ML23212B073
| ML23212B073 | |
| Person / Time | |
|---|---|
| Site: | 07103035, 07103004 |
| Issue date: | 07/31/2023 |
| From: | Garcia-Santos N Edlow International Co, Edlow, Storage and Transportation Licensing Branch |
| To: | |
| Shared Package | |
| ML23212B068 | List: |
| References | |
| 001794, L-2023-DOT-0005, L-2023-DOT-0006 | |
| Download: ML23212B073 (7) | |
Text
7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests Attendees:
U.S. Nuclear Regulatory Commission (NRC)
Norma Garcia Santos Bharatkumar Patel, Structural Reviewer Yong Kim, Peer Reviewer (Structural)
Christopher Bajwa, Containment Reviewer Jason Huang, Materials Reviewer Christopher Sydnor, Peer Reviewer (Materials)
Darrell Dunn, Peer Reviewer (Materials)
U.S. Department of Transportation (DOT)
Richard Boyle, Branch Chief Edlow Russell Neely U.S. Department of Energy (DOE)
Kiran Karath DISCUSSION:
On July 12, 2023, representatives of NRC, DOT, Edlow, and DOE participated on a phone call to discuss questions related to the first round of requests for additional information (RAIs) of DOTs request to review the applications for the revalidation of Model Nos. JMS-87Y-18.5T (JMS) and JRC-80Y-20T (JRC). The following items summarize the discussion during the telephone call.
JMS-87Y-18.5T (JMS)
GENERAL INFORMATION RAI-GEN-1 The main document including the sections of the safety analysis report (SAR) refers to an older version of the International Atomic Agency Regulations (IAEA)
SSR-6. The staff is requesting that the applicant revises the SAR to accurately reflect the version of the regulations applicable to the certificate. In this case, the IAEA SSR-6, 2018 Edition.
MATERIALS EVALUATION RAI-Ma-1 The staff is requesting that the applicant provides specific standards; qualification criteria (e.g., qualification criteria of personnel performing inspections); and acceptance criteria used in the evaluation process to determine compliance with 503(e), 613, and 809(f). For standards different than the ones used in the U.S.,
the applicant should include:
Enclosure NRC Form 699:
7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests
- a. a description of the relevant similarity(ies) with standards in the U.S.
- b. justification from deviations from a standard(s)
The response should include acceptance criteria for aging effects such as early stage fatigue cracks and localized corrosion of stainless steel components
[e.g., numeric criteria such as the flaw size is less than X This applies to RAI-Ma-1 a) - e)].
In general, the applicant should explain why the standard, numeric criteria, methods, and/or qualification credentials and process are adequate to perform the safety function. Stating that it is an inspector certified by JAEA is not sufficient.
RAI-Ma-1e) Based on information about the items mentioned in (II) Chapter F of the application, it appears that these items are intended to be used repeatedly. The applicant noted that there are packaging materials not intended to be used repeatedly and, therefore, not included in the scope of the evaluation. The staff needs clarification on the meaning of the responses and justification about the rationale and criteria to exclude such materials from the evaluation.
The staff asked the applicant to provide additional detail about the inspections performed on the package and the criteria associated with the inspections.
During this discussion, the staff referred to the requirements in IAEA Safety Standards Guide No. 26 (SSG-26), Advisory Material for the IAEA Regulations for the Safe Transport of Radioactive Material, 2018 Edition, paragraph 613A.3.
RAI-Ma-2 The staff noted that a potential mechanism of degradation is abrasion as mentioned in IAEA SSG-26. However, the evaluation in (II)F provided by the applicant did not consider abrasion. The staff was not able to find either a discussion in the SAR or an evaluation about abrasion as an aging mechanism.
The applicant mentioned in its response that an abrasion evaluation was not necessary because the package is not equipped with dynamic devices, etc.
Nevertheless, the staff needs the applicants evaluation to justify excluding abrasion as an ageing mechanism. The staff also needs clarification about the dynamic devices that the applicant is referring to in order to have a better understanding about the RAI response.
RAI-Ma-3 The applicant is requesting revalidation of the JMS package per the IAEA SSR-6, 2018 Edition. Guidance such as the IAEA SSG-26, Advisory Material for the IAEA Regulations for the Safe Transport of Radioactive Material, supplements the IAEA SSR-6.
Paragraph 809, items(f) and (k), of the IAEA SSR-6 includes the requirements for approving a package design. Paragraph 809(f) requires including considerations related to ageing management in the application. Per paragraph 809(k), the applicant must provide a gap analysis programme for packages used for shipment after storage. Per IAEA SSG-26, paragraph 613A.5, the applicant must provide an ageing management programme and a gap analysis programme. The applicant did not provide this information in its RAI response.
Therefore, the SAR should include the following:
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7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests
- a. a description of the ageing management programme
- b. a description of the gap analysis programme
- c. a gap analysis
- d. a reference to SSG-26 in the application, when necessary In summary, the applicant needs to meet requirements in paragraph 809 (f) and (k) of the IAEA SSR-6, 2018 Edition. Therefore, the response to the RAI is not sufficient. Reference 12 of the SSG-26 includes examples of the information requested by the staff.
