U.S. patent application number 14/045129 was filed with the patent office on 2014-04-10 for corrosion resistant neutron absorbing coatings.
The applicant listed for this patent is Lawrence Livermore National Security, LLC, Sandia Corporation, U.S Army Research Laboratory, United States Department of Energy. Invention is credited to Victor Champagne, Jor-Shan Choi, Joseph C. Farmer, Jon Kirkwood, Chuck K. Lee, Paige Russell, Jeffrey Walker, Nancy Yang.
Application Number | 20140099494 14/045129 |
Document ID | / |
Family ID | 38289905 |
Filed Date | 2014-04-10 |
United States Patent
Application |
20140099494 |
Kind Code |
A1 |
Choi; Jor-Shan ; et
al. |
April 10, 2014 |
CORROSION RESISTANT NEUTRON ABSORBING COATINGS
Abstract
A method of forming a corrosion resistant neutron absorbing
coating comprising the steps of spray or deposition or sputtering
or welding processing to form a composite material made of a spray
or deposition or sputtering or welding material, and a neutron
absorbing material. Also a corrosion resistant neutron absorbing
coating comprising a composite material made of a spray or
deposition or sputtering or welding material, and a neutron
absorbing material.
Inventors: |
Choi; Jor-Shan; (El Cerrito,
CA) ; Farmer; Joseph C.; (Tracy, CA) ; Lee;
Chuck K.; (Hayward, CA) ; Walker; Jeffrey;
(Gaithersburg, MD) ; Russell; Paige; (Las Vegas,
NV) ; Kirkwood; Jon; (Saint Leonard, MD) ;
Yang; Nancy; (Lafayette, CA) ; Champagne; Victor;
(Oxford, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lawrence Livermore National Security, LLC
U.S Army Research Laboratory
Sandia Corporation
United States Department of Energy |
Livermore
Adelphi
Albuquerque
Washington |
CA
MD
NM
DC |
US
US
US
US |
|
|
Family ID: |
38289905 |
Appl. No.: |
14/045129 |
Filed: |
October 3, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12888261 |
Sep 22, 2010 |
8580350 |
|
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14045129 |
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11595623 |
Nov 9, 2006 |
8187720 |
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12888261 |
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Current U.S.
Class: |
428/220 ;
252/478 |
Current CPC
Class: |
C23C 4/18 20130101; G21F
1/08 20130101; G21F 5/008 20130101; G21C 19/40 20130101; G21F 1/00
20130101; G21F 5/012 20130101; Y10T 428/12063 20150115; C23C 4/12
20130101; C23C 4/10 20130101; C23C 4/06 20130101; G21C 19/07
20130101; Y10T 428/12083 20150115; C23C 24/04 20130101; Y02E 30/30
20130101 |
Class at
Publication: |
428/220 ;
252/478 |
International
Class: |
G21F 1/00 20060101
G21F001/00 |
Goverment Interests
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH AND DEVELOPMENT
[0002] The United States Government has rights in this invention
pursuant to Contract No. DE-AC52-07NA27344 between the United
States Department of Energy and Lawrence Livermore National
Security, LLC for the operation of Lawrence Livermore National
Laboratory. The United States Government has rights in this
invention pursuant to DE-AC04-94AL85000 between Sandia Corporation
and the U.S. Department of Energy
Claims
1. A corrosion resistant neutron absorbing coating, comprising: a
composite material made of a spray or deposition or sputtering or
welding material, and a neutron absorbing material.
2. The corrosion resistant neutron absorbing coating of claim 1,
wherein said spray or deposition or sputtering or welding material
is thermally-sprayed iron-based amorphous metal.
3. The corrosion resistant neutron absorbing coating of claim 1,
wherein said neutron absorbing material is any concentration of
neutron-absorbing boron.
4. The corrosion resistant neutron absorbing coating of claim 1,
wherein said neutron absorbing material is any thermal-spray
coating with refractory boride particles.
5. The corrosion resistant neutron absorbing coating of claim 1,
wherein said neutron absorbing material is at least one of borides
of carbon, titanium, chromium, or nickel, and any combination of
borides of carbon, titanium, chromium, or nickel.
6. The corrosion resistant neutron absorbing coating of claim 1,
including a corrosion-resistant binder.
7. The corrosion resistant neutron absorbing coating of claim 1,
including a corrosion-resistant binder of aluminum, titanium, or
zirconium, or any combination of aluminum, titanium, or
zirconium.
8. The corrosion resistant neutron absorbing coating of claim 1,
including refractory boride particles.
9. The corrosion resistant neutron absorbing coating of claim 1,
including refractory boride particles of the borides of carbon,
titanium, chromium, or nickel, and any combination of borides of
carbon, titanium, chromium, or nickel.
10. The corrosion resistant neutron absorbing coating of claim 1,
wherein the coating has a thicknesses greater than one tenth
millimeter.
11. The corrosion resistant neutron absorbing coating of claim 1,
wherein the coating has a thicknesses in the range of from one
tenth millimeter to twenty millimeters.
12. The corrosion resistant neutron absorbing coating of claim 1,
wherein the coating has a thicknesses in the range of from three to
seven millimeters.
13. The corrosion resistant neutron absorbing coating of claim 1,
including neutron poisons.
14. The corrosion resistant neutron absorbing coating of claim 1,
including neutron poisons of gadolinium, hafnium, erbium,
dysprosium, or cadmium, and any combination of gadolinium, hafnium,
erbium, dysprosium, or cadmium.
15. The corrosion resistant neutron absorbing coating of claim 1,
including moderator materials.
16. The corrosion resistant neutron absorbing coating of claim 1,
including moderator materials of carbon, carbides, hydrogen
isotopes, or hydrides formed from any of the hydrogen isotopes.
17. (The corrosion resistant neutron absorbing coating of claim 1,
wherein said cold or thermal spray deposited, sputter deposited, or
weld processed material is an amorphous-metal alloy with yttrium,
chromium, molybdenum, tungsten, boron, carbon, and the possible
dispersion of neutron-absorbing or neutron-moderating ceramic
particles. Other elements may also be included in these
coatings.
18. The corrosion resistant neutron absorbing coating of claim 1,
including ceramic nano-particles, where the ceramic particles are
oxides, borides, carbides, or nitrides.
19. The corrosion resistant neutron absorbing coating of claim 1,
including ceramic nano-particles, where the ceramic particles are
hydrides for the purpose of neutron moderation.
