ML24144A271
| ML24144A271 | |
| Person / Time | |
|---|---|
| Site: | 07201042 |
| Issue date: | 05/22/2024 |
| From: | Christian Jacobs Storage and Transportation Licensing Branch |
| To: | TN Americas LLC |
| Shared Package | |
| ML24144A270 | List: |
| References | |
| EPID L-2022-LLA-0017 | |
| Download: ML24144A271 (4) | |
Text
RAI Response - staff clarification questions
RAI 4-18. Clarify how the values of the properties for ASTM A572 Steel Grade 50 included in the UFSAR Table 8-42 were obtained and how the values of the properties as a function of temperature are justified.
The elevated temperature yield strength values for A572 Grade 50 shown in UFSAR Table 8-42 are different from the values included in the 2023 ASME B&PV Code,Section II, Part D, for ASME SA-572 Grade 50 and the magnitude of the difference increases with temperature from 200 to 500 °F. For example, the yield strength value at 500 °F in UFSAR Table 8-42 is 41.5 ksi which is higher than the values of 35.4 to 40.6 ksi (depends on product form) at 500 °F for ASME SA-572 Grade 50 in 2023 ASME Code,Section II, Part D, Table Y-1, lines 3 and 4, pages 808-812. Staff are aware that ASTM A572 Grade 50 was not incorporated into the 2011 version of ASME B&PV Code.
Staff notes that the User Note in section NB3.3 of ANSI/AISC N690-18 addresses temperature-dependent material properties for conditions in excess of 250 °F and offers two resources for same: (1) Batelle Structural Alloys Handbook, and (2)Section II, Part D of the ASME Boiler and Pressure Vessel Code.
This information is needed to satisfy the requirements of 10 CFR Part 72.236(b) and (g).
Discussion between TN and NRC:
TN understands the clarification, resolution of RAI 8-3 needs to be incorporated into the analysis for Section 3.9.8.
RAI 8-2: See clarifications for RAI 8-3
RAI 8-3. Clarify how the values of the properties for steel grades included in the UFSAR Tables, were obtained and how the values of the properties as a function of temperature are justified.
Specifically explain and justify the material property values included in the following UFSAR Tables:
- Table 8-37, ASTM A572 Steel Grade 60
- Table 8-14a, ASTM A572 Steel Grade 65
- Table 8-40, ASTM A449 Type 1, <1 in. dia.
- Table 8-41, ASTM A449 Type 1, diameters > 1.0 in. to 1 1/2 in
(a) The mechanical properties of ASTM A572 Grade 60 in UFSAR Table 8-37 indicate the values of the yield strength are based on Figure 7-3 in UFSAR reference 8-12 Mark Fintel, Handbook of Concrete Engineering, Second Edition, September 1985.
However, the data displayed in Table 8-37 does not from appear to be based on the lowest rate of reduction but rather the highest reduction rate (or the curve with the greatest decrease as a function of temperature) in Figure 7-3 of reference 8-12. The upper value (lowest rate of decrease (less reduction in YS with temperature) is 57 ksi based on Figure 7-3 of Reference 8-12.
The staff notes that the values for the yield strength for ASTM A572 Grade 60 in UFSAR Table 8-37 at elevated temperatures are considerably higher than the values for yield strength of ASME SA-572 Grade 60 in the 2023 edition of ASME B&PV Code. For example, the yield strength of ASME SA-572 Grade 60 ranges from 35.4
Enclosure (Public) to 36.7 ksi (depends on thickness) at 500 °F in the 2023 ASME B&PV Code,Section II, Part D, Page 822, lines 10 and 11, whereas the value of yield strength for ASTM A572 Grade 60 in UFSAR Table 8-37 is listed as 49.8 ksi at 500 °F. The staff is aware that ASTM A572 Grade 60 was not incorporated into the 2011 version of ASME B&PV Code.
Discussion between TN and NRC:
TN will revise notes to clarify which curve is used.
(b) The elevated temperature yield strength values for A572 Grade 65 shown in UFSAR Table 8-14a are different from the values included in the 2023 ASME B&PV Code,Section II, Part D, and the magnitude of the difference increases with temperature from 150 °F to 500 °F. For example, the yield strength value at 500 °F in UFSAR Table 8-14a is 54.0 ksi which is considerably higher than the value of 45.9 ksi listed for ASME SA-572 Grade 65 in 2023 ASME B&PV Code,Section II, Part D, Table Y-1 line 23, pages 820-822. The staff is aware that ASTM A572 Grade 65 was not incorporated into the 2011 version of ASME B&PV Code.
Discussion between TN and NRC:
TN believes reduction values are sufficient. NRC asked how are values being justified? NRC cannot validate approach is sufficient using information TN has provided to date. TN next step: review references and determine what next step will be. TN understands the question.
