ML24215A237
| ML24215A237 | |
| Person / Time | |
|---|---|
| Site: | 05200050 |
| Issue date: | 08/02/2024 |
| From: | NuScale |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML24215A000 | List:
|
| References | |
| LO-169995 | |
| Download: ML24215A237 (1) | |
Text
Response to NuScale Topical Report Audit Question Question Number: A-NonLOCA.LTR-10 Receipt Date: 09/18/2023 Question:
RSI-15 (Page 458/723 RSI responses), states Therefore, the oscillations are expected to have minimal impact on the overall SG/DHRS heat transfer performance. This conclusion of minimal impact is consistent with the results of the NIST-2 SG/DHRS testing. The testing results for Run 2 show that measured heat transfer is reasonably predicted by NRELAP5 (( 2(a),(c) NuScale Nonproprietary NuScale Nonproprietary
Response
As identified in this audit question, the response to RSI-15, states Therefore, the oscillations are expected to have minimal impact on the overall SG/DHRS heat transfer performance. This conclusion of minimal impact is consistent with the results of the NIST-2 SG/DHRS testing. The testing results for Run 2 show that measured heat transfer is reasonably predicted by NRELAP5 (( }}2(a),(c) NuScale Nonproprietary NuScale Nonproprietary
(( }}2(a),(c) NuScale Nonproprietary NuScale Nonproprietary
(( }}2(a),(c) NuScale Nonproprietary NuScale Nonproprietary
((
}}2(a),(c) The non-LOCA topical report is updated to include revised assessment figures that more accurately demonstrate the ability of NRELAP5 to predict the SG/DHRS heat transfer in the NIST-2 Runs 1, 2, and 3 tests. In developing the non-LOCA NIST-2 test matrix, Run 1 was scaled for (( }}2(a),(c) the NPM design. The smaller and larger orifices installed in Runs 2 and 3, respectively, provide a parametric set of test conditions for the purpose of code validation.
((
}}2(a),(c) In conclusion, the figures in the non-LOCA topical report are corrected as shown in the mark-ups and further justification discussion in the topical report is not required.
NuScale Nonproprietary NuScale Nonproprietary
(( }}2(a),(b),(c),ECI Figure 1: Run 2 NRELAP5 to Data Comparison Decay Heat Removal System Condensate Flow Rate (( }}2(a),(b),(c),ECI Markups of the affected changes, as described in the response, are provided below: NuScale Nonproprietary NuScale Nonproprietary
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 390 (( }}2(a),(c) Audit Question A-NonLOCA.LTR-10 Figure 5-222 and Figure 5-223 show the DHRS heat exchanger and SG power comparison for the long-term and short-term respectively. Figure 5-224 and Figure 5-225 show the SG-DHRS loop flow comparison for the long-term and short-term respectively. (( }}2(a),(c) Figure 5-224a and Figure 5-225a show comparison of NRELAP5 results with the unaveraged flow meter data and NRELAP5 predicts the test data with reasonable to excellent agreement. (( }}2(a),(c) Overallas shown in Figure 5-222 and Figure 5-223, the NRELAP5 calculation has reasonable to excellent agreement with the test data. Figure 5-226 shows the code-to-data comparison for the PZR pressure and the secondary side pressure near the steam drum. Before the PZR heater is tripped, both data and code maintain the PZR pressure at approximately (( }}2(a),(c)
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 392 Figure 5-229 shows the code-to-data comparison for the DHRS heat exchanger inlet and outlet temperatures. Figure 5-230 shows the code-to-data comparison for the SG secondary side inlet and outlet temperatures. The SG secondary side outlet temperature and DHRS heat exchanger inlet temperatures are both close to the loop saturation temperature (Figure 5-231). The code predictions of these two temperatures both have reasonable to excellent agreement with the data, similar to the secondary side pressure. From Figure 5-229 and Figure 5-230, the predicted DHRS heat exchanger outlet temperature and SG secondary side inlet temperature are (( }}2(a),(c) Audit Question A-NonLOCA.LTR-10 Figure 5-232 shows the code-to-data comparison of the RCS primary temperatures at two locations: at the SG primary side's inlet (upper plenum) and outlet (mid downcomer). (( }}2(a),(c) Figure 5-233 shows the code-to-data comparison of the PZR level. Figure 5-234 shows the code-to-data comparison of the RPV level. (( }}2(a),(c) Figure 5-235 shows the code-to-data comparison of the RCS primary flow. The prediction has excellent agreement with the data during the transient. (( }}2(a),(c)
