Monitored retrievable storage of plutonium and nuclear toxic waste

A method of removing radioactivity from the interior of a building by transporting radioactive material within a slurry comprising water and metal salt hydrate, precipitating out or otherwise filtering out the then contaminated material outside the building, thus removing it in a continuous fluid recirculation system, and storing the precipitated out material while providing shielding of radiation, thereby to provide radiation protection without requiring conventional large mass to block the radioactivity. A toxic waste storage facility includes a building having a portion located below ground level, walls for bounding an interior space in the building, and recirculating fluid for removing thermal energy from the building and for providing radioactive shielding and absorption at least at part of the roof of the building.

TECHNICAL FIELD 
The present invention relates generally, as is indicated, to a plutonium 
and nuclear (sometimes referred to herein as radioactivity) toxic waste 
storage depot and method and, more particularly, to a facility and a 
method for storing plutonium and nuclear toxic waste material by using a 
recirculating system in addition to a massive structure that is 
economically feasible. The invention also relates to encasement of 
asbestos, lead and other toxic waste by an encasing material that includes 
a resin and epsom salt, such as that sold under the trademark 
STAYTEX.RTM., for disposal in ordinary land fills 
Cross reference is made to copending, commonly owned U.S. patent 
application Ser. No. 08/064,548, filed May 19, 1993, entitled 
Environmental Non-Toxic Encasement Systems for Covering In-Place Asbestos 
and Lead Paint, the entire disclosure of which hereby is incorporated by 
reference. Cross reference also is made to U.S. Pat. No. 4,122,203, the 
entire disclosure of which also hereby is incorporated by reference. 
BACKGROUND 
The storage of plutonium and nuclear toxic waste is becoming evermore a 
problem. A problem with plutonium and other nuclear waste is the need to 
store such waste for a very long time in view of the relatively long 
half-life of such material. For example, some nuclear waste material have 
a half-life that is more than 100 years. Substantial exposure to nuclear 
material can be a health hazard and, in fact, can be fatal. 
Monitored retrievable storage is sometimes referred to by the acronym MRS. 
It concerns intermediate length of time storage of waste, such as 
plutonium and nuclear toxic waste. It usually is considered storage of the 
waste for approximately 100 years or several hundred years compared to 
much longer term storage of, for example, 1,000 years or more. 
There are four types of radiation, as follows: 
a) Alpha--it often may be stopped by a sheet of paper, but it is dangerous 
if ingested. 
b) Beta--it does not penetrate very much, but it is dangerous if inhaled. 
c) Gamma--it is very penetrating and only is stopped by mass. 
d) Neutrons--these are very penetrating and produce secondary gamma 
radiation; they are stopped most effectively by hydrogen (usually in the 
form of H.sub.2 O) and absorbers such as boron. 
Protection of persons from unacceptable radiation doses often includes the 
following two considerations: 
a. Prevention of direct contact of personnel with radioactive materials 
(e.g., contamination of clothing or skin, inhalation, or ingestion with 
food or water). 
b. Protection against the penetrating radiations emitted by radionuclides, 
by the use of time limitations, distances and/or shielding. 
One technique for storing plutonium and other nuclear waste has been to 
place the waste in a container and to bury the container. (Hereinbelow, 
reference to nuclear waste includes plutonium as well as other nuclear 
materials, especially those which emit nuclear radiation or are 
radioactive.) A disadvantage to this technique is the possibility that the 
container can rust or otherwise corrode, and the nuclear waste can leak. 
For example, if the nuclear waste were to leak into the ground, it could 
contaminate the ground water and eventually cause harm to animals, fish, 
vegetable life, and possibly to humans. Another disadvantage is that the 
radiation from the nuclear waste can too easily be emitted into the 
external environment causing a health hazard, for example. 
Methods promoted in the past for protection against nuclear fallout 
depended almost exclusively on massive shielding. They were based on 
conventional construction methods and were the most practical and 
inexpensive at the time they were proposed. 
One technique for shielding nuclear waste has been to provide several 
inches, for example, at least three inches of lead shielding, to surround 
the nuclear waste. Such lead shielding tends to prevent the transmission 
of radiation to the external environment. Another technique has been to 
use at least three feet of water placed between the nuclear waste and the 
external environment to prevent transmission of radiation to the external 
environment. 
Storage of non-radioactive toxic waste also presents problems similar to 
those encountered with the storage of toxic nuclear waste. For example, if 
the toxic waste were placed in drums and buried, leakage due to rusting or 
corrosion can cause contamination of drinking water and other waters used 
by fish, animals and plant life. 
A difficulty encountered when storing toxic waste, whether nuclear or 
non-radioactive, is the heat often generated during storage. Excessive 
heat can trigger undesirable reactions, including the possibility of 
explosive activity. This, of course, is undesirable, as it tends to result 
in a release of the toxic waste to the external environment. 
One reason that nuclear waste has been buried in the ground in the past has 
been the good shielding provided by the ground. Also, prior above ground 
shelters considered for storing nuclear and other toxic waste contemplate 
or use concrete and metal wall and roofs; the heavy weight of the roof 
makes design and construction difficult and sturdiness of the structure 
questionable. If such structures are used, of necessity they must be 
small. Today there is no way permanently or substantially permanently to 
store large quantities of plutonium. Since 1988 over $20 billion has been 
spent by the U.S. Department of Energy for disposing of nuclear waste; but 
there has been no improvement in methods and techniques according the 
Secretary of the Department of Energy. However, when using the ground for 
shielding, a problem is encountered in the case of a spillage, leak, etc. 
of the primary containment medium, such as a metal drum or the like. 
Another problem with heavy weight roof designs for a structure that would 
provide such shielding is the increased possibility of collapse from 
earthquake forces or the like. It would be desirable to reduce the 
likelihood of such damage due to earthquake or the like. 
Encasement using STAYTEX.RTM. material can be used for asbestos, lead, etc. 
for disposal in ordinary landfills. An example of such encasement is 
described in commonly owned pending U.S. patent application Ser. No. 
08/064,548 filed May 19, 1993. 
With the foregoing in mind, it will be appreciated that improvements in 
storage of toxic waste, both of the nuclear type and the non-radioactive 
type are desired. 
SUMMARY 
An aspect of the invention relates to the use of a fluid material, such as 
a slurry, which contains a material intended to receive and to collect 
nuclear radiation, while preferably also blocking transmission of the 
nuclear radiation, and precipitating out such material from the fluid 
material for subsequent storage of the precipitated material. 
An exemplary material contained in the fluid or slurry mentioned in the 
preceding paragraph is epsom salt; and, therefore, an aspect is the use of 
epsom salt as summarized in the preceding paragraph. 
Other exemplary materials contained in the slurry or other carrier fluid 
include Na.sub.2 B.sub.4 O.sub.7.10H.sub.2 O and CoSO.sub.4.7H.sub.2 O, 
and an aspect is the use thereof as summarized in the paragraphs above. 
Still other materials may be used in the slurry or fluid carrier, as are 
described for use herein and equivalents thereof, and, therefore, the same 
are aspects hereof. 
Another aspect of the invention relates to a toxic waste storage depot 
where toxic waste can be stored, including a building have a portion 
located below ground, walls for bounding an interior space in the 
building, and fluid for removing thermal energy from the building and for 
providing radioactive shielding, at least as a part of the building. 
According to another aspect of the invention, a toxic waste storage depot 
uses the shielding effect of the ground to tend to prevent leakage of 
radiation in combination with a fluid of specific gravity characteristics 
greater than those of water to provide both radioactive shielding and 
thermal energy removal functions. 
