Method and apparatus for the management of hazardous waste material

A container for storing hazardous waste material, particularly radioactive waste material, consists of a cylindrical body and lid of precipitation hardened C17510 beryllium-copper alloy, and a channel formed between the mated lid and body for receiving weld filler material of C17200 copper-beryllium alloy. The weld filler material has a precipitation hardening temperature lower than the aging kinetic temperature of the material of the body and lid, whereby the weld filler material is post weld heat treated for obtaining a weld having substantially the same physical, thermal, and electrical characteristics as the material of the body and lid. A mechanical seal assembly is located between an interior shoulder of the body and the bottom of the lid for providing a vacuum seal.

RELATED INVENTION 
The invention of the present application is related to co-pending 
application Ser. No. 07/951,209, filed on Sep. 25, 1992, for METHOD AND 
APATUS FOR WELDING PRECIPITATION HARDENABLE MATERIALS. The teachings of 
this co-pending application are incorporated into this present application 
in their entirety by reference, provided any such teachings are not 
inconsistent with any teachings herein. 
BACKGROUND OF THE INVENTION 
1. Field of The Invention 
The field of the present invention relates generally to hazardous waste 
management, and more particularly to the management of radioactive waste 
materials. 
2. Discussion of Related Art 
The management of hazardous waste material, including radioactive, 
biological, and chemical waste, is of critical concern to maintaining a 
safe environment. The management of such waste is multifaceted. An initial 
concern is to insure a high level of safety in handling these wastes at 
any given time. As such waste material is produced at a given site, the 
first concern is the containment of such hazardous waste products or 
material. As the secured waste material accumulates at a given site, the 
next concern is to transport the material away from the site in approved 
shipping containers, for delivery to a specialized facility for either 
storage and/or processing. Typically, high-level nuclear waste material 
produced at nuclear utility sites must be locally secured for a period of 
about 10 to 20 years. Thereafter, the radioactive waste material is 
planned to be transported to a specialized facility for longer term 
storage, and/or waste processing. In such intermediate term storage 
facilities nuclear waste may be stored in containers for 40 to 100 years, 
with the contents being accessible, which requires that the high-level 
nuclear waste must be retrievable and inspectable. After the passage of 
the intermediate storage time, the nuclear waste material may be processed 
or transported to other specialized sites for long term storage, for 
periods ranging from 300 to 1,000 years, for example. One such long term 
storage site is currently planned for the Tuff Repository in Nevada. As 
previously indicated, the management of hazardous waste material is not 
limited to radioactive waste, and similar concerns are associated with the 
management of biological and chemical waste. For chemical and biological 
wastes, the hazardous material may be processed, and rendered benign while 
in the container. However, radioactive waste management is particularly 
difficult in view of certain nuclear waste materials retaining high levels 
of radio activity for thousands of years. 
Over the past 40 years there has been increasing concern and activity in 
providing appropriate containers and inspection apparatus for the storage 
of hazardous waste, particularly nuclear waste material. Recently, a 
number of articles have been published describing present activities in 
these areas. One article by T. W. Doering and D. Stahl, entitled "High 
Level Nuclear Waste Retrievability", appeared in The Proceedings of The 
Third International Conference on High Level Radioactive Waste Management, 
Apr. 12-16, 1992, pages 362-365, and describes a design of waste packages 
for deep geologic disposal of spent nuclear fuel, and high-level waste 
glass. The inspectability of such waste packages is also discussed. 
In another article by D. Peters, K. Kundig, and D. Medley, entitled 
"Multi-Barrier, Copper-Base Containers for HLW Disposal", from The 
Proceedings of The Third International Conference on High Level 
Radioactive Waste Management, Apr. 12-16, 1992, pages 366-376, the use of 
copper and aluminum bronze for such containers is discussed. Various types 
of containers using such materials are also shown and described. The use 
of copper for various portions of such containers is emphasized. 
Another article by K. Janberg, H. Spilker, and R. Huggenberg, entitled "The 
German Cask-Concept for Intermediate and Final Storage of Spent Fuel", 
from The Proceedings of The Third International Conference on High Level 
Radioactive Waste Management, Apr. 12-16, 1992, pages 385-394, shows and 
describes various designs for canisters for use in storing radioactive 
material. The basic design includes a final disposal cask or canister 
stored within an outer shielding cask or canister. Each canister is 
provided with its own lid. 
Over the past 40 years many U.S. patents have been obtained for various 
container designs for storing nuclear waste. A number of such patents are 
discussed immediately below. 
Dougherty, U.S. Pat. No. 2,758,367, shows a down welding process for 
welding closure caps to cylindrical containers. The cylindrical containers 
are oriented on a lathe-like device, with the longitudinal access of the 
container being parallel to the horizontal plane. A welding head is 
positioned proximate a circumferential groove for receiving a welding 
bead, with the welding head being above the cylinder and groove for 
providing down welding. As the cylinder is rotated the welding head is 
operated for causing a weld bead to be formed within the circumferential 
groove. 
Lloyd et al., U.S. Pat. No. 3,327,892, shows a stainless steel tubular 
container for storing nuclear material. The end of the container is sealed 
via a cup-shaped lid 2. The upper circumferential edge of the cup lid 2 is 
welded via a circumferential weld 7 to the top edge of the container 1. 
Copper brazing is used to seal the sides of the cup lid 2 to opposing 
sides of the container 1. 
Sannipoli, U.S. Pat. No. 3,734,387, teaches a tank fabrication system, 
whereby individual sections of a large cylindrical tank are oriented with 
their longitudinal axes parallel to the horizontal plane, and placed upon 
movable trollies. Apparatus is shown for rotating two sections to be 
joined for permitting welding thereof via a welding head positioned above 
the intersection between the two sections. 
Eroshkin et al., U.S. Pat. No. 4,187,410, teaches a method for joining two 
pieces of metal together through use of a multi-pass welding bead within a 
narrow groove formed between the pieces. 
Gesser et al, U.S. Pat. No. 4,320,847, shows a container for storing spent 
fuel elements that is substantially cylindrical in its main lower portion 
and has an uppermost portion that has diverging walls. A cup-like lid is 
fitted within the uppermost portion of the outwardly flaring wall members 
for sealing the container. The cup-like cap is welded about its 
circumferential lip to the interior wall portion of the frusto conical 
widening at the upper portion of the container. 
Janberg, U.S. Pat. No. 4,508,969, shows a cylindrical container for storing 
spent reactor fuel elements. The container is closed off by a dome shaped 
lid or top member. The material for the container is indicated as being 
carbon steel or high-grade steel where thinner walls can be used. The 
outer portion of the container is a shielding layer made of polyethylene 
or some other hydrocarbon for absorbing residual neutron radiation. 
Popp et al. U.S. Pat. No. 4,527,065, shows a storage container for the long 
term storage of radioactive material. The container is made from material 
such as cast iron and cast steel. A relatively flat cap or cover 6 is 
shaped to provide a circumferential weld groove between the bottom portion 
of the cap and the top lip of the container for permitting the cap to be 
welded to the container. 
Popp et al., U.S. Pat. No. 4,572,959, shows a container for the long term 
storage of radioactive waste. The container is cylindrical and includes in 
the topmost portion a circular recess for receiving a closure cap or plug 
4. A circumferential welding groove is formed between a beveled upper 
portion of the cap and a beveled or sloping interior topmost rim portion 
of the container, for receiving a weld bead. The container includes an 
interior base portion of cast iron, an outer wall layer 3 made of 
high-alloy austenitic nodular cast iron, and an interior cover 5 is fitted 
below the top cap 4. 
