Document: NRC Regulatory Guide
Document ID: ad61f8a3-1cce-4446-9542-dcdda55c1ec6
Document Type: regulatory_guide
Title: Comprehensive Vibration Assessment Program for Reactor Internals During Preoperational and Initial Startup Testing + HISTORY - HISTORY 07/2015 – DG-1323 , Proposed Revision 4 03/2013 – Periodic Review of Revision 3 – No Issues Identified 11/2006 – DG-1163 , Proposed Revision 3 (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1508/ML15083A390.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.20
CFR Part: 
CFR Title: 

Content:
sed to establish the limits fail before power ascension, the limits will need to be reestablished. Previous limits and accompanying benchmarking need to be updated at current plant conditions and with currently valid sensors. The updated limits and benchmarking need to be compared to previous results, but with the previous results also updated using only currently valid sensors. Any significant differences between previous and updated limits and benchmarking need to be resolved. (3) Power ascension for BWR steam dryer needs to be in small increments when approaching full power, with data taken at each increment (e.g., 5 percent). The approach to power ascension testing can vary depending on the purpose (e.g., new plant startup or EPU power ascension with existing, new, or modified steam dryer). The applicant or licensee should work with the NRC to develop an acceptable program that establishes power levels and durations where power level should be maintained at a suitable percentage and for a suitable period of time to allow for the acquisition of data. In addition, the applicant or licensee should establish specific power levels where power will be held for an additional time period after making the startup data available to the NRC project manager such that the NRC staff may evaluate the data. In the past, the NRC staff has accepted time periods of 72 to 96 hours; and power levels of approximately 5 percent above the original licensed thermal power for EPU power ascensions at BWR plants, and 75 percent, 85 percent, and 95 percent of licensed thermal power for new BWR startup plans. After the data are made available to the NRC staff, no further NRC action is necessary to authorize ascension to the next power level when the applicable time duration is reached; enforcement action (i.e., an order) would be necessary to halt power ascension if the NRC staff’s evaluation determined it was warranted. (4) Power ascension acceptance limit checks may be of in-plant