ML20115F531

Requests Temporary Regional Waiver of Compliance from TS 3.2.2,Action Statements a & B to Allow Operation at Full Power Until Scheduled Refueling Outage (Presently Scheduled for 920926),as Result of Stated Event on 920916

ML20115F531
Person / Time
Site:	Farley
Issue date:	09/18/1992
From:	Woodard J SOUTHERN NUCLEAR OPERATING CO.
To:	Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 9210230122
Download: ML20115F531 (5)

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$eptember 18, 1992 the 80we'n electre entEn T*.'J'A*/,0 Docket No. 50-348 Mr. 5. D. Ebneter U. S. Nucient Regulatorr Commission Region !! - Suite 2900 101 Marietta Street, NW Atlanta, reeorgia 30323 Joseph M. Farley, Unit 1 geovest for Remnal Waiver of Comolianct Gentlement A flux map perfomed on September 16, 1992, revealed that heat flux hot -

channti factor, F,(Z), had exceeded the limits contained in Technical Specification 3.2.2. by approximately 12%. As a result, power was reduced to BB% per the technical specification action statement.

Simila'rly, the Power Range Neutron Flux - High Trip setpoints were also reduced.

The[ action stater.ent tiso requires that the reactor be shutdown to at 1s4st hot standby within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in order to reduce the Overpower AT TfipSetpoints. The action statement further requirss identification pnd corrntion of the cause of the out of limit condition before thermal power can be increased. As a result & regional waiver of compliance of

Technical specification 3.2.2 action statements *a" and 'b' is requested

' to allow full power operation at Farley Nuclear Plant until the shutdown

' for the next refueling outage (presently scheduled for Se)tember 26 1992). This tcQuest is based on the existing F, limit be< ng i

conservativa. Based on using the NOTRUMP code as explained in the a higher F 111110wed for the Unit ! LOPAR fuel and will be Attachment, allowed fcr Unit I at {he startup from the upcotting refueling outage.

Therefore, there is no safety concern to granting this request.. A response is requested by 4:00 pm CDT on September 18, 1992 in order to prar.lude shutting down Unit i unnecessarily on Septer.ber 19, 1992, at i

5:10 pm.

If there are any Questions, please advise.

Respectfulgsubmitted, J.

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. Woodard Attachment cc: Mr. S. T. Hoffman L Mr. G. F. Maxwell Dr. Carola Samuelson .

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ATTACHMENT Temporary Waiver Justification 1

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1. Requirements for which a Walvar 15 Requested Action statement 'a' of Technical Specification 3.2.2 requires a is exceeded. In addition, the thermal power reduction when action statement requires a sim F.ilar reduction of the power range high flux setpoint and the reactor be placed in hot standby within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to allow reduction of the Overpower 41 Trip Setpoint.

Action statement 'b' requires identification and correction of the cause of the out of limit condition before thermal powe, can be increased above the reduced limit specified by 'a." A waiver is requested for action statements 'a' and 'b' requirements to allow operation at full power until the scheduled refueling outage (presently scheduled for September 26,1992).

2. Circumstance Requiring Prompt Action On September 16, 1992, while performing an F,, survalliance on Unit 1 of Joseph M. Farley Nuclear Plant, it was determined that the technical specification limit for the total peaking factor (F.) for 2 rods within assembly H-10 was exceeded at tho single measured point at the top elevation of 12.0 ft. At an elevation of 12.0 f t., an F, of approximately 1.1 was calculated. The current technical specification limit at 12.0 ft. is 1.0. All other axial points in this assembly were within the technicil specification limits. As a result, power was reduced to 8B% per the technical specification action statement. Similarly, the Power Range Neutron Flux - High Trip setpoints were also reduced.

3. Compensatory Actions Based on the discussion provided under the Significant Hazards Consideration (Section 6), no restrictions to operations are required. Power may be return 6d to 100%.

4. Safety significance and Potential Consequences There is r.o increase in probability or consequances of any accident previously evaluated. Since it has been demonstrated.

that scall break LOCA analytical margin exists (Section 6), the 10 CFR 50.46 acceptance criteria continue to be met.

S. Duration of the Regaest A waiver is requested from the requirements of action statements

'a' and 'b" to allow opera +f on at full power until the scheduled refueling outage (presently scheduled for September 26,1992).