Popp, U.S. Pat. No. 4,596,688, shows a container for the long term storage 
of radioactive materials that is made of steel, cast steel or similar 
material. The container is multilayered and substantially cylindrical in 
shape. The open top end is sealed by a multilayered cap which is shaped to 
form a circumferential groove with the top lip of the container for 
receiving a weld bead. Protective layers of the container are made of 
graphite, ceramic material or an enamel material. 
Warder et al., U.S. Pat. No. 4,872,563, shows a container for storing 
hazardous materials. The container is particularly designed for storing 
biological materials. 
Gaudin, U.S. Pat. No. 4,881,678, shows a robotic welding system that is 
remotely controlled. The system employs a welding process for applying a 
weld bead in multiple passes into a groove between two parts to be joined. 
Madle et al. U.S. Pat. No. 4,976,912, teaches an apparatus for welding and 
testing a weld on a cover for sealing a container storing radioactive 
material. The system provides for mounting the container vertically on a 
rotatable platform. The system further includes a bridge-like arrangement 
for retaining welding tools in a fixed position for welding the cap to the 
top of the container as the container is rotated. Inspection tools are 
also located on the bridge in a fixed container for permitting inspection 
of the weld as the container is rotated. 
Leebl, et al., U.S. Pat. No. 3,754,141, shows a storage container for 
radioactive material. The container is cylindrical and is provided with a 
shallow cup-like cap or lid. The container actually includes multiple 
containers surrounding one another. 
Backus, U.S. Pat. No. 3,770,964, shows a container for storing radioactive 
material. This container shows a pair of annular seals 32 disposed within 
circular grooves for sealing a bottom portion of a cap to an interior 
ledge-like lip portion of the container. 
Bock et al., U.S. Pat. No. 4,078,811, shows a sealing device that includes 
an elastic circumferential seal 3 for sealing a lid to the top of a 
container. 
Baatz et al., U.S. Pat. No. 4,274,007, shows the use of a plurality of a 
"O"-ring seals between a step-shaped lid member and the interior step-like 
ledge and side portions of the upper portion of a storage container. The 
"O"-rings are contained within annular grooves. 
Baatz et al. U.S. Pat. No. 4,445,042, shows a cylindrical container for 
radioactive waste that shows the use of metal "O"-rings, metal, 
elastomeric "O"-rings, and metal-to-metal seals, for sealing a converging 
step-like lid to a diverging stepped interior upper portion of the 
container. 
Fields, U.S. Pat. No. 4,535,250, shows a container for radioactive material 
including silicone rubber seals 20, 29 and 31 for sealing a lid to the top 
of the container. 
Popp et al., U.S. Pat. No. 4,594,214, shows a container for storing 
radioactive materials that includes a plurality of concentric layers or 
containers within a container. The innermost container is sealed by a 
screwed in cap. An intermediate portion of the container is sealed via a 
cup-like cap welded to an upper lip of the outer container via a topmost 
circumferential welding groove between the cap and interior side edge of 
the outer container. An outermost cap is screwed onto the top of the 
container. 
Schroeder et al., U.S. Pat. No. 4,673,814, shows a cylindrical container 
for storing radioactive material. The container includes an interior 
uppermost diverging wall portion for receiving a cap member having 
outwardly diverging sides. The cap is welded via a weld groove to an 
interior portion of the uppermost wall of the container. 
Koester et al, U.S. Pat. No. 4,702,391, disclose a corrosion resistant 
container for radioactive material. The container is lined with 
titanium-palladium alloy applied by explosion plating. Electron beam 
welding is used to close seams in the container. The bottom and cover lid 
of the container are apparently made of steel plates covered with a 
corrosion protected layer of titanium-palladium alloy applied by explosion 
plating. A circumferential weld is used about the bottom and top portions 
of the container. A cover plate 6 is used to cap off the container. 
Bienek et al, U.S. Pat. No. 4,738,388, shows a container for storing 
radioactive material. The container is cylindrically shaped. A dual 
element cap mechanism is used for closing off the container. The cap 
includes metal-to-metal sealing, and is provided with a main first member 
that screws into the interior upper portion of the container, and forms a 
topmost circumferential groove 17 with the inside edge of the top portion 
thereof for receiving a weld bead. 
Popp et al., U.S. Pat. No. 4,818,878, shows a double container for storing 
radioactive material. Several different embodiments are disclosed for 
sealing the top of the container through use of different capping 
mechanisms. Metal sealing rings are disclosed, as are the use of 
circumferential welding grooves for receiving a weld for sealing capping 
members to the container. 
Madle et al., U.S. Pat. No. 4,847,009, shows a container for storing 
radioactive material that includes an inner container provided with a dome 
lid 8. The inner container is contained within an intermediate container 
that also is sealed at its top end with a dome lid 12. 
McDaniels, Jr., U.S. Pat. No. 4,883,637, shows a closure arrangement for a 
container containing radioactive waste. "O"-ring seals 31 are used for 
sealing off one portion of a cap 26 to an interior flange or lip in an 
upper portion of a container. 
Takeshima et al., U.S. Pat. No. 5,015,863, shows the use of shielding 
material for shielding nuclear waste containers. Composite particles are 
used to form the radiation shield from a group of materials including, but 
not limited to, oxides of beryllium, beryllium alloys, copper, copper 
alloys, and so forth. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide an improved container for both the 
short and long term storage of hazardous waste material. 
Another object of the invention is to provide an improved lid for a 
container for hazardous waste, for facilitating the short term and 
intermediate term storage of such waste. 
Another object of the invention is to provide a lid for a container for 
hazardous waste, for facilitating the long term storage of such waste, 
whereby the improved lid further facilitates periodic inspection of the 
closure mechanism. 
Another object of the invention is to provide a container which can be 
unsealed, the contents inspected or modified, and the container resealed. 
Yet another object of the invention is to provide an improved container for 
storing hazardous waste that is compatible with common remote manipulator 
apparatus. 
Another object of the invention is to provide an improved container for 
storing and sealing hazardous waste using mechanical means. 
Another object of the invention is to provide a configuration of container, 
lid and weld all of which take advantage of mechanical stability, high 
strength and isotrophy inherent in precipitation hardenable material. 
Yet another object of the invention is to provide an improved container for 
storing hazardous waste that includes high mechanical integrity, and 
facilitates automatic welding of sealing lids or caps thereto. 
With these and other objects of the invention in mind, the present 
invention provides in one embodiment for intermediate and long term 
storage of hazardous waste, an elongated cylinder consisting of an age 
hardenable alloy, for example copper-beryllium alloy material. The 
container is provided with a dome shaped lid including three tapered 
horizontal holes at the ends of slots evenly spaced about the 
circumference, for receiving handling apparatus for both installing and 
removing the lid from the container, establishing the mechanical seal, and 
for lifting the container with the lid connected thereto. The lower 
portion of the dome lid is threaded for screwing into the top of the 
cylindrical container and forming a mechanical seal therewith. A groove is 
provided about the circumference of the dome lid where it meets with the 
top edge of the container for receiving a multi-turn helical weld bead. 
The weld filler material is also an age hardenable alloy, for example a 
copper-beryllium alloy material. After welding, the weld is heat-treated 
for causing the weld material to become precipitation hardened to have 
substantially the same mechanical characteristics as the material of the 
container. 
