Development of a reconstitution system of Charpy probes for the surveillance of vessels in nucleo electric plants

International Nuclear Information System (INIS)

Romero C, J.; Hernandez, R.; Fernandez, F.; Gonzalez M, A.

2007-01-01

This work describes the development of a welding system, for the rebuilding of halves of Charpy test tubes, the rebuilding consists on welding two implants in those ends of these halves of test tubes, in these welding the main requirement is not to alter the mechanical properties in a minimum volume of 1 cm 3 , the rebuilding is medullary in the surveillance programs of the reactor vessel. In these programs, the mechanical state of the vessel is evaluated, for it there are surveillance capsules with a Charpy witness test tubes series, subjected to a neutron flow similar or bigger to that of the vessel. The objective is to evaluate in advance on the vessel fragilization grade its life design. However the number of capsules with the witness test tubes it is only for the plant design life and at the moment the nucleo electric, negotiates an extension of life of these, until for 20 more years, of there the importance of this material witness's that stores the information of the damage accumulated by the neutron flow. This material requires to be taken advantage it after being rehearsed and the normative one settles down as obligatory to qualify the rebuilding process with all the requirements settled down in the ASTM Designation: E 1253-99 'Standard Guide for Reconstitution of irradiated Charpy-Sized Specimens', to obtain other reconstituted Charpy test tubes that are again introduced in the reactor. When being reconstituted the halves of the original test tubes it is obtained double reconstituted Charpy test tubes. Half of the test tubes they are used in the surveillance program of the vessel, with the surpluses test tubes, it can determine the fracture toughness, property of the material used in the extension methodology of life of vessel. (Author)

Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI Series 5

International Nuclear Information System (INIS)

Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O.; Menke, B.H.

1992-10-01

The Fifth Irradiation Series in the Heavy-Section Steel Irradiation Program obtained a statistically significant fracture toughness data base on two high-copper (0.23 and 0.31 wt %) submerged-arc welds to determine the shift and shape of the K Ic curve as a consequence of irradiation. Compact specimens with thicknesses to 101.6 mm (4 in) in the irradiated condition and 203.2 mm (8 in) in the unirradiated condition were tested, in addition to Charpy impact, tensile, and drop-weight specimens. Irradiations were conducted at a nominal temperature of 288 degree C and an average fluence of 1.5 x 10 19 neutrons/cm 2 (>l MeV). The Charpy 41-J temperature shifts are about the same as the corresponding drop-weight NDT temperature shifts. The irradiated welds exhibited substantial numbers of cleavage pop-ins. Mean curve fits using two-parameter (with fixed intercept) nonlinear and linearized exponential regression analysis revealed that the fracture toughness 100 MPa lg-bullet √m shifts exceeded the Charpy 41-J shifts for both welds. Analyses of curve shape changes indicated decreases in the slopes of the fracture toughness curves, especially for the higher copper weld. Weibull analyses were performed to investigate development of lower bound curves to the data, including the use of a variable K min parameter which affects the curve shape

Temper embrittlement, irradiation induced phosphorus segregation and implications for post-irradiation annealing of reactor pressure vessels

International Nuclear Information System (INIS)

McElroy, R.J.; English, C.A.; Foreman, A.J.; Gage, G.; Hyde, J.M.; Ray, P.H.N.; Vatter, I.A.

1999-01-01

Three steels designated JPB, JPC and JPG from the IAEA Phase 3 Programme containing two copper and phosphorus levels were pre- and post-irradiation Charpy and hardness tested in the as-received (AR), 1200 C/0.5h heat treated (HT) and heat treated and 450 C/2000h aged (HTA) conditions. The HT condition was designed to simulate coarse grained heat-affected zones (HAZ's) and showed a marked sensitivity to thermal ageing in all three alloys. Embrittlement after thermal ageing was greater in the higher phosphorus alloys JPB and JPG. Charpy shifts due to thermal ageing of between 118 and 209 C were observed and accompanied by pronounced intergranular fracture, due to phosphorus segregation. The irradiation embrittlement response was complex. The low copper alloys, JPC and JPB, in the HT and HTA condition exhibited significant irradiation induced Charpy shift but very low or even negative hardness changes indicating non-hardening embrittlement. The higher copper alloy, JPG, also exhibited irradiation hardening in line with its copper content. Fractographic and microchemical studies indicated irradiation induced phosphorus segregation and a transition from cleavage to intergranular failure at grain boundary phosphorus concentrations above a critical level. The enhanced grain boundary phosphorus level increased with dose in agreement with a kinetic segregation model developed at Harwell. The relevance of the thermal ageing studies to RPV Annealing for Plant-Life Extension was identified early in the program. It is of concern that annealing of RPV's has been performed, or is proposed, at temperatures in the range 425--475 C for periods of about 1 week (168h). Much attention has been given to the use of in-situ hardness measurements and machining miniature Charpy and tensile specimens from belt-line plate and weld materials. However, HAZ's, often containing higher phosphorus levels than the present materials, have largely been ignored. A post-irradiation annealing (PIA

Instrumentation of a Charpy-pendulum. Additional data obtained from it and its application to nuclear reactor pressure vessels surveillance programs; Instrumentacion de un pendulo Charpy. Datos adicionales obtenidos a partir de la misma y su aplicacion a programas de vigilancia de centrales nucleares

Energy Technology Data Exchange (ETDEWEB)

Chomik, Enrique P; Dhers, Horacio; Iorio, Antonio F [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Materiales; Ciriani, Dario F [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Combustibles Nucleares

1999-07-01

Charpy test gives information about a material dynamic fracture behavior. In a plain Charpy test, this information is the absorbed energy during fracture of the specimen, lateral deformation and the percentage of ductile fracture of the specimen. These parameters can then be used for the determination of the material response to a dynamic applied load, and are used at present to determine the brittle-ductile transition temperature of a material. However, there is a lot of additional information that can be obtained from a Charpy test, which is vital for the case of surveillance programs of nuclear power plants, where it is necessary to get the most available information from the specimens to be tested, because each one of them was irradiated for many years under temperature and neutronic flux conditions similar to that of the internal surface of the reactor pressure vessel, which converts these specimens in unique and very expensive ones. This additional information can be obtained from the curve that determines the evolution of the applied force to the specimen throughout the time involved in its fracture. It was possible to instrument a Charpy pendulum at a fraction of the cost necessary to buy an instrumentation package like the ones available in the market, and since the instrumentation equipment obtained is easy to transport. It has the additional advantage that can be used to instrument any other pendulum replacing only the hammer of the pendulum with a instrumented one for that pendulum. (author)

Laser weld reconstitution of conventional Charpy and Miniaturized Notch Test (MNT) specimens

International Nuclear Information System (INIS)

Manahan, M.P.; Williams, J.; Martukanitz, R.P.

1993-01-01

As nuclear power plants approach end-of-license (EOL) and consideration is given to license renewal, there is an ever increasing need to expand the amount of data obtainable from the original surveillance specimens. A laser welding technique to reconstitute broken Charpy specimens is being developed to produce both conventional and miniaturized Charpy specimens. This paper reports on early laser welding development efforts and summarizes previous proof-of-principle experiments on a 1/16 scale miniaturized Charpy test. In order to benchmark the laser welding procedure, the laser-reconstituted specimen data have been compared with the original specimen data. In addition, the microstructure after welding has been examined to ensure that the material in the vicinity of the notch is essentially unchanged after the welding process. Data which characterize the thermal transient during welding are obtained by attaching thermocouples to the specimens. Other important considerations include perturbation of the stress field near the notch, dynamic stress waves, and contact of the weld region with the tup. Precise control of welding parameters has been demonstrated, heat-affected zones as small as 0.25 mm can be achieved, and sufficient penetration depth can be obtained to enable welding thick sections (1T or greater) to yield conventional Charpy specimens or fracture toughness specimens and thin sections (∼5 mm) to yield Miniaturized Notch Test (MNT) specimens

Relationships between Charpy impact shelf energies and upper shelf Ksub(IC) values for reactor pressure vessel steels

International Nuclear Information System (INIS)

Witt, F.J.

1983-01-01

Charpy shelf data and lower bound estimates of Ksub(IC) shelf data for the same steels and test temperatures are given. Included are some typical reactor pressure vessel steels as well as some less tough or degraded steels. The data were evaluated with shelf estimates of Ksub(IC) up to and exceeding 550 MPa√m. It is shown that the high shelf fracture toughness representative of tough reactor pressure vessel steels may be obtained from a knowledge of the Charpy shelf energies. The toughness transition may be obtained either by testing small fracture toughness specimens or by Charpy energy indexing. (U.K.)

Prediction of the brittle fracture toughness value of a RPV steel from the analysis of a limited set of Charpy results

International Nuclear Information System (INIS)

Forget, P.; Marini, B.; Verdiere, N.

2001-01-01

Our objective is to establish a method to be able to determine fracture toughness of a reactor pressure vessel (RPV) by using the small number of Charpy specimens used in the reactor surveillance program. Previous studies have shown that it is possible to determine fracture toughness from Charpy tests. Another point is to determine if statistical effects are compatible with a restricted number of specimens, this paper deals with this point and presents a methodology that is applicable to the case of irradiated materials from the surveillance program. Several conclusions can be drawn from this study: -) When determining failure parameters, we gain most accuracy by increasing the number of samples from 3 to about 6; -) it is possible to evaluate brittle fracture toughness using local approach, either by using Beremin or Renevey model; -) The effect of using a small number of Charpy specimens to determine fracture toughness in brittle fracture is evaluated. The error in the evaluation of fracture toughness is much smaller than the experimental dispersion itself. (A.C.)

Instrumentation of a Charpy-pendulum. Additional data obtained from it and its application to nuclear reactor pressure vessels surveillance programs

International Nuclear Information System (INIS)

Chomik, Enrique P.; Dhers, Horacio; Iorio, Antonio F.; Ciriani, Dario F.

1999-01-01

Charpy test gives information about a material dynamic fracture behavior. In a plain Charpy test, this information is the absorbed energy during fracture of the specimen, lateral deformation and the percentage of ductile fracture of the specimen. These parameters can then be used for the determination of the material response to a dynamic applied load, and are used at present to determine the brittle-ductile transition temperature of a material. However, there is a lot of additional information that can be obtained from a Charpy test, which is vital for the case of surveillance programs of nuclear power plants, where it is necessary to get the most available information from the specimens to be tested, because each one of them was irradiated for many years under temperature and neutronic flux conditions similar to that of the internal surface of the reactor pressure vessel, which converts these specimens in unique and very expensive ones. This additional information can be obtained from the curve that determines the evolution of the applied force to the specimen throughout the time involved in its fracture. It was possible to instrument a Charpy pendulum at a fraction of the cost necessary to buy an instrumentation package like the ones available in the market, and since the instrumentation equipment obtained is easy to transport. It has the additional advantage that can be used to instrument any other pendulum replacing only the hammer of the pendulum with a instrumented one for that pendulum. (author)

Comparative study on Charpy specimen reconstitution techniques

International Nuclear Information System (INIS)

Bourdiliau, B.; Decroix, G.-M.; Averty, X.; Wident, P.; Bienvenu, Y.

2011-01-01

Highlights: → Welding processes are used to reconstitute previously tested Charpy specimens. → Stud welding is preferred for a quick installation, almost immediately operational. → Friction welding produces better quality welds, but requires a development effort. - Abstract: Reconstitution techniques are often used to allow material from previously fractured Charpy-V specimens to be reused for additional experiments. This paper presents a comparative experimental study of various reconstitution techniques and evaluates the feasibility of these methods for future use in shielded cells. The following techniques were investigated: arc stud welding, 6.0 kW CO 2 continuous wave laser welding, 4.5 kW YAG continuous wave laser welding and friction welding. Subsize Charpy specimens were reconstituted using a 400 W YAG pulsed wave laser. The best result was obtained with arc stud welding; the resilience of the reconstituted specimens and the load-displacement curves agreed well with the reference specimens, and the temperature elevation caused by the welding process was limited to the vicinity of the weld. Good results were also obtained with friction welding; this process led to the best quality welds. Laser welding seems to have affected the central part of the specimens, thus leading to different resilience values and load-displacement curves.

Charpy impact test results of ferritic alloys from the HFIR[High Flux Isotope Reactor]-MFE-RB2 test

International Nuclear Information System (INIS)

Hu, W.L.; Gelles, D.S.

1987-03-01

Miniature Charpy specimens of HT-9 in base metal, weld metal and heat affected zone (HAZ) metal conditions, and 9Cr-1Mo in base metal and weld metal conditions have been tested following irradiation in HFIR-MFE-RB2 at 55 0 C to ≅10 dpa. All specimen conditions have degraded properties (both DBTT and USE) in comparison with specimens irradiated to lower dose. 9Cr-Mo degraded more than HT-9 and weld metal performed worse than base metal which performed worse than HAZ material. Property degradation was approximately linear as a function of dose, indicating that degradation response had not saturated by 10 dpa

Irradiation, Annealing, and Reirradiation Effects on American and Russian Reactor Pressure Vessel Steels

International Nuclear Information System (INIS)

Chernobaeva, A.A.; Korolev, Y.N.; Nanstad, R.K.; Nikolaev, Y.A.; Sokolov, M.A.

1998-01-01

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. Even though a postirradiation anneal may be deemed successful, a critical aspect of continued RPV operation is the rate of embrittlement upon reirradiation. There are insufficient data available to allow for verification of available models of reirradiation embrittlement or for the development of a reliable predictive methodology. This is especially true in the case of fracture toughness data. Under the U.S.-Russia Joint Coordinating Committee for Civilian Nuclear Reactor Safety (JCCCNRS), Working Group 3 on Radiation Embrittlement, Structural Integrity, and Life Extension of Reactor Vessels and Supports agreed to conduct a comparative study of annealing and reirradiation effects on RPV steels. The Working Group agreed that each side would irradiate, anneal, reirradiate (if feasible ), and test two materials of the other. Charpy V-notch (CVN) and tensile specimens were included. Oak Ridge National Laboratory (ORNL) conducted such a program (irradiation and annealing, including static fracture toughness) with two weld metals representative of VVER-440 and VVER-1000 RPVs, while the Russian Research Center-Kurchatov Institute (RRC-KI) conducted a program (irradiation, annealing, reirradiation, and reannealing) with Heavy-Section Steel Technology (HSST) Program Plate 02 and Heavy-Section Steel Irradiation (HSSI) Program Weld 73W. The results for each material from each laboratory are compared with those from the other laboratory. The ORNL experiments with the VVER welds included irradiation to about 1 x 10 19 n/cm 2 (>1 MeV), while the RRC-KI experiments with the U.S. materials included irradiations from about 2 to 18 x 10 19 n/cm 2 (>l MeV). In both cases, irradiations were conducted at ∼290 C and annealing treatments were conducted at ∼454 C. The ORNL and RRC

Microstructural characterization of Charpy-impact-tested nanostructured bainite

Energy Technology Data Exchange (ETDEWEB)

Tsai, Y.T.; Chang, H.T.; Huang, B.M. [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC (China); Huang, C.Y. [Iron and Steel R& D Department, China Steel Corporation, Kaohsiung, Taiwan, ROC (China); Yang, J.R., E-mail: jryang@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC (China)

2015-09-15

In this work, a possible cause of the extraordinary low impact toughness of nanostructured bainite has been investigated. The microstructure of nanostructured bainite consisted chiefly of carbide-free bainitic ferrite with retained austenite films. X-ray diffractometry (XRD) measurement indicated that no retained austenite existed in the fractured surface of the Charpy-impact-tested specimens. Fractographs showed that cracks propagated mainly along bainitic ferrite platelet boundaries. The change in microstructure after impact loading was verified by transmission electron microscopy (TEM) observations, confirming that retained austenite was completely transformed to strain-induced martensite during the Charpy impact test. However, the zone affected by strained-induced martensite was found to be extremely shallow, only to a depth of several micrometers from the fracture surface. It is appropriately concluded that upon impact, as the crack forms and propagates, strain-induced martensitic transformation immediately occurs ahead of the advancing crack tip. The successive martensitic transformation profoundly facilitates the crack propagation, resulting in the extremely low impact toughness of nanostructured bainite. Retained austenite, in contrast to its well-known beneficial role, has a deteriorating effect on toughness during the course of Charpy impact. - Highlights: • The microstructure of nanostructured bainite consisted of nano-sized bainitic ferrite subunits with retained austenite films. • Special sample preparations for SEM, XRD and TEM were made, and the strain-affected structures have been explored. • Retained austenite films were found to transform into martensite after impact loading, as evidenced by XRD and TEM results. • The zone of strain-induced martensite was found to extend to only several micrometers from the fracture surface. • The poor Charpy impact toughness is associated with the fracture of martensite at a high strain rate during

Irradiation damage behavior of low alloy steel wrought and weld materials

International Nuclear Information System (INIS)

Stofanak, R.J.; Poskie, T.J.; Li, Y.Y.; Wire, G.L.

1993-01-01

A study was undertaken to evaluate the irradiation damage response of several different types of low alloy steel: vintage type ASTM A302 Grade B (A302B) plates and welds containing different Ni and Cu concentrations, 3.5% Ni steels similar to ASTM A508 Class 4, welds containing about 1% Ni (similar to type 105S), and 3.5% Ni steels with ''superclean'' composition. All materials were irradiated at several different irradiation damage levels ranging from 0.0003 to 0.06 dpa at 232C (450F). Complete Charpy V-notch impact energy transition temperature curves were generated for all materials before and after irradiation to determine transition temperature at 4IJ (30 ft-lb) or 47J (35 ft-lb) and the upper shelf energy. Irradiation damage behavior was measured by shift in Charpy 41J or 47J transition temperature (ΔTT4 41J or ΔTT 47J ) and lowering of upper shelf Charpy energy at a given irradiation damage level. It was found that chemical composition greatly influenced irradiation damage behavior; highest irradiation damage (greatest ΔTT) was found in an A302B type weld containing 1.28% Ni and 0.20% Cu while the least damage was found in 3.5% Ni, 0.05% Cu, superclean wrought materials. Combination of Ni and Cu was found to affect irradiation damage behavior at higher irradiation damage levels in the A302B welds where the 1.28% Ni, 0.20% Cu weld showed more damage than a 0.60% Ni, 0.31% Cu weld. For the 3.5% Ni steels, fabrication influenced irradiation behavior in that a silicon (Si) killed material showed greater irradiation damage than a low silicon material. In general, the 3.5% Ni materials with low copper showed less irradiation damage than the A302B materials

Validation Study of Unnotched Charpy and Taylor-Anvil Impact Experiments using Kayenta

Energy Technology Data Exchange (ETDEWEB)

Kamojjala, Krishna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lacy, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chu, Henry S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Brannon, Rebecca [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-03-01

Validation of a single computational model with multiple available strain-to-failure fracture theories is presented through experimental tests and numerical simulations of the standardized unnotched Charpy and Taylor-anvil impact tests, both run using the same material model (Kayenta). Unnotched Charpy tests are performed on rolled homogeneous armor steel. The fracture patterns using Kayenta’s various failure options that include aleatory uncertainty and scale effects are compared against the experiments. Other quantities of interest include the average value of the absorbed energy and bend angle of the specimen. Taylor-anvil impact tests are performed on Ti6Al4V titanium alloy. The impact speeds of the specimen are 321 m/s and 393 m/s. The goal of the numerical work is to reproduce the damage patterns observed in the laboratory. For the numerical study, the Johnson-Cook failure model is used as the ductile fracture criterion, and aleatory uncertainty is applied to rate-dependence parameters to explore its effect on the fracture patterns.

Recent advances on Charpy specimen reconstitution techniques

Energy Technology Data Exchange (ETDEWEB)

Andrade, Arnaldo H.P.; Lobo, Raquel M.; Miranda, Carlos Alexandre J., E-mail: aandrade@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-07-01

Charpy specimen reconstitution is widely used around the world as a tool to enhance or supplement surveillance programs of nuclear reactor pressure vessels. The reconstitution technique consists in the incorporation of a small piece from a previously tested specimen into a compound specimen, allowing to increase the number of tests. This is especially important if the available materials is restricted and fracture mechanics parameter have to be determined. The reconstitution technique must fulfill some demands, among them tests results like the original standard specimens and the loaded material of the insert must not be influenced by the welding and machining procedure. It is known that reconstitution of Charpy specimens may affect the impact energy in a consequence of the constraint of plastic deformation by the hardened weldment and HAZ. This paper reviews some recent advances of the reconstitution technique and its applications. (author)

Recent advances on Charpy specimen reconstitution techniques

International Nuclear Information System (INIS)

Andrade, Arnaldo H.P.; Lobo, Raquel M.; Miranda, Carlos Alexandre J.

2017-01-01

Charpy specimen reconstitution is widely used around the world as a tool to enhance or supplement surveillance programs of nuclear reactor pressure vessels. The reconstitution technique consists in the incorporation of a small piece from a previously tested specimen into a compound specimen, allowing to increase the number of tests. This is especially important if the available materials is restricted and fracture mechanics parameter have to be determined. The reconstitution technique must fulfill some demands, among them tests results like the original standard specimens and the loaded material of the insert must not be influenced by the welding and machining procedure. It is known that reconstitution of Charpy specimens may affect the impact energy in a consequence of the constraint of plastic deformation by the hardened weldment and HAZ. This paper reviews some recent advances of the reconstitution technique and its applications. (author)

Miniaturized Charpy test for reactor pressure vessel embrittlement characterization

Energy Technology Data Exchange (ETDEWEB)

Manahan, M.P. Sr. [MPM Research and Consulting, Lemont, PA (United States)

1999-10-01

Modifications were made to a conventional Charpy machine to accommodate the miniaturized Charpy V-Notch (MCVN) specimens which were fabricated from an archived reactor pressure vessel (RPV) steel. Over 100 dynamic MCVN tests were performed and compared to the results from conventional Charpy V-Notch (CVN) tests to demonstrate the efficacy of the miniature specimen test. The optimized sidegrooved MCVN specimens exhibit transitional fracture behavior over essentially the same temperature range as the CVN specimens which indicates that the stress fields in the MCVN specimens reasonably simulate those of the CVN specimens and this fact has been observed in finite element calculations. This result demonstrates a significant breakthrough since it is now possible to measure the ductile-brittle transition temperature (DBTT) using miniature specimens with only small correction factors, and for some materials as in the present study, without the need for any correction factor at all. This development simplifies data interpretation and will facilitate future regulatory acceptance. The non-sidegrooved specimens yield energy-temperature data which is significantly shifted downward in temperature (non-conservative) as a result of the loss of constraint which accompanies size reduction.

Comparative study for the estimation of To shift due to irradiation embrittlement

International Nuclear Information System (INIS)

Lee, Jin Ho; Park, Youn won; Choi, Young Hwan; Kim, Seok Hun; Revka, Volodymyr

2002-01-01

Recently, an approach called the 'Master Curve' method was proposed which has opened a new means to acquire a directly measured material-specific fracture toughness curve. For the entire application of the Master Curve method, several technical issues should be solved. One of them is to utilize existing Charpy impact test data in the evaluation of a fracture transition temperature shift due to irradiation damage. In the U.S. and most Western countries, the Charpy impact test data have been used to estimate the irradiation effects on fracture toughness changes of RPV materials. For the determination of the irradiation shift the indexing energy level of 41 joule is used irrespective of the material yield strength. The Russian Code also requires the Charpy impact test data to determine the extent of radiation embrittlement. Unlike the U.S. Code, however, the Russian approach uses the indexing energy level varying according to the material strength. The objective of this study is to determine a method by which the reference transition temperature shift (ΔT o ) due to irradiation can be estimated. By comparing the irradiation shift estimated according to the U.S. procedure (ΔT 41J ) with that estimated according to the Russian procedure (ΔT F ), it was found that one-to-one relation exists between ΔT o and ΔT F

Computer aided instrumented Charpy test applied dynamic fracture toughness evaluation system

International Nuclear Information System (INIS)

Kobayashi, Toshiro; Niinomi, Mitsuo

1986-01-01

Micro computer aided data treatment system and personal computer aided data analysis system were applied to the traditional instrumented Charpy impact test system. The analysis of Charpy absorbed energy (E i , E p , E t ) and load (P y , P m ), and the evaluation of dynamic toughness through whole fracture process, i.e. J Id , J R curve and T mat was examined using newly developed computer aided instrumented Charpy impact test system. E i , E p , E t , P y and P m were effectively analyzed using moving average method and printed out automatically by micro computer aided data treatment system. J Id , J R curve and T mat could be measured by stop block test method. Then, J Id , J R curve and T mat were effectively estimated using compliance changing rate method and key curve method on the load-load point displacement curve of single fatigue cracked specimen by personal computer aided data analysis system. (author)

Empirical correlation between mechanical and physical parameters of irradiated pressure vessel steels

International Nuclear Information System (INIS)

Tipping, P.; Solt, G.; Waeber, W.

1991-02-01

Neutron irradiation embrittlement of nuclear reactor pressure vessel (PV) steels is one of the best known ageing factors of nuclear power plants. If the safety limits set by the regulators for the PV steel are not satisfied any more, and other measures are too expensive for the economics of the plant, this embrittlement could lead to the closure of the plant. Despite this, the fundamental mechanisms of neutron embrittlement are not yet fully understood, and usually only empirical mathematical models exist to asses neutron fluence effects on embrittlement, as given by the Charpy test for example. In this report, results of a systematic study of a French forging (1.2 MD 07 B), irradiated to several fluences will be reported. Mechanical property measurements (Charpy tensile and Vickers microhardness), and physical property measurements (small angle neutron scattering - SANS), have been done on specimens having the same irradiation or irradiation-annealing-reirradiation treatment histories. Empirical correlations have been established between the temperature shift and the decrease in the upper shelf energy as measured on Charpy specimens and tensile stresses and hardness increases on the one hand, and the size of the copper-rich precipitates formed by the irradiation on the other hand. The effect of copper (as an impurity element) in enhancing the degradation of mechanical properties has been demonstrated; the SANS measurements have shown that the size and amount of precipitates are important. The correlations represent the first step in an effort to develop a description of neutron irradiation induced embrittlement which is based on physical models. (author) 6 figs., 27 refs

Computer simulation of the Charpy V-notch toughness test

International Nuclear Information System (INIS)

Norris, D.M. Jr.

1977-01-01

The dynamic Charpy V-notch test was simulated on a computer. The calculational models (for A-533 Grade B class 1 steel) used both a rounded and a flat-tipped striker. The notch stress/strain state was found to be independent of the three-point loading type and was most strongly correlated with notch-opening displacement. The dynamic stress/strain state at the time of fracture initiation was obtained by comparing the calculated deformed shape with that obtained in interrupted Charpy V-notch tests where cracking had started. The calculation was also compared with stress/strain states calculated in other geometries at failure. The distribution and partition of specimen energy was calculated and adiabatic heating and strain rate are discussed

The modelling of irradiation embrittlement in submerged-arc welds

International Nuclear Information System (INIS)

Bolton, C.J.; Buswell, J.T.; Jones, R.B.; Moskovic, R.; Priest, R.H.

1996-01-01

Until very recently, the irradiation embrittlement behavior of submerged-arc welds has been interpreted in terms of two mechanisms, namely a matrix damage component and an additional component due to the irradiation-enhanced production of copper-rich precipitates. However, some of the weld specimens from a recent accelerated re-irradiation experiment have shown high Charpy shifts which exceeded the values expected from the measured shift in yield stress. Microstructural examination has revealed the occurrence of intergranular fracture (IGF) in these specimens, accompanied by grain boundary segregation of phosphorus. Theoretical models were developed to predict the parametric dependence of irradiation-enhanced phosphorus segregation on experimental variables. Using these parametric forms, along with the concept of a critical level of segregation for the onset of IGF instead of cleavage, a three mechanism trend curve has been developed. The form of this trend curve, taking into account IGF as well as matrix and copper embrittlement, is thus mechanistically based. The constants in the equation, however, are obtained by a statistical fit to the actual Charpy shift database

Irradiation Effects at 160-240 deg C in Some Swedish Pressure Vessel Steels

Energy Technology Data Exchange (ETDEWEB)

Grounes, M [AB Atomenergi, Nykoeping (Sweden); Myers, H P [Chalmers Institute of Technology, Goeteborg (Sweden); Hannerz, N E [Motala Verkstads AB, Motala (Sweden)

1967-09-15

Tensile specimens, Charpy impact specimens and miniature impact specimens of six steels in different conditions were irradiated to 2.8 x 10{sup 18} and 5.6 x 10{sup 18} n/cm{sup 2} (> 1 MeV) at 160-240 deg C. The steels investigated were SIS 142103, 2103/R3, NO 345, Fortiweld, Fortiweld HS and OK 54 P. There is no correlation between the increase in transition temperature and initial transition temperature. However, changes in strength and ductility can be correlated to the initial yield strength. The increases in transition temperature due to strain aging and irradiation are approximately additive. The irradiation-induced changes in 2103/R3 and Fortiweld HS steels do not vary with position in the thickness of the plate. Different tempering treatments in Fortiweld HS steel do not change the extent of irradiation effects. Normal Charpy V-notch impact specimens and miniature specimens give the same irradiation-induced increase in transition temperature.

Irradiation Effects at 160-240 deg C in Some Swedish Pressure Vessel Steels

International Nuclear Information System (INIS)

Grounes, M.; Myers, H.P.; Hannerz, N.E.

1967-09-01

Tensile specimens, Charpy impact specimens and miniature impact specimens of six steels in different conditions were irradiated to 2.8 x 10 18 and 5.6 x 10 18 n/cm 2 (> 1 MeV) at 160-240 deg C. The steels investigated were SIS 142103, 2103/R3, NO 345, Fortiweld, Fortiweld HS and OK 54 P. There is no correlation between the increase in transition temperature and initial transition temperature. However, changes in strength and ductility can be correlated to the initial yield strength. The increases in transition temperature due to strain aging and irradiation are approximately additive. The irradiation-induced changes in 2103/R3 and Fortiweld HS steels do not vary with position in the thickness of the plate. Different tempering treatments in Fortiweld HS steel do not change the extent of irradiation effects. Normal Charpy V-notch impact specimens and miniature specimens give the same irradiation-induced increase in transition temperature

Material inertia and size effects in the Charpy V-notch test

DEFF Research Database (Denmark)

Desandre, D. A.; Benzerga, A. A.; Tvergaard, Viggo

2004-01-01

The effect of material inertia on the size dependence of the absorbed energy in the Charpy V-notch test is investigated. The material response is characterized by an elastic-viscoplastic constitutive relation for a porous plastic solid, with adiabatic heating due to plastic dissipation and the re......The effect of material inertia on the size dependence of the absorbed energy in the Charpy V-notch test is investigated. The material response is characterized by an elastic-viscoplastic constitutive relation for a porous plastic solid, with adiabatic heating due to plastic dissipation...

Influence of thermal conditioning media on Charpy specimen test temperature

International Nuclear Information System (INIS)

Nanstad, R.K.; Swain, R.L.; Berggren, R.G.

1989-01-01

The Charpy V-notch (CVN) impact test is used extensively for determining the toughness of structural materials. Research programs in many technologies concerned with structural integrity perform such testing to obtain Charpy energy vs temperature curves. American Society for Testing and Materials Method E 23 includes rather strict requirements regarding determination and control of specimen test temperature. It specifies minimum soaking times dependent on the use of liquids or gases as the medium for thermally conditioning the specimen. The method also requires that impact of the specimen occur within 5 s removal from the conditioning medium. It does not, however, provide guidance regarding choice of conditioning media. This investigation was primarily conducted to investigate the changes in specimen temperature which occur when water is used for thermal conditioning. A standard CVN impact specimen of low-alloy steel was instrumented with surface-mounted and embedded thermocouples. Dependent on the media used, the specimen was heated or cooled to selected temperatures in the range -100 to 100 degree C using cold nitrogen gas, heated air, acetone and dry ice, methanol and dry ice, heated oil, or heated water. After temperature stabilization, the specimen was removed from the conditioning medium while the temperatures were recorded four times per second from all thermocouples using a data acquisition system and a computer. The results show that evaporative cooling causes significant changes in the specimen temperatures when water is used for conditioning. Conditioning in the other media did not result in such significant changes. The results demonstrate that, even within the guidelines of E 23, significant test temperature changes can occur which may substantially affect the Charpy impact test results if water is used for temperature conditioning. 7 refs., 11 figs

Analysis of impact energy to fracture un-notched charpy specimens made from railroad tank car steel

Science.gov (United States)

2007-09-11

This paper describes a nonlinear finite element analysis : (FEA) framework that examines the impact energy to fracture : unnotched Charpy specimens by an oversized, nonstandard : pendulum impactor called the Bulk Fracture Charpy Machine : (BFCM). The...

Results of charpy V-notch impact testing of structural steel specimens irradiated at ∼30 degrees C to 1 x 1016 neutrons/cm2 in a commercial reactor cavity

International Nuclear Information System (INIS)

Iskander, S.K.; Stoller, R.E.

1997-04-01

A capsule containing Charpy V-notch (CVN) and mini-tensile specimens was irradiated at ∼ 30 degrees C (∼ 85 degrees F) in the cavity of a commercial nuclear power plant to a fluence of 1 x 10 16 neutrons/cm 2 (> 1MeV). The capsule included six CVN impact specimens of archival High Flux Isotope Reactor A212 grade B ferritic steel and five CVN impact specimens of a well-studied A36 structural steel. This irradiation was part of the ongoing study of neutron-induced damage effects at the low temperature and flux experienced by reactor supports. The plant operators shut down the plant before the planned exposure was reached. The exposure of these specimens produced no significant irradiation-induced embrittlement. Of interest were the data on unirradiated specimens in the L-T orientation machined from a single plate of A36 structural steel, which is the same specification for the structural steel used in some reactor supports. The average CVN energy of five unirradiated specimens obtained from one region of the plate and tested at room temperature was ∼ 99 J, while the energy of 11 unirradiated specimens from other locations of the same plate was 45 J, a difference of ∼ 220%. The CVN impact energies for all 18 specimens ranged from a low of 32 J to a high of 111 J. Moreover, it appears that the University of Kansas CVN impact energy data of the unirradiated specimens at the 100-J level are shifted toward higher temperatures by about 20 K. The results were an example of the extent of scatter possible in CVN impact testing. Generic values for the CVN impact energy of A36 should be used with caution in critical applications

Testing of irradiated and annealed 15H2MFA materials

International Nuclear Information System (INIS)

Gillemot, F.; Uri, G.

1994-01-01

A set of surveillance samples made from 15H2MFA material has been studied in the laboratory of AEKI. Miniature notched tensile specimens were cut from some remnants of irradiated and broke surveillance charpy remnants. The Absorbed Specific Fracture Energy (ASFE) was measured on the specimens. A cutting machine and testing technique were elaborated for the measurements. The second part of the Charpy remnants was annealed at 460 deg. C and 490 deg. C for 6-8 hours. The specimens were tested similarity and the results were compared. (author). 5 refs, 9 figs

Use of precracked Charpy and smaller specimens to establish the master curve

International Nuclear Information System (INIS)

Sokolov, M.A.; McCabe, D.E.; Nanstad, R.K.; Davidov, Y.A.

1997-01-01

The current provisions used in the U.S. Code of Federal Regulations for the determination of the fracture toughness of reactor pressure vessel steels employs an assumption that there is a direct correlation between K Ic lower-bound toughness and the Charpy V-notch transition curve. Such correlations are subject to scatter from both approaches which weakens the reliability of fracture mechanics-based analyses. In this study, precracked Charpy and smaller size specimens are used in three-point static bend testing to develop fracture mechanics based K k values. The testing is performed under carefully controlled conditions such that the values can be used to predict the fracture toughness performance of large specimens. The concept of a universal transition curve (master curve) is applied. Data scatter that is characteristic of commercial grade steels and their weldments is handled by Weibull statistical modeling. The master curve is developed to describe the median K Jc fracture toughness for 1T size compact specimens. Size effects are modeled using weakest-link theory and are studied for different specimen geometries. It is shown that precracked Charpy specimens when tested within their confined validity limits follow the weakest-link size-adjustment trend and predict the fracture toughness of larger specimens. Specimens of smaller than Charpy sizes (5 mm thick) exhibit some disparities in results relative to weakest-link size adjustment prediction suggesting that application of such adjustment to very small specimens may have some limitations

A reassessment of the effects of helium on Charpy impact properties of ferritic/martensitic steels

International Nuclear Information System (INIS)

Gelles, D.S.; Hamilton, M.L.; Hankin, G.L.

1998-01-01

To test the effect of helium on Charpy impact properties of ferritic/martensitic steels, two approaches are reviewed: quantification of results of tests performed on specimens irradiated in reactors with very different neutron spectra, and isotopic tailoring experiments. Data analysis can show that if the differences in reactor response are indeed due to helium effects, then irradiation in a fusion machine at 400 C to 100 dpa and 1000 appm He will result in a ductile to brittle transition temperature shift of over 500 C. However, the response as a function of dose and helium level is unlikely to be simply due to helium based on physical reasoning. Shear punch tests and microstructural examinations also support this conclusion based on irradiated samples of a series of alloys made by adding various isotopes of nickel in order to vary the production of helium during irradiation in HFIR. The addition of nickel at any isotopic balance to the Fe-12Cr base alloy significantly increased the shear yield and maximum strengths of the alloys. However, helium itself, up to 75 appm at over 7 dpa appears to have little effect on the mechanical properties of the alloys. This behavior is instead understood to result from complex precipitation response. The database for effects of helium on embrittlement based on nickel additions is therefore probably misleading and experiments should be redesigned to avoid nickel precipitation

Fracture toughness of A533B Part III - variability of A533B fracture toughness as determined from Charpy data

International Nuclear Information System (INIS)

Druce, S.G.; Eyre, B.L.

1978-08-01

This is the final part of a series of three reports examining the upper shelf fracture toughness of A533B Class 1 pressure vessel steel. Part I (AERE R 8968) critically reviews the current elasto plastic fracture mechanics methodologies employed to characterise toughness following extensive yielding and Part II (AERE R 8969) examines several sources of fracture mechanics data pertinent to A533B Class 1 in the longitudinal (RW) orientation. Part III is a review of the effects of (i) position and orientation within the plate (ii) welding processes and post weld heat treatment and (iii) neutron irradiation as measured by Charpy impact testing. It is concluded that the upper shelf factor energy is dependent on orientation and position and can be reduced by welding, extended post weld heat treatments and neutron irradiation. Neutron irradiation effects are known to be strongly dependent on composition and metallurgical conditions, but an explanation for the variability following extended post weld treatments has yet to be resolved. (author)

Irradiation, annealing, and reirradiation research in the ORNL heavy-section steel irradiation program

International Nuclear Information System (INIS)

Nanstad, R.K.; Iskander, S.K.; McCabe, D.E.; Sokolov, M.A.

1997-01-01

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPV) is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results from work performed as part of the Heavy-Section Steel Irradiation (HSSI) Program managed by Oak Ridge National Laboratory (ORNL) for the U.S. Nuclear Regulatory Commission. The HSSI Program focuses on annealing and re-embrittlement response of materials which are representative of those in commercial RPVs and which are considered to be radiation-sensitive. Experimental studies include (1) the annealing of materials in the existing inventory of previously irradiated materials, (2) reirradiation of previously irradiated/annealed materials in a collaborative program with the University of California, Santa Barbara (UCSB), (3) irradiation/annealing/reirradiation of U.S. and Russian materials in a cooperative program with the Russian Research Center-Kurchatov Institute (RRC-KI), (4) the design and fabrication of an irradiation/anneal/reirradiation capsule and facility for operation at the University of Michigan Ford Reactor, (5) the investigation of potential for irradiation-and/or thermal-induced temper embrittlement in heat-affected zones (HAZs) of RPV steels due to phosphorous segregation at grain boundaries, and (6) investigation of the relationship between Charpy impact toughness and fracture toughness under all conditions of irradiation, annealing, and reirradiation

Reduction of upper shelf energy of highly irradiated RPV steels

Energy Technology Data Exchange (ETDEWEB)

Otaka, M.; Osaki, T. [Japan Nuclear Energy Safety Organization (Japan)

2004-07-01

It is well known that as the embrittlement due to neutron irradiation of reactor pressure vessel (RPV) steels, there is the tendency of the decrease in Charpy absorbed energy at upper shelf region (USE), in addition to the shift of ductile-brittle transition temperature. Concerning to the regulation of the upper shelf region, no method is provided to evaluate integrity for RPV steels with USE of less than 68J in Japanese codes. Under the circumstance, the reduction tendency of USE using simulated Japanese RPV steels, irradiated by fast neutron up to 1 x 10{sup 24} n/m{sup 2}, E>1 MeV in the OECD Halden test reactor, was investigated to establish the basis of the USE prediction after 60 year plant operation for the integrity assessment of the RPVs. This paper describes the results of an atom probe tomography characterization of irradiated steels. A new form of USE prediction equation was developed based on the atom probe tomography characterization and the Charpy impact test results of the irradiated steels. And, the USE prediction equations have been determined through the regression analysis of the test reactor data combined with Japanese surveillance test data. (orig.)

Investigation of Ductile-to-Brittle Transition of RPV Materials by using the Pre-cracked Charpy Impact Data

International Nuclear Information System (INIS)

Lee, Ho Jin; Lee, Bong Sang; Hong, Jun Hwa

2005-01-01

Much recent work in the field of elastic-plastic fracture mechanics has been directed to developing a mechanics-based relationship between the onset of cleavage fracture in structural components and that of Charpy V-notch specimens. The assessing processes of the cracks located in the reactor pressure vessel (RPV) is described in the ASME code Sec. III, App. G and Sec. XI, App. A. The RTNDT obtained from the impact test using standard Charpy V-notch (CVN) specimens is used as a reference temperature to assess the integrity of RPV materials. The initial RTNDT, for the Linde 80 weld, was determined by the 67.8J Charpy impact energy instead of drop weight test. Generally, Linde 80 weld has low upper-shelf energy. The initial RTNDT obtained from the Charpy impact energy curve has been considered overly conservative. Recently, master curve method has been investigated to assess the integrity of RPV materials directly. The initial RTT0 obtained from the master curve method is considered more realistic than the initial RTNDT obtained from impact test for low upper-shelf fracture toughness RPV materials. In this research, the correlation of transition regions between the master curves and the Charpy impact energy curves was investigated using the dynamic fracture toughness curve and the impact energy curve obtained from the impact test of pre-cracked Charpy (PCC) specimens. For the low toughness RPV material the ductile-to-brittle transition corresponding to the static master curve was anticipated using the invested correlation

A new method for improving the reliability of fracture toughness surveillance of nuclear pressure vessel by neutron irradiated embrittlement

International Nuclear Information System (INIS)

Zhang Xinping; Shi Yaowu

1992-01-01

In order to obtain more information from neutron irradiated sample specimens and raise the reliability of fracture toughness surveillance test, it has more important significance to repeatedly exploit the broken Charpy-size specimen which had been tested in surveillance test. In this work, on the renewing design and utilization for Charpy-size specimens, 9 data of fracture toughness can be gained from one pre-cracked side-grooved Charpy-size specimen while at the preset usually only 1 to 3 data of fracture toughness can be obtained from one Chharpy-size specimen. Thus, it is found that the new method would obviously improve the reliability of fracture toughness surveillance test and evaluation. Some factors which affect the reasonable design of pre-cracked deep side-groove Charpy-size compound specimen have been discussed

Computer simulation of plastic deformation in the Charpy V-notch impact test

International Nuclear Information System (INIS)

Norris, D.M. Jr.; Quinones, D.F.; Moran, B.

1978-01-01

Calculations describe the dynamic stress and strain states in the standard Charpy specimen from impact to the start of cracking. We model A533 Grade B Class 1 nuclear-pressure-vessel steel at 100 0 C with an elastic-plastic constitutive law. Large deformation and rotation of the material are accounted for. The specimen velocity field during the impact transient is presented and how the early wave effects cause separation of the specimen from the striker is shown. The calculations show why correlations between Charpy fracture energy and fracture toughness have been largely unsuccessful and suggest methods to improve these correlations using the same specimen geometry

Prediction of fracture toughness K/sub Ic/ of steel from Charpy impact test results

Energy Technology Data Exchange (ETDEWEB)

Iwadate, Tadao; Tanaka, Yasuhiko; Takemata, Hiroyuki; Terashima, Shuhei

1986-08-01

This paper presents a method to predict the fracture toughness K/sub Ic/ and/or K/sub Id/ of steels using their Charpy impact test results and tensile properties. The fracture toughness, Charpy impact and tensile properties of 2 1/4 Cr-1Mo, ASTM A508 Cl.1, A508 Cl.2 A508 Cl.3 and A533 Gr.B Cl.1 steels were measured and analysed on the basis of the excess temperature (test temperature minus FATT) and Rolfe-Novak correlation. The relationship between K/sub Ic//K/sub Ic-us/ and the excess temperature, where K/sub Ic-us/ is the upper-shelf fracture toughness K/sub Ic/ predicted by Rolfe-Novak correlation, discloses that the K/sub Ic/ transition curves of several steels are representable by only one trend curve of K/sub Ic//K/sub Ic-us/ or K/sub Id//K/sub Id-us/ versus excess temperature relation. This curve is denoted as a ''master curve''. By using this curve, the fracture toughness of steel can be predicted using Charpy impact and tensile test results. By taking account of the scattering of both the fracture toughness and Charpy impact test results, the confidence limits of the master curve were also determined. Another approach to develop more general procedure of predicting the fracture toughness K/sub Ic/ is also discussed.

Charpy impact test results of ferritic alloys at a fluence of 6 x 1022n/cm2

International Nuclear Information System (INIS)

Hu, W.L.

1985-01-01

Charpy impact tests on specimens in the AD-2 reconstitution experiment were completed. One hundred ten specimens made of HT-9 base metal, 9Cr-1Mo base metal and 9Cr-1Mo weldment at various heat treatment conditions were tested in temperature range from -73 0 C to 260 0 C. The specimens were irradiated from 390 0 C to 550 0 C and the fluence of the specimens reached 6 x 10 22 n/cm 2 . This is the first time that the transition behavior of ferritic alloys at high fluence was obtained. This is also the first time that comprehensive results on the irradiated 9Cr-1Mo weldment are available. The test results show a small additional shift in transition temperature for HT-9 base metal irradiated at 390 0 C and 450 0 C as the fluence was raised to 6 x 10 22 n/cm 2 . At higher irradiation temperatures, however, the shift in transition temperature is less conclusive. Further reduction in USE was observed at higher fluence for all the irradiation temperatures. There is no apparent fluence effect for 9Cr-1Mo base metal at all the irradiation temperatures studied. Contrary to the previous finding on HT-9 base metal and weldment, the 9Cr-1Mo weldment shows a higher transition temperature ( + 60 0 C) and a higher USE ( + 100%) as compared to the 9Cr-1MO base metal for the same irradiation conditions. 6 references, 7 figures, 7 tables

Embrittlement of a 17Cr ferritic steel irradiated in Phenix

International Nuclear Information System (INIS)

Allegraud, G.; Boutard, J.L.; Boyer, J.M.

1987-01-01

Charpy V and tensile tests have been performed with samples made of 17Cr ferritic steel irradiated in Phenix at temperatures between 390 and 540C up to a maximum dose of 83.3 dpaF. All over the temperature and dose ranges, irradiation leads to an increase of the ductile brittle transition temperature (DBTT). The DBTT and hardening are decreasing functions of the irradiation temperature. Fast neutron flux at 390C hardens the material more than a sole thermal ageing does

Mechanical properties of 1950's vintage 304 stainless steel weldment components after low temperature neutron irradiation

International Nuclear Information System (INIS)

Sindelar, R.L.; Caskey, G.R. Jr.; Thomas, J.K.; Hawthorne, J.R.; Hiser, A.L.; Lott, R.A.; Begley, J.A.; Shogan, R.P.

1991-01-01

The reactor vessels of the nuclear production reactors at the Savannah River Site (SRS) were constructed in the 1950's from Type 304 stainless steel plates welded with Type 308 stainless steel filler using the multipass metal inert gas process. An irradiated mechanical properties database has been developed for the vessel with materials from archival primary coolant system piping irradiated at low temperatures (75 to 150 degrees C) in the State University of New York at Buffalo reactor (UBR) and the High Flux Isotope Reactor (HFIR) to doses of 0.065 to 2.1 dpa. Fracture toughness, tensile, and Charpy-V impact properties of the weldment components (base, weld, and weld heat-affected-zone (HAZ)) have been measured at temperatures of 25 degrees C and 125 degrees C in the L-C and C-L orientations for materials in both the irradiated and unirradiated conditions for companion specimens. Fracture toughness and tensile properties of specimens cut from an SRS reactor vessel sidewall with doses of 0.1 and 0.5 dpa were also measured at temperatures of 25 and 125 degrees C. The irradiated materials exhibit hardening with loss of work hardenability and a reduction in toughness relative to the unirradiated materials. The HFIR-irradiated materials show an increase in yield strength between about 20% and 190% with a concomitant tensile strength increase between about 15% to 30%. The elastic-plastic fracture toughness parameters and Charpy-V energy absorption both decrease and show only a slight sensitivity to dose. The irradiation-induced decrease in the elastic-plastic fracture toughness (J def at 1 mm crack extension) is between 20% to 65%; the range of J 1C values are 72.8 to 366 kJ/m 2 for the irradiated materials. Similarly, Charpy V-notch results show a 40% to 60% decrease in impact energies

The interpretation of Charpy impact test data using hyper-logistic fitting functions

International Nuclear Information System (INIS)

Helm, J.L.

1996-01-01

The hyperbolic tangent function is used almost exclusively for computer assisted curve fitting of Charpy impact test data. Unfortunately, there is no physical basis to justify the use of this function and it cannot be generalized to test data that exhibits asymmetry. Using simple physical arguments, a semi-empirical model is derived and identified as a special case of the so called hyper-logistic equation. Although one solution of this equation is the hyperbolic tangent, other more physically interpretable solutions are provided. From the mathematics of the family of functions derived from the hyper-logistic equation, several useful generalizations are made such that asymmetric and wavy Charpy data can be physically interpreted

Effects of irradiation on strength and toughness of commercial LWR vessel cladding

International Nuclear Information System (INIS)

Haggag, F.M.; Corwin, W.R.; Alexander, D.J.; Nanstad, R.K.

1987-01-01

The potential for stainless steel cladding to improve the fracture behavior of an operating nuclear reactor pressure vessel, particularly during certain overcooling transients, may depend greatly on the properties of the irradiated cladding. Therefore, weld overlay cladding irradiated at temperatures and to fluences relevant to power reactor operation was examined. The cladding was applied to a pressure vessel steel plate by the three-wire series-arc commercial method. Cladding was applied in three layers to provide adequate thickness for the fabrication of test specimens. The three-wire series-arc procedure, developed by Combustion Engineering, Inc., Chattanooga, Tennessee, produced a highly controlled weld chemistry, microstructure, and fracture properties in all three layers of the weld. Charpy V-notch and tensile specimens were irradiated at 288 0 C to fluence levels of 2 and 5 x 10 19 neutrons/cm 2 (>1 MeV). Postirradiation testing results show that, in the test temperature range from -125 to 288 0 C, the yield strength increased by 8 to 30%, ductility insignificantly increased, while there was almost no change in ultimate tensile strength. All cladding exhibited ductile-to-brittle transition behavior during Charpy impact testing, due to the dominance of delta-ferrite failures at low temperatures. On the upper shelf, energy was reduced, due to irradiation exposure, 15 and 20%, while the lateral expansion was reduced 43 and 41%, at 2 and 5 x 10 19 neutrons/cm 2 (>1 MeV), respectively. In addition, radiation damage resulted in 13 and 28 0 C shifts of the Charpy impact transition temperature at the 41-J level for the low and high fluences, respectively

Evaluation of ductile-brittle transition behavior with neutron irradiation in nuclear reactor pressure vessel steels using small punch test

International Nuclear Information System (INIS)

Kim, M. C.; Lee, B. S.; Oh, Y. J.

2003-01-01

A Small Punch (SP) test was performed to evaluate the ductile-brittle transition temperature before and after neutron irradiation in Reactor Pressure Vessel (RPV) steels produced by different manufacturing (refining) processes. The results were compared to the standard transition temperature shifts from the Charpy test and Master Curve fracture toughness test in accordance with the ASTM standard E1921. The samples were taken from 1/4t location of the vessel thickness and machined into a 10x10x0.5mm dimension. Irradiation of the samples was carried out in the research reactor at KAERI (HANARO) at about 290 .deg. C of the different fluence levels respectively. SP tests were performed in the temperature range of RT to -196 .deg. C using a 2.4mm diameter ball. For the materials before and after irradiation, SP transition temperatures (T sp ), which are determined at the middle of the upper and lower SP energies, showed a linear correlation with the Charpy index temperature, T 41J . T sp from the irradiated samples was increased as the fluence level increased and was well within the deviation range of the unirradiated data. The TSP had a correlation with the reference temperature (T 0 ) from the master curve method using a pre-cracked Charpy V-notched (PCVN) specimen

Significance of Charpy and COD tests in the determination of fracture toughness of welds

International Nuclear Information System (INIS)

Caminha Junior, H.M.; Bastian, F.L.

1983-01-01

A comparison is made between the Charpy and crack opening displacement (COD) tests used to acess the fracture toughness of metallic materials. The main problems inherent in these tests are discussed, such as scatter of results and their advantages and limitations. The chief experimental difficulties when they are applied to welds are indicated and the various methods available for calculating the COD from a test graph are described. Comments are made on the use of the Charpy test and the methods of calculating the COD in determing critical defect sizes in welded structures. (Author) [pt

Modeling and simulation of Charpy impact test of maraging steel 300 using Abaqus

Science.gov (United States)

Madhusudhan, D.; Chand, Suresh; Ganesh, S.; Saibhargavi, U.

2018-03-01

This work emphasizes the modeling and simulation of Charpy impact test to evaluate fracture energy at different pendulum velocities of armor maraging steel 300 using ABAQUS. To evaluate the fracture energy, V-notch specimen is fractured using the Johnson and Cook Damage model. The Charpy impact tests are of great importance related to fracture properties of steels. The objective of this work is to present absorbed energy variation at pendulum velocities of 5 m/sec, 6 m/sec, 7 m/sec and 9 m/sec in addition to stress distribution at v-notch. Finite Element Method of modeling for three dimensional specimens is used for simulation in commercial software of ABAQUS.

