As Japanese and other nuclear experts tried to contain the threat of plant meltdowns following Friday’s massive earthquake and tsunami, ETFs with a focus on the nuclear-power field fell sharply on Monday.

The Market Vectors Uranium & Nuclear Energy ETF (NLR) fell nearly 14% on very high volume Monday to trade below $22.

The iShares S&P Global Nuclear Energy ETF (NUCL) dropped 12% and was trading at $39.25 mid-day Monday, and the PowerShares Global Nuclear Energy ETF (PNK) declined about 12.7% to $18.20.

Year to date, the three ETFs tracking the nuclear industry have under-performed the Dow Jones Industrial Average, which is up about 4%. NUCL has risen about 3%, while the PKN is up about 1.5% and NLR 1%.

Over the past six months, however, NLR has outperformed the Dow. It’s risen about 20%, while, NUCL and PKN have moved at about the same pace as the Dow and are up roughly 14%.

Clean Energy ETFs

The iShares S&P Global Clean Energy Index ETF (ICLN) is having another strong day Monday, rising nearly 4.6% to trade above 17.  It jumped sharply last week, but is up only 2% for the year.

The First Trust Global Wind Energy ETF (FAN) is up 2% as of early afternoon trading on Monday, and the Market Vectors Global Alternative Energy ETF (GEX) has risen 3% to trade near $20.60.

PowerShares Global Wind Energy ETF (PWND) is moving at a similar pace, increasing 3% to trade near $20.50.

Earlier this year, investor interest in wind energy in the United States and overseas picked up due to government support of alternative- and renewable-energy programs.