In another embodiment of the invention, the cylindrical storage container 
is provided with a cup-like cap. The cup-like cap includes a smooth 
uppermost track surface similar to the lip of a cup for receiving a remote 
inspection tool that is able to rotate about the lip of the cup for 
inspecting the seals between the cap and the main cylinder body through 
use of ultrasonic or x-ray inspection. A groove is formed between the top 
of the container and the overlapping portion of the cup-like cap for 
accepting a multi-layer helical weld bead, similar to the dome-cap 
embodiment of the invention previously mentioned. The interior inside 
surface of the cup-like lid is indexed in order to permit the inspection 
tool to locate itself at all times relative to its position on the cap, 
thereby permitting rapid identification of any given area of the cap under 
inspection. 
In either of the dome lid or cup-like lid or cap embodiments of the 
invention, "O"-ring, laminate metal, and/or temperature triggered metal 
sealing means are used between the bottom of the lids or cap and adjoining 
shoulder or inside wall surface of the respective lids.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
As shown in FIGS. 1 and 6, the present container 2 includes an elongated 
cylindrically shaped body 4, but is not meant to be so limited. In the 
embodiment of FIG. 1, a dome lid 6 provides a closure for the open top of 
body 4. In the example of storing high-level nuclear waste, the embodiment 
of FIG. 1 provides for the securing for tens of years at the utility site 
and intermediate term storage under conditions where the container 2 is 
accessible for monitoring, and the high-level nuclear waste are 
retrievable and inspectable and for containment for containment for 
hundreds of years at a repository complex. The embodiment of FIG. 1 
represents either a stand alone container 2, or the container 2 of a 
container-shield set or the core of a containment system which is a 
concept where corrosion, mechanical integrity and shielding are discretely 
addressed. The design of the configuration of FIG. 1 is described in 
greater detail below. 
In another embodiment of the invention shown in FIG. 6, a container 12 is 
closed off by a cup-like lid or cap 8. This embodiment provides special 
advantages for long term storage of nuclear waste, typically requiring 
complete containment for periods of hundreds of years. This alternative 
embodiment is described in greater detail below. 
In one preferred embodiment of the invention, the container 4 is fabricated 
from precipitation hardenable alloys, as are the lids 6 and 8, and the 
weld filler material providing the weld 10 for securing the dome lid or 
cap 6 and cup-lid 8 to their associated containers 4. The present inventor 
determined that such alloys are desirable for use in containers for 
storing hazardous waste, in view of the superior mechanical stability, 
homogenous properties, cyclic fatigue capability, high fracture toughness, 
and significant impact strength. He recognized that the alloys are ideal 
for containing high-level radioactive waste material, for example. More 
specifically, he discovered that one of the preferred material for the 
body 4, lids 6 and 8, and weld 10, is copper-beryllium. However, the 
present invention is not meant to be limited to that family of alloys. 
Also, although the present description emphasizes the use of the various 
embodiments of the invention for providing containers for radioactive 
waste material, the containers in the various embodiments of the invention 
are also suitable for use for storing chemical, biological, and other such 
hazardous waste material. 
In FIG. 2, a partial sectional view is shown of the embodiment of the 
invention of FIG. 1. The body 4 of container 2 consists of a single-wall, 
corrosion-resistant metal material. The preferred material provides 
non-galling properties, suitability for use in high radiation dose 
environments, and high thermal conductivity. The container 2 and lid 6 are 
manufactured in the precipitation hardened condition. The present inventor 
chose the illustrated geometry for the container 2, and for container 12 
of FIG. 6, to provide a robust configuration with significant design 
margin by utilizing high levels of strength, ductility, fracture 
toughness, and fatigue resistance, for the safe storage of nuclear waste 
material. 
The dome lid 6 of FIG. 1, and cup lid 8 of FIG. 6, provide simple but 
effective closure designs. As will be described in greater detail below, 
these closures provide the capability to retrieve and inspect waste 
materials stored within the container bodies 4 and reseal. This is 
particularly applicable for the dome lid 6 closure preferred for use in 
storing radioactive waste materials within body 4 at local utilities. 
In closing the containers 2 and 12 of FIGS. 1 and 6, respectively, as will 
be shown in detail below, a mechanical, metal-to-metal seal 32 (see FIG. 
4) is provided between the associated lid 6, 8, respectively, and the top 
inner portion of the associated body 4. Prior to welding, the seal 32 is 
inspected to insure its integrity. Thereafter, the weld 10 is made to 
rigidly secure and seal off the lid 6 or 8 as mated to the associated 
container body 4. After welding, the weld 10 is heat treated. In this 
regard, the weld filler composition is selected from an age hardenable 
material that has a heat treatment temperature range which does not alter 
the characteristics of the material of the body 4 of the associated 
container 2 or 12 or the lids 6 and 8. As will be described in further 
detail below, the final weld 10 for the storage container 12 is 
inspectable through use of either or both ultrasonic transmission, and 
direct x-ray inspection techniques. 
As shown in FIG. 2, the dome cap or lid 6 is mated to the top portion of 
the body 4 through use of coarse threads on a lower reduced portion of 
dome lid 6 screwing into coacting internal threads near the interior top 
portion of body 4, in this example. With further reference to FIG. 2, in 
combination with FIGS. 3 and 4, in this example, the length of the 
container 2 with the dome cap 6 in place is shown as L1, and in one 
application is expected to be about 185 inches. The length of L2 from the 
bottom of the dome lid 6 when installed on the body 4 to the bottom of the 
body 4 is about 180 inches, in this example. The thickness T1 of the 
sidewalls of container 4 is 1.3 inch. The outside diameter D1 is 24 
inches. The thickness T2 of the bottom of the container is two inches, and 
the radius R1 at the bottom interior circumference of the body 4 is two 
inches. Note that all dimensions given in this example are for purposes of 
illustration only, and are not meant to be limiting. Depending upon the 
application, the dimensions can be set within any practical limit. 
The design of the dome lid 6 will now be described in greater detail, with 
further reference to FIGS. 1 through 4. In this example, three machined 
slots 18 are included about the top circumference of the dome lid 6 for 
providing alignment surfaces and torque loading points for use with 
handling devices. The back walls 20 of each of the slots 18 include a 
radially aligned horizontal tapered hole 22 from the bottom center portion 
of the backwall 20 toward the center of the dome lid 6. The width of each 
of the slots 18, L4, is in this example, 5.0 inches. The backwalls 20 of 
the slots 18 are located a distance L5 from the center of the dome lid 6, 
in this example, 6.5 inches. The depth L6 of the hole 20 in this example 
is 2.0 inches. Also, the rim 24 at the top of the body 4 is shaped to form 
half of a U-shaped weld channel 26, with the other half of the weld 
channel 26 being provided by a lower undercut circumferential portion 27 
of the dome lid 6, as shown. When the dome lid 6 is screwed completely 
into mating with the body 4 and the metal seal 28 is compressed, the weld 
channel 26 so formed has a sweep angle .beta. of 20.degree., in this 
example. The width L3 of the weld channel opening 26 is 1.0 inch, in this 
example. Also, the diameter D2 of the tapered holes 22 is 1.5 inches, in 
this example. The slots 18 are displaced in angle .alpha. from one 
another. In this example, slots 18 are evenly spaced with .alpha. being 
120.degree.. The distance L7 from the center of the tapered holes 22 to 
the top center portion of the dome lid 6 is shown as L7, and in this 
example is one inch. The back walls 20 of each of the slots 18 have a 
depth L8 of 3 inches in this example. The diameter D3 of the dome lid 6 is 
in this example equal to the diameter D1 of the cylindrical body 4, which 
as previously mentioned is 24 inches, in this example. 
