ML23158A246
| ML23158A246 | |
| Person / Time | |
|---|---|
| Site: | 07103004 |
| Issue date: | 06/14/2023 |
| From: | Garcia-Santos N Storage and Transportation Licensing Branch |
| To: | Boyle R US Dept of Transportation (DOT), Office of Hazardous Materials Safety |
| Garcia-Santos N | |
| Shared Package | |
| ML23158A141 | List: |
| References | |
| L-2023-DOT-0005, 001794 | |
| Download: ML23158A246 (7) | |
Text
Request for Additional Information U.S. Department of Transportation Japanese Approval Certificate No. J/2044/B(U)F Docket No. 71-3004 Certificate of Compliance No. 3004 Model No. JMS-87Y-18.5T
By letter dated April 3, 2023 (Agencywide Documents Access and Management System
[ADAMS] Accession Number ML23101A035), you submitted an applica tion to the U.S. Nuclear Regulatory Commission (NRC) for the review of the Japanese Cert ificate of Competent Authority No. J/2044/B(U)F, Model No. JMS-87Y-18.5T package. In your application you requested that the NRC provides a recommendation to revalidate the Model No. JMS-87Y-18.5T.
This request for additional information (RAI) identifies inform ation needed by the NRC staff (the staff) in connection with its review of the application. The st aff used International Atomic Energy Agency (IAEA) Specific Safety Requirements No. 6 (SSR-6), Regu lations for the Safe Transport of Radioactive Material, 2018 Edition, in its review of the application.
The RAI describes information needed by the staff to complete i ts review of the application and to determine whether the applicant has demonstrated compliance with the regulatory requirements of the IAEA SSR-6, 2018 Edition.
GENERAL INFORMATION
RAI-GEN-1 Replace all references to the IAEA transport safety regulations in the safety analysis report (SAR) for the Model No. JMS-87Y-18.5T to approp riately reflect the IAEA SSR-6, Revision 1 (2018 Edition).
For example, in Revision 1 of the SAR for the Model No. JMS-87Y -18.5T SAR, on page (II)-A-410, reference (29) is listed as IAEA/Radio act ive material safety transportation regulations (1985 transaction) safety series No. 6. However, since the SAR has been revised to meet the requirements of the IAEA S SR-6, Revision 1 (2018) and the SAR should accurately reference the a pplicable version or revision of the SSR-6 that the application complies with.
This information is needed to determine compliancet with the re quirements in Paragraph 102 the IAEA SSR-6, 2018 Edition.
MATERIALS EVALUATION
RAI-Ma-1 Provide a description of any national or international codes, standards, and/or other methods, programs, or procedures that are implemented to ensure that package maintenance activities (including visual inspections, s creening and evaluation of visual indications, and corrective actions such a s component repairs and replacements) are adequate to manage the effects of aging in
Enclosure 1 metallic package components that would see long-term use, such that the package components are capable of performing their requisite sa fety functions throughout the period of use.
The staff requests that this description address the following criteria:
- a. Inspection methods (e.g., bare metal visual exams and/or oth er types of nondestructive exams such as liquid penetrant exams or ultrason ic exams) for detection, characterization, and sizing of localized aging effects such as cracks, pits, and crevice corrosion.
- b. Inspection equipment and personnel qualification requirement s (e.g., lighting and visual acuity requirements for performing v isual exams) to ensure reliable inspections that can adequately detect and c haracterize indications of localized aging effects prior to component failu re or loss of safety function.
- c. Acceptance criteria for aging effects such as early stage fa tigue cracks and localized corrosion of stainless steel components, such as chloride induced stress corrosion cracking (SCC), pitting, and crevice c orrosion.
Examples of visual indications that may indicate potential loca lized corrosion of stainless steel components include the accumulatio n of atmospheric deposits such as salts, buildup of corrosion produc ts, rust-colored stains or deposits, and surface discontinuities or flaws associated with pitting, crevice corrosion, and/or SCC.
- d. Describe any surface cleaning requirements that are implemen ted to ensure that bare metal visual inspections of component surfaces are capable of detecting surface flaws, and for ensuring adequate r emoval of atmospheric deposits such as salts or other chemical compounds that may contribute to localized corrosion of stainless steel compon ents.
- e. Describe any flaw evaluation methods (such as flaw sizing an d flaw analysis methods) and associated flaw acceptance criteria that may be used to determine whether components containing flaws are accep table for continued service.
Per IAEA SSG-26, Advisory Material for the IAEA Regulations fo r the Safe Transport of Radioactive Material, 2018 Edition, Paragraph 613 A.3:
For packagings intended for repeated use, the effects of agein g mechanisms on the package should be evaluated during the design phase in the demonstration of compliance with the Transport Reg ulations.
Based on this evaluation, an inspection and maintenance program me should be developed. The programme should be structure so that the assumptions (e.g., thickness of containment wall, leaktightness, neutron absorber effectiveness) used in the demonstration of compliance of the package are confirmed to be valid through the lifetime of the p ackaging.
The staff was not able to locate a detailed description of nati onal or international codes, standards, and/or other methods, programs, or procedures that are
2 implemented to ensure that package maintenance activities are a dequate to manage the effects of aging in metallic package components that would see long-term use.
This information is needed to determine compliance with require ments in Paragraphs 503(e), 613A, and 809(f) of the IAEA SSR-6, 2018 Edi tion.
RAI-Ma-2 Provide an evaluation of abrasion as an aging mechanism for the JMS-87Y-18.5T package.
Per IAEA SSG-26, 2018 Edition, Paragraph 613A.1:
The designer of a package should evaluate the potential degrad ation phenomena over time, such as corrosion, abrasion, fatigue, crac k propagation, changes of material compositions or mechanical pro perties due to thermal loadings or radiation, generation of decompositi on gases and the impact of these phenomena on performance of safety func tions.
The staff was not able to locate a discussion on abrasion being evaluated as an aging mechanism.
This information is needed to determine compliance with the req uirements in Paragraph 613A of the IAEA SSR-6, 2018 Edition.
RAI-Ma-3 Provide the aging management program (per the structure and pro cedure in IAEA SSG-26, Paragraph 613A.3 (2018 Edition)) and gap analysis program.
Per IAEA SSG-26, Paragraph 613A.5:
For designs of Type B(U), B(M) and Type C packages these programmes are required to be included in the application for a pproval of packages for shipment after storage (see paras 809(f) and (k) o f the Transport Regulations). The results of the ageing management programme and the gap analysis programme should be taken into account when preparing an inspection plan prior to transport.
The staff was not able to locate an aging management program or gap analysis program as required by IAEA SSR-6, Paragraphs 809(f) and (k).
This information is needed to determine compliance with the req uirements in Paragraphs 809(f) and (k) of the IAEA SSR-6, 2018 Edition.
RAI-Ma-4 Provide the basis for the evaluation of the wood in the impact limiter including the analyzed range of temperatures. Also, revise the SAR, as necess ary, to address two inconsistencies identified between the maximum temperatures identified for the wood impact limiter in Section B.4.2 and SAR Section F.2 of the SAR.
In Section F.2, Table(II)-F.2, of the SAR, the applicant states that the maximum temperature identified at the surface of the package is [Withheld per 10 CFR 2.390] during transportation. However, in SAR Section B.4.2, Table (I I)-B.15 and B.16, the highest temperature listed is [Withheld per 10 CFR 2.390]. Secondly,
3 the applicant states in Table(II)-F.2 of the SAR that, based on te results of analysis, the temperature inside the shock absorber (wood) dur ing actual transportation is estimated to be below about 40°C. In the sam e table, the applicant later states that the average temperature data of the shock absorber of another package with a track record of transportation of spent fuel was evaluated and shown to be around 40°C to 70°C, which contradicts the prev ious temperature estimate.
This information is needed to determine compliance with require ments in Paragraphs 613A, 616, and 639 of the IAEA SSR-6, 2018 Edition.
RAI-Ma-5 Explain how the impact of potential water absorption by the sh ock absorber
In Section F.2 of the SAR, the applicant described the corrosio n that could affect the shock absorber material. In SAR Table III-B.1, a visual ins pection is described but does not include any mention of inspection of the welds or areas adjacent to the welds, nor is any specific acceptance criteria described.
This information is neede to determine compliance with requirem ents in Paragraph 613A of the IAEA SSR-6, 2018 Edition.
RAI-Ma-6 Provide a comparison between the maximum temperature expected during transport to the qualified temperature limit for the [Withheld per 10 CFR 2.390]
cladding material.
In SAR Section F.2, the applicant describes heat related aging mechanisms that can affect the aluminum alloy, stating that thermal analysis in dicated a substantial temperature difference between the maximum temperat ure expected during transport and the melting temperature of the aluminum al loy. However, the
[Withheld per 10 CFR 2.390] cladding material has a much lower melting temperature.
This information is needed to determine compliance with require ments in Paragraph 613A of the IAEA SSR-6, 2018 Edition.
STRUCTURAL EVALUATION
RAI St-1 Provide clarification on how stress concentration effects (high er stresses in the surrounding region of local geometric discontinuities of the co mponent parts) have been accounted for in the fatigue evaluations for the reus able package components. Justify omission of or consider stress concentratio n effects, where it is applicable.
The application evaluates fatigue for the lifting devices, cont ainment device and tie-down attachments in Sections (II)-A.4.4.3.3, (II)-A.10.5, ( II)-A.10.6.3(11) and (II)-A.10.6.4(3) of the SAR. However, the staff could not locat e any discussion on consideration of stress concentration factor to account for the effect of any irregularities or discontinuities of the component parts or jus tification thereof for not considering in the components fatigue evaluations. The str ess concentration
4 factor is typically used to account for the effect of discontin uities such as holes, grooves or notches, bolt threads, and head fillets that are not represented in detail in the finite element analysis (FEA) model.
This information is needed to determine compliance with the req uirements in Paragraphs 613A and 809(f) of the IAEA SSR-6, 2018 Edition.
RAI St-2 Justify the values of the maximum repetitive stress for the cas k body lifting lugs considered in Section (II)-A.4.4.3.3 of the SAR.
Based on the stress intensity (s) calculation at the hole of th e lifting lug in Section (II)-A.4.4.3.1, the staff finds that the maximum repetitive str ess should be
[Withheld per 10 CFR 2.390] N/mm2 instead of [Withheld per 10 CFR 2.390]
N/mm2 considered by the applicant in the evaluation of the cask body lifting lug.
This information is needed to determine compliance with the req uirements in Paragraphs 613A and 809(f) of the IAEA SSR-6, 2018 Edition.
RAI St-3 Verify and confirm that the stress amplitudes corresponding to the number of stress cycles from the design fatigue curves are properly adjus ted for differences between the moduli of elasticity on the design fatigue curvesan d that is used in the analysis of the component parts to determine allowable repe ated peak stress intensity in Section (II)-A.10.5 and possibly other Sections of the SAR. Revise the SAR, as necessary.
Section (II)-A.10.5 of the SAR, evaluates containment devices f or the combined repeated peak stress intensity. In this evaluation, the allowab le repeated peak stress intensity is determined by multiplying the stress amplit ude corresponding to the number of stress cycles from the design fatigue curves b y the ratio of modulus of elasticity on the fatigue curves to the modulus of e lasticity used in the analysis. Instead, it appears to the staff that the allowable p eak stress intensity should be determined by multiplying the stress amplitude by the ratio of modulus of elasticity used in the analysis to the modulus of elasticity on the fatigue curves.
This information is needed to determine compliance with the req uirements of the Paragraphs 613A of the IAEA SSR-6, 2018 Edition.
RAI St-4 Justify values in the Repeated Peak Allowable Stress Intensity column of the Table (II)-A.31 and confirm if they are values of the allowable stress intensity range or values of the alternating component, which is half of the allowable stress intensity range. Update this table as necessary, which n eeds to be addressed in conjunction with the resolution of other RAIs,as applicable.
Section (II)-A.10.5 of the SAR, evaluates the containment devic e and basket components for the combined repeated peak stress intensity. Alt hough conservative, it appears to the staff that the values in the R epeated Peak Allowable Stress Intensity column of the Table (II)-A.31 are v alues for the alternating component, which is half of the allowable stress in tensity range from the applicable design fatigue curves. The values in this column are compared against the combined repeated peak stress intensity values per the analysis and used to derive margin of safety in the design of the components.
5 This information is needed to determine compliance with the req uirements of the Paragraphs 613A of the IAEA SSR-6, 2018 Edition.
