Dubna Site Investigation

Initiated by JINR and supported by GDE

An Evaluation of a Proposed Site for the International Linear Collider near Dubna, Moscow Region, Russia

International Linear Collider Global Design Effort Joint Institute for Nuclear Research

18th November 2010

Authors JINR, Dubna, Russia Yulian Budagov Yury Denisov Andrey Dudarev Grigory Shirkov Grigori Trubnikov

GSPI, Moscow, Russia Valery Sokolov Vasiliy Kozhanov

Fermilab, Batavia, USA Victor Kuchler Tom Lackowski Marc Ross

Hansen Engineering, Springfield, USA Tracy Lundin

DESY, Hamburg, Germany Wilhelm Bialowons Nicholas Walker

ILC Report No. ILC-REPORT-2010-26 ILC-HiGrade Report No. ILC-HiGrade-2010-008-1

ILC-EDMS Document ID D*928865 ISBN: 978-5-9530-0265-3

Table of Contents 1 Executive Summary/Overview of the Site ...... 3 1.1 Introduction ...... 3 1.2 ILC Tunnel Configurations studied by the GDE ...... 4 1.3 The Dubna Site...... 5 2 Description of Current Dubna Site Design ...... 8 2.1 Preliminary Design (Shallow Bored Tunnel with Surface Level Gallery) ...... 8 2.2 Verification of GSPI Soil Boring Report ...... 9 2.3 Status of Cost Estimating Effort ...... 10 3 GSPI Soil Boring Report ...... 13 3.1 Results from the Soil Boring Report ...... 14 4 Near Term Topics for Further Investigation ...... 17 5 Summary ...... 18 6 References...... 18

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1 Executive Summary/Overview of the Site

1.1 Introduction In this Report we describe a study to consider siting the International Linear Collider (ILC) near Dubna, Russia, in the northern part of the Moscow region, initiated by the Joint Institute of Nuclear Research, (JINR, Dubna). This site (referred to as the ‘Dubna Site’) is well suited for the ILC because it: is located near JINR; has excellent geological conditions which would allow the collider to be constructed near the surface; is lightly populated; has well developed utilities infrastructure. The study reported here was intended to evaluate and describe the geotechnical aspects of the Dubna Site. It was proposed by JINR during the development of the ILC Reference Design in 2006, and the work in this Report was subsequently carried out by the State Specialized Project Institute (GSPI) part of ROSATOM, in 2008 [1].

The Dubna Site geotechnical study was done as part of the ILC Global Design Effort (GDE) Technical Design Phase. The GDE will use these results in three ways:

• The geotechnical details from the GSPI report will enable a preliminary analysis of a shallow site for ILC. Two specific shallow sites have been studied, the Dubna site and a site near DESY, in northern Germany, referred to as the ‘DESY site’ [2]. • The process of optimizing the site alignment, based on constraints identified in the proposed Dubna site, is instructive and we expect to be able to use this process as a model for the evaluation and alignment optimization of other potential sites. • The site evaluation and analysis process, whereby site-specific geotechnical, topographical, cultural and infrastructure considerations are taken together as a model is also quite instructive.

During the preparation of the ILC Reference Design, as reported in the Reference Design Report (RDR) [2], the GDE limited its attention to deep-rock sites. These involve a very different set of design criteria which, without extensive and costly deep-borehole studies, will not be understood in the same manner as a shallow site. As a result, the RDR sample site development was based on idealized conditions including, for example, parametric cost estimation based on projects done in similar conditions. In contrast, the study reported here includes specific alignment information and geologic borehole sample data.

In the RDR, two near surface European sites where mentioned (RDR pages 18 – 19):

“A second European sample site near DESY, Hamburg, Germany, has also been developed. This site is significantly different from the three reported sites, both in geology and depth (25 m deep), and requires further study. In addition, the Joint Institute for Nuclear Research has submitted a proposal to site the ILC in the neighborhood of Dubna, Russian Federation.” and

3 “The DESY and Dubna sites are examples of ‘shallow’ sites. A more complete study of shallow sites – shallow tunnel or cut-and-cover – will be made in the future as part of the Engineering Design phase.”

