Energies
2022
,
15
, 7804
20 of 24
Russia
Yeniseiskiy site in the
Krasnoyarsk Krai
HLW, SNF
Germany
Asse II (former salt and
potassium mine, past
practice, waste to be re-
trieved)
Waste
with negligible heat genera-
tion
ERAM (Morsleben) (for-
mer salt and potassium
mine, past practice, facil-
ity to be closed)
Waste with negligible heat genera-
tion
Konrad (former iron ore
mine, under construction
including new emplace-
ment vaults)
Waste with negligible heat genera-
tion
In the UK, the Nuclear Decommissioning Authority (NDA) has developed a set of
generic GDF concepts appropriate to the geological environments that have not yet been
selected although the experiences of GDF in Sweden and Finland are fully accounted for.
For
some types of nuclear waste, such as SNF, a possible approach is the use of deep and
very deep boreholes [22]. The well-advanced GDF in Sweden and Finland aim to dispose
of the SNF in a granitic bedrock using copper containers with cast-iron inserts. The con-
tainer will be placed into vertical holes within horizontal tunnels and will be backfilled
with highly compacted bentonite, which swells in contact with water.
The copper con-
tainer is expected to remain un-breached by corrosion for a period in the order of 100,000
years [22].
Germany is planning to dispose of the non-heat-generating nuclear wastes at the for-
mer Konrad iron ore mine with past disposal practices at the Asse II and Morsleben sites
[7,8]. The disposal of heat-generating wastes was planned within salt (halite) formations
with thick carbon steel containers placed in disposal holes or shafts and surrounded by
crushed halite. Halite exhibits plastic creep behaviour so that the nuclear waste containers
will rapidly be fixed within salt rock. The waste container is expected to remain intact
until short-lived radionuclides have decayed to background (exemption) levels. A salt
dome at Gorleben was thoroughly investigated with two access shafts being sunk to the
depth of a prospective national GDF [22].
6.2. Borehole Disposal Facilities (BDFs)
The borehole-type disposal facilities (BDFs) can effectively provide long-term isola-
tion of nuclear waste in suitable geological horizons [2,3,36–38]. Shallow BDFs have been
used within many decades in many countries for storage and disposal of radioactive waste
including disused sealed radioactive sources (DSRS) [39]. Compared with mined disposal
facilities, BDFs have shorter
periods of site selection, construction, operation, and closure
as well as a lower probability of human intrusion compared to mined shaft-type disposal
facilities. The concept of a BDF near the surface or at intermediate depths is supported by
the IAEA specifically for the disposal of DSRSs [39]. The interest in BDFs has recently
increased in many countries, e.g., the UK, the US, Russia, Sweden, Germany, Israel, Aus-
tralia, Croatia, Denmark, the
Netherlands, Norway, and Slovenia [36,40–43]. BDFs can be
reliable and effective disposal facilities, especially using horizontal drillholes (Figure 9)
by utilising the existing drilling technologies [36,44].