Yes sir you can.
Copy past this text into "Script Editor":
tell application "Safari"
repeat
activate
open location "URL of website. must be full URL and include http://"
delay put the amount of minutes you want to go by before refreshing multiplied by 60 here
end repeat
end tell
Now go to File>save as, give it a name, make sure to save it as an Application, deselect the "Run Only", Startup Screen" and "Stay Open" check boxes. Hit save.
Navigate to the place where you saved it and double click it.
Safari will now open the specified web-page and refresh at the specified interval!
Unfortunately Im not a very good scripter, so unless you put a number after "repeat" (example: repeat 5) it will keep repeating into infinity.
The only way to stop the beast is to use the command, option esc and force quit it......