ML18330A091
| ML18330A091 | |
| Person / Time | |
|---|---|
| Site: | 07109342 |
| Issue date: | 11/26/2018 |
| From: | Sewell P Daher-TLI |
| To: | Nishka Devaser Document Control Desk, Spent Fuel Licensing Branch |
| Shared Package | |
| ML18330A090 | List: |
| References | |
| LTR-20000-100-07 | |
| Download: ML18330A091 (21) | |
Text
1 of 21 LTR-20000-100-07 November 26, 2018 ATTN: Document Control Desk, Nishka Devaser, Project Manager Nuclear Regulatory Commission Spent Fuel Licensing Branch Division of Spent Fuel Management, NMSS
Dear Nishka:
Daher-TLI hereby submits the responses to the requests for additional information (RAIs) for Revision 10 to the Versa-Pac Safety Analysis Report, Docket No. 71-9342, as issued on September 26, 2018. Sections 1, 3, 6, and 7 of the Safety Analysis Report are resubmitted with change pages to incorporate clarifications as indicated in the RAI responses below. The changes made to SAR pages to address RAI comments are summarized in this letter below the RAI responses for reference.
In addition to the revision of the licensing drawings to address RAI S2-1 (the addition of Note 12),
there were some small changes made to multiple weld symbols for clarifications. These changes include the re-labeling and numbering of all MT weld symbols associated with the containment system (e.g. MT-1, MT-2, etc.) to provide a clearer link for MT inspection reports and corrected weld sizes where the weld callout was larger than the base material thickness. Additionally, new licensing drawing notes have been added to clarify the minimum specifications of the structural components of the packages.
The enclosures of this report are being submitted through the EIE system.
Please address any questions or comments to the undersigned.
Sincerely, Philip Sewell Email: psewell@tliusa.com Senior Engineer Work: (301) 421-4066 Daher-TLI Cell: (301) 514-6567 Digitally signed by Philip Sewell Date: 2018.11.26 09:24:10 -05'00'
2 of 21 Non-Proprietary
Enclosures:
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Description:==
File Name:
SAR Revision 10, Section 1 (Change Pages) 002 VP SAR Section 1 Rev 10 FINAL_pages_NP.pdf SAR Revision 10, Section 3 (Change Pages) 005 VP SAR Section 3 Rev 10 FINAL_pages.pdf SAR Revision 10, Section 6 (Change Pages) 006 VP SAR Section 6 Rev 10 FINAL_pages.pdf SAR Revision 10, Section 7 (Change Pages) 007 VP SAR Section 7 Rev 10 FINAL_pages.pdf Affidavit to Withhold Proprietary Information LTR-20000-100-08-Affidavit.pdf RAI T1.1 Reference 1 K-D-1894.pdf RAI T1.1 Reference 2 Aviation Combustion Toxicology.pdf Proprietary
Enclosures:
==
Description:==
File Name:
SAR Revision 10, Section 1 (Change Pages) 002 VP SAR Section 1 Rev 10 FINAL_pages_P.pdf
3 of 21 RAI C1-1 Address how the contents are a Type A quantity considering the enrichment weight percent (wt.%) of U-235 in Tables 1-1, U-235 Loading Table for VP-55 and VP-110 Standard Configuration, 1-1A, U-235 Loading Table for the VP-55 with 5-inch Pipe, 1-1B, 1S/2S Cylinder Limits for the VP-55 (up to 20wt.% U-235), and 1-1C, 1S/2S Cylinder Limits for the VP-55 with 5-inch Pipe (up to 100wt.% U-235), of the application.
The high enrichment weight percent of U-235 in Tables 1-1, 1-1A, 1-1B, and 1-1C of the application may result in additional radionuclides or impurities that could exceed a Type A quantity. Therefore, while the A2 value for U-235 is unlimited, it has not been shown in the application that the contents are a Type A quantity.
This information is needed to determine compliance with 10 CFR 71.33(b).
Response C1-1 All contents for the Versa-Pac package are limited to a Type A quantity, regardless of enrichment.
Section 1.2.2 of the SAR explicitly states that the contents are limited to a Type A quantity. Paragraph 5(b)(3) of Revision 12 the Versa-Pac CoC also states that The radionuclide inventory of the loaded contents, including U-234 and U-236, shall be less than the calculated mixture A2 value. In Section 7.1.1 of the SAR, the package user is required to ensure that the contents are within the limits of the Certificate of Compliance (in step b). As the exact impurity contents of the package can be variable, the package user must ensure prior to each shipment that the contents of the package meet the requirement of the CoC and are a Type A quantity in the same way that the user is required to meet any other limitation of the CoC, such as the content mass or the U-235 enrichment/mass limit.
The second paragraph of Section 7 has been revised to explicitly state that an A2 calculation must be performed per the guidance of 10CFR71 Appendix A, and highlight the isotopes of primary concern (U-233, U-234, and U-236).
4 of 21 RAI C4-1 Clarify Chapter 4, Containment, of the application to be consistent with Section 1.4.6.1, VP-55 with 5-inch Pipe Packaging Description, of the application. In addition, describe how the 5-inch pipe provides positive closure, summarize how it meets the containment requirements for normal conditions of transport and hypothetical accident conditions, and address any pressure rise within the 5-inch pipe during normal conditions of transport and hypothetical accident conditions. Also, ensure the analysis results in Chapter 3, Thermal Evaluation, are consistent with the description of the containment boundary.
Section 1.4.6.1 of the application describes, When using the 5-inch pipe in the VP-55 the containment boundary is defined as the 5-inch pipe, as all radioactive material is confined inside the pipe during transport conditions. Chapter 4 of the application does not describe the 5-inch pipe as the containment boundary, therefore it is not clear if the conclusions in that chapter continue to apply for that containment boundary. Chapter 4 of the application should describe the positive closure of the 5-inch pipe. Chapter 4 of the application should summarize that there is no loss or dispersal of radioactive material under normal conditions of transport for the 5-inch pipe by referencing specific sections of the application where this is demonstrated. Chapter 4 of the application should also summarize that the package must contain the contents to ensure subcriticality under both normal conditions of transport and hypothetical accident conditions by referencing specific sections of that application where this is demonstrated. In addition, Chapter 4 of the application should address any pressure rise within the 5-inch pipe during normal conditions of transport and hypothetical accident conditions. Also, the analysis results provided in Chapter 3 of the application that refer to the containment boundary should be consistent with the 5-inch pipe containment boundary description, when the 5-inch pipe is used in the VP-55 (e.g., Figures 3-27 through 3-30).
This information is needed to determine compliance with 10 CFR 71.43(c), 71.43(f), 71.55(d)(1),
71.55(e), 71.71(c)(1), and 71.73(c)(4).
Response C4-1 The current wording in Section 1.4.6.1 is incorrect, as the containment boundary of the package used to prevent the release of radioactive material is always the inner vessel of the Versa-Pac package, as described in Section 1.2.1.7. This wording in Section 1.4.6.1 has been corrected. The 5-inch pipe is only used for geometric criticality control by confining the fissile material to the smaller 5-inch diameter volume.
To ensure that the confinement of the fissile content, the structural performance of the 5-inch pipe is demonstrated via the bounding drop testing performed and detailed in Appendix 2.13.6 of the SAR.
Per Table 3-14 of the SAR, the maximum HAC temperature within the containment boundary of the Versa-Pac is on the containment body of 430°F. Thus, the temperature of the 5-inch pipe will be 430°F. Per Table 3-10 in the SAR, carbon steel is not expected to have a significant loss of thermal properties during NCT and HAC, as the temperature limit for carbon steel of 2600°F is well above this maximum experienced temperature. Since the 5-inch pipe can retain pressure, when the package heats up the pressure inside the pipe will increase slightly. Considering the pipe closed at 70°F (529.7 R) and heating up to 430°F (889.7 R), the maximum pressure inside the pipe due to the increase in temperature is calculated using the ideal gas law, as:
P" = P$ T" T$
= 14.7 psia 899.7 R 529.7 R = 25 psia = 10.3 psig The working pressure rating of standard 5-inch schedule 40 pipe and manufactured pipe cap is 580 psig. With the addition of the bottom plate, the pipe container forms a pressure retaining vessel. To evaluate the junction of the pipe and bottom plate, the stress due to bending, sxb, is:
5 of 21 sxb =
89:
- < = 638 psi The membrane stress sxm is; sxm =
=>
"; = 53 psi The membrane plus bending stress is sx(m+b) = 638 + 53 = 691 psi Comparing the membrane plus bending stress to the stress intensity of 19300 psi at 500°F for A36 carbon steel, the margin of safety is +27. Therefore, the ability of the 5-inch pipe to retain the fissile material will not be compromised due to the temperature increase from a fire accident.
