ML20247F979
| ML20247F979 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 05/19/1989 |
| From: | Morris K OMAHA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LIC-89-512, NUDOCS 8905300242 | |
| Download: ML20247F979 (2) | |
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1 Omaha Public Power District 1623 Hamey Omaha. Nebraska 68102 2247 402/536 4000 May 19, 1989 LIC-89-512 U. S. Nuclear Regulatory Lommission Attn: Document Control Desk Mail Station P1-137 Washington, DC 20555
Reference:
Docket No. 50-285 Gentlemen:
SUBJECT:
Special Report on Inoperability of Inadequate Core Cooling Instrumentation Used for Post Accident Monitoring The Omaha Public Power District (OPPD), holder of Operating License DPR-40, submits this report pursuant to the requirements of Fort Calhoun Station, Technical Specification 2.21, " Post-Accident Monitoring Instrumentation."
On April 21,1989, at 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br />, the Channel "A" signal processing equipment associated with the Inadequate Core Cooling Instrumentation (ICCI) parameters was taken out of service due to planned upgrades to the software which resides in meo ry chips in the electronic processing equipment.
The Channel A signal processing equipment software was being upgraded to accommodate indications of contain5ent instrument air isolation valves PCV-1849A and PCV-1849B on the Sar'ety P-rameter Display System (SPDS) in accordance with the requirements of NUREG-3737, Supplement 1.
PCV-1849A and B are redundant valves that were instal 1M during the 1988 refueling outage to replace the single valve PCV-1849 which m; part of the original plant design. The new software on Channel A will res alt in PCV-1849A being processed on the ICCI equipment and transmitted to the SPDS for display.
In addition to this, other software changes were being accomplished to address errors found in previous outage testing as follows:
1.
Operation of the BCD Digital Display in all modes.
2.
Correct operation of the analog outputs.
3.
Eliminate spurious thermocouple display.
4.
Modification of pressure out of range condition to occur at 2500 PSIG rather than 2501 PSIG.
5.
HJTC differential temperature alarm to occur at 25'F rather than 24*F.
l 8905300242 890519 PDR ADOCK 05000285 o
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U. S. Nuclear Regulatory Commission
.LjC-89-512 Page 2 The modification work was completed on April 29, 1989, at 0035 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br /> and the Channel "A" equipment was restored to an operable status at this time.
However, this exceeded the seven day time limit specified in Section 2.21 of the Technical Specification.
Because the ICCI parameters for Channel "A" were inoperable for more than seven days, several action statements were entered and apply to this Special Report:
1.
With the Channel "A" Subcooled Margin Monitor (SMM) being inoperable for more than seven days, an alternate means of monitoring this parameter is required by footnote (e). The alternate means of monitoring SMM is Channel "B" of the QSPDS in addition to the two channels which exist on the main control board. This satisfies footnote (e).
2.
With the number of operable Core Exit Thermocouple (CETs) being less than the four per quadrant as required by footnote (i), a Special Report is required. The minimum requirement of two CETs per core quadrant was available on Channel "B" of the (sPDS during the time that Channel "A" was inoperable.
3.
With only one channel of Reactor Vessel Level available, footnote (k) applies because the Channel "A" for the Heated Junction Thermocouple (HJTC) probe was out of service for more that even days while the modification work was in progress.
In summary, the three ICCI parameters, Subcooled Margin Monitoring, Core Exit Thermocouple and Reactor Vessel Level, are now considered operable on Channel "A".
The upgrade to add indication of PCV-1849A and B to the SPDS (via the ICCI signal processing equipment) is currently planned for completion by June 15, 1989 when the work (software replacement) on Channel B of the ICCI signal processing equipment is projected to be completed. The new software on Channel B will result in PCV-18498 being processed on the ICCI equipment and also transmitted to the SPDS for display.
Sincerely, Jr?llK. J. horrisam}hw U
Division Manager Nuclear Operations KJM/jak c: LeBoeuf, Lamb, i.eiby & MacRae R. D. Martin, NRC Regional Administrator P. D. Milano, NRC Project Manager P. H. Harrell, NRC Senior Resident Inspector 1
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