ML20196G955

Proposed Tech Specs,Revising Main Steam Safety Valve Relief Capacity/High Flux Trip Setpoint Relationship

ML20196G955
Person / Time
Site:	Davis Besse
Issue date:	03/04/1988
From:	TOLEDO EDISON CO.
To:
Shared Package
ML20196G923	List: ML20196G918 ML20196G933 ML20196G955
References
1487, NUDOCS 8803100037
Download: ML20196G955 (8)

Text

Doc 15t* No. 50,346

• License No. NPF-3 Serial No. 1487 ,

Page 10 .

TABLE 1 -

EQUATION 3.7-1 HATRIX (EQ 3.7-1) SP = Y / Z x W NUMBER OF OPERABLE HAIN STEAM SAFETY VALVES HODEL NO. 3777 QA (5 PERCENT OF RATED THERNAL CAPACITY) 0 1 2 (NOTE 1)

$ 0.177W y 0 NOTE 2 NOTE 2

< (1,167,148) u 0.217W 0.306W a 1 NOTE 2 m$ (1,429,333) (2,012,907) ax 0.257W 0.345W 0.434W

$b 2 gg (1,691,518) (2,275,092) (2,858,666) ee dj 0.385W 0.474W 0.563W

< 3

"$ (2,537,277) (3,120,851) (3,704,425)

NH yg 0.514W 0.602W 0.691W nu 4 x$

H&

(3,383,036) (3,966,610) (4,550,184)

$n

• 0.642W 0.731W 0.819W g 5 jg (4,228,795) (4,812,369) (5,395,943)

[Q A& 6 0.771W 0.859W 0.948W U"

(5,074,554) (5,658,128) (6,241,702) 0.899W 0.988W

$a 7 NOTE 2 Q$ (5,920,313) (6,503,887)

NOTES: 1. This column represents the existing Table 3.7-1 requirements for maximum High Flux Trip Setpoint (3 significant digits).

2. High Flux Trip Setpoint reductions are not applicable.

3. Top figure - Maximum allowable High Flux Trip Setpoint Bottom figure ( ) - Operable MSSV relief capacity per SG in lbs/hr

4. The allowable increase in trip setpoint fcr an inoperable 5 percent capacity MSSV can be read along a diagonal from upper right to lower left.

P$hbbobko$$00$$A P DCD

Docket No. 50-346 51cdnse No..NPF-3' - -

Serial 1487 Attachment 3 -

3/4.7 PLANT SYSTEMS. -

, 3/4.7.1 TURBINE CYCLE-SAFETY VALVES

- LIMITING CONDITION FOR OPERATION 3.7.1.1 A11' main steam line code safety valves shall be OPERABLE.

l APPLICABILITY: MODES 1, 2 and 3.

ACTION:

n~

( Wit onefor cre inyteam ine bde afe+y val es nope 'abl ; ope ti i

i MOD 5 1, a 3ryp eed ro ed hat i n4 ou , ei er e l f ope abl al is esto ed OPJ BL sta s th ig Flu ri

/

Set in s r due per abl 3 741; p e se i at east OT 5 N /witA n the n 6 urVand nC S DO wi inje 1 wig h rs. Thefprovi ion off'peci cati n }.0.4' re t applip b .

~ .

D r=*Eir T A SURVEILLANCE REQUIREMENTS 4.7.1.1 No additional Surveillance Requirernents cher than those required by 5 ecification 4,0 are applicable for the main steam line i: ode safety valv ... ..bli 4.7-1, e g -

ee O .

e E

h

Docket No. 50-346 License No. NPF-3 Serial No. 1487 Attachment 3 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE SAFETY VALVES LCO 3.7.1.1 ACTION INSERT A

______________________________ - _ _ - - = - ________-- ===_______--- ==_

With one or more main steam line code safety valves inoperable, a, operation in MODES 1, 2 and 3 may proceed provided, that within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, either,

1. the inoperable valve is restored to OPERABLE status, or,

2. a) the High Flux Trip Setpoint is reduced per Equation 3.7-1, below, and, b) there are a minimum of two OPERABLE safety valves per steam generator, at least one with a setpoint not greater than 1050 psig (+/-1%)*, and, c) no OPERABLE safety valve has a setpoint greater than 1100 psig (+/-1%)*;

othe rwise ,

b. 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 /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

c. The provisions of Specification 3.0.4 are not applicable.