A further aspect relates to the use of fluid, such as water, in combination 
with epsom salt or MgSO.sub.4.7H.sub.2 O or another material as disclosed 
herein and equivalents thereof to provide relatively high specific gravity 
slurry material to effect radiation shielding and thermal energy removal 
from a toxic waste storage facility. 
An aspect of the invention relates to a method of effecting radiation 
shielding and thermal energy removal from a toxic waste storage facility 
including using water in combination with epsom salt or another material 
as disclosed herein and equivalents thereof to provide relatively high 
specific gravity slurry material to block transmission of radiation and to 
remove thermal energy. 
Another aspect relates to a method of removing radioactivity from the 
interior of a building by transporting radioactive material within a 
slurry and filtering out the then contaminated material outside the 
building, thus removing it in a continuous fluid recirculation system. 
A further aspect relates to a toxic waste storage facility including a 
building having a portion located below ground level, walls for bounding 
an interior space in the building, and fluid for removing thermal energy 
from the building and for providing radioactive shielding at least at part 
of the roof of the building. 
An additional aspect relates to a toxic waste depot method including using 
the shielding effect of the ground to tend to prevent leakage of radiation 
in combination with a fluid of specific gravity characteristic greater 
than that of water to provide both radioactive shielding and thermal 
energy removal functions. 
Yet another aspect relates to a method of disposing of toxic material, such 
as asbestos, lead, and the like, including encasing the toxic material in 
a cured resin system including at least one liquid thermosetting resin 
having particulate solids dispersed therein, about 100% of the solids 
having a U.S. Standard mesh size of about 225 mesh or smaller and at least 
about 10% of the solids having a U.S. Standard mesh size of about 325 mesh 
or smaller, wherein the solids comprise crystalline hydrated inorganic 
salts, and placing the encased material in a conventional land fill. 
An aspect of the present invention relates to a prefabricated building 
system, which offers possibilities for incorporating a reasonable degree 
of radiation protection (containment) by optimizing the time, distance and 
shielding parameters while, at the same time, recognizing the importance 
of cost effectiveness. 
Another aspect relates to using a water solution or slurry of soluble 
and/or insoluble salts, such as magnesium sulfate heptahydrate 
(MgSO.sub.4. 7H.sub.2 O), sodium borate decahydrate (Na.sub.2 B.sub.4 
O.sub.7.10H.sub.2 O) and/or cobalt sulfate heptahydrate 
(CoSO.sub.4.7H.sub.2 O) to remove heat, to block radiation, and/or to 
remove radiation in a toxic waste storage facility and method; and another 
aspect relates to including other chemicals, such as boron salts (for 
example, sodium metaborate and boric acid crystals) in the solution or 
slurry; and/or another aspect relates to using in the water solution 
and/or slurry high neutron cross-section materials, such as lithium, 
boron, and/or cobalt. 
Another aspect relates to including in the water solution or slurry 
metallic fines, such as lead and/or iron. 
Another aspect relates to using the foregoing materials to scatter 
radiation in order to effect neutralizing thereof. 
Another aspect relates to the inclusion of water molecules, plastics, 
and/or hydrogen containing materials as part of a panel construction 
useful as a wall, ceiling or floor of a toxic waste storage facility in 
which radiation is to be contained in order to block transmission of or to 
shield the radiation. 
Another aspect relates to the forming of a liquid solution or slurry with a 
salt or other material to remove heat, to block radiation transmission, 
and/or to remove radiation, directing the solution or slurry through 
portions of a building or the like, and subsequently adding an ingredient 
to the solution or slurry to precipitate out the salt for removal and 
storage thereof, including radiation therein. 
Another aspect relates to the use of water in a solution or slurry with one 
or more ingredients to remove heat, to block radiation, and/or to remove 
radiation in a toxic waste facility. 
Another aspect relates to the use of a prefabricated building structure 
including replaceable panels to form a toxic waste storage facility, and 
yet another aspect includes forming such structure of steel with 
replaceable panels in order to make the structure substantially earthquake 
proof. 
Another aspect relates to the developing of energy output from a toxic 
waste storage facility including at least one of using solar energy to 
provide electrical power for the facility and/or generating electric 
energy from heat removed from the facility with toxic waste stored 
therein. 
Another aspect relates to the monitoring of one or more conditions of a 
toxic waste storage facility in which radioactive material and/or other 
material is stored using detectors and other instrumentation molded into 
prefabricated walls and a further aspect relates to using the information 
from such detectors and/or instrumentation to monitor such condition(s) 
and/or to provide control function(s), such as, for example, air 
circulation, liquid circulation, material contained in a water solution 
and/or slurry used to remove heat, to block radiation, and/or to remove 
radiation. 
Another aspect relates to MRS for plutonium and other nuclear toxic waste 
and facilitating off-site monitoring of the storage facility for inventory 
purposes, for preventing theft, and/or for other purposes. 
Another aspect relates to a toxic waste storage facility and method in 
which a water solution and/or slurry flows through pipes contained in one 
or more walls, ceilings or floors to remove heat, to block radiation, 
and/or to remove radiation, such that the fluids flow generally from the 
top of the facility toward the bottom to avoid clogging of pipes or 
settling out of solid material contained in the solution and/or slurry. 
These and other objects, aspects, features and advantages of the present 
invention will become more apparent as the following description proceeds. 
To the accomplishment of the foregoing and related ends, the invention, 
then, comprises the features hereinafter fully described and particularly 
pointed out in the claims. The following description and the annexed 
drawings setting forth in detail a certain illustrative embodiment of the 
invention. This embodiment is indicative, however, of but one of the 
various ways in which the principles of the invention may be employed. 
Although the invention is shown and described with respect to a certain 
embodiment, it is obvious that equivalents and modifications will occur to 
others who have ordinary skill in the art upon reading and understanding 
the specification. The present invention includes all such equivalents and 
modifications and is limited only by the scope of the claims.

DESCRIPTION 
Referring to the drawings, wherein like reference numerals designate like 
parts in the several figures, and initially to FIG. 1, a toxic waste depot 
in accordance with the present invention is generally indicated at 10. The 
depot 10 is in the form of a building 11 that is located at least partly 
in the ground 12. The building 11 has an interior space 13 in which waste 
material 14 may be stored in a storage location 15. The storage location 
15 preferably is located well below the surface 16 of the ground 12 in 
order to take advantage of the radiation shielding capability of the 
ground. The size of the storage location 15 in space 13 is suitably large 
to store a desired amount of radioactive material. Part of the storage 
location near ground level or above ground level may be used for toxic 
non-radioactive material, such as asbestos encased in STAYTEX.RTM. 
material. The building 11 also includes a fluid flow system generally 
designated 17 through which a fluid is conducted. The fluid is intended to 
provide both radiation shielding effect when necessary, and thermal energy 
removal, as is described in greater detail below. Also, the fluid provides 
for relatively easy removal and convenient storage of radiation-containing 
or radiation contaminated material therefrom. 
As is described in further detail below, the flow system 17 carries a fluid 
through portions of the building 17, such as the walls, roof, floors, etc. 
The fluid, for example, is a slurry. The fluid, for example, includes 
ingredients that contribute to the radioactive energy shielding by 
scattering, reflecting or otherwise reducing the energy of radioactive 
waves or particles. The energy reduction may result in transfer of heat 
energy to the slurry and the slurry preferably is well suited to transport 
the heat energy for subsequent removal thus avoiding excessive heat 
accumulation in the building. As such, the fluid may be used as a 
secondary coolant for all types of nuclear reactors. 
