With a rumble, the tower leaned to the side and collapsed upon itself — leaving a cloud of dust and multi-ton pile of rubble. It took less than 10 seconds and roughly 2,800 pounds of explosives to complete.
"It was amazing," said Wanda Obermeier, who was among the onlookers who gathered on both sides of the Columbia River to watch the implosion.
Portland General Electric, the utility that built and owns Trojan, ordered the tower destroyed as part of its decommissioning.
"It was sort of bittersweet," said Steve Nichols, PGE's general manager at Trojan. "The bitter part we sort of addressed when it closed down. The sweet part will be when we finish a job well done."
Trojan closed in 1993 for financial and safety reasons, and the facility has been decommissioned in stages since then. Set on the banks of the Columbia about 40 miles north of Portland, It was Oregon's first and only nuclear power plant.
The tower was the largest in the nation to be destroyed, according to Controlled Demolition Inc., the Maryland contractor that handled the implosion.
Carefully placed charges were detonated just after 7 a.m., reducing the concrete and steel tower to dust and chunks of debris no bigger than a basketball, said Mark Loizeaux, company president.
"It looks this morning like things went perfectly," said Loizeaux, whose daughter was part of the demolition team and observed the implosion from less than 600 feet away in a protective shelter.
"There was no more vibration than a passing truck," he said, noting there was barely any disturbance outside the wide safety zone established around the tower.
Obermeier, who saw the implosion from the Oregon side of the river, said it was strange to see it gone. "You always look for it, as a landmark," she said.
Her friend, Shawna Judkins, who was visiting from Tennessee, said the implosion added to the Northwest image of explosions, referring to the May 1980 eruption of Mount St. Helens.
"Now I want to see one of the mountains blow," Judkins said.
PGE estimates the plant will not be fully decommissioned until 2024. Remaining buildings will be destroyed gradually through 2008. The spent radioactive fuel rods, which sit above ground, must be moved to a federal repository that hasn't been developed yet.