ML18201A428

AOS-FM9054, Revision H-5, Radioactive Material Transport Packaging System Safety Analysis Report, for Models AOS-025, AOS-050 and AOS-100 Transport Packaged

ML18201A428
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Site:	07109316
Issue date:	07/20/2018
From:	Alpha-Omega Services
To:	Office of Nuclear Material Safety and Safeguards
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ML18201A426	List: ML18201A427 ML18201A428 ML18204A350
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FM9006.1-072018-002 AOS-FM9054, Rev. H-5
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AOS-FM9054 Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages Prepared by Alpha-Omega Services, Inc.

Bellflower, CA

NOTICE AND DISCLAIMER Alpha-Omega Services, Inc., solely for the use of the U.S. Nuclear Regulatory Commission (NRC) in licensing the AOS Radioactive Material Transport Packaging System (AOS Transport Packaging System), prepared this report. Alpha-Omega Services, Inc., and/or its Contractor assume no responsibility for liability nor damage, which may result from any other use of the information disclosed in this report.

The information contained in this report is believed to be an accurate and true representation of the facts known by or provided to Alpha-Omega Services, Inc., and/or its Contractor at the time this report was prepared. Alpha-Omega Services, Inc., and/or its contractor and the individual contributors to this report make no express nor implied warranty with respect to the accuracy, completeness, or usefulness of the information contained in this report, other than for the licensing of the AOS Transport Packaging System or that the use of any information disclosed in this report may not infringe privately owned rights, including patent rights.

The printed copy of this report, as submitted to the NRC, contains PDF files, one or more of which contains hyperlinks to other files (within the report) or to the Internet. These hyperlinks are either inoperable or are not essential to the use of the filing. Any material referenced by hyperlinks to the Internet that was essential for use of this filing has been submitted as part of the filing. Any material referenced by a hyperlink to another PDF that was essential for the use of this filing has either been included by reference or submitted as part of this filing.

Revision History Revision Date Description of Changes A

January 11, 2008 Preliminary release.

B June 20, 2009 Preliminary release.

C September 11, 2009 Preliminary release.

D September 28, 2010 Preliminary release.

E October 11, 2011 Preliminary release.

F February 1, 2012 Initial Release.

G July 27, 2012 Update to include cask lid elastomeric seal, and included text so the cask lid metallic seal is differentiated from the new elastomeric seal.

Applied miscellaneous corrections (table of changes included with cover page of the submittal).

H December 30, 2012 Updated in response to NRC RAIs.

Applied miscellaneous corrections (table of changes included with cover page of the submittal).

H-1 March 11, 2016 Updated to add new isotope, Ir-194.

General update to correct errors and incorporate changes communicated to NRC in letters dated April 4, May 14, and September 26, 2013, and May 6, June 5, and August 5, 2015.

Applied miscellaneous updates and corrections (table of changes included with cover page of the submittal).

H-2 June 27, 2016 Updated in response to NRC RAI.

H-3 May 3, 2017 Clarified Special Form material shipment requirements and applied miscellaneous corrections.

H-4 November 28, 2017 Updated Cask Thread Sealant-related information.

H-5 July 20, 2018 Chapter 1 - Revised Subsection 1.2.2 (added discussion relating to isotope mixtures); revised Table 1-2 (deleted footnote e and renumbered remaining footnotes); added Table 1-2b (Exclusive Use Activity Limits -

Models AOS-100A and AOS-100A-S); updated Table 1-5 drawing revisions Chapter 2 - Replaced Paragraph 2.5.3.1.4; added Appendix 2.12.16 (Shipping Cage LS-DYNA Impact Analysis - Model AOS-100)

Chapter 5 - Added Appendix 5.5.5 (Shipments of Multiple Isotopes -

Models AOS-100A and AOS-100A-S), Appendix 5.5.6 (Isotopes Insignificant to External Dose Rates), and Appendix 5.5.7 (Exclusive Use Activity Limits -

Models AOS-100A and AOS-100A-S)

Chapter 7 - Added Appendix 7.5.1 (Dose Rate and Decay Heat Limit Compliance)

Applied miscellaneous corrections (table of changes included with cover page of the submittal)

Radioactive Material Transport Packaging System Safety Analysis Report 1-9 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 1.2.1.2 Impact Limiter The impact limiter is a major component consisting of a thin-walled cylindrical shell, with a dish head at one end and a flat disk at the other end. At the flat-disk end, there is a cylindrical recess, with an internal profile identical to that of the cask end profile. This cavity accommodates the cask in the transport configuration.

Figure 2-5, Isometric View - Typical Impact Limiter, presents an isometric view of the impact limiter.

Twelve (12) squared ribs are attached to the inside wall of the cylindrical recess section. Eight (8) of these ribs extend beyond the flat disk plate, which are used as turnbuckle attachment points. The turnbuckles are used to join the impact limiters and to partially enclose the cask component. For the Model AOS-025, the two (2) impact limiters entirely cover the cask, and the turnbuckles are replaced with J hooks.

The transport package exterior incorporates one (1) or more tamper-indicating devices, that are not readily breakable. While intact (that is, not broken), these devices provide evidence that the package has not been opened by unauthorized persons. (For further details regarding the tamper-indicating devices, refer to Chapter 7, Package Operations.)

1.2.1.3 Cask Lid Seal Two (2) types of cask lid seals are used. One consists of two (2) elastomeric O-Rings, a cross-section captured within one (1) or two (2) flat metal retainer rings to form a unit. The other is a metallic, double C cross-section arrangement.

The seal design provides a means for leak testing between the two (2) O-Rings (elastomeric seal) or double C cross-sections (metallic seal), by way of the cask lids Test Port feature. (For further details regarding the cask lid seal, refer to Appendix 4.5.1, Garlock Helicoflex Cask Lid Metallic Seal and AOS Cask Lid Elastomeric Seal Drawings.)

1.2.1.4 Other Components In addition to the previously mentioned components, the AOS Transport Packaging System uses other components or structures, in support of its operations. A series of liners and shielding plates enhances the shielding characteristics for shipments of specific content. Refer to Table 1-2, Table 1-2a, and Table 1-2b for the requirements of when to use these shielding devices.

A transport pallet is used as a base for the transport packages, for tying down the package during transport.

The shipping cage is a five (5)-sided metal structure, with the pallet creating a sixth side, which completes a cube shape. Each side covered with an expandable metal mesh or screen material, that keeps unauthorized persons away from the transport package surfaces during transport, and provides a means to meet temperature regulation requirements.

The packages have no tie-down devices nor structural parts that can be used for unintended tie-down, thus satisfying the additional requirements of 10 CFR 71.45(b) [1.1].

The elastomeric seal is comprised of two (2) components:

O-Rings - Silicone, Parker Compound S1224-70, ASTM D2000 Retainer Rings - ASME SA-240/

ASTM A240, Type 304 or 316 Stainless Steel The metallic seal is comprised of three (3) components:

Jacket - Silver, ASTM B742 Spring - Nickel-chromium alloy 90 UNS N07090 Lining - SS304L UNS S30403 (may/may not be present)

1-10 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 1.2.2 Contents Table 1-2 and Table 1-2a provide a list of the isotopes authorized for use with the AOS Transport Packaging System. Isotope mixtures are permitted within the shipping cask contents when external dose rate and decay heat limit compliance is demonstrated per the guidance specified in Appendix 7.5.1, Dose Rate and Decay Heat Limit Compliance. Isotopes that emit only low-energy gammas (that is, all emissions are less than 0.3 MeV) and/or beta particles are permitted for transport. Isotopes that meet this criteria:

Do not need to be considered for dose rate calculations Need to be accounted for only when calculating the shipping cask contents total decay heat Table 1-2 and Table 1-2a demonstrate the use of curie content to meet the radioactive and thermal maximum limits specified in Table 1-3, for individual isotopes within each transport package model.

Furthermore, the shielding requirements specified in Table 1-2 and Table 1-2a apply, where applicable.

The activity limits presented in Table 1-2a should be interpreted as follows: for a shipment with a total Ir-194 impurity up to the specified activity, the corresponding Ir-192 activity limit is listed (for example, for Model AOS-050A, any shipment with a total Ir-194 activity up to 10 Ci, the Ir-192 activity limit is 1,117 Ci).

For Models AOS-100A and AOS-100A-S, when shipped as exclusive use, the activity limits for each isotope are specified in Table 1-2b.

The AOS Transport Packaging System can be used for transporting solid radioactive materials in Normal and Special Form. Any materials with a melting point less than 538°C (1,000°F) are required to be in Special Form. Special Form materials require a current Special Form Competent Authority Certificate.

Dispersible Normal Form materials are required to be enclosed within an inner container. An inner container is considered to be a shoring device.

Fissile materials and irradiated fissile materials containing fission products are not authorized for this packaging. In addition, no free-standing liquid is permitted.

The package can be shipped by surface or air transport, and meets the requirements for non-exclusive transport. (Refer to Table 1-2 and Table 1-2a.) For air transport, quantities are limited to the lesser of Table 1-2, Table 1-2a, or 3,000 A2.

All shoring materials used within the cask cavity must have a melting point greater than (i) 600°F for Co-60 in metallic form and Cs-137 in the form of cesium chloride and (ii) 900°F for all other contents.

Radioactive contents can be in any location within the cask cavity, and unconstrained within the inner containers. Holders, fixtures, and packaging materials (shoring devices) must be used to secure the inner containers, so that the inner containers are immobilized. The containers must be comprised of materials that are compatible with the radioactive contents and cask cavity.

Radioactive contents are limited by the external radiation levels specified in 10 CFR 71.47 and 71.51 [1.1],

and 49 CFR 173.441 [1.3]. Exclusive-Use mode of shipment is required whenever the radiation dose rates of the package exceed the external radiation standards in 10 CFR 71.47(a) [1.1] for non-exclusive use shipment. For Models AOS-100A and AOS-100A-S, when shipped as exclusive use, the activity limits for each isotope are specified in Table 1-2b.

There are no materials added to the package for the purpose of neutron absorption nor moderation.

Radiation shields (that is, liners, axial shielding plates, and/or cavity spacer plates) are required in certain cases, as stipulated in Table 1-2 and Table 1-2a.

The construction materials of the AOS Transport Packaging System and their proposed contents are compatible with one another; no chemical nor galvanic reactions are expected to occur, including the generation of combustible gas.

Radioactive Material Transport Packaging System Safety Analysis Report 1-10a for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

The transport packages shall be loaded under ambient atmospheric pressure and temperature conditions. The containment boundary will not normally be pressurized; however, internal heating of the enclosed gases can increase the pressure.

The maximum gross weight of the AOS Transport Packaging System, including contents, is listed in Table 1-1.

The maximum decay heat, listed in Table 1-2 and Table 1-2a, is calculated using the constants presented in Chapter 5, Shielding Evaluation.

1-10b Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

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1-11 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 1-2. Activity Limits (All Isotopes Except Ir-192 and Ir-194)a - All Models

a. Refer to Table 1-2a for Ir-192 and Ir-194 activity limits.

