ML20258A056

Enclosure 1: Holtec'S RAI Responses

ML20258A056
Person / Time
Site:	07109378
Issue date:	09/14/2020
From:	Holtec
To:	Office of Nuclear Material Safety and Safeguards
Shared Package
ML20258A052	List: ML20258A054 ML20258A056 ML20258A057 ML20258A058 ML20258A068
References
5026007, EPID L-2019-LLA-0242
Download: ML20258A056 (28)

Text

Enclosure 1 to Holtec Letter 5026007 RAI Responses CHAPTER 1 GENERAL INFORMATION 1-1 Specify tolerances on the licensing drawings.

NUREG/CR-5502, Engineering Drawings for 10 CFR Part 71 Package Approvals, provides guidance for preparing drawings of transportation packages and states that engineering drawings should have tolerances that are consistent with the package evaluation. Without tolerances, structural components could be fabricated in a way that alters load path, energy absorption capability of the component etc.

The staff recognizes that the applicant desires flexibility in the package design by allowing for dimensional variation that does not impact the packages design function (e.g., components fabricated slightly out of manufacturing tolerance). However, this flexibility may be achieved by specifying tolerances in the package design drawings that are large enough to bound reasonable variations in fabrication (see guidance in the staffs ISG-20). Using nominal dimensions versus dimensions at the bounding tolerances is a non-conservative departure from practices typically used in 10 CFR Part 71 applications. Also, the applicant is using design tolerances as margin to balance out other possibly non-conservative uncertainties, and the staff finds this to be an inappropriate consideration of design tolerances.

This information is required to demonstrate compliance with 10 CFR 71.33(a).

HOLTEC RESPONSE:

The analyses were reviewed to determine where small variations in the dimensions of safety significant components may have an effect on the conclusions of the safety analysis. Tolerances were added to the drawings and SAR, as seen below, to limit the acceptable variation in the manufactured dimensions that could impact the safety case.

1) Drawing 11101

a. A tolerance has been added to the thickness of Item 4

2) Drawing 11070

a. Diameters of Items 11 & 48 dimensioned.

b. The containment seal (inner seal) dimensions for both the Inner Lid and Outer Lid were deleted from the drawing and added to the tables in the Chapter 8 appendix. This will ensure that all groove dimensions are in one location and follow the same format as other SARs.

3) SAR Chapter 8

a. An appendix was added to chapter 8 to describe the seal groove dimensions. This is to be in compliance with ISG-20.

Page 1 of 28

Enclosure 1 to Holtec Letter 5026007 CHAPTER 2 MATERIALS AND STRUCTURAL REVIEW 2-1 Provide the material and welding specifications for each of the important-to-safety (ITS) structures, systems and components (SSCs) and welded joints, respectively, in the drawing for the Impact Limiter Version LW.

The Bill of Materials for the Impact Limiter Version LW contains ITS components for which the materials code or standard is not provided. These include austenitic stainless steel and low-alloy steel plates and aluminum 6061-T6 (no standard cited) crush material and bushings.

Absent a materials code or standard, it is unclear to the staff how these materials will be procured to ensure that the mechanical properties used in the structural analysis are met.

In addition, the drawings do not appear to describe the weld specifications for each of the joints. A weld symbol is provided only for one joint, between the lower strong back plate and the skirt plate (drawing items 1 and 2). It is not clear to the staff if there are additional joints between ITS SSCs that should be marked with weld symbols.

The staff requires information on the codes, standards, or other specifications for the material, welding, and weld examinations of the ITS SSCs to support its review of the structural performance of the impact limiter.

This information is required to demonstrate compliance with 10 CFR 71.31(c).

HOLTEC RESPONSE:

The material specifications for the following items has been revised in drawing 11758:

• ITEM 1 & 2 - SA 240 304 OR SA 516 GR. 70

• ITEM 4 - SB 209 6061 T651

• ITEMS 7 & 8 - SB211-6061-T6 OR SB209-6061-T6 OR SB241-6061-T6 Flag Note 4 has been added to clarify weld code and what weld shall meet this code.

2-2 Justify and clarify the material modeling assumptions used to describe item 4, the perforated aluminum 6061-T6 impact limiter component.

Item 4 of (perforated impact limiter) on Drawing 11758, Sheet 1 is made of 6061-T6 aluminum which goes to failure (fracture) in the 9 m side drop simulation (part ID 121 in LS-DYNA) as shown below:

Page 2 of 28

Enclosure 1 to Holtec Letter 5026007 The material model used is material model 120 (024), or:

MAT_PIECEWISE_LINEAR_PLASTICITY_(TITLE)(024).

Page 3 of 28

Enclosure 1 to Holtec Letter 5026007 A failure strain of 0.426 (true strain) has been specified (engineering strain of 53.1);

however, this material model does not account for strain rate, triaxiality, or uniform elongation.

Reference 2.2.6 in the application, Properties of Aluminum Alloys, Tensile, Creep, and Fatigue Data at High and Low Temperatures, ASM International, November 2006 reports a typical failure strain of only 17% (engineering strain) or a true strain of 0.157 at room temperature, which depends heavily on the product form. However, simulation results show effective strain rates greater than 5,000 in the 9 m side drop scenario.

Minimum allowable engineering failure strains for ASTM 6061-T6 are lower, approximately 8-10%, depending on the product form. Poissons ratio has also been set to 0.33 when it appears it should be 0.3.

Since supplied material properties of aluminum are most likely to be larger than those tabulated in ASME (i.e. yield strength) or have smaller values than those reported for elongation, it is reasonable to expect that higher loads will be observed by item 4 and thus potentially fracture under smaller ductility demands.

In addition, it has also been noted that Holtec document HI-2188068 does not report g-loads for the 9 m drop side like it does for other regulatory drops.

The applicant shall describe the condition of the package for all simulated drops that utilize strain rate, Poissons ratio, triaxiality, minimum allowable elongation, and both minimum and maximum ASME yield strength values in order to model Item 4, which is made from aluminum 6061-T6. The applicant shall update the calculations and simulations reported in the application, as necessary.

This information is required to demonstrate compliance with 10 CFR 71.71(c)(1),

71.73(c)(1), and 71.73(c)(3).

HOLTEC RESPONSE:

The true-stress-true-strain curve and failure strain limit used to characterize the perforated aluminum ring in LS-DYNA have been carefully determined and validated by performing benchmark comparisons with a series of quasi-static compression tests of 1:15 scale ring segments and tension tests of material. The benchmarked LS-DYNA model of the perforated aluminum ring accounts for triaxiality effects by using stress-state dependent failure strains. The details of this benchmark effort are provided in Holtec report HI-2200863.

The Poissons ratio used as input to the model is taken from Table PRD of the ASME Code,Section II, Part D, which gives a value of 0.33 for Alclad 6061 aluminum. The mean values of measured strength properties of the purchased 6061-T6/T651 material for fabrication are used for analyses.

All NCT and HAC drops have been reperformed using the newly benchmarked model for the perforated aluminum ring and considering the effects of strain rate over the entire range developed in the material during the drop event. The drop simulation results in SAR Sections 2.6 and 2.7 have been updated accordingly. The g-load for the 9-meter side drop is bounded by oblique drop and thus not reported. The complete details of the LS-DYNA drop simulations are provided in Revision 3 of Holtec report HI-2188068.

2-3 Perform a quasi-static testing of a mock-up of a slice of the perforated aluminum ring.

