ML25118A332

Enclosure 2, Public/Redacted, Safety Evaluation Report, Certificate of Compliance No. 9390, Revision 5, Model No. OPTIMUS-L (Docket No. 71-9390, CAC No. 001029, EPID No. L-2024-LLA-0019)

ML25118A332
Person / Time
Site:	OPTIMUS-L
Issue date:	04/30/2025
From:	Garcia-Santos N Storage and Transportation Licensing Branch
To:	Baldner H NAC International
References
CAC 001029, EPID L-2024-LLA-0019
Download: ML25118A332 (1)

Text

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION SAFETY EVALUATION REPORT Docket No. 71-9390 Model No. OPTIMUS-L Certificate of Compliance No. 9390 Revision No. 5

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION TABLE OF CONTENTS Page

SUMMARY

................................................................................................................................. 1 1.0 GENERAL INFORMATION............................................................................................. 1 1.1 Packaging........................................................................................................... 2 1.2 Package.............................................................................................................. 2 1.3 Drawings............................................................................................................. 2 1.4 Contents............................................................................................................. 2 1.5 Evaluation Findings............................................................................................. 3 2.0 STRUCTURAL EVALUATION........................................................................................ 3 2.1 Description of the Structural Design.................................................................... 3 2.2 Structural Analysis.............................................................................................. 4 2.3 Evaluation Findings............................................................................................. 5 3.0 THERMAL EVALUATION............................................................................................... 5 3.1 Thermal Evaluation............................................................................................. 5 3.2 Description of the Package................................................................................. 5 3.3 Thermal Analyses under NCT and HAC.............................................................. 6 3.3.1 Thermal Resistances............................................................................... 6 3.3.2 CCV Component Temperature Using Computational Models.................. 7 3.3.3 Shielded Devices Casing Temperature................................................... 8 3.3.4 Shielded Device Temperature................................................................. 9 3.3.5 Operating Pressure................................................................................. 9 3.4 Evaluation Findings............................................................................................. 9 4.0 CONTAINMENT EVALUATION...................................................................................... 9 4.1 Description of Containment Boundary and Content............................................10 4.2 General Considerations.....................................................................................10 4.3 Evaluation Findings............................................................................................11 5.0 SHIELDING EVALUATION........................................................................................... 11 5.1 Description of Shielding Design.........................................................................11 5.1.1 Shielding Design Features.....................................................................11 5.1.2 Summary Tables of Maximum External Radiation Levels.......................12 5.2 Radioactive Materials and Source terms............................................................12 5.2.1 Source-Term Calculation Methods.........................................................12 5.3 Shielding Model and Model Specifications.........................................................12

OFFICIAL USE ONLY - PROPRIETARY INFORMATION ii OFFICIAL USE ONLY - PROPRIETARY INFORMATION 5.3.1 Configuration of Source and Shielding...................................................12 5.3.2 Material Properties.................................................................................13 5.4 Shielding Evaluation..........................................................................................13 5.4.1 Methods.................................................................................................13 5.4.2 Code Input and Output Data...................................................................14 5.4.3 Fluence-Rate-To-Radiation-Level Conversion Factors...........................14 5.4.4 External Radiation Levels.......................................................................15 5.4.5 Shielded Devices Conditions..................................................................15 5.5 Evaluation Findings............................................................................................16 6.0 CRITICALITY SAFETY EVALUATION......................................................................... 16 7.0 PACKAGE OPERATIONS............................................................................................ 16 7.1 Compliance with Dose Rate Limits.....................................................................16 7.2 Evaluation Findings............................................................................................17 8.0 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM.......................................... 17 9.0 QUALITY ASSURANCE............................................................................................... 17 CONDITIONS........................................................................................................................... 17 CONCLUSION.......................................................................................................................... 19

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION SAFETY EVALUATION REPORT Docket No. 71-9390 Model No. OPTIMUS-L Certificate of Compliance No. 9390 Revision 5

SUMMARY

By letter dated July 8, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24191A044), as supplemented on July 17, 2024 (ML24204A170),

September 10, 2024 (ML24255A813), November 14, 2024 (ML24319A234), November 18, 2024 (ML24327A142), February 6, 2025 (ML25037A292), February 19, 2025 (ML25050A045),

and April 10, 2025 (ML25100A218), NAC International (NAC or the applicant), requested a revision to the Certificate of Compliance (CoC) for the Model No. OPTIMUS-L (OPTImal Modular Universal Shipping Cask) package design. The applicants request included the following changes:

1)

Drawing Nos. 70000.14-L502, Packaging Assembly OPTIMUS-L, Revision 1P, and 70000.14-L595, Shielded Device Insert Assembly, OPTIMUS-L, Revision 1P.

2)

Adding shielded devices containing special and normal form sealed sources as authorized contents

3)

Adding the shielded device insert assembly (SDIA) to the package design for transporting shielded devices containing special and normal form sealed source content.

Changes made to the enclosed certificate (Enclosure 1) are indicated by vertical lines in the margin.

The United States (U.S.) Nuclear Regulatory Commissions (NRC) staff (the staff thereafter) reviewed the safety analysis report (SAR) (also referred as the application in this document),

including its supplements, using the guidance in NUREG-2216, Standard Review Plan for Transportation Packages for Spent Fuel and Radioactive Material: Final Report (NUREG-2216). Based on the statements and representations in the application, as supplemented, and the conditions listed in this safety evaluation report (SER), the staff concludes that the package meets the requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 71, Packaging and Transportation of Radioactive Material.

1.0 GENERAL INFORMATION The applicant proposed adding shielded sources as authorized contents to be transported in the OPTIMUS-L package. The applicant updated added the Shielded Device Insert Assembly (SDIA) for transporting shielded normal and special form sources, updated and added drawings, and provided the analyses to demonstrate compliance with 10 CFR Part 71. These analyses included considering the cask containment vessel (CCV) of the OPTIMUS-L package under

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION required regulatory drop scenarios. Shielded devices are shielded steel weldments containing sealed sources meeting the specifications as described in Section 1.4 of this SER. The rest of the package remains unchanged by this new content. The application demonstrates that the stress induced in the CCV walls, by the change in content, is bounded by the stress computed for the previously approved design of the OPTIMUS-L package (i.e., Revision 4 of the CoC No.

9390). The evaluation of these changes is discussed in this SER.

1.1 Packaging Section 1.2.1 of the application includes a description of the changes to the packaging. The applicant added the SDIA to the design of the Model No. OPTIMUS-L. The OPTIMUS-L shielded devices application is a modified version of the OPTIMUS-L shipping package in which the spent fuel and basket assembly within the CCV is replaced with a Celotex insert to house the bounding size and shape of a Hopewell G10 series irradiator. The SDIA is the internal support structure that secures the shielded source within the OPTIMUS-L CCV, protecting the CCV from impact with the shielded source.