Isotopeb

b. Solid material, including metals, that meets Normal or Special Form criteria. Special Form materials require a current Special Form Competent Authority Certificate.

Decay Heat (W/Ci)c c.

For detailed calculations of these values, refer to Appendix 5.5.1, AOS Cask Isotopic Heat Load Calculations.

Model AOS-025 AOS-050 AOS-100 A (10W)

A (100W)

A, A-S (400W)

B (400W)

TBq Ci TBq Ci TBq Ci TBq Ci Co-60 1.55E-02 4.92E-03 1.33E-01 2.78E-02 7.50E-01 1.01E+01 2.73E+02 4.03E-01 1.09E+01 Co-60-B 1.55E-02 3.05E+01 8.23E+02 Co-60-Cd

d. For Co-60-C quantities, the maximum allowable specific activity is 350 Ci/g (that is, no more than 350 Ci of Co-60 in a gram of Cobalt).

1.55E-02 7.48E+02 2.02E+04 Cs-137 4.99E-03 3.70E-01 1.00E+01 7.13E-01 1.93E+01 1.32E+03 3.55E+04 2.15E+01 5.82E+02 Hf-181 4.33E-03 3.41E+00 9.23E+01 3.42E+03e

e. Activity limit based on cask decay heat limit.

9.24E+04e 1.62E+02 4.39E+03 Zr/Nb-95f f.

Activity limits for parent/daughter mixed isotope systems apply to the parent isotope. An equilibrium concentration of the daughter is assumed in the evaluations provided in Chapter 5, Shielding Evaluation, to provide limiting dose and heat responses for the AOS Transport Packaging System.

1.62E-02 1.07E-01 2.90E+00 1.34E+02 3.61E+03 2.70E+00 7.31E+01 Ho-166 4.29E-03 4.87E-01 1.32E+01 2.81E+00 7.59E+01 Yb-169 2.55E-03 1.45E+02e 3.92E+03e 3.49E+02 9.44E+03 Shipping Configuration Use of Liner 183C8485 is required No additional shielding is required Co-60-B quantities require use of Axial Shielding Plate 183C8491 Co-60-C quantities require use of Axial Shielding Plates 183C8491 and Cavity Spacer Plates 183C8518 No additional shielding is required

1-11a Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 1-2a. Ir-192 and Ir-194 Activity Limits - All Models Model Ir-192 Limit Ir-194 Impurity Decay Heat (W)a

a. Ir-192 and Ir-194 generate 6.13E-03 W/Ci and 5.30E-03 W/Ci, respectively. (Refer to Table 5-22, AOS Cask Isotopic Heat Load Results.)

Shipping Configuration TBq Ci TBq Ci AOS-025A (10W) 2.62 71 0.0185 0.5 0.44 Use of Liner 183C8485 is required 2.33 63 0.0740 2.0 0.40 2.10 57 0.1110 3.0 0.37 AOS-050A (100W) 41.32 1,117 0.37 10 6.90 Use of Axial Shielding Plates 183C8519 is required 39.84 1,077 0.74 20 6.71 36.88 997 1.48 40 6.33 33.92 917 2.22 60 5.94 30.96 837 2.96 80 5.56 28.04 758 3.70 100 5.18 AOS-100A, AOS-100A-S (400W) 2,286.37 61,794 148.00 4,000 400.00 No additional shielding is required 2,094.42 56,606 370.00 10,000 400.00 AOS-100B (400W) 89.31 2,414 3.70 100 15.33 No additional shielding is required 76.22 2,060 8.51 230 13.85

Radioactive Material Transport Packaging System Safety Analysis Report 1-11b for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 1-2b. Exclusive Use Activity Limits - Models AOS-100A and AOS-100A-Sa

a. Activity limits based on Table 5-39, Exclusive Use Activity Limit Maximum Dose Rates and Decay Heat -

Models AOS-100A and AOS-100A-S.

Isotope Decay Heat (W/Ci)b

b. For detailed calculations of these values, refer to Appendix 5.5.1, AOS Cask Isotopic Heat Load Calculations.

Models AOS-100A and AOS-100A-S (400W)

TBq Ci Co-60 1.55E-02 1.70E+01 4.60E+02 Co-60-B 1.55E-02 5.85E+01 1.58E+03 Co-60-Cc d c.

For Co-60-C quantities, the maximum allowable specific activity is 350 Ci/g (that is, no more than 350 Ci of Co-60 in a gram of Cobalt).

d. Activity limit based on the shipping casks decay heat limit.

1.55E-02 9.55E+02 2.58E+04 Cs-137 4.99E-03 2.09E+03 5.65E+04 Hf-181d 4.33E-03 3.42E+03 9.24E+04 Ir-192d 6.13E-03 2.41E+03 6.53E+04 Ir-194 5.30E-03 1.48E+03 4.00E+04 Zr/Nb-95e

e. Activity limits for parent/daughter mixed isotope systems apply to the parent isotope. An equilibrium concentration of the daughter is assumed in the evaluations provided in Chapter 5, Shielding Evaluation, to provide limiting dose and heat responses for the AOS Transport Packaging System.

1.62E-02 2.15E+02 5.81E+03 Shipping Configuration Co-60-B quantities require use of Axial Shielding Plate 183C8491 Co-60-C quantities require use of Axial Shielding Plates 183C8491 and Cavity Spacer Plates 183C8518 Table 1-3. Content Limitations - All Models Model Type Contenta

a. Special Form materials require a current Special Form Competent Authority Certificate.

Decay Heat Weightb

b. Maximum weight of contents including any additional shielding and shoring devices. Weight of contents can be adjusted so as not to exceed the maximum authorized gross weight of the package.

Watt Btu/hr.

kg lbs.

AOS-025A Solid Material Normal Form or Special Form 10 34.15 4.5 10 AOS-050A 100 341.5 27 60 AOS-100A 400 1,366 227 500 AOS-100B AOS-100A-S

Radioactive Material Transport Packaging System Safety Analysis Report 1-17 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 1.3 APPENDIX 1.3.1 AOS Transport Packaging System, Certification Drawings Table 1-5 lists the certification drawings for the AOS Transport Packaging Systems assembly, impact limiter, cask, liner, axial shielding plates, and cavity spacer plates, by model.

Table 1-5. AOS Transport Packaging System Certification Drawing List - All Models Component Drawing Part Number and Revision, by Model AOS-025A Rev.

AOS-050A Rev.

AOS-100A Rev.

AOS-100B Rev.

AOS-100A-S Rev.

Assembly 166D8142 J

105E9718 J

105E9711 K

105E9711 K

105E9711 K

Impact Limiter 105E9722 I

166D8138 I

105E9713 J

105E9713 J

105E9713 J

Caska

a. The G00x number appended to select drawing numbers represents a group within the drawing.

166D8143 I

166D8137 I

105E9712G001 K

105E9712G002 K

105E9719 K

Liner 183C8485 H

Axial Shielding Plates 183C8519 A

183C8491 I

183C8491 I

Cavity Spacer Plates 183C8518 B

183C8518 B

2-26 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Figure 2-12. Center of Gravity - Model AOS-100 Note: Dimensions are in inches.

(61)

(61)

(71.7)

(TOP VIEW)

(SIDE VIEW)

(30.5)

(34.5)

(30.5)

Radioactive Material Transport Packaging System Safety Analysis Report 2-55 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.5.3.1.4 Analysis of Shipping Cage Fasteners - Model AOS-100 Shipping Cage Properties Center of Gravity = H = 46.6 in.

Length = L = 61.0 in.

Mass = W = 450 lbs.

Fastener Properties 16-1/2 in. bolts A = 0.141 in2 Yield Stress =

Fy = 105 ksi (SST Type 410)

-or-Fy = 50 ksi (Nitronic 60 per ASTM A193 Grade B8S)

Yield Stress in shear =

Sy = 0.58 x Fy = 29 ksi Maximum Inertia Force G = 10.0g The acceleration of 10g tends to tip the Shipping Cage about one edge. The tipping moment, M is:

M = W x G x H = 450 x 10 x 46.6 = 209,700 in-lb.

The tipping of the Shipping Cage is conservatively assumed to be resisted by only four screws in shear. The total force on the screws is:

The shear stress within each screw is:

Therefore, the Margin of Safety is:

72" 209,700 in-lb.

61 in.

M L

F = = = 3,438 lbs.

3,438 lbs.

4 x 0.141 in2 F

4A

= = = 6,095 psi 29,000 psi 6,095 psi Sy MS = - 1 = - 1 = 3.8

Radioactive Material Transport Packaging System Safety Analysis Report 2-79 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.6.6 Water Spray The containment capabilities of the AOS Transport Packaging System are not compromised by water spray, because all external surfaces are comprised of stainless steel, and the closure seal is impervious to water. Furthermore, it is shown that the containment boundary of the AOS Transport Packaging System cask component is leak-tight, thus preventing water from entering the cask cavity. Refer to Chapter 4, Containment, for a description of the containment boundary and its capability to prevent leakage.

2.6.7 Free Drop Note: The following analysis does not consider the energy that the shipping cage absorbs during a free drop. For the Free Drop Shipping Cage analysis, refer to Appendix 2.12.16.

Each AOS Transport Packaging System model was analyzed to the effect of a free drop, using the LIBRA code. The transport package models were evaluated for a drop distance, based upon the models weight, as listed in Table 2-34. The Drop condition evaluation is based upon the energy displacement curves developed by the 30-ft. drop analysis. The maximum displacements are determined from the energy displacement curves, and are listed in Table 2-35.

The analyses conducted consider three (3) orientations, as illustrated in Figure 2-27. The orientation that produced the most stress upon the cask component of the AOS Transport Packaging System was used as the load condition to be included in the Load Combination procedure.

Table 2-34. Free-Drop Distance - All Models Model Maximum Authorized Package Weighta

a. The weights that comprise the maximum authorized package weight are defined in Table 2-7.

Free-Drop Distance kg lbs.

m ft.

AOS-025A 100 220 1.2 4

AOS-050A 681 1,500 1.2 4

AOS-100A 5,675 12,500 0.9 3

AOS-100B 4,994 11,000 AOS-100A-S 5,675 12,500 Table 2-35. Maximum Displacements in Free Drops, Normal Conditions of Transport - All Models Model Drop Head-On Side Cg/Corner cm in.

cm in.

cm in.

cm in.