Generally, each time a radioactive wave or particle is scattered or 
reflected by an ingredient in the slurry, the wave or particle loses 
energy, usually that loss is in the form of heat, or in any event energy 
is reduced. Since such energy usually is lost as heat, such heat can be 
removed by the flowing slurry. Preferably an ingredient in the slurry 
includes water molecules, which are particularly useful to absorb heat; 
and as is described in greater detail herein, such water molecules may be 
part of an hydrated salt, such as epsom salt, or other material. 
Each "scattering reaction" or event will result in departing photons from 
the wave or particle of radioactive energy. The energy released due to 
departing photons resulting from a particular scattering event usually 
will be less than the energy released during a prior scattering event or 
the original photon release. Therefore, energy is depleted from the 
radioactive wave or particle. When a scattering interaction takes place in 
a wall, the most likely paths for the photon to exit the wall is the 
shortest path from the scattering interaction to the surface of the wall. 
However, since the slurry continues to move during such events, there is 
in effect a moving wall which continues to absorb energy and to encounter 
and/or to cause additional scattering events further to deplete or to 
dissipate the energy from the radioactive wave or particle. 
Preferably the epsom salt or other equivalent ingredient, such as those 
described herein, is heavily loaded in the slurry, e.g., including a 
maximum amount dissolved in the carrier medium, which may be water or 
other fluid. The characteristic of solubility of the epsom salt in the 
water facilitates maximizing the loading of epsom salt in the water; 
however, solubility of the epsom salt or other material in the carrier 
medium is not a requirement of the broad principles of the invention. 
Additionally, since the slurry is flowing in the flow system 17, it 
provides a "moving target" to effect such reflection and scattering. Also, 
to enhance such reflection and scattering, the slurry may include 
reflective material, an example of which is metal fines. 
Briefly, The hydrate salt of the invention in effect is a heat sink, which 
functions to absorb energy, especially thermal energy. The relatively high 
water content of the hydrate helps to improve the heat sink function. The 
slurry used in the invention is in pumpable form; the preferred slurry is 
a hydrate salt in a liquid. The metal fines enhance scattering or 
reflection effect; preferably the fines are a relatively heavy material to 
accomplish the desired result, although other materials may be used for 
such purpose. 
The toxic waste depot 10 includes a large hole or open pit opening 20 
formed in the ground 12. Preferably adequate clearance and thickness of 
ground material, earth, etc. is located around the large hole 20 to 
provide adequate support for the building 11 and adequate shielding for 
radioactive energy. It has been found in the past that three feet of dirt 
often is adequate to provide satisfactory shielding of radiation. 
Additional thickness may be required in some circumstances; and possibly a 
thinner layer also may be adequate, depending on circumstances. There 
should be adequate support capability by the ground 12, including the base 
21 of the large hole 20 to support the building 11. If necessary, 
additional footers (not shown) may be used to provide the desired support. 
Also, pipes 23 in the walls and roof of building 11 provide reinforcement 
to help make them structural. 
The large hole 20 is lined by a liner 22. An exemplary liner 22 may be of 
heavy duty plastic or rubber material used conventionally to line the 
bottom of convention toxic waste storage facilities. The liner 22 should 
have adequate strength to avoid tearing, and it should have adequate fluid 
impermeability characteristics to avoid leakage. An exemplary liner 
material is that sold by Reef Industries, Inc. of Houston, Tex. under the 
designation of PERMALON PLY X-210. Preferably the liner 22 extends 
side-wise beyond the building 11 a distance adequate to tend to prevent 
water from the directly flowing into the ground 12 directly adjacent the 
building 11. Such side-wise extensions 23, 24 protecting the ground areas 
25, 26, respectively are seen in FIG. 1. Such extensions 23, 24 preferably 
fully circumscribe the building 11 for the described purpose, and by 
preventing water flow adjacent the sidewalls of the building 11, the 
tendency of the water to become radioactive and to leak into the water 
table and other water supplies is reduced. A catch basin and/or sump 26 
may be provided outside the building 11 to collect material from an 
emergency spill; a pump may be provided to pump such collected material 
for further treatment, storage and/or disposal. 
The building 11 has a floor 30, sidewalls 31, and a roof 32. The top plan 
view of the building 11 may be circular, rectangular, hexagonal, or some 
other shape, depending on the shape of the large hole 20, the layout of 
the sidewalls 31, etc. The exposed above ground portion 31 a of the 
sidewalls 31 and the roof 32 preferably are adequately thick to contain at 
least a portion of the fluid flow system 17. The below ground level 
portion 31b of the sidewalls 31 may be thinner than the portions 31a, as 
it may be unnecessary to have fluid flow system 17 therein or the extent 
of such fluid flow system therein may be less than is required in the 
portion 31a and roof 32. Specifically, since the fluid flow system 17 
provides both radioactive energy shielding and thermal energy removing 
function, for the portion of the fluid flow system 17 that is not within 
the ground 12, a larger capacity of fluid is required. However, for that 
portion of the building 11 within the ground 12, radioactive energy 
shielding is provided at least in part by the ground itself, and, 
therefore, the extent of need for shielding provided by the fluid flow 
system 17 is reduced. However, it may be that some shielding is desired by 
the fluid flow system 17 in the below ground portion 31b of the sidewalls 
31, and it also may be that thermal energy removal is desired in the 
portion 31b, too. The floor 30 is well below the surface 16 of the ground 
12, and, therefore, shielding function of the fluid flow system 17 also 
may be unnecessary there. However, it may be desirable to have thermal 
energy removal function provided by the fluid flow system 17 in the floor 
30. 
The building 11 preferably is several stories tall including about one 
story located above ground and several stories located below ground 
surface level, for example, at least three stories below ground. Each 
floor is made of structural prefabricated panels that are light weight 
compared to heavy concrete panels. Actual weight of a given panel may 
depend on whether the panel is used above ground or underground. The floor 
panels also include pipes in them to provide structural capability. The 
pipes are intended to carry the slurry described below to provide further 
shielding function. Since shielding is provided by the floors intermediate 
the bottom floor and the roof, the shielding function or burden required 
to be provided by the roof is reduced; and this reduces the thickness and 
other size and structure requirements of the roof. Such structure takes 
advantage of the shielding capacity of the ground 12 and also can take 
advantage of the support provided by the ground 12 reinforcing the 
sidewalls 31b located within the hole 20. The sidewalls 31 provide support 
for the roof 32. The sidewalls 31 and the floor 30 provide containment for 
the solid and liquid materials in the space 13 of the building 11. 
Furthermore, the sidewalls 31, floor 30 and roof 32 may include space to 
contain part of all of the fluid flow system 17. For example, a plurality 
of pipes may be located in the walls, floor and/or roof to conduct a 
slurry through the pipes for the described purpose of shielding and 
thermal energy removal. Pipes 23, also provide the structural integrity of 
the walls and roof. Concrete is too heavy for practical use for large 
structures (buildings) that are capable of radioactivity shielding. Three 
feet or other relatively large thickness of concrete is needed to provide 
adequate shielding would be so heavy that it would be difficult at best, 
and in cases impossible, to provide adequately strong side walls and 
reinforcement in the roof to support such a concrete roof. 
The walls 31, floor 30, and roof 32 may be formed of various materials. 
Preferably, though, the walls, floor and roof are formed in part by a 
material sold under the U.S. Registered Trademark STAYTEX.RTM.. An example 
of such STAYTEX.RTM. materials and methods of using it are disclosed in 
U.S. Pat. No. 4,122,203. Additional description of such material and 
methods of using it are described in copending, commonly owned U.S. patent 
application Ser. No. 08/064,548, filed May 19, 1993, entitled 
Environmental Non-Toxic Encasement Systems for Covering In-Place Asbestos 
and Lead Paint. The STAYTEX.RTM. material may provide both facing or 
surfacing functions as well as sealing functions. The STAYTEX.RTM. 
material may be sprayed onto joints between pre-fabricated panels making 
up the sidewalls 31, floor 30, or roof 32, for example, in the manner 
illustrated in FIG. 2. 
