neutron irradiation, uranium doping has no effect on critical current. Preliminary SEM data suggested that the uranium is homogeneously distributed throughout the oxide core of the tape. The presence of 2212 and other secondary phases in the doped tapes suggest further refinement of the sintering procedure is necessary. (authors)

  5. Simulating irradiation hardening in tungsten under fast neutron irradiation including Re production by transmutation

    Science.gov (United States)

    Huang, Chen-Hsi; Gilbert, Mark R.; Marian, Jaime

    2018-02-01

    Simulations of neutron damage under fusion energy conditions must capture the effects of transmutation, both in terms of accurate chemical inventory buildup as well as the physics of the interactions between transmutation elements and irradiation defect clusters. In this work, we integrate neutronics, primary damage calculations, molecular dynamics results, Re transmutation calculations, and stochastic cluster dynamics simulations to study neutron damage in single-crystal tungsten to mimic divertor materials. To gauge the accuracy and validity of the simulations, we first study the material response under experimental conditions at the JOYO fast reactor in Japan and the High Flux Isotope Reactor at Oak Ridge National Laboratory, for which measurements of cluster densities and hardening levels up to 2 dpa exist. We then provide calculations under expected DEMO fusion conditions. Several key mechanisms involving Re atoms and defect clusters are found to govern the accumulation of irradiation damage in each case. We use established correlations to translate damage accumulation into hardening increases and compare our results to the experimental measurements. We find hardening increases in excess of 5000 MPa in all cases, which casts doubts about the integrity of W-based materials under long-term fusion exposure.

  6. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Juergen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aaron, A. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, Gary L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burgess, Thomas W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ellis, Ronald James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans, James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lessard, Timothy L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ohriner, Evan Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Perkins, Dale E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Varma, Venugopal Koikal [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-20

    Fusion energy is the most promising energy source for the future, and one of the most important problems to be solved progressing to a commercial fusion reactor is the identification of plasma-facing materials compatible with the extreme conditions in the fusion reactor environment. The development of plasma–material interaction (PMI) science and the technology of plasma-facing components are key elements in the development of the next step fusion device in the United States, the so-called Fusion Nuclear Science Facility (FNSF). All of these PMI issues and the uncertain impact of the 14-MeV neutron irradiation have been identified in numerous expert panel reports to the fusion community. The 2007 Greenwald report classifies reactor plasma-facing materials (PFCs) and materials as the only Tier 1 issues, requiring a “. . . major extrapolation from the current state of knowledge, need for qualitative improvements and substantial development for both the short and long term.” The Greenwald report goes on to list 19 gaps in understanding and performance related to the plasma–material interface for the technology facilities needed for DEMO-oriented R&D and DEMO itself. Of the 15 major gaps, six (G7, G9, G10, G12, G13) can possibly be addressed with ORNL’s proposal of an advanced Material Plasma Exposure eXperiment. Establishing this mid-scale plasma materials test facility at ORNL is a key element in ORNL’s strategy to secure a leadership role for decades of fusion R&D. That is to say, our end goal is to bring the “signature facility” FNSF home to ORNL. This project is related to the pre-conceptual design of an innovative target station for a future Material–Plasma Exposure eXperiment (MPEX). The target station will be designed to expose candidate fusion reactor plasma-facing materials and components (PFMs and PFCs) to conditions anticipated in fusion reactors, where PFCs will be exposed to dense high-temperature hydrogen plasmas providing steady

  7. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    International Nuclear Information System (INIS)

    Rapp, Juergen; Aaron, A. M.; Bell, Gary L.; Burgess, Thomas W.; Ellis, Ronald James; Giuliano, D.; Howard, R.; Kiggans, James O.; Lessard, Timothy L.; Ohriner, Evan Keith; Perkins, Dale E.; Varma, Venugopal Koikal

    2015-01-01

    Fusion energy is the most promising energy source for the future, and one of the most important problems to be solved progressing to a commercial fusion reactor is the identification of plasma-facing materials compatible with the extreme conditions in the fusion reactor environment. The development of plasma-material interaction (PMI) science and the technology of plasma-facing components are key elements in the development of the next step fusion device in the United States, the so-called Fusion Nuclear Science Facility (FNSF). All of these PMI issues and the uncertain impact of the 14-MeV neutron irradiation have been identified in numerous expert panel reports to the fusion community. The 2007 Greenwald report classifies reactor plasma-facing materials (PFCs) and materials as the only Tier 1 issues, requiring a ''. . . major extrapolation from the current state of knowledge, need for qualitative improvements and substantial development for both the short and long term.'' The Greenwald report goes on to list 19 gaps in understanding and performance related to the plasma-material interface for the technology facilities needed for DEMO-oriented R&D and DEMO itself. Of the 15 major gaps, six (G7, G9, G10, G12, G13) can possibly be addressed with ORNL's proposal of an advanced Material Plasma Exposure eXperiment. Establishing this mid-scale plasma materials test facility at ORNL is a key element in ORNL's strategy to secure a leadership role for decades of fusion R&D. That is to say, our end goal is to bring the ''signature facility'' FNSF home to ORNL. This project is related to the pre-conceptual design of an innovative target station for a future Material-Plasma Exposure eXperiment (MPEX). The target station will be designed to expose candidate fusion reactor plasma-facing materials and components (PFMs and PFCs) to conditions anticipated in fusion reactors, where PFCs will be exposed to dense high-temperature hydrogen plasmas providing steady-state heat fluxes of

  8. Change in properties of superconducting magnet materials by fusion neutron irradiation

    International Nuclear Information System (INIS)

    Nishimura, Arata; Nishijima, Shigehiro; Takeuchi, Takao; Nishitani, Takeo

    2007-01-01

    A fusion reactor will generate a lot of high energy neutron and much energy will be taken out of the neutrons by a blanket system. Since some neutrons will stream out of a plasma vacuum vessel through neutral beam injection ports and penetrate a blanket system, a superconducting magnet system, which provides high magnetic field to confirm high energy particles, will be irradiated by a certain amount of neutrons. By developing the new NBI system or by reducing the penetration, the neutron fluence to the superconducting magnet will be able to be reduced. However, it is not easy to achieve the lower streaming and penetration at the present. Therefore, investigations on irradiation behavior of superconducting magnet materials are desired and some novel researches have been performed from 1970s. In general, the critical current of the superconducting wire increases under fast neutron environment comparing with that of the non-irradiated wire, and then decreased to almost zero as an increase of neutron fluence. On the other hand, the critical temperature of the wire starts to get down around 10 22 n/m 2 of neutron fluence and the temperature margin will be decreased during the operation by the neutron irradiation. In this paper, some aspects of irradiated materials will be overviewed and general tendency will be discussed focussing on knock-on effect of fast neutron and long range ordering of A15 compounds

  9. Fast neutron irradiation tests of flash memories used in space environment at the ISIS spallation neutron source

    Directory of Open Access Journals (Sweden)

    C. Andreani

    2018-02-01

    Full Text Available This paper presents a neutron accelerated study of soft errors in advanced electronic devices used in space missions, i.e. Flash memories performed at the ChipIr and VESUVIO beam lines at the ISIS spallation neutron source. The two neutron beam lines are set up to mimic the space environment spectra and allow neutron irradiation tests on Flash memories in the neutron energy range above 10 MeV and up to 800 MeV. The ISIS neutron energy spectrum is similar to the one occurring in the atmospheric as well as in space and planetary environments, with intensity enhancements varying in the range 108- 10 9 and 106- 10 7 respectively. Such conditions are suitable for the characterization of the atmospheric, space and planetary neutron radiation environments, and are directly applicable for accelerated tests of electronic components as demonstrated here in benchmark measurements performed on flash memories.

  10. Fast neutron irradiation tests of flash memories used in space environment at the ISIS spallation neutron source

    Science.gov (United States)

    Andreani, C.; Senesi, R.; Paccagnella, A.; Bagatin, M.; Gerardin, S.; Cazzaniga, C.; Frost, C. D.; Picozza, P.; Gorini, G.; Mancini, R.; Sarno, M.

    2018-02-01

    This paper presents a neutron accelerated study of soft errors in advanced electronic devices used in space missions, i.e. Flash memories performed at the ChipIr and VESUVIO beam lines at the ISIS spallation neutron source. The two neutron beam lines are set up to mimic the space environment spectra and allow neutron irradiation tests on Flash memories in the neutron energy range above 10 MeV and up to 800 MeV. The ISIS neutron energy spectrum is similar to the one occurring in the atmospheric as well as in space and planetary environments, with intensity enhancements varying in the range 108- 10 9 and 106- 10 7 respectively. Such conditions are suitable for the characterization of the atmospheric, space and planetary neutron radiation environments, and are directly applicable for accelerated tests of electronic components as demonstrated here in benchmark measurements performed on flash memories.

  11. Stability of thermally induced copper precipitates under neutron irradiation

    International Nuclear Information System (INIS)

    Phythian, W.J.; Dumbill, S.; Brown, P.; Sinclair, R.