AOS-025 121.9 48.0 1.52 0.60 0.96 0.38 2.54 1.00 AOS-050 121.9 48.0 3.81 1.50 3.05 1.20 6.73 2.65 AOS-100 91.4 36.0 6.60 2.60 5.08 2.00 12.19 4.80

Radioactive Material Transport Packaging System Safety Analysis Report 2-155 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12 APPENDIX This appendix presents the following information:

Data CDs Structural Evaluation Results - Models AOS-025, AOS-050, and AOS-100 Structural Evaluation Results - Model AOS-025A Structural Evaluation Results - Model AOS-050A Structural Evaluation Results - Models AOS-100A and AOS-100A-S Structural Evaluation Results - Model AOS-100B LIBRA Finite Element Analysis Program and Verification Problems Description of LIBRA Files and Post-Processors: AOS Safety Analysis Report Selected Material Properties References Impact (Free-Drop) Test Report Test Report: Drop Tests of the Alpha Omega Services Shipping Cask for Radioactive Material Free-Drop Test Activity Record - Pre-and Post-Leak Test Dimensional Inspection Report Analysis of Content-Cask Lid Impact Comparison of Libra Static and Dynamic Impact Analysis Effect of Ribs on Stress at Foam-Cask Interface Analysis of 30-Ft. Drops with Shipping Cages Analysis of Tie-Down Devices Certificate of Conformance, General Plastics FR-3700 Series Foam - AOS-165A Prototype Analysis of Shipping Cage Lifting Bars - Models AOS-050A and AOS-100 Shielding/Spacer Component Evaluation - Models AOS-050A, AOS-100A, and AOS-100A-S Shipping Cage LS-DYNA Impact Analysis - Model AOS-100

Radioactive Material Transport Packaging System Safety Analysis Report 2-942aq for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16 Shipping Cage LS-DYNA Impact Analysis - Model AOS-100 This appendix documents the Model AOS-100 transport packages shipping cage structural response during an NCT free drop, in accordance with 10 CFR 71.71 (Reference [2.35]), and quantifies the amount of damage that is sustained as input into the shielding analysis (refer to Chapter 5).

The shipping cage is used when transporting the loaded Model AOS-025, AOS-050, and AOS-100 transport packages. The shipping cage ensures that the transport packages accessible surfaces are protected. Therefore, the shipping cage must remain functional during and after NCT events to allow for safe transport package handling. Figure 2-131 illustrates a solid model rendering of the Model AOS-100 transport package with its shipping cage.

Additional analyses are also provided to bound the Model AOS-025 and AOS-050 transport packages.

Unlike the Model AOS-100, Models AOS-025 and AOS-050 do not include the gusset plates identified in Figure 2-131.

Because the Model AOS-100 is a scaled representation of Models AOS-025 and AOS-050, removing the gusset plates from the LS-DYNA model and re-running the worst case bounds the smaller packages.

Figure 2-131. AOS Transport Package Assembly (Model AOS-100 Transport Package with Shipping Cage Shown)

Shipping Cask with Gusset Plate Shipping Cage Tie-Down System Upper and Lower Impact Limiters Pallet

2-942ar Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

This evaluation illustrates that the shipping cage absorbs a significant amount of energy and thereby reduces the predicted impact limiter deformation. Table 2-365 illustrates the change in the predicted impact limiter deformation due to the impact energy reduction that results from shipping cage deformation.

Table 2-365. Maximum Impact Limiter Deformation during NCT Free Drops - Model AOS-100 Model Shipping Cage Drop Height (ft.)

Drop Type End (Head-On)

(in.)

Side (in.)

Cg/Corner (in.)

AOS-100 Without Shipping Cagea

a. Refer to Table 2-35.

3 2.60 2.00 4.80 With Shipping Cage 4

2.00 1.10 1.50 With Shipping Cage (Without Gusset Plates) 2.40 AOS-050 Without Shipping Cagea 4

1.50 Scaled to Model AOS-050b

b. The Model AOS-050 and AOS-025 calculations were scaled based on the Model AOS-100 results.

1.20 AOS-025 Without Shipping Cagea 4

0.60 Scaled to Model AOS-025b 0.60

Radioactive Material Transport Packaging System Safety Analysis Report 2-942as for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.1 Method The LS-DYNA (Reference [2.36]) dynamics program is used to determine the Model AOS-100 shipping cages structural response during NCT drop conditions onto an unyielding surface. A full-scale solid model was created in Autodesk Inventor (Reference [2.37]) and imported into ANSYS Workbench (Reference [2.38]), where a half-symmetry of the model was generated using DesignModeler. The LS-DYNA explicit export module, built into ANSYS Workbench, was used to create the finite element mesh and to generate a.k file, using ANSYS Mechanical (Reference [2.39]), as an input to LS-PrePost (Reference [2.36]). In this analysis, Head-On, Side, and Cg/Corner Drop orientations were considered to study the maximum damage that occurs the shipping cage during NCT. (Refer to Figure 2-132.)

Figure 2-132. NCT Drop Orientations Used for Shipping Cage LS-DYNA Impact Analysis Cg/Corner Drop Side Drop Head-On Drop

2-942at Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

After studying the structural responses and obtaining the impact analysis energy data, the energy deformation plots of the impact limiters without the shipping cage were used to determine the impact limiters deformation when they are dropped with the shipping cage.

The drop orientation that resulted in the worst impact limiter deformation was further studied to accommodate the Model AOS-025 and AOS-050 shipping cages. This was accomplished by removing the Model AOS-100 shipping cages gusset plates.

2.12.16.2 Model Description 2.12.16.2.1 Finite Element Model A 3D solid model of the Model AOS-100 packaging was developed using Autodesk Inventor, in accordance with the Model AOS-100 packaging certification drawings provided in Appendix 1.3.1.3, AOS Transport Packaging System Drawings - Model AOS-100A, AOS-100B, and AOS-100A-S. As illustrated in Figure 2-131, the model is a simplified model and includes the shipping cage, cask transport tie-down system, and a rigid body payload.

ANSYS DesignModeler (Reference [2.38]) was used to import the solid model (.STP file). The ANSYS Workbench explicit dynamic LS-DYNA export module was then used to generate the mesh. Following the meshing process, the model was exported as an LS-DYNA keyword (.k file), which is the default text input file format for the LS-DYNA program (Reference [2.36]). The LS-DYNA keyword file includes necessary control cards and boundary conditions. The keyword file is edited to call a separate text input file (.dyn file) that contains all the necessary material properties.

As illustrated in Figure 2-133, the finite element model is composed of shell and 3D brick elements, including LS-DYNA Type -1 (fully integrated selective-reduced solid). The wire mesh of the shipping cage is represented with thin-shell elements that contain the same amount of material per volume to the wire mesh. Spot welds represent the welds that connect the mesh to the shipping cages frame. Solid elements represent all other shipping cage and cask transport tie-down system parts.

Radioactive Material Transport Packaging System Safety Analysis Report 2-942au for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Figure 2-133. Transport Package Finite Element Model - Model AOS-100

2-942av Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.2.2 Transport Package Weight The Model AOS-100 transport packages maximum weight, including the shipping cage and shipping cask contents, is 12,500 lbs. The rigid bodys density was adjusted so that the overall weight matches the assembled transport package weight. The center of gravity is found to be 34.5 in. from the bottom surface.

(Refer to Figure 2-12.)

2.12.16.2.3 LS-DYNA Material Model The shipping cages aluminum frames and steel shells, and cask transport tie-down systems steel material parts were modeled using the *MAT_PIECEWISE_LINEAR_PLASTICITY LS-DYNA material model (Reference [2.41]). The payload, which includes the shipping cask and impact limiters, was modeled as *MAT_RIGID.

2.12.16.2.4 Contact Interface Contact between interfaces was modeled using three LS-DYNA control cards (Reference [2.40]):

• CONTACT_AUTOMATIC_SINGLE_SURFACE - Provided global contact control

• CONTACT_TIED_NODES_TO_SURFACE_OFFSET - Fastened welded components other than the steel shell

• CONSTRAINED_SPOTWELD - Used to model the spot welds that attached the wire mesh to the frames

Radioactive Material Transport Packaging System Safety Analysis Report 2-942aw for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.3 Boundary Condition 2.12.16.3.1 Symmetry Plane A symmetry boundary plane was used in the half model along the z-y plane, with translational constraint in the x-direction and rotational constraints in the y-and z-directions.

2.12.16.3.2 Initial Velocity The initial velocity was calculated based on the drop height and gravitational acceleration, using the following energy conservation formula:

1/2 x m x V2

=

m x g x H where:

m

=

Mass, lbs.

V

=

Initial velocity at the threshold of impact g

=

Gravity constant = 386.4 in/s2 H

=

NCT drop height = 4 ft.

Note: An NCT free-drop height of 4 ft. is conservatively used to bound all AOS family of transport packages. (Refer to Table 2-34.)

2.12.16.3.3 Gravity Acceleration due to gravity, 386.4 in/s2, was applied to all components in the drops direction, with an initial ramp-up period of 0.05 seconds.

V = 2 x g x H = 192.6 in/s

2-942ax Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.4 Impact Analysis Results This section presents the Model AOS-100 shipping cages impact analysis results, which include shipping cage stress and deformation, and rigid body velocity and global dynamic energy plots of the transport package. The dynamic energy time histories include kinetic energy, internal energy, hourglass energy, and sliding energy, as described in Table 2-366, and illustrated in Figure 2-136, Figure 2-139, and Figure 2-142, for Head-On, Side, and Cg/Corner, respectively.

Table 2-366. Dynamic Energy Time Histories Energy Type Description Kinetic Used to study how much of the packagings kinetic energy is dissipated during impact. For a normal and completed drop impact scenario, the kinetic energy must be decreasing to a minimum value, as close as possible to zero, and then start to increase (due to rebounding).

When kinetic energy reaches the minimum point, the primary impact event is complete.

Internal Measures how much of the kinetic energy is converted to strain energy, either elastic or inelastic. Most likely, the internal energy is a measure of inelastic strain energy that corresponds to the energy absorber materials permanent deformation. Internal energy that is much smaller than the initial kinetic energy indicates that energy is not being dissipated.

Hourglass Numerical term that is produced by the mathematic solver, but not derived from kinetic energy. Strain energy that is numerically produced and proportional to the energy that is used to control the brick finite element (solid element) distortion. As recommended by the LS-DYNA Keyword Users Manual (References [2.40] and [2.41]), the brick elements perform best during the solution when the hourglass energy is limited to less than 10% of the internal energy.

Sliding Numerical term that is produced by the mathematic solver, but not derived from kinetic energy. The sliding energy plots represent the contact interfaces efficiency and the level of penetration between adjacent parts, as follows:

Positive sliding energy - Indicates that the contact interface is working well and that there are no penetrations.

Negative sliding energy - Indicates that the contract interface is not working well and shows a high degree of penetration between adjacent parts.

Contact interface control parameters must be revised to allow for the use of different contact algorithms to help prevent part penetrations and pass-through.

Radioactive Material Transport Packaging System Safety Analysis Report 2-942ay for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.4.1 Head-On Drop Analysis Results Figure 2-134 through Figure 2-136 illustrate the Head-On Drop deformation, stress, and energy analysis results, respectively.

Figure 2-134. Shipping Cage Head-On Drop Deformation Contour (inches) - Model AOS-100 Figure 2-135. Shipping Cage Head-On Drop von Mises Stress Contour (psi) - Model AOS-100

2-942az Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Figure 2-136. Shipping Cage Head-On Drop Global Energy Data - Model AOS-100

Radioactive Material Transport Packaging System Safety Analysis Report 2-942ba for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.4.2 Side Drop Analysis Results Figure 2-137 through Figure 2-139 illustrate the Side Drop deformation, stress, and energy analysis results, respectively.

