ML20137G835
| ML20137G835 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 01/14/1986 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20137G738 | List: |
| References | |
| RTR-NUREG-0123, RTR-NUREG-123 NUDOCS 8601210233 | |
| Download: ML20137G835 (3) | |
Text
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4-PDAPS
. LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.10.C Spent Fuel S torage 4.10.C Spent Fuel Storage Pool Water Level Pool Water Level 1.
At least 22 feet of water Whenever irradiated fuel is sh'all be maintained over the stored in the spent fuel pool, top of the irradiated fuel the water level shall be seated in the spent fuel recorded daily, storage pool racks.
2.
If specification 3.10.C.1 4
cannot be satisfied, suspend all movement of fuel assemblies and crane operations with loads in the spent fuel storage pool area after placing the fuel assemblies and crane load in a safe condition.
D.-
Heavy Loads Over Spent Fuel Loads in excess of 1000 lbs. (excluding the rigging and transport vehicle) shall be prohibited from travel over i
fuel assemblies in the spent fuel storage pool.
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e 3.10 BASES (Cont' d)
The requirements for SRM Operability during these core alterations assure sufficient core monitoring.
B.
Core Monitoring The SRM's are provided to monitor the core during periods of station shutdown and to guide the operator during refueling operations and station startup.
Requiring two operable SRM's i
in or adjacent to any core quadrant where fuel or control rods are being moved assures adequate monitoring of that quadrant during such alterations.
The requirement of 3 counts per second provides assurance that neutron flux is being monitored and insures that startup is conducted only if the source range flux level is above the minimum assumed in the control rod drop accident.
During unloading of fuel, it is permissible to allow the SRM count rate to decrease below 3 cps.
Since all fuel moves during core unloading will reduce reactivity, the lower number of counts will not present a hazard.
Requiring the SRM's to be functionally tested prior to fuel removal assures that the SRM's will be operable at the start of fuel removal.
The daily response check of the SRM's ensures their continued operability until the count rate deminishes due to fuel removal.
Control rods in cells from which all fuel has been removed and which are outside the periphery of the then existing fuel matrix may be armed electrically and moved for maintenance purposes during fuel removal, provided all rods that control fuel are fully inserted and electrically disarmed.
During core loading, the loading of adjacent assemblies
.around the four SRM's before attaining the 3 cps is permissible because these assemblies were in a subcritical configuration when they were removed and therefore will remain subcritical when the same assemblies are placed back into their previous positions.
Since specification 3.10.A.2 requires that all control rods be fully inserted prior to loading fuel, inadvertent criticality is precluded during l
core loading.
C.
Spent Fuel Pool Water Level The intent of the Technical Specification is to provide, adequate water coverage for cooling and shielding at all times.
With the water at elevation 233' (its normal operating level at the top of the pool weir), approximately 23 ft. of water is maintained above fuel stored in the spent f
fuel storage racks.
The physical arrangement of the spent l
fuel pool overflow to the skimmer surge tanks may be adjusted such that the minimum operating water level provides 22 ft.
of water coverage over irradiated fuel in the storage racks.
For this reason, the specification for minimum water coverage has been established at 22 ft.
This level provides adequate i
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water coverage for both shielding and cooling at all times, including during fuel movement.
The minimum water coverage measurement is the distance between the top of the fuel rod plenum and the spent fuel pool water level at its lowest adjusted level.
With the water maintained at the minimum level, there is sufficient water depth to ensure that any
' iodine released from a hypothesized fuel handling accident would be reduced to acceptable levels before it reached the refueling floor.
There are no piping connections to the spent fuel pool at any lower elevation.
4.10 BASES A.
Refueling Interlocks Complete functional testing of all refueling interlocks before any refueling outage will provide positive indication that the interlocks operate in the situations for which they were designed.
By loading each hoist with a weight equal to the fuel assembly, positioning the refueling platform and withdrawing control rods, the interlocks can be subjected to valid operational tests.
Where redundancy is provided in the logic circuitry, tests can be performed to assure that each redundant logic element can independently perform its function.
B.
Core Monitoring
-Requiring the SRM's to be functionally tested prior to any core, alteration assures that the SRM's will be operable at the start of that alteration.
The daily response check of the SRM's ensures their continued operability.
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