According to “https://webb.nasa.gov/content/about/orbit.html”, NASA plans to exploit a quarter million mile radius “halo” orbit at L2.
And Webb will orbit around L2, not sit stationary precisely at L2. Webb's orbit is represented in this screenshot from our deployment video (below), roughly to scale; it is actually similar in size to the Moon's orbit around the Earth! This orbit (which takes Webb about 6 months to complete once) keeps the telescope out of the shadows of both the Earth and Moon. Unlike Hubble, which goes in and out of Earth shadow every 90 minutes, Webb will have an unimpeded view that will allow science operations 24/7.
I understand the semi-stable utility to this 3BP solution, but I don’t understand why the radius NASA is showing is so large. Since L2 is beyond the Sun-Earth umbra, there is no chance of hiding from the Sun, but why such a large radius? Is this radius a fuel expenditure compromise? Any smaller, you burn more fuel and any larger, you lose L2 lock?