ML20148Q133

From kanterella
Jump to navigation Jump to search
Proposed Tech Specs 3/4.2.3, Min Critical Power Ratio & 3/4.7.9, Main Turbine Bypass Sys & Associated Bases
ML20148Q133
Person / Time
Site: Fermi DTE Energy icon.png
Issue date: 01/27/1988
From:
DETROIT EDISON CO.
To:
Shared Package
ML20148Q130 List:
References
NUDOCS 8801290338
Download: ML20148Q133 (8)
v • d • e


Text

. _ . _ . . . . . _ . . _ __ __. ._.

POWER DISTRIBUTION LIMITS 3/4.2.3 MINIMUM CRITICAL POWER RATIO LIMITING CONDITION FOR OPERATION 3.2.3 The MINIMUM CRITICAL POWER RATIO (MCPR) shall be equal tc or greater than the MCPR limit shown in Figure 3.2.3-1 times the Ky shown in Figure 3.2.3-2, with:

,, (Iave I B)

T ~I A B where:

1 4 = 1.096 seconds, control rod average scram insertion time limit to notch 36 per Specification 3.1.3.3, vg = 0.852 + 1.65[ N.06, ,

n Ng I

i=1 n

I I

ave = i=1 Ng tj ,

n '

I Ng i=1 n = number of surveillance tests performed to date in cycle, th N g = number of active control rods measured in the i surveillance test, tj = average scram time to , notch 36 of all rods measured in the i th surveillance test, and N N total number of active rods measured in Specification y = 4.1.3.2.a.

APPLICABILITY:

OPERATIONAL CONDITION 1, when THERMAL POWER is greater than or equal to 25% of l RATED THERMAL POWER. '

ACTION

a. With MCPR less than the applicable MCPR limit shown in Figures 3.2.3-1 and 3.2.3-2, initiate corrective action within 15 minutes and restore MCPR to within the required limit within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or reduce THERMAL POWER to less i than 25% of RATED THERMAL POWER with n j g gu,rs I
b. With the main turbine bypass sys e inoperable per Specification 3.7.9, operation may continue and the provisions of Specification 3.0.4 are not '

applicable provided that, within one hour, MCPR is detemined to be equal to or greater than the MCPR limit as shown in Figure 3.2.3-1 by the main ,

erable curvitGiess the a g showninFigure3.2.3-2.l '

turbine bypass tendinop/,orin.es4on Seeara$Reke*+*pplicable K  !

F 8801290338 880127 3/4 1 6 j PDR ADOCK 05000341 P PDR

"*1 P'1 D

T.

e-o I **$ . _ _ . _ .

Z . . - _ , .

_,._-__....g

-4 n- f_ . -.__ ..

O . . .

N . . . p .VI g e a

1 3p .

I .

_ . ~ . . . . . . _ . _ _

- ' ' ' - ~ ~ - '

I ~ ~ -

_ . ~ ~ ---

CU pvt B . . -~' ___. -

p-_ . _ . _ _ . . _ _ . .

t g s.

. CUR v t a f-

~ . . a G _-_ -..

w a qgg -.

.- + _ . -

N _ .. .

p - . _ ~

N . . _ - - .

w .. ..

. .- -.. . . . . - - .l j q$ . -- . . . . . _

. . . . . . . - m .

1 10 -- - -

} _ ___ . _ . . _ . . _ _ _ . .

C7 08 09 10 01 02 03 C4 C' C6 0

coRvt A - MCPR t.tMIT WITH MAIN TUR0 TNT HYPASS M O/ &[Ok CURVE B - MCPR t tutT wifMOUT MAIN TURBINE HYPASS O_d IN/

T RoarATe g Ct:1tvE C - utPR orn:T wom ur Mase TuRBlaf evensi M w TseouT mos3TutE SEPAR A. OJt.

