Section, Pub. L. 85–846, § 4, Aug. 28, 1958, 72 Stat. 1084; Pub. L. 87–206, § 18, Sept. 6, 1961, 75 Stat. 479, related to guarantee contracts between the Atomic Energy Commission and operators of reactors under the cooperation program which were to extend no later than Dec. 31, 1975.