    1993-01-01

    Model Fe 1.3%Cu and Fe 1.3%Cu 1.1%Ni alloys have been thermally aged at 550 C for 2 hours (peak) and 10 hours prior to irradiation at 288 C to a dose of 5.10 22 n/m 2 . Results of a microstructural investigation using dedicated field emission gun scanning transmission electron microscopy (FEGSTEM) and small angle neutron scattering (SANS) to assess precipitate stability in the binary alloy, are presented. These data are then used to predict a hardness change as a result of copper precipitation for comparison with the measured values obtained using standard 5 kg Vickers hardness tests on the SANS samples. Implications of these data to the re-embrittlement of the RPV by subsequent copper precipitation is discussed. (authors). 16 refs., 5 figs., 5 tabs

  12. Stability of thermally induced copper precipitates under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Phythian, W J; Dumbill, S; Brown, P; Sinclair, R [AEA Technology, Harwell (United Kingdom)

    1994-12-31

    Model Fe 1.3%Cu and Fe 1.3%Cu 1.1%Ni alloys have been thermally aged at 550 C for 2 hours (peak) and 10 hours prior to irradiation at 288 C to a dose of 5.10{sup 22} n/m{sup 2}. Results of a microstructural investigation using dedicated field emission gun scanning transmission electron microscopy (FEGSTEM) and small angle neutron scattering (SANS) to assess precipitate stability in the binary alloy, are presented. These data are then used to predict a hardness change as a result of copper precipitation for comparison with the measured values obtained using standard 5 kg Vickers hardness tests on the SANS samples. Implications of these data to the re-embrittlement of the RPV by subsequent copper precipitation is discussed. (authors). 16 refs., 5 figs., 5 tabs.

  13. Microstructural evolution in fast-neutron-irradiated austenitic stainless steels

    International Nuclear Information System (INIS)

    Stoller, R.E.

    1987-12-01

    The present work has focused on the specific problem of fast-neutron-induced radiation damage to austenitic stainless steels. These steels are used as structural materials in current fast fission reactors and are proposed for use in future fusion reactors. Two primary components of the radiation damage are atomic displacements (in units of displacements per atom, or dpa) and the generation of helium by nuclear transmutation reactions. The radiation environment can be characterized by the ratio of helium to displacement production, the so-called He/dpa ratio. Radiation damage is evidenced microscopically by a complex microstructural evolution and macroscopically by density changes and altered mechanical properties. The purpose of this work was to provide additional understanding about mechanisms that determine microstructural evolution in current fast reactor environments and to identify the sensitivity of this evolution to changes in the He/dpa ratio. This latter sensitivity is of interest because the He/dpa ratio in a fusion reactor first wall will be about 30 times that in fast reactor fuel cladding. The approach followed in the present work was to use a combination of theoretical and experimental analysis. The experimental component of the work primarily involved the examination by transmission electron microscopy of specimens of a model austenitic alloy that had been irradiated in the Oak Ridge Research Reactor. A major aspect of the theoretical work was the development of a comprehensive model of microstructural evolution. This included explicit models for the evolution of the major extended defects observed in neutron irradiated steels: cavities, Frank faulted loops and the dislocation network. 340 refs., 95 figs., 18 tabs

  14. Presence of interleukin 6 at the cutaneous level after in vivo neutron irradiation

    International Nuclear Information System (INIS)

    Agay, D.; Pradeau, P.; Edgard, L.; Van Uye, A.; Mestries, J.C.

    1994-01-01

    In this study we investigated the in situ localization of IL-6 in mixed neutron-gamma irradiated baboons belly skin. Using immunohistochemical methods, we demonstrated the presence of IL-6 as early as the first day after the irradiation day. However experimental conditions did not allow us to conclude to a causality relation between irradiation and IL-6 cutaneous presence. (author)

  15. Utilization of boron irradiation filters in reactor neutron activation via epithermal (n,γ) and fast neutron reactions

    International Nuclear Information System (INIS)

    Chisela, F.

    1986-01-01

    The technique of instrumental neutron activation analysis based on irradiation with reactor epithermal and fast neutrons has been described and evaluated. Important characteristics of boron neutron absorbers used to remove thermal neutrons from the reactor neutron spectrum have been examined and compared with those of cadmium. Three boron compound shields, have been designed and constructed at the BER II 5MW reactor for use in epithermal neutron activation analysis of biological materials. The major advantages offered by these filters in this application include the flexibility of varying the filter thickness, the low radioactivity induced in the filters during irradiation, ease of fabrication and the relatively low cost of the filter materials. The radiation heating due to the 10 B(n,α) 7 Li-reaction has been experimentally investigated for the filters used and the results obtained confirm the necessity for efficient cooling of these filters during irradiation. Three irradiation facilities have been characterized with respect to the neutron flux density and the flux spatial distribution. An experiment has been designed and carried out to compensate the flux inhomogeneity in two irradiation positions of the DBV facility caused by the reactor geometry. Several biological samples including well characterized reference materials have been analysed after epithermal activation and the results compared with those obtained with the classical thermal neutron activation method. Improved sensitivity of determination has been found for elements with high resonance integral to thermal neutron cross section ratios (RI/σ 0 ). The range of elements that can be determined instrumentally is extended and the time scale of analysis is considerably reduced. (orig.) [de

  16. Impact of neutron irradiation on mechanical performance of FeCrAl alloy laser-beam weldments

    Science.gov (United States)

    Gussev, M. N.; Cakmak, E.; Field, K. G.

    2018-06-01

    Oxidation-resistant iron-chromium-aluminum (FeCrAl) alloys demonstrate better performance in Loss-of-Coolant Accidents, compared with austenitic- and zirconium-based alloys. However, further deployment of FeCrAl-based materials requires detailed characterization of their performance under irradiation; moreover, since welding is one of the key operations in fabrication of light water reactor fuel cladding, FeCrAl alloy weldment performance and properties also should be determined prior to and after irradiation. Here, advanced C35M alloy (Fe-13%Cr-5%Al) and variants with aluminum (+2%) or titanium carbide (+1%) additions were characterized after neutron irradiation in Oak Ridge National Laboratory's High Flux Isotope Reactor at 1.8-1.9 dpa in a temperature range of 195-559 °C. Specimen sets included as-received (AR) materials and specimens after controlled laser-beam welding. Tensile tests with digital image correlation (DIC), scanning electron microscopy-electron back scatter diffraction analysis, fractography, and x-ray tomography analysis were performed. DIC allowed for investigating local yield stress in the weldments, deformation hardening behavior, and plastic anisotropy. Both AR and welded material revealed a high degree of radiation-induced hardening for low-temperature irradiation; however, irradiation at high-temperatures (i.e., 559 °C) had little overall effect on the mechanical performance.

  17. Investigation of neutron fluence using fluence monitors for irradiation test at WWR-K

    International Nuclear Information System (INIS)

    Romanova, N.K.; Takemoto, N.

    2013-01-01

    Irradiation test of a Si ingot is planned using WWR-K in Institute of Nuclear Physics Republic of Kazakhstan (INP RK) to develop an irradiation technology for Si semiconductor production by Neutron Transmutation Doping (NTD) method in the framework of an international cooperation between INP RK and Japan Atomic Energy Agency (JAEA), Japan. It is possible to irradiate the Si ingot of 6 inch in diameter at the K-23 irradiation channel in the WWR-K. The preliminary irradiation test using 4 Al ingots was performed to evaluate the actual neutronic irradiation field at the K-23 channel in the WWR-K. Each Al ingot has the same dimension as the Si ingot, and 15 fluence monitors are equipped in it. Iron wire and aluminum-cobalt wire are inserted into them, and it is possible to evaluate both fast and thermal neutron fluxes by measurement of these radiation activities after irradiation. This report described the results of the preliminary irradiation test and the neutronic calculations by Monte Carlo method in order to evaluate the neutronic irradiation field in the irradiation position for the silicon ingot at the channel in the WWR-K. (authors)

  18. Neutron irradiation of sputtered NbN films

    International Nuclear Information System (INIS)

    Weber, H.W.; Gregshammer, P.; Gray, K.E.; Kampwirth, R.T.

    1989-01-01

    In addition to the excellent high-field superconducting properties of NbN, it is the strain and radiation tolerance, measured in bulk NbN, which makes the material so attractive for large high-field magnets, especially for fusion applications. The authors report neutron irradiation experiments on sputtered NbN films, up to a fluence of 10/sup 23/ m/sup -2/ (E > 0.1 MeV), which prove that NbN films are also extremely radiation-hard high-field superconductors. Both the transition temperatures, T/sub c/, and the normal state resistivities show only small changes with neutron fluence. Concerning the critical current densities, j/sub c/, degradations by as much as 30% are observed at low fields, whereas in an intermediate field range (11-15 T) virtually no change of j/sub c/ and at high fields near 20 T even an increase of j/sub c/ are found. The latter observation is ascribed to a radiation-induced increase of the upper critical field, B/sub c2/, and to the occurence of peak effects near B/sub c2/

  19. Resistivity measurements on the neutron irradiated detector grade silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng

    1993-11-01

    Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

  20. Superconductivity in irradiated A-15 compounds at low fluences. I. Neutron-irradiated V3Si

    International Nuclear Information System (INIS)

    Viswanathan, R.; Caton, R.; Pande, C.S.

    1978-01-01

    The behavior of the superconducting transition temperature T/sub c/ of single-crystal and polycrystalline V 3 Si was investigated as a function of low-fluence neutron irradiation. It is found that the initial degradation of T/sub c/ is sample-dependent, some specimens showing no degradation in T/sub c/ up to a fluence of 2 x 10 18 n/cm 2 . This and many other earlier observations on low-fluence behavior are explained in terms of a recently proposed model of radiation damage in A-15 compounds

  1. Results of neutron measurements in the spectral position of the Juelich FKS steel irradiation capsules

    International Nuclear Information System (INIS)

    Schneider, W.

    1986-10-01

    This is a report on the planning and results of neutron monitoring in the capsules of the Juelich steel irradiation for the research project on component safety (FKS). The table of results and their discussion is provided specifically for the spectral positions (for characterising the neutron spectrum) in each of the types of irradiation capsules used. The results are given for the reaction rates of the neutron measurement reactions used (activation or fission reactions), for the neutron flux densities and fluxes derived from them related to the actual or at least plausible neutron spectra and finally for the radiation damage (or exposure) of the irradiated material calculated from them, expressed as the atomic displacement figure (dpa) and its percentage in sections of the neutron spectrum. (orig.) [de

  2. Effects of neutron irradiation on red blood cell labeling with technetium-99m

    International Nuclear Information System (INIS)

    Eng, R.R.; Conklin, J.J.; Grissom, M.P.

