ML20079G569

Proposed Tech Spec Basis 3/4.2 Re WRB-1 Critical Heat Flux Correlation

ML20079G569
Person / Time
Site:	South Texas
Issue date:	10/03/1991
From:	HOUSTON LIGHTING & POWER CO.
To:
Shared Package
ML20079G567	List: ML20079G569 ST-HL-AE-3883, Application for Amends to Licenses NPF-76 & NPF-80,changing Tech Spec Basis 3/4.2 to Reflect WRB-1 Critical Heat Flux Correlation
References
NUDOCS 9110090171
Download: ML20079G569 (1)

Text

_ _ _ - - _ . __ _

' ' 1 MIA5HMEST ST HL AE 32 F.3 I

3/4.2 p0WER DISTRIBU110tj LlHITS _

=- @ --

e5n _ ___._ , _ _ _ _ . _ _ _ . _ ,

lhe specifications of this section provide assurance of fuel integrity  !

during Condition 1 (Norra) Operation) and 11 (Incidents of Moderate frequency) events by: (1) maintaining the minimum DNBR in the core greater than or equal ,

N 77th-W during normal operation and in short-term transients, and (2) limiting I the fission gas release, fuel pellet temperature, and cladding mechanical pro-  !

porties t.o within assumed design criteria. In addition, limiting the peak linear power density during Condition I events provides assurance that the Initial conditions assumed for the LOCA analyses are met and the ECCS accept- .

ance criteria limit of 2200*F is not exceeded. '

The definitions of certain hot channel and peaking factors as used in these specifications are as follows:

f q(2) Heat flux Hot Channel factor, is defined as the maximum local heat flux on the surface of a fuel rod at core elevation Z divided by the average fuel rod heat flux, allowing for manufacturing tolerances on fuel pellets and rods; Fh -

kuclear Enthalpy Rise Hot Channel Factor, is defined as the ratio of the integral of linear power along the rod with the highest integrated power to the average rod power; and f (2) Radial peaking factor, is defined as the ratio of peak power density to average power density in the horizontal plane at core elevation 2.

3M.2.1 AX1AL FLUX DIFFERENCE The linits on AXIAL FLUX Dif f EREt'CE (AfD) assure that the qf (Z) upper bound envelope of 2.50 times the normalized axial peaking factor is not exceeded during either normal operation or in the event of xenon redistribution following power changes.

Target flux difference is determined at equilibrium xenon conditions. The full-length rods may be positioned within the core in accordance with their respective insertion limits and should be inserted near their norm;l position for steady-state operation at high power levels. The value of the target flux dif ference obtained under these conditions divided by the fraction of RATED THERMAL POWER is the target flux difference at RATED THERMAL POWER for the associated core burnup conditions. Target flux differences for other THERMAL POWER levels are obtained by multiplying the RATED THERMAL POWER value by the appropriate fractional THERMAL POWER level. The periodic updating of the target flux difference value is necessary to reflect core burnup considerations.

9110090171 911003 PDR ADOCK 050004oG P PDR SOUTH TEXA5 - UNlls 1 & 2 B 3/4 2-1

-. - - . . - - - . .. - - _ . - ,- .