Operators have accelerated decommissioning plans following early plant closures and proposed changes to licensing rules are raising project risks, leading utility executives said at the 2016 Nuclear Decommissioning & Used Fuel Strategy Summit on October 3.

There are currently 18 U.S. nuclear power plants being decommissioned and this will soon increase following a recent spate of plant closure announcements due to sustained low power prices.

The Nuclear Regulatory Commission (NRC) is developing new rules to reduce the number of licensing amendments required post-shutdown but significant changes to existing regulatory frameworks could impact project timelines, Jim Madigan, CNO Technical Advisor and Director of Oversight, Regulatory Affairs & Nuclear Safety Culture, Southern California Edison (SCE), told conference attendees.

SCE is currently navigating through post-shutdown licensing for its 2.2 GW San Onofre Nuclear Generating Station (SONGS) plant.

"We could be hit with some unnecessary delays going forward if it gets complicated with all the things that are being asked for in the rulemaking process," Madigan said.

The majority of current U.S. decommissioning projects are being carried out under the SAFSTOR method of deferred decontamination rather than the DECON option of immediate action, mainly due to funding shortfalls and site-specific environmental regulation.

California's Pacific Gas and Electric Company (PG&E) announced June 21 it would shut down its two 1.1 GW Diablo Canyon reactors by 2025 and the decision on whether to use DECON or SAFSTOR will be largely driven by the level of available funds and whether the operator can complete required licensing actions and finalize modifications such as spent fuel pool islands before the plant is taken off the grid, Loren Sharp, Senior Director Decommissioning - Diablo Canyon & Humboldt Bay, PG&E, said.

PG&E expects to complete initial cost estimates for the Diabolo Canyon reactors by the end of 2016 and a full cost estimate is to be completed in the next few years, Sharp said.

Innovation wanted

Many operators have chosen the SAFSTOR method as the plants are being closed long before licenses expire and decommissioning involves high upfront costs, Thomas S LaGuardia of leading cost estimation firm LaGuardia & Associates, told Nuclear Energy Insider last month.

Project management costs can represent as much as 55% of total decommissioning costs, with 20-25% allocated for dismantling and around 25-30% for waste disposal, he said.

Entergy chose to submit its 620 MW Vermont Yankee plant for SAFSTOR due to a lack of funds in its decommissioning trust fund (DTF) and the company plans to use the same approach for other planned closures, Paul Paradis, Decommissioning Director, Entergy, told conference attendees.

Entergy may choose to accelerate decommissioning and dismantling (D&D) activities at a later stage, depending on the level of accumulated funds in the plant DTFs and whether vendors can provide new decommissioning solutions to improve efficiency, Paradis said.

"We do have a commitment with the state of Vermont to start planning for D&D as soon as we have enough money in the trust fund," he noted.

Cost risks

Experts have warned that deferred decommissioning exposes operators to delay-related costs, investment risks and loss of crucial expertise as workers leave the industry.

"The reason that we advocate for prompt decommissioning [DECON] is that there is certainty today. We know what the regulations are with the NRC, we know how to deal with the EPA [Environmental Protection Agency] and the state EPA's. There is certainty on the decision-making and the licensing process," John Sauger, Executive Vice President and CNO, EnergySolutions, told the conference.

EnergySolutions is the most active nuclear decommissioning contractor in the U.S. and currently operates 50% of active commercial decommissioning sites.

Growing project experience is improving efficiency and shortening D&D timelines, Sauger said.

"Our new schedules based on Zion [plant decommissioning project] are 6 and a half to 7 years to tear down the plant, from start to finish," he said.

In 2014, Southern California Edison (SCE) chose to use DECON for its SONGS plant. The cost of dismantling, managing the used fuel and restoring the site within 20 years was estimated at $4.4 billion and the operator had accumulated a substantial DTF of some $4.1 billion.

An assessment of regulatory risk also supported the DECON option, as the SONGS plant is located on federal land owned by the U.S. Navy and the SAFSTOR option was expected to present more environmental challenges from state and federal-level regulators, Madigan said.

"Looking at all the challenges, it made sense for us to fully engage in decommissioning right off the bat."

Nuclear Energy Insider