Document: NUREG-0800
Document ID: 02fef38f-79ed-4d55-825f-81551bcfdcdc
Document Type: srp
Title: LOSS-OF-COOLANT ACCIDENTS RESULTING FROM SPECTRUM OF
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550016.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.6.5
CFR Part: 
CFR Title: 

Content:
Regional Offices may be requested to provide data of this type from the startup tests for new designs and from periodic tests on duplicate designs. In the case of new reactor designs that use passive rather than active systems to provide ECCS to the reactor vessel, pressure drop test results should be reviewed to determine that the passive ECCS flow rate is consistent with that in the analyses of the system performance. 7. The results of the applicant's calculations are consistent with those of staff calculations for typical plants and also with the results of calculations performed for similar systems by previous applicants. The following variables should be reviewed on a generic basis and spot-checked thereafter: power transients for various breaks; pressure transients at various system locations; flow transients near the break, in the core, and in the downcomer; reactor coolant temperature and quality at core inlet, core outlet, and in-core; cladding temperature transients (core average, hot assembly, hot pin); heat transfer coefficients during blowdown, refill, and reflood; heat flux transients from piping and vessel walls; primary-secondary heat transfer (PWRs only); timing of clad rupture (if the peak clad temperature could be appreciably higher when perforation occurs at a different but equally probable time, calculations with modified assumptions are requested); peak clad temperature as a function of break size (if it is uncertain whether the peak value has been found, additional calculations are requested); predicted "end-of-bypass" time compared to calculated downcomer flow and to staff calculations for typical plants; pump speed transients; containment pressure transients (if staff calculations are not available, these are requested from containment systems reviewer); 15.6.5-11 Revision 3 - March 2007 and carryover fraction (if it is not an input to the calculations). The boric acid concentration should be shown as a function of time for the limiting