This document includes an overview of the Dubna site, including a conceptual layout of the ILC tunnels for the site, an analysis and review of the State Specialized Project Institute (GSPI) Dubna Geotechnical Site Study, initiated by JINR, and a short, parametric evaluation of potential cost savings for the site. For the latter, since the Site Study does not include construction cost information, results from a recent Illinois, (flat topography), US-based main linac tunnel configuration cost study were adjusted to fit the surface features of the Dubna site.

The cost savings evaluation indicates the importance of surface feature intersections for shallow site configurations. It is well known that such features, and the actual flatness of the topography, are cost – drivers for near surface, excavation-type construction. For the relatively uninhabited Dubna site, a number of road crossings and a railroad crossing would have to be modified to allow passage of the ILC. Including these, as was done for the Illinois tunnel study, effectively counteracts the anticipated cost savings. By ignoring the surface features, and assuming a very flat topography, one is able to see what basic near-surface construction costs might be.

1.2 ILC Tunnel Configurations studied by the GDE The general Conventional Facilities layout of the ILC is described as follows:

• Underground tunnels, about 31 km long, house the main accelerators and the Beam Delivery Systems (Beam Tunnel), and their associated support hardware. • Shafts or access tunnels along the length of the machine provide access to the above. In the RDR, they primarily support the large cryogenics plants at the surface required for the superconducting linacs. • A single collider hall at the Interaction Region (IR), large enough to support two physics detectors in a push-pull configuration. • A tunnel following a ‘racetrack’ shaped path located near the central IR region to house the electron and positron Damping Rings stacked above each other. • Several additional tunnels and service shafts house the electron and positron sources and injector linacs (injection into the Damping Ring), and connect the damping ring to the main accelerator housing.

The GDE has evaluated eight different main linac tunnel configurations [4]:

A twin deep tunnels with vertical access (RDR) B single deep tunnel with vertical access C twin near surface tunnels D single near surface tunnel with continuous buried surface service gallery E single near surface tunnel with surface support equipment buildings at 5 km F enclosure in open cut excavation with continuous surface service gallery G enclosure in open cut excavation with continuous buried service gallery H single tunnel enclosure in open cut excavation with surface support

4 Figure 1 shows the cross-sections of these tunnel configurations with a comparison matrix. The twin deep tunnel configuration (A) was chosen for all three sample sites in published in the RDR.

(A possible further alternative for study during the Technical Design Phase (TDP) is the single deep tunnel variant B [3].) The remaining configurations (C-H) represent near-surface sites, of which the Dubna and DESY sites are examples. To properly assess these options and get a realistic comparison with deep rock tunnel options developed for the RDR requires a re-evaluation of design criteria [4]. By optimizing the design to best suit tunnels situated in soil, we can maximize potential cost savings. In urban areas like the DESY site, only tunnel construction with a tunnel boring machine and shafts spaced by relatively large distances is possible. Other underground elements like caverns or penetration shafts between two tunnels have to be avoided in any case. Making use of these simple rules could provide significant potential cost savings. The situation is at least partially different for the relatively rural Russian site at Dubna, described in this report. An open cut and surface gallery solution is possible at the Dubna site and making use of this advantage could result in additional potential cost savings. In section 2.3, such cost savings are outlined, using the comparative ILC Tunnel Configuration Study done by the ILC – GDE Americas Regional Team.

1.3 The Dubna Site The Joint Institute for Nuclear Research JINR has proposed a shallow tunnel soft ground site in the neighborhood of Dubna in the Russian Federation. Figure 2 shows the general layout of the potential ILC site near Dubna. The tunnel alignment starts near the JINR Institute in Dubna and runs to the east, at a depth of about 20 m, south of the Volga River. Near sub-surface buildings would be constructed by an open pit method and the tunnel might best be constructed by a boring machine. However, cut/cover construction techniques are possible over nearly the whole length. In either case, a single underground enclosure solution is practical since most of the infrastructure would be installed at the surface. This promises to be a significant saving for the ILC civil construction cost which is the largest fraction of the total estimated cost in the Reference Design.

The investigations of this site are at an early stage. But it is already clear that this proposal is an interesting alternative, especially given the large degree of construction freedom.

