- Email: [email protected]
Reference neutron radiographs of nuclear reactor fuel
Modern real-time imaging systems may provide an excellent sensor for quantitative neutron radiographic measurements. The goal of this work is to develop an image processing approach that provides a quantitative relationship between grey scale and absorption over the entire image. The system removes the instrumental response of the sensor and the beam distribution and provides a direct contrast scale in units of micro-x, the effective absorption constant. The study has also been extended to develop a non-subjective approach to the evaluation of system quality and a means of predicting the level of hydrogen detectability as a function of total integrated fluence. A summary of data taken between 10/sup 6/to 10/sup 7/neutrons/era/sup 2/see is presented for varying integration times. Total system performance is summarized in a single figure of merit that predicts spatial and contrast sensitivity. 37862
Lindaay, J. T.; Jones, J.D.; Kauffman, C. W.
Real time neutron radiography a n d its' application to the study of internal combustion engines a n d fluid flow N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 579-586. D. Reidel Publishing Company Real time neutron radiography (RTNR) is now proving to be a valuable research tool in the study of hydrogenous fluid flow. Whereas neutron radiography compliments other forms of radiography by making it possible to image many objects and substances that otherwise can not be imaged, RTNR adds the important dimension of motion which greatly enhances the value of the technique. Further, video processing techniques used in real time radiography provide many ways in which the image can be enhanced and studied. The Phoenix Memorial Laboratory (PML) at the University of Michigan has recently developed and installed a facility dedicated to RTNR. The work at PML has shown that RTNR of dynamic events can provide information enabling the researcher to follow dynamic events that were previously impossible or impractical. 37861
Brenizer, J.S.; Hosticka, B.; Jenkins, R. W. Jr.; McRae, D.D.
37857
Ridal, A.; Ryan, N.E.
Neutron radiography of a l u m i n i n m alloy corrosion damage N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 463-472. D. Reidel Publishing Company The potential for neutron radiography to detect hydrogenous corrosion products in aircraft structures was examined using a series of naturally and artificially corroded aluminium alloy samples. The sensitivity of this technique for detecting corrosion damage was intiaUy assessed using the Moata reactor facility and commercial neutron radiography services. Neutron radiographs of the corroded samples were obtained using a portable accelerator and a californium- 252 isotope source. Reactor, accelerator and isotope neutron radiographs have been compared to assess the sensitivity of portable neutron sources. 37856
Rant, J.; llic, R.; Pregl, G.; Leskovar, P.; Znidar, B.
The sensitivity of neutron radiography for detection of aluminium corrosion products Neutron-Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 455-462. D. Reidel Publishing Company Within a feasibility study concerning the introduction of neutron radiography as a nondestructive method into the domestic aircraft industry and for the maintenance of domestic commercial civil aircraft, the sensitivity of this technique for detection of AI corrosion products was studied experimentally. The mass thickness of a large area surface corrosion deposit which could be easily detected through thick (1 - 2 era) AI slabs was found to be at least 0.02 g/era/sup 2/. The minimal detectable mass thickness of corrosion products depends on the relative amount of Al(OH)/sub 3/and A10(OH), moisture and possible organic materials in their composition and should be in the range of 0.01 - 0.02 g/cm/sup 2/.
An advanced video system for real-time neutron radiography N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 571-578. D. Reidel Publishing Company An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Reactor Facility and the Philip Morris Research Center. The system includes a neutron sensitive image intensifier with a modified video camera, a video timer, a special effects generator, a time base corrector, a high resolution video tape recorder and a digital image processor, The digital image processor permits quantitative analysis of the image with non-commercial as well as cc,mmercially supplied processing software. Each of the system components and other video accessories are discussed along with examples of their use.
