Document: 10 CFR Part 50
Document ID: ebc72932-4988-4c38-b485-e106d10d737c
Document Type: cfr
Title: Alternate fracture toughness requirements for protection against pressurized thermal shock events.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.61a
Revision Date: 
Chapter: 
Section ID: 50.61a
CFR Part: 50
CFR Title: 10

Content:
�F. ( 6 ) RT MAX-X means any or all of the material properties RT MAX-AW , RT MAX-PL , RT MAX-FO , RT MAX-CW , or sum of RT MAX-AW and RT MAX-PL , for a particular reactor vessel. ( 7 ) φt means fast neutron fluence for neutrons with energies greater than 1.0 MeV. φt is utilized under the provisions of paragraph (g) of this section and has units of n/cm 2 . ( 8 ) φ means average neutron flux for neutrons with energies greater than 1.0 MeV. φ is utilized under the provisions of paragraph (g) of this section and has units of n/cm 2 /sec. ( 9 ) ΔT 30 means the shift in the Charpy V-notch transition temperature at the 30 ft-lb energy level produced by irradiation. The ΔT 30 value is utilized under the provisions of paragraph (g) of this section and has units of °F. ( 10 ) Surveillance data means any data that demonstrates the embrittlement trends for the beltline materials, including, but not limited to, surveillance programs at other plants with or without a surveillance program integrated under 10 CFR part 50, appendix H . ( 11 ) T C means cold leg temperature under normal full power operating conditions, as a time-weighted average from the start of full power operation through the end of licensed operation. T C has units of °F. ( 12 ) CRP means the copper rich precipitate term in the embrittlement model from this section. The CRP term is defined in paragraph (g) of this section. ( 13 ) MD means the matrix damage term in the embrittlement model for this section. The MD term is defined in paragraph (g) of this section. ( b ) Applicability. The requirements of this section apply to each holder of an operating license for a pressurized water nuclear power reactor whose construction permit was issued before February 3, 2010 and whose reactor vessel was designed and fabricated to the ASME Boiler and Pressure Vessel Code, 1998 Edition or earlier. The requirements of this section may be implemented as an alternative to the requirements of 10 CFR 50.61 . ( c ) Request