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MICROCOPY RESOLUTION TEST CHART
NATIONAL BUREAU OF STANDARDS - 1963
LEGAL NOTICE
This report was prepared as an account of
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prepares, disseminates, or provides access
to, any information pursuant to his employ-
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his employment with such contractor.
JELLE
ORNLP 1188
CONF-658509-4
0XH1-AEC - OFFICIAL

LEGAL NOTICE
muo report no prepared u aa account of Covenant 1000rond work. Neither the Vallad
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A. Males may narraty or reprowautoa, exprewed or implied, with respect to the accu-
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An und in the abon, "pornou acting on behalf of the Commission" Laclode, any on-
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wu the Countealna, or kilo employment with such contractor.
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provides ruce. to, p
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went that
NONDESTRUCTIVE TESTING TECHNIQUES FOR RESEARCH AND PROCESS CONTROL*
D. A. Douglas, Jr., R. W. McClung, B. E. Foster, and C. V. Doda
Metals and Ceramics Division
Oak Ridge National laboratory
Oak Ridge, Tennessee, USA
ABSTRACT
Nondestructive test methods have been used primarily for the
detection of defects and rejection of faulty materials. The Oak Ridge
National Laboratory has found it valuable to employ special nondestructive
testing techniques as aids in materials research, component development,
and process control. This paper will show three 'recent examples of the
evolution of nondestructive testing techniques from research to process
control.
vibratorily compacted uranium and thorium oxide powder. A gamma attenu-
ation technique was developed to allow measurement of the homogeneity of
fuel loading and was used to aid development of fabrication techniques and
equipment. Later an inspection device was built to operate remotely in a
hermetically sealed and shielded facility and used for production process
control.
*Research sponsored by the U. S. Atomic Energy Commission under
contract with the Union Carbide Corporation.
C - OFFICIAL
PATENT CLEARANCE QETAINED. REUSSE
DE PUBLIC IS APPROVED. PROREDURA
CON ELLE IN THE REDBUYING SACI
ORNI -
ORHI-AIC - OFFICIAL
· Another fuel element required fuel plates containing a uranium oxide-
aluminum dispersion core with a programmed variation in the fuel loading
across the width. A continuous scanning, x-ray attenuation technique was
developed and used to measure fuel inhomogeneities and conformity to
design contour. The technique assisted the development for both core
pressing and plate rolling practices. A system was constructed for rapid
automatic evaluation of production fuel plates.
These fuel plates were pressed into involute shape and assembled
with alternate cooling channels. Stringent heat transfer requirements
imposed a tight tolerance on the channel dimensions. A unique eddy-
current device using the "lift-off" characteristic was invented to insert
in the very narrow channel and allow recording of dimensions both during
fabrication development and actual manufacture.
Another approach to fuel elements is the use of minute fuel-bearing
particles coated with pyrolytic carbon to retain the fission products.
Of concern are the core diameter, coating thickness and integrity, and
presence of fuel in the coating. Development of microradiographic tech-
niques has provided a powerful tool to evaluate the many variables in the
coating process for optimum fabrication. Further application allows eval-
uation of. the effects of service including heat treatment and in-reactor
testing. Results of these studies enhance realistic evaluation of
production lots and recycle of information to correct discrepancies.
INTRODUCTION
Nondestructive test methods have been used primarily for the
detection of defects and rejection of faulty materials. There is a
growing trend toward the application of these methods to monitor the
quality of manufactured products and use the attained information in
turn to modify or control the manufacturing process. The Oak Ridge
National Laboratory (ORNL) has found it valuable to develop and employ
special nondestructive testing techniques as aids in materials research
and component development for nuclear power reactors. Frequently the data
obtained from these techniques could not be derived in any other way.

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ORNI - AEC - OFFICIAL
OINI-AIC-Ois CIAL
After serving to obtain basic information and assisting in the determi-
nation of optimum fabrication procedures, the techniques can frequently
be adapted for process control and product evaluation during actual
manufacture.
