ML20078F563
| ML20078F563 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 11/08/1994 |
| From: | HOUSTON LIGHTING & POWER CO. |
| To: | |
| Shared Package | |
| ML20078F542 | List: |
| References | |
| NUDOCS 9411150303 | |
| Download: ML20078F563 (2) | |
Text
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REFUELING OPERATIONS 3/4.9.2 INSTRUMENTATION LIMITING CONDITION FOR OPERATION 3.9.2 As a minimum, two Source Range Neutron Flux Monitors
- shall be OPERABLE, each with continuous visual indication in the control room and one with audible indication in the containment and control room.
APPLICABILITY: MODE 6.
ACTION:
a.
With one of the above required monitors inoperable or not operating, immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes.
b.
With both of the above required monitors inoperable or not operating, determine the boron concentration of the Reactor Coolant System at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
1 SURVEILLANCE REQUIREMENTS 4.9.2 Each Source Range Neutron Flux Monitor shall be demonstrated OPERABLE by performance of:
a.
A CHANNEL CllECK at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, l
b.
A CHANNEL CALIBRATION,iexbluding the Neutr6nldeteetorgevery1181inonths3%n ANALOG CHANNEL OPERATIONAL TEST ithin 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s-prior to the initial start of CORE ALTERATIONS, aad c.
An ANALOG C41ANNEL OPERATIONAL TEST at least once per 7 daye
- An Extended' Range Neutron Flux M6 nit 6r may belsubstit6ted for onslof thiSoureclRaisge Neutron Flux Monitors provided the OPERABLE Source Range Neutron Flux _ Monitor is capable of providing audible indicationLin the containment and control room.
SOUTil TEXAS - UNITS 1 & 2 3/49-2 TSC-M 4411001 9411150303 941108 PDR ADOCK 05000498 P
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I 3/4.9 REFUELING OPERATIONS
. BASES 3/4.9.1 HORON CONCENTRATION The limitations on reactivity conditions during REFUELING ensure that: (1) the reactor will remain suberitical during CORE ALTERATIONS, and (2) a uniform boron concentration is maintained for reactivity control in the water volume having direct access to the reactor vessel. These limitations are consistent with the initial conditions assumed for the boron dilution incident in the safety analyses.
The value of 0.95 or less for K, includes a 1% Ak/k conservative allowance for uncertainties. Similarly, the boron concentration value of 2800 ppm or greater includes a conservative uncertainty allowance of 50 ppm boron. The locking closed of the required valves during refueling operations precludes the 4
possibility of uncontrolled boron dilution of the filled portion of the RCS. This action prevents flow to the RCS of unborated water by closing flow paths from sources of unborated water.
3/4.9.2 INSTRUMENTATION The OPERABILITY of the Source Range;ssid(6[Eptsnded Riii@ Neutron Flux Monitors ensures that redundant monitoring capability is available to detect changes in the reactivity condition of the core.
3/4.9.3 DECAY TIME The minimum requirement for reactor suberiticality prior to movement of irradiated fuel assemblies in the reactor vessel ensures that sufficient time has elapsed to allow the radioactive decay of the short-lived fission products. This decay time is consistent with the assumptions used in the safety analyses for the rapid refueling design.
3/4.9.4 CONTAINMENT HUILDING PENETRATIONS The requirements on containment building penetration closure and OPERABILITY ensure that a release of radioactive material within containment will be restricted from leakage to the environment.
The OPERABILITY and closure restrictions are sufficient to restrict radioactive material release from a fuel element rupture based upon the lack of containment pressurization potential while in the i
REFUELING MODE.
3/4.9.5 COMMUNICATIONS The requirement for communications capability ensures that refueling station personnel can be promptly informed of signiGeant changes in the facility status or core reactivity conditions during CORE ALTERATIONS.
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