The flow effect in the irradiation embrittlement in pressure vessel steels of nuclear power plants

International Nuclear Information System (INIS)

Kempf, Rodolfo A.; Cativa Tolosa, Sebastian; Fortis, Ana M.

2009-01-01

This paper deals with the advances in the study of the mechanical behavior of the Reactor Pressure Vessel steels under accelerate irradiations. The objective is to study the effect of lead factors on the interpretation of the mechanisms that induced the embrittlement of the RPV, like those of the reactors Atucha II and CAREM. It is described a device designed to irradiate Charpy specimens with V notch of SA-508 type 3 steel at power reactor temperature, installed in the RA-1 reactor. It is presented also an automatic digital image processing technique for partitioning Charpy fracture surface into regions with a clear physical meaning and appropriate for the work in hot cells. The aim is to obtain the fracture behavior of irradiated specimens with different lead factors in the range of high fluencies and to know the dependence with the composition of the alloy and with the diffusion of other alloy elements. (author)

Weld investigations by 3D analyses of Charpy V-notch specimens

DEFF Research Database (Denmark)

Tvergaard, Viggo; Needleman, Allan

2005-01-01

The Charpy impact test is a standard procedure for determining the ductile-brittle transition in welds. The predictions of such tests have been investigated by full three dimensional transient analyses of Charpy V-notch specimens. The material response is characterised by an elastic...... parameters in the weld material differ from those in the base material, and the heat a®ected zone (HAZ) tends to be more brittle than the other material regions. The effect of weld strength undermatch or overmatch is an important issue. Some specimens, for which the notched surface is rotated relative...... to the surface of the test piece, have so complex geometry that only a full 3D analysis is able to account for the interaction of failure in the three different material regions, whereas ther specimens can be approximated in terms of a planar analysis....

Applicability of the fracture toughness master curve to irradiated reactor pressure vessel steels

International Nuclear Information System (INIS)

Sokolov, M.A.; McCabe, D.E.; Alexander, D.J.; Nanstad, R.K.

1997-01-01

-thick (25-mm)] specimen. Thus, fracture toughness of the material can be described by a fracture toughness-based reference temperature rather that by a temperature derived from a combination of drop-weight and Charpy impact tests. A statistical size correction based upon weakest-link theory is used to adjust the measured fracture toughness to that expected from a 1T specimen. Although the details of a consensus procedure is still under development, the basic procedure is widely used now to characterize elastic-plastic K Jc values in the transition range. For application to commercial nuclear RPVs, however, various uncertainties are being investigated as part of the Heavy-Section Steel Irradiation (HSSI) Program managed by the Oak Ridge National laboratory (ORNL) for the U.S. Nuclear Regulatory Commission. These include the use of relatively small specimens, e.g., precracked CVN (PCVN) and smaller size specimens, the applicability of the master curve to highly irradiated steels, and the effects of intergranular fracture. (author)

Experimental study on variations in Charpy impact energies of low carbon steel, depending on welding and specimen cutting method

Energy Technology Data Exchange (ETDEWEB)

Yang, Zhaorui; Kang, Hansaem; Lee, Young Seog [Chung-Ang University, Seoul (Korea, Republic of)

2016-05-15

This paper presents an experimental study that examines variations of Charpy impact energy of a welded steel plate, depending upon the welding method and the method for obtaining the Charpy specimens. Flux cored arc welding (FCAW) and Gas tungsten arc welding (GTAW) were employed to weld an SA516 Gr. 70 steel plate. The methods of wire cutting and water-jet cutting were adopted to take samples from the welded plate. The samples were machined according to the recommendations of ASTM SEC. II SA370, in order to fit the specimen dimension that the Charpy impact test requires. An X-ray diffraction (XRD) method was used to measure the as-weld residual stress and its redistribution after the samples were cut. The Charpy impact energy of specimens was considerably dependent on the cutting methods and locations in the welded plate where the specimens were taken. The specimens that were cut by water jet followed by FCAW have the greatest resistance-to-fracture (Charpy impact energy). Regardless of which welding method was used, redistributed transverse residual stress becomes compressive when the specimens are prepared using water-jet cutting. Meanwhile, redistributed transverse residual stress becomes tensile when the specimens are prepared using wire cutting.

Current understanding of the effects of enviromental and irradiation variables on RPV embrittlement

International Nuclear Information System (INIS)

Odette, G.R.; Lucas, G.E.; Wirth, B.; Liu, C.L.

1997-01-01

Radiation enhanced diffusion at RPV operating temperatures around 290 degrees C leads to the formation of various ultrafine scale hardening phases, including copper-rich and copper-catalyzed manganese-nickel rich precipitates. In addition, defect cluster or cluster-solute complexes, manifesting a range of thermal stability, develop under irradiation. These features contribute directly to hardening which in turn is related to embrittlement, manifested as shifts in Charpy V-notch transition temperature. Models based on the thermodynamics, kinetics and micromechanics of the embrittlement processes have been developed; these are broadly consistent with experiment and rationalize the highly synergistic effects of most important irradiation (temperature, flux, fluence) and metallurgical (copper, nickel, manganese, phosphorous and heat treatment) variables on both irradiation hardening and recovery during post-irradiation annealing. A number of open questions remain which can be addressed with a hierarchy of new theoretical and experimental tools

Influence of Striking Edge Radius (2 mm versus 8 mm) on Instrumented Charpy Data and Absorbed Energies

Energy Technology Data Exchange (ETDEWEB)

Lucon, E.

2008-08-15

The most commonly used test standards for performing Charpy impact tests (ISO 148 and ASTM E 23) envisage the use of strikers having different radii of the striking edge, i.e. 2 mm (ISO) and 8 mm (ASTM). The effect of striker geometry on Charpy results was extensively studied in the past in terms of absorbed energy measured by the machine encoder, but few investigations are available on the influence of striker configuration on the results of instrumented Charpy tests (characteristic forces, displacements and integrated energy). In this paper, these effects are investigated based on the analysis of published results from three interlaboratory studies and some unpublished Charpy data obtained at SCK-CEN. The instrumented variables which are the most sensitive to the radius of the striking edge are the maximum force and its corresponding displacement, with 8mm-strikers providing systematically higher values. Absorbed energies, obtained both from the instrumented trace and from the pendulum encoder, are almost insensitive to the type of striker up to 200 J. For higher energy levels, the values obtained from 8mm strikers become progressively larger. Data scatter is generally higher for 2mm-strikers.

SCK-CEN Contribution to the IAEA Round Robin Exercise on WWER-440 RPV Weld Material Irradiation, Annealing and Re-Embrittlement

International Nuclear Information System (INIS)

Van Walle, E.; Chaouadi, R.; Puzzolante, J.L.; Fabry, A.; Van de Velde, J.

1998-01-01

The contribution of the Belgian Nuclear Research Centre SCK-CEN to the IAEA Round Robin Exercise on WWER-440 RPV weld material is reported. The objective of this contribution is twofold: (1) to gain experience in the field of the testing of WWER-440 steels; (2) to analyse the round-robin data according to in-house developed on used models in order to check their validity and applicability. Results from testing on unirradiated material are reported including data obtained from chemical analysis, Charpy-V impact testing, tensile testing and fracture toughness determination. Finally, irradiation strategies that can be used in the program to obtain irradiated, irradiated-annealed and irradiated-annealed-reirradiated conditions are outlined

Heavy-Section Steel Irradiation Program

International Nuclear Information System (INIS)

Corwin, W.R.

1990-08-01

The primary goal of the Heavy-Section Steel Irradiation Program is to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior (particularly the fracture toughness properties) of typical pressure-vessel steels as they relate to light-water-reactor pressure-vessel integrity. The program includes direct continuation of irradiation studies previously conducted by the Heavy-Section Steel Technology Program augmented by enhanced examinations of the accompanying microstructural changes. Effects of specimen size; material chemistry; product form and microstructure; irradiation fluence, flux, temperature, and spectrum; and postirradiation annealing are examined on a wide range of fracture properties. Detailed statistical analyses of the fracture data on K Ic shift of high-copper welds were performed. Analysis of the first phase of irradiated crack-arrest testing on high-copper welds was completed. Final analysis and publication of the results of the second phase of the irradiation studies on stainless steel weld-overlay cladding were completed. Determinations were made of the variations in chemistry and unirradiated RT NDT of low upper-shelf weld metal from the Midland reactor. Final analyses were performed on the Charpy impact and tensile data from the Second and Third Irradiation series on low upper-shelf welds, and the report on the series was drafted. A detailed survey of existing data on microstructural models and data bases of irradiation damage was performed, and initial development of a reaction-rate-based model was completed. 40 refs., 7 figs., 4 tabs

Charpy impact test results on five materials and NIST verification specimens using instrumented 2-mm and 8-mm strikers

International Nuclear Information System (INIS)

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

1995-01-01

The Heavy-Section Steel Irradiation Program at Oak Ridge National Laboratory is involved in two cooperative projects, with international participants, both of which involve Charpy V-notch impact tests with instrumented strikers of 2mm and 8mm radii. Two heats of A 533 grade B class I pressure vessel steel and a low upper-shelf (LUS) submerged-arc (SA) weld were tested on the same Charpy machine, while one heat of a Russian Cr-Mo-V forging steel and a high upper-shelf (HUS) SA weld were tested on two different machines. The number of replicate tests at any one temperature ranged from 2 to 46 specimens. Prior to testing with each striker, verification specimens at the low, high, and super high energy levels from the National Institute of Standards and Technology (NIST) were tested. In the two series of verification tests, the tests with the 2mm striker met the requirements at the low and high energy levels but not at the super high energy. For one plate, the 2mm striker showed somewhat higher average absorbed energies than those for the 8-mm striker at all three test temperatures. For the second plate and the LUS weld, however, the 2mm striker showed somewhat lower energies at both test temperatures. For the Russian forging steel and the HUS weld, tests were conducted over a range of temperatures with tests at one laboratory using the 8mm striker and tests at a second laboratory using the 2mm striker. Lateral expansion was measured for all specimens and the results are compared with the absorbed energy results. The overall results showed generally good agreement (within one standard deviation) in energy measurements by the two strikers. Load-time traces from the instrumented strikers were also compared and used to estimate shear fracture percentage. Four different formulas from the European Structural Integrity Society draft standard for instrumented Charpy test are compared and a new formula is proposed for estimation of percent shear from the force-time trace

Post-irradiation annealing of coarse-grained model alloys

Energy Technology Data Exchange (ETDEWEB)

Ray, P H.N.; Wilson, C; McElroy, R J [AEA Reactor Services, Harwell (United Kingdom)

1994-12-31

Thermal ageing and irradiation studies have been carried out on three model alloys (JPC, JPB, JPG) that have identical compositions except for different levels of phosphorus and/or copper. They have been irradiated in three conditions, as-received, heat treated to produce a coarse grained microstructure (similar to heat-affected-zone), and in this condition further aged at 450 C to produce a temper embrittled condition. One of the alloy have been subject to a post-irradiation anneal. The effect of these treatments on mechanical property changes has been characterized by Charpy testing and Vickers hardness measurements; the phosphorus segregation has been studied by a combination of STEM and Auger techniques.

Effect on fast neutron irradiation to 4 dpa at 400{degrees}C on the properties of V-(4-5)Cr-(4-5)Ti alloys

Energy Technology Data Exchange (ETDEWEB)

Zinkle, S.J.; Alexander, D.J.; Robertson, J.P. [Oak Ridge National Lab., TN (United States)] [and others

1997-04-01

Tensile, Charpy impact and electrical resistivity measurements have been performed at ORNL on V-4Cr-4Ti and V-5Cr-5Ti specimens that were prepared at ANL and irradiated in the lithium-bonded X530 experiment in the EBR-II fast reactor. All of the specimens were irradiated to a damage level of about 4 dpa at a temperature of {approximately}400{degrees}C. A significant amount of radiation hardening was evident in both the tensile and Charpy impact tests. The irradiated V-4Cr-4Ti yield strength measured at {approximately}390{degrees}C was >800 MPa, which is more than three times as high as the unirradiated value. The uniform elongations of the irradiated tensile specimens were typically {approximately}1%, with corresponding total elongations of 4-6%. The ductile to brittle transition temperature of the irradiated specimens was less than the unirradiated resistivity, which suggests that hardening associated with interstitial solute pickup was minimal.

On impact testing of subsize Charpy V-notch type specimens

International Nuclear Information System (INIS)

Mikhail, A.S.; Nanstad, R.K.

1994-01-01

The potential for using subsize specimens to determine the actual properties of reactor pressure vessel steels is receiving increasing attention for improved vessel condition monitoring that could be beneficial for light-water reactor plant-life extension. This potential is made conditional upon, on the one hand, by the possibility of cutting samples of small volume from the internal surface of the pressure vessel for determination of actual properties of the operating pressure vessel. The plant-life extension will require supplemental surveillance data that cannot be provided by the existing surveillance programs. Testing of subsize specimens manufactured from broken halves of previously tested surveillance Charpy V-notch (CVN) specimens offers an attractive means of extending existing surveillance programs. Using subsize CVN type specimens requires the establishment of a specimen geometry that is adequate to obtain a ductile-to-brittle transition curve similar to that obtained from full-size specimens. This requires the development of a correlation of transition temperature and upper-shelf toughness between subsize and full-size specimens. The present study was conducted under the Heavy-Section Steel Irradiation Program. Different published approaches to the use of subsize specimens were analyzed and five different geometries of subsize specimens were selected for testing and evaluation. The specimens were made from several types of pressure vessel steels with a wide range of yield strengths, transition temperatures, and upper-shelf energies (USEs). Effects of specimen dimensions, including depth, angle, and radius of notch have been studied. The correlation of transition temperature determined from different types of subsize specimens and the full-size specimen is presented. A new procedure for transforming data from subsize specimens was developed and is presented

SISTEMA DE AQUISIÇÃO DE DADOS PARA A MÁQUINA DE IMPACTO CHARPY

Directory of Open Access Journals (Sweden)

Jermana Lopes Moraes

2014-08-01

Full Text Available Este trabalho tem o objetivo de implementar e desenvolver um sistema de aquisição de dados para a máquina de impacto Charpy. Assim, é realizado um estudo da máquina de impacto Charpy, do ensaio de impacto e das ferramentas necessárias para desenvolvimento do projeto. Utiliza-se um acelerômetro para determinar a aceleração nos eixos x e y do pêndulo Charpy durante a realização do ensaio. Para leitura e interpretação dos dados enviados pelo acelerômetro utiliza-se a plataforma de hardware Arduino UNO com software específico. Os dados enviados ao Arduino são apresentados em uma interface gráfica desenvolvida no Matlab. Nesta interface é possível inserir os dados iniciais de ensaio Charpy e apresentar ao usuário final os resultados finais de ensaio, como a energia de impacto, a resistência de impacto e a força necessária para romper o corpo de prova. Além disso, é apresentado ao usuário um gráfico da aceleração ao longo da realização do ensaio e o gráfico de força ao longo do tempo. Desta forma, registram-se os dados em um arquivo específico para análise e estudo posterior. A porcentagem de erro entre o valor medidor no mostrador da máquina e o resultado automatizado não ultrapassa o limite de 8 %.

Comparison of different experimental and analytical measures of the thermal annealing response of neutron-irradiated RPV steels

International Nuclear Information System (INIS)

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

1997-01-01

The thermal annealing response of several materials as indicated by Charpy transition temperature (TT) and upper-shelf energy (USE), crack initiation toughness, K Jc , predictive models, and automated-ball indentation (ABI) testing are compared. The materials investigated are representative reactor pressure vessel (RPV) steels (several welds and a plate) that were irradiated for other tasks of the Heavy-Section Steel Irradiation (HSSI) Program and are relatively well characterized in the unirradiated and irradiated conditions. They have been annealed at two temperatures, 343 and 454 C (650 and 850 F) for varying lengths of time. The correlation of the Charpy response and the fracture toughness, ABI, and the response predicted by the annealing model of Eason et al. for these conditions and materials appears to be reasonable. The USE after annealing at the temperature of 454 C appears to recover at a faster rate than the TT, and even over-recovers (i.e., the recovered USE exceeds that of the unirradiated material)

Irradiation effects in strain aged pressure vessel steel

Energy Technology Data Exchange (ETDEWEB)

Grounes, M; Myers, H P

1962-02-15

Tensile specimens, Charpy-V notch and subsize impact specimens of an aluminium killed carbon manganese steel, have been irradiated at 160 - 190 deg C in the reactor G1. The total neutron dose received was 2.4 x 10{sup 18} n/cm{sup 2} (> 1 MeV). Specimens were prepared from normalized plate and from strain aged material from the same plate. It was found that the changes in brittle ductile transition temperature due to neutron irradiation and those due to strain ageing must be considered additive.

Influence of Loading Rate on the Calibration of Instrumented Charpy Strikers

Energy Technology Data Exchange (ETDEWEB)

Lucon, E.; Scibetta, M.; McColskey, D.; McCowan, C.

2009-01-15

One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. The conventional approach for establishing an analytical relationship between strain gage output and force applied to the transducer is the static calibration, which is preferably performed with the striker installed in the pendulum assembly. However, the response of an instrumented striker under static force application may sometimes differ significantly from its dynamic performance during an actual Charpy test. This is typically reflected in a large difference between absorbed energy returned by the pendulum encoder (KV) and calculated under the instrumented force/displacement test record (Wt). Such difference can be either minimized by optimizing the striker design or analytically removed by adjusting forces and displacements until KV = Wt (the so-called 'Dynamic Force Adjustment'). This study investigates the influence of increasing force application rates on the force/voltage characteristics of two instrumented strikers, one at NIST in Boulder, CO and one at SCK-CEN in Mol, Belgium.

Experimental study associated to irradiation of FBR structural material, (4)

International Nuclear Information System (INIS)

1976-01-01

The study presents one of the bases to evaluate the results of the post-irradiation tests to conduct the thermal control tests related to the second JMTR irradiation (70M-61P) of the demestic austenitic stainless steels for the structural material of the FBR performed by Power Reactor and Nuclear Fuel Development Corporation. The thermal control specimens were given the temperature history which simulated that of the irradiation temperature in vacuum by the electrical furnance, and then the tensile, fatigue and Charpy impact tests were performed. The changes of the material properties caused by the thermal history were investigated. (auth.)

Use of forces from instrumented Charpy V-notch testing to determine crack-arrest toughness

International Nuclear Information System (INIS)

Iskander, S.K.; Nanstad, R.K.; Sokolov, M.A.; McCabe, D.E.; Hutton, J.T.

1996-06-01

The objective of this investigation is an estimation of the crack-arrest toughness, particularly of irradiated materials, from voltage versus time output of an instrumented setup during a test on a Charpy V-notch (CVN) specimen. This voltage versus time trace (which can be converted to force versus displacement) displays events during fracture of the specimen. Various stages of the fracture process can be identified on the trace, including an arrest point indicating arrest of brittle fracture. The force at arrest, F a , versus test temperature, T, relationship is examined to explore possible relationships to other experimental measures of crack-arrest toughness such as the drop-weight nil-ductility temperature (NDT), or crack-arrest toughness, K a . For a wide range of weld and plate materials, the temperature at which F a = 2.45 kN correlates with NDT with a standard deviation, sigma, of about 11 K. Excluding the so-called low upper-shelf energy (USE) welds from the analysis resulted in F a = 4.12 kN and σ = 6.6 K. The estimates of the correlation of the temperature for F a = 7.4 kN with the temperature at 100-MPa√m level for a mean American Society of Mechanical Engineers (ASME) type K Ia curve through crack-arrest toughness values show that prediction of conservative values of K a are possible

Determination of the toughness of a low alloy steel from the Charpy V-notch impact testing

International Nuclear Information System (INIS)

Rossoll, A.

1998-12-01

Charpy V-notch (CVN) impact testing is widely used to characterize the resistance of a material to brittle fracture, by measuring the energy consumed by a specimen during impact. Notably materials undergoing a ductile-to-brittle transition, e.g. ferritic steels, are quality controlled by means of CVN testing, and their ductile-to-brittle transition temperature can be determined. Charpy testing is also widely used in the toughness assessment of large forged components, e.g. pressure vessels for pressurised water reactors (PWR). However, currently no satisfactory link between the Charpy impact energy CVN and the fracture toughness KIc exists. This study aims to establish a non-empirical relationship between the Charpy V-notch energy CVN, and the fracture toughness KIc, on the lower shelf of fracture toughness and the onset of the ductile-to-brittle transition of a A508 Cl.3 steel. The methodology employed is based on the so-called 'local approach'. Brittle cleavage fracture is modelled in terms of the Beremin (1983) model based on 'weakest link' statistics, whereas ductile crack advance preceding cleavage in the transition region is accounted for with the GTN model (Gurson, 1977; Tvergaard, 1982; Tvergaard and Needleman, 1984). Mechanical testing at different strain rates allowed for the establishment of the constitutive equations of the material in an elastic-viscoplastic formulation. Fracture tests on different specimen geometries provided the large data set necessary for statistical evaluation. All specimen types have been modelled with finite element analysis. However, the dynamic nature of the Charpy test requires special consideration. The origin of these dynamic effects was studied, as well as their implications on interpretation of experimental results and on modeling. After a proper modeling procedure had been defined, the local approach was employed for studying fracture. It is found that the fracture toughness can be predicted from the Charpy impact test

Re-utilization by '' Stud Welding'' of capsules charpy-V belonged to surveillance programs

International Nuclear Information System (INIS)

Lapena, J.; Perosanz, F. J.; Gachuz, M.

1998-01-01

The perspectives of nuclear plants life extension that are approximating to their end of design life compels to make new surveillance programs. The re-utilization of specimens belonging to surveillance capsules already tested in these new surveillance programs seems be a solution worldwide accepted. The two possible re-utilization processes of this irradiated material are: Subsized specimens and Reconstitution. While the first alternative (Subsized specimens) outlines serious problems for apply the results, the reconstitution eliminates this problem, since the resulting specimens after of the reconstruction procedure would be of the same dimensions that the original. The reconstruction process involves welds, and therefore it has associated the specific problems of this type of joints. Furthermore, by be tried to material irradiated with certain degree of internal damage, that is the variable to evaluate, requires that the heat contribution to the piece not originate local thermal treatments that alter its mechanical qualities. In this work has been followed the evolution by the variables of the weld process and their influence on the quality by the union from metallographic al point of view as well as mechanical for a weld procedure by Stud Welding. The principal objective is to optimize said parameters to assure a good mechanical continuity, without detriment of the microstructural characteristics of the original material. To verify this last have been accomplished with metallographical tests, temperature profile, hardness and will be carried out also Charpy tests. (Author)

Irradiation embrittlement of some 15Kh2MFA pressure vessel steels under varying neutron fluence rates

Energy Technology Data Exchange (ETDEWEB)

Valo, M; Bars, B [Technical Research Centre of Finland, Espoo (Finland); Ahlstrand, A [Imatran Voima Oy (IVO), Helsinki (Finland)

1994-12-31

Irradiation sensitivity of two forging materials was measured with Charpy-V and fracture mechanic tests, and with different fluence, fluence rate and irradiation time values. Irradiation sensitivity of the materials was found to be less or equal to the current Russian standard, and appears to be well described by the fluence parameter only. A slight additional effect on embrittlement from a long term low fluence irradiation is noticed, but it stays within the total scatter band of data. 7 refs., 17 figs., 4 tabs.

On the Effectiveness of the Dynamic Force Adjustment for Reducing the Scatter of Instrumented Charpy Results

International Nuclear Information System (INIS)

Lucon, E.

2008-01-01

One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. An interesting alternative to the conventional static calibration recommended by the standards is the Dynamic Force Adjustment (DFA), in which forces and displacements are iteratively adjusted until equality is achieved between absorbed energies calculated under the test record (Wt) and measured by the machine encoder (KV). In this study, this procedure has been applied to the instrumented data obtained by 10 international laboratories using notched and precracked Charpy specimens, in the framework of a Coordinated Research Project (CRP8) of IAEA. DFA is extremely effective in reducing the between-laboratory scatter for both general yield and maximum forces. The effect is less significant for dynamic reference temperatures measured from precracked Charpy specimens using the Master Curve procedure, but a moderate reduction of the standard deviation is anyway observed. It is shown that striker calibration is a prominent contribution to the interlaboratory variability of instrumented impact forces, particularly in the case of maximum forces.

On the Effectiveness of the Dynamic Force Adjustment for Reducing the Scatter of Instrumented Charpy Results

Energy Technology Data Exchange (ETDEWEB)

Lucon, E.

2008-09-15

One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. An interesting alternative to the conventional static calibration recommended by the standards is the Dynamic Force Adjustment (DFA), in which forces and displacements are iteratively adjusted until equality is achieved between absorbed energies calculated under the test record (Wt) and measured by the machine encoder (KV). In this study, this procedure has been applied to the instrumented data obtained by 10 international laboratories using notched and precracked Charpy specimens, in the framework of a Coordinated Research Project (CRP8) of IAEA. DFA is extremely effective in reducing the between-laboratory scatter for both general yield and maximum forces. The effect is less significant for dynamic reference temperatures measured from precracked Charpy specimens using the Master Curve procedure, but a moderate reduction of the standard deviation is anyway observed. It is shown that striker calibration is a prominent contribution to the interlaboratory variability of instrumented impact forces, particularly in the case of maximum forces.

Effects of irradiation on initiation and crack-arrest toughness of two high-copper welds and on stainless steel cladding

International Nuclear Information System (INIS)

Nanstad, R.K.; Iskander, S.K.; Haggag, F.M.

1990-01-01

The objective of the study on the high-copper welds is to determine the effect of neutron irradiation on the shift and shape of the ASME K Ic and K Ia toughness curves. Two submerged-arc welds with copper contents of 0.23 and 0.31 wt % were commercially fabricated in 220-mm-thick plate. Compact specimens fabricated from these welds were irradiated at a nominal temperature of 288 degree C to fluences from 1.5 to 1.9 x 10 19 neutrons/cm 2 (>1 MeV). The fracture toughness test results show that the irradiation-induced shifts at 100 MPa/m were greater than the Charpy 41-J shifts by about 11 and 18 degree C. Mean curve fits indicate mixed results regarding curve shape changes, but curves constructed as lower boundaries to the data do indicate curves of lower slopes. A preliminary evaluation of the crack-arrest results shows that the neutron-irradiation induced crack-arrest toughness temperature shift is about the same as the Charpy V-notch impact temperature shift at the 41-J energy level. The shape of the lower bound curves (for the range of test temperatures covered), compared to those of the ASME K Ia curve did not appear to have been altered by the irradiation. Three-wire stainless steel weld overlay cladding was irradiated at 288 degree C to fluences of 2 and 5 x 10 19 neutrons/cm 2 (>1 MeV). Charpy 41-J temperature shifts of 13 and 28 degree C were observed, respectively. For the lower fluence only, 12.7-mm thick compact specimens showed decreases in both J Ic and the tearing modulus. Comparison of the fracture toughness results with typical plate and a low upper-shelf weld reveals that the irradiated stainless steel cladding possesses low ductile initiation fracture toughness comparable to the low upper-shelf weld. 8 refs., 12 figs., 2 tabs

Neutron embrittlement of the reactor vessel in Borssele as determined from Charpy specimens

International Nuclear Information System (INIS)

Oosterkamp, W.J.; Dufour, L.B.

1983-01-01

Two sets of Charpy specimens have been retrieved from the reactor in the nuclear power plant at Borssele after two and four cycles of operation, respectively. The neutron fluxes at the sample positions and at the vessel wall have been calculated with a point-kernel method and S 2 calculations. The calculated fluxes at the two specimen positions are in fair agreement with fluences measured by threshold detectors. The Reference Temperature of Nil Ductility has been determined from the Charpy tests by a tan-h fit procedure. An extrapolation to a 40-year vessel life has been made on the basis of a square-root dependence of the change in the reference temperature with effective full-power years. Under these assumptions the heat-affected zone material will reach 296 K. The other materials will remain below 280 K. The vessel life therefore is not limited by embrittlement. (orig.)

Fractographic and microstructural aspects of fracture toughness testing in irradiated 304 stainless steel

International Nuclear Information System (INIS)

Cullen, W.H.; Hiser, A.L.; Hawthorne, J.R.; Abramczyk, G.A.; Caskey, G.R.

1987-01-01

Fracture toughness and Charpy impact test results on 304 stainless steel baseplate, weld and heat-affected zone (HAZ) tested at 25 0 C and 125 0 C are correlated with the microstructural and fractographic features observed in these materials. Specimens were collected from several sections of 12.7 mm (0.5 in.) wall thickness piping removed from a process system, and were characterized by different material chemistries and thermomechanical histories. As a result, mechanical properties vary over a considerable range from one pipe section to another. The presence of delta ferrite in some of the samples caused significant degradations in the toughness properties for certain crack orientations. Decreases in Charpy impact energies occur in the same material for different crack orientations. Materials irradiated showed 40% decreases in Charpy impact energy, but little change in fracture morphology. An increase in the test temperature resulted in an expected increase in Charpy energies for all materials. Fractographic features did not change appreciably with respect to the 100 0 C increase in test temperature. In unirradiated specimens, a test temperature increase caused lower J/sub Ic/ and J-R curve values with tearing modules values increased. The latter is due to the large decreases in tensile strength with increasing test temperature. The weld metals tend to have the highest tearing resistance, while the HAZ's tend to have the lowest. 30 figs., 3 tabs

Irradiation behavior of a submerged arc welding material with different copper content; Bestrahlungsverhalten einer UP-Versuchsschweissnaht mit unterschiedlichen Kupfergehalten

Energy Technology Data Exchange (ETDEWEB)

Langer, R [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Bartsch, R [Kernkraftwerk Obrigheim GmbH (Germany)

1998-11-01

Che report presents results of an irradiation program on specimens of submerged arc weldings with copper contents of 0.14% up to 0.42% and a fluence up to 2.2E19 cm{sup -2} (E>1MeV). Unirradiated and irradiated tensile- Charpy-, K{sub lc}- and Pellini-specimens were tested of material with a copper content of 0.22%. On the other materials Charpy tests and tensile tests were performed. The irradiation of the specimens took place in the KWO - ``RPV, a PWR with low flux and in the VAK - RPV, a small BWR with high flux. - The irradiation induced embrittlemnt shows a copper dependence up to about 30%. The specimens with a copper content higher than 0.30% show no further embrittlement. Irradiation in different reactors with different flux (factor > 33) shows the same state of embrittlement. Determination of a K{sub lc}, T-curve with irradiated specimens is possible. The conservative of the RT{sub NDT} - concept could be confirmed by the results of Charpy-V, drop weight- and K{sub lc}-test results. [Deutsch] Zur zusaetzlichen Absicherung des KWO-RDB wurde Ende 1979 eine UP-Versuchsschweissnaht mit vergleichbarer chemischer Zusammensetzung und vergleibaren mechanisch-technologischen Werkstoffen im unbestrahlten Ausgangszustand wie die RDB Core-Rundnaht hergestellt. Teile der Naht wurden durch Verkupfern der Schweissdraehte auf unterschiedliche Gehalte von Cu=0,14% bis 0,42% eingestellt. Aus dieser Schweissverbindung wurden Proben im VAK und KWO-RDB bestrahlt. Im Rahmen der Aktivitaeten zur Absicherung des KWO-RDBs erfolgte 1995 die Pruefung der bestrahlten Proben. Die mechanisch technologischen Werkstoffwerte vor und nach Bestrahlung werden gegenuebergestellt und praesentiert. Mit dem Ergebnis wurde ein weiterer Nachweis fuer die Konservativitaet des RT{sub NDT}-Konzeptes erbracht. Es wurde nachgewiesen, dass fuer den untersuchten Bereich kein Dose-Rate Effekt bzw. Bestrahlungszeiteinfluss existiert. Fuer UP-Schweissungen mit den vorliegenden Fertigungsparametern und bei

ASK Procedure for Instrumented Pre-cracked Charpy-Type Tests

International Nuclear Information System (INIS)

Varga, T.; Njo, D.H.; Prantl, G.

1981-01-01

The essential technical content of the ASK procedure originated from development work in Switzerland since 1963, and practical experiences gained since 1972. The remainder of the content and the format of the procedure are based on the ASTM E 24.03.03. (Tentative Draft Copy) 'Proposed Method for Pre-cracked Charpy Impact and Slow-Bend Testing of Metallic Materials' by C. E. Harbower, 1973. Two different velocities, 5 m/s and 0.1 m/s were used with a Schnadt-type machine of rigid construction. The stiffness of the machine proved to be very suitable for instrumented testing. The instrumented Schnadt-Type machine was equipped with strain gauges both on the top of the pendulum and on the chisel. A static force calibration was followed by energy calibration, comparing potential energy losses with the area under the force-deflection curve. Deflection was measured using a high frequency eddy current method on the pendulum, and for slow testing by means of an inductive gauge on the chisel. Charpy-Type specimens of 1.0 mm max notch depth and 0.12 mm max notch radius were pre-cracked using a resonant fatigue testing machine, or an eccentric drive machine. Crack propagation rate da/dN was measured using 'Russenberger' measuring gauges. In addition a new technique for the detection of dynamic crack initiation, developed at the Institute of Research and Technology (TVFA) in Vienna is discussed and some results presented

Charpy impact test pada kampas rem hybrid komposit phenolic resin matrik dengan penguat serbuk basalt-Alumina-kulit kerang

Directory of Open Access Journals (Sweden)

I N. G. Suma Wijaya

2017-03-01

Full Text Available Abstrak: Penelitian ini adalah difokuskan untuk mengamati ketahanan impact dari material kampas rem kendaraan bermotor. Kampasrem yang diujikan adalah kampas yang terbuat dari material hybrid komposit dengan penguat serbuk basalt – serbuk kulitkerang dan alumina dan pengikat phenolic resin. Material kampas rem hibrid komposit diproses melalui proses sinteringdengan penekanan 2 ton, temperatur 150ºC selama 30 menit. Tujuan penelitian adalah menginvestigasi kekuatan impact daripada bahan hybrid komposit untuk masing – masing variasi terhadap perlakuan impact charpy yang didasarkan pada standarASTM D6110–04. Pengujian dilakukan dengan menganalisa nilai energy yang mampu diserap oleh bahan akibat bebanimpact, selanjutnya patahan impact charpy dianalisa dengan SEM. Diperoleh hasil pengujian charpy impact untuk masing –masing variasi hybrid komposit adalah nilai kekuatan yang tinggi terjadi pada hibrid komposit variasi 2 (HK2 dengan nilai0,000339547 J/mm2, ini disebabkan karena mempunyai ikatan antara metrik dan basalt yang lebih kuat dan sempurnadibandingkan dengan hibrid komposit lainnya. Untuk nilai hibrid komposit variasi 1 (HK1 adalah 0,000304851 J/mm², hibridkomposit variasi 3 (HK3 adalah 0,000334516 J/mm², hibrid komposit variasi 4 (HK4 adalah 0,000325059 J/mm², hibridkomposit variasi 5 (HK5 adalah 0,0003327 J/mm². (2 Dari perbandingan antara kampas rem dipasaran dengan kampas remhibrid komposit maka didapat nilai kekuatannya berbeda pada hibrid komposit variasi 2 (HK2 dengan kampas pembanding(KP yang memiliki nilai kekuatannya lebih besar yaitu, 0,000374867 J/mm².Kata kunci : Kampas rem, Impact charpy, Hibrid komposit, Basalt, Aluminium, Kulit Kerang Abstract: This research is focused to observe the impact resistance of motor vehicles brake lining material. Brake tested are canvasmade of hybrid composite materials with basalt powder reinforced – seashells, alumina powder, and a phenolic resin matrix.Hybrid composite brake

Irradiation and annealing behavior of 15Kh2MFA reactor pressure vessel steel

International Nuclear Information System (INIS)

Popp, K.; Bergmann, U.; Bergner, F.; Hampe, E.; Leonhardt, W.D.; Schuetzler, H.P.; Viehrig, H.W.

1992-01-01

This work deals with the mechanical properties of RPV steels used WWER-440. The materials under investigation were a forging (base metal 15Kh2MFA) and the corresponding weld. Charpy V-notch specimens and tensile test specimens were irradiated in the WWER-2 Rheinsberg at about 270 C up to the two neutron fluence levels of 4 x 10 18 and 5 x 10 19 n/cm 2 (E>1MeV). Post-irradiation annealing heat treatments were performed, among others a 475 C/152 h treatment of technical interest. (orig.)

Numerical simulation of a Charpy test and correlation of fracture toughness with fracture energy. Vessel steel and duplex stainless steel of the primary loop

International Nuclear Information System (INIS)

Breban, P; Eripret, C.

1995-01-01

The analysis methods used to evaluate the harmlessness of defects in the components of the primary coolant circuit of pressurized water reactor are based on the knowledge of the failure properties of concerned materials. The toughness is used to be measured through tests performed on normalized samples. But in some cases, especially for the vessel steel submitted to irradiation effects or for cast components in duplex stainless steel sensitive to thermal ageing, these measurements are not available on the material aged in operation. Therefore, fracture resistance has been evaluated through Charpy tests. Toughness is thus obtained on the basis of an empirical correlation. To improve these predictions, a modeling of the Charpy test in the framework of the local approach to fracture has been performed, for both materials. For the vessel steel, a complete evaluation of toughness has been achieved on the basis of a bidimensional viscoplastic modeling under large strain assumptions and a post-treatment with a Weibull model (cleavage fracture). The main hypothesis (partition between plain stress and plain strain areas in the bidimensional modeling) was corrected after a three dimensional calculations with the finite element program Code-Aster. The fracture analysis put into evidence that damage considerations like cavity nucleation and growth have to be introduced in the model in order to improve the description of physical phenomena. Two ways of progress have been suggested and are in course of being investigated, one in the framework of local approach to failure, the other with the help of micro-macro relationship. With regard to the duplex steel, the description of a Charpy (U) test allowed to clearly discriminate between crack initiation and propagation phases. A modeling through an equivalent homogenous material with a damage law based on a modified Gurson potential enables to describe quantitatively both phases of fracture. It clearly appears that a reliable

Ductile crack initiation in the Charpy V-notch test

International Nuclear Information System (INIS)

Server, W.L.; Norris, D.M. Jr.; Prado, M.E.

1978-01-01

Initiation and growth of a crack in the Charpy V-notch test was investigated by performing both static and impact controlled deflection tests. Test specimens were deformed to various deflections, heat-tinted to mark crack extension and broken apart at low temperature to allow extension measurements. Measurement of the crack extension provided an estimate of crack initiation as defined by different criteria. Crack initiation starts well before maximum load, and is dependent on the definition of ''initiation''. Using a definition of first micro-initiation away from the ductile blunting, computer model predictions agreed favorably with the experimental results

Heavy-section steel irradiation program summary

International Nuclear Information System (INIS)

Corwin, W.R.; Nanstad, R.K.; Iskander, S.K.; Haggag, F.M.

1992-01-01

Since a failure of the RPV carries the potential of major contamination release and severe accident, it is imperative to safe reactor operation to understand and be able to accurately predict failure models of the vessel material. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established with its primary goal to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior, and in particular the fracture toughness properties, of typical pressure vessel steels as they relate to light-water RPVs. The program includes the direct continuation of irradiation studies previously conducted within the Heavy-Section Steel Technology Program augmented by enhanced examinations of the accompanying microstructural changes. Effects of specimen size, material chemistry, product form and microstructure, irradiation fluence, flux, temperature and spectrum, and postirradiation annealing are being examined on a wide range of fracture properties including fracture toughness (K Ic and J Ic ), crack-arrest toughness (K Ia ), ductile tearing resistance (dJ/da), Charpy V-notch impact energy, dropweight nil-ductility temperature (NDT), and tensile properties. Models based on observations of radiation-induced microstructural changes using field ion and high-resolution transmission electron microscopy provide a firmer basis for extrapolating the measured changes in fracture properties to wider ranges of irradiation conditions. The principal materials examined within the HSSI Program are highcopper welds since their postirradiation properties are most frequently limiting in the continued safe operation of commercial RPVs. In addition, a limited effort will focus on stainless steel weld overlay cladding, typical of that used on the inner surface of RPVs, since its postirradiation fracture properties have the potential for strongly affecting the extension of small surface flaws during overcooling transients. (orig./GL)

Investigation of irradiation embrittlement and annealing behaviour of JRQ pressure vessel steel by instrumented impact tests

Energy Technology Data Exchange (ETDEWEB)

Valo, M; Rintamaa, R; Nevalainen, M; Wallin, K; Torronen, K [Technical Research Centre of Finland, Espoo (Finland); Tipping, P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1994-12-31

Seven series of A533-B type pressure vessel steel specimens irradiated as well as irradiated - annealed - re-irradiated to different fast neutron fluences (up to 5.10{sup 19}/cm{sup 2}) have been tested with a new type of instrumented impact test machine. The radiation embrittlement and the effect of the intermediate annealing was assessed by using the ductile and cleavage fracture initiation toughness. Although the ductile fracture initiation toughness exhibited scatter, the transition temperature shift corresponding to the dynamic cleavage fracture initiation agreed well with the 41 J Charpy-V shift. The results indicate that annealing is beneficial in restoring mechanical properties in an irradiated nuclear pressure vessel steel. (authors). 8 refs., 11 figs., 1 tab.

Heavy-Section Steel Irradiation Program

International Nuclear Information System (INIS)

Anon.

1991-01-01

In FY1990 the Heavy-Section Steel Irradiation (HSSI) Program was arranged into 8 tasks: (1) program management, (2) K Ic curve shift in high-copper welds, (3) K Ia curve shift in high-copper welds, (4) irradiation effects on cladding, (5) K Ic and K Ia curve shifts in low upper-shelf (LUS) welds, (6) irradiation effects in a commercial LUS weld, (7) microstructural analysis of irradiation effects, and (8) in-service aged material evaluations. Of particular interest are the efforts in FY1990 concerning the shifts in fracture toughness and crack arrest toughness in high-copper welds, the unirradiated examination of a LUS weld from the Midland reactor, and the continued investigation into the causes of accelerated low-temperature embrittlement recently observed in RPV support steels. In the Fifth and Sixth Irradiation Series, designed to examine the shifts and possible changes in shape in the ASME K Ic and K Ia curves for two irradiated high-copper welds, it was seen that both the lower bound and mean fracture toughness shifts were greater than those of the associated Charpy-impact energies, whereas the shifts in crack arrest toughness were comparable. The irradiation-shifted fracture toughness data fell slightly below the appropriately indexed ASME K Ic curve even when it was shifted according to Revision 2 of Regulatory Guide 1.99 including its margins. The beltline weld, which was removed from the Midland reactor, fabricated by Babcock and Wilcox, Co. using Linde 80 flux, is being examined in the Tenth Irradiation Series to establish the effects of irradiation on a commercial LUS weld. A wide variation in the unirradiated fracture properties of the Midland weld were measured with values of RT NDT ranging from -22 to 54F through its thickness. In addition, a wide range of copper content from 0.21 to 0.45 wt % was found, compared to the 0.42 wt % previously reported

Development of PIE techniques for irradiated LWR pressure vessel steels

International Nuclear Information System (INIS)

Nishi, Masahiro; Kizaki, Minoru; Sukegawa, Tomohide

1999-01-01

For the evaluation of safety and integrity of light water reactors (LWRs), various post irradiation examinations (PIEs) of reactor pressure vessel (RPV) steels and fuel claddings have been carried out in the Research Hot Laboratory (RHL). In recent years, the instrumented Charpy impact testing machine was remodeled aiming at the improvement of accuracy and reliability. By this remodeling, absorbed energy and other useful information on impact properties can be delivered from the force-displacement curve for the evaluation of neutron irradiation embrittlement behavior of LWR-RPV steels at one-time striking. In addition, two advanced PIE technologies are now under development. One is the remote machining of mechanical test pieces from actual irradiated pressure vessel steels. The other is development of low-cycle and high-cycle fatigue test technology in order to clarify the post-irradiation fatigue characteristics of structural and fuel cladding materials. (author)

Accelerated irradiation test of Gundremmingen reactor vessel trepan material

Energy Technology Data Exchange (ETDEWEB)

Hawthorne, J.R. [Materials Engineering Associates, Inc., Lanham, MD (United States)

1992-08-01

Initial mechanical properties tests of beltline trepanned from the decommissioned KRB-A pressure vessel and archive material irradiated in the UBR test reactor revealed a major anomaly in relative radiation embrittlement sensitivity. Poor correspondence of material behavior in test vs. power reactor environments was observed for the weak test orientation (ASTL C-L) whereas correspondence was good for the strong orientation (ASTM C-L). To resolve the anomaly directly, Charpy-V specimens from a low (essentially-nil) fluence region of the vessel were irradiated together with archive material at 279{degrees}C in the UBR test reactor. Properties tests before UBR irradiation revealed a significant difference in 41-J transition temperature and upper shelf energy level between the materials. However, the materials exhibited essentially the same radiation embrittlement sensitivity (both orientations), proving that the anomaly is not due to a basic difference in material irradiation resistances. Possible causes of the original anomaly and the significance to NRC Regulatory Guide 1.99 are discussed.

Accelerated irradiation test of gundremmingen reactor vessel trepan material

International Nuclear Information System (INIS)

Hawthorne, J.R.

1992-08-01

Initial mechanical properties tests of beltline trepanned from the decommissioned KRB-A pressure vessel and archive material irradiated in the UBR test reactor revealed a major anomaly in relative radiation embrittlement sensitivity. Poor correspondence of material behavior in test vs. power reactor environments was observed for the weak test orientation (ASTL C-L) whereas correspondence was good for the strong orientation (ASTM C-L). To resolve the anomaly directly, Charpy-V specimens from a low (essentially-nil) fluence region of the vessel were irradiated together with archive material at 279 degrees C in the UBR test reactor. Properties tests before UBR irradiation revealed a significant difference in 41-J transition temperature and upper shelf energy level between the materials. However, the materials exhibited essentially the same radiation embrittlement sensitivity (both orientations), proving that the anomaly is not due to a basic difference in material irradiation resistances. Possible causes of the original anomaly and the significance to NRC Regulatory Guide 1.99 are discussed

Neutron irradiation effects on the ductile-brittle transition of ferritic/martensitic steels

Energy Technology Data Exchange (ETDEWEB)

Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

1997-08-01

Ferritic/martensitic steels such as the conventional 9Cr-1MoVNb (Fe-9Cr-1Mo-0.25V-0.06Nb-0.1C) and 12Cr-1MoVW (Fe-12Cr-1Mo-0.25V-0.5W-0.5Ni-0.2C) steels have been considered potential structural materials for future fusion power plants. The major obstacle to their use is embrittlement caused by neutron irradiation. Observations on this irradiation embrittlement is reviewed. Below 425-450{degrees}C, neutron irradiation hardens the steels. Hardening reduces ductility, but the major effect is an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy, as measured by a Charpy impact test. After irradiation, DBTT values can increase to well above room temperature, thus increasing the chances of brittle rather than ductile fracture.

Neutron irradiation embrittlement of reactor pressure vessel steel 20 MnMoNi55 weld

International Nuclear Information System (INIS)

Ghoneim, M.M.

1987-05-01

The effect of neutron irradiation on the mechanical and fracture properties of an 'improved' 20 MnMoNi 55 Pressure Vessel Steel (PVS) weld was investigated. In addition to very low residual element content, especially Cu (0.035 wt.%), and relatively higher Ni content (0.9 wt.%), this steel has higher strength (30% more) than the steels used currently in nuclear reactor pressure vessels. The material was irradiated to 3.5x10 19 and 7x10 19 n/cm 2 (E > 1 Mev) at 290 0 C and 2.5x10 19 n/cm 2 (E > 1 MeV) at 160 0 C in FRJ-1 and FRJ-2 research reactors at KFA, Juelich, F.R.G. Test methods used in the evaluation included instrumented impact testing of standard and precracked Charpy specimens, tensile, and fracture toughness testing. Instrumented impact testing provided load and energy vs. time (deflection) data in addition to energy absorption data. The results indicated that the investigated high strength improved steel is more resistant to irradiation induced embrittlement than conventional PVSs. (orig./IHOE)

Development of reconstitution technique of irradiated specimens. 3. Report for FY 1995 and FY 1996 on JAERI-IHI cooperated research program (joint research)

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, Yutaka; Fukaya, Kiyoshi; Onizawa, Kunio; Suzuki, Masahide [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakamura, Terumi; Kaihara, Shoichiro; Yoshida, Kazuo; Sato, Akira

1998-10-01

The cooperated research between Japan Atomic Energy Research Institute and Ishikawajima-Harima Heavy Industries Co., Ltd. on the development of reconstitution technique of irradiated reactor pressure vessel surveillance specimens has been performed from FY 1993. In FY 1993-1994, the method of surface activated joining (SAJ) was applied to reconstitution of Charpy impact specimens. Some verification tests using unirradiated reactor pressure vessel plate materials have shown that SAJ is feasible for a reconstitution technique, in particular, owing to low joining temperature. The present paper reports the results of the cooperated research performed in FY 1995-1996. To improve the quality of the SAJ, the configuration of the end tab surface to be joined with the insert material was modified. The torque measured during joining was also introduced in joining parameters. A nondestructive inspection, temperature measurements in the specimens during joining were performed. The effect of joining on Charpy impact properties was discussed. For practical application of the technique to irradiated specimens, we confirmed that the impact specimens with joining interface gave rise to no failure at the joining position during impact test after neutron irradiation. (author)

Newly developed non-destructive testing method for evaluation of irradiation brittleness of structural materials using ultrasonic

International Nuclear Information System (INIS)

Ishii, Toshimitsu; Ooka, Norikazu; Kato, Yoshiaki; Saito, Junichi; Hoshiya, Taiji; Shibata, Saburo; Kobayashi, Hideo

1999-01-01

Surveillance testing is important to evaluate neutron irradiation embrittlement of reactor pressure vessel material for long life operation. An alternative test method for evaluating the irradiation embrittlement of the pressure vessel material will have to be proposed to support the limited number of surveillance test specimens in order to manage the plant life to be extended. In this study, ultrasonic testing for irradiated A533B-1 steel and weld metal was applied to examine material degradation nondestructively. With increasing the shift of Charpy 41 J transition temperature, ultrasonic velocity decreased and attenuation coefficient of ultrasonic wave increased. Especially, the difference of ultrasonic velocity for 5 MHz shear wave between as-received and irradiated material is corresponding to the shift of transition temperature showing material degradation. (author)

Statistical analyses of fracture toughness results for two irradiated high-copper welds

International Nuclear Information System (INIS)

Nanstad, R.K.; McCabe, D.E.; Haggag, F.M.; Bowman, K.O.; Downing, D.J.

1990-01-01

The objectives of the Heavy-Section Steel Irradiation Program Fifth Irradiation Series were to determine the effects of neutron irradiation on the transition temperature shift and the shape of the K Ic curve described in Sect. 6 of the ASME Boiler and Pressure Vessel Code. Two submerged-arc welds with copper contents of 0.23 and 0.31% were commercially fabricated in 215-mm-thick plates. Charpy V-notch (CVN) impact, tensile, drop-weight, and compact specimens up to 203.2 mm thick [1T, 2T, 4T, 6T, and 8T C(T)] were tested to provide a large data base for unirradiated material. Similar specimens with compacts up to 4T were irradiated at about 288 degrees C to a mean fluence of about 1.5 x 10 19 neutrons/cm 2 (>1 MeV) in the Oak Ridge Research Reactor. Both linear-elastic and elastic-plastic fracture mechanics methods were used to analyze all cleavage fracture results and local cleavage instabilities (pop-ins). Evaluation of the results showed that the cleavage fracture toughness values determined at initial pop-ins fall within the same scatter band as the values from failed specimens; thus, they were included in the data base for analysis (all data are designated K Jc )

Charpy impact test of oxidized and hydrogenated zircaloy using a thin strip specimen

International Nuclear Information System (INIS)

Otsuka, Teppei; Hashizume, Kenichi; Sugisaki, Masayasu

2004-01-01

The impact properties of an oxidized and a hydrogenated Zircaloy have been studied with an instrumented Charpy machine by using a strip Charpy V-notch specimen (1 mm thick by 4mm wide). Fracture processes such as crack initiation and propagation were examined using load-displacement curves obtained in this study. In the case of the hydrogenated specimen containing preferentially oriented hydrides, an appreciable decrease in the absorbed energy was observed in the crack propagation rather than in the crack initiation. From results of fractographs of the specimen, it was suggested that the reduction of the crack propagation energy of hydrogenated specimen could be attributed to the change of the stress state in the Zircaloy matrix, which was caused by the fracture of hydride in the inner part of specimen. In the case of the specimen oxidized at 973k for 60 min, on which an oxide layer (4 μm in thickness) and oxygen incursion layer (4μm) were formed, the surface layers affected the crack initiation process. The growing oxygen incursion layer, in particular, resulted in the constraint of plastic deformation of the Zircaloy matrix not only in the crack initiation but also in the crack propagation as its thickness increased. (author)

Results of crack-arrest tests on two irradiated high-copper welds

International Nuclear Information System (INIS)

Iskander, S.K.; Corwin, W.R.; Nanstead, R.K.

1990-12-01

The objective of this study was to determine the effect of neutron irradiation on the shift and shape of the lower-bound curve to crack-arrest data. Two submerged-arc welds with copper contents of 0.23 and 0.31 wt % were commercially fabricated in 220-mm-thick plate. Crack-arrest specimens fabricated from these welds were irradiated at a nominal temperature of 288 degree C to an average fluence of 1.9 x 10 19 neutrons/cm 2 (>1 MeV). Evaluation of the results shows that the neutron-irradiation-induced crack-arrest toughness temperature shift is about the same as the Charpy V-notch impact temperature shift at the 41-J energy level. The shape of the lower-bound curves (for the range of test temperatures covered) did not seem to have been altered by irradiation compared to those of the ASME K Ia curve. 9 refs., 21 figs., 10 tabs

Heavy-section steel irradiation program: Embrittlement issues

International Nuclear Information System (INIS)

Corwin, W.R.

