Logical reasoning PrepTest 133 · Section 2 · Question 3

Incorrect. This answer doesn't establish if the cost of following safety regulations is higher for either of the plants, so it doesn't provide enough information to analyze.

Incorrect. If anything, this provides a reason to doubt the economic feasibility of the conventional plants compared to nuclear plants.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Nuclear plants have lower fuel costs than conventional plants, but they cost more to build, so they're not economically feasible.

Answer Anticipation:
While the conclusion isn't explicitly comparative here, it's clear from the premises that economic feasibility is measured against the conventional plants—a new plant has to be cost competitive with them to be feasible.

To show that nuclear plants aren't economically feasible, the premises here bring up a couple points of comparison between the conventional plants and nuclear ones. On the one hand, nuclear fuel is significantly lower. On the other, nuclear plant construction costs are much higher.

So this argument relies on these two points of comparison to draw a conclusion about the overall relative cost. There are two flaws with this.

First, the argument concedes that nuclear plant fuel is much cheaper than conventional plant fuel. If fuel costs determine the overall economics of a power plant (e.g., they make up 90% of all associated costs), then the argument falls apart. This argument is assuming that the construction costs drive the economic feasibility of the two plant types, so any answer that establishes the primacy of construction costs over fuel costs in this determination will strengthen the argument.

Which brings us to the second flaw—the argument ignores other potential costs. What about operating costs outside of fuel costs, or regulatory costs, or distribution costs? Each of these could add to the economic feasibility of the plants, but they're not discussed or compared. Any answer that establishes another relevant cost as being cheaper for conventional plants/more expensive for nuclear plants will also strengthen this argument.

Answer Explanation:
This answer provides a difference between nuclear and conventional plants that suggests the latter would be more economically feasible. If nuclear plants have to be "replaced" more often, that would drive the associated costs up—especially since construction is established as being a relatively high cost for them. This answer, therefore, strengthens the argument.

Key Takeaway:
When an argument relies on two things being different to reach a conclusion, you can generally strengthen it by finding another relevant difference between the two things being compared.

Incorrect. If anything, in saying that the cost of nuclear plants is relatively low, this answer is cutting against the argument. However, it doesn't do that because the construction costs are compared to old nuclear plants, not conventional plants, and so nuclear plants are still "far more" expensive to build. In short, this answer adds nothing to the current calculus of economic feasibility.

Incorrect. By suggesting that the cost of running a conventional plant will go up, this answer runs counter to an argument that nuclear plants are not economically feasible in comparison to them.