RAI-Ma-4 The applicant pointed out that the intent of the evaluation related to this RAI was to demonstrate that the temperatures selected to evaluate the performance of the wood on the impact limiter were bounding. The staff noted that there are discrepancies on the temperature data presented of the shock absorber of another package with a track record of transportation versus the estimated temperature determined by analysis, which creates confusion on whether the actual temperature is estimated to be less than 40 degrees or greater than 40 degrees but less than 70 degrees. The latter and any other discrepancies need to be corrected in the application (i.e., the SAR).
RAI-Ma-5 The staff noted that the applicant did not provide an evaluation or a procedure with the criteria to determine water absorption in the wood inside the impact limiters. For example, leak tests, etc. The applicant should provide the following information:
- a. Numerical value for the acceptance criteria for water absorption of the wood
- b. Explain how water absorption is determined.
- c. Explain the ageing mechanism considered. If it was not considered, justify why it was not considered.
- d. For visual inspections, provide the standard used to perform visual inspections.
- e. Explain what serious damage means in qualitative and quantitative terms.
- f. Provide a numerical value or a standard for the acceptance criteria for the leak test.
The staff needs additional information to confirm that the applicant considered potential ageing effects. If Japanese standards are referenced in this response, the applicant needs to explain similarities with U.S. industry standards and, if necessary, provide the sections of the standard(s) that the applicant is using.
RAI-Ma-6 The staff explained that performance issues with Boral are usually related the aluminum content in this alloy. Issues with Boral may start at 650 degrees Celsius. Table (II)-F.2, Heat criteria for Boral, mentions a temperature of 2,450 degrees Celsius, which is not in alignment with the information that the staff has about the temperature in which Boral start having performance issues.
The staff mentioned that the applicant needs to verify the temperature mentioned 3
7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests in Table (II)-F.2 and revise it, as necessary, and explain what could affect the performance of the Boral material as a whole.
STRUCTURAL EVALUATION RAI-St-1 The staff noted that the applicant refers to nominal stress values in their response related to fatigue calculations. The nominal stress values ignore the influence of any local stress-raising feature to accurately predict the behavior of the component, for example, at the discontinuity or change in cross section of the member (e.g., plate with a hole, bolt threads, etc.). The staff pointed out that the applicant needs to consider real stresses that account for stress increases at a local continuity or change in cross section of a member by considering stress concentration factors in their fatigue calculation. The staff noted that the JRC SAR includes stress concentration factors in fatigue calculations and a similar factor needs to be considered for the JMS package fatigue analyses.
RAI-St-2 In section II-4.4.3.1(1), page (II)-A-60, of the SAR, the applicant calculated the maximum stress as 74.6 Newtons per square millimeter (N/mm2) at the lifting lug weld. In section (II)-4.4.3.1(2), page (II) A-61, the applicant calculated the maximum stress as 118 N/mm2 at the hole of the lifting lug. In section A 4.4.3.3, page (II)-A-67, for the fatigue analysis of the lifting device, the applicant selected 74.6 N/mm2 as the maximum stress instead of 118 N/mm2. The applicant needs to make the necessary corrections in section 4.4.3.3 to use the maximum stress value, or provide justification for selecting 74.6 N/mm2 instead of 118 N/mm2 as the maximum stress value for the fatigue analysis.
RAI-St-3 If E1 = Modulus of elasticity for the material on the fatigue design curve (i.e.,1.95 x 105), and E2 = Modulus of elasticity of the material at the operating temperature, the applicant used the ratio of E1/E2 to multiply the repeated peak stress Intensity corresponding to an estimated number of cycles from the fatigue design curve in Section (II), Figure A.147, to find Sa = allowable repeated peak stress intensity. However, the staff noticed that the ratio of E1/E2 is incorrectly applied. Instead, the repeated peak stress intensity from the fatigue design curve should have been multiplied by the ratio E2/E1 to derive Sa. Therefore, the numerator (E1) and the denominator (E2) used in the equation must be swapped to calculate the allowable repeated stress values, Sa. Also, the calculation in section A.10.5, pages (II) A-375 and (II) A-376, needs to be revised to reflect the correct values.
RAI-St-4 Based on the information in Table (II)-A.31, page (II) A-377, the staff noted that the applicant is combining the NCT and ACT peak stresses and comparing to the repeated peak allowable stress intensity, which is conservative. However, for the fatigue evaluation, the applicant did not perform the calculation correctly and it is not conservative, because the applicant did not calculate repeated peak stresses in the components by accounting for the effects of stress concentration (see RAI St-1). Also, the applicant did not correctly adjust the allowable repeated peak stress intensity to account for differences between moduli of elasticity (see RAI St-3). Therefore, the current comparison in Table (II)-A.31 is not accurate. The staff mentioned that in order to be an accurate comparison, the applicant needs 4
7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests to calculate the repeated peak actual stress intensity for each applicable component by making necessary corrections mentioned above and listing these values in a separate column in Table (II)-A.31 to compare against the repeated peak allowable stress intensity.
