Neutron Sources and Their Appls [ANS Meeting Apr 19-21, 1971 - Sssions I, II]

298 Pages·1971·28.07 MB·English

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CON F-7 10402
VOl. II
General, Miscellaneous and
Progress Reports (TI 0-4500)
NEUTRON SOURCES AND APPLICATIONS
Proceedings of the American Nuclear Society
National Topical Meeting
April 19-21, 1971
Augusta, Georgia
Contributed Papers
SESSIONS I AND II
April 1971
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__
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DISCLAIMER

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FOREWORD
The speakers whose papers are published in Volume I were invited to
discuss subjects in which they are acknowledged experts. To provide
them with current information concerning the work of other scientists
and to acknowledge the work of other persons, papers covering the
many aspects of neutron sources and their applicationsw ere invited to
be submitted on an international basis. Papers were accepted until
March 1971. Submitted papers, which were summarized by invited
speakers who acted as rapporteurs, are published here in Volumes II and
Ill. The papers are reproduced from texts submitted by the authors and
are unedited.
This system of combining summary talks and submitted papers was
adopted because of the widely varying and interdisciplinary nature of
the rapidly growing field of neutron source application. It is hoped that
the publication of this material will provide a useful reference for all
who are interested in neutron sources and their applications. By being
available at the meeting, Volumes II and Ill may assist attendees and
help to stimulate discussion. Volume I will contain the invited papers,
the discussions at the meeting and the remaining contributed papers.
Publication will follow shortly after the meeting.
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CONTENTS
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SESSION I: NEUTRON SOURCES
Experimental Capabilities and Performance of TR IGA Research and Test Reactors
for Neutron Applications
. . . . . . . . . . . . . . . . . .
G. T. Schnurer and A. T. McMain 1-1
, .
The NBS Reactor as a Source of Neutrons
R. S. Carter. . . . . . . . . . . . . . . . . . . . . . . . 1-10
A Versatile Nuclear Reactor Facility
A. K. Furr . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
The Control of Neutron Beams by Vibrating Crystals
A. M. Jacobs, E. S. Kenney, and J. 0. E. Jeffries . . . . . . . . . . . . . 1-22
The Unique Research Potential of Neutron Pulses for Nuclear Explosions
R. L. Carter . . . . . . . . . . . . . . . . . . . . . . . . . 1-33
.f
Development of an Intense Pulsed 14-Mev Neutron Source
i 0. C. Gatesand L. J. Derneter . . . . . . . . . . . . . . . . . . . 1-39
Using a Meson Factory as an Intense Pulsed Neutron Source
R. R. Fullwood . . . . . . . . . . . . . . . . . . . . . . . . 1-50
Gas Target Source for Fast Neutron Cancer Therapy
C. A. Kelsey, M. L. M. Boone, J. M. Hevezi,
A. L. Wiley, G. C. Spalek, H. K. Forsen and W. R.'Winter. . . . . . . . . . 1-56
Mobile Accelerator Facility for Neutron Interrogation and Nondestructive Assay
B. R. Dennis, R. A. Forster, J. H. Menzel, M. M. Thorpe, and
0. B. Smith . . . . . . . . . . . . . . . . . . . . . . . . . 1-61
Preparation of Industrial 252Cf Neutron Sources at Savannah River Laboratory
W. R. McDonell, A. R. Boulogne, J. P. Faraci, S. F. Peterson,
B. L. Dahlen, W. C. Mosley, D. J. Mahoney, and V. Whatley . . . . . . . . . 1-72
Effects of Source Encapsulation Materials on the Thermal-Neutron Flux from a
252Cf Source in a Water Moderator
K. 0. Kok, R. Artigas, and J. W. Ray . . . . . . . . . . . . . . . . . 1-84