In FIG. 4, the dome lid or cap 6 is shown fully installed on the body 4. A 
mechanical seal region 28 is provided between an interior shoulder 30 of 
body 4 located immediately below the thread 16 at the top interior portion 
of body 4, for providing one sealing surface. A seal assembly 32, which 
will be described in greater detail below, is provided between the bottom 
of the dome lid 6 and the interior shoulder 30 of body 4, as shown. 
The dome lid 6 is fabricated from a solid piece of material, in this 
example. As shown in FIG. 5, the bottom of the dome lid 6 is substantially 
flat, for providing a proper mechanical interface with the seal assembly 
32. 
As previously mentioned, the container 2 with dome lid 6 of FIG. 1 is 
primarily intended for local securing of nuclear waste at a utility site, 
transport of the nuclear waste, and intermediate term storage of the 
nuclear waste to a designated site. For long term storage (hundreds of 
years) of the associated nuclear waste in the body 4, the dome lid 6 is 
removed from the body 4, waste material may be retrieved, inspected, 
and/or processed, and afterwards the cup lid 8 installed thereon. Further 
details of the second embodiment of the invention for providing the 
container with cup lid 12, will now be described. 
The container with cup lid 12 includes the cylindrical body 4, as 
previously described. FIG. 7 shows a longitudinal cross section of the 
container 12 including the cup lid or cap 8 installed on the body 4. As 
shown in FIGS. 7 through 9, the dimensioning of the cup lid 8 has been 
designed to conform to the greatest extent possible to the dimensioning 
and angular configurations associated with the dome cap 6. The cup lid 8 
includes a cylindrical well portion formed by vertical sidewalls 36, and a 
bottom portion 38. The side walls 36 have a thickness T2 of 1.3 inches, 
whereas the bottom portion 38 has a thickness T3 of 1.3 inches, in this 
example. Note that the diameter D3 of cup lid 8 is identical to that of 
the dome lid 6, 24 inches, in this example. Also in this example, three 
through holes 40, each having a diameter D4 of 2 inches, in this example, 
are located in the side wall 36 in radial orientation displaced an angle 
.alpha. from one another (.alpha. is 120.degree. in this example). The 
center of each of the through holes 40 are located a distance L9 from the 
top edge of the cup lid 8. In this example, L9 is 2.5 inches. As with the 
dome lid 6, the weld 10 is provided for securing the cup lid 8 to the body 
4. The bottom or lower narrowed portion of the cup lid 8 includes threads 
42 for mating with the interior thread 16 of body 4. For design 
compatibility, and for lid interchangeability, the lower reduced outside 
diameter portion of the cup lid 8 is in the preferred embodiment 
substantially identical to the lower portion of the dome lid 6. 
Accordingly, in the preferred embodiment, the bottom view of the cup lid 8 
is identical to the bottom view of the dome lid 6, as shown in FIG. 5. 
Note also that the handling apparatus for installing or screwing the cup 
lid 8 into the body 4 will have different design configuration details for 
the handling apparatus for installing the dome lid 6 into the body 4. The 
handling apparatus will, in either case, in addition to providing for 
installing and removing the lids 6 and 8, respectively, from the body 4, 
be capable of also lifting the containers 2 and 12 with their associated 
caps or lids 6 and 8 and contents, respectively. Further details of such 
apparatus is given below. 
The present inventor anticipated that an inspection tool or apparatus must 
be designed to facilitate rapid and remote inspection of the weld seal 10 
between the cup lid 8 and body 4. The cup lid 8 includes, as shown in FIG. 
10, holes 40 also providing position references. The position reference 
holes 40 provide a means for permitting an inspection apparatus to 
determine its location on the cup lid 8, that is its angular position from 
a datum point, for permitting identification of each portion of the weld 
10 that is either x-rayed or inspected by ultrasound, or some other known 
inspection technique. The track 44 also provides defect calibration for 
various flaw sizes and depths. In this manner, the condition of the weld 
10 from one inspection to another can be compared, and any defect in any 
portion of the weld 10 can readily be characterized, to permit appropriate 
analysis and repair. 
In a further embodiment of the invention, for facilitating periodic 
inspection of the weld 10, a cup-like insert 46 (see FIGS. 11 and 12) is 
dimensioned to frictionally fit within the cylindrical weld 34, against 
the mechanically indexed inside surface of the circular sidewalls 36 of 
cup lid 8. Partial circular through holes 48 are provided through the 
sidewall 50 of insert 46, for alignment with and as a continuation of the 
holes 40 of cup lid 8. In this manner, the through holes 40 are not 
blocked by the insert 46, for permitting an appropriate handling tool to 
be utilized with the container 12 having the insert 46 in place in cup lid 
8. In this example, the top edge 52 of insert 46 is below the top edge 54 
of cup lid 8. A shallow band-like channel 56 is formed about the 
circumference in the lower portion of the outside surface of sidewall 50 
of the film insert 46. The purpose of the channel 56 is to retain x-ray 
film 58 of FIG. 12 in facing the circumferential weld 10 located on the 
opposite side of the sidewall 36 of cup lid 8. As a standard industrial 
radiation source is rotated about the cup lid 8 or alternatively as the 
container is rotated and the radiation source remains stationary, x-rays 
are directed through the weld 10 for exposing the film 58, to provide both 
an indication of the condition of the weld 10, locations, indices and 
calibration defects, and a permanent record of each inspection made 
thereof, as a basis for comparison with previous or subsequent films 58 
produced during prior or subsequent inspections. 
The present closure design in its various alternative embodiments, as 
discussed in greater detail below, provides a simple, underwater (in the 
spent fuel storage pool) or hot cell assembly sequence, while retaining 
the capability to retrieve and inspect the hazardous waste material stored 
within the body 4, particularly with regard to the embodiment of container 
2 for securing and storing radioactive waste material at a local utility. 
In this example, the closure sequence for either of the containers 2 or 12 
is initiated by installing either the dome lid 6 or cup lid 8 onto the 
body 4, and insuring that the lids 6 or 8 are screwed tightly down against 
the seal assembly 32, for producing a tight mechanical, metal-to-metal 
seal. The integrity of the mechanical, metal-to-metal seal must then be 
inspected using either UT or trace gas techniques, whereafter the weld 10 
is applied, followed by post weld heat treating. In the preferred 
embodiment, as discussed in detail in the previously referenced co-pending 
application Serial No. 07/951,209, the weld process utilizes a weld filler 
composition for weld 10 which is age-hardenable at a temperature below the 
kinetic threshold temperature of the material of containers 2 and 12 and 
chemically comparable to material to be joined. Accordingly, heat 
treatment of the weld 10 does not alter the physical characteristics of 
the material of containers 2 and 12 and respective covers. Such heat 
treatment of weld 10 enhances the closure weld properties of the weld 10, 
and provides for making the physical electrical and thermal properties of 
the material of the weld 10 substantially comparable with the material of 
the dome lid 6 or cup lid 8, and body 4. As will be discussed in greater 
detail below, the weld closure sequence and heat treatment process uses 
known, demonstrated welding techniques. 
In the example of storing nuclear waste or radioactive waste material, the 
preferred material for containers 2 and 12, respectively, is 
copper-beryllium. The body 4 can be fabricated by either extrusion or 
casting of the chosen material. In this regard, the preferred 
copper-beryllium alloys exhibit excellent extrusion and casting 
characteristics. Otherwise, standard fabricating techniques are used in 
producing containers 2 and/or 12. The combination of the mechanical seal 
assembly 32, and weld 10, provide for a high reliability metal-to-metal 
seal consistent with high vacuum applications. As will be discussed below, 
the weld channel 26 provides for a weld zone of high mechanical integrity, 
using a demonstrated automatic welding procedure. 
