# Nukem Corporation — Hazardous Materials Safety Interpretation **Citation:** 06-0189 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2006-09-29 06-0189 response to Nukem Corporation concerning 173.412. ## Document text <<>> of Transportation U.S. Department 400 Seventh Street, S.W. Washington, D.C. 20590 Pipeline and Administration Hazardous Materials Safety SEP 29 2006 Mr. Stan Hodges Nukem Corporation Senior Project Manager Ref. No. 06-0189 3800 Fernandina Road Suite 200 Columbia, SC 29210 Dear Mr. Hodges: This is in response to your August 15, 2006 letter requesting clarification regarding the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to HEPA vents. Your question pertains to § 173.412(f) which requires the containment (3.6 psi). Specifically, you ask if a passive HEPA vent may be installed in a Type A system to retain its radioactive contents under the reduction of ambient pressure to 25 kPa package to meet the pressure requirement in § 173.412(f) as long as the resultant containment system would not release any radioactivity to the environment. The HMR do not prohibit the use of vents in Type A packagings containing Class 7 (radioactive) materials. However, the packaging must be an authorized packaging for the Class 7 (radioactive) material under the HMR, meet the HMR design specification (if applicable), and comply with the general packaging requirements in Part 173, Subpart B. The Type A packaging, with the vent, must meet the design and construction requirements in § 178.350, which also requires compliance with §§ 173.403, 173.410, 173.412, 173.415, 173.465 and 173.466. I hope this information is helpful. Tille z. Abbake Hattie L. Mitchell, Chief Regulatory Review and Reinvention Office of Hazardous Materials Standards 173.412(f) 060189 <<>> Message Satterthwaite Page 1 of 3 §173.412 Drakeford, Carolyn Packages From: Williams, James Sent: Tuesday, August 15, 2006 3:11 PM 06-0189 To: Drakeford, Carolyn Subject: FW: 49 CFR 173.412 (f) Attachments: 49 CFR 173.412(f).xls Second Interpretation Request Jim Williams From: Stan Hodges [mailto:shodges@nukem.com] -----Original Message----- Sent: Tuesday, August 15, 2006 8:08 AM To: Williams, James Subject: FW: 49 CFR 173.412 (f) Cc: Richard Byars; Nate Patterson Did you ever get a response to the question that I have underlined below? I suppose the question is - "Can Stan Hodges (0) 803-214-5848 Sr Project Manager (F) 803-214-5804 (M) 803-318-7493 From: Stan Hodges To: 'James. Williams@dot.gov' Sent: Tuesday, July 25, 2006 6:21 PM Subject: RE: 49 CFR 173.412 (f) pressures with various elevations and comparing these elevations with both DOT's regulation (49 CFR 173.412(f) After taking another look at it, I believe you are correct. I put together a spreadsheet comparing atmospheric reduction to 25 kPa) has a sounder technical argument. Take a look and see what you think from my argument on and IAEA paragraph 643). My recommendation is to adopt the reduction in atmospheric pressure to 60 kPa (vs. a the attached spreadsheet. Also, as another quick question - Is there anything in the regulations that allows you to utilize passive vents (i.e. 8/17/2006 <<>> Message Page 2 of 3 HEPA vents) in packages (i.e. Type A or IP-2 packages)? I did a quick search and could not find where this topic Stan Hodges (0) 803-214-5848 Sr Project Manager (F) 803-214-5804 (M) 803-318-7493 (Note - New Number) Sent: Tuesday, July 25, 2006 2:24 PM From: James. Williams@dot.gov [mailto:James.Williams@dot.gov] Subject: RE: 49 CFR 173.412 (f) To: Stan Hodges internal pressure of 11.1 psi. I read this as they agree with me - an ambient pressure drop from 14.7 to 3.6, which would result in an Jim Williams Office of Hazardous Materials Technology, Room 8430 Radioactive Materials Branch, PHH-23 Pipeline and Hazardous Materials Safety Administration 400 Seventh Street, S.W. U.S. Department of Transportation James. Williams@dot.gov Washington, D.C. 20590 (202) 366-6177 Website http://hazmat.dot.gov/ Subject: FW: 49 CFR 173.412 (f) Jim: I have highlighted the document in the below e-mail message relative to where I found the notation from e USNRC. I will take a look at the document link that you sent to me and get back to you. I left RNL relative to an internal pressure of 3.6 psi. Please note that I only skimmed the letler from ORNL 1 message for Fred to call me back. Stan Hodges 8/17/2006 <<>> Message Page 3 of 3 (0) 803-214-5848 Sr Project Manager (F) 803-214-5804 (M) 803-318-7493 (Note - New Number) Sent: Tuesday, July 25, 2006 12:13 PM From: Stan Hodges Subject: 49 CFR 173.412 (f) To: Richard Byars Richard: In a text (Document No. ORNL/NRC/LTR - 02/12 - address the design condition delineated in the subject regulatory section. They note in the text: "The most http://www.ornl.gov/~webworks/cppr/y2001/rpt/113628.pdf) prepared by ORNL for the USNRC, they f 11.1 psi) and a 1-ft drop of the package onto a flat horizontal surface. igniticant of the design conditions are the reduction of ambient pressure to 3.6 psi (i.e., internal pressure Based on this statement, I believe they are essentially saying that the container cannot release any radioactivity in a vacuum condition of 3.6 psi (equivalent to 7.33 inHg). lave a call into Jim Williams with the DOT (Rick Boyle is out this week) and will talk to him about th about the Type B () cask shipping scenarios. sue and whether or not a HEPA vent would be acceptable in a Type A package. I also want to talk to h delineated in a separate subsection of the regulation. Pls note that the drop test height is dependent on the weight of the package with contents and is Stan Hodges (0) 803-214-5848 Sr Project Manager (F) 803-214-5804 (M) 803-318-7493 (Note - New Number) 8/17/2006 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `a84072cc32976aaddad4e52c6719b13165e1a21a9d0a011b4be339831c574ac3` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T02:42:45.175Z - Document slug: `phmsa-interpretation-06-0189` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Nukem Corporation" ], "individuals": [ "Mr. Stan Hodges" ], "refIds": [ "06-0189" ], "catalogDates": [ "2006-09-29" ], "catalogParts": [ 173 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/50256" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "173.412", "173.412(f)", "178.350", "173.403", "173.410", "173.415", "173.465", "173.466" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/173412" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2006/060189.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2006/060189.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2006/060189.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/06-0189-fdda69c65b.pdf", "pdfArtifactSha256": "67fa5f81dce3e2925294a7e2d8ff58cb5cd5c8674cbf5f621a6a715f266e7c75", "extractedTextPath": "data/sources/phmsa-interpretations/06-0189-fdda69c65b.v2.txt", "extractedTextSha256": "33bfb881a823c1483c25c476a2c300b8743edf8917448f61522540ddaf7d09b1", "pageCount": 4, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```