When the heat is on, the reactors are pumping out the juice
It has been a hot week here in Maryland and throughout the eastern portion of North America. As a guy who enjoys his air conditioned comfort during heat waves, I want to send a thank you note to the people who are operating all of the power plants, but especially to those nuclear plant operators who have put up some rather impressive statistics during the past week.
As an example of the kind of product that they have been supplying, here is a list of the reported output from the nation’s 104 licensed reactors for July 9, 2010.
Region 1 Power Reactor Status Report for July 9, 2010
| Unit | Power |
|---|---|
| Beaver Valley 1 | 100 |
| Beaver Valley 2 | 100 |
| Calvert Cliffs 1 | 100 |
| Calvert Cliffs 2 | 100 |
| FitzPatrick | 93 |
| Ginna | 100 |
| Hope Creek 1 | 96 |
| Indian Point 2 | 100 |
| Indian Point 3 | 100 |
| Limerick 1 | 100 |
| Limerick 2 | 100 |
| Millstone 2 | 100 |
| Millstone 3 | 100 |
| Nine Mile Point 1 | 100 |
| Nine Mile Point 2 | 100 |
| Oyster Creek | 89 |
| Peach Bottom 2 | 100 |
| Peach Bottom 3 | 100 |
| Pilgrim 1 | 100 |
| Salem 1 | 0 |
| Salem 2 | 100 |
| Seabrook 1 | 100 |
| Susquehanna 1 | 100 |
| Susquehanna 2 | 94 |
| Three Mile Island 1 | 100 |
| Vermont Yankee | 100 |
Region 2 Power Reactor Status Report for July 9, 2010
| Unit | Power |
|---|---|
| Browns Ferry 1 | 100 |
| Browns Ferry 2 | 97 |
| Browns Ferry 3 | 100 |
| Brunswick 1 | 100 |
| Brunswick 2 | 100 |
| Catawba 1 | 100 |
| Catawba 2 | 100 |
| Crystal River 3 | 0 |
| Farley 1 | 100 |
| Farley 2 | 100 |
| Harris 1 | 100 |
| Hatch 1 | 100 |
| Hatch 2 | 100 |
| McGuire 1 | 100 |
| McGuire 2 | 100 |
| North Anna 1 | 100 |
| North Anna 2 | 100 |
| Oconee 1 | 100 |
| Oconee 2 | 100 |
| Oconee 3 | 100 |
| Robinson 2 | 0 |
| Saint Lucie 1 | 100 |
| Saint Lucie 2 | 100 |
| Sequoyah 1 | 100 |
| Sequoyah 2 | 100 |
| Summer | 100 |
| Surry 1 | 100 |
| Surry 2 | 100 |
| Turkey Point 3 | 100 |
| Turkey Point 4 | 100 |
| Vogtle 1 | 100 |
| Vogtle 2 | 100 |
| Watts Bar 1 | 100 |
Region 3 Power Reactor Status Report for July 9, 2010
| Unit | Power |
|---|---|
| Braidwood 1 | 100 |
| Braidwood 2 | 100 |
| Byron 1 | 100 |
| Byron 2 | 100 |
| Clinton | 97 |
| D.C. Cook 1 | 100 |
| D.C. Cook 2 | 100 |
| Davis-Besse | 100 |
| Dresden 2 | 100 |
| Dresden 3 | 100 |
| Duane Arnold | 100 |
| Fermi 2 | 100 |
| Kewaunee | 100 |
| La Salle 1 | 100 |
| La Salle 2 | 100 |
| Monticello | 100 |
| Palisades | 100 |
| Perry 1 | 100 |
| Point Beach 1 | 100 |
| Point Beach 2 | 100 |
| Prairie Island 1 | 100 |
| Prairie Island 2 | 100 |
| Quad Cities 1 | 100 |
| Quad Cities 2 | 100 |
Region 4 Power Reactor Status Report for July 9, 2010
| Unit | Power |
|---|---|
| Arkansas Nuclear 1 | 100 |
| Arkansas Nuclear 2 | 100 |
| Callaway | 100 |
| Columbia Generating Station | 100 |
| Comanche Peak 1 | 100 |
| Comanche Peak 2 | 100 |
| Cooper | 100 |
| Diablo Canyon 1 | 100 |
| Diablo Canyon 2 | 100 |
| Fort Calhoun | 100 |
| Grand Gulf 1 | 100 |
| Palo Verde 1 | 100 |
| Palo Verde 2 | 100 |
| Palo Verde 3 | 100 |
| River Bend 1 | 100 |
| San Onofre 2 | 100 |
| San Onofre 3 | 100 |
| South Texas 1 | 100 |
| South Texas 2 | 100 |
| Waterford 3 | 100 |
| Wolf Creek 1 | 100 |
You can find an NEI press release talking about the reactor fleet’s performance for the period from July 4-7 at As Eastern U.S. Sizzles, U.S. Nuclear Plants Operate at Exceptional Levels to Stabilize Grid
I wonder how wind farm output is doing right now? I guess we won’t know since their don’t post up-to-date readings of power output.
