Text

Proposed Tech Specs Re Reduction of Max Applicable Power Level for Operation W/One or More MSSVs Inoperable
	ML20080H009
Person / Time
Site:	Sequoyah
Issue date:	02/10/1995
From:	; TENNESSEE VALLEY AUTHORITY
To:	;
Shared Package
ML20080H005	List: ML20080H002; ML20080H009;
References
	NUDOCS 9502140346
	Download: ML20080H009 (9)
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ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SON-TS-94-07, SUPPLEMENTAL)

LIST OF AFFECTED PAGES I Unit 1 3/4 7-1 Unit 2 I

3/4 7-1 I i.

9502140346 950210 POR ADOCK 05000327 P. PDR

3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE pFETYVALVES LIll! TING CONDITION FOR OPERATION (stssVd 3.7.1.1 AH g+ein steam linc x 2 safety valves ::::ict s ith och 5tes-

-g:ra ctor shall be OPERABLE wi 'ft settings as specified in Table 3.7-APPLICABILITY: V00E5 1, 2 a M ACTION: ,

a. Wi 4 teactorholant loops hd associate teamgenethrsin ope tici and wi one or more in steam lin code safety alves e,e inope b 4 , operat n in MODES 1, 2 and 3 may p ceed provi , that within hours, eith r the inopera e valve is re tored to OPERABLE Mfe"p g status 0; the Power R ge Neutron F1 High Setpoi trip is re ed per T:. ole 7-1; otherw e, be in at I ast HOT STAND within the next 6 haur and in COLD UTDOWN withi the following 0 hours0 days 0 hours 0 weeks 0 months .

W h 3 reactor colant loops nd associate in g.d

b. team generato op ation and wi one or more main steam lin code safety v ves K

. asso 'ated with an perating lo inop,erabl e , eration in MOD 3 Rll "

may pr eed provide that within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , eithe the inoperable valve is restored to ERABLE stat or the Power nge Neutron F1 High Trip etpoint trip is reduced p Table 3.7-2; therwise,bein\ ,

t least H STANDBY wit 'n the next hours and in C D SHUTDOWN t

" thin the f lowing 30 ho s.

c. The rovisions Specificati 3.0.4 are n t applicable. ,

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SURVEILLANCE RE0VIREMENTS ;

4.7.1.1 No additional Surveillance Requirements other than those required by Specification 4.0.

With +he. r 4ch>r e + rip sp+e m brakes k the dosed '

p:Fo.s, kk l SMUOYAH - UNIT 1 3/4 7-1 Amancments No.114 May 5, 1959 l

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3/4.7 PLANT SYSTEMS I 3/4.7.1 TURBINE CYCLE

. SAFETY VALVES Ll.ilTING CONDITION FOR OPERATION

"' g::in steam linc adc safety valves (M SS %)

3.7.1.1 ;;;icted itF och ; team gener:te shall be OPERABLE with lif t settings as specified in Table 3.7-/

2.

APPLICABILITY: Modes 1, 2 an 3N ACTION:

_ _-w ctor co lant loops and a ociated stea enerators in eration and with e or more main eam line code afety valves g& i erable, operation 'n Modes 1, 2 an 3 may procee rovided, that 5 wit 'n 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , either e inoperable va e is restore o OPERABLE

,sd statu or the Power Range eutron Flux Hig Trip Setpoint 's reduced

\ per Tab next 6 hou 3.7-1; otherwise, e in at least H STANDBY with and in COLD SHUT WN within the fo lowing 30 hou the

b. ith 3 reactor colant loops and sociated steam g erators in op ation and wi one or more main team line code s ety valves

) asso lated with an perating loop inop rable, operation 'n MODE 3 may p eed provide , that within 4 hou either tM ino rable valve i estored to O RABLE status or th Power Rar.p Neu on R I.

Flux High ip Setpoint ' reduced per Table 3.7-2; otnerwise, be in at le HOT STANDB ithin the next 6 h rs and in COLD cHUT00WN with1 the followin 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

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c. The rovisions of ecification 0.4 are not applic le.

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SURVEILLAhqEREQUIREMENTS 4.7.1.1 No additional Surveillance Requirements other than those required by Specification 4.0.5.

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SEQUOYAH - UNIT 2 3/4 7-1 Amendment No. 104 May 5, 1989 l l

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ENCLOSURE 2 t i

PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE -

SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 - l DOCKET NOS. 50-327 AND 50-328 i

(TVA-SON-TS-94-07, SUPPLEMENTAL) !

DESCRIPTION AND JUSTIFICATION FOR .

i LIMITING MODE 3 APPLICABILITY .

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P Descriotion of Chanae TVA proposes to modify the Sequoyah Nuclear Plant (SON) Units 1 and 2 technical specifications (TSs) as originally proposed by TS 94-07. Specifically, ,

TS 94-07 is supplemented by modifying the mode of applicability such that Mode 3 is constrained to require the reactor trip breakers to be closed. The supplementalinformation provided is to add an asterisk to the Mode 3 [

applicability, which is annotated as follows: >

"*With the reactor trip system breakers in the closed position." !

Reason for Chance TS 3.7.1.1 requires the Nuclear Instrumentation System (NIS) high-neutron flux trip setpoint to be lowered if one or more main steam safety valves is determined to be inoperable. This TS is applicable in Modes 1, 2, and 3. >

However, reduction of the NIS trip setpoint with the reactor trip breakers (RTBs) open is an administrative burden, which provides no added safety benefit. ,

Justification for Chanaes [

The intended function for the NIS high-trip setpoint is to open the RTB upon detection of a neutron flux corresponding to certain required analytical limits.

