Document: NUREG-0800
Document ID: a7fafe76-5570-446b-96dd-3e53ec9bccb3
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340663.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4
CFR Part: 
CFR Title: 

Content:
in the full-out position must be made. In PWRs, operational reactivity control is carried out by movement of control rods and by adjustments of the concentration o'f soluble poison in the coolant. The reviewer must pay particular attention to the proposed rod inser- tion limits in the power operating range, to assure that the control rods are capable of rapidly reducing the power-and maintaining the reactor in the hot standby condition. This is an important point because the soluble poison concentration in the coolant could be decreased in order to raise reactor power, while the control rods were left inserted so far that in the event of a scram (rapid inser- tion of control rods), the available reactivity worth of the control rods on full insertion would not be enough to shut the reactor down to the hot standby condition. e. The reviewer determines that each of the independent reactivity control systems is capable of controlling the reactivity changes resulting from planned, normal power operation. This determination is made by comparing the rate of reactivity change resulting from planned, normal operation to the capabilities of each of the two control systems. Sufficient margin must exist to allow for the uncertainties in the rate. 5. The review procedures in the area of control rod patterns and reactivity worths are: 4.3-9 Rev. 2 - July 1981 a. The reviewer determines by inspection and study of the information described in subsection I.5 of this SRP section that the control rod and bank worths are reasonable. This determination involves evalua- tion of the appropriateness of the analytical models used, the appli- cability of experimental data used to validate the models, and the applicability of generic positions or those established in previous reviews of similar reactors. b. The reviewer determines the equipment, operating restrictions, and administrative procedures that are required to restrict possible control rod and bank worths, and the extent to which the