ML25248A026

Tn Americas LLC Application for Certificate of Compliance No. 9377 Revision 1 of the TN-32 Transportation Package

ML25248A026
Person / Time
Site:	07109377
Issue date:	09/05/2025
From:	Narayanan P TN Americas LLC
To:	Office of Nuclear Material Safety and Safeguards, Document Control Desk
Shared Package
ML25248A025	List: ML25248A026
References
E-64540
Download: ML25248A026 (1)

Text

Orano TN 7160 Riverwood Drive Suite 200 Columbia, MD 21046 USA Tel: 410-910-6900 Fax: 434-260-8480 Enclosures transmitted herein contain SUNSI. When separated from enclosures, this transmittal document is decontrolled.

September 5, 2025 E-64540 U. S. Nuclear Regulatory Commission Attn: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852

Subject:

TN Americas LLC Application for Certificate of Compliance No. 9377 Revision 1 of the TN-32 Transportation Package (Docket No. 71-9377)

Reference:

[1] NRC Certificate of Compliance No. 9377, Revision 0, dated July 7, 2024, Docket No. 71-9377 (Accession No. ML24180A132)

In accordance with 10 CFR 71.31(b), TN Americas LLC (TN) submits this application to revise the Certificate of Compliance (CoC) No. 9377 for the TN-32 Transportation Package. This application proposes changes to the Certificate of Compliance and Chapters 1, 2 and 5 related to intact/undamaged fuel. In addition, there are proposed changes to the impact limiter drawings to facilitate fabrication as well as Chapter 7 to provide additional detail associated with gas sampling and to reflect current operational steps to support transport activities.

A description of the changes to the Safety Analysis Report (SAR), as well as justifications for those changes, are provided in Enclosure 2.

The proposed changes to CoC 9377 Revision 0 [1] are annotated and provided as.

Safety Analysis Report changed pages are included as Enclosure 4, with a header on each changed page annotated as Rev. 1, 09/2025, and changes are indicated by italicized text and revision bars. The revised drawing shows clouds around changes and an alpha-numeric revision number. The redacted public version of these SAR changed pages and drawings is provided as Enclosure 5.

This submittal includes TN proprietary information that may not be used for any purpose other than to support the NRC staffs review of the application. In accordance with 10 CFR 2.390, an affidavit is provided specifically requesting that this proprietary information be withheld from public disclosure. This submittal also contains appropriately labeled security-related sensitive information, which should be withheld under 10 CFR 2.390.

E-64540 Document Control Desk Page 2 of 2 Should the NRC staff require additional information to support review of this application, please contact Doug Yates at (434) 832-3101 or by email at douglas.yates@orano.group.

Sincerely, Prakash Narayanan Chief Technical Officer cc:

Kristina Banovac (NRC), Storage and Transportation Licensing Branch, Division of Fuel Management

Enclosures:

1.

Affidavit Pursuant to 10 CFR 2.390

2.

Summary of Changes to CoC 9377 TN-32 SAR Revision 1A

3.

Proposed Certificate of Compliance No. 9377, Revision 0 Markup

4.

TN-32 Safety Analysis Report, Revision 1A (Proprietary version)

5.

TN-32 Safety Analysis Report, Revision 1A (Public version) to E-64540 Page 1 of 1 TN AMERICAS LLC AFFIDAVIT PURSUANT TO 10 CFR 2.390 State of Maryland:

County of HOWARD:

I, Prakash Narayanan, depose and say that I am the Chief Technical Officer of TN Americas LLC, duly authorized to execute this affidavit, and have reviewed or caused to have reviewed the information which is identified as proprietary and referenced in the paragraph immediately below. I am submitting this affidavit in conformance with the provisions of 10 CFR 2.390 of the Commissions regulations for withholding this information.

The information for which proprietary treatment is sought is listed below:

• - TN-32 Transportation Cask Safety Analysis Report, Revision 1A Changed Pages (Proprietary version)

This document has been appropriately designated as proprietary.

I have personal knowledge of the criteria and procedures utilized by TN Americas LLC in designating information as a trade secret, privileged or as confidential commercial or financial information.

Pursuant to the provisions of paragraph (b) (4) of Section 2.390 of the Commissions regulations, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure, included in the above referenced document, should be withheld.

1) The information sought to be withheld from public disclosure involves certain design details associated with the SAR analyses and SAR drawings for the TN-32B Transportation Cask, which are owned and have been held in confidence by TN Americas LLC.

2) The information is of a type customarily held in confidence by TN Americas LLC, and not customarily disclosed to the public. TN Americas LLC has a rational basis for determining the types of information customarily held in confidence by it.

3) Public disclosure of the information is likely to cause substantial harm to the competitive position of TN Americas LLC because the information consists of descriptions of the design and analysis of a radioactive material transportation system, the application of which provide a competitive economic advantage. The availability of such information to competitors would enable them to modify their product to better compete with TN Americas LLC, take marketing or other actions to improve their products position or impair the position of TN America LLCs product, and avoid developing similar data and analyses in support of their processes, methods or apparatus.

Further the deponent sayeth not.

Executed on: September 4th, 2025 Prakash Narayanan Chief Technical Officer, TN Americas LLC to E-64540 Page 1 of 2 Summary of Changes to CoC 9377 TN-32 SAR Revision 1A Item 1:

Description of Changes:

Clarify the definition of intact fuel assemblies to include assemblies containing undamaged fuel rods without any known or suspected cladding defects greater than hairline cracks or pinhole leaks.