20. The corrosion resistant neutron absorbing coating of claim 1,
including oxide ceramic nano-particles of at least one alloying
element involved in the metal matrix.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of pending patent
application Ser. No. 12/888,261, filed Sep. 22, 2010, which is a
Divisional of 11/595,623 filed Nov. 9, 2006, now issued as U.S.
Pat. No. 8,178,720 on May 29, 2012, which claims the benefit of
U.S. Provisional Patent Application No. 60/737,026 filed Nov. 14,
2005, the entire contents and disclosures of which are specially
incorporated by reference herein.
BACKGROUND
[0003] 1. Field of Endeavor
[0004] The present invention relates to corrosion resistant
materials and more particularly to corrosion resistant neutron
absorbing materials and methods of forming corrosion resistant
neutron absorbing materials and coatings. These coatings may
include either homogeneous metallic alloys, or metal-ceramic
composites, where the metallic alloy or the binder in the
metal-ceramic composite could be a boron-containing iron-based
amorphous metal, engineered for outstanding corrosion
resistance.
[0005] 2. State of Technology
[0006] U.S. Pat. No. 5,744,254 for composite materials including
metallic matrix composite reinforcements issued Apr. 28, 1998 to
Stephen L. Kampe and Leontios Christodoulou provides the following
state of technology information, "Metal matrix composites
comprising discontinuous ceramic reinforcements are under
consideration for an increasing number of applications. Such
composites have been highly touted as efficient material
alternatives to conventional ferrous and nickel-base alloys
presently incorporated in high performance, high temperature
applications. Prominent among those who have invested heavily in
the field are the automotive and aerospace industries, in efforts
to improve fuel efficiency and performance. Other industries with
interest in metal matrix composites include heavy equipment
manufacturers and tooling industries such as drilling, mining and
the like."
[0007] U.S. Pat. No. 6,767,419 for methods of forming hardened
surfaces issued Jul. 27, 2004 to Daniel J. Branagan provides the
following state of technology information, "Steel is a metallic
alloy which can have exceptional strength characteristics, and
which is accordingly commonly utilized in structures where strength
is required or advantageous. Steel can be utilized, for example, in
the skeletal supports of building structures, tools, engine
components, and protective shielding of modern armaments."
[0008] United States Patent Application No. 2005/0117687 by George
Carver et al for container and method for storing or transporting
spent nuclear fuel, published Jun. 2, 2005, provides the following
state of technology information: "Typically, spent nuclear fuel
discharged from fission reactors is stored in deep pools filled
with water to dissipate heat and to attenuate the gamma and neutron
radiation generated by the fuel. This is called a wet storage
system. An alternative method to storing the spent nuclear fuel is
a dry storage system that uses a horizontal or vertical
configuration having either a heavy wall protected vessel referred
to as a cask or over-pack, or a thin walled vessel called a
canister. Dry storage systems can also be used to transport spent
fuel between storage locations. For dry storage system, the
canister can be separately placed into the cask or over-pack. The
structure that provides support for the spent nuclear fuel for dry
storage and transportation systems is referred to as a fuel basket.
The fuel baskets are designed to meet the compressive loads
criteria contained within regulations, codes, and standards,
particularly conditions for storing and transporting nuclear spent
fuel. Dry storage and transportation basket designs include a tube
and disk flux trap configuration, an egg crate interlocking plate
configuration, a developed cell configuration and a stacked tube
configuration."
[0009] The article "Corrosion Characterization of Iron-Based
High-Performance Amorphous-Metal Thermal-Spray Coatings" by J. C.
Farmer et al, ASME Pressure Vessels & Piping Division
Conference, Denver, Colo., Jul. 17, 2005 through Jul. 21, 2005
provides the following state of technology information, "New
corrosion-resistant, iron-based amorphous metals have been
identified from published data or developed through combinatorial
synthesis, and tested to determine their relative corrosion
resistance. Many of these materials can be applied as coatings with
advanced thermal spray technology . . . . Such materials could also
be used to coat the entire outer surface of containers for the
transportation and long-term storage of spent nuclear fuel, or to
protect welds and heat affected zones, thereby preventing exposure
to environments that might cause stress corrosion cracking."
[0010] The article "Corrosion Resistance of Iron-based Amorphous
Metal Coatings" by J. C. Farmer et al, Pressure Vessels &
Piping Division, Conference, Vancouver, Canada, Jul. 23, 2006
through Jul. 27, 2006 provides the following state of technology
information, "New amorphous-metal thermal-spray coatings have been
developed recently that may provide a viable coating option for
spent nuclear fuel & high level waste repositories."
SUMMARY
[0011] Features and advantages of the present invention will become
apparent from the following description. Applicants are providing
this description, which includes drawings and examples of specific
embodiments, to give a broad representation of the invention.
Various changes and modifications within the spirit and scope of
the invention will become apparent to those skilled in the art from
this description and by practice of the invention. The scope of the
invention is not intended to be limited to the particular forms
disclosed and the invention covers all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention as defined by the claims.
[0012] Man-made materials with unusually long service lives are
needed for the construction of containers and associated structures
for the long-term storage or disposal of spent nuclear fuel (SNF)
and high-level waste (HLW) in underground repositories. Man has
never designed and constructed any structure or system with the
service life required by a SNF and HLW repository. Such systems
will be required to contain these radioactive materials for a
period as short as 10,000 years, and possibly as long as 300,000
years. The most robust engineering materials known are challenged
by such long times.
[0013] The present invention provides a method of forming a
corrosion resistant neutron absorbing coating comprising the steps
of spray or deposition or sputtering or welding processing to form
a composite material made of a spray or deposition or sputtering or
welding material, and a neutron absorbing material. The present
invention also provides a corrosion resistant neutron absorbing
coating comprising a composite material made of a spray or
deposition or sputtering or welding material, and a neutron
absorbing material.
[0014] This material can be either a homogeneous metallic alloy or
a metal-ceramic composite. The homogeneous metallic alloy or the
metallic binder in the metal-ceramic coating can be
boron-containing iron-based amorphous metals, engineered for
exceptional corrosion resistance.
