ML19326D977

Proposed Revisions to Tech Specs,Pages 2-3,-5,-7,B 2-5 & B 2-6,changing Flux/Flow Ratio

ML19326D977
Person / Time
Site:	Crystal River
Issue date:	07/22/1980
From:	FLORIDA POWER CORP.
To:
Shared Package
ML19326D975	List: ML19326D974 ML19326D977
References
NUDOCS 8007250330
Download: ML19326D977 (5)

Text

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.I I l l I l j - 120 . - - - - - - - --

('34.72,112) (20.16,112)

(-40,107)

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-110 ACCEPTABL,E 4 (39,100)

- 10 0 - ---- I - - -- --.

PUMP OPERATI0fl l

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(-34.72,B4.48) (20.16,84.48)

(-4D 7 E49T' [ l l

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. ._ . ! . ACCEPTABLE 3&4 _ _ 70 1 (39,72.48)

PUMP OPERAT10fi i

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-60 -50 -40 -30 -20 -10 0 *10 +20 +30 +40 +50 +60 l , .! j. ! _... _4.._.....l . . 4  : . .

AXIAL POWER IMBALANCE, %

F IC4"': 2.1-2 REACTOR CORE SAFETY LIMIT CRYSTAL RIVER - UNIT 3 2-3 80072503 M

. e TABLE 2.2-1 REACTOR PROTECTION SYSTEM INSTRUMENTATION TRIP SETPOINTS 9

FUNCTIONAL UNIT TRIP SETPOINT ALLOWABLE VALUES 5' 1. Manual Peactor Trip Not Applicable Not Applicable

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2. Nuclear Overpower $105.5% of RATED THERMAL POWER <105.5% of RATED THERMAL POWER with four pumps operating with four pumps operating E

la <77.98% of RATED THERMAL POWER 177.98% of RATED THERMAL POWER co with three pumps operating with three pumps operating

3. RCS Outlet Temperature-High <619 F <619'F

4. Nuclear Overpower Based on Trip Setpoint not to exceed the Allowable Values not to exceed RCS Flow gnq AXIAL POWER limit line of Figure 2.2-1 the limit line of Figure 2.2-1.

IMBALANCE \l i

5. RCS Pressure-Low (1) >1800 psig 21800 psig

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6. RCS Pressure-High 32300 psig 12300 psig

7. RCS Pressure-Variable Low (1) >(11.80 Tout F -5209.2) psig 1.(11.80 Tout F -5209.2) psig I

4

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,. _.. j . .ii0 i (-20.6,101.4) ,

(12,104.4) i

_ ... .. .... . . 100 . _ _ .

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(-2),95) i AC&EPTABLE 90 (29,h0) 4 (UMP

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l. OPERATION

.1-21,77.68) , 8 0 (12,77. 68).._ _

j . . 70 i

(29,63.58)

(-29,63 '58) 1 i

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OPERATION . . 50

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-50 -40 -30 -20 -10 0 +10 +20 +30 +40 +50 AX1AL POWER IMBALANCE, %

FIGURE 2.2-1 TRIP SETP0 INT FOR NUCLEAR OVERPOWER BASED ON RCS FLOW Ato AXI AL POWER IMBA! ANCE CRYSTAL RIVER - UNIT 3 2-7

O' O

LIMITING SAFETY SYSTEM SETTINGS BASES RCS Outlet Temperature - High The RCS Outlet Temperature High trip <619*F prevents the reactor outlet tem-perature from exceeding the design limits and acts as a backup trip for all power excursion transients.

Nuclear Overpower Based on RCS Flow and AXIAL POWER IMBALANCE The power level trip setpoint produced by the reactu coolant system flow is based on a flux-to-flow ratio which has been established to accommodate flow decreasing transients from high power.

The power level trip setpoint produced by the power-to-flow ratio provides both high power level and low flow protection in the event the reactor power level increases or the reactor coolant flow rate decreases. The power level setpoint produced by the power-to-flow ratio provides overpower DNB protec-tion for all modes of pump operation. For every flow rate there is a maxi-mum permissible power level, and' for every power level there is a minimum permissible low flow rate. Typical power level and low flow rate combina-tions for the pump situations of Table 2.2-1 are as follows:

1. Trip would occur when four reactor coolant pumps are operating if power is >104.4% and reactor flow rate is 100%, or flow rate is

<95.7% and power level is 100%.

2. Trip would occur when three reactor coolant t umps are operating if power is >77.98% and reactor flow rate is .4.7%, or flow rate is

<71.84% and power is 75%.

For safety calculations the maximum calibration and instrumentation errors for the powe'r level were used.

CRYSTAL RIVER - UNIT 3 B 2-5

4 LIMITING SAFETY SYSTEM SETTINGS BASES The AXI AL POWER IMSALANCE boundaries are established in order to prevent reactor thermal limits from being exceeded. These thermal limits are ei-ther power peaking kw/ft limits or DNBR limits. The AXI AL POWER IMBALAfiCE reduces the power level trip produced by the flux-to-flow ratio such that the boundaries of Figure 2.2-1 are produced. The flux-to-flow ratio reduc-es the power level trip and associated reactor power-reactor power-imbalance boundaries by 1.044%for a 1% flow reduction.

RCS Pressure - Low, High and Variable Low The High and low trips are provided to limit the pressure range in which reactor operation is permitted.

During a slow reactivity insertion startup accident from low power or a slow reactivity insertion from high power, the RCS Pressure-High setpoint is reached before the Nuclear Overpower Trip Setpoint. The trip setpoint for RCS Pressure-High, 2300 psig, has been established to naintain the sys-tem pressure below the safety li'mit, 2750 psig, for any design transient.

The RCS Pressure-High trip is backe'j up by the pressurized code safety valves for RCS over pressure protection, and is therefore set lower than the set pressure for these valves, 2500 psig. Tne RCS Pressure-High trip also backs up the Nuclear Overpower trip.

The RCS Pressure-Low, 1800 psig, and RCS 'ssure-Va riable Low, (11.80 Tout F-5209.2) psig, Trip Setpoints have bec established to main-tain the DNB ratio greater than or equal to 1.30 for those design accidents

-that result in a pressure reduction. It also prevents reactor operation at pressures below the valid range of DNB correlation limits, protecting against DNB.

Due to the Calibration and instrumentation errors, the safety analysis used a RCS Pressure-Variable Low Trip 50tpoint of (11.80 Tout F-5249.2) psig.

CRYSTAL RIVER - UNIT 3 B 2-6 i

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