ML20086E447
| ML20086E447 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/21/1991 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20086E441 | List: |
| References | |
| NUDOCS 9112020103 | |
| Download: ML20086E447 (4) | |
Text
Peach Bottom Atomic Power Station Unit 3 i
Docket No. 50-278 License No. DPR-56 TECHNICAL SPECIFICATIONS CHANGE REQUEST No. 91-10 REVISED TECHNICAL SPECIFICATION PAGES List of Attached Pages 225 226 229 l
l 9112O20103 911121 DR ADOCK 0500o27g PDR
PBAPS LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS
^
3.10 CORE AtTERATIONS 4.10 CORE ALTERATIONS Applicability Applicability Applies to the fuel handling Applies to the periodic and core reactivity limit-testing of those interlocks
- ations, and instrumentation used during refueling and core alterations.
_0bjective Objective To ensure that core reactivity To verify the operability is within the capability of of instrumentation and inter-the control rods and to pre-locks used in refueling and vent critically during core alterations.
refueling.
Specification Specification A. Refueling Interlocks A. Refueling Interlocks
- 1. The reactor mode switch
- 1. Prior to any core altera-shall be locked in the tions within or over the
" Refuel" position during reactor core, the reactor core alterations and the switch " Refuel" position refueling interlocks shall interlocks shall be func-be operable except as spec-tionally tested.
They shall ified in 3.10.A.2, 3.10.A.S be tested at weekly intervals and 3.10.A.6 below, thereafter until no longer required. They shall also be
- 2. Fuel-shall not be loaded '.co tested following any repair l
I the reactor core unk' I
work associated with the control rods are aserted interlocks.
with the folloi
.ption*:
- a. The reactor mod
. witch shall be
- 2. Prior to performing control locked in the Ae.cel" position, rod or control rod drive The refueling interlock maintenance on control which prevents fuel from cells without removing fuel being loaded with a control assemblies, it shall be rod withdrawn may be by demonstrated that the core passed for any number of can be made subcritical by a control rods, and those margin of 0.25 percent Ak at control rods withdrawn or removed any time during the from the core, if the four maintenance with the fuel assemblies surrounding each strongest operable control rod or control rod control rod mechanism to be withdrawn or removed from the core and/or reactor vessel This exception is in are removed from the core cell.
effect during the period Additionally, all fueled cells face prior to completion of and diagonally adjacent to each cell tensioning the reactor with a control rod withdrawn or re-vessel head bolts for the moved shall have their control rod Unit 3 Cycle 8 refueling fully inserted and their control
- outage, rod's directional control valves electrically disarmed. All other refueling interlocks shall be operable.
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i PBAPS l
i tlMITI AG CONDITIONS FOR OPER/ i10N SURVEltLANCE REQUIREMENTS I
3.10.A Refueling Interlock.s 4.10.A.2 (cont'd) 3.
The fuel grapple hoist load fully withdrawn and all switch shall be set at i 1000 other operable rods lbs.
fully inserted. Alternatively if the remaining control rods 4
If the frame-nounted are fully inserted and have auxiliary hoist, the monorail-their directional control mounted auxiliary hoist, valves electrically disarmed, or the service platform it is sufficient to hoist is to be used demonstrate that the for handling fuel with core is subcritical the head of' the reactor with a margin of at vessel, the load limit least 0.25% Ak at any switch on the hoist to time during the main-be used shall be set at tenance. A control 1 400 lbs.
rod on which maintenance is being performed shall be considered inoperable.
5.
A maximum of two nonadjacent 4.10.A.3*
control rods may he withdrawn from the core for the purpose Prior to loading fuel in of performing control rod the core without all control and/or control rod drive main-rods fully inserted it shall tenance, provided the following be demonstrated analytically conditions are satisfied:
that the core is subcritical with a margin of at least
- a. The reactor mode switch shall 1.0% Ak assuming a be locked in the " refuel" single fuel lodding error into position.
The refueling a cell with the control rod interlock which prevents withdrawn.
more than one control rod from being withdrawn may be bypassed for one of the This requirement is in effect control rods on which main-during the period prior to tenance is being performed.
completion of tensioning the All other refueling inter-reactor vessel head bolts for locks shall be operable.
Unit 3 Cycle 8 refueling outage,
- b. A sufficient number of control rods shall be operable so that the core can be made subcritical witF the strongest operable cor. rol rod fully withdrawn and all other operable controls rods fully inserted, or all
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PBAPS 3.10 BASES A.
Refueling Interlocks The refueling interlocks are designed to back up procedural core reactivity controls during refueling operations.
The interlocks prevent an.nadvertent 4
criticality during refueling operations when the reactivity potential of the core is being altered.
To minimize the possibility of Icading fuel into a cell containing no control rod, it is required that all control rods are fully inserted when l
fuel is being loaded into the reactor core *, This requirement assures that during refueling the refueling interlocks, as designed, will prevent inadvertent criticality.
The refueling interlocks reinforce operational procedures that prohibit taking the reactor critical under certain situations encountered during the refueling operations by restricting the movement of control rods and the operation of refueling equipment.
The refueling interlocks include circuitry which senses the condition of the refueling equipment and the control rods. Depenoing on the sensed condition, interlocks are actuated which prevent the movement of the refueling equipment or withdrawal of control rods (rod block).
Circuitry is provided which senses the following conJitions:
1.
All rods inserted.
2.
Refueling platform positioned near or over the core.
3.
Refueling platform hoists are fuel-loaded (fuel grapple, frame mounted hoist, monorail mounted hoist).
4.
Fuel grapple not full up.
5.
Service platform hoist fuel-loaded.
6.
One rod withdrawn.
When the mode switch is in the " Refuel" position, interlocks prevent the refueling platform from being moved over the core if a control rod is withdrawn and fuel is on a hoist. Likewir.e, if the refueling platform is over the core with fuel on a hoist, control rod motion is blocked by the interlocks. When the mode switch is in the refuel poistion, only one control rod can be withdrawn. The refueling interlocks, in combination with core nuclear design and refueling procedures, limit the probability of an inadvertent criticality. The nuclear characteristics of the core assure tha't the reactor This requirement is not in effect during the period prior to coupletion of tensioning the reactor vessel head bolts for Unit 3 Cycle 8 refueling outage.
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