ML20063K033
| ML20063K033 | |
| Person / Time | |
|---|---|
| Site: | 05200001 |
| Issue date: | 02/14/1994 |
| From: | Fox J GENERAL ELECTRIC CO. |
| To: | Poslusny C Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9402280122 | |
| Download: ML20063K033 (2) | |
Text
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i February 14,1994 Docket No.52-001 Chet Poslusny, Senior Project Manager Standardization Project Directorate Associate Directorate for Advanced Reactors and License Renewal Office of the Nuclear Reactor Regulation
Subject:
Submittal Supporting Accelerated ABWR Schedule -
Simultaneous Withdrawal of a Control Rod and FMCRD
Dear Chet:
Enclosed is the write-up on the consequences of simultaneous withdrawal of a control rod and its FMCRD you requested.
Please provide a copy of this transmittal to Dave Diec.
- Sincerel, C
h,j Ja k Fox Advanced Reactor Programs cc:
Alan Beard GE)
Gary Ehlert GE)
Norman Fletcher DOE)
Joe Quirk GE)
Craig Sawyer GE) i 1
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PDR ADOCK 05200001 A
l CONSEQUENCE OF SIMULTANEOUS WITIIDRAWAL OF CONTROL ROD AND FMCRD In the unlikely event that a control rod and its FMCRD are removed simultaneously, sufficient capability is available to maintain RPV water lever while emergency action is taken to plug the opening in the bottom of the vessel. The FMCRD orifice is 60mm in diameter, producmg an expected flow rate from the opening of 96 cubic meters /hr. Any motor driven ECCS Jump or condensate /feedwater pump can maintain water level. T1e lower drywell volume up to the equ'pment platform is 106 cubic meters. At this flow rate, it takes a little i
over an hour for the water level to reach the tunnel entrances and begin flowing into the access tunnels. It is expected that the plant personnel can close the equipment hatch and secure a sufficient number of bolts within this period of time.
The leakage around this hatch can be easily maintained by sump pumps in the secondary containment.
In the time it takes to fill the lower drywell up to the openings that connect the lower drywell to the upper drywell inside the connecting vents plant personnel on the refueling floor can replace the control rod. Plant personnel can easily perform this operation, because the fuel channels surrouding the missing control rod blade will act as guides for replacing the missing control rod blade.