ML20212A451
| ML20212A451 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/18/1986 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20211Q942 | List: |
| References | |
| NUDOCS 8607280202 | |
| Download: ML20212A451 (5) | |
Text
T PROPOSED CHANGES TO ANO-1 TECHNICAL SPECIFICATIONS 8607280202 860718 PDR ADOCK 05000313 PDR p
4 2.2 SAFETY LIMITS - REACTOR SYSTEM PRESSURE Applicability i
Applies to the limit on reactor coolant system pressure.
Objective To maintain the integrity of the reactor coolant system and to prevent the l
release of significant amounts of fission product activity.
Specification 2.2.1 The reactor coolant system pressure shall not exceed 2750 psig when there are fuel assemblies in the reactor vessel.
2.2.2 The setpoint of the pressurizer code safety valves shall be in accordance with ASME, Boiler and Pressurizer Vessel Code, Section l
III, Article 9, Summer 1968.
{
Bases The reactor coolant system (1) serves as a barrier to prevent radionuclides in the reactor coolant from reaching the atmosphere.
In the event of a fuel cladding failure, the reactor coolant ssstem is a barrier against the release of fission products.
Establishing a system pressure limit helps to 1
assure the integrity of the reactor coolant system.
The maximum transient pressure allowable in the reactor coolant system pressure vessel under the ASME code,Section III, is 110 percent of design pressure.(2) The maximum transient pressure allowable in the reactor coolant system piping, valves, and fittings under ANSI Section 831.7 is 110 percent of design pressure.
Thus,thesafetylimitof2750ggjg(110percentofthe2500psigdesign pressure) has been established.
The settings for the reactor high pressure trip (2355 psig) and the pressurizer code safety valves (2500 psig 11%) (3) have been established to assure that the reactor coolant system pressure safety limit is not exceeded.
The initial hydrostatic test is conducted at 3125 psig (125 percent of design pressure) to verify the l
integrity of the reactor coolant system. Additional assurance that the j
reactor coolant system pressure does not exceed the safety limit is provided by setting the pressurizer electromatic relief valve at 2450 psig.(4) l REFERENCES i
(1)
FSAR, Section 4 (2)
FSAR, Section 4.3.10.1 (3)
FSAR, Section 4.2.4 (4)
FSAR, Table 4-1 1
Amendment No. 49 10 l
t
1 -
n 6
pump (s).
The pump monitors also restrict the power level for the number of. pumps in operation.
C.
RCS Pressure
,r During a startup accident from low power or a slow rod withdrawal frora high power, the system high pressure trip is reached before the' nuclear overpower trip setpoint.
The trip setting limit shown in Figu're 2.3-1 for high reactor coolant system pressure (2355 psig) has been established to maintain the system pressure below the safety limit (2750 psig) for any design transient.(2)
The low pressure (1800 psig) and variable low pressure (11.75T
-5103)-trip setpoint shown is Figure 2.3-1 have been establish 88t
'to maintain the DNB ratio greater than or equal to 1.3 for those design' accidents that result in a pressure reduction.(2,3)
Due to the calibration and instrumentation errors, the safety
/ analysis used a variable low reactor coolant system pressure trip
' value of (11.75t
-5143).
out D.
Coolant outlet temperature The high reactor coolant outlet temperature trip setting limit (618F) shown in Figure 2.3-1 has been established to prevent ex::essive core coolant temperatures in the operating range.
Due to calibration and instrumentation errors, the safety analysis used a trip setpoint of 620F.
E.
Reactor Building Pressure The high rhetor building pressure trip setting limit (4 psig) provides positive assurance that a reactor trip will occur in the unlikely event of a steam line failure in the reactor building or a loss-of-coolant accident, even in the absence of a low reactor
~
coolar,t system pressure trip.
F.
Shutdown Bypass In order to provide for control rod drive tests, zero power physics testing, and startup procedures, there is provision for r
bypassing certain segments of the reactor protection system.
The reactor protection system segments which can be bypassed are shown in Table 2.3-1.
Two conditions are imposed when the bypass is used:
1.y A nuclear overpower trip setpoint of 55.0 percent of rated power is automatically imposed during reactor shutdown.
2.
A high reactor coolant system pressure trip setpoint of 1720 psig is automatically imposed, i
i Amendment No. 2,21,M,67 13
,'J' 2500 P:2355 PSIG T =618 *F 2355 2300 ACCEPTABLE Q
OPERATION E
/
D f
2100 Ec.
P:(11.75 T
-5103) PSIG out 8
/
o 1900 C
UNACCEPTABLE O
OPERATION W
N P=1800 PSIG 1700 4
s 1500 560 580 600 620 640 660 REACTOR OUTLET TEMPERATURE, oF PROTECTIVE SYSTEM MAXIMUM ALLOWABLE SETPOINT FIGURE 2.3-1 Amendment No. 77,M,67 14a
_.m Table 2.3-1 Reactor Protection System Trip Satting Limits 1
i One Reactor Coolant Pump Four Reactor Coolant Pumps Three Reactor _ Coolant Pumps Operating in Each Loop Operating (Nominal Operating (Nominal-(Nominal Operating Stiutdown i Operating Power - 100%)
Operating Power - 75%)
Power - 49%)
Bypass Nuclear power, % of 104.9 104.9 104.9 5.0(*)
rated,; max
-s Nuc1 gar Power based on 1.054 times flow minus 1.054 times flow minus 1.054 times flow minus Bypassed flow and imbalance, reduction due to reduction due to reduction due to
% of rated, max imbalance (s) imbalance (s) imbalance (s)
Nuclear Power based on NA NA 55 Bypassed pump monitops, % of rated, max a
High RC system 2355 2355 2355 1720 pressure, psig, max Low RC system 1800 1800 1800 Bypassed pressure, psig, min d
d d
Variable low RC 11.75 T
-5103 11.75 T
-5103 11.75 T
-5103 Bypassed out out out system pressure, psig, min l
RC temp, F, max 618 618 618 618 High reactor building 4(18.7 psia) 4(18.7 psia) 4(18.7 psia) 4(18.7 i
pressure, psig, max psia).
aAutomatically set when other segments of the RPS (as specified) are bypassed.
bReactor coolant system flow.
i c
The pump monitors also produce a trip on (a) loss of two RC pumps in one RC. loop, and (b) loss of one or two RC pumps-
'during two pump operation.
l dT is given in degrees Fahrenheit (F).
out r
l Amendment No. 2,21,43,49,52,67,92 15
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