Abstract
On-line monitoring of environmental conditions in harsh radiation environments
and at nuclear facilities in particular becomes more and more important.
Exploitation of standard electronic sensors is not an ideal solution due to radiation sensitivity and difficulties in installation of multiple sensors. In
contrast, radiation-hard optical fibres can sustain very high radiation doses
and naturally other multi-point or distributed monitoring of environmental parameters, such as strain and temperature. Multiple local electro-mechanical sensors can be replaced by just one measuring fibre.
Although many European countries have recently chosen to decrease the
impact of nuclear energy, there are more than 400 nuclear power reactors in
the world [1]. Moreover, a number of countries keep on building new nuclear
power plants and the present number will likely to grow in future. At the
same time the safety requirements are getting stricter, in particular after the
Fukushima Daiichi nuclear disaster, which demands constant monitoring and
awareness of processes and condition changes in controlled areas in order to
get authorisations for the nuclear power plants exploitation.
Electrical cables are inherent components of any nuclear power plant since
they are used to link power instrumentation end equipment used for monitoring
and controlling the plant. There are hundreds of kilometres of electrical
cables and wires of hundreds different types and sizes. They are supposed
to withstand normal operation conditions as well as design basis events and
post-design basis events conditions occurring at any time during their service
life. Economic reasons bring about the need of plant service life extension
[1]. This means that numerous components including cabling should endure
significantly longer operational life.
The biggest concern for the ageing of the cables is related to organic polymer
materials which are used as electrical insulators, dielectrics, and jacket materials. Most important factors speeding up ageing degradation of the polymers are temperature and ionising radiation. The hazard arising due to ageing degradation is mainly caused by mechanical properties changes, cracking of the insulator which might end up with an electrical failure and with ignition as
the worst.
and at nuclear facilities in particular becomes more and more important.
Exploitation of standard electronic sensors is not an ideal solution due to radiation sensitivity and difficulties in installation of multiple sensors. In
contrast, radiation-hard optical fibres can sustain very high radiation doses
and naturally other multi-point or distributed monitoring of environmental parameters, such as strain and temperature. Multiple local electro-mechanical sensors can be replaced by just one measuring fibre.
Although many European countries have recently chosen to decrease the
impact of nuclear energy, there are more than 400 nuclear power reactors in
the world [1]. Moreover, a number of countries keep on building new nuclear
power plants and the present number will likely to grow in future. At the
same time the safety requirements are getting stricter, in particular after the
Fukushima Daiichi nuclear disaster, which demands constant monitoring and
awareness of processes and condition changes in controlled areas in order to
get authorisations for the nuclear power plants exploitation.
Electrical cables are inherent components of any nuclear power plant since
they are used to link power instrumentation end equipment used for monitoring
and controlling the plant. There are hundreds of kilometres of electrical
cables and wires of hundreds different types and sizes. They are supposed
to withstand normal operation conditions as well as design basis events and
post-design basis events conditions occurring at any time during their service
life. Economic reasons bring about the need of plant service life extension
[1]. This means that numerous components including cabling should endure
significantly longer operational life.
The biggest concern for the ageing of the cables is related to organic polymer
materials which are used as electrical insulators, dielectrics, and jacket materials. Most important factors speeding up ageing degradation of the polymers are temperature and ionising radiation. The hazard arising due to ageing degradation is mainly caused by mechanical properties changes, cracking of the insulator which might end up with an electrical failure and with ignition as
the worst.
| Original language | English |
|---|---|
| Qualification | Doctor of Science |
| Awarding Institution |
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| Supervisors/Advisors |
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| Date of Award | 5 Sep 2014 |
| State | Published - Sep 2014 |