6 of 21 RAI C6-1 Clarify the maximum uranium mass limits for air transportation of 1S and 2S cylinders within the VP-55 transport container.
The uranium mass limits for transport of fissile material that is provided in Section 6.7.2 of the application appear to be inconsistent with the quantities that are indicated to be allowed in 1S and 2S cylinders. The maximum quantity of 100 wt% U-235 as shown in Table 6.1-3 of the application indicates that the total quantities of U-235 per VP-55 allowed for air transport are well above the minimum spherical critical masses for 100 wt% U-235 reported in LA-10860-MS, Critical Dimensions of Systems Containing U-235, Pu-239, and U-233, as well as the limits reported for optimally moderated H/X UO2F2 systems in ORNL/TM-12292, Estimated Critical Conditions for UO2F2-H2O Systems in Fully Water-Reflected Spherical Geometry. The discussion in Section 6.7 of the application has a much lower mass limit (i.e., 395 grams U-235 at 100 wt%) than either of the 1S and 2S configurations, and appear to exceed the 5-inch pipe U-235 mass limits for air transportation that is specified in Section 6.7.2.
This information is needed to determine compliance with 10 CFR 71.55(f).
Response C6-1 The maximum uranium mass limits for any contents shipped via air transport within a Versa-Pac, including 1S and 2S cylinders in the VP-55, are those as determined in Section 6.7.2. The air transport limit for any content is always set as the lesser between the ground transport limit of the specific content and the air transport limit determined in Section 6.7.2. The UO2F2 + H2O mixture of the 1S/2S cylinder analysis is bounded by the uranium metal + polyethylene mixture of the air transport analysis.
Thus, the air transport limits of Section 6.7.2 are applicable to 1S/2S cylinder contents with or without the 5-inch pipe. SAR changes:
- 1. Table 6.1-3 is revised to explicitly list air transport limits for the 1S/2S contents
- 2. A sentence was added in the paragraph prior to Table 6.1-3, which states that the 1S/2S cylinder air transport limits are set as the lesser of the 1S/2S cylinder limits and the air transport limits determined in Section 6.7.
- 3. Table 1-1B and Table 1-1C in and the preceding text of each in Section 1.1 are revised to match the Section 6 changes. (Note that the 100% limits for 1S cylinders in Table 1-1C are lower than the limits listed in Table 6.1-3, because only one 5-inch pipe can fit in the CCV cavity when the required 2-inch minimum foam layer is included for UF6 cylinders)
7 of 21 RAI S2-1 Describe the yield strength and ductility (grade) of carbon steel used to construct the 55-gallon drum, drum lid, 5/8-inch-11 hex head bolt, backing bar, and the drum ring, and the drum lid reinforcing ring.
The licensing drawings (VP-55-LD) specify that the drum (BOM 9), the drum ring (BOM 11), 5/8-inch-11 hex head bolt, and drum lid (BOM 26) are only identified as being made from carbon steel, while the drum reinforcing ring (BOM 11) and backing bar (BOM 6) are made of an unspecified grade of ASTM A1011. While the 55-gallon Versa-Pac was drop tested, it is unclear what the yield strength and ductility of the steel used to construct these components was made of. Without specified yield strength
& ductility (material grade), it is unclear how another package will perform during HAC drop test conditions due to the ambiguity of the materials yield strength and ductility. The aforementioned components used in the construction of the new 55-gallon Versa-Pac drum package would have to meet or exceed the yield strength and/or ductility of those components used during drop testing.
Staff is concerned that components made from material with unspecified yield strength and ductility (parameters that determine energy absorption) may fail during the 9 meter drop test and expose the contents such as the inner container and the 5-inch pipe that carries 1S or 2S cylinders directly to subsequent thermal test (a scenario that appears to not have been considered in Chapter 3 of the application) if left unspecified. Specify the minimum yield strength and ductility (grade) of the carbon steel used to construct these components and place this information in the safety analysis report and licensing drawings.
