ML19126A322
| ML19126A322 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 05/06/2019 |
| From: | Rad Z NuScale |
| To: | Document Control Desk, Office of New Reactors |
| References | |
| LO-0519-65421 | |
| Download: ML19126A322 (4) | |
Text
LO-0519-65421 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com Docket No.52-048 May 6, 2019 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738
SUBJECT:
NuScale Power, LLC Submittal of Revision 1 to Resolution Plans for Module Protection System Actuation Logic Changes Related to Initiation of Decay Heat Removal System and Emergency Core Cooling System
REFERENCES:
1.
Summary of the February 19, 2019, Public Meeting with NuScale Power, LLC, to Discuss NuScale Power LLCs Design Changes to the Decay Heat Removal System and Emergency Core Cooling System Actuation Logic (ML19056A289) 2.
Letter from NuScale Power, LLC to Nuclear Regulatory Commission, NuScale Power, LLC Submittal of the NuScale Standard Plant Design Certification Application, Revision 2, dated October 30, 2018 (ML18311A006) 3.
Letter from NuScale Power, LLC to Nuclear Regulatory Commission, NuScale Power, LLC Submittal of Resolution Plans for Module Protection System Actuation Logic Changes Related to Initiation of Decay Heat Removal System and Emergency Core Cooling System, March 14, 2019 (ML19073A328)
During a February 19, 2019 public teleconference (Reference 2) with Sam Lee, Omid Tabatabai and other members of the NRC Staff, NuScale Power, LLC (NuScale) discussed a proposed path forward for resolution of certain follow-up items from the discussion of NuScales design changes to the decay heat removal system and emergency core cooling system actuation logic presented in Reference 1. As a result of this discussion, NuScale submitted a proposed closure plan for these changes to the plant design (Reference 3). Attached to this letter is Revision 1 to the NuScale Closure Plan.
This letter makes no regulatory commitments and no revisions to any existing regulatory commitments.
If you have any questions, please feel free to contact Carrie Fosaaen at 541-452-7126 or at cfosaaen@nuscalepower.com Sincerely, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Samuel Lee, NRC, OWFN-8H12 Gregory Cranston, NRC, OWFN-8H12 Omid Tabatabai, NRC, OWFN-8H12
LO-0519-65421 Page 2 of 2 05/06/2019 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Attachment:
NuScale Closure Plan for Module Protection System (MPS) Actuation Logic Changes Related to Initiation of Decay Heat Removal System (DHRS) and Emergency Core Cooling System (ECCS) Revision 1
LO-0519-65421 Attachment Page 1 of 2 NuScale Closure Plan for Module Protection System (MPS) Actuation Logic Changes Related to Initiation of Decay Heat Removal System (DHRS) and Emergency Core Cooling System (ECCS) Revision 1 May 3, 2019 Overview The plant safety system actuation logic provided by the MPS is being revised to support operational ease during startup of a reactor.
Additionally, an uncredited ECCS initiation signal is being modified so that it will provide Type B post-accident parameter indication only.
Description of Changes
The existing DHRS actuation logic will be divided into two distinct initiations.
o Isolation of the secondary system steam generators by closure of steam and feedwater valves.
o Decay Heat Removal initiation by opening of the DHRS valves.
Removal of uncredited ECCS actuation on low reactor pressure vessel level.
Reanalysis of transients and accidents affected by the initiation logic changes.
Revision of relevant FSAR Tier 1 and Tier 2 sections, and Technical Specifications to reflect the modified design.
Implementation Process and Progress Task Predecessor Activities Forecast Completion Status 1
Completed design work and design reviews 2/20/19 Completed 2
Modify engineering design documents 1
5/22/19 Forecast 3
Complete confirmatory transient and accident re-analyses 1, 2 7/9/19 Submit changes to the NRC for consideration 4
FSAR Tier 1 Section 2.5, Tier 2 Chapters 7 and 10, and Technical Specifications 2
4/15/19 Completed 5
Chapter 6 and Containment Response Analysis Technical Report 2
5/10/19 6
Advanced Sensor Technical Report 2
5/15/19 7
Instrument Setpoint Methodology Technical Report 2
5/15/19
LO-0519-65421 Attachment Page 2 of 2 8
FSAR Chapter 3 and 17 and associated Tier 1 changes 2
5/31/19 9
FSAR Chapter 15 and 19 3
7/31/19 10 Technical Specifications reconciliation (if needed) 9 7/31/19