    1982-01-01

    The effects of in vivo and in vitro neutron irradiation on red blood cell radiolabeling with technetium-99m (Tc-99m) were studied. Blood from three dogs was irradiated with neutrons (725 rads, free in air dose) followed by radiolabeling with Tc-99m. The three dogs were subsequently whole body, neutron irradiated (250 rads, midline dose); and blood samples were drawn for radiolabeling at 24, 48, 72 and 96 hours post-irradiation. Blood from three control dogs was also drawn and radiolabeled on each day for comparison. The results show that there were no significant differences between the radiolabeling capacities of in vivo or in vitro neutron irradiated and control RBCs

  3. Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers

    International Nuclear Information System (INIS)

    Wang, R.X.; Xu, S.J.; Fung, S.; Beling, C.D.; Wang, K.; Li, S.; Wei, Z.F.; Zhou, T.J.; Zhang, J.D.; Huang Ying; Gong, M.

    2005-01-01

    GaN epilayers grown on sapphire substrate were irradiated with various dosages of neutrons and were characterized using Micro-Raman and photoluminescence. It was found that the A 1 (LO) peak in the Raman spectra clearly shifted with neutron irradiation dosage. Careful curve fitting of the Raman data was carried out to obtain the carrier concentration which was found to vary with the neutron irradiation dosage. The variation of the full width at half maximum height of the photoluminescence was consistent with the Raman results. The neutron irradiation-induced structural defects (likely to be Ge Ga ) give rise to carrier trap centers which are responsible for the observed reduction in carrier concentration of the irradiated GaN

  4. Neutron irradiated uranium silicides studied by neutron diffraction and Rietveld analysis

    International Nuclear Information System (INIS)

    Birtcher, R.C.; Mueller, M.H.; Richardson, J.W. Jr.; Faber, J. Jr.

    1989-11-01

    Uranium silicides have been considered for use as reactor fuels in both high power and low enrichment applications. However, U 3 Si was found to become amorphous under irradiation and to become mechanically unstable to rapid growth by plastic flow. U 2 Si 2 appears to be stable against amorphization at low displacement rates, but the extent of this stability is uncertain. Although the mechanisms responsible for plastic flow in U 3 Si and other amorphous systems are unknown, as is the importance of crystal structure for amorphization, it may not be surprising that these materials amorphize, in light of the fact that many radioactive nuclide - containing minerals are known to metaminctize (lose crystallinity) under irradiation. The present experiment follows the detailed changes in the crystal structures of U 3 Si and U 3 Si 2 introduced by neutron bombardment and subsequent uranium fission at room temperature. U-Si seems the ideal system for a neutron diffraction investigation since the crystallographic and amorphous forms can be studied simultaneously by combining conventional Rietveld refinement of the crystallographic phases with Fourier-filtering of the non-crystalline scattering component

  5. Effect of neutron irradiation on the microstructure of tungsten

    Directory of Open Access Journals (Sweden)

    M. Klimenkov

    2016-12-01

    Full Text Available Two grades of pure tungsten, single and polycrystalline, were irradiated for 282 days in the HFR reactor, Petten, at 900 °C to an average damage level of 1.6dpa. Each grade of tungsten was investigated using the transmission electron microscope (TEM to assess the effect of neutron irradiation on tungsten microstructure. Investigations revealed the formation of faceted cavities, whose diameter varies from 4 to 14nm in both materials. The cavities are homogeneously distributed only inside single crystalline tungsten. The local distribution of cavities in polycrystalline tungsten is strongly influenced by grain boundaries. The number densities of cavities were measured to be 4×1021 m−3 for polycrystalline and 2.5×1021 m−3 for single crystalline tungsten. This corresponds to volumetric densities of 0.45% and 0.33% respectively. High-resolution transmission electron microscopy (HRTEM revealed that faces of cavities are oriented in (110 plane. Analytical investigations showed precipitation of rhenium and osmium produced by a transmutation reaction around cavities and at grain boundaries.

  6. Neutron-Irradiated Samples as Test Materials for MPEX

    International Nuclear Information System (INIS)

    Ellis, Ronald James; Rapp, Juergen

    2015-01-01

    Plasma Material Interaction (PMI) is a major concern in fusion reactor design and analysis. The Material-Plasma Exposure eXperiment (MPEX) will explore PMI under fusion reactor plasma conditions. Samples with accumulated displacements per atom (DPA) damage produced by fast neutron irradiations in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) will be studied in the MPEX facility. This paper presents assessments of the calculated induced radioactivity and resulting radiation dose rates of a variety of potential fusion reactor plasma-facing materials (such as tungsten). The scientific code packages MCNP and SCALE were used to simulate irradiation of the samples in HFIR including the generation and depletion of nuclides in the material and the subsequent composition, activity levels, gamma radiation fields, and resultant dose rates as a function of cooling time. A challenge of the MPEX project is to minimize the radioactive inventory in the preparation of the samples and the sample dose rates for inclusion in the MPEX facility

  7. Testing of neutron-irradiated ceramic-to-metal seals

    International Nuclear Information System (INIS)

    Brown, R.D.; Clinard, F.W. Jr.; Lopez, M.R.; Martinez, H.; Romero, T.J.; Cook, J.H.; Barr, H.N.; Hittman, F.

    1990-01-01

    This paper reports on ceramic-to-metal seals prepared by sputtering a titanium metallizing layer onto ceramic disks and then brazing to metal tubes. The ceramics used were alumina, MACOR, spinel, AlON, and a mixture of Al 2 O 3 and Si 3 N 4 . Except for the MACOR, which was brazed to a titanium tube, the ceramics were brazed to niobium tubes. The seals were leak tested and then sent to Los Alamos National Laboratory, where they were irradiated using the spallation neutron source at the Los Alamos Meson Physics Facility. Following irradiation for ∼ 90 days to a fluence of 2.8 x 10 23 n/m 2 , the samples were moved to hot cells and again leak tested. Only the MACOR samples showed any measurable leaks. One set of samples was then pressurized to 6.9 MPa (1000 psi) and subsequently leak tested. No leaks were found. Bursting the seals required hydrostatic pressures of at least 34 MPa (5000 psi). The high seal strength and few leaks indicate that ceramic-to-metal seals can resist radiation-induced degradation

  8. Development of high temperature property database for Alloy 800H

    International Nuclear Information System (INIS)

    Yokoyama, Norio; Watanabe, Katsutoshi; Tsuji, Hirokazu; Nakajima, Hajime.

    1993-07-01

    JAERI Material Performance Database (JMPD) has been developed since 1989 in JAERI with a view to utilizing the various kinds of characteristic data of nuclear materials efficiently. Using relational database management system, PLANNER on the mainframe, the JMPD provides the retrieval supporting system, graphic and statistical analyses system. The data obtained with 7868 sets on characteristic data of metallic materials including fatigue crack growth data, etc. have been stored in the JMPD at the end of March in 1993. A ferritic superalloy, Alloy 800H is used for the structural material of the control rods of the High Temperature Engineering Test Reactor (HTTR). Thermal stress generates which might cause a severe creep damage at a reactor scram. It therefore needs to be designed with consideration on the fracture modes induced by creep deformation after neutron irradiation. The creep data (approximately 240 sets) and tensile data (approximately 100 sets) of Alloy 800H including the effects of test environment, aging treatment and neutron irradiation have been stored in the JMPD. Furthermore, using a personal computer, high temperature property database for Alloy 800H has been developed. The present report outlines the development of high temperature property database for Alloy 800H. (author)

  9. Neutron-irradiation + helium hardening and embrittlement modeling of 9% Cr-steels in an engineering perspective (HELENA)

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, Rachid

    2008-07-01

    This report provides a physically-based engineering model to estimate the radiation hardening of 9%Cr-steels under both displacement damage (dpa) and helium. The model is essentially based on the dispersed barrier hardening theory and the dynamic re-solution of helium under displacement cascades. However, a number of assumptions and simplifications were considered to obtain a simple description of irradiation hardening and embrittlement primarily relying on the available experimental data. As a result, two components were basically identified, the dpa component that can be associated with black dots and small loops and the He-component accounting for helium bubbles. The dpa component is strongly dependent on the irradiation temperature and its dependence law was based on a first-order annealing kinetics. The damage accumulation law was also modified to take saturation into account. Finally, the global kinetics of the damage accumulation kept defined, its amplitude is fitted to one experimental condition. The model was rationalized on an experimental database that mainly consists of {proportional_to}9%Cr-steels irradiated in the technologically important temperature range of 50 to 600 C up do 50 dpa and with a He-content up to {proportional_to}5000 appm, including neutron and proton irradiation as well as implantation. The test temperature effect is taken into account through a normalization procedure based on the change of the Young's modulus and the anelastic deformation that occurs at high temperature. Finally, the hardening-to-embrittlement correlation is obtained using the load diagram approach. Despite the large experimental scatter, inherent to the variety of the materials and irradiation as well as testing conditions, the obtained results are very promising. Improvement of the model performance is still possible by including He-hardening saturation and high temperature softening but unfortunately, at this stage, a number of conflicting experimental data

  10. Neutron-irradiation + helium hardening and embrittlement modeling of 9% Cr-steels in an engineering perspective (HELENA)

    International Nuclear Information System (INIS)

    Chaouadi, Rachid

    2008-01-01

    This report provides a physically-based engineering model to estimate the radiation hardening of 9%Cr-steels under both displacement damage (dpa) and helium. The model is essentially based on the dispersed barrier hardening theory and the dynamic re-solution of helium under displacement cascades. However, a number of assumptions and simplifications were considered to obtain a simple description of irradiation hardening and embrittlement primarily relying on the available experimental data. As a result, two components were basically identified, the dpa component that can be associated with black dots and small loops and the He-component accounting for helium bubbles. The dpa component is strongly dependent on the irradiation temperature and its dependence law was based on a first-order annealing kinetics. The damage accumulation law was also modified to take saturation into account. Finally, the global kinetics of the damage accumulation kept defined, its amplitude is fitted to one experimental condition. The model was rationalized on an experimental database that mainly consists of ∝9%Cr-steels irradiated in the technologically important temperature range of 50 to 600 C up do 50 dpa and with a He-content up to ∝5000 appm, including neutron and proton irradiation as well as implantation. The test temperature effect is taken into account through a normalization procedure based on the change of the Young's modulus and the anelastic deformation that occurs at high temperature. Finally, the hardening-to-embrittlement correlation is obtained using the load diagram approach. Despite the large experimental scatter, inherent to the variety of the materials and irradiation as well as testing conditions, the obtained results are very promising. Improvement of the model performance is still possible by including He-hardening saturation and high temperature softening but unfortunately, at this stage, a number of conflicting experimental data reported in literature should

  11. Self-ion emulation of high dose neutron irradiated microstructure in stainless steels

    Science.gov (United States)

    Jiao, Z.; Michalicka, J.; Was, G. S.

