Neutron radiation detectors: Neutron radiation detectors containing non-pressurized boron trifluoride gas in excess of 1 gram (0.035 ounces) and radiation detection systems containing such neutron radiation detectors as components may be transported by highway, rail, vessel, or cargo aircraft in accordance with the following: <br>a. Each radiation detector must meet the following conditions: <br>(1) The pressure in each neutron radiation detector must not exceed 105 kPa absolute at 20 °C (68 °F); <br>(2) The amount of gas must not exceed 13 grams (0.45 ounces) per detector; and <br>(3) Each neutron radiation detector must be of welded metal construction with brazed metal to ceramic feed through assemblies. These detectors must have a minimum burst pressure of 1800 kPa as demonstrated by design type qualification testing; and <br>(4) Each detector must be tested to a 1 × 10₋₁₀ cm 3/s leaktightness standard before filling. <br>b. Radiation detectors transported as individual components must be transported as follows: <br>(1) They must be packed in a sealed intermediate plastic liner with sufficient absorbent or adsorbent material to absorb or adsorb the entire gas contents. <br>(2) They must be packed in strong outer packagings and the completed package must be capable of withstanding a 1.8 meter (5.9 feet) drop without leakage of gas contents from detectors. <br>(3) The total amount of gas from all detectors per outer packaging must not exceed 52 grams (1.83 ounces). <br>c. Completed neutron radiation detection systems containing detectors meeting the conditions of paragraph a of this special provision must be transported as follows: <br>(1) The detectors must be contained in a strong sealed outer casing; <br>(2) The casing must contain include sufficient absorbent or adsorbent material to absorb or adsorb the entire gas contents; <br>(3) The completed system must be packed in strong outer packagings capable of withstanding a 1.8 meter (5.9 feet) drop test without leakage unless a system's outer casing affords equivalent protection. <br>d. Except for transportation by aircraft, neutron radiation detectors and radiation detection systems containing such detectors transported in accordance with paragraph a of this special provision are not subject to the labeling and placarding requirements of part 172 of this subchapter. <br>e. When transported by highway, rail, vessel, or as cargo on an aircraft, neutron radiation detectors containing not more than 1 gram of boron trifluoride, including those with solder glass joints are not subject to any other requirements of this subchapter provided they meet the requirements in paragraph a of this special provision and are packed in accordance with paragraph b of this special provision. Radiation detection systems containing such detectors are not subject to any other requirements of this subchapter provided they are packed in accordance with paragraph c of this special provision.