Gentilly 2 refurbishment postponed

18 August 2010

Hydro-Quebec has decided to postpone the start of refurbishment work at the Gentilly 2 reactor by about one year. The company decided in August 2008 to refurbish the Candu unit as an alternative to closing it in about 2011. 


Gentilly 2
Gentilly 2 (Image: Hydro-Quebec)
Gentilly 2 is a 638 MWe Candu pressurized heavy-water reactor (PHWR) built by state-owned Atomic Energy of Canada Ltd (AECL) between 1974 and 1982. The unit was commissioned in October 1983. Candu reactors require refurbishment and replacement of core components after about 25-30 years of operation. The process is meant to extend the unit's life by about the same amount.


Two years ago, Hydro-Quebec announced that it would invest some C$1.9 billion ($1.8 billion) to refurbish the Canadian province's sole operating nuclear power reactor, thereby extending the unit's operating life to about 2040. At that time it said that engineering and procurement work for the refurbishment would start before the end of 2008 and construction work would begin in 2011. Construction activities consist of refurbishing the reactor, the turbo-generator unit, as well as the control and support systems. The refurbished reactor was scheduled to return to service in 2012 with an increased power generating capacity, although no figure has been specified.


In February 2009, GE Energy was awarded a contract worth more than $120 million by Hydro-Quebec to refurbish the turbine island, replacing rotor windings and the moisture separator-reheaters. In addition, the two low-pressure steam turbine rotors and diaphragms must be replaced and adjustments made to the turbine base plate. A new control system will also be installed.


However, Hydro-Quebec has now said that the start of work on the refurbishment of the unit will now begin in 2012. In a statement, the company said that the decision to postpone the start of work was "made in the context of the revision of the schedule of repairs being made at the Point Lepreau Candu plant in News Brunswick and at Wolsung, South Korea." It added, "In addition, this postponement will provide the necessary assurances regarding the identity of the next owner of AECL, the leading supplier and contractor in the refurbishment project."


The Point Lepreau nuclear power plant in New Brunswick - considered Gentilly-2's twin as both use Candu-6 reactors - is currently being refurbished at a cost of C$1.4 billion ($1.3 billion) to add another 25 years of operating life.


Point Lepreau is the first Candu-6 reactor to undergo major refurbishment, including replacement of all of its 380 fuel channels and associated feeder tubes. When the reactor was shut down for refurbishment in March 2008 the project was expected to take 18 months to complete and thus only cover one winter. However, the first-of-a-kind work has over-run, and general contractor AECL subsequently pushed back the completion date to October 2010, then to February 2011. Recently AECL confirmed that the refurbishment will now take at least another year to complete, pushing the restart back to February 2012 at the earliest.


In 2006, AECL was awarded a large contract by Korea Hydro and Nuclear Power (KHNP) for the retubing of the Wolsong 1 Candu-6 reactor to enable the unit to operate for an additional 25 to 30 years. The terms of the contract include completion of the retubing for a fixed price and to a fixed schedule with an outage of about a year and a half. The retubing project started in April 2009.


Hydro-Quebec said that it will continue to invest in the regular operating activities at the plant and "will closely monitor the ongoing renovations at Point Lepreau and Wolsong to take full advantage of the lessons learned from this work."


In June 2009, the Canadian government announced that it would seek buyers for a stake AECL's nuclear reactor business and bring aboard private-sector management for its ailing Chalk River nuclear facility. In December, the minister of natural resources, Lisa Raitt, invited investors to submit proposals for AECL's commercial Candu reactor division, the next step in restructuring the Crown Corporation.


Researched and written

by World Nuclear News