Valve Adjustment Ups Nuclear Power Wppss Plant Produces $5 Million More In Electricity So Far

Gerald Droppo fixed the equivalent of a noisy faucet at the state’s only commercial nuclear power plant, a solution that cost about $10,000 and so far has produced $5 million more in electricity.

Washington Public Power Supply System’s Plant No. 2 turbine wasn’t working as efficiently as Droppo, a technical specialist, and Jim Zipperer, an engineer, believed it could.

Valves that allowed 544-degree steam into the turbine chamber were stealing energy.

Steam flowing through straight pipes and open valves loses little energy from turbulence.

But when steam must squeeze through a partially open valve, “you get a large restriction and a lot of turbulence. The steam presses in on itself. There’s a lot of energy lost because of that throttling,” Droppo said.

Such was the case at No. 2.

During normal operation, four valves allowed steam at 965 pounds of pressure per square inch onto turbine blades. Two of the valves were wide open, while the other two were slightly open.

Valves create a great amount of throttling when they are between 20 percent and 35 percent open, said Droppo.

“It’s like your faucet at home. When you turn it on just a little, there’s not much of a problem. But open it a little more, and that’s when you get all the noise,” Droppo said.

That noise means turbulence, and a loss of energy.

The solution Droppo came up with simply had one of the partially open valves set at about 14 percent and the other at about 50 percent - avoiding the region of highest turbulence.

“I’d like to say there was a point where we said, ‘Eureka,’ but there wasn’t. We had talked about it for years before, what we could do to decrease the loss and we came up with this,” he said.

Droppo’s idea boosted the plant’s output by about one-half of 1 percent, enough to supply the needs of about 3,500 Pacific Northwest homes.

“Gerry has been one of our more highly awarded employees,” said WPPSS spokeswoman Lisa Woehle.

Some of those awards have been cash prizes.

But for the valve solution, which will result in $29 million in extra electricity over the life of Plant No. 2?

“For this particular award, he got a certificate,” Woehle said.