Does the noun **uncovery** (noun of to uncover) exist?

I have seen this quite often in publications of nuclear reactor safety analyses.

For example: <http://www.sciencedirect.com/science/article/pii/0143817484900349>

> 
> Assessment of the uncertainties associated with the core **uncovery** time in TMI-type accidents
> 
> 
> 

I cannot find the word in <http://www.merriam-webster.com> Or do you have to use the gerund **uncovering**?

Matthias