ML20029B247
| ML20029B247 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/25/1991 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20029B246 | List: |
| References | |
| NUDOCS 9103060295 | |
| Download: ML20029B247 (3) | |
Text
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z PROPOSED TECHNICAL SPECIFICATION CHANGES t
1 h
9193060295 910225 PDR ADOCK 05000360 P
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4D l
l PEACTIV1TY CONTROL SYSTEMS BORON OILUTION 3.1.1.3 The flow rate of reactor coolant through the reactor coolant system shall be 22000 gpm whenever a reduction in Reactor Coolant System l
boren concentration is being made.
AEPLICABillll: ALL MODES.
ACTION:
With the flow rate of reactor coolant through the reactor c :lant system
<2000 gpm, immediately suspend all operations involving a reuuction in 1
boron concentration of the Reactor Coolant System.
t 4.1.1.3 Yhe flow rate of reactor coolant through the -eactor coolant system shall be determined to be 22000 gpm within one hour prior to the j
start of and at least once per hour during a reduction in the Reactor Coolant System boron concentration by either:
a.
Verifying at least one reactor coolant pump is in operation, or b.
Verifying that at least one low pressure safety injection pump or containment spray pump is in operation as a shutdown cooling pump and supplying 22000 gpm through the reactor coolant system.
S ARKANSAS - UNIT 2 3/4 1-4 Amendment No.
l l
-. -. -. -.. - ~. - -
J
).L4.J REACTIVITY CONTROL SYSTEMS
-3/4.1.1 BORATION CONTROL
')/4.1.L 1 and 3/4.1.1.2 SHUTDOWN MARGIN A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be made subcritical from all operating conditions, 2) the reactivity transients associated with postulated accident conditions ar.s controllable within acceptable limits, and 3) the reactor will be miintained suf ficiently suberitical to preclude inadvertent criticality in the shutdown condition.
ShuiDOWN MARGIN requirements vary throughout core life as a function.
of fuel depletion, RCS boron concentration, and RCS Tayg.
The most restrictive condition of: curs _at EOL, with Tavg.at no load operating
' temperature, and is associated with a postulated steam'line break
' accident,-and resulting uncontrolled RCS cooldown. In the analysis of this accident, a minimum SHUTDOWN MARGIN of 5.5% Ak/k is required to control the reactivity transient. Accordingly, the SHUTDOWN MARGIN. requirement is-based upon this limiting condition and is consistent.with FSAR' safety analysis assumptions. With Tavg 5200*F, the reactivity tr'ansients resulting from any postulated accident are minimal 1 a 5% ak/k shutdown
- margin provides adequate protection.
3/4.1.1.3 -BDRON DILUTIQS i
A-minimum flow rcte;of at least 2000 GPM provides adequate mixing,
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prevents stratification.and ensures that reactivity changes will be 1
' gradual during boron concentration reductions in'the Reactor Coolant.
System.-. A; flow-rate of at least 2000 GPM will circulate an equivalent e
' Reactor. Coolant. System volume of 6,650 cubic feet:in approximately 25 l minutes. LThe reactivity change rate associated with boron concentration
-reductions will the efore be within the capability of-o'peratorLrecognition and control.
3/4.1.1.4 MODERATOR TEMPERATURE COEFFICIENT JMTC)
JThe: limitations _on MTC-are provided to ensure.that.the assumptionsu used in the accident:and transient analysis:remainjvalid through each fuel P_. _
cycle..The surveillance requirements _ for measurement of the' MTC during each fuel: cycle =are adequate to confirm the MTC value since this coefficient: changes slowly due principally to the reduction in RCS boron.
O tconcentrations associated with fuel burnup.
The confirmation that the meas'ured MTC ~value is within-its limit provided assurances that the coef ficient will be maintained rii% acmptable : values throughnut-each
/
fuel cycle.
lA' J'
ARKANSAS - UNIT 2
.8 3/4 1-1 Amendment No. 2,4. BJ 2.
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