ML20071D140

Replacement Pages to 821122 Application to Amend License DPR-40,changing Tech Spec Limit on Total Planar Radial Peak Factor

ML20071D140
Person / Time
Site:	Fort Calhoun
Issue date:	02/28/1983
From:	OMAHA PUBLIC POWER DISTRICT
To:
Shared Package
ML20071D130	List: ML20071D128 ML20071D140
References
NUDOCS 8303090209
Download: ML20071D140 (4)

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1.0 SAFETY LIMITS AND LIMITING SAFETY SYSTEM SETTINGS 1.1 Eafety Limits - Reactor Core would cause DNB at a particular core location to the actual heat flux at that location, is indicative of the margin to DNB. The minimum value of the DNBR during steady state oper-ation, normal operational transients, and anticipated tran-sients is limited to 1.19. A DNBR of 1.19 corresponds to a .

,h 95% probability at a 95% confidence level that DNB will not occur, which is considered an appropriate margin to DNB for all operating conditions. (1)

The curves of Figure 1-1 represent the loci of points of re-actor thermal power (either neutron flux instruments of AT in-struments), reactor coolant system pressure, and cold leg temper-ature for which the DNBR is 1.19. The arfa of safe operation l 1

is below these lines.

The reactor core safety limits are based on radial peaks limited by the CEA insertion limits in Section 2-10 and axial shapes within the axial power distribution trip limits in Figure 1-2 3, and a total unrodded planar radial peak of 1.67. The LSSS in 'I Figure 1-3 is based on the 9ssumption that the unrodded inte-grated total radial peak (F )R is 1.62. This peaking factor is l slightly nigher (more conservative) than the maximum predicted unrodded total radial peak during core life, excluding measure-ment uncertainty.

Flow maldistribution effects for operation under less than full reactor coolant flow have been evaluated via model tests.(2) l The flow model data established the maldistribution factors I

and hot channel inlet temperature for the thermal analyses that were used to establish the safe operating envelopes pre-sented in Figure 1-1. The reactor protective system is designed to prevent any anticipated conbination of transient conditions for reactor coolant system temperature, pressure and thermal power level that would result in a DNBR of less than 1.19.(3) l References

(1) USAR, Section 3.6.7 (2) USAR, Section 1.4.6 (3) USAR, Section 3.6.2 Amendment No. 8, 32, 43, 47 1-2 8303090209 830228 p DR ADOCK 05000285 ATT/rHMENT A PDR

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2.0 LIMITING CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.4 Power Distribution Limits (Continued)

(ii) Be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

(2) Total Integrated Radial Peaking Factor

=Fp (1 T ) shall ThecalculatedvalueofFfdefinedbyFtsdeterminedYromapo be limited to $1.62. F R l tion map with no part length CEA's inserted and with all full length CEA's at or above the Long Term Steady Stato Insertion Limit for the existing Reactor Coolant Pump conbination. The azimuthal tilt, T , is the measured value of T at the time F is determined.'l R

9 With FTR >1.62 within 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />s:

l (a) Reduce power to bring power and Ff within the limits of Figure 2-9, withdraw the full Tength CEA's to or beyond the Long Term Steady State Insertion Limits of Specification 2.10.2(7), and fully withdraw the PLCEA's, or (b) Be in at least hot standby.

(3) Total Planar Radial Peaking Factor The endulated value of F T defined as F T=F be limited to < l.67. F *Is determined fEEm a pEEer(1+T di0tribu-) shall /l tion map with iio part IEEgth CEA's inserted and with all full length CEA's at or above the Long Term Steady State Insertion Limit for the existing Reactor Coolant Pump conbination. The azimuthat tilt, T , is the measured value of T at the time F is determined? 9 il With FxyT > 1.67 within 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />s: 'I (a) Reduce power to bring power and F T within the limits of Figure 2-9, withdraw the full length CEA's to or beyond the Long Term Steady State Insertion Limits of Specification 2.10.2(7), and fully withdraw the PLCEA's, or

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(b) Be in at least hot standby.

Amendment No. 33, #3, 47 2-57a

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0 i i i ii 1.64 1.68 1.72 1.76 1.80 1.84 F,1 A N D F ,'

F ,F ' and Core Power OmahaPublicPowerDistrict figure flaitations fortCalhounStation-UnitNo.f 2-9

JUSTIFICATION The early shutdown of the Cycle 7 core resulted in an end-of-cycle burnup_of 9725 MWD /T rather than the design value of 10,500 MUD /T. The early shutdown necessitated a verification of the Cycle 8 safety analysis to assure its validity for this lower Cycle 7 burnup. The lower Cycle 7 exposure.resulted in an in-crease in the predicted values of the bank 4 inserted values of PR and F xy. To account for these increases, it was necessary to in-crease the values of the bank 4 inserted radial peaking factors used in the Cycle 8 safety analysis. The bank 4 inserted value of FR used in the safety analysis is increased from 1.61 to 1.65 and the bank 4 inserted value of Fxy used in the safety-analysis is increased from 1.69 to 1.74.

All safety analyses and Technical Specifications were shown to be valid for these higher peaking f actors with the exception of the Technical Specification on the Total Planar Radial Peaking Factor (FxyT) and the Fx yT versus Core Power Limitations of Figure 2-9. To assure the valialty of the Cycle 8 safety analysis, it is necessary to reduce the F xy T limitation to 1.67 and revise Figure 2-9 for this lower limit No operating problems are anticipated with lowering the allowable F xy T value since the predicted value of F xy is less than the proposed limit.

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