ML20040D841
| ML20040D841 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 01/27/1982 |
| From: | William Jones OMAHA PUBLIC POWER DISTRICT |
| To: | Clark R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20040D842 | List: |
| References | |
| NUDOCS 8202020308 | |
| Download: ML20040D841 (2) | |
Text
e Omaha Public Power District 1623 HARNEY e OMAHA. NEBRASMA 68102 m TELEPHONE 536 4000 AREA CODE 402 January 27, 1982 8 I
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Mr. Robert A. Clark, Chief 7
U. S. Nuclear Regulatory Commission
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Office of Nuclear Reactor Regulation p
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Operating Reactors Branch No. 3
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Reference:
Docket No. 50-285
Dear Mr. Clark:
The Omcha Public Power District recently submitted an application for amendment to the operating license of the Fort Calhoun Station regarding revisions to the reactor coolant system heatup and cooldown limits for Cycle 7 operation.
Per a telephone conversation between T. Patterson and R. Kellogg (OPPD) and C. Trammell and N. Randall (NRC) on January 22, 1982, two changes to the subject submittal are necessary. Accordingly, please find enclosed revised Pages 2-7, 2-7a, 2-22, 2-23a, 2-23b, Figures 2-18, 2-2A, 2-2B, and a revised Discussion.
Discussion of the changes is provided below.
For reactor criticality, Appendix G to 10 CFR 50 requires the reactor coolant system (RCS) temperature to be greater than the minimum per-missible temperature for inservice hydrostatic testing of the RCS.
Article IWB-5000 of the ASME Boiler and Pressure Vessel Code,Section XI states that inservice hydrostatic testing of the RCS be conducted at 110 percent of the RCS operating pressure.
This corresponds to a 2310 0
psia hydrostatic testing pressure and temperature of 348 F for the Fort Calhoun Station. The enclosed Figures 2-2A and 2-28, regarding RCS pressure-temperature limits for critical heatup and cooldown, have been revised to reflect the 3480F minimum temperature. The District's pre-viously reported minimum temperature of 3780F was based upon RCS hydrostatic testing of 125 percent of system " design" pressure, which was the pressure required for pre-operational testing of the RCS.
The second change concerns the overpressurization limitations imposed by the low pressure safety injection (LPSI) pumps when cooling the RCS at the permissible 1000F/ hour cooldown rate. To prevent low temperature overpressurization during operation of the LPSI pumps, a limiting or minimum temperature (at which the 1000F/ hour cooldown rate must be stopped and the cooldown rate lowered) is necessary. This cutoff tempera-ture corresponds to the LPSI pump dead head or minimum flow pressure.
The District's previously reported dead head pressure of 206 psia, 8202020308 820127 f
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i Mr. Robert A. Clark, Chief January 27, 1982 U. S. Nuclear Regulatory Commission Page Two corresponding to a temperature of 158 F, was erroneously calculated and also used LPSI pump design information from the manufacturer's pump curves. The dead head pressure has been recalculated using data from the monthly LPSI pump pressure tests. These tests indicate the actual dead head pressure to be 200 psia at the elevation of the PORV's, 0
j corresponding to a temperature of 153 F on the 1000F/ hour cooldown rate curve. Since the monthly tests provide the true operating characteristics 4
of LPSI pumps, the District believes it is prudent to use this information in the cooldown curve.
The enclosed pages indicate this revision.
Sincerely,
/b
.C Jones
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DidtsionManager Production Operations t
WCJ/KJM/TLP/RWS/lp 4
1 Enclosures 3
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LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N. W.
Washington, D. C.
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