Figure 2-137. Shipping Cage Side Drop Displacement Contour (inch) - Model AOS-100 Figure 2-138. Shipping Cage Side Drop von Mises Stress Contour (psi) - Model AOS-100

2-942bb Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Figure 2-139. Shipping Cage Side Drop Global Energy Data - Model AOS-100

Radioactive Material Transport Packaging System Safety Analysis Report 2-942bc for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.4.3 Cg/Corner Drop Analysis Results Figure 2-140 through Figure 2-142 illustrate the Cg/Corner Drop deformation, stress, and energy analysis results, respectively.

Figure 2-140. Shipping Cage Cg/Corner Drop Displacement Contour (inch) - Model AOS-100 Figure 2-141. Shipping Cage Cg/Corner Drop von Mises Stress Contour (psi) - Model AOS-100

2-942bd Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Figure 2-142. Shipping Cage Cg/Corner Drop Global Energy Data - Model AOS-100

Radioactive Material Transport Packaging System Safety Analysis Report 2-942be for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.5 Impact Limiter Deformation Calculation The impact limiters were modeled as rigid bodies to simplify the shipping cage analysis. However, a review of the LS-DYNA results shows that a measurable amount of the free-drop energy was absorbed before one or both of the impact limiters were contacted. Therefore, the impact limiter deforms less during NCT drop events than what was previously calculated. Table 2-367 calculates the impact limiter deformation, using the remaining energy that was not absorbed by the shipping cage, and provides comparisons to previous calculated values.

Table 2-367. Maximum Impact Limiter Deformation during NCT Free Drops - Model AOS-100 Drop Type Parameter Value Head-On Velocity 125 in/s Unabsorbed Energy Displacement Calculation per this Analysis - 2.00 in.

Previous Calculation - 2.60 in.a

a. Refer to Table 2-35.

Side Velocity 60 in/s Unabsorbed Energy Displacement Calculation per this Analysis - 1.10 in.

Previous Calculation - 2.00 in.a Cg/Corner Velocity 40 in/s Unabsorbed Energy Displacement Calculation per this Analysis - 1.50 in.

Previous Calculation - 4.80 in.a 0.5 mv2 = 0.5 x ( ) x 1252 = 126,367 lb-in 0.5 x 12,500 386.4 0.5 mv2 = 0.5 x ( ) x 602 = 29,115 lb-in 0.5 x 12,500 386.4 0.5 mv2 = 0.5 x ( ) x 402 = 12,940 lb-in 0.5 x 12,500 386.4

2-942bf Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.6 Shipping Cage without Gusset Analysis Results This section documents the Model AOS-100 shipping cages structural response without the gusset plates, to accommodate the Model AOS-025 and AOS-050 shipping cage analysis results. In this analysis, the Head-On Drop orientation was considered because it resulted in the worst impact limiter deformation.

2.12.16.6.1 Head-On Drop (Shipping Cage without Gusset) Results Figure 2-143 through Figure 2-145 illustrate the Head-On Drop shipping cage without Gusset deformation, stress, and energy analysis results, respectively.

Figure 2-143. Shipping Cage (without Gusset) Head-On Drop Deformation Contour (inch) - Model AOS-100 Figure 2-144. Shipping Cage (without Gusset) Head-On Drop von Mises Stress Contour (psi) - Model AOS-100

Radioactive Material Transport Packaging System Safety Analysis Report 2-942bg for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Figure 2-145. Shipping Cage (without Gusset) Head-On Drop Global Energy Data - Model AOS-100

2-942bh Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 2.12.16.6.2 Additional Head-On Drop Shipping Cage Frame Analysis As indicated in Table 2-367 for the Head-On Drop, the rigid body shipping cask and impact limiters quickly bounce back before inducing sufficient stress to deform the shipping cage frames. However, because the impact limiters are deformable, they are predicted to crush before bouncing back, thereby causing the frame to buckle more. Hence, to study the maximum shipping cage frame deformation, an additional analysis was documented for the shipping cage without its gusset plates, in which the shipping cask and impact limiters were allowed to pass through the rigid wall by the distance that the impact limiters were predicted to deform. The maximum length that the impact limiters can deform is 2.4 in. The energy that was lost as the impact limiters crushed was conservatively neglected and no credit was taken for the wire mesh that supports the frames. As illustrated in Figure 2-146s displacement contour, the aluminum frames remain in place with some deformation.

Figure 2-146. Shipping Cage Frame Head-On Drop Deformation Contour (inch) - Model AOS-100

2-944 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

[2.20]

Communication from ATI Firth Sterling to Alpha-Omega Services, Inc., and GE Energy.

[2.21]

Parker O-Ring Division, Evaluation of Parker Compound S1224-70 to ASTM D2000 7GE705 A19 B37 EA14 EO16 E036 F19 G11 Compound Data Sheet, Kentucky, June 19, 1996.

[2.22]

Fitzroy, Nancy D., Ed., Heat Transfer Data Book, General Electric Company, New York, November, 1970 Edition, Section G502.5, p. 7.

[2.23]

Touloukian, Y. S., Thermophysical Properties of Matter, Metallic Elements and Alloys, 1971.

[2.24]

Fischer, L. E. and W. Lai, NUREG/CR-3854, Fabrication Criteria for Shipping Containers, Lawrence Livermore Laboratory, Prepared for U.S. Nuclear Regulatory Commission (NRC),

Livermore, California, March, 1985.

[2.25]

Monroe, R. E, H. H. Woo, and R. G. Sears, NUREG/CR-3019, Recommended Welding Criteria For Use in the Fabrication of Shipping Containers for Radioactive Materials, Lawrence Livermore Laboratory, Prepared for U.S. Nuclear Regulatory Commission (NRC), Livermore, California, March, 1984.

[2.26]

American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsections NB, NF, and NG, 2004 Ed., No Addendum.

[2.27]

ASTM International, ASTM F1145 - 05(2011), Standard Specification for Turnbuckles, Swaged, Welded, Forged, Table 3, West Conshohocken, PA, 2011.

[2.28]

Shigley, Joseph E., Mechanical Engineering Design, Chapter 6, The Design of Screws, Fasteners, and Connections, McGraw Hill, Inc., 3rd Edition, 1977.

[2.29]

American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code,Section VIII, Division 1, 2004 Ed., No Addendum.

[2.30]

U.S. Nuclear Regulatory Commission (NRC), Regulatory Guide 7.11, Fracture Toughness Criteria of Base Material for Ferritic Steel Shipping Cask Containment Vessels with a Maximum Wall Thickness of 4 Inches (0.1 m), 1991.

[2.31]

Holman, W.R, and R.T. Langland, NUREG/CR-1815, Recommendations for Protecting Against Failure by Brittle Fracture in Ferritic Steel Shipping Containers Up to Four Inches Thick, Lawrence Livermore National Laboratory, Prepared for U.S. Nuclear Regulatory Commission (NRC), June 15, 1981.

[2.32]

McConnell, J. W. Jr., A. L. Ayers, Jr., and M. J. Tyacke, NUREG/CR-6407, Classification of Transportation Packaging and Dry Spent Fuel Storage System Components According to Importance to Safety, Idaho National Engineering Laboratory, Prepared for U.S. Nuclear Regulatory Commission (NRC), Idaho Falls, Idaho, February, 1996.

[2.33]

American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code,Section III, Division 1, 2004 Ed., No Addendum.

[2.34]

ANSYS, Inc. ANSYS documentation release 15.0, November, 2013.

[2.35]

U.S. Nuclear Regulatory Commission (NRC), Title 10, Code of Federal Regulations, Part 71.71 (10 CFR 71.71), Packaging and Transportation of Radioactive Material - Normal conditions of transport, 2015.

[2.36]

Livermore Software Technology Corporation (LSTC), LS-PrePost, Version 4.3, 2016.

[2.37]

Autodesk, Autodesk Inventor Professional, 2016.

Radioactive Material Transport Packaging System Safety Analysis Report 2-945 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

[2.38]

ANSYS Inc., ANSYS Workbench, Release 15.0, 2015.

[2.39]

ANSYS Inc., ANSYS Mechanical, Release 15.0, 2015.

[2.40]

LSTC, LS-DYNA Keyword Users Manual, Volume I, Version 971, 2007.

[2.41]

LSTC, LS-DYNA Keyword Users Manual, Volume II, Version 971, 2012.

2-946 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

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3-2 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

The maximum decay heat for each AOS Transport Packaging System model is distributed across the cask cavity surface. Condition 3 (fire transient) analysis is initiated at the steady-state Condition 1, in which the maximum solar load is applied.

3.1.2 Contents Decay Heat Table 1-2, Activity Limits (All Isotopes Except Ir-192 and Ir-194) - All Models, and Table 1-2a, Ir-192 and Ir-194 Activity Limits - All Models, provide the maximum decay heat and radioactivity for the AOS Transport Packaging System contents. This includes Decay Heat (W/Ci) values for each radioisotope listed, showing that the decay heat is consistent with the maximum quantity of radioactivity contents.

A summary of the Decay Heat values is shown in Table 3-2. The method that is used for calculating the decay heat for isotope mixtures in Models AOS-100A and AOS-100A-S is presented in Appendix 5.5.5, Shipments of Multiple Isotopes - Models AOS-100A and AOS-100A-S.

Table 3-1. Transport Package Thermal Environment Conditions - All Models Condition Conditions of Transport Thermal Environment 1

Normal 38°C (100°F) ambient with maximum decay heat and maximum solar load.

2 Normal 38°C (100°F) ambient with maximum decay heat.

3 Hypothetical Accident (Fire)

Fire transient, t = 0 to 8.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />.

4 Normal

-40°C (-40°F) ambient with maximum decay heat.

5 Normal

-40°C (-40°F) ambient.

6 Normal

-29°C (-20°F) ambient with maximum decay heat.

7 Normal

-29°C (-20°F) ambient.

Table 3-2. Contents Decay Heat - All Models Model Contents Decay Heat (W)

AOS-025A 10 AOS-050A 100 AOS-100A 400 AOS-100B 400 AOS-100A-S 400

5-6 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 5.2 SOURCE SPECIFICATION Table 5-6 lists the activation products to be loaded in the AOS transport package, for each transport package model. Ir-194 impurities may be present in Ir-192 shipments, in quantities as designated in Table 1-2a, Ir-192 and Ir-194 Activity Limits - All Models. Nb-95 may be loaded with Zr-95 in Models AOS-050 and AOS-100, but only as specified in Subsection 5.2.1. Shipment of multiple isotopes is permitted in Models AOS-100A and AOS-100A-S, as specified in Appendix 5.5.5.

Because of the penetration power of neutral radiation, such as gamma rays, these were the main concern for shielding calculations. Charged particles, such as alpha and beta particles, are not able to penetrate the casks thick shield layers, and the assumption was made to ignore these charged particles and their secondary particles (such as bremsstrahlung photons induced by beta particles) for shielding evaluations.