Justification of Changes:

The change is to clarify the definition of intact fuel assemblies in the Certificate of Compliance (CoC).

The fuel assemblies, with or without hairline cracks or pinhole leaks, are considered as intact because they satisfy all the safety design functions (i.e., retrievability, structural, containment, shielding, criticality, thermal). By linking intact and undamaged fuel in the CoC, it clarifies the bounding conditions for acceptable contents in the package without altering the safety basis.

The revised definition is also consistent with the definitions in other 10 CFR Part 71 Certificates of Compliance (CoCs), e.g., 9302 (MP197HB), 9358 (TN-LC), 9313 (TN-40), 9382 (TN Eagle) 9389 (TN-40HT).

Impact:

CoC 9377 Section 5.(b)(1)(a) has been revised as described.

Item 2:

Description of Changes:

Revise intact fuel to intact/undamaged fuel for consistency in Safety Analysis Report (SAR)

Sections 1.2.1, 2.12.8, 2.12.8.2.2, 5.2, and 5.4.1.

Justification of Changes:

Linking intact and undamaged fuel assemblies in the SAR text is for clarification to eliminate ambiguity. It is also consistent with other sections of the TN-32 SAR, e.g., the structural analysis provided in Chapter 2 assumes intact or undamaged fuel assemblies.

Impact:

SAR Sections 1.2.1, 2.12.8, 2.12.8.2.2, 5.2, and 5.4.1 have been revised as described above.

to E-64540 Page 2 of 2 Item 3:

Description of Changes:

Chapter 7 changes are required to clarify the operational steps necessary to prepare and configure the demonstration cask for transport offsite and to reflect additional measures for consideration associated with gas sampling prior to transport.

Justification of Changes:

Clear and concise operational steps in Chapter 7 support the transportation of the TN-32B transportation cask offsite and ensure that any additional measures associated with gas sampling prior to shipment will be communicated to site personnel at the packages destination.

Impact:

SAR Sections 7.1.3, 7.2.1, 7.2.2, and 7.3 have been modified to address the changes described above.

Item 4:

Description of Changes:

1) The Impact Limiter (IL) SAR drawings have been revised to include fabrication tolerances for some dimensions.

2) Certain dimensions, detailed material specifications, and details are removed from the IL SAR drawings.

3) The Bill of Materials (BOM) for SAR Drawing 19885-71-9 has been revised to incorporate editorial corrections to the quality category and to revise material specifications of certain items.

Justification of Changes:

1) The tolerances are for ease of fabrication based on lessons learned from previous IL fabrication experience. The nominal dimensions of the impact limiters remain unchanged.

The modifications are consistent with other transportation package IL SAR drawings (e.g.,

TN-LC, TN-40, TN-40HT and MP197HB).

2) Certain dimensions, detailed material specifications, and details shown in these SAR drawings are not relevant to the safety evaluation of the package and are not used anywhere. Therefore, they are removed to facilitate fabrication.

3) The quality category of the single tie-rod brackets (Item 16) was corrected to Category B for consistency with similar tie-rod brackets given in Drawings 19885-71-9 and 19885-71-10.

Material specifications of certain NITS items were revised to be stainless steel for ease of fabrication.

Impact:

SAR Drawings 19885-71-9 and 19885-71-10 have been revised as described above.

to E-64540 Proposed Certificate of Compliance No. 9377, Revision 0 Markup

NRC FORM 618 (8-2000) 10 CFR 71 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR RADIOACTIVE MATERIAL PACKAGES 1.

a. CERTIFICATE NUMBER

b. REVISION NUMBER

c. DOCKET NUMBER

d. PACKAGE IDENTIFICATION NUMBER PAGE PAGES 9377 0

71-9377 USA/9377/B(U)F-96 1

OF 4

2.

PREAMBLE

a. This certificate is issued to certify that the package (packaging and contents) described in Item 5 below meets the applicable safety standards set forth in Title 10, Code of Federal Regulations, Part 71, Packaging and Transportation of Radioactive Material.

b. This certificate does not relieve the consignor from compliance with any requirement of the regulations of the U.S. Department of Transportation or other applicable regulatory agencies, including the government of any country through or into which the package will be transported.

3.

THIS CERTIFICATE IS ISSUED ON THE BASIS OF A SAFETY ANALYSIS REPORT OF THE PACKAGE DESIGN OR APPLICATION a.

ISSUED TO (Name and Address)

b. TITLE AND IDENTIFICATION OF REPORT OR APPLICATION TN Americas LLC 7160 Riverwood Drive, Suite 200 Columbia, MD 21046 TN-32 Transportation Cask Safety Analysis Report, dated June 2024.

4. CONDITIONS This certificate is conditional upon fulfilling the requirements of 10 CFR Part 71, as applicable, and the conditions specified below.

5.

(a) Packaging (1) Model No.: TN-32B (2)

Description:

The TN-32B packaging consists of a spent fuel basket assembly, a containment vessel, a forged steel shell body, a radial neutron shielding, and impact limiters.