Taniguchi, R.; Hiraoka, E.; Ono, A.; Sonoda, K.; Tazawa, S.; Nakanii, T. 37860
Statistical properties of real-time neutron radiographic image N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 555-562. D, Reidel Publishing Company The statistical quality of raw images produced by neutron radiography is very poor. The statistical properties of neutron images obtained from the cyclotron-based real-time neutron radiography system of Sumitomo Heavy Industries, Ltd., have been analysed using a set of LiF/ZnS(Ag) screens and high sensitive television camera. The distribution of image intensity at a constant neutron flux domain is represented well by a Poisson distribution and ripple noises appearing in the real-time image can be attributed to the fluctuation of the distribution of neutron flux. These suggest that some digital image processing techniques based on a local statistical method would be effective for a ruffled image like real-time neutron radiography. Some of the examples using contrast stretching, median filter etc. are also presented. 37859
Matsumoto, G.; Ohkubo, K,; lkeda, Y.
Real-time imaging with less intense neutron beam N e u t r o n Radiography, Proceedings of the Second World Conference, Pads (France), 16-20 Jun. 1986. pp. 547-554. D. Reidel Publishing Company Real-time imaging was attempted with small and weak neutron sources. A separate type of imaging system using an image orthicon tube was assembled for the tests. The neutron fluxes available at the exposure plane for these sources were 3 x 10/sup 3/to 3 x 10/sup 5/n/cm/sup 2/.s. Dynamic motions of samples could not be obtained at fluxes of less than 10/sup 4/n/cm/sup 2Ls. But at 10/sup 5/n/ern/sup 2/.s, fairly good neutron television images of dynamic motions were obtained. Image processing by electronic computers was very effective in improving image quality. 37858
Fischer, C.-O,; Laurenze, C.; Leuther, W.; Slusallek, K.
Autoradiography of oil paintings at the Berlin Experimental Reactor (BER II) N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 519-526. D. Reidel Publishing Company As part of the international research by art-historians about Rembrandt and his time, 15 paintings of the Gemaldegalerie in Berlin have been investigated by neutron activation autoradiography. The improved experimental technique is explained and results are described for a painting by Jan Vermeer van Delft.
NDT International August 1989
37855
Kedem, D.; Polichar, R.; Orphan, V.; Shreve, D.
Neutron imaging with low-intensity neutron sources N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 439-446, D, Reidel Publishing Company The performance of low intensity thermal neutron field radiography depends on the quality of the imaging system and the intensity and quality of the neutron beam. Therefore, the configuration and composition of the neutron moderator/collimator assembly were analyzed and optimized. The imaging system was designed to achieve maximum performance for the thermal neutron flux obtained. 37854 Bakker, J.; Baritello, A.; Beers, M.; Bordo, J.; Conrad, R.; Loelgen, R.; Markgraf, J.F. W.; Zeisser, P.
Neutron radiography of irradiation devices at the High Flux Reactor Petten N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 395-406. D. Reidel Publishing Company As a part of the irradiation testing programmes at the High Flux Reactor (HFR) Petten, neutron radiography is used for quality assurance and inspection of irradiation devices. The equipment, methods and typical results related to neutron radiography of irradiation devices at HFR are presented. The unique non-destructive test capability and importance of neutron radiography is shown for some representative applications.
Bakker, J.; Baritello, A.; Bordo, J.; Markgraf, J.F. W.; Leeflang, H.P.; Ruyter, L 37853
Neutron radiography of fight water reactor fuel rods at the High Flux Reactor Petten N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 381-394. D. Reidel Publishing Company Within the Light Water Reactor (LWR) fuel rod testing programmes at the High Flux Reactor, Petten (HFR) where more than 200 individual fuel rod tests have been performed -neutron radiography is an important and unique non-destructive test technique. Equipment, methods and typical results related to neutron radiography of LWR fuel rods at HFR are presented. The importance of neutron radiography is shown for some representative cases, addressing the condition of the fuel rod and fuel stack. 37852
Domanus, J. C.
Reference neutron radiographs of nuclear reactor fuel N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 375-380. D. Reidel Publishing Company Reference neutron radiographs of nuclear reactor fuel were produced by the Euratom Neutron Radiography Working Group and published in 1984 by the Reidel Publishing Company. In this collection a classification is given of the various neutron radiographic findings, that can occur in different parts of pelletized, annular and vibro-compacted nuclear fuel pins. Parts of the pins are shown where there are changes from their appearance at fabrication. Radiographs of these fabricated parts are included. The collection contains 158
247
neutron radiographs, reproduced on photographic paper (twice enlarged) and on duplicating film (original size). 37851
Moss, R.L.; Beers, M.
Use of epithermal neutron radiography to determine the extent of melting in mixed oxide LMFBR fuel pins i r r a d i a t e d in High Flux Reactor, Pctten N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 349-358. D. R e i d e l P u b l i s h i n g Company A series of mixed oxide fuel pins are being irradiated in the High Flux Reactor (HFR) at Petten. One of the aims of the experiments is to determine the extent of melting of the fuel under various operational conditions, including transients. By means of a cadmium filter inserted in the collimator of the reactor's neutron radiography installation, it is possible to create a source of predominately epithermal neutrons. This enables sufficient penetrations of neutrons through the fuel and produces on film distinct images of fuel melt patterns. The paper highlights some of the more revealing results within the present irradiation series. 37850
Domanus, J. C.
Euratom neutron radiography working group N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 339-348. D. R e i d e l P u b l i s h i n g Company In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Euratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Ad-hoc sub- groups on different topics within the field of neutron radiography are constituted. This paper reviews the actix;ities and achievements of the NRWG and its sub-groups. 37849
Aderhold, H.C.; Hover, K.C.," Najjar, W.S.
The Cornell neutron radiography facility and its applications to the study of the internal structure and microcracking of concrete N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 321-328. D. R e i d e l P u b l i s h i n g Company The horizontal thermal column of the Cornell University TRIGA Mark II reactor has been adapted for neutron radiography and is described in this paper. Both a gadolinium and a gadolinium oxy-sulfide screen have been used to study concrete, and results are compared. Internal discontinuities e.g. microcracks (small fractures) and air voids have been successfully identified due to their partial impregnation with a gadolinium nitrate contrast agent. Gadolinium oxide has also been used as a contrast agent, but it was successful only in identifying air voids. A neutron radiography of a nitrate impregnated specimen is compared with x-radiographs of the same specimen with and without impregnation. Neutron radiography seems much more effective in identifying microcracks than either x-radiograph. Practical applications are suggested.
Ikeda, Y.; Ohkubo, K.; Suzuki, H.; Tomatsu, Y.; Matsumoto, G.
37848
An evaluation of neutron radiography for non-destructive testing of defects N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 305-312. D. R e i d e l P u b l i s h i n g Company Neutron radiography (NR) for non-destructive testing (NDT) of defects in structural materials was studied. Sensitivities and resolutions for various combinations of converters and emulsion films were measured and evaluated. Some defect indicators were prepared and imaged with NR to obtain practically usable data for NDT for steels and plastics. Very fine fatigued cracks in steels were detected by using a simple image- enhancement technique. In order to obtain clearer images from blurred ones, a computer reconstruction technique was developed.
37847 Attwood, P.A.; Swift, P. Cold neutron radiography of mechanical connectors N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 281-294. D. R e i d e l P u b l i s h i n g Company The cold neutron radiography facility at Harwell has been used to investigate possible causes of serious corrosion and mechanical damage to a number of mechanical connectors installed on Shell Expro North Sea platforms. To date, neutron radiography has revealed that the elastomeric O-ring seals which are designed to prevent seawater ingress into the connector, can be displaced from their groove during assembly, resulting in severe O-ring distortion and crushing, and thereby causing ineffective sealing. Split O-rings and incomplete O-ring compression are features which have also been observed during the course of the neutron radiographic studies. Furthermore, the technique can be used to detect internal joint corrosion located within the relatively thick metal walls of the joints.
