UPDATE 2-Exelon shuts Ill. Byron 2 reactor for refuel

* Traders see unit back in about a month

* Unit completes breaker-to-breaker run
(Adds background)

NEW YORK, April 19 (BestGrowthStock) – Exelon Corp (EXC.N: ) shut the
1,136-megawatt Unit 2 at the Byron nuclear power station in
Illinois on Sunday, the company said in a release.

The company did not provide a return date for the unit in
Byron in Ogle County about 100 miles (161 km) west of Chicago.
Electricity traders guessed the outage would last about a
month.

Exelon said the outage marked the completion of a 541-day
breaker-to-breaker run (continuous operation between refueling
outages) for the unit – the longest continuous run for either
Byron unit.

During the outage, Exelon said workers would perform more
than 10,000 maintenance activities and replace about a third of
the reactor’s fuel assemblies.

To assist with the outage, the plant will pull in more than
1,500 additional workers to help the usual staff.

The unit last shut for refueling from about Oct. 6 to Nov.
6, 2008. It is on an 18-month refueling cycle.

Byron is located in Byron in Ogle County about 100 miles
(161 km) west of Chicago.
(Reporting by Scott DiSavino)

UPDATE 2-Exelon shuts Ill. Byron 2 reactor for refuel