This information is needed to determine compliance with 10 CFR 71.33(a)(5) and 10 CFR 71.73(c)(1),
10 CFR 71.73(c)(3), and 10 CFR 71.73(c)(4).
Response S2-1 Fabrication records show that the drum reinforcing ring (BOM 5), backing bars (BOM 6&7), stiffening rings (BOM 12&13) are fabricated from ASTM A1011 Grade 36, which is the sheet form of ASTM A36.
The nominal yield strength for ASTM A36 is 36000 psi. Note 12 was added to the Versa-Pac licensing drawings to specify that the material specification for ASTM A1011 components should be Grade 36 at a minimum.
The drum is classified as a Category C item per NUREG/CR-6407, which states: When used as an outer shell, the drum provides support for the contents in both normal and accident conditions. In order for the radioactive material to be released, both the outer drum and inner drum or container must be breached. That requires two failures. For the Versa-Pac packagings, the drum is used as an outer skin for handling. Additionally, the drum, lid and closure ring conform to the requirements for UN1A2 drums. The drum fabrication requirements are specified in 49 CFR 178.504(b)(1), which states the body and heads must be constructed of steel sheet of suitable type and adequate thickness in relation to the capacity and intended use of the drum. On the licensing drawing, the minimum drum specified is the UN1A2/Y425/S, which indicates that the specified drum is an open top (1A2), good for packing groups II or III (Y), has a maximum gross weight rating of 425 kg (937 lb) and can ship solids (S). Additionally, during the fabrication process, we receive certification that the drums meet the UN testing requirements. In regard to the drum material properties, typically carbon steel equates to A36.
The qualification requirements for these drums are based on the testing for non-bulk packagings and packages outlined in 49CFR178 Subpart M. Periodic retesting is required per 49CFR178.601(e), to guarantee the continued quality of fabricated drums to meet the requirements for the specification.
No grade specification is required for the bolt used to clamp the drum ring (BOM 26), as this bolt and the associated drum ring are not required for the outer drum lid closure. The outer drum lid is secured via the 4 bolts through the drum lid and reinforcing ring (BOM 25), with a material specification of ASTM A429/SAE J429, Gr5 Min.
8 of 21 RAI S2-2 Clarify the performance of the 55-gallon Versa-Pac package with respect to the puncture test and subsequent thermal test when the drum ring is struck directly for HAC conditions.
With reference to drawing (VP-55-LD sheet 1 of 2), describe the performance of the package when the package (lid side up) is dropped at a slight angle relative to the long axis of the package such that the puncture bar strikes (snags) the drum ring (BOM 11) and 5/8-inch-11 hex head bolt (BOM 26) potentially forcing the drum lid (BOM 10) to tear away from the drum portion of the package as depicted below:
Figure 1: Drawing in Reference to VP-55-LD (Appendix 1.4.1: Versa-Pac Shipping Package Licensing Drawings, sheet 1 of 2)
Staff is concerned that the package may be subjected to the free drop test, followed by the puncture test (forcing the lid to come off the package) in which case the contents such as the inner container and the 5-inch pipe that carries 1S or 2S cylinders directly to subsequent thermal test for which it appears that the package has not been examined.
This information is needed to determine compliance with 10 CFR 71.73(c)(1), 10 CFR 71.73(c)(3), and 10 CFR 71.73(c)(4).
9 of 21 Response S2-2 Positive closure of the Versa-Pac outer lid is accomplished with four (4) 1/2-13 UNC hex head bolts.
As Figures S2-2.1 and S2-2.2 show the bolts extend through the lid reinforcing ring that is welded to the drum lid. The supplemental drum ring attaches to the outer edge of the drum and drum lid, which is outside of the lid reinforcing ring which is attached a single 5/8-11 hex head bolt.
In regard to the puncture orientation described in the comment above, where the puncture probe hits the closure ring, the impact force will cause the drum ring 5/8-11 hex head bolt to rotate and potentially cause the closure ring to dislodge from the lid. However, since the drum reinforcing ring is inside the diameter of the drum ring, no significant prying loads are applied to the lid that can cause failure of the closure bolts.