Basket The spent fuel basket consists of a honeycomb-like structure of stainless-steel cells, housing 32 fuel assemblies, separated by aluminum and poison plates that form a sandwich panel. The aluminum plates provide heat conduction paths from the spent fuel assemblies to the cask cavity wall. The poison material provides the necessary criticality control. The opening of the cells is 8.7 in. x 8.7 in., leaving a minimum of 1/8 in. clearance around the fuel assemblies. The overall basket length (160.0 in.) is less than the cask cavity length to allow for thermal expansion and fuel assembly handling.

Containment Vessel The containment vessel consists of the inner shell and bottom inner plate, shell flange, closure lid outer plate, closure lid bolts, penetration cover plates and bolts, thermocouple lance assemblies and their seals, inner metallic seals of the lid, vent and drain seals. The containment vessel, which maintains an inert atmosphere (helium) in the cask cavity, is 171 inches long, with a wall thickness of 1.5 inch. The 1

NRC FORM 618 (8-2000) 10 CFR 71 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR RADIOACTIVE MATERIAL PACKAGES 1.

a. CERTIFICATE NUMBER

b. REVISION NUMBER

c. DOCKET NUMBER

d. PACKAGE IDENTIFICATION NUMBER PAGE PAGES 9377 0

71-9377 USA/9377/B(U)F-96 2

OF 4

5. (a)(2)

Description (Continued) cylindrical cask cavity has an inner diameter of 68.8 inches and a length of 163.4 inches. The closure lid outer plate is 4.5 inches thick and is secured to the body by 48 high-strength closure lid bolts.

Body The packaging body, i.e., a forged steel gamma shield shell, is around the inner shell and the bottom inner plate of the containment vessel. The 8.00 in. thick gamma shield shell and the 8.75 in. thick bottom plate completely surround the containment vessel shell and bottom plate, respectively. A 6.0 in. thick shield plate is also welded to the inside of the 4.5 in. thick lid outer plate, and 2.13 in. thick lance cover plates are placed over the thermocouple lances and welded to the closure lid outer plate.

The radial neutron shielding is enclosed within the welded steel outer shell. Radial neutron shielding is provided by a borated polyester resin compound surrounding the gamma shield shell. The total radial thickness of the resin and aluminum is 4.5 in.

Impact Limiters The impact limiters, consisting of balsa wood and redwood blocks encased in stainless steel plates, have an outside diameter of 144 in. and an inside diameter of 89 in. The impact limiters, attached to each other using tie-rods, are also attached to the outer shell of the package with bolts. A puncture-resistant steel plate is placed on the cask lid and bolted to the package body prior to mounting the top impact limiter, to provide a smooth contact surface between the closure lid and the top impact limiter, and to protect the thermocouple lance assemblies from puncture.

A transport frame, which is not part of the packaging, is used for tie-down purposes.

The TN-32B package is 263.2 inches long and has a diameter of 144 in. with the impact limiters installed.

The package body is 184.3 in. long (with the closure lid installed), and 87.75 in. in diameter. The closure lid is 79.50 in. in diameter. The cask outside diameter including the radial neutron shield is 98.14 in. The cask cavity is 163.38 in. long and 68.80 in in diameter. The total gross weight of the package is 269,000 lb.

5. (a)(3)

Drawings The packaging is fabricated and assembled in accordance with ORANO TN Drawing Nos.:

19885-71-1, Rev. 0 General Arrangement Assembly 19885-71-2, Rev. 0 General Assembly 19885-71-3, Rev. 0 Lid Assembly and Parts List 19885-71-4, Rev. 0 Puncture resistant Plate Assembly 1

NRC FORM 618 (8-2000) 10 CFR 71 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR RADIOACTIVE MATERIAL PACKAGES 1.

a. CERTIFICATE NUMBER

b. REVISION NUMBER

c. DOCKET NUMBER

d. PACKAGE IDENTIFICATION NUMBER PAGE PAGES 9377 0

71-9377 USA/9377/B(U)F-96 3

OF 4

5. (a)(3) Drawings (continued) 19885-71-5, Rev. 0 Trunnion Details 19885-71-6, Rev. 0 Basket Assembly and Parts List 19885-71-7, Rev. 0 Thermocouple Lance Assembly, Lance Cover Plate 19885-71-8, Rev. 0 General Assembly Impact Limiters 19885-71-9, Rev. 0 Bottom Impact Limiter Assembly 19885-71-10, Rev. 0 Top Impact Limiter Assembly

5. (b) Contents (1) Type and form of material (a) Only intact fuel assemblies limited to the following fuel types, with specifications listed in Table 1-2 of the application:

i.

One (1) Westinghouse LOPAR 17x17 fuel assembly with Zirc-4 cladding ii.

Twelve (12) Westinghouse NAIF 17x17 assemblies with ZIRLOTM cladding iii.

One (1) Westinghouse NAIF 17x17 assembly with Low SN Zr-4 cladding iv. Eighteen (18) AREVA Advanced MK-BW 17x17 assembly with M5TM cladding (b) Fuel assembly locations and poison rod assembly (PRA) locations shall be as provided in Figure 6-1 of the application.

(c) The maximum combined weight of a fuel assembly and a PRA shall not exceed 1,551 lb.

(d) The maximum initial enrichment of any fuel assembly is 4.55 wt.% 235U.

(e) The burnup for each assembly is greater than 50,000 MWd/MTU with the fuel burnup data for all 32 fuel assemblies being as provided in Table 1-3 of the application.

