**5.14 Facilities and Siting Requirements**

**5.14.1 Introduction**

FIRE will utilize a significant on-site tritium inventory, and will be a
major consumer of electrical power and liquid nitrogen. As a burning
plasma experiment, FIRE will cause both direct radiation and induced
radioactivity in its materials, resulting in a need to design for the
safe handling of radioactive material. FIRE will therefore need to be
licensed by the Nuclear Regulatory Commission, although it is expected
that it will qualify as a "low hazard facility". The design of
facilities and discussion of siting requirements have been approached
assuming that FIRE might be constructed at a new, undeveloped site,
where there are no constraints on the orientation and interaction
between buildings and systems.

**5.14.2 Functional Requirements**

Generally, the various buildings and site infrastructure comprising the
FIRE facilities must be designed to enclose, protect, support, and
provide key services to the systems and components which are located
within each building or structure. The facilities are also assigned the
functional requirements to protect workers and the public from radiation
or toxic hazards associated with FIRE operation. Spatial and geometric
requirements include space for the tokamak itself, and space to perform
assembly, operation, maintenance, and future decommissioning functions.
Because of containment and shielding needs, some FIRE maintenance
activities will involve the use of robotic remote handling equipment.
The FIRE test cell, hot cells, and remote maintenance systems facilities
must be large enough to house and shield the remote handling equipment
that performs these functions.

FIRE is designed to provide sufficient self-shielding so that the
exposed parts of the machine can be approached during shutdown by
maintenance workers. However, when operating, the tokamak cannot be
approached, and a suitable shielding boundary must be established around
the machine. This boundary must include labyrinths and access control
features to prevent unplanned worker exposure. In addition, FIRE must be
designed against certain accident events (see Section 5.15). To prevent
the uncontrolled spread of radioactive material, the tokamak building
must include a confinement boundary. This boundary must include features
such as airlocks, depressurization, exhaust filters, and perhaps water
removal systems to capture tritium, so as to mitigate the consequence of
any accidental releases. When radiation sources are enclosed inside the
tokamak vacuum vessel, it provides their containment. Whenever objects
or materials are removed from the tokamak, the confinement function must
be maintained. However, it is not desirable to permit radioactive
materials to contaminate the test cell. To deal with radioactive
materials and components, the facilities must include one or more hot
cells where objects can be maintained or processed as waste. The remote
handling system must be configured so that it can transport objects
between the tokamak and the hot cell without losing the containment
function.

The buildings and structures must be designed to resist all appropriate
forces, including gravity, seismic events, wind and extreme weather
loads, maintenance loads, and any dynamic loads imposed by operating
systems. The various buildings are categorized as either safety related,
or non-safety related, depending on the systems and materials they
contain, and the functions they are assigned. Safety related buildings
are designed and constructed so that they will not lose their
functionality during any event included within the design basis.
Non-safety-related buildings are designed so that they might fail to
perform all their functions during extreme events, however, they are
always designed to protect the health and safety of workers.

Figure 5.14.2-1 shows a generic site plan and includes a legend
indicating conceptual buildings and structures.

**5.14.3 Design Descriptions**

**5.14.3.1 Tokamak and Hot Cell Building**

The tokamak and hot cell building is a two-level reinforced concrete
structure. The building outside dimensions are 39 m wide at the south
end, 59 m wide at the north end, and 98 m long. An overhead bridge crane
serves the tokamak test cell and an adjacent space on the north side of
the test cell (used for remote handling cask operations).

![](media/image1.wmf){width="5.476388888888889in"
height="7.482638888888889in"}

Figure 5.14.2-1 -- FIRE Conceptual Site Plan

The rails for this crane also continue over the assembly and mockup
building at the south end of the test cell. The tokamak test cell and
remote maintenance area are enclosed by 1 m thick concrete walls and a
60 cm thick roof. These structural elements form a shielding and
confinement envelope around the tokamak and some of the remote handling
operations. The crane bay is approximately 20 m high. Other parts of the
building, which wrap around the remote handling area, contain hot cells
and remote handling tools service areas. These parts of the building are
approximately 10 m high. The below grade basement level of the building
has an internal height of 5 m, and the basemat is 3 m thick. The
building is arbitrarily oriented on the site with the longest side of
the building in the north-south direction.

The wall at the south end of the test cell is equipped with a large
movable section that can be raised to allow the crane to also serve the
assembly and mockup building. A similar movable shield wall is provided
at the north wall of the test cell. Both the north and south walls of
the test cell also have large door sections that can be moved
horizontally to allow the crane to carry loads from the assembly and
mockup area to any point in the test cell or remote maintenance
operating area. The horizontal and vertical shield wall sections at the
south end of the test cell are also equipped with inflatable seals,
since they form part of the confinement boundary.

