POWER August 2010 - 51

NUCLEAR POWER
plan for the refurbishment and restart project
at Bruce A has three essential goals:
■ Enhance the safety and reliability of the
Bruce A station.
■ Increase the combined plant's (Bruce A
and B) capacity to 6,200 MW.
■ Ensure that the station remains fit for service
through 2043, an additional 25 years
of operation beyond the original plant's
2018 lease.
To accomplish those goals, Bruce Power
developed a comprehensive project plant that
leveraged the expertise of many important
equipment suppliers (see table, p. TK) in order
to repair or replace just about every key
component on both units. Each component or
system has an interesting story to tell about
its refurbishment or replacement, but space
precludes in-depth discussions of them all.
Representative of the long list of components
and systems being refurbished are the steam
generators.
A First: Replacing CANDU
Steam Generators
The steam generators transfer heat from the
hot pressurized heavy water coming from the
reactor (known as the primary side) to raise
the temperature and boil light water on the
secondary side to produce the steam that supplies
the turbine generator with the energy to
generate electricity.
The steam generators at Bruce A were
close to the end of their useful service life
due to wear caused by erosion and corrosion
when the units were prematurely retired in
the late 1990s. Because the tubing was considered
a life-limiting feature, a business decision
was made to replace all of the steam
generators, thus providing up to 30 years of
additional life to match the remainder of the
plant refurbishment standards.
Babcock & Wilcox (B&W) Canada,
builder of the original Bruce A steam generators
more than 30 years ago, was contracted
to manufacture the replacement steam generators.
In August 2006 the first of 16 steam
generators were delivered, marking a major
project milestone. Eight steam generators
were installed in Unit 1 and another eight in
Unit 2, arranged in two banks of four on either
side of each reactor (Figures 8 and 9).
This was the first CANDU steam generator
replacement when the project was completed
in January 2008.
In August 2007, B&W Canada signed a
contract in excess of C$90 million to manufacture
eight additional replacement steam
generators for Unit 3. Unit 3 and 4 steam
generators were not replaced during their
earlier restart project. A replacement schedAugust
2010 | POWER
8. Can do. SNC-Lavalin Nuclear removed the old steam generators on Units 1 and 2 through
access holes in the roof using a special crane sourced from Alberta. A total of 16 old steam
generators were replaced. Courtesy: Bruce Power
9. Up and out. A 250-ton steam drum is lifted up and set aside to provide access to the four
steam generators below. The steam generators at Bruce A are arranged in two banks of four on
each unit. After the steam generators are replaced, the steam drum is lifted back into position
and reconnected to the tops of the new vessels. Courtesy: Bruce Power
ule for those units is being developed with
OPA.
Bruce Power is to be commended for
its creative thinking about the problem of
disposing of the old steam generators (see
sidebar " A Comprehensive Waste Management
Program, " p. TK). Instead of placing
them into long-term storage, the tubes will
be recycled. Approximately 90% of the
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metal from the steam generators can be decontaminated,
melted down, and sold back
into the scrap metal market by Studsvik, a
Swedish company that pioneered the treatment
and recycling of steam generators
from nuclear reactors. This method offers
an economically attractive approach to nuclear
clean-up that is also environmentally
responsible.
51

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POWER August 2010

Table of Contents for the Digital Edition of POWER August 2010