Page 4 of 28

Enclosure 1 to Holtec Letter 5026007 Given the computed structural performance anomalies observed in RAI 2-2 above, the staff expects that the perforated aluminum ring LS-DYNA modeling is benchmarked by quasi-static testing of a prototypical ring segment mock-up. The testing should be sufficiently representative of the perforated aluminum ring load-deformation structural performance parameters, including the predominant impact limiter loading direction and footprint size, as well as the steel backbone stiffness and its contact simulation.

Page 2.7-6 of the application, 3rd bullet, states, Following the same approach as used in the benchmarkingThe perforated aluminum ring used in version LW impact limiter designis also characterized by the true-stress-stress-true-strain relationship of thematerial model MAT_024. The staff notes that the impact limiter stainless steel casing modeled with shell elements, in lieu of brick elements, is generally not counted for energy dissipation in mitigating the cask free drop impact effect.

As such, contrary to the statement in the application, modeling of a perforated aluminum ring with the MAT_024 material model cannot be considered similar to that of other Hl-STAR impact limiters. Quasi-static testing of a prototypical ring segment mock-up is likely to provide the load-deformation relationship to correlate the LS-DYNA results with those observed in the testing.

This information is required to demonstrate compliance with 10 CFR 71.31(b) and 71.73(c)(1).

HOLTEC RESPONSE:

Quasi-static testing of 1:15 scale segments of the perforated aluminum ring has been performed by Holtec to support benchmarking of the LS-DYNA numerical model. The details of this benchmark effort are provided in Holtec report HI-2200863. The final benchmarked LS-DYNA model of the perforated aluminum ring is used to simulate the 9-meter free drop of the HI-STAR 100MB package per 10 CFR 71.73.

LS-DYNA material model *MAT_024, along with the triaxiality ratio dependent failure strain, is used to characterize the behavior of the perforated aluminum ring brick elements in the simulation of the quasi-static test. Material model *MAT_024 can account for energy dissipation in both brick elements (e.g., perforated aluminum ring elements) and thin shell elements (e.g., thin shell elements of impact limiter stainless steel casing) due to plastic deformation.

2-4 Clarify the evaluation, in Section 2.5.2 of the application, on the excessive load protection.

The application states: The results of the calculation are summarized in Table 2.5.4. The ultimate load capacity of the trunnion is governed by the cross section of the trunnion outboard of the cask. Loss of the external shank of the trunnion under excessive load, therefore, will not cause loss of any other structural or shielding function of the HI-STAR 100MB cask.

Table 2.5.4 lists the bending and shear stress safety factors of 27.7 and 32.0, respectively, for the solid trunnion. The bearing stress safety factor of 11.6 is reported for the hollow trunnion. Considering the smallest safety factor of 11.6, it is unclear what the loss of the external shank really mean with respect to the excessive load protection requirement per 71.45(b)(3).

If the trunnion assembly is to slip off the cask body under excessive load, the failure mode should clearly be presented in the application.

This information is required to demonstrate compliance with 10 CFR 71.45(b)(3).

Page 5 of 28

Enclosure 1 to Holtec Letter 5026007 HOLTEC RESPONSE:

The minimum safety factor of 11.6 reported in SAR Table 2.5.4 is the safety factor against the onset of material yielding in the hollow trunnion due to the bearing force reactions between the solid trunnion and the hollow trunnion under the 10g transport load. The purpose of this calculation is to show that the 10g transport load will not cause any permanent deformation to the cask. That said the onset of yielding due to excessive bearing forces is not considered to be a primary failure mode for the lifting trunnion. If an excessive load were applied to the lifting trunnion causing the hollow trunnion to yield due to bearing loads, the solid trunnion would rotate slightly as the inside diameter of the hollow trunnion locally deformed and the material hardened. Given that the trunnion is embedded in the cask body a full 8-3/4 (which is greater than the trunnion diameter), the solid trunnion would eventually reach its lock up point and further deformation of the hollow trunnion would cease. Based on the results in Table 2.5.4, the solid trunnion would eventually suffer a primary failure due to bending, causing the protruding portion of the solid trunnion to sever from the cask body before the trunnion assembly would slip off the cask body.

2-5 Provide specifics of the materials used for the impact limiter.

Drawing No. 11758, sheet 1 of 3, indicates that item 3 (impact limiter material) is made of aluminum honeycomb with a range of density and crush strength properties.

Supporting calculations indicate that this proprietary material is made only by Hexcel.

The specifics of the material have not been provided. Provide:

a) Exact material/product line names used to construct the impact limiter honeycomb material on the licensing drawings, including the fabricator. The product line CROSS-CORE from Hexcels product line is referenced in some of the calculations but this product line appears to no longer be carried by Hexcel.

See Appendix A for data sheet.

b) Catalog cuts/supporting technical data sheets of material used to construct the impact limiters (density, crush strength, aluminum alloy, etc.,) that support the values used in the document HI-2188068 and simulations performed using LS-DYNA.

c) Justification for interpolating between material properties in supporting calculation document HI-2188068 (i.e., Appendix c) for a specific crush strength that Hexcel does not fabricate.

d) Justification for 9500 psi yield strength of impact limiter crush material in supporting calculation document HI-2188068 (i.e., Appendix c) and used in the simulation models. It is unclear how this value was determined and how it is applicable to the entire range of impact limiter material(s) specified on the licensing drawings.

This information is required to demonstrate compliance with 10 CFR 71.71(c)(1),

71.73(c)(1), and 71.73(c)(3).

HOLTEC RESPONSE:

Item 3 in Holtec Drawing No. 11758 is a type of unidirectional aluminum honeycomb with explicitly defined crush strength requirements. This aluminum honeycomb impact limiter material can be purchased from multiple qualified suppliers including Hexcel, based on the results of initial sample testing performed by the suppliers.

Page 6 of 28

Enclosure 1 to Holtec Letter 5026007 a) Cross-Core is not used in the Impact Limiter Version LW (drawing number 11758).

The Upper Crush Material (Item 3) is made from aluminum unidirectional honeycomb.

This material is more available than the Cross-Core; therefore, multiple suppliers can be used. With multiple suppliers, it is not appropriate to explicitly specify the name of the fabricator and product line name. Otherwise any change to the above information would result in an unnecessary license amendment. Attached is a data sheet from an example supplier; however, other suppliers may be used as long as they meet the criteria specified in Flag Note 1 of Drawing No. 11758. Cross-core honeycombs were used in the earlier HI-STAR 100MB impact limiter design already approved by the NRC. Some technical data taken from Hexcels cross-core catalog was used to derive a few secondary parameters (e.g., elastic modulus) used by the LS-DYNA honeycomb material model based on the density of the honeycomb, and this approach was reviewed and accepted in all previous HI-STAR packages licensed by the NRC. These derived parameters have no significant impact to the impact limiters response, which is predominantly governed by the crush strength that defines the honeycomb compressive stress over almost the entire deformation process. Unlike the earlier impact limiter design, Version LW impact limiter proposed in this amendment only uses unidirectional honeycomb to protect the cask in vertical drop and CGOC drop scenarios.

b) The analysis was not done using a specific data sheet, rather the analysis was performed at both minimum and maximum values to produce a range for the critical material requirements. A data sheet is attached to response (a) above from an available supplier with material properties within this range, but this is just one example. Multiple suppliers can be used as long as they meet the criteria specified in Flag Note 1 of Drawing No. 11758.

c) Using the same principle as for the cross-core honeycomb in Appendix C of HI-2188068, the modulus of unidirectional honeycomb used in Version LW impact limiter is derived using linear interpolation. This method was reviewed and accepted by the NRC in all previously approved HI-STAR packages. Due to the behavior of unidirectional honeycomb which buckles quickly under load, the crush strength of the material is the governing parameter for energy absorption and the modulus has a secondary and insignificant effect. For the Version LW impact limiter design, both the strong and weak direction crush strength ranges of the unidirectional honeycomb are explicitly defined in the honeycomb purchase specification.

d) To predict potential lockup of the unidirectional honeycomb due to excessive deformation, a large stress value (i.e., 9,500 psi) significantly greater than honeycombs crush strength was used as the end point stress value to establish the slope of the final portion of the stress strain curve used by the honeycomb material model. The final portion of the stress strain curve has a steep slope as it is beyond the stroke of the unidirectional honeycomb that has a bounding crush strength of 600 psi. By including this portion of stress strain curve in the material model, one can tell if the impact limiter honeycomb is undersized in the direction of impact by examining if a significant deceleration increase is predicted near the end of impact. Therefore, the 9,500 psi stress value is not an important design parameter that needs to be specified on the impact limiter licensing drawing.

