Shares of NuScale Power (SMR -1.06%), a developmental-stage maker of small modular reactors, initially popped this morning on an announcement from the White House on expanding nuclear energy production.While the stock jumped as much as 13% in morning trading, it gave back those gains amid a broader pullback in small-cap stocks in a sign that the boom from Trump's election was fading.As a result, the stock closed down 1.1% while the Russell 2000 fell 1.8%, with the small-cap index giving back all of yesterda ...