The nor.destructive test development program at ORNL encompasses
many methods. Examples of recently completed work include gamma-ray
attenuation techniques for examining Lomogeneity in fuel rods, x-ray
attenuation to measure the content and distribution of uranium in fuel
plates, eddy-current devices for fuel-element coolant-channel spacing,
and a low-voltage microradiographic approach to the evaluation of minute
fuel particles. In each cited case the program started with materials
research and component development and continued into support of a manu-
facturing process.
EVALUATION OF FUEL RODS
About five years ago our Laboratory was faced with the probiem of
fabricating reactor fuel el.ements of thoria and urania (containing 233U).
These elements would need to be fabricated entirely inside a shielded
alpha-tight enclosure. A conceptual design for a complete process flow
sheet was formulated and ultimately over 1000 fuel rods were produced to
very rigid specifications. [1] One of the key developmental tasks
involved encapsulating the ceramic fuel in Zircaloy tubes. It was
decided that the best remote fabrication process would be to crush, size,
and blend the fuel and pour the ceramic powders into tubes. They would
be compacted by either electrodynamic or pneumatic shakers. Many questions
were to be answered during development of this technique. What particle
size distribution would provide the best compaction density? Which shaker
is superior, the pneumatic or the electrodynamic? How much does the
density vary along the length of fuel column in the tube? Foremost in
the mind of the engineer was how could he measure what occurred as he
changed the fabrication variables. We analyzed this problem and decided
that the attenuation of the gamma rays emitted by a 6°co source would
provide a sensitive measurement of changes in the compacted density of
ORNL - AEC - OFFICIAL
the fuel. Using a collimator to produce a focal spot of 3.2 mm (1/8 in.)
and a NaI crystal with a photomultiplier tube as the detector, we
constructed to aid in the fabrication research. The 6°co source is in
the large lead block and the detector is in the smaller overhead shielding.
Using our measurements to guide him, the engineer determined the optimum.
particle size distribution, learned that pneumatic shakers produced higher
densities than electrodynamic devices, and proved that fuel cersities
90% of theoretical could be routinely achieved.
General Principles
Lambert's Law is the basic principle of this inspection systeri,
although we prefer to use a modified coefficient which is based on mass
and is independent of the physical state of the absorder, rather than
the linear attenuation factor in Lambert's equation. Thus, for our
purposes we use
I/I. = exp(-x) :
where I is the incident intensity of the photon bean, I the transmitted
intensity of the photon beam, x is the thickness of the sample, yn is
the linear attenuation coefficient divided by the density of the absorber,
and p is the density of the absorber.
In the detection system, the sodium iodide crystal produces a
visible scintillation when struck by a transmitted photon. This scin-
tillation is detected by the photosensitive cathode of the photomultiplier
tube. Electrons are ejected and multiplied many thousand times, pro-
ducing a current pulse. This signal is integrated and fed to a strip-
chart recorder. The data are not readily interpretable unless they can
be compared with a standard. At first, an exact quantitative measurement
of the density was not needed, so we calibrated the system with a gold
foil whose thickness was calculated to provide an attenuation equivalent
to a 2% change in density.
Process Control
Once the fabricution cabineers rud fixed their parameters, the
second phase of the work commenceå. One specification was that no
single rod should deviate in average fuel density by more than any from
the mean density of the total lot. The mean density was selected as 8%.
A stricter requirement was that no area along the length of the ruel
column should deviate by more than 2 in density from the average for
the rod. To meet these requirements a scanner was obviously needed, as
part of the process line, to detect the rods that did not meet these
specifications. Thus, our objective charged from evaluation of research
to quality control.
Several new problemus emerged when we needed to design a. device for
process control. The gold foil was no longer and adequate standard. A
method was needed to integrate the signal at the recorder to provide the
engineer with data he could rapidly interpret, tests were needed to
determine the maximum scanning speed commensurate with the desired sensi-
tivity, and finally the system had to be mechanized so that it would
operate in a shielded facility. Figure 2 shows the finished equipment
reawy for installation.
The mechanical design for automatic indexing and traversing of the
rods was not difficult. We integrated the signal to obtain the averace
density by attaching a mechanical device to the slide wire of the strip-
chart recorder; also, an audible signal was added to ass16€ the operator
in recognizing undesirable rods. One of the most difficult tasks was to
prepare exact standards that would enable us to quantitatively measure
the density. We needed a size that would fit into a Zircaloy tube oi
the same dimensions as the fuel tube. Thus, the combined attenuation
effects of the cladding and the fuel would be reproduced. To vary the
density of a ceramic or a metal exactly and homogeneously was a difficult
task. Finally, our Ceramics Group was able to isostatically press satis-
factory pellets of thoria-urania, which ranged in density from 85 to 93%
in incremental changes of 2%.