Recent Developments in (an) Sources
K. H. Ansell and E. G. Hall . . . . . . . . . . . . . . . . . . . . 1-90
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High Intensity (u,n) Sources
K. H. Anselland E. G. Hall . . . . . . . . . . . . . . . . . . . 1-100 f
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1-1 12
Monolayer Ceramic Microsphere-Beryllium Plate Heterogeneous Isotopic Neutron Source
E. D. Jordan, T. E. Carew, and B. L. Barkley 1-1 17
1-128
1-136
1-742
1-147
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Absolute Measurements on Thermal Neutron Fluxes Prodyed in Water by (d,d) and (d,t)
Reactions with 150 kev Deuterons
L. Holland and J. Walker . . . . . . . . . . . . . . . . . . . . . . 1-154
Reactor and Neutron Physics Applications of Calibrated Ne,utron Sources ‘4
A. DeVolpi, K. Porges, R. Karam, W. Poenitz,
A. Cox, M. Bretscher, W. C. Redman, and S. Carpenter . . . . . . . . . . . 1-160
The Neutron Spectrum From a Radioactive 210Po-L~(a ,n) Source
K. W. Geiger and L. van der Zwan . . . . . . . . . . . . . . . . . . 1-166
Evaluation of the Neutron Source Absorption Correction in a Manganous Sulfate Bath
v. spiegel, Jr. . . . . . . . . . . . . . . . . . . . . . . . . . 1.170
Tissue Equivalent Proportional Counters in Thin Neutron Shield Studies
L. W. Brackenbush, G. W. R. Endres, and
L. G. Faust. . . . . . . . . . . . . . . . . . . . . . . . . . 1-172
1.182
Calculated and Measured Effectiveness of Californium-252 Source Shielding
D. H. Stoddard and R. A. Moyer . . . . . . . . . . . . . . . . . . . 1-187
1-196
1
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SESSION II: MEDICAL AND FORENSIC USES OF NEUTRONS
Neutron Radiation Therapy
M. Catterall, R. H. Thodinson,
S. B. Field, and C. C. Rogers . . . . . . . . . . . . . . . . . 11-1
Fast Neutron Depth Doses and Spectra Obtained by Bombarding Various Targets With
16 MeV Deuterons
C. J. Parnell. . . . . . . . . . . . . . . . . . . . . . . . . .
11-7
Experience in Treatment Dose Calculations for 25 2Cf Patients
G. D. Oliver, Jr., P. R. Wright, and
P. R. Almond . . . . . . . . . . . . . . . . . . . . . . . . .
11-16
Preliminary Clinical Experience with Californium-252 Interstitial Sources
J. R. Castro. . . . . . . . . . . . . . . . . . . . . . . . . 11-22
A Cytogenetic Determination of the OER and RBE of Californium-252
S. C. Bushong, N. Prasad, S. A. Briney, and
G. Oliver. . . . . . . . . . . . . . . . . . . . . . . 11-29
Introduction to Medical Neutrography *
R. Buchet . . . . . . . . . . . . . . . . . . . . . . . . . . 11-37
Neutrography in Medical Research and Pathology
M. J. Flynn, G. F. Knoll, and
A. K. Poznanski . . . . . . . . . . . . . . . . . . . . . . . . 11-49
Neutron Radiography in Dental Diagnosis
M. T. Weismanand M. Brown . . . . . . . . . . . . . . . . . 11-59
A 252Cf Focused Neutron Gun for Activation of Skin-Tissue to Detect Above-
Normal Amounts of Sodium
Z. M. Alvi . . . . . . . . . . . . . . . . . . . . . . . . 11-61
Practical Applications and LimiTations of Forensic Activation Analysis
. . . . . . . . . . . . . . . . .
C. M. Hoffman and M. J. Pro 11-67
The Role of Environmental Contamination in Criminalistics: A Case History
K. K. S. Pillay, C. C. Thomas, Jr., and
G. F. Mahoney. . . . . . . . . . . . . . . . . . . . . . . . 11-71
State-Wide Training and Service Program in Forensic Neutron Activation Analysis
J. R. Vogt, M. E. Eichor, and
R. E. Mason . . . . . . . . . . . . . . . . . . . . . . 11-77
Statistical Interpretation of Trace Element Patterns in Paper
H. R. Lukensand H. L. Schlesinger . . . . . . . . . . . . . . . . . 11-81
* Translated from the Journal de Rodiologie d' Electrologie et de Medecine Nucleaire 51, 269 (19 70).
