nuclear-news

Humboldt nuclear reactor is dead and gone, but its highly radioactive wastes live on.

Is this the final chapter? The NRC will soon revoke the operating license for PG&E Unit #3, formally ending its official existence. But the waste is still on-site. The NRC considers cask storage a temporary solution and suggests a 40-year life span. Some hope the casks can last up to 100 years but even this is far shorter than the time needed to safely store high-level waste.

Lori Dengler | Decommissioning a nuclear power plant is a long slow process,  https://www.times-standard.com/2021/11/20/lori-dengler-decommissioning-a-nuclear-power-plant-is-a-long-slow-process/By LORI DENGLER |November 20, Nothing happens quickly with a nuclear plant. Power is generated through fission, a process of splitting atoms in a controlled way. Once fission begins, it can be slowed or increased, but there’s no on-off switch and a controlled shutdown takes 6-12 hours. The radioactive byproducts last for millennia.

The fuel at PG&E’s former nuclear facility at King Salmon was small ceramic uranium oxide pellets compressed into fuel rods. A single new rod is only mildly radioactive, but when groups of rods (assemblies) are brought closely together in a reactor core, fission commences. PG&E’s Unit #3 was a boiling water reactor (BWR), where water pumped into the core was brought to a boil and steam produced electricity.

All first-generation nuclear reactors were BWRs. Built in the late 1950s to mid-1960s, seven became operational in the US and none are operating today. In the late 1960s, the second generation BWRs came online with improved efficiency, lifespan, containment, and safety features. The Fukushima-Daichi Nuclear Power Plant that failed during the 2011 Japan tsunami was this type. Of the 93 operating reactors in the US today, 31 are BWRs.

During its 13-year operational history, the Humboldt nuclear facility generated most of the county’s electricity. It was shut down yearly for refueling and maintenance and the spent fuel rods were placed in a cooling pool on the site. The pool was within the containment structure and made of steel-lined reinforced concrete several feet thick.

Spent fuel and reactor waste has been and continues to be the Achilles heel of the nuclear industry. In the early decades of the nuclear era, it was often glossed over as something that science and technology could solve. The Nuclear Regulatory Commission (NRC) classifies nuclear waste as high level or low level depending upon how long-lived the radioactive material is.

Low-level waste is produced by medical facilities, research labs, commercial facilities and in reactor operations. Often short-lived, it has radioactivity levels only slightly above background and can be safely handled with simple precautions. Small amounts can be disposed as ordinary trash and larger amounts moved on highways to approved low-level waste repositories.

It’s the high-level waste that is the big problem. High-level waste is predominately spent nuclear fuel rods. “Spent” is a misnomer as it still contains a substantial amount of energy. Unlike the new, unused fuel rods, they are now highly radioactive and very hot. That’s because once fission starts, can’t be totally stopped. Not all the uranium has been used up; it’s just no longer concentrated enough to be economically worthwhile. Fission is a complex process and creates toxic daughters such as cesium-137 and strontium-90. Fission releases neutrons which may be captured by other uranium atoms to form heavier elements such as plutonium. They aren’t as hot as the daughters but take much longer to decay. Plutonium-239 has a half-life (the time for half to be used up) of 24,100 years.

I admit to much ignorance when it comes to nuclear reactors. In talking about the Humboldt plant, I used to remark how silly it seemed that new fuel rods could be transported on highways and used ones could not. Now I understand why. There is no fission going on in the new ones and emissions are very low.

PG&E announced intentions to decommission Unit #3 in 1983. Three years later, the company requested a SAFTOR license amendment from the NRC. SAFSTOR means “possess-but-not-operate” so that the plant is maintained and monitored and much of the waste can decay before dismantling begins. In 2003, PG&E submitted an application to the NRC to begin transferring the spent fuel rods into dry cask storage.

The Humboldt plant produced 390 spent fuel assemblies in its lifetime. After several years in a storage pool, the NRC considers the waste cool enough to be moved into a dry cask storage facility on site. High-level waste repositories are known as ISFSIs (independent spent fuel storage installation). Finding an ISFSI spot on Buhne Point was problematic in many ways.