[0015] The invention is susceptible to modifications and
alternative forms. Specific embodiments are shown by way of
example. It is to be understood that the invention is not limited
to the particular forms disclosed. The invention covers all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are incorporated into and
constitute a part of the specification, illustrate specific
embodiments of the invention and, together with the general
description of the invention given above, and the detailed
description of the specific embodiments, serve to explain the
principles of the invention. The neutron-absorbing coating may be a
thermally sprayed, boron-containing iron-based amorphous metal,
engineered for exceptional corrosion resistance. Other amorphous
metal coatings, capable of unusual levels of hydrogen absorption,
may be used for moderator purposes. Neutron-absorbing and moderator
coatings may be combined for beneficial synergistic criticality
control effects.
[0017] FIG. 1 illustrates a coating being applied to a SNF
transportation and storage container.
[0018] FIG. 2 illustrates an amorphous metal and neutron absorbing
material used to form a coating.
[0019] FIG. 3 illustrates a coating being applied to a SNF
transportation and storage container by a deposition process.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring to the drawings, to the following detailed
description, and to incorporated materials, detailed information
about the invention is provided including the description of
specific embodiments. The detailed description serves to explain
the principles of the invention. The invention is susceptible to
modifications and alternative forms. The invention is not limited
to the particular forms disclosed. The invention covers all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the claims.
[0021] Referring now to the drawings and in particular to FIG. 1,
one embodiment of a system incorporating the present invention is
illustrated. This embodiment is designated generally by the
reference numeral 100. The embodiment 100 provides a neutron
absorbing coating for spent nuclear fuel (SNF) support structures,
particularly for a SNF transportation and storage container
101.
[0022] FIG. 1 is an illustration of a coating 102 being applied to
the SNF transportation and storage container 101. The coating 102
is being applied by a spray process. A spray device 103 is shown
applying a spray 104 to the SNF transportation and storage
container 101. In addition to the coating being applied to the SNF
transportation and storage container 101, the coating 102 can be
applied to spent nuclear fuel (SNF) support structures including
metallic support structure used in storage pool racks, in support
baskets inside the dry storage containers, inside the
transportation casks, and inside the disposal container for spent
nuclear fuels.
[0023] The coating 102 can be one or more of the following
materials: (1) thermally-sprayed iron-based amorphous metals with
relatively large concentrations of boron; (2) thermal-spray coating
with refractory boride particles including, but not limited to the
borides of carbon, titanium, chromium, nickel, and other similar
compounds; (3) cold-spray coatings with a relatively soft,
corrosion-resistant binder such as aluminum, titanium, zirconium,
or other similar metal, with refractory boride particles including,
but not limited to the borides of carbon, titanium, chromium,
nickel, and other similar compounds; and (4) thermal- or cold-spray
as a means of joining plates of boron-containing alloys for use in
nuclear fuel assembly support structures; and (5) and such
materials with moderators and neutron poisons added. The materials
discussed in (1) through (5) can be enhanced with neutron poisons
including, but not limited to: (a) gadolinium, (b) hafnium, (c)
erbium, (d) dysprosium, and (e) cadmium. The materials discussed in
(1) through (5) can also be enhanced with the addition of moderator
materials, including but not limited to: (i) carbon, (ii) carbides,
(iii) hydrogen isotopes, and (iv) hydrides formed from any of the
hydrogen isotopes.
[0024] These compositions of matter simultaneously achieve a low
reduced glass transition temperature, high heat transfer
coefficients, low critical cooling rates, enhanced corrosion
resistance, enhanced damage tolerance, and increased hardness. The
high content of boron in these compositions enhance the criticality
safety of the spent nuclear fuels when they are stored in storage
racks, inside the dry storage containers, inside the transportation
containers, and in the disposal containers.
[0025] The coating 102 and method of applying the coating 102 also
includes but is not limited to: the applications of dispersed
ceramic particles (diameters ranging from nanometers to several
microns), where the ceramic particles consist of at least one
alloying element involved in the metal matrix or binder as the
neutron-absorbing coatings to the metallic support structure, or as
the neutron-absorbing bulk-alloy structural support material to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal. The ceramic particles may be oxides,
borides, carbides, nitrides or hydrides.
[0026] This coating 102 and method of applying the coating 102
includes, but is not limited to: the applications of any thermal
spray feed that includes ceramic particles, with diameters ranging
from nanometers to several microns, and produced by reverse micelle
synthesis as the neutron-absorbing coatings to the metallic support
structure to enhance criticality safety for spent nuclear fuel in
storage pool racks, in baskets inside the dry storage containers,
inside the transportation cask, and eventually inside the disposal
container for repository disposal.
[0027] The coating 102 and method of applying the coating 102
includes, but is not limited to: the applications of any
metal-ceramic composite coating, where the ceramic particles are
oxides, carbides, or nitrides, using corrosion-resistant
amorphous-metal formulated matrix or binder as the
neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0028] The coating 102 and method of applying the coating 102 also
includes, but is not limited to: the applications of the
particle-size optimization method for achieving fully-dense
amorphous-metal coatings, a method that uses small enough amorphous
metal powders to ensure that the critical cooling rate is achieved
throughout, even in cases where the critical cooling rate may be
relatively high (.gtoreq.1000 K per second), as the
neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0029] Different spray processing systems can be used to form the
coating 102, for example the spray processing can be flame spray
processing, plasma spray processing, high-velocity oxy-fuel (HVOF)
spray processing, high-velocity air-spray (HVAF) processing, or
detonation gun processing. The spray processing can be thermal
spray processing or cold spray processing.
[0030] Unfortunately, if these materials are improperly processed,
the powders used to produce the coatings can undergo
devitrification, which results in the formation of precipitated
crystalline phases of both Cr2B and bcc ferrite. Frequently, these
crystalline phases form in particles of relatively large diameter,
since it is impossible to maintain the heat transfer conditions
above the critical cooling rate across the entire particle
diameter. In particular, if particles above 53 microns are
crystalline with the undesirable ferrite phase present the coating
is impaired. The presence of bcc ferrite has been correlated with
poor corrosion performance, and should not be used to produce
coatings. The undesirable ferrite may be from the amorphous metal
spray by a magnetic field. The magnetic separation can be performed
at various positions in the atomization and thermal spray
processes.
[0031] There are benefits of using magnetic fields in removing
deleterious bcc ferrite phases from iron-based amorphous metals,
which may served as either the homogeneous metallic alloy, or the
metallic binder in the metal-ceramic composite, which can be used
as neutron absorbing and/or moderating coatings. Note that a
moderator slows down (thermalizes) neutrons so that they can be
captured by the neutron-absorbing coating. There are various
methods of producing the ceramic (oxide, boride, carbide, nitride,
hydride and other) particles, including reverse micelle synthesis,
chemical precipitation, electrochemical deposition, chemical vapor
deposition, physical vapor deposition, and other such methods.
