ML20148J270

Proposed Tech Spec 3.1.1.1.2,reflecting Change in Shutdown Margin Switching Temp from 490 to 470 F

ML20148J270
Person / Time
Site:	Yankee Rowe
Issue date:	03/23/1988
From:	YANKEE ATOMIC ELECTRIC CO.
To:
Shared Package
ML20148J261	List: ML20148J256 ML20148J270
References
NUDOCS 8803300220
Download: ML20148J270 (4)

Text

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i REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR OPERATION 3.1.1.1.2 The shutdown margin requirement is as follows:

1.

4700F 1 T Shutdown Margin 1 6E k/k for Tavg = 5160F avg 2.

3300F 1 Tavg < 4700F Shutdown riargin 1 SEk/k for Tavg = 3300F APPLICABILITY: MODE 3*

ACTION:

With the SHUTDOWN MARGIN less than required, incediately initiate and continue boration at 1 26 gpm of 2200 ppm boron concentration or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REOUIREMENTS 4.1.1.1.2.1 The SHUTDOWN MARGIN shall be determined to be greater than or equal to that required:

a.

Within one hour after detection of an inoperable control rod (s) and at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereaf ter while the rod (s) is inoperable.

If the inoperable control rod is immovable or untrippable, the SHUTDOWN MARGIN shall be increased by an amount at least equal to the withdrawn worth of the immovable or untrippable control rod (s).

b.

When in Mode 3, at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by consideration of the following factors:

1.

Main Coolant System boron concentration, 2.

Control rod position, 3.

Main Coolant System average temperature, 4.

Fuel burnup based on gross thermal energy, eneration, 5.

Xenon concentration, and 6.

Samarium concentration.

4.1.1.1.2.2 During a reactor st rtup in which core reactivity or control positions for criticality are nc ; established, a plot of inverse multiplication rate (or count rate) versus reactivity shall be made.

• See Special Test Exception 3.10.1 YANKEE-ROWE 3/4 1-2a Amendment No. 82.)HI 8803300220 880323 PDR ADOCK 05000029 P

DCD

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TABLE 3.3-2 (Continued)

TABLE NOTATION

• • The provisions of Specification 3.0.4 are not applicable.

(1) Trip function may be bypassed in this MODE with main coolant pressure

<300 psig.

(2) Trip function may be bypassed in this MODE with main coolant pressure

<1800 psig and main coolant temperature <4700F.

(3) Automatic initiation of Actuation Channel #1 may be bypassed in this MODE during functional test of the Main Coolant System Loop 1 pressure channel.

Automatic initiation of Actuation Channel #2 may be bypassed in this MODE during functional test of the Main Coolant System Loop 2 pressure channel.

ACTION STATEMENTS ACTION 10 - With the number of OPERABLE channels or sensors one less than the total number of channels or sensors, be in at least HOT STANDBY within 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 />; however, one safety injection channel high containment pressure sensor may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing per Specification 4.3.2.1.

ACTION 6 -

W.th the number of OPERABLE channels one less than the total number of channels, STARTUP and POWER OPERATION may proceed provided both of the following conditions are satisfied:

1.

The inoperable channel is placed in the tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

2.

The minimum channels OPERABLE requirement is met; however, one additional channel may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing per Specification 4.3.1.1.

ACTION 8 -

With the number of channels OPERABLE less than required by the minimum channels OPERABLE requirement, be in at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

ACTION 22 - With the number of OPERABLF channels one less than the total number of channels, STARTUP and/or POWER OPERATION may proceed

)

until performance of the next required CHANNEL FUNCTIONAL TEST provided the inoperable channel is placed in the tripped condition within one hour.

l YANKEE-ROWE 3/4 3-13 Amendment No. 82, 83,,S4' i

l

BASES 3/4.1.1 BORATION CONTROL 3/4.1.1.1 and 3/4.1.1.2 SHUTDOWN MARGIN A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be made suberitical from all operating conditions, 2) the reactivity transients associated with postulated accident conditions are controllable within acceptable limits,'and 3) the reactor will be maintained sufficiently

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suberitical to preclude inadvertant criticality in the shutdown condition.

SHUTDOWN MARGIN requirements are a function of the plant operating status. For critical conditions, minimum shutdown margins are limited.by the Power Dependent Insertion Limits (PDIL) as given in Figure 3.1-2.

For j

4700F 1 Tavg, the requirement for a SHUTDOWN MARGIN is established by I

postulated steam line break considerations with ECCS and NRVs avcilable and covers the requirements to preclude inadvertent criticality.

For 3300F

< 4700F, the requirement for a SHUTDOWN MARGIN is sufficient to 1Tav precibdeinadvertentcriticalityandcoverstherequirementsofsteamline breaks with automatic initiation of ECCS and NRVs blocked. With T avg

< 3300F, the reactivity transients resulting from a steam line break cooldown are minimal. 5%Ak/k SHUTDOWN MARGIN (with all rods inserted) provides adequate pro'tection to preclude criticality for all postulated accidents with the reactor vessel head in place.

To eliminate possible errors in the calculations of the initial reactivity of the core and the reactivity depletion rate, the predicted relation between fuel burnup and the boron concentration, necessary to maintain adequate control characteristics, must be adjusted (normalized) to accurate'r reflect actual core conditions. Normally, when full power is reached atter each refueling, and with the control rod groups in the desired positions, the boron concentration is measured and the predicted steady-state curve is adjusted to this point. As power operation proceeds, the measured boron concentration is compared with the predicted concentration and the slope of the curve relating burnup and reactivity is compared with that predicted.

This process of normalization should be completed af ter about 10% of the total core burnup. Thereafter, actual boron concentration can be compared with prediction and the reactivity status of the core can be continuously evaluated, and any deviation would be thoroughly investigated and evaluated.

1 YANKEE-ROWE B3/4 1-1 Amendment No. 81, JMf'

FIGURE 1 MODE 3 SHUTDOWN MARGIN REQUIREMENTS

,o Tech Spec Requirement

/

Core 17 Data O

IO' l

l--

- MSLB without SI & NRV e

a y

',/

ss E

5-

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,- hSLB with S1 6 NRV

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4

,/

,/

,va:

2 2

,/

3:

,/

o o

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Boron Dilution

,/

based on tile fixed time for returni:1g to recritical I

f 470 F 490 F e

300 350 400 450 500 550 AVERAGE MCS TEMPERATURE (F)

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