ML20085A529
| ML20085A529 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/14/1982 |
| From: | GENERAL PUBLIC UTILITIES CORP. |
| To: | |
| References | |
| TASK-07, TASK-7, TASK-GB GPU-0495, GPU-495, NUDOCS 8307060555 | |
| Download: ML20085A529 (4) | |
Text
--
e
^s p
gy
- e..,,
y SUPPLEMENTAL INFORMATION FOR FIGURE 15E.6.2 Break in Instrument Line or Lines from Primary System that penetrate Contaf n=ent (FSAR Section 15.6.2).
The information in Section 15.6.2 shows that the initial transient is terminated by closure of the letdown,line isolation valve by ESTAS at an RC pressure of 1500 psig. The RCS is thus stabilized at a depressurized state with decay heat being removed by amr414mry feedwater injection to the steam generator with relief through the safety valves upstream of the main steam isolation valves. The lost RCS inventory is also being restored by the HPI system.
The systems operating sequence diagram is essentially the same as a small LOCA in the short term except no degraded containment conditions would occur.
This condition is considered to be a safe shutdown condition, with the reactor Maintenance temperature and pressure below the normal " hot" shutdown condition.
of this condition requires the operator to regulate only RC inventory. That is, j
the operator must control pressurizer level to prevent the HPI pumps from filling This is accomplished by-the pressurizer and increasing the systen pressure.
i securing the HPI pumps. To do this, the operator would first gain manual control over the HPI system by manually resetting the ESFAS system. The HPI pumps can then be stopped manually once a normal pressurizer level is established.
Either stop-start operation of the HPI pumps or realignment of the HPI system in the normal MU mode with suction from the makaup tank (if offsite power is available) may then be used for further RC inventory control.
The operator will coodown the plant ue414=4ng the steam generators immediately l
or upon return of normal offsite power, if lost. The cooldown sequence is given in the operating sequence. diagram, Figure 15C.9.
t I.'
l' sP u uw +<t S'an m1.
f/d/fdJt. A.RUDM
- ..n,.;rY G*.Tf.N.
~
s gg,51Bg' g
- s i
1..
li f's
~
il i*
i lf 8307060555 820414 PDR ADOCK 00000289
.,j l 7, P
HOL c
T21">G5
^
,n
. +
e
,~h ty3 u,,-
w y
SUPPLEMENTAL INFORMATION TO FIGURE 15E.2.6 s
Loss of Nonemergency AC never to the Station Auxiliaries (FSAR Section 15.2.6)
.e Upon loss of all offsite AC power, and loss of the turbine generator, the emer-Since gency diesels start and the preferred loads are sequenced automatically.
U, no ECCAS occurs, the LOP sequencers automatically accommodates functions for i
reactor coolant MU and decay heat removal without initiating ECCAS related functions. Inverters or station batteries provid power for vital instru-mentation and control, as appropriate.
At the beginning of the stabilization period (approximately 1.0 minutes), the i
situation that exists is:
t
'i, (1) Reactor coolant system (a). Stabilized at approximately 2000 psi and $50 F (equal to steam safety valve set point).
(b) Preasurizer level indicates low.
P, (c) EC pumps stopped with seal injection supplied.
E(
(d) Control rods inserted.
(2)
Steam /feedwater system a
(a) Main feedwater stopped.
1 (b)
Steam relief through the atmospheric dump valves and/or safety valves.
+
i (c)
Steam supply to stesa driven a'-414= 7 feedwater pump open.
(d) Motor and steam driven auxiliary feedwaterpaps supply,a'~414=7
~
feedwater to both steam generators.
W (a) Turbine bypass and turbine stop valves closed.
' 's (f) Steam pressure stabilized at approxima,tely 1050 psia.
N (3) Supporting systems
..C (a) Air system - Assumed inoperative due to no power to compressors.
ci (b) HVAC - In operation for critical components.
f.'i
~
d.
(c)
Cooling water N!
- Service water - Available to component cooling water system and auxiliary feedwater pumps.
,j
- Component cooling water available to:
- o*
.3 l Jf,j
- Makeup pumps 7gg7gg
- Seal return coolers -
a
g_ __ _
l i
r s
j
~ ~ ~
p
- Q) v2.
l/
Supplemental Information to Figure 15E.2.6 (d) Makeup system
- Letdown line closed.
- Seal injection line open.
- Makeup pump recirculation lines closed.
- Makeup pump operative with suction fromanceup tank.
- Normal makeup.line closed.
- EPI valves closed.
m
- Seal return closed.
As a result of this equipment lineup, the operator must perform the following functions:
(1) Maintain Seal Iniection: Upon loss of offsite power, the normally operating makeup pumps would stop; it would, however automatically restart once the emergency diesel generators become operative.
Seal injection to the RC pumps would thus be available since the valves in the seal injection flow path fail to open if air supplies
?
are lost. To maintain seal injection, the operator must open (from
/
the control' room) the E pump recirculation line and insure a continued
(
water supply in the naleap tank. Additional water from the MU tank can be acquired periodically from the BWST, if required.
q
~ ~;
(2) RCS Inventory Control: Because seal injection inleakage through the pump seals (>32 pgm) will gradually increase the pressurizer level, control of RCS inventory must be established. Letdown capability can be restored by manually opening the letdown cooler inlet valves N
and contairment isolation valves from the control room and manually V.l opening the air operated process valves in the letdown line at the 1'
local' stations (handwheel). Letdown flow can then be regulated D
by the manual bypass valve in the letdown line or by remote (open-h closed) operation of letdown isolation valves. Ample time (>l hour) exists to establish letdown prior to filling the pressurizar with I
water.
g-f The operator will also periodically adjust makeup in accordancc. with pressurizer level; makeup flow can be established by opening the L
HPI injection volves from the control room. As noted in #1 above, additional water to accommodate RC system contraction or for boron i.
control can be obtained by opening the MU pump suction valves to the BWST.
'[
Chemical addition via the boric acid pumps can also be provided since these pumps can also be hooked up manually to IE power supplies.
4jJ (3) Control of decay heat removal: The operators'1ong term actions are to monitor the operation of the auxiliary feedwater system to insure j"-
the desired steam generator level is :.aintained. Manual control of the auxiliary feedwater system control val.es from tha* control room is available if the automatic level control system malfunctions.
The reactor coolant is kept subcooled by Ma~intenance of RC Pressure:
y (4)
. pressurizer heaters, which are periodically energized to reheat the
'l pressurizer water inventory. The pressurizer heaters may be placed on the emergency diesel generators in case of a loss of offsite i
The pressurizer heaters and associated controls are not 1
power.
Further discussion regarding.the reliability of the controls J.3 Class 1E.
.- m c
F 2
e t
~3-4--b
/ '..
Supplemental Information to Figure 15E.2.6 and instrumentation related to safe shutdown and the pressurizer heaters is located in Subsections 7.4.1.1.6, 7.4.2.6, and Section 7.6.
normal cooldown, once Depressurization: The operator can per.orm i (5) offsite power has been restored, in accordan.:e with Figure 15.C.9.
.b.
- 1
'F o.'
a
~
5
.u.
..4,
> i.~.
g.
, P.,
l',
l..,'
4 1
4
+
1 :-
i
.I z
l t..:
l :.1l t.
l. Y*
l L*
v.,
r..;
k g'1 i
j : '*
T21"'G8 c,-
3..
_