Page 7 of 28

Enclosure 1 to Holtec Letter 5026007 2-6 Clarify the performance of whole parts subjected to drop and puncture tests that are made of multiple pieces with undefined weld information.

Note 6 on Sheet 1 of 3, Drawing 11758 states: PARTS MAY BE MADE OF MULTIPLE PIECES. WELD TYPE AND STYLE TO BE DETERMINED BY FABRICATOR PROVIDED SAFETY FACTORS ARE MAINTAINED.

It is unclear how components made in this fashion will perform for drop and puncture tests, given that material properties may not be the same as for the base materials, and may also have weaker joint details.

Provide weld design, weld dimensions/location, and calculated safety factors as compared to whole parts detailed in the safety analysis report.

This information is required to demonstrate compliance with 10 CFR 71.71(c)(7), 10 CFR 71.73(c)(1), and 10 CFR 71.73(c)(3).

HOLTEC RESPONSE:

The following clarifications were made to the drawing to describe the components that may be made of multiple pieces:

a) Note 11 was updated to include the following statement at the end: HOLTITE-B MAY BE MADE OF MULTIPLE PIECES WITH JOINTS NOT MECHANICALLY FASTENED TOGETHER. HOLTITE-B MOVEMENT RESTRAINED BY THE CAVITY IT IS CAPTURED WITHIN.

b) Note 6 was updated to the following: ITS PARTS MAY BE MADE OF MULTIPLE PIECES. ALL WELDS SHALL BE FULL PENETRATION WELDS UNLESS OTHERWISE SHOWN c) On sheet 2, a side view of the perforated aluminum ring was shown and a weld was added to show that if the thickness is created from multiple layers that the layers shall be welded together. This is an example to specify that a full penetration weld is not required if made of multiple pieces.

d) Note 12 was added to state: THE UNIDIRECTIONAL HONEYCOMB (ITEM 3)

MAY BE MADE FROM MULTIPLE PIECES PROVIDED SEPTUMS OR SIMILAR FEATURES ARE ADDED TO ACHIEVE THE CHARACTERISTICS CAPTURED IN FLAG NOTE 1.

2-7 Clarify the location, design, and performance of unspecified lifting features Note 9 on Sheet 1 of 3, Drawing 11758 states: ADDITIONAL LIFTING FEATURE MAY BE ADDED PROVIDED ALL SAFETY FACTORS ARE MAINTAINED.

Staff is concerned that undocumented lifting features will introduce unintended forces into the package due to unspecified material, geometric singularities, inherent component weakness, redirected forces etc., with respect to package drop test performance.

Staff cannot make a regulatory finding with respect to lifting devices for a lifting feature that is not described in the safety analysis report or licensing drawings.

This information is required to demonstrate compliance with 10 CFR 71.71(c)(7), 10 CFR 71.45(c)(1), and 10 CFR 71.73(c)(3).

HOLTEC RESPONSE:

The note has been deleted from drawing 11758. This is a generic note that has previously been applied to all of our licensing drawings.

Page 8 of 28

Enclosure 1 to Holtec Letter 5026007 2-8 Clarify how vague or unspecified NITS items will affect the package performance with respect to drop tests.

Note 10 on Sheet 1 of 3, Drawing 11758 states: NOT IMPORTANT TO SAFETY(NITS)

COMPONENTS ARE SHOWN FOR ILLUSTRATIVE PURPOSES AND MAY VARY.

ADDITIONAL NITS COMPONENTS MAY BE ADDED.

Staff is concerned that undocumented NITS features, and poorly defined NITS items, will affect ITS components as they could introduce increased package demands due to unspecified material, geometric singularities, inherent component weakness, redirected forces etc. with respect to regulatory drop tests, and cause unintended galvanic reactions between materials.

Staff cannot make a regulatory finding with respect to the packages drop test performance with unknown NITS features that are either poorly described or undefined in the safety analysis report or licensing drawings. The applicant shall detail this information on the licensing drawings and in the application, as appropriate.

This information is required to demonstrate compliance with 10 CFR 71.71(c)(7), 10 CFR 71.45(c)(1), and 10 CFR 71.73(c)(3).

HOLTEC RESPONSE:

The note has been deleted from drawing 11758. This is a generic note that has previously been applied to all of our licensing drawings.

2-9 Clarify the bolt engagement length and the surrounding tube depicted in Detail ZB on Sheet 3 of licensing Drawing 11758.

The bolt (Part 6) has an engagement length of 2 1/4 inches, but appears to be modeled as 3 inches long in the LS-DYNA drop simulations. The tube that houses this bolt appears to have no dimensions nor it is listed on the bill of materials.

Both bolt engagement and bolt tube housing affect the packages ability to retain its impact limiters during a drop. Provide this information on the licensing drawings and update any calculations/simulations as necessary.

This information is required to demonstrate compliance with 10 CFR 71.71(c)(1).and 71.73(c)(3).

HOLTEC RESPONSE:

The minimum required thread engagement length for the impact limiter attachment bolts is 2-1/4 as shown in Detail ZB on Sheet 3 of Licensing Drawing 11758. This insures that the axial load limit for the 1-1/2-6UNC attachment bolts is controlled by the tensile stress in the bolt shaft, not the shear stress in the internal or external threads. Moreover, as described in SAR Section 2.7.1 the HI-STAR 100MB impact limiters are equipped with Fastener Strain Limiters (FSL), which protect the impact limiter attachment bolts from excessive tensile strains. In other words, each individual FSL is designed to fail and alleviate the tensile load on the impact limiter attachment bolt if the axial demand load reaches the yield limit of the bolt in tension. The calculation of the design failure load for the FSL is presented in Appendix D of Holtec report HI-2188068 (Reference [2.6.2] in the SAR), and the resulting value is also reflected in SAR Table 2.2.8. Since the FSLs are included in the LS-DYNA drop simulation model for the HI-STAR 100MB package at each impact limiter attachment bolt location, and they have a lower failure limit by design than Page 9 of 28

Enclosure 1 to Holtec Letter 5026007 the bolts themselves, the modeling of the thread engagement length in LS-DYNA is not of primary importance. Any engagement length equal to or greater than 2-1/4 guarantees that the FSL will fail in tension before the threads fail in shear. To conclude, the 3-inch engagement length associated with the bolt (Part 6) in the LS-DYNA drop simulation model has no adverse effect on the performance of the impact limiters or the response of the HI-STAR 100MB package.

The access tubes for the 1-1/2 diameter attachment bolts are not important-to-safety (NITS), since they are not load bearing members. Therefore, as NITS items the access tubes are only shown on the drawing for illustrative purposes as their final dimensions may vary slightly. Only important-to-safety (ITS) items are listed in the bill of materials for Licensing Drawing 11758.

