report on the deep continuation period ......report on the deep continuation period techniques field...
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REPORT ON THE DEEP CONTINUATION PERIOD TECHNIQUES
FIELD TEST AND TRAINING ACTIVITY
FOR THE INTEGRATED FIELD EXERCISE IN 2014
This report describes the design, conduct and outcomes of the deep continuation period
techniques (CPT) field test and training activity carried out by the On-Site Inspection
Division on 24-28 March 2014 in Romhány, Hungary. The objective of the event was to
familiarize surrogate inspectors from the CPT sub-team with the active seismic and
electromagnetic equipment to be used during the forthcoming Integrated Field Exercise in
2014. It also provided the opportunity to consider resonance phenomena at a basic level.
Contents
Background ................................................................................................................................ 2
Objective .................................................................................................................................... 2
Scope .......................................................................................................................................... 2
Sites ............................................................................................................................................ 2
General Programme .................................................................................................................... 3
Field Test Activities ................................................................................................................... 3
Active Seismic Programme ........................................................................................................ 4
Electromagnetic Programme ...................................................................................................... 5
Conclusion .................................................................................................................................. 7
Annex I: Sites and Equipment ................................................................................................... 9
Annex II: List of Participants ................................................................................................... 12
Distr.:LIMITED
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7 November 2014
ENGLISH ONLY
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BACKGROUND
1. The Equipment and Implementation Section of the On-Site Inspection (OSI) Division of
the Provisional Technical Secretariat (PTS) undertakes field tests of inspection activities
and techniques with a view to refining and ultimately finalizing equipment
specifications and procedures for the detection of relevant signatures of nuclear
explosions, thus for the effective conduct of an OSI.
2. In preparation for the Integrated Field Exercise (IFE) in 2014, the PTS requested States
Signatories to provide inspection equipment as contributions in kind. As a result, the
PTS received offers of inspection equipment for both initial and continuation period
techniques (CPTs) and concluded bilateral agreements for contributions in kind with
nine States Signatories. Field tests have been conducted to familiarize IFE participants
with the equipment provided as contributions in kind. The final field test prior to the
IFE, focusing on deep ranging geophysical methods, was conducted in Hungary on
24‐28 March 2014.
OBJECTIVE
3. The primary objective of this activity was to prepare surrogate inspectors from the CPT
sub-team to use active seismic and electromagnetic equipment when performing their
technical roles during the IFE in 2014. The Training Section of the OSI Division
supported the implementation of the field test as a training event.
SCOPE
4. The participants1 were selected from the roster of surrogate inspectors from the first and
second training cycles on the basis of their role in the upcoming IFE and included six
trainees2 from six States Signatories (Annex II). The training was facilitated by three
PTS staff members and one external facilitator from Hungary. In addition, a team of
Hungarian geophysical experts led the field activities as owners of the equipment
provided as a contribution in kind, as providers and operators of additional technical
equipment (including the equipment used to generate seismic signals) and as hosts at the
test sites. The participants were separated into two groups, one focusing on active
seismic techniques and the other on electromagnetic techniques.
SITES
5. The activity took place at an abandoned clay mine at Felsőpetény near Romhány,
Hungary, about 80 km north of Budapest. This site was selected because it offers well known geological features of natural and man‐made origin that resemble possible
1 Participants are those who attended and contributed to the training course. Trainees are those to whom the
training was delivered and may include PTS staff. Those who designed, coordinated, facilitated and supported
the training are either external facilitators or PTS staff. Some trainees may also have had a role in facilitating
the training, but are counted as trainees. 2 The six trainees comprised one woman and five men.
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signatures of an underground nuclear explosion. In addition, an active seismic survey
was conducted at a former railway tunnel located at Somoskő, about 60 km north‐east
of Romhány. A playground near the hotel in Romhány served as a site for equipment
training activities.
6. The abandoned clay mine is connected to an oval shaped cavern with a diameter of
30 m, situated 100 m below the surface. The cavern is accessible through the mine
galleries. The deep basement is composed of Triassic limestone (Dachstein limestone
formation) which was formed some 270 million years ago. The cavern is located in the
overlying Oligocene sandstone formation and its rock matrix is interbedded with clay
layers. As a result of hydrothermal activity in the Pleistocene, a cave was formed in the
Dachstein limestone, which may have opened over time. The opening of the deep part
of the cave influenced the overlying sandstone formation, but the collapse did not reach
the surface.