(c) The elevated temperature yield and tensile strength values for ASTM A449 Type 1,
<1 in. dia. shown in UFSAR Table 8-40 are not the same as the those shown in the 2011 edition of ASME B&PV Code Section II, Part D, Tables Y-1 and U. In particular, the yield strength values shown in ASME B&PV Code,Section II, Part D, Table Y-1 for ASME SA-449 Type 1, <1 in. dia. are lower than those shown in UFSAR Table 8-40 at temperatures between 200 and 600 °F with the magnitude of the differences increasing with temperature. At 600 °F the yield strength value for ASME SA-449 Type 1, <1 in. dia. shown in ASME B&PV Code,Section II, Part D, Table Y-1, line 24, pages 553-555, is 62.0 ksi, whereas a yield strength of ASTM A449 Type 1, <1 in. dia. Is listed as 75.4 ksi in UFSAR Table 8-40.
Discussion between TN and NRC:
Related to part b, but using A449 Type 1. ASTM A449 was incorporated into the 2011 ASME Code.
(d) The elevated temperature yield and tensile strength values for ASTM A449 Type 1, diameters > 1.0 in. to 1 1/2 in shown in UFSAR Table 8-41 are not the same as the those shown in the 2011 edition of ASME B&PV Code,Section II, Part D, Tables Y-1 and U for ASME SA-449 Type 1, diameters > 1.0 in. to 1 1/2. In particular, the yield strength values shown in ASME B&PV Code,Section II, Part D, Table Y-1 are lower than those shown in UFSAR Table 8-41 at temperatures between 200 and 600 °F with the magnitude of the differences increasing with temperature. At 600 °F, the yield strength value for ASME SA-449 Type 1, > 1.0 in. to 1 1/2. dia. shown in ASME B&PV Code,Section II, Part D, Table Y-1, line 21, pages 552-555, is 54.6 ksi, whereas a yield strength of 66.4 ksi is listed in UFSAR Table 8-41 for ASTM A449 Type 1, diameters > 1.0 in. to 1 1/2.
Discussion between TN and NRC:
Related to parts b and c, but different material. TN understands the clarifications being requested.
Staff notes that the User Note in section NB3.3 of ANSI/AISC N690-18 addresses temperature-dependent material properties for conditions in excess of 250 °F and offers two resources for same: (1) Batelle Structural Alloys Handbook, and (2)Section II, Part D of the ASME Boiler and Pressure Vessel Code.
This information is needed to satisfy the requirements of 10 CFR Part 72.236(b) and (g).
Errors/Typos/Suggestions:
RAI 4-1: The response in Upper Side Wall (Component 19) states that Figure RAI 4-2, as been added as UFSAR Figure 3.9.8-11. However, the UFSAR Figure 3.9.8-11 depicts Figure RAI 4-1 and the UFSAR does not appear to include a depiction of Figure RAI 4-2. Please verify that Figure RAI 4-2 is not intended to be included in the UFSAR.
Discussion between TN and NRC:
FSAR is correct, TN will update response to RAI.
RAIs 4-5 and 12-1: In response to RAI 4-5, it is stated that ACI 349-13 is employed for the design of embedments and supplemental reinforc ing employed in the EOS-HSM-SC; UFSAR section 3.9.8.10.7 and Table 3.9.8-5 and -6 were updated accordingly. In RAI 12-1, in response to a question regarding the inspection of the EOS-HSM-SC, several areas of the application pertaining to the EOS-HSM-SC were updated to refer to ACI 349-06, rather than ACI 349-13:
UFSAR section 2.1.2, 2.4.2.2, 8.2.1.3, and TS section 4.4.1. Additionally, UFSAR section 10.1.1.2 cites both ACI 349-06 and ACI 349-13 for the concrete construction, placement and testing for the EOS-HSM-RC and EOS-HSM-SC, while it appears that ACI 349-13 only applies to the EOS-HSM-SC. Please review these ACI 349 citations and correct as necessary.
Discussion between TN and NRC:
UFSAR will be updated as necessary.
RAI 4-6: In response to RAI 4-6 the design calculation documents have been added as a reference via citing Enclosure 9 (ML23179A123) of the RSI response letter. However, in this RAI response submittal (ML24113A306), dated April 22, 2024, the calculations have been revised and are included in Enclosure 10 (ML24113A310). In the next submittal of the UFSAR, please update the reference in UFSAR section 3.9.8 to cite this most recent letter enclosure.
Discussion between TN and NRC:
TN will correct in next submittal (TN plans to list both references).
RAI 4-7: This RAI response states that the OVC does not serve a structural safety function. This is also stated in the TS section 4.4.4 in the Justification column of TS 4.4.4. for ANSI/AISC N690-18, section N9.1.1.(d). However, the bill of material on drawing EOS01-3300-SAR, rev.
0D, shows that the following OVC-related item numbers are either ITS Quality Category B or C: 24, 26, 29, 82. Please review and revise and correct the drawing, as necessary.
Discussion between TN and NRC:
If serving shielding function, provi de explanation and leave drawing as is.
RAI 16-1: The modal frequencies and seismic accelerations associated with the EOS-HSM-SC have been added in UFSAR section 12.3.2, but they do not agree with those presented in Table 3.9.8-2 of the UFSAR. Please review and revise as necessary.
Discussion between TN and NRC:
Values in 3.9.8 are correct. Values in section 12.3.2 will be referenced to section 3.9.8.