ML18232A173

2018/08/20 Vogtle COL Docs - Vogtle LAR-17-043 Draft RAI No2

ML18232A173
Person / Time
Site:	Vogtle
Issue date:	08/20/2018
From:	NRC
To:	NRC/NRO/DLSE/LB4
References
Download: ML18232A173 (3)

Text

1 DRAFT Request for Additional Information 2 Issue Date: August 20, 2018 Application Title: VEGP Units 3 and 4 - LARs Operating Company: Southern Nuclear Operating Co. Docket No.52-025 and 52-026 Review Section: 03.11 - Environmental Qualification of Mechanical and Electrical Equipment Application Section: LAR-17-043 EENB RAI QUESTION 1 10 CFR 50.49(e) states that the electric equipment qualification program must include and be based on temperature, pressure, humidity, chemical effects, radiation, aging, submergence, synergistic effects and margins. VEGP 3&4 UFSAR Section 3.D.4.3, "Mild Versus Harsh Environments," states that the AP1000 equipment qualification program conforms to the requirements of 10 CFR 50.49 for the qualification of harsh environment equipment. Furthermore, UFSAR Section 3.11.1.2, "Environmental Conditions," states that in the event of potential flooding/wetting, one of the following criteria is applied for protection of equipment for service in such an environment: 1) equipment will be qualified for submergence due to flooding/wetting, 2) equipment will be protected from wetting due to spray and 3) equipment will be evaluated to show that failure of the equipment due to flooding/wetting is acceptable since its safety-related function is not required or has otherwise been accomplished. Staff reviewed LAR-17-043, APP-SSAR-GSC-157, Revision 1, "AP1000 Long-Term LOCA Containment Integrity Analysis with WGOTHIC," APP-SSAR-GSC-166, Revision 1, "AP1000 Steamline Break Containment Integrity Analysis," and APP-GW-VPR-008, Revision 0, "Evaluation of Environmental Conditions Envelope Exceedances." The applicant in LAR-17-043, stated that mass and energy (M&E) releases for Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB) events are also recalculated. Furthermore, the applicant stated in LAR 17-043, Section 3.1.4, "Updates to Containment Integrity (Containment Peak Pressure) Analyses," that the updated containment pressure and temperature does not result in a change to the limiting profiles assumed in the equipment qualification testing program. In addition, the applicant stated in the LAR that there are no radiation zone changes or radiological access control changes required due to the proposed changes. Staff finds that the applicant has addressed the aspects of equipment qualification related to containment pressure and temperature as well as radiation but did not address equipment subject to submergence. Please discuss how the proposed changes affect equipment subject to submergence or please confirm that submerged equipment remains qualified as a result of the proposed changes. Please add a discussion in the LAR regarding the qualification of submerged equipment, as applicable.