1991-01-01

Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents and the potential for major contamination releases. The RPV is one of only two major safety- related components of the plant for which a duplicate or redundant backup system does not exist. In particular, it is vital to fully understand the degree of irradiation-induced degradation of the RPV's fracture resistance which occurs during service, since without that radiation damage it is virtually impossible to postulate a realistic scenario which would result in RPV failure. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established by the US Nuclear Regulatory Commission (USNRC) to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior, and in particular the fracture toughness properties, of typical pressure vessel steels as they relate to light-water reactor pressure-vessel integrity. Effects of specimen size, material chemistry, product form and microstructure, irradiation fluence, flux, temperature and spectrum, and postirradiation annealing are being examined on a wide range of fracture properties including fracture toughness crack arrest toughness ductile tearing resistance Charpy V-notch impact energy, dropweight nil-ductility temperature and tensile properties. Models based on observations of radiation-induced microstructural changes using the field on microprobe and the high resolution transmission electron microscopy provide improved bases for extrapolating the measured changes in fracture properties to wider ranges of irradiation conditions. The principal materials examined within the HSSI program are high-copper welds since their postirradiation properties are most frequently limiting in the continued safe operation of commercial RPVs

Postirradiation notch ductility tests of ESR alloy HT-9 and modified 9Cr-1Mo alloy from UBR reactor experiments

International Nuclear Information System (INIS)

Hawthorne, J.R.

1984-01-01

During this period, irradiation exposures at 300 0 C and 150 0 C to approx. 8 x 10 19 n/cm 2 , E > 0.1 MeV, were completed for the Alloy HT-9 plate and the modified Alloy 9Cr-1Mo plates, respectively. Postirradiation tests of Charpy-V (C/sub v/) specimens were completed for both alloys; other specimen types included in the reactor assemblies were fatigue precracked Charpy-V (PCC/sub v/), half-size Charpy-V, and in the case of the modified 9Cr-1Mo, 2.54 mm thick compact tension specimens

Post-irradiation mechanical tests on F82H EB and TIG welds

International Nuclear Information System (INIS)

Rensman, J.; Osch, E.V. van; Horsten, M.G.; D'Hulst, D.S.

2000-01-01

The irradiation behaviour of electron beam (EB) and tungsten inert gas (TIG) welded joints of the reduced-activation martensitic steel IEA heat F82H-mod. was investigated by neutron irradiation experiments in the high flux reactor (HFR) in Petten. Mechanical test specimens, such as tensile specimens and KLST-type Charpy impact specimens, were neutron irradiated up to a dose level of 2-3 dpa at a temperature of 300 deg. C in the HFR reactor in Petten. The tensile results for TIG and EB welds are as expected with practically no strain hardening capacity left. Considering impact properties, there is a large variation in impact properties for the TIG weld. The irradiation tends to shift the DBTT of particularly the EB welds to very high values, some cases even above +250 deg. C. PWHT of EB-welded material gives a significant improvement of the DBTT and USE compared to the as-welded condition

Effects of irradiation on crack-arrest toughness of two high-copper welds

International Nuclear Information System (INIS)

Iskander, S.K.; Corwin, W.R.; Nanstad, R.K.

1990-01-01

The objective of this study is to determine the effect of neutron irradiation on the shift and shape of the lower-bound curve to crack-arrest data. Two submerged-arc welds with copper contents of 0.23 and 0.31 wt % were commercially fabricated in 220-mm-thick plate. Crack-arrest specimens fabricated from these welds were irradiated at a nominal temperature of 288 degree C to an average fluence of 1.9 x 10 19 neutrons/cm 2 (>1 MeV). A preliminary evaluation of the results shows that the neutron-irradiation induced crack-arrest toughness temperature shift is about the same as the Charpy V-notch impact temperature shift at the 41-J energy level. The shape of the lower-bound curves, (for the range of test temperatures covered), compared to those of the ASME K Ia -curve did not seem to have been altered by irradiation. 10 refs., 9 figs., 7 tabs

Analysis of the irradiation data for A302B and A533B correlation monitor materials

International Nuclear Information System (INIS)

Wang, J.A.

1996-04-01

The results of Charpy V-notch impact tests for A302B and A533B-1 Correlation Monitor Materials (CMM) listed in the surveillance power reactor data base (PR-EDB) and material test reactor data base (TR-EDB) are analyzed. The shift of the transition temperature at 30 ft-lb (T 30 ) is considered as the primary measure of radiation embrittlement in this report. The hyperbolic tangent fitting model and uncertainty of the fitting parameters for Charpy impact tests are presented in this report. For the surveillance CMM data, the transition temperature shifts at 30 ft-lb (ΔT 30 ) generally follow the predictions provided by Revision 2 of Regulatory Guide 1.99 (R.G. 1.99). Difference in capsule temperatures is a likely explanation for large deviations from R.G. 1.99 predictions. Deviations from the R.G. 1.99 predictions are correlated to similar deviations for the accompanying materials in the same capsules, but large random fluctuations prevent precise quantitative determination. Significant scatter is noted in the surveillance data, some of which may be attributed to variations from one specimen set to another, or inherent in Charpy V-notch testing. The major contributions to the uncertainty of the R.G. 1.99 prediction model, and the overall data scatter are from mechanical test results, chemical analysis, irradiation environments, fluence evaluation, and inhomogeneous material properties. Thus in order to improve the prediction model, control of the above-mentioned error sources needs to be improved. In general the embrittlement behavior of both the A302B and A533B-1 plate materials is similar. There is evidence for a fluence-rate effect in the CMM data irradiated in test reactors; thus its implication on power reactor surveillance programs deserves special attention

Neutron irradiation effect on the strength of jointed Ti-6Al-4V alloy

International Nuclear Information System (INIS)

Ishiyama, Shintaro; Miya, Naoyuki

2002-01-01

In order to investigate applicability of Ti alloy to large scaled structural material for fusion reactors, irradiation effect on the mechanical properties of Ti-6Al-4V alloy and its TIG welded material was investigated after neutron irradiation (temperature: 746-788K, fluence: 2.8 x 10 23 n/m 2 (>0.18 MeV). The following results were obtained. (1) Irradiated Ti alloy shows about 20-30% increase of its tensile strength and large degradation of fracture elongation, comparing with those of unirradiated Ti alloy. (2) TIG welded material behaves as Ti alloy in its tensile test, however, shows 30% increase of area reduction in 373-473K, whereas 1/2 degradation of area reduction over 600K. (3) Irradiated TIG welded material behaves heavier embrittlement than that of irradiated Ti alloy. (4) Charpy impact properties of un- and irradiated Ti alloys shift to ductile from brittle fracture and transition temperature shift, ΔT was estimated as about 100K. (5) Remarkable increase of hardness was found, especially in HAZ of TIG welded material after irradiation. (author)

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

Anomalous fracture toughness of irradiated Cr-MoV - Reactor pressure vessel steel

Energy Technology Data Exchange (ETDEWEB)

Ahistrand, R [Imatran Voima Oy (IVO), Helsinki (Finland)

1994-12-31

The base metal Crack Opening Displacement (COD) specimens of the irradiation-induced embrittlement surveillance programme in Loviisa 1 revealed an anomalous behaviour of K{sub JC} compared to the Charpy-V results and to expected results according to standards: about 20% of the COD specimens showed an exceptionally low fracture toughness. Abnormal test specimens were analyzed through fractography, metallography and repeated tests using reconstitution technique: the anomalous behaviour appears to be caused by incorrect pre-fatigue cracking of base metal COD specimens. 7 refs., 9 figs.

Further Charpy impact test results of low activation ferritic alloys, irradiated at 430 degrees C to 67 dpa

International Nuclear Information System (INIS)

Schubert, L.E.; Hamilton, M.L.; Gelles, D.S.

1997-01-01

Miniature CVN specimens of four ferritic alloys, GA3X, F82H, GA4X and HT9, have been impact tested following irradiation at 430 degrees C to 67 dpa. Comparison of the results with those of the previously tested lower dose irradiation condition indicates that the GA3X and F82H alloys, two primary candidate low activation alloys, exhibit virtually identical behavior following irradiation at 430 degrees C to ∼67 dpa and at 370 degrees C to ∼15 dpa. Very little shift is observed in either DBTT or USE relative to the unirradiated condition. The shifts in DBTT and USE observed in both GA4X and HT9 were smaller after irradiation at 430 degrees C to ∼67 dpa than after irradiation at 370 degrees C to ∼15 dpa

Further Charpy impact test results of low activation ferritic alloys, irradiated at 430{degrees}C to 67 dpa

Energy Technology Data Exchange (ETDEWEB)

Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

1997-04-01

Miniature CVN specimens of four ferritic alloys, GA3X, F82H, GA4X and HT9, have been impact tested following irradiation at 430{degrees}C to 67 dpa. Comparison of the results with those of the previously tested lower dose irradiation condition indicates that the GA3X and F82H alloys, two primary candidate low activation alloys, exhibit virtually identical behavior following irradiation at 430{degrees}C to {approximately}67 dpa and at 370{degrees}C to {approximately}15 dpa. Very little shift is observed in either DBTT or USE relative to the unirradiated condition. The shifts in DBTT and USE observed in both GA4X and HT9 were smaller after irradiation at 430{degrees}C to {approximately}67 dpa than after irradiation at 370{degrees}C to {approximately}15 dpa.

Analysis of the Charpy V-notch test for welds

DEFF Research Database (Denmark)

Tvergaard, Viggo; Needleman, A.

2000-01-01

The ductile-brittle transition for a weld is investigated by numerical analyses of Charpy impact specimens. The material response is characterized by an elastic-viscoplastic constitutive relation for a porous plastic solid, with adiabatic heating due to plastic dissipation and the resulting thermal...... softening accounted for. The onset of cleavage is taken to occur when a critical value of the maximum principal stress is attained. The effect of weld strength undermatch or overmatch is investigated for a comparison material, and analyses are also carried out based on experimentally determined flow...... strength variations in a weldment in a HY100 steel. The predicted work to fracture shows a strong sensitivity to the location of the notch relative to the weld, with the most brittle behavior for a notch close to the narrow heat affected zone. The analyses illustrate the strong dependence of the transition...

Determination of the mechanical characteristics of irradiated metals from the results of microhardness tests

International Nuclear Information System (INIS)

Hofman, A.

1999-01-01

To predict the possibilities of using structural materials in nuclear and thermonuclear reactors, it is important to have data on changes of the mechanical characteristics and irradiation obtained from full-scale or simulation tests. Materials are irradiated in nuclear reactors with fast neutrons, the sources of high-energy neutrons with an energy of 14 MeV and the accelerators of charged particles. The restricted volumes for irradiation of these specimens in the systems and also the need to test large numbers of specimens under the same conditions make it necessary to reduce the size of irradiated specimens. To solve this problem, work is being carried out to develop various methods of testing miniature specimens, including tension extrusion of disc-shaped micro-specimens, microhardness, and the Charpy Method. In examination of the irradiation hardening of the materials, the main advantage of the microhardness method is that it makes it possible to examine small specimens. In single microhardness tests, only a small area of the irradiated specimens is examined. This makes it possible to increase the radiation dose and carry out subsequent tests of microhardness on the same specimens. The aim of this work was to determine the possibilities of using the microhardness measurement method for evaluating the mechanical characteristics of metallic materials. The comparison of the data, obtained in microhardness tests and in tensile loading specimens of 0Kh18N10Tsteel, irradiated with neutrons, shows the efficiency of the microhardness method as a tool for investigating the irradiation hardening of reactor materials

Survey of irradiation embrittlement effects on the mechanical properties of alloyed steels

International Nuclear Information System (INIS)

Gillemot, F.

1992-01-01

In the everyday engineering practice the neutron irradiation embrittlement of the PWR wall materials is measured by empirical methods like Charpy impact testing. New developments in fracture mechanics are given better material characteristics. The use of Absorbed Specific Fracture Energy Measured on tensile bars is a promising way to solve the problem. On the other hand the IAEA runs coordinated research program to correlate the chemical analysis with the rate of the neutron embrittlement. Better understanding of the physics of neutron embrittlement should help the life time management of the PWR vessels

Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI series 5

International Nuclear Information System (INIS)

Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O.; Menke, B.H.

1992-10-01

The Fifth Irradiation Series in the Heavy-Section Steel irradiation (HSSI) Program was aimed at obtaining a statistically significant fracture toughness data base on two weldments with high-copper contents to determine the shift and shape of the K lc curve as a consequence of irradiation. The program included irradiated Charpy V-notch impact, tensile, and drop-weight specimens in addition to compact fracture toughness specimens. Compact specimens with thicknesses of 25.4, 50.8, and 101.6 mm [1T C(T), 2T C(T), and 4T C(T), respectively] were irradiated. Additionally, unirradiated 6T C(T) and 8T C(T) specimens with the same K lc measuring capacity as the irradiated specimens were tested. The materials for this irradiation series were two weldments fabricated from special heats of weld wire with copper added to the melt. One lot of Linde 0124 flux was used for all the welds. Copper levels for the two welds are 0.23 and 0.31 wt %, while the nickel contents for both welds are 0.60 wt %. Twelve capsules of specimens were irradiated in the pool-side facility of the Oak Ridge Research Reactor at a nominal temperature of 288 degree C and an average fluence of about 1.5 x 10 19 neutrons/cm 2 (> 1 MeV). This volume, Appendices E and F, contains the load-displacement curves and photographs of the fracture toughness specimens from the 72W weld (0.23 wt % Cu) and the 73 W weld (0.31 wt % Cu), respectively

Conclusions regarding fracture mechanics testing and evaluation of small specimens - As evidenced by the finnish contribution to the IAEA CRP3 programme

Energy Technology Data Exchange (ETDEWEB)

Wallin, K; Valo, M; Rintamaa, R; Torronen, K [Technical Research Centre of Finland, Espoo (Finland); Ahlstrand, R [Imatran Voima Oy (IVO), Helsinki (Finland)

1994-12-31

An extensive mechanical property evaluation has been carried out on various specimens (a Japanese steel plate (JRQ), a French forging material (FFA) and a Japanese forging material (JFL)) in the as-received and irradiated conditions. The mechanical properties measured at different temperatures include Charpy-V notch and instrumented pre-cracked Charpy data and static and dynamic elastic-plastic fracture toughness based on the J-integral, with various specimen size and geometry. Test analysis lead to conclusions regarding the use of small specimen fracture mechanical tests for investigating irradiation effects: CVN{sub pc} and RCT type specimens are suitable for determining the materials fracture toughness even in the ductile/brittle transition region provided the elastic-plastic parameter K{sub JC} is applied together with a statistical size correction. These two specimen types yield equivalent results for the fracture toughness transition shift. Charpy-V appears not to be suitable for estimating the static fracture toughness transition shift. 8 refs., 11 figs.

Estimation of quasi-static J–R curves from Charpy energy and adaptation to ASTM E 1921 reference temperature estimation of ferritic steels

International Nuclear Information System (INIS)

Sreenivasan, P.R.

2014-01-01

Many researchers had suggested a sort of scaling procedure for predicting the quasi-static J–R curves from dynamic J–R curves obtained from instrumented Charpy V-notch (CVN) impact tests using key-curve, compliance or other procedures. Chaouadi, based on extensive tests and literature data, had quantitatively formalized the method and suggested general applicability of his method for a class of steels. In this paper, first, the Chauoadi-procedure is tried on some selected data from the literature (including the data used by Chaouadi and other workers) and an adaptation of the method is suggested using Wallin's as well as Landes's lower bound methods for upper-shelf J–R curve estimation from CVN energy. Using Chaouadi and other data as the benchmark, suitable scaling factors have been determined that enable estimation of quasi-static J–R curves from CVN energy alone, without the need for dynamic CVN J–R curves. The final formulae are given. This new method can be called modified Wallin–Landes procedure. Then this method is applied to fracture toughness and reference temperature (T 0 – ASTM E-1921) estimation from the full Charpy-transition data. The results are compared with those from the author's IGC-procedure, and modifications, if any, are suggested. Based on the new results, it is suggested that the IGC-procedure may be modified as: final T Q-est = T Q-IGC for T Q-Sch dy ≤ 20 °C (in the IGC-procedure the dividing temperature was 60 °C); and for T Q-Sch dy > 20 °C, T Q-IGC = T Q-WLm (different from the IGC-procedre and subscript WLm indicating modified Wallin–Landes procedure). For the 59 or more steels examined (including highly irradiated steels), the T Q-WL estimates at higher temperatures are consistent and conservative; a few non-conservative values are acceptably less than 20 °C, whereas other predictions show non-conservatism of up to 40–50 °C. At lower temperatures, T Q-IGC is consistently conservative and not over

Estimation of quasi-static J–R curves from Charpy energy and adaptation to ASTM E 1921 reference temperature estimation of ferritic steels

Energy Technology Data Exchange (ETDEWEB)

Sreenivasan, P.R., E-mail: sreeprs@yahoo.co.in

2014-04-01

Many researchers had suggested a sort of scaling procedure for predicting the quasi-static J–R curves from dynamic J–R curves obtained from instrumented Charpy V-notch (CVN) impact tests using key-curve, compliance or other procedures. Chaouadi, based on extensive tests and literature data, had quantitatively formalized the method and suggested general applicability of his method for a class of steels. In this paper, first, the Chauoadi-procedure is tried on some selected data from the literature (including the data used by Chaouadi and other workers) and an adaptation of the method is suggested using Wallin's as well as Landes's lower bound methods for upper-shelf J–R curve estimation from CVN energy. Using Chaouadi and other data as the benchmark, suitable scaling factors have been determined that enable estimation of quasi-static J–R curves from CVN energy alone, without the need for dynamic CVN J–R curves. The final formulae are given. This new method can be called modified Wallin–Landes procedure. Then this method is applied to fracture toughness and reference temperature (T{sub 0} – ASTM E-1921) estimation from the full Charpy-transition data. The results are compared with those from the author's IGC-procedure, and modifications, if any, are suggested. Based on the new results, it is suggested that the IGC-procedure may be modified as: final T{sub Q-est} = T{sub Q-IGC} for T{sub Q-Sch}{sup dy} ≤ 20 °C (in the IGC-procedure the dividing temperature was 60 °C); and for T{sub Q-Sch}{sup dy} > 20 °C, T{sub Q-IGC} = T{sub Q-WLm} (different from the IGC-procedre and subscript WLm indicating modified Wallin–Landes procedure). For the 59 or more steels examined (including highly irradiated steels), the T{sub Q-WL} estimates at higher temperatures are consistent and conservative; a few non-conservative values are acceptably less than 20 °C, whereas other predictions show non-conservatism of up to 40–50 °C. At lower temperatures

Effect of heat treatment and irradiation temperature on impact behavior of irradiated reduced-activation ferritic steels

International Nuclear Information System (INIS)

Klueh, R.L.; Alexander, D.J.

1998-01-01

Charpy tests were conducted on eight normalized-and-tempered reduced-activation ferritic steels irradiated in two different normalized conditions. Irradiation was conducted in the Fast Flux Test Facility at 393 C to ∼14 dpa on steels with 2.25, 5, 9, and 12% Cr (0.1% C) with varying amounts of W, V, and Ta. The different normalization treatments involved changing the cooling rate after austenitization. The faster cooling rate produced 100% bainite in the 2.25 Cr steels, compared to duplex structures of bainite and polygonal ferrite for the slower cooling rate. For both cooling rates, martensite formed in the 5 and 9% Cr steels, and martensite with ∼25% δ-ferrite formed in the 12% Cr steel. Irradiation caused an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy. The difference in microstructure in the low-chromium steels due to the different heat treatments had little effect on properties. For the high-chromium martensitic steels, only the 5 Cr steel was affected by heat treatment. When the results at 393 C were compared with previous results at 365 C, all but a 5 Cr and a 9 Cr steel showed the expected decrease in the shift in DBTT with increasing temperature

Characterization by notched and precracked Charpy tests of the in-service degradation of RPV steel fracture toughness

International Nuclear Information System (INIS)

Fabry, A.

1997-01-01

The current engineering and regulatory practice to estimate fracture toughness safety margins for nuclear reactor pressure vessels (RPVs) relies heavily on the CVN impact test. Techniques to estimate in-service toughness degradation directly using a variety of precracked specimens are under development worldwide. Emphasis is on their miniaturization. In the nuclear context, it is essential to address many issues such as representativity of the surveillance programs with respect to the vessel in terms of materials and environment, transferability of test results to the structure (constraint and size effects), lower bound toughness certification, creadibility relative to trends of exising databases. An enhanced RPV surveillance strategy in under development in Belgium. It combines state-of-the-art micromechanical and damage modelling to the evaluation of CVN load-deflection signals, tensile stress-strain curves and slow-bend tests of reconstituted precracked Charpy specimens. A probabilistic micromechanical model has been established for static and dynamic transgranular cleavage initiation fracture toughness in the ductile-brittle transition temperature range. This model allows to project toughness bounds for any steel embrittlement condition from the corresponding CVN and static tensile properties, using a single scaling factor defined by imposing agreement with toughness tests in a single condition. The outstanding finding incorporated by this toughness transfer model is that the microcleavage fracture stress is affected by temperature in the ductile-brittle transition and that this influence is strongly correlated to the flow stress: this explains the shape of the K Ic n K Id temperature curves as well as the actual magnitude of the strain rate and irradiation effects. Furthermore, CVN crack arrest loads and fracture appearance are also taken advantage of in order to estimate K Ia degradation. Finally, the CVN-tensile load-temperature diagram provides substantial

Visual interface for the automation of the instrumented pendulum of Charpy tests used in the surveillance program of reactors vessel of nuclear power plants; Interfase visual para la automatizacion del pendulo instrumentado de pruebas Charpy utilizado en el programa de vigilancia de la vasija de reactores de centrales nucleares

Energy Technology Data Exchange (ETDEWEB)

Rojas S, A.S.; Sainz M, E.; Ruiz E, J.A. [ININ, Carretera Mexico-Toluca Km.36.5, Mpio. de Ocoyoacac, Estado de Mexico (Mexico)]. E-mail: asrs@nuclear.inin.mx; esm@nuclear.inin.mx; jare@nuclear.inin.mx

2004-07-01

Inside the Programs of Surveillance of the nuclear power stations periodic information is required on the state that keep the materials with those that builds the vessel of the reactor. This information is obtained through some samples or test tubes that are introduced inside the core of the reactor and it is observed if its physical characteristics remain after having been subjected to the radiation changes and temperature. The rehearsal with the instrumented Charpy pendulum offers information on the behavior of fracture dynamics of a material. In the National Institute of Nuclear Research (ININ) it has an instrumented Charpy pendulum. The operation of this instrument is manual, having inconveniences to carry out rehearsals with radioactive material, handling of high and low temperatures, to fulfill the normative ones for the realization of the rehearsals, etc. In this work the development of a computational program is presented (virtual instrument), for the automation of the instrumented pendulum. The system has modules like: Card of data acquisition, signal processing, positioning system, tempered system, pneumatic system, compute programs like it is the visual interface for the operation of the instrumented Charpy pendulum and the acquisition of impact signals. This system shows that given the characteristics of the nuclear industry with radioactive environments, the virtual instrumentation and the automation of processes can contribute to diminish the risks to the personnel occupationally exposed. (Author)

Application of small specimens to fracture mechanics characterization of irradiated pressure vessel steels

International Nuclear Information System (INIS)

Sokolov, M.A.; Wallin, K.; McCabe, D.E.

1996-01-01

In this study, precracked Charpy V-notch (PCVN) specimens were used to characterize the fracture toughness of unirradiated and irradiated reactor pressure vessel steels in the transition region by means of three-point static bending. Fracture toughness at cleavage instability was calculated in terms of elastic-plastic K Jc values. A statistical size correction based upon weakest-link theory was performed. The concept of a master curve was applied to analyze fracture toughness properties. Initially, size-corrected PCVN data from A 533 grade B steel, designated HSST Plate O2, were used to position the master curve and a 5% tolerance bound for K Jc data. By converting PCVN data to IT compact specimen equivalent K Jc data, the same master curve and 5% tolerance bound curve were plotted against the Electric Power Research Institute valid linear-elastic K Jc database and the ASME lower bound K Ic curve. Comparison shows that the master curve positioned by testing several PCVN specimens describes very well the massive fracture toughness database of large specimens. These results give strong support to the validity of K Jc with respect to K Ic in general and to the applicability of PCVN specimens to measure fracture toughness of reactor vessel steels in particular. Finally, irradiated PCVN specimens of other materials were tested, and the results are compared to compact specimen data. The current results show that PCVNs demonstrate very good capacity for fracture toughness characterization of reactor pressure vessel steels. It provides an opportunity for direct measurement of fracture toughness of irradiated materials by means of precracking and testing Charpy specimens from surveillance capsules. However, size limits based on constraint theory restrict the operational test temperature range for K Jc data from PCVN specimens. 13 refs., 8 figs., 1 tab

Generic analyses for evaluation of low Charpy upper-shelf energy effects on safety margins against fracture of reactor pressure vessel materials

International Nuclear Information System (INIS)

Dickson, T.L.

1993-07-01

Appendix G to 10 CFR Part 50 requires that reactor pressure vessel beltline material maintain Charpy upper-shelf energies of no less than 50 ft-lb during the plant operating life, unless it is demonstrated in a manner approved by the Nuclear Regulatory Commission (NRC), that lower values of Charpy upper-shelf energy provide margins of safety against fracture equivalent to those in Appendix G to Section XI of the ASME Code. Analyses based on acceptance criteria and analysis methods adopted in the ASME Code Case N-512 are described herein. Additional information on material properties was provided by the NRC, Office of Nuclear Regulatory Research, Materials Engineering Branch. These cases, specified by the NRC, represent generic applications to boiling water reactor and pressurized water reactor vessels. This report is designated as HSST Report No. 140

Belgian Contribution to the IAEA CRP-IV Programme on Assuring Structural Integrity of Reactor Pressure Vessel

International Nuclear Information System (INIS)

Van Walle, E.; Chaouadi, R.; Scibetta, M.; Puzzolante, J.L.; Fabry, A.; Van de Velde, J.

1997-10-01

This report contains the actual status of the Belgian contribution to the IAEA CRP-IV program. Besides Charpy-V impact tests on as-received CRP-IV JRQ-specimens, fracture toughness tests were performed on two geometries: PCCV-specimens and CRB-specimens. The Charpy-V impact results correspond very well with the as-received CRP-III results. The fracture toughness data are also very consistent with identical tests recently performed on remaining as-received CRP-III material. Irradiated broken Charpy-V samples were reconstituted and tested in PCCV-mode. This was done in order to investigate the evolution of the ASME-curve versus the evolution of the mastercurve with irradiation. Initial results were reported. A new CHIVAS-irradiation in the CALLISTO-loop of the BR-2-reactor to support this investigation, is under preparation

Experimental data base for assessment of irradiation induced ageing effects in pre-irradiated RPV materials of German PWR

Energy Technology Data Exchange (ETDEWEB)

Hein, H.; Gundermann, A.; Keim, E.; Schnabel, H. [AREVA NP GmbH (Germany); Ganswind, J. [VGB PowerTech e.V (Germany)

2011-07-01

The 5 year research program CARISMA which ended in 2008 has produced a data base to characterize the fracture toughness of pre-irradiated original RPV (Reactor Pressure Vessel) materials being representative for all four German PWR construction lines of former Siemens/KWU company. For this purpose tensile, Charpy-V impact, crack initiation and crack arrest tests have been performed for three base materials and four weld metals irradiated to neutron fluences beyond the designed EoL range. RPV steels with optimized chemical composition and with high copper as well as high nickel content were examined in this study. The RTNDT concept and the Master Curve approach were applied for the assessment of the generated data in order to compare both approaches. A further objective was to clarify in which extent crack arrest curves can be generated for irradiated materials and how crack arrest can be integrated into the Master Curve approach. By the ongoing follow-up project CARINA the experimental data base will be extended by additional representative materials irradiated under different conditions and with respect to the accumulated neutron fluences and specific impact parameters such as neutron flux and manufacturing effects. The irradiation data cover also the long term irradiation behavior of the RPV steels concerned. Moreover, most of the irradiated materials were and will be used for microstructural examinations to get a deeper insight in the irradiation embrittlement mechanisms and their causal relationship to the material property changes. By evaluation of the data base the applicability of the Master Curve approach for both crack initiation and arrest was confirmed to a large extent. Moreover, within both research programs progress was made in the development of crack arrest test techniques and in specific issues of RPV integrity assessment. (authors)

Impact behavior of 9-Cr and 12-Cr ferritic steels after low-temperature irradiation

International Nuclear Information System (INIS)

Klueh, R.L.; Vitek, J.M.; Corwin, W.R.; Alexander, D.J.

1987-01-01

Miniature Charpy impact specimens of 9Cr-1MoVNb and 12Cr-1MoVW steels and these steels with 1 and 2% Ni were irradiated in the High-Flux Isotope Reactor (HFIR) at 50 0 C to displacement damage levels of up to 9 dpa. Nickel was added to study the effect of transmutation helium. Irradiation caused an increase in the ductile-brittle transition temperature (DBTT). The 9Cr-1MoVNb steels, with and without nickel, showed a larger shift than the 12Cr-1MoVW steels, with and without nickel. The results indicated that helium also increased the DBTT. The same steels were previously irradiated at higher temperatures. From the present and past tests, the effect of irradiation temperature on the DBTT behavior can be evaluated. For the 9Cr-1MoVNb steel, there is a continuous decrease in the magnitude of the DBTT increase up to an irradiation temperature of about 400 0 C, after which the shift drops rapidly to zero at about 450 0 C. The DBTT of the 12Cr-1MoVW steel shows a maximum increase at an irradiation temperature of about 400 0 C and less of an increase at either higher or lower irradiation temperatures

Kinetics of annealing of irradiated surveillance pressure vessel steel

International Nuclear Information System (INIS)

Harvey, D.J.; Wechsler, M.S.

1982-01-01

Indentation hardness measurements as a function of annealing were made on broken halves of Charpy impact surveillance samples. The samples had been irradiated in commercial power reactors to a neutron fluence of approximately 1 x 10 18 neutrons per cm 2 , E > 1 MeV, at a temperature of about 300 0 C (570 0 F). Results are reported for the weld metal, which showed greater radiation hardening than the base plate or heat-affected zone material. Isochronal and isothermal anneals were conducted on the irradiated surveillance samples and on unirradiated control samples. No hardness changes upon annealing occurred for the control samples. The recovery in hardness for the irradiated samples took place mostly between 400 and 500 0 C. Based on the Meechan-Brinkman method of analysis, the activation energy for annealing was found to be 0.60 +- 0.06 eV. According to computer simulation calculations of Beeler, the activation energy for migration of vacancies in alpha iron is about 0.67 eV. Therefore, the results of this preliminary study appear to be consistent with a mechanism of annealing of radiation damage in pressure vessel steels based on the migration of radiation-produced lattice vacancies

Development of Reconstitution Technology for Surveillance Specimens

International Nuclear Information System (INIS)

Yasushi Atago; Shunichi Hatano; Eiichiro Otsuka

2002-01-01

The Japan Power Engineering and Inspection Corporation (JAPEIC) has been carrying out the project titled 'Nuclear Power Plant Integrated Management Technology (PLIM)' consigned by Japanese Ministry of Economy, Trade and Industry (METI) since 1996FY as a 10-years project. As one of the project themes, development of reconstitution technology for reactor pressure vessel (RPV/RV) surveillance specimens, which are installed in RPVs to monitor the neutron irradiation embrittlement on RPV/RV materials, is now on being carried out to deal with the long-term operation of nuclear power plants. The target of this theme is to establish the technical standard for applicability of reconstituted surveillance specimens including the reconstitution of the Charpy specimens and Compact Tension (CT) specimens. With the Charpy specimen reconstitution, application of 10 mm length inserts is used, which enables the conversion of tests from the LT-direction to the TL-direction. This paper presents the basic data from Charpy and CT specimens of RPV materials using the surveillance specimens obtained for un-irradiated materials including the following. 1) Reconstitution Technology of Charpy Specimens. a) The interaction between plastic zone and Heat Affected Zone (HAZ). b) The effects of the possible deviations from the standard specimens for the reconstituted specimens. 2) Reconstitution Technology of CT specimens. a) The correlation between fracture toughness and plastic zone width. Because the project is now in progress, this paper describes the outline of the results obtained as of the end of 2000 FY. (authors)

A study on the Charpy-V impact energy and impact properties of stainless steel

International Nuclear Information System (INIS)

Han, Gill Young

1988-01-01

It has been thought that by analyzing and considering the shock strength and fracture of impact load. We can accurtely determine strength and thus it will be helpful in optimum design. In this experimental study the following results were obtained by using the instrumented impact test for SUS 316 1) The total charpy impact energy is progressively decreased by increasing the shock pressure. 2) The dynamic yield strength is increased by increasing the shock pressure for all test temperatures. 3) The ratio of dynamic yield to static yield strength was found to decrease with increasing shock pressure. (Author)

Crack-arrest tests on two irradiated high-copper welds

International Nuclear Information System (INIS)

Iskander, S.K.; Corwin, W.R.; Nanstad, R.K.

1994-03-01

The objective of the Heavy-Section Steel Irradiation Program Sixth Irradiation Series is to determine the effect of neutron irradiation on the shift and shape of the lower-bound curve to crack-arrest toughness data. Two submerged-arc welds with copper contents of 0.23 and 0.31 wt % were commercially fabricated in 220-mm-thick plate. Crack-arrest specimens fabricated from these welds were irradiated at a nominal temperature of 288 degrees C to an average fluence of 1.9 x 10 19 neutrons/cm 2 (>1 MeV). This is the second report giving the results of the tests on irradiated duplex-type crack-arrest specimens. A previous report gave results of tests on irradiated weld-embrittled-type specimens. Charpy V-notch (CVN) specimens irradiated in the same capsules as the crack-arrest specimens were also tested, and a 41-J transition temperature shift was determined from these specimens. open-quotes Mean close-quote curves of the same form as the American Society of Mechanical Engineers (ASME) K la curve were fit to the data with only the open-quotes reference temperatureclose quotes as a parameter. The shift between the mean curves agrees well with the 41-J transition temperature shift obtained from the CVN specimen tests. Moreover, the four data points resulting from tests on the duplex crack-arrest specimens of the present study did not make a significant change to mean curve fits to either the previously obtained data or all the data combined

Visual interface for the automation of the instrumented pendulum of Charpy tests used in the surveillance program of reactors vessel of nuclear power plants

International Nuclear Information System (INIS)

Rojas S, A.S.; Sainz M, E.; Ruiz E, J.A.

2004-01-01

Inside the Programs of Surveillance of the nuclear power stations periodic information is required on the state that keep the materials with those that builds the vessel of the reactor. This information is obtained through some samples or test tubes that are introduced inside the core of the reactor and it is observed if its physical characteristics remain after having been subjected to the radiation changes and temperature. The rehearsal with the instrumented Charpy pendulum offers information on the behavior of fracture dynamics of a material. In the National Institute of Nuclear Research (ININ) it has an instrumented Charpy pendulum. The operation of this instrument is manual, having inconveniences to carry out rehearsals with radioactive material, handling of high and low temperatures, to fulfill the normative ones for the realization of the rehearsals, etc. In this work the development of a computational program is presented (virtual instrument), for the automation of the instrumented pendulum. The system has modules like: Card of data acquisition, signal processing, positioning system, tempered system, pneumatic system, compute programs like it is the visual interface for the operation of the instrumented Charpy pendulum and the acquisition of impact signals. This system shows that given the characteristics of the nuclear industry with radioactive environments, the virtual instrumentation and the automation of processes can contribute to diminish the risks to the personnel occupationally exposed. (Author)

Heavy-section steel irradiation program. Semiannual progress report, September 1993--March 1994

International Nuclear Information System (INIS)

Corwin, W.R.

1995-04-01

Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents that have the potential for major contamination release. The RPV is the only component in the primary pressure boundary for which, if it should rupture, the engineering safety systems cannot assure protection from core damage. It is therefore imperative to understand and be able to predict the capabilities and limitations of the integrity inherent in the RPV. In particular, ft is vital to fully understand the degree of irradiation-induced degradation of the RPV's fracture resistance that occurs during service. The Heavy-Section Steel (HSS) Irradiation Program has been established; its primary goal is to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior, and in particular the fracture toughness properties of typical pressure-vessel steels, as they relate to light-water RPV integrity. The program includes the direct continuation of irradiation studies previously conducted within the HSS Technology Program augmented by enhanced examinations of the accompanying microstructural changes. During this period, the report on the duplex-type crack-arrest specimen tests from Phase 11 of the K la program was issued, and final preparations for testing the large, irradiated crack-arrest specimens from the Italian Committee for Research and Development of Nuclear Energy and Alternative Energies were completed. Tests on undersize Charpy V-notch (CVN) energy specimens in the irradiated and annealed weld 73W were completed. The results are described in detail in a draft NUREG report. In addition, the ORNL investigation of the embrittlement of the High Flux Isotope RPV indicated that an unusually large ratio of the high-energy gamma-ray flux to fast-neutron flux is most likely responsible for the apparently accelerated embrittlement

Irradiation damage of ferritic/martensitic steels: Fusion program data applied to a spallation neutron source

International Nuclear Information System (INIS)

Klueh, R.L.

1997-01-01

Ferritic/martensitic steels were chosen as candidates for future fusion power plants because of their superior swelling resistance and better thermal properties than austenitic stainless steels. For the same reasons, these steels are being considered for the target structure of a spallation neutron source, where the structural materials will experience even more extreme irradiation conditions than expected in a fusion power plant first wall (i.e., high-energy neutrons that produce large amounts of displacement damage and transmutation helium). Extensive studies on the effects of neutron irradiation on the mechanical properties of ferritic/martensitic steels indicate that the major problem involves the effect of irradiation on fracture, as determined by a Charpy impact test. There are indications that helium can affect the impact behavior. Even more helium will be produced in a spallation neutron target material than in the first wall of a fusion power plant, making helium effects a prime concern for both applications. 39 refs., 10 figs

Characterization by notched and precracked Charpy tests of the in-service degradation of RPV steel fracture toughness

Energy Technology Data Exchange (ETDEWEB)

Fabry, A.

1997-01-01

The current engineering and regulatory practice to estimate fracture toughness safety margins for nuclear reactor pressure vessels (RPVs) relies heavily on the CVN impact test. Techniques to estimate in-service toughness degradation directly using a variety of precracked specimens are under development worldwide. Emphasis is on their miniaturization. In the nuclear context, it is essential to address many issues such as representativity of the surveillance programs with respect to the vessel in terms of materials and environment, transferability of test results to the structure (constraint and size effects), lower bound toughness certification, creadibility relative to trends of exising databases. An enhanced RPV surveillance strategy in under development in Belgium. It combines state-of-the-art micromechanical and damage modelling to the evaluation of CVN load-deflection signals, tensile stress-strain curves and slow-bend tests of reconstituted precracked Charpy specimens. A probabilistic micromechanical model has been established for static and dynamic transgranular cleavage initiation fracture toughness in the ductile-brittle transition temperature range. This model allows to project toughness bounds for any steel embrittlement condition from the corresponding CVN and static tensile properties, using a single scaling factor defined by imposing agreement with toughness tests in a single condition. The outstanding finding incorporated by this toughness transfer model is that the microcleavage fracture stress is affected by temperature in the ductile-brittle transition and that this influence is strongly correlated to the flow stress: this explains the shape of the K{sub Ic}n K{sub Id} temperature curves as well as the actual magnitude of the strain rate and irradiation effects. Furthermore, CVN crack arrest loads and fracture appearance are also taken advantage of in order to estimate K{sub Ia} degradation. Finally, the CVN-tensile load-temperature diagram

Detection of irradiated ingredients included in low quantity in non-irradiated food matrix. 1. Extraction and ESR analysis of bones from mechanically recovered poultry meat

NARCIS (Netherlands)

Marchioni, Eric; Horvatovich, Péter; Charon, Helène; Kuntz, Florent

2005-01-01

Protocol EN 1786 for the detection of irradiated food by electron spin resonance (ESR) spectroscopy was not conceived for the detection of irradiated bone-containing ingredients included in low concentration in non-irradiated food. An enzymatic hydrolysis method, realized at 55 degrees C, has been

Definition of the minimum longitude of insert in the rebuilding of Charpy test tubes for surveillance and life extension of vessels in Mexico; Definicion de la longitud minima de inserto en la reconstitucion de probetas Charpy para vigilancia y extension de vida de vasijas en Mexico

Energy Technology Data Exchange (ETDEWEB)

Romero C, J.; Hernandez C, R.; Rocamontes A, M., E-mail: jesus.romero@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2011-11-15

In the National Institute of Nuclear Research (Mexico) a welding system for the rebuilding of Charpy test tubes has been developed, automated, qualified and used for the surveillance of the mechanical properties (mainly embrittlement) of the vessel. This system uses the halves of the rehearsed Charpy test tubes of the surveillance capsules extracted of the reactors, to obtain, of a rehearsed test tube, two reconstituted test tubes. This rebuilding process is used so much in the surveillance program like in the potential extension of the operation license of the vessel. To the halves of Charpy test tubes that have been removed the deformed part by machine are called -insert- and in a very general way the rebuilding consists in weld with the welding process -Stud Welding- two metallic implants in the ends of the insert, to obtain a reconstituted test tube. The main characteristic of this welding are the achieved small dimensions, so much of the areas welded as of the areas affected by the heat. The applicable normative settles down that the minim longitude of the insert for the welding process by Stud Welding it should be of 18 mm, however according to the same normative this longitude can diminish if is demonstrated analytic or experimentally that the central volume of 1 cm{sup 3} in the insert is not affected. In this work the measurement of the temperature profiles to different distances of the welding interface is presented, defining an equation for the maximum temperatures reached in function of the distance, on the other hand the real longitude affected in the test tube by means of metallography is determined and this way the minimum longitude of the insert for this developed rebuilding system was determined. (Author)

Irradiation effects on tensile ductility and dynamic toughness of ferritic-martensitic 7-12 Cr steels

International Nuclear Information System (INIS)

Preininger, D.

2006-01-01

the reduction of toughness USE. As the model-assisted analyse of data observed on various RAFM steels at 60 dpa have shown, the comparably weaker normalised toughness reductions U = USE/USEo at lower irradiation temperatures of 100-300 o C are caused mainly by strain-induced fracture appearance. The superimposed formation in 10-12CrMoVNb steels strongly increases DBTT and particularly also the normalised toughness reduction U due to pronounced work hardening in connection with evident reductions of ductile and dynamic fracture stresses. The DBTT generally increases with decreasing uniform ductility more stronger at smaller precipitate sizes and weaker initial hardening. Dynamic toughness USE otherwise increases with increasing fracture strain and uniform ductility indicating that these are qualitative similar properties. The obtained analytical and numerical results are especially used for analyses of experimental results of ductility and Charpy-impact properties obtained from 10-12CrMoVNb and (7-9)CrWVTa(Ti)-RAFM steels including Eurofer'97 below 60 dpa at T I =100-500 o C. Additionally, the possible methods for extrapolating ductility and toughness data to high doses will be considered including the effect of oxide dispersion hardening in ODS-RAFM steels

Relationship between irradiation hardening and embrittlement of pressure vessel steels

International Nuclear Information System (INIS)

Odette, G.R.; Lombrozo, P.M.; Wullaert, R.A.

1984-01-01

Based on a large body of test and power reactor data, empirical relationships between irradiation strengthening and embrittlement are derived. It is shown that the Charpy V-notch (C /SUB v/ ) 41-J indexed transition temperature increases and the upper-shelf energy decreases systematically with increases in the yield stress. The transition temperature shifts are related to two mechanisms: increases in the maximum temperature of elastic-cleavage fracture, and decreases in the slope of the C, energy versus test temperature curve associated with reductions in the upper-shelf energy. The cleavage shift contribution, which is usually dominant, can be predicted from the initial temperature of fracture at general yield and the change in ambient temperature static yield stress. In developing this simplified cleavage fracture model, it is shown that: (a) yield stress changes are independent of temperature and strain rate; (b) the increase in yield stress with decreasing temperature is independent of the strain rate, irradiation, and metallurgical state; and (c) the microcleavage fracture stress is independent of irradiation and temperature. A semi-empirical procedure for estimating the shift contribution due to upper-shelf energy decreases and the total temperature shift at 41 J, based on the observation of an approximately constant temperature interval of the transition regime, is proposed, along with a method for forecasting the entire irradiated C, curve

Dynamic Toughness Testing of Pre-Cracked Charpy V-Notch Specimens. Convention ELECTRABEL - SCK-CEN

Energy Technology Data Exchange (ETDEWEB)

Lucon, E

1999-04-01

This document describes the experimental and analytical procedures which have been adopted at the laboratories of the Belgian Nuclear Research Centre SCK-CEN for performing dynamic toughness tests on pre-cracked Charpy-V specimens. Such procedures were chosen on the basis of the existing literature on the subject, with several updates in the data analysis stages which reflect more recent developments in fracture toughness testing. Qualification tests have been carried out on PCCv specimens of JRQ steel, in order to assess the reliability of the results obtained; straightforward comparisons with reference data have been performed, as well as more advanced analyses using the Master Curve approach. Aspects related to machine compliance and dynamic tup calibration have also been addressed.

Radiation annealing mechanisms of low-alloy reactor pressure vessel steels dependent on irradiation temperature and neutron fluence

International Nuclear Information System (INIS)

Pachur, D.

1982-01-01

Heat treatment after irradiation of reactor pressure vessel steels showed annealing of irradiation embrittlement. Depending on the irradiation temperature, the embrittlement started to anneal at about 220 0 C and was completely annealed at 500 0 C with 4 h of annealing time. The annealing behavior was normally measured in terms of the Vickers hardness increase produced by irradiation relative to the initial hardness as a function of the annealing temperature. Annealing results of other mechanical properties correspond to hardness results. During annealing, various recovery mechanisms occur in different temperature ranges. These are characterized by activation energies from 1.5 to 2.1 eV. The individual mechanisms were determined by the different time dependencies at various temperatures. The relative contributions of the mechanisms showed a neutron fluence dependence, with the lower activation energy mechanisms being predominant at low fluence and vice versa. In the temperature range where partial annealing of a mechanism took place during irradiation, an increase in activation energy was observed. Trend curves for the increase in transition temperature with irradiation, for the relative increase of Vickers hardness and yield strength, and for the relative decrease of Charpy-V upper shelf energy are interpreted by the behavior of different mechanisms

Development of a miniaturized bulge test (small punch test) for post-irradiation mechanical property evaluation

International Nuclear Information System (INIS)

Eto, Motokuni; Suzuki, Masahide; Nishiyama, Yutaka; Fukaya, Kiyoshi; Jitsukawa, Shiro; Misawa, Toshihei

1993-01-01

To examine the effectiveness of the small punch test for evaluating strength and toughness of irradiated ferritic steels, detailed procedures are described aiming at standardization of the test. The statistical approach to analysis of the SP energy as a function of temperature for evaluation of DBTT was also reviewed. The method was then applied to neutron-irradiated ferritic steels, which included F-82, F-82H, HT-9, and 2 1/4 Cr-1Mo steel. Fluence and irradiation temperatures ranged from 2 to 12 x 10 23 n/m 2 (E ≥ 1 MeV) and from 573 to 673 K, respectively. Comparison of parameters obtained from the small punch test with the properties measured by the conventional method indicated that: (a) the 0.2% offset stress and the ultimate tensile strength at room temperature can be correlated well with the parameters, P y /(t 0 ) 2 and P max /(t 0 ) 2 , respectively. Here, P y and P max are the loads corresponding to the yield and the maximum, and t 0 is the initial thickness of a specimen; (b) fracture toughness, J IC , can be evaluated using equivalent fracture strain, anti ε qf , and the previously established relationship between these values; and (c) DBTT measured by a Charpy test can be predicted from the results of temperature dependence of SP energy determined from the area under the load-deflection curve using a statistical analysis based on a Weibull distribution

Definition of the minimum longitude of insert in the rebuilding of Charpy test tubes for surveillance and life extension of vessels in Mexico

International Nuclear Information System (INIS)

Romero C, J.; Hernandez C, R.; Rocamontes A, M.

2011-11-01

In the National Institute of Nuclear Research (Mexico) a welding system for the rebuilding of Charpy test tubes has been developed, automated, qualified and used for the surveillance of the mechanical properties (mainly embrittlement) of the vessel. This system uses the halves of the rehearsed Charpy test tubes of the surveillance capsules extracted of the reactors, to obtain, of a rehearsed test tube, two reconstituted test tubes. This rebuilding process is used so much in the surveillance program like in the potential extension of the operation license of the vessel. To the halves of Charpy test tubes that have been removed the deformed part by machine are called -insert- and in a very general way the rebuilding consists in weld with the welding process -Stud Welding- two metallic implants in the ends of the insert, to obtain a reconstituted test tube. The main characteristic of this welding are the achieved small dimensions, so much of the areas welded as of the areas affected by the heat. The applicable normative settles down that the minim longitude of the insert for the welding process by Stud Welding it should be of 18 mm, however according to the same normative this longitude can diminish if is demonstrated analytic or experimentally that the central volume of 1 cm 3 in the insert is not affected. In this work the measurement of the temperature profiles to different distances of the welding interface is presented, defining an equation for the maximum temperatures reached in function of the distance, on the other hand the real longitude affected in the test tube by means of metallography is determined and this way the minimum longitude of the insert for this developed rebuilding system was determined. (Author)

The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

International Nuclear Information System (INIS)

Toivonen, A.; Moilanen, P.; Pyykkoenen, M.; Taehtinen, S.; Rintamaa, R.; Saario, T.

1998-01-01

Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (orig.)

The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

Energy Technology Data Exchange (ETDEWEB)

Toivonen, A.; Moilanen, P.; Pyykkoenen, M.; Taehtinen, S.; Rintamaa, R.; Saario, T. [Valtion Teknillinen Tutkimuskeskus, Espoo (Finland)

1998-11-01

Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (orig.)

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

Change of Charpy impact fracture behavior of precracked ferritic specimens due to thermal aging in sodium

International Nuclear Information System (INIS)

Hu, W.L.

1985-12-01

A series of tests were conducted to evaluate the effect of sodium on the impact fracture behavior of precracked Charpy specimens made of HT-9 weldment. One set of samples was precracked prior to sodium aging and the other set was precracked after aging in sodium. Both set of specimens exhibited the same DBTT. Samples precracked prior to sodium exposure, however, showed a 40% reduction in the upper shelf energy (USE) as compared to the set precracked after aging. The results suggest that the fracture toughness of the material may be reduced if an existing crack was soaked in sodium at elevated temperature for a period of time

Guidelines for prediction of irradiation embrittlement of operating WWER-440 reactor pressure vessels

International Nuclear Information System (INIS)

2005-06-01

This TECDOC has been developed under an International Atomic Energy Agency Coordinated Research Project (CRP) entitled Evaluation of Radiation Damage of WWER Reactor Pressure Vessels (RPV) using Database on RPV Materials to develop the guidelines for prediction of radiation damage to WWER-440 PRVs. The WWER-440 RPV was designed by OKB Gidropress, Russian Federation, the general designer. Prediction of irradiation embrittlement of RPV materials is usually done in accordance with relevant codes and standards that are based on the large amounts of information from surveillance and research programmes. The existing Russian code (standard for strength calculations of components and piping in NPPs - PNAE G 7-002-86) for the WWER RPV irradiation embrittlement assessment was approved more than twenty years ago and based mostly on the experimental data obtained in research reactors with accelerated irradiation. Nevertheless, it is still in use and generally consistent with new data. The present publication presents the analyses using all available data required for more precise prediction of radiation embrittlement of WWER-440 RPV materials. Based on the fact that it contains a large amount of data from surveillance programmes as well as research programmes, the IAEA International Database on RPV Materials (IDRPVM) is used for the detailed analysis of irradiation embrittlement of WWER RPV materials. Using IDRPVM, the guideline is developed for assessment of irradiation embrittlement of RPV ferritic materials as a result of degradation during operation. Two approaches, i.e. transition temperatures based on Charpy impact notch toughness, as well as based on static fracture toughness tests, are used in RPV integrity evaluation. The objectives of the TECDOC are the analysis of irradiation embrittlement data for WWER- 440 RPV materials using IDRPVM database, evaluation of predictive formulae depending on chemical composition of the material, neutron fluence, flux, and

Multimodal approaches including three-dimensional conformal re-irradiation for recurrent or persistent esophageal cancer. Preliminary results

International Nuclear Information System (INIS)

Yamaguchi, Shinsaku; Ohguri, Takayuki; Imada, Hajime

2011-01-01

The purpose of this study was to assess the toxicity and efficacy of multimodal approaches, including three-dimensional conformal re-irradiation, for patients with recurrent or persistent esophageal cancer after radiotherapy. Thirty-one patients with esophageal cancer treated with three-dimensional conformal re-irradiation were retrospectively analyzed. Of the 31 patients, 27 patients received concurrent chemotherapy, and 14 patients underwent regional hyperthermia during the re-irradiation. We divided the patients into two groups on the basis of their clinical condition: the curative group (n=11) or the palliative group (n=20). Severe toxicities were detected in one patient with Grade 3 esophageal perforation in the curative group, and 5 patients had a Grade 3 or higher toxicity of the esophagus in the palliative group. Advanced T stage at the time of re-irradiation was found to be significantly correlated with Grade 3 or higher toxicity in the esophagus. For the curative group, 10 (91%) of 11 patients had an objective response. For the palliative group, symptom relief was recognized in 8 (57%) of 14 patients with obvious swallowing difficulty. In conclusion, in the curative group with early-stage recurrent or persistent esophageal cancer, the multimodal approaches, including three-dimensional conformal re-irradiation, may be feasible, showing acceptable toxicity and a potential value of promising results, although further evaluations especially for the toxicities of the organs at risk are required. In the palliative group, the benefit of our therapy may be restrictive because severe esophageal toxicities were not uncommon in the patients with advanced T stage at the time of re-irradiation. (author)

Detection of irradiated ingredients included in low quantity in non-irradiated food matrix. 2. ESR analysis of mechanically recovered poultry meat and TL analysis of spices

NARCIS (Netherlands)

Marchioni, Eric; Horvatovich, Péter; Charon, Helène; Kuntz, Florent

2005-01-01

Protocols EN 1786 and EN 1788 for the detection of irradiated food by electron spin resonance spectroscopy (ESR) and thermoluminescence (TL) were not conceived for the detection of irradiated ingredients included in low concentration in nonirradiated food. An enzymatic hydrolysis method, realized at

Quantitative analysis of biological responses to low dose-rate γ-radiation, including dose, irradiation time, and dose-rate

International Nuclear Information System (INIS)

Magae, J.; Furukawa, C.; Kawakami, Y.; Hoshi, Y.; Ogata, H.

