The second example is the combination of the chemical sensitivity of the centralized melter to changes in waste composition and the limit on the highest melt temperature achievable in a centralized melter.
(The second example; is; the combination of the chemical sensitivity of the centralized melter to changes in waste composition and the limit on the highest melt temperature achievable in a centralized melter)
The second example
is
the combination of the chemical sensitivity of the centralized melter to changes in waste composition and the limit on the highest melt temperature achievable in a centralized melter