248
Tazawa, S.; Yano, M.; Nakanii, T.; Hiraoka, E.; Taniguchi, R.; Tsuji, Y.; Furuta, J. 37846
Cyclotron-based neutron radiography facility N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 231-238. D. R e i d e l P u b l i s h i n g Company Neutron radiography is not widely used yet due to a lack of high intense thermal neutron source which are convenient and economical. A new neutron radiography facility, installing a sub-compact cyclotron accelerating 18 MeV proton and equipped with both vertical and horizontal ports, is presented. Typical neutron intensity at the collimator end of L/D = 30 is 1.1 x 10/sup 6/ n/cm/sup 2//see with a field size of 14 x 17 and used mainly for real-time experiments. Prior to the construction, preliminary experiments were performed by using a proton beam from a high energy cyclotron to investigate thermal neutron intensity and neutron radiography image quality at several energy points. By optimization of neutron intensity and cost, a new facility using a 30 MeV proton cyclotron with neutron flux of 5 x 10/sup 6/n/cm/sup 2//see at field size of 14 x 17 is proposed.
Fukushima, Y.; Nakamura, T. Hiraoka, E.; Sekita, J.; Yokochi, H.; Yamada, T.; Yamaki, S.
37845
Neutron radiography using ultra-compact cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 215-222. D. R e i d e l P u b l i s h i n g Company Neutron radiography testing was performed with an ultracompact cyclotron named BABY CYCLOTRON which produces 16 MeV protons./sup 9/Be (p,n) /sup 9/B reaction was applied for the neutron source. The collimation system has two collimators arranged horizontally, each having cross section 14 in. x 17 in., L/D ratio : 52, and thermal neutron flux of 3 x 10/sup 5/n/cm/sup 2/.s was applied at the object. Radiographic image qualities have shown very useful results and inspection of explosive devices have been carried out. 37844
Wilson, M.N.; Finlan, M.F.
The superconducting cyclotron as a transportable neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 199-206. D. R e i d e l P u b l i s h i n g Company Oxford Instruments, working in close collaboration with Amersham International, are developing a compact lightweight superconducting cyclotron. Although primarily intended for use as a local generator of short lived isotopes for PET microcomputer the same machine could also be made into a neutron generator by directing the extracted proton beam onto a beryllium target. With a proton energy of 17 MeV and a beam current of 200 micro A, the expected total neutron yield is 1.8 x 10/sup 13/neutrons/see. Using a moderator of high density polythene, this total output may be transformed into thermal neutron flux of about 1.8 x 10/sup 11/n era/sup -2/s/sup -1/. With a weight of just 200 kg, the source will be fully transportable using quite simple mechanical handling equipment. 37843
Jin Si-Kwon; Whittemore, W.L.
Neutron radiography with Van De Graaff neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 191-198. D. R e i d e l P u b l i s h i n g Company An neutron radiograph (NR) system was installed in 1983 to produce routine high quality neutron radiographs with a Van de Graaff neutron source. Two divergent beam ports emerge on opposite sides of the moderator. Two shielded walk-in cells are provided for radiography. Special features of the moderator are of interest. The moderator is especially contoured and constructed to permit at least two modes of operation: in one, a high quality NR beam is produced with a very low content of gamma rays; in the other, the NR beam contains a greatly increased fraction of very highly collimated gamma rays. For some NR objects, the compound beam compared to an essentially pure neutron beam offers particular advantages for radiographic imaging. 37842
Hawkesworth, M.R.
Reactor-quality neutron radiographs with a new mobile machine - a superconducting magnet cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 183-190. D. R e i d e l P u b l i s h i n g Company The neutron radiographic performance of a new mobile cyclotron from Oxford Instruments Limited, which uses superconducting magnet technology, is assessed. It is concluded that thermal neutron beams comparable with those from some reactors used for neutron radiography are achievable (10/sup 5/n.cm/sup -2/s/sup-I/ at L/D = 250), and radiographs of reactor quality will therefore be available from a mobile source for the first time. There are moreover, no major technical disadvantages to militate against the cyclotron's clear neutronic advantage over other mobile sources. The machine, moderator system and immediate shielding are readily transportable as a whole, the technologies involved are all proven and reliable, and the use of the Be(p,n) reaction offers a durable target and beams with low photon contamination. 37841
Steichele, E.; Gutsmiedl, E.