A number of different seal assembly 32 configurations have been designed 
for use with the container configurations 2 and 12 of the present 
invention. These seal assembly 32 configurations are considered 
alternative embodiments of the invention. Each of the seal assembly 32 
configurations has specific advantages depending on the particular waste 
and storage/process applications. A detailed description of each of the 
three alternative seal assembly 32 configurations follows below. 
A first embodiment for seal assembly 32 is shown in FIGS. 13 through 16. In 
this embodiment, a double-metal "O"-ring design includes a metal disk 60 
which can be composed of stainless steel, in this example, which has 
mounted on a bottom side two concentric "O"-rings consisting of an 
outermost "O"-ring 62, concentric with an inner "O"-ring 64. As shown in 
FIG. 13, a top view of this seal assembly 32 shows a flat top surface or 
disk 60, and a bottom view (see FIG. 14) of this assembly shows the 
positioning of "O"-rings 62 and 64 on the bottom 68 surface of disk 60. 
Both this seal assembly 32, and the alternative two embodiments described 
below, were particularly designed to be compatible with remote manipulator 
techniques, and for providing metal-to-metal seals of high vacuum 
integrity. The disk 60 acts as a bearing surface in mating with the 
bottoms of the lid 6 or 8, as the lid is torqued into position. Also, the 
disk 60 provides a metallic barrier, sealing the container contents. 
Typically, this seal assembly 32 for providing a double "O"-ring seal is 
fabricated by plastically deforming the welded/metallic "O"-rings 62 and 
64 such that each has a continuous flat surface. The "O"-rings 62 and 64 
are then annealed and welded to disk 60. 
In this example, disk 60 is about 0.5 inch thick. The resultant seal 
assembly 32 is shown in FIG. 15 in the process of being screwed down by a 
lid 6 or 8 into position within body 4, whereby the bottom surfaces of 
"O"-rings 62 and 64 rest upon the top interior rim or shoulder 66 of body 
4. Shoulder 66 is fabricated to be sufficiently flat for providing a good 
seal with the mating surfaces of "O"-rings 62 and 64. Also, shoulder 66 
and the mating flat of the "O"-rings 62 and 64 are plated with an 
appropriate metal, such as silver, for example. In FIG. 16, the resultant 
sealing mechanism is shown, whereby the associated lid 6 or 8 has been 
screwed tightly down into body 4, causing compression of the "O"-rings 62 
and 64 into the plastic regime, thereby establishing a metal-to-metal 
vacuum quality seal. Initially, when the associated lid 6 or 8 is torqued 
or screwed into the body 4, the seal assembly 32 of this example 
experiences circumferential and compressive loading. When the "O"-rings 62 
and 64 come into hard contact with the surface of shoulder 66, 
specifically when the plated surfaces engage, the circumferential motion 
of the "O"-rings 62 and 64 stops, and slip occurs at the interface between 
the bottom of the associated lid 6, 8where it contacts the top of the disk 
60. This action causes pure compressive loading of the "O"-rings 62 and 64 
into the surface of shoulder 66 without any rotational component, causing 
the latter to be compressed into the plastic range of the "O"-ring 
material and the "O"-ring plating thereof and the silver plated surface of 
the shoulder 66, in this example. It should be noted that the associated 
seal surfaces require protection from mechanical damage during the loading 
of waste material into body 4. 
The seal assembly 32 is provided in another embodiment of the invention by 
a temperature triggered seal as shown in FIGS. 17 through 20. In this 
embodiment, a sealing disk 70 of material such as nickel titanium (NiTi) 
provides the seal assembly 32, in this example, in combination with a 
semicircular groove 72 located proximate to the shoulder 66 of body 4. As 
shown in FIGS. 18, 19, and 20, the groove 72 is cut into the inner 
sidewall of body 4 below the thread 16 and immediately above the shoulder 
66, for forming a circumferential groove 72 juxtaposed to shoulder 66. The 
top and bottom views of the sealing disk 70 are shown in FIG. 17, and are 
identical, in that the sealing disk 70 is provided by a circular disk with 
radiused edge, in this example. The diameter of sealing disk 70 is 
initially made slightly smaller than the diameter of thread 16, for 
permitting sealing disk 70 to be delivered to the shoulder 66 region in 
the envelope of the threads 16 upon installation of either dome lid 6 or 
cup lid 8 onto body 4. Note that the shoulder 66, can be made narrower 
than otherwise required for other sealing embodiments of the invention 
described herein for providing seal assembly 32. In this embodiment, 
shoulder 66 need only be wide enough to retain sealing disk 70 once the 
associated lid 6 or 8 has been rotated into a maximum downward position 
upon body 4. Heat is then applied to the dome lid 6 or cup lid 8 proximate 
to the sealing disk 70, for transferring heat to sealing disk 70 to 
temperature trigger the NiTi material into radial expansion, causing the 
sealing disk 70 to expand into the semicircular groove 72 of the inside 
wall of body 4, as previously described. FIG. 19 shows sealing disk 70 
just prior to temperature triggering. The detailed view 74 shows sealing 
disk 70 after thermal expansion, whereby it has expanded into circular 
groove 72, centered on the semicircular portions of circular groove 72, as 
shown in FIG. 20. Note that the sealing disk 70 expands in such a way that 
it forms a perimeter seal with circular groove 72 effectively comprising 
two seal rings, one at the corner 76 or upper edge 76 of groove 72 
relative to shoulder 66, and the other seal ring being formed between disk 
72 and the surface of shoulder 66 slightly before groove 72 at about 
region 78. In this manner, the seal ring regions formed at 76 and 78 
provide a metal-to-metal, high quality vacuum seal. Note that as a result 
of the seal ring 78 being so formed, in practice there will be a very 
small gap between the bottom of disk 70 and a substantial portion of 
shoulder 66, as shown in FIG. 20. The lid 6 or 8 has been rotated into a 
maximum downward position with the final position set by the closing of 
the weld channel opening L3 (see FIG. 4), a position which results in a 
closed gap weld preparation and the delivery of the sealing disk 70 to a 
position slightly above the container shoulder 66 of body 4. 
Seal assembly 32 can also be provided in a third sealing embodiment of the 
invention as shown in FIGS. 21 through 25. In the example of this 
embodiment, a three layer metallic laminate seal disk 80 is provided by a 
top layer 82 of UNS 7718 (a nickel based alloy), a middle layer 84 of UNS 
C10700 material (a copper alloy), and a bottom layer 86 of UNS 7718 
material. Other metal combinations can be used. The material of the top 
layer 82 is in its age hardened condition, whereas the material of middle 
layer 84 is in an annealed condition. In this embodiment, two concentric 
ridges 88 and 90 are formed in a circle and protrude from the top of 
shoulder 66, as shown in FIG. 23, for example. Note that the top layer 82 
of laminate sealing disk 80 acts as a slip surface between the rotating 
lid and seal disk. This results in the seal disk 80 experiencing 
compression into the ridges 88 and 90 without rotational transform. The 
bottom laminate layer 86 is included to provide planar rigidity to the 
structure of laminate seal disk 80. The laminate seal disk 80 is attached 
to the lid 6 or 8 by a weak adhesive, for example, and is moved downward 
into sealing position by the rotation of the lid (either 6 or 8), whereby 
as the associated lid 6 or 8 is screwed down into the to of body 4, the 
bottom surface of the associated lid abuts against the top of layer 82 of 
sealing disk 80. When the lid 6 or 8 is rotated into body 4 into its 
downwardmost positioning therein, the ultimate torquing of the associated 
lid causes the ridges 66 and 88 to plastically deform the annealed copper 
center layer 84 of sealed disk 80, for forming at least four 
circumferential metal-to-metal seal boundaries, as shown in FIGS. 24A and 
24B. A detail of the sealing region 92 shown in FIG. 24A (in phantom) is 
shown in FIG. 24B with plastically deformed copper 84 highlighted. It is 
preferred that the ridges 88 and 90 have a trapezoidal shape as shown. As 
a result of such shaping, when the associated lid 6 or 8 is torqued into 
the top of body 4, the center copper layer 84 undergoes plastic 
deformation as indicated by the narrow cross-hatched areas 93, thereby 
forming four circumferential metal-to-metal seals at the two top corners 
of each of ridges 88 and 90. As shown, the ring seals are formed at the 
ridge corners 94, 96, 98, and 100. 