(f). The post-irradiation minimum cooling time is 11.6 years and the maximum total decay heat load shall be 25.84 kW, with a maximum of 0.878 kW for any fuel assembly.

(2) Maximum quantity of material per package 32 PWR assemblies as described in 5.b(1) with a combined weight (fuel assemblies and PRAs) not exceeding 50,000 lb.

(i.e., assemblies containing undamaged fuel rods without any known or suspected cladding defects greater than hairline cracks or pinhole leaks) 1

/undamaged 1

1

NRC FORM 618 (8-2000) 10 CFR 71 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR RADIOACTIVE MATERIAL PACKAGES 1.

a. CERTIFICATE NUMBER

b. REVISION NUMBER

c. DOCKET NUMBER

d. PACKAGE IDENTIFICATION NUMBER PAGE PAGES 9377 0

71-9377 USA/9377/B(U)F-96 4

OF 4

5.(c)

Criticality Safety Index:

0.0 6.

In addition to the requirements of Subpart G of 10 CFR Part 71:

(a)

The package must be prepared for shipment and operated in accordance with the Operating Procedures in Chapter 7 of the application, as supplemented.

(b)

Each packaging must be acceptance tested and maintained in accordance with the Acceptance Tests and Maintenance Program in Chapter 8 of the application, as supplemented.

7. Transport by air is not authorized.

8. The personnel barrier shall be installed at all times during transport to meet package surface temperature and/or package dose rates requirements.

9. The package shall be transported under exclusive-use.

10. The package authorized by this certificate is hereby approved for use under the general license provisions of 10 CFR 71.17.

11. Expiration date: July 31, 2029.

REFERENCES TN Americas LLC, application TN-32 Transportation Cask Safety Analysis Report dated June 2024.

FOR THE U.S. NUCLEAR REGULATORY COMMISSION Yoira Diaz-Sanabria, Chief Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards Date:-XO\\

YOIRA DIAZ-SANABRIA Digitally signed by YOIRA DIAZ-SANABRIA Date: 2024.07.02 15:54:08 -04'00' 1

to E-64540 TN-32 Safety Analysis Report, Revision 1A Changed Pages (Proprietary version)

Withheld Pursuant to 10 CFR 2.390 to E-64540 TN-32 Safety Analysis Report, Revision 1A (Public version)

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 1-3 Package Description Packaging The TN-32B HBU demonstration cask will be used to transport 32 intact/undamaged pressurized water reactor (PWR) HBU spent fuel assemblies with six poison rod assemblies (PRAs) inserted into specific assemblies. In its transport configuration, the TN-32B HBU demonstration cask consists of the following components:

A basket assembly that locates and supports the fuel assemblies, transfers heat to the cask inner shell, and provides sufficient neutron absorption to satisfy nuclear criticality requirements.

A containment vessel, including a closure lid, vent and drain covers, metallic O-ring seals, and the thermocouple lance assemblies, which provide containment of the radioactive materials, and maintains an inert gas atmosphere.

A thick-walled, forged steel gamma shield shell, a bottom shield, and closure lid shield plate provide shielding that surrounds the containment vessel.

A radial neutron shield surrounding the gamma shield shell that provides additional radiation shielding. The neutron shielding is enclosed within a welded steel outer shell.

A set of impact limiters consisting of redwood and balsa wood, encased in stainless steel shells, which are attached to each end of the cask body during transport. A puncture resistant plate over the closure lid, and lance cover plates that cover the lance assemblies are also present to prevent a postulated puncture bar impact from contacting the thermocouple lance assemblies. The puncture resistant plate also provides a smooth contact surface between the upper impact limiter and the closure lid. The impact limiters are secured to the cask with tie-rods and attachment bolts.

Sets of upper and lower trunnions that provide lifting and rotational capability, respectively, for the cask.

A personnel barrier is mounted to the transport skid to prevent unauthorized access to the surface of the cask body. The overall dimensions of the TN-32B HBU demonstration cask are 263.2 inches long and a diameter of 144 inches with the impact limiters installed. The cask body is 184.3 inches long (with the closure lid installed), and 87.75 inches in diameter. The closure lid is 79.50 inches in diameter.

The cask outside diameter including the radial neutron shield is 98.14 inches. The cask cavity is 163.38 inches long and 68.80 inches in diameter. The general arrangement of the TN-32B HBU demonstration cask is illustrated in Figure 1-1.

Detailed design drawings for the TN-32B HBU demonstration cask are provided in Appendix 1.4.1. The materials utilized to fabricate the cask are provided in the Parts List on Drawings 19885-71-1 through 19885-71-7, and the materials utilized to fabricate the impact limiters are presented in the Parts List on Drawings 19885-71-8 through 19885-71-10. Where more than one material has been specified for a component, the most limiting properties are used in the analyses in the subsequent chapters of this SAR.

Proprietary and Security Related Information for Drawing 19885-71-9, Rev. 1A Withheld Pursuant to 10 CFR 2.390

Proprietary and Security Related Information for Drawing 19885-71-10, Rev. 1A Withheld Pursuant to 10 CFR 2.390

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 2.12.8-1 Proprietary Information on This Page Withheld Pursuant to 10 CFR 2.390

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 2.12.8-7 Proprietary Information on This Page Withheld Pursuant to 10 CFR 2.390

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 5-2 Summary of Maximum Radiation Levels Because the cask contains spent nuclear fuel and only one cask will be transported per vehicle (railcar), exclusive use dose rate limits are applied.

