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:
lds, for Cu >0.072 26.4 35.5 30.8 27.5 25.1 23.2 21.7 Plates, for Cu >0.072 21.2 28.5 24.7 22.1 20.2 18.7 17.5 Forgings, for Cu >0.072 19.6 26.4 22.8 20.4 18.6 17.3 16.1 Weld, Plate or Forging, for Cu ≤0.072 18.6 25.0 21.7 19.4 17.7 16.4 15.3 Table 6—T MAX Values for the Slope Deviation Test (Significance Level = 1%) Number of available data points (n) T MAX 3 31.82 4 6.96 5 4.54 6 3.75 7 3.36 8 3.14 9 3.00 10 2.90 11 2.82 12 2.76 13 2.72 14 2.68 15 2.65 Table 7—Threshold Values for the Outlier Deviation Test (Significance Level = 1%) Number of available data points (n) Second largest allowable normalized residual value (r*) Largest allowable normalized residual value (r*) 3 1.55 2.71 4 1.73 2.81 5 1.84 2.88 6 1.93 2.93 7 2.00 2.98 8 2.05 3.02 9 2.11 3.06 10 2.16 3.09 11 2.19 3.12 12 2.23 3.14 13 2.26 3.17 14 2.29 3.19 15 2.32 3.21 [ 75 FR 23 , Jan. 4, 2010, as amended at 75 FR 5495 , Feb. 3, 2010; 75 FR 10411 , Mar. 8, 2010; 75 FR 72653 , Nov. 26, 2010] Footnotes - 50.61a [ 1 ] For forgings susceptible to underclad cracking the determination of the flaw density for that forging from the licensee's inspection shall exclude those indications identified as underclad cracks. [ 2 ] Because flaws greater than three-eights of the vessel wall thickness from the inside surface do not contribute to TWCF, flaws greater than three-eights of the vessel wall thickness from the inside surface need not be analyzed for their contribution to PTS. [ 3 ] Regulatory Guide 1.190 dated March 2001, establishes acceptable methods for determining neutron flux. [ 4 ] Data from reactor vessels fabricated to the same material specification in the same shop as the vessel in question and in the same time is an example of “generic data.” [ 5 ] The class of material for estimating RT NDT(U) must be determined by the type of welding flux (Linde 80, or other) for welds or by the material specification for base metal.