2003-01-01

Full text: Because biological responses to radiation are complex processes dependent on irradiation time as well as total dose, it is necessary to include dose, dose-rate and irradiation time simultaneously to predict the risk of low dose-rate irradiation. In this study, we analyzed quantitative relationship among dose, irradiation time and dose-rate, using chromosomal breakage and proliferation inhibition of human cells. For evaluation of chromosome breakage we assessed micronuclei induced by radiation. U2OS cells, a human osteosarcoma cell line, were exposed to gamma-ray in irradiation room bearing 50,000 Ci 60 Co. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, cytoplasm and nucleus were stained with DAPI and propidium iodide, and the number of binuclear cells bearing micronuclei was determined by fluorescent microscopy. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [3H] thymidine was pulsed for 4 h before harvesting. Dose-rate in the irradiation room was measured with photoluminescence dosimeter. While irradiation time less than 24 h did not affect dose-response curves for both biological responses, they were remarkably attenuated as exposure time increased to more than 7 days. These biological responses were dependent on dose-rate rather than dose when cells were irradiated for 30 days. Moreover, percentage of micronucleus-forming cells cultured continuously for more than 60 days at the constant dose-rate, was gradually decreased in spite of the total dose accumulation. These results suggest that biological responses at low dose-rate, are remarkably affected by exposure time, that they are dependent on dose-rate rather than total dose in the case of long-term irradiation, and that cells are getting resistant to radiation after the continuous irradiation for 2 months. It is necessary to include effect of irradiation time and dose-rate sufficiently to evaluate risk

An Expanded UV Irradiance Database from TOMS Including the Effects of Ozone, Clouds, and Aerosol Attenuation

Science.gov (United States)

Herman, J.; Krotkov, N.

2003-01-01

The TOMS UV irradiance database (1978 to 2003) has been expanded to include five new products (noon irradiance at 305,310,324, and 380 nm, and noon erythemal-weighted irradiance), in addition to the existing erythemal daily exposure, that permit direct comparisons with ground-based measurements from spectrometers and broadband instruments. The new data are available on http://toms.gsfc.nasa.gov/>http://toms.gsfc.nasa.gov. Comparisons of the TOMS estimated irradiances with ground-based instruments are given along with a review of the sources of known errors, especially the recent improvements in accounting for aerosol attenuation. Trend estimations from the new TOMS irradiances permit the clear separation of changes caused by ozone and those caused by aerosols and clouds. Systematic differences in cloud cover are shown to be the most important factor in determining regional differences in UV radiation reaching the ground for locations at the same latitude (e.g., the summertime differences between Australia and the US southwest).

The irradiation embrittlement of two pressure vessel steels -Contribution of local approach

Energy Technology Data Exchange (ETDEWEB)

Soulat, P; Marini, B [CEA Centre d` Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service de Recherches Metallurgiques Appliquees; Miannay, D; Horowitz, H [CEA Centre d` Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Schill, R [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Mecanique et de Technologie

1994-12-31

Within the IAEA Coordinated Research Programme on ``Optimizing the Reactor Pressure Vessel Surveillance Programmes and their Analyses``, the French participation has been focused on the contribution of the local approach to the determination of the sensitivity to radiation embrittlement of two different pressure vessel steels: a low sensitive French forging steel (FFA) and a high sensitive ``monitor`` Japanese plate steel (JRQ) were irradiated to a fluence of 3.10{sup 19} n/cm{sup 2} at 290 C. The irradiation embrittlement of the two steels measured by the shift of Charpy V transition curves is in good agreement with the estimated shifts given by theoretical prediction. The fracture toughness properties were examined at low temperature with brittle fracture, and at service temperature (290 C), with ductile tearing. The values of K{sub 1C} or K{sub JC} for the brittle fracture and J{sub 1C} for the ductile fracture are compared to predictions established using the local approach of cleavage fracture (Weibull analysis) and the critical rate of void growth respectively. 8 refs., 14 figs., 10 tabs.

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish

International Nuclear Information System (INIS)

Smith, Richard W.; Seymour, Colin B.; Moccia, Richard D.; Mothersill, Carmel E.

2016-01-01

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48 h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyed eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. - Highlights: • We evaluated the transgenerational effect of early life irradiation in rainbow trout. • Trout irradiated as eggs, yolk sac larvae or first feeders were crossed. • A transgenerational effect was evident in two generations after irradiation. • F1 and F2 generation fish induced a bystander effect in non-irradiated fish. • The precise effects were tissue specific and dependent on

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish

Energy Technology Data Exchange (ETDEWEB)

Smith, Richard W., E-mail: rich.wilson.smith@gmail.com [Department of Animal Biosciences, University of Guelph, Guelph, Ontario (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario (Canada); Seymour, Colin B. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario (Canada); Moccia, Richard D. [Department of Animal Biosciences, University of Guelph, Guelph, Ontario (Canada); Mothersill, Carmel E. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario (Canada)

2016-02-15

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48 h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyed eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. - Highlights: • We evaluated the transgenerational effect of early life irradiation in rainbow trout. • Trout irradiated as eggs, yolk sac larvae or first feeders were crossed. • A transgenerational effect was evident in two generations after irradiation. • F1 and F2 generation fish induced a bystander effect in non-irradiated fish. • The precise effects were tissue specific and dependent on

Models for embrittlement recovery due to annealing of reactor pressure vessel steels

International Nuclear Information System (INIS)

Eason, E.D.; Wright, J.E.; Nelson, E.E.; Odette, G.R.; Mader, E.V.

1995-05-01

The reactor pressure vessel (RPV) surrounding the core of a commercial nuclear power plant is subject to embrittlement due to exposure to high energy neutrons. The effects of irradiation embrittlement can be reduced by thermal annealing at temperatures higher than the normal operating conditions. However, a means of quantitatively assessing the effectiveness of annealing for embrittlement recovery is needed. The objective of this work was to analyze the pertinent data on this issue and develop quantitative models for estimating the recovery in 30 ft-lb (41 J) Charpy transition temperature and Charpy upper shelf energy due to annealing. Data were gathered from the Test Reactor Embrittlement Data Base and from various annealing reports. An analysis data base was developed, reviewed for completeness and accuracy, and documented as part of this work. Independent variables considered in the analysis included material chemistries, annealing time and temperature, irradiation time and temperature, fluence, and flux. To identify important variables and functional forms for predicting embrittlement recovery, advanced statistical techniques, including pattern recognition and transformation analysis, were applied together with current understanding of the mechanisms governing embrittlement and recovery. Models were calibrated using multivariable surface-fitting techniques. Several iterations of model calibration, evaluation with respect to mechanistic and statistical considerations, and comparison with the trends in hardness data produced correlation models for estimating Charpy upper shelf energy and transition temperature after irradiation and annealing. This work provides a clear demonstration that (1) microhardness recovery is generally a very good surrogate for shift recovery, and (2) there is a high level of consistency between the observed annealing trends and fundamental models of embrittlement and recovery processes

On the ductile-to-brittle transition behavior of martensitic alloys neutron irradiated to 26 dpa

International Nuclear Information System (INIS)

Hu, W.L.; Gelles, D.S.

1987-01-01

Charpy impact tests were conducted on specimens made of HT-9 and 9Cr-1Mo in various heat treatment conditions which were irradiated in EBR-II to 26 dpa at 390 to 500 0 C. The results are compared with previous results on specimens irradiated to 13 dpa. HT-9 base metal irradiated at low temperatures showed a small additional increase in ductile brittle transition temperature and a decrease in upper shelf energy from 13 to 26 dpa. No fluence effect was observed in 9Cr-1Mo base metal. The 9Cr-1Mo weldment showed degraded DBTT but improved USE response compared to base metal, contrary to previous findings on HT-9. Significant differences were observed in HT-9 base metal between mill annealed material and normalized and tempered material. The highest DBTT for HT-9 alloys was 50 0 C higher than for the worst case in 9Cr-1Mo alloys. Fractography and hardness measurements were also obtained. Significant differences in fracture appearance were observed in different product forms, although no dependence on fluence was observed. Failure was controlled by the preirradiation microstructure

Effect of chemical composition on irradiation embrittlement and annealing in Ni-Cr-Mo-V reactor pressure vessel steel

Energy Technology Data Exchange (ETDEWEB)

Novosad, P [Czech Nuclear Society, Prague (Czech Republic)

1994-12-31

Results concerning copper and phosphorus influence on radiation-induced changes in the Ni-Cr-Mo-V steel mechanical properties, are presented. Correlations between different mechanical properties for steels with different chemical composition, are presented. A comparison of transition temperature shifts obtained for static and dynamic fracture toughness tests and Charpy impact tests, is discussed. Recovery of radiation hardening, measured by hardness test after isochronal annealing of steels with different compositions, is also shown. Copper content strongly affects irradiation-induced changes of mechanical properties, but phosphorus content in connection with variable copper content has only a small effect. (author). 4 refs., 4 figs., 4 tabs.

Fracture Toughness Evaluation of Kori-1 RPV Beltline Weld for a Long-Term Operation

International Nuclear Information System (INIS)

Lee, Bong-Sang; Kim, Min-Chul; Ahn, Sang-Bok; Kim, Byung-Chul; Hong, Jun-Hwa

2007-01-01

Irradiation embrittlement of RPV (reactor pressure vessel) material is the most important aging issue for a long-term operation of nuclear power plants. KORI unit 1, which is the first PWR in Korea, is approaching its initial licensing life of 30 years. In order to operate the reactor for another 10 years and more, it should be demonstrated that the irradiation embrittlement of the reactor will be adequately managed by ensuring that the fracture toughness properties have a certain level of the safety margin. The current regulation requires Charpy V-notch impact data through conventional surveillance tests. It is based on the assumption that Charpy impact test results are well correlated with the fracture toughness properties of many engineering steels. However, Charpy V-notch impact data may not be adequate to estimate the fracture toughness of certain materials, such as Linde 80 welds. During the last decade, a tremendous number of fracture toughness data on many RPV steels have been produced in accordance with the new standard test method, the so-called master curve method. ASTM E1921 represents a revolutionary advance in characterizing fracture toughness of RPV steels, since it permits establishing the ductile to brittle transition portion of the fracture toughness curve with direct measurements on a relatively small number of relatively small specimens, such as pre-cracked Charpy specimens. Actual fracture toughness data from many different RPV steels revealed that the Charpy test estimations are generally conservative with the exception of a few cases. Recent regulation codes in USA permit the master curve fracture toughness methodology in evaluating an irradiation embrittlement of commercial nuclear reactor vessels

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish.

Science.gov (United States)

Smith, Richard W; Seymour, Colin B; Moccia, Richard D; Mothersill, Carmel E

2016-02-01

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyed eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of the strength ratio for pre-cracked Charpy specimens for the measuring, of the dynamic toughness of steels

International Nuclear Information System (INIS)

Pereira, L.C.; Darwish, F.A.I.

1981-01-01

The specimen strength ratio (R sub(sb)) determined for precraked Charpy specimens fractured in dynamic bending was correlated with plane strain fracture toughness (K sub(Id)) obtained through valid measurements of the J-integral at the moment of fracture initiation in various microstructures of the AISI 4140 steel. The results indicate a linear relationship between K sub(Id) and R sub(sb) for the microstructures considered in this work. The range of validity of this linear correlation is presented and discussed in terms of the ASTM E399 specimen size criterion. (Author) [pt

Parenteral nutrition including polyamine under experimental irradiation of the abdomen

International Nuclear Information System (INIS)

Moroz, B.B.; Fedorovskij, L.L.; Lyashchenko, Yu.N.

1982-01-01

White rats-males were used in experiments. Irradiation dose of abdomen area is 13.5 Gy (1400 R). Parenteral nutrition using aminoacid preparation of polyamine affects favourably during radiation damage resulted from local irradiation of abdomen area. This was manifested in weakening of gastroenteric syndrom, reduction of 3.5 day death of animals and increase of their 30 day survival rate, intensification of recovery processes in small intestine, decrease of cell devastation in bone marrow

Effect of mechanical alloying atmosphere on the microstructure and Charpy impact properties of an ODS ferritic steel

International Nuclear Information System (INIS)

Oksiuta, Z.; Baluc, N.

2009-01-01

Two types of oxide dispersion strengthened (ODS) ferritic steels, with the composition of Fe-14Cr-2W-0.3Ti-0.3Y 2 O 3 (in weight percent), have been produced by mechanically alloying elemental powders of Fe, Cr, W, and Ti with Y 2 O 3 particles either in argon atmosphere or in hydrogen atmosphere, degassing at various temperatures, and compacting the mechanically alloyed powders by hot isostatic pressing. It was found in particular that mechanical alloying in hydrogen yields a significant reduction in oxygen content in the materials, a lower dislocation density, and a strong improvement in the fast fracture properties of the ODS ferritic steels, as measured by Charpy impact tests.

The Change of the Seebeck Coefficient Due to Neutron Irradiation and Thermal Fatigue of Nuclear Reactor Pressure Vessel Steel and its Application to the Monitoring of Material Degradation

International Nuclear Information System (INIS)

Niffenegger, M.; Reichlin, K.; Kalkhof, D.

2002-05-01

The monitoring of material degradation, that might be caused by neutron irradiation and thermal fatigue, is an important topic in lifetime extension of nuclear power plants. We therefore investigated the application of the Seebeck effect for determining material degradation of common reactor pressure vessel steel. The Seebeck coefficient (SC) of several irradiated Charpy specimens made from Japanese JRQ-steel were measured. The specimens suffered a fluence from 0 up to 4.5 x 10 19 neutrons per cm 2 with energies higher than 1 MeV. The measured changes of the SC within this range were about 500 nV, increasing continuously in the range under investigation. Some indications of saturation appeared at fluencies larger than 4.55 x 10 19 neutrons per cm 2 . We obtained a linear dependency between the SC and the temperature shift ΔT 41 of the Charpy-Energy- Temperature curve which is widely used to characterize material embrittlement. Similar measurements were performed on specimens made from the widely used austenitic steel X6CrNiTi18-10 (according to DIN 1.4541) that were fatigued by applying a cyclic strain amplitude of 0.28%. For this kind of fatigue the observed change of SC was somewhat smaller than for the irradiated specimens. Further investigations were made to quantify the size of the gage volume in which the thermoelectric power is generated. It appeared that the information gathered from a Thermo Electric Power (TEP) measurement is very local. To overcome this problem we propose a novel TEP-method using a Thermoelectric Scanning Microscope (TSM). We finally conclude that the change of the SC has a potential for monitoring of material degradation due to neutron irradiation and thermal fatigue, but it has to be taken into account that several influencing parameters could contribute to the TEP in either an additional or extinguishing manner. A disadvantage of the method is the requirement of a clean surface without any oxide layer. A part of this disadvantage can

A study of the mechanical property changes of irradiation embrittled pressure vessel steels and their response to annealing treatments

International Nuclear Information System (INIS)

Tipping, P.; Waeber, W.B.; Mercier, O.

1991-01-01

Isochronal and isothermal heat treatments have been used to study the recovery of hardness of a neutron irradiated pressure vessel steel forging for the purposes of planning and realizing IAR (Irradiated-Annealed-Reirradiated) experiments. Charpy V notch tests have been performed to assess the toughness of the material irradiated to various fluences up to a maximum of 5 x 10 19 n/cm 2 , E>1 MeV at 290 o C with and without an intermediate annealing treatment at 450 o C x 168 h. The effect of the intermediate annealing was evident. The recovery of the upper shelf energies was strongly enhanced by a thermal ageing effect due to the annealing treatment for all fluence levels investigated compared to the irradiated condition. The transition temperature shifts exhibited a less straightforward behaviour due to the mentioned ageing effect which opposed the recovery process for this property leading to a net shift increase at lower and to a net recovery benefit at higher fluence levels. A phenomenological model description for the IAR embrittlement-recovery path is suggested. For this material and these irradiation conditions a plant life extension (PLEX) may be brought about if a specific annealing treatment is applied at a fluence level that is half the anticipated target fluence F for PLEX. In this case it was found that F>1.6 x 10 19 n/cm 2 . (author)

Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels

Science.gov (United States)

Cao, Wenquan; Zhang, Mingda; Huang, Chongxiang; Xiao, Shuyang; Dong, Han; Weng, Yuqing

2017-02-01

Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400-450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0-1.2 GPa at room temperature, which is nearly 3-5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry.

Comparison between instrumented precracked Charpy and compact specimen tests of carbon steels

International Nuclear Information System (INIS)

Nanstad, R.K.

1980-01-01

The General Atomic Company High Temperature Gas-Cooled Reactor (HTGR) is housed within a prestressed concrete reactor vessel (PCRV). Various carbon steel structural members serve as closures at penetrations in the vessel. A program of testing and evaluation is underway to determine the need for reference fracture toughness (K/sub IR/) and indexing procedures for these materials as described in Appendix G to Section III, ASME Code for light water reactor steels. The materials of interest are carbon steel forgings (SA508, Class 1) and plates (SA537, Classes 1 and 2) as well as weldments of these steels. The fracture toughness behavior is characterized with instrumented precracked Charpy V-votch specimens (PCVN) - slow-bend and dynamic - and compact specimens (10-mm and 25-mm thicknesses) using both linear elastic (ASTM E399) and elastic-plastic (equivalent Energy and J-Integral) analytical procedures. For the dynamic PCVN tests, force-time traces are analyzed according to the procedures of the Pressure Vessel Research Council (PVRC)/Metal Properties Council (MPC). Testing and analytical procedures are discussed and PCVN results are compared to those obtained with compact specimens

Embrittlement recovery due to annealing of reactor pressure vessel steels

International Nuclear Information System (INIS)

Eason, E.D.; Wright, J.E.; Nelson, E.E.; Odette, G.R.; Mader, E.V.

1998-01-01

The irradiation embrittlement of nuclear reactor pressure vessels (RPV) can be reduced by thermal annealing at temperatures higher than the normal operating conditions. The objective of this work was to analyze the pertinent data and develop quantitative models for estimating the recovery in 41 J (30 ft-lb) Charpy transition temperature (TT) and Charpy upper shelf energy (USE) due to annealing. An analysis data base was developed, reviewed for completeness and accuracy, and documented as part of this work. Models were developed based on a combination of statistical techniques, including pattern recognition and transformation analysis, and the current understanding of the mechanisms governing embrittlement and recovery. The quality of models fitted in this project was evaluated by considering both the Charpy annealing data used for fitting and a surrogate hardness data base. This work demonstrates that microhardness recovery is a good surrogate for shift recovery and that there is a high level of consistency between the observed annealing trends and fundamental models of embrittlement and recovery processes. (orig.)

An improved technique for breast cancer irradiation including the locoregional lymph nodes

NARCIS (Netherlands)

Hurkmans, C. W.; Saarnak, A. E.; Pieters, B. R.; Borger, J. H.; Bruinvis, I. A.

2000-01-01

PURPOSE: To find an irradiation technique for locoregional irradiation of breast cancer patients which, compared with a standard technique, improves the dose distribution to the internal mammary-medial supraclavicular (IM-MS) lymph nodes. The improved technique is intended to minimize the lung dose

Evaluation and prediction of neutron embrittlement in reactor pressure vessel materials. Final report

International Nuclear Information System (INIS)

Hawthorne, J.R.; Menke, B.H.; Loss, F.J.; Watson, H.E.; Hiser, A.L.; Gray, R.A.

1982-12-01

This study evaluates the effects of fast neutron irradiation on the mechanical properties of eight nuclear reactor vessel materials. The materials include submerged arc weldments, three plates, and one forging. The materials are in the unirradiated and irradiated conditions with regard to tensile, Charpy impact, and static and dynamic fracture toughness properties. Correlations between impact and fracture toughness parameters are developed from the experimental results. The observed shifts in transition temperature and the drop in upper-shelf energy are compared with predictions developed from the Regulatory Guide 1.99.1 trend curves

Development of reconstitution method for surveillance specimens using surface activated joining

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Terumi; Kaihara, Shoichiro; Yoshida, Kazuo; Sato, Akira [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan); Onizawa, Kunio; Nishiyama, Yutaka; Fukaya, Kiyoshi; Suzuki, Masahide

1996-03-01

Evaluation of embrittlement of reactor vessel steel due to irradiation requires surveillance tests. However, many surveillance specimens are necessary for nuclear plants life extension. Therefore, a specimen reconstitution technique has become important to provide the many specimens for continued surveillance. A surface activated joining (SAJ) method has been developed to join various materials together at low temperatures with little deformation, and is useful to bond irradiated specimens. To assess the validity of this method, Charpy impact tests were carried out, and the characteristics caused by heating during joining were measured. The test results showed the Charpy impact values were almost the same as base materials, and surface activated joining reduced heat affected zone to less than 2 mm. (author).

Design, fabrication and irradiation test report on HANARO instrumented capsule (03M-06U) for researches of universities in 2003

International Nuclear Information System (INIS)

Choo, K. N.; Kim, B. G.; Kang, Y. H.; Choi, M. H.; Cho, M. S.; Son, J. M.; Shin, Y. T.; Park, S. J.

2005-03-01

As a part of 2003 project for active utilization of HANARO, an instrumented capsule (03M-06U) was designed, fabricated and irradiated for the irradiation test of various nuclear materials under irradiation conditions requested by external researchers from universities. The basic structure of 03M-06U capsule was based on the 00M-01U, 01M-05U and 02M-05U capsules successfully irradiated in HANARO as 2000, 2001 and 2002 projects. However, because of the limited number of specimens and budget of 4 universities, the remained space of the capsule was charged with KAERI specimens for the development of the precise temperature control technology under irradiation. The material of the specimens is mainly Fe-based alloys partially mixed with Zr, Al and Cu-Ag alloys. The capsule is composed of 5 stages having many kinds of specimens and independent electric heater in each stage. During the irradiation test, the temperature of the specimens and the thermal/fast neutron fluences were measured by 14 thermocouples and 5 sets of Ni-Ti-Fe neutron fluence monitors installed in the capsule. Various types of specimens such as tensile, Charpy, TEM, toughness, electrical resistance specimens were inserted in the capsule. The capsule was firstly irradiated in the CT test hole of HANARO of 30MW thermal output at 275∼500±10 .deg. C up to a fast neutron fluence of 5.4 x 10 20 (n/cm 2 ) (E>1.0MeV). The obtained results will be very valuable for the related researches of the users

Effect of effective grain size on Charpy impact properties of high-strength bainitic steels

International Nuclear Information System (INIS)

Shin, Sang Yong; Han, Seung Youb; Lee, Sung Hak; Hwang, Byoung Chul; Lee, Chang Gil

2008-01-01

This study is concerned with the effect of Cu and B addition on microstructure and mechanical properties of high-strength bainitic steels. Six kinds of steels were fabricated by varying alloying elements and hot-rolling conditions, and their microstructures and tensile and Charpy impact properties were investigated. Their effective grain sizes were also characterized by the electron back-scatter diffraction analysis. The tensile test results indicated that the B- or Cu-containing steels had the higher yield and tensile strengths than the B- or Cu-free steels because their volume fractions of bainitic ferrite and martensite were quite high. The B- or Cu-free steels had the higher upper shelf energy than the B- or Cu-containing steels because of their higher volume fraction of granular bainite. In the steel containing 10 ppm B without Cu, the best combination of high strengths, high upper shelf energy, and low energy transition temperature could be obtained by the decrease in the overall effective grain size due to the presence of bainitic ferrite having smaller effective grain size

Use of miniature and standard specimens to evaluate effects of irradiation temperature on pressure vessel steels

International Nuclear Information System (INIS)

Haggag, F.M.; Nanstad, R.K.; Byrne, S.T.

1991-01-01

The effects of neutron irradiation on the steel reactor vessel for the modular high-temperature gas-cooled reactor (MHTGR) are being investigated, primarily because the operating temperatures are low [121 to 210 degrees C (250--410 degrees F)] compared to those for commercial light-water reactors (LWRs) [∼288 degrees C (550 degrees F)]. The need for design data on the reference temperature shift necessitated the irradiation at different temperatures of A 533 grade B class 1 plate. A 508 class 3 forging, and welds used for the vessel shell, vessel closure head, the vessel flange. This paper presents results from the first four irradiation capsules of this program. The four capsules were irradiated in the University of Buffalo Reactor to an effective fast fluence of 1 x10 18 neutron/cm 2 [0.68 x 10 18 neutron/cm 2 (>1 MeV)] at temperatures of 288, 204, 163, and 121 degrees C (550, 400, 325, and 250 degrees F), respectively. The yield and ultimate strengths of both steel plate materials of the MHTGR Program increased with decreasing irradiation temperature. Similarly, the 41-J Charpy V-notch (CVN) transition temperature shift increased with decreasing irradiation temperature (in agreement with the increase in yield strength). The miniature tensile and automated ball indentation (ABI) test results (yield strength and flow properties) were in good agreement with those from standard tensile specimens. The miniature tensile and ABI test results were also used in a model that utilizes the changes in yield strength to estimate the CVN ductile-to-brittle transition temperature shift due to irradiation. The model predictions were compared with CVN test results obtained here and in earlier work. 5 refs., 11 figs., 6 tabs

Heat treatment effects on impact toughness of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated to 100 dpa

Energy Technology Data Exchange (ETDEWEB)

Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

1997-08-01

Plates of 9Cr-1MoVNb and 12Cr-1MoVW steels were given four different heat treatments: two normalizing treatments were used and for each normalizing treatment two tempers were used. Miniature Charpy specimens from each heat treatment were irradiated to {approx}19.5 dpa at 365{degrees}C and to {approx}100 dpa at 420{degrees}C in the Fast Flux Test Facility (FFTF). In previous work, the same materials were irradiated to 4-5 dpa at 365{degrees}C and 35-36 dpa at 420{degrees}C in FFTF. The tests indicated that prior austenite grain size, which was varied by the different normalizing treatments, had a significant effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize impact properties.

Heat treatment effects on impact toughness of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated to 100 dpa

International Nuclear Information System (INIS)

Klueh, R.L.; Alexander, D.J.

1997-01-01

Plates of 9Cr-1MoVNb and 12Cr-1MoVW steels were given four different heat treatments: two normalizing treatments were used and for each normalizing treatment two tempers were used. Miniature Charpy specimens from each heat treatment were irradiated to ∼19.5 dpa at 365 degrees C and to ∼100 dpa at 420 degrees C in the Fast Flux Test Facility (FFTF). In previous work, the same materials were irradiated to 4-5 dpa at 365 degrees C and 35-36 dpa at 420 degrees C in FFTF. The tests indicated that prior austenite grain size, which was varied by the different normalizing treatments, had a significant effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize impact properties

Charpy impact test results of four low activation ferritic alloys irradiated at 370{degrees}C to 15 DPA

Energy Technology Data Exchange (ETDEWEB)

Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

1996-10-01

Miniature CVN specimens of four low activation ferritic alloys have been impact tested following irradiation at 370{degrees}C to 15 dpa. Comparison of the results with those of control specimens indicates that degradation in the impact behavior occurs in each of these four alloys. The 9Cr-2W alloy referred to as GA3X and the similar alloy F82H with 7.8Cr-2W appear most promising for further consideration as candidate structural materials in fusion energy system applications. These two alloys exhibit a small DBTT shift to higher temperatures but show increased absorbed energy on the upper shelf.

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.

Development for advanced materials and testing techniques

Energy Technology Data Exchange (ETDEWEB)

Hishinuma, Akimichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Recent studies using a JMTR and research reactors of JRR-2 and JRR-3 are briefly summarized. Small specimen testing techniques (SSTT) required for an effective use of irradiation volume and also irradiated specimens have been developed focussing on tensile test, fatigue test, Charpy test and small punch test. By using the small specimens of 0.1 - several mm in size, similar values of tensile and fatigue properties to those by standard size specimens can be taken, although the ductile-brittle transition temperature (DBTT) depends strongly on Charpy specimen size. As for advanced material development, R and D about low activation ferritic steels have been done to investigate irradiation response. The low activation ferritic steel, so-called F82H jointly-developed by JAERI and NKK for fusion, has been confirmed to have good irradiation resistance within a limited dose and now selected as a standard material in the fusion material community. It is also found that TiAi intermetallic compounds, which never been considered for nuclear application in the past, have an excellent irradiation resistance under an irradiation condition. Such knowledge can bring about a large expectation for developing advanced nuclear materials. (author)

Chapter 2: Irradiators

Energy Technology Data Exchange (ETDEWEB)

NONE

2018-04-01

The chapter 2 presents the subjects: 1) gamma irradiators which includes: Category-I gamma irradiators (self-contained); Category-II gamma irradiators (panoramic and dry storage); Category-III gamma irradiators (self-contained in water); Category-IV gamma irradiators (panoramic and wet storage); source rack for Category-IV gamma irradiators; product transport system for Category-IV gamma irradiators; radiation shield for gamma irradiators; 2) accelerators which includes: Category-I Accelerators (shielded irradiator); Category-II Accelerators (irradiator inside a shielded room); Irradiation application examples.

Uncertainty of rotating shadowband irradiometers and Si-pyranometers including the spectral irradiance error

Science.gov (United States)

Wilbert, Stefan; Kleindiek, Stefan; Nouri, Bijan; Geuder, Norbert; Habte, Aron; Schwandt, Marko; Vignola, Frank

2016-05-01

Concentrating solar power projects require accurate direct normal irradiance (DNI) data including uncertainty specifications for plant layout and cost calculations. Ground measured data are necessary to obtain the required level of accuracy and are often obtained with Rotating Shadowband Irradiometers (RSI) that use photodiode pyranometers and correction functions to account for systematic effects. The uncertainty of Si-pyranometers has been investigated, but so far basically empirical studies were published or decisive uncertainty influences had to be estimated based on experience in analytical studies. One of the most crucial estimated influences is the spectral irradiance error because Si-photodiode-pyranometers only detect visible and color infrared radiation and have a spectral response that varies strongly within this wavelength interval. Furthermore, analytic studies did not discuss the role of correction functions and the uncertainty introduced by imperfect shading. In order to further improve the bankability of RSI and Si-pyranometer data, a detailed uncertainty analysis following the Guide to the Expression of Uncertainty in Measurement (GUM) has been carried out. The study defines a method for the derivation of the spectral error and spectral uncertainties and presents quantitative values of the spectral and overall uncertainties. Data from the PSA station in southern Spain was selected for the analysis. Average standard uncertainties for corrected 10 min data of 2 % for global horizontal irradiance (GHI), and 2.9 % for DNI (for GHI and DNI over 300 W/m²) were found for the 2012 yearly dataset when separate GHI and DHI calibration constants were used. Also the uncertainty in 1 min resolution was analyzed. The effect of correction functions is significant. The uncertainties found in this study are consistent with results of previous empirical studies.

Heavy-Section Steel Irradiation Program. Volume 2, No. 1: Semiannual progress report, October 1990--March 1991

International Nuclear Information System (INIS)

Corwin, W.R.

1994-07-01

Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents that have the potential for major contamination release. The RPV is the only key safety-related component of the plant for which a duplicate or redundant backup system does not exist. It is therefore imperative to understand and be able to predict the capabilities and limitations of the integrity inherent in the RPV. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established with its primary goal to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior, and in particular the fracture toughness properties, of typical pressure-vessel steels as they relate to light-water reactor pressure-vessel integrity. The HSSI Program is arranged into nine tasks: (1) program management, (2) K ic curve shift in high-copper welds, (3) K ia curve shift in high-copper welds, (4) irradiation effects on cladding, (5) K ic and K ia curve shifts in low upper-shelf (LUS) weld, (6) irradiation effects in a commercial LUS weld, (7) microstructural analysis of irradiation, (8) in-service aged material evaluations, and (9) correlation monitor materials. During this period, additional analyses on the effects of precleavage stable ductile tearing on the toughness of high-copper welds 72W and 73W demonstrated that the size effects observed in the transition region are not due to substantial differences in ductile tearing behavior. Possible modifications to irradiated duplex crack-arrest specimens were examined to increase the likelihood of their successful testing. Characterization of a second batch of 72W and 73W welds was begun and results of the Charpy V-notch testing is provided. A review of literature on the annealing response of reactor pressure vessel steels was initiated

Test and evaluation of pressure vessel materials

International Nuclear Information System (INIS)

Choi, Sun Pil; Hong, Jun Hwa; Nho, Kye Hoe; Han, Dae June; Chi, Se Hwan

1985-01-01

We have prepared a method for analyzing the Charpy impact test data, which is deduced from ''the standard anelastic solid equation''. The theoretical expression for the absorbed energy is in a form of W=Wsub(U)+(Wsub(R)-Wsub(U))/ [1+(ωtau) 2 ] showing the Debye characteristics and where tau is given by the Arrhenius equation; tau=tau 0 exp(ΔH/ksub(B)T). Four measurable parameters, at the present stage, can characterize the dynamic hehavior of cracking (Charpy impact result). They are the upper shelf energy(Wsub(R), the lower shelf energy (Wsub(U)), the activation energy of crack (ΔH, and wtau(0) where w tau(0) are the resonance frequency of the specimen and the jumping pre-exponential factor of propagating crack respectively. However the states of R (relaxed) and U (un-relaxed) should be defined from reasonable physical conditions in the future and it is possible that Wsub(U) is small enough to be taken as zero. The effects of irradiation, alloying elements, and heat treatment on the impact results should be interpreted as changes in the above characteristic parameters. The present method has been applied for weld metal of SA 508-2 irradiated up to a fluence of 4x10 18 n/cm 2 , E>1.0Mev, resulting in about 29% decrease in Wsub(R), negligible change in Wsub(U), 5.6 times increase in ωtau 0 , and no change in ΔH. This seems to indicate that irradiation degrades an average value of YOUNG's modulus so that cracks propagate more easily and it does not effect on breaking the lattice bond. However much more systematic analyses should be necessary for correct judgment. It is concluded that the present method is quite adequate for analyzing the Charpy impact data even though plastic deformation in the specimen was not considered separately so that the method should be applied for various cases in order to evaluate the proper trend of effects of irradiation, alloying elements, and heat treatment on the Charpy impact results. (Author)

Postirradiation fracture toughness tests of ESR alloy HT-9 and modified 9Cr-1Mo alloy from UBR reactor experiments

International Nuclear Information System (INIS)

Hawthorne, J.R.; Reed, J.R.; Sprague, J.A.

1984-01-01

Alloy HT-9 and Modified 9Cr-1Mo are being evaluated for potential applications as first wall materials in magnetic fusion reactors. Objectives of the current research task were to test fatigue-precracked Charpy-V (PCC/sub v/) specimens from representative plates irradiated in the UBR reactor at 149 0 C or 300 0 C, and, to compare the results against postirradiation notch ductility data developed previously for the materials. Both plates represent electroslag refined (ESR) melt processing. PCC/sub v/ specimens of Alloy HT-9 and Modified 9Cr-1Mo alloy were irradiated at 300 0 C and 149 0 C, respectively, to approx.0.8 X 10 20 n/cm 2 , E > 0.1 MeV. During this period, postirradiation tests for fracture toughness were completed and results compared to notch ductility determinations from standard Charpy-V (C/sub v/) specimens irradiated in the same reactor experiments. Fracture surface examinations by SEM are also reported

Effects of thermal aging and neutron irradiation on the mechanical properties of three-wire stainless steel weld overlay cladding

International Nuclear Information System (INIS)

Haggag, F.M.; Nanstad, R.K.

1997-05-01

Thermal aging of three-wire series-arc stainless steel weld overlay cladding at 288 degrees C for 1605 h resulted in an appreciable decrease (16%) in the Charpy V-notch (CVN) upper-shelf energy (USE), but the effect on the 41-J transition temperature shift was very small (3 degrees C). The combined effect of aging and neutron irradiation at 288 degrees C to a fluence of 5 x 10 19 neutrons/cm 2 (> 1 MeV) was a 22% reduction in the USE and a 29 degrees C shift in the 41-J transition temperature. The effect of thermal aging on tensile properties was very small. However, the combined effect of irradiation and aging was an increase in the yield strength (6 to 34% at test temperatures from 288 to -125 degrees C) but no apparent change in ultimate tensile strength or total elongation. Neutron irradiation reduced the initiation fracture toughness (J Ic ) much more than did thermal aging alone. Irradiation slightly decreased the tearing modulus, but no reduction was caused by thermal aging alone. Other results from tensile, CVN, and fracture toughness specimens showed that the effects of thermal aging at 288 or 343 degrees C for 20,000 h each were very small and similar to those at 288 degrees C for 1605 h. The effects of long-term thermal exposure time (50,000 h and greater) at 288 degrees C will be investigated as the specimens become available in 1996 and beyond

A Physically Based Correlation of Irradiation-Induced Transition Temperature Shifts for RPV Steels

Energy Technology Data Exchange (ETDEWEB)

Eason, Ernest D. [Modeling and Computing Services, LLC; Odette, George Robert [UCSB; Nanstad, Randy K [ORNL; Yamamoto, Takuya [ORNL

2007-11-01

The reactor pressure vessels (RPVs) of commercial nuclear power plants are subject to embrittlement due to exposure to high-energy neutrons from the core, which causes changes in material toughness properties that increase with radiation exposure and are affected by many variables. Irradiation embrittlement of RPV beltline materials is currently evaluated using Regulatory Guide 1.99 Revision 2 (RG1.99/2), which presents methods for estimating the shift in Charpy transition temperature at 30 ft-lb (TTS) and the drop in Charpy upper shelf energy (ΔUSE). The purpose of the work reported here is to improve on the TTS correlation model in RG1.99/2 using the broader database now available and current understanding of embrittlement mechanisms. The USE database and models have not been updated since the publication of NUREG/CR-6551 and, therefore, are not discussed in this report. The revised embrittlement shift model is calibrated and validated on a substantially larger, better-balanced database compared to prior models, including over five times the amount of data used to develop RG1.99/2. It also contains about 27% more data than the most recent update to the surveillance shift database, in 2000. The key areas expanded in the current database relative to the database available in 2000 are low-flux, low-copper, and long-time, high-fluence exposures, all areas that were previously relatively sparse. All old and new surveillance data were reviewed for completeness, duplicates, and discrepancies in cooperation with the American Society for Testing and Materials (ASTM) Subcommittee E10.02 on Radiation Effects in Structural Materials. In the present modeling effort, a 10% random sample of data was reserved from the fitting process, and most aspects of the model were validated with that sample as well as other data not used in calibration. The model is a hybrid, incorporating both physically motivated features and empirical calibration to the U.S. power reactor surveillance

A Study on Conjugate Heat Transfer Analysis of Reactor Vessel including Irradiated Structural Heat Source

Energy Technology Data Exchange (ETDEWEB)

Yi, Kunwoo; Cho, Hyuksu; Im, Inyoung; Kim, Eunkee [KEPCO EnC, Daejeon (Korea, Republic of)

2015-10-15

Though Material reliability programs (MRPs) have a purpose to provide the evaluation or management methodologies for the operating RVI, the similar evaluation methodologies can be applied to the APR1400 fleet in the design stage for the evaluation of neutron irradiation effects. The purposes of this study are: to predict the thermal behavior whether or not irradiated structure heat source; to evaluate effective thermal conductivity (ETC) in relation to isotropic and anisotropic conductivity of porous media for APR1400 Reactor Vessel. The CFD simulations are performed so as to evaluate thermal behavior whether or not irradiated structure heat source and effective thermal conductivity for APR1400 Reactor Vessel. In respective of using irradiated structure heat source, the maximum temperature of fluid and core shroud for isotropic ETC are 325.8 .deg. C, 341.5 .deg. C. The total amount of irradiated structure heat source is about 5.41 MWth and not effect to fluid temperature.

Extended analysis of WWER-1000 Charpy test data

International Nuclear Information System (INIS)

Vodenicharov, St.; Kamenova, Tz.

2001-01-01

The aim of this work is to study the embrittlement rate of WWER-1000 RPV weld metal with high Ni content and to determine influence of neutron irradiation on partial energies of ductile crack initiation, stable and unstable crack propagation and post crack arrest. (author)

Atucha I nuclear power plant surveillance programme

International Nuclear Information System (INIS)

Jinchuk, D.

1993-01-01

After a review of the main characteristics of the Atucha I nuclear power plant and its pressure vessel, the embrittlement surveillance capsules and the irradiation conditions are described; Charpy impact tests and tensile tests were performed on the irradiated samples, and results are discussed and compared to theoretical calculations: transition temperature shifts, displacement per atom values. 6 refs., 16 figs., 7 tabs

Atucha I nuclear power plant surveillance programme

Energy Technology Data Exchange (ETDEWEB)

Jinchuk, D [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

1994-12-31

After a review of the main characteristics of the Atucha I nuclear power plant and its pressure vessel, the embrittlement surveillance capsules and the irradiation conditions are described; Charpy impact tests and tensile tests were performed on the irradiated samples, and results are discussed and compared to theoretical calculations: transition temperature shifts, displacement per atom values. 6 refs., 16 figs., 7 tabs.

Effects of the neutronic irradiation on the impact tests. Efectos de la irradiacion neutronica sobre los ensayos de resiliencia

Energy Technology Data Exchange (ETDEWEB)

Lapea, 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.

Investigation of the effects on Charpy impact characteristics by shape of pendulum striking edge

International Nuclear Information System (INIS)

Kawai, Toshihiko; Etoh, Mikio; Hanawa, Namio; Shibaike, Masayuki; Inoue, Kazuo.

1983-01-01

Charpy impact test is used versatilely and practically as the method of evaluating the toughness of metals. In Japan, usually the JIS type testing machines are used, but recently, the test with ASTM type testing machines has been often demanded for steel materials for export or for nuclear use. Accordingly, the testing machines of both types must be installed, the testing works become troublesome, and the costs of initial investment, maintenance, management and so on increase. When the standards in various countries were investigated, the stipulation on the various particulars of the testing machines was almost similar except the shape of striking edges, which are 8mm radius in ASTM and 2mm radius in other standards. Recently it was clarified that there was some difference between the impact values of high toughness steel using JIS and ASTM machines. In order to clarify the cause of this difference and to unify the shape of edges, the investigation was carried out by the working group. The investigation of the effect of the difference of edge shapes on impact values, the analysis of fracture phenomena in impact test and the consideration on the results are reported. ASTM type testing machines should not be used for mild steel when absorbed energy exceeds 10kgf-m. (Kako, I.)

Proceedings of a C.S.N.I. specialist meeting on instrumented pre-cracked Charpy testing

Energy Technology Data Exchange (ETDEWEB)

Wullaert, R A [Fracture Control Corp., 340 South Kellogg Avenue, Suite G, Goleta, California 93017 (United States)

1981-11-15

This report presents the status of the testing and data analysis procedures for the instrumented pre-cracked Charpy test with emphasis on the application of the test technique to the nuclear industry. The report (Proceedings) consist of invited technical papers by specialists in the field and a synopsis of the comments, conclusions, and recommendations reached in a workshop session. The CSNl-sponsored and EPRI-hosted meeting confirmed both the popularity of the test technique in the nuclear industry and the problems associated with the test technique due to the lack of a national or international consensus standard. Major emphasis in the meeting was devoted to evaluating the existing industry testing procedure (EPRI procedure) and proposed national standards (ASTM, ASK). The EPRI procedures were considered adequate by specialists concerned with engineering applications, but too restrictive by specialists concerned with research applications. As a result of the conference, a compilation of state-of-the-art papers is now available to code and standard committees. Specific comments concerning test and data analysis procedures, applications in the nuclear industry, and future research areas are also contained in the proceedings

Updated embrittlement trend curve for reactor pressure vessel steels

International Nuclear Information System (INIS)

Kirk, M.; Santos, C.; Eason, E.; Wright, J.; Odette, G.R.

2003-01-01

The reactor pressure vessels of commercial nuclear power plants are subject to embrittlement due to exposure to high energy neutrons from the core. Irradiation embrittlement of RPV belt-line materials is currently evaluated using US Regulatory Guide 1.99 Revision 2 (RG 1.99 Rev 2), which presents methods for estimating the Charpy transition temperature shift (ΔT30) at 30 ft-lb (41 J) and the drop in Charpy upper shelf energy (ΔUSE). A more recent embrittlement model, based on a broader database and more recent research results, is presented in NUREG/CR-6551. The objective of this paper is to describe the most recent update to the embrittlement model in NUREG/CR-6551, based upon additional data and increased understanding of embrittlement mechanisms. The updated ΔT30 and USE models include fluence, copper, nickel, phosphorous content, and product form; the ΔT30 model also includes coolant temperature, irradiation time (or flux), and a long-time term. The models were developed using multi-variable surface fitting techniques, understanding of the ΔT30 mechanisms, and engineering judgment. The updated ΔT30 model reduces scatter significantly relative to RG 1.99 Rev 2 on the currently available database for plates, forgings, and welds. This updated embrittlement trend curve will form the basis of revision 3 to Regulatory Guide 1.99. (author)

Food irradiation

International Nuclear Information System (INIS)

Soothill, R.

1987-01-01

The issue of food irradiation has become important in Australia and overseas. This article discusses the results of the Australian Consumers' Association's (ACA) Inquiry into food irradiation, commissioned by the Federal Government. Issues discussed include: what is food irradiation; why irradiate food; how much food is consumer rights; and national regulations

Experimental assessments of notch ductility and tensile strength of stainless steel weldments after 1200C neutron irradiation

International Nuclear Information System (INIS)

Hawthorne, J.R.; Menke, B.H.; Awadalla, N.G.; O'Kula, K.R.

1986-01-01

The Charpy-V (C/sub v/) properties of AISI 300 series stainless steel plate, weld, and weld heat-affected zone (HAZ) materials from commercial production weldments in 406-mm-diameter pipe (12.7-mm wall) were investigated in unirradiated and irradiated conditions. Weld and HAZ tensile properties were also assessed in the two conditions. The plates and weld filler wires represent different steel melts; the welds were produced using the multipass MIG process. Weldment properties in two test orientations were evaluated. Specimens were irradiated in the UBR reactor to 1 x 10 20 n/cm 2 , E >0.1 MeV in a controlled temperature assembly. Specimen tests were performed at 25 0 C and 125 0 C. The radiation-induced reductions in C/sub v/ energy absorption at 25 0 C were about 42 percent for the weld and HAZ materials evaluated. A trend of energy increase with temperature was observed. The concomitant elevation in yield strength was about 53%. In contrast, the increase in tensile strength was only 16%. The postirradiation yield strength of the axial test orientation in the pipe was less than that of the circumferential test orientation. Results for the HAZ indicate that this component may be the weakest link in the weldment from a fracture resistant viewpoint

Miniature Precracked Charpy Specimens for Measuring the Master Curve Reference Temperature of RPV Steels at Impact Loading Rates

Energy Technology Data Exchange (ETDEWEB)

Lucon, E.; Scibetta, M.; Puzzolante, L.

2008-10-15

In the framework of the 2006 Convention, we investigated the applicability of fatigue precracked miniature Charpy specimens of KLST type (MPCC - B = 3 mm, W = 4 mm and L = 27 mm) for impact toughness measurements, using the well-characterized JRQ RPV steel. In the ductile to-brittle transition region, MPCC tests analyzed using the Master Curve approach and compared to data previously obtained from PCC specimens had shown a more ductile behavior and therefore un conservative results. In the investigation presented in this report, two additional RPV steels have been used to compare the performance of impact-tested MPCC and PCC specimens in the transition regime: the low-toughness JSPS steel and the high-toughness 20MnMoNi55 steel. The results obtained (excellent agreement for 20MnMoNi55 and considerable differences between T0 values for JSPS) are contradictory and do not presently allow qualifying the MPCC specimens as a reliable alternative to PCC samples for impact toughness measurements.

A perspective on thermal annealing of reactor pressure vessel materials from the viewpoint of experimental results

International Nuclear Information System (INIS)

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

1996-01-01

It is believed that in the next decade or so, several nuclear reactor pressure vessels (RPVs) may exceed the reference temperature limits set by the pressurized thermal shock screening criteria. One of the options to mitigate the effects of irradiation on RPVs is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. This paper summarizes recent experimental results from work performed at the Oak Ridge National Laboratory to study the annealing response, or ''recovery'' of several irradiated RPV steels. The fracture toughness is one of the important properties used in the evaluation of the integrity of RPVs. Optimally, the fracture toughness is measured directly by fracture toughness specimens, such as compact tension or precracked Charpy specimens, but is often inferred from the results of Charpy V-notch impact specimens. The experimental results are compared to the predictions of models for embrittlement recovery which have been developed by Eason et al. Some of the issues in annealing that still need to be resolved are discussed

Different approaches to estimation of reactor pressure vessel material embrittlement

Directory of Open Access Journals (Sweden)

V. M. Revka

2013-03-01

Full Text Available The surveillance test data for the nuclear power plant which is under operation in Ukraine have been used to estimate WWER-1000 reactor pressure vessel (RPV material embrittlement. The beltline materials (base and weld metal were characterized using Charpy impact and fracture toughness test methods. The fracture toughness test data were analyzed according to the standard ASTM 1921-05. The pre-cracked Charpy specimens were tested to estimate a shift of reference temperature T0 due to neutron irradiation. The maximum shift of reference temperature T0 is 84 °C. A radiation embrittlement rate AF for the RPV material was estimated using fracture toughness test data. In addition the AF factor based on the Charpy curve shift (ΔTF has been evaluated. A comparison of the AF values estimated according to different approaches has shown there is a good agreement between the radiation shift of Charpy impact and fracture toughness curves for weld metal with high nickel content (1,88 % wt. Therefore Charpy impact test data can be successfully applied to estimate the fracture toughness curve shift and therefore embrittlement rate. Furthermore it was revealed that radiation embrittlement rate for weld metal is higher than predicted by a design relationship. The enhanced embrittlement is most probably related to simultaneously high nickel and high manganese content in weld metal.

Effect of rhenium and osmium on mechanical properties of a 9Cr-2W-0.25V-0.07Ta-0.1C steel

International Nuclear Information System (INIS)

Klueh, R.L.; Alexander, D.J.; Sokolov, M.A.

2000-01-01

The nuclear transmutation of tungsten to rhenium and osmium in a tungsten-containing steel irradiated in a fission or fusion reactor will change the chemical composition of the steel. To determine the possible consequences of such compositional changes on the mechanical properties, tensile and Charpy impact properties were measured on five 9Cr-2W-0.25V-0.07Ta-0.1C steels that contained different amounts of rhenium, osmium, and tungsten. The mechanical properties changes caused by these changes in composition were minor. Observations were also made on the effect of carbon concentration. The effect of carbon on tensile behavior was minor, but there was a large effect on Charpy properties. Several of the steels showed little effect of tempering temperature on the Charpy transition temperature, a behavior that was tentatively attributed to the low silicon and/or manganese concentration of the experimental steels

Development of Mini-Compact Tension Test Method for Determining Fracture Toughness Master Curves for Reactor Pressure Vessel Steels

Energy Technology Data Exchange (ETDEWEB)

Sokolov, Mikhail A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-05-01

Small specimens are playing the key role in evaluating properties of irradiated materials. The use of small specimens provides several advantages. Typically, only a small volume of material can be irradiated in a reactor at desirable conditions in terms of temperature, neutron flux, and neutron dose. A small volume of irradiated material may also allow for easier handling of specimens. Smaller specimens reduce the amount of radioactive material, minimizing personnel exposures and waste disposal. However, use of small specimens imposes a variety of challenges as well. These challenges are associated with proper accounting for size effects and transferability of small specimen data to the real structures of interest. Any fracture toughness specimen that can be made out of the broken halves of standard Charpy specimens may have exceptional utility for evaluation of reactor pressure vessels (RPVs) since it would allow one to determine and monitor directly actual fracture toughness instead of requiring indirect predictions using correlations established with impact data. The Charpy V-notch specimen is the most commonly used specimen geometry in surveillance programs. Validation of the mini compact tension specimen (mini-CT) geometry has been performed on previously well characterized Midland beltline Linde 80 (WF-70) weld in the unirradiated condition. It was shown that the fracture toughness transition temperature, To, measured by these Mini-CT specimens is almost the same as To value that was derived from various larger fracture toughness specimens. Moreover, an International collaborative program has been established to extend the assessment and validation efforts to irradiated Linde 80 weld metal. The program is underway and involves the Oak Ridge National Laboratory (ORNL), Central Research Institute for Electrical Power Industry (CRIEPI), and Electric Power Research Institute (EPRI). The irradiated Mini-CT specimens from broken halves of previously tested Charpy

Results of crack-arrest tests on irradiated a 508 class 3 steel

International Nuclear Information System (INIS)

Iskander, S.K.; Milella, P.P.; Pini, M.A.