5.2.1 Gamma Source The source description for activation products is obtained from isotope decay schemes that detail the gamma particle energies and their absolute probabilities of emission per disintegration (decay). For all isotopes except Zr/Nb-95, these decay schemes are explicitly modeled in the cask, based on discrete gamma energy and emission probability source terms extracted from the SCALE 6.1 ORIGEN (Reference [5.2]) gamma spectrum library origen.rev04.mpdkxgam.data. All available gamma energies from the library are considered in the shielding calculations. Total photon/decay values are also calculated and used, based on the information contained in the gamma spectrum library, by summing the total absolute probability of emission, per decay, from all possible energies for a given isotope.

Table 5-23 through Table 5-31 in Appendix 5.5.2 list the source spectra used in the shielding models.

Table 5-6. Isotopes Analyzed for AOS Transport Packages - All Models Isotope Model AOS-025 AOS-050 AOS-100 Co-60

Cs-137

Hf-181

Ir-192

Ir-194

Zr/Nb-95

Ho-166

Yb-169

Radioactive Material Transport Packaging System Safety Analysis Report 5-21 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

For the activity limits of all individual isotopes other than Ir-192 and Ir-194, refer to Table 1-2, Activity Limits (All Isotopes Except Ir-192 and Ir-194) - All Models. For the activity limits of Ir-192 sources with Ir-194 impurities, refer to Table 1-2a, Ir-192 and Ir-194 Activity Limits - All Models.

Shipment Transportation Index (TI) can be calculated by using the highest dose at 1m from the deformed impact limiter for each isotope and transport package combination. These numbers are defined in Table 5-13 through Table 5-20. The dose rates reported result in a single package always having a TI less than 10, allowing for non-exclusive shipment of a single cask. If multiple casks are shipped together, their respective TI values must be summed to determine whether their shipment must be for exclusive or non-exclusive use.

Table 5-13. Maximum Radiation Levels (All Isotopes Except Ir-192 and Ir-194)a - Model AOS-025A

a. Refer to Table 5-17 for Ir-192 and Ir-194 maximum radiation levels.

Isotope Source Strength (Ci)

Photon/Bq Location Maximum Dose Rate/

Curie (mrem/hr/

Ci)

Peak Dose Rate (mrem/hr)

Limit (mrem/hr)

Shipping Configuration Co-60 1.33E-01 1.9986 External Surface 1.355E+03 180.00 200 Use of Tungsten Alloy Liner (183C8485) is required 1m from Cask Surface 1.879E+01 2.50 1,000 1m from External Surface 1.713E+01 2.28 10 Cs-137 1.00E+01 0.9811 External Surface 1.800E+01 180.00 200 1m from Cask Surface 3.252E-01 3.25 1,000 1m from External Surface 2.835E-01 2.83 10 Ho-166 1.32E+01 0.20611 External Surface 1.366E+01 180.00 200 1m from Cask Surface 1.906E-01 2.51 1,000 1m from External Surface 1.736E-01 2.29 10 Yb-169 1.59E+05 3.7623 External Surface 1.131E-03 180.00 200 1m from Cask Surface 2.307E-05 3.67 1,000 1m from External Surface 1.995E-05 3.18 10

Radioactive Material Transport Packaging System Safety Analysis Report 5-23 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 5-15. Maximum Radiation Levels (All Isotopes Except Ir-192 and Ir-194)a b -

Model AOS-100A and AOS-100A-S

a. Refer to Table 5-19 for Ir-192 and Ir-194 maximum radiation levels.

b. Higher activity limits are permissible when transporting exclusive use. Refer to Appendix 5.5.7.

Isotope Source Strength (Ci)

Photon/Bq Location Maximum Dose Rate/

Curie (mrem/hr/

Ci)

Peak Dose Rate (mrem/hr)

Limit (mrem/hr)

Shipping Configuration Co-60 2.73E+02 1.9986 External Surface 3.912E-01 106.95 200 No Liner 1m from Cask Surface 5.545E-02 15.16 1,000 1m from External Surface 3.292E-02 9.00 10 Co-60-B 8.23E+02 1.9986 External Surface 1.139E-01 93.77 200 Use of Tungsten Alloy Axial Shielding Plates (183C8491) is required 1m from Cask Surface 1.833E-02 15.09 1,000 1m from External Surface 1.093E-02 9.00 10 Co-60-Cc c.

For Co-60-C quantities, the maximum allowable specific activity is 350 Ci/g (that is, no more than 350 Ci of Co-60 in a gram of Cobalt).

2.02E+04 1.9986 External Surface 3.947E-03 79.80 200 Use of Tungsten Alloy Axial Shielding Plates (183C8491) and Cavity Spacer Plates (183C8518) are required 1m from Cask Surfaced

d. Dose rates based on Co-60-B configuration, assuming that only the tungsten alloy axial shielding plates survive Hypothetical Accident conditions of transport.

1.833E-02 370.27 1,000 1m from External Surface 4.452E-04 9.00 10 Cs-137 3.55E+04 0.9811 External Surface 3.188E-03 113.31 200 1m from Cask Surface 4.152E-04 14.76 1,000 1m from External Surface 2.532E-04 9.00 10 Hf-181 4.34E+05 1.8501 External Surface 2.595E-04 112.50 200 1m from Cask Surface 3.413E-05 14.80 1,000 1m from External Surface 2.076E-05 9.00 10 Zr/Nb-95 3.61E+03 3.2000 External Surface 3.098E-02 111.80 200 1m from Cask Surface 4.106E-03 14.82 1,000 1m from External Surface 2.494E-03 9.00 10

5-24 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 5-16. Maximum Radiation Levels (All Isotopes Except Ir-192 and Ir-194)a - Model AOS-100B

a. Refer to Table 5-20 for Ir-192 and Ir-194 maximum radiation levels.

Isotope Source Strength (Ci)

Photon/Bq Location Maximum Dose Rate/

Curie (mrem/hr/

Ci)

Peak Dose Rate (mrem/hr)

Limit (mrem/hr)

Shipping Configuration Co-60 1.09E+01 1.9986 External Surface 9.217E+00 100.29 200 No Additional Components 1m from Cask Surface 1.358E+00 14.77 1,000 1m from External Surface 8.271E-01 9.00 10 Cs-137 5.82E+02 0.9811 External Surface 1.871E-01 108.84 200 1m from Cask Surface 2.515E-02 14.63 1,000 1m from External Surface 1.547E-02 9.00 10 Hf-181 4.39E+03 1.8501 External Surface 2.527E-02 110.93 200 1m from Cask Surface 3.354E-03 14.72 1,000 1m from External Surface 2.051E-03 9.00 10 Zr/Nb-95 7.31E+01 3.2000 External Surface 1.459E+00 106.60 200 1m from Cask Surface 2.000E-01 14.62 1,000 1m from External Surface 1.232E-01 9.00 10

5-28 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 5.5 APPENDIX This appendix presents the following information:

AOS Cask Isotopic Heat Load Calculations Isotope Values for Calculations MCNP6 Input and Output Files for Dose Calculations Cobalt-60-C Volume Source Calculation Shipments of Multiple Isotopes - Models AOS-100A and AOS-100A-S Isotopes Insignificant to External Dose Rates Exclusive Use Activity Limits - Models AOS-100A and AOS-100A-S 5.5.1 AOS Cask Isotopic Heat Load Calculations Table 5-21 provides the decay heat values generated from SCALE 6.1 ORIGEN [5.2] decay library origen.rev03.decay.data for each isotope analyzed in this chapter. This library provides a Q value, in MeV/disintegration, for each isotope. For each isotope, Table 5-21 also provides the isotope identifier and Q value in the ORIGEN decay library.

For Cs-137, it is assumed that this isotope is combined with Ba-137m (due to the short half-life of Ba-137m). As a result, the heat load for Cs-137 is calculated using the Cs-137 and Ba-137m Q-value sum.

To be consistent with the shielding evaluation supporting Zr/Nb-95, the heat load is determined by multiplying the higher Q value of the two isotopes (Zr-95 as seen in Table 5-21) by a factor of 3.2. The resulting value is 1.62E-02 W/Ci for Zr/Nb-95.

Table 5-22 summarizes the final heat load values applicable to the isotopes analyzed in this chapter.

These values, along with the respective cask decay heat limits reported in Table 1-2, Activity Limits (All Isotopes Except Ir-192 and Ir-194) - All Models, and Table 1-2a, Ir-192 and Ir-194 Activity Limits -

All Models, are used to calculate activity limits based on heat loads. The heat load presented in Table 5-22 for each isotope is calculated as shown in Equation 5-8. Refer to Appendix 5.5.5 for the heat load calculations that are to be used for shipping multiple isotopes in Models AOS-100A and AOS-100A-S.

(5-8)

W Ci MeV disintegration J

MeV disintegrations s

Ci

Radioactive Material Transport Packaging System Safety Analysis Report 5-44a for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 5.5.5 Shipments of Multiple Isotopes - Models AOS-100A and AOS-100A-S This appendix documents the method that is used to demonstrate external dose rate and decay heat requirement compliance when mixing multiple isotopes within a single shipping casks contents.

Table 5-34 lists the equations that are used to calculate the total dose rate and decay heat from multiple isotopes. These equations are based on the dose rate acceptance criteria, as identified in Subsection 5.4.4 and the Model AOS-100 400-W decay heat limit.

where:

Ai

=

Isotope i activity within the shipping cask contents (Ci) n

=

Quantity of isotopes within the shipping cask contents RSi

=

External surface dose rate/curie for isotope i within the shipping cask contents (mrem/hr/Ci)

R1mCi

=

1m from the shipping cask surface dose rate/curie for isotope i within the shipping cask contents (mrem/hr/Ci)

R1mPi

=

1m from the external surface dose rate/curie for isotope i within the shipping cask contents (mrem/hr/Ci)

Qi

=

Isotope i decay/curie within the shipping cask contents (W/Ci)

QLimit

=

AOS shipping cask decay heat limit (for example, 400W for Models AOS-100A and AOS-100A-S)

Table 5-34. Dose Rate Acceptance Criteria - Models AOS-100A and AOS-100A-S Criteria Value Transport Package Surface (External Surface)

Ai x RSi 180 mrem/hr Transport Index (1m from External Surface)

Ai x R1mPi 9 mrem/hr 1-m HAC (1m from Shipping Cask Surface)

Ai x R1mCi 900 mrem/hr Decay Heat Ai x Qi QLimit

n i

n i

n i

n i

5-44b Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

For Models AOS-100A and AOS-100A-S, the total external dose rates at each regulatory location and total decay heat are calculated using each isotopes activity within the shipping cask contents and their respective reference values in Table 5-35. Note that this method for mixing isotopes within a single content is applicable to all AOS shipping cask variants, using the dose rate information provided in Subsection 5.4.4 and decay heat values in Table 5-22. For Models AOS-100A and AOS-100A-S, an isotope that does not appear in Table 5-35 or fall within one of the categories addressed in Appendix 5.5.6 (that is, low-energy gamma and/or beta emitters) is not acceptable for shipment. For any mixture of isotopes in which the Co-60-B or Co-60-C dose rate/curie values are used, the required axial shielding and cavity spacer plate components shall be used. For isotopes other than Co-60 (that is, those for which the axial shielding and cavity spacer plates were not analyzed), the added use of these components will decrease external dose rates, thereby providing additional margin to the values listed in Table 5-35.