[0032] The coating 102 and method of applying the coating 102
includes, but is not limited to: the applications of the
modification of such thermal-spray coatings with post-spray,
high-density infrared fusing (HDIF) to achieve lower porosity,
higher density, enhanced metallurgical bonding, and better damage
tolerance through controlled de-vitrification as the
neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0033] The coating 102 and method of applying the coating 102
includes, but is not limited to: the applications of physical vapor
deposition: [0034] Electron beam evaporation of amorphous metals in
any manner to maintain cooling the deposit film at a rate higher
than the critical cooling rate; [0035] Laser ablation of the
homogeneous metallic alloy or any of its constituents in a manner
to produce the neutron absorbing coating; [0036] Direct current
(dc) and radiofrequency (rf) magnetron sputter deposition of the
homogeneous metallic alloy or any of its constituents in a manner
to produce the neutron absorbing coating; [0037] Laser ablation of
the metallic binder or any of its constituents in a manner to
produce the neutron absorbing metal-ceramic composite coating;
[0038] Direct current (dc) and radiofrequency (rf) magnetron
sputter deposition of the metallic binder or any of its
constituents in a manner to produce the neutron absorbing
metal-ceramic composite coating; [0039] Direct current (dc) and
radiofrequency (rf) magnetron sputter deposition of alloy
constituents in multi-layer fashion, with subsequent
inter-diffusion and reaction, to create the desired amorphous metal
composition as the neutron-absorbing coatings to the metallic
support structure to enhance criticality safety for spent nuclear
fuel in storage pool racks, in baskets inside the dry storage
containers, inside the transportation cask, and eventually inside
the disposal container for repository disposal. The applications
would probably be done with multi-magnetron sputtering and rotating
turntables, as demonstrated with other materials. Variations can
also be used, such as the deposition of reactive multi-layers for
the purpose of bonding amorphous metals, ceramics, glasses and
other material.
[0040] The coating 102 and method of applying the coating 102 also
includes, but is not limited to: the applications of welding
processes for bulk amorphous metals, using amorphous metals with
critical cooling rates less than 100K per second as a weld filler
as the neutron-absorbing coatings to the metallic support structure
to enhance criticality safety for spent nuclear fuel in storage
pool racks, in baskets inside the dry storage containers, inside
the transportation cask, and eventually inside the disposal
container for repository disposal. One example of applying such a
glassy weld filler metal is the tungsten-modified SAM1651, a
material with an exceptionally low critical cooling rate, which
will therefore enable it to be used as an amorphous-metal weld
filler material for bulk amorphous metals. The high content of
boron in the SAM1651 applied as weld filler material will enhance
the criticality safety of the spent nuclear fuels when they are
stored in storage racks, inside the dry storage containers, inside
the transportation containers, and in the disposal containers.
[0041] The coating 102 for metallic support structural material can
be less corrosion-resistant stainless steel, or borated stainless
steel (such as Boraflex, BORAL.TM., etc.), or other metallic-based
materials (such as carbon steel, the aluminum-based boron-carbide
composite METAMIC.TM., and the nickel-based gadolinium alloy,
etc.). These boron-containing iron-based structure amorphous
materials (SAM) can also be applied as bulk alloy structural
support material for spent nuclear fuels used in storage pool
racks, in support baskets inside the dry storage containers, inside
the transportation casks, and inside the disposal container
emplaced in geologic environment.
[0042] The present coating 102 and method of applying the coating
102 provides the application of a new class of boron-containing
High-Performance Corrosion-Resistant Metal (HPCRM) as coatings. The
use of advanced corrosion-resistant materials to prevent corrosion
of these important surface areas is extremely beneficial. In
addition, the corrosion prevention also prevents nuclear
criticality in spent fuel storage, transportation, and/or disposal,
neutron-absorbing materials (or neutron poisons, such as borated
stainless steel, BORAL.TM., METAMIC.TM., Ni--Gd, and others).
[0043] Referring now to FIG. 2, another embodiment of a system
incorporating the present invention is illustrated. This embodiment
is designated generally by the reference numeral 200. The
embodiment 200 provides neutron absorbing coatings for spent
nuclear fuel (SNF) support structures, particularly for SNF
transportation and storage containers. The corrosion resistant
coating is produced by spray processing to form a composite
material made of amorphous metal and neutron absorbing material. As
illustrated in FIG. 2, an amorphous metal 201 and neutron absorbing
material 202 are used to form a coating 204.
[0044] The coating 204 is formed by spray processing 203 as
illustrated in FIG. 2. The spray processing 204 can be thermal
spray processing or cold spray processing. Different spray
processing 204 can be used to form the coating 204, for example the
spray processing can be flame spray processing, plasma spray
processing, high-velocity oxy-fuel (HVOF) spray processing,
high-velocity air-spray (HVAF) processing, or detonation gun
processing.
[0045] The articles, "Corrosion Characterization of Iron-Based
High-Performance Amorphous-Metal Thermal-Spray Coatings" by J. C.
Farmer et al, ASME Pressure Vessels & Piping Division
Conference, Denver, Colo., Jul. 17, 2005 through Jul. 21, 2005 and
"Corrosion Resistance of Iron-based Amorphous Metal Coatings" by J.
C. Farmer et al, Pressure Vessels & Piping Division,
Conference, Vancouver, Canada, Jul. 23, 2006 through Jul. 27, 2006
describe new amorphous-metal thermal-spray coatings that have been
developed recently that may provide a viable coating option for
spent nuclear fuel & high level waste repositories. The
disclosures of the articles, "Corrosion Characterization of
Iron-Based High-Performance Amorphous-Metal Thermal-Spray Coatings"
by J. C. Farmer et al, ASME Pressure Vessels & Piping Division
Conference, Denver, Colo., Jul. 17, 2005 through Jul. 21, 2005 and
"Corrosion Resistance of Iron-based Amorphous Metal Coatings" by J.
C. Farmer et al, Pressure Vessels & Piping Division,
Conference, Vancouver, Canada, Jul. 23, 2006 through Jul. 27, 2006
are incorporated herein by this reference.
