ML19329E143

Chapter 10 of AR Nuclear 1 PSAR, Steam & Power Conversion Sys. Includes Revisions 1-18

ML19329E143
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/24/1967
From:	ARKANSAS POWER & LIGHT CO.
To:
References
NUDOCS 8005300724
Download: ML19329E143 (9)

Text

,..

J l

l l

. .p i

• s...

O N ff

.es

== y s o o3 3, o 7 7

~ I in I

' :.! ]

.;,- ./

L

TABLE OF CONTENTS SECTION TITLE PAGE 10 STEAM AND POWER CONVERSION SYSTEM 10-1 10.1 DESIGN BASES 10-1 10.1.1 OPERATING AND PERFORMANCE REQUIREME.YfS 10-1 10.1.2 FUNCTICNAL LIMITATIONS 10-1 10.1 3 SECONDARY FUNCTIONS 10-1 10.2 SYSTEM DESIGN AND OPERATION 10-1 10.2.1 SCHEMATIC FLCW DIAGRAM 10-1

,10.2.2 CODES AND STANDARDS 10-2 10.2 3 DESIGN FEATURES 10-2 10.2.4 SHIELDING 10-2 10.2 5 CORROSION PROTECTION 10-2 10.2.6 IMPURITIES CONTROL 10-3 10.2 7 RADIOACTIVITY 10-3 10 3 SYSTEM ANALYSIS 10-3 10 3 1 TRIPS, AUTOMATIC CONTROL ACTIONS AND ALARMS 10-3 10 3 2 TRANSIENT CONDITIONS 10 4 10 3 3 MALFUNCTIONS 10 4 1034 OVERPRESSURE PROTECTION 10 4 1

1035 IDTERACTIONS 10 4 1036 OPERATIONAL LIMITS 10-5 0242 10.4 TESTS AND INSPECTIONS s

10-5 W 10-1

LIST OF FIGUDES (At Rear of Section)

Figure No. Title 10-1 Schematic Flow Diagram 0243

p__

10 S" AM AND WNED CON 7m RON SYSE M 10.1 DESIG?T BASES 10.1.1 OPERATING AND FERFORMANCE REQUIREMCITS The steam and power conversion system vill be designed to remove heat energy from the reactor coolant in the two steam generators and convert it to elect-rical energy. The closed feedvater cycle vill condense the steam, and the heated feedvater vill be returned to the steam generators. The entire system vill be designed for the maximum expected energy from the nuclear steam supply system.

Upon loss of full load, the syste= v111 dissipate all the energy existent or produced in the reactor coolant system through steam relief to the condenser and the atmosphere. The unit will be designed to maintain station auxiliary load without a reactor trip on loss of full load. The steem bypass to the condenser and atmospheric relief valves vill be utilized as necessary to achieve this load reduction.

10.1.2 FUNCTIONAL LDiITATIONS The rate of change of reactor power vill be limited to values consistent with the characteristics of the reactor coolant system and its control systems.

Further limitations in the steam power conversion system may reduce the reactor coolant system functional limits as given in Section 7.2.1.1.

10.1 3 SECONDARY FUNCTIONS The steam and power conversion system vill provide steam for driving the two steam generator feedvater pu=ps. Steam vill also be used for the condenser air removal equipment and the 5 per cent emergency feedvater pump when required.

10.2 SYSTEM DESIGil AND OPERATION 10.2.1 SCHEMATIC FLOW DIAGRAM The steam and power conversion system is shown in Figure 10-1. The closed cycle feedvater heaters vill be half-size units (two parallel strings).

Deaeration vill be accomplished in the condenser hotwell. A bypass of 15 per cent of full-load min steam flow to the condenser vill be provided.

Two of the three one-half capacity condensate pu=ps vill be in normal use.

Each ,f two feedvater pu=ps vill be at least one-half capacity.

,0244 C . .

10-1

i There vill be a total of six (6) minutes condensate storage at full load in the condenser hotwells. . ,f There vill also be a 5 per cent capacity, turbine-driven, emergency feedvater pump which takes its suction directly from the hotvell discharge and pumps to the steam generators. Steam for the turbine drive vill come from the main steam line and exhaust to atmosphere.

The main steam lines and the feedvater lines vill be tlie only lines of the steam and power conversion system which penetrate the Reactor Building. These lines can be isolated by the main stop valves and the feedvater line valving.

Each of the lines leaving the main steam line before the main stop valves has valves to complete the isolation of a steam generator. These lines are:

-(a) Steam bypass.

(b) Supply to feed pu=p turbines.

(c) Supply to steam reheaters.

(d) Supply to condenser air ejectors.

(e) Supply to emergency feed pump turbine.

10.2.2 CODES AND STANDARDS The turbine-generator equipment vill conform to the applicable ASA, ASME and IEEE standards.

The design, materials and details of construction of the feedvater heaters vill be in accordance with both the ASME Code,Section VIII, Unfired Pressure Ves-sels and the Standards of Feedvater Heater Manufacturers Association, Inc.

10.2 3 DESIGN F MPS The condenser air ejector off-gas vill be continuously monitored with an alarm to indicate high radiation levels. The air ejector off-gas vill be released through the station vent.

10.2.4 SHIELDING No radiation shielding vill be required for the co=ponents of the steam and power conversion system. Continuous access to the components of this system vill be possible during normal conditions.

