ML18191B262

LLC - Submittal of Changes to Final Safety Analysis Report, Section 10.4.7, Condensate and Feedwater System

ML18191B262
Person / Time
Site:	NuScale
Issue date:	07/10/2018
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
References
LO-0718-60742
Download: ML18191B262 (3)

Text

• --=:. **:*.:.. NuScALE POWER" LO-0718-60742 July 10, 2018 Docket No.52-048 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 Changes to Final Safety Analysis Report, Section 10.4.7, "Condensate and Feedwater System"

REFERENCES:

Letter from NuScale Power, LLC to Nuclear Regulatory Commission , "NuScale Power, LLC Response to NRC Request for Additional Information No. 275 (eRAI No. 9122)," dated December 15, 2017 (ML17349B004)

During a June 20 , 2018 , closed teleconference with Omid Tabatabai-Yazdi , NRC Project Manager, and Angelo Stubbs , NRC reviewer of the NRC staff, NuScale Power, LLC (NuScale) discussed potential updates to Final Safety Analysis Report (FSAR), Section 10.4.7, "Steam and Feedwater System Materials." As a result of this discussion , NuScale revised Section 10.4.7. The Enclosure to this letter provides a mark-up of the FSAR pages incorporating the revisions in red line/strikeout format.

NuScale will include this change as part of a future revision to the Nu Scale Design Certification Application.

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

Please feel free to contact Carrie Fosaaen , Licensing Project Manager at 541-542-7126 or cfosaaen@nuscalepower.com if you have any questions.

Sincerely,

~~*

~-~~

Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Samuel Lee, NRC, OWFN-8G9A Gregory Cranston , NRC, OWFN-8G9A Omid Tabatabai-Yazdi , NRC, OWFN-8G9A

Enclosure:

"Changes to NuScale Final Safety Analysis Report Section 10.4.7, "Condensate and Feedwater System" NuScale Power, LLC 1100 NE Circle Blvd , Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

LO-0718-60742

Enclosure:

Changes to NuScale Final Safety Analysis Report Section 10.4.7, Condensate and Feedwater System NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

NuScale Final Safety Analysis Report Other Features of Steam and Power Conversion System RAI 10.04.07-3 Refer to Section 3.6.3 for a description of SG design features implemented to prevent fluid flow water hammer. The potential for water hammer in the CFWS is minimized by design features such as pipe slope, the use of available drains before startup, and adjustment of valve closure timing. The potential for water hammer can be further reduced through the use of operating and maintenance procedures as described in NUREG 0927, Evaluation of Water Hammer Occurrence in Nuclear Power Plants.

General Design Criterion 5 was considered in the design of the condensate and feedwater system. The components in the CFWS are not shared among NPMs; therefore, failure of the CFWS does not impair the ability of other NPMs to perform their safety functions.

The condensate and feedwater system is designed to avoid FAC:

• feedwater piping and components are constructed using material resistant to FAC

• flow velocity and changes in flow direction is limited consistent with the guidance of NSAC-202L (Reference 10.4-4)

• feedwater chemistry is continuously monitored and controlled The CFWS and supporting systems monitor and control secondary water chemistry to maintain water quality specifications during normal operation and AOOs. Flow-accelerated corrosion is discussed further in Section 10.3.6.

RAI 10.04.07-1 The CFWS system is nonsafety-related. Each FWRV is designed to provide backup to the FWIV safety function. Both valves are designed to fail closed on loss of motive force or loss of control signal.

General Design Criterion 60 was considered in the design of the condensate and feedwater system. Consistent with GDC 60, the CFWS design controls radioactive material releases to the environment. Consistent with 10 CFR 20.1101(b), the CFWS design supports keeping radiation exposures ALARA. To maintain the radiation exposure to operating and maintenance personnel ALARA, the CFWS is designed to facilitate maintenance, inspection, and testing in accordance with the guidance in RG 8.8. The CFWS design satisfies the requirements of 10 CFR 20.1406 in that it supports minimization of contamination of the facility and the environment. Primary-to-secondary leakage from an SGTF has the potential to introduce radioactive material into the CFWS. Main steam and condensate monitoring with MSS and CFWS isolation capabilities minimize the contamination and release to the environment. The CFWS drains to the BPDS, which discharges to the radioactive waste drain system should the CFWS become contaminated.

Detected radioactive material in the condenser is managed by the CARS (Section 10.4.2). Radiation monitors are also provided on the exhaust from the gland seal condenser (Section 10.4.3).

RAI 10.03-5 Tier 2 10.4-38 Draft Revision 2