Segregation distance table.

(a) Table IV applies to the stowage of packages of Class 7 (radioactive) materials on board a vessel with regard to transport index numbers which are shown on the labels of individual packages.

(b) RADIOACTIVE YELLOW-II or YELLOW-III labeled packages may not be stowed any closer to living accommodations, regularly occupied working spaces, spaces that may be continually occupied by any person (except those spaces exclusively reserved for couriers specifically authorized to accompany such packages), or undeveloped film than the distances specified in TABLE IV.

(c) Where only one consignment of a Class 7 (radioactive) material is to be loaded on board a vessel under exclusive use conditions, the appropriate segregation distance may be established by demonstrating that the direct measurement of the radiation level at regularly occupied working spaces and living quarters is less than 7.5 microsieverts per hour (0.75 mrem per hour).

(d) More than one consignment may be loaded on board a vessel with the appropriate segregation distance established by demonstrating that direct measurement of the radiation level at regularly occupied working spaces and living quarters is less than 7.5 microSieverts per hour (0.75 mrem per hour), provided that:

(1) The vessel has been chartered for the exclusive use of a competent person specialized in the carriage of Class 7 (radioactive) material; and

(2) Stowage arrangements have been predetermined for the entire voyage, including any Class 7 (radioactive) material to be loaded at ports of call enroute.

(e) The radiation level must be measured by a responsible person skilled in the use of monitoring instruments.

(f) Table IV is as follows:

Table IV Sum of transport indexes of the packages Minimum distance in feet from living accommodation or regularly occupied working space Minimum distance in feet from undeveloped film and plates 1 day voyage 2 day voyage 4 day voyage 10 day voyage 20 day voyage 30 day voyage 40 day voyage 50 day voyage Cargo thickness in feet (unit density) Nil 3 Nil 3 6 Nil 3 6 Nil 3 6 Nil 3 6 Nil 3 6 Nil 3 6 Nil 3 6 Nil 3 6 0.1 to 0.5 5 X 6 X X 8 X X 11 X X 17 4 X 25 6 X 30 7 X 35 8 X 39 9 X 0.6 to 1 6 X 8 X X 11 X X 16 4 X 25 6 X 35 8 X 42 10 X 50 12 X 55 13 X 1.1 to 2 9 X 11 X X 16 4 X 22 5 X 35 8 X 50 12 X 61 14 X 70 17 X 78 19 X 2.1 to 3 10 X 14 X X 19 5 X 27 6 X 42 10 X 61 14 X 74 18 X 86 20 X 96 23 X 3.1 to 5 13 X 17 4 X 25 6 X 35 8 X 55 13 X 78 19 X 96 23 X 110 26 X 124 29 7 5.1 to 10 19 4 25 6 X 35 8 X 50 12 X 78 19 X 110 26 X 135 33 8 155 37 9 175 42 10 10.1 to 20 26 6 35 8 X 50 12 X 69 17 X 110 26 X 155 37 9 190 46 11 220 53 13 250 59 14 20.1 to 30 32 8 43 10 X 61 14 X 85 20 X 135 32 8 190 45 11 235 56 13 270 65 16 305 72 17 30.1 to 50 42 10 55 13 X 78 19 X 110 26 X 175 42 10 245 58 14 300 73 17 350 84 20 390 94 22 50.1 to 100 59 14 78 19 X 110 26 X 155 37 9 245 59 14 350 82 20 430 105 24 515 118 28 550 130 32 100.1 to 150 72 17 96 23 X 135 32 8 190 46 11 300 72 17 425 100 24 525 125 30 600 145 35 (7 ) 165 39 150.1 to 200 84 20 110 26 X 155 37 9 200 53 13 350 84 20 490 115 28 600 140 35 (7 ) 165 40 (7 ) 190 45 200.1 to 300 105 24 135 32 X 190 46 11 270 64 15 425 105 25 600 145 35 (7 ) 180 42 (7 ) 205 49 (7 ) 230 55 300.1 to 400 120 28 160 37 9 220 53 13 310 75 18 500 120 28 (7 ) 165 40 (7 ) 205 49 (7 ) 235 57 (7 ) 265 63 Note: (1) X—indicates that thickness of screening cargo is sufficient without any additional segregation distance. (2) By using 6 feet of intervening unit density cargo for persons and 10 feet for film and plates, no distance shielding is necessary for any length of voyage specified. (3) Using 1 steel bulkhead or steel deck—multiply segregation distance by 0.8. Using 2 steel bulkheads or steel decks—multiply segregation distance by 0.64. (4) “Cargo of Unit Density” means cargo stowed at a density of 1 ton (long) per 36 cubic feet; where the density is less than this the depth of cargo specified must be increased in proportion. (5) “Minimum distance” means the least in any direction whether vertical or horizontal from the outer surface of the nearest package. (6) The total consignment on board at any time must not exceed transport indexes totalling 200 except if carried under the provisions of § 176.704(f). The figures below the double line of the table should be used in such a contingency. (7) Not to be carried unless screening by other cargo and bulkheads can be arranged in accordance with the other columns.

[Amdt. 176-15, 48 FR 10245, Mar. 10, 1983, as amended by Amdt. 176-37, 60 FR 50334, Sept. 28, 1995]