Y Equation 3.7-1: SP = ------ x W Z

where, SP = Reduced High Flux Trip Setpoint (Not to exceed W)

W = High Flux Trip Setpoint for four pump operation as specified in Table 2.2-1 Y = Total OPERABLE relieving capacity per steam generator based on a summation of individual OPERABLE safety valve relief capacities per steam generator in 1bs/hr Z = Required relieving capacity per steam generator of 6,585,600 lbs/hr

• The lift setting pressure shall correspond to ambient conditions of the valve at nominal operating temperature and pressure.

N E DE E1EE

- e. P. [.

R~*2 ESE g

TABLE 3.7-1

'ky U l' Y MAXIMIM ALLOWABl.E HIGH FLUX TRIP SETPOINT WITH INOPERABLE 9*

k0; STfAH LINE SATETY VALVES m

owable Maximum E Maximum Number o noperable Safety High Flu rip Setpoint*

l I

U. Valves on Any St b Generator

. fFercen f RATED THERMAL P6WER)

. 1 O.95W

. =-

/

2 0.82W cM [9 <-  !

3 0.69W R.

f gI 7

m 4 0.56W I

h g

(3 _4 5 -

0.43W k . 6-.

0,31W E

.jk

~5 O.18W - [ l -

s

• Based on High Flux Trip Setpoint for four pump operation. H. as per Table 2.2-1. .

i D

8 *4 N $N a 2.4 eSER R *z

~

E ~&F.

" z 8; g TABLE 4.7-1 yh w.m U STEAM LINE SAFETY VALVES PER STEAM GENERATOR a

NUM8 ER STEAM GENERATOR LIFT SETTI (t 11)*

E 5 G a. 2 0 psig -

/

,N gL \

b. 2 1070 psig 40,7

- 4

c. 3 l'090 psig i

.f r  : ,

f q -l (7

d. 2 - - 1100 psig i <-

w g r> aL F

r t

~

,4 I .h A

G 1 'i

• The lift setting p, ssure shall correspond to ambient conditions f the valve 1) <

at nominal oper ting temperature and pressure. -l

~

j I

Ecchet No. 50-346, i l

' Lic.ense.Nos NPF-3 Serial 1487

.Attac nt 3 3/4.7 PLANT SYSTEMS BASES .

3/4.7.1 TURBINE CYCLE 3/4.7.1.1 SAFETY VALVES The OPERABILITT of the main steam line code safety valves ensures that the secondary system pressure will be limited to within 110% its design pressure of 1050 psig during the most severe anticipated system opera-tional transient. The maximum relieving capacity is associated with a turbine trip from 100% RATED THERMAL POWER coincident with an assumed loss of condenser heat sink (i.e., no steam bypass to the condenser).

f The ecifie valve ft sett ogs and elievin capacit s are in cord-an with e requ ements o Sectio III of e ASME iler and ressure V ssel Co e, 1971 dition. The tot reliev'ns capac" y for al valves /n I all of e stea ines is 4,175,0 lbs/hr which i 120 perce t of th(

total 60,000 1 s POVEi)jecondary

. A miof' mum ofsteam 2 PERABLEf ew of 11 safety vafve/hr at 100% RATED THER.sj pe tha t' suf f f'ent reli ng capa ity is avsilable for the allowable f POWER res iction in able 3.7-1.