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Figure 1: Tunnel configuration cross sections and comparison matrix.

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Figure 2: General layout of the potential ILC site near Dubna.

There are several advantages for the ILC in Dubna:

• The presence of JINR as a basic scientific and organizational body. The Joint Institute is an international intergovernmental organization, which includes 18 member and five associate member states. A Federal Law has put into effect the agreement between the Russian Federation and JINR on the special status of the scientific organization. • The territory around the proposed site is extremely thinly populated and practically free of industry, rivers and roads. There are no reserves or monuments at the site. The site does not affect national parks. The proposed position of the accelerator tunnels is in relatively dry drift clay or ‘loam’, which is impermeable and inhibits groundwater flow. • The area is seismically steady and has stable geological characteristics. • A flat relief and the unique geological conditions allows the placement of the ILC close to the surface (at a depth of about 20 m) and enables the construction of the tunnels, experimental halls and other underground buildings at low cost. Cut-and-cover construction is possible over nearly the whole length. • An additional attractive feature of placing the ILC complex on this territory is the opportunity of using the land without additional cost. Prevalent legal practice makes it possible to get the land at the ILC location for permanent free use, just as has been done for JINR, according to the agreement with the Russian Federation government. • There are sources of electric power of sufficient capacity in this area, i.e. a 500 kV power line and two power stations. • There is a developed system of transport and communication services, highways, railways and a waterway (the Volga River) with good connections to central Europe.

7 • Presence of a modern communication infrastructure, including one of the largest satellite communication centers in Europe. • A special economic zone established in Dubna in December 2005 provides preferential terms for development and manufacture of high-technology components.

Currently no further projects are planned in this territory. The ground is available for the ILC. The site is located within one administrative area, the Moscow region. The regional government has approved the JINR initiative to locate the ILC there.

The path of the accelerator traverses two small settlements and a railway between the towns Taldom and Kimry. The region around the accelerator path is mainly covered with forest and a small proportion of agricultural land. The Elevation is nearly flat with some surface swamp. The tertiary soil is stable as has been confirmed by the geological survey carried out during the site selection for the U-70 accelerator in the 1960’s. Geological characteristics of the territory allow tunnel construction in a stable geological layer at a relatively small depth of about 20 meters (See section 3).

The JINR Institute and the town of Dubna have all of the necessary infrastructure to accommodate specialists for the period of the accelerator construction; to accumulate the equipment; and to provide for the project production support during manufacturing of special purpose equipment. The international airport Sheremetyevo is at a distance of about 100 kilometers from Dubna. It is connected with Dubna by means of a highway. There is also a small aerodrome in the immediate vicinity at Borki. The electricity supply network located in the vicinity of Dubna is capable of providing the needed power supply for the accelerator (about 330 MW). The area reserved for the accelerator complex is 50 km long and 1 km wide, giving the opportunity to adjust the orientation.

2 Description of Current Dubna Site Design

2.1 Preliminary Design (Shallow Bored Tunnel with Surface Level Gallery) The present baseline design at Dubna presupposes the construction of an underground accelerator tunnel and a surface klystron gallery equivalent to the configuration represented in the referenced Tunnel Configuration Report, alternate “D” (see Figure 1). The inner diameter of the tunnel is about 5 m. The distance to the surface is large enough to meet the structural stability and the requirements of the radiation safety when the staff is in the gallery during accelerator operation. The tunnel is connected to the surface by vertical shafts, which are at a distance of about 5 km and provide for access, and for loading the necessary services into the tunnel like electricity, ventilation and cooling water. The RF units in the accelerator tunnel are supplied from the klystron gallery by small cross penetrations at intervals of approximately 12 m.

A one-tunnel solution for the accelerator structure and conventional facilities is possible for the Dubna Site. A cross section of the proposed design is shown in Figure 3. The primary tunnel housing the accelerator will be put at a depth of ~20 m, so that from below and above the tunnel there will be an impermeable stratum preventing breakthrough of underground water. A communication tunnel will be placed directly above the underground accelerator tunnel near the ground surface at

8 the depth of 3-4 m. This tunnel is necessary for power supplies, RF power sources, data storage devices, electronic and control systems, etc.

