Studies determine the feasibility of preparing fuel-bearing glasses and glasses bearing neutron-absorbing materials for use as crystalline fuel and control rods for reactors. Properties investigated were devitrification resistance, urania solubility, and density

Lynch, E. D.

English

NASA Technical Reports Server

April 1968	 Brief 68-10103 
OUICY C
AEC-NASA TECH BRIEF 
t4rrs
AEC-NASA Tech Briefs describe innovations resulting from the research and development program 
of the U.S. AEC or from AEC-NASA interagency efforts. They are issued to encourage commercial 
application. Tech Briefs are published by NASA and may be purchased, at 15 cents each, from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Glassy Materials Investigated for Nuclear 
Reactor Applications 
Studies were made to determine the feasibility of 
preparing fuel-bearing glasses and glasses bearing 
neutron-absorbing materials for use as crystalline 
fuel and control rods for reactors. Primarily, the 
properties which would determine the usefulness of 
the glasses as a reactor fuel were investigated—
namely, devitrification resistance, urania solubility, 
and density. 
A preliminary study was made of the effects of 
urania additions on some properties of selected 
This document was prepared under the sponsorship of the Atomic 
Energy Commission and/or the National Aeronautics and Space 
Administration. Neither the United States Government nor any per-
son acting on behalf of the United States Government assumes any
Fabrication methods were devised to form crystal- 
line-glass mixtures of usable densities. Shapes were 
formed by pressing and sintering, warm pressing at 
600°C, vibratory compaction and sintering, and 
extrusion at 8000 C. A control-rod loading was fabri- 
cated by vibratory compaction of B4C-glass into the 
cladding. Induction heating was used to bond the 
materials in the cladding tube. Glass-bonded uranium 
dioxide samples were prepared for Doppler-coefficient 
measurements. 
The study revealed the most promising glasses to be 
based on compositions in the system Na20-K20- 
Si02. Compositions containing equivalent to about 60 
w/o UO2 were melted to single-phase glasses at 
1500°C. Glasses containing up to 30 w/o UO2 were 
extremely resistant to devitrification. Several composi- 
tions within this maximum range were maintained for 
14 days in a gradient of 300°-950°C without crystal- 
line development. One sample containing approxi- 
mately 20 w/o UO2 has been held in the same tem- 
perature gradient for 100 days without devitrification. 
The work done on glassy coating materials for 
irradiation chambers involved the development of a 
technique for obtaining a uniform glaze on the inside 
of a porcelain tube, in which Sr 90 would be used as 
the source of beta emission. The hazards involved in 
handling Sr90 prevented the use of the usual spraying 
or dipping technique for glaze application. 
A uniform glaze was achieved by simultaneously 
rotating the porcelain tube and adding the glaze 
through a pipette. After the tube was rotated for a 
predetermined time, the excess glaze was drained out 
and an Sr90 solution was introduced through a cali- 
brated pipette. Following the Sr 90
 addition, a blast of 
hot air was directed against the outside of the tube. 
liability resulting from the use of the information contained in this 
document, or warrants that the use of any information, apparatus, 
method, or process disclosed in this document may not infringe pri-
vately owned rights. 
glasses in the systems PbO-Na20-Si02, Na20-CaO-
Si02, Na20-Si02, and NaO-K20-Si02. Primary 
areas of possible application investigated were: 
(I) glass containing fissile material as a single-phase 
fuel, (2) glass containing one or more high-thermal-
cross-section materials as a single-phase control 
material, (3) glass as a dispersion medium or bonding 
agent in admixture with crystalline high-cross-section 
control materials, and (4) fissile-glass as a dispersion 
medium and sintering agent in admixture with crystal-
line fissile materials. Some work has been done on 
glassy coating materials for irradiation chambers and 
for neutron absorbers. 
For application as a reactor fuel, a glassy material 
should have these general characteristics: 
1. The glass should contain as high a content of 
fissile material as possible. 
2. The glass should have a softening point below the 
operating temperature. 
3. The glass should retain integrity as a solution, 
without a tendency to crystallize, for long periods 
of time within the operating-temperature range. 
4. The glass must be compatible with the jacketing 
metal, since they will be in intimate contact dur-
ing operation.
(continued overleaf)
https://ntrs.nasa.gov/search.jsp?R=19680000103 2020-03-12T05:26:45+00:00Z
while rotating, to speed drying and to reduce exposure 
time. The glaze was then fired in a sealed furnace 
chamber. 
Complete details of this investigation are contained 
in Glassy Materials for Nuclear Reactor Applications, 
by E. D. Lynch, ANL-7062, November 1965, Argonne 
National Laboratory, Argonne Illinois. Copies of 
this report are available from the Clearinghouse for 
Federal Scientific and Technical Information, Spring-
field, Virginia 22151; price $3.00, microfiche $0.65. 
Note: 
Inquiries concerning this innovation may be di-
rected to:
Office of Industrial Cooperation 
Argonne National Laboratory 
9700 South Cass Avenue 
Argonne, Illinois 60439 
Reference: B68-10103
Source: E. D. Lynch
Metallurgy Division
(ARG- 10075)
Patent status: 
Inquiries about obtaining rights for commercial 
use of this innovation maybe made to: 
Mr. George H. Lee, Chief 
Chicago Patent Group 
U.S. Atomic Energy Commission 
Chicago Operations Office 
9800 South Cass Avenue 
Argonne, Illinois 60439 
Brief 68-10103	 Category 03


Glassy materials investigated for nuclear reactor applications

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server