ML17192A675

Emergency Procedure DGA-6, Revision 4, Reactor High Pressure.

ML17192A675
Person / Time
Site:	Dresden
Issue date:	09/30/1979
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML17192A611	List: ML17192A610 ML17192A671 ML17192A672 ML17192A673 ML17192A674 ML17192A675 ML17192A676 ML17192A677 ML17192A678 ML17192A679 ML17192A680 ML17192A681 ML17192A682 ML19323A953
References
DGA-6, NUDOCS 8005080503
Download: ML17192A675 (5)

Text

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DGA 6 Revision 4 REACTOR HIGH PRESSURE Sep~ember 1979 A. SYMPTOMS

1. Reactor high pressure indication.

2. Alarms.

a. RX VESSEL HIGH PRESSURE, 902-5 (903-5) *

. b. CHANNEL A/B REACTOR HIGH PRESSURE, 902-5 (903-5).

c. TARGET ROCK VALVE OPEN, 902-3 (903-3).

d. ELECT RELIEF VALVES OPEN 902-3 (903-3).

e. MSIV NOT FULL OPEN.

f. GROUP I ISOL*VALVE CH TRIP.

B. AUTOMATIC ACTIONS

1. Electromatic relief valves open.

2. Reactor scram.

3. Isolation Condenser initiates after 15 seconds above 1070 psig.

4. Group I isolation.

C. Il1MEDIATE OPERATOR ACTIONS

1. Verify that the reactor has scrammed. (Pressure greater than 1060 psig.)

2. Carry out scram action in accordance with DGP 2-3.

3. Manually initiate the isolation condenser to control pressure, if needed. Throttle .the condensate valve to limit cooldown rate and vessel differential temperatures.

4. Electromatic relief valves may be used to control pressure, however there must be means to make up water to the reactor.

Alternate relief valves to minimize suppression pool localized heating. See Figure 2 (Unit 2) or Figure 3 (Unit 3) for valve blowdown line locations.

APPROv:_D NG"V O6'79 1

o.o.s.R.

_, __ -* --------*~--- .,.....__... *.---

DGA 6 5.

• • Revision 4 "* * *'.*~ *..*

If HPCI and the isolation condenser fail to operate and the first electromatic relief valve opens, start LPCI and core spray, .. take manual control of all five relief valves and open all of them. This is to allow pressure to drop to 350 psig so LPCI and core spray will start adding water.

D. SUBSEQUENT OPERATOR ACTIONS

1. Continually monitor torus temperature and also record it every five minutes until the heat addition to the torus is terminated.

Record data on Figure I and file in operating surveillance.*

files.

2.

• Depressurize the reactor to less than 150 psig at normal cooldown rates if the torus water temperature reaches 120°F.

3. If relief valves were actuated and th~ torus water temperature reached 160°F or greater with the reactor pressure greater than 150 psig, an extern~! visual exam of the torus must be conducted before resuming power operation.

E. DISCUSSION

1. This procedure assumes an isolation of reactor pressure vessel.

Reactor pressure is increasing and the main condenser is not available as a heat sink.

2. The manual blowdown Will commence with approximately -70 inches in the vessel *. When 350 psig is reached, level in the vessel will be approximately -105 inches. Carefully monitor all level indication to verify that the water level in the vessel stays above the active fuel.

~NOVO 6 '79 0.0.S.R.

2

• .a.

9 FIGURE 1

, :.*e .*' DGA 6 Re.vis ion 4 * * ....

'i.1 Torus Temperature and Time Temperature was taken Time Temperature Time*

• Temp. Time Temp. Time Temp. _

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, .... APPROVcJ 3 NOVO 6'79 0.0.S.R.

• **- FIGURE 2 DGA 6.

Revision 4 NORTH 2-203-3C 2-203-3E 2-203-3B LOCATIONS OF UNIT 2 AP PROV ti)

Target Rock and Electromatic NOVO 679 Blowdown Lines into Torus D.0. S.R.

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4.

'.:: FIGURE 3-.*

• --., . DGA 6 :-* ,

Rev i s Ton 4 * .

- -~ORTH 3-203-3A

.3-203-3E

/

i .

.3-203-3C 3-203-3B

. ~

LOCATIONS OF UNIT 3 APPROVEID Target Rock ~nd Electromatic NOVO 6 '79 Blowdown Lines into Torus

,,, 5 ( f i na J) 0.0.S.R.

• ~ .... J' ' '