We have some information about using internet radio in our KB.
Roon can play back stations that stream in MP3, AAC, and FLAC formats, and also supports TuneIn web page URLs
It also provides some examples of URLs that will work with Roon:
http://newmedia.kcrw.com/legacy/pls/kcrwsimulcast.pls
http://tunein.com/radio/KCRW-899-s32152/
I tried a couple of the above examples you shared both in Roon and in iTunes, and unfortunately, they didn’t work for either.
The best option is to look for alternative URLs for these streams. TuneIn and this thread are great places to start looking.