Page 10 of 28

Enclosure 1 to Holtec Letter 5026007 CHAPTER 3 THERMAL REVIEW 3-1 Clarify and then justify the allowable temperature limits for: (a) the Parker V1289-75 and VM125-75 elastomeric containment seals, and (b) the metallic containment seals used for the HI-STAR 100MB package.

(a) Table 2.2.11a shows that the short-term temperature limits of the elastomeric seals (Parkers V1289-75 and VM125-75) are increased in Rev. 3 of the application, when compared to Rev. 2, to meet the increased temperatures for the additional margin under the HAC fire (see Table below). The applicant needs to clarify that any change in elastomeric seal temperature limits is justified and provide applicable references.

(b) Table 2.2.11b shows that the short-term minimum upper operating temperature limit of the metallic seals (190oC, 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />) which is lower than the short-term limit of the elastomeric seals Parkers V1289-75 and VM125-75 (270oC, 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />). In general, the metallic seals have a higher temperature limit than the elastomeric seals. The applicant needs to provide references (e.g., publications or material source book) to clarify the minimum upper operating temperature limits of the metallic seals.

SAR Rev. 2 SAR Rev. 3 (HI-2188080) (HI-2188080)

Elastomeric seals Parkers Parkers V1289-75 and V1289-75 and VM125-75 VM125-75 Maximum lower operating temperature limit -30oC -40oC Minimum upper operating temperature limit Sustained 150oC 150oC Short Term 190oC 270oC 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> 250oC 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> This information is required to demonstrate compliance with 10 CFR 71.51(a)(2) and 71.73(c)(4).

HOLTEC RESPONSE:

a) The Heat Aging data in the attached Parker data sheets meet the short term requirements of Table 2.2.11a. See Appendix B for data sheets.

b) The metallic seal temperature limits can be seen in the attached data sheets. See Appendix C for data sheets.

3-2 Clarify the thermal properties of the impact limiter Version LW used in the thermal evaluations. Specifically provide:

(a) The basis for the minimum and maximum thermal conductivities of the impact limiter Version LW upper crush material in Table 3.2.2, along with the testing results or analyses that were performed to identify these values, and show how the properties Page 11 of 28

Enclosure 1 to Holtec Letter 5026007 used in Report No. HI-2188066 Rev. 4 are bounding.

(b) The values of densities and heat capacities of the upper and lower crush materials used in the bounding NCT and HAC thermal evaluations, instead of citing see impact limiter drawing in SAR Section 1.3 in Table 2.2.8, for the impact limiter upper crush material and citing ASM [3.2.3] in Table 3.2.1 for the impact limiter lower crush material (Aluminum 6061-T6). Also provide the basis for using these densities and heat capacities for the upper and lower crush materials in the bounding NCT and HAC thermal evaluations.

The applicant stated in Section 3.3.9 that the impact limiter Version LW consists of two types of crushable material: an upper crush material and a lower crush material (perforated Aluminum 6061-T6 lower crush material). It is not clear to the staff how the thermal properties of the impact limiter Version LW are applied to the thermal evaluations and whether the thermal properties selected for the thermal evaluation are appropriate for the bounding evaluation to ensure the temperatures of fuel cladding and packaging components, including the containment seals, are below their maximum allowable limits.

This information is required to demonstrate compliance with 10 CFR 71.71 and 71.73(c)(4).

HOLTEC RESPONSE:

To address the reviewers comment, Table 3.2.2 of the SAR [3.2] is updated with appropriate reference to a Holtec Report [3.4] which presents the test results for the material properties of the impact limiter Version LW upper crush material. The thermal conductivity values adopted in the NCT and HAC evaluations of the cask with Impact Limiter Version LW bound the value presented in the test report [3.4].

The values of densities and heat capacities of the upper and lower crush materials are presented in Table S.3.2 of thermal calculation package [3.1]. Appropriate references are also added within the Table S.3.2 of [3.1].

3-3 Explain the difference between the maximum outer lid seal temperature shown in Table 3.1.3 (Report HI-2188080 Rev. 3) and the maximum outer lid seal temperature shown in Figure S.6.1 of Report HI-2188066 Rev. 4, during the HAC fire/post-fire conditions.

Table 3.1.3 of the application shows a maximum outer lid seal temperature of 233oC (451oF) for the F-32M during the HAC post-fire cooldown. However, Figure S.6.1 of Report No. HI-2188066R4 shows that the F-32M maximum outer lid seal temperature is always below 230oC (gray curve in Figure S.6.1) during the entire HAC fire, including the post-fire cooldown. The applicant needs to explain this difference between Table 3.1.3 and Figure S.6.1.

This information is required to demonstrate compliance with 10 CFR 71.51(a)(2) and 71.73(c)(4).

HOLTEC RESPONSE:

Upon verifying the HAC calculations corresponding to Table 3.1.3 of the SAR [3.2], it is confirmed that the maximum outer lid seal temperature is 223C. The value presented in Page 12 of 28

Enclosure 1 to Holtec Letter 5026007 Table 3.1.3 is a typo. We regret this error. Table 3.1.3 of the SAR [3.2] is updated to rectify this error.

3-4 Provide the time variant metallic seal temperatures (temperature history) of the F-32M to verify that the metallic seals, located at the vent/drain ports, maintain their temperatures below the operation limits during the HAC fire.

Table 2.2.11b of the application shows that the metallic containment seals have the lower short-term operating temperature limits of 190oC ( 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />) and 250oC ( 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />), when compared to the short-term operating temperature limit of 270oC ( 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />) for the elastomeric containment seal, as shown in Table 2.2.11a of the application.

The applicant displayed the time variant elastomeric seal temperatures of the F-32M during the HAC fire in Figure S.6.1 of Report HI-2188066 Rev. 4. Given that thermal properties and temperature limits of the metallic seal are different from those of the elastomeric seal, the applicant needs to also provide the time variant metallic seal temperatures (temperature history) of the F-32M during the HAC fire to verify that the metallic seals at the vent/drain ports meet the short-term operating temperature limits during the HAC fire.

This information is required to demonstrate compliance with 10 CFR 71.51(a)(2) and 71.73(c)(4).

HOLTEC RESPONSE:

Time variant seal temperatures are presented in Figure S.6.1 of thermal calculation package [3.1] for licensing basis evaluation. Time variant seal temperatures are also presented for the HAC sensitivity study Impact Limiter Version LW in Figure S.6.2 of [3.1].

The variation of temperature with time does not depend on the material of the seal.

Therefore, these figures represent time variant temperature of both elastomeric and metallic seals. They demonstrate that the maximum seal temperatures during fire are within the short term temperature limits for the elastomeric/metallic seals presented in Table 2.2.11b of [3.2].

3-5 Provide an evaluation for the postulated scenario that a flame, from an HAC fire, may penetrate the perforated 6061-T6 aluminum block through its holes and reach the lid under the HAC 30-minute fire and its post-fire cooldown, or provide a justification that this postulated scenario cannot occur.

The impact limiter Version LW consists of the upper crush material and the lower crush material (perforated 6061-T6 aluminum block). The holes on the perforated 6061-T6 aluminum block are almost 2.5-inch wide and go all the way through the aluminum block (see Drawing No. 11758, sheet 2 of 3).

The flames during the HAC fire may penetrate the perforated 6061-T6 aluminum block through its holes and reach the lid (such that the flame has a direct contact with the lid).

The applicant needs to evaluate whether the flame penetration could raise the PCT and the package component temperatures (e.g., seal temperatures) over the respective PCT and component design temperature limits during the HAC fire and its post-fire cooldown.

Page 13 of 28

Enclosure 1 to Holtec Letter 5026007 Alternatively, the applicant shall provide a justification that this scenario cannot occur.

