I'm sorry to see that the 'Russia Fires Warning Shots at British Destroyer in the Black Sea' thread has been locked. Leaving aside the nationalist tone that arose in some comment, perhaps there's potential in discussing navigation technologies and cyberwar under the Secret Projects banner...
It is likely for electronic warfare.
Anyway here is the excellent article by Bart Hendrick, reads like a detective novel.
t seems like it’s part of general fashion for nuclear powered military projects in Russia at the moment.