1998-02-01

Ten crack-arrest toughness values for irradiated specimens of A 508 class 3 forging steel have been obtained. The tests were performed according to the American Society for Testing and Materials (ASTM) Standard Test Method for Determining Plane-Strain Crack-Arrest Fracture Toughness, K la of Ferritic Steels, E 1221-88. None of these values are strictly valid in all five ASTM E 1221-88 validity criteria. However, they are useful when compared to unirradiated crack-arrest specimen toughness values since they show the small (averaging approximately 10 degrees C) shifts in the mean and lower-bound crack-arrest toughness curves. This confirms that a low copper content in ASTM A 508 class 3 forging material can be expected to result in small shifts of the transition toughness curve. The shifts due to neutron irradiation of the lower bound and mean toughness curves are approximately the same as the Charpy V-notch (CVN) 41-J temperature shift. The nine crack-arrest specimens were irradiated at temperatures varying from 243 to 280 degrees C, and to a fluence varying from 1.7 to 2.7 x 10 19 neutrons/cm 2 (> 1 MeV). The test results were normalized to reference values that correspond to those of CVN specimens irradiated at 284 degrees C to a fluence of 3.2 x 10 19 neutrons/cm 2 (> 1 MeV) in the same capsule as the crack-arrest specimens. This adjustment resulted in a shift to lower temperatures of all the data, and in particular moved two data points that appeared to lie close to or lower than the American Society of Mechanical Engineers K la curve to positions that seemed more reasonable with respect to the remaining data. A special fixture was designed, fabricated, and successfully used in the testing. For reasons explained in the text, special blocks to receive the Oak Ridge National Laboratory clip gage were designed, and greater-than-standard crack-mouth opening displacements measured were accounted for. 24 refs., 13 figs., 12 tabs

Use of miniaturized compact tension specimens for fracture toughness measurements in the upper shelf regime. Electrabel/Tractebel-SCK-CEN Convention 2004 Task 1.1.4/2

International Nuclear Information System (INIS)

Lucon, E.; Scibetta, M.; Chaouadi, R.; Walle, E. van

2005-04-01

In the nuclear field, the importance of direct fracture toughness measurements on RPV materials has been nowadays widely recognized, as opposed to Charpy-based estimations. However, sample dimensions have to be kept small in order to optimize the use of available material (often in the form of previously broken Charpy specimens) or, in the case of new irradiations, make effective use of the limited space available inside irradiation facilities. One of the most appealing geometries for fracture toughness measurements is the miniature Compact Tension specimen, MC(T), which has the following dimensions: B = 4.15 mm, W = 8.3 mm, cross section 10 x 10 mm 2 . Four MC(T) specimens can be machined out of a broken half Charpy, and in the case of irradiation ten MC(T) samples occupy approximately the same volume as a full-size Charpy specimen. The MC(T) geometry was already successfully applied and qualified for fracture toughness assessments in the ductile-to-brittle transition regime, using the Master Curve method (ASTM E1921-03). A further, comprehensive investigation is presented in this report, aimed at assessing the applicability of MC(T) specimens to measure fracture toughness in fully ductile (upper shelf) conditions. In this study, 18 1TC(T) and 20 MC(T) specimens have been tested at different temperatures from three RPV steels and one low-alloy C-Mn steel. The results obtained clearly show that MC(T) samples exhibit lower fracture toughness properties, both in terms of initiation of ductile tearing (according to various test standards) and resistance to ductile crack propagation (J-R curve). The reduction of tearing resistance might be attributed to work hardening prevailing over loss of constraint in the uncracked ligament in a side-grooved specimen, or to the inadequacy of J-integral to represent ductile crack extension in very small specimens. Both arguments will have to be verified with further investigations. (author)

Experimental tests of irradiation-anneal-reirradiation effects on mechanical properties of RPV plate and weld materials

International Nuclear Information System (INIS)

Hawthorne, J.R.

1996-01-01

The Charpy-V (C V ) notch ductility and tension test properties of three reactor pressure vessel (RPV) steel materials were determined for the 288 degree C (550 degree F) irradiated (I), 288 degree C (550 degree F) irradiated + 454 degree C (850 degree F)-168 h postirradiation annealed (IA), and 288 degree C (550 degree F) reirradiated (IAR) conditions. Total fluences of the I condition and the IAR condition were, respectively, 3.33 x 10 19 n/cm 2 and 4.18 x 10 19 n/cm 2 , E > 1 MeV. The irradiation portion of the IAR condition represents an incremental fluence increase of 1. 05 x 10 19 n/cm 2 , E > 1 MeV, over the I-condition fluence. The materials (specimens) were supplied by the Yankee Atomic Electric Company and represented high and low nickel content plates and a high nickel, high copper content weld deposit prototypical of the Yankee-Rowe reactor vessel. The promise of the IAR method for extending the fluence tolerance of radiation-sensitive steels and welds is clearly shown by the results. The annealing treatment produced full C V upper shelf recovery and full or nearly full recovery in the C V 41 J (30 ft-lb) transition temperature. The C V transition temperature increases produced by the reirradiation exposure were 22% to 43% of the increase produced by the first cycle irradiation exposure. A somewhat greater radiation embrittlement sensitivity and a somewhat greater reirradiation embrittlement sensitivity was exhibited by the low nickel content plate than the high nickel content plate. Its high phosphorus content is believed to be responsible. The IAR-condition properties of the surface vs. interior regions of the low nickel content plate are also compared

Irradiation Facilities at CERN

CERN Document Server

Gkotse, Blerina; Carbonez, Pierre; Danzeca, Salvatore; Fabich, Adrian; Garcia, Alia, Ruben; Glaser, Maurice; Gorine, Georgi; Jaekel, Martin, Richard; Mateu,Suau, Isidre; Pezzullo, Giuseppe; Pozzi, Fabio; Ravotti, Federico; Silari, Marco; Tali, Maris

2017-01-01

CERN provides unique irradiation facilities for applications in many scientific fields. This paper summarizes the facilities currently operating for proton, gamma, mixed-field and electron irradiations, including their main usage, characteristics and information about their operation. The new CERN irradiation facilities database is also presented. This includes not only CERN facilities but also irradiation facilities available worldwide.

Surveillance extension experience at WWER-440 type reactors

International Nuclear Information System (INIS)

Gillemot, F.; Uri, G.; Oszwald, F.; Trampus, P.

1993-01-01

In WWER-440 reactors, the surveillance specimens are located in accelerated irradiation positions. After 5 years, all specimens are withdrawn and the operational changes are not monitored. At Paks NPP a new surveillance program extension has been settled in order to avoid these original program disadvantages and generate further data for plant lifetime management. This paper includes: research performed to prepare the surveillance extension programme, the evaluation method for the surveillance extension, and first results (Charpy and tensile tests). (authors). 6 refs., 12 figs., 3 tabs

Surveillance extension experience at WWER-440 type reactors

Energy Technology Data Exchange (ETDEWEB)

Gillemot, F; Uri, G [Budapesti Mueszaki Egyetem, Budapest (Hungary); Oszwald, F; Trampus, P

1994-12-31

In WWER-440 reactors, the surveillance specimens are located in accelerated irradiation positions. After 5 years, all specimens are withdrawn and the operational changes are not monitored. At Paks NPP a new surveillance program extension has been settled in order to avoid these original program disadvantages and generate further data for plant lifetime management. This paper includes: research performed to prepare the surveillance extension programme, the evaluation method for the surveillance extension, and first results (Charpy and tensile tests). (authors). 6 refs., 12 figs., 3 tabs.

Modelling property changes in graphite irradiated at changing irradiation temperature

CSIR Research Space (South Africa)

Kok, S

2011-01-01

Full Text Available A new method is proposed to predict the irradiation induced property changes in nuclear; graphite, including the effect of a change in irradiation temperature. The currently used method; to account for changes in irradiation temperature, the scaled...

Detection of irradiated spice in blend of irradiated and un-irradiated spices using thermoluminescence method

International Nuclear Information System (INIS)

Goto, Michiko; Yamazaki, Masao; Sekiguchi, Masayuki; Todoriki, Setsuko; Miyahara, Makoto

2007-01-01

Five blended spice sample were prepared by mixing irradiated and un-irradiated black pepper and paprika at different ratios. Blended black pepper containing 2%(w/w) of 5.4 kGy-irradiated black pepper showed no maximum at glow1. Irradiated black pepper samples, mixed to 5 or 10%(w/w), were identified as 'irradiated' or 'partially irradiated' or 'un-irradiated'. All samples with un-irradiated pepper up to 20%(w/w) were identified as irradiated'. In the case 5.0 kGy-irradiated paprika were mixed with un-irradiated paprika up to 5%(w/w), all samples were identified as irradiated'. The glow1 curves of samples, including irradiated paprika at 0.2%(w/w) or higher, exhibited a maximum between 150 and 250degC. The results suggest the existence of different critical mixing ratio for the detection of irradiation among each spices. Temperature range for integration of the TL glow intensity were compared between 70-400degC and approximate 150-250degC, and revealed that the latter temperature range was determined based on the measurement of TLD100. Although TL glow ratio in 150-250degC was lower than that of 70-400degC range, identification of irradiation was not affected. Treatment of un-irradiated black pepper and paprika with ultraviolet rays had no effect on the detection of irradiation. (author)

Effects of boron addition on tensile and Charpy impact properties in high-phosphorous steels

Energy Technology Data Exchange (ETDEWEB)

Hong, Seokmin; Lee, Junghoon [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Park, Kyong Su [Next Generation Products Research Group, Technical Research Laboratories, POSCO, Pohang 790-785 (Korea, Republic of); Lee, Sunghak, E-mail: shlee@postech.ac.kr [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2014-01-01

In order to provide a new possibility for improving the steel-making productivity by fabricating plain carbon steels containing high phosphorous (P), effects of microstructures on tensile and Charpy impact properties were investigated in this study. Nine plain carbon steels were fabricated by controlling the addition of P and boron (B), and isothermal or quench heat-treatments were conducted on these steels to make ferrite–bainite-based or martensite-based microstructures. The addition of B positively influenced the grain refinement and the formation of bainites, thereby leading to the increase in strength. The upper shelf energy (USE) decreased with increasing P content, while the energy transition temperature (ETT) increased, in all the steels. The B addition beneficially affected both the USE and ETT as the dimpled ductile fracture mode prevailed in the B-added steels. This was because B preferentially covered grain boundaries, which reduced the grain boundary segregation of P. Thus, it effectively suppressed the intergranular fracture due to the segregation of P. According to the fractographic results, the increased tendency of intergranular fracture mode was observable in the 20-ppm-B-added steels rather than in the 10-ppm-B-added steels. When an excess amount of B, e.g., 20 ppm of B, was added, the severe segregation of B on grain boundaries occurred, and led to the precipitation of boro-carbides, which could act as intergranular crack initiation sites.

Experimental assessments of notch ductility and tensile strength of stainless steel weldments after 1200C neutron irradiation

International Nuclear Information System (INIS)

Hawthorne, J.R.; Menke, B.H.; Awadalla, N.G.; O'Kula, K.R.

1987-01-01

The Charpy-V (C/sub V/) properties of American Iron and Steel Institute (AISI) 300 series stainless steel plate, weld, and weld heat-affected zone (HAZ) materials from commercial production weldments in 406-mm-diameter pipe (12.7-mm wall) were investigated in unirradiated and irradiated conditions. Weld and HAZ tensile properties were also assessed in the two conditions. The plates and weld filler wires represent different steel melts; the welds were produced using the multipass metal inert gas (MIG) process. Weldment properties in two test orientations were evaluated. Specimens were irradiated in a light water cooled and moderated reactor to 1 x 10/sup 20/ n/cm/sup 2/, E > 0.1 MeV, using a controlled temperature assembly. Specimen tests were performed at 25 and 125 0 C. The radiation-induced reductions in C/sub V/ energy absorption at 25 0 C were about 42% for the weld and the HAZ materials evaluated. A trend of energy increase with temperature was observed. The concomitant elevation in yield strength was about 53%. The increase in tensile strength in contrast was only 16%. The postirradiation yield strength of the axial test orientation in the pipe was less than that of the circumferential test orientation. Results for the HAZ indicate that this component may be the weakest link in the weldment from a fracture resistance viewpoint

Food irradiation

Energy Technology Data Exchange (ETDEWEB)

Gruenewald, T

1985-01-01

Food irradiation has become a matter of topical interest also in the Federal Republic of Germany following applications for exemptions concerning irradiation tests of spices. After risks to human health by irradiation doses up to a level sufficient for product pasteurization were excluded, irradiation now offers a method suitable primarily for the disinfestation of fruit and decontamination of frozen and dried food. Codex Alimentarius standards which refer also to supervision and dosimetry have been established; they should be adopted as national law. However, in the majority of cases where individual countries including EC member-countries so far permitted food irradiation, these standards were not yet used. Approved irradiation technique for industrial use is available. Several industrial food irradiation plants, partly working also on a contractual basis, are already in operation in various countries. Consumer response still is largely unknown; since irradiated food is labelled, consumption of irradiated food will be decided upon by consumers.

Assessment of the effects of neutron fluence on Swedish nuclear pressure vessels

International Nuclear Information System (INIS)

Rao, S.

1980-11-01

Nuclear pressure vessels are subject to neutron irradiation during service causing embrittlement. This is one important factor in the overall problem of reactor vessel integrity. At present the irradiation effects are mainly assessed by the Charpy V-notch test. Two measures of embrittlement are defined: the increase of the ductile/brittle transition temperature and the decrease in the upper-shelf energy. The object of the present work is to assess these changes for the Swedish nuclear pressure vessels. On the basis of data from irradiations carried out in other countries and Swedish surveillance programmes, the expected end of life embrittlement is estimated for Swedish vessels. The results show that the embrittlement of most reactor vessels is expected to be quite small. Oskarshamn 1 and PWR-vessels, however, will probably show moderate changes, the former due to the higher copper content, and the latter due to the high end of life fluences. Some of the vessel materials which exhibit marginal properties in the upper-shelf energy, as measured by the Charpy V-notch impact test, are identified. It is recommended that fracture mechanics analyses be applied in these cases. (author)

Application of subsize specimens in nuclear plant life extension

International Nuclear Information System (INIS)

Rosinski, S.T.; Kumar, A.S.; Cannon, N.S.; Hamilton, M.L.

1993-01-01

The US Department of Energy is sponsoring a research effort through Sandia National Laboratories and the University of Missouri-Rolla to test a correlation for the upper shelf energy (USE) values obtained from the impact testing of subsize Charpy V-notch specimens to those obtained from the testing of full-size samples. The program involves the impact testing of unirradiated and irradiated full-, half-, and third-size Charpy V-notch specimens. To verify the applicability of the correlation on LWR materials, unirradiated and irradiated full-, half-, and third-size Charpy V-notch specimens of a commercial pressure vessel steel (ASTM A533 Grade B) will be tested. The correlation methodology is based on the partitioning of the USE into crack initiation and crack propagation energies. To accomplish this partition, both precracked and notched-only specimens will be used. Whereas the USE of notched-only specimens is the sum of both crack initiation and crack propagation energies, the USE of precracked specimens reflects only the crack propagation component. The difference in the USE of the two types of specimens represents a measure of the crack initiation energy. Normalizing the values of the crack initiation energy to the fracture volume of the sample produces similar values for the full-, half-, and third-size specimens. In addition, the ratios of the USE and the crack propagation energy are also in agreement for full-, half-, and third-size specimens. These two observations will be used to predict the USE of full-size specimens based on subsize USE data. This paper provides details of the program and presents results obtained from the application of the developed correlation methodology to the impact testing of the unirradiated full-, half-, and third-size A533 Grade B Charpy V-notch specimens

Computation of transverse muon-spin relaxation functions including trapping-detrapping reactions, with application to electron-irradiated tantalum

International Nuclear Information System (INIS)

Doering, K.P.; Aurenz, T.; Herlach, D.; Schaefer, H.E.; Arnold, K.P.; Jacobs, W.; Orth, H.; Haas, N.; Seeger, A.; Max-Planck-Institut fuer Metallforschung, Stuttgart

1986-01-01

A new technique for the economical evaluation of transverse muon spin relaxation functions in situations involving μ + trapping at and detrapping from crystal defects is applied to electron-irradiated Ta exhibiting relaxation maxima at about 35 K, 100 K, and 250 K. The long-range μ + diffusion is shown to be limted by traps over the entire temperature range investigated. The (static) relaxation rates for several possible configurations of trapped muons are discussed, including the effect of the simultaneous presence of a proton in a vacancy. (orig.)

Effects of thermal annealing and reirradiation on toughness of reactor pressure vessel steels

International Nuclear Information System (INIS)

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

1996-01-01

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPV) is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. This paper summarizes recent experimental results from work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response, or open-quotes recovery,close quotes of several irradiated RPV steels; it also includes recent results from both ORNL and the Russian Research Center-Kurchatov Institute (RRC-KI) on a cooperative program of irradiation, annealing and reirradiation of both U.S. and Russian RPV steels. The cooperative program was conducted under the auspices of Working Group 3, U.S./Russia Joint Coordinating Committee for Civilian Nuclear Reactor Safety (JCCCNRS). The materials investigated are an RPV plate and various submerged-arc welds, with tensile, Charpy impact toughness, and fracture toughness results variously determined. Experimental results are compared with applicable prediction guidelines, while observed differences in annealing responses and reirradiation rates are discussed

Effects of thermal annealing and reirradiation on toughness of reactor pressure vessel steels

International Nuclear Information System (INIS)

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

1997-01-01

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPV) is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. This paper summarizes recent experimental results from work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response, or open-quotes recovery,close quotes of several irradiated RPV steels; it also includes recent results from both ORNL and the Russian Research Center-Kurchatov Institute (RRC-KI) on a cooperative program of irradiation, annealing and reirradiation of both U.S. and Russian RPV steels. The cooperative program was conducted under the auspices of Working Group 3, U.S./Russia Joint Coordinating Committee for Civilian Nuclear Reactor Safety (JCCCNRS). The materials investigated are an RPV plate and various submerged-arc welds, with tensile, Charpy impact toughness, and fracture toughness results variously determined. Experimental results are compared with applicable prediction guidelines, while observed differences in annealing responses and reirradiation rates are discussed

Standard Guide for Predicting Radiation-Induced Transition Temperature Shift in Reactor Vessel Materials, E706 (IIF)

CERN Document Server

American Society for Testing and Materials. Philadelphia

2002-01-01

1.1 This guide presents a method for predicting reference transition temperature adjustments for irradiated light-water cooled power reactor pressure vessel materials based on Charpy V-notch 30-ftlbf (41-J) data. Radiation damage calculative procedures have been developed from a statistical analysis of an irradiated material database that was available as of May 2000. The embrittlement correlation used in this guide was developed using the following variables: copper and nickel contents, irradiation temperature, and neutron fluence. The form of the model was based on current understanding for two mechanisms of embrittlement: stable matrix damage (SMD) and copper-rich precipitation (CRP); saturation of copper effects (for different weld materials) was included. This guide is applicable for the following specific materials, copper, nickel, and phosphorus contents, range of irradiation temperature, and neutron fluence based on the overall database: 1.1.1 MaterialsA 533 Type B Class 1 and 2, A302 Grade B, A302 G...

Irradiation hardening of Fe–9Cr-based alloys and ODS Eurofer: Effect of helium implantation and iron-ion irradiation at 300 °C including sequence effects

Energy Technology Data Exchange (ETDEWEB)

Heintze, C. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany); Bergner, F., E-mail: f.bergner@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany); Hernández-Mayoral, M. [CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Kögler, R.; Müller, G.; Ulbricht, A. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany)

2016-03-15

Single-beam, dual-beam and sequential iron- and/or helium-ion irradiations are widely accepted to emulate more application-relevant but hardly accessible irradiation conditions of generation-IV fission and fusion candidate materials for certain purposes such as material pre-selection, identification of basic mechanisms or model calibration. However, systematic investigations of sequence effects capable to critically question individual approaches are largely missing. In the present study, sequence effects of iron-ion irradiations at 300 °C up to 5 dpa and helium implantations up to 100 appm He are investigated by means of post-irradiation nanoindentation of an Fe9%Cr model alloy, ferritic/martensitic 9%Cr steels T91 and Eurofer97 and oxide dispersion strengthened (ODS) Eurofer. Different types of sequence effects, both synergistic and antagonistic, are identified and tentative interpretations are suggested. It is found that different accelerated irradiation approaches have a great impact on the mechanical hardening. This stresses the importance of experimental design in attempts to emulate in-reactor conditions. - Highlights: • The single-beam He-ion implantations do not give rise to significant hardening. • The single-beam Fe-ion irradiations give rise to significant hardening, ΔH{sub Fe}. • Hardening due to sequential He-/Fe-ion irradiation is smaller than ΔH{sub Fe}. • Hardening due to simultaneous He-/Fe-ion irradiation is larger than ΔH{sub Fe}. • The He–Fe synergism for ODS-Eurofer is less pronounced than for Eurofer97.

Irradiation creep under 60 MeV alpha irradiation

International Nuclear Information System (INIS)

Reiley, T.C.; Shannon, R.H.; Auble, R.L.

1980-01-01

Accelerator-produced charged-particle beams have advantages over neutron irradiation for studying radiation effects in materials, the primary advantage being the ability to control precisely the experimental conditions and improve the accuracy in measuring effects of the irradiation. An apparatus has recently been built at ORNL to exploit this advantage in studying irradiation creep. These experiments employ a beam of 60 MeV alpha particles from the Oak Ridge Isochronous Cyclotron (ORIC). The experimental approach and capabilities of the apparatus are described. The damage cross section, including events associated with inelastic scattering and nuclear reactions, is estimated. The amount of helium that is introduced during the experiments through inelastic processes and through backscattering is reported. Based on the damage rate, the damage processes and the helium-to-dpa ratio, the degree to which fast reactor and fusion reactor conditions may be simulated is discussed. Recent experimental results on the irradiation creep of type 316 stainless steel are presented, and are compared to light ion results obtained elsewhere. These results include the stress and temperature dependence of the formation rate under irradiation. The results are discussed in relation to various irradiation creep mechanisms and to damage microstructure as it evolves during these experiments. (orig.)

Correlation of irradiation-induced transition temperature increases from Cv and KJc/KIc data

International Nuclear Information System (INIS)

Hiser, A.L.

1990-03-01

Reactor pressure vessel (RPV) surveillance capsules contain Charpy-V (C v ) specimens, but many do not contain fracture toughness specimens; accordingly, the radiation-induced shift (increase) in the brittle-to-ductile transition region (ΔT) is based upon the ΔT determined from notch ductility (C v ) tests. Since the ASME K Ic and K IR reference fracture toughness curves are shifted by the ΔT from C v , assurance that this ΔT does not underestimate ΔT associated with the actual irradiated fracture toughness is required to provide confidence that safety margins do not fall below assumed levels. To assess this behavior, comparisons of ΔT's defined by elastic-plastic fracture toughness and C v tests have been made using data from RPV base and weld metals in which irradiations were made under test reactor conditions. Using ''as-measure'' fracture toughness values (K Jc ), average comparisons between ΔT(C v ) and ΔT(K Jc ) are: (a) All data: ΔT(K Jc at sign 100 MPa√ bar m) = ΔT(C v at sign 41 J) +10 degree C; (b) Plates only: ΔT(K Jc at sign 100 MPa√ bar m) = ΔT(C v at sign 41 J) +15 degree C; and (c) Welds only: ΔT(K Jc at sign 100 MPa√ bar m) = ΔT(C v at sign 41 J) -1 degree C. Fluence rate is found to have no significant effect on the relationship between ΔT(C v ) and ΔT(K Jc ). 12 refs., 12 figs., 5 tabs

Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy include senescence, necrosis, and autophagy, but not apoptosis

International Nuclear Information System (INIS)

Frame, Fiona M.; Savoie, Huguette; Bryden, Francesca; Giuntini, Francesca; Mann, Vincent M.; Simms, Matthew S.; Boyle, Ross W.; Maitland, Norman J.

2015-01-01

In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer

Radiation embrittlement in pressure vessels of power reactors

International Nuclear Information System (INIS)

Kempf, Rodolfo; Fortis, Ana M.

2007-01-01

It is presented the project to study the effect of lead factors on the mechanical behavior of Reactor Pressure Vessel steels. It is described the facility designed to irradiate Charpy specimens with V notch of SA-508 type 3 steel at power reactor temperature, installed in the RA-1 reactor. The objective is to obtain the fracture behavior of irradiated specimens with different lead factors and to know their dependence with the diffusion of alloy elements. (author) [es

Design, fabrication and irradiation test report on HANARO instrumented capsule (05M-07U) for the researches of universities in 2005

Energy Technology Data Exchange (ETDEWEB)

Choo, K. N.; Kim, B. G.; Kang, Y. H.; Choi, M. H.; Cho, M. S.; Son, J. M.; Choi, M. H.; Shin, Y. T.; Park, S. J.

2006-09-15

As a part of the 2005 project for an active utilization of HANARO, an instrumented capsule (05M-07U) was designed, fabricated and irradiated for an irradiation test of various unclear materials under irradiation conditions which was requested by external researchers from universities. The basic structure of the 05M-07U capsule was based on the 00M-01U, 01M-05U, 02M-05U, 03M-06U and 04M-07U capsules which had been successfully irradiated in HANARO as part of the 2000, 2001, 2002, 2003 and 2004 projects. However, because of a limited number of specimens and the budget of one university, the remaining space in the capsule was filled with various KAERI specimens for researches on a nuclear core and SMART materials, and parts of a nuclear fuel assembly of KNFC. Various types of specimens such as tensile, Charpy, TEM, hardness, compression and growth specimens made of Zr 702, Ti and Ni alloys, Zirlo, Inconel, STS 316L and Cr-Mo alloys were placed in the capsule. Especially, this capsule was designed to evaluate the nuclear characteristics of the parts of a nuclear fuel assembly and the Ti tubes in HANARO. The capsule was composed of 5 stages having many kinds of specimens and an independent electric heater at each stage. During the irradiation test, the temperature of the specimens and the thermal/fast neutron fluences were measured by 14 thermocouples and 5 sets of Ni-Ti-Fe neutron fluence monitors installed in the capsule. The capsule was irradiated in the CT test hole of HANARO of a 30MW thermal output at 270 ∼ 400 .deg. C up to a fast neutron fluence of 5.7 x 10{sup 20} (n/cm{sup 2}) (E >1.0MeV). The obtained results will be very valuable for the related research of the users.

Evaluation of aging degradation of structural components

International Nuclear Information System (INIS)

Chopra, O.K.; Shack, W.J.

1992-03-01

Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at 8 n/cm 2 ·s at the low operating temperature of the Shippingport NST, i.e., 55 degrees C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J IC of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of ∼15 y

Fracture toughness evaluation in the transition region of reactor pressure vessel steel

International Nuclear Information System (INIS)

Onizawa, K.; Suzuki, M.

1995-01-01

The fracture toughness (K jc and Jc) values at the cleavage fracture initiation in the transition region of a RPV steel were investigated using mainly precracked Charpy specimens. A conventional statistical approach and a fractographic study were applied to analyze the scatter of the fracture toughness values from precracked Charpy specimens. The material used was an ASTM A533B class 1 steel, which was designated as an IAEA correlation monitor material, JRQ. A lower bound transition curve of the fracture toughness for unirradiated condition was determined by the 5% confidence limit from the Weibull and fractographic analyses. The lower bound transition curve after irradiation was evaluated based on the statistics of unirradiated specimens. The results indicated that the shift of the fracture toughness transition curbe were somewhat larger than the Charpy 41J transition temperature. The parameters to determine the lower bound toughness such as the Weibull slope and the amount of ductile crack growth are discussed. The results are also compared with a model based on weakest link theory. (author). 12 refs, 12 figs, 5 tabs

Detection of low amount of irradiated ingredients in non-irradiated precooked meals

Science.gov (United States)

Marchioni, Eric; Horvatovich, Peter; Ndiaye, Bara; Miesch, Michel; Hasselmann, Claude

2002-03-01

The application of the European Standards for the detection of irradiated food by thermoluminescence of silicates, electron-spin resonance spectroscopy of bones or gas chromatography-mass spectrometry of 2-alkylcyclobutanones does not allow the detection of irradiated ingredients included in small quantity in the matrix of a food which has not been irradiated, but which could be subjected to various processing technologies such as cooking, freezing or storage. The use of an enzymatic food hydrolysis carried out at moderated temperature, for the extraction of the food-contaminating silicate minerals and bone fragments, followed by a purification of the extracts by a high-density aqueous solution of sodium polytungstate, allows a simultaneous detection of weak inclusions (0.1% m:m) of irradiated spices and mechanically deboned turkey meat (MRM) included in various precooked foods. Moreover, the use of a supercritical fluid extraction procedure for the 2-alkylcyclobutanones or an additional purification step of the lipid extracts made it possible to lower the detection limit of the 2-alkylcyclobutanones radiation-induced from triglycerides. Using gas chromatography-mass spectrometry, down to 0.5% (m:m) of irradiated MRM included in non-irradiated chicken quenelles could be detected.

Detection of low amount of irradiated ingredients in non-irradiated precooked meals

International Nuclear Information System (INIS)

Marchioni, Eric; Horvatovich, Peter; Ndiaye, Bara; Miesch, Michel; Hasselmann, Claude

2002-01-01

The application of the European Standards for the detection of irradiated food by thermoluminescence of silicates, electron-spin resonance spectroscopy of bones or gas chromatography-mass spectrometry of 2-alkylcyclobutanones does not allow the detection of irradiated ingredients included in small quantity in the matrix of a food which has not been irradiated, but which could be subjected to various processing technologies such as cooking, freezing or storage. The use of an enzymatic food hydrolysis carried out at moderated temperature, for the extraction of the food-contaminating silicate minerals and bone fragments, followed by a purification of the extracts by a high-density aqueous solution of sodium polytungstate, allows a simultaneous detection of weak inclusions (0.1% m:m) of irradiated spices and mechanically deboned turkey meat (MRM) included in various precooked foods. Moreover, the use of a supercritical fluid extraction procedure for the 2-alkylcyclobutanones or an additional purification step of the lipid extracts made it possible to lower the detection limit of the 2-alkylcyclobutanones radiation-induced from triglycerides. Using gas chromatography-mass spectrometry, down to 0.5% (m:m) of irradiated MRM included in non-irradiated chicken quenelles could be detected

Tensile and Charpy impact properties of an ODS ferritic/martensitic steel 9Cr–1.8W–0.5Ti–0.35Y{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Guangming; Zhou, Zhangjian, E-mail: zhouzhj@mater.ustb.edu.cn; Wang, Man; Li, Shaofu; Zou, Lei; Zhang, Liwei

2014-04-15

Highlights: • The tensile property and Charpy impact were tested. • Both strength and plasticity in LT direction are better than that of TL direction. • The LSE was more than 65% of the USE from absorbed energy curve. • The initiation and propagation energy at different temperatures were calculated. • High LSE and dimples on the fracture surface indicated good toughness at −60 °C. - Abstract: A 9Cr-ODS ferritic/martensitic steel with a composition of 9Cr–1.8W–0.5Ti–0.35Y{sub 2}O{sub 3} was fabricated by mechanical alloying and hot isostatic pressing, followed by hot rolling. Tensile properties were measured at room temperature (23 °C) and 700 °C in the rolling direction (LT) and the transverse direction (TL). The ultimate tensile strength (UTS) of the as-rolled samples in both directions reached 990 MPa at 23 °C, and still maintained at 260 MPa at 700 °C. The tensile strength and elongation of the rolling direction was greater than that of the transverse direction. The Charpy impact was tested from −100 to 100 °C in the LT direction. The lower shelf energy (LSE) was more than 65% of the upper shelf energy (USE). The total absorbed energy was separated into the energies for crack initiation and propagation. The propagation energy was always higher than the initiation energy in the range of temperatures tested. The ductile-to-brittle transition temperature (DBTT) of the rolled 9Cr ODS evaluated by an absorbed energy curve was about 0 °C. However, the high LSE and the fracture surface that still contained dimples at lower shelf indicated good toughness of the as-rolled 9Cr ODS steels at temperature of −60 °C.

Present status of mechanical testing technology at the Research Hot Laboratory

International Nuclear Information System (INIS)

Kizaki, M.; Tobita, T.; Koya, T.; Kikuchi, T.

1993-01-01

Mechanical tests of irradiated metallic materials at the Research Hot Laboratory(RHL) have been carried out for 30 years to support material research in JAERI and to evaluate the irradiation integrity of pressure vessel steel in commercial power plant. Two tensile testing machines and one Charpy impact testing machine are available for the examinations. One of the tensile testing machines has 1000 kgf load capacity under the vacuum of ∼ 10 -7 torr at the temperature of 1300degC max.. The other one has 10 tonf load capacity, and is utilized for the multi-purpose tests such as tensile and compressive tests in air atmosphere at the temperature between -160 and 900degC. Examinations cover tensile test, bending test, J ic fracture toughness test, low cycle fatigue test and so on. Charpy impact testing machine with notched-bar specimen is instrumented with 30 kgf-m capacity in the temperature range of -140 - 240 degC. To support these mechanical tests in RHL, special jigs, devices and instruments have been developed. (author)

Curve collection, extension of databases

International Nuclear Information System (INIS)

Gillemot, F.

1992-01-01

Full text: Databases: generally calculated data only. The original measurements: diagrams. Information loss between them Expensive research eg. irradiation, aging, creep etc. Original curves should be stored for reanalysing. The format of the stored curves: a. Data in ASCII files, only numbers b. Other information in strings in a second file Same name, but different extension. Extensions shows the type of the test and the type of the file. EXAMPLES. TEN is tensile information, TED is tensile data, CHN is Charpy informations, CHD is Charpy data. Storing techniques: digitalised measurements, digitalising old curves stored on paper. Use: making catalogues, reanalysing, comparison with new data. Tools: mathematical software packages like quattro, genplot, exel, mathcad, qbasic, pascal, fortran, mathlab, grapher etc. (author)

Fracture mechanics investigations within the swiss surveillance programme for the pressure vessel of modern nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Ullrich, G; Krompholz, K [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1994-12-31

In the frame of surveillance programmes of Swiss nuclear power plants, irradiation tests have been performed on tensile, impact and wedge opening load specimens as well as on three point bend-type specimens (for J-integral investigations) and pre-cracked Charpy impact specimens (for dynamical stress intensities K{sub ID}). An experimental method (potential drop technique) is used together with a mathematical procedure which allow for the determination of the stress intensity K{sub IC} for small CT-samples instead of large ones: agreement of these both methods is found excellent, and the mapping of both methods to fatigue pre-cracked small specimens (3 PB and Charpy) is possible. The application of the analysis method to dynamical tests is also possible. 15 refs., 9 figs., 1 tab.

Model for prognostication of population irradiation dose at the soil way of long-living radionuclides including in food chains

International Nuclear Information System (INIS)

Prister, B.S.; Vinogradskaya, V.D.

2009-01-01

On the basis of modern pictures of cesium and strontium ion absorption mechanisms a soil taking complex was build the kinetic model of radionuclide migration from soil to plants. Model parameter association with the agricultural chemistry properties of soil, represented by complex estimation of soil properties S e f. The example of model application for prognostication of population internal irradiation dose due to consumption of milk at the soil way of long-living radionuclides including in food chains

Irradiation and inhomogeneity effects on ductility and toughness of (ODS)-7 -13Cr steels

International Nuclear Information System (INIS)

Preininger, D.

2007-01-01

Full text of publication follows: The superimposed effect of irradiation defect and structural inhomogeneity formation on tensile ductility and dynamic toughness of ferritic-martensitic 7-13CrW(Mo)VTa(Nb) and oxide dispersion-strengthened (ODS)-7-13CrWVTa(Ti)- RAFM steels has been examined by work hardening and local stress/strain-induced ductile fracture models. Structural inhomogeneities which strongly promoting plastic instability and localized flow might be formed by the applied fabrication process, high dose irradiation and additionally further during deformation by enhanced local dislocation generation around fine particles or due to slip band formation with localized heating at high impact strain rates ε'. The work hardening model takes into account superimposed dislocation multiplication from stored dislocations, dispersions and also grain boundaries as well as annihilation by cross-slip. Analytical relations have been deduced from the model describing uniform ductility and ductile upper shelf energy (USE) observed from Charpy-impact testes. Especially, the influence of different irradiation defects like atomic clusters, dislocation loops and coherent chromium-rich α'- precipitates have been considered together with effects from strain rate as well as irradiation (TI) and test temperature TT. Strengthening by clusters and more pronounced by dislocation loops formed at higher TI>250 deg. C reduces uniform ductility and also distinctly stronger dynamic toughness USE. A superimposed hardening by the α'- formation in higher Cr containing 9-13Cr steels strongly reduces toughness assisted by a combined grain-boundary embrittlement with reduction of the ductile fracture stress. But that improves work hardening and uniform ductility as observed particularly due to nano-scale Y 2 O 3 - dispersions in ODS-RAFM steels. For ODS- steels additionally the strength-induced reduction of toughness is diminished by a combined microstructural-induced increase of the ductile

Irradiation Embrittlement Monitoring Programs of RPV's in the Slovak Republic NPP's

International Nuclear Information System (INIS)

Kupca, Ludovik

2006-01-01

Four types of surveillance programs were (are) realized in Slovak NPP's: 'Standard Surveillance Specimen Program' (SSSP) was finished in Jaslovske Bohunice V-2 Nuclear Power Plant (NPP) Units 3 and 4, 'Extended Surveillance Specimen Program' (ESSP), was prepared for Jaslovske Bohunice NPP V-2 with aim to validate the SSSP results, For the Mochovce NPP Unit 1 and 2 was prepared completely new surveillance program 'Modern Surveillance Specimen Program' (MSSP), based on the philosophy that the results of MSSP must be available during all NPP service life, For the Bohunice V-1 NPP was finished 'New Surveillance Specimen Program' (NSSP) coordinated by IAEA, which gave arguments for prolongation of service life these units for minimum 20 years, New Advanced Surveillance Specimen Program (ASSP) for Bohunice V-2 NPP (units 3 and 4) and Mochovce NPP (units 1, 2) is approved now. ASSP is dealing with the irradiation embrittlement of heat affected zone (HAZ) and RPV's austenitic cladding, which were not evaluated till this time in surveillance programs. SSSP started in 1979 and was finished in 1990. ESSP program started in 1995 and will be finished in 2007, was prepared with aim of: increasing of neutron fluence measurement accuracy, substantial improvement the irradiation temperature measurement, fixed orientation of samples to the centre of the reactor core, minimum differences of neutron dose for all the Charpy-V notch and COD specimens, the dose rate effect evaluation. In the year 1996 was started the new surveillance specimen program for the Mochovce RPV's unit-1 and 2, based on the fundamental postulate - to provide the irradiation embrittlement monitoring till the end of units operation. The 'New Surveillance Specimen Program' (NSSP) prepared in the year 1999 for the Bohunice V-1 NPP was finished in the year 2004. Main goal of this program was to evaluate the weld material properties degradation due to the irradiation and recovery efficiency by annealing too. The

Food irradiation

International Nuclear Information System (INIS)

Hetherington, M.

1989-01-01

This popular-level article emphasizes that the ultimate health effects of irradiated food products are unknown. They may include vitamin loss, contamination of food by botulism bacteria, mutations in bacteria, increased production of aflatoxins, changes in food, carcinogenesis from unknown causes, presence of miscellaneous harmful chemicals, and the lack of a way of for a consumer to detect irradiated food. It is claimed that the nuclear industry is applying pressure on the Canadian government to relax labeling requirements on packages of irradiated food in order to find a market for its otherwise unnecessary products

Public status toward radiation and irradiated potatoes at 'Youngster's Science Festival' in several cities including Tokyo, Osaka, and Hiroshima, Japan

International Nuclear Information System (INIS)

Furuta, Masakazu; Hayashi, Toshio; Kakefu, Tomohisa; Nishihara, Hideaki

2000-01-01

'Youngster's Science Festival' has been held in several big cities in various districts in Japan for the purpose of induction of young students' interests in science and scientific experiments. On the basis of the survey results from the participants of the 'Radiation Fair' in Osaka, Japan, which was presented at the last IMRP, we expanded the area of survey and distributed questionnaires to the visitors of the above event to inquire their status toward radiation and irradiated products including irradiated potatoes. The survey results indicated the same trends as that of the 'Radiation Fair' survey. That is, more than half of the older visitors (16 years old and upward) indicated that they recognized the word of 'radiation' when they were at elementary school and the most significant sources of this information were school lessons and the mass media. We will discuss the relationship between consumer's image toward radiation and the description of radiation related topic in school textbooks. (author)

Irradiation of UO2

International Nuclear Information System (INIS)

Stevanovic, M.

1965-10-01

Based on the review of the available literature concerned with UO 2 irradiation, this paper describes and explains the phenomena initiated by irradiation of the UO 2 fuel in a reactor dependent on the burnup level and temperature. A comprehensive review of UO 2 radiation damage studies is given as a broad research program. This part includes the abilities of our reactor as well as needed elements for such study. The third part includes the definitions of the specific power, burnup level and temperature in the center of the fuel element needed for planning and performing the irradiation. Methods for calculating these parameters are included [sr

Consultation on microbiological criteria for foods to be further processed including by irradiation

International Nuclear Information System (INIS)

1989-01-01

Many foods carry microorganisms that may have serious consequences for the health of the consumer. There is thus often a need for processing to eliminate the resulting health hazards. Concern has been expressed that treatments, especially irradiation, might be applied to clean up food that has not been hygienically processed. Adherence to good manufacturing practice can greatly assist food processors to ensure food quality and safety. Figs

Food irradiation

International Nuclear Information System (INIS)

Kobayashi, Yasuhiko; Kikuchi, Masahiro

2009-01-01

Food irradiation can have a number of beneficial effects, including prevention of sprouting; control of insects, parasites, pathogenic and spoilage bacteria, moulds and yeasts; and sterilization, which enables commodities to be stored for long periods. It is most unlikely that all these potential applications will prove commercially acceptable; the extend to which such acceptance is eventually achieved will be determined by practical and economic considerations. A review of the available scientific literature indicates that food irradiation is a thoroughly tested food technology. Safety studies have so far shown no deleterious effects. Irradiation will help to ensure a safer and more plentiful food supply by extending shelf-life and by inactivating pests and pathogens. As long as requirement for good manufacturing practice are implemented, food irradiation is safe and effective. Possible risks of food irradiation are not basically different from those resulting from misuse of other processing methods, such as canning, freezing and pasteurization. (author)

Dosimetry and irradiation methods for the ANSTO gamma technology research irradiator (GATRI)

International Nuclear Information System (INIS)

Izard, M.E.

1988-07-01

The Australian Nuclear Science and Technology Organisation's gamma technology research irradiator (GATRI) at Lucas Heights, New South Wales, has been modified for use as a research and small-scale commercial irradiation facility to be available to government agencies and private industry for the technical and economic evaluation of irradiation processing. The new source rack was designed around existing mechanical components to optimise the limited space available within the irradiation cell. Irradiation parameters investigated during commissioning included the effect of source-to-target distance on relative dose rates within targets of the same density; effect of density on dose-rate distribution within targets irradiated at the same distance from the source; and the contribution of transit dose to low absorbed doses as the source is raised and lowered. The efficiency of the irradiator was determined for various target densities and overdose ratios

Food irradiation

International Nuclear Information System (INIS)

Anon.

1984-01-01

Food preservation by irradiation is one part of Eisenhower's Atoms for Peace program that is enjoying renewed interest. Classified as a food additive by the Food, Drug, and Cosmetic Act of 1958 instead of a processing technique, irradiation lost public acceptance. Experiments have not been done to prove that there are no health hazards from gamma radiation, but there are new pressures to get Food and Drug Administration approval for testing in order to make commercial use of some radioactive wastes. Irradiation causes chemical reactions and nutritional changes, including the destruction of several vitamins, as well as the production of radiolytic products not normally found in food that could have adverse effects. The author concludes that, lacking epidemiological evidence, willing buyers should be able to purchase irradiated food as long as it is properly labeled

Irradiation creep models - an overview

International Nuclear Information System (INIS)

Matthews, J.R.; Finnis, M.W.

1988-01-01

The modelling of irradiation creep is now highly developed but many of the basic processes underlying the models are poorly understood. A brief introduction is given to the theory of cascade interactions, point defect clustering and dislocation climb. The range of simple irradiation creep models is reviewed including: preferred nucleation of interstitial loops; preferred absorption of point defects by dislocations favourably orientated to an applied stress; various climb-enhanced glide and recovery mechanisms, and creep driven by internal stresses produced by irradiation growth. A range of special topics is discussed including: cascade effects; creep transients; structural and induced anisotropy; and the effect of impurities. The interplay between swelling and growth with thermal and irradiation creep is emphasized. A discussion is given on how irradiation creep theory should best be developed to assist the interpretation of irradiation creep observations and the requirements of reactor designers. (orig.)

Determinación de la tenacidad a la fractura de muestras de Acero 45 fundido, empleando las correlaciones entre el KIC y la energía de impacto medida en el ensayo de Charpy. // Determination of the fracture tenacity of cast Steel grade 45 samples, using th

Directory of Open Access Journals (Sweden)

F. Ramos Morales

2005-05-01

Full Text Available En el presente trabajo se determinan los valores de tenacidad a la fractura (KIC de muestras de Acero 45 fundido,empleando las correlaciones entre la tenacidad a la fractura y la energía de impacto (CVN obtenida del ensayo de Charpy.Se hace una discusión sobre las correlaciones que más se ajustan en la región de transición y en upper shelf. Se comparanlos valores obtenidos de estas correlaciones a valores de tenacidad a la fractura establecidos en la literatura.Palabras claves: Fractura, energía de impacto, acero fundido.______________________________________________________________________________Abstract.In this paper, the values of fracture toughness (KIC are determined on specimens of cast steel grade 45, using thecorrelations among the fracture toughness (KIC and the impact energy (CVN obtained from a Charpy test. A discussion ismade on the correlations that are better adjusted in the transition region and in upper shelf region. The obtained values arecompared from these correlations to values of fracture toughness (KIC settled down in the literature.Key words. Fracture, impact energy, cast steel.

Dosimetry for Crystals Irradiation

CERN Document Server

Lecomte, Pierre

2005-01-01

Before shipment to CMS, all PbWO4 crystals produced in China are irradiated there with 60 Co , in order to insure that the induced absorption coefficient is within specifications. Acceptance tests at CERNand at ENEA also include irradiation with gamma rays from 60 Co sources. There were initially discrepancies in quoted doses and doserates as well as in induced absorption coefficients. The present work resolves the discrepancies in irradiation measurements and defines common dosimetry methods for consistency checks between irradiation facilities.

Gamma irradiation devices

International Nuclear Information System (INIS)

Foeldiak, Gabor; Stenger, Vilmos.

1983-01-01

The main parameters and the preparation procedures of the gamma radiation sources frequently applied for irradiation purposes are discussed. In addition to 60 Co and 137 Cs sources also the nuclear power plants offer further opportunities: spent fuel elements and products of certain (n,γ) reactions can serve as irradiation sources. Laboratory scale equipments, pilot plant facilities for batch or continuous operation, continuous industrial irradiators and special multipurpose, mobile and panorama type facilities are reviewed including those in Canada, USA, India, the Soviet Union, Hungary, UK, Japan and Australia. For irradiator design the source geometry dependence of the spatial distribution of dose rates can be calculated. (V.N.)

Development of Irradiation Procedure for Gamma Irradiation Chamber Bio beam GM 8000

International Nuclear Information System (INIS)

Shuhaimi Shamsudin; Affrida Abu Hassan; Zaiton Ahmad; Abdul Rahim Harun; Ahmad Zainuri Mohd Dzomir

2015-01-01

Bio Beam GM 8000 gamma irradiation chamber obtained a conditional approval to operate on March 27, 2012, and later acquired a full approval on December 13, 2012. The objective for the procurement of this gamma chamber is to develop an acute irradiation facility for biological samples, including plants tissues, insects, pupae, microorganisms, as well as animal and human cells. To ensure a smooth and efficient operation, irradiation procedures were developed and improved over time. This paper discusses the operation and management of the Bio Beam GM 8000 facility, including irradiation procedures and sample preparation, application for services through online e-client system, consultancy, quality assurance and information dissemination to internal as well as external clients. In addition, this paper also discusses the potential, constraints and improvement measures taken to optimize the use of this facility in order to meet its objectives. (author)

A master curve-mechanism based approach to modeling the effects of constraint, loading rate and irradiation on the toughness-temperature behavior of a V-4Cr-4Ti alloy

International Nuclear Information System (INIS)

Odette, G.R.; Donahue, E.; Lucas, G.E.; Sheckherd, J.W.

1996-01-01

The influence of loading rate and constraint on the effective fracture toughness as a function of temperature [K e (T)] of the fusion program heat of V-4Cr-4Ti was measured using subsized, three point bend specimens. The constitutive behavior was characterized as a function of temperature and strain rate using small tensile specimens. Data in the literature on this alloy was also analysed to determine the effect of irradiation on K e (T) and the energy temperature (E-T) curves measured in subsized Charpy V-notch tests. It was found that V-4Cr-4Ti undergoes open-quotes normalclose quotes stress-controlled cleavage fracture below a temperature marking a sharp ductile-to-brittle transition. The transition temperature is increased by higher loading rates, irradiation hardening and triaxial constraint. Shifts in a reference transition temperature due to higher loading rates and irradiation can be reasonably predicted by a simple equivalent yield stress model. These results also suggest that size and geometry effects, which mediate constraint, can be modeled by combining local critical stressed area σ*/A* fracture criteria with finite element method simulations of crack tip stress fields. The fundamental understanding reflected in these models will be needed to develop K e (T) curves for a range of loading rates, irradiation conditions, structural size scales and geometries relying (in large part) on small specimen tests. Indeed, it may be possible to develop a master K e (T) curve-shift method to account for these variables. Such reliable and flexible failure assessment methods are critical to the design and safe operation of defect tolerant vanadium structures

Detection of low amount of irradiated ingredients in non-irradiated precooked meals

NARCIS (Netherlands)

Marchioni, E; Horvatovich, P; Ndiaye, B; Miesch, M; Hasselmann, C

The application of the European Standards for the detection of irradiated food by thermo luminescence of silicates, electron-spin resonance spectroscopy of bones or gas chromatography-mass spectrometry of 2-alkylcyclobutanones does not allow the detection of irradiated ingredients included in small

Effect of lead factors on the embrittlement of RPV SA-508 cl 3 steel

Energy Technology Data Exchange (ETDEWEB)

Kempf, Rodolfo, E-mail: kempf@cnea.gov.ar [CNEA, Unidad Actividad Combustibles Nucleares, División Caracterización, Avda. Gral Paz 1499, C.P.B1650KNA, San Martín, Buenos Aires (Argentina); Troiani, Horacio, E-mail: troiani@cab.cnea.gov.ar [Centro Atómico Bariloche (CNEA) e Instituto Balseiro (UNCU), CONICET, Av. Bustillo 9500, CP 8400, Rio Negro (Argentina); Fortis, Ana Maria, E-mail: fortis@cnea.gov.ar [CNEA, Departamento Estructura y Comportamiento, UNSAM, Avda. Gral Paz 1499, C.P.B1650KNA, San Martín, Buenos Aires (Argentina)

2013-03-15

This paper presents a project to study the effect of lead factors on the mechanical behaviour of the SA-508 type 3 Reactor Pressure Vessel (RPV) steel used in the reactor under construction Atucha II in Argentina. Charpy-V notch specimens of this steel were irradiated at the RA1 experimental reactor at a temperature of 275 °C with two lead factors (186 and 93). The neutron flux was 3.71 × 10{sup 15} n m{sup −2} s{sup −1} and 1.85 × 10{sup 15} n m{sup −2} s{sup −1} (E > 1 MeV) respectively. In both cases, the fluence was 6.6 × 10{sup 21} n m{sup −2}, which is equivalent to that received by the PHWR Atucha II RPV in 10 years of full power irradiation. The results of Charpy tests revealed significant embrittlement both in the ΔT = 14 °C and ΔT = 21 °C shifts of the ductile–brittle transition temperatures (DBTT) and in the reduction of the maximum energy absorbed. This result shows that the shift of the DBTT with a lead factor of 93 is larger than that obtained with a lead factor of 186. Then, the results of irradiation in experimental reactors (MTR) with high lead factors may not be conservative with respect to the actual RPV embrittlement.

Specimen size effects in Charpy impact testing

International Nuclear Information System (INIS)

Alexander, D.J.; Klueh, R.L.

1989-01-01

Full-size , half-size, and third-size specimens from several different steels have been tested as part of an ongoing alloy development program. The smaller specimens permit more specimens to be made from small trail heats and are much more efficient for irradiation experiments. The results of several comparisons between the different specimen sizes have shown that the smaller specimens show qualitatively similar behavior to large specimens, although the upper-shelf energy level and ductile-to-ductile transition temperature are reduced. The upper-shelf energy levels from different specimen sizes can be compared by using a simple volume normalization method. The effect of specimen size and geometry on the ductile-to-ductile transition temperature is more difficult to predict, although the available data suggest a simple shift in the transition temperature due to specimen size changes.The relatively shallower notch used in smaller specimens alters the deformation pattern, and permits yielding to spread back to the notched surface as well as through to the back. This reduces the constraint and the peak stresses, and thus the initiation of cleavage is more difficult. A better understanding of the stress and strain distributions is needed. 19 refs., 3 figs., 3 tabs

The present situation of irradiation services

International Nuclear Information System (INIS)

Hironiwa, Takayuki

2014-01-01

The present state of food irradiation in Japan is presented from a point of view of a trustee for irradiation business. Radiation sprout inhibition of potatoes, only approved by Government, and spice treatment, now being applied for, are explained. Existing establishments capable of entrusting irradiation services as business in Japan are outlined including Co-60 gamma ray and X-ray irradiation and electron beam irradiation. Principles of irradiation-induced physical and chemical effects in irradiated materials specifically organic polymers and brief explanation of facilities together with safety devices are also explained. (S. Ohno)

Adequacy of Current Equivalent Margins Analysis (EMA) Guidance, Data and Methodologies for 60+ Years of Operation

International Nuclear Information System (INIS)

Server, W.; Hardin, T.; Cipolla, R.; Hall, B.

