ITER ITA NEWSLETTER
No. 13, FEBRUARY 2004

INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, AUSTRIAISSN 1727–9852

COMMON MESSAGE FROM SECOND PREPARATORY MEETING FORMINISTERIAL MEETING FOR ITER
Delegations from China, the European Union, Japan, the Republic of Korea, the Russian Federation, and theUnited States of America met at the IAEA headquarters in Vienna on 21 February 2004 to advance the ITER
negotiations.
The delegations recognized the intensive work done following the Ministerial Meeting for ITER that took place
on 20 December 2003.
The delegations agreed to convene a meeting of experts in early March for a joint appreciation in common
terms of a number of key topics *), in order to bring the further technical analysis to completion.
ITER Parties will continue their discussions, including further exploration of a broader project approach tofusion power.
All delegations reaffirmed their commitment to the consensual process towards joint implementation of ITER.
*) Key topics: Transport; Seismicity; Licensing Issues including Codes and Standards; PF Coil Manufacture; Cost Issue;
Climate; Scientific, Technological and Industrial Environment; Living Conditions; Readiness andPreparedness for Siting

PROGRESS ON BUILDING DESIGN AND SITE LAYOUT,AND PREPARATION FOR PROCUREMENT
by Dr. R. Haange, Head of Site, ITER Naka JWS
1.

Introduction

The ITER site layout and buildings (figure 1) retain many of the major features worked out for the original 1998
design of ITER. By mid-2001, the design had been adjusted to take account of the reductions in size of thetokamak and in the performance and capability of its supporting plant systems, with a view to providing abuilding construction cost reduction near the target of 50%.
Following the Final Design Report (FDR), work has mainly concentrated on developing detailed designs of
the time-critical buildings, so that procurement can be initiated as soon as the ITER site has been selected
and the ITER Legal Entity (ILE) has been set up. In addition, work has been devoted to improving layout froma functional point of view, to save cost and to provide additional space for potential future upgrades.
The present status of the site layout and buildings is that, with the exception of the hot cell building, designs
are available for the ITER buildings and site layout, in different degrees of detail, ready for final review as soon
as the drawings and 3D models have been updated.
The overall site layout may have to be further adjusted in accordance with the characteristics of the chosensite, as the relative orientations of incoming electrical power, outgoing sewers and main site access roads may
differ from those assumed for the generic site. However, the indications are that, for the potential sites, thisLatest bird’s-eye view of generic site

aspect of site layout will be rather minor. Having available all building blocks for the generic site, such an adaptation will not require significant effort.
2.

Optimization of Building Design and Site Layout after 2001

The ITER site layout is determined by the functions of the various plant systems provided in support of the
ITER tokamak. These systems are located in different buildings on the ITER site. Changes in the plant layout
inside buildings can, therefore, have an important impact on the overall site layout. The general layout of thesite assumes electrical power comes in from the west, heat rejection is on the east, access into the main building for assembly is from the south, and removal of waste is from the north. These orientations are purely
notional, determining only the relative positions.
As a result of increased detailing of the buildings and site layout for the procurement specification, further
important modifications since the July 2001 description in the FDR have been foreseen, driven by– improved detailing of the functional specification of the buildings and the equipment in them;– design improvements of both buildings and equipment, with a view to obtaining increasingly realistic cost
margins within the original estimates;– design progress/evolution.
These foreseen changes are described below. The review and approval process is not complete and not allof the updated designs and layout described here may be adopted.
2.1

Combine Switching Network Building with Diagnostic Building

The switching network building has been combined with the (enlarged) diagnostic building. To enable the combination, the diagnostic building has been somewhat enlarged in footprint and two floor levels have been
added. At the same time, the self-standing diagnostic building has been attached to the tokamak building, andplaced on the same basemat. This gives some important improvements in terms of avoiding relative movements between the diagnostic and the tokamak buildings, and hence the diagnostic penetrations and others
are easier to design and are now considered more reliable. Also, this change reduces the length of the large
busbar systems and places the switching network resistors (SNR) and fast discharge units (FDU) on the same2

basemat as the tokamak. Moreover, the tokamak complex as a whole becomes a much more symmetric structure, as the diagnostic building on the west side more or less balances the tritium plant building on the east
side, reducing torque during a seismic event. The coolant water station, originally inside the switching networkbuilding, has now been placed inside a light structure, just south of the magnet power conversion buildings.
2.2