    2018-04-01

    Solution-annealed 304L stainless steel (SS) was irradiated to 130 dpa at 380 °C, and to 15 dpa at 500 °C and 600 °C, and cold-worked 316 SS (CW 316 SS) was irradiated to 130 dpa at 380 °C using 5 MeV Fe++/Ni++ to produce microstructures and radiation-induced segregation (RIS) for comparison with that from neutron irradiation at 320 °C to 46 dpa in the BOR60 reactor. For the 304L SS alloy, self-ion irradiation at 380 °C produced a dislocation loop microstructure that was comparable to that by neutron irradiation. No voids were observed in either the 380 °C self-ion irradiation or the neutron irradiation conditions. Irradiation at 600 °C produced the best match to radiation-induced segregation of Cr and Ni with the neutron irradiation, consistent with the prediction of a large temperature shift by Mansur's invariant relations for RIS. For the CW 316 SS alloy irradiated to 130 dpa at 380 °C, both the irradiated microstructure (dislocation loops, precipitates and voids) and RIS reasonably matched the neutron-irradiated sample. The smaller temperature shift for RIS in CW 316 SS was likely due to the high sink (dislocation) density induced by the cold work. A single self-ion irradiation condition at a dose rate ∼1000× that in reactor does not match both dislocation loops and RIS in solution-annealed 304L SS. However, a single irradiation temperature produced a reasonable match with both the dislocation/precipitate microstructure and RIS in CW 316 SS, indicating that sink density is a critical factor in determining the temperature shift for self-ion irradiations.

  12. Irradiation temperature dependence of production efficiency of lattice defects in some neutron-irradiated oxides

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Moritami [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 5900494 (Japan)]. E-mail: okada@rri.kyoto-u.ac.jp; Atobe, Kozo [Faculty of Science, Naruto University of Education, Naruto, Tokushima 7728502 (Japan); Nakagawa, Masuo [Faculty of Education, Kagawa University, Takamatsu, Kagawa 7608522 (Japan)

    2004-11-01

    Temperature dependence of production efficiency of irradiation-induced defects in neutron-irradiated oxides has been investigated. Some oxide single crystals, MgO, {alpha}-Al{sub 2}O{sub 3} (sapphire) and TiO{sub 2} (rutile), were irradiated at several controlled temperatures, 10, 20, 50, 100, 150 and 200 K, using the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL), and at ambient temperature ({approx}370 K) in the same facility. Irradiation temperature dependence of production efficiency of a 1 {mu}m band in TiO{sub 2} differs greatly from that of anion vacancy (F-type centers) in MgO and {alpha}-Al{sub 2}O{sub 3}. Results for MgO and {alpha}-Al{sub 2}O{sub 3} show steep negative gradients from 10 to 370 K, whereas that for TiO{sub 2} includes a valley between 40 and 60 K and a hump at about 130 K, and then disappear at about 200 K. In MgO and {alpha}-Al{sub 2}O{sub 3}, this behavior can be explained by the recombination of Frenkel pairs, which is activated at higher temperature. In TiO{sub 2}, in addition to the recombination mechanism, a covalent bonding property is thought to be exerted strong influence, and it is suggested that a disappearance of the 1 {mu}m band at above 200 K is due to the recombination process of Frenkel pairs which is caused by the irradiation-induced crystallization.

  13. Biomedical irradiation system for boron neutron capture therapy at the Kyoto University Reactor

    International Nuclear Information System (INIS)

    Kobayashi, T.; Kanda, K.; Ujeno, Y.; Ishida, M.R.

    1990-01-01

    Physics studies related to radiation source, spectroscopy, beam quality, dosimetry, and biomedical applications using the Kyoto University Reactor Heavy Water Facility are described. Also, described are a Nickel Mirror Neutron Guide Tube and a Super Mirror Neutron Guide Tube that are used both for the measurement of boron concentration in phantom and living tissue and for precise measurements of neutron flux in phantom in the presence of both light and heavy water. Discussed are: (1) spectrum measurements using the time of flight technique, (2) the elimination of gamma rays and fast neutrons from a thermal neutron irradiation field, (3) neutron collimation without producing secondary gamma rays, (4) precise neutron flux measurements, dose estimation, and the measurement of boron concentration in tumor and its periphery using guide tubes, (5) the dose estimation of boron-10 for the first melanoma patient, and (6) special-purpose biological irradiation equipment. Other related subjects are also described

  14. Biomedical irradiation system for boron neutron capture therapy at the Kyoto University reactor

    International Nuclear Information System (INIS)

    Kobayashi, T.; Kanda, K.; Ujeno, Y.; Ishida, M.R.

    1990-01-01

    Physics studies related to radiation source, spectroscopy, beam quality, dosimetry, and biomedical applications using the Kyoto University Reactor Heavy Water Facility are described. Also, described are a Nickel Mirror Neutron Guide Tube and a Super Mirror Neutron Guide Tube that are used both for the measurement of boron concentration in phantom and living tissue and for precise measurements of neutron flux in phantom in the presence of both light and heavy water. Discussed are: (1) spectrum measurements using the time of flight technique, (2) the elimination of gamma rays and fast neutrons from a thermal neutron irradiation field, (3) neutron collimation without producing secondary gamma rays, (4) precise neutron flux measurements, dose estimation, and the measurement of boron concentration in tumor and its periphery using guide tubes, (5) the dose estimation of boron-10 for the first melanoma patient, and (6) special-purpose biological irradiation equipment. Other related subjects are also described

  15. Irradiation tests of ITER candidate Hall sensors using two types of neutron spectra

    International Nuclear Information System (INIS)

    Duran, I.; Bolshakova, I.; Holyaka, R.; Viererbl, L.; Lahodova, Z.; Sentkerestiova, J.; Bem, P.

    2010-01-01

    We report on irradiation tests of InSb based Hall sensors at two irradiation facilities with two distinct types of neutron spectra. One was a fission reactor neutron spectrum with a significant presence of thermal neutrons, while another one was purely fast neutron field. Total neutron fluence of the order of 10 16 cm -2 was accumulated in both cases, leading to significant drop of Hall sensor sensitivity in case of fission reactor spectrum, while stable performance was observed at purely fast neutron spectrum. This finding suggests that performance of this particular type of Hall sensors is governed dominantly by transmutation. Additionally, it further stresses the need to test ITER candidate Hall sensors under neutron flux with ITER relevant spectrum.

  16. Supersymmetry at high temperatures

    International Nuclear Information System (INIS)

    Das, A.; Kaku, M.

    1978-01-01

    We investigate the properties of Green's functions in a spontaneously broken supersymmetric model at high temperatures. We show that, even at high temperatures, we do not get restoration of supersymmetry, at least in the one-loop approximation

  17. Electron-microscopic investigation of a pressure vessel steel after neutron irradiation

    International Nuclear Information System (INIS)

    Klaar, H.J.

    1975-01-01

    As an introduction, changes in the mechanical properties of pressure vessel steels on neutron irradiation and the causes of radiation embrittlement are discussed. After this, the author describes his own experiments with steel of the composition 0.19% C; 3.88% Ni; 1.57% Cr; 0.51% Mo; 0.2% V. Samples of this material were irradiated in-pile at 300 0 C with various neutron doses. To study the influence of neutron dose, irradiation temperature, and heat treatment on the mechanical properties, tensile tests, notched bar impact bending tests, hardness tests and structural analyses were carried out. The findings are reported. (GSC) [de

  18. Activation of 45-MeV proton irradiation and proton-induced neutron irradiation in polymers

    International Nuclear Information System (INIS)

    Ra, Se-Jin; Kim, Kye-Ryung; Jung, Myung-Hwan; Yang, Tae-Keon

    2010-01-01

    During beam irradiation experiments with more than a few MeV energetic protons, the sample activation problem can be very severe because it causes many kinds of additional problems for the post-processing of the samples, such as time loss, inconvenience of sample handling, personal radiation safety, etc. The most serious problem is that immediate treatment of the sample is impossible in some experiments, such as nano-particle synthesizing. To solve these problems, we studied why the samples are activated and how the level of the activation can be reduced. It is known that the main reasons of activation are nuclear reactions with elements of the target material by primary protons and secondary produced neutrons. Even though the irradiation conditions are same, the level of the activation can be different depending on the target materials. For the nanoparticle synthesizing experiments, the target materials can be defined as the container and the sample itself. The reduction of the activation from the container is easier than the reduction from the sample. Therefore, we tried to reduce the activation level by changing the container materials. In this paper, the results are displayed for some candidate container materials, such as polymethyl methacrylate, polystyrene, Glass, etc., with 45-MeV and 10-nA proton beams. As a result, PS is the most suitable material for the container because of its relatively low level of the activation by protons. Also the contribution of secondary produced neutrons to the activation is negligible.

