Document: NUREG-0800
Document ID: a4f5c92f-1c1f-4a9c-b4d4-cb2fcc282cae
Document Type: srp
Title: PUMP FLYWHEEL INTEGRITY (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340666.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.1.1
CFR Part: 
CFR Title: 

Content:
r coolant pump motors in light-water-cooled power reactors. Specific criteria necessary to meet the relevant requirements of GDC 1 and 4 and 10 CFR Part 50, §50.55a(a)(1) are as follows: 1. Materials Selection The applicant's selection of flywheel material is acceptable if it is in accordance with the following criteria: The flywheel material must be produced by a process (such as vacuum melting or degassing) that minimizes flaws in the material and improves its fracture toughness properties. The material must be examined and tested to meet the following criteria: a. The nil-ductility transition (NDT) temperature of the flywheel material, as obtained from dropweight tests (DWT) performed in accordance with the specification ASTM E-208 (Ref. 3), should be no higher than 100F. b. The Charpy V-notch (C ) upper-shelf energy level in the "weak" direction (WR orientation in plates) of the flywheel material should be at least 50 ft-lbs. A minimum of three C specimens should be tested from each plate or forging, in accordance with ASTM A-370 (Ref. 4). 2. Fracture Toughness The following fracture toughness criteria are derived from Regulatory Guide 1.14, C.l.c, and the ASME Boiler and Pressure Vessel Code (hereafter "the Code"), Section III, Appendix G. The pump flywheel fracture toughness properties are acceptable if they are in compliance with the following criteria: The minimum static fracture toughness of the material at the normal operating temperature of the flywheel should be quivalent to a critical stress intensity factor, K , of at least 150 ksi 4in. Compliance can be demonstrated by either of the following: a. Testing of the actual material to establish the KIC value at the normal operating temperature. b. Determining that the normal operating temperature is at least 1000F above the RTNDT. 3. Preservice Inspection The following preservice inspection criteria are derived from Regulatory Guide 1.14, C.l.d, C.l.e, and C.l.f. The applicant's 5.4.1.1-3 Rev. 1 - July