The SDIA is placed in the CCV cavity for transporting the shielded normal and special form sources. The insert consists of two axial aluminum spacers, placed at the bottom and top of the configuration, with an insert between the axial spacers. Both axial spacers are equivalent and can be used at either the top or bottom of the configuration. Additional axial dunnage shall be inserted below and above the shielded devices to fill the axial gaps.

1.2 Package The OPTIMUS-L package provides leaktight containment of the radioactive contents under normal conditions of transport (NCT) and hypothetical accident conditions (HAC). The package can be transported by truck under exclusive use and it is not authorized for transport by air.

1.3 Drawings The applicant proposed changes to drawing No. 70000.14-L502, Packaging Assembly OPTIMUS-L, Revision 1P, and added drawing No. 70000.14-L595, Shielded Device Insert Assembly, OPTIMUS-L, Revision 1P, to reflect the location and the design, respectively, of the new SDIA for transporting shielded normal and special form sources.

The staff reviewed the drawings and found them to be an adequate representation of the package.

1.4 Contents The applicant requested adding shielded normal and special form sources as authorized contents of the Model No. OPTIMUS-L as specified in Table 1 of the SER.

There were no changes related to the maximum allowable decay heat of the contents of the package. The staff finds the applicants description of the chemical and physical form of the package contents to be acceptable.

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION Table 1. Specifications of Shielded Devices Parameter Shielded Device Maximum weight (Shielded Device) 2,200 pounds (lb.)

997 reference kilograms (kg ref.)

Maximum Content Activity (Shielded Device)

Cobalt-60 (60Co) - 5 Curies (Ci) and Cesium-137 (

137Cs) - 2,800 Ci Maximum Surface Dose Rate (Shielded Device) 100 millirem per hour (mrem/hr)

Maximum Dimensions Height 40 inches (in.)

(101.6 centimeters reference; cm ref.)

Diameter 14 in. excluding the beam port, if present (35.56 cm ref.)

1.5 Evaluation Findings

The staff reviewed documentation provided by the applicant including package and packaging descriptions as well as design drawings to verify that statements presented by the applicant are acceptable for the review and approval of the revision of the CoC for the Model No. OPTIMUS-L, as required by 10 CFR 71.33. Based on the review of the statements and representations provided by the applicant, the staff concludes that the package, packaging, and contents have been adequately described to meet the requirements of 10 CFR Part 71.

2.0 STRUCTURAL EVALUATION The objective of the structural evaluation is to ensure that the applicant demonstrates that the structural performance of the transportation package does not exceed the level of risk associated with the OPTIMUS-L package design configuration. Thereby, confirming that the revised package design continues to comply with the regulatory requirements in 10 CFR Part

71. Section 1.0 of this SER includes a brief description of the changes. The following sections summarize the staffs structural evaluation.

2.1 Description of the Structural Design The staff reviewed the modifications to the OPTIMUS-L package design to determine if these changes may adversely impact the structural integrity of the package. The only risk identified by the staff was the risk of over stressing the CCV walls from internal impact loads from the irradiator during transportation drops.

The applicant added the SDIA to the package design for transporting shielded sources. The SDIA is placed inside the CCV during transport. The SDIA, when configured to transport, consists of four major components designed to protect the CCV and support the shielded source during NCT and HAC free drops. These components are the following:

a.

Modular Cylindrical Fiber Board Insert. The modular cylindrical fiber board insert is split into an upper and lower segment that surrounds the shielded device in the radial direction, except for a cutout designed to accommodate the shielded device's side beam port, which protrudes from the cylindrical body of the device.

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b.

Fiberboard Insert Segments. The fiberboard insert segments are fabricated from laminated sheets of ASTM C208, Standard Specification for Cellulosic Fiber Insulation Board, Type IV, Grade 1, insulating board, colloquially referred to using the brand name "Celotex.

The Celotex inserts are designed to spread load from a side drop into the CCV shell and protect it from any structural discontinuities on the outer surface of the shielded device (e.g., side port, beam port, gate, etc.). In a side drop event, the Celotex inserts absorb impact energy and minimize the response acceleration on the device, thereby reducing the inertial forces experienced by the shielded device and the resulting load on the CCV shell.

c.

Spacer Plates. In the axial direction, spacer plates are positioned above and below the shielded device and serve as a load spreader for the CCV bottom plate and lid for bottom end and top end drop loadings, respectively. The spacer plate is comprised of a solid disc of aluminum that provides the bearing surface for the shielded device and an annular ring that interfaces with the surface of the CCV bottom plate or lid.

d.

Dunnage. Dunnage is used above and below the shielded device (between the device and spacer plates) to accommodate variations in device length, position the device's side port within the Celotex insert's cutout, and limit potential movement of the device during transport. As needed, dunnage is also used around the device (in the radial direction, between the device and ID of Celotex insert) to accommodate devices of smaller diameter and limit potential movement of the device during transport.

2.2 Structural Analysis The structural analysis evaluates the CCV to demonstrate that the inertial loads generated in the CCV resulting from the change in payload is bounded by the CCV design of the licensed OPTIMUS-L transportation package. The applicant utilized the drop analysis results from the OPTIMUS-L transportation package design and implemented the same methodology in the structural analysis of the OPTIMUS-L shielded device shipping configuration of the CCV.

The mass and center of gravity of the OPTIMUS-L package with a shielded source is enveloped by the values used in the original design. The staff performed an analysis using the acceleration time histories associated with the drop conditions for NCT and HAC provided in the OPTIMUS-L application for spent fuel transport. Then, the staff applied the analysis of the CCV with the shielded devices. The inertial forces are generated because of the deceleration caused by the resistance of the Celotex insert within the CCV. The response of the Celotex insert is modeled using LS-DYNA [

OFFICIAL USE ONLY - PROPRIETARY INFORMATION Information Withheld per 10 CFR 2.390

] Based on this calculation, the staff accepted the interpolation methodology for this specific case.

The staff compared the results provided by the applicant of the analysis under both the NCT and HAC conditions for this application with the approved design of the OPTIMUS-L CCV, Revision 5 of the CoC No. 9390. This comparison showed that, in a side drop, the peak forces

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION on the CCV wall have a factor of safety greater than 1.0 when compared to the allowable contact forces. In addition, the forces considered for the CCV shell in the approved OPTIMUS-L CCV design bound the results of the current analysis. Section 2.7.1.1 of the application includes the end drop analysis for the package. In all stress types, the factor of safety is greater than 1.0.

