ML18173A291

U.S. Nuclear Regulatory Commission Report of Regulatory Audit for Nuscale Power, LLC Seismic Category 1 Equipment and Environment Qualification of Electrical Equipment Specifications

ML18173A291
Person / Time
Site:	NuScale
Issue date:	10/25/2018
From:	Amadiz M V NRC/NRO/DNRL/LB1
To:	Lee S L NRC/NRO/DLSE/LB1
VERA M/415-5861
References
Download: ML18173A291 (12)

Text

/RA/

Code of Federal Regulations The application must contain a level of design information sufficient to enable the Commission to judge the applicant's proposed means of assuring that construction conforms to the design and to reach a final conclusion on all safety questions associated with the design before the certification is granted. The information submitted for a design certification must include performance requirements and design information sufficiently detailed to permit the preparation of acceptance and inspection requirements by the [U.S. Nuclear Regulatory Commission] NRC, and procurement specifications and construction and installation specifications by an applicant. The Commission will require, before design certification, that information normally contained in certain procurement specifications and construction and installation specifications be completed and available for audit if the information is necessary for the Commission to make its safety determination.

• Intended for the seismic and dynamic portion of the loads, the test input motion should be applied to one vertical axis and one principal horizontal axis (or two orthogonal horizontal axes) simultaneously, unless it can be demonstrated that the equipment response in the vertical direction is not sensitive to the vibratory motion in the horizontal direction, and vice versa. The time phasing of the inputs in the vertical and horizontal directions must be such that a purely rectilinear resultant input is avoided. An acceptable alternative is to test with vertical and horizontal inputs in-phase, and then repeat the test with inputs 180 degrees out-of phase. In addition, the test must be repeated with the equipment rotated 90 degrees horizontallyThe test response spectrum (TRS) and required response spectrum (RRS) for the seismic qualification are also identified in the equipment qualification record file (EQRF). The RRS is bounded by the TRS to demonstrate the conservative qualification of equipment. The testing also simulates the effects of aging, such as the fatigue effects of five OBEs plus the loadings associated with normal operation for the design life of the equipment prior to simulating the effects of an SSE, which is equivalent to two SSEs, with 10 stress cycles each, per Section 3.10.1.1. Seismic qualification of mechanical and electrical equipment by testing is performed in accordance with the requirements of IEEE 344-2004. For equipment qualified by testing, the test simulates normal loadings, such as thermal and flow induced loads, concurrently with the seismic and other dynamic loadings. The loads include forces imposed by piping onto the equipment. The survival and operability of the equipment is verified during and after the testing.

NuScale Power, LLC (NuScale) response: The design specifications will be revised.

NuScale response:

NuScale indicated that IEEE 344-2004 will be followed and referenced.

NuScale response: Addressed in QME-1 section QR-A7222 NuScale response: The design specifications will be revised.

NuScale response: The design specifications will be revised.

NuScale response: The design specifications will be revised.

NuScale response: The design specifications will be revised.

NuScale response: Used the 1974 version, will change the definition to make it consistent.

Code of Federal Regulations

• NuScale response: NuScale will revise the definitions in the design specifications documents to ensure they are consistent with IEEE Std. 323-1974 and IEEE Std. 317-1983 definition NuScale response: NuScale stated that radiation is not a significant aging mechanism and that the standard allows the specimen not to be subjected to radiation if it can be demonstrated that radiation does not degrade the equipment.(NuScale found an incorrect reference to Section 3.6.1, instead to Section 3.7, which discusses why radiation aging is not needed. The applicant NuScale issued a condition report to correct this reference.)

NuScale response: NuScale issued a condition report to correct the IEEE Std. 323 year from 1983 to 1974.

NuScale response: NuScale will update the reference to change the year of the standard form 2003 to 1974. In addition, Section 5.3, "Wiring," states that heater element wiring and power cables shall be qualified in accordance with IEEE Std. 323 for the design conditions.

NuScale response: NuScale stated that the Pressurizer Heater Bundles are not important to safety, therefore, the cables are not required to be qualified. NuScale will update the design documentation to remove the environmental qualification requirements since is not required for the Pressurizer Heater Bundles cables.

NuScale response: Addressed in QME-1 section QR-A5600. Qualification plan and test plan developed by vendor.

NuScale response: NuScale agreed to update DCD Tier 2 and the design specification.