Briefly referring to FIG. 2, a plurality of pre-fabricated wall panels 33 
are illustrated. The panels may be made of the following materials and/or 
by the following methods. 
An exemplary wall panel 33 is illustrated in FIGS. 3-7. The wall panel 33 
includes pipes 23, for example of steel, polyvinyl chloride (pvc), or 
other metal, plastic material or other synthetic or natural material. A 
core material 34 of a panel is made of the mentioned STAYTEX.RTM. material 
34a, preferably in combination with fiberglass sheets 34b. The 
STAYTEX.RTM. material can be molded or sprayed relative to the pipes to 
form therewith an integral structure. The fiberglass may provide 
reinforcement and a base to which the STAYTEX.RTM. material easily can 
adhere. 
An exemplary manufacturing line 35 to manufacture the panels 33 is 
illustrated schematically in FIG. 8. To make a panel, the pipes 23 are 
connected in the manner desired for structural and fluid carrying 
purposes. The fiberglass sheets 34b are placed relative to pipes 23 on a 
conveyor 35a for carrying to a spray booth 35b and then to a mold 35c. The 
STAYTEX.RTM. material is applied to the pipes and fiberglass, e.g., in the 
spray booth 35b to make an integral structure thereof, particularly after 
the STAYTEX.RTM. material has cured to solid relatively rigid form. The 
STAYTEX.RTM. material may be applied by spraying, troweling, roller 
coating, etc. The panel may be heated at the infrared heater 35d to 
complete or to expedite curing. The panels may be shaped during molding by 
using a specifically shaped mold and/or molding press 35d to shape the 
panel during the formation of the panel. 
The pipes 23 may be arranged in a plurality of horizontal or vertical rows 
or in some other pattern in the panel 33. The pipes 23 may be connected 
for serial flow (see FIG. 4) of slurry through a panel; they may be 
connected for generally parallel flow (see FIG. 5) of slurry through a 
respective panel 33 or through plural panels (the latter case being where 
plural pipes of one panel are connected to plural pipes of another panel). 
One or more nipples 36 or other pipe connectors is exposed from each panel 
for connection to the flow system of the invention, i.e., to the pipes in 
another panel, to another portion of the flow system, etc. 
The wall panels, floor panels and roof panels may be identical. Where 
needed, additional facing or skin material to prevent damage to the panels 
and/or to provide particular characteristics to the panels may be used. 
Exemplary outer skin material include steel, brick, various natural and/or 
synthetic materials, composite materials, etc. In FIG. 6 is illustrated 
schematically a panel 33 with concrete facing material 33a, e.g., for 
contact with the earth of the large hole 20, and with brick facing 
material 33b, e.g., for exposure inside the building 11, say as the inside 
wall or top surface of a floor on which a vehicle easily may travel. In 
FIG. 7 is illustrated schematically a panel 33 with concrete facing 
material 33a, e.g., for contact with the earth of the large hole 20, and 
with steel facing material 33c, e.g., for exposure inside the building 11. 
At the seams 36 between adjacent panels 33 STAYTEX.RTM. material may be 
applied, for example, by spraying, troweling, roller coating, etc. to seal 
the joints. The STAYTEX.RTM. material also may be used to provide a 
sealing function between the sidewalls 31 and the floor 30 and/or roof 32 
as well as between other portions of the overall structure of the building 
11. 
Referring to the fluid flow system 17, a plurality of pipes 23 are located 
in the roof 32, in the sidewalls 31, including both the portions 31a, 31b, 
and in the floor(s). A liquid slurry 41 flows through the pipes 23, 
preferably being pumped therethrough by pumping equipment 42. The pumping 
equipment may include one or more standard water pumps, outside the 
building 11, either above ground, in ground, for example in a sump 42, 
and/or in a treatment system 43 located in the space 13 of the building 11 
and/or outside the building. There may be one or more treatment systems 
and/or parts thereof, and each may be located inside or outside building 
11. The sump 42 may be separate from, the same as, or a part of the sump 
or catch basin 26. A filter system 44 also is provided in the treatment 
system 43 to filter excessive radioactive material from the slurry 41, to 
filter other particular material from the slurry 41, and to provide such 
removed material to a storage container 46 for storage in the storage 
location or area 15 (FIG. 1). 
The slurry 41 in the pipes 23 preferably has a relatively high specific 
gravity compared to the specific gravity of water, which is 1. Exemplary 
relatively high specific gravity is from about 1.2 to about 1.6. Other 
relatively high specific gravities also may be used for the slurry 41. A 
specific gravity of 1.6 is obtainable by making a slurry of water and a 
relatively high concentration of epsom salt, as is elsewhere described 
herein. A slurry of water and boron also may be used. 
The slurry may contain water and a metal salt hydrate. The metal salt 
hydrate generally has the following formula: 
EQU M.sub.x Y.sub.z.nH.sub.2 O 
in the formula, M represents a metal. X represents the number of metal 
atoms in a metal salt hydrate molecule. X is generally a number between 
about 0.5 and about 10, and preferably about 1 to about 5. Y is a salt. Z 
represents the number of salt components in the metal salt hydrate 
molecule. Z is generally a number from about 0.5 to about 10, and more 
preferably about 1 to about 5. n is the amount of water contained in the 
metal salt hydrate molecule. n is from about 0.5 to about 20. More 
preferably, n is about 1 to about 15, and even more preferably, n is about 
2 to about 10. 
The relative amount of metal salt hydrate included in the slurry is any 
amount so long as the slurry is in a liquid or semiliquid state so that it 
may be circulated throughout the structure, or through the pipes. In one 
embodiment, the amount of metal salt hydrate added to water is governed by 
the resultant specific gravity of the slurry. 
The metal of the metal salt hydrate may be any metal capable of forming a 
metal salt hydrate. For example, the metal may be an alkali metal, an 
alkaline earth metal, a transition metal or another metal. Examples of 
alkali metals include Li, Na, K, Rb, Cs and Fr. Alkaline earth metals 
include Be, Mg, Ca, Sr and Ba. Transition metals include Sc, Ti, V, Cr, 
Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, 
Re, Os, Ir, Pt, Hg and Au. Other metals include Al, Ga, Ge, In, Sn, Sb, 
TI, Pb, Bi and Po. In a preferred embodiment, the metal of the metal salt 
hydrate is selected from Al, Ca, Co, Cu, Mg, Ni, Na and Zn. 
The salt component is any salt capable of forming a metal salt hydrate. 
Examples of salts include sulfate, nitrate, chloride, bromide, acetate, 
borate, metaborate, carbonate, hydrogen phosphate, bicarbonate, and 
thiosulfate. Preferred embodiments of the salt include sulfate, borate and 
metaborate salts. 
Specific examples of the metal salt hydrate include Al.sub.2 
(SO.sub.4).18H.sub.2 O, CaCl.sub.2.2H.sub.2 O, CaCl.sub.2.6H.sub.2 O, 
Ca(NO.sub.3).sub.2.4H.sub.2 O, CaSO.sub.4.0.5H.sub.2 O, 
CaSO.sub.4.2H.sub.2 O, CoSO.sub.4.7H.sub.2 O, CuCl.sub.2.2H.sub.2 O, 
Cu(NO.sub.3).sub.2.3H.sub.2 O, CuSO.sub.4.5H.sub.2 O, MgBr.sub.2. 