This information is required to demonstrate compliance with 10 CFR 71.51(a)(2) and 71.73(c)(4).

HOLTEC RESPONSE:

The lower crush material (perforated 6061-T6 aluminum block) is completely enclosed in a stainless steel skin, as presented in the Impact Limiter Version LW licensing drawing [3.3].

Also, the upper crush material above the lower crush material prevents it from being directly exposed to fire. On the sides, the cask lid is surrounded by top flange. Due to these design features, the scenario of flame reaching cask lid by penetrating through the perforated 6061-T6 aluminum block is not credible.

3-6 Provide a justification for the derivation of the Holtite rib effective thermal conductivity, when used as the radial and tangential thermal conductivities of the rib, in the thermal model.

As presented in Appendix B of Report No. HI-2188066 R4, the applicant derived the Holtite rib effective thermal conductivity using the temperature difference between the rib ID surface and the rib OD surface.

The applicant defined the derived effective thermal conductivities as a function of the rib ID surface temperatures of 200°F, 300°F, 550°F, 800°F and 1100°F, when used as the radial and tangential thermal conductivities in the thermal model.

Temperature at rib ID surface, °K (°F) 366.5 422.0 560.9 699.8 866.5 (200) (300) (550) (800) (1100)

Temperature at rib OD surface,°K 310.9 366.5 505.4 644.3 810.9

(°F) (100) (200) (450) (700) (1000)

Average value of the rib ID and OD (150) (250) (500) (750) (1050) surface temperatures (°F)

Effective thermal conductivity 55.14 53.18 47.44 41.84 35.15 (W/(m-°K)

The staff reviewed Appendix B of Report No. HI-2188066 Rev. 4 and finds that the effective thermal conductivity is calculated from the temperature difference between the rib ID surface and the rib OD surface. Therefore, it may be more appropriate and bounding to define the effective thermal conductivities (row #4 in Table) as a function of the average temperatures of the rib ID surface and the rib OD surface (150°F, 250°F, 500°F, 750°F, and 1050°F as seen at Row #3 in Table).

Given the fact that the rib is one of the main components to transfer heat from the package, the appropriate use of the effective thermal conductivity in the thermal evaluation is important. Therefore, the applicant needs to justify whether the effective thermal conductivity (Row #4) should be defined as a function of the rib ID surface temperatures (Row #1), or as a function of the average rib ID/OD surface temperatures (Row #3) for the Page 14 of 28

Enclosure 1 to Holtec Letter 5026007 bounding thermal analysis.

This information is required to demonstrate compliance with 10 CFR 71.71 and 71.73(c)(4).

HOLTEC RESPONSE:

To address the reviewers comment, a sensitivity study is presented in Section S.6.13 of the thermal calculation package [3.1]. The effective thermal conductivity of the holtite rib is defined as a function of average temperature of the rib inner diameter and outer diameter surfaces. The results of the evaluation are presented in Table S.6.24 of [3.1]. It is demonstrated that the impact is insignificant and the temperatures are essentially same as those for the evaluations presented in Section S.6.12 of [3.1].

References:

[3.1] Thermal Evaluations of HI-STAR 100MB in Transport, Holtec Report HI-2188066, Revision 6.

[3.2] Safety Analysis Report for the HI-STAR 100 MB Package, Holtec Report HI-2188080, Revision 4.

[3.3] HI-STAR 100MB Cask Assembly, Holtec Drawing 11070, Revision 6.

[3.4] Aluminum Unidirectional Honeycomb Test Report, Holtec Report HI-2200212, Revision 0.

Page 15 of 28

Enclosure 1 to Holtec Letter 5026007 Chapter 5 SHIELDING REVIEW 5-1 Provide the cobalt impurity information in Table 5.2.2.

In Section 5.2.1, the applicant states Table 5.2.2 provides the steel and Inconel masses of the design basis fuel assembly outside the active fuel zone. The table also provides the mass of the non-zircaloy parts of the grid spacers. In addition to the steel and Inconel masses, the masses of Co59 impurity levels are also provided. (Emphasis added.)

Staff reviewed Table 5.2.2 and the cobalt impurity level is not present in the table.

This information is required to demonstrate compliance with 10 CFR 71.31(b).

HOLTEC RESPONSE:

The comment is accepted. The text is updated stating Table 5.2.2(c) provides 59Co impurity masses. The 59Co impurity masses have been added to Table 5.2.2(c).

5-2 Justify the 0.5 g/kg or 500 ppm Co59 impurity level for both steel and Inconel fuel structural hardware.

On page 5.2-2 of Revision 3 of the application, the applicant states: Subsection 5.2.1 of HI-STAR 100 SAR indicates that the Co59 impurity level in steel was 800 ppm or 0.8 g/kg and in Inconel was approximately 4700 ppm or 4.7 g/kg. Since mid-1980s, major fuel vendors have reduced the Co59 impurity level in both Inconel and steel to less than 500 ppm or 0.5 g/kg. In the calculations performed here, a Co59 impurity level of 0.5 g/kg Is used for the steel and Inconel components of PWR fuel assemblies Regulatory Guide 3.54 Revision 2 concludes that 0.8 g/kg was a conservative cobalt impurity assumption for Type 304 stainless steel. The guide notes that manufacturers currently (as of 2009) measured concentrations suggesting significantly lower cobalt levels than used in the calculations for the guide.

The applicant refers to HI-STAR 100 SAR Section 5.2.1, which used 0.8 and 4.7 g/kg for steel and Inconel, respectively. The applicant did not provide any data to support the reduction in Co59 impurity. The applicant also did not provide any information on a time from which the 0.5 g/kg impurity assumption would be an appropriate assumption.

This information is required to determine if the activation source calculated at 0.5 g/kg Co59 is still conservative for older fuel that may not meet this impurity requirement.

This information is required to demonstrate compliance with 10 CFR 71.47(b) and 71.51(a)(2).

HOLTEC RESPONSE:

The calculations for HI-STAR 100MB with F-32M and MPC-32 are revised to increase the 59 Co content to 0.8 g/kg. The allowable loading patterns in Chapter 7 are revised, if needed, to meet the transportation cask dose rate limits.

The calculations for HI-STAR 100MB with F-24M are revised by evaluating 3 levels of 59 Co impurity, as shown in HI-STAR 100MB SAR Table 5.2.2(a). The allowable loading patterns in Chapter 7 are revised, if needed, to meet the transportation cask dose rate limits.

Page 16 of 28

Enclosure 1 to Holtec Letter 5026007 Appendix A: Attachments Supporting RAI Response 2-5(a)

Page 17 of 28

Enclosure 1 to Holtec Letter 5026007 PRODUCT DATA SHEET pAA-core 5052 Aluminum Honeycomb DeScripTion PAA-CORE 5052 aluminum honeycomb is phosphoric acid anodized and coated with a proprietary primer. PAA-CORE has unsurpassed corrosion resistance, (with minimal weight loss after 31 days in an acidified salt spray chamber). PAA-CORE outperforms non-metallic core materials due to significantly higher strength-to-weight ratio and hot/wet strength.

ApplicATionS Aircraft control surfaces Longer service aircraft flooring Aircraft landing gear doors Extended service aircraft engine nacelles Marine and naval panels Advanced energy absorbers High performance composite structures Replacement for non-metallic core materials FeATureS

• Unsurpassed corrosion resistance and bond durability

• Excellent strength-to-weight ratio

• Elevated temperature performance to 350°F/177°C

• Fire and fungus resistant

• Eliminates need for priming or pour-coat

• Easily machined and formed

• Resistant to hostile environments

• Exceeds AMS-C-7438 and many other aerospace specifications AvAilAbiliTy Unexpanded blocks, Unexpanded slices, Expanded sheets, Pieces cut to size.