We decided that two scans would be made on each rod 90° apart.
Because of the large number of rods to be inspected, scanning them very
FR
:
6
rapidly was desirable. However, our scanning speed is limited by the
recorder response time and by the beam intensity at the detector. The
latter is the most sericus restriction, particularly in this case,
because approximately 1.3 cm (0.5 in.) of very dense material was the
absorber. The statistical accuracy of the system for any spot on the
rod is related to the accumulated radiation as determined by the dwell
time and the intensity of the transmitted beam. One technique we used
to increase the effective scanning speed was to enlarge the collimator
And make a rectangular slot 3.2 x 9.5 mm (1/8 X 3/8 in.). This smoothed
out many of the irregularities produced by variations in fuel-particle
size but did rot appear to reduce the sensitivity. Nevertheless, we
had to limit the speed to 10 cm/min (4 in./min) to achieve an overall
accuracy of 1%.
The scanner operated very successruliy for over a year as one
unit of quality control in the process. The only operational difficulty
occurred when the photomultiplier tube rapidly lost sensitivity over a
period of only a few weeks. We thought that the level of gamma activity
in the cell might have curtailed its life. However, when we substituted
the same type of tube used in our laboratory machine no further difficulty
was encountered.
The use of our simple laboratory device for density measurement
helped the engineer solve his fabrication problems. It also provided
us with sufficient knowledge to optimize the design of a quality control
machine with very little extra development. The production unit demon-
strated its worth in routinely determining the quality of compacted fuel
rods.
FUEL HOMOGENEITY IN DISPERSION-CORE FUEL PLATES
During fabrication development for the High Flux Isotope Reactor
(HFIK) fuel element (2) we studied, developed,' and applied several non-
destructive testing methods to the evaluation of various fuel element
properties. The basic fuel-bearing unit is a 0.127 x 61 x approximately
10 cm (0.050 x 24 x 6 in.) plate with a nonsymmetrical fuel-bearing
section as shown in Fig. 3. The iuel is in the form of minute particles
of U308 interspersed with aluminum. This core section is then completely
encased and bonded within an aluminum frame and cladding. Each fuel
plate is formed into an involute in the width direction and 540 of these
plates are assembled into two annular assemblies. This fuel element,
designed to develop a very intense neutron flux in the center of the core,
will generate approximately 100 Mw of thermal power. Because of this
large rate of heat production, one of the requirements for a nondestruc-
tive testing technique was to provide assurance that the generation of
heat would be uniform, thus enhancing the reliability of the reactor core.
During fabrication development, a nummer of variables could affect the
achieved fuel homogeneity. These included the particle size distribution,
the particle blending, the die top design, techniques for filling the
die and pressing a core, and the detailed practices for rolling the
finished plate. Again we chose a radiation attenuation method 13) as
the optimum approach to evaluate the effect of each of these variables
and assist the selection of the proper fabrication procedure. . The
homogeneity evaluation required on the HFIR fuel plates included inspec-
tions to assure that no 2-mm-(5/64-in.-) diam spot exceeded the nominal
fuel loading by more than 30% as well as to assure that the average fuel
loading within any 2-mm- (5/64-in.-) wide x 1.3-cr- (1/2-in.-) long
than £10%. This stringent homogeneity requirement for such a small area,
3.1 mm2 (0.0048 in.) far exceeded that of any other known specification.
The necessity for 100% inspection of a large number of plates each day
demanded a rapid inspection method.
Theory
As noted earlier, x rays transmitted through a material are atten-
uated in accordance with the relation:
I = I, exp(2x) • .
The mass attenuation coefficient, une increases with increasing atomic
number and, in general, decreases with increasing X-ray energy. Under
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Oo
constant operating conditions, therefore, as the amount of high atomic
number material (uranium) in the dispersion core changes, the intensity
of the transmitted radiation will change. Appropriate calibration
techniques allow correlation of intensity change to fuel concentration
change.