The staff reviewed the information provided by the applicant and concluded that the Celotex provides adequate protection against overloading the OPTIMUS-L CCV shell from interactions with the irradiator. The staff also concludes that the changed use of the OPTIMUS-L cask with the Celotex shock absorption shell does not increase the accepted risk in the OPTIMUS-L package design.

2.3 Evaluation Findings

Based on review of the statements and representations in the application, the staff finds that the package design continues to meet the requirements in 10 CFR 71.71(c)(7) and 10 CFR 71.73 (c)(1). Therefore, the package design meets the structural requirements of 10 CFR Part 71.

3.0 THERMAL EVALUATION The purpose of this thermal evaluation is to verify that the applicants proposed changes to the Model No. OPTIMUS-L package (designated as Type B(U)F) design continues to:

1) provide reasonable assurance of adequate protection against the thermal tests specified in 10 CFR Part 71 under NCT and HAC, and

2) meet the thermal performance requirements of 10 CFR Part 71.

Regulations applicable to the thermal review include 10 CFR 71.31, 71.33, 71.35, 71.43, 71.71, and 71.73. The following sections summarize the staffs thermal evaluation.

3.1 Thermal Evaluation Thermal-related changes associated with this amendment were limited to the addition of a shielded device (e.g., irradiator holding sealed sources) inside of a Shielded Device Insert Assembly (SDIA) placed within the CCV containment boundary. Section 3.5.4 of the application indicated that the shielded device has a maximum decay heat of 13.5 W. The staff notes that the package is certified to transport other radioactive material up to 50 W.

3.2 Description of the Package Sections 1.1 and 1.2.2.4 of the application stated that the shielded devices are shielded steel weldments containing special form or normal form sealed sources. In addition, sections 1.2.1.3 and 1.2.2.4 of the application and section 5(b)(1) of the CoC noted that the allowable radionuclide and maximum activity within the shielded device is limited to 2,800 Ci of 137Cs and 5 Ci of 60Co. The shielded devices have a maximum weight of 2,200 lbs and are placed within a SDIA and held by Celotex fiberboard sections, aluminum spacers, and dunnage; the SDIA is then inserted within the CCV containment boundary. The applicant noted in Sections 1.2.2.4 and 2.12.6.2 and drawing No. 70000.14-L595 of the application that dunnage and the fiberboard meet specifications greater than or equal to ASTM C208, Type IV, Grade 1, cellulosic fiber

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION insulating board (Celotex). Section 1.2.2.4 of the application also indicated the dunnage does not react negatively with other packaging materials or shielded device contents and has a maximum allowable temperature of at least 250 degrees Fahrenheit (°F).

Fabrication and details associated with the fiberboard were referenced in sections 2.12.6.2.1 and 2.12.6.3 of the application and Celotex Structural Properties Tests (document No. WSRC-TR-20000-00444, Celotex Structural Properties Tests (ML25113A020)); in addition, fiberboard thermal conductivity was provided in section 3.5.4.1 of the application. Properties (e.g., density, thermal conductivity, emissivity) of other materials associated with the new content (e.g.,

aluminum, lead) were provided in sections 2.12.6.2.1 and 3.5.4 of the application, document No.

70000.14-2110, OPTIMUS-L Shielded Device Shipping Configuration Structural Evaluation, Revision 2 (ML25037A292), and document No. 70000.14-3003, OPTIMUS-L Shielded Device Thermal Analysis, Revision 0 (ML24191A0430).

Sections 2.12.6.2.1 and 3.5.4, and table 3.5.4-1 of the application1 indicated that the fiberboard associated with the SDIA was tested between -40°F and 250°F at NCT and had a maximum allowable temperature of 410°F at HAC. The applicant noted in section 3.5.4.2 of the application that the shielded devices are made from lead, carbon steel, and stainless steel. These materials have allowable temperatures greater than those reported in section 3.5.4 of the application during NCT and HAC.

The staff notes that the details of other packaging components (e.g., CCV, outer packaging, shield insert assembly) were evaluated in earlier OPTIMUS-L package certifications for a decay heat up to 50 W.

Section 2.12.6.2.2 of the application indicated that there were no known mechanisms for reactions of the fiberboard (made of cellulose and polyvinyl acetate glue) with other package components. In addition, per the Thermal RAI 3-3 response (ML24319A234), the packages temperatures would stay low and thermolysis, a chemical decomposition of a substance caused by heat, would not occur. However, section 4.5.6 of the application and calculation document No. 70000.14-4102, Revision 1, provided the radiolysis calculation when transporting the shielded devices within the SDIA. Results showed that hydrogen generated from radiolysis would reach volume concentrations of approximately 3.4 percent per volume (% v/v) during a 365-day transport period. Additional discussion is provided in chapter 4 of this SER.

3.3 Thermal Analyses under NCT and HAC 3.3.1 Thermal Resistances Section 3.5.4 of the application discussed the thermal analyses for determining temperatures associated with the shielded device and SDIA within the OPTIMUS-L CCV during NCT and fire HAC. The first thermal calculation described in section 3.5.4 of the application determined by hand calculation the thermal resistances (R) associated with the three heat transfer channels (i.e., pathways) from the shielded device through the SDIA and outward to the package exterior.

The three heat transfer channels between the shielded device and the inner CCV surface via the SDIA were identified in section 3.5.4.1 of the application as follows:

1 Based on Chapter 3 of the application, reference 3.19 titled Demonstration of Equivalency of Cane and Softwood Based Celotex for 9975 Packaging, document No. WSRC-TR-2007-004533, Revision 0, Savannah River National Laboratory, November 2007, ML25115A128.

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a.

the cylindrical channel pathway (i.e., radial heat transfer to the CCV shell),

b.

the top channel pathway (i.e., axial heat transfer to the CCV lid), and

c.

the bottom channel pathway (i.e., axial heat transfer to the CCV bottom plate).

The thermal resistance of the cylindrical pathway was analyzed as a series of three distinct resistances calculated using one-dimensional conduction and radiative heat transfer terms.

These three resistances consisted of the following:

a.

the inner gap resistance associated with the inner air gap,

b.

the resistance associated with the layer of fiberboard, and

c.

the resistance associated with the outer air gap.

Both the inner air gap and outer air gap consisted of parallel thermal resistances associated with conduction heat transfer and radiative heat transfer across the air gap. The top channel thermal resistance consisted of the conduction through the aluminum plate and top air gap. The bottom channel thermal resistance consisted of the conduction through the fiberboard; the resistance across the aluminum plate and air gap were not considered. The resistances were used in subsequent calculations for determining SDIA (i.e., fiberboard) and shielded device temperatures. The staff notes that the calculation did not consider:

a.

the resistance associated with the radiative heat transfer for the top axial channel and

b.

the conduction heat transfer through the air gap and bottom aluminum plate for the bottom axial channel.

