Atomic Insights

Atomic energy technology, politics, and perceptions from a nuclear energy insider who served as a US nuclear submarine engineer officer

When the heat is on, the reactors are pumping out the juice

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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

Reader Interactions

Comments

  1. 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.

  2. 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.

    • 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.

      • 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.

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