Complex sentence: Two uranium mines in northern Portugal, Quinta do Bispo and Cunha Baixa, have been inactive since 1991 to pump acidic water out of the mines for neutralization and precipitation of radionuclides using calcium hydroxide.
Split into simpler sentences: Two uranium mines in northern Portugal, Quinta do Bispo and Cunha Baixa, have been inactive since 1991. Acidic water is pumped out of the mines for neutralization and precipitation of radionuclides using calcium hydroxide.