# RADIAC Program Operations — Hazardous Materials Safety Interpretation **Citation:** 14-0120 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2014-07-15 14-0120 response to RADIAC Program Operations concerning 172.102. ## Document text <<>> of Transportation U.S. Department Washington, D.C. 20590 1200 New Jersey Avenue, SE Materials Safety Pipeline and Hazardous Administration JUL 1 5 2014 Mr. Melvin J. Simon NAVSEA 04ND3 RADIAC Program Operations Acting Technical Warrant Holder Naval Sea Systems Command 1333 Isaac Hull Avenue, SE Stop 4120 Washington Navy Yard, DC 20376-4120 Ref. No.: 14-0120 Dear Mr. Simon: This is in response to your email dated June 16, 2014, requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) relating to the transportation of neutron radiation detectors containing boron trifluoride. Section 172.102(c)(1) Special Provision 238 paragraph (c) offers relief from the other requirements of the HMR for neutron radiation detectors containing not more than 1 gram of boron trifluoride when packaged as specified and transported by highway, rail, vessel, or as cargo on an aircraft. You describe the construction of a neutron radiation detection system and your proposal to place a sufficient quantity of activated alumina or activated carbon desiccant within a sealed outer moderator that also acts as the outer case of the system. The outer moderator which is made of polyethylene also encases the detector probe containing the boron trifluoride. You ask if this described method of packaging meets the intent of the requirements of paragraph a. (4) of Special Provision 238. As described, the neutron radiation detection system would meet the requirements Special Provision 238 paragraph a.(4) relating to the requirement for a liner surrounding the detector. The sealed polyethylene outer moderator would serve as the required liner. Provided the radiation detector meets all other requirements of paragraph (a) of Special Provision 238 and the system is packaged in a strong outer packaging capable of withstanding a 1.8 meter (6-foot) drop without leakage, or the system itself, without packaging is capable of withstanding a 1.8 meter (6-foot) drop without leakage, the described radiation detection system is eligible for the relief from the HMR provided by paragraph (c) of Special Provision 238. <<>> I trust this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, Shane C. Kelley Acting International Standards Coordinator Standards and Rulemaking Division <<>> Babich 172.102 Special Provisions Dodd, Alice (PHMSA) 14-0120 From: Sent: Lehman, Victoria CTR (PHMSA) Monday, June 16, 2014 3:37 PM To: Hazmat Interps Subject: FW: Letter of Interpretation - Request DOT Concurrence with US Navy Proposed Packaging Method for BF3 Neutron Detector Attachments: AN-PDR-70 Probe Exploded View.pdf Signed By: victoria.lehman@dot.gov Please submit this request for a formal letter of interpretation. Mr. Simon previously discussed this question with Adam Lucas in the HMIC on 6/4/2014. Thanks, Victoria -----Original Message---- From: Simon, Melvin J CIV SEA 04 [mailto:melvin.simon@navy.mill Sent: Monday, June 16, 2014 10:45 AM To: INFOCNTR (PHMSA) Cc: Murray, Jessica M CTR SEA 04; Reale, Steven G CIV SEA 04; Jeff Cherry (jeffcherry@orbisinc.net); Gadbois, Jon CIV SEA 04; Simon, Melvin J CIV SEA 04 Subject: Letter of Interpretation - Request DOT Concurrence with US Navy Proposed Packaging Method for BF3 Neutron Detector 9492 Ser 04ND3/137 16 JUN 2014 From: U.S. Navy, Naval Sea Systems Command, Radiation Detection, Indication and Computation (RADIAC) Program Office Subj: Letter of Interpretation - Request DOT Concurrence with U. S. Navy Proposed Packaging Method for BF3 Neutron Detector Ref: (a) 49 CFR 172.102, Special Provisions Attachment: (1) AN/PDR-70 RADIAC Probe Exploded View 1. Background. Reference (a), Special Provision (SP) 238, was recently updated and provides new guidance for transporting neutron radiation detectors containing Boron Trifluoride (BF3) gas. The U.S. Navy uses a portable neutron radiation detector (AN/PDR-70) that utilizes a proportional counter (Reuter-Stokes/RSN-320-M2) containing less than 1 gram of BF3 gas at less than atmospheric pressure (60 cm/Hg). These detectors are now being transported under the new provisions per SP 238, paragraph c. This topic was discussed with DOT PHMSA's Office of Hazardous Materials Safety, Hazardous Materials Information Center (202-366-4488) who suggested the submission of a written request for interpretation via email or letter per 49 CFR 105.20. 2. Discussion. SP 238, paragraph c., provides conditions and exceptions when 1 <<>> MAINTENANCE AN/PDR-70 EE700-CV-OMI-010/CELR2-PDR70 Figure 5-1 LEGEND FOR FIGURE 5-1. Name Desig• Ref. 2. 1. Handle assembly 1A1 3. Thumbscrew - 4. Nut, self-locking O-ring - - 5. Screw 6. Outer moderator 8. Screw 7. Rubber bumper 1MP7 IMPI 10. Attenuator, sleeve 9. Attenuator, rear IMP4 IMP3 11. Inner moderator 1MP6 13. Proportional counter 12. Attenuator, front IMP2 14. and connector 1V1 15. Cable assembly Plug, moderator 1A2 IMP5 17. 16• Gasket, probe IMP8 18. Washer Cap, probe IMP9 19. Screw - - 19 REF DESIG PREFIX 1 Figure 5-1. Radiac Probe, Exploded View ORIGINAL 5-3 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `1fc3f41161a365ca244bc3fada9384392c115d664093bf5e912f9e8ad7f1f818` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T11:51:43.094Z - Document slug: `phmsa-interpretation-14-0120` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "RADIAC Program Operations" ], "individuals": [ "Mr. Melvin J. 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