ML20113G890

Proposed Tech Specs 3.1.1.2 & Bases 3/4.1.1.2 Re Boron Dilution Requirements

ML20113G890
Person / Time
Site:	Davis Besse
Issue date:	05/01/1992
From:	CENTERIOR ENERGY
To:
Shared Package
ML20113G887	List: ML20113G885 ML20113G888 ML20113G890
References
NUDOCS 9205130188
Download: ML20113G890 (6)

Text

Dockot Nur.ber 50-346-  ;

License Nusber-NPF-3

' Serial Nu ber 2007-At t at:hment Page 6 REACTIVIT" C"NTROL SYSTEF5 BORON DILUTION LIMITING CONDITION FOR OPERATION

^

3.1.1.2 The flow rate of reactor coolant through the Reactor Coolant I.

System snall be t 2800 gpm whenever a r ion in Reactor Coolant f System baron concentration is being ma APPLICABILITY: All MODES.

ACTION:

With the-flow rate of reactor coolant through the Reactor Coolant System < 2800 gpm, immediately suspend all operations involving a reouction in baron concentration of the Reactor Coolant System.

l l

SURVEILLANCE REOUIREMENTS E

4.1.1.2 The flow rate of. reactor coolant througn the Reactor Coolant System snall be determined to be > 2800 gpm within one nour prior to the- start of and at least once per hour-curing a- reduction in the React:,-

Coolant System boron concentration by either:

! a. Verifying at least one reactor coolant pump is in operation.

I or

b. Verifying that at least one OHR bune is in operation and supplying t 2800 gpm to the Reactor Coolant System.

/ ~

y L

C~

WAM&&A m 5M wf_' ' (

t )

9205130188 920501

.PDR ADOCK 05000346 P PDR lluav n-er.str.. UNIT 1 3/4 1--3 ,

_ _ = _ _ _ - - _ _ - _ _ _ _ _ _ _ .

v.

40 . . Docket' Number 50-346 License Number NPF-3

-p Serial Number 2007

'ottachment Page 7 f

Insert to 3/4.1.1.2 In MODE 6 the Reactor Coolant System (RCS) boron concentration may be greater than the boron concentration of water available for addition. If the flovrate of. reactor coolant through the RCS is less than 2800 gpm, vater of lover boron concentration than the existing RCS concentration may be added to the RCS-

.provided'that the. boron concentration of the water to be added is equal to or greater than the boron concentration corresponding to the more restrictive reactivity condition specified in Specification 3.9.1.

h -

I L

p-H ,

. Docket Numbst 50-346

. License Number NPF-3 .

, Serial Number 2007 Attachment Page 8 1

l 3/4.1 REACTIVITY CONTROL SYSTEv5 1 ev M3 p' BASES _

v

3/4.1.1 BORAT10N CONTROL ,

I ^y _) l

\ t  ; 3/4.1.1.1 SHUT 00WN MARG!N A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be nde

(

" subcritical from all operating conditions, 2) the reactivity transients C associated with postulated accident conditions are controllable within 9 acceptable limits, and 3) the reactor will be maintained sufficiently

-I suberitical to preclude inadvertent criticality in the shutdown condition.

During Modes 1 and 2 the SHUTDOWN MARGIN is known to be within limits 2 if all control rods are OPERABLE and withdrawn to or beyond the insertion (3 t

! I limits.

h ' / SHUTDOWN MARGIN requirements vary throughout core life as a function l

J k of fuel depletion, RCS boron concentration and RCS T 8 . The most-l 5h J /

restrictive condition occurs at EOL, with T temperature.

at no Mad operating The SHUTDOWN MARGIN required N 9 consistent with FSAR safety y P\ analysis a;sumptions.

i b )

( 2L i 3/4.1.1. 2 BORON DILUTION ,

A minimum flow rate of at least 2800 GPM provides adequate mixing, f\ ,; $' prevents stratification and ensures that reactivity changes will be gradual through the Reactor Coolant System in the core during baron

concentration reductions in the Reactor Coolant System. A flow rate of X at least 2800 GPM will circulate an equivalent Reactor Coolant System

\ I volume of 12,110 cuoic feet in approximately 30 minutes. The reactivity Q

f \ h change rate associated with baron concentration reduction the capability for operator recognition and control.  %

w

\ ,P ? $

,, s - '94.1.1.3 MODERATOR TEMPERATURP. COEFFICIENT The limitations on moderator temperature coefficient (MTC) are provided to ensure that the assumptions t sed in the accident and transient analyses remain valid through eacn fuel cycle. The surveillance recuire-ment for measurement of the MTC each fuel cycle are adequate to confirm the MTC value since this coefficient changes slowly due principally to the reduction in RCS boron concentration associated with fuel burnuo.

