SORU: aşağıdaki parçaya göre cevaplayınız
It is clear from the passage that the safe disposal of radioactive waste ----.
The world's nuclear plants have accumulated vast stocks
of highly radioactive waste. Worldwide, high-level waste is
currently stored above ground, and no government has
a clear policy on its eventual disposal. While most
experts believe that burying the waste is the safest bet in
the long term, the problem is finding sites that everyone
can agree are geologically stable. Decaying radioactive
isotopes release heat. As a result, high-level waste must
be constantly cooled; otherwise, it becomes dangerously
hot. This is why many experts want to store waste above
ground until it has decayed and is cool enough to be
stored safely in sealed repositories several hundreds of
metres below ground. According to one recent theory,
however, waste should be lowered down boreholes
drilled to 4 kilometres. The trick is to exploit heat
generated by the waste to fuse the surrounding rock and
contain any leaking radioactivity.