Technical connections between the accelerator tunnel and collector will be provided by vertical shafts of various diameters made by drilling. Connection of ground and underground structures will be provided by vertical and horizontal shafts (stairs, elevators, etc).

Figure 3: One tunnel solution for the ILC at the Dubna site

A Tunnel Boring Machine (TBM) will construct the main accelerator tunnel (depth ~20 m). The TBM’s average speed in the chosen geological structure can reach 30 meters per day. The underground halls and shafts are constructed in an open pit method and connected directly to the main accelerator tunnel.

The total length of the site is also well suited for second stage of the research facility with a center- of-mass energy of 1000 GeV.

2.2 Verification of GSPI Soil Boring Report The Information provided in the GSPI Soil Boring Report describes a geological profile along the proposed path of the ILC that is compatible with the current baseline criteria for the project. A more detailed summary of the report can be found in section 3. The alignment in the northern part of the Moscow region extends in a northeasterly direction from the town of Dubna where the Joint Institute for Nuclear Research is located. The alignment continues though the sparsely populated Taldom area passing through a southwest suburb of Mjakishevo village and a northern suburb of Hrabrovo village. A railway that connects the towns of Taldom and Kimry as well as some roadways cross the proposed alignment. The proposed location is situated within the Upper Volga or

9 Lamskoe-Dubna Lowland. The specific feature of this area is the uniformity and monolithic character of the surface.

Although establishing the complete surface elevation along the suggested alignment was not part of the report, the information provided does indicate a relatively uniform surface elevation over most of the alignment. The elevation begins to rise toward the northeast end of the proposed alignment, varying in the range of 5–15 meters. The surface conditions indicate swampy conditions that contain layers of water-bearing, near surface alluvial deposits (fine water saturated sands) which serve as the water shed that carries precipitation to the local system of drainage courses and rivers. These surface layers vary in thickness from 1-5 meters. Below these surface layers there is a moraine layer of semisolid drift clay from the Moscovian and Dnieper glacial period with inclusions of detritus and igneous rocks with a reasonably uniform thickness of 30-40 meters and is about 100 meters above sea level. It is in this geologic layer that the ILC tunnel elevation is proposed. This layer is relatively dry and easily supports tunnel construction using a shielded TBM and simultaneous wall construction using precast concrete segments or shotcrete. Below this layer of drift clay is a layer of fluvial-glacial, water-saturated sands and loam approximately 5 meters thick. The alluvial strata above and below the drift clay layer contributes to the dry nature of the strata in which the accelerator tunnel is planned to be constructed. Finally there is the bedrock layer of Jurassic clays and carboniferous limestone which comprise the Russian plate with surface elevations 50-60 meters below the surface.

The report also describes the level of seismic hazard along the proposed alignment in the low hazard category which also supports the suitability of the proposed site for the construction of the ILC project. In addition, the overburden for the proposed Main Linac tunnel elevation provides suitable shielding protection at the surface along the alignment of the tunnel.

At this time, only very preliminary schematic design efforts have been completed. The information contained in the GSPI report indicates suitable geology for the construction of the accelerator tunnels and surface buildings; however more design and soil information will be required to develop a suitable solution for the support of the Detectors and the Interaction Hall.

2.3 Status of Cost Estimating Effort The current status of the cost estimate for the proposed Dubna siting of the ILC project is in a very preliminary stage. An initial cost estimate was developed in November, 2006 and was based on the criteria used to develop the Reference Design Report and before the benefit of the information contained in the GSPI soil investigation and report. No further work on the cost estimate for the proposed Dubna site has been completed since the original November, 2006 effort. However, the information contained in the GSPI Soil boring Report can be validated in part by a tunnel configuration study that was developed by the Americas Regional CFS Group in conjunction with Hanson Professional Services, Inc., a consulting Architectural/Engineering firm [4].

The “ILC Tunnel Configuration Study” describes an evaluation of different deep and near surface tunnel configurations for the Main Linac portion of the ILC project. The report does not apply to the Damping Ring, Beam Delivery System and Interaction Region areas of the ILC project design. The study compares seven alternate tunnel configurations with the updated Reference Design Report baseline layout which consists of two parallel tunnels in a deep rock formation for the Main Linac

10 portion of the ILC layout. The configuration study refers to three separate variations of the basic RDR cost estimate referred to as A, A’ and A”:

• Version A represents the cost estimate included in the Reference Design Report. • Version A’ is the base RDR cost corrected for math and bookkeeping errors in the original version A. • Version A’’ includes a reduction in costs due to Value Engineering and improved design of the Process Cooling systems.

