Document: NUREG-0800
Document ID: 9697248b-d015-42be-8808-2202db24977a
Document Type: srp
Title: STANDBY LIQUID CONTROL SYSTEM (BWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070680186.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.3.5
CFR Part: 
CFR Title: 

Content:
tion, and boron-10 isotope enrichment, accounting for RPV volume, that the resulting reactivity control is at least equivalent to that resulting from injection of 326 Lpm (86 gpm) of 13-weight-percent sodium pentaborate decahydrate solution at the natural boron-10 isotope abundance into a 638-cm (251-in.) inside diameter RPV for a given core design. The requirement allows flexibility in its implementation (i.e., the equivalence can be obtained by increasing flow rate, boron concentration, or boron enrichment). The important parameters considered in establishing equivalence are the vessel boron concentration required to achieve shutdown and the time required to achieve that vessel boron concentration (see GL 85-03). The reviewer evaluates the system arrangement and associated features, including the injection location(s), to determine that they will facilitate reliable, undiverted injection of borated solution to the reactor vessel. The reviewer should also confirm that sufficient allowance is provided for imperfect mixing and leakage. For BWRs, that are required to provide automatic SLCS initiation under the rule, the reviewer coordinates with the organization responsible for the review of instrumentation and controls systems, as described in Subsection I, to verify that the system has acceptable provisions for automatic initiation. 9.3.5-9 Revision 3 - March 2007 E. The reviewer verifies that the SAR and the system P&IDs indicate that adequate means are to be provided to maintain the system temperature above the saturation temperature of the neutron absorber solution for all designs (i.e., BWRs, ABWRs, and ESBWRs). The reviewer also verifies that the SAR and the system P&IDs indicate that means are to be provided to maintain the minimum boron solution tank level and maximum solution temperature to ensure net positive suction head for the positive displacement pumps for the older BWRS, as indicated by NRC Information Notice (IN) 91-012. In addition, adequate means