Maximum normal conditions of transport (NCT) and hypothetical accident conditions (HAC) dose rates when transporting the TN-32B HBU demonstration cask irradiated payload are reported in Table 5-2. Occupied Location dose rates for NCT for a typical railcar length of 40 feet are also reported. These maximum radiation levels are applicable to the fuel specifications (e.g., burnup, enrichment, cooling time, position in the cask) of the payload evaluated.

The cask is transported in a horizontal orientation in an open vehicle. Because the transport vehicle type is open with an enclosure, the NCT dose rate limits per 10 CFR 71.47 are 1000 mrem/hr for the enclosed package surface, 200 mrem/hr for the vehicle surface, 10 mrem/hr at 2 meters from the vehicle surface, and 2 mrem/hr for occupied locations. The HAC dose rate limit per 10 CFR 71.51(a)(2) is 1000 mrem/hr at 1 meter from the cask surface.

The railcar is assumed to be 10 feet-8 inches wide (128 inches or 325.12 cm) and 40 feet long (1219.2 cm). The fuel inside the cask is assumed to have the bottom fuel assembly fitting in contact with the bottom of the cavity inside the cask, as in the storage configuration. The package surface is the enclosed surface of the cask, and the undersides of the impact limiters underneath the personnel barrier. The bottom end of the cask is oriented to face forward toward the locomotive. Because the sides of the impact limiters will overhang the sides of a standard railcar (144 inches compared to 128 inches), and there is a personnel barrier spanning the space between the upper and lower impact limiters, the vehicle surface is taken to be the cylindrical side of the personnel barrier loaded onto the railcar, with a diameter of 128 inches. The front and back vehicle surfaces are the lower and upper impact limiters, respectively. The 2-meter dose rate is computed 2 meters from the vehicle surfaces, while the occupied location (i.e., the operator and engineer inside the cab of the locomotive) is computed +/-20 feet at approximately the axial center of the fuel in the cask.

All dose rates are below applicable limits. Under NCT, the maximum enclosed package surface dose rate is 211.8 mrem/hr, the maximum vehicle surface dose rate is 35.2 mrem/hr, the maximum dose rate 2 meters from the vehicle surface dose rate is 7.6 mrem/hr, and the dose rate in the occupied location for a 40 foot railcar is 0.7 mrem/hr. Under HAC, the maximum dose rate at 1 m from the cask is 505 mrem/hr.

Source Specification The source term is calculated using the ORIGEN-ARP module of the SCALE 6.1 code system and the ENDF/B-VII nuclear data cross-section library. The payload is 32 unique, intact/undamaged high burnup spent fuel assemblies from the North Anna Power Station (NAPS).

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 5-8 The NCT models calculate primary gamma, secondary gamma, and neutron dose rates, which are summed to determine the maximum dose rate for each specified tally location. Package dose rates are calculated by mesh tallies over the external surface of the radial neutron resin shield and along the undersides of the impact limiters (surfaces enclosed by the personnel barrier), and over the exposed surfaces of the impact limiters. Vehicle dose rates are calculated by mesh tallies over the personnel barrier and over the exposed surfaces of the impact limiters. As the mesh tallies over the exposed surfaces of the impact limiters are defined to be the same for both package and vehicle surfaces, some of the mesh tallies are redundant. Mesh tallies calculate dose rates 2 meters from the personnel barrier and top and bottom vehicle surfaces. Also, mesh tallies calculate dose rates at potential occupied locations. The closest occupied space would be the locomotive cab that houses the engineer and the operator; however, because the length of the railcar or locomotive to be used is unknown, occupied dose tallies are set up at regular intervals from the top and bottom of the package.

The HAC models calculate primary gamma, secondary gamma, and neutron dose rates, which are summed to determine the maximum dose rate. The HAC models have mesh tallies calculate dose rates at 1 meter from the cask cylindrical surface with the neutron shield and impact limiters absent.

The cross-section data used in the primary gamma shielding models is the continuous energy ENDF/B-VI Release 8 library provided with the MCNP5 code. For the neutron and secondary gamma shielding models, the cross-section data used is the continuous energy ENDF/B-VII.0 library, unless the cross-section data is not available in that library, then an alternative library is used. For the source terms, ORIGEN relies on decay data in ENDF/B-VII that is distributed with SCALE 6.1. The cross-section data allow a coupled neutron/gamma dose rate evaluation to be made to account for secondary gamma radiation. Dose rates from secondary gammas are calculated by using gamma (photon) tallies in MODE N P in the MCNP neutron source model. Since all 32 HBU fuel assemblies are intact/undamaged, reconfiguration of the fuel is not modeled.

