PITTSBURGH (KDKA) -- What may be the most dangerous nuclear waste dump in the nation sits just 40 miles north of Pittsburgh, in Armstrong County.
As the government plans to excavate that waste, people who live nearby are nervous.
"Grew up across the street," said Patty Ameno. "We used to go over to the yard in the office building, go play whiffle ball."
Ameno grew up in Apollo, Pennsylvania, a stone's throw from the NUMEC nuclear materials plant and the waste it stored in 55 gallons drums.
They left her with this:
"Two brain tumors," she said. "I still have one, uterine cancer."
Today, Ameno is a survivor and an activist -- who like the residents who recently voiced their concerns at a meeting -- continue to ask questions about the nuclear waste NUMEC and its successor buried down the road in shallow trenches at a 144-acre site in Parks Township.
"What's in there?" asked one resident. "Do you guys really know what's in there?"
As the U.S. Army Corps of Engineers plans to spend more than $400 million to clean up the site, those most familiar with the production and disposal of the waste says the government has grossly underestimated both the amount and dangerous nature of the material.
KDKA'S ANDY SHEEHAN: "When the Army Corps. or their contractor gets in there, they're going to discover more nuclear material than they bargained for."
TOM HALEY: "Yes, absolutely. They already got more than they bargained for."
An initial attempt to excavate the site failed two years when the contractor encountered unexpected nuclear material it could not handle, and much more of it than they anticipated.
Haley is a nuclear engineer who worked for NUMEC, which produced nuclear fuel for power plants and atomic submarines and disposed of the waste at Parks Township.
"No one knows everything that's there," Haley said.
But Haley says government estimates have already proved to be less than 5 percent of what may be there. There are 10 known trenches of nuclear waste and the government excavated just half of one of them.
But Haley says the amount of volatile Uranium-235 unearthed, was more than what the government had estimated for the entire site.
"Oh yes, it's grossly underestimated," he said. "Seriously."
SHEEHAN: "Is that true?"
MIKE HELBLING: "I don't know if it's true or not, sir. We have the estimates that we produced based on the records that we have."
The Army Corps. project manager Mike Helbling told us the government estimates are based on the records kept by the NUMEC and others.
SHEEHAN: "But you have bad records or incomplete records?"
HELBING: "There probably aren't any complete records."
A recent investigation by the Nuclear Regulatory Commission confirms that NUMEC and its successors accepted un-inventoried waste from other parts of the country, and says NUMEC developed complex fuels for secret defense contracts known as "black projects."
"Well, here's a good example right here: Project Pluto," said Ameno.
Project Pluto was a missile that would carry nuclear warheads and circle the earth continually. Ameno -- who's collected tens of thousands of documents on the site -- says more than 700 barrels of special fuel was developed for Project Pluto, some was recycled and the rest was buried at Parks Township after the project was scrapped.
SHEEHAN: "What are black projects?"
HELBING: "Things that are classified."
But even though the government is flying blind to some degree, it says it will be prepared when it resumes excavation.
"The records that we have are the best that we can attain, and we're going to go into this expecting a full range of materials, and we'll be prepared to deal with anything that's there," said Helbing.
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