2015-01-01

In order to assure the structural integrity of reactor pressure vessels (RPVs), the fracture toughness of the ferritic steels used to fabricate the RPV must be shown to be adequate during their entire operating life, including extended license life. The Charpy V-notch (CVN) impact test has been used in the nuclear industry since it uses a small test specimen that can be irradiated in surveillance programs and provides an indirect way of assessing the fracture toughness of RPV steels. The effects of embrittlement typically are characterized by changes to the average Charpy curves measured before and after irradiation: shift of the 30 ft-lb (41 J) index temperature, and decrease in the CVN upper shelf energy (USE). Requirements in the USA for the USE of RPV belt-line materials are codified in Title 10, Code of Federal Regulations, Part 50 (10 CFR 50), Appendix G. Before irradiation, USE in the transverse (T-L) orientation for base materials and crack extension in the welding direction for weld materials must be greater than or equal to 75 ft-lb (102 J), and it is not to become less than 50 ft-lb (68 J) due to radiation embrittlement throughout the license of the RPV. If the projected USE of any RPV belt-line steel falls below 50 ft-lb (68 J), the projected value must be demonstrated to provide a margin of safety against ductile fracture equivalent to that required by Appendix G of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI. The analytical evaluation method used is called an equivalent margin analysis (EMA). This paper reviews the current status of EMAs and recommends improvements and clarifications that can be made to meet the needs of extended license life to 80 years. Focus is placed on analytical methodology, material property needs and proper implementation. (authors)

Studies of blood irradiator application

International Nuclear Information System (INIS)

Li Wenhong; Lu Yangqiao

2004-01-01

Transfusion is an important means for medical treatment, but it has many syndromes such as transfusion-associated graft-versus-host disease, it's occurrence rate of 5% and above 90% death-rate. Now many experts think the only proven method is using blood irradiator to prevent this disease. It can make lymphocyte of blood product inactive, so that it can not attack human body. Therefore, using irradiation blood is a trend, and blood irradiator may play an important role in medical field. This article summarized study of blood irradiator application, including the meaning of blood irradiation, selection of the dose for blood irradiation and so on

Legislations the field of food irradiation

International Nuclear Information System (INIS)

1987-05-01

An outline is given of the national legislation in 39 countries in the field of food irradiation. Where available the following information is given for each country: form of legislation, object of legislation including information on the irradiation treatment, the import and export trade of irradiated food, the package labelling and the authorization and control of the irradiation procedures

Analysis of mechanical property data obtained from nuclear pressure vessel surveillance capsules

International Nuclear Information System (INIS)

Perrin, J.S.

1977-01-01

A typical pressure vessel surveillance capsule examination program provides mechanical property data from tensile, Charpy V-notch impact, and, in some cases, fracture mechanics specimens. This data must be analyzed in conjunction with the unirradiated baseline mechanical property data to determine the effect of irradiation on the mechanical properties. In the case of Charpy impact specimens, for example, irradiation typically causes an increase in the transition temperature, and a decrease in the upper shelf energy level. The results of the Charpy impact and other mechanical specimen tests must be evaluated to determine if property changes are occurring in the manner expected when the reactor was put into service. The large amount of data obtained from surveillance capsule examinations in recent years enables one to make fairly good predictions. After the changes in the mechanical properties of specimens from a particular surveillance capsule have been experimentally determined and evaluated, they must be related to the reactor pressure vessel. This requires a knowledge of the neutron fluence of the surveillance capsule, and the ratio of the surveillance capsule fluence to the pressure vessel wall fluence. This ratio is frequently specified by the reactor manufacturer, or can be calculated from a knowledge of the geometry and materials of the reactor components inside the pressure vessel. A knowledge of the exact neutron fluence of the capsule specimens and the capsule to vessel wall neutron fluence ratio is of great importance, since inaccuracies in these numbers cause just as serious a problem as inaccuracies in the mechanical property determinations. A further area causing analysis difficulties is problems encountered in recent capsule programs relating to capsule design, construction, operation, and dismantling. (author)

Statistical evaluation of fracture characteristics of RPV steels in the ductile-brittle transition temperature region

International Nuclear Information System (INIS)

Kang, Sung Sik; Chi, Se Hwan; Hong, Jun Hwa

1998-01-01

The statistical analysis method was applied to the evaluation of fracture toughness in the ductile-brittle transition temperature region. Because cleavage fracture in steel is of a statistical nature, fracture toughness data or values show a similar statistical trend. Using the three-parameter Weibull distribution, a fracture toughness vs. temperature curve (K-curve) was directly generated from a set of fracture toughness data at a selected temperature. Charpy V-notch impact energy was also used to obtain the K-curve by a K IC -CVN (Charpy V-notch energy) correlation. Furthermore, this method was applied to evaluate the neutron irradiation embrittlement of reactor pressure vessel(RPV) steel. Most of the fracture toughness data were within the 95 percent confidence limits. The prediction of a transition temperature shift by statistical analysis was compared with that from the experimental data. (author)

Irradiation preservation of seafood: Literature review

International Nuclear Information System (INIS)

Molton, P.M.

1987-10-01

The application of gamma-irradiation for extending the shelf life of seafood has been of interest for many years. This report reviews a number of studies on seafood irradiation conducted over the past several years. Topics covered include seafood irradiation techniques and dosages, species applicability and differences, the effects of packaging on seafood preservation, and changes in organoleptic acceptability as a result of irradiation. Particular attention is given to radiation effects (likely and unlikely) of concern to the public. These include the potential for generation of toxic chemical products, botulinum toxin production, and other health concerns. No scientifically defensible evidence of any kind was found for any harmful effect of irradiation of seafoods at the doses being considered (less than 300 krad), and all indications are that irradiation is an acceptable and needed additional tool for seafood preservation. 49 refs., 14 figs., 14 tabs

Irradiation preservation of seafood: Literature review

Energy Technology Data Exchange (ETDEWEB)

Molton, P.M.

1987-10-01

The application of gamma-irradiation for extending the shelf life of seafood has been of interest for many years. This report reviews a number of studies on seafood irradiation conducted over the past several years. Topics covered include seafood irradiation techniques and dosages, species applicability and differences, the effects of packaging on seafood preservation, and changes in organoleptic acceptability as a result of irradiation. Particular attention is given to radiation effects (likely and unlikely) of concern to the public. These include the potential for generation of toxic chemical products, botulinum toxin production, and other health concerns. No scientifically defensible evidence of any kind was found for any harmful effect of irradiation of seafoods at the doses being considered (less than 300 krad), and all indications are that irradiation is an acceptable and needed additional tool for seafood preservation. 49 refs., 14 figs., 14 tabs.

Preliminary irradiation test results from the Yankee Atomic Electric Company reactor vessel test irradiation program

International Nuclear Information System (INIS)

Biemiller, E.C.; Fyfitch, S.; Campbell, C.A.

1993-01-01

The Yankee Atomic Electric Company test irradiation program was implemented to characterize the irradiation response of representative Yankee Rowe reactor vessel beltline plate materials and to remove uncertainties in the analysis of existing irradiation data on the Yankee Rowe reactor vessel steel. Plate materials each containing 0.24 w/o copper, but different nickel contents at 0.63 w/o and 0.19 w/o, were heat treated to simulate the Yankee vessel heat treatment (austenitized at 1800 deg F) and to simulate Regulatory Guide 1.99 database materials (austenitized at 1600 deg. F). These heat treatments produced different microstructures so the effect of microstructure on irradiation damage sensitivity could be tested. Because the nickel content of the test plates varied and the copper level was constant, the effect of nickel on irradiation embrittlement was also tested. Correlation monitor material, HSST-02, was included in the program to benchmark the Ford Nuclear Reactor (U. of Michigan Test Reactor) which had never been used for this type of irradiation program. Materials taken from plate surface locations (vs. 1/4T) were included to test whether or not the improved toughness properties of the plate surface layer, resulting from the rapid quench, is maintained after irradiation. If the improved properties are maintained, pressurized thermal shock calculations could utilize this margin. Finally, for one experiment, irradiations were conducted at two irradiation temperatures (500 deg. F and 550 deg. F) to determine the effect of irradiation temperature on embrittlement. The preliminary results of the irradiation program show an increase in T 30 shift of 69 deg. F for a decrease in irradiation temperature of 50 deg. F. The results suggest that for nickel bearing steels, the superior toughness of plate surface material is maintained after irradiation and for the copper content tested, nickel had no apparent effect on irradiation response. No apparent microstructure

Preliminary irradiation test results from the Yankee Atomic Electric Company reactor vessel test irradiation program

International Nuclear Information System (INIS)

Biemiller, E.C.; Fyfitch, Stephen; Campbell, C.A.

1994-01-01

The Yankee Atomic Electric Company test irradiation program was implemented to characterize the irradiation response of representative Yankee Rowe reactor vessel beltline plate materials and to remove uncertainties in the analysis of existing irradiation data on the Yankee Rowe reactor vessel steel. Plate materials each containing 0.24 w/o copper, but different nickel contents at 0.63 w/o and 0.19 w/o, were heat treated to simulate the Yankee vessel heat treatment (austenitized at 982 o C (1800 o F)) and to simulate Regulatory Guide 1.99 database materials (austenitized at 871 o C (1600 o F)). These heat treatments produced different microstructures so the effect of microstructure on irradiation damage sensitivity could be tested. Because the nickel content of the test plates varied and the copper level was constant, the effect of nickel on irradiation embrittlement was also tested. Correlation monitor material, HSST-02, was included in the program to benchmark the Ford Nuclear Reactor (University of Michigan Test Reactor) which had never been used before for this type of irradiation program. Materials taken from plate surface locations (versus 1/4 T) were included to test whether or not the improved toughness properties of the plate surface layer, resulting from the rapid quench, are maintained after irradiation. If the improved properties are maintained, pressurized thermal shock calculations could utilize this margin. Finally, for one experiment, irradiations were conducted at two irradiation temperatures (260 o C and 288 o C) to determine the effect of irradiation temperature on embrittlement. (Author)

Cost-benefit analysis of irradiation of vegetables and fruits at the Shanghai irradiation centre

International Nuclear Information System (INIS)

Xu Zhicheng; Sha Zhenyuan

1993-01-01

Differences between the developing and the developed countries in development and application of food irradiation are discussed, including the objectives of irradiation, scale, and the operation and control of facilities. These represent the chief problems of development of food irradiation in the developing countries. A proposal concerning the economic benefit of a gamma irradiation facility is discussed. In the light of many years' operating experience at the Shanghai Irradiation Centre, the operation cost per hour and coefficient of economic benefit are presented. These data can be used to estimate the economic benefit of gamma irradiated products at any time, and are useful for directing the daily operation of gamma irradiation facilities. From examples of cost-benefit analysis of irradiated garlic and apples it is shown that to improve the benefit of gamma irradiation facilities the annual hours of operation must be increased, so as to reduce the cost of operation. Food irradiated with a low dose provides more economic benefit than other irradiated products; the coefficients of economic benefit will increase as the irradiated processing throughput increases. Practical examples are given relating to garlic and apples, showing the economic benefit to wholesalers and retailers. (author). 4 refs, 3 figs, 7 tabs

Food irradiation control

International Nuclear Information System (INIS)

Ley, F.J.

1988-01-01

A brief review is given of the control and monitoring of food irradiation with particular emphasis on the UK situation. After describing legal aspects, various applications of food irradiation in different countries are listed. Other topics discussed include code of practice for general control for both gamma radiation and electron beam facilities, dose specification, depth dose distribution and dosimetry. (U.K.)

Food Irradiation Newsletter. V. 14, no. 2

International Nuclear Information System (INIS)

1990-12-01

This issue reports specific training activities on Food Irradiation Process Control School, both for technical supervisors of irradiation facilities and food control officials/inspectors, and summary reports of Workshops on dosimetry techniques for food irradiation and on techno-economic feasibility of food irradiation for Latin American countries are included. After 12 years of operation, the International Facility for Food Irradiation Technology (IFFIT) will cease to function after 31 December 1990. This issue reports the last inter-regional training course organized by IFFIT, and also features reports on food irradiation in Asia. Active developments in the field in several Asian countries may be found in the reports of the Workshop on the Commercialization of Food Irradiation, Shanghai, and the Research Co-ordination Meeting on the Asian Regional Co-operative Project on Food Irradiation (with emphasis on acceptance and process control), Bombay. Status reports of programmes in these countries are also included. Refs and tabs

SCK-CEN Contribution to the''Relation between different measures of exposure-induced shifts in ductile-brittle transition temperatures'' (REFEREE). Progress Report

International Nuclear Information System (INIS)

Chaouadi, R.; Van Walle, E.; Fabry, A.; Puzzolante, J.L.

1998-08-01

The relationship between Charpy-V (CVN) impact, fracture toughness and tensile properties for selected reactor pressure -vessel steels in the transition temperature range are investigated. Data on the testing of unirradiated material are reported. The applied methods include chemical analysis, Charpy-V impact testing, tensile testing and fracture toughness determination

Fluorescence of irradiated hydrocarbons

International Nuclear Information System (INIS)

Gulis, I.G.; Evdokimenko, V.M.; Lapkovskij, M.P.; Petrov, P.T.; Gulis, I.M.; Markevich, S.V.

1977-01-01

A visible fluorescence has been found out in γ-irradiated aqueous of carbohydrates. Two bands have been distinguished in fluorescence spectra of the irradiated solution of dextran: a short-wave band lambdasub(max)=140 nm (where lambda is a wave length) at lambdasub(β)=380 nm and a long-wave band with lambdasub(max)=540 nm at lambdasub(β)=430 nm. A similar form of the spectrum has been obtained for irradiated solutions of starch, amylopectin, lowmolecular glucose. It has been concluded that a macromolecule of polysaccharides includes fluorescent centres. A relation between fluorescence and α-oxiketon groups formed under irradiation has been pointed out

The utilize of gamma radiation on the examination of mechanical properties of polymeric materials

Directory of Open Access Journals (Sweden)

F. Greškovič

2012-04-01

Full Text Available The article deals about the application area of radiation crosslinking of plastics, which follows after the injection moulding. The main objective of the presented article is the research of influence irradiation dosage on mechanical properties of materials: PP filled by 15 % of mineral filler – talc. Mechanical properties - tensile strength and impact strength by Charpy were examined in dependence on absorbed dose of the gamma rays on various conditions and were compared with non-irradiated samples. Radiation processing involves mainly the use of either electron beams from electron accelerators or gamma radiation from Cobalt-60 sources.

Food Irradiation in Japan

Energy Technology Data Exchange (ETDEWEB)

Kawabata, T.

1981-09-15

Since 1967 research activities on food irradiation in Japan have been carried out under the National Food Irradiation Programme by the Japanese Atomic Energy Commission. The programme has been concentrated on the technological and economical feasibility and wholesomeness testings of seven irradiated food items of economic importance to the country, i.e. potatoes, onions, wheat, rice, 'kamaboko' (fish-paste products), 'Vienna' sausages and mandarin oranges. By now most studies, including wholesomeness testings of these irradiated food items, have been completed. In Japan, all foods or food additives for sale are regulated by the Food Sanitation Law enforced in 1947. Based on studies made by the national programme, irradiated potatoes were given 'unconditional acceptance' for human consumption in 1972. At present, irradiated potatoes are the only food item which has so far been approved by the Minister of Health and Welfare. Unless the Minister of Health and Welfare has declared that items are not harmful to human health on obtaining comments from the Food Sanitation Investigation Council, no irradiated food can be processed or sold. In addition, the import of irradiated foodstuffs other than potatoes from foreign countries is prohibited by law.

Facts about food irradiation. A series of fact sheets from the International Consultative Group on Food Irradiation

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-12-01

The safety and benefits of foods processed by ionizing radiation are well documented. In an effort to provide governments, especially those of developing countries, with scientifically accurate information on issues of general interest to the public, the International Consultative Group on Food Irradiation (ICGFI), which was established under the aegis of the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the IAEA, decided at its 7th Annual Meeting in Rome, Italy, on October 1990, to issue a series of ''Fact Sheets'' on the subject. ICGFI, an inter-governmental body with a membership of 37 governments, has as one of its mandates the function to provide information to Member States of the FAO, WHO, and IAEA and to the three organizations themselves on the safe and proper use of food irradiation technology. The Fact Sheets included here cover issues relating to: status and trends; scientific and technical terms; food irradiation and radioactivity; chemical changes in irradiated food; nutritional quality of irradiated foods; genetic studies; microbiological safety of irradiated food; irradiation and food safety; irradiation and food additives and residues; packaging of irradiated foods; safety of irradiation facilities; controlling the process; food irradiation costs; and irradiated foods and the consumer. The Fact Sheets have been separately indexed and included in the INIS Database under Reference Numbers 23011206-23011217, 23011319 and 23012743. The Fact Sheets were first issued by the ICGFI Secretariat (Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna, Austria) in May 1991.

Facts about food irradiation. A series of fact sheets from the International Consultative Group on Food Irradiation

International Nuclear Information System (INIS)

1991-12-01

The safety and benefits of foods processed by ionizing radiation are well documented. In an effort to provide governments, especially those of developing countries, with scientifically accurate information on issues of general interest to the public, the International Consultative Group on Food Irradiation (ICGFI), which was established under the aegis of the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the IAEA, decided at its 7th Annual Meeting in Rome, Italy, on October 1990, to issue a series of ''Fact Sheets'' on the subject. ICGFI, an inter-governmental body with a membership of 37 governments, has as one of its mandates the function to provide information to Member States of the FAO, WHO, and IAEA and to the three organizations themselves on the safe and proper use of food irradiation technology. The Fact Sheets included here cover issues relating to: status and trends; scientific and technical terms; food irradiation and radioactivity; chemical changes in irradiated food; nutritional quality of irradiated foods; genetic studies; microbiological safety of irradiated food; irradiation and food safety; irradiation and food additives and residues; packaging of irradiated foods; safety of irradiation facilities; controlling the process; food irradiation costs; and irradiated foods and the consumer. The Fact Sheets have been separately indexed and included in the INIS Database under Reference Numbers 23011206-23011217, 23011319 and 23012743. The Fact Sheets were first issued by the ICGFI Secretariat (Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna, Austria) in May 1991

Fabrication, irradiation and post-irradiation examinations of MO2 and UO2 sphere-pac and UO2 pellet fuel pins irradiated in a PWR loop

International Nuclear Information System (INIS)

Linde, A. van der; Lucas Luijckx, H.J.B.; Verheugen, J.H.N.

1982-01-01

The document reports in detail the fuel pin fabrication data and describes the irradiation conditions and history. All the relevant results of the non-destructive and destructive post-irradiation examinations are reported. They include: visual inspection and chemical analysis of crud; length and diameter measurements; neutron radiography and gamma scanning; juncture tests and fission gas analysis (including residual gas in fuel samples); microscopy and alpha + beta/gamma autoradiography; microprobe investigations; burn-up and isotopic analysis; and hydrogen analysis in clad. The data and observations obtained are discussed in detail and conclusions are given. The irradiation and post-irradiation examinations of the R-109 pins have shown the safe, pre-calculable performance of LWR fuel pins containing mixed-oxide sphere-pac fuel with the fissile material mainly present in the large spheres

Radiation facilities and irradiation technology for food irradiation

International Nuclear Information System (INIS)

Sunaga, Hiromi

2005-01-01

Progress made during these 30 years in the field of radiation treatment of food is reviewed by describing features of the process including elementary processes, quality control of the products and the dosimetric techniques widely employed. The Co-60 gamma-ray irradiation facilities to be used for radiation-sterilization of medical supplies and food preservation are presented. For electron beam irradiation, accelerators for processing with the energy from 0.3 to 10 MeV are generally employed. The electron-guns, the method of acceleration such as rectification, types of acceleration as Cockcroft-Walton, dynamitron, or linear acceleration and X-ray producing facility, with various countermeasures for safety management, are briefly explained. The concepts of dose and traceability are given. The dosimeters including reference dosimeter and routine ones with validation are explained. (S. Ohno)

Identification of irradiated foods prospects for post-irradiation estimate of irradiation dose in irradiated dry egg products

International Nuclear Information System (INIS)

Katusin-Raxem, B.; Mihaljievic, B.; Razem, D.

2002-01-01

Radiation-induced chemical changes in foods are generally very small at the usual processing doses. Some exception is radiation degradation of lipids, which are the components most susceptible to oxidation. A possible use of lipid hydroperoxides (LOOH) as indicators of irradiation is described for whole egg and egg yolk powders. A sensitive and reproducible spectrophotometric method for LOOH measurement based on feric thiocyanate, as modified in our laboratory, was applied. This method enabled the determination of LOOH, including oleic acid hydroperoxides, which is usually not possible with some other frequently used methods. The lowest limit of 0.05 mmol LOOH/kg lipid could be measured. The measurements were performed in various batches of whole egg and egg yolk powders by the same producer, as well as in samples supplied by various producers. Baseline level in unirradiated egg powder 0.110 ± 0.067 mmol LOOH /kgL was established. The formation of LOOH with dose, as well as the influence of age, irradiation conditions, storage time and storage conditions on LOOH were investigated. The irradiation of whole egg and egg yolk powders in the presence of air revealed an initially slow increase of LOOH, caused by an inherent antioxidative capacity, followed by a fast linear increase after the inhibition dose (D o ). In all investigated samples D o of 2 kGy was determined. Hydroperoxides produced in irradiated materials decay with time. In whole egg and egg yolk powders, after an initially fast decay, the level of LOOH continued to decrease by the first-order decay. Nevertheless, after a six months storage it was still possible to unambiguously identify samples which had been irradiated with 2 kGy in the presence of air. Reirradiation of these samples revealed a significant reduction of D o to 1 kGy. In samples irradiated with 4 kGy and kept under the same conditions, the shortening of D o to 0.5 kGy was determined by reirradiation. This offers a possibility for the

Food irradiation scenario in India

International Nuclear Information System (INIS)

Thomas, Paul

1998-01-01

Over 3 decades of research and developmental effort in India have established the commercial potential for food irradiation to reduce post-harvest losses and to ensure food safety. Current regulations permit irradiation of onions, potatoes and spices for domestic consumption and operation of commercial irradiators for treatment of food. In May 1997 draft rules have been notified permitting irradiation of several additional food items including rice, wheat products, dry fruits, mango, meat and poultry. Consumers and food industry have shown a positive attitude to irradiated foods. A prototype commercial irradiator for spices set up by Board of Radiation and Isotope Technology (BRIT) is scheduled to commence operation in early 1998. A commercial demonstration plant for treatment of onions is expected to be operational in the next 2 years in Lasalgaon, Nashik district. (author)

RERTR-12 Insertion 1 Irradiation Summary Report

International Nuclear Information System (INIS)

Perez, D.M.; Lillo, M.A.; Chang, G.S.; Woolstenhulme, N.E.; Roth, G.A.; Wachs, D.M.

2012-01-01

The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications. RERTR-12 insertion 1 includes the capsules irradiated during the first two irradiation cycles. These capsules include Z, X1, X2 and X3 capsules. The following report summarizes the life of the RERTR-12 insertion 1 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

RERTR-12 Insertion 2 Irradiation Summary Report

International Nuclear Information System (INIS)

Perez, D.M.; Chang, G.S.; Wachs, D.M.; Roth, G.A.; Woolstenhulme, N.E.

2012-01-01

The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications.1 RERTR-12 insertion 2 includes the capsules irradiated during the last three irradiation cycles. These capsules include Z, Y1, Y2 and Y3 type capsules. The following report summarizes the life of the RERTR-12 insertion 2 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

Currently developing opportunities in food irradiation and modern irradiation facilities

International Nuclear Information System (INIS)

Wanke, R.

1997-01-01

I. Factor currently influencing advancing opportunities for food irradiation include: heightened incidence and awareness of food borne illnesses and causes. Concerns about ensuring food safety in international as well as domestic trade. Regulatory actions regarding commonly used fumigants/pesticides e.g. Me Br. II. Modern irradiator design: the SteriGenics M ini Cell . A new design for new opportunities. Faster installation of facility. Operationally and space efficient. Provides local o nsite control . Red meat: a currently developing opportunity. (Author)

Monitoring of irradiation effects on the pressure vessel steels of Calder, Chapelcross and Windscale Advanced Gas Cooled Reactor (WAGR) nuclear reactors

International Nuclear Information System (INIS)

Turner, F.

1980-01-01

Tensile, Charpy and bend specimens of plate, forging and weld metal are exposed in the lower and upper zones of the reactors to neutron fluxes covering the range experienced by the vessels. The test conditions are described, the results presented and discussed. (author)

Food irradiation

International Nuclear Information System (INIS)

Beishon, J.

1991-01-01

Food irradiation has been the subject of concern and controversy for many years. The advantages of food irradiation include the reduction or elimination of dangerous bacterial organisms, the control of pests and insects which destroy certain foods, the extension of the shelf-life of many products, for example fruit, and its ability to treat products such as seafood which may be eaten raw. It can also replace existing methods of treatment which are believed to have hazardous side-effects. However, after examining the evidence produced by the proponents of food irradiation, the author questions whether it has any major contribution to make to the problems of foodborne diseases or world food shortages. More acceptable solutions, he suggests, may be found in educating food handlers to ensure that hygienic conditions prevail in the production, storage and serving of food. (author)

Clinical target volume delineation including elective nodal irradiation in preoperative and definitive radiotherapy of pancreatic cancer

Directory of Open Access Journals (Sweden)

Caravatta Luciana

2012-06-01

Full Text Available Abstract Background Radiotherapy (RT is widely used in the treatment of pancreatic cancer. Currently, recommendation has been given for the delineation of the clinical target volume (CTV in adjuvant RT. Based on recently reviewed pathologic data, the aim of this study is to propose criteria for the CTV definition and delineation including elective nodal irradiation (ENI in the preoperative and definitive treatment of pancreatic cancer. Methods The anatomical structures of interest, as well as the abdominal vasculature were identified on intravenous contrast-enhanced CT scans of two different patients with pancreatic cancer of the head and the body. To delineate the lymph node area, a margin of 10 mm was added to the arteries. Results We proposed a set of guidelines for elective treatment of high-risk nodal areas and CTV delineation. Reference CT images were provided. Conclusions The proposed guidelines could be used for preoperative or definitive RT for carcinoma of the head and body of the pancreas. Further clinical investigations are needed to validate the defined CTVs.

IAEA and food irradiation

International Nuclear Information System (INIS)

Machi, Sueo

1995-01-01

IAEA was founded in 1957. 122 countries take part in it. It is operated with the yearly ordinary budget of about 20 billion yen and the technical cooperation budget of about 6 billion yen and by 2200 personnel. Its two important roles are the promotion of the peaceful utilization of atomic energy and the prevention of nuclear proliferation. The activities of IAEA are shown. The cooperation with developing countries and the international research cooperation program are the important activities. The securing of foods is an urgent subject, and the utilization of radiation and isotopes has been promoted, aiming at sustaining agriculture. The necessity of food irradiation is explained, and at present, commercial food irradiation is carried out in 28 countries including Japan. The irradiation less than 10 kGy does not cause poisonous effect in any food, according to JECFI. The new international agreement is expected to be useful for promoting the international trade of irradiated foods. The international cooperation for the spread of food irradiation and the public acceptance of food irradiation are reported. (K.I.)

International acceptance of irradiated food. Legal aspects

International Nuclear Information System (INIS)

1979-01-01

The three international organizations competent in the field of irradiation processing for the preservation of food (FAO, WHO, IAEA), convened, at the end of 1977, an Advisory Group to revise and update the recommendations of a similar group which met in early 1972. The Advisory Group considered how national regulations could be harmonized so as to facilitate the international movement of irradiated food. This publication contains the Report of the Advisory Group, which summarizes the considerations of the Group on regulatory control over the irradiation plant and irradiation of foods, and on assurances for comparability of control (international labelling and documentation). Annexes 1 to 6 are included in order to complete the relevant information on the legal aspects of this subject. They include a Draft General Standard for Irradiated Foods, a Draft Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Foods, Recommendations of a Consultation Group on the Legal Aspects of Food Irradiation, a Listing of the Legislation on Food Irradiation Adopted in Member States (1971-1976), and Model Regulations for the Control of and Trade in Irradiated Food

Currently developing opportunities in food irradiation and modern irradiation facilities

Energy Technology Data Exchange (ETDEWEB)

Wanke, R [Director Business Development. SteriGenics International Inc. 17901 East Warren Avenue No. 4, Detroit, Michigan 48224-1333 (United States)

1998-12-31

I. Factor currently influencing advancing opportunities for food irradiation include: heightened incidence and awareness of food borne illnesses and causes. Concerns about ensuring food safety in international as well as domestic trade. Regulatory actions regarding commonly used fumigants/pesticides e.g. Me Br. II. Modern irradiator design: the SteriGenics {sup M}ini Cell{sup .} A new design for new opportunities. Faster installation of facility. Operationally and space efficient. Provides local {sup o}nsite control{sup .} Red meat: a currently developing opportunity. (Author)

Currently developing opportunities in food irradiation and modern irradiation facilities

Energy Technology Data Exchange (ETDEWEB)

Wanke, R. [Director Business Development. SteriGenics International Inc. 17901 East Warren Avenue No. 4, Detroit, Michigan 48224-1333 (United States)

1997-12-31

I. Factor currently influencing advancing opportunities for food irradiation include: heightened incidence and awareness of food borne illnesses and causes. Concerns about ensuring food safety in international as well as domestic trade. Regulatory actions regarding commonly used fumigants/pesticides e.g. Me Br. II. Modern irradiator design: the SteriGenics {sup M}ini Cell{sup .} A new design for new opportunities. Faster installation of facility. Operationally and space efficient. Provides local {sup o}nsite control{sup .} Red meat: a currently developing opportunity. (Author)

Small specimen test technology of fracture toughness in structural material F82H steel for fusion nuclear reactors

International Nuclear Information System (INIS)

Wakai, Eiichi; Ohtsuka, Hideo; Jitsukawa, Shiro; Matsukawa, Shingo; Ando, Masami

2006-03-01

Small specimen test technology (SSTT) has been developed to investigate mechanical properties of nuclear materials. SSTT has been driven by limited availability of effective irradiation volumes in test reactors and accelerator-based neutron and charged particle sources, and it is very useful for the reduction of waste materials produced in nuclear engineering. In this study new bend test machines have been developed to obtain fracture behaviors of F82H steel for very small bend specimens of pre-cracked t/2-1/3CVN (Charpy V-notch) with 20 mm-length and DFMB (deformation and fracture mini bend specimen) with 9 mm-length and disk compact tension of 0.18DCT type, and fracture behaviors were examined to evaluate DBTT (ductile-brittle transition temperature) at temperature from -180 to 25degC. The effect of specimen size on DBTT of F82H steel was also examined by using Charpy type specimens such as 1/2t-CVN, 1/3CVN and t/2-1/3CVN. In this paper, it also provides the information of the specimens irradiated at 250degC and 350degC to about 2 dpa in the capsule of 04M-67A and 04M-68A of JMTR experiments. (author)

Applicability of the Modified Ritchie-Knott-Rice Failure Criterion to Examine the Feasibility of Miniaturized Charpy Type SE(B Specimens

Directory of Open Access Journals (Sweden)

Toshiyuki Meshii

2016-01-01

Full Text Available This paper examined whether the modified Ritchie-Knott-Rice (RKR failure criterion can be applied to examine the feasibility of miniaturized Charpy type SE(B specimens of thickness-to-width ratio B/W=1. The modified RKR failure criterion considered in this paper is the (4δt,σ22c criterion which predicts the onset of cleavage fracture when the midplane crack-opening stress measured at a distance equal to four times the crack-tip opening displacement, denoted as σ22d, exceeds a critical stress σ22c. Specimens with B values of 25, 10, 3, and 2 mm (denoted as 25t, 10t, 3t, and 2t specimens, resp. manufactured with 0.55% carbon steel were tested at 20°C. The results showed that the modified RKR criterion could appropriately predict the occurrence of cleavage fracture accompanied by negligibly small stable crack extension (denoted as KJc fracture naturally for the 25t and 10t specimens. The modified RKR criterion could also predict that KJc fracture does not occur for the 2t specimen. The σ22c obtained from specimens for the 25t and 10t specimens exhibited only a small difference, indicating that the Jc obtained from the 10t specimens can be used to predict the Jc that will be obtained with the 25t specimens.

Statutory control of the irradiation of foodstuffs

International Nuclear Information System (INIS)

Stevens, G.J.H.

1989-01-01

The statutory control of foodstuffs in South Africa is discussed. Regulations and statutes controlling the irradiation of food in South Africa are quoted. These include the regulations concerning the food irradiation facilities; the packaging and labelling of irradiated products, and the marketing and sale of these products

HRB-22 irradiation phase test data report

International Nuclear Information System (INIS)

Montgomery, F.C.; Acharya, R.T.; Baldwin, C.A.; Rittenhouse, P.L.; Thoms, K.R.; Wallace, R.L.

1995-03-01

Irradiation capsule HRB-22 was a test capsule containing advanced Japanese fuel for the High Temperature Test Reactor (HTTR). Its function was to obtain fuel performance data at HTTR operating temperatures in an accelerated irradiation environment. The irradiation was performed in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). The capsule was irradiated for 88.8 effective full power days in position RB-3B of the removable beryllium (RB) facility. The maximum fuel compact temperature was maintained at or below the allowable limit of 1300 degrees C for a majority of the irradiation. This report presents the data collected during the irradiation test. Included are test thermocouple and gas flow data, the calculated maximum and volume average temperatures based on the measured graphite temperatures, measured gaseous fission product activity in the purge gas, and associated release rate-to-birth rate (R/B) results. Also included are quality assurance data obtained during the test

Consumer acceptance of irradiated food: theory and reality

International Nuclear Information System (INIS)

Bruhn, Christine M.

1998-01-01

For years most consumers have expressed less concern about food irradiation than other food processing technologies. Attitude studies have demonstrated that when given science-based information, from 60% to 90% of consumers prefer the advantages irradiation processing provides. When information is accompanied by samples, acceptance may increase to 99%. Information on irradiation should include product benefits, safety and wholesomeness, address environmental safety issues, and include endorsements by recognized health authorities. Educational and marketing programs should now be directed toward retailers and processors. Given the opportunity, consumers will buy high quality, safety-enhanced irradiated food

Correlation of irradiation-induced transition temperature increases from C sub v and K sub Jc /K sub Ic data

Energy Technology Data Exchange (ETDEWEB)

Hiser, A.L. (Materials Engineering Associates, Inc., Lanham, MD (USA))

1990-03-01

Reactor pressure vessel (RPV) surveillance capsules contain Charpy-V (C{sub v}) specimens, but many do not contain fracture toughness specimens; accordingly, the radiation-induced shift (increase) in the brittle-to-ductile transition region ({Delta}T) is based upon the {Delta}T determined from notch ductility (C{sub v}) tests. Since the ASME K{sub Ic} and K{sub IR} reference fracture toughness curves are shifted by the {Delta}T from C{sub v}, assurance that this {Delta}T does not underestimate {Delta}T associated with the actual irradiated fracture toughness is required to provide confidence that safety margins do not fall below assumed levels. To assess this behavior, comparisons of {Delta}T's defined by elastic-plastic fracture toughness and C{sub v} tests have been made using data from RPV base and weld metals in which irradiations were made under test reactor conditions. Using as-measure'' fracture toughness values (K{sub Jc}), average comparisons between {Delta}T(C{sub v}) and {Delta}T(K{sub Jc}) are: (a) All data: {Delta}T(K{sub Jc} 100 MPa{radical}{bar m}) = {Delta}T(C{sub v} 41 J) +10{degree}C; (b) Plates only: {Delta}T(K{sub Jc} 100 MPa{radical}{bar m}) = {Delta}T(C{sub v} 41 J) +15{degree}C; and (c) Welds only: {Delta}T(K{sub Jc} 100 MPa{radical}{bar m}) = {Delta}T(C{sub v} 41 J) {minus}1{degree}C. Fluence rate is found to have no significant effect on the relationship between {Delta}T(C{sub v}) and {Delta}T(K{sub Jc}). 12 refs., 12 figs., 5 tabs.

High-dose irradiation of food

International Nuclear Information System (INIS)

Diehl, J.F.

1999-01-01

Studies performed on behalf of the International Project on Food Irradiation in the period from 1971 until 1980 resulted in the concluding statement that ''.the irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard; hence, toxicological testing of foods so treated is no longer required.'' Since then, licenses for food irradiation have been restricted to this maximum dose in any country applying this technology. Further testing programmes have been carried out investigating the wholesomeness or hazards of high-dose irradiation, but there has been little demand so far by the food industry for licensing of high-dose irradiation, as there is only a small range of products whose irradiation at higher doses offers advantages for given, intended use. These include eg. spices, dried herbs, meat products in flexible pouch packagings for astronauts, or patients with immune deficiencies. (orig./CB) [de

Food irradiation now

International Nuclear Information System (INIS)

1982-01-01

From the start the Netherlands has made an important contribution to the irradiation of food through microbiological and toxicological research as well as through the setting-up of a pilot plant by the government and through the practical application of 'Gammaster' on a commercial basis. The proceedings of this tenth anniversary symposium of 'Gammaster' present all aspects of food irradiation and will undoubtedly help to remove the many misunderstandings. They offer information and indicate to the potential user a method that can make an important contribution to the prevention of decay and spoilage of foodstuffs and to the exclusion of food-borne infections and food poisoning in man. The book includes 8 contributions and 4 panel discussions in the field of microbiology; technology; legal aspects; and consumer aspects of food irradiation. As an appendix, the report 'Wholesomeness of irradiated food' of a joint FAO/IAEA/WHO Expert Committee has been added. (orig./G.J.P.)

Development of food irradiation technology and consumer attitude toward irradiated food in Korea

International Nuclear Information System (INIS)

Kwon, Joong-Ho; Byun, Myung-Woo; Cho, Han-Ok

1992-01-01

In Korea, the well-integrated research of biological effects of radiation has been launched from the late 1960s. As research activities, the following food items have been dealt with: sprouting foods, fruits, mushrooms, grains, spices or mixed condiments, fish or fishery products, meat or meat products, and fermented foods. The usage of gamma radiation from 60 Co source is now authorized for food irradiation of the following items: potato, onion, garlic, chestnut, mushroom, dried mushroom, dried spices (including red pepper, garlic, black pepper, onion, ginger, and green onion), dried meat, powdered fish and shellfish, soybean paste powder, hot pepper paste powder, soybean sauce powder, and starch. Since the authorization of food irradiation in 1985, consumers' acceptance has been considered the most important. The survey evaluating the basic perception and attitule toward food irradiation revealed the following results. Consumers' awareness of food irradiation was 82%, with significantly higher in radiation workers than the general public (p<0.0001). Seventy-five percent distinguished the contaminated food by radionuclides from irradiated food. In purchasing irradiated foods, 50.9% required more information. The contribution of irradiated foods to wholesomeness was suspicious in 51%, acceptable in 33%, and uncertain in 16%. If information about the benefits of irradiation is provided to consumers, positive response was increased to 60%. The most critical impediment in the commercial application of food irradiation was found to have resulted from the general consumers' slow acceptance; however, consumers' attitude to irradiated food became positive if they understood the safety and advantages of this technology. The most important task is to overcome consumers' psychological resistance and transporting matters of the products to be irradiated. (N.K.)

Irradiation's promise: fewer foodborne illnesses?

International Nuclear Information System (INIS)

Roberts, T.

1986-01-01

Food irradiation offers a variety of potential benefits to the food supply. It can delay ripening and sprouting of fruits and vegetables, and substitute for chemical fumigants to kill insects. However, one of the most important benefits of food irradiation is its potential use for destroying microbial pathogens that enter the food supply, including the two most common disease causing bacteria: salmonella and campylobacter. Animal products are one of the primary carriers of pathogens. Food borne illnesses are on the rise, and irradiation of red meats and poultry could significantly reduce their occurrence. Food irradiation should be examined more closely to determine its possible benefits in curtailing microbial diseases

Phytosanitary irradiation - Development and application

Science.gov (United States)

Hallman, Guy J.; Loaharanu, Paisan

2016-12-01

Phytosanitary irradiation, the use of ionizing radiation to disinfest traded agricultural commodities of regulated pests, is a growing use of food irradiation that has great continued potential for increase in commercial application. In 2015 approximately 25,000 t of fresh fruits and vegetables were irradiated globally for phytosanitary purposes. Phytosanitary irradiation has resulted in a paradigm shift in phytosanitation in that the final burden of proof of efficacy of the treatment has shifted from no live pests upon inspection at a port of entry (as for all previous phytosanitary treatments) to total dependence on certification that the treatment for target pests is based on adequate science and is commercially conducted and protected from post-treatment infestation. In this regard phytosanitary irradiation is managed more like a hazard analysis and critical control point (HACCP) approach more consistent with food safety than phytosanitation. Thus, phytosanitary irradiation offers a more complete and rigorous methodology for safeguarding than other phytosanitary measures. The role of different organizations in achieving commercial application of phytosanitary irradiation is discussed as well as future issues and applications, including new generic doses.

Multivariable modeling of pressure vessel and piping J-R data

International Nuclear Information System (INIS)

Eason, E.D.; Wright, J.E.; Nelson, E.E.

1991-05-01

Multivariable models were developed for predicting J-R curves from available data, such as material chemistry, radiation exposure, temperature, and Charpy V-notch energy. The present work involved collection of public test data, application of advanced pattern recognition tools, and calibration of improved multivariable models. Separate models were fitted for different material groups, including RPV welds, Linde 80 welds, RPV base metals, piping welds, piping base metals, and the combined database. Three different types of models were developed, involving different combinations of variables that might be available for applications: a Charpy model, a preirradiation Charpy model, and a copper-fluence model. In general, the best results were obtained with the preirradiation Charpy model. The copper-fluence model is recommended only if Charpy data are unavailable, and then only for Linde 80 welds. Relatively good fits were obtained, capable of predicting the values of J for pressure vessel steels to with a standard deviation of 13--18% over the range of test data. The models were qualified for predictive purposes by demonstrating their ability to predict validation data not used for fitting. 20 refs., 45 figs., 16 tabs

Numerical modelling of Charpy-V notch test by local approach to fracture. Application to an A508 steel in the ductile-brittle transition range; Modelisation de l'essai Charpy par l'approche locale de la rupture. Application au cas de l'acier 16MND5 dans le domaine de transition

Energy Technology Data Exchange (ETDEWEB)

Tanguy, B

2001-07-15

Ferritic steels present a transition of the rupture mode which goes progressively of a brittle rupture (cleavage) to a ductile rupture when the temperature increases. The following of the difference of the transition temperature of the PWR vessel steel by the establishment of toughness curves makes of the Charpy test an integrating part of the monitoring of the French PWR reactors. In spite of the advantages which are adapted to it in particular its cost, the Charpy test does not allow to obtain directly a variable which characterizes a crack propagation resistance as for instance the toughness used for qualifying the mechanical integrity of a structure. This work deals with the establishment of the through impact strength-toughness in the transition range of the vessel steel: 16MND5 from a non-empirical approach based on the local approach of the rupture. The brittle rupture is described by the Beremin model (1983), which allows to describe the dispersion inherent in this rupture mode. The description of the brittle fissure is carried out by the GTN model (1984) and by the Rousselier model (1986). This last model has been modified in order to obtain a realistic description of the brittle damage in the case of fast solicitations and of local heating. The method proposed to determine the parameters of the damage models depends only of tests on notched specimens and of the inclusion data of the material. The behaviour is described by an original formulation parametrized in temperature which allows to describe all the tests carried out in this study. Before using this methodology, an experimental study of the behaviour and of the rupture modes of the steel 16MND5 has been carried out. From the toughness tests carried out in quasi-static and dynamical conditions, it has been revealed that this steel does not present important unwedging of its toughness curve due to the velocity effect. In the transition range, local heating of about 150 C have been measured in the root

Irradiation treatment of sewage sludge: History and prospects

International Nuclear Information System (INIS)

Bao Borong; Wu Minghong; Zhou Ruimin; Zhu Jinliang

1998-01-01

This paper first reviews the history of irradiation treatment of sewage sludge in the world. The first sludge irradiation plant was built in Geiselbullach, West Germany in 1973 and used 60 Co as irradiation source. Since then, many sludge irradiators were constructed in U.S.A., India, Japan, Canada, Poland, etc., which used 60 Co, 137 Cs or electron beam as irradiation sources. The paper then describes some basic research on irradiation treatment of sewage sludge including optimization of irradiation parameters, synergistic effect of radiation with heat, oxygenation, irradiation-composting and potential applications of treated sludge. Some proposals have been suggested for further development of this technology in the future

Food irradiation 2009

International Nuclear Information System (INIS)

Narvaiz, Patricia

2009-01-01

Food irradiation principles; its main applications, advantages and limitations; wholesomeness, present activities at Ezeiza Atomic Centre; research coordinated by the International Atomic Energy Agency; capacity building; and some aspects on national and international regulations, standards and commercialization are briefly described. At present 56 countries authorize the consumption of varied irradiated foods; trade is performed in 32 countries, with about 200 irradiation facilities. Argentina pioneered nuclear energy knowledge and applications in Latin America, food irradiation included. A steady growth of food industrial volumes treated in two gamma facilities can be observed. Food industry and producers show interest towards new facilities construction. However, a 15 years standstill in incorporating new approvals in the Argentine Alimentary Code, in spite of consecutive request performed either by CNEA or some food industries restricts, a wider industrial implementation, which constitute a drawback to future regional commercialization in areas such as MERCOSUR, where Brazil since 2000 freely authorize food irradiation. Besides, important chances in international trade with developed countries will be missed, like the high fresh fruits and vegetables requirements United States has in counter-season, leading to convenient sale prices. The Argentine food irradiation facilities have been designed and built in the country. Argentina produces Cobalt-60. These capacities, unusual in the world and particularly in Latin America, should be protected and enhanced. Being the irradiation facilities scarce and concentrated nearby Buenos Aires city, the possibilities of commercial application and even research and development are strongly limited for most of the country regions. (author) [es

In situ transmission electron microscope studies of ion irradiation-induced and irradiation-enhanced phase changes

International Nuclear Information System (INIS)

Allen, C.W.

1992-01-01

Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing transmission electron microscopes (TEM) have been performed for several decades, involving irradiation-induced and irradiation-enhanced microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact; the development of TEM specimen holder sin which specimen temperature can be controlled in the range 10-2200 K and the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes and presents two case studies involving in situ experiments performed in an HVEM to illustrate the strategies of such an approach of the materials research of irradiation effects

Technology of food preservation by irradiation

International Nuclear Information System (INIS)

Thomas, Paul

1997-01-01

Food Technology Division, Bhabha Atomic Research Centre, Mumbai has demonstrated that radiation processing of foods can contribute to nations food security by reducing post-harvest losses caused by insect infestation, microbial-spoilage and physiological changes. The technology has commercial potential for the conservation of cereals, pulses and their products, spices, onions, potatoes, garlic, some tropical fruits, sea foods, meat and poultry. Irradiation can ensure hygienic quality in foods including frozen foods by eliminating food borne pathogens and parasitic organisms. It offers a viable environment friendly alternative to chemical fumigants for quarantine treatment against insect pests in agricultural and horticultural products entering international trade. The safety and nutritional adequacy of irradiated foods for human consumption is well established. About 40 countries including India have regulations permitting irradiation of foods and 28 countries are irradiating foods for processing industries and institutional catering

Food Irradiation Newsletter. V. 11, no. 2

International Nuclear Information System (INIS)

1987-09-01

This issue includes a report of the ICGFI's Workshop on Food Irradiation for Food Control Officials, convened in Budapest, Hungary, May 1987. To provide further assurance on the safety and wholesomeness of irradiated food in general and details about polyploidy (increase in number of chromosomes) resulting from consumption of freshly irradiated wheat in particular, ICGFI Secretariat issued a fact sheet on ''Safety and Wholesomeness of Irradiated Foods: International Status - Facts and Figures'' to its member countries in July 1987. The Newsletter also contains summary reports of two important market testings of irradiated food, i.e. papaya in California in March and strawberries in France in June, which proved that consumers will buy irradiated foods, and status reports on food irradiation in France and Mexico. Ref, 1 tab

Researches and commercialization of food irradiation technology in China

International Nuclear Information System (INIS)

Gao Meixu; Ha Yiming; Chen Hao; Liu Chunquan; Chen Xiulan

2007-01-01

The status of food irradiation on research, standard and commercialization is described in the paper. The main research fields now include degradation of chloramphenicol residue by irradiation, promoting safety of meat products, frozen seafood and ready-to-eat products by irradiation, lower activity of allergic protein by irradiation, identification of irradiated food and irradiation as a phytosanitary treatment. The existed standards need to be revised, and new standard need to be established. The commercialization stages of food irradiation and quality assurance system of irradiation company are also analyzed. (authors)

Irradiation of Northwest agricultural products

International Nuclear Information System (INIS)

Eakin, D.E.; Tingey, G.L.; Anderson, D.B.; Hungate, F.P.

1985-01-01

Irradiation of food for disinfestation and preservation is increasing in importance because of increasing resrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides

Irradiation emerges as processing alternative

International Nuclear Information System (INIS)

Hatfield, D.

1985-01-01

Anticipating that food irradiation may soon become an important addition to the many food processing techniques currently available, this article discusses many aspects of this process. Primarily, the benefits of irradiation for all foods include insect and bacterial control, increasing the potential to reduce incidences of food-borne illnesses, in addition to delaying the deterioration of fruits and vegetables. Currently approved uses of food irradiation in the U.S. and other countries, a summary of the proposed rule for wider application, and the labeling issue encompassed in the proposal are addressed. Additionally, the areas of great consumer concern--safety and public health implications, are talked about with the conclusion that food irradiation has been declared safe

Irradiation of Northwest agricultural products

International Nuclear Information System (INIS)

Eakin, D.E.; Tingey, G.L.

1985-02-01

Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides

Food irradiation and combination processes

International Nuclear Information System (INIS)

Campbell-Platt, G.; Grandison, A.S.

1990-01-01

International approval of food irradiation is being given for the use of low and medium doses. Uses are being permitted for different categories of foods with maximum levels being set between 1 and 10 kGy. To maximize the effectiveness of these mild irradiation treatments while minimizing any organoleptic quality changes, combination processes of other technologies with irradiation will be useful. Combinations most likely to be exploited in optimal food processing include the use of heat, low temperature, and modified-atmosphere packaging. Because irradiation does not have a residual effect, the food packaging itself becomes an important component of a successful process. These combination processes provide promising alternatives to the use of chemical preservatives or harsher processing techniques. (author)

Alaskan Commodities Irradiation Project

International Nuclear Information System (INIS)

Zarling, J.P.; Swanson, R.B.; Logan, R.R.

1988-01-01

The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology. 40 refs., 50 figs., 53 tabs

Present and future of food irradiation in China

International Nuclear Information System (INIS)

Chen Hao; Cai Jiming; Pan Pingchuan; Liu Ge

2006-01-01

The treatment of foods and agricultural products by irradiation technology in China has become an increasingly accepted practice and has been recognized as a public health intervention measure for controling pathogenic microbes and pests on foods since early 1980s. This paper gives an outline on the history and the current status of food irradiation in China, including the research interest, commercial application, public acceptance, regulations and hygienic standards of irradiated foods, and the irradiation facilities for food irradiation. The newly finished or scheduled irradiation facilities in China up to 2007 are introduced. And problems with the food irradiation studies, especially in analysis of food quality during irradiation, the implementation of GMP and HACCP in the food irradiation production and harmonization of food irradiation regulations with international standards, are also discussed. (authors)

Phage T4 endonuclease V stimulates DNA repair replication in isolated nuclei from ultraviolet-irradiated human cells, including xeroderma pigmentosum fibroblasts

International Nuclear Information System (INIS)

Smith, C.A.; Hanawalt, P.C.

1978-01-01

The repair mode of DNA replication has been demonstrated in isolated nuclei from uv-irradiated human cells. Nuclei are incubated in a mixture containing [ 3 H]thymidine triphosphate and bromodeoxyuridine triphosphate in a 1:5 ratio. The 3 H at the density of parental DNA in alkaline CsCl density gradients is then a measure of repair. In nuclei prepared from WI38 cells 30 min after irradiation, repair replication is uv-dependent and proceeds at approximately the in vivo rate for 5 min. Repair replication is reduced in irradiated nuclei or in nuclei prepared immediately after irradiation. It is Mg 2+ -dependent and stimulated by added ATP and deoxyribonucleoside triphosphates. No repair replication is observed in nuclei from xeroderma pigmentosum (complementation group A) cells. However, upon addition of coliphage T4 endonuclease V, which specifically nicks DNA containing pyrimidine dimers, repair replication is observed in nuclei from irradiated xeroderma pigmentosum cells and is stimulated in WI38 nuclei. The reaction then persists for an hour and is dependent upon added ATP and deoxyribonucleoside triphosphates. The repair label is in stretches of roughly 35 nucleotides, as it is in intact cells. Added pancreatic DNase does not promote uv-dependent repair synthesis. Our results support the view that xeroderma pigmentosum (group A) cells are defective in the incision step of the DNA excision repair pathway, and demonstrate the utility of this system for probing DNA repair mechanisms

Thermal conductivity of electron-irradiated graphene

Science.gov (United States)

Weerasinghe, Asanka; Ramasubramaniam, Ashwin; Maroudas, Dimitrios

2017-10-01

We report results of a systematic analysis of thermal transport in electron-irradiated, including irradiation-induced amorphous, graphene sheets based on nonequilibrium molecular-dynamics simulations. We focus on the dependence of the thermal conductivity, k, of the irradiated graphene sheets on the inserted irradiation defect density, c, as well as the extent of defect passivation with hydrogen atoms. While the thermal conductivity of irradiated graphene decreases precipitously from that of pristine graphene, k0, upon introducing a low vacancy concentration, c reduction of the thermal conductivity with the increasing vacancy concentration exhibits a weaker dependence on c until the amorphization threshold. Beyond the onset of amorphization, the dependence of thermal conductivity on the vacancy concentration becomes significantly weaker, and k practically reaches a plateau value. Throughout the range of c and at all hydrogenation levels examined, the correlation k = k0(1 + αc)-1 gives an excellent description of the simulation results. The value of the coefficient α captures the overall strength of the numerous phonon scattering centers in the irradiated graphene sheets, which include monovacancies, vacancy clusters, carbon ring reconstructions, disorder, and a rough nonplanar sheet morphology. Hydrogen passivation increases the value of α, but the effect becomes very minor beyond the amorphization threshold.

Food Irradiation Newsletter. Vol. 15, no. 1

International Nuclear Information System (INIS)

1991-05-01

This Newsletter contains reports of the Final FAO/IAEA Research Coordination Meeting (RCM) on the Latin American Regional Cooperative Programme on Food Irradiation, the first FAO/IAEA RCM of the Research Coordination Programme on Analytical Detection Methods for Irradiation Treatment of Foods, and the final FAO/IAEA RCM on the Use of Irradiation as a Quarantine Treatment of Food and Agriculture Commodities. Also included are excerpts of the Seventh Annual Meeting of the International Consultative Group on Food Irradiation (ICGFI) and a summary of an ICGFI Task Force Meeting on Irradiation as a Quarantine Treatment of Fresh Fruits and Vegetables. The new regulations on food irradiation in the United Kingdom, effective 1 January 1991, are summarized

Research on food irradiation in Indonesia

International Nuclear Information System (INIS)

Hilmy, N.; Maha, M.; Chosdu, R.

