What is the fixed cost vs. variable cost breakdown for a nuclear power plant?

In summary, nuclear power plants have high fixed costs and low variable costs. The fixed costs include capital costs, payroll, and NRC charges, while variable costs include fuel costs and maintenance costs. The plants can adjust their output, but it is most efficient to run them at full capacity. In comparison to other types of power plants, nuclear is relatively expensive in terms of fixed costs but has lower variable costs. However, advanced nuclear technology in countries like China, South Korea, Russia, and India has proven to be more cost-effective than solar plus battery storage. The cost of disposing of spent fuel remains uncertain.
  • #1
EnumaElish
Science Advisor
Homework Helper
2,350
124
I am trying to understand the fixed cost of a nuclear power plant relative to variable cost.

By fixed cost I mean "cost that does not vary with the amount of the power outputted over a given time period."

By variable cost I mean "cost items that vary with the amount of the power outputted over a given time period."

Does the whole plant have to be either on or off? Or can its output be scaled down pretty much on a continuum? Or perhaps on a discrete scale? In either case, what are the cost savings during scaled-down times, e. g. off-peak demand, relative to total cost of operating?
 
Engineering news on Phys.org
  • #2
I am not a financial type so Take the following with a grain of salt.

Let's look at an 1100 MWe reactor. Assume it cost $8 billion, and runs at 90% capacity.

First, the $8 billion capital cost, spread evenly over the initial 40 year license, would be $200,000,000 per year. I know finance is more complicated than that, what with interest, depreciation, etc. but that $200 million gives a rough idea of the cost. That's fixed.

Then, the payroll. If the unit has 600 employees at say $100,000 per year salary, that's $60,000,000 per year. That's fixed.

The NRC charges licensees about $5 million per year. That's fixed.

So that adds up to $265,000,000 per year fixed costs.

Now, the fuel. The fuel cost is about 3/4 of a cent per kw-hr. For the 1100 MWe reactor that's about $65 million per year. Is this a fixed cost? Well, kind of, since the power company buys the fuel for the cycle all at once, they are making payments on it whether the plant operates or not. On the other hand, a load of fuel will last for a certain burnup so it really isn't fixed cost.

I can't think of too many other big ticket items that are not fixed; there are things like burnup on the incore instruments (a few million to replace every few cycles). I'm sure there are others that might be identified by those closer to daily operations than I am.

I don't really know what the maintenance costs are and how closely tied they are to power production.

Looking forward to hearing from others.
 
  • Like
Likes mheslep, russ_watters and EnumaElish
  • #3
EnumaElish said:
I am trying to understand the fixed cost of a nuclear power plant relative to variable cost.

By fixed cost I mean "cost that does not vary with the amount of the power outputted over a given time period."

By variable cost I mean "cost items that vary with the amount of the power outputted over a given time period."

Does the whole plant have to be either on or off? Or can its output be scaled down pretty much on a continuum? Or perhaps on a discrete scale? In either case, what are the cost savings during scaled-down times, e. g. off-peak demand, relative to total cost of operating?

The United States Energy Information Administration has some cost estimates for nuclear and other types of power plants on page 2-10 (PDF page 44) of this report. As can be seen, nuclear has high fixed costs and low variable costs. In fact, the interest rate on construction bonds are one of the largest costs for a nuclear power plant.

Nuclear power plants can adjust output, but due to their high fixed costs it makes the most sense to operate them at full output. French nuclear power plants are modified to be load following, but that requires careful coordination because plants with older cores have low/no ability to increase output if adjusted downwards due to loss of reactivity.
 
  • Like
Likes EnumaElish
  • #5
Per the 2016 referenced, the capital cost of solar plus battery storage is about the same as nuclear in the US, and the variable O&M for nuclear is 3X cheaper than solar plus battery storage. In several other countries, China, S. Korea, Russia, India, advanced nuclear is far cheaper than solar plus battery storage.
 
  • #6
I'm not sure of any good numbers for the disposal of spent fuel since many plants haven't yet disposed of any.
 

1. What is the difference between fixed costs and variable costs for a nuclear power plant?

Fixed costs are expenses that do not change based on the level of electricity production, such as the cost of land, building construction, and equipment. Variable costs, on the other hand, are directly related to electricity production and may include fuel, maintenance, and labor costs.

2. How do fixed costs and variable costs affect the overall cost of a nuclear power plant?

The fixed costs are typically larger and have a greater impact on the overall cost of a nuclear power plant. Variable costs can vary depending on the level of electricity production, but they are generally lower than fixed costs.

3. Can you provide an example of a fixed cost vs. variable cost breakdown for a nuclear power plant?

For a hypothetical nuclear power plant, the fixed costs may be $500 million for land, building construction, and equipment. The variable costs may be $100 million for fuel, maintenance, and labor. This would result in a total cost of $600 million.

4. How do fixed costs and variable costs impact the profitability of a nuclear power plant?

Fixed costs are a necessary investment for a nuclear power plant, but they can make it challenging for the plant to be profitable if electricity demand is low. Variable costs, however, can be adjusted based on electricity production levels, which can help improve profitability.

5. Are fixed costs and variable costs for a nuclear power plant the same for every plant?

No, the fixed and variable costs for a nuclear power plant can vary depending on factors such as location, size, and technology used. Some plants may have higher fixed costs due to more expensive land or equipment, while others may have lower variable costs due to more efficient operations.

Similar threads

I Nuclear power plant vs coal power plant efficiency
    • Thermodynamics
Replies
32
Views
733
How long can nuclear plants last without power? (CME hit)
    • Nuclear Engineering
2
Replies
52
Views
7K
Chernobyl loses power, spent fuel storage question #Ukraine
    • Nuclear Engineering
Replies
20
Views
2K
Service Limits of a Nuclear Reactor
    • Nuclear Engineering
Replies
2
Views
1K
Understanding Nuclear Fission in Power Plants
    • Mechanics
Replies
1
Views
1K
Power plant generator improvement
    • Electrical Engineering
Replies
20
Views
2K
Submersed nuclear power plants
    • Nuclear Engineering
Replies
4
Views
6K
Power Plants and Micro-Regulation
    • Electrical Engineering
Replies
1
Views
896
Exploring the Possibility of 100% Renewable Grid w/ Super Power
    • General Discussion
Replies
8
Views
882
Effect of Solar Storms on the Grid and Nuke Plants?
    • Nuclear Engineering
2
Replies
50
Views
19K

Hot Threads

Recent Insights

Back
Top