  19. The effects of fast-neutron irradiation on the mechanical properties of austenitic stainless steel

    International Nuclear Information System (INIS)

    Dalton, J.H.

    1978-01-01

    The paper reviews the effects of fast-neutron irradiation on the tensile properties of austenitic stainless steels at irradiation temperatures of less than 400 degrees Celcius, using as an example, work carried out at Pelindaba on an AISI 316 type steel produced in South Africa. Damage produced in these steels at higher irradiation temperatures and fluences is also briefly discussed. The paper concludes with a discussion of some methods of overcoming or decreasing the effects of irradiation damage [af

  20. Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Manuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-08-01

    The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential

  1. Tensile property changes of metals and irradiated to low doses with fission, fusion and spallation neutrons

    International Nuclear Information System (INIS)

    Heinisch, H.L.; Hamilton, M.L.; Sommer, W.F.; Ferguson, P.D.

    1992-01-01

    The objective of this work is to investigate the effects of the neutron energy spectrum in low dose irradiations on the microstructures and mechanical properties of metals. Radiation effects due to low doses of spallation neutrons are compared directly to those produced by fission and fusion neutrons. Yield stress changes of pure Cu, alumina-dispersion-strengthened Cu and AISI 316 stainless steel irradiated at 36-55 C in the Los Alamos Spallation Radiation Effects Facility (LASREF) are compared with earlier results of irradiations at 90 C using 14 MeV D-T fusion neutrons at the Rotating Target Neutron Source and fission reactor neutrons in the Omega West Reactor. At doses up to 0.04 displacements per atom (dpa), the yield stress changes due to the three quite different neutron spectra correlate well on the basis of dpa in the stainless steel and the Cu alloy. However, in pure Cu, the measured yield stress changes due to spallation neutrons were anomalously small and should be verified by additional irradiations. With the exception of pure Cu, the low dose, low temperature experiments reveal no fundamental differences in radiation hardening by fission, fusion or spallation neutrons when compared on the basis of dpa

  2. Neutron activation analysis of several elements in the unicellular alga Cyanidium caldarium irradiated by α particles from neutron captured boron

    International Nuclear Information System (INIS)

    Yamaguchi, Shuho; Oota, Tadachika; Otani, Mayumi; Aso, Sueo

    1984-01-01

    The TRIGA MARK 2 atomic reactor was used not only for instrumental neutron activation analysis (INAA) but also as the irradiation source of α particles derived from the 10 B(n, α) 7 Li reaction for biological samples. The acidophilic and thermophilic unicellular alga (Cyanidium caldarium Geitler) was incubated for 20 hours after irradiation and then its elemental concentrations were analysed by INAA. An increase in the quantities of 56 Mn, 28 Al and 38 Cl, and a decrease of 27 Mg and 42 K were detected in the irradiated cells in contrast to non-irradiated cells. (author)

  3. Colony form variation of Bacillus pumilus E601 after cultured and neutron irradiation

    International Nuclear Information System (INIS)

    Chen Xiaoming; Wei Baoli; Zhang Jianguo

    2008-01-01

    The distribution of two colony forms of Bacillus pumilus E601 and the effect of neutron irradiation on the colony form were reported. The translucent and opaque colonies were cultured several generations to observe the proportion of two form colonies. The spores of opaque colony were irradiated at 80, 800 and 2000 Gy of fast neutron from CFBR-II pulse pile, and the survivors of opaque colony were irradiated again at the same doses. The results showed that: (1) Bacillus pumilus E601 observed two types of colony form: translucent and opaque colony; (2) the translucent colony could produce both translucent and opaque colonies in equal, while the opaque colony couldn't produce translucent colony generally; (3) neutron irradiation could affect the colony form distribution. The ratio of survival translucent colony was increased with the increase of the first neutron irradiation doses, and the second neutron irradiation also increased the ratio of translucent colony. It was concluded that the instability of translucent colony was the main reason to produce two colony forms of Bacillus pumilus E601. The strain of translucent colony had a stronger ability to resist neutron irradiation than the opaque colony. (authors)

  4. Formation of austenite in high Cr ferritic/martensitic steels by high fluence neutron irradiation

    Science.gov (United States)

    Lu, Z.; Faulkner, R. G.; Morgan, T. S.

    2008-12-01

    High Cr ferritic/martensitic steels are leading candidates for structural components of future fusion reactors and new generation fission reactors due to their excellent swelling resistance and thermal properties. A commercial grade 12%CrMoVNb ferritic/martensitic stainless steel in the form of parent plate and off-normal weld materials was fast neutron irradiated up to 33 dpa (1.1 × 10 -6 dpa/s) at 400 °C and 28 dpa (1.7 × 10 -6 dpa/s) at 465 °C, respectively. TEM investigation shows that the fully martensitic weld metal transformed to a duplex austenite/ferrite structure due to high fluence neutron irradiation, the austenite was heavily voided (˜15 vol.%) and the ferrite was relatively void-free; whilst no austenite phases were detected in plate steel. Thermodynamic and phase equilibria software MTDATA has been employed for the first time to investigate neutron irradiation-induced phase transformations. The neutron irradiation effect is introduced by adding additional Gibbs free energy into the system. This additional energy is produced by high energy neutron irradiation and can be estimated from the increased dislocation loop density caused by irradiation. Modelling results show that neutron irradiation reduces the ferrite/austenite transformation temperature, especially for high Ni weld metal. The calculated results exhibit good agreement with experimental observation.

  5. Simulation of a high energy neutron irradiation facility at beamline 11 of the China Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Tairan, Liang [School of Physics and Electronic Information Inner Mongolia University for the Nationalities, Tongliao 028043 (China); Zhiduo, Li [Dongguan Branch, Institute of High Energy Physics, CAS, Beijing 100049 (China); Wen, Yin, E-mail: wenyin@aphy.iphy.ac.cn [Dongguan Branch, Institute of High Energy Physics, CAS, Beijing 100049 (China); Institute of Physics, CAS, P.O. Box 603, Beijing 100190 (China); Fei, Shen [Dongguan Branch, Institute of High Energy Physics, CAS, Beijing 100049 (China); Quanzhi, Yu [Dongguan Branch, Institute of High Energy Physics, CAS, Beijing 100049 (China); Institute of Physics, CAS, P.O. Box 603, Beijing 100190 (China); Tianjiao, Liang [Dongguan Branch, Institute of High Energy Physics, CAS, Beijing 100049 (China)

    2017-07-11

    The China Spallation Neutron Source (CSNS) will accommodate 20 neutron beamlines at its first target station. These beamlines serve different purposes, and beamline 11 is designed to analyze the degraded models and damage mechanisms, such as Single Event Effects in electronic components and devices for aerospace electronic systems. This paper gives a preliminary discussion on the scheme of a high energy neutron irradiation experiment at the beamline 11 shutter based on the Monte Carlo simulation method. The neutron source term is generated by calculating the neutrons scattering into beamline 11 with a model that includes the target-moderator-reflector area. Then, the neutron spectrum at the sample position is obtained. The intensity of neutrons with energy of hundreds of MeV is approximately 1E8 neutron/cm{sup 2}/s, which is useful for experiments. The displacement production rate and gas productions are calculated for common materials such as tungsten, tantalum and SS316. The results indicate that the experiment can provide irradiation dose rate ranges from 1E-5 to 1E-4 dpa per operating year. The residual radioactivity is also calculated for regular maintenance work. These results give the basic reference for the experimental design.

  6. Evaluation of neutron irradiation embrittlement in the Korean reactor pressure vessel steels (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, J. H.; Lee, B. S.; Chi, S. H.; Kim, J. H.; Oh, Y. J.; Yoon, J. H.; Kwon, S. C.; Park, D. G.; Kang, Y. H.; Choo, K. N.; Oh, J. M.; Park, S. J.; Kim, B. K.; Shin, Y. T.; Cho, M. S.; Sohn, J. M.; Kim, D. S.; Choo, Y. S.; Ahn, S. B.; Oh, W. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-05-01

    Reactor pressure vessel materials, which were produced by a domestic company, Doosan Heavy Industries and construction Co., Ltd., have been evaluated using the neutron irradiation facility HANARO. For this evaluation, instrumented capsules were used for neutron irradiation of various kinds of specimens made of different heats of steels, which are VCD(Y4), VCD+Al(U4), Si+Al(Y5), U4 weld metal, and U4 HAZ, respectively. The fast neutron fluence levels ranged 1 to 5 (x10{sup 19} n/cm{sup 2}, E>1MeV) depending on the specimens and the irradiation temperature was controlled within 290{+-}10 deg C. The test results showed that, in the ranking of the material properties of the base metals, both before and after neutron irradiation, Y5 is the best, U4 the next and Y4 the last. Y4 showed a substantial change by neutron irradiation as well as the properties was worse than others in the unirradiated state. However, Y5, which showed the best properties in unirradiated state, was also the best in the resistance for irradiation embrittlement and one can hardly detect the property change after irradiation. The weldment showed a reasonably good resistance to irradiation embrittlement while the unirradiated properties were worse than base metals. The RPV steels are all expected to meet the screening criteria of the USNRC codes and regulations during the end of plant life. 39 refs., 42 figs., 27 tabs. (Author)

  7. Physical aspects on the neutron irradiation. 4. Dosimetry with ionization chamber

    International Nuclear Information System (INIS)

    Hiraoka, Takeshi; Takada, Masashi

    2008-01-01

    Absolute measurements of the absorbed dose for irradiation are generally made using ionization chambers, which should be calibrated by the standard radiation source. The neutron dose measurements are not simple since gamma rays always contaminate the neutron flux and a variety of charged particles are induced by neutrons. Following subjects are described: (1) The method by ICRU 45 to estimate total dose of neutrons and gamma ray, (2) The method to measure the neutron dose and the gamma ray dose separately using paired ionization-chambers, and (3) The calibration of ionization chambers. The stability of the standard ionization-chambers is also presented. (K.Y.)