Review of previous drop testing shows that the Versa-Pac drum ring does come off the package without breaching the lid. During the latest drop test program, the drop orientations considered where chosen to provide maximum damage to the closure system (see Appendix 2.13.7). The package was first dropped from 30 feet (CG over closure) to maximize the damage to the closure ring followed by the dynamic crush test with the package positioned horizontally on the drop pad to ovalize the package and attempt to pop the lid off. Third test in the sequence was the 40-inch puncture to the center of the lid. Based on the design principles presented in NUREG/CR-6007, maximum prying load on closure bolts occurs when the package is subject to a puncture at the center of the lid. Following the test sequence, it was noted the lid stayed in position without separation occurring. Therefore, the thermal performance of the package was maintained.
Figure S2-2.1 Cut-away View of the VP-55 Closure
10 of 21 Figure S2-2.2 Detailed View of the VP-55 Closure Components
11 of 21 RAI S2-3 Clarify the performance of the 55-gallon Versa-Pac package with respect to shallow angle drops for normal conditions of transport (NCT) and hypothetical accident conditions (HAC) conditions and the 1 meter puncture drop.
Appendix 2.13.4 (referenced in Section 2.13 of the application) indicates that the package was drop tested for shallow angles and for the 1 meter puncture tested at a weight of 644.5 lbs. for Revision 9 of the application. However, the package now weighs 750 lbs. and it is unclear how the package will perform at this weigh (Revision 10). Describe the condition of the package for shallow angle drops for NCT and HAC conditions and the 1 meter puncture drop as described in Appendix 2.13.4 given that the package can now weigh 100 lbs. more than previously tested. Further details regarding shallow angle drops on barrel type packages can be found in NUREG/CR-6818.
This information is needed to determine compliance with 10 CFR 71.71(c)(7), 10 CFR 71.73(c)(1), and 10 CFR 71.73(c)(3).
Response S2-3 As discussed in the response to RAI 2-2, the latest 750 lb drop testing results are provided in Appendix 2.13.7 with orientations chosen to maximize the damage to the closure system.
Even though the package weight was increased to 750 pounds, as shown in Figure S2-3.1, there is significant post impact secondary response. This behavior is common for drum type packages where the length/diameter ratio is approximately 1.5. The combination of CG over corner followed by dynamic crush (side) and puncture at the center of the lid shows that the package meets the HAC performance requirements.
Figure S2-3.1 30-Foot CG Over Corner The dynamic crush test was performed on the VP-55 as described in the 10 CFR 71.73(c)(2) for packages that weigh less than 500 kg (1100 lb). Figure S2-3.2 shows the damaged package post impact and the ovalization that occurs during the event. The kinetic energy absorbed during the dynamic crush test is 44,145 Joules compared with the VP-55 side drop at 340 kg (750), which is 30,902 Joules. Therefore, for the shallow angle drop to impose the same amount of energy as the dynamic crush test, an additional 30% kinetic energy is necessary. As noted above, the corner drop test for the VP-55 results in significant elastic rebound, which results in energy dissipation over several secondary impacts. However, as Figure S2-3-2 shows, during the dynamic crush test the package is laid directly on the rigid impact surface and no secondary impact occurred. Therefore, the amount of force available to ovalize the package was significantly higher during the dynamic crush test and bounds shallow angle drops.
12 of 21 Figure S2-3.2 VP-55 Following 30-Foot Dynamic Crush
13 of 21 RAI S2-4 Justify how the champion package is representative of the 55-gallon Versa-Pac package. In Section 2.7.6 of the application, the applicant states that the champion package was used to bound the 55-gallon Versa-Pac with respect to water immersion. However, it is unclear how the construction of the champion package is similar to the 55-gallon Versa-Pac package. Clarify how the materials, dimensions, configuration etc., is similar enough to that of the 55-gallon Versa-Pac package.
This information is needed to determine compliance with 10 CFR 71.73(c)(6).
Response S2-4 During the initial design phase of the Versa-Pac package, an accompanying Type B configuration, named The Champion, was planned. The Champion packaging was a nearly identical design to the Versa-Pac, with some changes to the internal structure of the package to provide increased thermal protection and a sealed inner cavity that allowed for leak testing. The Champion design was abandoned prior to licensing, but the testing performed on this configuration is still applicable to the Versa-Pac due to the similarities in the support structure of the designs.
In Appendix 2.13.3, the specific differences between the Versa-Pac and Champion designs are outlined under the header Design Comparison. The structural support features of the two designs are identical, in that they include inner and outer sheet metal liners with vertical (square tube) and horizontal stiffeners (ring). This includes the materials of construction as all carbon steel with identical specifications.
