ML17037A703
| ML17037A703 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 02/06/2017 |
| From: | Niagara Mohawk Power Corp |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML17037A703 (1) | |
Text
NMPNS-2 TABLE 7.2-1 (CONT'D)
Line Isolated Dryvell air sample Number of
~ines Approximate Pipe Size, In.
1/2 Valve Per Line rou B
B Valve Location Relative to Primary Containment Inside Outside Valve and/or Operator
~r.
~~en,6)
A-c D-c Power to
~~~"',6)
Spring Spring Isolation
~S',F,Z Standard Standard Open Open Closing Normal
~Time
,11,12)
Status (9 1O) emarks Suppression chamber air samples Suppression chamber air samples Drywell and suppression chamber purge exhaust fan suction 1/2 18 B
B B
B Inside Outside Inside Outside Inside Outside SO valve SO valve SO valve SO valve AO 'butterfly AO butterfly A-c D-c A-c D-c A-c/Air A-c/Air Spring Spring Spring Spring Spring Spring A,F,Z A,F,Z ApF,Z Standard Standard Standard Standard.
Standard Standard Open Open Open Open Closed Closed These notes are keyed by number to correspond to numbers in parentheses.
- 1. Main steam isolation valves vill require that both solenoid pilots be de-energized to close valves.
Accumulator air pressure plus spring set together to close valves when both pilots are de-energized.
Voltage failure at only one pilot will not cause valve closure.
The valves will be designed to fully close in less than 10 seconds.
4.
Control rod hydraulic lines can be isolated by the solenoid valves outside the primary containment.
Lines tnat extend. outside the primary containment will be small and terminate in a system that is designed to prevent out-leakage.
Solenoid valves normally will be closed, but they will open on rod movement and during reactor scram.
8.
Reactor building ventilation/exhaust high radi cion signal "Z" will be generated by tvo trip channels, each channel will have two trip units.
This will require one unit at high trip or one unit at downscale (instrument failure) trip, on one trip channel and one unit at high trip or one unit at downscale trip on the other trip channel in order to initiate isolation.
- 2. Containment spray and suppression cooling valves will have interlocks that allow them to be manually reopened after automatic closure.
This setup will permit containment spray, for high dry veil pressure con-ditions, and/or suppression water cooling.
When automatic signals are not present these valves may be opened for test or operating convenience.
- 3. Testable check valves will be designed for remote opening with zero differential pressure across the valve seat.
The valves vill close on reverse flov even though the test, switches may be positioned for open.
The valves vill open vhen pump pressure exceeds reactor pressure even though the test switch may be for close.
A-c motor operated valves required for isolation functions shall be powered. from the a-c stand-by pover buses.
D-c operated isolation valves will be powered from the station batteries.
6.
All motor operated isolation valves vill remain in the last position upon failure of valve power.
Allair operated valves will close on motive air failure.
7.
The standard.
minimum closing rate for automatic isolation valves vill be based on a nominal line size of 12 in.
Using the standard.
closing rate, 12 in. line will be isolated, in 60 seconds.
Con-version to closing time can be made on this basis using the actual size of the line in which the valve is installecl.
9.
Valve can be opened or closed. by remote manual switch for operating convenience during any mode of reactor operation except when automatic signal is present.
10.
Normal status position of valve (open or closed) is the position during normal power operation of the reactor (see "Normal Status" column).
11.
The specified closure rates are as required for containment isolation'nly.
12.
Minimum closing rate is based.
on valve and line size.
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