Outage FAQ and Potential Jobs - Frequently Asked Questions
Why do outage lengths vary?
outage length depends on the amount of work initially planned and the problems
(called emergent work) found during the outage.
What type of work is done during an outage?
a minimum, a refueling outage involves replacement of about 25% to 35% of the
core fuel assemblies. BWR refueling activities will take longer than PWRs
because there are almost 4 times the number of fuel assemblies in the BWR.
maintenance work that cannot be done when the reactor and turbine-generator are
on-line must be done during an outage. This includes:
Turbine and generator inspections and
Circulating Water Pump, Condenser,
Feedwater Pump and Heat Exchanger work
Steam Generator Eddy Current
Inspections, tube plugging and tube sleeving.
Reactor and reactor cooling system
inspections and work on components connected to the reactor cooling system that
cannot be isolated during normal operations.
For older BWRs, work in the drywell
(since it may be inerted using nitrogen during operation).
Electrical bus inspections, breaker and
relay testing on major 4.16 and 6.9 KV buses
Transformer inspections and doble
Major safety system components that are
not allowed to be taken out of service for extended periods of time during
What is a maintenance outage?
outages often are those that are caused by a failure or degradation of a major
component that cannot be repaired when the unit is on-line. These can take
anywhere from 1 day to 3 months, depending on the component. As an example, a
plant might be able to remain at over 500 F for a day to fix a minor problem
with the feedwater system, but may be out of service for 3 months or more if a
generator fire occurs or a generator transformer explosion occurs.
outages cannot be predicted with reliability as can a refueling outage.
Why does the interval for refueling outages vary between plants?
a refueling outage occurs depends on an overall schedule maintained by the
utility for all their plants. The schedule is based on economics. Often, you
will not see outages during the summer, because the utility needs the power
since demand is often highest throughout the summer. The interval depends on how
much new fuel into the reactor (and how high it is enriched).
What types of jobs are contract workers needed for?
workers are often used in major projects - turbine overhauls, steam generator
eddy current testing and repair - and modifications. Specialties needed during a
given outage will vary and include welders, machinists, millwrights, crane
is usually demand for radiation protection specialist contractors at any plant
during an outage.
Contractors providing outage support
|Bartlett Nuclear||Plymouth, MA|
|GTS Duratek||Offices throughout US|
|Gutierrez - Palmenberg, Inc.||Phoenix, AZ|
|MDM Services Corporation||Clearwater, FL|
|Onsite Companies||Offices throughout US|
|Philotechnics, Ltd.||Clairton, PA|
|Radiological Services Inc.||New London, CT|
|Safety & Ecology Corporation||Knoxville, TN|
|SPEC Group (ATS)||Offices throughout US|
Contractor and Outage-related Websites
Copyright © 1996-2006. The Virtual Nuclear Tourist. All rights reserved. Revised: January 3, 2006.