Note that the inner ridge 88 is formed about the top edge of shoulder 66, 
whereas ridge 90 is formed radially outward of this inner ridge, 
concentric with and spaced away from ridge 88. FIG. 25 shows a full 
cross-sectional view through the center longitudinal axis of either 
container 2 or 12, when using the laminate seal disk 80. Also note that in 
this example, layer 86 is 0.1 inch thick, layer 84 is 0.2 inch thick, and 
upper layer 82 is 0.1 inch thick. Different applications may require 
different thicknesses, and the example of the thicknesses provided are not 
meant to be limiting. The laminate seal, as well as other seal designs may 
be resealed a number of times. This is an important feature when 
inspection and retrievability are design goals. 
Note that as the associated lid 6 or 8 and laminate seal disk 80 are 
delivered to the seal region by screwing in the associated lid, the 
mechanical loading at the interface between top layer 82 and center layer 
84 is a combination of circumferential motion and surface compression. 
Ultimately, as torquing of the lid 6 or 8 continues, there is contact 
between layer 82 and the ridges 88 and 90, resulting in plastic 
deformation of the annealed copper layer 84, whereby the torquing 
component of the loading at the 84/88-90 interface ultimately terminates, 
and compressive loading then dominates. The top layer 82 interface with 
copper layer 84 becomes a slip surface to the rotating lid 6 or 8. 
Note further that the diameter of upper layer 82 and center layer 84 of 
laminate seal disk 80 is slightly smaller than the inside diameter of 
threads 16. The bottom layer 86 has a diameter that is slightly smaller 
than the inside diameter of the main portion of body 4. 
The loading of body 4 with a nuclear spent fuel assembly 102 is shown in 
FIG. 26. A crane hook 104 is used to position the fuel assembly 102 over 
the top opening of the body 4. In this example, the body 4 is shown 
substantially enclosed within a pit or pool immersed in the spent fuel 
storage water 106. Also in this example, a protective funnel guide 108 is 
installed in the top of body 4, as shown, for protecting the threads 16, 
and the seal area including shoulder 66. The funnel guide 108 guides the 
fuel assembly 102 into body 4 as the former is lowered via crane hook 104. 
A significant advantage of this concept is the reduction in personnel 
radiation exposure. The spent fuel assemblies 102 may be loaded into the 
container 4 and sealed under water or in a hot cell, both significantly 
reducing exposure. 
The next operation to be performed is to use a dome lid handling tool 110 
to carry a dome lid 6 to body 4 (see FIG. 27), and to thereafter screw the 
dome lid 6 which contains the appropriate seal assembly 32, into the top 
of body 4. Although a dome lid 6 is shown in this example as being 
installed, for the long term storage configuration of FIG. 6, the cup-lid 
8 would be installed instead of dome lid 6. The handling tool 110 provides 
the torquing required for the metal-to-metal seal, and then is used to 
carry the container 2 via interaction with dome lid 6 to automated welding 
apparatus 112 (see FIG. 28), for welding dome lid 6, in this example, to 
body 4. 
The welding apparatus includes a base member 114, upon which a container 
rotational index table 116 is mounted. The container 2 is first vertically 
lowered into position via handling tool 110, for retention in a rotatable 
(vertical to horizontal) holder assembly 118. Once secured to the holder 
assembly 118, container 4 is then rotated from vertical alignment to 
horizontal alignment with the weld groove positioned between an automated 
welder head 120 and an automated weld surface grinder 122 of an automated 
welding apparatus 124. Welder head 120 is retained in an arc down 
position. A rotational mechanism (not shown) is included on container 
index table 116 for rotating body 4, as automated welding is carried out 
for installing the weld 10. After the installation of the capping pass and 
a review of the weld quality, the weld bead is ground flush by 122. Note 
that an air filtration system 126 is included with the welding apparatus 
124 for venting welding vapors and filtering particulate generated during 
welding and grinding. 
The weld 10 is applied in a multiple number of passes but single bead as 
shown in FIGS. 29 through 33. The initial rotation of container 2 or 12, 
in this example, is made for installing a root pass weld 128 in weld 
groove 24, as shown in FIG. 29. This pass is scheduled for deep 
penetration into parts 6 or 8 and 4. Part 4 rotation is continuous for the 
five passes. The second 360.degree. rotation is for installing a first 
fill pass weld bead 130, as shown in FIG. 30. This is followed by three 
successive 360.degree. rotations of container 2, for applying a second 
fill weld 132, third fill weld 134, and a capping pass 136, as shown in 
FIGS. 31 through 33, respectively. After the capping weld 136 is applied, 
and weld inspection is completed, grinder 122 is operated to grind the 
capping weld flush with the outside diameter of body 4. This process both 
enhances the mechanical properties of the weld allowing more reliable weld 
inspection, and produces surface residual compression in the weld bead 10. 
Note that the weld 10 so formed is a continuous weld bead, as a result of 
performing the welding operation in one step through five successive 
360.degree. rotations of container 2 or 12, in this example. Such rotation 
is accomplished by use of an index table in welding apparatus 124, for 
providing a programmed torch head or welder head 120 travel rate relative 
to the rotating container 2 or 12, regardless of the radial position of 
the associated weld pool. The automated welding controller addresses all 
weld process parameters including arc travel speed, arc voltage, arc 
current, wire feed rate, and arc shield gas flow. The automated welding 
apparatus 124 is remotely controlled and equipped with an arc/weld pool 
viewing and recording system. The viewing system has an optical field 
which includes portions of both the associated lid 6 or 8, and container 
body 4, in order to record part serial numbers and key reference positions 
for the lid 6 or 8 and body 4. While these features are not shown in 
detail, it is anticipated that the field of view will record the weld 
pool, the solidified weld bead, and the upcoming weld preparation area or 
prior weld pass bead. In this example, it is expected that a video tape 
record will be made of the 375-inch long weld pass, an important 
supplement to the ultrasonic transmission and x-ray weld inspections. Note 
also that the arc down welding position of welder head 120 optimizes the 
welding process by maximizing the arc mass transfer rate, enhancing the 
stability of the plasma arc, and allowing optimum solidification of the 
weld pool. 
