ML20083B900
| ML20083B900 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 05/03/1995 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20083A392 | List: |
| References | |
| NUDOCS 9505120266 | |
| Download: ML20083B900 (2) | |
Text
Reissued by NRC Letter dated:
May 3, 1995 3/4.9 REFUELING OPERATIONS BASES 3/4.9.1 BORON CONCENTRATION The limitations on reactivity conditions during REFUELING ensure that:-(1) the reactor will remain subtritical 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. The limitation on K of no greaterthan0.95issufficienttopreventreactorcriticalitydEMingrefueling operations. The locking closed of the required valves during refueling operations precludes the possibility of uncontrolled boron dilution of the filled portions of the Reactor Coolant System via the CVCS blending tee.
This i
action prevents flow to the RCS of unborated water by closing all automatic flow paths from sources of unborated water. Administrative controls will limit the volume of unborated water which can be added to the refueling pool for decontamination activities in order to prevent diluting the refueling pool below the limits specified in the LCO.
These limitations are consistent with the i
initial conditions assumed for the boron dilution incident in the safety analyses.
3/4.9.2 INSTRUMENTATION The OPERABILITY of the Source Range 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 subcriticality 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 fuel handling accident radiological consequence and spent fuel pool thermal-hydraulic analyses.
i 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS The requirements on containment building penetration closure and OPERABILITY ensure that a release of radioactive material within containment will be i
restricted from leakage to the environment. The OPERABILITY and closure l
restrictions are sufficient to restrict radioactive material release from a fuel element rupture based upon the lack of containment pressurization potential while in the REFUELING MODE.
The OPERABILITY of this system ensures the containment purge penetrations will be automatically isolated upon detection of high radiation levels within containment.
The OPERABILITY of this system is required to restrict the release of radioactive materials from the containment atmosphere to the environment.
The restriction on the setpoint for GT-RE-22 and GT-RE-33 is based on a fuel handling accident inside the Containment Building with resulting damage to one SE fuel rod and subsequent release of 0.1% of the noble gas gap activity, except eo for 0.3% of the Kr-85 gap activity.
The setpoint concentration of SE-3 Ci/cc p
is equivalent to approximately 150 mR/hr submersion dose rate.
3/4.9.5 COMMUNICAT10NS
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The requirement for communications capability ensures that refueling station personnel can be promptly informed of significant changes in the facility status or core reactivity conditions during CORE ALTERATIONS.
i CALLAWAY - UNIT 1 B 3/4 9-1 Amendment No.40r54,97
REFUELING OPERATIONS BASES 3/4.9.6 REFUELING MACHINE
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The OPERABILITY requirements for the refueling machine and auxiliary hoist ensure that:
(1) manipulator cranes will be used for movement of drive rods and fuel assemblies, (2) each crane has sufficient load capacity to lift a drive rod or fuel assembly, and (3) the core internals and reactor vessel are protected from excessive lifting force in the event they are inadvertently engaged during lifting operations.
3/4.9.7 CRANE TRAVEL - SPENT FUEL STORAGE FACILITY i
The restriction on movement of loads in excess of the nominal weight of a i
fuel and control rod assembly and associated handling tool over other fuel assemblies in the storage pool areas ensures that in the event this load is i
dropped: (1) the activity release will be limited to that contained in a single fuel assembly, and (2) any possible distortion of fuel in the storage racks will not result in a critical array. This assumption is consistent with i
j the activity release assumed in the safety analyses.
The spent fuel pool transfer gates are excluded from this restriction because with a limited gate lift height, the spent fuel pool racks will absorb the impact of a dropped gate without damage to fuel assemblies.
In addition, redundant trolleys and supports are used when moving the gates to preclude dropping a gate on the spent fuel racks, the time and distance the gates are moved over fuel is minimized as much as practical, and gate travel over fuel l
assemblies containing RCCAs is prohibited. The spent fuel pool transfer gates are only moved for refueling activities, fuel handling system maintenance, and to change gate seals.
3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION t
i The requirement that at least one residual heat removal (RHR) loop be in operation ensures that: (1) sufficient cooling capacity is available to remove 4
decay heat and maintain the water in the reactor vessel below 140F as required during the REFUELING MODE, and (2) sufficient coolant circulation is maintained through the core to minimize the effect of a boron dilution incident and prevent boron stratification.
The requirement to maintain a 1000 gpm flowrate ensures that there is 1
adequate flow to prevent boron stratification. The RHR flow to the RCS will provide adequate cooling to prevent exceeding 140F and to allow flowrates i
which provide additional margin against vortexing at the RHR pump suction while in partial drain operation.
The requirement to have two RHR loops OPERABLE when there is less than 23 feet of water above the reactor vessel flange ensures that a single failure of i
the operating RHR loop will not result in a complete loss of residual heat i
CALLAWAY - UNIT I B 3/4 9-2 Amendment No. 47,81 j
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