  8. Characterization of defect accumulation in neutron-irradiated Mo by positron annihilation spectroscopy

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Li, Meimei; Snead, L.L.

    2008-01-01

    Positron annihilation lifetime spectroscopy measurements were performed on neutron-irradiated low carbon arc cast Mo. Irradiation took place in the high flux isotope reactor, Oak Ridge National Laboratory, at a temperature of 80 +/- 10 degrees C. Neutron fluences ranged from 2 x 10(21) to 8 x 10(......, as predicted by molecular dynamics simulations. (C) 2008 Elsevier B.V. All rights reserved....... at a very low-dose of similar to 10(-4) dpa. The average size of the cavities did not change significantly with dose, in contrast to neutron-irradiated bcc Fe where cavity sizes increased with increasing dose. It is suggested that the in-cascade vacancy clustering may be significant in neutron-irradiated Mo...

  9. Materials irradiation subpanel report to BESAC neutron sources and research panel

    International Nuclear Information System (INIS)

    Birtcher, R.C.; Goland, A.N.; Lott, R.

    1992-01-01

    The future success of the nuclear power option in the US (fission and fusion) depends critically on the continued existence of a healthy national materials-irradiation program. Consideration of the requirements for acceptable materials-irradiation systems in a new neutron source has led the subcommittee to identify an advanced steady-state reactor (ANS) as a better choice than a spallation neutron source. However, the subcommittee also hastens to point out that the ANS cannot stand alone as the nation's sole high-flux mixed-spectrum neutron irradiation source in the next century. It must be incorporated in a broader program that includes other currently existing neutron irradiation facilities. Upgrading and continuing support for these facilities must be planned. In particular, serious consideration should be given to converting the HFIR into a dedicated materials test reactor, and long-term support for several university reactors should be established

  10. In Vitro antileishmanial properties of neutron-irradiated meglumine antimoniate

    Directory of Open Access Journals (Sweden)

    Samanta Etel Treiger Borborema

    2005-10-01

    Full Text Available Pentavalent antimony, as meglumine antimoniate (Glucantime® or sodium stibogluconate (Pentostam® , is the main treatment for leishmaniasis, a complex of diseases caused by the protozoan Leishmania, and an endemic and neglected threat in Brazil. Despite over half a century of clinical use, their mechanism of action, toxicity and pharmacokinetic data remain unknown. The analytical methods for determination of antimony in biological systems remain complex and have low sensitivity. Radiotracer studies have a potential in pharmaceutical development. The aim of this study was to obtain a radiotracer for antimony, with suitable physical and biological properties. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor, producing two radioisotopes 122Sb and 124Sb, with high radionuclidic purity and good specific activity. This compound showed the same antileishmanial activity as the native compound. The use of the radiotracers, easily created by neutron irradiation, could be an interesting tool to solve important questions in antimonial pharmacology.Os antimoniais pentavalentes, como o antimoniato de meglumina (Glucantime® ou estibogluconato de sódio (Pentostam® , são o principal tratamento para a leishmaniose, um complexo de doenças causadas pelo protozoário parasita Leishmania, uma doença endêmica e negligenciada no Brasil. Apesar do seu uso clínico por mais de meio século, seu mecanismo de ação, toxicidade e dados de farmacocinética permanecem desconhecidos. Os métodos analíticos para determinação de antimônio em sistemas biológicos são complexos e apresentam baixa sensibilidade. Estudos utilizando radiotraçadores têm papel potencial no desenvolvimento farmacológico. O objetivo deste estudo foi desenvolver um radiotraçador de antimônio, com propriedades físicas e biológicas adequadas. O antimoniato de meglumina foi irradiado por nêutrons no reator nuclear IEA-R1, produzindo dois radioisótopos: 122

  11. Mechanical compression tests of beryllium pebbles after neutron irradiation up to 3000 appm helium production

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V., E-mail: vladimir.chakin@kit.edu [Karlsruhe Institute of Technology, Institite for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R.; Moeslang, A. [Karlsruhe Institute of Technology, Institite for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/Josep Pla, no. 2, Torres Diagonal Litoral, Edificio B3, 08019 Barcelona (Spain)

    2015-04-15

    Highlights: • Compression tests of highly neutron irradiated beryllium pebbles have been performed. • Irradiation hardening of beryllium pebbles decreases the steady-state strain-rates. • The steady-state strain-rates of irradiated beryllium pebbles exceed their swelling rates. - Abstract: Results: of mechanical compression tests of irradiated and non-irradiated beryllium pebbles with diameters of 1 and 2 mm are presented. The neutron irradiation was performed in the HFR in Petten, The Netherlands at 686–968 K up to 1890–2950 appm helium production. The irradiation at 686 and 753 K cause irradiation hardening due to the gas bubble formation in beryllium. The irradiation-induced hardening leads to decrease of steady-state strain-rates of irradiated beryllium pebbles compared to non-irradiated ones. In contrary, after irradiation at higher temperatures of 861 and 968 K, the steady-state strain-rates of the pebbles increase because annealing of irradiation defects and softening of the material take place. It was shown that the steady-state strain-rates of irradiated beryllium pebbles always exceed their swelling rates.

  12. Ion irradiation used as surrogate of neutron irradiation in graphite: Consequences on 14C and 36Cl behavior and structural evolution

    Science.gov (United States)

    Galy, N.; Toulhoat, N.; Moncoffre, N.; Pipon, Y.; Bérerd, N.; Ammar, M. R.; Simon, P.; Deldicque, D.; Sainsot, P.

    2018-04-01

    Graphite has been widely used as neutron moderator, reflector or fuel matrix in different types of reactors such as gas cooled nuclear reactors (UNGG, Magnox, AGR), RBMK reactors or high temperature gas cooled reactors. Their operation produces a great quantity of irradiated graphite or other carbonaceous waste (around 250,000 tons worldwide) that requires a special management strategy. In the case of disposal, which is a current management strategy, two main radionuclides, 14C and 36Cl might be dose determining at the outlet. Particular attention is paid to 14C due to its long half-life (T∼5730 years) [1] and as major contributor to the radioactive dose. 14C has two main production routes, i) transmutation of nitrogen (14N(n,p)14C) where nitrogen is mainly adsorbed at the surfaces of the irradiated graphite; ii) activation of carbon from the matrix (13C(n,γ)14C). According to leaching tests, it was shown that even if the quantity of 14C released in the solution is low (less than 1% of the initial inventory), around 30% is in the organic form that would be mobile in repository conditions [2,3]. 36Cl is mainly produced through the activation of 35Cl (35Cl(n,γ)36Cl) which is an impurity in nuclear graphite. Its activity is low but it might be highly mobile in clay host rocks. Thus, in order to make informed decisions about the best management process and to anticipate potential radionuclide dissemination during dismantling and in the repository, it is necessary to collect information on 14C and 36Cl location and speciation in graphite, after reactor closure. The goal of the present paper is therefore to use ion irradiation to simulate neutron irradiation and to evaluate the irradiation effects on the behavior of 36Cl and 14C as well as on the induced graphite structure modifications. For that, to understand and model the underlying mechanisms, we used an indirect approach based on 13C or 37Cl implantation to simulate the respective presence of 14C or 36Cl. These

  13. Nuclear graphite based on coal tar pitch; behavior under neutron irradiation between 400 and 14000C

    International Nuclear Information System (INIS)

    Mottet, P.; Fillatre, A.; Schill, R.; Micaud, G.

    1977-01-01

    Two nuclear grades of coal tar pitch coke graphites have been developed and tested under neutron irradiation. The neutron irradiation induced dimensional changes between 400 and 1400 0 C, at fluences up to 1,2.10 22 n.cm -2 PHI.FG show a behavior comparable to anisotropic petroleum coke graphites. Less than 10% variation in thermal expansion, maximum decrease by a factor four in thermal conductivity, and large increase of the Young modulus have been observed

  14. Present status of ESNIT (energy selective neutron irradiation test facility) program

    International Nuclear Information System (INIS)

    Noda, K.; Ohno, H.; Sugimoto, M.; Kato, Y.; Matsuo, H.; Watanabe, K.; Kikuchi, T.; Sawai, T.; Usui, T.; Oyama, Y.; Kondo, T.

    1994-01-01

    The present status of technical studies of a high energy neutron irradiation facility, ESNIT (energy selective neutron irradiation test facility), is summarized. Technological survey and feasibility studies of ESNIT have continued since 1988. The results of technical studies of the accelerator, the target and the experimental systems in ESNIT program were reviewed by an International Advisory Committee in February 1993. Recommendations for future R and D on ESNIT program are also summarized in this paper. ((orig.))

  15. Deuterium Depth Profile in Neutron-Irradiated Tungsten Exposed to Plasma

    International Nuclear Information System (INIS)

    Shimada, Masashi; Cao, G.; Hatano, Y.; Oda, T.; Oya, Y.; Hara, M.; Calderoni, P.

