ML24108A122

LLC Response to NRC Request for Additional Information No. 10105 (RAI-10105) on the NuScale Standard Design Approval Application

ML24108A122
Person / Time
Site:	05200050, 99902078
Issue date:	04/17/2024
From:	Fosaaen C NuScale
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
RAIO-157891
Download: ML24108A122 (1)

Text

RAIO-157891

April 17, 2024 Docket No. 052-050

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738

SUBJECT:

NuScale Power, LLC Response to NRC Request for Additional Information No. 10105 (RAI-10105) on the NuScale Standard Design Approval Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, Request for Additional Information No. 10105 (RAI-10105), dated November 18, 2023

The purpose of this letter is to provide the NuScale Power, LLC (NuScale) response to the referenced NRC Request for Additional Information (RAI).

The Enclosure to this letter contain NuScale's response to the following RAI Question from NRC RAI-10105:

x 9.1.5-6

This letter makes no regulatory commitments and no revisions to any existing regulatory commitments.

If you have any questions, please contact Thomas Griffith at 541-452-7813 or at tgriffith@nuscalepower.com.

I declare under penalty of perjury that the foregoing is true and correct. Executed on April 17, 2024.

Sincerely, Sincerely,

Carrie Fosaaen CarrieFosaaen Vice President, Regulatory Affairs NuScale Power, LLC

Distribution: Mahmoud Jardaneh, NRC Getachew Tesfaye, NRC Greg Cranston, NRC

NuScale Response to NRC Request for Additional Information RAI-10105, nonproprietary

NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com RAIO-157891

NuScale Response to NRC Request for Additional Information RAI-10105, nonpropri etary

NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com NuScaleNonproprietary NuScaleNonproprietary

NuScale Final Safety Analysis Report Overhead Heavy Load Handling Systems

RAI 9.1.5-6

Heavy load exclusion zones and sSafe load paths are defined in operating procedures and equipment drawings. This restriction reduces the probability of a heavy load drop that could result in safe shutdown equipment damage or result in a release of radioactive material that could cause unacceptable radiation exposures.

RAI 9.1.5-6

The position control system assists in aligning the RBC with the NPM for engagement before performing lifting operations. The RBC control system is capable of load-dependent travel restrictions Heavy load exclusion zones are dependent on the load on the RBC hoist. The travel path is chosen to accommodate this information. Repeatability, proper load path, and proper locations are ensured by semi-automatic crane operation.

Refueling Operations

Refueling operations for an individual NPM are independent of the operating status of the remaining NPMs because only one NPM can be moved at a time.

This section presents the process of moving an NPM from the operating bay to the refueling pool and preparing the vessel for fuel movement. Section 9.1.4 presents the process of moving fuel assemblies into an open reactor vessel.

The RBC is moved to the operating bay containing the NPM that is shutdown for refueling. When the RBC is within a predefined position, the lower block assembly is lowered over the NPM lifting lugs. The LBA is manipulated until its lugs are fully engaged with the NPM lifting lugs. Verification of pin position is achieved by sensor feedback on the LBA and visual indicators. The LBA is raised until the load sensing system detects load, indicating NPM lifting lugs are fully engaged with the LBA. The NPM is raised to a pre-defined elevation and moved through the predefined path to the CFT in the refueling pool.

Once the RBC is aligned over the CFT, the NPM is lowered onto the stand of the CFT. With the LBA still attached to the NPM, the CFT de-tensions and removes the CNV flange closure bolts. The RBC lifts the upper CNV, with the RPV attached, from the lower CNV and transfers it into location over the RFT.

The lower CNV remains in the CFT during the remaining refueling process.

The RBC lowers the upper CNV with the RPV onto the stand in the RFT. With the LBA still attached to the upper CNV, the RFT de-tensions and removes the RPV flange closure bolts. Once the bolts are removed, the RBC lifts the upper CNV with the upper RPV and transports it to the module inspection rack in the flooded dry dock. The RBC lowers the upper NPM into the module inspection rack. The NPM is confirmed to be properly seated in the module inspection rack and the LBA is disconnected from the module.

The process is performed in reverse to reassemble the NPM and move it back into the operating bay.

NuScale US460 SDAA 9.1-46 Draft Revision 2