CHAPTER I}, SECTION 3 a a Figure 2-61. STATION: PURPOSE: SITE: USER: PARTICIPATION: CONSTRUCTION: OCCUPANCY: Station 1220.07 Figure 2-62. 1310 Alpha Recording Station Yvonne LASL 6, 7 and 24 12-2-55/4-28-56 3-4-56 This station was a non-expendable 56’ x 70’ x 16’-high reinforced concrete building, with 5’- 6”-thick walls; it was divided into three scientific equipment rooms and one utility room with connecting corridors for ingress and egress. The entrance corridor had two 90-degree offsets for reducing the possibility of a radiation hazard. An entrance tunnel maze extended from one corner of the building and a separate vestibule provided emergency access in case blast pressures rendered the main entrance unusable. Surrounding the’ tunnel and on three sides of the building was a 24-foot high retaining wall which held back a 12-foot earth cover over the station. The leading edge of the fill was sand- bagged. The exterior walls and slabs of the station were 5’-6” thick with most of the re- inforcing placed in two layers to provide rea- sonable bar spacing for the concrete pour. A large quantity of stirrup reinforcing was used in order to obtain a flexible structure and allow Station 1310-15% Complete inch pipe sleeves. Steel blast doors were installed at the ends of the tunnel maze, the entrance to the forward room, and the emergency access vestibule. Two ventilation pipe doors located in one retaining wall permitted extending 12- inch piping through the fill into the station. A j-ton capacity crane with removable rail was provided over the main entrance corridor door for lifting heavy equipment off trucks. Power was supplied from the island distribution system to two dry-type 150 KVA, 3phase transformers in the utility room, with secondaries at 120/208 volt, 4-wire. One trans- former supplied scientific and the other utility power. The utility system consisted of air conditioning units, de-humidifiers, room heaters, trailer receptacles, and vacuum pumps for Station 1841. The scientific system comprised special instruments, detectors, normal lighting, and a postshot recovery panel. The postshot panel provided for emergency lighting to the corridor, utility room (A), instrument rooms (B and C), and the general purpose room (D). During preshot operations, the emergency panel was supplied by the scientific system, but for post-shot recovery, a User-furnished portable generator was provided. Room B was divided into three parts: an for high shear loads. The interior walls were 3’-6” and/or 4’ thick in order to carry the roof and base slab reactions. Numerous openings in the roof coupled with a relatively thin roof slab required special design considerations with respect to blast loadings. Embedded 24-inch Ibeams spaced between the sleeves and conduits took the shear loads and acted as the tension isolated screened section, large instrument section, and light channel section. The isolated screened section was built of wood with a copper screen between two layers of plywood. All copper-screened connections were lapped and soldered for maximum continuity and insulated from one layer of the plywood by a sheath of polystrene plastic. All electrical circuits leading used as supports for sliding steel-framed lead doors which covered the lower end of the 12- furnished filter panel. The outlet boxes and wire coverings within the room were nonmetalic. The station was used as a distribution point for reinforcing the slab. The lower flanges of the I-beams were set flush with the ceiling and Page 2-80 into the screened room passed through a User-