ML18130A817
| ML18130A817 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 05/10/2018 |
| From: | NRC |
| To: | NRC/NRO/DNRL/LB4 |
| References | |
| Download: ML18130A817 (70) | |
Text
(i) There is no significant hazards consideration.
(ii) There is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite. (iii) There is no significant increase in individual or cumulative occupational radiation exposure.
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Design Certification Rule for the AP1000 Design, Scope and Contents
Design Certification Rule for the AP1000 Design, Scope and Contents,Finality of design certificationsSpecific exemptionsSpecific exemptionsDesign Certification Rule for the AP1000, cation Rule for the APation Rule fo
Proper operation of the core makeup tanks to perform their reactor water makeup and boration function is verified by initiating recirculation flow through the tanks during hot functional testing with the reactor coolant system at 530°F. This testing is initiated by simulating a safety signal which opens the tank discharge isolation valves, and stops reactor coolant pumps after the appropriate time delay. The proper tank recirculation flow after the pumps have coasted down is verified. Based on the cold leg temperature, CMT discharge temperature, and temporary CMT flow instrumentation, the net mass injection rate into the reactor is verified.
Note that this verification is required only for the first three plants.[During hot functional testing of the reactor coolant system, proper operation of automatic depressurization is verified by blowing down the reactor coolant system. This testing verifies proper operation of the stage 1, 2, and 3 components including the ability of the spargers to limit loads imposed on the in-containment refueling water storage tank by the blowdown. Proper operation of the stage 1, 2 and 3 valves is demonstrated during blowdown conditions. Note that this verification is required only for the first three plants
.]* In conjunction with the verification of the core makeup tanks to perform their reactor water makeup function and boration function described in item k) above, the proper operation of the core makeup tanks to transition from their recirculation mode of operation to their draindown mode of operation after heatup will be verified. This testing will also verify the proper operation of the core makeup tank level instrumentation to operate during draining of the heated tank fluid. The in-containment refueling water storage tank initial level is reduced to at least 3 feet below the spillway level as a prerequisite condition for this testing in order to provide sufficient ullage to accept the mass discharged from the reactor coolant system via the automatic depressurization stage 1. The recirculation operation in Item k) above, should be continued until the core makeup tank fluid has been heated to 350°F. The core makeup tank isolation valves are then closed, the reactor coolant pumps are started, and the reactor coolant system is reheated up to hot functional testing conditions. This testing is initiated by shutting off the reactor coolant pumps, opening the core makeup tank isolation valves, and by opening one of the automatic depressurization stage 1 flow paths to the in-containment refueling water storage tank. This will initiate a large loss of mass from the reactor coolant system, depressurization of the reactor coolant system to the bulk fluid saturation pressure, and additional recirculation through the core makeup tank. Core makeup tank draindown initiates in response to the continued g hot functional testing g hot functional teessurization is verified essurization is verifiedper operation of the stagr operation oers to limit loads imposemit loaown. Proper operation o wn. Proper operations. Note that this verNote that this verform their reactor waterform their reactor wateroper operation of theroper operation operation to the peration to thso verifyso verifyurin urin
depressurization and mass loss from the reactor coolant system. The automatic depressurization stage 1 flow path is closed after the core makeup tank level has decreased below the level at which stage4 actuation occurs.
Note that this verification is required only for the first three plants.
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