Reprinted with permission from the publisher.
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Session I
NEUTRON SOURCES
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EXPERIMENTAL CAPABILITIES AND PERFORMANCE
OF TRIGA RESEARCH AND TEST REACTORS FOR
NEUTRON APPLICATIONS
George T. Schnurer
Albert T. McMain
Gulf Energy & Environmental Systems, Inc.
San Diego, California
This paper presents an overview of the various types of TRIGA reactors and their
experimental facilities and performance capabilities. Recently developed designs and new
experimental facilities and performance capabilities are discussed in detail, and current
development work in these areas is reviewed. Typical neutron research and test applica-
tions are discussed in the context of the experimental facilities and performance capabili-
ties. Since the associated building and auxiliary equipment are important considerations
in planning a neutron source facility, these aspects are also reviewed for the various types
of TRIGA reactors. Similarly, operating considerations, including maintenance and staffing
requirements, are discussed.
INTRODUCTION applied to a family of reactors varying in
both configuration and performance but
TRIGA research and test reactors have sharing a common fuel technology.
found extensive application as a flexible
and versatile neutron source. This accep- The safety characteristics of TRIGA are
tance is in large measure due to the experi- exemplified by its pulsing capability, which
mental capabilities and performance, together in addition to being a useful research capa-
with the safety, that have been exhibited by bility in its own right has resulted in other
TRIGA reactors. benefits. For example, TRIGAs are normally
installed in buildings of conventional con-
Historically, the first TRIGA was un- struct3on without pressure containment, a
veiled as part of the U.S. Government's direct result of the TRIGA's demonstrated
exhibit at the Second United Nations Con- safety characteristics. Further, by virtue
ference on the Peaceful Uses of Atomic of the reactor's safety and other character-
Energy in 1958. The original TRIGA proto- istics, TRIGA cores can be cooled by natural
type had gone critical in San Diego just a convection cooling for power levels up to
few months earlier. It is still being used 2000 kW, thereby increasing their flexibility
today to perform very valuable research in and substantially simplifying the associated
support of major programs, as well as to cooling systems. As a result, smaller oper-
perform approximately 95% of all the work ating staffs are required and maintenance is
load of the Gulf Energy & Environmental kept to a minimum.
Systems Neutron Activation Analysis Service,
which processes samples on a routine basis The history of TRIGA has been one of
for well over 600 organizations. continuing improvement. The initial design
goal of 10 kW steady-state has evolved into
The TRIGA concept was developed to ful- a whole class of reactors having performance
fill the requirements for a research reactor levels in the megawatt range with pulsing to
whose safety was inherent in its intrinsic thousands of megawatts. P.t present, there
properties and not primarily dependent on are 49 TRIGA reactors in operation or under
mechanical or electronic safety devices. construction in 14 countries, representing
This goal was fully achieved with the more than 250 reactor years of operating
development of the uranium-zirconium hydride experience.