GENERAL PROGRAMME
7. An overview of the general programme for the CPT field test and training event is
provided in Table 1.
Table 1. Programme Overview Date Activity
23 Mar. 2014 Arrival of international and PTS participants in Hungary 24 Mar. 2014 Equipment familiarization and active seismic/electromagnetic survey planning 25 Mar. 2014 Equipment check, mobilization to test site and initial system deployment/operation 26 Mar. 2014 Active seismic/electromagnetic data acquisition, pre-processing, basic
interpretation 27 Mar. 2014 Active seismic/electromagnetic data acquisition, pre-processing, basic
interpretation 28 Mar. 2014 Active seismic data acquisition, analysis of data sets, equipment
demobilization/check 29 Mar. 2014 Departure of international and PTS participants from Hungary
FIELD TEST ACTIVITIES
8. The field test was carried out in three phases:
Familiarization (equipment demonstration including unpacking, pre‐deployment
check, set‐up, packing);
Operational training (guided survey planning, system deployment, data
acquisition, basic analysis);
Trainee operation (autonomous survey planning, system deployment, data
acquisition, basic analysis).
Activities for the active seismic programme and the electromagnetic programme were
carried out in parallel, as described below.
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ACTIVE SEISMIC PROGRAMME
9. Within the objective described above, the main goal of the active seismic component of
the field test was to familiarize and train three surrogate inspectors in using the
DAQlink III seismic data acquisition system provided by Hungary as a contribution in
kind. DAQlink III is a cabled engineering system which consists of three 24 channel
units.
10. Functionality tests were performed on the active seismic equipment and its accessories
prior to the field test. In addition to the DAQlink III system, six REF TEK data loggers
were used to detect the seismic signals in autonomous offline mode.
11. The encoder sweep generator and the electronic control unit of the 150 kilonewton peak
force IVI seismic vibrator were also tested using different parameter settings. The first
setting was a 10-80 Hz, 16 second linear seismic sweep signal used for 2-D active
seismic acquisition. The second setting was a 10-25 Hz, 30 second signal used for
resonance seismic detection. The field measurements were made at OSI relevant targets,
i.e. above the railway tunnel at Somoskő and above the cavern at Felsőpetény.
Tunnel Detection by Active Seismic Method
12. Two dimensional active seismic profiling was carried out using 48 seismic channels
with 1 m geophone spacing. The source was a sledgehammer with 2 m separation. The
target was a railway tunnel with a burial depth of 8 m and an inner height of 4.5 m. The
tunnel is located in the siliceous sandstone formation, a characteristic alluvial deposit of
the Oligocene/Lower Miocene age.
Cavern Detection by Active Seismic Method
13. Two dimensional active seismic profiling was carried out using 92 seismic channels
with 2.5 m geophone spacing. The source was a sledgehammer with 5 m separation.
Using the same spread, the following activities were also undertaken:
Resonance seismic detection using as the source a hydraulic vibrator emitting a
10-25 Hz, 30 second signal with 20 m separation;
2-D active seismic profiling using as the source a hydraulic vibrator emitting a
10-80 Hz sweep signal;
Comparison of different seismic sources, including a sledgehammer, an
accelerated weight drop, a shotgun and a hydraulic vibrator.
Controlled aftershock detection was also carried out using two perpendicular seismic
arrays at the surface, each consisting of 24 channels. The controlled aftershock signals
were simulated by sledgehammer hits in the mine gallery near the cavern.
14. In addition, an underground seismic array station was deployed in the gallery of the
mine to detect the near field signals.
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15. The activities carried out during the active seismic programme are presented in detail in
Table 2.
