No appropriation shall be made to carry out the provisions and purposes of this chapter unless previously authorized by legislation enacted by Congress.

There are authorized to be appropriated the sum of $518,000 at Oak Ridge, the sum of $2,215,000 at Richland and the sum of $8,719,000 at Los Alamos for construction, modification, or expansion of municipal installations and utilities authorized to be transferred pursuant to subchapters VI and VII of this chapter.