ML23304A464

LLC Response to NRCs Request for Docketing of Resolved Audit Responses, Chapter 11, Response to SDAA Question 11.1-2, Re Information Related to Source Terms

ML23304A464
Person / Time
Site:	05200050
Issue date:	10/31/2023
From:	NuScale
To:	Office of Nuclear Reactor Regulation
Shared Package
ML23306A049	List: ML23304A397 ML23304A446 ML23304A447 ML23304A448 ML23304A449 ML23304A450 ML23304A451 ML23304A464 ML23304A465 ML23304A466 ML23304A467 ML23304A468 ML23304A469 ML23304A470 ML23304A471 ML23304A472 ML23304A473 ML23304A474 ML23304A475 ML23304A476 ML23304A477 ML23304A478 ML23304A479 ML23304A480 ML23304A482 ML23304A483 ML23304A485 ML23304A486 ML23304A487 ML23304A488 ML23304A489 ML23304A490 ML23304A492 ML23304A493 ML23304A494 ML23304A495 ML23304A496 ML23304A516 ML23304A517 ML23304A519 ML23304A521 ML23304A522 ML23304A524
References
LO-152560
Download: ML23304A464 (1)

Text

NuScale Nonproprietary Response to SDAA Audit Question Question Number: A-11.1-2 Receipt Date: 04/10/2023 Question:

In review of SDAA Section 11.1 the NRC staff seeks to understand the differences between the NuScale SDAA and DCA source term information that is provided in the SDAA Section 11.1 tables and technical report. What modified parameters are causing the SDAA source term values to be different from the previous DCA source term values?

In review of SDAA Table 11.1-1, the staff observes that some of the source term information was scaled for power level, while others were not. For example, please describe the differences for determining Kr-85, Kr-87, Xe-131m, Xe-135, Xe-138, I-129, Cs-134 Cs-135m, Cs-136, Cs-137, Sr-90, Y-90, Tc-99, Rh-105, Sb-125, Te-125m, Ba-137m, C-14, and H-3 since these radionuclides appear to scale from more than just power level differences.

Response

The Chapter 11 source term values reflect several parameters that changed and are shown in Table 11.1-2 and 11.1-3. For Table 11.1-1 specifically, the main contributors are the change in cycle length, increase in burnup, and the change in thermal power. The US600 design has a 160 MWth design with a two year cycle length, whereas the NuScale Standard US460 Plant Design has a 250 MWth design with a 1.5 year cycle length. The US600 design also evaluates a maximum of 60 GWd/MTU, whereas the NuScale Standard US460 Plant Design evaluates up to 62 GWd/MTU. Additionally, the uranium mass per fuel assembly changed. Therefore, the changes are not necessarily scalable by thermal power.

As requested during the clarification call on April 18, 2023, NuScale has provided EC-101293, Revision 1, Fuel Assembly Activity Calculation, for staff review in the eRR location "SDAA Chapter 11 Audit Response A-11.1-2." NuScale letter number LO-140095 provides the supporting files for staff review.

NuScale Nonproprietary

NuScale Nonproprietary No changes to the SDAA are necessary.

NuScale Nonproprietary