ML20151F047
| ML20151F047 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 07/19/1988 |
| From: | Morris K OMAHA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| LIC-88-605, NUDOCS 8807260319 | |
| Download: ML20151F047 (4) | |
Text
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Omaha Public Power District 1623 Harney Omaha, Nebraska 68102 2247 402/536-4000 July 19, 1988 LIC-88 605 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station Pl-137 Washington, DC 20555
Reference:
1.
Docket No. 50-285 2.
Letter from OPPD (R. L. Andrews) to NRC (Document Control Desk) dated April 14, 1988 (LIC-88-219)
Gentlemen:
SUBJECT:
Correction to Special Report on Inoperability of Post-Accident Monitoring Instrumentation This correction is being submitted to correct the maintenance order number specified in the fourth paragraph of Reference 2.
The entire text of Reference 2 is reproduced here, thus superceding Reference 2 in its entirety.
The Omaha Public Power District, holder of Operating License DPR-40, submits this special report pursuant to the requirements of Fort Calhoun Station Unit No.1 Technical Specification 2.21, "Post-Accident Monitoring Instrumentation."
Fort Calhoun Station Unit No.1 Technical Specification 2.21 Table 2-10 Item 8, specifies the requirements for the core exit thermocouples (CETs). Action (i) requires with the number of Operable Core Exit Thermor.ouples less than the four required by NUREG-0737, either restore the number of operable channels to at least four within seven (7) days of discovery of the inoperability, or prepare and submit a special report to the Nuclear Regulatory Commission.
This report is being submitted because for more than seven days core quadrant I had only three operable CETs.
On March 15, 1988 at 0401, alarms were received in the Control Room indicating problems with the Qualified Safety Parameter Display System Channel A (QSPDS A). The situation was assessed and QSPDS A was declared inoperable.
At 0417 Operations personnel noticed the smell of hot insulation emanating from within the QSPDS A panel AI-208A and immediately de-energized the panel.
De-energi-zing the panel resulted in halting the source of the fumes.
Maintenance Order #881110 was issued to investigate the problem.
It was dis-covered that the Isolated Expander Module on the DT-1748-1 Expander Card had been overheated resulting in the failure of the QSPDS A panel. The DT-1748-1 Expander Card collects and relays the inputs from 8 Core Exit Thermocouples and PDR ADOCK 05000285 dh 8807260319 880719 S
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V. S. Nuclear Regulatory Commission LIC-88-605 Page 2 the inputs from 4 Heated Junction Thermocouples (2 heated and 2 unheated) to the QSPDS A central processing unit.
The damaged card was replaced and function testing initiated.
l The number of core exit thermocouples per quadrant for each channel is shown'in i
Figure 1.
Figure 2 indicates the number of CETs affected and the number of CETs operable. Only quadrant I had less than four operable CETs as a result of
}
the card failure.
Table 1 indicates that the number of Heated Junction Thermo-couples (HJTCs) was within Technical Specification requirements during the equipment failure.
4 During the trouble shooting on March 23, 1988, the ISBC-544 Communications Con-troller Board was found to be inoperable.
The ISBC-544 Communications Control-1er Board interfaces the central processing unit with the screen in the QSPDS A panel and with the Emergency Response Facility Computer System as part of the Safety Parameter Display System (SPDS).
The defective board was subsequently l
replaced. After replacement of the DT-1748-1 card, the QSPDS A panel was calibrated. sing procedure CP-A/QSPDS.
Surveillance tests ST-SCMM-1 F.1 and ST-HJTC-1 F.1 were satisfactorily performed following the replacement of the ISBC-544 Communications Controller Board.
The equipment was returned to e
service and declared operable on March 23, 1988 at 1705.
Subsequently it was discovered that some seismic bracing had not been reinstal-led in the panel since the March 23 repair.
Therefore, at 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> on April 6, 1988 QSPDS A was again declared operable. The required repairs were comple-ted at 1117 hours0.0129 days <br />0.31 hours <br />0.00185 weeks <br />4.250185e-4 months <br /> on April 9, 1988.
Corrective actions have been completed.
This special report was being issued within the 30 day limit as specified in Technical Specification 2.21 Table 2-10, Item 8 (i).
t Sincerely, Division Manager Nuclear Operations KJM/jb i
l Attachment i
c:
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Ave., N.W.
Washington, DC 20036 R. D. Martin, NRC Regional Administrator P. D. Milano, NRC Project Manager P. H. Harrell, NRC Senior Resident Inspector I
l
\\
,l
Numeer of Core Exit Thermocoales installed In QSPOS Channele A & 8 N,
t CETs CErs CETs CETs QJeorant 1 Queorant 2 Quadrant i QJadrant 2 4
4 3
3 4
7 3
4 4
3 QJacrent 4 Qasorant 3 Ouserent 4 Qasarant 3 CETs CETs CETs CETs QSPOS Channel A 0$PDS Channel B Hureg-0737 ltem 111.2 recutres each core ouserant to be monitoreo ey 4 Core Exit nermocowotes tf this can not to maintaineo restere to at least four per core quaorsat within 7 days or wittan 3C days cf the ciscwery of inoperability sutmit a report to the Nuclear Regulatory Ccmmiesten.
Fert Calhoun Technical Sotelfication 2.21 recutres et least 2 Core Exit Therrnoccuoles per core queorant or restore to a least 2 per core queccent within 7 days or be in het shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. lf no Core Exit Thermocovoles are opersale in a core cusarant either restors tne inocereele channel (s) within 46 hours5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br /> er be in het shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
Figure 1 Number of Core Exit Thermocouelas Affected in 03POS Channels A & B by Damageo OSPDS Card CETs CITs CErs CETs Quaerantt QJadrant 2 hadrant 1 Wadrant 2 4 (0) 2 (1) 0(3) 0 (4h 0(3) 2 (2) 0(4) 0(3) 0;scrent 4 Ouaorant 3 QJadrant 4 (ksdrant 3 CETs CETs CEra CEtt 0$903 Channel A QSPOS Channel B Humoers represent the number of effected Core Exit Thermocouples in each cutarant.
s4 Numbers in carenthesis recresent coersels Core Exit Thermoccuoles
.."s.
Figure 2 5Ii?
n
'Affected Hested Juncuen Themocouples by OSPOS Chemel A Ineperehtlity HEATfD NTC
>#!CTED UNHEATED NTC AFFECTED TNIA NO TU1A NO TN2A NO TU2A NO TH3A N0*
11J3A N0*
THdA NO TU4A NO THSA No TV5A N0 IN6A NO TU6A N0 TH7A YES TU7A YES TH8A YES TU8A YES
'PfEVIOUSLYIN0PtRAtt!
Hested Junction Thermoccuoles ooersta se e cele (one hoeled and one unheeled comorise a funcuonal Hested Juncuen Thermocouple). Hested Junction Thermocouples 1-4 comprise the Upper string end Hested Junction Thermocovoles 5-6 comprise the Lower $tring.
Technical Specification 2.21 defines en coerable string as having four furetionel Hested Juncuon Thermocouelas with et least 2 each in the Upper and Lower $trings.
Tettei d
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