Soak the beans in cold water overnight, rinse, drain, and put in a pot with the carrot, onion, celery, bay leaf and plenty of water. Boil for an hour, adding salt towards the end. In a casserole pot with a little bit of water, simmer the radicchio for 5 minutes; drain off the water and chop finely. Bring the broth to a boil, and then sprinkle the corn meal over it, adding slowly; mix and after 10 minutes, add the beans and cook for 15 minutes. Remove from the heat, add the radicchio, a bit of salt and pepper, and finally pour into a soup tureen, and serve.