Equipment
We used industrial x-ray equipment for the irradiation source.
Careful control of all operating conditions resulted in a very stable
and reproducible operation. The detection system for monitoring the
x-ray intensity changes consisted of a NaI(Tl) crystal optically coupled
to a photom_ltiplier tube. Figure 4 shows the system.
The collimator array restricts the primary beam to an appropriate
spot size on the specimen and prevents scattered radiation from reaching
the detector. Thus, as either the fuel concentration or the thickness
of the specimen changes, a corresponding fluctuation in the amount of
transmitted radiation is detected, amplified, and recorded.
Mechanical X-Y scanning of the plate was necessary to evaluate the
entire surface area. Figure 5 shows the system that we designed and
assembled to mount the radiation source and detector and to allow the
horizontal plate to be driven longitudinally through the radiation beam.
Transverse indexing was automatically programmed at the end of each
longitudinal scan.
Of course, the useful longitudinal scanning speeds are limited by
the instrumentation-response time and the beam intensity that can be
accurately sensed by the detector. The latter is a major consideration
in the determination of the statistical accuracy. Fuel plates have been
scanned for go-no-go inspections at a linear speed as high as 6.1 m/min
(240 in./min), but for strip-chart recording with full response for all
2-mm- (5/64 in.-) diam variations, the scanning speed has been apprɔxi-
mately 1.6 m/min (64 in./min). We selected wide-chart instruments des-
pite their slower response because of the need for extreme sensitivity
over the wide range of fuel concentration.
Calibration and Standards
As is true with most nondestructive tests, the measurement of
inhomogeneity required special standards to establish and calibrate the
technique. We had to establish a quantitative relationship between
changes in fuel concentration and X-ray attenuation. Pressed compacts
of U30g-Al were rolled into thin foils of different thickness having
various amounts of U308 per unit area. We then combined these foils
with an appropriate thickness of aluminum to simulate tota. thickness
of a fuel plate it discrete points across the fuel concentration gradient
in the core. Although these standards were not completely homogeneous,
'extensive scanning and integration of attenuation values coupled with
chemical analyses produced a relacively smooth curve relating fuel
content to instrument response. The fuel concentration gradient of
the HFIR plate, the concomitant requirement for recalibration at each
integral position across the width of the plate, and the need for singie-
point standardization for go-no-go inspections demanded the use of mate-
rials for standards that were very homogeneous and readily machinable.
We investigated several materials including tool steel, Al-13% U alloy
and 6061-T6 aluminum. The aluminum was selected because of its good
homogeneity, its ease of machining and the relaxed machining tolerances
that resulted from increased thicknesses for equivalent attenuation.
Each standard, since it was related to the changing values of attenuation
across the width of the fuel plate, had a contour that resembled the non-
symmetrical core shown in Fig. 3. These standards which were fabricated
to be equivalent in attenuation to the respective fuel concentrations of
nominal and +30% and +10% from nominal, were placed by each end of the
fuel plate. Thus, immediately before each successive scan was made, the
attenuation value for the go-no-go conditions was recorded or the strip
chart and/or used to set alarming circuitry. Then direct comparisons
could be made between the reference levels and the actual values on the
plate.
Results
We used the scanning system throughout the latter stages of the
development of the fuel plates, where it proved quite useful in evalu-
ating the effect of changes in the fabrication procedure. The system
was instrumental in altering the fabrication technique to reduce the
excessive accumulation of fuel at the ends of the finished fuel plate.
The effect of changing the particle size was graphically illustrated.
The system was used to obtain the values necessary to correct the die
tops in which the fuel cores are pressed. The scanner is also used
for rapia location of any fuel that is outside the maximum core outline.
Frequent checks with primary attenuation standards and occasional
comparison of predicted fuel content with chemical analyses indicate a
system accuracy of approximately +1%. The design criteria that we
developed on the versatile laboratory model enabled the building of one
pilot and two production scanners for evaluation of the HFIR production
cores. These latter three scanners incorporated X-Y plotters to allow
recording of out-of-tolerance conditions on . plan view.