Figure S2-4.1 below shows a comparison of the two package designs in cross section views from design drawings of The Champion and the Versa-Pac licensing drawing. The top view of both designs shows the four-square tube vertical stiffeners. The cross-section view of The Champion package shows the two axial locations of the stiffening rings. The Versa-Pac design has stiffening rings identical to The Champion design, however they are not shown in the cross section view in the figure below because the cross section view in the drawing was taken through the vertical square tubes.
The material specifications for the components of the outer support structure of the Champion and Versa-Pac packages are provided in the simplified drawing views for each package shown in Figure S2-4.2. The primary components that provide support from an increased external pressure event are the vertical tubes (TB), the inner and outer reinforcing sheets (SA & FC), the bottom reinforcing plate (PE), and the stiffening ring web (FA & PI). Figure S2-4.2 shows that the material specifications for these components are identical, with the exception that the Versa-Pac allows for the use of either A36 or A1011 for parts FA and PI.
As the structural support features of these two designs are identical, the effects on the packaging due to the external pressure applied to the packaging due to the immersion accident scenario in 10CFR71.71(c)(6) would be identical.
14 of 21 Figure S2-4.1 Comparison of the Champion and Versa-Pac
15 of 21 Figure S2-4.2 Comparison of the Champion and Versa-Pac Outer Structures
16 of 21 RAI T1-1 Address the pressurization of the UF6 cylinders, as well as the ability of the 5-inch pipe and overpack to withstand any release of pressurization of the UF6 cylinders under hypothetical accident conditions, specifically considering air transport where the thermal test in 10 CFR 71.73(c)(4) must be 60 minutes rather than 30 minutes.
The pressurization of the UF6 cylinders, as well as the ability of the overpack and 5-inch pipe to withstand any release of pressurization of the UF6 cylinders considering the potential chemical, galvanic, or other reaction among the packaging components, among package contents, or between the packaging components and the package contents, including possible reaction resulting from inleakage of water has not been addressed. For example, generation of HF gas during the air transport 60 minute thermal test has not been addressed. Depending on the integrity of the overpack and 5-inch pipe, pressurization may result in release of UF6 vapor and HF gas (in the presence of water),
and high velocity projectiles from the UF6 cylinders, 5-inch pipe, or overpack. It is noted that because of the heat capacity of the UF6, a partially filled cylinder may be more susceptible to hydraulic failure than a full cylinder.
This information is needed to determine compliance with 10 CFR 71.43(d) and 71.55(f)(1)(iv).
Response T1-1 Historical fire test data of bare UF cylinders of various sizes shows that explosive failure can occur for cylinders 5 inches in diameter and larger (Mallet). However, review of the test report shows that the failure mechanism for small sample cylinders such as 1S and 2S cylinders is the threaded joint or solder between the value and cylinder. The report also concludes that the cylinders do not rupture during either fire test performed. It was also noted that a small cloud of UF was released but completely dispersed due to the heat and no contamination was recorded during the post fire examination.
Assuming the packaging does not survive the 60-minute fire and the cylinder pressure is relieved, the majority of UF material will remain inside the cylinder. The 800°C environment will evaporate all water, so the UF will thermally decompose. The products of this thermal decomposition are UOF, F, UF, UOx, and fluorocarbon compounds. All of the uranium compounds will decompose or convert to UO, which is a stable solid. This conversion happens throughout the 60-minute period and once the process is complete, the material will remain in this stable solid state throughout the duration of the fire and after cooling, allowing for the safe recovery of the material once the fire is extinguished.
For any material that escapes, complete dispersion of the UF vapor by the heat will occur immediately. Once the release of material has dissipated, the compounds are highly diluted.
Following the fire, any remaining fumes will cool and condense in the surrounding area. However, the byproducts will be sufficiently dispersed by the fire that they will not be detectable and not cause an undo safety concern.
The Versa-Pac is a Type AF package limited to Type A quantities of radiative material. Therefore, a full release of material from the packaging in HAC is not a concern in terms of the radiological consequences. It should be noted that the requirement of 10 CFR 71.55(f)(1) is specific to criticality concerns, which are addressed in Section 6.7 of the Versa-Pac SAR. In this analysis, complete failure of all packaging (including the Versa-Pac and 1S/2S cylinder(s) is assumed. Without the concern of a criticality accident, the material in these specific contents is the same as natural UF material, which is acceptable for air transport.
