Document: NUREG-0800
Document ID: 866c6ef6-2f4a-45c7-9e71-43e1f66a8422
Document Type: srp
Title: Draft Revision 3– July 2018
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1807/ML18071A066.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5
CFR Part: 
CFR Title: 

Content:
nd submit the PTLR to the NRC for information. 4. Pressurized Thermal Shock (PWR only) 4.1 Pressurized Thermal Shock Requirements The following is a summary of requirements in 10 CFR 50.61 for the PWR reactor vessels: BTP 5-3-8 Draft Revision 3 – July 2018 (1) RTPTS values must be projected using EOL fluence for each weld, plate or forging in the reactor vessel beltline region. The projected EOL RTPTS values must be approved by the NRC. (2) PTS screening criteria is 132 °C (270 °F) for plates, forgings, and axial weld materials, and 149 °C (300 °F) for circumferential weld materials. (3) If reactor vessel is projected to exceed the PTS screening criteria, 10 CFR 50.61(b)(3) requires the applicant to implement a flux reduction program that is reasonably practicable to avoid exceeding the PTS screening criteria. (4) If the flux reduction program does not prevent the reactor vessel from exceeding the PTS screening criterion at the EOL, the applicant must choose between the two options in 10 CFR 50.61 to meet PTS requirements: (a) submit a safety analysis pursuant to 10 CFR 50.61(b)(4) to determine what, if, any, modifications to equipment, systems, and plant operation are necessary to prevent failure of the reactor vessel from a postulated PTS event, (b) perform a thermal-annealing treatment of the reactor vessel pursuant 10 CFR 50.61(b)(7) to recover fracture toughness. 10 CFR 50.61 requires details of the approach selected to be submitted for NRC approval at least 3 years before the reactor vessel is projected to exceed the PTS screening criteria. (5) Since 2010, another option became available in 10 CFR 50.61a to use the alternative PTS screening criteria for plants which could not prevent their reactor vessels from exceeding the PTS screen criteria of 10 CFR 50.61 at the EOL. 4.2 Alternative Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events For PWRs for which a construction permit was issued under 10 CFR Part 50 before