THE DETECTION AND MEASUREMENT OF FAULTS IN CLAY.

Project Information

Grant agreement ID: FI1W0088

Project closed

Start date 1 July 1986

End date 31 August 1989

Funded under

• Research and development programme (Euratom) on the management and storage of radioactive waste, 1985-1989

Total cost No data

EU contribution No data

Coordinated by

University of Exeter
United Kingdom

Objective

IF FAULTS OCCUR IN THE ROCK MASS SURROUNDING A NUCLEAR WASTE REPOSITORY, THERE IS A RISK THAT THE RETURN OF HAZARDOUS RADIONUCLIDES TO THE BIOSPHERE WILL TAKE PLACE BY MIGRATION ALONG THESE ZONES OF HIGHER PERMEABILITY. HOWEVER, THE DETECTION AND CHARACTERISATION OF FAULTS IS DIFFICULT, ESPECIALLY IN SOFT ROCKS SUCH AS CLAY, AND LITTLE DEVELOPMENT OF TECHNIQUES HAS TAKEN PLACE.

THE OBJECTIVE OF THIS PROGRAMME IS TO DEVELOP TECHNIQUES THAT WIIL BE SUITABLE FOR ROUTINE USE IN BOTH THE PRELIMINARY AND DETAILED STAGES OF SITE INVESTIGATION.
THE APPROACH USED IS BASED ON THE OBSERVATION THAT FAULTS ACT AS ZONES OF PREFERENTIAL MIGRATION IN THE NATURAL DEGASSING OF THE EARTH. SOIL GAS EXPLORATION METHODS ARE APPLIED TO DETECT ZONES OF ANOMALOUS GAS GEOCHEMISTRY.
THE PROCEDURE FOLLOWED IS BASED UPON SAMPLES OBTAINED FROM A DEPTH OF ABOUT 0.5M ALONG A SERIES OF TRAVERSE LINES. ONCE A FAULT HAS BEEN LOCATED, SPIKING OF THE HIGH PERMEABILITY ZONE FROM A BOREHOLE DRILLED TO INTERSECT THE FAULT PLANE, WILL TAKE PLACE WITH SPECIFIC GASES OF DIFFERENT COMPOSITIONS. THE GROUND WILL THEN BE RESURVEYED TO DETERMINE THE MIGRATION CHARACTERISTICS OF THE GAS WITHIN THE FAULT.
TEST SITES IN THE UK AND ITALY ARE TO BE INVESTIGATED IN COOPERATION WITH BGS AND ISMES.
BGS AND ISMES ARE RESPONSIBLE FOR SITE SELECTION AND THE DRILLING PROGRAMME, BUT SOME TRIALS WILL BE CONDUCTED AT SITES NEAR EXETER.

B.1. EQUIPMENT AND DEVELOPMENT.
B.2. SITE SELECTION.
B.3. SOIL GAS GEOCHEMISTRY.
B.3.1. RECONNAISSANCE SOIL GAS SURVEYS MEASURING 4HE, 220RN, 222RN, 02, CO0, AND SOME ORGANIC GASES.
B.3.2. DETAILED SOILGAS SURVEYS OF ANOMALOUS ZONES IDENTIFIED IN THE RECONNAISSANCE SURVEYS.
B.3.3. SPIKING OF VERTICAL BOREHOLES AND RESURVEY OF SOIL GASES.
B.3.4. SPIKING OF INCLINED BOREHOLES AND RESURVEY OF SOIL GASES.
B.4. MODELLING AND INTERPRETATION OF RESULTS.

Fields of science

• engineering and technology › other engineering and technologies › nuclear engineering › nuclear waste management
• natural sciences › earth and related environmental sciences › geochemistry
• natural sciences › earth and related environmental sciences › atmospheric sciences › meteorology › biosphera
• natural sciences › chemical sciences › nuclear chemistry › radiation chemistry

Programme(s)

• FP1-RADWASTOM 3C - Research and development programme (Euratom) on the management and storage of radioactive waste, 1985-1989

Topic(s)

Data not available

Call for proposal

Data not available

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

University of Exeter

• EU contribution: No data
• Address: Northcote House Queen's Drive ; EX4 4QJ Exeter ; United Kingdom
• Total cost: No data

Participants (1)

Istituto Sperimentale Modelli e Strutture SpA

Italy

• EU contribution: No data
• Address: Viale Giulio Cesare 29 ; 24100 Bergamo
• Total cost: No data