The A” version is used as the baseline cost for comparison to the other tunnel configuration alternatives in the study. All of the tunnel configurations studied utilized geological conditions for the Americas Sample Site and construction and cost estimation methods used in the Americas Region. These same geological conditions and construction and cost estimating methods were used to produce the design and cost estimate for the Reference Design Report.

Listed below are the eight main Linac Tunnel alternatives that were studied in the referenced report:

Version A” twin deep tunnels with vertical access (Updated RDR Design) Alternative B single deep tunnel with vertical access Alternative C twin near surface tunnels Alternative D single near surface tunnel with continuous surface service gallery Alternative E Single near surface tunnel Alternative F enclosure in open cut excavation with continuous surface service gallery Alternative G enclosure in open cut excavation with continuous buried service gallery Alternative H single tunnel enclosure in open cut excavation

Of the alternative Main Linac tunnel configurations studied in the report, Alternative D most closely matches the configuration of the schematic design for the Dubna report (see figure 7 in section 3.1 above). Below is a schematic drawing taken from the “ILC Tunnel Configuration Study” that depicts the configuration of Alternative D.

11 Figure 4: Cross section of ‘Alternative D’, which most closely matches the Dubna site scheme.

Using the parameters described above, cost estimates for the Electron and Positron Main Linacs were developed as part of the tunnel configuration study. These cost estimates include Civil engineering, electrical, Air Treatment Equipment, Piped Utilities, Process Cooling Water, Handling Equipment, Safety Equipment and Survey and Alignment thus representing the complete construction cost for the Conventional Facilities portion of these parts of the overall ILC project. The same Work Breakdown Structure (WBS) was used to develop the cost estimates for the Reference Design Report (RDR) and the Tunnel Configuration Study and all costs were developed in the same year dollars so the cost estimates for the various alternatives can be easily compared. These costs were also developed using construction methods, labor rates and material costs commonly found in United States construction practices. In the Tunnel Configuration Study, the cost estimate was developed for Alternative D using a specific alignment in Northern Illinois and included a cost for a specific number of railroad, major highway, minor roadway and stream crossings that were encountered using that specific alignment. In an effort to adapt the cost of Alternate D to the Dubna alignment, the number of crossings was adjusted to more appropriately reflect the more rural nature of the Dubna area. Using this adjusted cost for Alternative D with respect to the Dubna alignment, the cost was approximately 20% higher than the cost for the baseline design (version A”) contained in the RDR for the construction of both Main Linacs. Table 1 lists the intersections assumed in the Northern Illinois and the Dubna alignment. A comparison between Northern Illinois Alternative D and the adapted Dubna Alternative D shows the two are roughly equivalent. This is because the estimated cost of mitigating Rail and Major Road intersections are roughly equal and account for 75% of the total mitigation cost, and both the Northern Illinois and Dubna alignments have six such intersections.

Table 1: Number and types of surface feature intersections. Each is assumed to require mitigation in the cost Study Northern Illinois Dubna / Taldom Streams 7 2 Rail 3 1 Major Road 3 5 Minor Road 16 11

The cost study also includes an open cut Alternative (H). As noted above, open cut construction may be possible for the Dubna geology but this was not part of the GSPI study. For this alternative, a very simple approach was adopted by the Tunnel Configuration Study that does not consider any variation in surface topography. Such variation can be a cost-driver in open cut excavation. Adapted to the Dubna site alignment, the Alternative H cost estimate is 17% less than the reference, A’’, and 31% less than the adapted Alternative D cost estimate. According to the Tunnel Configuration Study, the potential cost impact of the mitigations is substantial. If these are removed altogether, the estimate for Alternative H is 33% less than the reference A’’.

