Section 63.72 - Construction records(a) DOE shall maintain records of construction of the geologic repository operations area at the Yucca Mountain site in a manner that ensures their usability for future generations in accordance with § 63.51(a)(3) .(b) The records required under paragraph (a) of this section must include at least the following- (1) Surveys of the underground facility excavations, shafts, ramps, and boreholes referenced to readily identifiable surface features or monuments;(2) A description of the materials encountered;(3) Geologic maps and geologic cross-sections;(4) Locations and amount of seepage;(5) Details of equipment, methods, progress, and sequence of work;(6) Construction problems;(7) Anomalous conditions encountered;(8) Instrument locations, readings, and analysis;(9) Location and description of structural support systems;(10) Location and description of dewatering systems;(11) Details, methods of emplacement, and location of seals used; and(12) Facility design records (e.g, design specifications and "as built" drawings).