Disable hyphenation for proper nouns in Romanian language

I’m not sure that my question is related to hyphenat package or to Romanian hyphen pattern that are loaded in LaTeX.

According to Romanian grammar definition:

Proper nouns name objects of the same kind to distinguish them from others and are written in capital letters, regardless of the place they occupy in the sentence.

So I want in my thesis to globally disable hyphenation for proper nouns.
There is a problem involved here: detection of proper noun at the beginning of a sentence

1. Bucharest is the capital of Romania.

and

2. According to John Doe we don’t get the bonus.

In 1st sentence words Bucharest & Romania must not be hyphenate BUT in 2nd sentence let According to be hyphenate but NOT John OR Doe.