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
Paris (France), 16-20 Jun. 1986. pp. 151-160. D. Reidel Publishing
Company
Neutron guides are useful collimators for radiography, because they produce
pure neutron beams of high intensity. For wavelengths beyond 5 A, however,
the divergency of neutrons from a nickel coated guide tube is too large for high
resolution radiography. An essential improvement can be obtained with a
conically divergent guide. Due to garland- and zig-zag-refiections in a curved
guide differences in the neutron divergency of different wavelength can be
equalized.
Abdul Ghaffar Ramli; Azali Muhamad; Rosly Jaafar;
Sheriffa Noor Khamseah.
37840
Status of neutron radiography in Malaysia
Neutron Radiography, Proceedings of the Second World Conference,
Paris (France), 16-20 Jun. 1986. pp. 69-78. D. Reidel Publishing
Company
The development of neutron radiography (NR) in Malaysia began with the
availability of the country's first research reactor. The Reaktor TRIGA
PUSPATI (RTP) was commissioned in June 1982 and plans to construct the
neutron radiography facility commenced soon after that. In late 1983, a NR test
facility (NuR 1) was constructed out of small modular concrete blocks. Tests
carried out in this facility enabled the design of the permanent facility (NuR 2) to
be finalized. The construction of NuR 2 took place in November 1984 and it was
completed in February 1985. NuR 2 is now actively used in developmental work
in NR to ensure that an efficient local NR service can be given in the near future.
A number of shortcomings in the design of NuR 2 have been identified, and
efforts to rectify these are under way.
37839 Markgraf, J.F. W.
Neutron radiography working group (NRWG)
Neutron Radiography, Proceedings of the Second World Conference,
Paris (France), 16-20 Jun. 1986. pp. 59-68. D. Reidel Publishing
Company
This contribution briefly summarizes the activities and publications of the
Neutron Radiography Working Group (NRWG). This group was constituted in
1979 under the auspices of the Commission of the European Communities. The
members are experts in neutron radiography associated with nuclear research
centres within the European Communities. The main tasks of NRWG are the
coordination of common interest activities in the field of neutron radiography
and the promulgation of information and knowledge on neutron radiography,
e.g. by sponsoring international conferences and research projects, publication
of books, reports and an international newsletter on neutron radiography.
37838 Domanus, J. C.
International neutron radiography newsletter
Neutron Radiography, Proceedings of the Second World Conference,
Paris (France), 16-20 Jun. 1986. pp. 55-58. D. Reidel Publishing
Company
At the First World Conference on Neutron Radiography it was decided to
continue the Neutron Radiography Newsletter, published previously by J. P.
Barton, as the International Neutron Radiography Newsletter (INRNL), with
J.C. Domanos as editor. The British Journal of Non- Destructive Testing
(BJNDT) has agreed to publish the INRNL in its column NDT Bookcase. The
Revue Pratique de Control Industriel has also agreed to publish the French
version of the INRNL. Up till now 12 issues of the INRNL were published and
they are reviewed below.
37837 Underhill, P.E.
Industrial neutron radiography in the United States
Neutron Radiography, Proceedings of the Second World Conference,
Paris (France), 16-20 Jun. 1986. pp. 47-54. D. Reidel Publishing
Company
This paper covers the neutron radiographic activities in the industrial
community as experienced at Aerotest Operations over the last five years. A
brief description of the Aerotest facilities, the neutron beam, the physical
configuration and special capabilities are discussed. Several unique neutron
radiographic applications are described, including a specific weld inspection of
the vernier control engines for the space shuttle, the inspection of rubber
diaphragms used to pressurize the fuel for operating engines under zero gravity
conditions, the inspection of graphite phenolic blocks from which artificial hip
joints are machined, and special fixture designs.
37836 Moghadam, K.K.; Tabatabaeian, Z.; Mirhabibi, N.
Neutron radiography facility for AEOI nuclear research center
Neutron Radiography, Proceedings of the Second World Conference,
Paris (France), 16-20 Jun. 1986. pp. 25-32. D. Reidel Publishing
Company
Recently a Neutron Radiography System has been designed, constructed and
installed at the research reactor of Tehran Nuclear Research Center (TNRC).
The 6 inch through tube was chosen because of its low gamma intensity. A
collimator was made of two parts, iron and lead, which were covered thoroughly
with cadmium. Cylindrical slabs of bismuth and graphite of calculated lengths
were made to reduce gamma intensity and to thermalize fast neutrons
respectively. The collimated thermal flux is uniform in direction and intensity,
and at the reactor wall and thermal power of 1 MW, the beam has following
characteristics: Average thermal flux of 6.1 4/n/cm/sup 2/-see, cadmium ratio
(thermal per total activity) of 98% and neutron gamma ratio of 5 5/n/cm/sup
2/mR.