1986-01-01

Studies on various aspects of food irradiation have been done in Indonesia since 1968, mainly at the Centre for the Application of Isotopes and Radiation, National Atomic Energy Agency of Indonesia. Three irradiation facilities available at the Centre are gamma cell-220, panoramic batch irradiator, and latex irradiator with the present source capacities of about 1.1, 40, and 163.8 kCi Co-60, respectively. In this paper, the present status of research and development on irradiation is presented, covering (1) spices and medicinal plants, (2) rice, wheat flour and coffee bean, (3) fish and fishery products, (4) animal feed, and (5) ongoing projects including fresh fruits, cacao beans, and cashew nut. The Sub-Committee for the Control of Irradiation of Food and Medical Products, set up in August 1984, has prepared the draft of recommendations regarding the regulation for application of food irradiation in Indonedia and the draft of Regulation for the Control of and Trade in Irradiated Food and Traditional Drug to be issued by the government. (Namekawa, K.)

γ-ray irradiation of cooked dishes

International Nuclear Information System (INIS)

Lin Ruotai; Cheng Wei; Wen Shengli; Xiong Guangquan; Ye Lixiu; Chen Yuxia; Zhang Jinmu; He Jianjun; Lin Yong; Zhan Hanping

2005-01-01

Ready-to-eat cooked dishes, including stir-fried dishes, steamed dishes, roast meat, deep dried dishes, shrimps and seashells, and dishes of local flavor, etc were irradiated with 60 Co γ-rays, and the decontamination effects were studied. The results showed that most of the cooked dishes are suitable for irradiation. The effective dose is 4 kGy to 8 kGy. Index of microbe of the irradiated dishes was conformed to the National Food-Health standards, and no significant sensory changes was observed with the irradiated dishes. The quality guarantee period (0-5 degree C) is 60 days. (authors)

Gamma irradiation of onions and garlic

International Nuclear Information System (INIS)

Baraldi, D.

1975-01-01

Technological and economic feasibility of gamma irradiation of onions and garlic on an industrial scale are studied. Statistical data on production, consumption, exportation and losses during storage are analyzed. Traditional methods of food preservation are reviewed and gamma irradiation techniques are presented as an alternative to sprout inhibition. Requirements for the irradiation of onions and garlic on a commercial scale including a cost benefit analysis are discussed. Some conclusions are formulated on licensing and prospects

e-Learning Course on Food Irradiation

International Nuclear Information System (INIS)

Hénon, Yves

2016-01-01

Since May 2015, an online, interactive, multi-media and self-study course on Food Irradiation - Technology, Applications and Good Practices has been made available by the Food and Environmental Protection Section. This e-learning Course on Food Irradiation was initiated during a project (RAS/05/057) of the Regional Cooperative Agreement (RCA) Implementing Best Practices of Food Irradiation for Sanitary and Phytosanitary Purposes. Each module contains: • A lesson, largely based on the Manual of Good Practice in Food except for the first part (Food Irradiation) for which expanding the contents and addressing frequently asked questions seemed necessary. The latest chapters will help operators of irradiation facilities to appreciate and improve their practices. • A section called ‘Essentials’ that summarizes the key points. • A quiz to assess the knowledge acquired by the user from the course material. The quiz questions take a variety of forms: answer matching, multiple choice, true or false, picture selection, or simple calculation. Videos, Power Point presentations, pdf files and pictures enrich the contents. The course includes a glossary and approximately 80 downloadable references. These references cover safety of irradiated food, effects of irradiation on the nutritional quality of food, effects of irradiation on food microorganisms, insects and parasites, effects of irradiation on parasites, sanitary and phytosanitary applications of irradiation, packaging of irradiated food, food irradiation standards and regulations, history of food irradiation, and communication aspects.

Irradiation in adulthood as a new model of schizophrenia.

Directory of Open Access Journals (Sweden)

Yasuhide Iwata

Full Text Available BACKGROUND: Epidemiological studies suggest that radiation exposure may be a potential risk factor for schizophrenia in adult humans. Here, we investigated whether adult irradiation in rats caused behavioral abnormalities relevant to schizophrenia. METHODOLOGY/PRINCIPAL FINDINGS: A total dose of 15-Gy irradiation in six fractionations during 3 weeks was exposed to the forebrain including the subventricular zone (SVZ and subgranular zone (SGZ with male rats in the prone position. Behavioral, immunohistochemical, and neurochemical studies were performed three months after fractionated ionizing irradiation. Three months after fractionated ionizing irradiation, the total numbers of BrdU-positive cells in both the SVZ and SGZ zones of irradiated rats were significantly lower than those of control (sham-irradiated rats. Hyperactivity after administration of the dopaminergic agonist methamphetamine, but not the N-methyl-D-aspartate (NMDA receptor antagonist dizocilpine, was significantly enhanced in the irradiated rats although spontaneous locomotion in the irradiated rats was significantly lower than that of controls. Behavioral abnormalities including auditory sensory gating deficits, social interaction deficits, and working memory deficits were observed in the irradiated rats. CONCLUSION/SIGNIFICANCE: The present study suggests that irradiation in adulthood caused behavioral abnormalities relevant to schizophrenia, and that reduction of adult neurogenesis by irradiation may be associated with schizophrenia-like behaviors in rats.

Electron irradiation of power transistors

International Nuclear Information System (INIS)

Hower, P.L.; Fiedor, R.J.

1982-01-01

A method for reducing storage time and gain parameters in a semiconductor transistor includes the step of subjecting the transistor to electron irradiation of a dosage determined from measurements of the parameters of a test batch of transistors. Reduction of carrier lifetime by proton bombardment and gold doping is mentioned as an alternative to electron irradiation. (author)

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.

Mechanical properties test data of Alloy 718 for liquid metal fast breeder reactor applications

International Nuclear Information System (INIS)

Korth, G.E.

1983-01-01

Mechanical property test data are reported for Alloy 718 with two heat treatments: conventional heat treatment (CHT) for base metal and Idaho National Engineering Laboratory (INEL) heat treatment (IHT) for base and weld metal. Tests were conducted in air from 24 to 704 degree C and include elastic properties (Young's modulus, shear modulus, Poisson's ratio), tensile properties, creep-rupture properties, fatigue properties, creep-fatigue properties, and Charpy impact behavior. Effects of long term thermal aging at 538, 593, 649, and 704 degree C for times to 25,000 h are also reported for CHT material (tensile, creep-rupture, fatigue, and Charpy), and IHT material (tensile, and Charpy). 18 refs., 63 figs., 36 tabs

Reactor pressure vessel structural integrity research in the US Nuclear Regulatory Commission HSST and HSSI Programs

International Nuclear Information System (INIS)

Pennell, W.E.; Corwin, W.R.

1994-01-01

This report discusses development on the technology used to assess the safety of irradiation-embrittled nuclear reactor pressure vessels containing flaws. Fracture mechanics tests on reactor pressure vessel steel have shown that local brittle zones do not significantly degrade the material fracture toughness, constraint relaxation at the crack tip of shallow surface flaws results in increased fracture toughness, and biaxial loading reduces but does not eliminate the shallow-flaw fracture toughness elevation. Experimental irradiation investigations have shown that the irradiation-induced shift in Charpy V-notch versus temperature behavior may not be adequate to conservatively assess fracture toughness shifts due to embrittlement and the wide global variations of initial chemistry and fracture properties of a nominally uniform material within a pressure vessel may confound accurate integrity assessments that require baseline properties

Numerical modelling of Charpy-V notch test by local approach to fracture. Application to an A508 steel in the ductile-brittle transition range; Modelisation de l'essai Charpy par l'approche locale de la rupture. Application au cas de l'acier 16MND5 dans le domaine de transition

Energy Technology Data Exchange (ETDEWEB)

Tanguy, B

2001-07-15

Ferritic steels present a transition of the rupture mode which goes progressively of a brittle rupture (cleavage) to a ductile rupture when the temperature increases. The following of the difference of the transition temperature of the PWR vessel steel by the establishment of toughness curves makes of the Charpy test an integrating part of the monitoring of the French PWR reactors. In spite of the advantages which are adapted to it in particular its cost, the Charpy test does not allow to obtain directly a variable which characterizes a crack propagation resistance as for instance the toughness used for qualifying the mechanical integrity of a structure. This work deals with the establishment of the through impact strength-toughness in the transition range of the vessel steel: 16MND5 from a non-empirical approach based on the local approach of the rupture. The brittle rupture is described by the Beremin model (1983), which allows to describe the dispersion inherent in this rupture mode. The description of the brittle fissure is carried out by the GTN model (1984) and by the Rousselier model (1986). This last model has been modified in order to obtain a realistic description of the brittle damage in the case of fast solicitations and of local heating. The method proposed to determine the parameters of the damage models depends only of tests on notched specimens and of the inclusion data of the material. The behaviour is described by an original formulation parametrized in temperature which allows to describe all the tests carried out in this study. Before using this methodology, an experimental study of the behaviour and of the rupture modes of the steel 16MND5 has been carried out. From the toughness tests carried out in quasi-static and dynamical conditions, it has been revealed that this steel does not present important unwedging of its toughness curve due to the velocity effect. In the transition range, local heating of about 150 C have been measured in the root

Food Irradiation Newsletter. V. 12, no. 1

International Nuclear Information System (INIS)

1988-04-01

This Newsletter reports summaries of work carried out in the past year. A coordinated research programme on ''Use of Irradiation to Control Infectivity of Food-borne Parasites'' was implemented in early 1987. The first Research Coordination Meeting of this programme was held in Poznan, Poland, August 1987 and its report is included. Another important development is ''Food Irradiation Plant: Project Profile'' of the International Finance Corporation (IFC), a subsidiary of the World Bank. IFC is in principle ready to finance installations on food irradiation facilities in developing countries provided that the proposals are submitted through Governmental channels. Details on developing such proposals for possible funding by IFC are included. This issue also contains a supplement, an up-dated list of clearance of irradiated foods. Refs, 1 fig., 1 tab

Effect of neutron irradiation on the impact properties of A533B steel

International Nuclear Information System (INIS)

Schubert, L.E.; Kumar, A.S.; Rosinski, S.T.; Hamilton, M.L.

1994-01-01

A new methodology is proposed to correlate the upper shelf energy (USE) of full size and subsize Charpy specimens of a nuclear reactor pressure vessel plate material, ASTM type A 533 Grade B (A533B) having a low USE (USE 19 n/cm 2 (E > 1 MeV) by 78 degree, 83 degree, and 70 degree C for full, half, and third size specimens, respectively. These shifts in DBTT appeared to be independent of specimen size and notch geometry

The method of estimating the irradiated lung volume in primary breast irradiation

International Nuclear Information System (INIS)

Leite, Miguel Torres Teixeira; Marques, Iara Silva; Geraldo, Jony Marques

1999-01-01

Tangential breast fields irradiation usually includes some volume of lung and it is occasionally associated with pneumonitis. The estimation of the amount of lung irradiated can be determined measuring the central lung distance (CLD) by the port films, and it must be inferior to 2.5 cm. The purpose of this study was to determine through a linear regression analysis the relationship between CLD and the geometrical parameters of the treatment, and to develop an equation to predict this volume. The studied population consisted of 100 patients who received definitive radiation for clinical stage I and II breast cancer between January, 1996 and June, 1997. According to the contour of the breast and thorax was determined the angle of the tangential fields. In 71% of the patients the CLD measured by the portal films were superior to 2.5 cm, requiring a new beam arrangement. We develop a simple and convenient quantitative model to predict the irradiated lung volume based on portal films. We need further analysis in order to include variables and antomical variations. (author)

Radiation research of materials using irradiation capsules

International Nuclear Information System (INIS)

Chamrad, B.

1976-01-01

The methods are briefly characterized of radiation experiments on the WWR-S research reactor. The irradiation capsule installed in the reactor including the electronic instrumentation is described. Irradiated samples temperature is stabilized by an auxiliary heat source placed in the irradiation space. The electronic control equipment of the system is automated. In irradiation experiments, experimental and operating conditions are recorded by a digital measuring centre with electric typewriter and paper tape data recording and by an analog compensating recorder. The irradiation experiment control system controls irradiated sample temperature, the supply current size and the heating element temperature of the auxiliary stabilizing source, inert and technological pressures of the capsule atmosphere and the thermostat temperature of the thermocouple junctions. (O.K.)

Longevity of irradiated burros

International Nuclear Information System (INIS)

Lushbaugh, C.C.; Brown, D.G.; Frome, E.L.

1986-01-01

During the course of external radiation exposures of burros to establish a dose-response curve for acute mortality after total irradiation, some of the animals at the three lowest exposures to gamma photons survived. These groups of 10, 9, and 10 burros were exposed to 320, 425, and 545 R, respectively. There were 10 unirradiated controls. In 1953, 20 burros were exposed to 375 R (gamma) in 25-R/week increments without acute mortality and were added to the life-span study. In 1957, 33 burros were exposed to mixed neutron-gamma radiation from nuclear weapons, and 14 controls were added. The total number of irradiated burros in the study was increased to 88 by the addition of 6 animals irradiated with 180 rads of neutron and gamma radiation (4:1) in a Godiva-type reactor in 1959. In this experiment two acute deaths occurred which were not included in the analysis. In the first 4 years after the single gamma exposures, there were deaths from pancytopenia and thrombocytopenia, obviously related to radiation-induced bone-marrow damage. After that period, however, deaths were from common equine diseases; no death has resulted from a malignant neoplasm. Of the original 112 burros, 15 survive (10 irradiated and 5 controls). Survival curves determined for unirradiated and neutron-gamma- and gamma-irradiated burros showed significant differences. The mean survival times were: controls, 28 years; gamma irradiation only, 26 years; and neutron-gamma irradiation, 23 years. 3 refs., 4 figs., 1 tab

Sewage sludge disinfection by irradiation (ENEA-ACEA collaboration)

International Nuclear Information System (INIS)

Baraldi, D.

1997-01-01

The Municipal Association for Electricity and Water (ACEA) of Rome and the Lazio Regional Administration are implementing a programme of intervention aimed at protecting the water quality of the hydrogeological basin of Lake Bracciano. With support from ENEA, a pilot plant is being constructed for sewage-sludge direction by irradiation with accelerated electrons, in order to use the sludge as a fertilizer for agriculture, as is practised abroad mainly in Germany and the United States. The work to be carried out within the ENEA-ACEA agreement includes: sludge digestion, drying, and sterilization by irradiation. Results achieved so far, including preliminary analyses of irradiated sludge, are presented. The irradiation plant and processes involved are also described. (author)

Fluorescence of irradiated hydrocarbons. [. gamma. rays

Energy Technology Data Exchange (ETDEWEB)

Gulis, I G; Evdokimenko, V M; Lapkovskii, M P; Petrov, P T; Gulis, I M; Markevich, S V [AN Belorusskoj SSR, Minsk. Inst. Fiziko-Organicheskoj Khimii

1977-01-01

A visible fluorescence has been found out in ..gamma..-irradiated aqueous solutions of carbohydrates. Two bands have been distinguished in fluorescence spectra of the irradiated solution of dextran: a short-wave band lambdasub(max)=140 nm (where lambda is a wave length) at lambdasub(..beta..)=380 nm and a long-wave band with lambdasub(max)=540 nm at lambdasub(..beta..)=430 nm. A similar form of the spectrum has been obtained for irradiated solutions of starch, amylopectin, low molecular glucose. It has been concluded that a macromolecule of polysaccharides includes fluorescent centers. A relation between fluorescence and ..cap alpha..-oxiketon groups formed under irradiation has been pointed out.

Irradiating strand material

International Nuclear Information System (INIS)

Austin, J.R.; Brown, M.J.; Loan, L.D.

1975-01-01

Conductors covered with insulation which is to be irradiated are passed between two groups of coaxial sheaves mounted rotatably individually. Successive sections of the conductors are advanced past the window of one accelerator head, around the associated sheave or sheaves, and then past the window of another accelerator head. The accelerators face in substantially opposite directions and are staggered along the paths of the conductors to avoid any substantial overlap of the electron beams associated therewith. The windows extend vertically to encompass all the generally horizontal passes of the conductors as between the two groups of sheaves. Preferably, conductors are strung-up between the sheaves in a modified figure eight pattern. The pattern is a figure eight modified to intermittently include a pass between the sheaves which is parallel to a line joining the axes of the two groups of sheaves. This reverses the direction of travel of the conductors and optimizes the uniformity of exposure of the cross sectional area of the insulation of the conductors to irradiation. The use of a figure eight path for the conductors causes the successive sections of the conductor to turn about the longitudinal axes thereof as they are advanced around the sheaves. In this way the insulation is more uniformly irradiated. In a preferred embodiment, twisted conductor pairs may be irradiated. The twist accentuates the longitudinal turning of the conductor pair. The irradiation of twisted pairs achieves obvious manufacturing economies while avoiding the necessity of having to twist irradiation cross-linked conductors

International training workshop on quality control and management of food irradiation

International Nuclear Information System (INIS)

2004-01-01

The International Training Workshop on Quality Control and Management of Food Indantrione was hold from 28-30, August, 2004 in Beijing, China and organized by Chinese Society of Nuclear Agriculture and China Isotope and Radiation Association. 10 Articles were collected in this symposium including training lectures. The contents included: international developments in food irradiation, Quality control and magement of food irradiation, industrializing development of irradiated food in China, Food irradiator and its quality management, research in setting standard for enterprise about irradiated products and etc.

Final report on graphite irradiation test OG-2

International Nuclear Information System (INIS)

Price, R.J.; Beavan, L.A.

1975-01-01

Results are presented of dimensional, thermal expansivity, thermal conductivity, Young's modulus, and tensile strength measurements on specimens of nuclear graphites irradiated in capsule OG-2. About half the irradiation space was allocated to H-451 near-isotropic petroleum-coke-based graphite or its subsized prototype grade H-429. Most of these specimens had been previously irradiated. Virgin specimens of another near-isotropic graphite, grade TS-1240, were irradiated. Some previously irradiated specimens of needle-coke-based H-327 graphite and pitch-coke-based P 3 JHAN were also included

Numerical modelling of Charpy-V notch test by local approach to fracture. Application to an A508 steel in the ductile-brittle transition range

International Nuclear Information System (INIS)

Tanguy, B.

2001-07-01

Ferritic steels present a transition of the rupture mode which goes progressively of a brittle rupture (cleavage) to a ductile rupture when the temperature increases. The following of the difference of the transition temperature of the PWR vessel steel by the establishment of toughness curves makes of the Charpy test an integrating part of the monitoring of the French PWR reactors. In spite of the advantages which are adapted to it in particular its cost, the Charpy test does not allow to obtain directly a variable which characterizes a crack propagation resistance as for instance the toughness used for qualifying the mechanical integrity of a structure. This work deals with the establishment of the through impact strength-toughness in the transition range of the vessel steel: 16MND5 from a non-empirical approach based on the local approach of the rupture. The brittle rupture is described by the Beremin model (1983), which allows to describe the dispersion inherent in this rupture mode. The description of the brittle fissure is carried out by the GTN model (1984) and by the Rousselier model (1986). This last model has been modified in order to obtain a realistic description of the brittle damage in the case of fast solicitations and of local heating. The method proposed to determine the parameters of the damage models depends only of tests on notched specimens and of the inclusion data of the material. The behaviour is described by an original formulation parametrized in temperature which allows to describe all the tests carried out in this study. Before using this methodology, an experimental study of the behaviour and of the rupture modes of the steel 16MND5 has been carried out. From the toughness tests carried out in quasi-static and dynamical conditions, it has been revealed that this steel does not present important unwedging of its toughness curve due to the velocity effect. In the transition range, local heating of about 150 C have been measured in the root

Effectiveness of irradiation in killing pathogens

International Nuclear Information System (INIS)

Yeager, J.G.; Ward, R.L.

1980-01-01

United States Environmental Protection Agency regulations include gamma ray irradiation of sludge as an approved Process to Further Reduce Pathogens (PFRP) prior to land application. Research at Sandia National Laboratories on pathogen inactivation in sludge by gamma irradiation has demonstrated that the 1 Mrad PFRP dose is capable, by itself, of eliminating bacterial, fungal, and parasitic pathogens from sludge. Gamma irradiation of sludge in conjunction with the required Processes to Significantly Reduce Pathogens (PSRP) should also eliminate the viral hazard from wastewater sludges

Food irradiation in perspective

International Nuclear Information System (INIS)

Henon, Y.M.

1995-01-01

Food irradiation already has a long history of hopes and disappointments. Nowhere in the world it plays the role that it should have, including in the much needed prevention of foodborne diseases. Irradiated food sold well wherever consumers were given a chance to buy them. Differences between national regulations do not allow the international trade of irradiated foods. While in many countries food irradiation is still illegal, in most others it is regulated as a food additive and based on the knowledge of the sixties. Until 1980, wholesomeness was the big issue. Then the ''prerequisite'' became detection methods. Large amounts of money have been spent to design and validate tests which, in fact, aim at enforcing unjustified restrictions on the use of the process. In spite of all the difficulties, it is believed that the efforts of various UN organizations and a growing legitimate demand for food safety should in the end lead to recognition and acceptance. (Author)

Irradiation test of borosilicate glass burnable poison

International Nuclear Information System (INIS)

Feng Mingquan; Liao Zumin; Yang Mingjin; Lu Changlong; Huang Deyang; Zeng Wangchun; Zhao Xihou

1991-08-01

The irradiation test and post-irradiation examinations for borosilicate glass burnable poison are introduced. Examinations include visual examination, measurement of dimensions and density, and determination of He gas releasing and 10 B burnup. The corrosion and phenomenon of irradiation densification are also discussed. Two type glass samples have been irradiated with different levels of neutron flux. It proved that the GG-17 borosilicate glass can be used as burnable poison to replace the 10 B stainless steel in the Qinshan Nuclear Power Plant, and it is safe, economical and reasonable

Marine Science

African Journals Online (AJOL)

Zanzibar (Tanzania), La Reunion Island and Okinawa,. Japan (Abed et al., 2003; Charpy et al., 2007; Bauer et al.,. 2008; Charpy et al., 2010, Charpy et al., 2012). Charpy et al. (2012) have reviewed the role of cyano- bacteria in coral reef ecosystems. They occur as part of the reef (microbialites), inside (endoliths), and.

Effect of irradiation on the Porphyromonas gingivalis

Energy Technology Data Exchange (ETDEWEB)

Lee, Chang Hee; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

2008-03-15

The aim of this study was to observe a direct effect of irradiation on the periodontopathic Porphyromonas gingivalis (P. gingivalis). P. gingivalis 2561 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Changes in viability and antibiotic sensitivity, morphology, transcription, and protein profile of the bacterium after irradiation were examined by pour plating method, disc diffusion method, transmission electron microscopy, RT-PCR, and immunoblot, respectively. Viability of irradiated P. gingivalis drastically reduced as irradiation dose was increased. Irradiated P. gingivalis was found to have become more sensitive to antibiotics as radiation dose was increased. With observation under the transmission electron microscope, the number of morphologically abnormal cells was increased with increasing of irradiation dose. In RT-PCR, decrease in the expression of fim A and sod was observed in irradiated P. gingivalis. In immunoblot, change of profile in irradiated P. gingivalis was found in a number of proteins including 43-kDa fimbrillin. These results suggest that irradiation may affect the cell integrity of P. gingivalis, which is manifested by the change in cell morphology and antibiotic sensitivity, affecting viability of the bacterium.

Effect of irradiation on the Porphyromonas gingivalis

International Nuclear Information System (INIS)

Lee, Chang Hee; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

2008-01-01

The aim of this study was to observe a direct effect of irradiation on the periodontopathic Porphyromonas gingivalis (P. gingivalis). P. gingivalis 2561 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Changes in viability and antibiotic sensitivity, morphology, transcription, and protein profile of the bacterium after irradiation were examined by pour plating method, disc diffusion method, transmission electron microscopy, RT-PCR, and immunoblot, respectively. Viability of irradiated P. gingivalis drastically reduced as irradiation dose was increased. Irradiated P. gingivalis was found to have become more sensitive to antibiotics as radiation dose was increased. With observation under the transmission electron microscope, the number of morphologically abnormal cells was increased with increasing of irradiation dose. In RT-PCR, decrease in the expression of fim A and sod was observed in irradiated P. gingivalis. In immunoblot, change of profile in irradiated P. gingivalis was found in a number of proteins including 43-kDa fimbrillin. These results suggest that irradiation may affect the cell integrity of P. gingivalis, which is manifested by the change in cell morphology and antibiotic sensitivity, affecting viability of the bacterium.

Evolution of glycaemia during irradiation syndrome; Evolution de la glycemie au cours du syndrome d'irradiation

Energy Technology Data Exchange (ETDEWEB)

Raisonnier, A [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

1967-03-15

The evolution of glycaemia following irradiation has been followed in the rat and pig. The results concerning a case of human accidental exposure have also been included. The author has tried to see whether the observed variations are reproducible and have a prognostic value. (author) [French] L'evolution de la glycemie a ete suivie, chez le rat et le porc, apres irradiation. Les resultats relatifs a une irradiation accidentelle humaine sont egalement rapportes. L'auteur cherche a definir si les variations observees sont reproductibles et ont une valeur pronostique. (auteur)

Irradiation effects on hydrases for biomedical applications

International Nuclear Information System (INIS)

Furuta, Masakazu; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio

2000-01-01

To apply an irradiation technique to sterilize 'Hybrid' biomedical materials including enzymes, we selected papain, a well-characterized plant endopeptidase as a model to examine durability of enzyme activity under the practical irradiation condition in which limited data were available for irradiation inactivation of enzymes. Dry powder and frozen aqueous solution of papain showed significant durability against 60 Co-gamma irradiation suggesting that, the commercial irradiation sterilizing method is applicable without modification. Although irradiation of unfrozen aqueous papain solution showed an unusual change of the enzymatic activity with the increasing doses, and was totally inactivated at 15 kGy, we managed to keep the residual activity more than 50% of initial activity after 30-kGy irradiation, taking such optimum conditions as increasing enzyme concentration from 10 to 100 mg/ml and purging with N 2 gas to suppress the formation of free radicals. (author)

PR-EDB: Power Reactor Embrittlement Data Base, Version 2. Revision 2, Program description

Energy Technology Data Exchange (ETDEWEB)

Stallmann, F.W.; Wang, J.A.; Kam, F.B.K.; Taylor, B.J. [Oak Ridge National Lab., TN (United States)

1994-01-01

Investigations of regulatory issues such as vessel integrity over plant life, vessel failure, and sufficiency of current codes Standard Review Plans (SRP`s) and Guides for license renewal can be greatly expedited by the use of a well-designed computerized data base. Also, such a data base is essential for the validation of embrittlement prediction models by researchers. The Power Reactor Embrittlement Data Base (PR-EDB) is such a comprehensive collection of data for US commercial nuclear reactors. The current version of the PR-EDB contains the Charpy test data that were irradiated in 252 capsules of 96 reactors and consists of 207 data points for heat-affected-zone (HAZ) materials (98 different HAZ), 227 data points for weld materials (105 different welds), 524 data points for base materials (136 different base materials), including 297 plate data points (85 different plates), 119 forging data points (31) different forging), and 108 correlation monitor materials data points (3 different plates). The data files are given in dBASE format and can be accessed with any computer using the DOS operating system. ``User-friendly`` utility programs are used to retrieve and select specific data, manipulate data, display data to the screen or printer, and to fit and plot Charpy impact data. The results of several studies investigated are presented in Appendix D.

Development of data base on food irradiation

International Nuclear Information System (INIS)

Ito, Hitoshi; Kume, Tamikazu; Hashimoto, Shoji; Izumi, Fumio.

1995-12-01

For the exact understanding on food irradiation in Japan, it is important to provide information of food irradiation to consumers, industries and government offices. However, many of information on food irradiation are only restricted in a few experts or institutes relating to this field. For this reason, data base of food irradiation has been completed together with the systems necessary for input the data using computer. In this data base, about 630 data with full reports were inputted in computer in the field of wholesomeness studies, irradiation effects on food, radiation engineering, detection methods of irradiated food and Q and A of food irradiation for easy understanding. Many of these data are inputted by Japanese language. Some English reports on wholesomeness studies are also included which were mainly obtained from international projects of food irradiation. Many of data on food irradiation are responsible in the fields of food science, dietetics, microbiology, radiation biology, molecular biology, medical science, agricultural science, radiation chemistry, radiation engineering and so on. Data base of food irradiation contains many useful data which can apply to many other fields of radiation processing not only on food irradiation but also on sterilization of medical equipments, upgrading of agricultural wastes and others. (author)

Development of data base on food irradiation

Energy Technology Data Exchange (ETDEWEB)

Ito, Hitoshi; Kume, Tamikazu; Hashimoto, Shoji [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Izumi, Fumio

1995-12-01

For the exact understanding on food irradiation in Japan, it is important to provide information of food irradiation to consumers, industries and government offices. However, many of information on food irradiation are only restricted in a few experts or institutes relating to this field. For this reason, data base of food irradiation has been completed together with the systems necessary for input the data using computer. In this data base, about 630 data with full reports were inputted in computer in the field of wholesomeness studies, irradiation effects on food, radiation engineering, detection methods of irradiated food and Q and A of food irradiation for easy understanding. Many of these data are inputted by Japanese language. Some English reports on wholesomeness studies are also included which were mainly obtained from international projects of food irradiation. Many of data on food irradiation are responsible in the fields of food science, dietetics, microbiology, radiation biology, molecular biology, medical science, agricultural science, radiation chemistry, radiation engineering and so on. Data base of food irradiation contains many useful data which can apply to many other fields of radiation processing not only on food irradiation but also on sterilization of medical equipments, upgrading of agricultural wastes and others. (author).

Do you know 'food irradiation'?. A survey of consumer status toward food irradiation in Japan

International Nuclear Information System (INIS)

Furuta, Masakazu

1998-01-01

In Japan potatoes have been irradiated for the purpose of sprout inhibition for more than 20 years and more than ten thousand irradiated potatoes are circulated in Japanese market in recent years. Nevertheless, there are few surveys about the consumer status toward food irradiation in Japan. We have been held 'Radiation Fair -- The relationship between daily life and radiation--' during summer vacation season in August for more than 10 years in Osaka, the largest city of western Japan, for the purpose of public education and information transfer of radiation and radiation-related technology especially to school kids. We displayed 200 kg of irradiated potatoes together with explanatory panels. We distributed questionnaires to the senior high school students (16 years old) and upward visitor for recent 3 years to inquire their status toward radiation and irradiated products including irradiated potatoes as well as impression toward the displays. According to the survey results in 1997, the ratio of respondents who had heard of irradiated potatoes was 51% of 228 answers. This value was smaller than those of the Gallop survey conducted in the United States (73%). After viewing the display and description of irradiated potatoes, almost half of the respondents indicated a positive feeling for tasting the irradiated potatoes. Most of the respondents chose one of the following issues, Freshness' (37%), 'Open date' (13%), or 'Food additives' (34%) as the major concerns about food safety. Interestingly, 'Pesticide' and/or 'Foodborne pathogen' highly were chosen by only 15% of the respondents in total even though these issue were highly ranked in the US surveys. These results indicate that original methodology is necessary for distributing the information related food irradiation related food irradiation efficiently. (J.P.N)

Irradiation Creep of Ferritic-Martensitic Steels EP-450, EP-823 and EI-852 Irradiated in the BN-350 Reactor over Wide Ranges of Irradiation Temperature and Dose

International Nuclear Information System (INIS)

Porollo, S.I.; Konobeev, Y.V.; Ivanov, A.A.; Shulepin, S.V.; Garner, F.

2007-01-01

Full text of publication follows: Ferritic/martensitic (F/M) steels appear to be the most promising materials for advanced nuclear systems, especially for fusion reactors. Their main advantages are higher resistance to swelling and lower irradiation creep rate as has been repeatedly demonstrated in examinations of these materials after irradiation. Nevertheless, available experimental data on irradiation resistance of F/M steels are insufficient, with the greatest deficiency of data for high doses and for both low and high irradiation temperatures. From the very beginning of operation the BN-350 fast reactor has been used for irradiation of specimens of structural materials, including F/M steels. The most unique feature of BN-350 was its low inlet sodium temperature, allowing irradiation at temperatures over a very wide range of temperatures compared with the range in other fast reactors. In this paper data are presented on swelling and irradiation creep of three Russian F/M steels EP-450, EP-823 and EI-852, irradiated in experimental assemblies of the BN-350 reactor at temperatures in the range of 305-700 deg. C to doses ranging from 20 to 89 dpa. The investigation was performed using gas-pressurized creep tubes with hoop stresses in the range of 0 - 294 MPa. (authors)

Irradiation probe and laboratory for irradiated material evaluation

International Nuclear Information System (INIS)

Smutny, S.; Kupca, L.; Beno, P.; Stubna, M.; Mrva, V.; Chmelo, P.

1975-09-01

The survey and assessment are given of the tasks carried out in the years 1971 to 1975 within the development of methods for structural materials irradiation and of a probe for the irradiation thereof in the A-1 reactor. The programme and implementation of laboratory tests of the irradiation probe are described. In the actual reactor irradiation, the pulse tube length between the pressure governor and the irradiation probe is approximately 20 m, the diameter is 2.2 mm. Temperature reaches 800 degC while the pressure control system operates at 20 degC. The laboratory tests (carried out at 20 degC) showed that the response time of the pressure control system to a stepwise pressure change in the irradiation probe from 0 to 22 at. is 0.5 s. Pressure changes were also studied in the irradiation probe and in the entire system resulting from temperature changes in the irradiation probe. Temperature distribution in the body of the irradiation probe heating furnace was determined. (B.S.)

Stabilization by hals and phenols in γ-irradiated polyproplyene

International Nuclear Information System (INIS)

Carlsson, D.J.; Falicki, S.; Cooke, J.M.; Gosciniak, D.J.

1994-01-01

The γ-radiation initiated oxidation of polypropylene films and test strips has been studied both immediately after irradiation and also during post-irradiation accelerated aging at 60 degrees C. Stabilizers included blocked and unblocked phenols as well as secondary and tertiary hindered amines (HALS) including an oligomeric HALS. Oxidation product formation, yellowing and embrittlement (as measured in an instrumented bend test) have been compared with product formation. A partial correlation between suppression of oxidation during the irradiation step with long term, post-irradiation oven aging at 60 degrees C was found, but complicated by extensive destruction during irradiation of the active phenolic functionality in some additives, essential for peroxyl radical scavenging. Very long lifetimes with barely detectable yellowing were found for combinations of the amines with completely unhindered or only partially hindered phenols

Experimental study of the effect of neutron radiation on pressurised water reactor vessel steel resilience - First part

International Nuclear Information System (INIS)

Verdeau, Jean-Jacques

1969-12-01

After having outlined the importance of the embrittlement of vessel steels by neutrons during the exploitation of pressurised water reactors, the author reports a set of tests which aimed at determining the effect of neutron irradiation on vessel steel resilience for operated, under construction or projected pressurized water reactors. He also tries to highlight the influence of irradiation temperature and of initial thermal treatments, and to look for a restoration thermal treatment of neutron-induced damages which could be applied to the considered vessels. Tests were performed on V Charpy resilience samples. Some samples have been irradiated by the Pile Department of the Grenoble CEN and then broken by the Laboratory of very high activity, whereas other samples have been irradiated in a prototype vessel and broken by a Cadarache department. The author presents characteristics of the studied steels (chemical compositions, thermal treatments), describes sample irradiation conditions, and the method of assessment of the transition temperature after irradiation, presents experimental results, discusses their interpretation, and presents future tests to be performed [fr

Dosimetry of blood irradiator - 2000

International Nuclear Information System (INIS)

Mhatre, Sachin G.V.; Shinde, S.H.; Bhat, R.M.; Rao, Suresh; Sharma, D.N.

2008-01-01

Full text: Blood transfusion to an immunodeficient or immunosuppressed patient has a high risk involved due to occurrence of Transfusion Graft Versus Host Disease (T-GVHD). In order to eliminate this problem, blood is routinely exposed to ionizing radiation (gamma) prior to transfusion. Doses ranging from 15 Gy to 50 Gy can prevent T-GVHD. Aim of the present work was to perform dosimetry of 60 Co Blood Irradiator-2000 developed by Board of Radiation and isotope Technology (BRIT), India; using FBX dosimetric system. Dose-rate measured by FBX dosimeter was intercompared with Fricke dosimeter, which is a Reference Standard dosimeter. Experiments included measurement of dose-rate at the centre of irradiation volume, dose mapping in the central vertical plane within the irradiation volume and measurement of average dose received by blood sample using blood bags filled with FBX dosimeter by simulating actual irradiation conditions. During irradiation, the sample chamber is retracted into a cylindrical source cage, so that the sample is irradiated from all sides uniformly. Blood irradiator-2000 has sample rotation facility for increasing the dose uniformity during irradiation. The performance of this was investigated by measuring the central vertical plane dose profile in stationary state as well in rotation using the sample rotation facility (60 rpm). FBX being an aqueous dosimetric system fills container of irregular shape being irradiated hence can be used to integrate the dose over the volume. Dose-rate measured by FBX dosimeter was intercompared with Fricke dosimeter, which was in good agreement. Average dose-rate at the centre of irradiation volume and within the blood bag was measured by FBX and Fricke dosimeters. It was observed that dose profiles measured by FBX and Fricke dosimeters agreed within ± 2%. Dose uniformity within the irradiation volume was found to reduce from 21% to 17% when the sample rotation facility was used. Thus, it is suggested by the

Post-irradiation data analysis for NRC/PNL Halden assembly IFA-431

International Nuclear Information System (INIS)

Nealley, C.; Lanning, D.D.; Cunningham, M.E.; Hann, C.R.

1979-10-01

Results are presented for the post irradiation examination performed on IFA-431, which was a 6-rod test fuel assembly irradiated in Halden Reactor, Norway, under sponsorship of the Nuclear Regulatory Commission. The irradiation conditions included: peak powers of 33 kW/m; coolant pressure and temperature of 3.3 MPa and 240 0 C, respectively; and peak burnup of 4300 MWd/MTM. IFA-431 included instrumented rods of basic boiling water reactor design, with variations in fill gas composition, gap size, and UO 2 fuel type. The irradiation was designed to measure the effect of these variations upon fuel rod thermal and mechanical performance. The post irradiation examination assessed the permanent changes to the rods, including induced radioactivity, cladding deformation, fission gas release, and fuel densification

The Next Spaceflight Solar Irradiance Sensor: TSIS

Science.gov (United States)

Kopp, Greg; Pilewskie, Peter; Richard, Erik

2016-05-01

The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

Fractography evaluation of impact and tensile specimens from the HFBR [High Flux Beam Reactor

International Nuclear Information System (INIS)

Czajkowski, C.J.

1989-10-01

The Materials Technology Group of the Department of Nuclear Energy (DNE) at Brookhaven National Laboratory (BNL) has performed a fractographic examination of neutron irradiated and unirradiated tensile and Charpy ''V'' notch specimens. The evaluation was carried out using a scanning electron microscope (SEM) to evaluate the fracture mode. Photomicrographs were then evaluated to determine the extent of ductility present on the fracture surfaces of the unirradiated specimens. Ductility area measurements ranged from 4.6--9.5% on typical photomicrographs examined. 12 figs

Analysis of Low Dose Irradiation Damages in Structural Ferritic/Martensitic Steels by Proton Irradiation and Nanoindentation

International Nuclear Information System (INIS)

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

2016-01-01

As a result, ferritic-martensitic steels find applications in the in-core and out-of-core components which include ducts, piping, pressure vessel and cladding, etc. Due to ferromagnetism of F/M steel, it has been successfully employed in solenoid type fuel injector. Although the irradiation induced degradation in ferritic martensitic steels is lower as compare to (i) reduced activation steels, (ii) austenitic steels and (iii) martensitic steels, F/M steels are still prone to irradiation induced hardening and void swelling. The irradiation behavior may become more sophisticated due to transmutation and production of helium and hydrogen. The ductile to brittle transition temperature of F/M steels is also expected to increase due to irradiation. These irradiation induced degradations may deteriorate the integrity of F/M components. As a result of these investigations, it has found that the F/M steels experience no irradiation hardening above 400 .deg. C, but below this temperature, up to 350 .deg. C, weak hardening is observed. The irradiation hardening becomes more pronounced below 300 .deg. C. Moreover, the irradiation hardening has also found dependent upon radiation damage. The hardening was found increasing with increasing dose. Due to pronounced irradiation hardening below 300 .deg. C and increasing radiation damage with increasing dose (even at low dpa), it is required to investigate the post irradiation mechanical properties of F/M steel, in order to confirm its usefulness in structural and magnetic components which experience lifetime doses as low as 1x10"-"5 dpa.

Analysis of Low Dose Irradiation Damages in Structural Ferritic/Martensitic Steels by Proton Irradiation and Nanoindentation

Energy Technology Data Exchange (ETDEWEB)

Waseem, Owais A.; Ryu, Ho Jin; Park, Byong Guk [KAIST, Daejeon (Korea, Republic of); Jeong, Jong Ryul [Chungnam University, Daejeon (Korea, Republic of); Maeng, Cheol Soo; Lee, Myoung Goo [KEPCO, Daejeon (Korea, Republic of)

2016-05-15

As a result, ferritic-martensitic steels find applications in the in-core and out-of-core components which include ducts, piping, pressure vessel and cladding, etc. Due to ferromagnetism of F/M steel, it has been successfully employed in solenoid type fuel injector. Although the irradiation induced degradation in ferritic martensitic steels is lower as compare to (i) reduced activation steels, (ii) austenitic steels and (iii) martensitic steels, F/M steels are still prone to irradiation induced hardening and void swelling. The irradiation behavior may become more sophisticated due to transmutation and production of helium and hydrogen. The ductile to brittle transition temperature of F/M steels is also expected to increase due to irradiation. These irradiation induced degradations may deteriorate the integrity of F/M components. As a result of these investigations, it has found that the F/M steels experience no irradiation hardening above 400 .deg. C, but below this temperature, up to 350 .deg. C, weak hardening is observed. The irradiation hardening becomes more pronounced below 300 .deg. C. Moreover, the irradiation hardening has also found dependent upon radiation damage. The hardening was found increasing with increasing dose. Due to pronounced irradiation hardening below 300 .deg. C and increasing radiation damage with increasing dose (even at low dpa), it is required to investigate the post irradiation mechanical properties of F/M steel, in order to confirm its usefulness in structural and magnetic components which experience lifetime doses as low as 1x10{sup -5} dpa.

Irradiation and the food industry in France

International Nuclear Information System (INIS)

Boisseau, P.

1994-01-01

Part of a special section on food irradiation. The historical development in France of some industrial applications of food irradiation resulting from efficient technology transfer to the food industry is discussed. The 4 basic steps in successfully marketing any technology transfer, including irradiated foods, are that research must define conditions of the product's application, legislation must specify conditions of its application, consumers must accept the product, and appropriate processing capacity must exist

Food Irradiation Newsletter. V.13, no. 1

International Nuclear Information System (INIS)

1989-03-01

The International Conference on the Acceptance, Control of, and Trade in Irradiated Food, jointly sponsored by FAO, IAEA, WHO and ITC-UNCTAD/GATT, Geneva, Switzerland, December 1988, recognized that (1) food irradiation has the potential to reduce the incidence of foodborne diseases; (2) food irradiation can reduce post-harvest food losses and make available a larger quantity and a wider variety of foodstuffs for consumers - It can also be an effective quarantine treatment for certain food and thus contribute to international trade; (3) international trade in irradiated foods would be facilitated by harmonization of national procedures based on internationally recognized standards for the control of food irradiation. The ''International Document on Food Irradiation'' adopted by consensus at the Conference is included in this issue, which also contains excerpts of the 5th Annual Meeting of the International Consultative Group on Food Irradiation (ICGFI), convened in Vienna, September 1988, and reports of two co-ordinated meetings, the second Research Co-ordination Meeting on the Use of Irradiation as a Quarantine Treatment of Food and Agricultural Commodities, and the Second Co-ordination Meeting on Food Irradiation Programme for Developing Countries in Middle East and Europe. 3 tabs

γ irradiation facility at ENEA-Casaccia Centre (Rome)

International Nuclear Information System (INIS)

Baccaro, S.; Cecilia, A.; Pasquali, A.

2005-09-01

A description of Calliope γ irradiation plant of ENEA-Casaccia Centre (Rome) is presented in this paper. In particular the main characteristics of the irradiation facility necessary to define time and irradiation procedure are summarised. The plant is equipped with dosimetric services that evaluate absorbed doses in materials during irradiation. Dosimetric techniques used are Fricke, RedPerspex and alanine-ESR dosimetries. In the first case, absorbed dose is determined by chemical changes induced in a solution by irradiation and the second method uses the optical density increase induced in dosimeter by irradiation. The last method is based on the analysis of the free radical concentration induced in α-alanine amino-acid during irradiation. The paper provides also a simulation of the γ radiation field inside the irradiation cell realised by using FLUKA code, which includes a good description of the electromagnetic physics down to about 0.1 KeV [it

A model for phase stability under irradiation

International Nuclear Information System (INIS)

Abromeit, C.

The combination of two theoretical models leads to modified criteria of stability of precipitates under heavy particle irradiation. The size of existing or under irradiation newly formed precipitates is limited by a stable radius. Precipitate surface energy effects are included in a consistent manner

Time to come clean on food irradiation

International Nuclear Information System (INIS)

Allan, Ian.

1986-01-01

Early adoption of the National Health and Medical Research Council's guidelines on food irradiation in Australia is unlikely without widespread public education. The issues involved in food irradiation are discussed including the implications of United States and WHO guidelines, and the reaction of consumer groups

Total lymphoid irradiation

International Nuclear Information System (INIS)

Anon.

1980-01-01

An outline review notes recent work on total lymphoid irradiation (TLI) as a means of preparing patients for grafts and particularly for bone-marrow transplantation. T.L.I. has proved immunosuppressive in rats, mice, dogs, monkeys and baboons; when given before bone-marrow transplantation, engraftment took place without, or with delayed rejection or graft-versus-host disease. Work with mice has indicated that the thymus needs to be included within the irradiation field, since screening of the thymus reduced skin-graft survival from 50 to 18 days, though irradiation of the thymus alone has proved ineffective. A more lasting tolerance has been observed when T.L.I. is followed by an injection of donor bone marrow. 50% of mice treated in this way accepted allogenic skin grafts for more than 100 days, the animals proving to be stable chimeras with 50% of their peripheral blood lymphocytes being of donor origin. Experiments of a similar nature with dogs and baboons were not so successful. (U.K.)

Food irradiation

International Nuclear Information System (INIS)

Sato, Tomotaro; Aoki, Shohei

1976-01-01

Definition and significance of food irradiation were described. The details of its development and present state were also described. The effect of the irradiation on Irish potatoes, onions, wiener sausages, kamaboko (boiled fish-paste), and mandarin oranges was evaluated; and healthiness of food irradiation was discussed. Studies of the irradiation equipment for Irish potatoes in a large-sized container, and the silo-typed irradiation equipment for rice and wheat were mentioned. Shihoro RI center in Hokkaido which was put to practical use for the irradiation of Irish potatoes was introduced. The state of permission of food irradiation in foreign countries in 1975 was introduced. As a view of the food irradiation in the future, its utilization for the prevention of epidemics due to imported foods was mentioned. (Serizawa, K.)

Evolution of glycaemia during irradiation syndrome; Evolution de la glycemie au cours du syndrome d'irradiation

Energy Technology Data Exchange (ETDEWEB)

Raisonnier, A. [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

1967-03-15

The evolution of glycaemia following irradiation has been followed in the rat and pig. The results concerning a case of human accidental exposure have also been included. The author has tried to see whether the observed variations are reproducible and have a prognostic value. (author) [French] L'evolution de la glycemie a ete suivie, chez le rat et le porc, apres irradiation. Les resultats relatifs a une irradiation accidentelle humaine sont egalement rapportes. L'auteur cherche a definir si les variations observees sont reproductibles et ont une valeur pronostique. (auteur)

Awareness on food irradiation among students

International Nuclear Information System (INIS)

Seri Chempaka Mohd Yusof; Foziah Ali; Salahbiah Abdul Majid; Ros Anita Ahmad Ramli; Zainab Harun

2009-01-01

This survey was conducted to determine the level of understanding on radiation and irradiated food products amongst students during an exhibition in conjunction with Nuclear Malaysia Innovation Day 2008, on 16-18 July 2008 at Dewan Tun Dr. Ismail, Malaysian Nuclear Agency. Data were collected from 180 respondents comprising students from various schools visiting the exhibition. The results revealed that 55.56 % of the respondents knew of radiation and 81.11 % agreed that food could be irradiated. However, 53.33 % respondents misunderstood that there was presence of radioactivity in the food after irradiation. The results also showed that respondents knew that various foods can be irradiated and the type of radiation used in irradiation of food products. This survey indicates more aggressive work must be done to educate and introduce the public the application of nuclear technology in modern life, including in food preservation. (Author)

Commercialization of irradiated foods in Pakistan

International Nuclear Information System (INIS)

Khan, I.

2001-01-01

Preservation of food by gamma radiation is technically feasible and economically viable under conditions existing in Pakistan. To educate the consumers, programme for dissemination of information regarding food irradiation was implemented to educate the consumers. Test marketing of irradiated products was carried out for 5-6 years and more than 8 tons of irradiated vegetables were sold to consumers who were briefed about the advantages of radiation technology. A number of condiments including pepper and chillies were irradiated on a large scale (more than 10 tons) at the Pakistan Radiation Service (PARAS) during the years 1996-1998. Comprehensive Harmonised food irradiation regulations, covering all foods in seven classes, were approved in 1996. The charges for irradiating various food commodities ranged from US$19.71/ton potatoes (0.10 kGy) to US$38.32/ton for spices (10.0 kGy). Once the techno-economic feasibility is demonstrated, huge post-harvest losses of different food commodities can be avoided. This will make the country not only self-sufficient in food, but with enough surplus for export. (author)

A Practical Irradiance Model for Bifacial PV Modules

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-21

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using ray tracing software.

An analysis of irradiation creep in nuclear graphites

International Nuclear Information System (INIS)

Neighbour, G.B.; Hacker, P.J.

2002-01-01

Nuclear graphite under load shows remarkably high creep ductility with neutron irradiation, well in excess of any strain experienced in un-irradiated graphite (and additional to any dimensional changes that would occur without stress). As this behaviour compensates, to some extent, some other irradiation effects such as thermal shutdown stresses, it is an important property. This paper briefly reviews the approach to irradiation creep in the UK, described by the UK Creep Law. It then offers an alternative analysis of irradiation creep applicable to most situations, including HTR systems, using AGR moderator graphite as an example, to high values of neutron fluence, applied stress and radiolytic weight loss. (authors)

NSUF Irradiated Materials Library

Energy Technology Data Exchange (ETDEWEB)

Cole, James Irvin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-01

The Nuclear Science User Facilities has been in the process of establishing an innovative Irradiated Materials Library concept for maximizing the value of previous and on-going materials and nuclear fuels irradiation test campaigns, including utilization of real-world components retrieved from current and decommissioned reactors. When the ATR national scientific user facility was established in 2007 one of the goals of the program was to establish a library of irradiated samples for users to access and conduct research through competitively reviewed proposal process. As part of the initial effort, staff at the user facility identified legacy materials from previous programs that are still being stored in laboratories and hot-cell facilities at the INL. In addition other materials of interest were identified that are being stored outside the INL that the current owners have volunteered to enter into the library. Finally, over the course of the last several years, the ATR NSUF has irradiated more than 3500 specimens as part of NSUF competitively awarded research projects. The Logistics of managing this large inventory of highly radioactive poses unique challenges. This document will describe materials in the library, outline the policy for accessing these materials and put forth a strategy for making new additions to the library as well as establishing guidelines for minimum pedigree needed to be included in the library to limit the amount of material stored indefinitely without identified value.

Irradiation distribution diagrams and their use for estimating collectable energy

International Nuclear Information System (INIS)

Ronnelid, M.; Karlsson, B.

1997-01-01

A method for summarising annual or seasonal solar irradiation data in irradiation distribution diagrams, including both direct and diffuse irradiation, is outlined. The practical use of irradiation distribution diagrams is discussed in the paper. Examples are given for the calculation of collectable irradiation on flat plate collectors or trough-like concentrators like the compound parabolic concentrator (CPC), and for the calculation of overhang geometries for windows to prevent overheating of buildings. (author)

Allograft tolerance in pigs after fractionated lymphoid irradiation. I. Skin grafts after partial lateral irradiation and bone marrow cell grafting

International Nuclear Information System (INIS)

Vaiman, M.; Daburon, F.; Remy, J.; Villiers, P.A.; de Riberolles, C.; Lecompte, Y.; Mahouy, G.; Fradelizi, D.

1981-01-01

Experiments with pigs have been performed to establish bone marrow chimerism and skin graft tolerance between SLA genotyped animals. Recipients were conditioned by means of fractionated partial irradiation from lateral cobalt sources (partial lateral irradiation (PLI)). The head, neck, and lungs were protected with lead, the rest of the body being irradiated including the thymus, the majority of lymphoid organs with spleen, and most of the bone marrow sites

Food Irradiation Technology in the Philippines

International Nuclear Information System (INIS)

De Guzman, Zenaida M.