A conically divergent radiography
guide tube
as a collimator
for neutron
N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e ,
NDT International August 1989
Lindaay, J. T.; Jones, J.D.; Kauffman, C. W.
Real time neutron radiography a n d its' application to the study of internal combustion engines a n d fluid flow N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 579-586. D. Reidel Publishing Company Real time neutron radiography (RTNR) is now proving to be a valuable research tool in the study of hydrogenous fluid flow. Whereas neutron radiography compliments other forms of radiography by making it possible to image many objects and substances that otherwise can not be imaged, RTNR adds the important dimension of motion which greatly enhances the value of the technique. Further, video processing techniques used in real time radiography provide many ways in which the image can be enhanced and studied. The Phoenix Memorial Laboratory (PML) at the University of Michigan has recently developed and installed a facility dedicated to RTNR. The work at PML has shown that RTNR of dynamic events can provide information enabling the researcher to follow dynamic events that were previously impossible or impractical. 37861
Brenizer, J.S.; Hosticka, B.; Jenkins, R. W. Jr.; McRae, D.D.
37857
Ridal, A.; Ryan, N.E.
Neutron radiography of a l u m i n i n m alloy corrosion damage N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 463-472. D. Reidel Publishing Company The potential for neutron radiography to detect hydrogenous corrosion products in aircraft structures was examined using a series of naturally and artificially corroded aluminium alloy samples. The sensitivity of this technique for detecting corrosion damage was intiaUy assessed using the Moata reactor facility and commercial neutron radiography services. Neutron radiographs of the corroded samples were obtained using a portable accelerator and a californium- 252 isotope source. Reactor, accelerator and isotope neutron radiographs have been compared to assess the sensitivity of portable neutron sources. 37856
Rant, J.; llic, R.; Pregl, G.; Leskovar, P.; Znidar, B.
The sensitivity of neutron radiography for detection of aluminium corrosion products Neutron-Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 455-462. D. Reidel Publishing Company Within a feasibility study concerning the introduction of neutron radiography as a nondestructive method into the domestic aircraft industry and for the maintenance of domestic commercial civil aircraft, the sensitivity of this technique for detection of AI corrosion products was studied experimentally. The mass thickness of a large area surface corrosion deposit which could be easily detected through thick (1 - 2 era) AI slabs was found to be at least 0.02 g/era/sup 2/. The minimal detectable mass thickness of corrosion products depends on the relative amount of Al(OH)/sub 3/and A10(OH), moisture and possible organic materials in their composition and should be in the range of 0.01 - 0.02 g/cm/sup 2/.
An advanced video system for real-time neutron radiography N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 571-578. D. Reidel Publishing Company An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Reactor Facility and the Philip Morris Research Center. The system includes a neutron sensitive image intensifier with a modified video camera, a video timer, a special effects generator, a time base corrector, a high resolution video tape recorder and a digital image processor, The digital image processor permits quantitative analysis of the image with non-commercial as well as cc,mmercially supplied processing software. Each of the system components and other video accessories are discussed along with examples of their use.
Taniguchi, R.; Hiraoka, E.; Ono, A.; Sonoda, K.; Tazawa, S.; Nakanii, T. 37860
Statistical properties of real-time neutron radiographic image N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 555-562. D, Reidel Publishing Company The statistical quality of raw images produced by neutron radiography is very poor. The statistical properties of neutron images obtained from the cyclotron-based real-time neutron radiography system of Sumitomo Heavy Industries, Ltd., have been analysed using a set of LiF/ZnS(Ag) screens and high sensitive television camera. The distribution of image intensity at a constant neutron flux domain is represented well by a Poisson distribution and ripple noises appearing in the real-time image can be attributed to the fluctuation of the distribution of neutron flux. These suggest that some digital image processing techniques based on a local statistical method would be effective for a ruffled image like real-time neutron radiography. Some of the examples using contrast stretching, median filter etc. are also presented. 37859
Matsumoto, G.; Ohkubo, K,; lkeda, Y.