COOLANT CHANNEL SPACING
Another problem facing the fabrication engineer on the HFIR fuel.
element was the assembly of the large number of plates while maintaining
careful control on the coolant channel space between plates. If this
spacing deviates excessively from the intended value, it would affect
the coolant flow and could cause excessive fuel plate temperature and
possible failure. We selected an eddy-current approach (4,5) as being
best for this measurement.
Principles
current, it produces an electromagnetic field. This field will induce
the flow of eddy currents in nearby electrical conductors. The eddy-
current flow, which is influenced by the electrical properties of the
specimen and the coil-to-specimen distance, will be a factor in
determining the electrical impedance of the eddy-current coil. Thus,
as the coil-to-specimen spacing changes, the coil impedance changes
correspondingly. Figure 6 shows a cross-sectional view of the probe
designed to use this principle for the measurement of coolant channel
spacing. The coil is mounted on a long thin metal strip which serves as
the insertion handle. Attached to the end of the tape is a metal leaf
spring, which is curved so that it overhangs the coil. When inserted in a
face and the spring pushes against the opposing surface. The electrical
excitation of the coil generates the eddy currents in the spring. Thus,
as the channel spacing varies, the movement of the leaf spring toward or
away from the coil will generate a change in the coil impedance that can
be calibrated in terms of the channel thickness.
Application
o
We used elementary hand-held probes throughout fabrication develop-
ment for measuring experimental fuel elements to reveal poor dimensional
control and to assist corrective measures. Figure 7 shows a probe being
inserted into a channel of a prototype HFIR fuel core. For dimensional
control on production cores a motor-driven inspection station was built
containing five probes for simultaneous multipoint measurement and con-
tinuous recording in a channel cross section. The accuracy of measure-
ment is a function of the total range of measurements but has been
demonstrated to be better than 0.025 mm (0.001 in.) 1.n this particular
application.
MICRORADIOGRAPHY OF MINUTE FUEL PARTICLES
Another approach to fuel elements is the use of minute fuel-bearing
particles that have been coated with pyrolytic carbon to retain the .
fission products. These materials seem very promising to the nuclear
industry because of their high-temperature, capabilities and good neutron
economy. Typical dimensions for such a specimen are a 0.15-mm (0.006-in.)
core and a 0:05-mm (0.002-in.) coating thickness. The coating is intended
ORNI - AEC - OFFICIAL

12
to prevent the fission products produced during reactor operation from
escaping into the coolant. To establish the overall quality of these
minute particles, new nondestructive testing techniques were necessary
for evaluating the coating thickness, fuel-particle shape, presence of
fuel in the coating, and integrity of both coating and cora. A micro-
radiographic technique (6,7) has been shown to be a powerful tool for
this. We have used the method to inspect fabricated particles for
acceptability and to evaluate the results of changes in manufacturing
procedure and of thermal and radiation proof-testing.
General Principles
The application of radiography to the evaluation of very small
coated particles required extensive modification of conventional tech-
niques. The radiographic method records on film the variation in radia-
tion absorption (which is energy dependent) across a specimen. To be
useful the absorption must vary enough for an interpretable contrast of
density to be achieved on the film or other detector. The very small
dimensions of the coated particles and the low absorption of radiation
by the pyrolytic carbon coating required the use of low-energy (low-
voltage) radiation.
Equipment and Materials
In the program we used commercial radiographic instrumentation
modified to provide better control over x-ray energy and exposure time.
The use of very low energy x rays made the presence of absorbers other
than the specimen most undesirable. Therefore, we needed to remove all
extraneous material that could cause, absorption, scattering, or uneven
filtration of the soft x-ray beam between the target and the detector
film. The radiation-absorbing material was removed by use of an x-ray
tube head containing a beryllium window only 0.2 mm thick and a helium-
filled chamber between the x-ray head and the specimen, since even air
effectively attenuates the x rays at the energy level required. The
helium was retained in the chamber by 0.0125-mm (0.0005-in.)
polyethylene diaphragms, which had no measurable effect on the x-ray
13
transmission. Figure 8 shows the 107-cn- (42-in.-) high chamber that
we used in the program. With the 1.5-mm (0.06-in.) focal spot, the
effective penumbral shadow contribution to unsharpness is approximately
0.3 H. Later we made a 47-cm- (18.5-in.-) high chamber that reduced the
exposure time to one-fourth but increased the penumbral shadow only to
0.6 M. Also we reduced unnecessary absorption by the use of bare photo-
graphic plates (without cassettes or film holders). This change
necessitated the use of darkroom exposure techniques.
