ML20151B827
| ML20151B827 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 07/11/1988 |
| From: | Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Morris K OMAHA PUBLIC POWER DISTRICT |
| References | |
| CAL-88-11, NUDOCS 8807210121 | |
| Download: ML20151B827 (3) | |
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1.
t JUL I I B l
In Reply Refer To:
Docket:
50-285/88-22/ CAL 88-11 Omaha Public Power District ATTH:
K. J. Morris, Division Manager-Nuclear Operations 1623 Harney Street Omaha, Nebraska 68102 Gentlemen:
SUBJECT:
CONFIRMATORY ACTION LETTER Thank you for your letter of July 1,1988, in response to the June 30, 1988, telephone conference call between NRR, Region IV, and Omaha Public Power District (0 PPD) regarding two nonconservative errors discovered in the Cycle 11 setpoint analysis and the corrective actions you have init.iated. The two nonconservative errors affect Technical Specification Figure 1-3 for the Thermal Margin / Low Pressure Trip Setpoint and Technical Specification Figure 2-6 for the Excore Monitoring Linear Heat Rate (LHR) Limiting Condition for Operation (LCO).
It is our understanding, based on your July 1,1988, letter, that Combustion Engineering (CE) has independently reanalyted your Cycle 11 setpoints and the results of the reanalysis have been verified by OPPD to determine that no additional nonconservative errors exist.
Further, it is our understanding, based on your July 1,1988, letter, that for the remainder of Cycle 11 the following corrective measures have been taken:
1.
The RPS Thermal Margin / Low Pressure Calctlator Setpoints have been adjusted by 100 psia to conservatively account for the 79 psia nonconservatism identified in the reanalysis.
This 79 psia corresponds to a 2.63 percent T
nonconservatism in the total integrated radial peaking factor (FR)which resulted from a failure to apply the penalty factor.
2.
It has been determined that Cycle 11 operations have not resulted in a full power total integrated radial peaking factor in excess of 1.70 (e.g., actual maximum has been 1.68). The Technical Specification limit for this parameter is 180 yielding an additional Cycle 11 operating margin of 5.56 percent (for F 7=1 to the Thermal Marjin Evar eq.70) or approximately a 180 psia conservatism uation.
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It has been concluded that prior to revising the Thermal Margin / Low Pressure Trip Setpoints in (1) above, that at no time during Cycle 11 operation had the setpoint margin requirements been exceeded.
4.
Should loss of the incore monitoring ability combined with lack of a valid power distribution result in the use of the excore monitoring LHR LC0 (e.g., Technical Specification Figure 2-6) versus the normally used incore monitoring DNB LC0 (Technical Specification Figure 2-7), power shall be immediately reduced to 80 percent of rated power. Revisions to the Technical Data Book Figures III.16.b, III.16.b.1, III.16.b.2, and III.16.c have been prepared and implemented into the Operating Manual, Volume I.
It should be noted that use of the excore monitoring LHR LC0 has not been required within at least the previous 12 years of operation and that use of this LC0 is not expected to be required during the remainder of Cycle 11 operation.
5.
It has been concluded that should use of the excore monitoring LHR LC0 have been necessary during Cycle 11 operation, sufficient margin would haveexistep)duetomarginbetweentheactualtotalplanarradialpeaking factor (F and the Technical Specification limit of 1.85 to have T prevented Exceeding any of the required LHR margins. The maximum F X
occurring during Cycle 11 to date has been 1,72 which yields a margN of 7.0 percent.
6.
An Operations memo has been issued notifying Operations to utilize the Technical Data Book figures in lieu of Technical Specification Figures 1-3 and 2-6, and to limit core inlet temperature to 542 F.
Please contact me immediately should our understanding of your actions and corrective measures differ from that set forth above.
/ s/
Robert D. Martin Regional Administrator cc:
Fort Calhoun Station ATTH:
W. G. Gates, Manager P.O. Box 390 Fort Calhoun, Nebraska 68023 Harry H. Voigt, Esq.
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, NW Washington, D. C.
?'J036 Kansas Radiation Control Program Director Nebraska Radiation Control Program Director
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e Omaha Public Power District bec to DMB (IE36) bec distrib. by RIV:
R. D. Martin, RA RPB-DRSS Section Chief (DRP/8)
MIS System RIV File DRP RSTS Operator Project Engineer, DRP/B Lisa Shea, RM/ALF P. Milano, NRR Project Manager DRS G. F. Sanborn, E0 RRI L. J. Chandler, Asst GC/0GC J. M. Taylor, DEDR0 T. E. Murley, D/NRR J. L. Lieberman, D/0E L. J. Callan, D/DRP J. L. Milhoan, D/DRS R. L. Bangart, D/DRSS J. L. Carson, RA Sect'y