ML20070E341

Proposed Tech Specs Re Improved Protection to Safety Related Electrical Equipment from Loss of Capability

ML20070E341
Person / Time
Site:	Oyster Creek
Issue date:	07/08/1994
From:	GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20070E340	List: ML20070E338 ML20070E341
References
NUDOCS 9407150017
Download: ML20070E341 (1)

Text

- i FUNCTION LIMITING SAFETY SYSTEM SETTINGS K. Reac. tor Low-Low Water Level, 27'2" above the top of the active fuel Core Spray Initiation L. Reactor Low-Low Water Level, 17'2" above the top of the active fuel isolation Condenser Initiation with time delay 53 seconds ,

M. Turbine Trip, Scram 10 percent turbine stop valve (s) closure [

from full open l N. Generator Load Rejection, Initiate upon loss of oil pressure Scram from turbine acceleration relay O. Recirculation Flow, Scram 571.4 Mlb/hr (117% of rated flow) ,

P. Loss of Power

1) 4.16 KV Emergency Bus 0 volts with 3 seconds 1 Undervoltage (Loss of 0.5 seconds time delay Voltage)

2) 4.16 KV Emergency Bus 3840 (+20V, -40V) volts l Undervoltage (Degraded 10 1 10% (1.0) second time -

Voltage) delay i

BAiei" Safety limits have been established in Specifications 2.1 and.2.2 to protect the integrity of the fuel cladding and reactor coolant system barriers, respectively. Automatic protective devices have been provided in the plant design for corrective actions to prevent the safety limits from being exceeded in normal operation or operational transients caused by reasonably expected ,

single operator error or equipment malfunction. This Specification establishes the trip settings for these automatic protection devices. ,

1 The Average Power Range Monitor, APRM(U trip setting has been established to ,

assure never reaching the fuel cladding integrity safety limit. The APRM system I responds to changes in neutron flux. However, near the rated thermal power, the APRM is calibrated ucing a plant heat balance, so that the neutron flux that is j sensed is read out as percent of the rated thermcl power. For slow maneuvers, i such as those vhere core thermal power, surface heat flux, and the power i transferred to the water follow the neutron flux, the APRM will. read reactor thermal power. For fast transients, the neutron flux will lead the power transferred irom the cladding to the water due to the effect of the fuel time tonstant. Therefore, when the neuron flux increases to the scram setting, the i percent increase in heat flux and power transferred to the water will be less j than the percent increase in neutron flux.

TheAPRMtripsettingwillbevariedautomatica}lywithrecirculationflow,with the trip setting at the rated flow of 61.0 x 10 lb/hr of greater being 115.7%

of rated n- .ron flux. Based on a complete evaluation of the reactor dynamic performance during normal operation as well as expected maneuvers and the various mechanical failures, it was concluded that sufficient protection 4

nYSTFR CREEK- 2.3-3 Amendment No. 71, 75, 80 9407150017 940709 PDR ADOCK 05000219 P PDR

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