MINIMUM CRITICAL POWER' RATIO (MCPR) VERSUS r AT RATED FLOW FIGURE 3.2.3-1 W

1 POWER DISTRIBUTION LIMITS BASES l 3/4.2.3 MINIMUM CRITICAL POWER RATIO The required operating limit MCPRs at steady-state operating conditions as specified in Specification 3.2.3 are derived from the established fuel cladding integrity Safety Limit MCPR of 1.06, and an analysis of abnormal operational transients. For any abnormal operating transients analysis evaluation with the initial condition of the reactor being at the steady state operating limit, it is required that the resulting MCPR does not decrease below the Safety Limit MCPR at any time during the transient assuming instrument trip setting given' in l Specification 2.2. J To assure that the fuel cladding integrity Safety Limit is not exceeded i during any anticipated abnormal operational transient, the most limiting i transients have been analyzed to determine which result in the largest reduction in, CRITICAL POWER RATIO (CPR). The type of transients evaluated y re loss of flow, increa n in pressure and power, positive reactivity insertion, ,

and coolant temperature decrease. The limiting transient yields the largest I

delta MCPR. When added to the Safety Limit MCPR of 1.06, the required minimum I cperating limit MCPR of Specification 3.2.3 is obtained and presented in o- Figure 3.2.3-1.

. .T annn -t 5.c - I Th( evaluation of a given transient begins with the system initial parameters shown in46AR Tabled"'.^ ; that are input to a GE-core dynamic .

behavior transient computer program. The code used to evaluate pressurization events is described in NEDO-24154(3) and the program used in nonpressurization events is described in NED0-10802(2) . The outputs of this program along with the initial MCPR form the input for further analyses of the thermally limiting bundle with the sir.gle channel transient thermal hydraulic TASC code described in NEDE-25149(4) The principal result of this evaluation is the reduction in MCPR caused by the transient.

y The purpose of the fK factor of Figure 3.2.3-2 is to define operating limits at other than rated core flow conditions. At less than 100% of rated flow the required MCPR is the product of the MCPR and the Kf factor. The K f factors assure that the Safety Limit MCPR will not be violated during a flow increase transient resulting from a motor generator speed control failure. The Kf factors may be applied to both manual and automatic flow control modes.

The Kf factor values shown in Figure 3.2.3-2 were developed generically and are applicable to all BWR/2, BWR/3, and BWR/4 reactors. The Kf factors were derived using the flow control line corresponding to RATED THERMAL POWER at rated core flow.

For the manual flow control mode, the Kf factors were calculated such that for the maximum flow rate, as limited by the pump scoop tube setpoint and the corresponding THERMAL POWER along the rated flow control line, the limiting bundle's relative power was adjusted until the MCPR changes with different core flows. The ratio of the MCPR calculated at a given point of core flow, divided by the operating limit MCPR, determines the Kf.

FERMI - UNIT 2 B 3/4 2-4

l

.s INSEIG' TO PAGE B 3/4 2-4 The !CPR curves illustrated in Figure 3.2.3-1 were derived as dercribed above for the.following assumed operating conditions:

Curve A - ICPR limit with the main turbine bypass system and moisture separator reheater available. This represents a total reactor steam flow bypass capability of approximately 36 percent.

Curve B - bCPR limit with the main turbine bypass system inoperative and moisture separator reheater available.

This represents a total reactor steam flow bypass capability of approximately 10 percent.

Curve C - FCPR limit with both the main turbine bypass system and moisture separator reheater inoperative. This represents no reactor steam flow bypass capability.

Curve A provides the FCPR limit assuming operation above 25 percent PATED THEBMAL POWER with both the moisture separator reheater and main turbine bypass system operable. The curve was developed based upon the operating ICPR limits for a Rod WitMrawal Error transient (UFSAR, Section 15.4.2) and a Main Turbine Trip with Turbine Bypass Failure transient (UFSAR, Section 15.2.3) . The analysis of the Main Wrbine Trip with Turbine Bypass Failure takes credit for the steam flow to the moisture separator reheater.

Curve B provides the ICPR limit assuming operation above 25 percent RATED WEPJfAL PWER with the moisture separator reheater operable and the main turbine bypass system inoperable. 'Ihe curve was developed based upon the operating FCPR limits for a Feedwater Controller Failure with Inoperable W rbine Bypass transient. The analysis of the Feedwater Controller Failure transient also takes credit for steam flow to the moisture separator reheater.

Operation with the main turbine bypass inoperable or with a moisture separator reheater inoperable results in a total reactor steam flow bypass capability of approxi;nately 10 percent and 26 percent, respectively. The inpact of operation with the moisture separator reheater inoperable but with bypass operable arxl utilization of curve E, is conservative because the 26 percent bypass capability 1a less limiting with regard to the existing analysis used to establish Curve B which assunes only 10 percent bypass capability (with the main turbine bypass system inoperable) . Therefore, the operation above 25 percent RATED THEPMAL PONER with either the moisture separator reheater inoperable or main turbine bypass system inoperable is bounded by the existing Curve B.