The biggest problem was that the ISFSI had to be on the PG&E site. Buhne Point site is exposed to earthquake and tsunami threats, erosion, and sea-level rise. Many people were involved with environmental and hazards studies over the years including a number of HSU geology grads. A site was selected at an elevation of 44 feet just to the west of Unit #3 with the capacity to store 37 tons of high-level waste in six casks.

I attended a community meeting about the ISFSI plan in the early 2000s. It was well attended with scientists, environmental organizations, and other community representatives. What surprised me most was that everyone agreed it was the best solution to a problem all of us wish we never had. Oh, if only time travel were possible – PG&E would be the first in line to reverse the decision to build the Humboldt nuclear facility. But given the legal realities, this was the best option.

NRC issued the Humboldt SAFSTOR license to PG&E in November 2005. By 2008, all of the spent fuel had been moved to the dry casks. The active decommissioning of the site began in 2009 and included removal of the reactor vessel, nuclear systems, containment structure, and other infrastructure. Even the soils at the site were removed. The final step was site restoration and soil remediation. It’s unclear what the footprint of the former nuclear facility may eventually become; at present, it is a parking lot.

Is this the final chapter? The NRC will soon revoke the operating license for PG&E Unit #3, formally ending its official existence. But the waste is still on-site. The NRC considers cask storage a temporary solution and suggests a 40-year life span. Some hope the casks can last up to 100 years but even this is far shorter than the time needed to safely store high-level waste.

Note: The Humboldt ISFSI is covered at http://archive.wmsym.org/2010/pdfs/10217.pdf. If anyone wants to get into the weeds with nuclear reactor technology, see https://www.amacad.org/sites/default/files/academy/pdfs/nuclearReactors.pdf.

Lori Dengler is an emeritus professor of geology at Humboldt State University, an expert in tsunami and earthquake hazards. Questions or comments about this column, or want a free copy of the preparedness magazine “Living on Shaky Ground”? Leave a message at 707-826-6019 or email Kamome@humboldt.edu.   https://www.times-standard.com/2021/11/20/lori-dengler-decommissioning-a-nuclear-power-plant-is-a-long-slow-process/

November 22, 2021 Posted by Christina Macpherson | Reference, USA, wastes | Leave a comment

”Cocooning” Hanford nuclear reactors conveniently leaves the $600 billion clean-up to future generations

Future generations will decide the final disposition of the eight Hanford reactors.

The bigger question is whether future generations will be willing to pay the massive costs of Hanford cleanup, he said.

Carpenter said the estimated cost to completely clean up just the tank wastes at the Hanford site is around $660 billion.

“It’s rather grim. It’s multigenerational,” he said.

“This will cost more than anyone thought possible,” Carpenter said of the tank wastes and other wastes that were dumped into the ground at Hanford. “It’s a hidden cost of the (nuclear) buildup.

US government works to ‘cocoon’ old nuclear reactors  https://abcnews.go.com/Technology/wireStory/us-government-works-cocoon-nuclear-reactors-80964651

Costs to clean up a massive nuclear weapons complex in Washington state are usually expressed in the hundreds of billions of dollars and involve decades of work, By NICHOLAS K. GERANIOS Associated Press5 November 2021   SPOKANE, Wash. — Costs to clean up a massive nuclear weapons complex in Washington state are usually expressed in the hundreds of billions of dollars and involve decades of work.

 usually expressed in the hundreds of billions of dollars and involve decades of work.

But one project on the Hanford Nuclear Reservation is progressing at a much lower price.

The federal government is moving forward with the “cocooning” of eight plutonium production reactors at Hanford that will place them in a state of long-term storage to allow radiation inside to dissipate over a period of decades, until they can be dismantled and buried.

“It’s relatively non-expensive,” Mark French, a manager for the U.S. Department of Energy, said of cocooning. “The cost of trying to dismantle the reactor and demolish the reactor core would be extremely expensive and put workers at risk.”

The federal government built nine nuclear reactors at Hanford to make plutonium for atomic bombs during World War II and the Cold War. The site along the Columbia River contains America’s largest quantity of radioactive waste.