It must be noted that this is a comparison based on Americas Region costs and methods and demonstrates the need for further work on a design and cost estimate that is based on the Dubna

12 geological conditions, construction methods and labor rates, in order to provide a true comparative study of the feasibility of the proposed Dubna ILC alignment.

3 GSPI Soil Boring Report The GSPI “Report on the results of the preliminary geological engineering surveys along the supposed route of the International Linear Collider (ILC) in the Taldom area of the Moscow region” is a comprehensive description of the results of a geological investigation conducted during the period of October through December 2008 [1]. The investigation consisted of initial Vertical Electric Sounding (VES) at 35 points along the planned ILC alignment analyzed by seismic profiling by the high-resolution shear waves reflection method. VES data was analyzed to identify locations that varied significantly from neighboring VES curves. These locations were then selected as appropriate locations for specific Soil Borings, shown in Figure 5 and Figure 6. Three soil borings were completed at the specified locations; identified as ‘1-08’, ‘2-08’ and ‘3-08’, respectively. Soil Boring 3-08 is summarized in Figure 8. From these three borings, a total of 40 samples of monolithic clay, 16 samples of disturbed sandy soil and 10 water samples were collected. Bore holes were also analyzed using Vertical Seismic Profiling (VSP) to further understand the subsurface structure.

The report fully documents the results of the Vertical Electric Sounding, Soil Boring and Vertical Seismic Profiling information. The VSP data was used to construct two deep seismic profile sections that identified reflecting boundaries indicating changes in the geologic profile below. Data for each of the three boreholes was presented in vertical log form with all soil variation and depths indicated as well as the vertical hodograph for the results of the VSP analysis. A complete hydro-geological description of each local soil layer was provided in table form with supporting text that described the geologic period and origin of the deposit. The report also contains several maps of the investigation area, including an overall seismic map of the Russian Federation, a map of the location of the different age glacial moraines, several maps and aerial photographs of the investigation area showing VES probe and Soil boring locations, and the proposed ILC alignment with a cross section through it showing the composition of the undersurface substructure.

In addition, the report describes the following natural conditions of the region:

• Climatic Features • Physiographic and Technographic Conditions • Seismic Conditions • Geological Structure of the Territory • Hydro-Geological conditions of the Territory

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Figure 5. Geological Strata to a depth of roughly 140 m along the proposed 50 km Dubna site showing a geological engineering section. The location of the 3 soil boring wells are shown.

Figure 6: Layout of the proposed Dubna site in the Moscow region showing the location of the 3 soil boring wells 3.1 Results from the Soil Boring Report Figure 7 shows a detail of the geological cut for the Dubna sample site together with soil boring profiles. This area is within the Russian plate, a part of the Eastern European ancient platform. This is a stable, steady structural element of the earth’s crust. The characteristic feature of this territory is the uniform and monolithic character of the surface. The surface deviates from the curvature of earth with single hills and ridges that have smoothed shapes, soft outlines and small peaks. The absolute surface marks range from 125 to 135 m with regard to the Baltic Sea level. The whole area is waterlogged.

The proposed ILC site is located in the southern part of a very gently sloping saucer-shaped structure known as the Moscow syncline. Alluvial deposits, i.e. fine water-saturated sands, 1 to 5 m of

14 thickness, are bedded above. Below one can find semisolid drift clay or loam from the Moscow glacial period with inclusions of detritus and igneous rocks. The thickness of moraine deposits is 30 to 40 m. Under the moraine from the Moscow glacial period fluvioglacial water-saturated sands and loams of the Dnieper glacial period are bedded. Jurassic clays and carboniferous limestone of the platform mantle are spread under the overburdens at the depth of 50 to 60 m. The depth of the International Linear Collider at Dubna is proposed in the drift clay 20 m below the surface, at 100 m above the sea level. Watertight soil below should prevent the tunnel from groundwater inrush. This makes a tunneling method possible using tunnel shields with simultaneous wall construction by tubbings (precast concrete lining sections) or shotcrete. Standard boring machines provide a more than sufficient tunneling speed in drift clay. Vertical shafts, experimental and service halls, and other underground volumes could be constructed by cut-and-cover, further reducing the civil engineering scope.