2015-01-01

The applications of ionizing radiation for the preservation of food and agricultural products by delaying ripening, destruction of insect pests and pathogenic microorganisms have shown great promise in the country. For more than 30 years, the Philippine Nuclear Research Institute (PNRI) in collaboration with other government and private sectors, has undertaken research and development studies and pilot and semi-commercial scale irradiation of foods. Some of the foods found to be benefit from the use of irradiation technology are mangoes and papayas for disinfestations and delay ripening; onions and garlic for inhibition of sprouting; spices and dehydrated products for reduction of microbial growth and rice and corn for insect and shelf-life extension. Two regulations approved by the Department of Health and the Bureau of Plant Industry are in place creating an enabling environment for food safety and trade of irradiated food. The conduct of awareness program in various parts of the country provided knowledge and information about the food irradiation technology. The Institute has been part of the international projects (IAEA and USDA) on the use of irradiation for sanity and phytosanitary treatment of food. The projects not only established the potential benefits of food irradiation for socio-economic development of the country but also built considerable capacity to properly treat foods. Some of the recent developments in the area of food irradiation include publication of Philippine National Standard (PNS) on Food Irradiation: Code of Good Irradiation Practices which will serve as a guide for stakeholders to irradiate food, a newly-established Electron Beam Facility to demonstrate the potential use of EB and a feasibility study of putting-up a commercial irradiation facility in the country. (author)

Fuel or irradiation subassembly

International Nuclear Information System (INIS)

Seim, O.S.; Hutter, E.

1975-01-01

A subassembly for use in a nuclear reactor is described which incorporates a loose bundle of fuel or irradiation pins enclosed within an inner tube which in turn is enclosed within an outer coolant tube and includes a locking comb consisting of a head extending through one side of the inner sleeve and a plurality of teeth which extend through the other side of the inner sleeve while engaging annular undercut portions in the bottom portion of the fuel or irradiation pins to prevent movement of the pins

Irradiation of dehydrated vegetables

International Nuclear Information System (INIS)

Esterhuyse, A; Esterhuizen, T.

1985-01-01

The reason for radurization was to decreased the microbial count of dehydrated vegetables. The average absorbed irradiation dose range between 2kGy and 15kGy. The product catagories include a) Green vegetables b) White vegetables c) Powders of a) and b). The microbiological aspects were: Declining curves for the different products of T.P.C., Coliforms, E. Coli, Stap. areus, Yeast + Mold at different doses. The organoleptical aspects were: change in taste, flavour, texture, colour and moisture. The aim is the marketing of irradiated dehydrated vegetables national and international basis

Food Irradiation Newsletter. V. 12, no. 2

International Nuclear Information System (INIS)

1988-07-01

This Newsletter reports activities of two ICGFI training workshops convened in Santiago, Chile, and Rehovot, Israel, in the past six months. The summary report of the FAO/IAEA Seminar on Food Irradiation for Developing Countries in Africa is also included. A follow-up to this Seminar is the ''Co-ordinated Research Programme on Food Irradiation for African Countries'' which will be implemented as soon as funds become available. Further, this issue contains a report of the Working Group on Food Irradiation of the European Society for Nuclear Agriculture convened in Stara Zagora, Bulgaria in 1987 and status reports of practical applications of food irradiation in different countries. 2 tabs

Irradiation of Argentine MOX fuels: Post-irradiation results and analysis

International Nuclear Information System (INIS)

Marino, A.C.; Perez, E.; Adelfang, P.

1997-01-01

The irradiation of the first Argentine prototypes of PHWR MOX fuels began in 1986. These experiments were made in the HFR-Petten reactor, Holland. The rods were prepared and controlled in the CNEA's facility. The postirradiation examinations were performed in the Kernforschungszentrum, Karlsruhe, Germany and in the JRC, Petten. The first rod has been used for destructive pre-irradiation analysis. The second one as a pathfinder to adjust systems in the HFR. Two additional rods including iodine doped pellets were intended to simulate 15000 MWd/T(M) burnup. The remaining two rods were irradiated until 15000 MWd/T(M) (BU15 experiment). One of them underwent a final ramp with the aim of verifying fabrication processes and studying the behaviour under power transients. BACO code was used to define the power histories and to analyze the experiments. This paper presents the postirradiation examinations for the BU15 experiments and a comparison with the BACO outputs for the rod that presented a failure during the ramp test of the BU15 experiment. (author). 17 refs, 30 figs, 5 tabs

Food irradiation

International Nuclear Information System (INIS)

Lindqvist, H.

1996-01-01

This paper is a review of food irradiation and lists plants for food irradiation in the world. Possible applications for irradiation are discussed, and changes induced in food from radiation, nutritional as well as organoleptic, are reviewed. Possible toxicological risks with irradiated food and risks from alternative methods for treatment are also brought up. Ways to analyze weather food has been irradiated or not are presented. 8 refs

Food irradiation

International Nuclear Information System (INIS)

Roberts, P.B.

1997-01-01

Food can be provided with extra beneficial properties by physical processing. These benefits include a reduced possibility of food poisoning, or an increased life of the food. We are familiar with pasteurisation of milk, drying of vegetables, and canning of fruit. These physical processes work because the food absorbs energy during treatment which brings about the changes needed. The energy absorbed in these examples is heat energy. Food irradiation is a less familiar process. It produces similar benefits to other processes and it can sometimes be applied with additional advantages over conventional processing. For example, because irradiation causes little heating, foods may look and taste more natural. Also, treatment can take place with the food in its final plastic wrappers, reducing the risk of re-contamination. (author). 1 ref., 4 figs., 1 tab

Food irradiation: Technology transfer in Asia, practical experiences

Science.gov (United States)

Kunstadt, Peter; Eng, P.

1993-10-01

Nordion International Inc., in cooperation with the Thai Office of Atomic Energy for Peace (OAEP) and the Canadian International Development Agency (CIDA) recently completed a unique food irradiation technology transfer project in Thailand. This complete food irradiation technology transfer project included the design and construction of an automatic multipurpose irradiation facility as well as the services of construction and installation management and experts in facility operation, maintenance and training. This paper provides an insight into the many events that led to the succesful conclusion of the world's first complete food irradiation technology transfer project.

Food irradiation: technology transfer in Asia, practical experiences

International Nuclear Information System (INIS)

Kunstadt, P.

1993-01-01

Nordion International Inc., in cooperation with the Thai Office of Atomic Energy for Peace (OAEP) and the Canadian International Development Agency (CIDA) recently completed a unique food irradiation technology transfer project in Thailand. This complete food irradiation technology transfer project included the design and construction of an automatic multipurpose irradiation facility as well as the services of construction and installation management and experts in facility operation, maintenance and training. This paper provides an insight into the many events that led to the successful conclusion of the world's first complete food irradiation technology transfer project. (Author)

Economic costs and benefits of commercial food irradiation

International Nuclear Information System (INIS)

Wills, P. A; Freeman, D. J.

1985-01-01

Decisions about commercialization of potential food irradiation applications usually involve pre-feasibility and feasibility studies to assess the expected return on investment. In this paper treatment costa/charges in theory and practice, investment philosophy, and the role of the multi-purpose plant in food irradiation are discussed. Other countries benefit commercially from the irradiation of a limited range of foods, including spices and frozen shrimps, exported from Southeast Asia. Some aspects of the feasibility of commercially irradiating these products, as well as mangoes and grains, in ASEAN countries and Australia are examined

Recent status and improvement of reduced-activation ferritic-martensitic steels for high-temperature service

Energy Technology Data Exchange (ETDEWEB)

Tan, L., E-mail: tanl@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Katoh, Y. [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Tavassoli, A.-A.F.; Henry, J. [DMN/Dir, DEN, CEA Saclay, 91191, Gif-sur-Yvette Cedex (France); Rieth, M. [Karlsruhe Institute of Technology, Karlsruhe, 76021 (Germany); Sakasegawa, H. [National Institutes for Quantum and Radiological Science and Technology, Rokkasho, Aomori, 039-3212 (Japan); Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Tanigawa, H. [National Institutes for Quantum and Radiological Science and Technology, Rokkasho, Aomori, 039-3212 (Japan); Huang, Q. [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)

2016-10-15

Reduced-activation ferritic-martensitic (RAFM) steels, candidate structural materials for fusion reactors, have achieved technological maturity after about three decades of research and development. The recent status of a few developmental aspects of current RAFM steels, such as aging resistance, plate thickness effects, fracture toughness, and fatigue, is updated in this paper, together with ongoing efforts to develop next-generation RAFM steels for superior high-temperature performance. In addition to thermomechanical treatments, including nonstandard heat treatment, alloy chemistry refinements and modifications have demonstrated some improvements in high-temperature performance. Castable nanostructured alloys (CNAs) were developed by significantly increasing the amount of nanoscale MX (M = V/Ta/Ti, X = C/N) precipitates and reducing coarse M{sub 23}C{sub 6} (M = Cr). Preliminary results showed promising improvement in creep resistance and Charpy impact toughness. Limited low-dose neutron irradiation results for one of the CNAs and China low activation martensitic are presented and compared with data for F82H and Eurofer97 irradiated up to ∼70 displacements per atom at ∼300–325 °C.

Effects of irradiation on platelet function

International Nuclear Information System (INIS)

Rock, G.; Adams, G.A.; Labow, R.S.

1988-01-01

Current medical practice involves the irradiation of blood components, including platelet concentrates, before their administration to patients with severe immunosuppression. The authors studied the effect of irradiation on in vitro platelet function and the leaching of plasticizers from the bag, both immediately and after 5 days of storage. The platelet count, white cell count, pH, glucose, lactate, platelet aggregation and release reaction, and serotonin uptake were not altered by the irradiation of random-donor or apheresis units with 2000 rads carried out at 0 and 24 hours and 5 days after collection. The leaching of di(2-ethylhexyl)phthalate from the plastic bags followed by the conversion to mono(2-ethylhexyl)phthalate was not increased by irradiation. Therefore, it is possible to irradiate platelet concentrates on the day of collection and subsequently store them for at least 5 days while maintaining in vitro function. This procedure could have considerable benefit for blood banks involved in the provision of many platelet products

Food irradiation: technology transfer to developing countries

International Nuclear Information System (INIS)

Kunstadt, Peter

1990-01-01

This paper discusses Nordion's experiences to-date with the Food Irradiation Project in Thailand (1987-1990). This project will enable the Government of Thailand and the Thai food industry to benefit from established Canadian technology in food irradiation. It includes the design and the construction in Thailand of a multipurpose irradiation facility, similar to the Canadian Irradiation Centre. In addition Canada provides the services, for extended periods of time, of construction and installation management and experts in facility operation, maintenance and training. The Technology Transfer component is a major part of the overall Thai Food Irradiation Project. Its purpose is to familiarize Thai government and industry personnel with Canadian requirements in food regulations and distribution and to conduct market and consumer tests of selected Thai irradiated food products in Canada, once the products have Canadian regulatory approval. On completion of this project, Thailand will have the necessary facility, equipment and training to continue to provide leadership in food irradiation research, as well as scientific and technical support to food industries not only in Thailand but also in the ASEAN region. (author)

Food irradiation: Technology transfer to developing countries

Science.gov (United States)

Kunstadt, Peter

This paper discusses Nordion's experiences to-date with the Food Irradiation Project in Thailand (1987-1990). This project will enable the Government of Thailand and the Thai food industry to benefit from established Canadian technology in food irradiation. It includes the design and the construction in Thailand of a multipurpose irradiation facility, similar to the Canadian Irradiation Centre. In addition Canada provides the services, for extended periods of time, of construction and installation management and experts in facility operation, maintenance and training. The Technology Transfer component is a major part of the overall Thai Food Irradiation Project. Its purpose is to familiarize Thai government and industry personnel with Canadian requirements in food regulations and distribution and to conduct market and consumer tests of selected Thai irradiated food products in Canada, once the products have Canadian regulatory approval. On completion of this project, Thailand will have the necessary facility, equipment and training to continue to provide leadership in food irradiation research, as well as scientific and technical support to food industries not only in Thailand by also in the ASEAN region.

Food irradiation: technology transfer to developing countries

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, Peter [Nordion International Inc., Kanata, ON (Canada)

1990-01-01

This paper discusses Nordion's experiences to-date with the Food Irradiation Project in Thailand (1987-1990). This project will enable the Government of Thailand and the Thai food industry to benefit from established Canadian technology in food irradiation. It includes the design and the construction in Thailand of a multipurpose irradiation facility, similar to the Canadian Irradiation Centre. In addition Canada provides the services, for extended periods of time, of construction and installation management and experts in facility operation, maintenance and training. The Technology Transfer component is a major part of the overall Thai Food Irradiation Project. Its purpose is to familiarize Thai government and industry personnel with Canadian requirements in food regulations and distribution and to conduct market and consumer tests of selected Thai irradiated food products in Canada, once the products have Canadian regulatory approval. On completion of this project, Thailand will have the necessary facility, equipment and training to continue to provide leadership in food irradiation research, as well as scientific and technical support to food industries not only in Thailand but also in the ASEAN region. (author).

Irradiation proctitis

International Nuclear Information System (INIS)

Minami, Akira

1977-01-01

Literatures on late rectal injuries are discussed, referring to two patients with uterine cervical cancer in whom irradiation proctitis occurred after telecobalt irradiation following uterine extirpation. To one patients, a total of 5000 rads was irradiated, dividing into 250 rads at one time, and after 3 months, irradiation with a total of 2000 rads, dividing into 200 rads at one time, was further given. In another one patient, two parallel opposing portal irradiation with a total of 6000 rads was given. About a year after the irradiation, rectal injuries and cystitis, accompanying with hemorrhage, were found in both of the patients. Rectal amputation and proctotoreusis were performed. Cystitis was treated by cystic irradiation in the urological department. Pathohistological studies of the rectal specimen revealed atrophic mucosa, and dilatation of the blood vessels and edema in the colonic submucosa. Incidence of this disease, term when the disease occurs, irradiation dose, type of the disease, treatment and prevention are described on the basis of the literatures. (Kanao, N.)

Irradiation proctitis

Energy Technology Data Exchange (ETDEWEB)

Minami, A [Osaka Kita Tsishin Hospital (Japan)

1977-06-01

Literatures on late rectal injuries are discussed, referring to two patients with uterine cervical cancer in whom irradiation proctitis occurred after telecobalt irradiation following uterine extirpation. To one patients, a total of 5000 rads was irradiated, dividing into 250 rads at one time, and after 3 months, irradiation with a total of 2000 rads, dividing into 200 rads at one time, was further given. In another one patient, two parallel opposing portal irradiation with a total of 6000 rads was given. About a year after the irradiation, rectal injuries and cystitis, accompanying with hemorrhage, were found in both of the patients. Rectal amputation and proctotoreusis were performed. Cystitis was treated by cystic irradiation in the urological department. Pathohistological studies of the rectal specimen revealed atrophic mucosa, and dilatation of the blood vessels and edema in the colonic submucosa. Incidence of this disease, term when the disease occurs, irradiation dose, type of the disease, treatment and prevention are described on the basis of the literatures.

A survey of large scale gamma irradiators in the United States

International Nuclear Information System (INIS)

Smyth, R.C.; Simmons, R.C.; Dougherty, D.K.

1987-01-01

NUS Corporation (NUS) was contracted by the US Department of Energy (DOE) to perform a survey of Cs-137 and Co-60 irradiators in the US. The results of this survey, in the form of matrix listings of irradiators and their specifications, are included in subsequent sections of this report. The US Department of Agriculture (USDA) will use the survey results as a preliminary guide for potential use in regionalized food irradiation research. The survey was limited to the identification of operable irradiators which are owned and/or operated by private industry, educational institutions, and government facilities. To the extent available, specific information for each unit was included in the report. This information includes radioactive material, chemical matrix of fuel, containment capsule material and form, curies per capsule and total activity, sample chamber size, and irradiator availability

ORNL evaluation of the ORR-PSF metallurgical experiment and blind test

International Nuclear Information System (INIS)

Stallmann, F.W.

1984-01-01

A methodology is described to evaluate the dosimetry and metallurgical data from the two-year ORR-PSF metallurgical irradiation experiment. The first step is to obtain a three-dimensional map of damage exposure parameter values based on neutron transport calculations and dosimetry measurements which are obtained by means of the LSL-M2 adjustment procedure. Metallurgical test data are then combined with damage parameter, temperature, and chemistry information to determine the correlation between radiation and steel embrittlement in reactor pressure vessels including estimates for the uncertainties. Statistical procedures for the evaluation of Charpy data, developed earlier, are used for this investigation. The data obtained in this investigation provide a benchmark against which the predictions of the PSF Blind Test can be compared. The results of this investigation and the Blind Test comparison are discussed

Use of irradiation to ensure the microbiological safety of processed meats

International Nuclear Information System (INIS)

Thayer, D.W.; Lachica, R.V.; Huhtanen, C.N.; Wierbicki, E.

1986-01-01

Research studies are reviewed, concerning the use of ionizing radiation to extend the shelf life and improve the safety of processed meats. Topics include: the historical background of food irradiation research; the determination of fractional destruction (D) values for a microorganism at a given irradiation dose; the effect of chilling and of NaCl on D values; and a brief review of the irradiation research for different cured and uncured meats (bacon; ham; frankfurters; corned beef and pork sausage; and beef, chicken, and pork). Guidelines for producing safe processed meats through irradiation are included

Identification of gamma-irradiated Chinese herbs by thermoluminescence analysis

International Nuclear Information System (INIS)

Yu Bai; Chinese Academy of Sciences, Changchun; Jilin Medical College, Jilin; WenYue Jiang; Zhongying Liu; He Lin; Changchun University of Traditional Chinese Medicine, Changchun; Zhiqiang Liu

2014-01-01

The feasibility of thermoluminescence (TL) to differentiate irradiated Chinese medicinal herbs from non-irradiated was investigated. Thirty different dried Chinese herbs were tested, including root, flower, ramulus, rhizome, cortex, and whole plant samples. Irradiation of Chinese herbs was associated with strong TL peaks at ∼150-250 deg C, while TL curves of non-irradiated herbs had very low intensities above 250 deg C, which was also confirmed by the TL ratio (non-irradiated, TL 1 /TL 2 1 /TL 2 > 0.1) except for sterculia lychnophora, semen cassia, flos inulae, and anemone root. TL ratios of some herbs indicated irradiation (TL 1 /TL 2 > 0.1) even if the irradiated components were as low as 0.1 %. Thus we demonstrated that TL analysis had excellent sensitivity and reliability for the identification of irradiated Chinese herbs. (author)

Prospects of establishing food irradiation facilities in Kenya

International Nuclear Information System (INIS)

Mustapha, A.O.; Patel, J.P.; Rathore, I.V.S.; Hashim, N.O.; Kinyua, A.M.

2001-01-01

Full text: A national project of food irradiation in the country is being proposed. At present there are no facilities for food irradiation (and food irradiation research) in Kenya. This report is therefore largely comparative between the traditional and the conventional food preservation methods on the one hand and the irradiation technique on the other. The report is also based on information from other countries where food irradiation is practiced (Kawabata, 1981) or is being also contemplated (Diop et al, 1997), as well as on the relevant report of the International Atomic Energy Agency (IAEA) on this topic (IAEA, 1993). The paper presents the statement of the research problem, i.e., in Kenya large quantities of food and other farm produces go to waste annually as a result of the inadequacies of the preservation techniques currently in use. These (other) preservation techniques, although often less controversial than the irradiation techniques, have also been found to be more expensive to run when compared to irradiation techniques. Such techniques, presently employed in Kenya, include the traditional methods (e.g. sun drying, smoke and fire drying, etc.) and modern techniques such as freezing or refrigeration, lyophilization, etc., as well as application of chemicals like insecticides and fumigants. The latter combines the disadvantages of high costs with environmental pollution and associated health risks. In this preliminary research, aimed at studying the prospects of a national food irradiation project, the following food items that are selected for their importance to the economy of the country, include potatoes, rice, maize, coffee, tea, various fruits, fish and meat. The paper also explores the economic feasibility as well as the human and technological requirements of establishing a commercial food irradiation plant, with aim of assessing the applicability of food irradiation as alternative or a complimentary approach for preservation technique in

Quality Properties of Cakes Containing Gamma-Irradiated Egg White

International Nuclear Information System (INIS)

Lee, J.W.; Seo, J.H.; Ahn, H.J; Byun, M.W; Kim, Y.H.; Choi, J.M.; Yook, H.S.

2003-01-01

As a research on the practical approaches of gamma irradiation for the reduction of egg allergy, cakes including gamma-irradiated egg white were manufactured, and rheological characteristics and sensory qualities of the cakes were evaluated. Egg white was separated from whole egg and then gamma-irradiated with the absorbed dose of 10 or 20 kGy

Alexandre - a multi-project, multi-material and multi-technique action for an irradiation experiment in Osiris and post irradiation examination

International Nuclear Information System (INIS)

Averty, X.; Brachet, J.C.; Bertin, J.L.; Pizzanelli, J.P.; Rozenblum, F.

1999-01-01

This paper presents the data obtained on different classes of steels neutron irradiated at 325 deg C in pressurized water with a PWR-type chemistry. This irradiation, nicknamed 'Alexandre', took place in the OSIRIS reactor and finished in November 1999, for a maximum irradiation damage of ∼9 dpa. The preliminary results (up to 3.4 dpa), discussed in relation to chemical composition and initial metallurgical conditions, are listed below: - Evolution of the mechanical properties as a function of irradiation dose including the measurements of the Reduction-in-Area to failure by image analysis. - Comparison between out-of-pile and in-pile uniform corrosion. - Microstructural aspects (fractography, Transmission Electron Microscopy, and Small Angle Neutron Scattering measurements). - Post-irradiation evolution of residual. activity. (authors)

Electron beam irradiation of gemstone for color enhancement

Science.gov (United States)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi

2012-09-01

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Electron beam irradiation of gemstone for color enhancement

Energy Technology Data Exchange (ETDEWEB)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A' iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi [Malaysian Nuclear Agency, Bangi, Selangor (Malaysia); School of Chemicals and Material Engineering, NUST Islamabad (Pakistan); Malaysian Nuclear Agency, Bangi, Selangor (Malaysia)

2012-09-26

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Electron beam irradiation of gemstone for color enhancement

International Nuclear Information System (INIS)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi

2012-01-01

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Food irradiation: Gamma processing facilities

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

1997-12-31

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Food irradiation: Gamma processing facilities

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, P [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

1998-12-31

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Food irradiation: Gamma processing facilities

International Nuclear Information System (INIS)

Kunstadt, P.

1997-01-01

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Evaluation of irradiation hardening of proton irradiated stainless steels by nanoindentation

International Nuclear Information System (INIS)

Yabuuchi, Kiyohiro; Kuribayashi, Yutaka; Nogami, Shuhei; Kasada, Ryuta; Hasegawa, Akira

2014-01-01

Ion irradiation experiments are useful for investigating irradiation damage. However, estimating the irradiation hardening of ion-irradiated materials is challenging because of the shallow damage induced region. Therefore, the purpose of this study is to prove usefulness of nanoindentation technique for estimation of irradiation hardening for ion-irradiated materials. SUS316L austenitic stainless steel was used and it was irradiated by 1 MeV H + ions to a nominal displacement damage of 0.1, 0.3, 1, and 8 dpa at 573 K. The irradiation hardness of the irradiated specimens were measured and analyzed by Nix–Gao model. The indentation size effect was observed in both unirradiated and irradiated specimens. The hardness of the irradiated specimens changed significantly at certain indentation depths. The depth at which the hardness varied indicated that the region deformed by the indenter had reached the boundary between the irradiated and unirradiated regions. The hardness of the irradiated region was proportional to the inverse of the indentation depth in the Nix–Gao plot. The bulk hardness of the irradiated region, H 0 , estimated by the Nix–Gao plot and Vickers hardness were found to be related to each other, and the relationship could be described by the equation, HV = 0.76H 0 . Thus, the nanoindentation technique demonstrated in this study is valuable for measuring irradiation hardening in ion-irradiated materials

Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

International Nuclear Information System (INIS)

Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

2004-01-01

Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed

Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

Energy Technology Data Exchange (ETDEWEB)

Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

2004-08-01

Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed.

Food irradiation newsletter. V. 17, no. 2

International Nuclear Information System (INIS)

1993-07-01

This issue of the Food Irradiation Newsletter includes reports of a number of activities of the Food Preservation Section of the FAO/IAEA from the final quarter of 1992 to the middle of 1993. In addition there is a summary of food irradiation activities in the USA, an excerpt from the Official Gazette of the French Republic concerning the use of ionizing radiation to treat camembert made from raw milk, and a discussion of the potential for the application of food irradiation in Russia

Post irradiation test report of irradiated DUPIC simulated fuel

International Nuclear Information System (INIS)

Yang, Myung Seung; Jung, I. H.; Moon, J. S. and others

2001-12-01

The post-irradiation examination of irradiated DUPIC (Direct Use of Spent PWR Fuel in CANDU Reactors) simulated fuel in HANARO was performed at IMEF (Irradiated Material Examination Facility) in KAERI during 6 months from October 1999 to March 2000. The objectives of this post-irradiation test are i) the integrity of the capsule to be used for DUPIC fuel, ii) ensuring the irradiation requirements of DUPIC fuel at HANARO, iii) performance verification in-core behavior at HANARO of DUPIC simulated fuel, iv) establishing and improvement the data base for DUPIC fuel performance verification codes, and v) establishing the irradiation procedure in HANARO for DUPIC fuel. The post-irradiation examination performed are γ-scanning, profilometry, density, hardness, observation the microstructure and fission product distribution by optical microscope and electron probe microanalyser (EPMA)

Facts about food irradiation: Irradiated foods and the consumer

International Nuclear Information System (INIS)

1991-01-01

This fact sheet discusses market testing of irradiate food, consumer response to irradiated products has always been positive, and in some countries commercial quantities of some irradiated food items have been sold on a regular basis. Consumers have shown no reluctance to buy irradiated food products. 4 refs

Food irradiation by low energy electrons

International Nuclear Information System (INIS)

Bird, J.R.

1985-01-01

For some special cases, the use of low energy electrons has advantages over the use of gamma-rays or higher energy electrons for the direct irradiation of food. These advantages arise from details of the interaction processes which are responsible for the production of physical, chemical and biological effects. Factors involved include depth of penetration, dose distribution, irradiation geometry, the possible production of radioactivity and costs

Safety evaluation on irradiated food ingestion

International Nuclear Information System (INIS)

1986-01-01

This paper reports double-blind observations of volunteers who took 35 kinds of irradiated foods as their main diet for 90 days. The subjects consisted of 70 medical students and 8 staff members in the Shanghai Medical University. They were randomly divided into two groups. One group was supplied with irradiated foods, the other acted as controls eating the same food but non-irradiated. The 35 kinds of irradiated foods were grain, meat products, vegetables, fruits, dried fruits etc. The absorbed dose of irradiation from the processed foods varied from 0.1 to 8.0 kGy. The irradiated foods made up 60.3% of the total food intake by weight. Observations during 90 days indicated that the subjects were all pleased with their diets and no adverse effects on their health were seen. Clinical and laboratory examinations included routine blood and urine tests, blood biochemical examinations, hepatic and renal function tests, endocrinological assays, cellular immunity tests, and mutagenetic studies (such as the incidence of polyploid cells, chromosomal structural aberration, rates of sister chromatid-exchanges, micronuclei test, urine Ames' test). These studies showed that the ingestion of these foods are safe for humans

Symposium on irradiation for national development. Proceedings

International Nuclear Information System (INIS)

Adesanmi, C.A.; Ogbadu, G.H.

1998-01-01

This document is the full proceedings of the symposium on irradiation for national development held at SHESTCO in 1996. It contains the full texts of a forward, opening and special remarks, welcome and keynote addresses and abstracts and texts of 23 technical papers. The subjects covered included regulations, codes of practice, irradiation technology in food, agriculture and industry, radiation protection and dosimetry. The questions, answers and comments in the discussion sessions are also included. Additionally, the abstracts of 8 other papers are included. We wish to thank the Coordinator of SHESTCO for making available this proceedings

Symposium on irradiation for national development. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Adesanmi, C A; Ogbadu, G H [eds.

1998-12-01

This document is the full proceedings of the symposium on irradiation for national development held at SHESTCO in 1996. It contains the full texts of a forward, opening and special remarks, welcome and keynote addresses and abstracts and texts of 23 technical papers. The subjects covered included regulations, codes of practice, irradiation technology in food, agriculture and industry, radiation protection and dosimetry. The questions, answers and comments in the discussion sessions are also included. Additionally, the abstracts of 8 other papers are included. We wish to thank the Coordinator of SHESTCO for making available this proceedings.

Food irradiation

International Nuclear Information System (INIS)

Matsuyama, Akira

1990-01-01

This paper reviews researches, commentaries, and conference and public records of food irradiation, published mainly during the period 1987-1989, focusing on the current conditions of food irradiation that may pose not only scientific or technologic problems but also political issues or consumerism. Approximately 50 kinds of food, although not enough to fill economic benefit, are now permitted for food irradiation in the world. Consumerism is pointed out as the major factor that precludes the feasibility of food irradiation in the world. In the United States, irradiation is feasible only for spices. Food irradiation has already been feasible in France, Hollands, Belgium, and the Soviet Union; has under consideration in the Great Britain, and has been rejected in the West Germany. Although the feasibility of food irradiation is projected to increase gradually in the future, commercial success or failure depends on the final selection of consumers. In this respect, the role of education and public information are stressed. Meat radicidation and recent progress in the method for detecting irradiated food are referred to. (N.K.) 128 refs

Gamma Irradiation does not Cause Carcinogenesis of Irradiated Herbs

International Nuclear Information System (INIS)

Thongphasuk, Jarunee; Thongphasuk, Piyanuch; Eamsiri, Jarurut; Pongpat, Suchada

2009-07-01

Full text: Microbial contamination of medicinal herbs can be effectively reduced by gamma irradiation. Since irradiation may cause carcinogenicity of the irradiated herbs, the objective of this research is to study the effect of gamma irradiation (10 and 25 kGy) from cobalt-60 on carcinogenicity. The herbs studied were Pueraria candollei Grah., Curcuma longa Linn. Zingiber montanum, Senna alexandrina P. Miller, Eurycoma Longifolia Jack, Gymnostema pentaphylum Makino, Ginkgo biloba, Houttuynia cordata T., Andrographis paniculata, Thunbergia laurifolia L., Garcinia atroviridis G., and Cinnamomum verum J.S.Presl. The results showed that gamma irradiation at the dose of 10 and 25 kGy did not cause carcinogenicity of the irradiated herbs

Tensile and impact testing of an HFBR [High Flux Beam Reactor] control rod follower

International Nuclear Information System (INIS)

Czajkowski, C.J.; Schuster, M.H.; Roberts, T.C.; Milian, L.W.

1989-08-01

The Materials Technology Group of the Department of Nuclear Energy (DNE) at Brookhaven National Laboratory (BNL) undertook a program to machine and test specimens from a control rod follower from the High Flux Beam Reactor (HFBR). Tensile and Charpy impact specimens were machined and tested from non-irradiated aluminum alloys in addition to irradiated 6061-T6 from the HFBR. The tensile test results on irradiated material showed a two-fold increase in tensile strength to a maximum of 100.6 ksi. The impact resistance of the irradiated material showed a six-fold decrease in values (3 in-lb average) compared to similar non-irradiated material. Fracture toughness (K I ) specimens were tested on an unirradiated compositionally and dimensionally similar (to HFBR follower) 6061 T-6 material with K max values of 24.8 ± 1.0 Ksi√in (average) being obtained. The report concludes that the specimens produced during the program yielded reproducible and believable results and that proper quality assurance was provided throughout the program. 9 figs., 6 tabs

Food irradiation

International Nuclear Information System (INIS)

Duchacek, V.

1989-01-01

The ranges of doses used for food irradiation and their effect on the processed foods are outlined. The wholesomeness of irradiated foods is discussed. The present food irradiation technology development in the world is described. A review of the irradiated foods permitted for public consumption, the purposes of food irradiaton, the doses used and a review of the commercial-scale food irradiators are tabulated. The history and the present state of food processing in Czechoslovakia are described. (author). 1 fig., 3 tabs., 13 refs

Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

International Nuclear Information System (INIS)

Itoh, Satoshi; Inomata, Taisuke; Ogawa, Yasuhiro; Yoshida, Shoji; Sonobe, Hiroshi; Ohtsuki, Yuji

1999-01-01

The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

Energy Technology Data Exchange (ETDEWEB)

Itoh, Satoshi; Inomata, Taisuke; Ogawa, Yasuhiro; Yoshida, Shoji; Sonobe, Hiroshi; Ohtsuki, Yuji [Kochi Medical School, Nankoku (Japan)

1999-05-01

The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

Pharmacology of post-irradiation damage of blood capillaries

International Nuclear Information System (INIS)

Pospisil, J.; Pouckova, P.

1979-01-01

Available literature data are summed up on the effect of a number of substances on irradiation damage to blood capillaries. The substances include vitamins, bioflavonoids, serotonine, histamine, bradykinin, ACTH, adrenal hormones, vasopressin, estrogens, prostaglandins, escin 1-butanol, diisopropylfluorophosphate, phenoxybenzamine, 1,4-dihydroxybenzenesulphonic acid derivatives, and xi-aminohexanoic acid. The data include the effects of the substances administered before and after irradiation on blood capillary damage and on mortality. (Ha)

Effect of electron beam irradiation on seed germination

Energy Technology Data Exchange (ETDEWEB)

Han, Seunghee; Bae, Youngmin [Changwon Univ., Changwon (Korea, Republic of)

2013-07-01

Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber.

Effect of electron beam irradiation on seed germination

International Nuclear Information System (INIS)

Han, Seunghee; Bae, Youngmin

2013-01-01

Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber

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

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.

Heavy-section steel technology program. Volume 1. Quarterly progress report, January-March 1983. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Pugh, C.E.

1983-09-01

A thermal-strain modification was made to the deformation-plasticity model in the ADINA-ORVIRT fracture-mechanics analysis system in order to be more applicable to combined pressure and thermal loadings. Subcontractors continued studies on crack arrest, cleavage fracture transition, and environmentally assisted crack growth. Charpy testing of state-of-the-art weld specimens in the Fourth HSST Irradiation Series was performed on unirradiated specimens and on a few irradiated specimens for scoping purposes. Finite-flaw capabilities were incorporated into the OCA-II computer code, and parametric studies were carried out to compare fracture predictions with two-dimensional and specific finite flaws. Preparations continued for thermal-shock experiment TSE-7 to be conducted in May. Preparations for the first pressurized-thermal-shock experiment continued.

Slag recycling of irradiated vanadium

International Nuclear Information System (INIS)

Gorman, P.K.

1995-01-01

An experimental inductoslag apparatus to recycle irradiated vanadium was fabricated and tested. An experimental electroslag apparatus was also used to test possible slags. The testing was carried out with slag materials that were fabricated along with impurity bearing vanadium samples. Results obtained include computer simulated thermochemical calculations and experimentally determined removal efficiencies of the transmutation impurities. Analyses of the samples before and after testing were carried out to determine if the slag did indeed remove the transmutation impurities from the irradiated vanadium

Irradiated foods

International Nuclear Information System (INIS)

Darrington, Hugh

1988-06-01

This special edition of 'Food Manufacture' presents papers on the following aspects of the use of irradiation in the food industry:- 1) an outline view of current technology and its potential. 2) Safety and wholesomeness of irradiated and non-irradiated foods. 3) A review of the known effects of irradiation on packaging. 4) The problems of regulating the use of irradiation and consumer protection against abuse. 5) The detection problem - current procedures. 6) Description of the Gammaster BV plant in Holland. 7) World outline review. 8) Current and future commercial activities in Europe. (U.K.)

Food preservation by irradiation

International Nuclear Information System (INIS)

Kooij, J. van

1981-01-01

Twenty-five years of development work on the preservation of food by irradiation have shown that this technology has the potential to reduce post-harvest losses and to produce safe foods. The technological feasibility has been established but general acceptance of food irradiation by national regulatory bodies and consumers requires attention. The positive aspects of food preservation by irradiation include: the food keeps its freshness and its physical state, agents which cause spoilage (bacteria, etc.) are eliminated, recontamination does not take place, provided packaging materials are impermeable to bacteria and insects. It inhibits sprouting of root crops, kills insects and parasites, inactivates bacteria, spores and moulds, delays ripening of fruit, improves the technological properties of food. It makes foods biologically safe, allows the production of shelf-stable foods and is excellent for quarantine treatment, and generally improves food hygiene. The dose ranges needed for effective treatment are given

The irradiation effects and processing dose for pet foods decontamination

International Nuclear Information System (INIS)

Zhu Jiating; Feng Min; Liu Chunquan; Zhao Yongfu; Jin Yudong; Ji Ping; Ha Yiming; Gao Meixu; Li Shurong; Wang Feng; Zhou Hongjie

2009-01-01

The applied dose range of irradiation processing of 4 kinds of pet foods had been studied. More than 92% microorganisms was inactive at the irradiation dose of 4 kGy, while more than 99% was inactive at 6 kGy. The microorganism load of irradiated pet food by 8 kGy met the requirement of national standards. The 10 kGy irradiation could sterilize the treated pet food. Salmonella had not been checked in irradiated or unirradiated samples. When irradiation dose ranged 4-10 kGy, there was no significant difference on contents of moisture, fat, protein, coarse fiber, carbohydrates, minerals (not including Calcium) or amino acids between irradiated and un-irradiated pet food. There was also no significant change on sensory quality of irradiated samples within this dose range. It is concluded that the recommended irradiation processing dose range for pet foods is 4-10 kGy. (authors)

Startup of the Whiteshell irradiation facility

International Nuclear Information System (INIS)

Barnard, J.W.; Stanley, F.W.

1989-01-01

Recently, a 10-MeV, 1-kW electron linear accelerator was installed in a specially designed irradiation facility at the Whiteshell Nuclear Research Establishment. The facility was designed for radiation applications research in the development of new radiation processes up to the pilot scale level. The accelerator is of advanced design. Automatic startup via computer control makes it compatible with industrial processing. It has been operated successfully as a fully integrated electron irradiator for a number of applications including curing of plastics and composites, sterilization of medical disposables and animal feed irradiation. We report here on our experience during the first six months of operation. (orig.)

Startup of the whiteshell irradiation facility

Science.gov (United States)

Barnard, J. W.; Stanley, F. W.

1989-04-01

Recently, a 10-MeV, 1-kW electron linear accelerator was installed in a specially designed irradiation facility at the Whiteshell Nuclear Research Establishment. The facility was designed for radiation applications research in the development of new radiation processes up to the pilot scale level. The accelerator is of advanced design. Automatic startup via computer control makes it compatible with industrial processing. It has been operated successfully as a fully integrated electron irradiator for a number of applications including curing of plastics and composites, sterilization of medical disposables and animal feed irradiation. We report here on our experience during the first six months of operation.

Byproducts Utilization Program: Sewage Sludge Irradiation Project. Progress report, July-December 1983

Energy Technology Data Exchange (ETDEWEB)

1984-12-01

Engineering support for a demonstration-scale irradiator design included assisting the City of Albuquerque in preparing a comprehensive site plan for their proposed sludge handling and treatment facilities. The solar sludge dryer has been delivered to SNLA. A preliminary sludge drying experiment indicated the importance of optimizing stirring and air flow. Installation of instrumentation and mechanical equipment continued. The Sandia Irradiator for Dried Sewage Solids (SIDSS) was used to irradiate 23 tons of dried, digested sewage sludge for the New Mexico State University (NMSU) Department of Crop and Soil Sciences. Gamma Irradiation Facility (GIF) operations included irradiation of ground pork for Toxoplasma gondii inactivation experiments, irradiation of surgical supplies and soil samples. Beneficial Uses Shipping Systems (BUSS) cask activities included near completion of the two full-scale cask bodies. Work continued on the Cask Safety Analysis Report (SAR) including additional analyses to reconfigure the six strontium fluoride capsules and/or reduce the number of capsules accommodated. NMSU has indicated no regrowth of salmonellae occurred in the irradiated sludge stockpile, while salmonellae did regrow in the unirradiated stockpile. Analyses of raw and digested sewage sludge from the Albuquerque Waste Water Treatment Plant showed levels of Yersinia enterocolitica (a human pathogen of emerging significance) to be below detection limits.

Byproducts Utilization Program: Sewage Sludge Irradiation Project. Progress report, July-December 1983

International Nuclear Information System (INIS)

1984-12-01

Engineering support for a demonstration-scale irradiator design included assisting the City of Albuquerque in preparing a comprehensive site plan for their proposed sludge handling and treatment facilities. The solar sludge dryer has been delivered to SNLA. A preliminary sludge drying experiment indicated the importance of optimizing stirring and air flow. Installation of instrumentation and mechanical equipment continued. The Sandia Irradiator for Dried Sewage Solids (SIDSS) was used to irradiate 23 tons of dried, digested sewage sludge for the New Mexico State University (NMSU) Department of Crop and Soil Sciences. Gamma Irradiation Facility (GIF) operations included irradiation of ground pork for Toxoplasma gondii inactivation experiments, irradiation of surgical supplies and soil samples. Beneficial Uses Shipping Systems (BUSS) cask activities included near completion of the two full-scale cask bodies. Work continued on the Cask Safety Analysis Report (SAR) including additional analyses to reconfigure the six strontium fluoride capsules and/or reduce the number of capsules accommodated. NMSU has indicated no regrowth of salmonellae occurred in the irradiated sludge stockpile, while salmonellae did regrow in the unirradiated stockpile. Analyses of raw and digested sewage sludge from the Albuquerque Waste Water Treatment Plant showed levels of Yersinia enterocolitica (a human pathogen of emerging significance) to be below detection limits

Developing Ultra-small Scale Mechanical Testing Methods and Microstructural Investigation Procedures for Irradiated Materials

Energy Technology Data Exchange (ETDEWEB)

Hosemann, Peter; Kaoumi, Djamel

2018-04-02

-beam irradiations have been utilized for decades to foster the understanding of materials’ behavior under radiation, and significant efforts at comparing ion-beam irradiations to neutron irradiations are ongoing [1]. While extensive microstructural and chemical characterizations of neutron-irradiated and ion-irradiated materials are essential to the understanding of the underlying physics of materials’ degradation in nuclear environments, the ultimate test is the mechanical performance of a material under the anticipated condition, since it is the final criterion for a material to be accepted for use in a specific nuclear component. Again, standard, large-scale, bulk evaluations are key for the licensing of materials in a specific component, but additional, more basic scientific testing can accelerate the process by targeting specific areas of interest. Small-scale mechanical testing has been applied on nuclear materials for decades [2]. Traditionally the driving forces to use non-standard-size samples are the limited space in reactors, the availability of new alloys, and a reduction in radioactive-materials volume. Shear punch testing [3,5], sub-sized micro tensile testing [4], sub-sized compact tension and charpy testing [6,7], micro bulge testing [8], and micro hardness testing [3] have been used. Small-scale mechanical testing also allows the targeting of specific regions of interest, be they single grains to evaluate a specific deformation mechanism [9], grain boundaries, heat-affected zones in welds, or any other specific critical area of interest. With further reducing of the sample size, it also holds the promise to obtain quantitative data from ion-beam irradiations and to compare such data to the microstructural changes observed. Over the last few decades, a number of small-scale mechanical characterization techniques have been developed and utilized for irradiated materials. In addition to the above-mentioned sample test techniques at the mm and sub mm length scale

Detection methods of irradiated foodstuffs

Energy Technology Data Exchange (ETDEWEB)

Ponta, C C; Cutrubinis, M; Georgescu, R [IRASM Center, Horia Hulubei National Institute for Physics and Nuclear Engineering, PO Box MG-6, RO-077125 Magurele-Bucharest (Romania); Mihai, R [Life and Environmental Physics Department, Horia Hulubei National Institute for Physics and Nuclear Engineering, PO Box MG-6, RO-077125 Magurele-Bucharest (Romania); Secu, M [National Institute of Materials Physics, Bucharest (Romania)

2005-07-01

Full text: Food irradiation has, in certain circumstances, an important role to play both in promoting food safety and in reducing food losses. The safety and availability of nutritious food are essential components of primary health care. WHO actively encourages the proper use of food irradiation in the fight against foodborne diseases and food losses. To this end, it collaborates closely with FAO and IAEA. Food irradiation can have a number of beneficial effects, including delay of ripening and prevention of sprouting; control of insects, parasites, helminths, pathogenic and spoilage bacteria, moulds and yeasts; and sterilization, which enables commodities to be stored unrefrigerated for long periods. The 1990s witnessed a significant advancement in food irradiation processing. As a result, progress has been made in commercialization of the technology, culminating in greater international trade in irradiated foods and the implementation of differing regulations relating to its use in many countries. Codex General Standard for Irradiated Foodstuffs and Recommended International Code of Practice for the Operation of Irradiation Facilities Used for the Treatment of Foods regulate food irradiation at international level. At European Union level there are in power Directive 1999/2/EC and Directive1999/3/EC. Every particular country has also its own regulations regarding food irradiation. In Romania, since 2002 the Norms Regarding Foodstuffs and Food Ingredients Treated by Ionizing Radiation are in power. These Norms are in fact the Romanian equivalent law of the European Directives 1999/2/EC and 1999/3/EC. The greater international trade in irradiated foods has led to the demand by consumers that irradiated food should be clearly labeled as such and that methods capable of differentiating between irradiated and nonirradiated products should be available. Thus a practical basis was sought to allow consumers to exercise a free choice as to which food they purchase. If a

Food irradiation and its biological effects

International Nuclear Information System (INIS)

Shah, Alok; Nanjappa, C.; Chauhan, O.P.

2014-01-01

Irradiation of foods drew attention mostly in 1960s for disinfestation of food grains, spices and sprout inhibition in mainly potato and onion. γ-irradiation at 0.25 to 1 kGy dosage levels are usually used for irradiating grains, legumes, spices and sprout-prone vegetables. Irradiation of foods with in permissible dosage levels of 0.25 to 5 kGy is usually considered fairly safe from human consumption point of view not withstanding usual health concerns about its usage in foods. Irradiation of foods, in mostly solid or semi-solid form, at 5 kGy levels of γ-irradiation can achieve radicidation or, radiation equivalent of pasteurization and, if γ-irradiation is used at 10 kGy, it can achieve radappertization or, radiation equivalent of thermal commercial sterilization. However, the food industry uses γ-irradiation at 0.25 to 2 kGy only for mostly disinfestation of food grains/legumes, spices, sprout inhibition in potato and onion and, for surface sanitation of frozen fish, poultry and meat. Exposure to irradiation creates free radicals in foods that are capable of destroying some of the spoilage and pathogenic microflora but the same can also damage vitamins and enzymes besides creating some new harmful new chemical species, called unique radiolytic products (URPs), by combining with certain chemicals that a food may be laced with (like pesticides/fungicides). Exposure to high-energy electron beams are also known to create deleterious biological effects which may even lead to detection of trace amounts of radioactivity in the food. Some possible causes delineated for such harmful biological effects of irradiation include: irradiation induced vitamin deficiencies, the inactivity of enzymes in the foods, DNA damage and toxic radiolytic products in the foods. Irradiation, a non-thermal food preservation technique, has a role in salvaging enormous post harvest losses (25-30%) in developing economies to increase the per capita availability of foods. (author)

Biochemical and Tissue Studies on Post Irradiation Recovery in Mammals

International Nuclear Information System (INIS)

Abdou, M.I.M.

2004-01-01

three main studies were performed in this thesis, namely, mortality and survival study, biochemical studies, and studies on tissue alterations cobalt-60 gamma irradiation for low let was used for the external whole body irradiation of the irradiated animal groups. a total number of animals of 722 virgin female adult wister rats of approximately the same age and weight were used for the three studies that were performed, including the control and irradiated animal groups. the animals were housed and kept with special care at fixed temperature, humidity and diet. the study on mortality and survival included 370 animals divided into control and groups irradiated with 4,5,6,7,8 and 9 Gy. this study was followed up for one year to record the number and date of animal deaths for the different irradiated groups. for the 8 and 9 Gy irradiated groups the follow up ended after 12 weeks and 11 days respectively when animal mortality reached 100%. the maximum percent mortality was noted at the second week (3.3,8,14 and 29%) for the 4,5,6 and 7 Gy irradiated groups respectively. for the 8 and 9 Gy irradiated groups, the maximum percent mortality was noted at the first week (42.9 and 90% respectively). regression equations were applied for the percent of mortality of the 5-8 Gy irradiated groups to estimate the LD 50/30, which was found to be 6.4 Gy

Nitrogen compounds behavior under irradiation environment

International Nuclear Information System (INIS)

Ichikawa, Nagayoshi; Takagi, Junichi; Yotsuyanagi, Tadasu

1991-01-01

Laboratory experiments were performed to evaluate nitrogen compounds behavior in liquid phase under irradiation environments. Nitrogen compounds take a chemical form of ammonium ion under reducing condition by gamma irradiation, whereas ammonium ions are rather stable even under oxidizing conditions. Key reactions were pointed out and their reaction rate constants and activation energies were estimated through computer code simulation. A reaction scheme for nitrogen compounds including protonate reaction was proposed. (author)

A Practical Irradiance Model for Bifacial PV Modules: Preprint

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-15

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors (CFs) to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using the RADIANCE ray tracing program.

Histopathological investigation of radiation necrosis. Coagulation necrosis in the irradiated and non-irradiated brain tumors and in the normal brain tissue

Energy Technology Data Exchange (ETDEWEB)

Nakamura, N [Niigata Univ. (Japan). Brain Research Inst.

1977-01-01

Eighty four irradiated tumors (including 59 gliomas) and the surrounding brain tissue were analyzed. In 'normal' brain tissue, typical coagulation necrosis attributable to irradiation was observed in the cerebral white matter, presenting a whitish-yellow color but no remarkable changes in volume. Histologically there was complete desintegration of myelin and axon. Vascular changes included hyalinous thickening, concentric cleavage, fibrinoid degeneration, adventitial fibrosis and edema of small arteries, fibrin thrombi or occlusion of arterioles and capillaries, and telangiectasia of small veins and venules. While other tumors showed hyalinous or fibrous scar tissue and decrease in volume, the gliomas maintained their original volume without residual tumor cells. Massive coagulation necrosis was occasionally found even in full volume, non-irradiated gliomas (controls), although the changes were fewer and not so varied as in typical radiation necrosis. With small dosages, it was difficult to judge whether the necrosis was caused by irradiation or occurred spontaneously. Coagulation necrosis in tumor tissue was found in 25 of 59 cases (42%) of irradiated gliomas, but in only 2 of 49 cases (4%) of the nonirradiated gliomas. In 49 cases no coagulation necrosis of the surrounding tissue was found. Although histopathological judgement is difficult, it is suggested that there is a significant correlation between coagulation necrosis and irradiation. Discussion of the relationship between coagulation necrosis and NSD (nominal standard dose) led to the conclusion that coagulation necrosis will not be caused by irradiation of less than 1400 rets in NSD.

Gamma irradiation treatment of secondary sewage effluent

International Nuclear Information System (INIS)

Vajdic, A.H.

The operation and monitoring of a pilot scale Co-60 gamma irradiation unit treating secondary sewage effluent is described. The disinfecting efficiency of the unit is compared to that of an experimental 'ideal' chlorination unit and to the plant chlorination process. A cost estimate for disinfection by gamma irradiation on a full plant scale is included. (author)

Technological quality of irradiated Moroccan citrus fruits

International Nuclear Information System (INIS)

Moussaid El Idrissi, M.; R'Kiek, C.; Farahat Laaroussi, S.; Zantar; Mouhib, M.; El Guerrouj, D.; Toukour, L.

2002-01-01

The effect of irradiation at doses of 125, 250, 375, and 500 Gy, commonly used for quarantine treatment, on the quality of Maroc-late orange, the most common export variety of Morocco was investigated. In the first study fruits were irradiated without any previous cold conditioning treatment as practiced by the export trade for quarantine purposes. In the second study fruits obtained from the normal chain after conditioning was irradiated. Storage of irradiated fruits was studied at room temperature and 10 deg. C at 0 deg. C in case of control fruits. The parameters studied included juice yield, total solids, reducing and total sugars, total acids and volatile acids, dry weight and weight loss. The results showed that irradiation did not affect the technological quality of citrus fruits during four weeks storage. The result thus far points to the possibility for the successful application of irradiation as an alternative quarantine treatment to the classical methods, which result in browning of the peel. The browning phenomenon could be controlled by waxing and will be the subject of a future study. (author)

An analysis of food irradiation : genetic effects

International Nuclear Information System (INIS)

MacPhee, D.; Hall, W.

1988-01-01

A series of studies undertaken at the National Institute of Nutrition (NIN) in India in the 1970s reported the occurrence of polyploidy in bone-marrow or peripheral lymphocytes in a number of species, including children, fed on freshly irradiated wheat. Opponents of food irradiation use these studies as evidence that genetic damage is caused by the consumption of irradiated food. This review of those NIN studies and of the attempts to replicate them and of two other relevant studies concludes that the claim that consumption of irradiated food causes genetic damage has not been substantiated. Other researchers have been unable to replicate the NIN studies. Polyploidy appears to be a poor indicator of genetic damage and the NIN results are biologically implausible

Comparison of normal tissue dose with three-dimensional conformal techniques for breast cancer irradiation including the internal mammary nodes

NARCIS (Netherlands)

van der Laan, Hans Paul; Dolsma, Willemtje; van t Veld, Aart; Bijl, HP; Langendijk, JA

2005-01-01

PURPOSE: To compare the Para Mixed technique for irradiation of the internal mammary nodes (IMN) with three commonly used strategies, by analyzing the dose to the heart and other organs at risk. METHODS AND MATERIALS: Four different three-dimensional conformal dose plans were created for 30 breast

An introduction to the irradiation processing of foods

International Nuclear Information System (INIS)

Hackwood, S.

1991-01-01

The food industry has used a variety of methods over the years to preserve or extend the shelf life of food. These have included cooking, packaging, smoking, chilling, freezing, dehydrating and using chemical additives. More recently, ionising radiation has been used to extend the storage life of foods. More research has been focussed on the effects of irradiation on foods than has been directed at any other form of food processing. This research has spanned 40 years and has been carried out in many countries. Food irradiation can be used to: (a) inhibit the sprouting of vegetables; (b) delay the ripening of fruits; (c) kill insect pests in fruit, grains or spices; (d) reduce or eliminate food spoilage organisms; (e) reduce food poisoning bacteria on some meats and sea food products. This chapter includes sections on the historical background; general aspects of radiation; scientific, technological, microbiological and toxicological aspects of food irradiation; nutritional aspects of food irradiation; consumer attitudes; current status and legislation; labelling. It concludes that the relatively new process of preserving food by irradiation compliments rather than competes with the presently available traditional methods. (author)

Storage tests with irradiated and non-irradiated onions

International Nuclear Information System (INIS)