The reactors are now shut down and sit like cement fortresses near the southeastern Washington city of Richland. Six have already been cocooned for long-term storage, and two more are headed in that direction. The ninth reactor was turned into a museum as part of the Manhattan Project National Historical Park.

While World War II ended in 1945 and the Cold War ended in 1989, the United States is still paying billions of dollars per year for the disposal of the nuclear waste produced by the atomic weapons that played a big role in ending those conflicts. The biggest expense is dealing with a massive volume of liquid wastes left over from the production of plutonium, a key ingredient in nuclear weapons.

While the liquid wastes stored in 177 underground tanks will take decades of work and hundreds of billions of dollars to clean, efforts to secure the nine plutonium reactors are much closer to completion.

The last two reactors, shut down in 1970 and 1971, are about to enter the cocooning stage, when they are covered with steel and cement to prevent radioactivity from escaping into the environment, French said.

The cocoons are expected to last about 75 years, by which time the radioactivity inside will have dramatically decreased and there presumably will be a plan for final disposition of the remaining parts, French said.

Every five years, workers enter the reactor building to make sure there are no leaks or rodent or bird infestations, he said.

Cleanup of Hanford, which has about 11,000 employees and is half the size of Rhode Island, started in the late 1980s, and now costs about $2.5 billion per year. The work has been slowed by technical issues, lack of funding, lawsuits from state regulators, worker exposure to radiation and turnover of contractors on the complex job.

But the handling of the old reactors is a bright spot.

The nine reactors — called B Reactor, C Reactor, D Reactor, DR Reactor, F Reactor, H Reactor, K-East Reactor, K-West Reactor, and N Reactor — were built from 1943 through 1965.

They were constructed next to the Columbia River because of the abundance of hydropower and cooling water needed by the reactors during operation.

All have been cocooned except K-East and K-West. Work on cocooning the K-East reactor has already started and should be finished by 2023, French said. Work on the K-West reactor is scheduled for completion in 2026.

The cocoon plan for K-East and K-West is to basically construct steel buildings around them. Each building is 158 feet (48.2 meters) long, 151 feet (46 meters) wide and 123 feet (37.5 meters) tall, French said. The two steel buildings will cost less than $10 million each.

The government also operated five plutonium production reactors at the Savannah River Site in South Carolina during the Cold War. All of those are also shut down, although three of the reactor buildings are being used to store radioactive materials Two of the reactors at Savannah River are closed but under a different procedure than the Hanford reactors, said Amy Boyette, a spokeswoman for Savannah River.

Future generations will decide the final disposition of the eight Hanford reactors, French said. They will likely be dismantled and buried in the central area of the Hanford site, away from the river.

Robots may be deployed in the future” for that work, French said.

Hanford watchdogs generally agree with this process, said Tom Carpenter, director of the Seattle-based watchdog group Hanford Challenge.

“Nobody is raising any concerns about cocooning,” Carpenter

said. “We’re all worried about the tank waste that needs immediate and urgent attention.”

The bigger question is whether future generations will be willing to pay the massive costs of Hanford cleanup, he said.

Carpenter said the estimated cost to completely clean up just the tank wastes at the Hanford site is around $660 billion.

“It’s rather grim. It’s multigenerational,” he said.

“This will cost more than anyone thought possible,” Carpenter said of the tank wastes and other wastes that were dumped into the ground at Hanford. “It’s a hidden cost of the (nuclear) buildup.

By then, there might be bigger budget concerns such as dealing with the effects of climate change, Carpenter said.

The most intriguing of the old reactors is the B Reactor, the first one built during World War II. It will not be cocooned, and can be visited by tourists at the national historical park. B Reactor, which shut down in 1968, was cleaned up enough to allow some 10,000 tourists to visit each year and learn the history of Hanford. It has been designated a National Historic Landmark.

Plutonium from Hanford’s B Reactor was used in the testing of the world’s first atomic bomb in July 1945. Called the Trinity Test, the bomb was blown up in the New Mexico desert. Hanford plutonium was also used for the bomb that was dropped over Nagasaki, Japan, on Aug. 9, 1945. 

November 6, 2021 Posted by Christina Macpherson | Reference, USA, wastes | Leave a comment