ML17289A971
| ML17289A971 | |
| Person / Time | |
|---|---|
| Site: | Technical Specifications Task Force |
| Issue date: | 10/16/2017 |
| From: | Excel Services Corp |
| To: | Office of Nuclear Reactor Regulation |
| Honcharik M | |
| Shared Package | |
| ml17289A902 | List: |
| References | |
| Download: ML17289A971 (1) | |
Text
Page 1 EXCEL Services Corporation Draft Variation for BWR/5 and BWR/6 Plants for Functions 3.a and 3.e.
Table 3.3.5.2-1 is revised to reflect the [plant name] design. Function 3, High Pressure Core Spray (HPCS) System, Function 3.a, "Reactor Vessel Water Level - High, Level 8," and Function 3.e, "Manual initiation," that appear in TSTF-542 are not included in the proposed Technical Specifications. This corrects an error in TSTF-542 that affects the BWR/5 and BWR/6 ECCS instrumentation requirements.
The purpose of the manual initiation function is to allow manual actuation of the ECCS subsystem required by TS 3.5.2 to mitigate a draining event. The Reactor Vessel Water Level -
High, Level 8 signal prevents overfilling of the reactor vessel into the main steam lines by closing the HPCS injection valves when the water level is above the Level 8 setpoint. Therefore, if HPCS is the required ECCS subsystem and the water level is above Level 8, manually actuating Function 3.e will not inject inventory into the reactor vessel. This is not the desired response. If the Level 8 function is retained in Table 3.3.5.2-1, the function would need to be rendered inoperable in order to inject water when above the Level 8 water level. This would not be consistent with including the function in Table 3.3.5.2-1.
[Plant name] has the capability to manually start the HPCS pump and to open the HPCS injection valve if needed, not utilizing Functions 3.a and 3.e. If desired to inject water into the reactor pressure vessel using the HPCS, the reactor operator can follow procedural steps to take manual control of the pump and injection valve to add inventory. If the water level is above Level 8, then manual override of the Level 8 function can be performed to allow the HPCS injection valve to be opened. These actions can be performed from the control room and can be accomplished well within the 1-hour minimum drain time limit specified in TS 3.5.2, Condition E. Consequently, the Function 3.a and 3.e instrumentation functions are not needed to actuate the HPCS subsystem components to mitigate a draining event.