Reid Gardner Implosion Leaves Unit 4 Smokestack Still Standing
By VERNON ROBISON
Moapa Valley Progress
The remnants of more than 50 years of coal-generated power production in Moapa came crashing down in a huge cloud of dust last week. Most of what was left of the Reid Gardner Power Station was imploded on Thursday evening, July 18, just before sunset.
Demolition crews contracted by Reid Gardner owner NV Energy, initiated a final countdown at around 7:30 pm. They then ignited explosive charges meant to bring down the boiler structures of Units 1-3 and all four smoke stacks at the decommissioned plant.
But all did not go entirely according to plan. The smokestack for Unit 4, the largest and tallest of the structures, teetered slightly in the explosion, but remained standing. When the dust had cleared, the approximately 250-foot-tall structure was the only implosion target left standing, though it was leaning slightly northward.
“The demolition contractor is still doing an evaluation to determine the condition of the structure,” said NV Energy spokeswoman Jennifer Schuricht in an interview Friday morning. “They did determine that the explosives all detonated. Now they are doing an assessment on what needs to be done next.”
It is possible that a second explosive charge may have to be detonated on the structure in the next few days to finish bringing the structure down, Schuricht said.
Preparations for the implosion were extensive and took months. Since early in 2018, demolition contractor Remedial Construction Services (RECON) has been systematically dismantling the coal burning plant which was decommissioned in February 2017. They had torn out all the concrete, wiring, steel, fixtures, auxiliary buildings and anything else that was not necessary to give structural support to the huge boilers at the heart of the four units.
Earlier this year, on February 21, RECON crews coordinated an implosion which brought down the Unit 4 boiler structure and a mill bay tower nearby. Then they went to work clearing away the debris from that explosion.
All that was left standing on the site then were the four smoke stacks and the remaining three boilers. Demolition of these three boilers had been delayed last February because asbestos materials had been found in their structures which had to be abated by expert crews before demolition.
Standing just adjacent to the east of the boilers were also a series of coal silos that were to be left standing. It was determined that these structures could be demolished without explosives and would act as a buffer to protect the still-active switchyard about 300 feet to the east, experts said.
Last week’s implosion took several weeks of careful planning. Engineering studies of each structure were completed to develop detailed felling plans. These identified a series of precise cuts to structural supports were be done manually in advance to weaken each structure and prepare for placement of explosives. Strategic spots were identified to place explosive charges that were calculated to bring down the buildings in exactly the right directions.
Explosives were delivered to the site on Monday and kept under strict security. Then the crews set the charges in the structures as planned without connecting to the detonation source.
As the scheduled time for the implosion approached on Thursday, the crews connected the charges and all was ready for detonation.
All the roads into the area of the plant were closed to traffic. A large area within a 1500 foot radius around the plant was cleared of people.
NV Energy employees who had worked at the facility had been notified approximately when the implosion would take place so that they could be present to watch from a safe distance. The word got out to many other Moapa Valley residents who gathered and parked their vehicles along the Hidden Valley Road, and on hilltops in the vicinity, to watch the demolition.
The explosives went off just after 7:30 pm with a loud boom that sent shock waves felt in every direction. Each of the smokestacks emitted a final burst of smoke and then started to fall.
A huge plume of dust and smoke rose from the fallen structures and slowly drifted with the wind toward the northeast of the plant.
When the dust had settled, all appeared to go precisely as planned with the exception of the last Unit 4 smokestack which still remained standing.