We evaluated several different detectors and showed that the opti-
mum was high-resolution plates coated with an emulsion having a reported
resolution capability of 1,500 lines/mm (38,000 lines/in.). We viewed
radiographs on these plates at magnifications up to 500X with little
difficulty caused by emulsion grain size.
Of the several high-contrast fine-grained developing solutions
tested for the high-resolution plates, we found the standard x-ray film
developer to be as good as or betšer than any other solution tested and
to have the added advantage of being near the x-ray exposure room. con-
siderable care was exercised in handling and drying the high-resolution
plates to prevent undesirable artifacts caused by contamination.
Procedure
The particles were placed directly on the radiographic plate beneath
the helium chamber. The helium atmosphere was maintained in the chamber
with a very slight positive internal pressure retained by the thin
helium chamber, they were easily changed before and after exposure with-
out disturbing the helium in the chamber. With the available x-ray
exposure field, samples from a number of batches could be radiographed
simultaneously. The energy levels used for particle evaluation varied
up to about 10 kvp. A typical exposure included the following values:
10-kvp, 30-ma, 50-cm (20-in.) film-to-focus distance,, and 15-min exposure
detail or resolution in the plates is limited by electron diffusion in
the emulsion, which is rated at about 1 H at the energy level being used.
14
Transmitted light microscopy is used for viewing the radiographs
and for preparing photomicrographs.
Results
The technique has become a vital link in the development of ruel
particle technology. It is now regularly used in the evaluation of
as-fabricated particles for coating thickness and core diameter with
an accuracy better than I do Qualitative information is obtained about
the shape and integrity of the core and coatings and whether fuel has
migrated into the coating during fabrication. Figure 9 is a micro-
radiograph of particles selected to show many of these characteristics.
When particles are evaluated during and immediately after manufacture,
the desired information is used to make appropriate correction to coating-
gas mixture, the coating time, or temperature. This has been particularly
valuable when particles have been made with layers of coating of different
densities. Other applications have included the evaluation of all par-
ticles intended for in-pile testing. They are examined to assure the
removal of all imperfect particles to give added assurance of a success-
ful test. The technique has also assisted in determining the effects of
service testing such as heat treatment or in-pile testing. Figure 10
shows fuel migration detected after heat, treatment in a batch of par-
ticles.
Several fuel particles that han undergone as much as 6 at.
burnup were microradiographed. The radiation levels at contact were as
high as 3000 r/hr of beta and 120 r/hr of gamma. Slight modification
of the standard technique allowed valuable evaluation with only slight
loss of detail on these highly radioactive particles.
CONCLUSIONS
The projects that have been discussed show some of the benefits
that have been obtained at ORNL through the use of specially developed
nondestructive techniques. The valuable information derived during
the early stages of material research and the assistance provided in.
OXH1-MEC - OFFICIAL
15
revealing the effects of process variation in prototype component
development make this technology indispensable in research and develop-
ment. In addition there is usually much destructive analysis during
process development that can be correlated with nondestructive test
results. Therefore, when these tests are adapted for production con-
troi, the correlation will allow more intelligent interpretation of
data. As newer test methods are developed, these benefits will become
even more apparent in the future.
ORNI-A8C-OFFICIAL
REFERENCES
(1)
[2]
C. C. Haws, J. L. Matherne, F. W. Miles, and J. E. Vancleve,
ORNL-3681 (1964). Summary of the Kilorod Project - A Semiremote
1,0-kg/day Demonstration of 233UO 2-ThO 2 Fuel Element Fabrication
by the ORNL Sol-Gel Vibratory-compaction Method.
M. M. Martin, J. H. Erwin, and C. F. Leitten, Jr., Research Reactor
Fuel Element Conference, September 17–19, 1962, Gatlinburg, Tenn.,
TID-7642, pp. 268-289. Fabrication Development of the Involute-
Shaped High Flux Isotope Reactor Fuel Plates.