Real-time imaging with less intense neutron beam N e u t r o n Radiography, Proceedings of the Second World Conference, Pads (France), 16-20 Jun. 1986. pp. 547-554. D. Reidel Publishing Company Real-time imaging was attempted with small and weak neutron sources. A separate type of imaging system using an image orthicon tube was assembled for the tests. The neutron fluxes available at the exposure plane for these sources were 3 x 10/sup 3/to 3 x 10/sup 5/n/cm/sup 2/.s. Dynamic motions of samples could not be obtained at fluxes of less than 10/sup 4/n/cm/sup 2Ls. But at 10/sup 5/n/ern/sup 2/.s, fairly good neutron television images of dynamic motions were obtained. Image processing by electronic computers was very effective in improving image quality. 37858
Fischer, C.-O,; Laurenze, C.; Leuther, W.; Slusallek, K.
Autoradiography of oil paintings at the Berlin Experimental Reactor (BER II) N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 519-526. D. Reidel Publishing Company As part of the international research by art-historians about Rembrandt and his time, 15 paintings of the Gemaldegalerie in Berlin have been investigated by neutron activation autoradiography. The improved experimental technique is explained and results are described for a painting by Jan Vermeer van Delft.
NDT International August 1989
37855
Kedem, D.; Polichar, R.; Orphan, V.; Shreve, D.
Neutron imaging with low-intensity neutron sources N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 439-446, D, Reidel Publishing Company The performance of low intensity thermal neutron field radiography depends on the quality of the imaging system and the intensity and quality of the neutron beam. Therefore, the configuration and composition of the neutron moderator/collimator assembly were analyzed and optimized. The imaging system was designed to achieve maximum performance for the thermal neutron flux obtained. 37854 Bakker, J.; Baritello, A.; Beers, M.; Bordo, J.; Conrad, R.; Loelgen, R.; Markgraf, J.F. W.; Zeisser, P.
Neutron radiography of irradiation devices at the High Flux Reactor Petten N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 395-406. D. Reidel Publishing Company As a part of the irradiation testing programmes at the High Flux Reactor (HFR) Petten, neutron radiography is used for quality assurance and inspection of irradiation devices. The equipment, methods and typical results related to neutron radiography of irradiation devices at HFR are presented. The unique non-destructive test capability and importance of neutron radiography is shown for some representative applications.
Bakker, J.; Baritello, A.; Bordo, J.; Markgraf, J.F. W.; Leeflang, H.P.; Ruyter, L 37853
Neutron radiography of fight water reactor fuel rods at the High Flux Reactor Petten N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 381-394. D. Reidel Publishing Company Within the Light Water Reactor (LWR) fuel rod testing programmes at the High Flux Reactor, Petten (HFR) where more than 200 individual fuel rod tests have been performed -neutron radiography is an important and unique non-destructive test technique. Equipment, methods and typical results related to neutron radiography of LWR fuel rods at HFR are presented. The importance of neutron radiography is shown for some representative cases, addressing the condition of the fuel rod and fuel stack. 37852
Domanus, J. C.
Reference neutron radiographs of nuclear reactor fuel N e u t r o n Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 375-380. D. Reidel Publishing Company Reference neutron radiographs of nuclear reactor fuel were produced by the Euratom Neutron Radiography Working Group and published in 1984 by the Reidel Publishing Company. In this collection a classification is given of the various neutron radiographic findings, that can occur in different parts of pelletized, annular and vibro-compacted nuclear fuel pins. Parts of the pins are shown where there are changes from their appearance at fabrication. Radiographs of these fabricated parts are included. The collection contains 158
247
neutron radiographs, reproduced on photographic paper (twice enlarged) and on duplicating film (original size). 37851
Moss, R.L.; Beers, M.
