Q24 - After a nuclear power plant accident,

[ohthatpatrick]

Question Type:
Inference (Most strongly support)

Stimulus Breakdown:
We found some material (I/T/C, but no heavy) in the atmosphere downwind from a power plant.

The material came from Fuel Rods or the Core.
The Fuel Rods never have T (infer: the T must have come from the Core. We still don't know where the I and C came from).

If stuff had ejected out of the Core, it would have included heavy.
The material we found had no heavy (infer: by contrapositive, the material did not eject out of the Core).

There was some steam released that might have come into contact with the core. The core has I/T/C, and I/T/C is easily absorbed into steam clouds.

Answer Anticipation:
Jeez, what a nightmare. The two biggest themes of Inference are Conditional Logic and Causality. This had both, and more. We had two conditional rules that we were able to apply to specific facts:

("If it came from Fuel Rods, then no T" + "This material had some T in it" = The T in the material did not come from the Fuel Rods.)
("If radioactive material ejects into atmosphere directly from the Core, then it would have heavy isotopes" + "this radioactive material in the atmosphere did not have heavy isoptopes" = This material did not eject directly from the Core.)

The T didn't come from the Fuel Rods, and it didn't eject directly from the Core. Yet, we know this material came from Fuel Rods or Core. We're only left with the possibility that it came from the Core, but it didn't eject directly from it. How do we solve this mystery? Steam ... which apparently blew by the Core and picked up some I/T/C, which we later detected downwind from the power plant.

Correct Answer:
B

Answer Choice Analysis:
(A) This is trying to make a fake blend of the two conditional rules. We only know that directly ejected stuff wouldn't have heavy isotopes. It could potentially have T.

(B) Yes! It's not 100% provable, but this is "most strongly supported". It's the #1 suspect for solving the mystery of where the I/T/C material came from.

(C) We never talked about functional vs. damaged. We know that T didn't come from the Fuel Rods, but they still might have been damaged.

(D) This is a tempting overreach. Since we know the Fuel Rods didn't contribute the T to the I/T/C material, we might be tempted to think, "I guess the Fuel Rods provided the I and C, and the Core provided the T." But we have no support for making that division. It could just as easily be that Fuel Rods provided C and the Core provided I/T. It could just as easily be that Fuel Rods provided nothing and the Core provided I/T/C.

(E) Just like (A), this is trying to make a fake blend of the two conditional rules. We only know that Fuel Rods don't have T. We have no idea whether they have heavy.

Takeaway/Pattern: This is a very tough question (in my opinion). We might get it right by sensing that the other ones are wrong, but it definitely takes some time to organize all the information, make the correct inferences as you go, and arrive with the "Detective's Hypothesis" at the end that, "The steam did it."

#officialexplanation

[PierreR118]

This is one of those questions that I thought was actually quite easy. I'm not sure why. I just kept the material found in mind, marking them in the passage. Then when I came to the details explaining what material comes from each source, I took notes in the margins (/T, H) and circled the possible sources and drew lines between them and the appropriate note. And then as soon as it got to talking about what was released from the plant, it all felt unnecessary. I felt certain the answer was going to be about the source of the material found downwind.

That you call this a difficult question makes me disappointed in myself. In this test, I tended to get most of difficult questions right, but I missed sooo many easy questions!

[ThaoN810]

I got tripped up by this: "Spent fuel rods never contain significant quantifies of tellurium isotopes." This sounds like one could infer that it is possible for spent fuel rods to contain SOME tellurium isotopes. The first sentence of the stimulus doesn't specify how much of each isotope was found.

I ended up choosing (E) because I reasoned that the material must have come from spent fuel rods and the amount of tellurium isotopes must have been quite small. Thus we would know another fact about spent fuel rods, hat it contained no heavy isotopes, and certainly no heavy isotopes in large quantity.

How did @ohthatpatrick infer "If it came from Fuel Rods, then no T" from "Spent fuel rods never contain significant quantifies of tellurium isotopes."?

[DPCTE4325]

Hi Patrick,
Doesn’t dissolve mean disappear? I eliminated B because I thought dissolve meant disappear so that the three I/T/C would be eliminated upon contact with the steam.

If I dissolve a penny by putting in a cup of Coca Cola, doesn’t the penny cease to exist?

Question Type:
Inference (Most strongly support)

Stimulus Breakdown:
We found some material (I/T/C, but no heavy) in the atmosphere downwind from a power plant.

The material came from Fuel Rods or the Core.
The Fuel Rods never have T (infer: the T must have come from the Core. We still don't know where the I and C came from).

If stuff had ejected out of the Core, it would have included heavy.
The material we found had no heavy (infer: by contrapositive, the material did not eject out of the Core).

There was some steam released that might have come into contact with the core. The core has I/T/C, and I/T/C is easily absorbed into steam clouds.

Answer Anticipation:
Jeez, what a nightmare. The two biggest themes of Inference are Conditional Logic and Causality. This had both, and more. We had two conditional rules that we were able to apply to specific facts:

("If it came from Fuel Rods, then no T" + "This material had some T in it" = The T in the material did not come from the Fuel Rods.)
("If radioactive material ejects into atmosphere directly from the Core, then it would have heavy isotopes" + "this radioactive material in the atmosphere did not have heavy isoptopes" = This material did not eject directly from the Core.)

The T didn't come from the Fuel Rods, and it didn't eject directly from the Core. Yet, we know this material came from Fuel Rods or Core. We're only left with the possibility that it came from the Core, but it didn't eject directly from it. How do we solve this mystery? Steam ... which apparently blew by the Core and picked up some I/T/C, which we later detected downwind from the power plant.

Correct Answer:
B

Answer Choice Analysis:
(A) This is trying to make a fake blend of the two conditional rules. We only know that directly ejected stuff wouldn't have heavy isotopes. It could potentially have T.

(B) Yes! It's not 100% provable, but this is "most strongly supported". It's the #1 suspect for solving the mystery of where the I/T/C material came from.

(C) We never talked about functional vs. damaged. We know that T didn't come from the Fuel Rods, but they still might have been damaged.

(D) This is a tempting overreach. Since we know the Fuel Rods didn't contribute the T to the I/T/C material, we might be tempted to think, "I guess the Fuel Rods provided the I and C, and the Core provided the T." But we have no support for making that division. It could just as easily be that Fuel Rods provided C and the Core provided I/T. It could just as easily be that Fuel Rods provided nothing and the Core provided I/T/C.

(E) Just like (A), this is trying to make a fake blend of the two conditional rules. We only know that Fuel Rods don't have T. We have no idea whether they have heavy.

Takeaway/Pattern: This is a very tough question (in my opinion). We might get it right by sensing that the other ones are wrong, but it definitely takes some time to organize all the information, make the correct inferences as you go, and arrive with the "Detective's Hypothesis" at the end that, "The steam did it."

#officialexplanation

[ohthatpatrick]

The penny ceases to exist (the complex molecular structure), but all the copper atoms are now in that delicious Coke.

Coca-Cola Copper®, suspended during World War II, but back on the shelves now!

When I dissolve (too much) sugar in my coffee, the solid crystal form of sugar gets broken down into much tinier, invisible molecules but that glucose is still in my coffee. The sugar is the solute, the coffee is the solvent, the delicious mug full of Philz is the solution.

Since iodine, tellurium, and cesium are elements, i.e. atoms (I think), they cannot disappear. Dissolving into steam would essentially mean "mixing into the steam, at a tiny microscopic level ... dispersing atoms of iodine, tellurium, and cesium throughout the gaseous H2O"