[0046] The present invention provides neutron absorbing coatings
for spent nuclear fuel (SNF) support structures including the
following:
[0047] Structural support baskets inside containers for the
transportation and long-term storage of spent nuclear fuel (SNF),
coated with boron-containing iron-based corrosion-resistant
amorphous-metal or metal-ceramic coatings, that are applied with
thermal- or cold-spray processes, physical vapor deposition,
chemical vapor deposition, sputter deposition, or any other
application process.
[0048] Applying the thermally sprayed, or otherwise deposited
(cold-spray, physical vapor deposition, chemical vapor deposition,
etc.), ceramic coating, based on either oxides or carbides, using
boron-containing, corrosion-resistant amorphous metal formulations,
and boron-containing corrosion-resistant binders for the sprayed
ceramics to the structural support baskets inside spent fuel
storage, transportation, and disposal containers.
[0049] Materials for such long-lived corrosion-resistant
neutron-absorbing coatings including, but not limited to: (a)
thermally-sprayed iron-based amorphous metals with any
concentration of neutron-absorbing boron; (b) any thermal-spray
coating with refractory boride particles including, but not limited
to the borides of carbon, titanium, chromium, nickel, and other
similar compounds; (c) cold-spray coatings with a relatively soft,
corrosion-resistant binder such as aluminum, titanium, zirconium,
or other similar metal, with refractory boride particles including,
but not limited to the borides of carbon, titanium, chromium,
nickel, and other similar compounds; and (d) the use of thermal- or
cold-spray as a means of joining plates of boron-containing alloys
for use in nuclear fuel assembly support structures; (e) and such
materials with moderators and neutron poisons added; (f) any such
coatings with thicknesses greater than one millimeter, a thickness
known to significantly reduce the overall effective criticality
factor in spent nuclear fuel storage, transportation and disposal
canisters. Coatings of particular interest are those that range
from one to twenty millimeters, with particular interest in
coatings with thickness ranging from three to seven
millimeters.
[0050] Enhanced materials for such coatings with neutron poisons
including, but not limited to: (a) gadolinium, (b) hafnium, (c)
erbium, (d) dysprosium, and (e) cadmium.
[0051] Enhanced materials for such coatings with the addition of
moderator materials, including but not limited to: (i) carbon, (ii)
carbides, (iii) hydrogen isotopes, and (iv) hydrides formed from
any of the hydrogen isotopes.
[0052] A neutron absorbing material for the support of nuclear fuel
rods formed from amorphous-metal alloys with enhanced
concentrations of yttrium (.gtoreq.1 atomic %), chromium (10 to 20
atomic %), molybdenum (.gtoreq.5 atomic %), tungsten additions
(.gtoreq.1 atomic %), boron (.ltoreq.10 atomic %), carbon, and
possible dispersions of ceramic particles, to simultaneously
achieve neutron absorption, neutron moderation, low reduced glass
transition temperature, high heat transfer coefficients, enhanced
corrosion resistance, enhanced damage tolerance, and increased
hardness, to the structural support baskets inside spent fuel
storage, transportation, and disposal containers.
[0053] A neutron absorbing material for the support of nuclear fuel
rods formed from amorphous-metal alloys containing yttrium,
chromium, molybdenum, tungsten, boron, carbon, and dispersed
ceramic particles, to simultaneously achieve neutron absorption,
neutron moderation, low reduced glass transition temperature, high
heat transfer coefficients, enhanced corrosion resistance, enhanced
damage tolerance, and increased hardness, to the structural support
baskets inside spent fuel storage, transportation, and disposal
containers.
[0054] Applying all modified Fe-based amorphous metal formulations,
with the intentional inclusion of oxide ceramic nano-particles,
where the oxide consists of at least one alloying element involved
in the metal matrix, for the purpose of enhancing hardness or
damage tolerance to the structural support baskets inside spent
fuel storage, transportation, and disposal containers.
[0055] Applying the HVOF coatings with post-spray high-density
infrared fusing to achieve enhanced metallurgical bonding, and to
control damage tolerance through controlled de-vitrification to the
structural support baskets inside spent fuel storage,
transportation, and disposal containers.
[0056] Applying the High-Performance Corrosion Resistant Materials
such as LMDAR1922 discovered through the application of the
statistical-thermochemical methodology to the structural support
baskets inside spent fuel storage, transportation, and disposal
containers.
[0057] Applying the sputter deposition of alloy constituents in
multi-layer fashion, with subsequent inter-diffusion and reaction,
to create the desired amorphous metal composition to the structural
support baskets inside spent fuel storage, transportation, and
disposal containers. This would probably be done with
multi-magnetron sputtering and rotating turntables, as demonstrated
with other materials, but could also use other variations.
[0058] Applying the amorphous metal welding process using SAM1651
or compositional modifications thereof to the structural support
baskets inside spent fuel storage, transportation, and disposal
containers. This material (SAM1651) has an exceptionally low
critical cooling rate, which will enable it to be used as an
"amorphous metal weld filler material" for bulk materials. The high
content of boron in SAM1651 can enhance the criticality safety at
the joint and weld locations.
[0059] Applying the coating processes that use cold-spray
methodology to deposit mechanically hard, corrosion-resistant
amorphous metals, using a softer corrosion-resistant metal or
binder to enable this low-temperature coating process to the
structural support baskets inside spent fuel storage,
transportation, and disposal containers.
[0060] Applying the processes for the deposition
phosphorous-containing iron-based amorphous-metal coatings, that
rely on cold-spray methodology to overcome problems associated with
the thermal-spray of phosphorous containing materials (including
the possible generation of volatile, organo-phosphorous compounds)
to the structural support baskets inside spent fuel storage,
transportation, and disposal containers. The refinement of
particle-sizes for thermal- and cold-spray processes through the
use of cryogenic milling.
[0061] The use of advanced corrosion-resistant materials to prevent
corrosion of these important surface areas is extremely beneficial.
In addition, the corrosion prevention also prevents nuclear
criticality in spent fuel storage, transportation, and/or disposal,
neutron-absorbing materials (or neutron poisons, such as borated
stainless steel, BORAL.TM., METAMIC.TM., Ni--Gd, and others).
