NEW-YORK (Bllomberg) — The Trump administration opened an investigation into whether uranium imports threaten national security, a move that may lead to tariffs on the nuclear power plant fuel. U.S. uranium miners rallied on the news while utilities that operate reactors slipped.

The Commerce Department said Wednesday it will probe “whether the present quantity and circumstances of uranium ore and product imports into the U.S. threaten to impair the national security.” The probe will cover the entire uranium sector, from the mining industry to enrichment, defence and industrial consumption, the department said.

Overall, in 2017 America purchased $2.1 bln worth of enriched and natural uranium exported by about a dozen trade partners around the globe. That dollar amount reflects a -39.6% reduction from the $2.9 bln that the US spent on imported uranium 5 years earlier in 2013.

As it was reported, the uranium producers in the US asked the authorities to protect them from competition from Kazakhstan and a number of other countries.

Below are the 8 countries from which the United States purchases the highest dollar value worth of natural uranium including its compounds. These suppliers accounted for all US imports of natural uranium during 2017:

1. Canada: $585.4 mln (90.6% of US natural uranium imports)
2. Kazakhstan: $46.2 mln (7.2%)
3. South Africa: $14.5 mln (2.3%)
4. Sweden: $74,000 (0.01%)
5. Switzerland: $34,000 (0.01%)
6. United Kingdom: $14,000 (0.002%)
7. France: $13,000 (0.002%)
8. Japan: $4,000 (0.001%)

Fastest-growing among exporters of natural uranium to America from 2013 to 2017 were Sweden (up from nil in 2013) then Kazakhstan (up 460.3%), the United Kingdom (up 250%) then Canada (up 40%). Leading the declining suppliers of natural uranium to the US were Japan (down -99.8%), South Africa (down -63.1%) and Switzerland (down -33.3%).

Below are the 9 countries from which the United States purchases the highest dollar value worth of enriched U-235 uranium. These suppliers accounted for all US imports of enriched uranium during 2017:

1. Russia: $639.9 mln (45.5% of US enriched uranium imports)
2. United Kingdom: $224.8 mln (16%)
3. Germany: $218.5 mln (15.5%)
4. Netherlands: $194.1 mln (13.8%)
5. France: $80.3 mln (5.7%)
6. Sweden: $18 mln (1.3%)
7. China: $13.6 mln (1%)
8. Spain: $12 mln (0.9%)
9. Kazakhstan: $4.2 mln (0.3%)

Fastest-growing among America’s enriched uranium suppliers from 2013 to 2017 were Spain and Sweden (both up from nil in 2013) then France (up 19%). Leading the decliners was Kazakhstan (down -93%) followed by China (down -90.2%), the United Kingdom (down -70.3%) and the Netherlands (down -62.7%).