NDT International August 1989
37835 Mysak, F.; Krejci, M.
Comparison of neutron induced autoradiography by means of a
neutron source/sup 2 5 2 / C f and by a reactor
Isotoperpraxis, Vol. 23, No. 11, pp. 399-401
For study of distribution of several elements (mainly boron) in the brazed
joints of Ni-base alloys and for optimization of post-bond heat treatment of the
joints the neutron induced autoradiography (NIAR) using solid state nuclear
track detectors (SSNTD) has been applied. For a big isotopic neutron source
/sup 252/Cf a special hexagonal tank was constructed, which is filled with water
and in which walls the irradiation channels are placed. The comparative
autoradiographs of the same samples have been performed both on the isotopic
neutrons source/sup 252/Cf and the reactor SRO.
Anisimov, Yu.S.; Chernenko, S.P.; lvanov, A.B.;
Peshekhonov, V.D.; Smykov, L.P.; Zanevsky, Yu. V.; Knourek, J.;
Moucka, L.; Netusil, T.; Pellar, L.
37834
A device with a low-pressure multistep avalanche chamber for neutron
radiography
Isotopenpraxis, Vol. 23, No. 11, pp. 405-407 (Nov. 1987)
A device with a low-pressure multistep avalanche chamber for thermal
neutron imaging was developed and tested on a neutronographic beam of the
nuclear reactor. The device operates on-line with a minicomputer. The detection
efficiency of thermal neutrons is better than 3%, while the detection efficiency
of 60 keV gamma-quanta is less than 10/sup - 6/.
37833 Domanus, J. C.
International neutron radiography newsletter No 15 - N R W G Test
Program Part 1
British Journal of Nondestructive Testing, ¥o1. 30, No. 1, pp. 40-42
(Jan. 1988)
This report was prepared by Mr. J. C. Domanus, chairman of the Euratom
NRWG and project leader of the Test Program. It covers the first part of the
Test Program performed at Riso National Laboratory, Roskilde, Denmark,
under contract to the Commission of the European Communities (Joint
Research Centre, Petten).
37829 Antal, J.J.
A renaissance in neutron radiography via accelerator neutron sources
Materials Characterization for Systems Performance and Reliability.
Proceedings of the 31st Sagamore A r m y Materials Research
Conference, Lake Luzerne, New York (United States), 13-17 Aug.
1984. pp. 385-401. Plenum Press, 616 pp. (1986)
As a nondestructive inspection tool, neutron radiography could complement
the application of x-ray radiography to in-process inspection. However, the best
source of neutrons for this purpose is the nuclear reactor which is both
uneconomical and inconvenient to apply to the task. Small accelerator sources of
neutrons seem to be a way of bringing neutron radiography out of the reactor
and into the workplace. The recent successful demonstration of a mobile small
accelerator-based system has highlighted possible new applications for neutron
radiography. The paper includes a review of neutron radiography technology,
particularly the problem of finding an efficient and economical source of
neutrons.
37823 Brenizer J.S. Jr.; Gilpin, H.E.
Observations of unsaturated water flow using real-time neutron
radiography
Soil Science, Vol. 144, No. 2, pp. 122-127 (Aug. 1987)
Real-time neutron radiography was demonstrated to be a viable and useful
tool in studying water flow in unsaturated media. The experiment was designed
to test the method for following water flow. The wetting front advance,
water-flow patterns, and neutron attenuation density were observed in a 7.7-cm
diameter sand column. The advance was fit with a simple i = A t/sup B/equation
yielding an excellent correlation. Theoretical calculations presented estimate the
minimum and maximum detectable water content in various sizes of columns.
The ability of reai-time neutron radiography to allow both qualitative and
quantitative spatial and time measurements to be made in a nonintrusive manner
was demonstrated.
37601 Berger, H.
Neutron radiographic detection of corrosion
Corrosion Monitoring in Industrial Plants using Nondestructive
Testing and Electrochemical Methods. A symposium sponsored by
ASTM Committee E-7 on Nondestructive Testing and Committee G-1
on Corrosion of Metals, Montreal, Canada, 22-24 May 1984. pp. 5-16.
ASTM Special Technical Publication 908
Many nondestructive testing (NDT) methods for corrosion detection depend
on the reduced thickness of the component following corrosive attack. This is
normally the underlying concept for corrosion detection by NDT methods such
as X-radiography, ultrasonics, and eddy currents. For neutron radiography,
however, the basis for the detection is the neutron attenuation by the hydrogen
in the corrosion product itself. This difference in the approach gives neutron
radiography an advantage over many other NDT methods because of the
potential for early detection of corrosion, before extensive attack and thinning
of the material have occurred. Neutron radiographic methods are reviewed and
some initial results are given for corrosion detection in aluminum. Practical
neutron sources are becoming available and can be combined with established
image detectors, including reai-time detection systems. Corrosion in aluminum
resulting from a 6.5-h supersaturated salt-water spray is shown to be detectable.
249