RAI St-5 The staff noted that the fatigue analyses and response provided to this RAI are inadequate and incomplete because the response do not properly address combined effects of applicable stress cycles. Therefore, applicants should provide the following:
- a. A complete fatigue evaluation combining effects of all applicable types of accumulated stress cycles (i.e., lifting, pressurization, thermal, and vibration) in components during normal service conditions to show that fatigue failure will not occur. In addition, the applicant should also address the following staff comments:
- i. Lifting cycles - The staff noted that the package including containment device is made of a single wall construction which is not isolated from the overlapping effects of stress cycles from lifting device attached on the outside and those from pressurization, thermal, and vibration cycles. Therefore, the applicant should provide proper justification for not combining applicable accumulating stress cycles or provide combined evaluation.
ii. Pressurization and thermal stress cycles - The staff agrees with the applicant response for consideration of 1,000 cycles for the thermal stress fatigue evaluation for the condition when fuel content is loaded for the transportation. However, as part of the aging management program, the applicant should also address and combine the thermal stress cycles effects due to daily changes in spatial temperatures when the package is in unloaded condition, which could significantly exceed 1,000 cycles over 40-year service life.
iii. Vibration cycles - The staff agrees with the applicants fatigue evaluation of the package lifting and tie-down attachment components for 4,000 lifting operation cycles for the 40-year service life. However, the applicant did not provide a fatigue analysis for the vibration cycles that occurs during transport operations. The package components could experience many vibration cycles from numerous vehicle transports by road during the 40-year service life. As part of aging management program, the applicant should perform fatigue analysis for vibrations cycles during transport to show fatigue failure will not occur. There is a guidance in IAEA SSG-26, revision 1, appendix IV, paragraph 12 and 18, which recommends: in addition to the strength analysis, the package designer should also take into account the effects of cyclic loads under routine conditions of transport that could lead to the failure of components of the package.
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7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests OR
- b. If such a complete fatigue evaluation cannot be performed, or if the fatigue evaluation cannot show adequate protection against fatigue failure considering the combined effects, the applicant should provide proposed inspection methods, inspection equipment, and personnel qualification requirements for detection of fatigue effects like those requested in RAI-Ma-1(c).
JRC-80Y-20T (JRC) Package GENERAL INFORMATION RAI-GEN-1 Same comments for the JMS apply to the JRC.
MATERIALS EVALUATION RAI-Ma-1 Same comments about the RAI-Ma-1 for the JMS apply to the JRC.
RAI-Ma-2 Same comments that the staff noted about abrasion for the JMS apply to the JRC.
RAI-Ma-3 Same comments that the staff noted about the RAI-Ma-3 for the JMS apply to the JRC.
RAI-Ma-3 The question should be numbered as RAI-Ma-4. The response provided by the applicant for this RA question is acceptable.
STRUCTURAL EVALUATION RAI-St-1 The staff noted that the fatigue analyses and response provided to this RAI are incomplete without properly addressing combined effects of applicable different stress cycles. Therefore, applicant should provide the following:
- a. A complete fatigue evaluation combining effects of all applicable types of accumulated stress cycles (i.e., lifting, pressurization, thermal, vibration) in components during normal service conditions to show that fatigue failure will not occur. In addition, the applicant should also address the following comments:
- i. Lifting cycles - The applicant responded that the lifting device is attached to the outside of the package, so the stresses caused by the pressurization cycle and thermal stress cycle do not need to be considered. The staff noted that this response is not adequate, because the package including containment device (body) is made of a single wall construction which is not isolated from the overlapping effects of stress cycles from lifting device attached on the outside and those from pressurization, thermal, and vibration 6
7/12/23, Conference Summary Call, NRC, DOT, Edlow, and DOE, Discussion of Responses to Requests for Additional Information for the Model Nos. JMS-87Y-18.5T and JRC-80Y-20T Revalidation Requests cycles. Therefore, the applicant should revise and elaborate on the rationale for not combining applicable accumulating stress cycles or provide combined evaluation.
ii. Pressurization and thermal stress cycles - The staff agrees with the applicant response for consideration of 300 cycles for the thermal stress fatigue evaluation for the condition when fuel content is loaded for the transportation. However, as part of the aging management program, the applicant should also address and combine the thermal stress cycles effects due to daily changes in spatial temperatures when the package is in unloaded condition, which could significantly exceed 300 cycles over 70-year service life.
iii. Vibration cycles - The staff noted that the applicant did not provide a fatigue analysis for the vibration cycles. There is a guidance in IAEA SSG-26, Revision 1, Appendix IV, paragraph 12 and 18, which recommends: in addition to the strength analysis, the package designer should also take into account the effects of cyclic loads under routine conditions of transport that could lead to the failure of packages components. As part of aging management program, the applicant should perform fatigue analysis for vibrations cycles during transport to show fatigue failure will not occur.
- b. If such a complete fatigue evaluation cannot be performed, or if the fatigue evaluation cannot show adequate protection against fatigue failure considering the combined effects, the applicant should provide proposed inspection methods, inspection equipment, and personnel qualification requirements for detection of fatigue effects like those requested in RAI-Ma-1(c).
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