Move Location of Hot Cell Facility

In earlier layouts the hot cell (HC) facility, which includes the hot cell building with the attached radwaste andpersonnel access buildings, was set north of the tokamak building. The entrance from the tokamak building
to the HC was through the large main lift, and the entrance corridor was along the inside of the east wall of
the HC. The HC facility has now been moved as far as possible to the east, so that the entrance corridor toand from the main lift is along the inside of the west wall of the HC. The main reason for this change was toallow simplified, rather straight routing of the neutral beam (NB) high voltage lines, reducing their lengths andnumber of elbows. This increases reliability and reduces cost. The added (important) advantage of this movehas been to allow installation of the NB lines inside the tokamak building using large prefabricated andpretested modules. Originally, access to the NB cell for installation was only feasible via the main lift, which
required the large beamlines to be assembled in situ from small parts.
The NB power supply area has been rearranged north of the tokamak building.
The relocation of the HC building is not a simple move, but requires detailed redesign work. This is also
required for the personnel access and radwaste buildings, which interconnect with the HC building. Moreover,
the access into the tokamak complex has now moved from the west to the east side of the buildings. This has
involved the move of the main office and control buildings also to that side.
The office and control buildings were previously placed at the SE corner of the site. However, as the main
human access will be required through the personnel access control building, from where the HC, radwaste,
tritium plant and tokamak buildings are accessed, the new location for the main office building in the NE corner gives a much shorter and more direct route.

Tokamak building cutaway
showing services routing

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2.3.

Exchange the Cryoplant Cold Box and Compressor Buildings

The size of these buildings is determined by their initial function, i.e. for the on-site fabrication of the poloidal
field coils. An industrial study has been made that showed that the footprint of the buildings had to be
increased substantially over the size required for their later use for the cryoplant, to enable coil fabrication as
per the ITER construction schedule.
The advantage of also exchanging their function is that both buildings now provide ample space for the plantsystems collocated in them, so that any (limited) future upgrades can be handled within the available space.
Moreover, the helium compressors for the isotope separation cold box of the tritium plant, as well as the compressors for some additional small cryopumps, can now all be moved into the cryoplant compressor building.
This puts all the very noisy systems in one building and is also advantageous from a maintenance point ofview.
Even in the event of the installation of additional equipment and of one additional cryo-compressor station, as
almost certainly will be required for long (steady state) burn plasma discharges, space inside the building
would still be sufficient to also incorporate the emergency power supply generators, although this would
require the construction of special containments using concrete walls to provide fireproof segregated areas
for the redundant diesel generators. These were previously located in a separate building.
2.4

Move Coolant Systems from the Assembly/RF building to the Site Services Building

An area of 35 m x 12 m footprint inside the assembly hall, approximately 6 m high, was previously earmarked
to locate a chilled water unit, heat exchangers and pumps to supply chilled, raw and component cooling waterto radiofrequency (RF) power supply systems and to other systems that will be installed in the assembly hallfollowing completion of machine assembly. These coolant systems are now installed instead inside the site
services building, alongside similar systems. The installation can proceed while assembly operations of themain machine are still in progress and, more importantly, the freed space inside the expensive assembly hall
is available for any future upgrade of the RF systems. This does require, however, a modest enlargement of
the less expensive, steel frame type site services building.
2.5

Improve Tritium Plant Layout

The processing and storage systems with the main tritium inventories have been moved below ground level,
providing increased protection against external events. As a result, the safety-related chiller units have had tobe moved out of the basemat level. These provide chilled coolant for safety systems inside the tokamak complex (and HC). To avoid crossing the seismic gap with the coolant pipes (except for the HC), it is advantageous
for these units to remain inside the tokamak complex. However, space for these large units was not found andtherefore it was decided to put them on the roof of the tritium plant and the diagnostic building as redundant
systems.
To reduce the fire loading in the tritium processing areas, and especially the risk of fire initiation, all control
and power cubicles have been moved into special rooms separated from the processing rooms by fire barriers. The rooms are on the south side inside the tritium plant building.
2.6

Layout of Steady State Electrical Power Supplies

Considerable effort has been spent on investigating the layout and development of the detailed design of thesteady state electrical power supplies, in terms of layout and design of load centres and distribution panels,
as well as sizing and routing of cables into the main tokamak building and tritium plant and distribution of
cabling around the plant and the site. A task with the EU Participant Team has recently produced a large
amount of information. This is being further refined to achieve acceptable deployment of cabling and cubicles
inside the main tokamak building. The information is also used for the design and layout of the utility tunnels
on the site.
The safety-related power has to be routed through seismically qualified tunnels, in redundant paths separated
by fire barriers, into seismically qualified, redundant load centres and from there to the loads in seismicallyqualified buildings.

4

Two seismically qualified load centres at the SW and NW sides of the main tokamak complex are used to provide the low voltage, safety-relevant power for these buildings. Very powerful heaters are used in both the heattransfer systems inside the tokamak building and in the tritium plant. These cannot be powered by medium orhigh voltage, and this results in a vast amount of 400 V cable bundles from load centres through the tokamak
and tritium building to their loads. This leads to long cables and to very large cable tunnels and vertical cable
shafts, which therefore also need to be large inside the buildings. Moreover, it requires the two safety-relatedload centres to be increased considerably in footprint for many non-safety-relevant loads. Therefore, it has
been decided to have two additional load centres (for non-safety-relevant loads) installed on the roofs of thetritium and the diagnostic buildings, inside light, metal frame structures.
Although the full information is still being developed, it is assumed that, for routing of power and control cables
inside the tokamak building, there will be cable trays along the inside of all four outer perimeter walls at every
floor level (see figure 2), reaching from floor level to just underneath the ducts for local air coolers. The original idea was to have a double row of trays above power and control cubicles deployed in this area, but theavailable space at the vacuum vessel port levels is in that case not adequate. Moreover, the results of R&D
done by both the EU PT and the JA PT indicate that the fluctuating magnetic fields in these areas are toostrong for many conventional components inside these cubicles.
Therefore, the present strategy is to place cubicles needed for plant operation in the corners of the tokamakbuilding, where the magnetic field strength is considerably lower, or to place them in adjacent buildings. Initiallayouts have been produced for cubicles in the diagnostic building and near the load centres on the roofs of
the tritium and diagnostic buildings.
2.7.

