PrepTest 151

Incorrect. The stimulus states that the fuel rods don't have T, not that the core doesn't have those isotopes. In fact, the stimulus establishes that the core does have T, so (if anything) the stimulus provides evidence against this answer.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Scientists found some isotopes in the atmosphere after a nuclear accident. They either came from fuel rods or the plant's core, but the isotopes aren't all in the rods but are in the core. Steam was released in the accident that would dissolve the isotopes, and it might have hit the core.

Answer Anticipation:
The stimulus effectively rules out fuel rods as the source of all the elements since they lack one of the elements detected, so some of the elements must have come from the core. The stimulus proposes a means by which that could have happened—this steam that was released. While the argument doesn't establish without a doubt that the steam picked up the isotopes from the core ("may have been in contact), this is a most strongly supported question, and that source of the isotopes in the atmosphere is very strongly supported by the statements, so we should look for that answer.

Answer Explanation:
This answer matches our anticipation. Since the stimulus establishes that there are only two potential sources (rods, core) of these isotopes and rules one out (rods), the other (the core) must be the source. Since the means by which the steam would have picked up these isotopes from the core is established in the stimulus, it's strongly supported that the steam is the source.

Key Takeaway:
This question is clearly trying to distract you with the scary science words—don't fall for it! This argument is about ruling out alternatives, and providing a causal chain explaining a phenomenon. You know how to handle both of those concepts without appealing to science, so don't get distracted by words like "tellurium" and "isotope."

Incorrect. There's no indication that damage is related to the fuel rods releasing these radioactive isotopes, so this answer is out of scope.

Incorrect. While there may be evidence that the researchers found material from the plant's core (assuming isotopes count as material), there's no indication that the rods also contributed to the isotopes in the atmosphere since the core can serve as a complete explanation for those isotopes.

Incorrect. It's noted that spent fuel rods never have significant quantities of one heavy isotope (tellurium), but it doesn't discuss the other isotopes.