Val John Christensen is out as EnergySolutions Inc.’s president and chief executive officer and David Lockwood is in, the Salt Lake City nuclear-waste company suddenly announced Monday.

The news sent EnergySolution’s shares into a nosedive Monday morning. The company’s shares were trading down $1.89, or 53 percent, at $1.70.

A seasoned operating executive in the technology industry and current member of the company’s executive board, Lockwood was appointed by the board effective immediately.

"The Board determined that the time is right for new leadership, so that the company is positioned to take advantage of its full long-term potential in a changing industry environment," said board chairman Steven R. Rogel.

Christensen, who submitted his resignation on Sunday, will remain a strategic adviser to the company at a consulting fee of $25,000 per month, the company said in papers filed with the U.S. Securities and Exchange Commission.

In addition, Energy Solutions Chief Financial Officer William R. Benz also resigned.

Christensen, and Benz will receive severance payouts — $3 million for Christensen and $1,085,400 for Benz.

In a conference call with investors, Lockwood noted the company’s annual earnings before income taxes and other expenses will not be as high as projected. Instead of the $150 to $160 million forecasted last month, the company expects earnings in the $130 to $140 million range.

"Our board is focused on maximizing shareholder value," said Lockwood, adding that the company is rethinking its growth path and profitability. "We know we have years of work ahead of us."

Lockwood noted the company is not seeing the savings it expected on its ZionSolutions nuclear cleanup project in Illinois and absorbing higher costs than anticipated. In addition, business is down from government contracts and even commercial ones.

Meanwhile, the company trimmed its 5,000-plus worldwide workforce in February, according to company spokesman Mark Walker. Now the company’s Tooele County landfill employees around 200 workers, instead of more than 400 who worked at the site in busy 2006.

Walker said there would be no changes at the mile-square landfill, which has been the company’s most dependable asset for more than two decades.

"Operations will remain the same," Walker said.

Last week, an industry newsletter, RadWaste Monitor, reported that the company was looking to sell off its government services business, the part of the company that had been working on the Atlas uranium tailings cleanup outside of Moab before it lost the $121-million, 5-year contract to continue the job.

Lockwood has served on the board of directors since November 2010. Greg Wood is the new executive vice president and chief financial officer.