In the preferred embodiment, the weld 10 is applied in accordance with the 
teachings of co-pending application Ser. No. 07/951,209, filed on Sep. 25, 
1992, for "Method and Apparatus For Welding Precipitation Hardenable 
Materials". Accordingly, body 4 and dome lid 6, and cup lid 8, are 
fabricated from copper-beryllium alloy UNS C17510. The weld filter 
material is preferred to be copper-beryllium alloy UNS C17200. Copper 
beryllium alloy UNS C17510 is an age-hardenable, high strength/high 
thermal conductivity composition of a nominal 0.5 weight percent beryllium 
and 2 weight percent nickel. Copper beryllium alloy UNS C17200 is also 
age-hardenable, and has high strength/high thermal conductivity, but this 
alloy also contains a nominal 2 weight percent beryllium. Precipitation 
age hardening is a processing procedure where deliberately shaped and 
distributed precipitation is triggered in the solid phase to enhance the 
properties of the material. The physical property enhancement is typically 
not directional, and improves fatigue strength and thermal and electrical 
conductivity. 
These materials were further chosen for the preferred embodiment, in this 
example, in that C17510 is a well characterized alloy exhibiting an 
elastic modulus of the order of 20 million psi, a thermal conductivity of 
140 Btu/(ft. hr. .degree.F.), and a melting temperature greater than 
1,900.degree. F. Also, copper beryllium alloys can be readily forged, 
extruded, and cast. The alloy also is resistant to stress relaxation and 
corrosion at elevated temperatures and under severe environments. Also, 
copper-beryllium is non-sparking, non-magnetic, and non-swelling under 
high radiation dosage. These alloys are also characteristically 
non-galling, provide high fracture toughness, impact strength, tensile 
strength, fatigue life under a wide range of R conditions, compressive 
strength, broad operating temperature range, excellent electrical and 
thermal conductivity, and excellent heat capacity and thermal diffusivity. 
As a result of all of these characteristics, this alloy material is 
considered preferred for providing the intermediate storage container 2 
embodiment of the invention with the ability to be mechanically sealed 
with a metal-to-metal, high quality vacuum seal, yet reopened for 
inspection or the addition of more waste, without undue effort or 
deterioration of the integrity of the container 2. In addition, the welded 
configuration may be opened and resealed. 
Also, the copper-beryllium alloy of the preferred embodiment provides an 
element of self-shielding. High level radioactive wastes have different 
radiation spectra, depending upon composition and age. If desired, an 
inner liner may be selected for thermalizing the high energy radiation 
stream (not shown). By lowering the radiation level at the container 
surface, radiation accelerated corrosion is depressed. Copper-beryllium 
alloy has a high thermal conductivity and diffusivity as compared to other 
material options. The added thermal loading of the container inner surface 
is dissipated without significantly raising the temperature of the secured 
waste within body 4. Alternatively, for a given wall thickness, the 
preferred copper-beryllium container 2 or 12 and contents 102 will reach a 
lower equilibrium temperature than containers fabricated from most other 
materials. Also, for a given container wall strength or corrosion 
integrity, the copper-beryllium provides a wall thickness that can be made 
thinner than possible with other materials, thereby lowering the operating 
temperature of the contents. 
The containers 2 or 12 are provided with the closure weld 10 for insuring a 
high integrity seal, and a unified structural integrity for the associated 
container 2 or 12. After heat treating, the weld properties are 
significantly enhanced, approaching the properties of the bulk container 4 
material. 
The illustrated preferred weld technique produces a heat affected zone 
which is narrow and exhibits characteristics of both cast material and 
material in the solution annealed condition. By selecting materials as 
indicated above, a weld filler material is provided having a low heat 
treatment temperature. Accordingly, the mechanical strength of the 
precipitation hardened weld filler 10 can be heat treated to approach the 
Yield and Ultimate levels of the surrounding material of the dome lid 6 or 
cup lid 8 and body 4. Also, heat treating is conducted, as indicated 
below, for recovering the heat affected zone properties and enhancing, to 
approach physical levels of the container 2 or 12 material prior to 
welding. Also, elongation, fatigue integrity and thermalelectrical 
conductivity are favorably altered through a preferred heat treatment 
sequence to be described. In addition, this heat treating process relieves 
the residual stresses produced during the welding operation, thereby 
enhancing the corrosion resistance of the weld filler 10, heat affected 
zone and adjacent parent material of body 4 and the associated lid 6 or 8. 
The heat treatment of the weld zone is accomplished in the preferred 
embodiment through use of the heat treating apparatus 138 shown in FIG. 
34. As will be described, this apparatus 138 permits the weld heat 
treatment to be carried out at a temperature-time combination that does 
not affect the properties of the container material. The apparatus 138 
provides a method of heating and heat sinking that limits the thermal 
effects to a narrow zone surrounding the weld. In this manner, residual 
stresses, resulting from the prior welding operation, are attenuated 
through the heat treatment operation. 
With further reference to FIG. 34, the heat treating apparatus 138 is shown 
in cross section, and is formed in a shape of a substantially cylindrical 
cap or jacket for fitting over the top portion of either of the container 
embodiments 2 or 12, respectively, as will be described in greater detail 
below. The assembly may be installed, operated and monitored remotely. The 
heat treating device or apparatus 138 includes a securing band 140 
attached to the outside surface of secondary wall 162, for securing the 
apparatus 138 onto the containers 2 or 12, after appropriate positioning. 
The securing band 140 is of a conventional type, and includes a rotating 
element 142 for either tightening the band to secure heat treating 
apparatus 138 to a container 2 or 12, or turning in the opposite direction 
for loosening the securing band 140 to permit removal of the heat treating 
apparatus 138 from its associated container 2 or 12. Spring loaded 
thermocouples 144 are mounted on and through holes in top portion 154, and 
are provided for monitoring the temperature of the dome lid 6, in this 
example, having its weld 10 heat treated via apparatus 138. An inflatable 
cooling pad 146 including a plurality of interconnected cooling tubes 148 
have coolant circulated continually therethrough. Cooling tubes 148 can be 
arranged in any practical configuration, such as that shown in FIG. 36, 
for example. The coolant is received from a fluid input port 150, 
circulated through tubes 148, and discharged from a fluid output port 152. 
The top portion 154 of the heat treating apparatus 138 is closed, and in 
this example has an upwardly projecting curvature relative to the 
container 2 or 12. A heater array 156 is positioned in an area about the 
circumference of the inside sidewalls 158 for permitting the band heater 
156 to be centered upon and surrounding the weld 10 of a lid 6 or 8 being 
heat treated (see FIG. 35). The top 154 and sidewalls 158 form a cap-like 
housing for heat treating apparatus or device 138. An inflatable cooling 
jacket 160 is attached to approximately the lower half circumferential 
portion of the inside surface of sidewall 158, as shown. These sidewalls 
158 form a secondary sidewall portion 162 slightly less in diameter than 
the main sidewall portion 158. The inside diameter of the collar-like 
secondary sidewall portion 162 is dimensioned to have a close fit with the 
sidewalls of an associated body 4, as shown in FIG. 35. Sidewall portion 
162 is tightened on assembly with the securing band 140 and mechanism 142. 
Note that the bottom-most portion 164 extending from the secondary 
sidewall 162 is flared outward and away from the sidewall 162, as shown. 
The flared portion 164 serves to provide an easy guide for initially 
centering the heat treating device or apparatus 138 on the top portion of 
a container 2 or 12, allowing remote installation. 
The cooling jacket 160 consists of a cooling tube coil 166 that includes at 
one end a fluid input port 168 for receiving coolant, and at the other end 
a fluid output port 170 for discharging coolant circulated through the 
cooling coil 166. Lastly, a lifting bracket 172 is fixed to the top 154 of 
heat treating apparatus 138, for permitting handling apparatus to hook 
onto the heat treating device 138 for remotely positioning it onto the top 
portion of a container 2 or 12 to initiate heat treating of an associated 
weld 10. 