A GSPI team examined the ground at several points along the tunnel route between October and December 2008. This investigation includes:

• Boring of 3 wells in depth of 36 to 47 m with full core extraction. • Selection of 40 soil monoliths and 16 disturbed soil samples for investigations of their physical-mechanical properties. • Selection of 10 ground water probes for chemical analysis. • 35 points of vertical electric sounding. • Gamma-ray logging, thermometry and vertical seismic profiling in boreholes. • High-resolution surface seismic survey using shear wave reflection method.

The obtained data (geological structure and hydro-geological conditions, geotechnical soil properties, weak development or absence of adverse natural and engineering-geological processes) are favorable for placing the linear collider in the investigated territory. The results contained in the GSPI Soil Boring Report supports the positioning of a site that is compatible with the current ILC criteria in the Dubna area and supports a near surface design solution.

Figure 8 shows the log file of one borehole together with the (surface) wave velocity measurement. The file indicates clearly the permeable and non-permeable layers. The water is pressurized. The pressure is proportional to the water column difference in the borehole. The measured wave velocity increases slightly with the depth starting with 300 m/s at the surface.

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Figure 7: Detail of the geological cut for the Dubna sample site together with the soil boring profiles.

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Figure 8: Profile of one bore hole at Dubna together with the (surface) wave velocity measurements.

4 Near Term Topics for Further Investigation Near term topics for further investigation include: 1) Identification of Optimal Location for Dubna Sample Site, 2) Additional Field Investigation for Site Definition, 3) Investigation of Alternative Tunnel Configurations for Shallow Siting with Cost Estimates, and 4), Analysis of Life Safety and Egress Strategies of Alternative Tunnel Configurations. Of these, 2) (boring 14 additional wells) is expected to take four to five months. Coupled with 3), we would be better able to consider the potential attractive cost saving associated with the near surface site.

17 5 Summary This report represents an important step in the overall work of the Conventional Facilities and Siting (CFS) group as part of the Global Design Effort (GDE). This study were initiated by the Joint Institute for Nuclear Research (JINR) and supported by GDE. To date it is the first site specific investigation that has been completed for any site anywhere in the world. It should be noted that two sites are currently being considered in Japan, however specific site investigation is in the process of being initiated and no results are available at this time. Similar preliminary investigation by local concerns will naturally be performed before any site can be realistically considered in any global region or country. As a result, this instructive study of a considered ILC site can serve as a model to other countries or regions that are considering the possibility of hosting the ILC Project.

This report provides a comprehensive initial review of the Taldom area of the Moscow region near JINR. Further, in contrast to the current ILC Reference Design, it provides the first consideration of a near surface or shallow depth site within the present ongoing ‘Technical Design Phase’ of the project. All previous CFS work was devoted to deep tunnel sites which require considerably more costly site investigation techniques including very deep borehole investigation. While some limited local information from previous projects is available at some of the sample regional sites, there have been no other site specific studies conducted at those locations with respect to the ILC design process. This report will also provide valuable information for near-surface design studies currently being planned by the CFS group.

Equally important, the information contained in this report can directly support any future work for the ILC alignment near the JINR laboratory. This work is briefly described in section 4.0 above. The report identifies the geologic nature of the strata along the ILC alignment and provides valuable information that can be used to refine and optimize the current schematic design and cost estimate for the Dubna shallow site configuration. The refinement of this preliminary design can then be compared to future shallow site studies developed in other regional locations. This comparison is important to be able to understand differences in design approach and costing for various similar near surface configurations in other global regions.

In conclusion, JINR and GSPI are to be commended for their initiative to provide specific site investigation efforts and the development of a comprehensive report that delineates their findings. It is a valuable step in the design process for the Dubna site and will serve as a useful model for specific site investigations for sample sites in other regions of the world.

6 References

1 A.V.Kurnaev et. al. Report on the Results of the Preliminary Geological Engineering Surveys Along the Supposed Route of the International Linear Collider (ILC) in Taldom Area of the Moscow Region (Russian and English versions). 2 ILC Reference Design Report, ILC-REPORT-2007-001 3 SB2009 Proposal http://ilc-edmsdirect.desy.de/ilc-edmsdirect/document.jsp?edmsid=*900425 4 Tunnel Configuration Report, copy available on request from [email protected].

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