The confirmation that the measured MTC value is within its limit provides assurance that the coefficient will be maintained within acceptable values throughout each fuel cycle.

DAVI5-BESSE, UNIT 1 B 3/4 1-1

Docket Number 50-346 License Number NPF-3 Serial Number 2007 Attachment

~Page 9 Insert to Bases 3/4.1.1.2 In MODE 6, the RCS boron concentration is typically somewhat higher than the minimum boron concentration required by Specification 3.9.1, and could be higher than the boron concentration of normal sources of water addition. At reduced inventory conditions in the RCS, in order to reduce the possibility of vortexing, the flovrate through the decay heat system may be procedurally restricted to somewhat less than 2800 gpm. In this situation, if water with a boron concentration equal to or greater than the boron concentration required by Specification 3.9.1, is added to the RCS, the RCS is assured to remain above the Specification 3.9.1 requirement, and a flovrate of less than 2800 gpm is not of concern.

Docket Number 50-346

, - License Number NPP-3

. Serial Number 2007 Attachment Page 10

(

3/4.9 REFUELING OPERATIONS

.' /h,tl U' I' i V ff81..V I

BORON CONCE!!TRAf!ON LIMITING CONDITION FOR OPERATION 3.9.1 The boron concentration of all filled portions of the Reactor Coolant l System and the refueling canal shall be maintained unifonn and sufficient to ensure that the more restrictive of the following reactivity conditions is met:

a. Either a K of 0.95 or less, which includes a 1% ak/k conservatiNfallowance for uncertainties, or

b. A boron concentration of > 1800 ppm, which includes a 50 ppm conservative allowance for uncertainties.

APPLICABILITY: f10DE 6. l ACTION:

With the requirements of the above specification not satisfied, immediately suspend all operations involving CORE ALTERATIONS or positive reactivity cnanges and initiate and continue boration at >_ 10 gpm of 8750 ppm boric acid solution or its equivalent until Kgf is reduced to < 0.95 or the boron contentration is restored to 1 1800 ppm, whichever is the more restrictive.

The provisions of Spt<ification 3.0.3 are not applicable.

SURVEILLANCE REOUIREMENTS 4.9.1.1 The more restrictive of the above two reactivity conditions shall be determined prior to:

a. Removing or unbolting the reactor vessel head, and

b. Withdrawal of any safety or regulating rod in excess of 3 feet from its fully inserted position within the reactor pressure vessel.

4.E.1.2 The boren concentration of the react. pressure vessel and the refueling canal shall be detemined by cheinical analysis at least once each 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

t i

DAVIS-BESSE, UNIT 1 3/4 9-1 Amendment No. 143

Docket Number 50-346

. ,. License Number NPF-3 *

. Serial Number 2007 Attachment

• ' 3/4.9 REFUEL!'1 OPEDAT!ONS EASES 3/4.9.1 BORON CONCENTRATION

- The limitations on reactivity conditions during REFUEL.ING ensure that:

1) the reactor will remain subcritical' during CORE ALTERATIONS, and R) a unifom boron concentration is maintained for reactivity control in the water volumes having direct accea to the reactor vessel. These limita-tions are consistent with the initial conditions assumed for the boron dilution incident in the accident analysis.

3/4.9.2 INSTRUMENTATION .

The OPEPABILITY of source range neutron flux monitors ensures that redundant ronitoring capability is available to detect changes in the reactivity condition of the core.

3/4.9.3 DECAY TIME The minimum requirement for reactor suberic' 'ity prior to covement of irradiatea fuel assemblies in the reactor pre. cr vessel ensures i

' that sufficient time has elapsed to allow the radioactive uecay of the short lived fission products. This decay time is consistent with the j

assumptions used in the safety analyses.

l 3/4.9.4 CONTAINMENT PEHETRATIONS_

The requirements on containment penetration closure and OPERABILITY l

ensure that a release of radioactiva materialThe within containment will be OPERABILITY and closure l

restricted from leakage to the environment.

requirements are sufficient to restrict radioactive material release from a fuel element rupture based upon the lack of containment pressuriza-tion potential while in the REFUELING MODE.

3/4.9.5 CLMMUNICATIONS 1

The requirement for cermunications capability ensures that refueling station personnel can be proeptly informed of significant changes in the facility status or core reactivity condition during CORE ALTERATIONS.

DAVIS-BESSE, UNIT 1 B 3/4 9-1