Design and Layout of Utility Tunnels

Utility tunnels are used to interconnect piping networks and cables between buildings and areas at the ITER
site. As stated before, cables are divided into two trains that have to be fully separated in fireproof compartments, including cable tunnels. Tunnels are also needed to route piping for the water circulation system that
feeds water from the cooling tower cold basin to users and returns it to the hot basin near the cooling tower.
A pipe break would fill the tunnels with water, as the basin volumes are much larger than the volume of thetunnels. Therefore it is necessary to strictly separate the cable tunnels from the piping tunnels. Space on thesite is limited. Moreover, crossing of tunnels leads to complex structures. Therefore it has been decided toroute, in general, the cable tunnels above the piping tunnels but as independent, segregated and watertightcontainments, having separate access points, ventilation etc.
In the present layout the upper level of tunnels is more than 2 m below grade. The 2 m of soil fill achieves anacceptable spread of loads, which is important when tunnels cross roadways. Moreover, it allows crossing ofmany other utilities that are buried below grade, e.g. fire and potable water ring mains, sewers, storm andindustrial drains, street lighting and communication cabling.
Pipes of very large diameter are used for coolant water (up to 2 m) and also for cryogenic lines (1.2 m). In
some areas, especially near the site services building and the main pumping station near the cooling towers,
there is a proliferation of pipes to be routed in different directions. To avoid large tunnels with complex intersections, a combination of tunnels and pipe bridges will be used in this area. Feed pipes to the heat exchangers inside the tokamak building are routed from the pumping station via a pipe bridge over the road into thetritium plant building. The return pipes are routed along the east wall of the tritium plant building into a pipe
trench from where they reach the large collector pipe inside a deep pipe tunnel. A similar approach is foreseen for the feed pipes from the pumping station that connect with systems inside the site service building.
The large helium cryogenic lines that interconnect the cryoplant cold box building and the distribution systems
located inside the tokamak building now exit the tokamak building and pass along the side wall of the assembly building up to a pipe bridge where they cross the road into the cryoplant cold box building.
3.

Site Adaptation and Procurement

Both the European and Japanese potential ITER sites will most likely use seismic isolation of the main tokamak complex. As a result, the detailed design of these buildings and in particular the piping connections tothem developed for the “generic” ITER site will require redesign. Also, the footprint of the main tokamak complex will increase, and hence the layout of the utility tunnel network will have to be updated.

5After a final review of the building designs for the generic site, the designs must be adapted for the specificsite and seismic and other analyses performed to confirm the design, to determine the amount of steel reinforcement required and to provide the floor response spectra for the analyses of the systems and components
located in the buildings. Initial seismic analyses assuming seismic isolation, using seismic data for theEuropean and Japanese sites, have indicated that the main tokamak complex building design is acceptable.
A draft Site Facilities Procurement Specification has been written by the International Team. This will requireconsiderable specific input when the site has been selected. Furthermore, the present site layout will have tobe reviewed in detail. The generic site has been kept compact. Once a site is available, it may be advantageous to leave a bit more space between buildings, which would also minimize the length of tunnels routed
underneath roads. Tunnel construction, including the installation of pipes (cables can be installed after thetunnels have been completed), which must be completed as one of the first site activities, does severely
restrict site access, especially when it prevents the timely availability of access roads.
The drafting of the Procurement Specification for the time-critical buildings has commenced with the compilation of a room-by-room description of the functions and facilities. The building models are being updated toshow the small, necessary modifications in line with detailed studies.
It is intended to have an internal final review in April 2004 of the site and building details, to obtain formal internal approval for the changes, and then to update the drawings and documentation as necessary for any external review and for procurement.

ROBERT SANTORO †The ITER International Team was very sad to hear of the sudden death ofRobert (Bob) Santoro on 8 March 2004. During the ITER EDA Bob was a leading US member of the Joint Central Team at the Garching Joint Work Site, where
he led the neutronics analysis. Bob brought great expertise to this work, andbound together the efforts of his multinational group, as well as others in the
Home Teams, resulting in a highly motivated, hard working and tightly knit groupof experts in both analytical and computational work. It is not only this legacy
that remains with the project, but also the memory of his gregarious and positive personality. Our deepest sympathies go to his wife, Jan, and his family.

Printed by the IAEA in Austria
April 200404-15071

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