PAA-CORE 5052 aluminum honeycomb is available with cell perforations to facilitate venting.

Custom dimensions, cell sizes, tolerances and mechanical properties are also available.

AvAilAble DiMenSionS Standard Maximum Tolerance inches mm inches mm inches mm Ribbon (L) 48 1219 100 2540 +2.0 / -0.0 +50.8 / -0.0 Transverse (W) 96 2438 144 3658 +4.0 / -0.0 +101.6 / -0.0 Thickness (T) 35 889 up to 4 inches (102mm) T +/-0.005 +/-0.127 over 4 inches (102mm) T +/-0.062 +/-1.575 Density see mechanical characteristics chart +/-10%

Cell Size see mechanical characteristics chart +/-10%

F203 - 01/20 4056 Easy Street, El Monte, CA 91731-1087, USA info@thegillcorp.com 626-443-4022 www.thegillcorp.com Page 18 of 28

pAA-core 5052 Enclosure 1 to Holtec Letter 5026007 Aluminum Honeycomb product Data Sheet page 2 of 3 HoW To orDer When ordering, please specify PAA-CORE 5052 using the following format:

Example: PAA - 5052 - 3.1 - 3/16 - N - E, where perforated or expanded or product Alloy Density cell Size non-perforated unexpanded PAA 5052 3.1 3/16 P or N E or U HeAlTH precAuTionS This product is safe to use and apply when recommended precautions are followed. Before using this product, read and understand the Safety Data Sheet (SDS), which provides information on health, physical and environmental hazards, handling precautions and first aid recommendations. A SDS is available at www.thegillcorp.com/products/msds/html.

For industrial use only. Keep away from children. Additional information can be found at: www.thegillcorp.com. For sales and ordering information call 1-626-443-6094.

All recommendations, statements, values and technical data herein are based on tests The Gill Corporation believes to be reliable and correct, but accuracy and completeness of said tests are not guaranteed and are not to be construed as a warranty, either expressed or implied. Users shall rely on their own information and tests to determine suitability of the product for the intended use and assume all risks and liability resulting from their use of the product. The Gill Corporations sole responsibility shall be to replace that portion of the product that proves to be defective. The Gill Corporation will not be liable to the buyer or any third person for any injury, loss or damage directly or indirectly resulting from use of, or inability to use, the product. Recommendations or statements not contained in a written agreement signed by an officer of The Gill Corporation shall not be binding upon The Gill Corporation.

PAA-CORE is a registered trademark of The Gill Corporation.

F203 - 01/20 © The Gill Corporation. All rights reserved. www.thegillcorp.com Page 19 of 28

pAA-core 5052 Enclosure 1 to Holtec Letter 5026007 Aluminum Honeycomb product Data Sheet page 3 of 3 compressive Stabilized crush plate Shear Shear Modulus Density(pcf) - l-Direction W-Direction l-Direction W-Direction cell Size(in) - 75° 350° 75° 75° 350° 75° 350° 75° Foil Gauge(in) Strength (psi) Strength (psi) Strength (psi) Strength (ksi) typ MPa min typ MPa min typ MPa typ MPa min typ MPa min typ MPa min typ MPa min typ MPa typ MPa 3.1 - 1/8 - 0.0007 305 2.10 215 200 1.38 141 145 1.00 215 1.48 155 145 1.00 109 132 0.91 90 90 0.62 59 32 221 16 110 4.5 - 1/8 - 0.001 580 4.00 405 380 2.62 252 270 1.86 345 2.38 285 240 1.65 200 225 1.55 168 150 1.03 109 51 352 25 172 6.1 - 1/8 - 0.0015 1030 7.10 680 660 4.55 446 450 3.10 565 3.90 455 400 2.76 319 345 2.38 272 220 1.52 177 77 531 37 255 8.1 - 1/8 - 0.002 1575 10.86 1100 1075 7.41 722 760 5.24 810 5.58 670 575 3.96 469 540 3.72 400 310 2.14 260 112 772 50 345 10.0 - 1/8 - 0.0025 1875 12.93 1500 1300 8.96 981 1070 7.38 1075 7.41 860 810 5.58 602 610 4.21 490 415 2.86 319 140 965 60 414 12.0 - 1/8 - 0.003 2920 20.13 1910* 1550 10.69 1263 1400 9.65 1955* 13.48 1250* 1300* 8.96 875 950* 6.55 750* 440 3.03 325 160 1103 75 517 2.6 - 5/32 - 0.0007 245 1.69 160 150 1.03 105 105 0.72 170 1.17 120 110 0.76 84 102 0.70 70 80 0.55 46 24 165 12 83 3.8 - 5/32 - 0.001 415 2.86 300 280 1.93 197 210 1.45 275 1.90 215 200 1.38 151 168 1.16 125 140 0.97 81 41 283 20 138 5.3 - 5/32 - 0.0015 730 5.03 535 500 3.45 341 340 2.34 425 2.93 370 340 2.34 259 275 1.90 215 200 1.38 140 64 441 31 214 6.9 - 5/32 - 0.002 1140 7.86 800 780 5.38 525 570 3.93 595 4.10 540 500 3.45 378 380 2.62 328 275 1.90 213 91 627 42 290 8.4 - 5/32 - 0.0025 1615 11.14 1180 1150 7.93 774 800 5.52 770 5.31 690 590 4.07 483 480 3.31 420 330 2.28 273 116 800 51 352 2.0 - 3/16 - 0.0007 180 1.24 100 100 0.69 62 70 0.48 122 0.84 80 80 0.55 56 71 0.49 46 65 0.45 30 17 117 9 62 3.1 - 3/16 - 0.001 340 2.34 215 200 1.38 141 145 1.00 215 1.48 155 145 1.00 109 128 0.88 90 90 0.62 59 32 221 16 110 4.4 - 3/16 - 0.0015 555 3.83 385 375 2.59 253 270 1.86 335 2.31 280 235 1.62 196 220 1.52 160 145 1.00 104 50 345 24 165 5.7 - 3/16 - 0.002 870 6.00 600 600 4.14 394 410 2.83 465 3.21 410 380 2.62 287 305 2.10 244 200 1.38 159 70 483 34 234 6.9 - 3/16 - 0.0025 1185 8.17 800 780 5.38 525 570 3.93 600 4.14 540 500 3.45 378 380 2.62 328 275 1.90 213 91 627 42 290 8.1 - 3/16 - 0.003 1735 11.96 1100 1075 7.41 722 760 5.24 735 5.07 670 575 3.96 469 490 3.38 400 310 2.14 260 112 772 50 345 1.6 - 1/4 - 0.0007 102 0.70 70 70 0.48 43 50 0.34 88 0.61 60 60 0.41 42 51 0.35 32 35 0.24 21 13 90 6 41 2.3 - 1/4 - 0.001 215 1.48 130 125 0.86 82 85 0.59 145 1.00 100 90 0.62 70 88 0.61 57 70 0.48 37 21 145 11 76 3.4 - 1/4 - 0.0015 375 2.59 250 235 1.62 164 160 1.10 235 1.62 180 160 1.10 126 145 1.00 105 100 0.69 68 35 241 18 124 4.3 - 1/4 - 0.002 545 3.76 370 365 2.52 243 250 1.72 325 2.24 265 235 1.62 186 205 1.41 155 140 0.97 101 48 331 24 165 5.2 - 1/4 - 0.0025 770 5.31 510 500 3.45 335 330 2.28 415 2.86 360 330 2.28 252 270 1.86 200 160 1.10 130 62 427 31 214 6.0 - 1/4 - 0.003 1110 7.65 660 650 4.48 433 430 2.96 535 3.69 445 390 2.69 312 350 2.41 265 210 1.45 172 75 517 36 248 7.9 - 1/4 - 0.004 1505 10.38 1050 1025 7.07 689 720 4.96 710 4.90 650 550 3.79 455 450 3.10 390 300 2.07 254 108 745 49 338 1.6 - 3/8 - 0.001 98 0.68 70 70 0.48 43 50 0.34 88 0.61 60 60 0.41 42 51 0.35 32 35 0.24 21 13 90 6 41 2.3 - 3/8 - 0.0015 205 1.41 130 125 0.86 82 85 0.59 145 1.00 100 90 0.62 70 88 0.61 57 70 0.48 37 21 145 11 76 3.0 - 3/8 - 0.002 315 2.17 200 190 1.31 131 135 0.93 205 1.41 145 140 0.97 102 128 0.88 85 85 0.59 55 30 207 15 103 3.7 - 3/8 - 0.0025 415 2.86 290 265 1.83 190 200 1.38 255 1.76 205 190 1.31 144 165 1.14 120 105 0.72 78 40 276 20 138 4.2 - 3/8 - 0.003 565 3.90 350 340 2.34 236 240 1.65 315 2.17 255 230 1.59 179 205 1.41 150 130 0.90 98 47 324 23 159 5.4 - 3/8 - 0.004 810 5.58 540 540 3.72 367 360 2.48 435 3.00 380 355 2.45 266 285 1.97 228 180 1.24 148 66 455 32 221 6.5 - 3/8 - 0.005 1015 7.00 760 750 5.17 499 510 3.52 555 3.83 500 440 3.03 350 360 2.48 300 265 1.83 195 83 572 40 276 2.6 - 1/2 - 0.0025 200 1.38 150 1.03 105 0.72 150 1.03 110 0.76 88 0.61 80 0.55 24 165 12 83 3.0 - 1/2 - 0.003 250 1.72 190 1.31 135 0.93 180 1.24 140 0.97 106 0.73 85 0.59 30 207 15 103 4.0 - 1/2 - 0.004 400 2.76 320 2.21 220 1.52 290 2.00 220 1.52 170 1.17 120 0.83 44 303 22 152 0.8 - 3/4 - 0.001 23 0.16 20 0.14 15 0.10 25 0.17 25 0.17 19 0.13 25 0.17 5 34 2 14 1.8 - 3/4 - 0.0025 100 0.69 90 0.62 60 0.41 90 0.62 70 0.48 50 0.34 40 0.28 15 103 7 48 2.1 - 3/4 - 0.003 131 0.90 105 0.72 75 0.52 105 0.72 85 0.59 60 0.41 75 0.52 18 124 9 62 3.0 - 3/4 - 0.004 250 1.72 190 1.31 135 0.93 180 1.24 140 0.97 105 0.72 85 0.59 30 207 15 103 4.2 - 3/4 - 0.006 450 3.10 340 2.34 240 1.65 320 2.21 230 1.59 190 1.31 130 0.90 47 324 23 159

