The assessment of human intrusion into underground repositories for radioactive waste

European Union

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Appendices
Nuclear energy and safety
Energy research

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• Sciences et techniques

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• Publié par: EUROPEAN-UNION
• Nombre de lectures: 37
• Langue: English
• Poids de l'ouvrage: 4 Mo

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Commission of the European Communities
nuclear science
and technology
The assessment of human intrusion into
underground repositories
for radioactive waste
Volume 2: Appendices
-^
\f
Report
EUR 12691/2 EN Commission of the European Communities
nuclear science
and technology
The assessment of human intrusion into
underground repositories
for radioactive waste
Volume 2: Appendices
D. J. Nancarrow, R. H. Little, J. Ashton, G. M. Staunton
Associated Nuclear Services Limited
Eastleigh House, 60 East Street
Epsom Surrey KT17 1HB
United Kingdom
Final report
Work carried out for HM Inspectorate of Pollution (Contract PECD 7/9/423) and
the Commission of the European Communitiest FI1W.0170.UK (H))
. in the framework of the CEC programme on 'Management and storage
of radioactive waste' - Task 5: Safety of geological disposal
PAUL EUROP, Biblioth.
Directorate-General I N CT^no?
Science, Research and Development | N.C./EUR
t—p=™
1990 CL EUR 12691/2 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Telecommunications, Information Industries and Innovation
L-2920 Luxembourg
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting
on behalf of the Commission is responsible for the use which might be made of
the following information
ISBN 92-826-1401-8 (Volume 1)
ISBN 92-826-1400-X (Volumes 1 and 2)
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1990
ISBN 92-826-1402-6 Catalogue number: CD-NB-12691 -EN-C
© ECSC-EEC-EAEC, Brussels • Luxembourg, 1990
Printed in Belgium CONTENTS
APPENDIX A CHARACTERISATION OF GROUNDWATER ABSTRACTION ACTIVITIES
APPENDIX BN OF MINERAL AND OTHER RESOURCE
EXPLOITATION
APPENDIX C ASSESSING PROBABILITIES OF HUMAN INTRUSION
- Ill APPENDIX A
CHARACTERISATION OF GROUNDWATER ABSTRACTION ACTIVITIES
by
R.H. Little, ANS Ltd.
CONTENTS
Al INTRODUCTION
A2 GROUNDWATER AS A RESOURCE
A2.1 Groundwater in Europe
A2.2 Sources of groundwater
A2.3 Depths of boreholes
A2.4 Yields ofs
A3 INVESTIGATION TECHNIQUES
A3.1 Repository and contaminated groundwater characteristics
A3.2 Investigation techniques
A3.3 Discussion
A4 PRODUCTION BOREHOLES
A4.1 Development of test boreholes
A4.2 Water quality analysis
A4.3 Life expectancy
A5 POSSIBLE LONG-TERM DEVELOPMENTS
A5.1 Technological developments
A5.2 Increased demand
A5.3 Climatic changes
A6 CHARACTERISATION OF BOREHOLE PARAMETERS
A6.1 Borehole depths, yields and life expectancies
A6.2 Frequency of borehole occurrence
TABLES
FIGURES
' REFERENCES Al INTRODUCTION
The purpose of this study is to characterise groundwater ab­
straction activities from aquifers which might result in intrusion into
a repository and/or associated contaminated groundwater.
In the PAGIS programme [Al] which is concerned with under­
ground disposal concepts for vitrified high level waste, four geolog­
ical formations have been considered as being potentially suitable as
hosts :
granite;
clays;
salt (domes and bedded formations);
sub-seabed sediments.
The depth of the repository at reference and variant sites considered
in PAGIS [Al] is at least 200 m below ground level (Table AI) although
it is possible that the repository might be shallower in certain
cases.
Groundwater is abstracted directly from granite; however, in
the case of the clay and salt formations it is not usually abstracted
directly from the formation due to the low yield of the former and the
low water and high salt content of the latter [Al]. It is possible
nevertheless, that groundwater could be abstracted from vertically ad­
jacent aquifers involving the penetration of the repository and/or the
intersection of contaminated groundwater. For example, at Mol,
Belgium, the PAGIS reference site for the clay option, there are aqui­
fers both above and below the clay horizon and at the salt variant site
in France three main aquifers have been identified within the bedded
salt formation [Al]. Abstraction from sub-seabed sediments is discoun­
ted due to the economic and logistic impracticalities of such a method
of groundwater abstraction. Therefore this study is concerned with the
characterisation of groundwater abstractions solely from granite, and
from sedimentary strata associated with clay and salt formations such
as limestone, chalk and sandstone.
Section A2 illustrates the importance of groundwater in pres­
ent day Europe and notes typical depths and yields of boreholes in gra­
nite and sedimentary formations and the factors which influence their
depth and yield. Sections A3 and A4 consider, respectively, ground­
water investigation techniques and development processes especially in
relation to the early detection of contaminated groundwater associated
with a repository. Section A5 considers possible long term changes in
groundwater abstraction resulting from technological, population and
climatic changes within Europe. Finally, in Section A6, an attempt is
made to characterise borehole depths, yields, life expectancies, and
frequencies in granite and sedimentary lithologies under a range of
climatic conditions. A2 GROUNDWATER AS A RESOURCE
A2.1 Groundwater in Europe
In the EC countries, abstracted groundwater is used mainly
for public supply although, in certain of the countries, industrial and
agricultural uses can be important (Table All). As a percentage of the
public supply, groundwater can be important, the relative importance
varying between countries (Table AIII). Tables All and AIII make no
distinction between deep groundwater and groundwater springs; for this
reason, Table AIV has been included which gives such a breakdown for
ten European (but not all EC) countries. The licensing requirements
for groundwater abstractions are also variable, ranging from Belgium,
where a licence is required for each abstraction, to Ireland, where
there is no licensing system (Table AV). In England and Wales in 1972,
16% of all water came from groundwater sources [A2]. Groundwater has
several advantages over surface water:
a relatively low cost of development;
a low cost of maintenance;
a low cost of operation;
minimum treatment cost due to a generally better water quality
than surface water;
a smaller area of land is required.
Ineson [A3] has stated that, in certain parts of England which are
underlain by aquifers, the 2 to 3 boreholes required for a 100 1 s"1
scheme would cost between 5 and 10 times less than the equivalent sur­
face water scheme. However, groundwater resources can only be develop­
ed in regions which are underlain by suitable aquifers. Hence, in
areas underlain by aquitards or aquicludes surface waters are used in
preference to groundwater. Table AVI shows the regional variation on
the importance of groundwater in England and Wales. For example, in
the Welsh Water Authority region, which is mostly underlain by imperme­
able lithologies, only 6% of the public water supply comes from ground­
water sources. In contrast, in the Southern Water Authority region,
underlain by mainly chalk aquifer, 75% of the public supply comes from
groundwater sources. Thus within a country there can be considerable
regional variation in the relative importance of groundwater as a
source of public water supply.
Groundwater supply can come from three sources; direct ab­
straction, recharge and conjunctive use schemes [A4]. Direct abstrac­
tion involves the abstraction of groundwater from an aquifer via bore­
holes sunk into the aquifer. Recharge schemes involve the use of the
aquifer as an underground storage reservoir from which water is ab­
stracted via boreholes and water is recharged to the aquifer via sur­
face lagoons or an injection well. In the case of conjunctive use
schemes, groundwater is used to augment river flows during the summer
(low river flow period) whilst the river is used to recharge the aqui­
fer during the winter (high river flow period). An example of such a
scheme is the River Lambourn Scheme which has been developed by the
Thames Water Authority in the UK [A4].