TRIGA fuel with its large prompt negative
temperature coefficient of reactivity. It As advanced power reactors are developed,
is the use of this fuel that is most closely there is increasing interest in the use of
associated with the name TRIGA, a term TRIGA research reactors to provide a test bed
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for power reactor fuel development. Compact 3. Stainless bteel clad U-ZrH1-7,
core TRIGA reactors have already been used (steadv-state/Dulsiiig). Bv increasing the
to perform extensive experiments on fission hydrogen conte. nI t by ruO-% , the troublesovm e phase
product diffusion in power reactor fuel transition is eliminated and the fuel material
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matrices. The development of an annular core can tolerate temperatures well in excess of
TRIGA reactor a few years ago for Sandia 1000°C. The stainleI ss steel cladding also
Corporation, a USAEC prime contractor, has withstands higher teIm peratures. These fuel
stimulated considerable interest in the use elements have been operated at steady-state
of this concept for testing segments of power levels of 150N kW with natural convec-
power reactor fuels, including fast reactor tion cooling of the core, and have been
fuels under simulated accident conditions-- repetitively tested with core reactivity in-
up to and including fuel melt-down. sertions up to $5.04) (3.5% 6k/k). With a
$3.00 reactivity insertion, the peak power is
TYPES OF TRlGA REACTORS approximately 20 MW per element. In the
Advanced TRIGA Prot:,type (ATPR) at Gulf Energy
GENERAL & Environmental Systiems the peak power is
approximately 6500 !Iw for a $4.60 reactivity
TRIGA reactors are available in several inserti on.
different configurations which use many
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similar parts or components to permit ease 4. Fuel Lifetime Improvement Program
of upgrading the performance level Q). (FLIP). This fuel, dimensionally similar to
Therefore, the reactor user can acquire a standard TRIGA fuel, was specifically
reactor facility with minimum capital invest- developed to provid( core lifetimes in the
ment; then as the user's requirements range from 7 to 10 NW-yr. This fuel is avail-
develop, the facility can be upgraded to able with enrichmentls of 70% or 93%. It also
avoid technical obsolescence. incorporates the USE: of erbium as a burnable
poison (1.6 wt-% widh the 70% enriched fuel),
The performance of any given TRIGA re- The initial cores of' TRIGA FLIP fuel will be
actor type is determined by the type of fuel installed early in 1.971 in a TRIGA reactor at
and reflector configuration used. Pulsing Gulf Energy & Envircmmental Systems (San
parameters will vary slightly with the re- Diego) and at the USAEC reactor facility in
flector material. For a given reactivity in- Puerto Rico, which is now in the process of
sertion, the graphite-reflected Mark I and I1 being converted to a TRIGA core.
give a lower, broader pulse than the water-
reflected Mark 111. The peak power achieved 5. Conversion Clusters. In order to
during the pulse for a given reactivity in- facilitate the conversion of existing reactors
sertion is a function of the total number of presently designed to accommodate MTR plate-
fuel elements, although the flux is essen- type fuel, a four-rcld cluster of TRIGA fuel
tially independent of the number of fuel was developed (Figure lb). These clusters
elements for the same reactivity insertion. may be formed from Etandard stainless steel
clad U-ZrHlS6 fuel clr from the FLIP fuel.
The following types of uranium-zirconium End fittings can be adjusted to either square
hydride fuel elements (Figure la) can be em- or circular grid pkte holes.
ployed in any of the TRIGA configurations
described in succeeding sections :
STANDARD TRIGA REACTORS
1. Aluminum-clad U-ZrHiS0 (steady
Mini-TRIGA. Tie newest and simplest of
stace), fully enriched uranium; 8.5 wt-%
the TRIGA models, tkis reactor represents a
uranium for operation up to 100 kW. This
budget price reactor! with considerable flexi-
fuel was developed for use on the mini-TRIGA
bility and a high fl!ux per watt;kwith an added
to permit a small compact core giving a high
capability for futu1.e upgrading. (See
flux per watt.
Figure 2.) The star!dard mini-TRIGA can
operate for short p{riods of time at steady-
2. Aluminum-clad U-ZrH1 n (steady
state power levels u,p to 100 kW, providing
state), 20% enriched uranium; 8.5 wt-% ura-
nium. This fuel is used for steady-state
*In order to achieve this, the mini-
operation up to 250 kW with natural convection
TRIGA utilizes a s m h c ompact core of fully
cooling of the core. Higher power operation
,
with these fuel elements is limited to fuel enriched aluminum-Glad U-ZrH1. fuel ele-
ments.
temperatures below 500°C because of a phase
transition at %53OoC.
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