200k. She has a lot of momentum from the Loud era and We Found Love will be #1, but even with 2 #1's last era she only opened with 207k. Plus We Found Love won't be encouraging grandma's to go out and buy the album.
There's no way she's going #1 though. She has way too much competition. It's possible for Mary J. Blige, Nickelback, and Daughtry to all have better first week sales. Then you have to factor holdovers like Drake from the week before who's debut will be absolutely huge with Black Friday helping sustain the second week sales, Adele who's sales will sell even better with the holidays, and Susan Boyle who's a perenial holiday power. Then there are all the big name Christmas albums whose sales rise every week. Justin Beiber's will be huge, Michael Buble already opened with 100k, and Jackie Evancho who outsod Rihanna last year during the holidays with her Christmas EP. Rihanna may be lucky to get a Top 10 debut.
Riri might become one of those artists who debut with bigger sales in the UK than in the US.. to my knowledge LOUD also has a bigger total number in the UK than in the US which is quite impressive.