ML20206A489
| ML20206A489 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/01/1987 |
| From: | VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| Shared Package | |
| ML20206A465 | List: |
| References | |
| RTR-NUREG-0452, RTR-NUREG-452 NUDOCS 8704080046 | |
| Download: ML20206A489 (5) | |
Text
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REFUELING OPERATIONS WATER LEVEL - REACTOR VESSEL LIMITING CONDITION FOR OPERATION i
3.9.10 At least 23 feet of water shall be maintained over the top of the reactor pressure vessel flange.
APPLICABILITY: During movement of fuel assemblies or control rods within the i
reactor pressure vessel while in MODE 6.
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ACTION:
l With the requirements of the above specification not satisfied, suspend all i
operations involving movement of fuel assemblies or control rods within the pressure vessel. The provisions of Specification 3.0.3 are not applicable, l
SURVEILLANCE RE0UIREMENTS 4.9.10 The water level shall be determined to be at least its minimum required depth within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> prior to the start of and at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter during movement of fuel assemblies or control rods.
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8704080046 870401 PDR ADOCK O 38 P
NORTH ANNA - UNIT 1 3/4 9-10
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REFUELING OPERATIONS WATER LEVEL - REACTOR VESSEL LIMITING CONDITION FOR OPERATION 3.9.10 At least 23 feet of water shall be maintained over the top of the reactor pressure vessel flange.
APPLICABILITY: During movement of fuel assemblies or control rods within the reactor pressure vessel while in MODE 6.
ACTION:
With the requirements of the above specification not satisfied, suspend all operations involving movement of fuel assemblics or control rods within the pressure vessel. The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIREMENTS 4.9.10 The water level shall be determined to be at least its minimum required depth within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> prior to the start of and at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter during movement of fuel assemblies or control rods, i
l NORTH ANNA - UNIT 2 3/4 9-11
ATTACHMENT 2 SAFETY EVALUATION Virginia Electric and Power Company
l DISCUSSION The Technical Specification 3.9.10 for North Anna Units 1 and 2 requires that "At least 23 feet of water shall be maintained over top of the reactor pressure vessel flange".
The APPLICABILITY for Tech Spec 3.9.10 "During CORE ALTERATIONS while in MODE 6",
will be changed to conform to Standard Technical Specifications for Westinghouse Pressurized Water Reactors, NUREG 0452, Rev. 3 which is, " APPLICABILITY: During movement of fuel assemblics or control rods within the reactor pressure vessel while in MODE 6".
This change will allow the removal of vessel internal assemblies with less than the specified water level but will still require 23 faet of water above the vessel flange whenever fuel assemblies or control rods are to be moved. This is consistent with the Standard Technical Specifications and the North Anna Accident Analysis.
The bases for the North Anna Technical Specification and the Standard Technical Specification state "the restrictions on minimum water level ensure that sufficient water depth is available to rencve 99% of the assumed 10% iodine gap activity released from the rupture of an irradiated fuel assembly. The minimum water depth is consistent with the assumptions of the accident analysis."
The Updated Final Safety Analysis Report (UFSAR) Accident Analysis for North Anna lists the " FUEL-HANDLING ACCIDENT INSIDE CONTAINMENT" as "... a fuel assembly is assumed to drop, underwater, and rupture the cladding of all rods in that bundle."
The analysis shows that the postulated release of radioactivity to the environment to be well below 10 CFR 100 limits.
BASIS FOR NO SIGNIFICANT HAZARDS DETERMINATION The proposed change does not involve a significant hazards consideration because operation of North Anna Units 1 & 2 in accordance with this change would not:
(1) involve a significant increase in the probability or consequence of an accident previously evaluated.
This change does not alter the conditions or assumptions of the accident analysis or the basis of the current Technical Specification.
Fuel handling operations during refueling are unchanged and the refueling water level requirement remains consistent with the accident analysis assumptions in the UFSAR concerning the minimum required water -level.
Therefore the probability and the consequences of the fuel handling accident are not increased.
(2) create the possibility of a new or different kind of accident from any accident previously identified.
This change does not alter the conditions or assumptions of the accident analysis or the basis of the current Technical Specification.
Fuel handling operations during refueling are unchanged 2nd therefore the fuel handling accident evaluated in the UFSAR remains bounding in terms of the type of accidents that may occur and a new and different kind of accident is not created.
4 (3) involve a significant reduction in a margin of safety.
This change does not alter the conditions or assumptions of the accident analysis or the basis of the current Technical Specification.
Fuel handling l
operation during refueling are unchanged and the refueling water level requirement remains consistent with the assumptions of the -accident analysis.
Consequently, the margin to 10 CFR Part 100 dose limits is not reduced.
Therefore, pursuant to 10 CFR 50.92, based on the above consideraticns, i
it has been determined that this change does not involve a significant hazards consideration.
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