However, the effects on the OPTIMUS-L SDIAs calculated fiberboard temperature would be small because the resistances would be small, and the dominant thermal direction is through the cylindrical pathway.

3.3.2 CCV Component Temperature Using Computational Models Section 3.5.4.1 of the application included a discussion of a second analysis that used the computational models2 described in sections 3.3 (NCT analysis) and 3.4 (HAC analysis) of the application, whereby a heat flux corresponding to a shielded device decay heat was applied to the models CCV inner surface. These sections indicated that the NCT FEA analysis was based on a 13.5 W decay heat and the HAC fire FEA analysis conservatively assumed a 50 W decay heat. Section 3.5.4 of the application noted that the applicant considered the shielded device with the shortest length in this analysis (i.e., highest decay heat per unit volume). The purpose of the computational model analysis was to determine the maximum temperature of the CCV components (i.e., lid, shell, bottom plate) for NCT and fire HAC.

2 ANSYS finite-element analysis (FEA)

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION 3.3.3 Shielded Devices Casing Temperature A third analysis was performed to determine the shielded device casing temperature, which was calculated as an energy balance between the shielded device decay heat and the summation of the temperature difference (T) and resistance term (e.g., T/R) values associated with the thermal pathways between the shielded device and the inner CCV surface via the SDIA. These pathways included:

a.

the cylindrical channel pathway,

b.

top channel pathway, and

c.

bottom channel pathway, as noted above.

The T value was the difference of the shielded device casing temperature (TSD) and the CCV inner surface temperature (TICCV). The applicant assumed that the CCV inner surface temperature corresponded to the maximum temperature of the CCV components mentioned above. The T value equation mentioned previously was solved for the shielded device casing temperature and then conservatively assumed to be the maximum fiberboard temperature, which was less than the NCT allowable temperature of 250°F.

A similar energy balance calculation was performed when determining the maximum fiberboard temperature during the HAC fire. However, rather than using the singular maximum temperature of the CCV components when defining the temperature difference term (T), the corresponding maximum temperatures associated with the cylindrical channel pathway, top channel pathway, and bottom channel pathway from the FEA results were used (conservatively based on a 50 W decay heat). The energy balance equation was solved for the shielded device casing temperature, which was calculated to be 332°F. The maximum fiberboard temperature was assumed to be the FEA calculated CCV bottom plate temperature of 338°F, which was greater than the above-mentioned shielded device casing temperature of 332°F. Both temperatures were below the HAC allowable fiberboard temperature of 410°F.

Staff notes that the above method, particularly the NCT calculation, averaged the contributions of heat transfer from the cylindrical channel, top channel, and bottom channel such that it may not correspond to the heat transfer paths as found in a more accurate two-dimensional spatially resolved numerical solution (i.e., finite element analysis). However, some of the assumptions applied to the NCT hand calculation would tend to increase the calculated CCV inner surface temperature, and correspondingly, the calculated fiberboard temperature. For example, the NCT calculation assumed a single maximum CCV temperature for the cylindrical channel, top channel, and bottom channel terms. However, the above-mentioned HAC fire calculation used spatially resolved ANSYS FEA results analysis to determine distinct maximum temperatures associated with each individual channel pathway. For example, the HAC fire CCV temperature associated with the side channel, which is the dominant heat transfer path through the package (i.e., most of the decay heat is transferred through the cylindrical fiberboard), was over 80°F less than the maximum CCV temperature at the bottom channel. Therefore, it is reasonable that applying the NCT calculations maximum FEA CCV inner surface temperature of the side channel (rather than the maximum temperature of the entire CCV) would result in a lower calculated shielded device casing temperature at NCT, and correspondingly, a lower fiberboard temperature.

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OFFICIAL USE ONLY - PROPRIETARY INFORMATION 3.3.4 Shielded Device Temperature Finally, section 3.5.4.2 of the application discussed the calculation for determining the shielded device temperature. The calculation was based on the one-dimensional cylindrical heat equation with volumetric heating within a cylinder. The applicant made conservative assumptions such as:

(1) using solid air properties (i.e., treating air as a solid without convection), rather than the metal component properties within the shielded device, and (2) assuming adiabatic conditions at the top and bottom of the shielded device.

In addition, the applicant assumed the shielded devices outer temperature (which is used when solving for the devices maximum temperature) was based on conservative assumptions mentioned above, including assuming a 50 W decay heat for HAC and using a singular maximum CCV temperature for NCT. Solving for the temperature at the cylinders center resulted in temperatures of 366°F at NCT and 459°F for the fire HAC. Section 3.5.4.2 of the application noted that these temperatures are below allowable temperatures for the types of metal within the shielded device.

3.3.5 Operating Pressure Section 4.5.7 of the application discussed the calculation for determining pressure within the OPTIMUS-L cavity during NCT when transporting the sealed source within the SDIA. The calculation was based on adding the pressure effect from the increased number of moles generated during radiolysis calculated in section 4.5.6 to the initial pressure of 19.16 pounds per square inch absolute (psia); the radiolysis calculation indicated a hydrogen concentration of approximately 3.4% v/v during a transport period of 365 days. The results showed that pressure increased by 2.32 psi. The staff notes that this NCT pressure is less than the 100 psi maximum normal operating pressure (MNOP) value reported in section 3.1.4 of the application as bounding for the content.

Similarly, the pressure calculation at fire HAC considered the effects of radiolysis on package pressures. The radiolysis analysis adjusted the net gas generation value (G) to account for higher temperatures during the fire HAC; conservatively, the additional moles of gas generation for one year of transport (a conservative assumption) were then considered in the pressure calculation. Results showed a package pressure of 25.6 psia, which is also less than the MNOP for bounding content.

3.4 Evaluation Findings

Based on review of the statements and representations in the application, the staff concludes that the thermal changes to the design of the Model No. OPTIMUS-L package have been adequately described and evaluated and the package design meets the thermal requirements of 10 CFR Part 71.

4.0 CONTAINMENT EVALUATION The purpose of this evaluation is to verify that the proposed changes to the design of the Model No. OPTIMUS-L package for transporting proposed content would meet regulations

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 10 OFFICIAL USE ONLY - PROPRIETARY INFORMATION under NCT and HAC. Regulations applicable to the containment review include 10 CFR 71.31, 71.33, 71.35, 71.43, and 71.51.

