ML20086F433

Proposed Tech Spec 2.10 Re Moderator Temp Coefficient

ML20086F433
Person / Time
Site:	Fort Calhoun
Issue date:	11/27/1991
From:	OMAHA PUBLIC POWER DISTRICT
To:
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ML20086F416	List: ML20086F415 ML20086F423 ML20086F433 ML20086F445
References
NUDOCS 9112030226
Download: ML20086F433 (5)

Text

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ATTACHMENT A l

-' 112030;;6 911127 1%R ADOci 000002: FDR T

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\ 2.0 LIMITING CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.2 [eactivity Control Systems and Core Phystes Parametet.s Lireits Applicability Applies to operation of esntrol element assemblies and monitoring of selected core parameters whenever the reactor is in cold or hot shutdown, hot standby, or power operation conditions.

Objective To ensure (1) adequate shutdown margin following a reactor trip.

(2) the HTC is within the limits of the safety analysis, and (3) control element assembly operation is within the limits of the setpoint and safety analysis.

Specification (1) Shutdown Margin With Yeold >210'T Whenever the reactor is in hot shutdown, hot standby or power operation conditions, the shutdown margin shall be >4.0% Ak/k.

With the shutdown sargin (4.0% Ak/k, initiate and continue boration until the required shutdown margin is achieved.

(2) Shutdown Margin With T cold 1210*T Whenever the reactor is in cold shutdown conditions, the shut-down margin shall be 13.0% ak/k. With the chutdown margin

<3,0% ak/k, initiate and continue boration until the required shutdown margin is achieved.

(3) Moderator Temperature Coefficient The moderator temperature coefficient (NTC) shall bei

a. Less positive than +0.2x10~4 ao/or including uncertaintieu l for power levels at or above 80% of rated power.

b. Less positive than +0.5x10-4 ao/oF including uncertainties for power levels below 80% of rated power.

3, o41o ^ 4

c. .

More positive than 2J57710' ap/or including uncertainties at rated power.  !

With the moderator temperature coefficient confirmed outside any one of the above limits, change reactivity control parameters to '

bring the extrapolated MTC value within the above limits within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> or be in at least hot shutdown wtthin b hours.

Amendment No. 8. 32, 43. 47, 62, 10. 77 2-50

2.0 Llh1HING__ CONDITIONS FOR OPERATION 2.10 Reactor Core (Continued) 2.10.- Reactivity Control Systems and Core Physes Paran1cicis l_imits Almilcability Applies to operation of control element assemblics and monitoring of selected core parameters whenever the reactor is in cold or hot shutdown, hot standby, or power operation conditions.

ObjecibT To ensure (1) adequate shutdown margin following a reactor trip, (2) the h1TC is within the limits of the safety analysis, and (3) control element assembly operation is within the limits of the setpoint and safety analysis.

Ssciftcalimi (1) Shutdown hfargin With Tm >2107 Whenever the reactor is in hot shutdown, hot standby or power operation conditions, the shutdown margin shr.ll be A4.0% ak/k. With the shutdown margin < 4.0% ak/k, initiate and continue boration until the required shutdown margin is achieved.

(2) Shutdown h1argin With T4210rF Whenever the reactor is in cold shutdown conditions, the shutdown margin shall be 13.0%

Ak/k. With the shutdown margin < 3.0% ak/k, initiate and continue boration until the required shutdown margin is achieved.

(3) bioderator Temocrapre Coefficient The moderator temperature coef0cient (h1TC) shall be:

a. Less positive than +0.2x10d ap/'F including uncertainties for power levels at or above 80% of rated power.

b. Less positive than +0.5x10d ap/*F including uncertainties for power levels below S0%

of rated power,

c. Afore positive than -3.0x104 Ap/"F including uncertainties at rated power. l With the moderator temperature coefficient confirmed outside any one of above limits, change reactivity control parameters to bring the extrapolated h1TC value within the above limits within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> or be in at least hot shutdown within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

2-50 Amendment No. 8,32,43,47,62,70,77

ATTACHMENT B J

Description of Annendment itequest to Chnnge the Mmt Negnthe Moderntor Tennpernture t Coefficient 8o-3.0 x 104 ApFF  ;

The proposed change to Technical Specification 2.10.2(3)e. on page 2-50 revises the negative ,

limit for the Moderator Temperature Coellicient (h1TC) of scactivity from -2.7 x 10 4 ApF F to

-3.0 x 104 ApFP, The Cycle 14 Reload Analysis concluded that the most negative h1TC value, including uneenainties, was more negative than the cuirent Technical Specification 2.10.2(3)c. limit.

Although the revised negative h1TC limit was less conservative for the most limiting negative MTC event (i.e., Main Ste:un 1 ine lireak), the new limit remained conservatively bounded by the Cycle 8 steam line break cooldown curve in the USAlt. Justification for the change is contained in the attached Fon Calhoun Cycle 14 Core Reload livaluation, specifically the Main i Steam l_ine Break analysis as well as other couldown awoelated Anticipated Operational Occurrences ( AOO).

hsis for No Significant llazards Drittmination  :

This proposed amendment does not involve a significant hazards consideration because the operation of Fort Calhoun Station in accordance with this amendment would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated. The safety analysis most impacted by a change to the negative h1TC Technical Specification limit is the main steam line break event. The steam line

break conldown curves (for hot zero power and hot full power) for an MTC of -3.0 x

.ind ApFF were calculated and found to be bounded by the US AR (Cycle 8) cooldown curves. Other transient analyses were reanalyzed and/or reevaluated with the more

. negative MTC and found to yield acceptable results in accordance with the acceptance criteria contained in OPPD's reload analysis methodology topical reports. Thus, this change does not increase the probability or consequences of a previously evaluated accident, c

2. Create the possibility of a new or different kind of accident from any accident previously evaluated. It has been determined that a new or different type of accident is not created because no new or different modes of operation are proposed for the plant. The continued use of the same Technical Specification administrative controls prevents the possibility of a new or different kind of accident.

3. Involve a significant reduction in a margin of safety. The revised negative MTC limit results in a steam line break cooldown curve which remains bounded by the USAR steam line break cooldown curve (Cycle 8). Therefore, this change does not reduce or alter the margin of safety.

Dased on the above considerations, it is OPPD's position that this proposed amendment does not involve a significant hazards consideration as defined by 10CFR50.92.

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