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 396 Audit Question A-NonLOCA.LTR-10 Figure 5-222 NIST-2 Run 1 steam generator and decay heat removal system heat exchanger power comparison (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 397 Audit Question A-NonLOCA.LTR-10 Figure 5-223 NIST-2 Run 1 steam generator and decay heat removal system heat exchanger power comparison - short-term (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 399 Audit Question A-NonLOCA.LTR-10 Figure 5-224a NIST-2 Run 1 decay heat removal condensate line flow comparison (without time average) (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 401 Audit Question A-NonLOCA.LTR-10 Figure 5-225a NIST-2 Run 1 decay heat removal condensate line flow comparison (without time average) - short-term (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 419
(( }}2(a),(b),(c),ECI The valve configuration and execution of the Run 2 test was the same as described for Run 1 in Section 5.3.7.6. The sequence of events of the Run 2 test is shown in Table 5-20. RSI 15 RSI 15 5.3.7.9 Run 2 Test Results RSI 15 Figure 5-243 through Figure 5-264 show the code-to-data comparison of the key parameters for Run 2. RSI 15 Figure 5-243 shows the core power. Figure 5-244 shows the SG/DHRS active loop inventory. (( }}2(a),(c) The active loop inventory is discussed in greater detail for Run 1 in Section 5.3.7.7. Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-245 and Figure 5-246 show the DHRS heat exchanger and SG power comparison for the long-term and short-term, respectively. Figure 5-247 and Figure 5-248 show the SG/DHRS loop flow comparison for the long-term and short-term, respectively. As described in Section 5.3.7.7 for Run 1, (( }}2(a),(c) Table 5-20 NIST-2 Run 2 sequence of events (( }}(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 420 (( }}2(a),(c) The results are consistent with those observed in Run 1 in Section 5.3.7.7. Audit Question A-NonLOCA.LTR-10 RSI 15 (( }}2(a),(c) Figure 5-249 compares the DHRS loop flow data without time average with the NRELAP5 results. Both are DHRS condensate line flow rates. (( RSI 15 }}2(a),(c) Figure 5-250 shows the differential pressure across the DHRS condensate line flow meter, (( RSI 15 Audit Question A-NonLOCA.LTR-10 RSI 15 }}2(a),(c)
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 421 (( }}2(a),(c) RSI 15 Figure 5-251 shows the code-to-data comparison for the pressurizer pressure and secondary side pressure near the steam drum. (( }}2(a),(c) Overall the secondary side pressure has reasonable to excellent agreement with the test data. RSI 15 Figure 5-252 shows the code-to-data comparison for the DHRS heat exchanger level and SG level. (( }}2(a),(c) Overall, the predicted DHRS heat exchanger and SG levels have reasonable to excellent agreement with the test data. RSI 15 Figure 5-253 shows the code-to-data comparison for the DHRS heat exchanger inlet and outlet temperatures. Figure 5-254 shows the code-to-data comparison for the SG secondary side inlet and outlet temperatures. (( }}2(a),(c) The code predictions of these two temperatures both have reasonable to excellent agreement with the data, similar to the secondary side pressure. RSI 15 From Figure 5-253 and Figure 5-254, (( }}2(a),(c) Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-256 shows the code-to-data comparison of the RCS primary temperatures. (( }}2(a),(c)
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 422 (( }}2(a),(c) RSI 15 Figure 5-257 shows the code-to-data comparison of the PZR level. Figure 5-258 shows the code-to-data comparison of the RPV level. (( }}2(a),(c) RSI 15 Figure 5-259 shows the code-to-data comparison of the RCS primary flow. The prediction has excellent agreement with the data during the transient. (( }}2(a),(c) RSI 15 Figure 5-260 shows the code-to-data comparison of the CPV level. The prediction has excellent agreement with data (( }}2(a),(c) RSI 15 Figure 5-263 shows the code-to-data comparison of the DHRS steam line differential pressure. Figure 5-264 shows the comparison of the DHRS steam line orifice differential pressure. Reasonable to excellent agreements are shown (( }}2(a),(c)