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e Significant Hanrds Censideration ~

The F at the 12.0 ft. elevation impacts only the small break LOCA analysis. The followir>g LOCA related analyses are not reactor adversely affected by an increased F, at the 12.0 ft, elevation vessel and loop LOCA blowdown forces, het leg switchover to preclude boron precipitation, rod ejection mass and energy release, post LOCA long term core cooling, and large break LOCA.

These analyses are not affected since the increased F, at the 12.0 ft. elevation does not change the safeguards systems actuations or assumptions used in the analysis of the events and since the increased F, at 12.0 f t, does not create conditions more limiting than those assumed in the analysis of these LOCA events.

The recently approved small break LOCA analysis of record covering the transition from LOPAR fuel to a full core of Vantage 5 fuel was performed for Farley Units 1 and 2 using the NRC approved NOTRUMP Evaluation Model. The analysis modeled Yantage 5 fuel, an of 1.70, and a core power F, of 2.5, an enthalpy rise f actor (FM) d that the limits of 10 level of 2775 MWt and it was demonstrate CFR 50.46 are met. (Farley Unit 2 is currently The licensed and current LOPAR operating with this analysis of record.)

licensing basis analysis for Farley Unit 1, Cycle 11, assumed an F, of 2.32 and an FM of 1.55 at a core power level of 2652 MWt.

The F, of 2.32 and FM of 1.55 have remained the same for all LOPAR analyses, including those covered by the Yantage 5 reload transition safety report. Since the major change in the thermal hydraulic input parameters due to the smaller optimized Yantage 5 fuel rod is a slight increase in core pressure drop, the small break ECCS results with Vantage 5 fuel with the associated higher power level and peaking f actors would bound a full core analysis The of LOPAR fuel at lower power level and core pelkli.. factors.

NOTRUMP Evaluation Model used to calculate the small break LOCA has only one core fhw channel and the core flow rate is relatively low during the small break LOCA event, so enough time is available to maintain flow ecuilibrium between vantage 5 and Therefore, the Vantage 5 core.

LOPAR fuel assemblies in a mixec fuel small break LOCA analysis with increased power level and peaking factors will bound both a mixed core of Yanta s e 5 fuel and LOPAR fuel (Var,tage 5 Reload Transitica Safety Report for Joseph H. f arley Nuclear Plant - Units 1 and 2, May 1991) and also will bound a complete 9 a of LOPAR fuel with lower power level and core peaking facidr) ihich is curiently in Cycle 11 of Farley Unit

1. Therefore, it cu. be concluded that the current Yantage 5 analysis with increased peaking factors and power level is bounding with respect to the LOPAR fuel currentiy in Farley Unit

1. Cycle 11.

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A conservative, top skewed power shape was selected for the small break LOCA analysis for Vantage 5 fuel. For Yantage 5 anelysis, the limitK(Z1o' Lcurve 33 atwhich 12.0 bounds f t. Applying tie small break analysis the hasFan F* it 11m is calcul s ed to be 2.16 at 12.0 ft. During Cycle to the LOPAR F.,!! oper.

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the heat flux hot channel factor, F,(Z), has been calculated to be approximately 1.1 at 12.0 ft, which exceeded the Technical  :

Specification limit. Since the recently approved small break LOCA analysis of record shows significant F margin to this value, an approximate F of 1.1 at 12.0 ft. could not result in the acceptance crlteria of 10 CFR 50.46 being exceeded. Thus ~

operation at full licensed power is justified. Cycle 12 for Unit 1 will be covered by the approved Vantage 5 analysis.

Therefore approval of this waiver will not involve a significant increase in the probability or consequences of an accident

)reviously evaluated. The currently ap > roved NOTRUMP analysis for

/antage 5 is bounding with respect to tie LOPAR fuel currently in Unit 1.

Approval of this waiver will not create the possibility of a new or differ (nt kind of act.ident from any accident previously evaluated. No shysical changes are being made to the plant and the plant will se operated within the bounds of an analysis

• approved for use in the next cycle and currently in use on Unit 2.

Approval of this waiver will not involve a significant reduction in a margin of safety since the plcnt will continue to be operated within the bounds of an analysis approved for use b the next cycle and currently in use on Unit 2.-

7. Environmental Consequences A waiver of Technical Specification 3.2.2 action statements "a" and 'b' requirements will not involvo any significant change in the t/ pes of effluents that may be-released offsite and no significant increase in the individual or cumulative occupational-radiation exposure. Therefore, t'is waiver of compliance does not involve any irreversible environmental consequences.

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