• Values determined by Beam Flexure Shear All recommendations, statements, values and technical data herein are based on tests The Gill Corporation believes to be reliable and correct, but accuracy and completeness of said tests are not guaranteed and are not to be construed as a warranty, either expressed or implied. Users shall rely on their own information and tests to determine suitability of the product for the intended use and assume all risks and liability resulting from their use of the product. The Gill Corporations sole responsibility shall be to replace that portion of the product that proves to be defective. The Gill Corporation will not be liable to the buyer or any third person for any injury, loss or damage directly or indirectly resulting from use of, or inability to use, the product. Recommendations or statements not contained in a written agreement signed by an officer of The Gill Corporation shall not be binding upon The Gill Corporation.

PAA-CORE is a registered trademark of The Gill Corporation.

F203 - 01/20 © The Gill Corporation. All rights reserved. www.thegillcorp.com Page 20 of 28

Enclosure 1 to Holtec Letter 5026007 Appendix B: Attachments Supporting RAI Response 3-1 (a)

Page 21 of 28

Enclosure 1 to Holtec Letter 5026007 V1289-75 Low Temperature FKM Low temperature performance:

Parkers V1289-75 fluorocarbon com-pound offers the best low temperature sealing performance of any fluorocarbon rubber material available in the market.

Low temperature performance has long been the Achilles heel of fluorocar-bon elastomer technology. Standard fluorocarbon copolymer compounds seal down to about -15°F (-26°C). Low temperature (GLT-type) fluorocarbon compounds offer low temperature flex-ibility at Tg of -22°F (-30°C) and improved HTS oil stability but sacrifice compres-sion set. With a Tg of -40°F (-40°C),

V1289-75 offers reliable dynamic sealing down to -40°F and static sealing down to

-55°F (-48°C) in the most demanding seal applications.

Contact Advantages:

Information:

• Better low temperature rating

• Better high temperature rating than AMS-R-83485 FKM and than nitrile and fluorosilicone Parker Hannifin Corporation AMS 7276 FKM

• Better wear and tear proper-O-Ring Division 2360 Palumbo Drive

• Lower volume swell in fuels ties than fluorosilicone Lexington, KY 40509 than fluorosilicone and nitrile

• Better compression set than phone 859 269 2351 nitrile fax 859 335 5128

• Better wear resistance than fluorosilicone

• No dry-out shrinkage www.parker.com Page 22 of 28

Enclosure 1 to Holtec Letter 5026007 V1289-75 (AS568-214 size, AMS 7379 spec) Typical Applications:

Spec Test Original Physical Properties Test method limits results

• MIL-PRF-5606 Hardness, Shore A, pts. ASTM D2240 75 +/- 5 76

• MIL-PRF-83282 Tensile strength, psi ASTM D412 1300 1549

• MIL-PRF-87257 hydraulics

• Jet fuel Ultimate elongation, % ASTM D412 120 129

• Biojet Modulus at 100% elongation, psi ASTM D412 1075

• HTS turbine oils Specific Gravity ASTM D297 1.87 (MIL-PRF-23699)

Compression Set 336 hrs. @ 275°F in MIL-PRF-83282

• Bleed air

% of original deflection, max. ASTM D395 Method B 35 14

• Environmental sealing Compression Set 22 hrs. @ 392°F

% of original deflection, max. ASTM D395 Method B 20 14 Compression Set 336 hrs. @ 392°F Reference Oil 300

% of original deflection, max. ASTM D395 Method B 55 50 Dry Heat Resistance (70 hrs. @ 518°F)

Hardness change, pts. ASTM D573 -10 to + 5 0 Tensile change, % -45 -30 Elongation change, % -10 +18 Weight loss % 10 -4 Fluid Immersion Reference Oil 300, (70 hrs. @ 392°F)

Hardness change, Shore A pts. ASTM D471 -10 0 Tensile strength change, % -30 -8 Ultimate elongation change, % -20 +17 Volume change, % 0 to +10 +5 Fluid Immersion Fuel B, (70 hrs. @ R.T.)