10H.sub.2 O, Mg(NO.sub.3).sub.2.6H.sub.2 O, MgSO.sub.4.7H.sub.2 O, 
NiOAc.3H.sub.2 O, NiSO.sub.4.7H.sub.2 O, NaOAc.3H.sub.2 O, Na.sub.2 
B.sub.4 O.sub.7.10H.sub.2 O, Na.sub.2 CO.sub.3.10H.sub.2 O, Na.sub.2 
HPO.sub.4.12H.sub.2 O, Na.sub.2 SO.sub.4.10H.sub.2 O, Na.sub.2 S.sub.2 
O.sub.3.5H.sub.2 O and ZnSO.sub.4.6H.sub.2 O (OAc=acetate). 
The slurry may also contain fines. Fines are small metallic particles 
capable of being dispersed in the slurry. The fines enhance the scatter 
effect of the slurry. The amount of fines in the slurry is any amount such 
that the metallic fines remain substantially dispersed in the slurry. 
Fines may be made of heavy metallic particles. Examples of heavy metallic 
particles include iron fines, nickel fines, copper fines, zinc fines, 
palladium fines, silver fines, tin fines, antimony fines, platinum fines, 
gold fines and lead fines. In another embodiment, the fines may be an 
alloy made of one or more of the heavy metallic particles listed above. 
Although the size of the fines is not critical, the size should be 
appropriately large to deflect (or otherwise suppress) radiation, and not 
too large or too small so as to cause packing or clogging of the slurry. 
The size of the metallic particles may be from about 25 mesh to about 200 
mesh. In a preferred embodiment, the size is from about 50 mesh to about 
100 mesh. 
A preferred exemplary material for use to raise the specific gravity of the 
slurry is epsom salt. In particular, it has been found that water 
containing up to about 30% epsom salt will have a specific gravity of 
about 1.2. Thirty percent is about the maximum amount of epsom salt that 
can be held in slurry in water without having to elevate the water 
temperature. However, higher concentration will be used by raising 
temperature of the slurry to try load the slurry with as much epsom salt 
as possible. See the graphs of FIGS. 9-11 for data regarding composition 
and characteristics of such slurries of water and epsom salt. For example, 
at a temperature of 36.degree. C. the specific gravity is about 1.35 for 
30% MgSO.sub.4 by weight. As an example, the slurry is formed by mixing 
epsom salt with water and elevating the temperature of the mixture to 
increase the amount of epsom salt that can be dissolved in the water than 
that possible at usual room ambient temperature. The slurry also can 
contain solid particles of epsom salt. The percent of salts are regulated 
by the temperature of the slurry to maintain maximum salt levels for most 
efficient operation. The radiation level is monitored by a conventional 
monitor 48 located in the treatment station 43 and/or elsewhere in the 
building 11 or even outside the building 11, for example, and by adjusting 
the temperature of the slurry proportionally to the radiation level, salt 
level can be increased or decreased as a function of radiation. Preferably 
such proportion is in direct proportion, although such direct proportion 
may be nonlinear. Such temperature control and salt level can be increased 
or decreased as a function of radiation. Such temperature control and salt 
level are adjusted by operation of the heat exchanger 45, for example, 
which is described hereinbelow. 
The use of 30% epsom salt in the water tends to reduce the freezing point 
of the water to about 0.degree. F. This feature advantageously helps to 
avoid the possibility of the slurry 41 freezing in the pipes 23. 
Continuous circulation of the fluid in the pipes under the influence of 
the pump 42 also helps to avoid freezing. Furthermore, thermal energy 
generated in the building 11 by the toxic waste stored therein also helps 
to avoid freezing of the solution. 
By using a slurry 41 that has a relatively high specific gravity, the 
shielding effectiveness of the slurry is enhanced. Therefore, the 
thickness of the roof 32 does not have to be a full three feet, which is 
the thickness necessary if water alone were used for radiation shielding 
purposes. 
Preferably the epsom salt dissolves in the carrier medium e.g., water, of 
the slurry. However, solubility is not a requirement. Solubility usually 
increases the amount of epsom salt or other ingredient that can be loaded 
into the slurry. Some or all of the epsom salt or other ingredient in the 
slurry may be undissolved or even not soluble in the carrier medium. 
It is noted that sodium chloride and other salts would not be particularly 
useful for the function provided by the epsom salt. Sodium chloride is 
corrosive and would tend to destroy the pipes 23 and/or other portions of 
the depot 10. Epsom salt, on the other hand, is not corrosive and is 
non-toxic. 
Exemplary materials which may be useful in the invention are presented in 
Table I and Table II below. The tables present solubility data. Preferred 
characteristics of the materials presented in the tables include 
solubility in the carrier medium, e.g., aqueous solution, and water of 
hydration molecules for the absorption of heat energy. 
Many inorganic salt hydrates can be utilized as heat storage or heat pump 
materials by undergoing a change in the degree of hydration. Table I 
presents data on solubility and specific gravity of common salt hydrates 
in aqueous solution. Where possible, tables of solubility as a function of 
temperature and specific gravity as a function of composition have been 
included. Table II presents data on solubility of common salt hydrates in 
aqueous solution at other temperatures. 
TABLE I 
______________________________________ 
Common inorganic salt hydrates 
HYDRATE SOLUBILITY.sup.a 
METAL SALT FORMULA cold hot S.G. 
______________________________________ 
aluminum sulfate 
Al.sub.2 (SO.sub.4).18H.sub.2 O 
86.90.sup.0 
1104.sup.100 
1.77 
calcium chloride 
CaCl.sub.2.2H.sub.2 O 
97.7.sup.0 
326.sup.60 
0.835 
calcium chloride 
CaCl.sub.2.6H.sub.2 O 
279.sup.0 
536.sup.20 
1.71 
calcium nitrate 
Ca(NO.sub.3).sub.2.4H.sub.2 O 
266.sup.0 
660.sup.30 
-- 
calcium sulfate 
CaSO.sub.4.0.5H.sub.2 O 
0.3.sup.20 
sl s -- 
CaSO.sub.4.2H.sub.2 O 
0.241 0.222.sup.100 
2.30- 
2.37 
cobalt sulfate 
CoSO.sub.4.7H.sub.2 O 
60.4.sup.3 
67.sup.70 
1.948.sup.25 
copper chloride 
CuCl.sub.2.2H.sub.2 O 
110.4.sup.0 
192.4.sup.100 
2.54 
copper nitrate 
Cu(NO.sub.3).sub.2.3H.sub.2 O 
137.8.sup.0 
1270.sup.100 
2.32.sup.25 
copper sulfate 
CuSO.sub.4.5H.sub.2 O 
31.6.sup.0 
203.3.sup.100 
2.28 
magnesium bromide 
MgBr.sub.2.10H.sub.2 O 
316.sup.0 
vs 2.00 
magnesium nitrate 
Mg(NO.sub.3).sub.2.6H.sub.2 O 
125 vs 1.6363.sup.25 
magnesium sulfate 
MgSO.sub.4.7H.sub.2 O 
71.sup.20 
91.sup.40 
1.675- 
1.679 
nickel acetate 
NiOAc.3H.sub.2 O 
-- -- 1.744 
nickel sulfate 
NiSO.sub.4.7H.sub.2 O 
75.6.sup.15.5 
475.8.sup.100 
1.948 
sodium acetate 
NaOAc.3H.sub.2 O 
76.2.sup.0 
138.8.sup.50 
1.45 
sodium borate 
Na.sub.2 B.sub.4 O.sub.7.10H.sub.2 O 
2.01.sup.0 
170.sup.100 
1.715 
sodium carbonate 
Na.sub.2 CO.sub.3.10H.sub.2 O 
21.52.sup.0 
421.sup.104 
1.44.sup.15 
sodium hydrogen 
Na.sub.2 HPO.sub.4.12H.sub.2 O 
4.15 87.4.sup.34 
1.52 
phosphate 
sodium sulfate 
Na.sub.2 SO.sub.4.10H.sub.2 O 
11.sup.0 
92.7.sup.30 
1.490 
sodium thiosulfate 
Na.sub.2 S.sub.2 O.sub.3.5H.sub.2 O 
79.4.sup.0 
291.1.sup.45 
1.729.sup.17 
zinc sulfate 
ZnSO.sub.4.6H.sub.2 O 
s 117.5.sup.40 
1.978 
______________________________________ 
.sup.a Units: solubility gram per 100 cc 
temperature .degree.C. 
s -- soluble 
sl -- slight soluble 
vs -- very soluble 
superscripts indicate the temperature of measurement 
TABLE II 
______________________________________ 
Common inorganic salt hydrates 
Solubility Data at Other Temperatures 
Temp., .degree.C. 
