| MATERIAL | 1/2 VALUE LAYER THICKNESS[*] | |||
|---|---|---|---|---|
| STEEL | 1.8 CM | (.7") | ||
| CONCRETE | 5.6 CM | (2.2") | ||
| EARTH | 8.4 CM | (3.3") | ||
| WATER | 12.2 CM | (4.8") | ||
| WOOD | 22.4 CM | (8.8") | ||
[*] 1/2 VALUE LAYER THICKNESS—THICKNESS OF A GIVEN MATERIAL WHICH REDUCES THE DOSE OR DOSE RATE TO APPROXIMATELY ONE-HALF OF THAT FALLING UPON IT. | ||||
Table H-2. Transmission factors for Nuclear Radiation[*]
| INITIAL | |||
|---|---|---|---|
| ENVIRONMENTAL SHIELDING | NEUTRONS | GAMMA | RESIDUAL |
| BUILT-UP CITY AREA (IN OPEN) | 1.0 | 0.5 | 0.7 |
| FOXHOLES | 0.3 | 0.2 | 0.1 |
| FRAME HOUSE: | |||
| FIRST FLOOR | 1.0 | 0.9 | 0.5 |
| BASEMENT | 0.5 | 0.3 | 0.1 |
| MULTISTORY BUILDINGS: | |||
| TOP FLOOR | 1.0 | 0.9 | 0.1 |
| INTERMEDIATE FLOORS | 0.9 | 0.9 | 0.02 |
| LOWER FLOOR | 0.9 | 0.5 | 0.1 |
| BASEMENT | 0.5 | 0.3 | 0.01 |
| SHELTER, CLOSED 91 CM (3 FT) | |||
| (EARTH COVER) | 0.05 | 0.02 | 0.005 |
| ARMORED VEHICLES: | |||
| ARMORED PERSONNEL CARRIER | 0.3 | 0.2 | 0.1 |
| TANKS | 0.3 | 0.2 | 0.1 |
| WOODED FOREST | 1.0 | 1.0 | 0.8 |
| [*] INSIDE DOSE = TRANSMISSION FACTOR TIMES OUTSIDE DOSE. | |||
H-3. Expedient Shelters for Protection Against Radiation
a. In many cases it will be unnecessary to construct field expedient or other types of fallout shelters. There are many structures and terrain features available that afford a degree of fallout protection. Existing fallout shelters are tunnels, caves, culverts, overpasses, ditches, ravines, and man-made structures. The best existing shelters are basements. [Figure H-1] shows typical protection provided in buildings. Windows can be sandbagged or covered with dirt from the outside to provide additional protection.
Figure H-1. Typical shelter protection provided in buildings.
b. Planners should attempt to locate HSS units near existing shelters, whenever possible. However, if an HSS unit is already established, or must be established where fallout shelters are not available, then a shelter must be constructed. Elaborate shelters are not required, since they usually only need to be occupied for a few days. There are a number of field expedients that will serve to save personnel and patients even though they may not be comfortable for those few days.