Table 5-35. Multiple Isotope Calculation Reference Value Summary -

Models AOS-100A and AOS-100A-S Isotope Dose Rate Locationa (mrem/hr/Ci)

a. Dose rates in units of mrem/hr/Ci, from Table 5-19 (Ir-192 and Ir-194 only) and Table 5-15 (all others).

Decay Heat Qi b

(W/Ci)

b. Decay heat in units of W/Ci, from Table 5-22.

External Surface RSi 1m from External Surface R1mPi 1m from Shipping Cask Surface R1mCi Co-60 3.912E-01 3.292E-02 5.545E-02 1.55E-02 Co-60-Bc c.

Use of these dose rate/curie values requires the use of axial shielding plates.

1.139E-01 1.093E-02 1.833E-02 1.55E-02 Co-60-Cd

d. Use of these dose rate/curie values requires the use of axial shielding plates and cavity spacer plates.

3.947E-03 4.452E-04 1.833E-02 1.55E-02 Cs-137 3.188E-03 2.532E-04 4.152E-04 4.99E-03 Hf-181 2.595E-04 2.076E-05 3.413E-05 4.33E-03 Ir-192 5.802E-04 4.619E-05 7.547E-05 6.13E-03 Ir-194 4.502E-03 3.871E-04 6.536E-04 5.30E-03 Zr/Nb-95 3.098E-02 2.494E-03 4.106E-03 1.62E-02

Radioactive Material Transport Packaging System Safety Analysis Report 5-44c for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 5.5.6 Isotopes Insignificant to External Dose Rates This appendix addresses isotopes that are considered insignificant to external dose rates by defining the requirements and minimum gamma emission energy at which the effect on external dose rates is considered significant. Additionally, W/Ci values are provided for multiple low-energy gamma and beta emitter isotopes as examples of typical values that are necessary for calculating the decay heat of each isotope.

To determine the minimum gamma emission energy at which the effect on external dose rates is considered significant, multiple additional MCNP cases were run to calculate external dose rates for low-energy gammas for the Model AOS-100A and AOS-100A-S configurations. These additional MCNP cases are identical to the MCNP cases defined in Section 5.3, with only the source spectra changed. Top, side, and corner dose rate cases are analyzed with identical model materials and geometry (refer to Paragraph 5.3.1.1) and tallies (refer to Paragraph 5.3.1.4). For each case analyzed within this appendix, the only change was the source energy, from an isotope spectrum to a single emission energy of either 0.2 or 0.3 MeV.

Only Models AOS-100A and AOS-100A-S without their axial shielding or cavity spacer plates are being analyzed for low-energy gamma emissions. Thus, the determined minimum significant gamma energy is applicable only to the Model AOS-100A and AOS-100A-S configurations, and no exclusion criteria for low-energy gamma emitters is set for the other AOS shipping cask variants. This refers to the Model AOS-100A and AOS-100A-S in any configuration (that is, with or without axial shielding or cavity spacer plates) because the configurations with the axial shielding or cavity spacer plates are bounded by the bare cask cavity configuration without these plates. Table 5-36 presents a summary of the calculated values.

Table 5-36. Low-Energy Gamma External Dose Rates - Models AOS-100A and AOS-100A-S Gamma Energy (MeV)

Direction Dose Rates External Surface 1m from External Surface 1m from Shipping Cask Surface (mrem/hr/Ci)a

a. Dose rates in units of mrem/hr/Ci, based on 1 /decay (MCNP output).

(mrem/hr)b

b. Maximum dose rate contribution based on limiting activity from decay heat limit (3.374E5 Ci for 0.2 MeV and 2.249E5 for 0.3 MeV).

(mrem/hr/Ci)a (mrem/hr)b (mrem/hr/Ci)a (mrem/hr)b 0.2 Top 1.774E-12 5.985E-07 3.065E-13 1.034E-07 4.747E-13 1.601E-07 Side 5.425E-15 1.831E-09 3.706E-16 1.250E-10 5.233E-16 1.766E-10 Corner 2.087E-09 7.042E-04 1.623E-10 5.478E-05 2.679E-10 9.038E-05 0.3 Top 4.464E-09 1.005E-03 7.397E-10 1.664E-04 1.137E-09 2.559E-04 Side 1.466E-11 3.299E-06 1.267E-12 2.851E-07 1.716E-12 3.862E-07 Corner 2.379E-06 5.353E-01 1.869E-07 4.206E-02 3.056E-07 6.876E-02 Maximum Location Dose Ratec c.

Based on the maximum allowable dose rate at each location plus the maximum dose rate that accounts for 400W of 0.3-MeV gammas (that is, the maximum possible dose rate that accounts for the maximum quantity of 0.3-MeV gammas).

180.54 mrem/hr 9.04 mrem/hr 900.07 mrem/hr

5-44d Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

The flux values calculated in MCNP have been converted to dose rates, using the ANSI/ANS-6.1.1 1977 (Reference [5.5]) dose conversion factors (refer to Subsection 5.4.3) and a 3.7E10 multiplier (refer to Subsection 5.4.4). Thus, the dose rates listed in Table 5-36 can be considered for 1 Ci of an isotope that emits one gamma/decay. For a source that emits gammas at an energy of 0.2 or 0.3 MeV, the limiting activity (assuming 1 /decay) based on the Model AOS-100A and AOS-100A-S shipping casks 400-W decay heat limit is calculated as follows:

0.2-MeV gammas -

0.3-MeV gammas -

Note that although the isotopes might emit more or fewer gammas/decay, thereby resulting in a different activity that is equivalent to a 400-W decay heat, the total quantity of gammas/sec emitted is the same.

Thus, the maximum dose rate values listed in Table 5-36 are bounding, regardless of the isotopes actual gammas/decay quantity when the limiting activity is based on the decay heat. It should also be considered that these calculated activities equivalent to the 400-W decay heat limit do not consider any electron emissions that are characteristic of low-energy gamma isotopes. If electron emissions were accounted for as well, the total quantity of gammas/sec would be decreased, thereby also decreasing the calculated maximum dose rate.

The maximum dose rate at each regulatory location based on this activity limit is provided in Table 5-36.

Based on the statistical convergence information in each MCNP output (that is, statistical checks, tally fluctuation charts, fractional standard deviations, and probability density function plots), it was determined that all tallies are sufficiently converged, and that the reported dose rate results are accurate. Because there is a 10% margin built into all external dose rate limits per Subsection 5.1.2, the regulatory dose rate limits would not be exceeded even if these neglected low-energy gamma isotopes were accounted for.

Evaluating the Maximum Location Dose Rate row in Table 5-36 shows that in the worst-case scenario for all dose rate locations, the remaining margin to the regulatory dose rate limit would still be greater than 9.5%. Additionally, it should be noted that although the total allowable activity based on the 400-W decay heat increases with lower gamma energy emissions, the maximum resulting dose rates decrease because the reduction in dose rate/curie is greater than the increase in activity for lower energies (comparison of 0.2 and 0.3MeV maximum dose rate results in Table 5-36). Thus, based on the results of this additional calculation, Models AOS-100A and AOS-100A-S in any configuration (with or without axial shielding and cavity spacer plates) may transport any isotope with all gamma emissions below 0.3 MeV without accounting for its contribution to external dose rates. Some examples of isotopes that fall within this category are Fe-55, V-49, and I-125.

For all AOS shipping cask variants, beta particles and their secondary radiation (that is, bremsstrahlung photons) cannot sufficiently penetrate an AOS shipping casks shielding to contribute to external dose rates. Note that although the term beta particles specifically refers to electrons that are emitted through beta decay, in this context, beta particles refers to any electron that is emitted from an isotope regardless of decay mode (that is, including electrons emitted by way of other decay modes, such as internal conversion of the auger effect). Thus, isotopes that emit only beta particles can be transported within any of the AOS shipping casks, in any configuration, without accounting for any contribution to external dose rates. Some common examples of pure beta emitters are H-3, C-14, P-32, and Ni-63.

400 J s

1 eV 1.602167E-19J 1

0.2E6 eV 1 Ci 3.7E10 x

x x

= 3.374E5 Ci

S 400 J s

1 eV 1.602167E-19 1

0.3E6 eV 1 Ci 3.7E10 x

x x

= 2.249E5 Ci

S

Radioactive Material Transport Packaging System Safety Analysis Report 5-44e for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

As determined earlier in this appendix, low-energy gamma emitters (that is, all gammas that are less than 0.3 MeV) and pure beta emitters do not need to be accounted for in dose rate calculations. However, the decay heat from these isotopes must be accounted for when calculating the shipping cask contents total decay heat output. The method defined in Appendix 5.5.1 can be used to determine any isotopes decay heat value (in units of W/Ci), using reference decay heat Q-values from the SCALE 6.1 ORIGEN (Reference [5.2]) decay library origen.rev03.decay.data. The decay heat contribution of all radioisotopes within the shipping cask contents must be accounted for, regardless of whether they contribute to external dose rates. Table 5-37 provides calculated decay heat values for some example isotopes that would not be included in dose rate calculations, but must be considered for decay heat calculations. It should be noted that Table 5-37 is not a comprehensive list of all low-energy gamma and beta emitters, but provides examples of some typical isotopes. These calculated decay heat values can be used along with the decay heat values provided in Table 5-35 to determine the decay heat of shipping cask contents that have a mixture of isotopes, as defined in Appendix 5.5.5.

Table 5-37. Example Low-Energy Gamma and Beta Emitter Decay Heat Values Isotope Library Isotope Identifier (origen.rev03.decay.data)a

a. Reference [5.2].

Q Value (MeV/Disintegration)

Decay Heat (W/Ci)

H-3 10030 5.6900E-03 3.38E-05 C-14 60140 4.9470E-02 2.94E-04 P-32 150320 6.9490E-01 4.12E-03 V-49 230490 4.4514E-03 2.64E-05 Fe-55 260550 5.8421E-03 3.47E-05 Ni-63 280630 1.7425E-02 1.04E-04 I-125 531250 6.0467E-02 3.59E-04

5-44f Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 5.5.7 Exclusive Use Activity Limits - Models AOS-100A and AOS-100A-S This appendix analyzes Models AOS-100A and AOS-100A-S under the conditions permitted for Exclusive Use shipments and establishes applicable activity limits. The activity limits established in Subsection 5.4.4 for all AOS shipping cask models are based on compliance with 10 CFR 71.47(a) and 71.51(a)(2)

(Reference [5.1]) for NCT and HAC, respectively. However, 10 CFR 71.47(b) (Reference [5.1]) allows for the use of alternative dose rate limits if 10 CFR 71.47(a) dose rate limits are exceeded. Thus, if the activity limits established in Subsection 5.4.4 are exceeded, the shipping cask contents may still be acceptable for shipment under 10 CFR 71.47(b) requirements, as long as the shipment is exclusive use. 10 CFR 71.47(a) requirements are applicable to both exclusive and non-exclusive use shipments. For simplicity within this appendix, however, 10 CFR 71.47(a) requirements are referred to as non-exclusive use limits, and 10 CFR 71.47(b) requirements are referred to as exclusive use limits.