Input and Output Data The vehicle surfaces are taken to be a horizontal cylinder the diameter of the personnel barrier (128 inches or 325.12 cm) increasing to the diameter of the impact limiters (144 inches or 365.76 cm) with vertical surfaces along the top and bottom surfaces of the impact limiters. As the width of a railcar is 10 feet-8 inches (128 inches) and the diameter of the impact limiters is 144 inches, the impact limiters will overhang the sides of the railcar. Since a personnel barrier is installed between the impact limiters that will restrict access to the side surface of the cask, the transport vehicle type is considered Open with Enclosure, per Reference [7]. Because of this classification, the package surface of the cask (enclosed by a personnel barrier) is limited to a dose rate of 1000 mrem/hr. The 200 mrem/hr limit in Reference [7] is applicable to the vehicle surface bounded axially by the external surfaces of the impact limiters and radially by the vertical planes extending from a 10 feet-8 inches wide rail car and the top of the personnel barrier. The model calculates dose rates along the curved surfaces, which produces more conservative dose rates in comparison to the dose rates at the vertical planes projected from the edges of the rail car. Sketches of the mesh tally configurations are in Figures 5-6, 5-7, and 5-8.

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 7-1 Operating Procedures This chapter contains TN-32B HBU demonstration cask loading and unloading procedures that are intended to demonstrate the general approach to cask operational activities. A separate Operations and Maintenance (O&M) Manual will be prepared for the TN-32B HBU demonstration cask to describe the operational steps in greater detail. The O&M manual, along with the information in this chapter, will be utilized to prepare the site-specific procedures that will address the particular operational considerations for the unique TN-32B HBU demonstration cask. The operations required to convert the TN-32B HBU demonstration cask from its storage configuration to its transport configuration are also described here.

Package Loading The TN-32B HBU demonstration cask was loaded with 32 high burnup (HBU) spent fuel assemblies from the North Anna Power Station (NAPS) in November 2017. The loaded cask was then placed on the NAPS Independent Spent Fuel Storage Installation (ISFSI) for storage under 10 CFR 72 [1] requirements in accordance with the NAPS site-specific license (NRC Docket 72-16), and the amended NAPS Special Nuclear Materials (SNM) License No. 2507 for this special storage cask.

Preparation for Loading The TN-32B HBU demonstration cask was previously prepared for loading the HBU spent fuel payload in November 2017. Therefore, no additional loading preparations of the cask are required.

Loading of Contents The TN-32B HBU demonstration cask was previously loaded with the HBU spent fuel payload in November 2017. Therefore, no additional loading operations for the cask are required.

Preparation for Transport The TN-32B HBU demonstration cask was designed for storage as well as transport.

The following steps are required to convert the TN-32B HBU demonstration cask from its storage configuration to its transport configuration.

The accessible surfaces of the cask shall be visually inspected for evidence of cracks in the carbon steel shell.

Review the maintenance records of the cask for seal integrity while on the storage pad. If seal integrity has been lost while it was in its storage configuration, perform an evaluation prior to transportation of the HBU fuel cladding for potential rod splitting due to exposure to an oxidizing atmosphere utilizing the methodology provided in ISG-22 [2].

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 7-2

1.

Disconnect and remove the thermocouple (TC) lance data logger system (cart, conduit, electrical connectors, mounting bracket, and securement straps) from the cask.

2.

Move the cask to the crane enclosure and work pit of the NAPS Decontamination Building.

3.

Deleted.

4.

Deleted.

5.

Deleted.

6.

Depressurize or evacuate the overpressure (OP) system to atmospheric pressure.

7.

Remove the access cover bolts and disconnect the OP system from the access cover.

8.

Disconnect the TC leads from the junction box that is mounted on the protective cover.

9.

Remove the the protective cover.

10. Remove the vent port access plug in the top neutron shield cover.

11. Remove the vent port cover.

12. Collect a cavity gas sample through the vent port quick-disconnect coupling. If desired, additional samples may also be collected for supplemental analysis of the cavity gas.

13. Analyze the gas sample for radioactive material and add necessary precautions based on the cavity gas sample results.

Note: If the Kr-85 gas concentration is greater than the 3% of the total Kr-85 concentration from all the fuel rods, assess the impact of the fuel cladding defects. Additional measures, appropriate for the specific conditions, are to be planned, reviewed, and approved by appropriate site personnel, as well as implemented to minimize worker exposure and radiological releases to the environment. These additional measures may include provision of filters, as well as respiratory protection and other methods to control releases and exposure to ALARA and these additional measures will be communicated with the site personnel at the package destination.

14. Install a new metallic O-ring seal and re-install the vent port cover. Tighten the vent port cover SHCS to 85 +/-15 lbf-ft, following the tightening sequence illustrated in Figure 7-1.

15. Perform a leakage rate test of the vent port O-ring seal in accordance with Section 8.2.2, Leakage Rate Tests.

16. Disconnect the OP system metal hose from the thermocouple lance valve manifold. The connection is at the end of the manifold.

17. Disconnect the thermocouple lance OP tubing for each lance from the manifold.

The connection is upstream of the shutoff valve.

18. Remove the OP tank assembly, including the thermocouple lance OP manifold, the OP port bolts and cover, and the top neutron shield.

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 7-3

19. Install a plug into each of the OP tubing connected to the thermocouple lances per the details delineated in the drawings in Appendix 1.4.1.

20. Install the transport OP port cover with a new metallic O-ring seal. Tighten the bolts to 25 +/-5 lbf-ft torque following the tightening sequence illustrated in Figure 7-1.