[0062] The present invention provides the application of a new
class of boron-containing High-Performance Corrosion-Resistant
Metal (HPCRM) as coatings to the metallic support structure used in
storage pool racks, in support baskets inside the dry storage
containers, inside the transportation casks, and inside the
disposal container for spent nuclear fuels. These materials
include: (1) thermally-sprayed iron-based amorphous metals with
relatively large concentrations of boron; (2) any thermal-spray
coating with refractory boride particles including, but not limited
to the borides of carbon, titanium, chromium, nickel, and other
similar compounds; (3) cold-spray coatings with a relatively soft,
corrosion-resistant binder such as aluminum, titanium, zirconium,
or other similar metal, with refractory boride particles including,
but not limited to the borides of carbon, titanium, chromium,
nickel, and other similar compounds; and (4) the use of thermal- or
cold-spray as a means of joining plates of boron-containing alloys
for use in nuclear fuel assembly support structures; and (5) and
such materials with moderators and neutron poisons added. The
materials discussed in (1) through (5) can be enhanced with neutron
poisons including, but not limited to: (a) gadolinium, (b) hafnium,
(c) erbium, (d) dysprosium, and (e) cadmium. The materials
discussed in (1) through (5) can also be enhanced with the addition
of moderator materials, including but not limited to: (i) carbon,
(ii) carbides, (iii) hydrogen isotopes, and (iv) hydrides formed
from any of the hydrogen isotopes. The metallic support structural
material can be the less corrosion-resistant stainless steel, or
borated stainless steel (such as Boraflex, BORAL.TM., etc.), or
other metallic-based materials (such as carbon steel, the
aluminum-based boron-carbide composite METAMIC.TM., and the
nickel-based gadolinium alloy, etc.). The applications of these
boron-containing, iron-based amorphous metals are achieved with
advanced thermal spray technology. These boron-containing
iron-based structure amorphous materials (SAM) can also be applied
as bulk alloy structural support material for spent nuclear fuels
used in storage pool racks, in support baskets inside the dry
storage containers, inside the transportation casks, and inside the
disposal container emplaced in geologic environment.
[0063] Uses of the present invention include the applications of:
[0064] Thermally-sprayed iron-based amorphous metals with
relatively large concentrations of boron; [0065] Such coatings with
refractory boride particles including, but not limited to the
borides of carbon, titanium, chromium, nickel, and other similar
compounds; [0066] Cold-spray coatings with a relatively soft,
corrosion-resistant binder such as aluminum, titanium, zirconium,
or other similar metal, with refractory boride particles including,
but not limited to the borides of carbon, titanium, chromium,
nickel, and other similar compounds; [0067] The use of thermal- or
cold-spray as a means of joining plates of boron-containing alloys
for use in nuclear fuel assembly support structures; [0068] Such
materials with moderators and neutron poisons added. [0069] The
enhancement of these materials with neutron poisons including, but
not limited to: (a) gadolinium, (b) hafnium, (c) erbium, and (d)
dysprosium, and
[0070] The enhancement of these materials with the addition of
moderators, including but not limited to: (a) carbon, (b) carbides,
(c) hydrogen isotopes, and (d) hydrides formed from any of the
hydrogen isotopes as the neutron-absorbing coatings to the metallic
support structure, or as the neutron-absorbing bulk-alloy
structural support material to enhance criticality safety for spent
nuclear fuel in storage pool racks, in baskets inside the dry
storage containers, inside the transportation cask, and eventually
inside the disposal container for repository disposal.
[0071] These compositions of matter simultaneously achieve a low
reduced glass transition temperature, high heat transfer
coefficients, low critical cooling rates, enhanced corrosion
resistance, enhanced damage tolerance, and increased hardness. The
high content of boron in these compositions enhance the criticality
safety of the spent nuclear fuels when they are stored in storage
racks, inside the dry storage containers, inside the transportation
containers, and in the disposal containers.
[0072] The invention also includes but is not limited to: the
applications of dispersed oxide ceramic particles (diameters
ranging from nanometers to several microns), where the oxide
particles consist of at least one alloying element involved in the
metal matrix or binder as the neutron-absorbing coatings to the
metallic support structure, or as the neutron-absorbing bulk-alloy
structural support material to enhance criticality safety for spent
nuclear fuel in storage pool racks, in baskets inside the dry
storage containers, inside the transportation cask, and eventually
inside the disposal container for repository disposal.
[0073] This invention includes, but is not limited to: the
applications of any thermal spray feed that includes ceramic
particles, with diameters ranging from nanometers to several
microns, and produced by reverse micelle synthesis as the
neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0074] The invention includes, but is not limited to: the
applications of any metal-ceramic composite coating, where the
ceramic particles are oxides, carbides, or nitrides, using
corrosion-resistant amorphous-metal formulated matrix or binder as
the neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0075] The invention also includes, but is not limited to: the
applications of the particle-size optimization method for achieving
fully-dense amorphous-metal coatings, a method that uses small
enough amorphous metal powders to ensure that the critical cooling
rate is achieved throughout, even in cases where the critical
cooling rate may be relatively high (.gtoreq.1000 K per second), as
the neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0076] The invention includes, but is not limited to: the
applications of the modification of such thermal-spray coatings
with post-spray, high-density infrared fusing (HDIF) to achieve
lower porosity, higher density, enhanced metallurgical bonding, and
better damage tolerance through controlled de-vitrification as the
neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0077] The invention includes, but is not limited to the
applications of: [0078] Electron beam evaporation of amorphous
metals in any manner to maintain cooling the deposit film at a rate
higher than the critical cooling rate; [0079] Laser ablation of the
homogeneous metallic alloy or any of its constituents in a manner
to produce the neutron absorbing coating; [0080] Direct current
(dc) and radiofrequency (rf) magnetron sputter deposition of the
homogeneous metallic alloy or any of its constituents in a manner
to produce the neutron absorbing coating; [0081] Laser ablation of
the metallic binder or any of its constituents in a manner to
produce the neutron absorbing metal-ceramic composite coating;
[0082] Direct current (dc) and radiofrequency (rf) magnetron
sputter deposition of the metallic binder or any of its
constituents in a manner to produce the neutron absorbing
metal-ceramic composite coating; [0083] Direct current (dc) and
radiofrequency (rf) magnetron sputter deposition of alloy
constituents in multi-layer fashion, with subsequent
inter-diffusion and reaction, to create the desired amorphous metal
composition as the neutron-absorbing coatings to the metallic
support structure to enhance criticality safety for spent nuclear
fuel in storage pool racks, in baskets inside the dry storage
containers, inside the transportation cask, and eventually inside
the disposal container for repository disposal. The applications
would probably be done with multi-magnetron sputtering and rotating
turntables, as demonstrated with other materials. Variations can
also be used, such as the deposition of reactive multi-layers for
the purpose of bonding amorphous metals, ceramics, glasses and
other material.