10.2 5 CORROSION PROTECTION Hydrazine vill be added to the feedvater for oxygen control, and ammonia vill be used to maintain the pH at the optimm value for the materials of con-struction for the system. No other additives are conte = plated.

10-2 OM5 ,

/

l 10.2.6 IMPURITIES CONTROL Impurities in the steam and power conversion system will be contr:11ed to maintain specified steam generator water purity. The condensate will be treated by a separate, at least cne half size, demineralizer.

10.2.7 RADIOACTIVITY Under normal operating conditions, there will be no radioactive contaminants present in the steam and power conversion system. It is possible for this system to become contaminated only through steam generator tube leaks. In this event, monitoring of the steam generator shell side sample points and the air ejector off-gas win detect any contamination.

10.3 SYSTEM ANALYSIS 10.3 1 TRIPS, AUIOMATIC CONTROL ACTIONS AND AIARMS Trips, automatic control actions and alams will be initiated by deviations of system variables within the steam and power conversion system. In the case of automatic corrective action in the steam and power conversion system, approp-riate corrective action will be taken to protect the reactor coolant system.

The more significant malfunctions or faults which cause trips, automatic actions or alarms in the steam and power conversion system are:

(a) Turbine Trips

1. Generator /electricalfaults.

2. Loss of condenser vacuum.

3. Thrust bearing wear.

4. Mas of generator coolant capability.

5. Ioss of both feedwater pumps.

6. Turbine overspeed.

7. Reactor trip.

(b) Automatic Control Actions ,

1. Feedwater flow lagging feedwater demand results in a reduction in power demand.

2. Low feedwater temperature results in a reduction in power demand.

3. High level in steam generator results in a reduction in feedwater flow.

4 Iow level in steam generator results in an increase in feedwater

, flow.

ks '

'10-3 6

(c) Principal Alarms

1. Low pressure at feedwater pump suction.

2. Low vacuum in condenser.

3 Low water level in condenser hotwell.

4 High water level in condenser hotwell.

5 High water level in steam generator.

6. Low water level in stea' generator.

7. High pressure in steem generator.

8. Low pressure in steam generator.

9 Low feedwater temperature.

10.3.2 TRANSIENT CONDITIONS The analysis of the effects of loss of full load on the reactor coolant system is discussed in 14.1.2.8. Analysis of the effects of partial loss of load on the reactor coolant system is discussed in 7.2 3.4 10 3 3 MALFUNCTIONS The effects of inadvertent steam relief of steam bypass are covered by the I analysis of the steam line failure given in 14.1.2 9. The effects of an inadvertent rapid throttle valve closure are covered by the loss of full load discussion in 14.1.2.8.

10.3.h OVERPRESSURE PROTECTION Pressure relief is required at the system design pressure of 1050 psig, and the first safety valve bank will be set to relieve at this pressure. The design pressure is based on the operating pressure of 925 psia plus a 10 per cent allowance for transients and a h per cent allowance for blowdown.

Additional safety valve banks will be set at pressures up to 1102.5 psig, as allowed by the ASME Code.

The pressure relief capacity will be such that the energy generated at the reactor high-power level trip setting can be dissipated through this system.

10.3.5 INTERACTIONS Following a turbine trip, the control system will reduce reactor power output immediately. The safety valves will relieve excess steam until the output is reduced to the point at which the steam bypass to the condenser can handle all the steam generated.

10-4 N 2-8-68 Amendment No.1

=

In the event of failure of a single feedvater pu=p, there vill be an automatic runback of the power de=and. The one feedvater pu=p ~~4-ing in service vill carry approx * " tely 60 per cent of full load feedvater flow.

If both feedvster pu=ps fail, the turbine vill be tripped, and the e=er-gency feedvater pu=p started. If reactor coolant system conditions reach trip li=its, the reactor vill trip. ,

On failure of a condensate pu=p, the spare condensate pu=p vill be auto-matically started.

10 3.6 OPERATIONAL LIMITS The air ejector off-gas vill be monitored for radioactivity, and safe operating limits will be established for the station.

10.4 TESTS AND INSPEC IONS As is essential in successful operation of.any =cdern power station, frequent functional operational checks will be made on vital valves, centrol systems and protective equip =ent.

\

~

J I

v (Y'48 h ..

-5 l

- I

e I

\

J

+

a ATWos.

(TT P)

Rv E t4 G R G.

' C 6P PT o , O t i-- @][

JO --ti C

C

. X-D X@

X l'

S T e A M 10 STtAM 10 51t Au St PASS RtMEATER cotLS QL AuD STE AM To CountuSEL C ou1 Rotte R Tv CV CV TV b b N , /

H. P. T L' O. Et u &

TV 1v

- >4 @ @H=

cv cv 46

• A y.. ... .

?

e

,k

e 1 i

'(TTR) 1.

-j [' a, s .

I D

o o ii (HC X-D y n S T t A t4 TO 9tt0 PUMP TU R &tutt

_____.____.q l

i G G I

~

I I - _

I mas cens l

c,s u . c, u .

I  ;

I I

I I

I I l l STEAM AND POWER L_ _ _ __ _ _ _ _ _ _ _ _ _ . _J lae actot Stos CONVERSION SYSTEM e- , Figure 10-1 V

FtE DWAttR FROM Q.fe egits.

i Amendment No.1 O'J 50 ,

I REVISED 2-8-68 l

. . ._ _