$178.121 Specification 21PF fire and shock resistant, phenolic-foam insulated, metal overpack.

[Amdt. 178-35, 39 FR 45250, Dec. 31, 1974]

§ 178.121-1 General requirements.

(a) Each overpack must meet all of the applicable requirements of §§ 173.24, 173.411, and 173.412 of this subchapter.

(1) Specification 21PF-1 overpacks includes the series of 21PF-1, 21PF1A, and 21PF-1B models. Details of the three models are included in CAPE-1662, Revision 1 and Supplement 1.

(2) Drawings in CAPE-1662, Revision 1 and Supplement 1, which include bills of materials, and K/SS-471, are a part of this specification.

(b) Each overpack is authorized for use in applications where the maximum gross weight of the package, including the inner container and contents does not exceed 3725 kilograms (8200 pounds), (horizontally-loaded specification 21 PF-1 unit), or 3900 kilograms (8600 pounds), (end-loaded specification 21 PF-2 unit).

(c) The general configuration of the overpack must be a right cylinder, consisting of a steel inner liner (at least 16-gauge) and steel outer shell (at least 14-gauge) with the intervening cavity filled with a molded-in-place, fire-resistant, phenolic foam insulation and interspersed wooden members for bracing and support. Two specific configurations are authorized; a horizontal loading unit (specification 21PF-1) consisting of insulated base and top sections jointed in a longitudinal peripheral closure joint; or an end-loading unit (specification 21PF-2), consisting of an insulated main section, a steel plate liner lid, and an insulated end cap. For either type each joint between sections must be stepped at least 1.8 centimeters (0.75-inch) and gaps between mating surfaces may not exceed 5 millimeters (0.2-inch). Bolted closures, which must each be gasketed against moisture penetration, must be in accordance with CAPE-1662. Each bolt must be equipped with a locking device to prevent loosening from vibration. Outer steel bracing and support

framework must be attached to the shell to facilitate normal handling.

(d) Specification 21PF-1 overpacks in use or under construction before April 1, 1989, must be modified to Specification 21PF-1A before April 1, 1991. All new construction to Specification 21PF-1 beginning after March 31, 1989, must meet Specification 21PF-1B. Use of unmodified 21PF-1 overpacks after March 31, 1991, is prohibited.

[Amdt. 178-35, 39 FR 45250, Dec. 31, 1974; 40 FR 2435, Jan. 13, 1975, as amended by Amdt. 178-90, 53 FR 36551, Sept. 20, 1988]

§ 178.121-2 Materials of construction and other requirements.

(a) Phenolic foam insulation must be fire resistant and fabricated in accordance with USDOE Material and Equipment Specification SP-9, Rev. 1 and Supplement, which is a part of this specification. (Note: Packagings manufactured under USAEC Specification SP-9, and Rev. 1 thereto are authorized for continued manufacture and use.) A 5.5-inch (14 centimeter) minimum thickness of foam must be provided over the entire liner except where:

(1) Wood spacers replace the foam material; or

(2) At protrusions of liner or shell, such as flanges, baffles, etc., where the minimum thickness of foam, wood, or a combination of these is 10 centimeters (4 inches).

(3) Solid wood or laminated wood solidly glued may be used to replace the foam between liner and shell (i.e., in ends of overpack). In this case, minimum wood thickness is 10 centimeters (4 inches). Average density of insulation must be 0.1g/cc (6.75 pounds per cubic foot (pcf)) minimum, except that 0.13 g/cc (8 pcf) is required in the removable end cap of the specification 21PF-2, which must have a minimum foam thickness of 12.7 centimeters (5 inches).

(b) Gaskets for inner liner, outer shell, or where otherwise specified in CAPE-1662, Revision 1, must be as specified in CAPE-1662, Revision 1.

(c) Support and pressure pads for the inner liner must be of neoprene, sponge rubber, or equivalent.

(d) Fire-retardant (intumescent) paint must be applied to any wood blocking which is located at any joint in the shell.

(e) Vent holes 5 millimeters (0.2inch) diameter must be drilled in the outer shell to provide pressure relief during the insulation foaming and in the event of a fire. These holes, which must be drilled in all areas of the shell which made with the foam insulation, must be spaced in accordance with CAPE-1662.

(f) Welding must be by a fusion process in accordance with the American Welding Society Code. Body seams and joints for the liner and shell must be continuous welds.

(g) Waterproofing. Each screw hole in the outer shell must be sealed with appropriate resin-type sealing material, or equivalent, during installation of the screw. All exposed foam surfaces, including any vent hole, must be sealed with either:

(1) Waterproofing material as prescribed in USDOE Material and Equipment Specification SP-9, Rev. 1 and Supplement, or

(2) As specified in CAPE-1662, Revision 1.

[Amdt. 178-35, 39 FR 45250, Dec. 31, 1974, as amended by Amdt. 178-56, 44 FR 49459, Aug. 23, 1979; Amdt. 178-90, 53 FR 36551, Sept. 20, 1988]

§ 178.121-3 Modification of Specification 21PF-1 overpacks.

(a) Each Specification 21PF-1 overpack for which construction began or was completed before to April 1, 1989, in conformance with drawing E-S31536-J, Revision 11, of CAPE-1662 must be modified in conformance with drawing S1E-31536-J1-D of CAPE1662, Revision 1, Supplement 1, before April 1, 1991.

(b) Each such existing Specification 21PF-1 overpack must be dried and weighed in accordance with the following procedures:

(1) Drill out or otherwise clean the plug material from the vent holes originally provided for foam expansion. See drawing S1E-31536-J1-D of CAPE-1662, Revision 1, Supplement 1, for locations.

(2) Weigh each packaging element (top and bottom halves) separately to

an accuracy of +/-5 pounds (+/-2.3 kilograms) and record the weights. If this measured weight is greater than 25 pounds (11.3 Kg) more than the initially measured weight at the time of fabrication (indicating a significant retained water content), the packaging element must be dried.

(3) Place overpack element in drying oven; maintain temperature between 190° and 210°F (87.8–98.9 °C) for a minimum of 72 hours. The oven should have a provision for air exchange or other means of removing moisture driven from the foam structure.

(4) Drying may be discontinued after 72 hours if the weight of the packaging element is not higher than 25 pounds (11.3 Kg) more than the initially measured tare weight of that element at the time of fabrication. If the weight of the packaging element is greater than 25 pounds (11.3 Kg) more than the initial fabricated weight (indicating a significant remaining water content), drying must be continued until the weight differential is not higher than 25 pounds (11.3 Kg), or until the rate of weight loss is less than 2.5 pounds (1.1 Kg) per day.

(5) As an alternate moisture measurement, a calibrated moisture meter reading for 20 percent maximum water content may be used to indicate an end point in the drying cycle (see details in report "Renovation of DOT Specification 21PF-1 Protective Shipping Packages," Report No. K-2057, Revision 1, November 21, 1986, available from the USDOE and part of USDOE Report No. K/SS-471).

(6) Following drying, each overpack element (top and bottom halves) must be weighed and the weight in both pounds and kilograms must be engraved on the identification plate required by § 178.121-5(c).

(c) After modification as provided for herein, each Specification 21PF-1 overpack must be marked "USA-DOT21PF-1A". See the marking requirements of § 178.121-5(b).

[Amdt. 178-90, 53 FR 36551, Sept. 20, 1988] § 178.121-4 Construction of Specification 21PF-1B overpacks.

(a) Each Specification 21PF-1 overpack for which construction began