Wednesday, March 5, 2014

CANDUs with 80 year operating life!

Astute readers of Ontario's "Long-term energy plan" raised an eyebrow at the refurbishment schedule.
Mr. Jones seems explains what's happening here ...

CANDUs with 80 year operating life! – 2014 March | The Don Jones Articles:
According to Ontario’s 2013 Long-Term Energy Plan the last nuclear unit to be refurbished will be Bruce unit 8 with its refurb scheduled to start in 2028. Since this unit was brought into service in 1987 it means it would have operated for 41 years before its mid-life refurbishment. Bruce unit 5 would have operated for 37 years before its refurb and units 6 and 7 for 40 years. Conventional wisdom calls for refurbishment at 25-30 years. "
The pressure tube life for a CANDU 6 unit was originally predicted to be 210,000 Equivalent Full Power Hours (EFPH) or 30 years at an 80 percent capacity factor. Point Lepreau had operated for 25 years with a life time capacity factor of 79.5 percent (based on CANDU Owners Group data in the 2009 Nuclear Canada Yearbook produced by the Canadian Nuclear Association) when the unit went into its refurb outage in 2008 accumulating 174,105 EFPH. For Wolsong unit 1 the most life limiting aging mechanism based on regular inspections was found to be pressure tube axial elongation, expected at around 190,000 EFPH. With a lifetime capacity factor of 84.1 percent Wolsong 1 reached this limit in 2009 and went into its refurb outage. Gentilly 2 had run for 29 years up to 2012 December, when it was permanently shutdown, at a lifetime capacity factor of 76.9 percent so it had accumulated 195,356 EFPH by that time.

Now getting back to the Bruce B units. Bruce B would have had the same 210,000 EFPH prediction as CANDU 6 units since they went into service around the same time in the early 1980s. Up to 2012 December Bruce B had a four unit average lifetime capacity factor of 83.3 percent and Bruce unit 8 had a lifetime capacity factor of 82.6 percent meaning it had accumulated 180,894 EFPH by the end of 2012 after 25 years of operation. Extrapolating this to 2028, the start of refurbishment, at an assumed capacity factor of 80 percent, means it would accumulate an additional 112,128 EFPH for a grand total of 293,022 EFPH, substantially more than 210,000 EFPH.
Read the entire article at The Don Jones Articles

Note: Donald Jones is one of the reasons this blog exists - and the entire reason I created another specifically for his writings.

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