ML20116L323
| ML20116L323 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 08/12/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20116L316 | List: |
| References | |
| NUDOCS 9608160227 | |
| Download: ML20116L323 (5) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 20666 4 001
.....,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.166 TO FACILITY OPERATING LICENSE N0. DPR-35 BOSTON EDIS0N COMPANY PILGRIM NUCLEAR POWER STATION DOCKET NO. 50-293 l.0 INTRODUCTION By application dated May 1, 1996, Boston Edison Company (the licensee) requested changes to the Technical Specifications (TSs) for the Pilgrim Nuclear Power Station.
The proposed changes will modify the definition of
" Core Alteration," and the limiting condition for operation, Surveillance conditions and Bases section associated with Technical Specification 3.7.C,
2.0 DEFINITION OF CORE ALTERATION The licensee's May 1,1996, letter to the NRC proposes to modify definition 1.0.Q, " Alteration of the Reactor Core." The current TS defines core alteration as the act of moving any component in the region above the core support plate, below the upper grid and within the shroud. The definition excludes normal control rod movement with the control rod drive hydraulic system and normal core instrumentation movement. The definition is being modified so that the term will apply only to those activities that create the potential for a r,! activity excursion. Those activities that could cause a reactivity excursion would warrant special precautions such as:
secondary containaant operable, control room emergency ventilation operable, minimum number of AC and DC power supplies operable and refueling interlocks operable.
The new definition would allow the movement of source range monitors, local power range monitors, intermediate range monitors, traversing incore probes, special movable detectors (including under vessel replacement), cameras, lights, tools, etc. Movement of items that require no special controls to prevent a reactivity excursion will not be considered a core alteration. For instance, removal of a control rod from a core cell where there are no associated fuel assemblies is not considered a core alteration. The removal of the four fuel bundles surrounding a control rod reduces the reactivity worth of the associated control rod to the point where removal of that rod no longer has the potential to cause a reactivity excursion. This fact is recognized in the design of the control rod velocity limiter which precludes removal of a control rod prior to the removal of the four adjacent fuel bundles.
In the refueling mode, the only mode in which core alterations are allowed, the one-rod-out interlock precludes moving more than a single control rod at a time and requires all other rods to be fully inserted.
By the new definition, even though one rod movement is allowed by TS, this control rod movement would 9608160227 960812 PDR ADOCK 05000293 P
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. now be considered a core alteration. This control rod movement will now reach e various precautions such as refueling interlocks, secondary containment and the SCRAM function to be operable. The staff has determined that this change provides the licensee some additional operational flexibility during refueling while still providing assurances that activities that could cause a reactivity excursion are defined as a core al'.eration and would warrant special precautions.
In addition, the wordfag is consistent with the improved standard technical specifications (STS). Sased on the above, the staff concludes that this TS change is acceptable.
3.0 SECONDARY CONTAINMENT The licensee's May 1,1996, letter to the NRC proposes to modify existing TS Sections 3.7.C.1 and 3.7.C.2, " Containment Systems," and the associated Bases section.
In addition, Surveillance requirements 4.7.C.1.a and b are being deleted and Surveillance 4.7.C.I.c is being reworded for clarity and renumbered to reflect deletion of 4.7.C.I.a and b.
The TS for the secondary containment integrity is currently written to define when secondary containment is not required.
If the secondary containment integrity cannot be maintained then the current TS require that actions be initiated to establish conditions for which secondary containment is not necessary. The proposed TS is written to define when secondary containment integrity is required and the actions to take if secondary containment is inoperable and the time frames for completing the actions.
4 The current.TS requires the following four conditions to be satisfied when secondary containment integrity is not maintained:
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The reactor is subcritical and Specification 3.3.A is met, b.
The reactor water temperature is below 212 *F and the reactor coolant system is vented, c.
No activity is being performed which can reduce the shutdown margin below that specified in Specification 3.3.A, and d.
The fuel cask or irradiated fuel is not being moved in the reactor building.
These conditions would require the plant to be either in the cold shutdown mode or in the refueling mode but with fuel not being moved.
Specification 3.3.A, " Reactivity Margin - core loading," requires a reactivity condition such that the core could be made subcritical in the most reactive condition during the operating cycle with the strongest operable control rod in its full out position and all other rods fully inserted.
The shutdown margin is determined as part of the reload analysis and confirmed by insequence criticality testing during startup and monthly monitoring of critical rod configuration during the cycle.
In the shutdown or refueling mode all rods are inserted and only in the refueling mode can one rod be moved. This
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9 control rod movement will require various precautions such as refueling interlocks, secondary containment and the SCRAM function be operable. This assures that Specification 3.3.A is maintained in the cold shutdown and refueling modes.
The revised TS would require that secondary containment integrity be operable in Run, Startup, and Hot Shutdown Modes, during movement of irradiated fuel assemblies in the secondary containment, and during movement of new fuel over the spent fuel pool, and during core alterations, and during operations with a potential for draining the reactor vessel. These conditions essentially include all conditions except cold shutdown and refueling mode when fuel is not being moved. Therefore, the applicability requirements for the secondary containment have not changed.
In addition, as noted above, Specification 3.3.A is maintained in the cold shutdown and refueling modes when secondary containment is not necessary. The revised TS provides action statements and completion times specifying the actions to take if secondary containment is not operable. The previous TS had one action statement that required that, when the secondary containment integrity was needed but unavailable, the plant initiate actions to place the plant in a condition in which the secondary containment integrity was not necessary but with no time restraints.
Therefore, the new TS is more restrictive as it requires specific actions and completion times.
The staff has concluded that the revised TS specify more clearly when secondary containment integrity is required, what actions to take if secondary containment is inoperable, and time frames for completing the actions.
Based on the above, the staff concludes that the revisions enhance the current TS by making them more definitive and supplementing them with action statements and required completion times and, therefore, the changes are acceptable.
The amendment deletes Surveillance requirements 4.7.C.1.a and b as they were required only during the preoperational testing.
Surveillance 4.7.C.I.c was reworded and the changes were purely editorial in nature.
In addition, Surveillance 4.7.C.1.c was renumbered to 4.7.C.1 to reflect the deletion of Surveillances 4.7.C.I.a and b.
This was also an editorial change.
Based on the above, the staff concluded that the proposed changes are acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Massachusetts State official was notified of the proposed issuance of the amendment. The State official had no comments.
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5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. This also changes surveillance requirements.
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no 1
public comment on such finding (61 FR 28606). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR-51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
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6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common e
defense and security or to the health and safety of the public.
Principal Contributor:
A. Wang Date:
August 12, 1996 4
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L DATED:
Au8ust 12, 1996 l~
POWER STATION AMENDMENT NO.166 TO FACILITY OPERATING LICENSE NO. DPR-35-PILGRIM NUCLEAR Docket. File l
PUBLIC PDI-1 Reading S. Varga, 14/E/4 J. Mitchell l
S. Little A. Wang OGC G. Hill (2), T-5 C3 S. Black C. Grimes, ll/E/22 ACRS L. Doerflein, Region I C. Grimes cc:
Plant Service list l
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