I love it when people blithely say you should ask for money. Based on what exactly?
There may be numerous factors worthy of consideration such as:
* the type of show - news media, entertainment - what?
* the size of viewing audience - local or national?
* the broadcast slot - prime time or sleep time?
* likelihood of repeat broadcasts
* the length of the segment
* the purpose of the segment
* it's context
* the context of usage of your image
* the specific nature & value (relative to context) of the image
* any rights that you may have to forego by having the image broadcast publicly
* any benefits that you may accrue by having the image broadcast publicly
... put my sites url on the picture so it is clear and require that it remain clear
Nice try... and what will you do after the segment is broadcast and you find that they erased your web address? And, if the segment usage is but a split second, what value then? Find out more before committing yourself.