As discussed above, assuming the destruction of the Versa-Pac packaging from the drop, a 60-minute fire would either result in the failure of the 1S/2S cylinder valve soldering and full release and dispersal of the UF material or, if the cylinder does not fail, thermal decomposition into stable fluoride UO compounds. In either case with no water or water vapor present during the fire event, due to the high
17 of 21 temperatures of the fire, the chemical reaction generating hydrofluoric acid is not possible. Additional research into the effect of aviation combustion toxicology shows that hydrogen fluoride, hydrogen chloride and nitrogen dioxide compounds are created during the combustion of polymers used in aircraft construction with nitrogen dioxide compounds with the greatest toxicology risk (Chaturvedi).
Therefore, the potential release of hydrofluoric acid fumes from an aircraft fire event does not increase the exposure risk to the public or first responders.
Reference:
Mallett, A.J., ORGDP Container Test and Development Program Fire Tests of UF-Filled Cylinders, Report Number K-D-1894, Union Carbide Corporation Nuclear Division, Oak Ridge Gaseous Diffusion Plant, Oak Ridge, Tennessee, January 12, 1966, page 6.
Chaturvedi, Arvind K., Aviation Combustion Toxicology: An Overview, Journal of Analytical Toxicology, Vol. 34, January/February 2010
18 of 21 RAI T3-1 Confirm whether the package will be shipped by exclusive or non-exclusive use. If the package is shipped by non-exclusive use, clarify Chapter 3 of the application to describe that the maximum accessible surface temperature meets the non-exclusive use temperature limit, and Chapter 7 of the application to describe that the package is shipped by non-exclusive use.
In Chapter 3 (page 3-3) and application Section 3.3.1.1 the applicant states that the NCT evaluation results meet the exclusive use shipment requirement of 10 CFR 71.43(g). However, the applicant does not indicate the package is being shipped by exclusive use anywhere else in the application, or in the last revision of the Certificate of Compliance. The applicant should update application Chapter 7 to state that package is being shipped by non-exclusive use. Additionally, if the package is being transported by non-exclusive use, Chapter 3 (page 3-3) and application Section 3.3.1.1 should be clarified to describe that the package meets the non-exclusive use shipment requirements of 10 CFR 71.43(g).
This information is needed to determine compliance with 10 CFR 71.43(g).
Response T3-1 The Versa-Pac package is intended for and meets the requirements of non-exclusive use transport.
Change pages in Sections 3 are provided to make the package temperature comparison to the proper non-exclusive use requirements and in the first sentence of Section 7 to state that the package is intended for non-exclusive use.
19 of 21 SAR Changes shown below highlighted in gray (unaffected rows in tables not shown):
Page 1-2 The air transport U-235 mass limits in Table 1-1B are the lesser of the 1S/2S cylinder limits and the air transport limits determined in Section 6.7.
Table 1-1B: 1S/2S Cylinder Limits for the VP-55 (up to 20wt.% U-235)
Content Maximum Cylinders per VP-55 Mass UF6 per VP-55 (lb/g)
Enrichment U-235 (wt.%)
U-235 Mass Limit per VP-55 (g)
Air U-235 Mass Limit (g) 1S Cylinder 7
7.0 / 3,175
£ 20 429.8 429.8 2S Cylinder 2
9.8 / 4,445
£ 20 600.8 495 Page 1-2 The air transport U-235 mass limits in Table 1-1B are the lesser of the 1S/2S cylinder limits and the air transport limits determined in Section 6.7.
Table 1-1C: 1S/2S Cylinder Limits for the VP-55 with 5-inch Pipe (up to 100wt.% U-235)
Content Maximum Cylinders per VP-55 (in 5-inch Pipe(s))
Mass UF6 per VP-55 (lb/g)
Enrichment U-235 (wt.%)
U-235 Mass Limit per VP-55 (g)
Air U-235 Mass Limit (g) 1S Cylinder 1 a 1.0 / 454
£ 100 306 306 2S Cylinder 1
4.9 / 2,223
£ 100 1497 395 Notes: a Limited to one cylinder based on fit inside of the VP-55 cavity with the required 2-inch thick foam liner.