Use of epithermal neutron radiography to determine the extent of melting in mixed oxide LMFBR fuel pins i r r a d i a t e d in High Flux Reactor, Pctten N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 349-358. D. R e i d e l P u b l i s h i n g Company A series of mixed oxide fuel pins are being irradiated in the High Flux Reactor (HFR) at Petten. One of the aims of the experiments is to determine the extent of melting of the fuel under various operational conditions, including transients. By means of a cadmium filter inserted in the collimator of the reactor's neutron radiography installation, it is possible to create a source of predominately epithermal neutrons. This enables sufficient penetrations of neutrons through the fuel and produces on film distinct images of fuel melt patterns. The paper highlights some of the more revealing results within the present irradiation series. 37850
Domanus, J. C.
Euratom neutron radiography working group N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 339-348. D. R e i d e l P u b l i s h i n g Company In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Euratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Ad-hoc sub- groups on different topics within the field of neutron radiography are constituted. This paper reviews the actix;ities and achievements of the NRWG and its sub-groups. 37849
Aderhold, H.C.; Hover, K.C.," Najjar, W.S.
The Cornell neutron radiography facility and its applications to the study of the internal structure and microcracking of concrete N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 321-328. D. R e i d e l P u b l i s h i n g Company The horizontal thermal column of the Cornell University TRIGA Mark II reactor has been adapted for neutron radiography and is described in this paper. Both a gadolinium and a gadolinium oxy-sulfide screen have been used to study concrete, and results are compared. Internal discontinuities e.g. microcracks (small fractures) and air voids have been successfully identified due to their partial impregnation with a gadolinium nitrate contrast agent. Gadolinium oxide has also been used as a contrast agent, but it was successful only in identifying air voids. A neutron radiography of a nitrate impregnated specimen is compared with x-radiographs of the same specimen with and without impregnation. Neutron radiography seems much more effective in identifying microcracks than either x-radiograph. Practical applications are suggested.
Ikeda, Y.; Ohkubo, K.; Suzuki, H.; Tomatsu, Y.; Matsumoto, G.
37848
An evaluation of neutron radiography for non-destructive testing of defects N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 305-312. D. R e i d e l P u b l i s h i n g Company Neutron radiography (NR) for non-destructive testing (NDT) of defects in structural materials was studied. Sensitivities and resolutions for various combinations of converters and emulsion films were measured and evaluated. Some defect indicators were prepared and imaged with NR to obtain practically usable data for NDT for steels and plastics. Very fine fatigued cracks in steels were detected by using a simple image- enhancement technique. In order to obtain clearer images from blurred ones, a computer reconstruction technique was developed.
37847 Attwood, P.A.; Swift, P. Cold neutron radiography of mechanical connectors N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 281-294. D. R e i d e l P u b l i s h i n g Company The cold neutron radiography facility at Harwell has been used to investigate possible causes of serious corrosion and mechanical damage to a number of mechanical connectors installed on Shell Expro North Sea platforms. To date, neutron radiography has revealed that the elastomeric O-ring seals which are designed to prevent seawater ingress into the connector, can be displaced from their groove during assembly, resulting in severe O-ring distortion and crushing, and thereby causing ineffective sealing. Split O-rings and incomplete O-ring compression are features which have also been observed during the course of the neutron radiographic studies. Furthermore, the technique can be used to detect internal joint corrosion located within the relatively thick metal walls of the joints.