[0084] The invention also includes, but is not limited to: the
applications of welding processes for bulk amorphous metals, using
amorphous metals with critical cooling rates less than 100K per
second as a weld filler as the neutron-absorbing coatings to the
metallic support structure to enhance criticality safety for spent
nuclear fuel in storage pool racks, in baskets inside the dry
storage containers, inside the transportation cask, and eventually
inside the disposal container for repository disposal. One example
of applying such a glassy weld filler metal is the
tungsten-modified SAM1651, a material with an exceptionally low
critical cooling rate, which will therefore enable it to be used as
an amorphous-metal weld filler material for bulk amorphous metals.
The high content of boron in the SAM1651 applied as weld filler
material will enhance the criticality safety of the spent nuclear
fuels when they are stored in storage racks, inside the dry storage
containers, inside the transportation containers, and in the
disposal containers.
[0085] Referring now to FIG. 3, another embodiment of a system
incorporating the present invention is illustrated. This embodiment
is designated generally by the reference numeral 300. The
embodiment 300 provides a neutron absorbing coatings for spent
nuclear fuel (SNF) support structures, particularly for SNF
transportation and storage containers.
[0086] FIG. 3 is a perspective view of an embodiment of a container
301 with a tube assembly inside the container 301 that stores spent
nuclear fuel. Examples and additional details of the container 301
are shown in United States Patent Application No. 2005/0117687 by
George Carver et al for container and method for storing or
transporting spent nuclear fuel, published Jun. 2, 2005. United
States Patent Application No. 2005/0117687 by George Carver et al
for container and method for storing or transporting spent nuclear
fuel, published Jun. 2, 2005 is incorporated herein by reference.
Other components for the handling and storage of spent nuclear
material include storage pool racks, in baskets inside the dry
storage containers, inside the transportation cask, and eventually
inside the disposal container for repository disposal.
[0087] The container 301 includes a plurality of elongated tubes
302 that links together to form the tube assembly. The elongated
tubes 302 include four sidewalls and four corners that can be
arranged to form a square-like or rectangular-like cross section.
In alternative embodiments, the tubes can be arranged in other
geometric shapes, e.g., circle, triangle, heptagon, hexagon and
octagon. The components for the handling and storage of spent
nuclear material such as storage pool racks, baskets inside the dry
storage containers, inside the transportation cask, and inside the
disposal container for repository disposal undergoing corrosion.
The use of advanced corrosion-resistant materials to prevent
corrosion of these important surface areas would be extremely
beneficial. In addition, the corrosion prevention also needs to
prevent nuclear criticality in spent fuel storage, transportation,
and/or disposal, neutron-absorbing materials (or neutron poisons,
such as borated stainless steel, BORAL.TM., METAMIC.TM., Ni--Gd,
and others).
[0088] The tubes 302 are mounted with first rods (not shown) or
second rods (not shown) or both. Preferably, the first rods are
cylindrical and have openings that are located about the center
diameter and along the length of the first rods. The second rods
are cylindrical and have no openings. The first rods enable the
tubes 302 to be linked together. The first rods and the second rods
facilitate horizontal design load transfer through the tube
assembly and provide structural stability during the tube
assembling and handling activities. In an alternative embodiment,
the first rods and second rods can be in other geometric shapes,
e.g., triangle, hexagon, and octagon. The container 301 and other
components for the handling and storage of spent nuclear material
are coated with advanced corrosion-resistant materials to prevent
corrosion of these important surface areas.
[0089] The present invention provides the application of the new
class of boron-containing High-Performance Corrosion-Resistant
Metal (HPCRM) as coatings to the metallic support structure used in
storage pool racks, in support baskets inside the dry storage
containers, inside the transportation casks, and inside the
disposal container for spent nuclear fuels. These materials
include: (1) thermally-sprayed iron-based amorphous metals with
relatively large concentrations of boron; (2) any thermal-spray
coating with refractory boride particles including, but not limited
to the borides of carbon, titanium, chromium, nickel, and other
similar compounds; (3) cold-spray coatings with a relatively soft,
corrosion-resistant binder such as aluminum, titanium, zirconium,
or other similar metal, with refractory boride particles including,
but not limited to the borides of carbon, titanium, chromium,
nickel, and other similar compounds; and (4) the use of thermal- or
cold-spray as a means of joining plates of boron-containing alloys
for use in nuclear fuel assembly support structures; and (5) and
such materials with moderators and neutron poisons added. The
materials discussed in (1) through (5) can be enhanced with neutron
poisons including, but not limited to: (a) gadolinium, (b) hafnium,
(c) erbium, (d) dysprosium, and (e) cadmium. The materials
discussed in (1) through (5) can also be enhanced withh the
addition of moderator materials, including but not limited to: (1)
carbon, (ii) carbides, (iii) hydrogen isotopes, and (iv) hydrides
formed from any of the hydrogen isotopes. The metallic support
structural material can be the less corrosion-resistant stainless
steel, or borated stainless steel (such as Boraflex, BORAL.TM.,
etc.), or other metallic-based materials (such as carbon steel, the
aluminum-based boron-carbide composite METAMIC.TM., and the
nickel-based gadolinium alloy, etc.). The applications of these
boron-containing, iron-based amorphous metals are achieved with
advanced thermal spray technology. These boron-containing
iron-based structure amorphous materials (SAM) can also be applied
as bulk alloy structural support material for spent nuclear fuels
used in storage pool racks, in support baskets inside the dry
storage containers, inside the transportation casks, and inside the
disposal container emplaced in geologic environment.