INSERI' 'IO PAGE B 3/4 2-4 (cont.)

Curve C provides the EPR limit asst lJning Operation above 25 percent RATFD THEREL PONER with both the moisture separator reheater. and main -

turbine bypass. system inoperable. The curve was developed based upon the operating MCPR limits for a Feodwater Controller Failure with Inoperable 'nirbine Bypass transient assuming no steam flow through the moisture separator. reheater.

There is no mode change restraint should the main turbine bypass or the moisture separator reheater te inoperable. However, should the main turbine bypass system or the moisture separator reheater be inoperable as 25 percent FATED THEINAL PGER is exceeded, the !CPR check nust be conpleted within one hour.

1

(

PLANT SYSTEMS 3/4.7.9 MAIN TURBINE BYPASS SYSTEM  ;

LIMITING CONDITION FOR OPERATION a d Meistume formaama R h +.,

l 3.7.9 The main turbine bypass systemishall be OPERABLE.

APPLICABILITY: OPERATIONAL CONDITION 1 when THERMAL POWER is greater than or equal to 25% of RATED THERMAL POWER.

daa Madona So aawe Rehe.+.e ACTION: With the mair turbine bypass systeDinoperable, restore the system to l UTERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or take the ACTION required by Specification 3.2.3. .

SURVEILLANCE REQUIREMENTS 2

4.7.9 The main turbine bypass' system shall be demonstrated OPERABLE at least once per:

a. 92 days and during each COLD SHUTDOWN, by cycling each turbine bypass valve through at least one complete cycle of full travel, and
b. 18 months by: '

)

1. Performing a system functional test which includes simulated automatic actuation and verifying that each automatic valve actuates to its correct position.
2. Demonstrating TURBINE BYPASS SYSTEM RESPONSE TIME to be less than or equal to 300 milliseconds.

/

4 l

FERMI - UNIT 2 3/4 7-40 _ __ .__

9 PLANT SYSTEMS l BASES s

3/4.7.9 MAIN TURBINE BYPASS SYSTEM noroanir ,.onete+.n+ ut+g vm. . u ...m u ,_u._... , ,_ _ .......

4,

...a

.. u__ _

...ia., lm 8-m E(8

,AL E_ J A A _11 __ E_21. _m gg,

..m...,. , . . . . . . .... ..... ... ...... ..... ... . _ . - _.._ . ,

bhmbam k( -

  • ~r -

C Y

l I

! /

FERMI - UNIT 2 B 3/4 7-5

I A

INSEld' 70 PAGE B 3/4 7-5 3/4 7.9 MAIN 7URBINE BYPASS SYSTB1 ihe main turbine bypass. system is an active bypass system designed to

, open the bypass valves in the event of a turbine trip to decrease the severity of the pressure transient. Each valve is sized to pass a nominal 13 percent reactor steam flow in the full-open position for a controlled total bypass of approximately 26 percent resctor steam flow. The main turbine bypass system is required to be OPEPABLE consistent with the assunptions of the Feedwater Controller Failure with Inoperable Turbine Bypass analysis.

The primary purpose of the moisture separator reheater is to inprove cycle efficiency by using primary system steam to heat the high pressure turbine exhaust before it enters the low-pressure turbines.

In doing so, it also provides a passive steam bypass flow of about 10 percent that mitigates the early effects of over-pressure transients.

The moisture separator reheater is required to be OPEPABLE consistent with the assunptions of the Main ibrbine Trip with Turbine Bypass Failure analysis and the Fecdwater Controller Failure analysis.

The operation with one or both of the main turbine bypasses inoperable or the moisture separator reheater inoperable to perform preventive or corrective maintenance above 25 percent FATED THEINAL POVER, requires, after one hour, the evaluation of the MCPR in accordance with Specification 3.2.3. If the MCPR is within the bounds established by Specification 3.2.3, power increases to or operation above 25 percent PATED THEH4AL PGiER is allowed.

l

._, . , - _ _ . _ - _ _ _ . _. ___. - _ _ _ _ _ _ _.

Retrieved from "https://kanterella.com/w/index.php?title=ML20148Q133&oldid=2845382"