21. Verify and retighten (as necessary) all of the closure lid, vent and drain port cover bolts, and the thermocouple lance jacking screws to the following specified tightening torque and pattern per Figure 7-1:

Closure lid bolts: 1,085 +/-145 lbf-ft Vent and drain port bolts: 85 +/-15 lbf-ft Thermocouple lance socket head jacking screws: 65 +/-5 lbf-ft

22. Install a lance cover plate over each thermocouple lance penetration in the closure lid per the details delineated in Appendix 1.4.1, General Arrangement Drawings.

23. Wrap each thermocouple cable and OP tubing around its lance cover plate.

When fully wrapped around the lance cover, secure the cable/OP tubing to one of the sheet metal extensions using a metallic cable tie-wrap.

24. Perform a neutron and gamma dose rate survey over the entire surface of the cask to demonstrate the adequacy of the shielding design and to check if the surface dose rates are within the regulatory limits. Check surface contamination levels to verify that levels satisfy the requirements of 49 CFR 173.443 [3].

25. Install the puncture resistant plate over the closure lid and then remove the plate lifting eye bolts.

26. Install the puncture resistant plate SHCSs and tighten to 80 +/-10 lbf-ft torque.

27. Remove the test port cap and plug from the puncture resistant plate test port.

Connect a vacuum pump to the test port. Perform a pre-shipment a high-vacuum test of the inner and outer elastomer O-ring seals. The acceptable vacuum level is less than 200 mTorr (0.266 mbar).

28. Disconnect the vacuum pump from the test port, and re-install the test port plug and test port cap. Tighten the plug and cap to 8 to 10 lbf-ft torque.

29. Position the cask lift yoke over the cask.

30. Engage the lifting arms and lift the cask to the designated lift height.

31. Move the cask to the upending/downending frame that is in line with the transport frame and place the front (bottom) trunnions on the trunnion supports.

32. Rotate the cask from the vertical to the horizontal position onto the transport frame, with the closure lid end oriented on the rear of the frame.

33. Deleted.

34. Install the tie-down straps to the transport frame.

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35. Prior to installing the impact limiters, inspect them visually for damage. If any wood has been exposed, the impact limiters may not be utilized without repair.

Damage due to handling other than small dings and scratches must be evaluated for their effect on the performance during the hypothetical free and puncture drop accidents.

36. Install the 8 impact limiter brackets to the welded bars on the cask outer shell on each end. Secure the brackets to the cask body by tightening the bracket bolts and nuts to 9 +/-1 lbf-ft torque.

37. Install the front (bottom) and the rear (top) impact limiters onto the cask.

38. Lubricate the impact limiter attachment bolts with Loctite N-5000 or an equivalent and tighten to 70 +/-10 lbf-ft torque on the final pass.

39. Install 13 impact limiter attachment tie-rods between the front and rear impact limiters. Secure the tie-rods to the impact limiters with the hex nuts by tightening the nuts to a snug tight condition. Install a lock sleeve on the end of each tie-rod.

40. Render the impact limiter lifting lugs inoperable by covering the lifting holes or installing a bolt inside the holes to prevent their inadvertent use.

41. Install the security seal on one tie-rod and lock sleeve.

42. Install the personnel barrier. Verify that the surface temperature on all accessible surfaces is less than 185 °F (85 °C).

43. Perform a final radiation survey of the cask radiation levels to ensure compliance with 49 CFR 173.441.

44. Verify that surface contamination levels of the cask comply with the limits of 49 CFR 173.443.

45. Apply appropriate NRC and DOT labels and placards in accordance with 10 CFR 71.85(c) [1] and 49 CFR 172 [4], respectively.

46. Prepare the final shipping documentation.

47. Release the loaded cask for shipment.

Package Unloading Receipt of Package from Carrier

1.

Upon arrival of the loaded cask, perform a receipt inspection of the cask to check for any damage or irregularities. Verify that the security seal is intact and perform a radiation survey.

2.

Verify that the records for the packaging are complete and accurate.

3.

Remove the personnel barrier, the security seal, tie-rods, and the associated hardware. Remove the impact limiter attachment bolts.

4.

Render the impact limiter lifting lugs operable by removing the covering on the lifting holes, or the bolt inside the lifting holes, that prevented their inadvertent use.

5.

Remove the front and rear impact limiters, using a suitable crane and a two-legged sling or equivalent.

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 7-5

6.

Remove the tie down straps.

Note: The puncture resistant plate may be removed with the cask in the horizontal orientation utilizing the two threaded holes on the outer diameter of the plate while positioned in the transport frame.

7.

Place an upending/downending frame near the transport frame.

8.

Deleted.

9.

Attach the lift beam to the cask handling crane hook and then engage the lift beam to the two upper (top) trunnions.

10. Rotate the cask slowly from the horizontal to the vertical position.

11. Lift the cask from the upending/downending frame and place it in the designated work area.

12. Disengage the lift beam from the cask and move the crane as well as the lift beam from the area.

13. Remove the SHCSs and the puncture resistant plate from the top of the cask.

14. Clean the external surfaces of the cask, if necessary, to remove any accumulated road/rail debris.

15. To demonstrate that the seals did not degrade during transport, perform a leakage rate test of the cask O-ring seals. Leakage rate test the closure lid, vent and drain port cover seals, and the thermocouple lance assembly seals by utilizing the sniffer technique per Section A.5.8, Trace gas-sniffer technique (hood technique), of ANSI N14.5 [5]. The maximum acceptable cask seal leakage rate is 1 x 10-4 ref-cm³/sec. The use of a helium mass spectrometer leak detector (MSLD) is the preferred method for this test. After the leakage rate test, replace the storage overpressure port cover with the transport overpressure port cover.

