Document: NUREG-0800
Document ID: 81a2e18b-7311-4c4e-822e-8dfe1b0ba7aa
Document Type: srp
Title: REACTOR PRESSURE VESSEL INTERNALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0702/ML070230009.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.5
CFR Part: 
CFR Title: 

Content:
e effects of earthquakes without loss of capability to perform their safety functions. The reactor internals perform or may (through their failure) affect the performance of safety functions like core cooling and fission product confinement. Application of GDC 2 to the reactor internals provides assurance that they will withstand earthquakes without damaging fuel cladding or interfering with core cooling. 3. GDC 4, in relevant part, requires that SSCs important to safety be designed to accommodate the effects of and to be compatible with environmental conditions of normal operations, maintenance, testing, and postulated accidents, including LOCAs. The reactor internals perform or (through their failure) may affect the performance of safety functions like reactivity monitoring and control, core cooling, and fission product confinement. Application of GDC 4 to the reactor internals provides assurance that the effects of environmental conditions to which they are exposed over their installed life will not diminish the likelihood of performance of these safety functions under all operating conditions, including accidents. This provides assurance that failures of the reactor internals from environmental service conditions that could cause loss of capability to monitor reactivity, fuel damage from loss of reactivity control, structural damage to fuel cladding, or interference with core cooling are not likely to occur. 3.9.5-7 Revision 3 - March 2007 NUREG-0609 evaluates certain postulated pipe ruptures (e.g., double-ended guillotine breaks of primary reactor coolant loop piping) known to cause asymmetric blowdown loadings on the reactor internals. GDC 4 allows such dynamic effects of postulated pipe ruptures to be excluded from the design basis when analyses approved by the staff demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping. Application of GDC 4 to the reactor internals