4.1 Description of Containment Boundary and Content Although there were no changes in the amendment related to the containment boundary or containment boundary testing, the applicant requested adding shielded devices as authorized contents. Section 1.2.2.4 of the application described the shielded devices as shielded steel weldments containing special form or normal form sealed sources. In addition, section 1.2.2.4 of the application and section 5(b)(1) of the CoC stated that the allowable radionuclide and maximum activity within the shielded device is limited to 2,800 Ci of 137Cs activity and 60Co with 5 Ci activity.

Sections 1.1, 2.12.6 and 3.5.4 of the application noted that a shielded device, with a maximum decay heat of 13.5 W as noted in section 3.5.4, is held within a shielded device Insert Assembly (SDIA), which is then placed within the Cask Containment Vessel (CCV). The response to RAI 4-1 (ML24319A234) indicated that the OPTIMUS-L CCV remains the containment boundary of the package; there is no credit to the confining nature of the shielded device or the sealed sources. Section 1.2.1.12 of the application noted that the CCV containment boundary included the CCV body weldment (i.e., shell, bottom, flange), bolted closure lid, bolted port cover, Viton lid O-ring seals, and Viton port cover O-ring seal. Staff notes that the details of packaging components (e.g., CCV, outer packaging, shield insert assembly) were evaluated in earlier OPTIMUS-L package certifications for decay heats up to 50 W.

There were no changes to the containment boundary or substantial changes to chapter 4, Containment, of the application and, therefore, the CCV remained the containment boundary for the shielded device content and containment performance was maintained with the new content. Section 4.2.2 and section 4.3.2 of the application indicated that the package is designed and tested to a leaktight containment criterion (1x10-7 ref cubic centimeters per second (cm3/s), air) per ANSI N14.5, American National Standard for Radioactive Materials -

Leakage Tests on Packages for Shipment. In addition, sections 4.2.3 and 4.3.3 of the application indicated that the analysis to support the conclusions that there would be no loss or dispersal of radioactive contents are included in section 2.12 for NCT and HAC as well as in sections 2.6 and 2.7, respectively.

4.2 General Considerations The SDIA is fabricated from Celotex, composed of cellulose and polyvinyl acetate glue, which can undergo radiolysis during transport but not thermolysis because of the low temperatures within the package, according to Thermal RAI-3-3 response (ML24319A234). Calculation document No. 70000.14-4102, OPTIMUS-L Hydrogen Gas Generation and CCV pressure for Sources and Devices Insert Assembly, (ML24319A234) and section 4.5.6 of the application provided a radiolysis analysis based on method, equations, and radiolytic inputs (e.g., G-values) of NUREG/CR-6673, Hydrogen Generation in TRU Waste Transportation Packages. Section 5.5.4.4.5 of the application described the MCNP model analysis to calculate the energy deposited from the shielded device decay heat to the Celotex; the application noted the results had small statistical uncertainty. Two NCT calculations were performed because of the differences in absorption of the deposited decay heat between the cellulose and polyvinyl acetate glue that composed the Celotex material. Therefore, one calculation assumed the deposited decay heat was completely absorbed by the cellulose material and used the cellulose GH2 and Gnet values; the other calculation assumed the deposited decay heat was completely

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 11 OFFICIAL USE ONLY - PROPRIETARY INFORMATION absorbed by the polyvinyl acetate glue and used the polyvinyl acetate glue GH2 and Gnet values.

Section 4.5.6 of the application presented the hydrogen generation results, which showed the absorption and radiolysis of cellulose was bounding and indicated that hydrogen concentration would be approximately 3.4% v/v during a 365-day transport period at NCT. The analysis at the thermal (i.e., fire) HAC similarly used the NCT calculation method but considered the higher HAC temperatures with correspondingly higher net gas generation values (Gnet); these results showed transport at these higher temperatures for 365 days (a conservative assumption) would result in a 4.55% v/v hydrogen concentration.

4.3 Evaluation Findings

Based on review of the statements and representations in the application, the staff concludes that the amendment has not changed the previously reviewed OPTIMUS-L containment design. The package has been adequately described and evaluated, and the package design meets the containment requirements of 10 CFR Part 71.

5.0 SHIELDING EVALUATION The purpose of this evaluation is to verify that the proposed changes to the shielding features of the Model No. OPTIMUS-L transport package provide adequate protection against direct radiation from its contents and to verify that the package design meets the external radiation requirements of 10 CFR Part 71 under NCT and HAC.

5.1 Description of Shielding Design 5.1.1 Shielding Design Features The shielding design feature of the Shielded Devices to be transportable into the OPTIMUS-L package relies on shielded weldments which house the sources. Lead provides gamma shielding from the sources within a stainless-steel structure. The shielded devices also are composed of a source rod located in the device cavity steel tube. A bolted closure plate assures that the source rod remains within the device cavity. The source rod typically contains one or more 137Cs or 60Co regions, and tungsten axial shielding. Shielding specifically for neutrons is not necessary for the specified radioactive material contents. Shielded devices are shielded steel weldments containing sealed sources.

The applicant states that this type of device is permitted to be manufactured in a range of dimensions to account for the potential of lower strength sources loaded into smaller/lighter devices. The applicant used for the shielding analysis of each six G10 configurations where device heights are reduced from their maximum values to minimize axial shielding consistent with these heights. Similarly, the applicant pro source tubes are provided with minimum and maximum values; the maximum outer diameter is used to minimize the radial lead shielding.

The source regions are modeled as void, and the source radii and heights are assumed values.

Each design is specified with a maximum source magnitude specified as maximum curie and/or decay heat content but also maintains a 100 millirem per hour (mrem/hr) surface dose rate limit which constrains the implemented lead reduction evaluation.

The staff found acceptable that the applicant uses dimensions, tolerances, configurations, and densities of materials for gamma shielding and those packaging components that can affect package shielding performance.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 12 OFFICIAL USE ONLY - PROPRIETARY INFORMATION 5.1.2 Summary Tables of Maximum External Radiation Levels The applicant presents the maximum OPTIMUS-L dose rates for the configurations mentioned in the previous section of this SER in table 1-1 of the NAC calculation report No. 70000.14-5202, Revision 3 (ML24327A142). The minimum shielded device models conservatively do not credit the 100 mrem/hr device surface dose rate limit. Bottom dose rates are bounding for the G10 devices. In general, the 60Co sources are governing due to the higher energy gamma produced by this source type.

The staff confirmed that the application describes the type of use or shipment for which the package is designed or evaluated (i.e., exclusive use). The staff also reviewed the applications summary tables 1-1 and 1-2 of the calculation report that include the maximum radiation levels for the surface of this package design. Tables 1-1 and 1-2 of the application include total radiation levels of gamma radiation levels.

