ML19322B996

Proposed Revision to Tech Spec 2.3 Re Cycle 5

ML19322B996
Person / Time
Site:	Oconee
Issue date:	08/21/1978
From:	DUKE POWER CO.
To:
Shared Package
ML19322B995	List: ML19322B994 ML19322B996
References
NUDOCS 7912200711
Download: ML19322B996 (4)

Text

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Attachment 2 Pr'opeted Technical Specification Revision Pages l

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,7 912 20 0 7ll

4 2.3 LIMITING SAFETY SYSTEM SE" TINGS, PROTECTIVE INSTRUMENTATION Applicebility Applies to instruments monitoring reactor power, reactor power imbalance, reactor coolant system pressure, reactor coolant outlet temperature, flow, number of pumps in operation, and high reactor building pressure.

Objective -

To provide automatic protective action to prevent any combination of process variables from exceeding a safety limit.

Specification The reactor protective system trip setting limits and the permissible bypasses for the instrument channels shall be as stated in Table 2.3.1A-Unit I and 2.3-1B-Unit 2 2.3-LC-Unit 3 Fisure 2.3-2A-Unit 1 2.3-2B-Unit 2 2.3-2C-Unit 3 The pump monitors shall produce a reactor trip for the following conditions:

d

a. Loss of two pumps and reactor power level is greater than 55% of rated I power.

b. Loss of two pumps in one reactor coolant loop and reactor power level is I greater than 0.0% of rated power.

c. Loss of one or two pumps during two-pump operation. I Bases The reactor protective system consists of four instrument channels to monitor each of several selected plant conditions which will cause a reactor trip if any one of these conditions deviates from a pre-selected operating range to the degree that a safety limit may be reached.

The trip setting limits for protective system instrumentation are listed in Table 2.3-1A-Unit 1. The safety analysis has been based upon these protective 2.3-1B-Unit 2 2.3-LC-Unit 3 system instrumentation trip setpoints plus calibration and instrumentation errors.

Nuclear Overpower A reactor trip at high power level (neutron flux) is provided to prevent damage to the fuel cladding from reactivity excursions too rapid to be detected by pressure and temperature measurements.

2.3-1

leveltrihandas)ociatedreactorpouar/reactorpower-imbalanceboundaries

~

by 1.055% for 1% flow reduction.

Pump Monitors The pump monitors prevent the minimum core DNBR from decreasing below 1.3 by tripping the reactor due to the loss of reactor coolant pump (s). The circuitry monitoring pump operational status provides redundant trip pro-tection for DNB by tripping the reactor on a signal diverse from that of the power-to-flow ratio. The pump monitors also restrict the power level for the number of pumps in operation.

Reactor Coolant System Pressure During a startup accident from low power or a slow rod withdrawal from high power, the system high pressure setpoint is reached before the nuclear over-power trip setpoint. The trip setting limit shown in Figure 2.3-1A - Unit 1 2.3-1B - Unit 2 2.3-lc - Unit 3 for high reactor coolant syste'm pressure (2355 psig) has been established to maintain the system pressure below the safety limit (2750 psig) for any design transient. (1)

The low pressure (1800) psig and variable low pressure (11.14 T -4706 trip (1800) psig (11.14 T g -4706) o (1800) psig (11.14 T out -4706) setpoints shown in Figure 2.3-1A have been established to maintain the DNB 2.3-1B 2.3-1C 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 (11.14 Tg g -4746)

(11.14 T -4746)

(11.14 Tout -4746) .

1 Coolant Outlet Temperature l l

The high reactor coolant outlet temperature trip setting limit (619 F) shown in Figure 2.3-1A has been established to prevent excessive core coolant

'2.3-1B 2.3-1C temperatures in the operating range. Due to calibration and instrumentation errors, the safety analysis used a trip setpoint of 620 F.

l 2.3-3 i 4

\

(N)  %.

Table 2.)-IA Unit 1

.*j Reac tor l*s ot ect ive Sjnta an Ts ige Set t la11 5mit s inie s Reactor Four iteartair Tierce Reactor Coolant Pimsp Coolaest Pumps Cosalant Pumps Opesating las opes at Ing operattug Isach loop (Opesatlong Power (Operatlug Power (Operating Power Sleutdown 8U E'E**"I IER. Ratyd) -752 RateJJ -49Z Rated) A pass I. Nuclear Power Ham. 105.5 105.5 105.5 5.0 (1 Rated)

2. N.eclear Power Ham. Saeed I.055 times flow I.055 timca flow I.055 times flow Bypassed sus Flow 12) ase.1 laint elasere, siilaues s ediac t f un m a ines r e elisc t iosi aniseesas reduct ions (1 k.ateJ) due to lab 4tance due to iml.alance due to Imbalance

1. Meec t ems Powes H.e x . B.smed NA NA 551 Bypassed l osa Pump Muse ! E oa m. (Z , R.a t e.1)

4. liigle Reactor Coolant System Psessure, psig Haa.

2155 2155 2355 1720 I u

5. Low Reactor Coolant 8800 1800

• 1800 Itypasi6ed

,. System Pressure, pulg. Hin, e.

6. V.or table IAPw Nc. actor - 4706)

Coolant Systese Piemeure (ll.147*** (ll.14T"" - 4706)( (ll.14T

- 4706) Rypassed psig. Min.

7. Neactor Coolaast Temp. F., H.nz. 619 f> a 9 619 619 S. IIInis Reactor hullding 4 4 4 4 Pressuse, psig. Ham.

( ! ) T,,,,, is in degrecas Falis eniecit ("F).

(2) Neacteer Coolant Fys t em l'Iow, %.

- (11) Adelailst rat lwely const rolle.1 reiluct ion act only during reas:t or 6Instdown.

(4) Autumatically met wleen ollaer negments sof the RPS .ase bypauseet.

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