Table 2. Training Activities for the Active Seismic Programme Date Time Activity
24 Mar. 2014 a.m. Initial tests with the control software of the data acquisition system
(setting data acquisition parameters, applying display, gain and basic
filtering functions) p.m. Assembly and disassembly of the system at the playground (24, 48 and
72 channel spreads with 1 m geophone spacing, triggering, automatic and
manual stacking) 25 Mar. 2014 a.m. Geophone tests at the playground and subsequent mobilization to the test
site at the hilltop above the cavern at Felsőpetény p.m. Deployment of the system with a 72 channel spread (2 m geophone
spacing) and recording of seismic data with signals triggered by a
sledgehammer 26 Mar. 2014 a.m. Continued operation of the system and recording of seismic data in
different modes (including long time recording)
p.m. Source comparison by recording seismic data with signals triggered by
an accelerated weight drop and a broadband vibrator 27 Mar. 2014 a.m. Continued operation of the system and recording of seismic data
(including initial resonance seismic tests with signals triggered by a
broadband vibrator set to cover a range of 10‐25 Hz, calculated to include
resonance frequency of the cavern) p.m. Dismantling of geophones
28 Mar. 2014 a.m. Deployment of the system above a railway tunnel at Somoskő with a
48 channel spread (1 m geophone spacing) and recording of seismic data
with signals triggered by a sledgehammer
p.m. Handling and converting the collected data and basic spectrum analysis
functions
ELECTROMAGNETIC PROGRAMME
16. Within the objective described above, the main goal of the electromagnetics component
of the activity was to familiarize and train three surrogate inspectors in using the Zonge
transmitters NanoTEM NT‐20 and ZeroTEM ZT‐30 and the receiver GDP32, which are
owned by the PTS.
17. The electromagnetics programme took advantage of the different features of the sites in
order to allow training on site specific estimations of the sounding parameters required
for each location (transmitter loop size, minimum current, transmitter/receiver layout,
etc.). This also facilitated the assessment and selection of the most suitable equipment
set‐up, sounding deployment and operational behaviour. Different decay curves were
expected at each site, which would allow comparison during data interpretation.
Preliminary data processing, synthetic forward modelling and 1-D inversion were
carried out using the specialized software Emigma and IX1D.
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Functionality
18. All components of the Zonge equipment were tested, with the exception of the generator
and its transmitter. A number of problems were identified, including:
(a) Motherboard battery failure in one of the GDP units, possibly due to the age of the
equipment;
(b) Malfunctioning of the Zero-TEM ZPB-600 power booster and ZT-30 power
source units;
(c) Problems in synchronization between the GDP32 and XMT-32 transmitter
controller units;
(d) Out of date manuals.
Problems (b) and (c) were resolved during the training. The motherboard was sent to
Zonge headquarters for repair.
19. The three trainees had limited prior experience using the Zonge equipment. Sounding
deployment, instrument configuration as well as data downloading, processing and
interpretation carried out during the training allowed the trainees to acquire useful
knowledge and basic skills in operation of the system.
Preparing Field Layouts
20. During the training time domain electromagnetic (TDEM) sounding was performed
using rectangular transmitter and receiver loops. It was recommended that several
‘standard’ transmitter loops be prepared (e.g. 20 m × 20 m, 50 m × 50 m and 100 m × 100 m)
and included in the OSI equipment inventory.
Assembling and Packing Field Equipment
21. It was suggested that the field equipment be rearranged within the original boxes so that
the instruments and accessories for shallow and deep investigative techniques can be
easily identified, maintained and transported to the field as necessary.
22. The activities carried out during the electromagnetics programme are presented in detail
in Table 3.