    2011-01-01

    The effect of radiation damage has been mainly simulated using high-energy ion bombardment. The ions, however, are limited in range to only a few microns into the surface. Hence, some uncertainty remains about the increase of trapping at radiation damage produced by 14 MeV fusion neutrons, which penetrate much farther into the bulk material. With the Japan-US joint research project: Tritium, Irradiations, and Thermofluids for America and Nippon (TITAN), the tungsten samples (99.99 % pure from A.L.M.T., 6mm in diameter, 0.2mm in thickness) were irradiated to high flux neutrons at 50 C and to 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). Subsequently, the neutron-irradiated tungsten samples were exposed to a high-flux deuterium plasma (ion flux: 1021-1022 m-2s-1, ion fluence: 1025-1026 m-2) in the Tritium Plasma Experiment (TPE) at the Idaho National Laboratory (INL). First results of deuterium retention in neutron-irradiated tungsten exposed in TPE have been reported previously. This paper presents the latest results in our on-going work of deuterium depth profiling in neutron-irradiated tungsten via nuclear reaction analysis. The experimental data is compared with the result from non neutron-irradiated tungsten, and is analyzed with the Tritium Migration Analysis Program (TMAP) to elucidate the hydrogen isotope behavior such as retention and depth distribution in neutron-irradiated and non neutron-irradiated tungsten.

  16. Improvement of radiation response characteristic on CdTe detectors using fast neutron irradiation

    International Nuclear Information System (INIS)

    Miyamaru, Hiroyuki; Takahashi, Akito; Iida, Toshiyuki

    1999-01-01

    The treatment of fast neutron pre-irradiation was applied to a CdTe radiation detector in order to improve radiation response characteristic. Electron transport property of the detector was changed by the irradiation effect to suppress pulse amplitude fluctuation in risetime. Spectroscopic performance of the pre-irradiated detector was compared with the original. Additionally, the pre-irradiated detector was employed with a detection system using electrical signal processing of risetime discrimination (RTD). Pulse height spectra of 241 Am, 133 Ba, and 137 Cs gamma rays were measured to examine the change of the detector performance. The experimental results indicated that response characteristic for high-energy photons was improved by the pre-irradiation. The combination of the pre-irradiated detector and the RTD processing was found to provide further enhancement of the energy resolution. Application of fast neutron irradiation effect to the CdTe detector was demonstrated. (author)

  17. Void formation by annealing of neutron-irradiated plastically deformed molybdenum

    International Nuclear Information System (INIS)

    Petersen, K.; Nielsen, B.; Thrane, N.

    1976-01-01

    The positron annihilation technique has been used in order to study the influence of plastic deformation on the formation and growth of voids in neutron irradiated molybdenum single crystals treated by isochronal annealing. Samples were prepared in three ways: deformed 12-19% before irradiation, deformed 12-19% after irradiation, and - for reference purposes -non-deformed. In addition a polycrystalline sample was prepared in order to study the influence of the grain boundaries. All samples were irradiated at 60 0 C with a flux of 2.5 x 10 18 fast neutrons/cm 2 . After irradiation the samples were subjected to isochronal annealing. It was found that deformation before irradiation probably enhanced the formation of voids slightly. Deformation after irradiation strongly reduced the void formation. The presence of grain boundaries in the polycrystalline sample had a reducing influence on the growth of voids. (author)

  18. On the studies of thermodynamics properties of fast neutron irradiated (Li{sub x}K{sub 1-x}){sub 2}SO{sub 4} crystals

    Energy Technology Data Exchange (ETDEWEB)

    El-Khatib, A.M.; Kassem, M.E.; Gomaa, N.G.; Mahmoud, S.A. [Alexandria Univ. (Egypt). Dept. of Physics

    1996-12-31

    The effect of fast neutron irradiation on the thermodynamic properties of (Li{sub x}K{sub 1-x}){sub 2}SO{sub 4}, (x = 0.1, 0.2,......0.5) has been studied. The measurements were carried out in the vicinity of phase transition. The study reveals that as the lithium content decreases the first high temperature phase T{sub c} 705K disappears, while the second one is shifted to lower temperature. It is observed also that the specific heat, C{sub p}, decreases sharply with neutron integrated fluence {phi} and increases once more. Both entropy and enthalpy changes increase with the increase of neutron integrated fluence. (Author).

  19. Irradiation damage in graphite due to fast neutrons in fission and fusion systems

    International Nuclear Information System (INIS)

    2000-09-01

    Gas cooled reactors have been in operation for the production of electricity for over forty years, encompassing a total of 56 units operated in seven countries. The predominant experience has been with carbon dioxide cooled reactors (52 units), with the majority operated in the United Kingdom. In addition, four prototype helium cooled power plants were operated in the United States and Germany. The United Kingdom has no plans for further construction of carbon dioxide units, and the last helium cooled unit was shutdown in 1990. However, there has been an increasing interest in modular helium cooled reactors during the 1990s as a possible future nuclear option. Graphite is a primary material for the construction of gas cooled reactor cores, serving as a low absorption neutron moderator and providing a high temperature, high strength structure. Commercial gas cooled reactor cores (both carbon dioxide cooled and helium cooled) utilise large quantities of graphite. The structural behaviour of graphite (strength, dimensional stability, susceptibility to cracking, etc.) is a complex function of the source material, manufacturing process, chemical environment, and temperature and irradiation history. A large body of data on graphite structural performance has accumulated from operation of commercial gas cooled reactors, beginning in the 1950s and continuing to the present. The IAEA is supporting a project to collect graphite data and archive it in a retrievable form as an International Database on Irradiated Nuclear Graphite Properties, with limited general access and more detailed access by participating Member States. Because of the large size of the database, the complexity of the phenomena and the number of variables involved, a general understanding of graphite behaviour is essential to the understanding and use of the data

  20. Apoptosis of nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation

    International Nuclear Information System (INIS)

    Liang Ke; He Shaoqin; Feng Yan; Tang Jinhua; Feng Qinfu; Shen Yu; Yin Weibo; Xu Guozhen; Liu Xinfan; Wang Luhua; Gao Li

    1999-01-01

    Objective: To study the apoptotic response of the nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation. Methods: CNE-2 cells were cultured as usual. Using the techniques of DNA agarose gel electrophoresis and DNA special fluorescent staining, the status of apoptosis in CNE-2 cells after neutron irradiation was detected. Results: It was shown that the apoptosis can be induced in CNE-2 cell after neutron radiation. Six hrs, after different doses of neutron (0/0.667/1.333/2.000/2.667/3.333 Gy) and X-ray 0/2/4/6/8/10 Gy) irradiation the apoptotic rates were 2.4%, 6.3%, 7.1%, 9.5%, 13.5%, 14.6% and 2.4%, 3.8%, 5.7%, 7.8%, 10.4%, 11.7%, respectively; at 48 hrs they were 18.3%, 21.5%, 22.8%, 29.3%, 34.2% and 13.7%, 17.6%, 21.3%, 25.6%, 28.9%, respectively. At 10 hrs after neutron irradiation the DNA ladder of apoptosis could be detected between 0.667-3.333 Gy doses in CNE-2 cells by DNA agarose gel electrophoresis. Conclusion: Neutron radiation can induce apoptosis in tumor cells. Compared with the X-ray, neutron induces apoptosis in larger extent than X-ray in the same condition; meanwhile, apoptosis after irradiation is dose and time dependent

  1. Neutron irradiation test of copper alloy/stainless steel joint materials

    International Nuclear Information System (INIS)

    Yamada, Hirokazu; Kawamura, Hiroshi

    2006-01-01

    As a study about the joint technology of copper alloy and stainless steel for utilization as cooling piping in International Thermonuclear Experimental Reactor (ITER), Al 2 O 3 -dispersed strengthened copper or CuCrZr was jointed to stainless steel by three kinds of joint methods (casting joint, brazing joint and friction welding method) for the evaluation of the neutron irradiation effect on joints. A neutron irradiation test was performed to three types of joints and each copper alloy. The average value of fast neutron fluence in this irradiation test was about 2 x 10 24 n/m 2 (E>1 MeV), and the irradiation temperature was about 130degC. As post-irradiation examinations, tensile tests, hardness tests and observation of fracture surface after the tensile tests were performed. All type joints changed to be brittle by the neutron irradiation effect like each copper alloy material, and no particular neutron irradiation effect due to the effect of joint process was observed. On the casting and friction welding, hardness of copper alloy near the joint boundary changed to be lower than that of each copper alloy by the effect of joint procedure. However, tensile strength of joints was almost the same as that of each copper alloy before/after neutron irradiation. On the other hand, tensile strength of joints by brazing changed to be much lower than CuAl-25 base material by the effect of joint process before/after neutron irradiation. Results in this study showed that the friction welding method and the casting would be able to apply to the joint method of piping in ITER. This report is based on the final report of the ITER Engineering Design Activities (EDA). (author)

  2. Model of defect reactions and the influence of clustering in pulse-neutron-irradiated Si

    International Nuclear Information System (INIS)

    Myers, S. M.; Cooper, P. J.; Wampler, W. R.

    2008-01-01

    Transient reactions among irradiation defects, dopants, impurities, and carriers in pulse-neutron-irradiated Si were modeled taking into account the clustering of the primal defects in recoil cascades. Continuum equations describing the diffusion, field drift, and reactions of relevant species were numerically solved for a submicrometer spherical volume, within which the starting radial distributions of defects could be varied in accord with the degree of clustering. The radial profiles corresponding to neutron irradiation were chosen through pair-correlation-function analysis of vacancy and interstitial distributions obtained from the binary-collision code MARLOWE, using a spectrum of primary recoil energies computed for a fast-burst fission reactor. Model predictions of transient behavior were compared with a variety of experimental results from irradiated bulk Si, solar cells, and bipolar-junction transistors. The influence of defect clustering during neutron bombardment was further distinguished through contrast with electron irradiation, where the primal point defects are more uniformly dispersed

  3. Point defects and magnetic properties of neutron irradiated MgO single crystal

    Directory of Open Access Journals (Sweden)

    Mengxiong Cao

    2017-05-01

    Full Text Available (100-oriented MgO single crystals were irradiated to introduce point defects with different neutron doses ranging from 1.0×1016 to 1.0×1020 cm-2. The point defect configurations were studied with X-ray diffuse scattering and UV-Vis absorption spectra. The isointensity profiles of X-ray diffuse scattering caused by the cubic and double-force point defects in MgO were theoretically calculated based on the Huang scattering theory. The magnetic properties at different temperature were measured with superconducting quantum interference device (SQUID. The reciprocal space mappings (RSMs of irradiated MgO revealed notable diffuse scattering. The UV-Vis spectra indicated the presence of O Frenkel defects in irradiated MgO. Neutron-irradiated MgO was diamagnetic at room temperature and became ferromagnetic at low temperature due to O Frenkel defects induced by neutron-irradiation.