The Subsection 5.4.4 activity limits that are based on non-exclusive use dose rate limits that are usually limited by the 1m from external surface (TI) dose rate limit. However, when shipping exclusive use, the TI limit may be neglected, thus allowing for higher activity limits. Per 10 CFR 71.47(b), there are additional dose rate limits for exclusive use, for 2m from the transport vehicle trailers outer lateral surfaces and any normally occupied space (that is, the driver cab). Applying a 10% margin to all regulatory dose rate limits results in the additional exclusive use shipment activity limits listed in Table 5-38. These additional activity limits are calculated only for the Model AOS-100A shipping cask variant and are also applicable to the Model AOS-100A-S shipping cask variant.

Table 5-38. Additional Exclusive Use Dose Rate Locations and Activity Limits -

Models AOS-100A and AOS-100A-S Conditions of Transport Dose Rate Location Limit Value (mrem/hr)

NCT External Surface 180 2m from Trailer Surface 9

Driver Cab 1.8 HAC 1m from Shipping Cask Surface 900

Radioactive Material Transport Packaging System Safety Analysis Report 5-44g for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

The NCT external surface and HAC 1m from shipping cask surface dose rates for each isotope are already calculated in Subsection 5.4.4 for each isotope. Thus, to allow for higher activity limits for exclusive use transport, the NCT 2m from trailer surface and driver cab dose rates for each isotope must be determined.

The Model AOS-100A and AOS-100A-S shipping casks are always transported in the upright position; thus, the NCT 2m from trailer surface and driver cab dose rates are applicable only to the shipping casks lateral (radial) direction. Additionally, the following requirements are set for exclusive use shipments to support these additional dose rate location calculations:

Only one transport package may be shipped per trailer Trailer used for transporting the transport package must be standard width (8-ft. wide),

at minimum Transport package must be secured to the trailers center (side-to-side) and at least 20 ft. back from the driver cab (transport package centerline to driver cab)

With these parameters set, the lateral distances from the shipping casks centerline to the NCT 2m from trailer surface and driver cab dose rate locations are determined as follows:

NCT 2m from trailer surface location - Shipping cask centerline to the outer lateral vehicle surfaces (4 ft) + 2-m tally distance NCT Driver cab location - Shipping cask centerline to the drivers cab (20 ft.)

For the additional exclusive use dose rate calculations, the same MCNP model as defined in Paragraph 5.3.1.1 was used with the spacer components defined in Paragraph 5.3.1.2 for the relevant configurations (that is, Co-60-B and Co-60-C). The source is modeled as a point source in the top corner of the available cask cavity, as defined in Paragraph 5.3.1.3, to allow for streaming around the tungsten alloy axial shielding plates and provide bounding calculated dose rates. The exception to this is the Co-60-C calculation, where the source is modeled as a small volume. Per the results provided in Table 5-33, the most restrictive source geometry is an arc segment with an ID= 6.00 in. and inner angle of = 80°. Thus, this source geometry is used for the Co-60-C configurations exclusive use dose rate calculations. In Table 5-33, the tallies at each lateral distance are divided into a column of small tally cells so that the flux is not averaged over too large a volume. Note that the tally cells do not curve in the same way as the tallies shown in Figure 5-7. Instead, the tally cells form a single column because the new dose rate locations are applicable only in the lateral direction. The cell tally at the maximum calculated dose rates axial location is used as the dose rate for each of those locations.

4 ft.

30.48 cm 1 ft.

x x

+

= 321.92 cm 2m 100 cm 1m

= 321.92 cm 20 ft.

30.48 cm 1 ft.

x

5-44h Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 5-39 summarizes the exclusive use MCNP calculation results, which include each regulatory dose rate locations maximum dose rate and each isotopes W/Ci factor. Based on these values, each isotopes maximum activity limit is determined based on the limiting dose rate location or decay heat. A review of the statistical convergence information in each MCNP output (that is, statistical checks, tally fluctuation charts, fractional standard deviations, and probability density function plots) indicates that all tallies are sufficiently converged, and that the reported dose rate results are accurate.

Table 5-39. Exclusive Use Activity Limit Maximum Dose Rates and Decay Heat -

Models AOS-100A and AOS-100A-Sa

a. Maximum allowable activity at which all dose rate locations do not exceed exclusive use dose rate limits, and the decay heat does not exceed 400W.

Isotope Dose Rate Location (mrem/hr/Ci)

Decay Heatb (W/Ci)

b. Decay heat in units of W/Ci, from Table 5-22.

Exclusive Use Activity Limit (Ci)

NCT HAC External Surfacec c.

Dose rates in units of mrem/hr/Ci, from Table 5-19 (Ir-192 and Ir-194 only) and Table 5-15 (all others).

2m from Trailer Surface Driver Cab 1m from Shipping Cask Surfacec Co-60 3.912E-01 2.457E-03 5.011E-04 5.545E-02 1.55E-02 460.2 Co-60-B 1.139E-01 4.973E-04 7.277E-05 1.833E-02 1.55E-02 1,580.3 Co-60-C 3.947E-03 5.577E-05 1.534E-05 1.833E-02 1.55E-02 25,806.5 Cs-137 3.188E-03 1.152E-05 2.240E-06 4.152E-04 4.99E-03 56,460.4 Hf-181 2.595E-04 7.384E-07 1.416E-07 3.413E-05 4.33E-03 92,378.8 Ir-192 5.802E-04 2.065E-06 3.957E-07 7.547E-05 6.13E-03 65,252.9 Ir-194 4.502E-03 3.130E-05 6.375E-06 6.536E-04 5.30E-03 39,982.4 Zr/Nb-95 3.098E-02 1.264E-04 2.471E-05 4.106E-03 1.62E-02 5,811.0

Radioactive Material Transport Packaging System Safety Analysis Report 5-44j for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Based on the Table 5-39 isotope activity limits, the Table 5-40 results show the dose rate at each exclusive use regulatory dose rate location and the total decay heat. Each isotopes limiting value is bolded. It can be noted from the Table 5-40 results that all activity limits are based on either the external surface dose rate location or decay heat. Neither of the exclusive use regulatory locations (that is, 2m from trailer surface or driver cab dose rate location) are close to the respective regulatory dose rate limit. For all isotopes, there is a significant margin between the maximum dose rates at the NCT 2m from trailer surface or driver cab locations and their respective regulatory limits. The activity increase is solely due to the removal of the non-exclusive use, NCT 1m from external surface activity limit.

Table 5-40. Exclusive Use Maximum Activity Dose Rates and Decay Heat - Model AOS-100A Isotope Dose Rate Locationa (mrem/hr)

a. Calculated based on Table 5-39 exclusive use activity limit and dose rate/curie values.

Decay Heatb (W)

b. Calculated based on Table 5-39 exclusive use activity limit and watt/curie (W/Ci) values.

NCT HAC External Surface 2m from Trailer Surface Driver Cab 1m from Shipping Cask Surface Co-60 180.00 1.13 0.23 25.52 7.13 Co-60-B 180.00 0.79 0.11 28.96 24.49 Co-60-C 101.87 1.44 0.40 472.93 400.00 Cs-137 180.00 0.65 0.13 23.44 281.74 Hf-181 23.97 0.07 0.01 3.15 400.00 Ir-192 37.86 0.13 0.03 4.92 400.00 Ir-194 180.00 1.25 0.25 26.13 211.91 Zr/Nb-95 180.00 0.73 0.14 23.86 94.14

5-44k Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

It is acceptable to transport mixtures of analyzed isotopes when shipping the Model AOS-100A and AOS-100A-S exclusive use by following the method defined in Appendix 5.5.5. Using the dose rate equations for the NCT external surface location, HAC 1-m from shipping cask surface location, and total decay heat defined in Appendix 5.5.5, and the equations for the NCT 2m from trailer surface and driver cab dose rate locations provided below, the total dose rates and decay heat for the isotope mixture within the shipping cask contents can be calculated. To complete these calculations, the transport packages user needs each isotopes activity within the mixture and the dose rate/curie values listed in Table 5-41.

Isotope mixtures are limited to the radionuclides listed in Table 5-41 and low-energy gamma and beta emitters, as defined in Appendix 5.5.6. For any isotope mixtures in which the Co-60-B or Co-60-C dose rate/curie values are used, axial shielding and cavity spacer plates shall be used.

NCT 2m from trailer surface location - Shipping cask centerline to the outer lateral vehicle surfaces (4 ft)

NCT Driver cab location - Shipping cask centerline to the drivers cab (20 ft.)

where:

Ai

=

Isotope i activity within the shipping cask contents (Ci) n

=

Quantity of isotopes within the shipping cask contents R2mi

=

2m from trailer surface dose rate/curie for isotope i within the shipping cask contents (mrem/hr/Ci)

R2Cabi

=

Driver cab dose rate/curie for isotope i within the shipping cask contents (mrem/hr/Ci)

n i

Ai x R2mi 9 mrem/hr

n i

Ai x RCabi 1.8 mrem/hr

Radioactive Material Transport Packaging System Safety Analysis Report 5-44m for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Table 5-41. Multiple Isotope Exclusive Use Calculation Reference Values - Model AOS-100A Isotope Dose Rate Locationa (mrem/hr/Ci)

a. Maximum dose rates in units of mrem/hr/Ci, from Table 5-39.

Decay Heat Qi b

(W/Ci)

b. Decay heat in units of W/Ci, from Table 5-39.

NCT HAC External Surface RSi 2m from Trailer Surface R2mi Driver Cab RCabi 1m from Shipping Cask Surface R1mCi Co-60 3.912E-01 2.457E-03 5.011E-04 5.545E-02 1.55E-02 Co-60-Bc c.

Use of these dose rate/curie values requires the use of axial shielding plates.

1.139E-01 4.973E-04 7.277E-05 1.833E-02 1.55E-02 Co-60-Cd

d. Use of these dose rate/curie values requires the use of axial shielding plates and cavity spacer plates.

3.947E-03 5.577E-05 1.534E-05 1.833E-02 1.55E-02 Cs-137 3.188E-03 1.152E-05 2.240E-06 4.152E-04 4.99E-03 Hf-181 2.595E-04 7.384E-07 1.416E-07 3.413E-05 4.33E-03 Ir-192 5.802E-04 2.065E-06 3.957E-07 7.547E-05 6.13E-03 Ir-194 4.502E-03 3.130E-05 6.375E-06 6.536E-04 5.30E-03 Zr/Nb-95 3.098E-02 1.264E-04 2.471E-05 4.106E-03 1.62E-02

5-44n Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

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7-6 Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 7.1.1.2 Removing the Transport Package from the Transport Vehicle To remove the transport package from the transport vehicle:

a.

Position the transport vehicle, in the job staging area, for transport package removal.

This operation can be aided by the use of a overhead crane or forklift truck.

b.

Position the spreader bar or forks, then connect the appropriate slings and shackles to remove the shipping cage.

c.

Remove the shipping cage and tie-down hardware.

d.