Rod – your readers may also like to know that many (if not all) of the reactors slightly below 100% are in the midst of a ‘coast-down’. This means their performance allowed them to get the maximum use from their fuel. The fissile U-235 that remains is not enough to sustain 100% and they will enter their planned rufuelling outages when demand comes down (with the temperatures) this autumn.
Jason – all generators in Ontario Canada are required to post their output numbers. Here is the table for July 9, 2010
http://reports.ieso.ca/public/GenOutputCapability/PUB_GenOutputCapability_20100709_v25.xml
There is a new xml file put up every hour each day. You can find an archive list at
http://reports.ieso.ca/public/GenOutputCapability/
So far, I have not found any similar sites in the US except for the one published by Bonneville Power Authority at http://www.transmission.bpa.gov/Business/Operations/Wind/baltwg.aspx
It looks like a big breeze just blew in last night after about four days of less than 20% output.
Californian wind is here:
http://www.caiso.com/outlook/SystemStatus.html
And Danish power is available here (DK1 and DK2):
http://www.nordpoolspot.com/reports/production/
though it isn’t broken down by type. If you want to work, you can correlate production with price:
http://www.nordpoolspot.com/reports/areaprice/
Best wishes on your new career.
Interesting. Never knew that.
I would have imagined that the end of a cycle would be somewhat dramatic (in that once k < 1, in any state of the core with all rods out, multiplication would cease entirely in every state of the core), but I forgot about the negative temperature coefficient. So, I’m guessing that the coast-down begins once you start being unable to maintain k >= 1 at full operating temperature with all rods out. The reactor operating temperature then slowly drops as the core has less and less reactivity, so as to maintain k >= 1. Since there’s consequently less ?T between the turbine inlet temperature and the condenser, the plant slowly produces less output, until the end of cycle in the fall, when it’s time to refuel, and the plant is entirely shut down.
Is this explanation right?
@Dave – though I have never operated a commercial nuclear plant, I would bet that you are right on the money there.
One thing that is completely different about nuclear reactor cores is that “running out of gas” is a very slow and fuzzy process that does not have a sharp end point like it does for other thermal plants. The full explanations can require numerous credit hours in reactor physics and thermodynamics, but you have done a great summary for a light water reactor with a negative temperature coefficient of reactivity that is feeding a steam plant secondary.
Thanks for the link, I’ve actually been searching for something like that for a long time.
You’re correct Dave, as Rod said. Also remember that some of the reactors are BWRs (with the cardinal sin of sins in PWRs and Navy Subs… boiling in the core). BWR operation is significantly effected by a ‘void coefficient of reactivity’ that is typically an order of magnitude greater than the temperature coefficient. Think if it this way; with k<1, less fission, less energy, less voids, less fast and thermal neutron leakage, positive reactivity, k=1.