Figure 5.14.3-1 shows an east-west elevation view, or cross-section of
the tokamak building. The tokamak is located so that its vertical
centerline is in the center of the test cell, and its horizontal
centerline is 4.2 m above the operating floor. This elevation is chosen
to allow space around the tokamak for the operation of remote handling
casks. This view also shows the approximate location of waveguides for
the ICRF system, magnet busbars, and the minor structures located east
and west of the test cell to facilitate horizontal entry to the test
cell basement from the adjacent buildings. Services such as ICRF
waveguides, cryopumping, diagnostics, and divertor cooling will connect
to the tokamak via vacuum vessel ports. The current test cell layout
strategy calls for services that will connect to ports to be routed
through the test cell basement and penetrate the test cell through the
operating floor. Because port closure assemblies (except one blocked by
a diagnostic neutral beam) are designed to be replaceable, the space
immediately in front of each port must be kept clear of permanent
installations. Penetrations through the floor must be located in areas
aligned with the magnet centerlines, and de-mountable sections of
piping, waveguides, or other systems used to complete the connection to
the ports.

Other services, such as magnet power leads, magnet pre-cooling and
vacuum vessel cooling, will connect to the tokamak at locations other
than the ports. The current layout strategy calls for these connections
to be made through the test cell basement and to penetrate the tokamak
pedestal or test cell floor in the space below the cryostat. This area
will be congested because of the tokamak support system. The current
concept for these supports is a ring of flexing columns located below
each TF coil. Because of space constraints, the tokamak support system
must be integrated with the clamps for PF coil 3L.

Figure 5.14.3-2 shows an above grade plan view and North-South elevation
view of the assembly, tokamak and hot cell buildings. The test cell size
is determined by the space required to maneuver and dock remote handling
casks at ports. Because of the length of the port closure assemblies,
remote handling casks are expected to be approximately 8 m in length and
about 1.9 m in width. There are several strategies under consideration
for the design of remote handling cask vehicles. Casks could be
transported between the tokamak and the hot cell using the building
overhead crane, or they could be designed to move on the building floor
using either wheels or air cushion supports. Because of the expected
weight of these objects, it is likely that air cushions will be superior
to wheels. A strategy for cask access to the inclined upper and lower
horizontal ports has not yet been determined, however, the facilities
layout assumes that casks for each of the three horizontal locations
will be mated with a vehicle designed to support the cask at the correct
level from the floor. A floor-supported vehicle will move the cask to a
pre-determined position in front of the port established by guide pins
or stops. The vehicle frame system will provide the final motion along
the axis of the port.

When port inserts are removed from the tokamak they need to be
transported to and transferred into one of the hot cells. It is expected
that the radioactivity level of these components will require enough
dose attenuation to make it impractical for the casks and remote
handling vehicles to include shielding. Therefore, object transfer
operations are planned as remote handling activities. When radioactive
sources are being moved between the tokamak and the hot cells, the test
cell and remote handling vehicle areas must be made inaccessible to
workers. The test cell will also be inaccessible whenever a port insert
is removed and not replaced by a new insert or a dummy shield. It should
be possible to restrict all transfer operations to night shifts.

It will also be necessary to maintain the divertor and first wall. To
access these components, an in-vessel manipulator is proposed. This
device should be capable of being inserted through any port (except the
port blocked by the DNBI cell) and able to reach one eighth of the
vessel in either direction. The in-vessel manipulator may be mounted at
a port for an extended time, and there are several potential strategies
for re-closing the tokamak shield to make the test cell accessible.
These include movable shield walls that could be erected around the
manipulator cask, or shielding within the manipulator or cask that
prevent radiation streaming from reaching unacceptable levels. Figure
5.14.3-3 is a plan view in the basement of the complete building. Space
is available for the roughing vacuum pumping system and for the tritium
processing systems. In earlier FIRE reports, these systems were located
in a dedicated Vacuum Pumping and Tritium Building, which has now been
eliminated. ![](media/image2.wmf){width="4.9625in"
height="3.4590277777777776in"}