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Table 3. Training Activities for the Electromagnetic Programme Date Time Activity
24 Mar. 2014 a.m. Unpacking of equipment, initial configuration and functional checks
(setting data acquisition parameters, testing batteries, checking cables and
accessories) p.m. Deployment of the NT‐20 transmitter and GDP32 receiver at the
playground (transmitter loop: 10 m × 10 m), targeting anticipated shallow
depth man‐made structures 25 Mar. 2014 a.m. Equipment mobilization and deployment on the hilltop above the
abandoned mine at Felsőpetény (site with homogeneous resistive sub‐surface above the cavern)
p.m. Shallow TDEM sounding in central loop configuration using the NT‐20
transmitter and GDP32 receiver (transmitter loop: 50 m × 50 m), dismantling
and packing of equipment 26 Mar. 2014 a.m. Central loop deep TDEM sounding at the site as before, using the ZT‐30
transmitter and GDP32 receiver (transmitter loop: 50 m × 50 m), testing of
the transmitter booster, dismantling and packing of equipment p.m. Delimitation of a profile along the road above the mine gallery for central
loop TDEM sounding, equipment set‐up and test sounding 27 Mar. 2014 a.m. Central loop TDEM sounding using the NT‐20 transmitter and GDP32
receiver (transmitter loops: 20 m × 20 m, 50% overlap), dismantling and
packing of equipment p.m. On-site data downloading, installation and familiarization with the
available modelling software 28 Mar. 2014 a.m. Continued familiarization with the software, data display, processing and
1-D inversion of selected data sets p.m. Clean‐up and packing of equipment
CONCLUSION
23. The participants in the active seismic programme used a 72 channel line set‐up for
reflection surveys. This included using a sledgehammer and an accelerated weight drop
as well as an industrial broadband vibrator as seismic sources. The participants in the
electromagnetics programme underwent several full work cycles of acquisition
planning, layout, measurement, data quality control and interpretation using two
transmitters and several loop configurations. Both groups of participants ultimately
reached a level of confidence in planning and implementing field measurements and
were able to operate their respective equipment autonomously.
24. Feedback from the trainees suggested that this activity was a useful and essential part of
preparations for the IFE, in particular because it provided the only opportunity during
the OSI training cycles to familiarize trainees with active seismic and deep
electromagnetic equipment and its operation.
25. The observations made by both organizers and participants resulted in general
recommendations, including step by step guidance for system operations and the
packing of equipment, to be implemented prior to the IFE.
26. Data processing and interpretation for both of the deep ranging geophysical methods
applied during the field test remain a challenge, and specific training modules on
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appropriate software are needed. In addition, participants highlighted the complexity of
the Zonge equipment and requested further training by specialists.
27. This activity also offered a glimpse at resonance phenomena, which are not yet fully
understood, in particular within the OSI context.
28. The cavern at Felsőpetény appears to be a suitable location for OSI training activities in
relation to such phenomena because of the well studied site characteristics and the
proximity of the cavern to the surface. Provided that signals from a well controlled
source are generated (e.g. broadband vibrator), it should be possible in a focused field
test to examine whether there are resonance effects and whether signals can be detected.
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ANNEX I
SITES AND EQUIPMENT
The cavern at Felsőpetény. The abandoned railway tunnel at Somoskő.
The underground target, a 50 m long portal section of the mine gallery.
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Similarity test of the geophones prior to the survey.
Topographical map showing the surface projection of the cavern and the
galleries of the abandoned mine (indicated in yellow and blue). The active
seismic measuring and source points are indicated by the peg numbers.
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A high mobility repeatable active
seismic source: the accelerated
weight drop device.
The DAQlink III lightweight telemetry
active seismic unit can detect 24 seismic
channels and communicate with the next
unit via Wi-Fi.
The classic seismic source: the sledgehammer in
action.
The hydraulic vibrator is the appropriate
seismic source for deep penetration and high
resolution active seismic measurements.
A stress test in the field using the Zonge
equipment.
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ANNEX II
LIST OF PARTICIPANTS
Name Function Country Region
Trainees
Mr Claude ANTOINE Active seismic France NAWE
Mr Martin MUELLER Electromagnetic Germany NAWE
Mr Zsolt PRÓNAY Active seismic Hungary EE
Ms Stefka STEFANOVA Electromagnetic Canada NAWE
Mr Samuel TOON Active seismic UK NAWE
Mr Abdelhalim ZAOUI Electromagnetic Algeria AFRICA
External Coordinator and Facilitator
Mr Endre HEGEDUS External Coordinator Hungary EE
PTS Coordinators and Facilitators
Mr Rainier ARNDT PTS Coordinator PTS
Mr Ron GAVISH PTS Observer PTS
Mr Gregor MALICH PTS Observer PTS
Local Geophysical Experts
Mr Attila Csaba KOVÁCS Local expert Hungary EE
Mr István TOROK Local expert Hungary EE
Ms Éva BUJDOSÓ Local expert Hungary EE
Mr Kristóf KAKAS Local expert Hungary EE
Mr Zsolt PRÓNAY Local expert Hungary EE
Ms Izabella TÓTH Local expert Hungary EE