  4. Fast neutron irradiation deteriorates hippocampus-related memory ability in adult mice.

    Science.gov (United States)

    Yang, Miyoung; Kim, Hwanseong; Kim, Juhwan; Kim, Sung-Ho; Kim, Jong-Choon; Bae, Chun-Sik; Kim, Joong-Sun; Shin, Taekyun; Moon, Changjong

    2012-03-01

    Object recognition memory and contextual fear conditioning task performance in adult C57BL/6 mice exposed to cranial fast neutron irradiation (0.8 Gy) were examined to evaluate hippocampus-related behavioral dysfunction following acute exposure to relatively low doses of fast neutrons. In addition, hippocampal neurogenesis changes in adult murine brain after cranial irradiation were analyzed using the neurogenesis immunohistochemical markers Ki-67 and doublecortin (DCX). In the object recognition memory test and contextual fear conditioning, mice trained 1 and 7 days after irradiation displayed significant memory deficits compared to the sham-irradiated controls. The number of Ki-67- and DCX-positive cells decreased significantly 24 h post-irradiation. These results indicate that acute exposure of the adult mouse brain to a relatively low dose of fast neutrons interrupts hippocampal functions, including learning and memory, possibly by inhibiting neurogenesis.

  5. Neutronics analysis of International Fusion Material Irradiation Facility (IFMIF). Japanese contributions

    International Nuclear Information System (INIS)

    Oyama, Yukio; Noda, Kenji; Kosako, Kazuaki.

    1997-10-01

    In fusion reactor development for demonstration reactor, i.e., DEMO, materials tolerable for D-T neutron irradiation are absolutely required for both mechanical and safety point of views. For this requirement, several kinds of low activation materials were proposed. However, experimental data by actual D-T fusion neutron irradiation have not existed so far because of lack of fusion neutron irradiation facility, except fundamental radiation damage studies at very low neutron fluence. Therefore such a facility has been strongly requested. According to agreement of need for such a facility among the international parties, a conceptual design activity (CDA) of International Fusion Material Irradiation Facility (IFMIF) has been carried out under the frame work of the IEA-Implementing Agreement. In the activity, a neutronics analysis on irradiation field optimization in the IFMIF test cell was performed in three parties, Japan, US and EU. As the Japanese contribution, the present paper describes a neutron source term as well as incident deuteron beam angle optimization of two beam geometry, beam shape (foot print) optimization, and dpa, gas production and heating estimation inside various material loading Module, including a sensitivity analysis of source term uncertainty to the estimated irradiation parameters. (author)

  6. Effect of neutron irradiation on the properties of the repair welds of the 15Kh2MFA steel

    International Nuclear Information System (INIS)

    Morozov, A.M.; Khachaturyants, L.V.

    1986-01-01

    The authors studied the effect of neutron irradiation on the tendency of the metal belonging to the heat affected zone of the weld toward brittle fracture (an increase in the critical temperature of brittleness). For comparison, the authors studied the radiation embrittlement of the original base metal (steel 15Kh2MFA) subjected to the conventional heat treatment of the reactor frames consisting of hardening and high-temperature tempering. Along with these materials, the radiational embrittlement of the base metal in the rehardened condition without tempering was studied. It was concluded that the presence of the regions repaired according to this technology and located in the frame at the level of the reactor core does not pose the problem of decreased resistance to brittle fracture

  7. Behavior of structural and target materials irradiated in spallation neutron environments

    International Nuclear Information System (INIS)

    Stubbins, J.F.; Wechsler, M.; Borden, M.

    1995-01-01

    This paper describes considerations for selection of structural and target materials for accelerator-driven neutron sources. Due to the operating constraints of proposed accelerator-driven neutron sources, the criteria for selection are different than those commonly applied to fission and fusion systems. Established irradiation performance of various alloy systems is taken into account in the selection criteria. Nevertheless, only limited materials performance data are available which specifically related to neutron energy spectra anticipated for spallation sources

  8. Behavior of structural and target materials irradiated in spallation neutron environments

    Energy Technology Data Exchange (ETDEWEB)

    Stubbins, J.F. [Univ. of Illinois, Urbana, IL (United States); Wechsler, M. [North Carolina State Univ., Raleigh, NC (United States); Borden, M. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-10-01

    This paper describes considerations for selection of structural and target materials for accelerator-driven neutron sources. Due to the operating constraints of proposed accelerator-driven neutron sources, the criteria for selection are different than those commonly applied to fission and fusion systems. Established irradiation performance of various alloy systems is taken into account in the selection criteria. Nevertheless, only limited materials performance data are available which specifically related to neutron energy spectra anticipated for spallation sources.

  9. International fusion materials irradiation facility and neutronic calculations for its test modules

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.

    1997-01-01

    The International Fusion Material Irradiation Facility (IFMIF) is a projected high intensity neutron source for material testing. Neutron transport calculations for the IFMIF project are performed for variety of here explained reasons. The results of MCNP neutronic calculations for IFMIF test modules with NaK and He cooled high flux test cells are presented in this paper. (author). 3 refs., 2 figs., 3 tabs

  10. Neutron Irradiation Tests of Pressure Transducers in Liquid Helium

    CERN Document Server

    Amand, J F; Casas-Cubillos, J; Thermeau, J P

    1999-01-01

    The superconducting magnets of the future Large Hadron Collider (LHC) at CERN will operate in pressurised superfluid helium (1 bar, 1.9 K). About 500 pressure transducers will be placed in the liquid helium bath for monitoring the filling and the pressure transients after resistive transitions. Their precision must remain better than 100 mbar at pressures below 2 bar and better than 5% for higher pressures (up to 20 bar), with temperatures ranging from 1.8 K to 300 K. All the tested transducers are based on the same principle: the fluid or gas is separated from a sealed reference vacuum by an elastic membrane; its deformation indicates the pressure. The transducers will be exposed to high neutron fluence (2 kGy, 1014 n/cm2 per year) during the 20 years of machine operation. This irradiation may induce changes both on the membranes characteristics (leakage, modification of elasticity) and on gauges which measure their deformations. To investigate these effects and select the transducer to be used in the LHC, a...

  11. Optical properties of CsI single crystals irradiated with neutrons at low temperature

    International Nuclear Information System (INIS)

    Okada, M.; Atobe, K.; Itatani, N.; Ozawa, K.

    1998-01-01

    Optical properties of the irradiation-induced-defects in neutron-irradiated CsI single crystals have been investigated. The nominally pure CsI crystals are irradiated by reactor fast neutrons (E>0.1 MeV) with a fluence of 1.4 x 10 15 n/cm 2 at 20 K and by γ-rays from 60 Co source to a dose of 1.5 x 10 4 Gy at liquid nitrogen temperature (LNT). After the irradiations, isochronal annealings are performed to investigate the thermal behavior of the defects. The glow peaks of the thermoluminescence (TL) in each sample irradiated with neutrons at 20 K and with γ-rays at LNT are observed at about 100, 160 and 220 K. In the neutron-irradiated samples at 20 K, the emission band at 338 nm is observed at LNT. It is supposed that this emission band occurs by an excitation of γ-rays from 134 Cs, which is radioactivated by thermal neutrons among the reactor radiations. It is confirmed that the temperature dependence of the 338 nm band is similar with that of the emission band due to the self-trapped exciton which is introduced into the non-irradiated samples illuminated by higher energy photons. (orig.)

  12. Optical properties of CsI single crystals irradiated with neutrons at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Okada, M. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Nakagawa, M. [Faculty of Education, Kagawa Univ., Takamatsu, Kagawa (Japan); Atobe, K. [Faculty of Science, Naruto Univ. of Education, Naruto, Tokushima (Japan); Itatani, N.; Ozawa, K. [Horiba Ltd., Minamiku, Kyoto (Japan)

    1998-05-01

    Optical properties of the irradiation-induced-defects in neutron-irradiated CsI single crystals have been investigated. The nominally pure CsI crystals are irradiated by reactor fast neutrons (E>0.1 MeV) with a fluence of 1.4 x 10{sup 15} n/cm{sup 2} at 20 K and by {gamma}-rays from {sup 60}Co source to a dose of 1.5 x 10{sup 4} Gy at liquid nitrogen temperature (LNT). After the irradiations, isochronal annealings are performed to investigate the thermal behavior of the defects. The glow peaks of the thermoluminescence (TL) in each sample irradiated with neutrons at 20 K and with {gamma}-rays at LNT are observed at about 100, 160 and 220 K. In the neutron-irradiated samples at 20 K, the emission band at 338 nm is observed at LNT. It is supposed that this emission band occurs by an excitation of {gamma}-rays from {sup 134}Cs, which is radioactivated by thermal neutrons among the reactor radiations. It is confirmed that the temperature dependence of the 338 nm band is similar with that of the emission band due to the self-trapped exciton which is introduced into the non-irradiated samples illuminated by higher energy photons. (orig.) 13 refs.

  13. A review of the effect of neutron irradiation on the deformation behaviour of copper and copper alloys

    International Nuclear Information System (INIS)

    Higgy, H.R.

    1976-08-01

    The basic mechanisms of