RAI St-5 Provide a complete evaluation of fatigue for the reusable packa ge components for the 40-year period of use that considers the combined effec ts of all applicable types of accumulated stress cycl es in components during normal service conditions, including the following cycle types (as described i n this question):
- a. Lifting cycles
- b. Pressurization cycles
- c. Thermal stress cycles
- d. Vibration cycles
The staff needs a complete fatigue evaluation that considers th e combined effects of all applicable types of stress cycles during normal service, including consideration of the cycle types listed above. Also, the approp riate number of cycles need to be considered in fatigue evaluation depending up on the type of cycle being evaluated. If certain types of stress cycles are no t applicable or negligible for certain components, explain why these are not ap plicable or are negligible.
If such a complete fatigue evaluation cannot be performed, or i f the fatigue evaluation cannot show adequate protection against fatigue fail ure considering the combined effects of all applicable types of accumulated str ess cycles in components, provide the following information:
a.1 a description about how periodic maintenance inspections wi ll be used to identify and address fatigue cracks in components of the packag e.
b.1 A description of the corrective actions that will be taken for any detected fatigue cracks, such as analytical flaw evaluation with follow-up inspections, repair/replacement of components with cracks, etc.
The following items provide additional descriptions about accum ulated stress cycles as provided in the application:
- 1. Lifting cycles - The staff recognizes that these cycles are already evaluated in Section (II)-A.4.4.3.3 for the cask body and lid l ifting device, Section (II)-A.10.6.4(3) for the skid lifting device and table (II)-F.2 of the SAR. However, the staff noted that the lifting cycles are evalu ated without considering the other types of stress cycles that may also be a ccumulated by the lifting devices for the cask body and the lid. To perfor m an adequate analytical evaluation that demonstrates sufficient saf ety margin against fatigue failure of these components, the combined effec ts of accumulated lifting cycles along with other applicable types of accumulated stress cycles in these components (including consid eration
6 of cycle types listed herein) on the potential for fatigue of l ifting devices should be considered.
- 2. Pressurization and thermal stress cycles - The staff recogni ze that pressure and thermal cycles are already evaluated in Sections ( II)-A.10.5 and table II-F.2 for the containment device (i.e., cask body, l id and connecting bolts). However, the staff noted that the containmen t device pressurization and thermal cycles are evaluated for 1,000 cycle s (times) over 30 years, which is contrary to the 40-year service life co nsidered for the components fatigue evaluations elsewhere. Also, the staff noted that thermal stress cycles may occur in components due to cyclical f luctuation of spatial temperature gradients within components, which could exceed 1,000 cycles over 40-year service life. In addition, the staff noted that this evaluation does not address the potential for fatigue of packag e components due to the combined effects of other types of stress cycles that may also be accumulated by the containment device componen ts. To perform an adequate analytical evaluation that demonstrates suf ficient safety margin against fatigue failure of these components, the combined effects of accumulated pressurization and thermal cycles along with other applicable types of accumulated stress cycles in these componen ts (including consideration of cycle types listed herein) on the p otential for fatigue of containment device components should be considered.
- 3. Vibration cycles - The staff noted that Section (II)-A.4.7 p rovide an evaluation that demonstrates that package resonance is a not a concern considering package vibration caused by vehicle transport. The staff also recognizes that the tie-down attachments are already evaluated in Section (II)-A.10.6.3(11) of the SAR for fatigue cycles. Howeve r, the staff noted that the tie-down attachment components are evaluated for 4,000 cycles, which the applicant has inappropriately considere d as lifting cycles, and not as vibratory cycles. The package components cou ld experience many vibration cycles from numerous vehicle transports by road during the 40-year service life, which may exceed 4,000 li fting cycles considered in the fatigue evaluation. In addition, the staff no ted that this evaluation does not address the potential for fatigue of packag e components due to the combined effects of the accumulation of m any vibration cycles resulting from the allowed transports of the p ackage over 40-year service life, along with the accumulation of other appl icable types of stress cycles, including consideration of the cycle types li sted herein.
To determine that fatigue as not an aging concern, as indicated in Section (II)-F of the application, the staff needs a complete fatigue evaluati on that considers the combined effects of all applicable types of stress cycles d uring normal service, including considerati on of the cycle types listed abov e. Also, the appropriate number of cycles need to be considered in fatigue e valuation depending upon the type of cycle being evaluated.
This information is requested to determine compliance with the requirements in Paragraphs 503(e), 613, 613A, and 809(f) of the IAEA SSR-6, 201 8 Edition.
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