By John Stang
The schedule for decommissioning of reactor Unit 2 at the Three Mile Island nuclear power plant in Pennsylvania is being coordinated with the timetable for teardown of Unit 1, even though they have separate owners.
There is a hint that the two reactors could together accelerate their schedules for decommissioning, possibly by decades, at the plant near Harrisburg.
FirstEnergy Corp.’s TMI-2 is in a condition similar to “safe storage,” or SAFSTOR, under which federal regulations allow final decommissioning to be delayed for up to 60 years. Meanwhile, Exelon is preparing the newly retired TMI-1 to be placed into SAFSTOR by 2023.
Unit 2 famously partially melted down in March 1979 after just a few months of operation, and never resumed operations. It is owned by Ohio-based FirstEnergy via its 2001 acquisition of General Public Utilities Corp. (GPU). The power company hopes later this year to sell the reactor to nuclear services firm EnergySolutions, which would assume full responsibility for decommissioning through its TMI-2 Solutions LLC subsidiary.
Exelon retired its reactor at Three Mile Island last September after nearly 45 years of power production. To date, the Chicago-based power company has said it would retain ownership of the reactor and delay completion of decommissioning and license termination to 2079.
“With the closure of TMI Unit 1, the decommissioning schedule for Unit 2 is being adjusted. The plan had long been to decommission the two units in conjunction,” said FirstEnergy spokeswoman Jennifer Young in a Feb. 28 email.
She did not have any additional details on how the coordination with Exelon would be handled. The Nuclear Regulatory Commission has also noted the potential for decommissioning coordination between the two owners. It says the reactors share certain equipment, and that Exelon provides maintenance and monitoring on contract for GPU.
“There are currently no plans to sell TMI-1. However, Exelon Generations regularly evaluates its facilities and assets, and considers all options, including sales, to optimize our value for energy customers, communities and stakeholders,” Exelon spokeswoman Liz Williamson said by email Thursday. “We are in communications with Energy Solutions and FirstEnergy, and continue to evaluate opportune to coordinate decommissioning activities.”
Last month, GPU and TMI-2 Solutions said they expect to submit revised decommissioning calculations for Unit 2 to the Nuclear Regulatory Commission in the fourth quarter of 2020. Officials did not discuss more specifics of the schedule beyond the final three months of the year.
TMI 2 Solutions is expected to assume ownership in the second half of 2020, according to the third revision of the site’s post-shutdown decommissioning activities report (PSDAR). That document, dated Dec. 26, 2019, and submitted to the Nuclear Regulatory Commission, set a $1.06 billion price tag for decommissioning on a schedule that would end in roughly 2037.That is faster than the second revision’s target completion date of roughly 2054. The $1.06 billion figure in the PSDAR’s third revision listed $28 million for site restoration, but did not have a cost estimate for dealing with spent nuclear fuel.
All of TMI-1’s spent nuclear fuel, estimated to fill 46 canisters, is supposed to be moved to dry storage by December 2022. The used fuel is to eventually be moved to a consolidated interim storage site — probably in New Mexico or Texas — once one of those sites is built and receives NRC licensing. Spent fuel core debris from TMI-2 is stored at the Idaho National Laboratory.
“Since TMI-1 closed earlier than expected, the revised PSDAR will change TMI-2’s decommissioning status from Post Shutdown Defueling Monitored Storage (PDMS) to DECON,” Young wrote. “The updated PSDAR will outline the change in schedule and cost associated with DECON status.”
“DECON” is the term for tearing down a reactor site, collecting the debris, and shipping the wastes to a storage site over several years.
Also scheduled for the fourth quarter of this year will be a license amendment request to the NRC by GPU to change TMI-2’s technical specifications to fit in with a DECON status.
Meanwhile, TMI-1’s SAFSTOR schedule — unveiled in April 2019 — has an estimated $1.2 billion cost.