Hardness change, Shore A, pts. ASTM D471 -10 0 Tensile strength change, % -35 -23 Ultimate elongation change, % -20 -4 Volume change, % 1 to +10 +4 Fluid Immersion Reference Oil 300, (70 hrs. @ 275°F)

Hardness change, Shore A pts. ASTM D471 -10 -1 Tensile strength change, % -30 -8 Ultimate elongation change, % -20 +15 Volume change, % 0 to +10 +3 Fluid Immersion MIL-PRF-83282, (70 hrs. @ 275°F)

Hardness change, Shore A, pts. ASTM D471 -7 -1 Tensile strength change, % -25 -6 Ultimate elongation change, % -15 +19 Volume change, % +6 +1 Low Temperature TR-10, °C ASTM D1329 -38 -39

© 2009 Parker Hannifin Corporation ORD 5760 3/09 Page 23 of 28

Enclosure 1 to Holtec Letter 5026007 VM125-75 for Aerospace Applications O-Ring Division AMS7287 Applications AMS7287 supersedes the long time specification, AMS-R-83485, for the aerospace industry. Covering a wide variety of gas turbine engine lubricants, higher thermo-oxidative stability (HTS) lubricants like Mil-PRF-23699 (HTS), Mil-PRF-7808 Grade 4 and AS5780 Class HPC, as well as a variety of jet fuels, the specification demands a material with superior chemical resistance. With respect to temperature, AMS7287 also calls for a thermally stable compound, for seal functionality at very high and low temperatures.

Parkers VM125-75 has the chemical resistance, high temperature compression set resistance and low temperature flexibility to meet the increasing demands of the industry. Approved to qualified products list, VM125-75 meets AMS7287, as well as the preceeding document, AMS-R-83485.

Contact Information: Product Features:

Parker Hannifin Corporation

• Best in class compression set O-Ring Division 2360 Palumbo Drive * -40°F to +400°F (-40°C to +204°C)

PO Box 11751

• Outstanding HTS turbine oil compatibility Lexington, KY 40512-1751

• Outstanding jet fuel compatibility phone 859 269 2351

• Outstanding hydraulic fluid compatibility fax 859 335 5128

• AMS7287 QPL approved, AMS-R-83485 approved www.parkerorings.com Page 24 of 28

Enclosure 1 to Holtec Letter 5026007 Compression Set Resistance AS568-214 Test Data (Date: June 14, 2013)

PROPERTY AMS7287 VM125-75 VM125-75 offers improved high Original Physical Properties ASTM D1414, D2240, D297 temperature compression set resistance Shore A hardness 75 +/- 5 73 compared to typical industry GLT Tensile strength, min., psi 1600 1825 type fluorocarbon elastomers. Both Ultimate elongation, min., % 120 202 short and long term testing at 392°F Specific Gravity As determined 1.77 (200°C) show a marked difference in Low Temperature Retraction, D1329 TR-10, max, °F -20 -22 elastomer rebound.

Compression Set, ASTM D395 Method B 22h @ 392°F, max, % loss of original deflection 20 9 Broad Temperature Resistance 336h @ 392°F, max, % loss of original deflection 50 44 Heat Age (70h @ 527°F) ASTM D573 VM125-75 has comparable high Hardness change, pts. +/- 5 +1 temperature stability as traditional Tensile strength change, max., % -35 -18 A-type fluorocarbon elastomers, Ultimate elongation change, max., % -10 +7 but offers improved performance Weight change, max., % -12 -12 at cold temperatures. Traditional Fluid Resistance Fuel B (70h @ 73°F) ASTM D471 fluorocarbons lose resiliency and Hardness change, pts. +/- 5 -3 Tensile strength change, max., % -30 -18 begin to leak at around -15°F (-26°C) Ultimate elongation change, max., % -20 -11 in many applications. VM125-75 is a Volume change, % +1 to +10 +4 low temperature fluorocarbon that Fluid Resistance AMS 3085 Mobile Jet Oil (70h @ 392°F) ASTM D471 results in seal performance down to Hardness change, pts. -10 to 0 -3

-40°F (-40°C). This sealing ability Tensile strength change, max., % -35 -16 Ultimate elongation change, max., % -20 +13 across a wide range of temperatures Volume change, % +1 to +20 +15 makes VM125-75 an excellent material Compression set, ASTM D395 Method B, 15 0 for broad temperature applications.  % loss of original deflection Outstanding Fluid Resistance Fluorocarbon elastomers, as a family, Compression Set at 392°F (200°C) have outstanding chemical resistance.

70%

VM125-75 is fully compatible with all Typical GLT aerospace jet fuels and hydrocarbon- 60%

based hydraulic oils. VM125-75 50%

VM125-75 is specifically designed for maximum service life in aggressive HTS 40%

turbine oils. Even in long-term testing, the material does not significantly 30%

harden, lose elongation, or take a 20%

severe compression set.

10%

0%

22 Hours 366 Hours

© 2013 Parker Hannifin Corporation ORD 6010 09/13 Page 25 of 28

Enclosure 1 to Holtec Letter 5026007 Appendix C: Attachments Supporting RAI Response 3-1(b)

Page 26 of 28

Enclosure 1 to Holtec Letter 5026007 Technetics Group France 90, rue de la Roche du Geai 42029 Saint Etienne cedex 1, FRANCE Tél: +33 (0) 4 77 43 51 00 Fax: +33 (0) 4 77 43 51 51 www.techneticsgroup.com Savit Sinha Senior Project Manager Holtec International Phone: 856-797-0900 Extn: 3685 E-mail: s.sinha@holtec.com Cc: Mr. Chris Cosgrove (Technetics)

Ms. Stéphanie Ruel (Technetics)

Mr. Florent Ledrappier (Technetics)

Subject:

Maximum temperature on seals Date: September 5th, 2019

Dear Mr Sinha,

Youll find below recommendations regarding maximum reachable temperature for Silver seals on your cask container.

The Helicoflex Silver seals (HN-200) can function under the following conditions:

Temperature Duration

>200°C* Leak tight up to 50 years

>250°C* Leak tight up to 1 year

>450°C* Leak tight up to 1 Week

>450°C* Leak tight up to 5 days

• Upper limit is not known These are based on Technetics experience with silver seals in similar conditions.

It has been stated by Holtec that no unloading on the seal will occur.

Best regards, Frédéric Sauvinet HELICOFLEX seals Product Manager EnPro Industries companies Sige Social : 90 rue de la Roche du Geai. 42029 Saint Etienne Cedex 1 France - france@techneticsgroup.com Page 27 of 28 S.A.S. au capital de 4 840 000 - RCS : B 400 072 997 Saint Etienne

Enclosure 1 to Holtec Letter 5026007 Technetics Group France 90, rue de la Roche du Geai 42029 Saint Etienne cedex 1, FRANCE Tél: +33 (0) 4 77 43 51 00 Fax: +33 (0) 4 77 43 51 51 www.techneticsgroup.com Savit Sinha Senior Project Manager Holtec International Phone: 856-797-0900 Extn: 3685 E-mail: s.sinha@holtec.com Cc: Mr. Chris Cosgrove (Technetics)

Ms. Cindy Held (Technetics)

Mr. Florent Ledrappier (Technetics)

Mr. Adrien Bommenel (Technetics)

Subject:

Maximum temperature on seals Date: June 18th, 2020

Dear Mr Sinha,

Youll find below recommendations regarding maximum reachable temperature for Aluminium on your cask container.

The Helicoflex Aluminum seals (HN-200) can function under the following conditions:

Transportation:

Temperature Duration 130°C max Leak tight up to 5 years 160°C max Leak tight up to 1 year

>350°C Leak tight up to 1 Week

>350°C Leak tight up to 5 days These data are based on Technetics experience with aluminum seals in similar conditions and has been extrapolated.

It has been stated by Holtec that no unloading on the seal will occur.

Best regards, Frédéric Sauvinet HELICOFLEX seals Product Manager EnPro Industries companies Sige Social : 90 rue de la Roche du Geai. 42029 Saint Etienne Cedex 1 France - france@techneticsgroup.com S.A.S. au capital de 4 840 000 - RCS : B 400 072 997 Saint Etienne Page 28 of 28