Metal Hydrate superscripts indicate 
Salt Formula References 
______________________________________ 
calcium chloride 
CaCl.sub.2.2H.sub.2 O 
25 
CaCl.sub.2.6H.sub.2 O 
20, 25, 50, 180 
cobalt sulfate 
CoSO.sub.4.7H.sub.2 O 
25 
copper chloride 
CuCl.sub.2.2H.sub.2 O 
25 
copper sulfate 
CuSO.sub.4.5H.sub.2 O 
25, 50, 75 
magnesium sulfate 
MgSO.sub.4.7H.sub.2 O 
10-50, 40, 50 
nickel sulfate 
NiSO.sub.4.7H.sub.2 O 
10, 20, 40 
sodium acetate 
NaOAc.3H.sub.2 O 
20 
sodium carbonate 
Na.sub.2 CO.sub.3.10H.sub.2 O 
0, 20, 25 
30, 60, 90 
sodium hydrogen 
Na.sub.2 HPO.sub.4.12H.sub.2 O 
25 
phosphate 
sodium sulfate 
Na.sub.2 SO.sub.4.10H.sub.2 O 
0, 25 
zinc sulfate ZnSO.sub.4.6H.sub.2 O 
25, 40, 50 
______________________________________ 
It is a purpose of the fluid flow system 17 to control the temperature in 
the space 13 of the building 11. For this purpose a heat exchanger 45 in 
the treatment center 43 receives fluid from the filter 44 and is able to 
cool the fluid and to transfer the thermal energy thereof to the 
environment external of the building 11. Heat from the heat exchanger is 
an energy source to use for other purposes, such as heating and cooling 
building 11, another building, or form some other purpose. The treatment 
center 43 may be located either inside or outside of the building 11; part 
may be in each location; or part or all of the treatment center may be 
redundantly located both inside and outside the building 11. An advantage 
to locating the heat exchanger or part of it outside the building is to 
use outside ambient temperature and/or supplemental heating or cooling 
provided there to control salt loading or salt level of the slurry. 
The shielding effectiveness of the slurry 41 in the pipes 23 of the fluid 
flow system 17 preferably is approximately equivalent to the shielding 
effectiveness of about three feet of water and/or approximately equivalent 
to about three inches of lead shielding. However, the weight of the lead 
shielding, the environmental hazard of the lead in general, the weight and 
containment requirements for three feet of water, and so on are not 
required in the present invention. Rather, the pipes 23 may be included 
within the roof 32 and the exposed above ground sidewalls 31a. Pipes 23 of 
the fluid flow system 17 also may be included in the below ground portions 
31b of the sidewalls and/or in the floor 30. Further, the pipes 23 may be 
used to conduct slurry 41 in other places in the building 11 for the 
purpose of generally controlling the temperature in the building. The 
thickness of the below ground portions 31b of the sidewalls and the 
thickness of the floor 30 need not be as great as the thickness of the 
roof 32 or of the above ground portion 31a of the sidewalls, since the 
ground 12 can be relied on to provide shielding function, as was described 
above. 
In operation of the toxic waste depot 10, then, waste, such as toxic waste 
in general, radioactive waste in particular, etc. may be stored in the 
building. The pump 42 pumps slurry 41 through the pipes 23 of the fluid 
flow system 17. The slurry tends to prevent leakage of radiation through 
the roof 32 and above ground portion 31a of the sidewalls. The epsom salt 
in the slurry tends to absorb radiation. The ground 12 tends to prevent 
leakage of radiation to the above ground external environment or to the 
external environment more than several feet away from the building 11. The 
slurry 41 tends to remove thermal energy (heat) from the interior space 13 
of the building in order to control the temperature therein. The excess 
heat can be conducted by the heat exchanger 45 to the environment external 
of the building 11 or to some other location without contaminating the 
external environment. 
The filter 44 may be used to remove radioactive material, e.g., the epsom 
salt or equivalent and/or similar functioning material, from the slurry 41 
and/or particulates from the slurry 41 as waste. Such waste may be placed 
in drums or otherwise delivered to the storage area 15 in the space 13 of 
the building 11. 
In the filter 44 of the treatment plant 43 the slurry is cooled to cause 
the contaminated salt particles to drop out. The contaminated solid 
particles can be filtered from the slurry and then can be processed for 
detoxification and/or they can be stored. For such storage, for example, a 
settling pit 49 can be used to store the particles. Such a settling pit 49 
is depicted schematically in FIG. 1. The settling pit may have at least 
three feet deep of water as a shield for blocking upward emission of 
radiation. 
The slurry can be pumped into the settling pit 49, and the settling pit can 
serve a filtering function in addition to or alternatively to the filter 
44. The slurry will remain below the water level due to the larger 
specific gravity of the slurry. The contaminated salt particles will 
precipitate out to the bottom of the pit by maintaining the temperature of 
the pit relatively cool, e.g., sufficiently cool to effect such 
precipitating function. The remaining slurry which is substantially 
uncontaminated can be removed from the settling pit; subsequently loaded 
as much as possible with epsom salt; and pumped through the flow system 17 
again. 
A door 50 provides an access to the interior space 13 of the building 11. 
The door 50 may be made of the same type of material of which the above 
ground portion 31a of the side walls is made and preferably the door also 
includes a portion of the fluid flow system 17 to provide for radiation 
shielding and for temperature control functions. The height of the door 50 
preferably is adequate to provide, when open, access to a forklift vehicle 
or other vehicle that is used to carry into the space 13 fifty-five gallon 
drums 46 of toxic waste or some other size containers for storage within 
the space 13 of the building 11. 
A top plan view of the door 50 is shown in FIG. 12. The door 50 preferably 
includes one or a plurality of baffle walls which provide a circuitous 
route into the interior 13 of the building 11 while preventing a direct 
path for radiation leakage through the door. As is seen in FIG. 12, the 
door includes an outer door 50a in the outer wall 50b, which is comprised 
of panels 33, for example. The outer door 50a can be opened for access to 
the building interior 13 or closed. A baffle wall 50c blocks a direct path 
into the building interior from the door 50a. The interior wall 50d has an 
opening 50e which provides direct entrance to the interior 13. The space 
50f between the walls 50b, 50c, 50d is a circuitous path between the 
outside ambient environment and the interior of the building. The size of 
the space 50f preferably is adequate for a vehicle to drive therealong in 
order to carry waste, containers, or equipment into or from the building. 
Each of the walls 50b, 50c, 50d is made of a plurality of the panels 33. 