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 425 Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-245 NIST-2 Run 2 steam generator and decay heat removal system heat exchanger power comparison (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 426 Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-246 NIST-2 Run 2 steam generator and decay heat removal system heat exchanger power comparison - short-term (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 445
(( }}2(a),(b),(c),ECI RSI 15 The valve configuration and execution of the Run 3 test was the same as described for Run 1 in Section 5.3.7.6. The sequence of events of the Run 3 test is shown in Table 5-21. RSI 15 RSI 15 5.3.7.11 Run 3 Test Results RSI 15 Figure 5-265 through Figure 5-285 show the code-to-data comparison of the key parameters for Run 3. RSI 15 Figure 5-265 shows the core power. Figure 5-266 shows the SG/DHRS active loop inventory. (( }}2(a),(c) The active loop inventory is discussed in greater detail for Run 1 in Section 5.3.7.7. Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-267 and Figure 5-268 show the DHRS heat exchanger and SG power comparison for the long-term and short-term, respectively. Figure 5-269 and Figure 5-270 show the SG/DHRS loop flow comparison for the long-term and short-term, respectively. As described in Section 5.3.7.7 for Run 1, (( }}2(a),(c) Table 5-21 NIST-2 Run 3 sequence of events (( }}(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 446 (( }}2(a),(c) The results are consistent with those observed in Run 1 in Section 5.3.7.7. Audit Question A-NonLOCA.LTR-10 RSI 15 (( }}2(a),(c) Figure 5-271 compares the DHRS condensate line flow data without time average with the NRELAP5 results. (( }}2(a),(c) RSI 15 Figure 5-272 shows the code-to-data comparison for the pressurizer pressure and secondary side pressure near the steam drum. (( }}2(a),(c) The predicted secondary side pressure shows excellent agreement with the test data for the entire transient, including the peak pressure. RSI 15 Figure 5-273 shows the code-to-data comparison for the DHRS heat exchanger level and SG level. (( }}2(a),(c) Overall the predicted DHRS heat exchanger and SG levels have reasonable to excellent agreement with the test data. RSI 15 Figure 5-274 shows the code-to-data comparison for the DHRS heat exchanger inlet and outlet temperatures. Figure 5-275 shows the code-to-data comparison for the SG secondary side inlet and outlet temperatures. (( }}2(a),(c) The code predictions of these two temperatures both have reasonable to excellent agreement with the data, similar to the secondary side pressure. RSI 15 From Figure 5-274 and Figure 5-275, (( }}2(a),(c)
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 447 (( }}2(a),(c) Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-277 shows the code-to-data comparison of the RCS primary temperatures. (( }}2(a),(c) RSI 15 Figure 5-278 shows the code-to-data comparison of the PZR level. Figure 5-279 shows the code-to-data comparison of the RPV level. (( }}2(a),(c) The predictions have reasonable agreement with test data. RSI 15 Figure 5-280 shows the code-to-data comparison of the RCS primary flow. The prediction has excellent agreement with the data during the transient. (( }}2(a),(c) RSI 15 Figure 5-281 shows the code-to-data comparison of the CPV level. The prediction has excellent agreement with data (( }}2(a),(c) RSI 15 Figure 5-284 shows the code-to-data comparison of the DHRS steam line differential pressure. Figure 5-285 shows the comparison of the DHRS steam line orifice differential pressure. Predicted differential pressures have reasonable to excellent agreement with test data.
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 450 Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-267 NIST-2 Run 3 steam generator and decay heat removal system heat exchanger power comparison (( }}2(a),(b),(c),ECI
Non-Loss-of-Coolant Accident Analysis Methodology TR-0516-49416-NP Draft Revision 5 © Copyright 2023 by NuScale Power, LLC 451 Audit Question A-NonLOCA.LTR-10 RSI 15 Figure 5-268 NIST-2 Run 3 steam generator and decay heat removal system heat exchanger power comparison - short-term (( }}2(a),(b),(c),ECI}}