Omaha Public Power District ratepayers will chip in more than $1 billion over the next seven years toward decommissioning the now-closed Fort Calhoun nuclear power plant.

The utility is at the beginning of a 50-year project to clean up the 660-acre site, with its concrete buildings and radioactive waste.

The spending to shut down Fort Calhoun isn’t expected to boost OPPD’s general electric rates for at least the next five years, utility officials said. The monthly fixed fee for homeowners will increase by $5 to $25 in January 2018 and to $30 in January 2019, but on average those increases will be offset by reductions in usage rates.

OPPD had built much of the money to tear down Fort Calhoun into its rate structure, and it no longer has to cover the plant’s operating losses.

Yet the newly outlined $1 billion in spending shows that the plant will continue to be a burden on ratepayers for years to come.

OPPD declined to say how much of an average utility bill is earmarked for decommissioning, even though it is a public body with a state-granted energy monopoly.

But in 2017 alone, OPPD’s $147.5 million contribution to the decommissioning trust fund is equal to about 13 percent of the utility’s $1.13 billion in budgeted expenses.

OPPD had a federal license to operate Fort Calhoun until 2033, but it was shut down in October 2016 because it was so expensive to run.

Now OPPD is working out the details of its plan to tear down the plant 20 miles north of Omaha, clean up the radioactive materials and ship some of the waste to landfills in Utah and Texas.

In all, spending on the project could hit $3 billion. But OPPD’s projected obligation is about $1.38 billion in 2016 dollars, and the utility thinks it can cover most of that with $382 million already held in trust, plus the $1 billion in contributions over the next seven years and decades of investment earnings before the biggest shutdown costs hit, starting in 2059.

OPPD President and Chief Executive Tim Burke has estimated it cost OPPD as much as $250 million a year to operate the plant.

OPPD also spent 2½ years and nearly $300 million to recover from disastrous Missouri River flooding in mid-2011. By the time the plant was restarted in late 2013, extremely low natural gas prices and significant additions of new renewable power sources had reshaped the national and regional power markets, and the plant had become too costly to continue operating.

Time is on OPPD’s side under the decommissioning procedure — if all works as expected.

Known as SAFSTOR, for “safe storage,” the cleanup process calls for operators to sit on their trust funds and let them appreciate in value while on-site radioactivity decays on its own.

Radioactivity in some elements can take tens of thousands or even billions of years to decay by half, but decay rates for other elements are measured in seconds or weeks.

In other words, OPPD just has to hurry up and wait, maintaining safety and security of a few key systems at Fort Calhoun still in use in the interim.

“Our No. 1 priority as it stands today is to maintain safe operations of our spent fuel pool,” said Mary Fisher, senior decommissioning director.

A major portion of the project’s early expense is the storage of spent fuel on-site, both in sealed concrete-and-steel casks and in a massive pool that holds 215,000 gallons of specially treated water. That’s equivalent to one-third the volume of an Olympic-size swimming pool.

Today about 950 nuclear fuel rods are cooling off in the 40-foot-deep pool, where they will stay until 2022. Then the last of the rods there will be moved to the dry storage casks.

At that time there will be a total of 1,264 spent fuel rods, each about 13 feet long, in dry storage on-site.

After the spent fuel is out of the pool, the site will go dormant for about 36 years. During that time, federal regulations require a 24-hour security force and the upkeep of security systems, along with adequate lighting, ventilation and radiation monitoring.

Staffing at the plant is expected to fall from about 200 full-time employees to about 75.

There are currently 10 dry storage units on-site at Fort Calhoun, each holding 32 fuel rods. Each unit is 15 feet tall and weighs about 100 tons.

OPPD plans to build 30 more units for the rods remaining in the pool today.

The storage containers are on an elevated pad that was not threatened by the flooding of 2011. And they are built to withstand the impact of a 747 airliner.

“That’s about the worst accident we can conceive. They’re safe where they are, but is this the best way to do it? No,” said Thomas LaGuardia, a decommissioning expert and managing member of Florida-based LaGuardia & Associates LLC. “They should be put in permanent, central isolation.”

Eventually the utility will send those casks to a federal storage site for spent nuclear fuel, which is the most dangerous radioactive waste byproduct from a nuclear power plant.

Plans for a permanent nuclear waste repository at Yucca Mountain in Nevada have been stalled for years after political wrangling during the Obama administration eliminated funding for the project. That leaves highly radioactive nuclear waste piling up at nuclear plants until permanent storage is available; there are also efforts in the works to establish interim storage sites for off-site spent fuel storage in Texas and New Mexico until that happens.

Back at Fort Calhoun, smaller-scale work already is happening, including removing asbestos from various portions of the site and engineering modifications to help the decommissioning effort run more smoothly.

For example, OPPD is combining three spent-fuel cooling systems, now in separate buildings, into a single building covering an area the size of about half a football field.

All of that, of course, requires approval from the Nuclear Regulatory Commission, Fisher said.

“We can’t just go in and change things,” she said. “We have to do all the paperwork upfront and then we can release some of the systems.”

The long timetable for the decommissioning plan involves some financial risks, such as changes in inflation and interest rates.

“We’re doing OK now, but if the economy turns around and the stock market doesn’t perform as well as it has, then monies will be lost in the market and the value of trust funds will be decreased,” LaGuardia said.

If that scenario were to play out it wouldn’t be the first time volatility in the markets affected a decommissioning project.

Decommissioning stalled at Exelon’s Zion Nuclear Power Station at Lake Michigan in 2008 when financial markets slid and took about 10 percent of the plant’s $900 million balance with it. The Chicago-based nuclear operator contracted decommissioning of the Zion facility to EnergySolutions, a Utah-based company that is also contracted to help move the effort along at Fort Calhoun.

“OPPD can obviously go back to (ratepayers) and get more money if they need it,” LaGuardia said. “Nobody likes that, but that’s maybe what would have to happen.”

cole.epley@owh.com, 402-444-1534

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