An elevator 51 includes an elevator shaft 52 and an elevator car 53 for 
transporting the forklift truck and/or the waste as well as individuals 
between various levels in the building 11. Also, a ramp 54 is provided to 
enable the forklift truck and/or individuals to drive or to walk between 
levels of the building 11. A floor 55 part way across the building or 
across the entire building is provided for various storage, equipment, 
and/or other functions as may be desired. Racks 47 for storing drums 46 or 
other material may be provided on one or more floors. The racks also may 
be used to store encased asbestos, lead painted objects, or other 
material. 
In using the toxic waste depot 10 to store radioactive material, the 
radioactive material preferably is stored at the lowest levels of the 
building. The radiation tends to emit horizontally and perpendicularly in 
straight lines through the walls into the ground. The ground is a good 
shield and prevents the radiation from reaching other sources of water, 
etc. The fluid system 17 also may reduce such radiation that is emitted 
into the ground, depending on the extend to which slurry 41 is located in 
the side walls which are below ground. That radiation which tends to emit 
vertically is finally blocked by the slurry 41 flowing through the pipes 
23 in the fluid flow system in the roof 32. Temperature in the space 13 of 
the building 11 is controlled by the fluid flow system and the heat 
exchanger 45 associated therewith so that the possibility of dangerous 
conditions due to high temperature in the building is avoided. 
The radiation blocking and/or absorbing function of the floors of the 
building 11, especially the ones intermediate the bottom floor and the 
roof, also reduce the radiation blocking and/or shielding requirement of 
the roof 32. This allows the roof to have a practical thickness that will 
be both efficient and economical. That is, the roof can be of reduced 
thickness, mass, etc., compared to the requirements for roofs in prior 
primarily concrete storage facilities. 
The building 11 provides a storage facility for nuclear and other toxic 
waste. The waste may be stored in drums 46. The waste and/or drums 46 may 
be stored in racks 47, if desired. Contaminated equipment from a 
dismantled nuclear plant or from a refurbished nuclear plant also may be 
stored in the building 11 either in a drum, on a rack, or placed on the 
floor of the building. Since the bottom floor 30 has maximum direct 
support, e.g., from the earth beneath, it is desirable to place heavier 
material on the bottom floor and to place less heavy material on the upper 
floor level(s) 55. 
Additionally, as was mentioned above, the building 11 provides a place for 
storage of asbestos, objects painted with lead paint and/or other types of 
materials which have been encased in STAYTEX.RTM. material according to 
the disclosure of U.S. patent application Ser. No. 08/064,548. However, 
alternatively such encased materials can be placed directly in a 
conventional land fill. 
The building 11 of the present invention preferably is of a modular design 
in that multiple panels can be used to form walls, floor and ceiling 
thereof. Preferably the building 11 is provided with gravity ventilation 
and with anti-corrosive coatings, where needed. Desirably the height 
between floor and ceiling permits double stacking of drums or other 
storage containers. Seismic tie-downs may be provided for securing the 
building in the event of a tremor. Concrete underground structures are 
suspect; they may crack. The building of the present invention using 
panels 33 in walls, floors and ceiling/roof is more flexible than concrete 
and is less subject to damage due to earth tremors than conventional 
concrete structures. 
Other features includable in the building 11 of the invention include a 
fire suppression system. Desirably the various fixtures are explosion 
proof, such as the mechanical equipment, ventilation equipment, lighting, 
and HVAC system. The various parts of the building may be non-combustible 
having a fire rating of 1 to 4 hours. Sprinkler systems and monitoring 
systems for fire, gas, etc. may be provided. Exemplary toxic gas 
monitoring products are sold by Kem Medical Products Corp. The sumps 
described preferably are segregated for security and backup; and walls may 
be provided in the building to separate various portions. The building may 
be temperature controlled using appropriate HVAC equipment, and may take 
advantage of the heat exchanger 45 and flow system 17 of the invention, if 
desired. Further, if desired FM explosion relief panels may be used in the 
building. 
It will be appreciated that in the present invention an improved building 
structure provides a storage depot for plutonium and nuclear waste, for 
example. A fluid circulation system may provide temperature control for 
the storage depot and also blocks transmission and absorbs nuclear 
radiation. Such nuclear radiation absorption may be in epsom salt which is 
loaded into the fluid to form a slurry. The epsom salt may be removed from 
the slurry and subsequently stored in the building. The fluid can be 
re-loaded with epsom salt for further circulation in the depot to block 
and to absorb additional radiation. 
In addition to the above ingredients of the water solution or slurry, such 
fluid may include metallic fines, such as lead and iron. These metallic 
fine materials can block transmission of radiation from radioactive 
material stored in the facility. Typically such fines will tend to reflect 
the radiation and to increase the likelihood that such radiation will 
encounter water molecules of the salt for absorption thereby. 
The fines are metallic materials which are good absorbers or suppressors of 
radioactivity. The fines also may reflect or scatter the radioactive wave 
or particle. The fines may be retained in the slurry and then filtered out 
when they become too radioactive. An advantage of metallic fines over the 
hydrated salt is that the fines may be heavier than the salt and provide 
better shielding. The invention reduces the thickness of the walls and 
roof of the building to get the same effective shielding as was possible 
in the past using a much heavier structure. 
Preferably the material of which the sidewalls are made includes water 
molecules, plastics and hydrogen-containing materials as part of panel 
construction. Such materials are good radiation shielding materials. The 
water molecules not only are part of the circulating fluid of the slurry, 
but the water of hydration molecules in the salt that is included in the 
slurry also provide for radiation shielding and absorption. Further, 
plastic material, such as that included, e.g. as the resin, of the Staytex 
material also is a relatively good radiation shielding and absorbing 
material--shielding due to the nature of the plastic and 
absorbing/shielding due to the water of hydration in the epsom salt 
included in the Staytex material itself. Additionally, it is known that 
hydrogen-containing material tends to provide shielding for radiation, and 
the polyester resin of which the Staytex material is formed includes an 
abundance of hydrogen molecules. 
The panels, or the sidewalls, are made of materials including compounds 
containing water molecules, plastics and hydrogen-containing materials. 
Compounds containing water molecules may be any metal salt hydrate 
described above. In one embodiment, the plastic is a thermoplastic resin. 
In another embodiment, the plastic is a thermoset resin. Exemplary plastic 
materials include polyesters, polycarbonates, polyethers, and polyalkylene 
materials. Hydrogen-containing materials are materials containing an 
abundance of hydrogen molecules. For example, various resins such as 
polyester resins and polyalkylene resins such as polyethylene and 
polypropylene resins may be used. 
Turning to FIG. 13, a modified treatment system 100 for treating the slurry 
after it has been circulated through the pipes 23 and/or elsewhere in the 
facility, includes a mixer 101, the filter 49, a recirculate/discard 
liquid valve 102, and the pump 42. The slurry is received by the mixer 101 
where a precipitating agent is added. An exemplary precipitating agent is 
ethanol. For a water and epsom salt slurry, by adding sufficient quantity 
of ethanol thereto at the mixer 101, the epsom salt will precipitate out 
from the slurry and can relatively easily be filtered by the filter 49. 
The precipitating agent may be supplied from a separate reservoir 103 and 
a conventional dispensing control 104, which controls the amount of 
precipitating agent added to the slurry based on the known amount or 
measured amount of epsom salt (or the like) in the slurry. The removed 
precipitate and/or other solids can be directed along a path 105 to a drum 
or other storage container for storage in the facility, if desired or for 
removal from the facility and storage elsewhere. It is anticipated that 
the removed precipitate would be radioactive having absorbed radiation 
during circulation in the slurry; and, therefore, appropriate care in 
handling and storage is given, e.g., as is described herein. 
