This was recommended in the podcast thread and I looked at the page but it’s somewhat inconvenient how they serve it. It’s a bunch of video files even though they only contain audio and they can only be streamed.
I took the liberty of dumping them and converting them to normal mp3s that you can put on your phone to listen while you’re on a plane and don’t have internet or something. Hope it’s useful!
Source: https://www.nhk.or.jp/radiosp/kodomoq/schedule.html
MP3 Folder: kodomokagaku - Google Drive