report on the deep continuation period ......report on the deep continuation period techniques field...

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

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