Figure 5.14.3-2. It is expected that cryopumps located in upper and
lower horizontal ports will operate during tokamak pulsing. Between
pulses (three hours), cryopumps will be warmed and regenerated back to
the vacuum vessel, which will be pumped using mechanical vacuum pumps
located in the outer part of some of the mid-plane ports. Because of the
high magnetic field, these mechanical pumps will only operate between
pulses. The mechanical pumps will exhaust to roughing pumps located in
the tokamak building basement. This area will also contain fuel gas
purification systems and isotopic separation systems. Tritium and D-T
mixtures recovered from the fuel gas will be stored on hydride beds in a
secure vault. All tritium processing equipment will be housed in glove
boxes. The hot cell concept is based on the expectation that some port
mounted objects can be repaired and returned to the tokamak. To
facilitate this, part of the hot cell system will allow port objects to
be placed into a cell wall penetration that is physically identical to
the tokamak port. Inside the cell, which provides shielding and
containment, a remotely controlled work center will be provided, which
can perform repair operations on plasma facing components. Meanwhile,
the outboard end of the port assembly remains accessible for hands-on
work. Divertors and plasma facing objects that cannot be repaired will
be transferred through a docking port into a second, larger hot cell.
This hot cell will house remotely controlled equipment and workstations
used to remove and replace the
![](media/image3.wmf){width="6.179861111111111in"
height="5.177777777777778in"}

finger elements on divertor modules, which will then be returned to
service in the tokamak. Discarded divertor fingers and other irradiated
components will be stored and eventually processed for disposal. The
extent and nature of ![](media/image4.wmf){width="6.470138888888889in"
height="7.235416666666667in"}

these hot cell processes are not yet well developed, but it is expected
that they will include divertor repair (replacement of individual
finger-tiles), tritium recovery from beryllium, size reduction by sawing
or cutting, and encapsulation of radioactive material for subsequent
shipment to a waste repository.

The tools that operate within the remote handling casks are likely to
become contaminated with tritium or radioactive dust, but are unlikely
to become radioactive sources. They will need development and periodic
maintenance and testing. To serve these functions, facilities are
provided where remote handling casks can dock and discharge tools to a
decontamination facility. Tools are subsequently moved to a storage and
repair facility.

**5.14.3.2 Other Safety Related Buildings**

The tokamak and hot cell building, and other safety related buildings
will generally be constructed using cast-in-place reinforced concrete.
They will be designed to resist seismic forces and extreme weather
hazards such as tornado missiles. For the tokamak and hot cell building,
which is also assigned a shielding function; the thickness required for
shielding is generally more than the thickness required to resist
tornado missiles.

The radioactive system support building (Building 12) will be used to
provide locker and change facilities for workers entering radiation
controlled areas and to support systems used in remote repair and
processing in the hot cell. This building will also provide space to
store materials and supplies used by radwaste encapsulation systems,
tritium recovery systems, and waste shipping to offsite disposal
locations.

The radwaste systems building (Building 14) will be used to house
treatment systems for water which has become contaminated with tritium
or activated corrosion products. All floor drains and other intentional
drainage from cooling systems which could be contaminated will be
processed in this building to remove particulate and ionic activity.
Water which is contaminated with tritium or which is recovered from
atmospheric detritiation units in the plant HVAC systems will be treated
in a water detritiation system. This system will use established
technology including vapor phase catalytic exchangers and a tall
distillation column.

The emergency power supply building (Building 15) will be used to house
a backup power generating system. Presently, the need for safety related
backup power is not well known, but the loads are likely to include the
HVAC systems and any other loads associated with maintenance of the
confinement function. If these loads are small, the safety related power
supply system could consist of two small auto-start diesel generators.
Some systems will require battery powered un-interruptable power
supplies, which could also be located in this building, or which could
be distributed on the site.

**5.14.3.3 Non-Safety Related Buildings**

Non-safety related buildings will generally be constructed using the
lowest cost building technology that is suitable for their purpose. This
usually means a steel-framed structure built on a concrete slab
foundation at grade. The assembly and mock-up hall (Building 21) is
provided to facilitate assembly and maintenance functions. The width of
this building is set so that the overhead crane used in the test cell
and remote handling staging area can also operate here. The assembly and
mockup hall will have a below grade level dedicated to diagnostic signal
acquisition and processing, and will be built from reinforced concrete
below grade. The floor loading capability of the assembly hall will be
the same as the tokamak and hot cell building, tentatively 20 tons/m^2^.
The above grade portions of the building will be steel framing with
architectural siding and roofing.

The magnet power conversion building (Building 22) will be used to house
the indoor portions of the magnet power supplies. Transformers will be
kept outdoors as a safety measure, and rectifier sets and power
conditioning and switching apparatus located indoors. This building will
be a single floor, steel frame on concrete slab structure. To minimize
the length of busbars and cables, the shape proposed for this building
uses a main corridor and three transformer-rectifier bays.