With the RTBs open, the intended function is already complete. In this ;

configuration, adjustment of the NIS trip setpoint provides no added safety benefit. ,

Environmental Impact Evaluation The proposed change does not involve an unreviewed environmental question because operation of SON Units 1 and 2 in accordance with this change would not:

1. Result in a significant increase in any adverse environmental impact previously evaluated in the Final EnvironmentaljStatement (FES) as modified by NRC's testimony to tha Atomic Sakty and Licensing Board, supplements to the FES, environmental impact appraisals, or decisions of -

the Atomic Safety and Licensing Board.

2. Result in a significant change in effluents or power levels.

3. Result in matters not previously reviewed in the licensing basis for SON that may have a significant environmentalimpact.

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i ENCLOSURE 3 I PROPOSED TECHNICAL SPECIFICATION CHANGE l 4

SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 l DOCKET NOS. 50-327 AND 50-328 (TVA-SON-TS-94-07, SUPPLEMENTAL)

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION ' -l l

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, Significant Hazards Evaluation l TVA has evaluated the proposed technical specification (TS) change and has determined that it does not represent a significant hazards consideration based )

on criteria established in 10 CFR 50.92(c). Operation of Sequoyah Nuclear Plant (SON) in accordance with the proposed amendment will not:

1. Involve a significant increase in the probability or consequences'of an accident previously evaluated.

This change reduces the power level at which the reactor may be operated :

with one or more main steam safety valves (MSSVs) inoperable, to ensure '!

that the secondary system is not overpressurized during the most severe l pressurization transient of the secondary side. Additionally, this change ;

will combine the TS action statements for 3- and 4-loop operation with one ;

or more MSSVs inoperable, revise the mode requirements and times of 7 Action Statement 3.7.1.1.a, and correct a reference in the bases section E to Table 3.7-1. Reduction of the high neutron flux (HNF) trip setpoint will ;

continue to be used as the means to ensure that the required reactor I power level reductions are met. Mode 3 will be limited to application j whan the reactor trip breakers (RTB) are closed. Lack of NIS trip setpoint !

adjustments with the RTB open has no effect on the accident analysis. l There is no change to the function of the MSSVs by the proposed change. !

This change will not alter any accident analysis assumptions or results for SON. The proposed change will reduce the amount of relief capacity I required to mitigate the consequences of the transient by reducing the i total amount of energy in the primary system. Therefore, this change will not increase the probability of an accident.

1 This change is consistent with current SON accident analysis assumptions i for the MSSVs and does not change the containment response for any )

design basis event. Therefore, no change in the mitigation of an accident- 1 will result from this proposed change and no change will occur in the ;

consequences of any accident currently analyzed. j

2. Create the possibility of a new or different kind of accident from any !

previously analyzed. I I

Inadvertent opening of a MSSV is currently analyzed es an initiating event for accidental depressurization of the main steam system. The proposed

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i change does not alter the valves or any other plant component. The l valves will continue to perform as analyzed in current accident analyses. ]

The proposed change will not create the possibility for any new or different kind of accident. . !

i By retaining the use of the HNF trip setpoint reduction, no change is being !

proposed in the methodology used to ensure that power reductions are carried'out; therefore, this will not create the possibility of placing the :

plant into any new unanalyzed condition. Not adjusting the Nuclear Instrumentation System trip setpoint with the RTBs open will not create an !

accident. The existing accident analysis is still bounding. l Combining the separate action statements for 3- and 4-loop operation into !

I a single action does not create the possibility for a new or different kind of accident. Operation with 4 loops will continue to be required in Modes 1 .

and 2 by TS 3.4.1.1. Operation with less than 4 loops will continue to be governed by TS 3.4.1.2 in Mode 3 and TS 3.4.1.3 in Mode 4. This change will not place the plant in a configuration not currently bounded by :

existing acciaent analysis. i Revising the roode requirements and their associated times, consistent ' !

with the requirements in NUREG-1431, will continue to ensure that if the i unit is unable to comply with the limiting condition for operation, the unit !

will begin an orderly shutdown until a mode is reached where the I specification is not applicable. !

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3. Involve a significant reduction in a margin of safety. ;

i The proposed change reduces the total energy of the reactor coolant _

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system that will ensure the ability of the MSSVs to perform their intended function as assumed in current accident analyses. This change has been .

g evaluated on a generic basis for Westinghouse Electric Corporation :

designed 4-loop nuclear steam supply systems. SON plant specific .

j features have been evaluated including power limit calculations and the j interaction of the reactor protection system trip time delay and the - ;

anticipated transient without scram mitigating system actuation circuitry. . 'l Correcting this nonconservatism restores the margin of safety to what was -l originally envisioned. Therefore, the margin of safety assumed in the !

accident analysis is not reduced by this ghange. !

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. Combining the separate' action statements for 3- and 4-loop operation into a single action has no effect on the margin of safety for 4-loop operation .

with one or more MSSVs inoperable. Under the revised TS, 3-loop operation with one or more MSSVs inoperable would only be allowed in .

Mode 3, and 4-loop operation will be required in Modes 1 and 2 in ,

accordance with current TSs 3.4.1.1 and 3.4.1.2.

Revising the mode requirements and their associated times, consistent with the requirements in NUREG-1431, will not reduce the safety margin since the new requirements will continue to place the unit in a mode where the TS is no longer applicable. The new completion times for mode changes are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner without challenging unit systems. :

The margin of safety is unaffected by modifying the limits of Mode 3 applicability to require the RTBs to be closed as the intended safety function is already completed when they are open.

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ML20080H009

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