[0090] Uses of the present invention include the applications of:
[0091] Thermally-sprayed iron-based amorphous metals with
relatively large concentrations of boron; [0092] Such coatings with
refractory boride particles including, but not limited to the
borides of carbon, titanium, chromium, nickel, and other similar
compounds; [0093] Cold-spray coatings with a relatively soft,
corrosion-resistant binder such as aluminum, titanium, zirconium,
or other similar metal, with refractory boride particles including,
but not limited to the borides of carbon, titanium, chromium,
nickel, and other similar compounds; [0094] The use of thermal- or
cold-spray as a means of joining plates of boron-containing alloys
for use in nuclear fuel assembly support structures; [0095] Such
materials with moderators and neutron poisons added. [0096] The
enhancement of these materials with neutron poisons including, but
not limited to: (a) gadolinium, (b) hafnium, (c) erbium, and (d)
dysprosium, and [0097] The enhancement of these materials with the
addition of moderators, including but not limited to: (a) carbon,
(b) carbides, (c) hydrogen isotopes, and (d) hydrides formed from
any of the hydrogen isotopes as the neutron-absorbing coatings to
the metallic support structure, or as the neutron-absorbing
bulk-alloy structural support material to enhance criticality
safety for spent nuclear fuel in storage pool racks, in baskets
inside the dry storage containers, inside the transportation cask,
and eventually inside the disposal container for repository
disposal.
[0098] These compositions of matter simultaneously achieve a low
reduced glass transition temperature, high heat transfer
coefficients, low critical cooling rates, enhanced corrosion
resistance, enhanced damage tolerance, and increased hardness. The
high content of boron in these compositions enhance the criticality
safety of the spent nuclear fuels when they are stored in storage
racks, inside the dry storage containers, inside the transportation
containers, and in the disposal containers.
[0099] The invention also includes but is not limited to: the
applications of dispersed oxide ceramic particles (diameters
ranging from nanometers to several microns), where the oxide
particles consist of at least one alloying element involved in the
metal matrix or binder as the neutron-absorbing coatings to the
metallic support structure, or as the neutron-absorbing bulk-alloy
structural support material to enhance criticality safety for spent
nuclear fuel in storage pool racks, in baskets inside the dry
storage containers, inside the transportation cask, and eventually
inside the disposal container for repository disposal.
[0100] This invention includes, but is not limited to: the
applications of any thermal spray feed that includes ceramic
particles, with diameters ranging from nanometers to several
microns, and produced by reverse micelle synthesis as the
neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0101] The invention includes, but is not limited to: the
applications of any metal-ceramic composite coating, where the
ceramic particles are oxides, carbides, or nitrides, using
corrosion-resistant amorphous-metal formulated matrix or binder as
the neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0102] The invention also includes, but is not limited to: the
applications of the particle-size optimization method for achieving
fully-dense amorphous-metal coatings, a method that uses small
enough amorphous metal powders to ensure that the critical cooling
rate is achieved throughout, even in cases where the critical
cooling rate may be relatively high (.gtoreq.1000 K per second), as
the neutron-absorbing coatings to the metallic support structure to
enhance criticality safety for spent nuclear fuel in storage pool
racks, in baskets inside the dry storage containers, inside the
transportation cask, and eventually inside the disposal container
for repository disposal.
[0103] The invention includes, but is not limited to the
applications of: [0104] Electron beam evaporation of amorphous
metals in any manner to maintain cooling the deposit film at a rate
higher than the critical cooling rate; [0105] Laser ablation of the
homogeneous metallic alloy or any of its constituents in a manner
to produce the neutron absorbing coating; [0106] Direct current
(dc) and radiofrequency (rf) magnetron sputter deposition of the
homogeneous metallic alloy or any of its constituents in a manner
to produce the neutron absorbing coating; [0107] Laser ablation of
the metallic binder or any of its constituents in a manner to
produce the neutron absorbing metal-ceramic composite coating;
[0108] Direct current (dc) and radiofrequency (rf) magnetron
sputter deposition of the metallic binder or any of its
constituents in a manner to produce the neutron absorbing
metal-ceramic composite coating; [0109] Direct current (dc) and
radiofrequency (rf) magnetron sputter deposition of alloy
constituents in multi-layer fashion, with subsequent
inter-diffusion and reaction, to create the desired amorphous metal
composition as the neutron-absorbing coatings to the metallic
support structure to enhance criticality safety for spent nuclear
fuel in storage pool racks, in baskets inside the dry storage
containers, inside the transportation cask, and eventually inside
the disposal container for repository disposal. The applications
would probably be done with multi-magnetron sputtering and rotating
turntables, as demonstrated with other materials. Variations can
also be used, such as the deposition of reactive multi-layers for
the purpose of bonding amorphous metals, ceramics, glasses and
other material.
[0110] The invention also includes, but is not limited to: the
applications of welding processes for bulk amorphous metals, using
amorphous metals with critical cooling rates less than 100K per
second as a weld filler as the neutron-absorbing coatings to the
metallic support structure to enhance criticality safety for spent
nuclear fuel in storage pool racks, in baskets inside the dry
storage containers, inside the transportation cask, and eventually
inside the disposal container for repository disposal. One example
of applying such a glassy weld filler metal is the
tungsten-modified SAM1651, a material with an exceptionally low
critical cooling rate, which will therefore enable it to be used as
an amorphous-metal weld filler material for bulk amorphous metals.
The high content of boron in the SAM1651 applied as weld filler
material will enhance the criticality safety of the spent nuclear
fuels when they are stored in storage racks, inside the dry storage
containers, inside the transportation containers, and in the
disposal containers.
[0111] FIG. 3 shows the coating 305 being applied to the SNF
transportation and storage container 301. The coating 305 is being
applied by a deposition process. A deposition device 304 is shown
applying a spray 303 to the SNF transportation and storage
container 301. In addition to the coating being applied to the SNF
transportation and storage container 301, the coating 305 can be
applied to spent nuclear fuel (SNF) support structures including
metallic support structure used in storage pool racks, in support
baskets inside the dry storage containers, inside the
transportation casks, and inside the disposal container for spent
nuclear fuels.
[0112] In the case of a boron-containing iron-based amorphous
metal, engineered for exceptional corrosion resistance through
manipulation of chromium, molybdenum and tungsten concentration, it
has been shown that a coating with a thickness of approximately one
millimeter (1 mm) on the spent fuel support structure (also known
as the basket) inside of a proposed spent fuel disposal container
for a proposed geologic repository can reduce the criticality
factor (k-effective) by as much as ten percent (10%). This is a
dramatic improvement in criticality safety in such engineered
systems.
[0113] While the invention may be susceptible to various
modifications and alternative forms, specific embodiments have been
shown by way of example in the drawings and have been described in
detail herein. However, it should be understood that the invention
is not intended to be limited, to the particular forms disclosed.
Rather, the invention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention as defined by the following appended claims.
* * * * *