The cooling system building (Building 23) will be used to house the
indoor parts of the heat rejection system, which provides secondary
coolant to the divertor and vacuum vessel cooling systems. Under present
site assumptions, secondary coolant is pumped to cooling towers and
rejects heat to the atmosphere. This building will also house the plant
component cooling water system, which provides water cooling to many of
the plant's power supply and plasma heating systems.

The cryogenics systems building (Building 24) is used to house indoor
parts of the liquid nitrogen system used to pre-cool FIRE magnets.
Liquid nitrogen storage tanks are located outdoors. Because FIRE will
consume large amounts of liquid nitrogen for magnet pre-cooling, it has
been proposed that FIRE should be co-located with a commercial air
liquefaction plant. Under ideal circumstances, the liquid nitrogen
system could be filled by pipeline. Building 24 also houses a liquid
helium refrigerator that provides liquid helium to the vacuum vessel
cryopumps. Other liquid helium users will be the diagnostic neutral
beam, and the isotopic separation system in the fuel process. These
systems are not yet well developed, and the size of the system
components and building are very preliminary.

The ion cyclotron heating system power supply building (Building 25)
will be similar in design and construction to the magnet power supply
building. It will house the indoor portions of the ICRH system,
including power supply cubicles, and tetrode signal generator modules.
The ICRH system will deliver 30 MW to the plasma via 16 trains; hence
each train will be sized for about 2 MW. Waveguides from the ICRH
building and busbars from the power supply building will be routed
through access structures on the east and west sides of the tokamak
building, so that they can enter the tokamak building below grade.

The laboratory office building (Building 26) and the control and
operations building (Building 27) will be designed and constructed to
conventional office building standards. The laboratory office building
will be sized for 500 to 700 scientists, engineers, administrators, and
other site workers. The LOB will be located near the perimeter of the
FIRE site, to permit relative freedom of public access. The control and
operations building, on the other hand, will be located as close to the
tokamak buildings as reasonably possible, to facilitate easy physical
access to FIRE facilities. The control and operations building will
include facilities for operator interface with all FIRE control systems,
and will include space dedicated to management of abnormal events.

The utility systems building (Building 28) will be dedicated to
necessary site infrastructure, and will house compressed air systems,
potable and demineralized water treatment systems, site central heating
and chilled water systems, and storage of clean parts and supplies.

**5.14.3.4 Site Improvements and General Arrangement**

In addition to safety and non-safety-related buildings, the FIRE site
will include improvement needed to meet the functional requirements of
outdoor equipment. The switchyard to receive grid power and step it down
to voltages suitable for FIRE systems must be capable of handling
approximately 1000 MW. Cooling towers will be required to reject heat
from the divertor and vacuum vessel cooling systems. If the heat
rejection system is able to average the heat load, the total capacity of
the cooling towers could be quite small. Magnet pre-cooling will use
liquid nitrogen, supplied by pipeline from a commercial on-site plant or
a nearby offsite plant. Because FIRE will be a licensed nuclear
facility, perimeter fencing and multiple levels of access control will
be required. These features will be further developed in future work.

**5.14.5 Site Selection Process**

The FIRE design process has been based on the assumption that the
experiment will be sited at a new, undeveloped location - a "greenfield"
site. This assumption presents the minimum set of design constraints.
However, it is likely that several current experimental sites could also
provide a good basis for design. The following key criteria are expected
to be important to the process of selecting a site for FIRE:

-   *Availability of land.* Since FIRE will be a licensed nuclear
    facility, it will be necessary for the operating organization to be
    able to control land use within a distance of 500 to 1000 meters
    from the tokamak building. This exclusion distance is related to the
    analysis of radiation release events, and suitability of the site
    for a nuclear facility.

-   *Access to electrical power* FIRE will require input power on the
    order of 1000 megawatts for periods at least as long as the plasma
    pulse plus the ramp-up time. If an otherwise good site does not have
    a sufficient electrical supply, some form of energy storage could be
    considered. However, the high power demand and relatively long pulse
    could require total energy storage on the order of 20 gigajoules.

-   *Access to industrial infrastructure.* Supply of construction labor
    and material, transportation for the delivery of tokamak and other
    large components, and the availability of industrial commodities
    such as liquid nitrogen will be factors which could effect the cost
    and schedule.

-   *Ability to transport radioactive materials.* It *must* be
    acceptable to the surrounding community that the FIRE facility
    receives shipments of tritium and issue shipments of encapsulated
    radioactive waste.

-   *Access to amenities for FIRE staff* . The scientists, engineers,
    and technicians who build and operate FIRE will require adequate
    schools, health care, and community infrastructure.

In the future, candidate sites will be identified and evaluated for
their technical acceptability and their influence on the cost and
schedule of the project.