Energy Secretary Steven Chu told Sandia National Laboratories workers this morning that their work will become even more vital to the nation as our nuclear stockpile shrinks.

Chu's talk came five days after President Obama delivered his first major nuclear weapons policy address, promising to work in the long run toward a world without nuclear weapons via a series of near-term steps that included negotiating arms cuts with the Russians and winning ratification of the Comprehensive Test Ban Treaty.

Chu, on the second day of a quick trip that took him to Los Alamos Thursday, said the cuts would increase the importance of the labs' scientific work done to understand and maintain the U.S. nuclear stockpile. As the numbers of weapons come down, and in the absence of testing, good scientific understanding of the weapons to ensure their safety and reliability grows in importance, Chu said.

Chu also laid out a broad research agenda in the areas of energy and climate change that he said demand the sort of large-team science in which the national labs specialize.