Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of the Isotopic Evolution of Pressurized Water Reactor Fuel
  Using an Antineutrino Detector   By operating an antineutrino detector of simple design during several fuel
cycles, we have observed long term changes in antineutrino flux that result
from the isotopic evolution of a commercial Pressurized Water Reactor (PWR).
Measurements made with simple antineutrino detectors of this kind offer an
alternative means for verifying fissile inventories at reactors, as part of
International Atomic Energy Agency (IAEA) and other reactor safeguards regimes.

24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci