Preheat a grill or grill pan to medium high. Toss the radicchio, fennel wedges and bell peppers in a large bowl with 1/4 cup olive oil. Season with salt and pepper and grill, turning occasionally, until charred and crisp-tender, about 4 minutes for the peppers and radicchio and 6 minutes for the fennel. Let cool, then cut into small pieces.
Bring a large pot of salted water to a boil. Add the pasta and cook as the label directs. Drain and rinse under cold water; shake off the excess. Transfer to a large bowl.
Add the grilled vegetables and cannellini beans to the pasta; toss well. Add the remaining 1/4 cup olive oil, the lemon juice, parsley, 1/4 teaspoon salt and pepper to taste; toss. Add the Parmesan and fennel fronds and toss gently.