5.2 Radioactive Materials and Source terms 5.2.1 Source-Term Calculation Methods 5.2.1.1 Gamma Sources For this application, the applicant submitted document No. 70000.14-5201, Revision 1, (ML24204A170) where the source terms (on a per Ci basis) for the sample shielded devices are evaluated. The gamma bins used provide improved granularity over the 60Co and 137Cs energy lines when compared to the standard 19-group structure from SCALE code. Both isotopes produce energy by radioactive decay. The decay energy is deposited during slow down and absorption of the emitted beta (electron) and/or gamma radiation. Beta decay energy is absorbed in the near vicinity of the decay while gamma radiation, in particular higher energy gammas, is absorbed in the shielding around the source. Maximum radionuclide activity of the sources is limited to 2,800 Ci of 137Cs and 5 Ci of 60Co.

5.2.1.2 Neutron Sources Shielding specifically for neutrons is not necessary for the specified radioactive material contents.

5.3 Shielding Model and Model Specifications 5.3.1 Configuration of Source and Shielding The applicant evaluated the dose rates using MCNP6.2 mesh tallies. Models were generated using the design drawings and inputs shown in Section 4 of document No. 70000.14-5202, Revision 3 (ML24327A142). The per Ci spectra discussed above are used directly as energy spectra and the maximum activity values for each source device are used to compute tally multipliers. Due to their different source spectra, MCNP inputs model either 60Co or 137Cs.

Variance reduction is performed using the weight window option and initialized using ADVANTG. The staff found the use of this code acceptable since ADVANTG simply generates weight windows to accelerate convergence of the solution, therefore, it is not considered a code requiring verification/validation.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 13 OFFICIAL USE ONLY - PROPRIETARY INFORMATION The applicant performed several configurations. The G10 devices contain between one and three sources. For the single source devices, maximum dose rates are from either the 60Co or 137Cs source. For the two source devices, both 60Co up and 137Cs down and 60Co down and 137Cs up configurations are analyzed; maximum dose rates are the sum of either the up/down and down/up dose rates. The three-source device contains only 137Cs, with up, down, and middle locations; each of these locations is analyzed at the maximum activity to determine the bounding location. 60Co produces direct gamma radiation and emits beta particles while the 137Cs decay chain emits beta particles and produces direct gamma radiation.

The applicant uses two cask models to compute dose rates. The first model uses the 1.5-in.

CCV bottom support plate when computing dose rates. This model is used to compute all radial and top axial dose rates and to determine the bounding payload(s) and device surface dose rates for bottom dose rates. The second model uses the SDIA bottom plate, which is a 3-in.

thick aluminum plate with a 0.5-in. void in the center. This model is used to compute bottom dose rates. Neither model credits the SDIA top plate. The 1.5-in. difference in height will have a negligible effect on radial and top dose rates.

The staff verified the shielding model for this application and found it acceptable because the applicant calculated a response function for each particle type and for each energy bin in the particle types energy spectrum. Also, the response functions were used only for the shielding and source configuration (geometric and material properties) for which the response functions were calculated. The source properties (material and geometric) were appropriate for the contents for which the functions were calculated.

5.3.2 Material Properties The applicant presents the material properties in Table 4-7 of document No. 70000.14-5202, Revision 3 (ML24327A142). Material properties for stainless steel 304 and foam are taken from CN-16007-5I2. Properties for carbon steel, lead, and aluminum are taken from the Pacific Northwest National Laboratory (PNNL) material compendium.

The staff evaluated the material properties and found them acceptable because the applicant described and used appropriate material properties (e.g., composition, mass densities, and atom densities) in the shielding models for all packaging components, package contents, and the conveyance.

5.4 Shielding Evaluation 5.4.1 Methods The staff reviewed the shielding models presented in Section 6.1.1 of the NAC report No.

70000.14-5202, Revision 3 (ML24327A142). As mentioned in Section 5.3.1 of this SER, the applicant used two models to compute dose rates, the first with the 1.5-in. thick steel CCV bottom support plate and the second with the 3-in. aluminum SDIA bottom plate. Both have a 32-in. outer diameter. Neither model credits the SDIA top plate. Dose rate results were based on F4 mesh tallies. Surface cylindrical mesh detectors use 4 cm divisions on the perpendicular and parallel planes to the surface of interest. The radial cylindrical detectors use 36 azimuthal divisions, while the top and bottom cylindrical detectors apply 18 azimuthal divisions at 2 meters and under. The vehicle surface tally uses an 8 cm spacing in the y and z direction. Tally multipliers in the figures are for the Gl0-1-360 60Co payload. The vehicle surface detector is based on half of the pallet width, rounded down to 25 in. (63.5 cm).

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 14 OFFICIAL USE ONLY - PROPRIETARY INFORMATION The staff verified that the methods used for the shielding evaluation were appropriate for evaluating the radiation levels of this package with the proposed shielded devices. The methods used by the applicant are adequate to effectively represent and evaluate the material properties, geometries and configurations of the packaging components and package contents, and the contents radiation source-term properties (e.g., radiation types, energies, spectra, and secondary sources such as from (n,) reactions in the packaging materials).

5.4.1.1 Design Minimum Lead Thickness The applicant shows the bottom dose rates for both the steel CCV bottom support plate and the SDIA aluminum plate; bottom dose rates are bounding for the G10 devices. In general, the 60Co sources are governing. Results for the design minimum lead thicknesses are presented in Table 6-2 of NAC report No. 70000.14-5202, Revision 3 (ML24327A142).

5.4.1.2 Device Surface Dose Rate Limit of 100 mrem/hr Calculations performed by the applicant showed that the 100 mrem/hr device surface dose rate limit is exceeded with the design maximum activity levels and design minimum lead thickness.

To meet the 100 mrem/hr, the applicant increases the minimum top lead thickness because only the top lead thickness is increased due to the minimum margin to the 200 mrem/hr surface dose rate limit at the bottom of the OPTIMUS-L. The staff found this approach appropriate to comply with the dose rates regulatory limits in 10 CFR 71.47.

5.4.1.3 Reduced Lead Thickness The applicant determined the amount of reduced lead based on the margin to regulatory limits after crediting the 100 mrem/hr device surface dose rate limit. Dose rates calculations for the G10 devices show that reduced lead yields acceptable dose rates for NCT and HAC.

5.4.2 Code Input and Output Data The applicant used the ORIGEN module of the SCALE code package, version 6.2, to determine the source terms (on a per Ci basis) for the sample shielded devices. The calculations were imported from calculation report No. 70000.14-5201 (ML24204A170). The gamma bins used provide improved granularity over the 60Co and 137Cs energy lines when compared to the standard 19-group structure. The staff found the use of the ORIGEN code acceptable for this evaluation as ORIGEN is considered the industry standard and is recommended for use by NUREG/CR-6802, Recommendations for Shielding Evaluations for Transport and Storage Packages, March 2003 (ML031330514).