Removal of Contents Since the objective of the TN-32B HBU demonstration cask is to obtain spent fuel properties after a minimum 5.87-year storage period, the contents should only be unloaded in a hot cell to avoid quenching the fuel rods and potentially altering the mechanical properties.

1.

Remove the vent port bolts and cover.

2.

Collect a cavity gas sample through the vent port quick-disconnect coupling.

3.

Analyze the gas sample for any radioactive material, and add necessary precautions based on the cavity gas sample results. If desired, additional samples may also be collected for supplemental analysis of the cavity gas.

Note: If degraded fuel is suspected, additional measures, appropriate for the specific conditions, are to be planned, reviewed, and approved by the appropriate site personnel, as well as implemented to minimize worker exposures and radiological releases to the environment. These additional measures may include provision of filters, as well as respiratory protection and other methods to control releases and exposures to as low as reasonably achievable (ALARA).

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4.

In accordance with the site requirements, vent the cavity helium gas through the vent port until atmospheric pressure is reached.

5.

Re-install the vent port cover and bolts.

6.

Loosen the closure lid bolts and remove all but six bolts, approximately equally spaced. Install the alignment pins through the closure lid.

7.

Attach the lifting equipment to the closure lid and connect the crane to the lifting trunnions.

8.

Raise the cask to the required height and move the cask to the transfer skid for the hot cell.

9.

Lower the cask to the hot cell transfer skid and disconnect the crane.

10. Move the TN-32B HBU demonstration cask into the hot cell in accordance with the site procedures.

11. Connect the hot cell crane to the lifting equipment on the closure lid, remove the six remaining closure lid bolts and seven thermocouple lance assemblies separately if desired, and lift the closure lid until it clears the cask body.

Note: The thermocouple lance assemblies extend 155.33 in. (~13 ft) below the closure lid. In order to clear the thermocouple lance assemblies from the cask body, the hot cell crane must have a minimum of 13 ft of height clearance to remove the closure lid/thermocouple lances.

12. Optional: Remove the funnel guides from the seven spent fuel assemblies.

13. Optional: Remove the six poison rod assemblies (PRAs) from the spent fuel assemblies.

14. Unload the spent fuel assemblies in accordance with the site procedures.

15. Using the hot cell crane and lifting equipment, lower the closure lid, placing it on the cask shell flange over the three alignment pins.

16. Re-install six closure lid bolts equally spaced around the lid, and tighten to a snug tight condition. Disconnect the hot cell crane from the lifting equipment.

17. Move the TN-32B HBU demonstration cask out of the hot cell in accordance with site procedures.

18. Re-install the remaining closure lid bolts and tighten to 400 +/-20 lbf-ft torque, following the tightening sequence illustrated in Figure 7-1.

Preparation of Empty Package for Transport

1.

Verify that the cask is empty and decontaminate the cask until acceptable inner and outer surface contamination levels are obtained in accordance with Department of Transportation (DOT) regulations for empty packages as directed in 49 CFR 173.428 [3].

2.

If not previously installed, lubricate and install the closure lid bolts and washers.

Tighten to 400 +/-20 lbf-ft torque, following the tightening sequence illustrated in Figure 7-1. A circular pattern of tightening may be used afterwards to eliminate further bolt movement.

TN-32 Transportation Cask Safety Analysis Report Rev. 1, 09/25 Page 7-7

3.

Remove the plug from the neutron shield vent, and reinstall the pressure relief valve, ensuring that it is operable and set.

4.

Install the vent and drain port covers.

5.

Re-engage the lift beam to the upper (top) trunnions of the cask.

6.

Move the transport vehicle with transport frame installed into the loading position and place the upending/downending frame near the transport frame.

7.

Lift the cask off the decontamination pad, and place the front (bottom) trunnions on the rear trunnion supports of the upending/downending frame.

8.

Rotate the cask from the vertical to the horizontal position.

9.

Deleted.

10. Install the tie-down straps.

Note: If the impact limiters are to be shipped separately, skip the next four steps.

11. Install the SHCSs and the puncture resistant plate over the closure lid, and then remove the plate lifting eye bolts. Tighten the SHSCs to 80 +/-10 lbf-ft torque.

12. Install the front (bottom) and the rear (top) impact limiters onto the cask.

13. Lubricate the impact limiter attachment bolts with Loctite N-5000 or an equivalent, and tighten to 70 +/-10 lbf-ft torque on the final pass.

14. Install 13 impact limiter attachment tie-rods between the front and the rear impact limiters. Secure the tie-rods to the impact limiters with the hex nuts by tightening the nuts to a snug tight condition. Install a lock sleeve on the end of each tie-rod.

15. Render the impact limiter lifting lugs inoperable, by covering the lifting holes or installing a bolt inside the holes to prevent their inadvertent use.

16. Perform a final radiation and contamination survey to ensure compliance with 49 CFR 173.428 [3].

17. Remove or cover previous DOT labels and placards and attach an Empty label to the package in accordance with 49 CFR 172.450 [4], and prepare the final shipping documentation.

18. Release the empty cask for shipment.

Other Operations There are no other operations required to operate the TN-32B HBU demonstration cask.