I suspect that NH, with what SHOULD be massive Federal "assistance", will buy the trackage as far as the Mass. state line. As Rockingham Racer said about security, importance, or whatever, there will come a time when Seabrook Nuclear is decommissioned, and the track will be needed to haul out large numbers of low level contamination, debris.
Saw this done with Maine Yankee, and in fact, th only "real money" made on the Rockland Branch, was by Safe Handling Rail, who operated the line for the State from Jan. 2001 through March 2003. This was the "peak" of the demolition period, and hundreds of MHFX covered gons took the "very low level" contaminated debris to an out of state disposal area. This time period, also was WHEN the Rockland Branch was being REHABED, and Safe Handling hauled in many loads of rails, ties, plates, ballast etc, and even several CWR trains. Yup, they made "good money" as compared toMaine Coast(1990-2000) and Maine Eastern(2003-present)
So, expect NH to buy the defunct line, and rehab it prior to the demolition(I have even heard the remote possibilty of an "expansion at Seabrook", and the was the last time any real "work" was done of the "Hampton Runner, Portsmouth Branch/yard, was when Seabrook was being built.) But DON'T expect any "expansion" if the Democrats win thw White House, and keep control of Congress!
But in "fairness", Fed Govt. should pay for most of the rehab work, along with PS of NH!!
Bud