Depending upon site-specific constraints, do one of the following:

Remove the upper impact limiter from the cask, then place the impact limiter into temporary storage.

Install trunnions. Prior to the installation, apply an anti-vibration compound on the trunnion bolt threads.

Lift and remove the entire package from the transport vehicle, then set down the package in an appropriate location. Next, remove the impact limiters from the cask, and place them into temporary storage.

e.

Remove the cask, using the appropriate rigging equipment.

f.

Transfer the cask to the loading area.

7.1.2 Loading of Contents 7.1.2.1 Preparing for Loading To prepare the transport package for loading:

a.

Verify that the content to be loaded is authorized by the current transport packages Certificate of Compliance. (Refer to the Pre-Shipment Engineering Evaluation in Section 7.1 and guidance in Appendix 7.5.1.)

b.

Perform a visual inspection. Note any damage or unusual conditions. If part functionality is impaired, repair or replace the part, as required, and document the repair or replacement, then re-inspect the part. Notification and approval of AOS is required. Replacement or repair of any component requires that all original examinations and tests initially prescribed be performed.

c.

Depending upon the particular transport package model, remove the cask trunnions and install a lifting device specific to the facility. If using a forklift to transport the cask, protect the cask surface and secure the cask to the forks with straps. If lifting by crane, with or without a spreader bar, the lifting slings must not make an angle greater than 30°, measured from the vertical.

d.

With proper radiological protection and monitoring, remove the cask lid and cask lid plug for visual inspection of the cavity.

e.

Record any finding(s), and notify the Job Supervisor for disposition of the finding(s).

Findings must be evaluated against 10 CFR 71.95 [7.2], to determine whether they require regulatory notification, so that proper action can be taken.

f.

Visually inspect the cask and cask lid sealing surfaces for damage or foreign material.

Repair or replace damage noted, as required, then re-inspect.

g.

Remove the cask drain port, test port, and cask vent port covers, and pipe plugs. Completely remove all thread sealant from the pipe plugs.

h.

Optional - Install the lid guide pins, 90° apart. Use of the lid guide pins is mainly needed for proper alignment of the cask lid with the cask lid attachment bolt holes. The lid guide pins also protect the cask lid elastomeric or metallic seal.

Radioactive Material Transport Packaging System Safety Analysis Report 7-15 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 7.2 PACKAGE UNLOADING Note: The operational steps provided in this section apply to all AOS Radioactive Material Transport Packaging System models (Models AOS-025A, AOS-050A, AOS-100A, AOS-100B, and AOS-100A-S).

Any step specific to a given Model is identified within the step.

Operations at the unloading facility are largely the reverse of the loading operations. Each unloading facility must provide fully trained personnel, and supply detailed operating procedures to cover all activities, as required by 10 CFR 71.89 [7.2].

Before handling the packages, consider the following items:

a.

Review all shipping manifests against what is expected.

b.

Ensure that personnel involved in operations of the AOS Transport Packaging System are familiar with all documents pertinent to the operation and maintenance of the transport packages, and that they have received HAZMAT training, per 49 CFR 172.704 [7.7].

c.

Review Table 2-7, AOS Transport Packaging System Maximum Authorized Package Weight and Cg Locations - All Models (which lists the packages and their components weights), for the purpose of selecting the proper handling devices.

d.

Review Table 3-3, Maximum Temperature Summary, Normal Conditions of Transport - All Models, Table 3-4, Maximum Temperature Summary, Hypothetical Accident Conditions of Transport (Condition 3) - All Models, Table 4-6, Maximum Cask Cavity Pressure Due to Normal Conditions of Transport - All Models, and Table 4-7, Maximum Cask Cavity Pressure Due to Fire Condition - All Models, to be apprised of the packaging surface temperature and cavity pressures. These values represent maximum conditions.

e.

Review the Activity Limits listed in Table 1-2, Activity Limits (All Isotopes Except Ir-192 and Ir-194) - All Models, and Table 1-2a, Ir-192 and Ir-194 Activity Limits - All Models. These values represent maximum conditions. For shipping multiple isotopes in Models AOS-100A and AOS-100A-S, refer to Appendix 5.5.5, Shipments of Multiple Isotopes -

Models AOS-100A and AOS-100A-S.

f.

Review the AOS Transport Packaging System certification drawings listed in Table 1-5, AOS Transport Packaging System Certification Drawing List - All Models, in preparation for Receiving Inspection.

g.

All repairs require AOS approval prior to performing the repairs. Any replacement of components requires notification to AOS.

7.2.1 Receipt of Package from Carrier To receive the transport package from the carrier:

a.

Verify the integrity of the transport packages security seals. If seals are broken, indicating package tampering, isolate the transport package and immediately notify the sites Safeguards organization, then wait for their instructions. Otherwise, remove the security seal, by cutting the wires, then properly dispose of them.

Note: Safeguards organization refers to the organization or person at the facility responsible for radioactive material control and accounting.

b.

Repeat steps a through d in Paragraph 7.1.1.1, and steps b through e in Paragraph 7.1.1.2, to remove the package from the carrier.

c.

Perform radiological and smear surveys of the cask surfaces, as described in step a in Paragraph 7.2.2.

Radioactive Material Transport Packaging System Safety Analysis Report 7-19 for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316) 7.5 APPENDIX 7.5.1 Dose Rate and Decay Heat Limit Compliance Dose rate and decay heat limit compliance should be demonstrated through one of the following methods:

Shipping cask contents that contain a single radioisotope (or mixture of only Ir-192 and Ir-194) - Ensure that the isotopes activity does not exceed its limit for the appropriate shipping cask variant listed in Section 1.2.2. If the isotope is not listed for the shipping cask variant,

-or-the isotopes activity within the shipping cask contents is greater than the listed activity limit, the shipping cask contents are not acceptable for shipment.

Shipping cask contents that contain multiple radioisotopes, including low-energy gamma and/or beta emitters (as defined in Appendix 5.5.6, Isotopes Insignificant to External Dose Rates) - Calculate the external dose rates and shipping cask contents total decay heat, using the method defined in Appendix 5.5.5, Shipments of Multiple Isotopes -

Models AOS-100A and AOS-100A-S. All dose rate and decay heat calculations should be documented on an AOS QA program-approved form, similar to the example provided in Figure 7-8. When shipping Model AOS-100A or AOS-100A-S as exclusive use, refer to Appendix 5.5.7, Exclusive Use Activity Limits - Models AOS-100A and AOS-100A-S, for the external dose rate calculation methodology.

7-19a Radioactive Material Transport Packaging System Safety Analysis Report for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

Calculation Sheet - Procedure for Mixing Isotopes in AOS-100A PR9110.5 Table 1 Column No. 1 Enter proposed shipment activity in this column (Ci)

PR9110.5 (6.3)

Table 1 Column No. 2 PR9110.5 (6.5)

Table 1 Column No. 3 PR9110.5 (6.4)

Table 1 Column No. 4 PR9110.5 (6.6)

Table 1 Column No. 5 Ai Isotope RSi Dose Rate/

Curie on External Surface (mrem/hr/Ci)

R1mCi Dose Rate/

Curie at 1m from Shipping Cask Surface (mrem/hr/Ci)

R1mPi Dose Rate/

Curie at 1m from Transport Package Surface (mrem/hr/Ci)

Qi Heat Generation Rate (W/Ci)

Co-60 3.912E-01 5.545E-02 3.292E-02 1.550E-02 Co-60-B 1.139E-01 1.833E-02 1.093E-02 1.550E-02 Co-60-C 3.947E-03 1.833E-02 4.452E-04 1.550E-02 Cs-137 3.188E-03 4.152E-04 2.532E-04 4.990E-03 Hf-181 2.595E-04 3.413E-05 2.076E-05 4.330E-03 Ir-192 5.802E-04 7.547E-05 4.619E-05 6.130E-03 Ir-194 4.502E-03 6.536E-04 3.871E-04 5.300E-03 Zr-95/Nb-95 3.098E-02 4.106E-03 2.494E-03 1.620E-02 H-3 0

0 0

3.380E-05 C-14 0

0 0

2.940E-04 P-32 0

0 0

4.120E-03 V-49 0

0 0

2.640E-05 Fe-55 0

0 0

3.470E-05 Ni-63 0

0 0

1.040E-04 I-125 0

0 0

3.590E-04 Calculated Total Radiation Levels:

Maximum ValueP Dose Rate on External Surface =

0.00E+00 mrem/hr TRUE 180 mrem/hr maximum Dose Rate at 1m from Shipping Cask Surface =

0.00E+00 mrem/hr TRUE 900 mrem/hr maximum Dose Rate at 1m from Transport Package Surface =

0.00E+00 mrem/hr TRUE 9.0 mrem/hr maximum Calculated Total Heat:

Total Heat Generation =

0.00E+00 W TRUE 400 W maximum NOTE: Only those isotopes identified in the SAR, AOS Document No. FM9054 and low energy gamma/beta emitters are to be evaluated and shipped (See PR9110.5 Table 1)

Document Approval:

Completed By:

Engineering Approval:

Name/Signature:

Date:

Name/Signature:

Date:

QA:

President:

Name/Signature:

Date:

Name/Signature:

Date:

Figure 7-8. Example Dose Rate/Decay Heat Calculation Sheet (Model AOS-100A Non-Exclusive Shipment Version Shown)

Radioactive Material Transport Packaging System Safety Analysis Report 7-19b for Model AOS-025, AOS-050, and AOS-100 Transport Packages, Rev. H-5, July 20, 2018 (Docket No. 71-9316)

7.6 REFERENCES

[7.1]

International Atomic Energy Agency (IAEA) Safety Standards Series No. TS-R-1 (IAEA TS-R-1), Regulations for the Safe Transport of Radioactive Material, 1996 Ed.

(as amended 2003).

[7.2]

U.S. Nuclear Regulatory Commission (NRC), Title 10, Code of Federal Regulations, Part 71 (10 CFR 71), Packaging and Transportation of Radioactive Material.

[7.3]

U.S. Department of Transportation (DOT), Title 49, Code of Federal Regulations, Part 173 (49 CFR 173), Shippers - General Requirements for Shipments and Packagings.

[7.4]

U.S. Nuclear Regulatory Commission (NRC), Title 10, Code of Federal Regulations, Part 20 (10 CFR 20), Standards for Protection Against Radiation.

[7.5]

U.S. Nuclear Regulatory Commission (NRC), Title 10, Code of Federal Regulations, Part 21 (10 CFR 21), Reporting of Defects and Noncompliance.

[7.6]

U.S. Department of Transportation (DOT), Title 49, Code of Federal Regulations, Part 171 (49 CFR 171), General Information, Regulations, and Definitions.

[7.7]

U.S. Department of Transportation (DOT), Title 49, Code of Federal Regulations, Part 172 (49 CFR 172), Hazardous Materials Table, Special Provisions, Hazardous Materials Communications, Emergency Response Information, and Training Requirements.

[7.8]

American National Standards Institute, ANSI N14.5-1997, Radioactive Materials -

Leakage Tests on Packages for Shipment, February 5, 1998.