STARTUP and/or POWER OPERATION is allowable with safety valves inoperable within the limitations of the ACTION requirements on the basis of the reduction in secondary system steam flow and THERMAL POWER required by the reduced reactor trip settings of the High Flux channels. The reactor trip setpoint reductions are derived on the following bases:

-g- W.::E5 Q C,,

SP = ( ) ~'(I)(V) x V vbe  :

SP = re uced Trip S tpoint in pe cent of RA ot to Excee W)

THERMAL POWER \

\ V maximum n er of inope ble safety lves per sta generater

= High T1 Trip Setpo t for four operation as speci- '

fied 6 Table 2.2-X = Totil relieving 'c pacity of all safety valv s per steam gen'erator in lb / hour, 7,087,500 lbs/ hour /

/ I T = Naximum relie ng capacity of any one sp'fety valve '

/ibs/ hour, 84 759 lbs/ hour Z = Required relieving capacity per steam generator < a lbs/hr, i 6,585,600 lbs/hr.

DAVIS-BESSE, UNIT 1 83/4 7-1 ,

Amendment No. 48

, IMc(et so. 50-346, Lic.ense Nos NPF-3 i Serial 1487 i Attachment 3 l I

TECH EPEQ BASES i

1 3/4.7.1 TURBINE CYCLE 3/4.7.1.1 SAFETY VALVES ,

l INSERT R l The safety valve set pressures and relieving capacities are in accordance with Section III of ASHE Boiler and Pressure Vessel Code, 1971 Edition. The Code requires the following:

1. At least two pressure-relief valves are required to provide l relieving capacity for steam systems.

2. The capacity of the smallest pressure-relief valve shall not be less than 50 percent of that of the largest pressure-relief device.

3. The set pressure of one of the pressure-relief devices shall not be greater than the maximum allowable working pressure of the system at design temperature.

4. Total rated relieving capacity of the pressure-relief devices  ;

shall prevent a rise in pressure of more than 10 percent above ,

system design pressure at design temperature under any pressure transients anticipated to arise.

These requirements are, respectively, met as follows:

1. Nine safety valves are installed per steam generator.

2. The relief capacity of two of the nine safety valves per steam generator is 583,574 lbs/hr each, and the capacity of the remaining seven is 845,759 lbs/hr each.  !

3. A minimum of two OPERABLE safety valves per steam generator, with a combined total relief capacity of at least 1,167,148 lbs/hr, one with a setpoint not greater than 1050 psig (+/-1%), ,

and one with a setpoint not greater than 1100 psig (+/-1%).  ;

4. The total relieving capacity of all safety valves on both main steam lines is 14,175,000 lbs/hr which is 120 percent of the total secondary system flow of 11,760,000 lbs/hr at 100 percent of rated thermal power. A maximum safety valve setpoint pressure of 1100 psig (+/- 1%) assures main steam system pressure remains below 110 percent, or 1155 psig.

l

o M et No. 50-346 l . Licensy No. NPF-3 Serial' 1487 Attachment 3 '

TECH SPEC BASES 3/4.7.1 TURBINE CYCLE 3/4.7.1.1 SAFETY VALVES INSERT C Y

SP = xW Z

where:

SP = Reduced High Flux Trip Setpoint (Not to exceed W)

W = High Flux Trip Setpoint for four pump operation as specified in Table 2.2-1 Y = Total OPERABLE relieving capacity per steam generator based on a summation of individual safety valve relief capacities per steam generator in lbs/hr Z = Required relieving capacity per steam generator of 6,585,600 lbs/hr This equation is graphically represented below. Operation is restricted to the area below and to the right of line A (6.585600, 1.00W) =D

1. 0 0 W - ------------------ -------------------+ '

lE= (7.087500,

$ 0.90W - l 1.00W)

E I

$ 0.80W -

w UNACCEPTABLE l I

" O.70W - RECION l

$ I g 0.60W - l l

j O.50W - E ACCEPTABLE l A o

' l O. 40W - REGION l x o l

0.30W -

C

@ 0.20W - .,

4 l z C= (1.167148, 0.18W) l C 0.10W - '

l j < B= (1.167148, 0.00W) l 0 00W i, i 0.0 1.0 2 .i0 3.0 4.0 5 .i0 6 .i0 7 .i0 OPERABLE SAFETY VALVE CAPACITY PER STEAM GENEBATOR (x 10E-06 LBS/HR) u