Pages 1-12 to 1-15 (Updated Licensing Drawings)
Page 1-16 (Note 9)
The nameplate shall be a minimum of 6 x 6 x 22 gauge stainless steel, ASTM 300 Series. The letters shall be at least 1/2 high as follows and include at a minimum the following information Page 1-17 (Note 14)
For the minimum UN specification in Part DA, equivalency between X and Y packing groups is based off of the drop heights required for testing in 49CFR178.603(e). Packing group I (X) requires a test drop height of 1.8 meters and packing group II (Y) requires a test drop height of 1.2 meters. Based on the potential energy, the equivalent mass for the higher drop (X) is equal to (1.2/1.8)*425 = 283.3 kg for the VP-55 and (1.2/1.8)*409
= 272.7 kg for the VP-110. The minimum X specification for both of these is rounded up to 350 kg Page 1-21 When utilized in the VP-55, the 5-inch pipe is simply used for geometric confinement of the fissile material in the contents. Although all radioactive material is confined inside the pipe during all transport conditions, the containment boundary of the package is always the inner vessel of the Versa-Pac package Page 3-1 The thermal analysis results show that the NCT maximum exterior surface temperature meets the non-exclusive use shipment requirement of 10 CFR 71 § 71.43(g).
20 of 21 Page 3-4 Table 3-2 NCT Steady State Thermal Evaluation Results - Standard Versa-Pac Configuration Component Part Number Temperature
(°F)
Maximum Allowable Temperature (°F)
Drum lid DL 154 Drum lid gasket GA 145 Drum DA 144 Package surface DA/DL 154 Page 3-10 Table 3-10 Temperature Limits Component or Material NCT Temperature Limit (°F)
HAC Temperature Limit (°F)
Accessible Surfaces of Package 122 e
References:
[1] [1] Accessible Surfaces of Package: Non-exclusive use requirements per 10 CFR 71.43(g).
Notes:
e Based on 10CFR71.43(g) non-exclusive use limit, only applies for case in the shade (no solar insolation).
Page 3-17 Results of the NCT evaluation show that a maximum exterior surface temperature in the shade (i.e. Case II) of 102°F is observed on the drum. This meets the non-exclusive use shipment requirement of 10 CFR 71.43(g).
Page 3-32 Table 3-16 NCT Steady State Thermal Evaluation Results - 1S/2S UF6 Cylinder VP-55 Configuration Component Part Number Temperature
(°F)
Maximum Allowable Temperature (°F)
Drum lid DL 154 Drum lid gasket GA 144 Drum DA 143 Package Surface DA/DL 154 Page 3-37 Results of the NCT evaluation show that the maximum interior cavity temperature is 138°F. The results for selected components are documented in Table 3-19 below and the overall body temperature is displayed in Figure 3-22 and Figure 3-23. The case without solar insolation is not analyzed for these contents as it is bounded by Case II in Section 3.3.1.
Page 6-3 Air transport U-235 mass limits in Table 6.1-3 are the lesser of the 1S/2S cylinder limits and the air transport limits determined in Section 6.7.
21 of 21 Page 6-3 Table 6.1-3: Maximum Quantity of 1S/2S Cylinders and Uranium Limits for the VP-55 Content Enrichment U-235 (wt.%)
Maximum Cylinders per VP-55 Total Mass UF6 per VP-55 (lb/g)
Total Mass U-235 per VP-55 (g)
Total Mass Uranium per VP-55 (g)
Air U-235 Mass Limit (g) 1S Cylinder
£ 20 7
7.0 / 3,175.2 429.8 2,149 429.8
£ 100 (5-inch pipe) 3 3.0 / 1,360.8 918 918 395 2S Cylinder
£ 20 2
9.8 / 4,445.2 600.8 3,004 495
£ 100 (5-inch pipe) 1 4.9 / 2,222.6 1,497 1,497 395 Page 7-1 The Versa-Pac Shipping Package is used to transport a variety of materials, typically by non-exclusive use. It is to be loaded, inspected and handled in accordance with standard, plant operating procedures.
Page 7-1 As a Type AF package, the contents of the Versa-Pac are always limited to be less than or equal to an A2 quantity, calculated per the guidance of 10CFR71 Appendix A. All radioisotopes in the contents shall be included in the A2 calculation (typically uranium isotopes: U-233, U-234, and U-236).