ML20235H212
| ML20235H212 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 02/15/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20235H211 | List: |
| References | |
| NUDOCS 8902230516 | |
| Download: ML20235H212 (2) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION n
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g SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 55 TO FACILITY OPERATING LICENSE N0. NPF-29 SYSTEM ENERGY RESOURCES, INC., et al GRAND GULF NUCLEAR STATION, UNIT 1 l
DOCKET NO. 50-416
1.0 INTRODUCTION
By letter dated August 19, 1988, as supplemented October 10, 1988, System Energy Resources. Inc. (the licensee). requested an amendment to Facility 07.erating License No. NPF-29 for the Grand Gulf Nuclear Station Unit 1.
The proposed amendment would change the Technical Specifications (TS) by changing the downtravel power cutoff setpoint for the refueling platform hoist in TS 3/4.9.6, " Refueling Equipment." The change is needed to allow for expected thermal and irradiation growth of fuel assemblies and to have a setpoint indexed to a fixed point, the fuel top guide.
2.0 EVALUATION The downtravel for the refueling platform main hoist is limited to prevent the fuel assembly grapple from being lowered below the fuel top guide, thus precluding damage to the reactor internals or the hoist grapple by inadvertently engaging the top guide with the grapple. Currently, the top of the fuel assembly mandles is a reference point for the setpoint.
However, as the fuel assemblies grow slightly with burnup, the fuel assembly handle moves gward creating a problem for the grapple engagement.
In addition to handling fuel assem>11es, this heist is used to handle double blade guide assemblies and single blade guide assemblies. These guide assemblies are used during refueling to provide lateral support and guidance for control rods in control cells from which two or more fuel assemblies have been removed. While the handles for the double blade guides are at about the same elevation as the fuel assembly handles, the single blade guide handles are at a lower elevation.
During the last refueling outage, with the downtravel power cutoff setpoint i
close to the lowest allowable value, it was difficult to engage the j
grapple on the handle of the single blade guide assemblies. For these j
reasons, the licensee has requested that the reference point for i
establishing the setpoint for the downtravel power cutoff be changed to the fuel top guide. Thus, the allowable fuel grapple downtravel distance wi'l remain constant for future fuel cycles.
In addition, the allowable downtravel cutoff distance would be lowered by approximately 0.5 inches to facilitate engaging the grapple on the single blade guide assemblies.
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The present TS is for the downtravel setpoint of 3.5 + 0.5 inches below the top of the fuel assembly handles. For a new fue1~ assembly, the top of a fuel channel is about 4 inches below the top of the handle; and tne top of the fuel top guide is about 1.5 inches below the top of the fuel channel. Therefore, the present setpoint, if referenced on a new fuel assembly, would allow the grapple to contact fuel channels of irradiated fuel and would keep the grapple at least 1.5 inches above the fuel top guide. However, operational problems occur, as noted above.
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The proposed setpoint of equal to or greater than 1.0 inch abcVe the fuel i
top guide will prevent potential damage to the refueling platform main i
hoist and the reactor internals during lifting operations. The new setpoint will not allow engaging the top guide with the fuel grapple.
The impact force of the grapple on the fuel channel would not damage the channel because of the light weight of the grapple, which is suspended from a cable. Accordingly, the proposed setpoint is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes the surveillance requirements. The staff has determined that the amendment involves no significant increase in the i
amounts, and no significant change in the types, of any effluents that may be released off site; and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves i
no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibilit criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9)y Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
i The Commission made a proposed determination that this amendment involves no significant hazards cor sideration, which was published in the Federal
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Register on November 2, 1988 at 53 FR 44252, and consulted with the state of Mississippi. No public coments or requests for hearing were received, and the State of Nississppi did not have any coments.
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the ublic will not be endangered by operation in the proposed manner, and p(2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and the security, or to the health and safety of the public.
Principal Contrib'utor:
L. L. Kintner, Project Directorate II-1 Dated:
February 15, 1989
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