The applicant evaluated the dose rates using MCNP 6.2 mesh tallies. Models are generated using the design drawings and inputs shown in Section 4 of the report. The per Ci spectra discussed above are used directly as energy spectra and the maximum activity values for each source device are used to compute tally multipliers. Due to their different source spectra, MCNP inputs model either 60Co or 137Cs.

5.4.3 Fluence-Rate-To-Radiation-Level Conversion Factors The MCNP code calculates a fluence per emitted particle. Then this fluence is converted into a dose rate by using fluence-to-dose rate conversion factors to arrive at the dose rate per emitted

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 15 OFFICIAL USE ONLY - PROPRIETARY INFORMATION particle. The applicant used the fluence-to-dose-rate conversion factors recommended by NUREG-2216, the 1977, ANS/ANSI-6.1.1 standard and are therefore acceptable to the staff.

The applicant added an additional two sigma to the fluence calculated by MCNP to account for the statistical uncertainty of the Monte Carlo code. The staff found it to be a conservative and acceptable way to account for this uncertainty.

5.4.4 External Radiation Levels The MCNP code uses tallies when determining particle flux at a location of interest. The tally cell represents the volume in space that the particles are collected. Tally cells need to be small enough to reasonably represent a maximum dose (versus an average). The applicant uses F4 mesh tally for the dose rate results. Also, the applicant uses exponential transform with F2 tallies on the outer surface of the OPTIMUS-L to initialize weight windows. The F4 tally description includes two global meshes and a second set of tallies to facilitate tabulation of results. Tally meshes are used to evaluate the planes at the surface of the vehicle and 2 meters from the vehicle. The vehicle surface tally uses an 8 cm spacing in the y and z direction. The vehicle surface detector is based on half of the pallet width, rounded down to 25 in. (63.5 cm).

The staff used its judgment and consideration for the conservatism within the source term modeling (e.g., point source and energy bins represented as upper values) and found that the size of the tally for the dose rate calculations is acceptable with these considerations. The location of the tally cells is based on the locations specified in 10 CFR Part 71, e.g., surface, 2 meters, and 1 meter under HAC.

When the package is placed near the edge of the trailer, theres less distance than when it is in the center, which is why the applicant has different loading tables for these two configurations.

For HAC the applicant located the tallies at 1 meter from the package surface. This is appropriate and acceptable to the staff as dose rate limits under HAC in 10 CFR 71.51(a)(2) are defined at one meter from the package.

The results of the applicants calculations for dose rates are summarized in table 6-2 of the NAC report No. 70000.14-5202, Revision 3 (ML24327A142).

As required by the loading procedure in section 7.5-1 of the application, the minimum distance from the driver cab to the centered package is 15 feet to ensure that driver cab location does not exceed regulatory limits. If dose rates exceed 50% of regulatory limits, the distance from the driver cab to the centered package is required to increase to at least 20 feet. The staff found that this demonstrates that the OPTIMUS-L meets the dose rate requirement in 10 CFR 71.47(b)(4) pertaining to the normally occupied space should the OPTIMUS-L not be transported by a private carrier with exposed personnel wearing radiation dosimetry devices in conformance with 10 CFR 20.1502.

5.4.5 Shielded Devices Conditions The bounding conditions for Shielded Devices for transport within the OPTIMUS-L are the dimensions of the shielded device, the surface dose rate on the surface of the shielded device, activity of the sources, and the maximum weight of the shielded device. Shielded Devices bounded by these restrictions are considered allowable content within the analyzed envelope as depicted in table 1 The Shielded Device may have a beam port feature protruding radially from the main body of the Shielded Device. The beam port shall fit within the cutout of the SDIA and shall extend into

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 16 OFFICIAL USE ONLY - PROPRIETARY INFORMATION the cutout section a maximum of 2.9. To reduce the effective port dimension (i.e., limiting the length the beam port extends into the cutout), the annular gap between the shielded devices and fiberboard sections may be filled with metal, wood, or fiberboard segments to provide a net radial compressive strength greater than or equal to ASTM C208, Type IV, Grade 1, cellulosic fiberboard. Free space between the Shielded Device and radial wall of the shielded device Insert Assembly will have dunnage to limit the movement during routine transport conditions.

Axial dunnage shall be placed below and above the Shielded Device to ensure the beam port is within the bounds of the lower insert port cutout dimensions.

5.5 Evaluation Findings

The staff concludes that the shielding design of the OPTIMUS-L when used as described in the application is in compliance with 10 CFR Part 71 and that the applicable design and acceptance criteria have been satisfied. The staff has reasonable assurance that the OPTIMUS-L design will provide safe transportation of the shielded devices. This finding is based on a review that considered the regulation itself, the appropriate regulatory guides, applicable codes, and standards, the applicants analysis, and responses to requests for additional information, and acceptable engineering practices. Based on its review of the statements and representations provided in the application, the staff has reasonable assurance that the shielding evaluation is consistent with the appropriate codes and standards for shielding analyses and NRC guidance.

Therefore, the staff finds that the package design and contents satisfy the dose rate limits in 10 CFR Part 71. Based on its review of the information and representations provided in the application and the staffs evaluation, the staff has reasonable assurance that the proposed changes to the package design and contents satisfy the shielding requirements. Therefore, the staff found that the shielding design of the Model No. OPTIMUS-L transport package continues to provide adequate protection against direct radiation from its contents and that the package design meets the external radiation requirements of 10 CFR Part 71 under NCT and HAC.

6.0 CRITICALITY SAFETY EVALUATION The changes requested by the applicant did not impact the previous criticality review findings.

Therefore, the staff did not perform a criticality review.

7.0 PACKAGE OPERATIONS The staff reviewed the operating procedures for the OPTIMUS-L in Chapter 7 of the application to ensure that the procedures reflect the acceptable operating sequences, guidance, and generic procedures for key operations as represented in the shielding analysis and meet the requirements of 10 CFR Part 71. The staff reviewed the loading procedures and finds that the applicant considered ALARA principles and contamination and has steps associated with loading the SDIA when needed.

7.1 Compliance with Dose Rate Limits Appendix 7.5-1 of the application contains the loading procedure for determining if the contents are acceptable for loading. The staff reviewed this procedure and found that it is consistent with the analysis in the shielding evaluation in chapter 5 of the application as discussed in section 5.4.2 of this SER and that the procedure will ensure that the package as loaded will be below regulatory dose rate limits.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 17 OFFICIAL USE ONLY - PROPRIETARY INFORMATION

7.2 Evaluation Findings

The staff concludes that the operating procedures meet the requirements of 10 CFR Part 71, and that these procedures are adequate to ensure the package will be operated in a manner consistent with its evaluation for approval.