After the solids have been removed at the filter 49, the liquid, e.g., 
water, can be directed by the valve 102 through pipe 106 and pump 42 for 
recirculation in the pipes 23 or elsewhere in the facility. Additional 
salt, e.g., epsom salt, or one or more of the above materials, may be 
added to the water prior to such recirculation. Alternatively, the water 
may be directed via the valve 102 and pipe 107 for discarding. If it has 
been sufficiently cleaned of radiation and/or other ingredients, the water 
may be discharged into the local water system, stream, lake, etc., and, if 
desired, the water may be further filtered by artificial or natural means, 
such as a filter, the earth, etc. prior to discarding. 
Briefly referring back to FIG. 1, the toxic waste storage depot or facility 
10 and building 11 thereof may include at or on the exposed surfaces 
thereof, e.g., on the roof 32 and/or on the sidewalls 31 a exposed above 
ground, solar panels 120 to receive solar energy and to convert that 
energy to electricity for use in operating the facility. One or more 
storage batteries or the like 121 may be used to store electrical energy 
from the solar panels 120. An electric generator 122 also may be included 
in the facility 10 to generate electricity from heat energy removed from 
the slurry in the heat exchanger(s) 45. The electricity from such electric 
generator may be used to operate the facility, such as to operate the 
pump(s) 42, and/or for other operations; alternatively or additionally, 
such electricity also may be fed back into the local power system or power 
company. 
One or more detectors and/or other instruments generally designated 123 may 
be embedded within the sidewalls 31, floor(s), ceiling(s), etc. of the 
building 11. For example, the detectors may be molded into the respective 
walls, etc. Such detectors may be used to detect heat, radiation, 
humidity, pressure, or other characteristic or parameter. The detectors 
123 may be connected to a monitor and control system 124, such as a 
computer, to provide information representing the detected characteristic 
thereto via connection lines 125, radio link, etc. The control system 124 
may be on the premises of the building 11 or it may be off-site, as may be 
desired. Having the control system 124 off-site facilitates a remotely 
located operator to supervise operation of the equipment and stored 
materials in the building 11 and associated therewith and preferably to 
supervise several such facilities. Being able to provide off-site 
monitoring facilitates controlling inventory and helps to prevent the 
possibility of theft. 
The monitor and control system 124 may store the information or may control 
operation of one or more parts of the depot 10 based on the information. 
Connection lines 126 provide such control information or function to such 
other components of the depot 10. For example, if the detected temperature 
inside the building 11 is relatively low or the detected radiation is 
relatively low, it may be possible to circulate in the pipes 23 a slurry 
which is relatively lightly loaded with epsom salt (or other radiation 
absorbing or shielding material); this being in contrast to a relatively 
high temperature or high radiation level in which case a greater loading 
or concentration of the epsom salt in the slurry may be desired and 
effected by the control system 124. 
Turning, now, to FIG. 14, there is illustrated a slurry control system 130 
for controlling the amount of additive, whether epsom salt, some other 
salt, some other ingredient, metal fines, etc., as described herein and 
equivalents thereof in the slurry. The slurry control system 130 may be 
interposed at various places in the fluid circulating or fluid flow system 
17 of the invention; however, in the illustrated embodiment hereof the 
slurry control system 130 is located just upstream of the pump 42, which 
also is shown in FIGS. 1 and 13. In the portion of the flow system 17 
shown in FIG. 13, the slurry control system 130 may be located between the 
recirculate/discard liquid control valve 102 and the pump 42. 
One or more detectors 123 sends information to the controller 124 
representing information based on which the controller determines and 
controls the amount of loading of the liquid by the epsom salt or other 
material being added to the water to form or to constitute the slurry. The 
additive, e.g, epsom salt, is supplied from a reservoir or storage 
container therefor, which is represented at 131. The liquid ingredient of 
the slurry is provided from a reservoir, source, or the recirculating 
valve 102 and is represented at 132. 
The controller is coupled by lines 126a, 126b to the additive and liquid 
supplies 131, 132 and determines the amount of each delivered to the 
liquid/additive slurry formation device, such as a mixer 133 (blender or 
the like), in which the slurry is formed. The controller 124 also may be 
coupled by line 126c to the mixer 133 to control operation thereof to 
assure appropriate consistency, specific gravity, dissolving, particle 
mixing, etc. of the slurry ingredients. Also, the controller 124 may be 
connected by line 126d to the pump 42 to control the operation thereof, 
e.g., to determine the head pressure, flow volume, etc. of the slurry. 
In operation of the toxic waste storage depot 10, by monitoring radiation, 
temperature, and/or the like, the slurry control system 130 is able to 
keep radioactivity at safe levels. For example, the amount of loading of 
the slurry with radiation absorbing and/or shielding material, such as 
epsom salt, the amount of radiation absorbed and/or blocked from 
transmitting from the building 11 can be controlled. By controlling the 
flow rate of slurry, the amount of heat removal from the building 11 can 
be controlled. By controlling flow rate, loading, and/or salt removal, 
e.g., by the precipitating method of FIG. 13 or by some other method, the 
amount of reloading of the slurry and amount of radiation subsequently 
absorbed can be controlled to provide safe operation for the facility 10 
to store toxic waste, especially nuclear or radioactive waste without 
damaging leakage. 
Another embodiment of building 141 in accordance with a modified toxic 
waste storage depot 10' of the invention is disclosed in FIG. 15. The 
storage depot 10' may be the same as the storage depot 10 described above, 
except that the building 111 is modified from the building 11. The 
building 141 is made of a combination of a steel or other strong and stiff 
supportive frame structure 142. Other exemplary materials for the frame 
structure 142 include aluminum, other metals, alloys, or the like, and/or 
synthetic materials, such as polymeric material or other material. The 
frame structure 142 includes a plurality of horizontal, vertical and 
diagonal rib-like members (also referred to below as "ribs"), struts or 
the like, such as C-shape, Z-shape, I-shape, etc. beams 143 of steel or 
some other material as mentioned or equivalents. These ribs are secured 
together to form a strong rigid structure. Wall panels, such as the 
pre-fabricated wall panels 33 described above, are inserted between and 
secured to the respective ribs 143 by conventional fasteners, such as 
screws, clips, adhesive material, etc. Such wall panels form the sidewalls 
31 of the building 141. The floor 144 of the building 141 is made from 
concrete that can be poured in place or can be prefabricated. Preferably 
the floor 144 is poured in place to maximize integrity thereof. The floor 
144 may be mounted by plural stilts 145 above the base 21 of the large 
hole 20 in the ground 12 or the floor 144 may be mounted on or poured 
directly onto the ground 12 over which the liner 22 preferably first is 
placed, as was described above. Alternatively, the floor 144 and roof 145 
of the building 141 may be substantially the same as the floor 30 and roof 
32 described above, although in the building 141 the floors and roof are 
supported from respective ribs 142. A portion of the building 141 and the 
sidewalls thereof preferably are located below ground level in a manner 
similar to the building 11 of FIG. 1, for example. 
The building 141 is of modular construction. The sidewall panels 33 may be 
load bearing in which case the load capacity of the ribs 142 may be 
reduced compared to the load capacity thereof if the panels 33 were not 
load bearing. In the illustrated example of building 141, the transverse 
ceiling ribs 150 are Z-section steel beams and the longitudinal ceiling 
ribs 151 are C-section steel beams connected as shown. The floor structure 
includes transverse Z-section steel beams 1 52 and longitudinal C-section 
ribs 153. Vertical columns 154 and diagonal braces 155 are C-section steel 
beams. Other equivalent components may be used to construct the building 
141 to provide the desired containment facility for toxic waste storage in 
accordance with the invention hereof. 
It will be appreciated that the various features of the invention described 
in connection with one of the embodiments or drawings hereof may be used 
in connection with other embodiments and/or systems, devices, structures, 
etc., of the various other drawings hereof.