Darlington Refurbishment - Ontario Power Generation

April 3, 2013
Darlington Refurbishment – Turbine Generators
Each unit at the Darlington Nuclear Generating Station (DNGS) has a turbine
generator (TG) set, which consists of one high-pressure turbine and three lowpressure
turbines connected by a common shaft (rotor) to a generator. The DNGS
TG sets have been operating safely and reliably since they came into service in
the early 1990’s.
A TG set works when high pressure steam produced by the boilers passes over
the turbine blades attached to the rotor to create rotational energy. The generator
at the end of the rotor then converts the rotational energy into electrical energy.
At full operating power, a Darlington TG set turns at a speed of 1,800 revolutions
per minute and generates 935 megawatts (MW) of electricity.
Based on a thorough review conducted of the major turbine and generator
components at DNGS, it was determined that there are no life-limiting issues to
the TG sets (i.e. the TG sets can operate reliably for another 30 years postrefurbishment.)
However, factors that might have an impact on the remaining life
of TG sets will be addressed during the Darlington refurbishment:
Steam turbines and turbine auxiliaries – inspections, repairs and/or
replacements of high-pressure and low-pressure turbine components and
auxiliaries;
Generator and generator auxiliaries – inspections, repairs and/or
replacements of generator components and generator auxiliaries;
Moisture separator reheater – inspections, overhaul and/or replacements of
Moisture separator reheater internals and auxiliaries;
Turbine controls replacement – replacement of the analog turbine generator
electronic control system with a new digital system; and
Generator excitation control replacement – replacement of the analog
Generator excitation control system with a new digital system.
The work will be completed in two stages. The definition phase work involves
component engineering and the supply of materials and components. The second
stage will occur during project execution and involves the installation of the
components into the station, during the refurbishment outages.

For further information, please contact:
OPG Media Relations
416-592-4008
1-877-592-4008
Follow us @ontariopowergen
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