8.0 ACCEPTANCE TESTS AND MAINTENANCE PROGRAM The staff reviewed the acceptance tests and maintenance programs that are important to ensure the shielding in the as-fabricated package meets the design specified in the technical drawings, as evaluated in the shielding analysis at the time of fabrication and use and will continue to do so over the course of its service life. The staff evaluated the information in section 8.1.6 of the application related to Shielding Tests. The applicant states that no acceptance testing is required because shielding components are made from solid steel. The staff accepts inspections of the package dimensions as a sufficient acceptance test for ensuring shielding performance of the steel components. These components are manufactured to industry standard specifications, and they are not subject to the material irregularities faced from non-standard materials or a poured lead shield. Section 8.1.1 of the application requires that the dimensions and tolerances be verified by measurement on each package. The staff found this acceptable to ensure that the shielding is manufactured in accordance with the drawings in lieu of acceptance tests.

The applicant did not identify any maintenance tests that will need to be performed on the OPTIMUS-L in relation to the shielding performance. The staff has not identified any degradation mechanisms that would affect the shielding performance during the service lifetime of the package and found this acceptable. The staff finds that the inspections performed on the shielding materials ensure that the packaging meet the requirements of 10 CFR Part 71.

9.0 QUALITY ASSURANCE There were no changes proposed that would impact the staffs quality assurance evaluation from the CoC No. 9390 for the OPTIMUS-L transport package. The changes described in section 7.0 of this SER do not affect the requirements to perform package operations according to established procedures. As a result, the staff determined that a new evaluation was not required.

CONDITIONS Besides the technical changes to the CoC, the applicant proposed changes to ease use of the CoC of the package. The revised certificate of compliance includes the following conditions of approval and changes:

1)

Increased the revision No. to 5.

2)

Condition No. 3.b., Title and Identification of Report or Application, includes the title and date of the consolidated application.

3)

Condition No. 5.(a)(2), added a description of the SDIA as follows:

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 18 OFFICIAL USE ONLY - PROPRIETARY INFORMATION The Shielded Device Insert Assembly (SDIA) is placed inside the CCV cavity for transporting shielded devices containing special and normal form sealed source content.

The SDIA is placed in the CCV cavity during transport. The insert consists of two (2) axial aluminum spacers, placed at the bottom and top of the configuration, with an insert between the axial spacers. Both axial spacers are equivalent and can be used at either the top or bottom of the configuration. Additional axial dunnage shall be inserted below and above the Shielded Devices to fill the axial gaps.

4)

Condition No. 5.(a)(3), Drawings, contains the latest revision of the licensing drawings and added drawing No. 70000.14-L595, Revision 1P, Shielded Device Insert Assembly, OPTIMUS-L

5)

Added Condition No. 5.(b)(1)(vii) and Table 2 as follows:

(vii)

Shielded Devices are shielded steel weldments containing sealed sources meeting the specifications in Table 2.

Table 2. Specifications of Shielded Devices Parameter Shielded Device Maximum weight (Shielded Device) 2,200 lb. (997 kg ref.)

Maximum Content Activity (Shielded Device) 60Co - 5 Ci and 137Cs - 2,800 Ci Maximum Surface Dose Rate (Shielded Device) 100 mrem/hr Maximum Dimensions Height 40 in. (101.6 cm ref.)

Diameter 14 in. excluding beam port, if present (35.56 cm ref.)

6)

Condition No. 5.(b)(2)(iii), revised reference from Table 2 to Table 3 and renumbered Table 2, TRU Waste FGE Limits to Table 3.

7)

Condition No. 5.(b)(2)(iv), revised reference from Table 3 to Table 4 and renumbered Table 3, IFW Waste FEM Limits to Table 4.

8)

Condition No. 5.(b)(2)(v), revised reference from Table 4 to Table 5 and renumbered Table 4, TRU Waste and IFW Activity Limits for Key Isotopes to Table 5.

9)

Added title to the table under Condition No. 5.(b)(2)(viii) as Table 6, TRISO Compacts Parameters and added titles to the tables columns.

10)

Added Condition No. 5.(b)(2)(ix), as follows:

(ix)

For Shielded Devices, as described in Item 5.(b)(1)(vii):

Shielded Devices, contents, are limited to special and normal form sealed source content. The Shielded Device Insert Assembly is configured in the CCV cavity for transportation, shown General Arrangement Drawing No. 70000.14-L595. The insert consists of two (2) axial aluminum spacers, placed at the bottom and top of the configuration, with cellulosic fiberboard radial insert situated between the axial spacers.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION 19 OFFICIAL USE ONLY - PROPRIETARY INFORMATION

11)

Added the criticality safety index for shielded devices to Condition No. 5.(c)

12)

Added Condition No. 8:

Shoring or dunnage must be placed between loose fitting contents and the CCV cavity, baskets and/or tubes to prevent excessive movement during transport. The shoring or dunnage material shall not react negatively with the packaging materials or contents and should have an auto-ignition temperature above 300°F to ensure the material being transported maintains its geometry under routine and normal conditions of transport.

13)

Added Condition No. 9.

Non-metallic components must have an auto-ignition temperature of 300°F or higher and must be evaluated, prior to shipment, for gas generation in accordance with.5-3 of the application Non-metallic components must have an auto-ignition temperature of 300°F or higher and must be evaluated, prior to shipment, for gas generation in accordance with Attachment 7.5-3 of the application.

14)

Renumbered Condition Nos. 9, 10, 11, 12, and 13 as Condition Nos. 10, 11, 12, 13, and 14, respectively.

15)

Revised former Condition No. 10, currently Condition No. 11, as follows:

TRISO Compacts shall be shipped dry, i.e., no free liquids, and may include non-metallic components, such as spacers and/or adhesive-backed seals or labels, as contents.

16)

Revised former Condition No. 12, currently Condition No. 13, as follows:

The package is not authorized for air transport.

17)

Removed former Condition No. 14 as requested by the applicant.

The References section includes the consolidated application provided as part of the review process and the supplements include the submittals of the calculation reports. The staff also made some editorial changes to the certificate.

CONCLUSION Based on the statements and representations contained in the application, as supplemented, and the conditions listed above, the staff concludes that the design has been adequately described and evaluated, and the Model No. OPTIMUS-L package meets the requirements of 10 CFR Part 71.

Issued with Certificate of Compliance No. OPTIMUS-L, Revision 5, on April 30, 2025.