B. E. Foster, s. D. Snyder, and R. W. McClung, ORNL-3737 (1965).
continuous Scanning X-Ray Attenuation Technique for Determining
Fuel Inhomogeneities in Dispersion Core Fuel Plates.
C. V. Dodd and R. W. McClung, CRNL-TM-129 (March 1962). Fuel
Element Coolant Channel and Other Spacing Measurements vy day-
Current Techniques.
C. V. Dodd, ORNL-3580 (1964). Design and Construction of Eddy-
Current Coolant Channel Spacing Probes.
Gas-Cooled Reactor Program Quarterly Progress Report March 31, 1962,
ORNL-3302, pp. 165–167.
R. W. McClung, E. S. Bomar, and R. J. Gray, ORNL-3577 (1964). Use
of Microradiography Combined with Metallography for Evaluation of
coated Particles.
[4]
151
OXNI-AIC-ONDICIAL
FIGURES
Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
(ORAL Photo 65331) Gamma attenuation device used to assist
fabrication development of fuel rods.
(ORNL Photo 59560A) Gamma attenuation device used for process
control during manufacture of fuel rods.
(ORNL-LR-DWG 72235) Cross section of the High Flux Isotope
Reactor fuel plate.
(ORNL-LR-DWG 71127R2) Block diagram of the gamma-scintillation
detection system.
(ORNL Photo 60925) Mechanical scanning system for inhomogeneity
measurement in fuel plates.
(ORNL-LR-DWC 50492) Probe for measuring coolant-channel spacing
between fuel plates.
(ORNL Photo 49610) Measuring probe inserted in coolant channel
of prototype High Flux Isotope Reactor fuel core.
(ORNL Photo 65327) Equipment arranged for microradiography of
coated particles. Note helium chamber.
(Y-45429) Microradiograph of coated particles selected to show
different qualities of interest.
(Y-47861) Microradiograph of fuel particles showing fuel
migration after heat treatment.
Fig. 6.
Fig. 7.
Fig. 8.
Fig. 9.
Fig. 10.
IL-AEC-OFFICIAL
07:1-d!! -OISICIAL
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OR PL -MEC - OFFICIAL

Fig. 1. Gamma attenuation device used to assist fabrication
development of fuel rods.
w PHOTOMULTIPLIER
TUBE.
iv
TROLLEY
n:
FUEL ROD. :D
* --
COLLIMATORI
LEAD PIG CONTAINING
COGO SOURCES
-
Fig. 2. Gamma attenuation device used for process control during manufacture of fuel rods.
OEN! -Arrosiciel
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UNCLASSIFIED
ORNL-LR-DVG 72235
CLADDING
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O*NI-AC - OFFICIAL
Fig. 3. Cross Section of the High Flux Isotope Reactor fuel plate.
ORN1-A1C - OISICIAL
UNCLASSIFIED
ORNL-LR-DWG 71127R2

-X-RAY TUBE
- FUEL PLATE
CRYSTAL
PHOTOMULTIPLIER
DATA READ-OUT
INSTRUMENTATION
- COLLIMATORS
Fie. 4. Block diagram of the Cun-cintillation dicicction system.
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OFM - AC - OFFICIAL
Fig. 5. Mechanical scannin: system for inhomogeneity measurement in fuel plates.
ORNL-AIC - OPSICIAL

UNCLASS! IED
ORNL-LR-DWG 50492
FUEL PLATE
.
-
.
.
- LEAF
LUI
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FUEL PLATE
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Fig. 6. Probe for measuring coolant-channel spacing between fuel plates.
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Fig. 7. veasuring probe inserted in coolant channel of prototype
High Flux Isotope Reactor fuel core.
OFMI-ACC-OFFICIAL
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Fig. 8. Equipment arranged for microradiography of coated
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ORHIVAIC - OFFICIAL


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Fig. 9. Microradiograph of coated particles selected to show different
qualities of interest.
OEHL-AEC - OFFICIAL
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Fig. 10. Microradiograph of fuel particles shoving fuel migration
after heat treatment.
O&P
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O*NE-ACC-OISICIAL
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8 / 13 /65
DATE FILMED
END
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