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Tazawa, S.; Yano, M.; Nakanii, T.; Hiraoka, E.; Taniguchi, R.; Tsuji, Y.; Furuta, J. 37846
Cyclotron-based neutron radiography facility N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 231-238. D. R e i d e l P u b l i s h i n g Company Neutron radiography is not widely used yet due to a lack of high intense thermal neutron source which are convenient and economical. A new neutron radiography facility, installing a sub-compact cyclotron accelerating 18 MeV proton and equipped with both vertical and horizontal ports, is presented. Typical neutron intensity at the collimator end of L/D = 30 is 1.1 x 10/sup 6/ n/cm/sup 2//see with a field size of 14 x 17 and used mainly for real-time experiments. Prior to the construction, preliminary experiments were performed by using a proton beam from a high energy cyclotron to investigate thermal neutron intensity and neutron radiography image quality at several energy points. By optimization of neutron intensity and cost, a new facility using a 30 MeV proton cyclotron with neutron flux of 5 x 10/sup 6/n/cm/sup 2//see at field size of 14 x 17 is proposed.
Fukushima, Y.; Nakamura, T. Hiraoka, E.; Sekita, J.; Yokochi, H.; Yamada, T.; Yamaki, S.
37845
Neutron radiography using ultra-compact cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 215-222. D. R e i d e l P u b l i s h i n g Company Neutron radiography testing was performed with an ultracompact cyclotron named BABY CYCLOTRON which produces 16 MeV protons./sup 9/Be (p,n) /sup 9/B reaction was applied for the neutron source. The collimation system has two collimators arranged horizontally, each having cross section 14 in. x 17 in., L/D ratio : 52, and thermal neutron flux of 3 x 10/sup 5/n/cm/sup 2/.s was applied at the object. Radiographic image qualities have shown very useful results and inspection of explosive devices have been carried out. 37844
Wilson, M.N.; Finlan, M.F.
The superconducting cyclotron as a transportable neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 199-206. D. R e i d e l P u b l i s h i n g Company Oxford Instruments, working in close collaboration with Amersham International, are developing a compact lightweight superconducting cyclotron. Although primarily intended for use as a local generator of short lived isotopes for PET microcomputer the same machine could also be made into a neutron generator by directing the extracted proton beam onto a beryllium target. With a proton energy of 17 MeV and a beam current of 200 micro A, the expected total neutron yield is 1.8 x 10/sup 13/neutrons/see. Using a moderator of high density polythene, this total output may be transformed into thermal neutron flux of about 1.8 x 10/sup 11/n era/sup -2/s/sup -1/. With a weight of just 200 kg, the source will be fully transportable using quite simple mechanical handling equipment. 37843
Jin Si-Kwon; Whittemore, W.L.
Neutron radiography with Van De Graaff neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 191-198. D. R e i d e l P u b l i s h i n g Company An neutron radiograph (NR) system was installed in 1983 to produce routine high quality neutron radiographs with a Van de Graaff neutron source. Two divergent beam ports emerge on opposite sides of the moderator. Two shielded walk-in cells are provided for radiography. Special features of the moderator are of interest. The moderator is especially contoured and constructed to permit at least two modes of operation: in one, a high quality NR beam is produced with a very low content of gamma rays; in the other, the NR beam contains a greatly increased fraction of very highly collimated gamma rays. For some NR objects, the compound beam compared to an essentially pure neutron beam offers particular advantages for radiographic imaging. 37842
Hawkesworth, M.R.
Reactor-quality neutron radiographs with a new mobile machine - a superconducting magnet cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 183-190. D. R e i d e l P u b l i s h i n g Company The neutron radiographic performance of a new mobile cyclotron from Oxford Instruments Limited, which uses superconducting magnet technology, is assessed. It is concluded that thermal neutron beams comparable with those from some reactors used for neutron radiography are achievable (10/sup 5/n.cm/sup -2/s/sup-I/ at L/D = 250), and radiographs of reactor quality will therefore be available from a mobile source for the first time. There are moreover, no major technical disadvantages to militate against the cyclotron's clear neutronic advantage over other mobile sources. The machine, moderator system and immediate shielding are readily transportable as a whole, the technologies involved are all proven and reliable, and the use of the Be(p,n) reaction offers a durable target and beams with low photon contamination. 37841
Steichele, E.; Gutsmiedl, E.
A conically divergent radiography
guide tube
as a collimator
for neutron
N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e ,
NDT International August 1989