In FIG. 35, the heat treating apparatus 138 is properly positioned and 
secured over the top portion of a container 2, in this example, for heat 
treating the weld 10 between a dome lid 6 and body 4. Electrical power is 
provided to heater 156 via an electrical cable 174, as shown. In this 
example, the weld 10 in the associated weld zone is heat treated for a 
predetermined time at a predetermined temperature. The required heat 
treatment is determined for providing that the properties of the material 
of the associated lid 6, in this example, and body 4 remain substantially 
unaffected, while triggering age hardening of the heat affected zone about 
the weld 10, and more importantly of the weld filler 10. It is important 
to note that the heat treatment for the weld filler is predetermined for 
precipitation hardening the weld filler 10 from the cast state. The weld 
filler material is beryllium-copper C17200 in the preferred embodiment, as 
previously mentioned. In the preferred embodiment, heat treating is 
carried out for the weld 10 and surrounding heat affected zone from 0.5 to 
5 hours at a temperature ranging from 775.degree. F. to 950.degree. F. The 
preferred values for these ranges are up to 5 hours at a nominal 
850.degree. F. However, in other applications, and for different 
materials, different temperatures and time periods may be utilized. As the 
heat treating is carried out through use of the heat treating apparatus 
138, coolant is circulated through the cooling pad 146, and cooling jacket 
160, while monitoring the temperature at points along the dome lid 6 
through use of thermal couples 144, as shown. 
Note that the present inventor anticipates that the heater or heat coil 156 
will have localized Eddy current measuring transducers equally spaced from 
one another and included in segments of the heater 156, for permitting 
resistance measurements of the weld zone given areas. In this manner, the 
heat treating or aging process can be monitored for completeness 
non-destructively. For example, it is anticipated that the Eddy current 
transducers (not shown) will consist of single turn coils used to pick up 
Eddy currents induced into the weld. It should further be noted that all 
of the processing illustrated herein is to be carried out remotely in view 
of the radioactivity hazard presented by the spent fuel assembly 102, in 
this example. 
As previously mentioned, the design of the cup lid 8 facilitates the 
attainment of strict quality requirements for the long term storage of 
nuclear waste material within associated container 12. As shown in FIG. 
10, an index track 44 is provided on cup lid 8 for facilitating the 
identification of weld positions during either x-ray inspection or 
reflected wave ultrasonic transmission inspection. Reflection ultrasonic 
transmission inspection can be provided through an immersion technique 
whereby the interior of cup lid 8 is filled with a coupling liquid, and by 
keying to the indexed track 44 on the interior sidewall of the cup 8, such 
inspection can be carried out. Alternatively, for wave transmission 
examination through the weld 10, a ring container can be attached to the 
outer wall of body 4 or rim of cup lid 8, and filled with a coupling 
fluid. In conjunction therewith, a bracket holding the 
transmitter/receiver transducers can then be driven around the weld 
perimeter for scanning the weld 10 to provide an inspection thereof. Such 
commercially available inspection equipment must be customized for this 
specific application. 
The sidewalls of slots 18 of dome lid 6, and interior walls of the holes 40 
of cup lid 8 provide torquing surfaces for screwing the associated lids 
into the top of a body 4. Also, the tapered holes 22 of dome lid 6, and 
through holes 40 of cup lid 8, provide lifting surfaces. Accordingly, the 
dome lid 6 and cup lid 8 each provide as described above symmetric 
lifting/torquing surfaces, integrated into the associated lid design in a 
manner avoiding any protrusions from the lids, for simplifying remote 
handling. With either of the dome lid 6 or cup lid 8 configurations, the 
associated container 2 or 12, respectively, provides for use of a remote 
manipulator having a 3 point finger assembly for centering itself on an 
associated dome lid 6 or cup lid 8. The remote manipulator must be 
designed to first center itself on the top of a dome lid 6 or cup lid 8, 
whereafter downward translation of the remote manipulator relative to the 
associated lid 6 or 8 causes triggering of a centering cam of the 
manipulator upon contact with the top of the associated lid 6 or 8, 
causing appropriate lifting studs to engage either the tapered holes 22 of 
dome lid 6, or through holes 40 of cup lid 8 via the driving of three 
lifting studs radially into these holes, respectively. The manipulator 
mechanism can then be used for lifting the associated lid 6 or 8 into 
position upon a body 4 for thereafter screwing the associated lid into the 
body 4, and for thereafter lifting the mechanically sealed container 2 or 
12, respectively, to a desired location. It is believed that presently 
available manipulators can be easily modified to provide the required 
manipulator mechanism in association with the dome lid 6, or cup lid 8. 
Different manipulator mechanisms are required for use with each one of the 
dome lid 6 or cup lid 8, respectively. 
FIG. 37 details the weld region of the cup lid 8 which has been welded to 
the container. Since the cup lid 8 is particularly suited to long term 
storage of high level nuclear waste, the weld 10 integrity is an important 
feature to document. The cup lid 8 design allows the inspection of the 
weld region 10 using ultrasonic (UT) through transmission, ultrasonic 
reflection inspection techniques, and/or through transmission of X-rays. 
FIG. 37 illustrates the UT techniques. Integral with the cup lid are a 
series of drilled holes 180, usually flat bottom. These holes 180 are of 
various sizes and drilled to various depths. The design analysis of the 
structure identified a critical flaw size for the weld 10. The drilled 
holes 180 represent built-in calibration defects of a range of sizes and 
at various relevant depths. Typically the calibration sizes include a size 
one half and one quarter the critical size which are the reportable defect 
size thresholds. The calibration holes 180 must be drilled into the outer 
wall surface 182 and inner wall surface 184 since the UT reflection 
inspection signal may be sourced from either side 182 or 184 of side wall 
186. 
Procedurally, a container 188 is attached to the outside of the cup type 
lid 8, as shown, and both the container 188 and the lid 8 are filled with 
UT coupling fluid 190. A fixture 192 which is indexed circumferentially 
and contains two transmitter/receiver assemblies or transducers 194 is 
referenced with a channel or groove 196 on the top of lid 8. The defect 
calibration standards are scanned with the transducers 194 at an elevation 
above the weld 10 zone. The circumferential position is established with 
reference to the location of specific calibration defects. The weld 10 
zone is then inspected using both ultrasonic through transmission and 
ultrasonic reflection inspection techniques from both directions, that is 
from either side of wall 186. 
An apparatus in support of the X-ray inspection of the weld region is 
illustrated in FIG. 38 (also see FIG. 12). The film holder/film shield 46 
is an assembly which supports the X-ray film 58 at a precise location, 
aligns it with respect to the weld 10 and calibration holes 180 and locks 
into a circumferential position. The calibration holes 180 are flat 
bottom, drilled holes of various sizes relative to the critical defect 
size of the weld filter and side wall, as previously described for FIG. 
37. These holes 180 are plugged with a rod 200 such that the entrapped 
volume is relevant in size to a critical defect. The exposed X-ray film 58 
contains a record of the weld 10, the side wall 186 and the calibration 
defects which also record absolute position. An X-ray source 198 radiates 
the weld 10 zone, and calibration hole 180 regions in a manner exposing 
film 58 with X-rays passed through these regions. 
Although various embodiments of the invention are described herein for 
purposes of illustration, they are not meant to be limiting. Those of 
skill in the art may recognize modifications to these embodiments, which 
modifications are meant to be covered by the spirit and scope of the 
appended claims.