Document: 10 CFR Part 50
Document ID: cfc9c7b0-bbcd-4774-97ce-900cbc760408
Document Type: cfr
Title: Codes and standards.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.55a
Revision Date: 
Chapter: 
Section ID: 50.55a
CFR Part: 50
CFR Title: 10

Content:
OVs within the scope of ASME OM Code, Appendix III, not later than 5 years or three refueling outages (whichever is longer) from initial implementation of ASME OM Code, Appendix III. ( B ) MOV testing impact on risk. Licensees shall ensure that the potential increase in core damage frequency and large early release frequency associated with the extension is acceptably small when extending exercise test intervals for high risk MOVs beyond a quarterly frequency. ( C ) MOV risk categorization. When applying Appendix III to the ASME OM Code, licensees shall categorize MOVs according to their safety significance using the methodology described in ASME OM Code Case OMN-3, “Requirements for Safety Significance Categorization of Components Using Risk Insights for Inservice Testing of LWR Power Plants,” subject to the conditions applicable to OMN-3 which are set forth in the appropriate NRC regulatory guides, as incorporated by reference in paragraph (a)(3) of this section, or using an MOV risk ranking methodology accepted by the NRC on a plant-specific or industry-wide basis in accordance with the conditions in the applicable safety evaluation. ( D ) MOV stroke time. When applying Paragraph III-3600, “MOV Exercising Requirements,” of Appendix III to the ASME OM Code, licensees shall verify that the stroke time of MOVs specified in plant technical specifications satisfies the assumptions in the plant's safety analyses. ( iii ) OM condition: New reactors. In addition to complying with the provisions in the ASME OM Code with the conditions specified in paragraph (b)(3) of this section, holders of operating licenses for nuclear power reactors that received construction permits under this part on or after August 17, 2018, and holders of combined licenses issued under 10 CFR part 52 , whose initial fuel loading occurs on or after August 17, 2018, must also comply with the following conditions, as applicable: ( A ) Power-operated valves. Licensees must periodically verify