ML020850603
| ML020850603 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 03/15/2002 |
| From: | Witt W AmerenUE |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ULNRC-4623 | |
| Download: ML020850603 (8) | |
Text
Union Electric PO Box 620 Callaway Plant Fulton, MO 65251 March 15, 2002 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 ULNRC-4623 Gentlemen:
DOCKET NUMBER 50-483
, Ber CALLAWAY PLANT UNIT 1 UE UNION ELECTRIC CO.
FACILITY OPERATING LICENSE NPF-30 SPECIAL REPORT 2002-01 GT-RT-21B Radiation Monitor Inoperable This Special Report is submitted in accordance with Final Safety Analysis Report (FSAR) Technical Specification (T/S) 16.3.3.4 (c) which states:
"With the number of OPERABLE channels for the unit vent-high range noble gas monitor less than the Minimum channels OPERABLE requirement of Table 16.3-7, initiate the preplanned alternate method of monitoring the appropriate parameter(s) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and either restore the inoperable channel to OPERABLE status within 7 days, or prepare and submit a Special Report to the Commission within the following 14 days outlining the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the channel to OPERABLE status."
This Special Report documents the failure of radiation monitor GT-RT-21B and the actions taken to return the aforementioned radiation monitor to OPERABLE status.
Warren A. Witt Manager, Callaway Plant WAW/ewh Enclosure a subsidiary ofAmeren Corporation
ULNRC-4623 March 15, 2002 Page 2 cc: U. S. Nuclear Regulatory Commission (Original and 1 copy)
Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 Mr. Ellis W. Merschoff Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Jack N. Donohew (2 copies)
Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 7E1 Washington, DC 20555-2738 Manager, Electric Department Missouri Public Service Commission PO Box 360 Jefferson City, MO 65102 Mr. John O'Neill Shaw, Pittman, Potts & Trowbridge 2300 N. Street N.W.
Washington, DC 20037 Records Center Institute of Nuclear Power Operations 700 Galleria Parkway Atlanta, GA 30339
Special Report 2002-01 ULRNC- 4623 March 15, 2002 Page 1 Description of Event At 1130, 3/4/02, maintenance activities were being performed on the Unit Vent system.
When Unit Vent air flow was reduced to below 46,900 standard cubic feet per minute (scfhi), Unit Vent radiation monitor GT-RT-21B failed due to a loss of isokinetic sampling flow. Compensatory sampling measures of the Unit Vent were instituted and investigation of the GT-RT-21B failure was commenced. An error in the software programming for GT-RT-21B was discovered and corrected. This error had been present from 1/16/02 until corrected on 3/5/02 making GT-RT-21B Inoperable for this time period. Subsequent testing restored GT-RT-21B to Operable status.
Root Cause The root cause of the event was inadequate guidance from the equipment vendor Sorrento Electronics, to modify the installed software data base used in GT-RT-21B.
GT-RT-21B has two air flow rates that can be employed depending on radiation level sensed at the radiation detector, low air flow used in low to medium radiation level channels, and high flow used for medium to high range radiation level channels with the low range channel normally in service. When not in service, the medium and high range channels have a different color status indicated on plant monitors than the operating channel. Modification Package 99-1028 was created to alter the status color of out of service channels to match the operating channel since the radiation monitor was operational with any of the three channels in service. Equipment vendor Sorrento Electronics supplied hardware and software upgrades to accomplish the desired Modification. Imbedded within the software package upgrade was an omission to modify a correction factor and when this Modification was installed, the net result was that with air flow rates lower than 46,900 scfm, GT-RT-21B would isolate air flow to the detection chamber and this rendered the unit Inoperable.
Corrective Actions Investigations initiated when GT-RT-21B failed, exposed the fault in the Modification software package. Proper correction factor values were obtained and applied to the software program. Channel operability was re-established utilizing plant approved surveillance procedures.
Special Report 2002-01 ULNRC- 4623 March 15, 2002 Page 2 Basis for Reportabilitv This event is being reported as a Special Report per FSAR Technical Specification 16.3.3.4 (c) because GT-RT-21B was Inoperable from 0902, 1/16/02 until 1833, 3/5/02, for a total of 48 days, 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />, 31 minutes which is greater than the 7 days allowed by the FSAR Technical Specification 16.3.3.4 (c).
If you have any questions or require additional information, contact Mark Reidmeyer, Supervisor, Regional Regulatory Affairs, at (573) 676-4306.
Sincerely, Warren A. Witt Manager, Callaway Plant WAW/ewh
Union Electric PO Box 620 Callaway Plant Fulton, MO 65251 March 15, 2002 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 ULNRC-4623 Gentlemen:
wAoieren DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UF UNION ELECTRIC CO.
FACILITY OPERATING LICENSE NPF-30 SPECIAL REPORT 2002-01 GT-RT-21B Radiation Monitor Inoperable This Special Report is submitted in accordance with Final Safety Analysis Report (FSAR) Technical Specification (T/S) 16.3.3.4 (c) which states:
"With the number of OPERABLE channels for the unit vent-high range noble gas monitor less than the Minimum channels OPERABLE requirement of Table 16.3-7, initiate the preplanned alternate method of monitoring the appropriate parameter(s) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and either restore the inoperable channel to OPERABLE status within 7 days, or prepare and submit a Special Report to the Commission within the following 14 days outlining the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the channel to OPERABLE status."
This Special Report documents the failure of radiation monitor GT-RT-2 1B and the actions taken to return the aforementioned radiation monitor to OPERABLE status.
Warren A. Witt Manager, Callaway Plant WAW/ewh Enclosure a subsidiary of Ameren Corporation
ULNRC-4623 March 15, 2002 Page 2 cc: U. S. Nuclear Regulatory Commission (Original and 1 copy)
Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 Mr. Ellis W. Merschoff Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Jack N. Donohew (2 copies)
Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 7E1 Washington, DC 20555-2738 Manager, Electric Department Missouri Public Service Commission PO Box 360 Jefferson City, MO 65102 Mr. John O'Neill Shaw, Pittman, Potts & Trowbridge 2300 N. Street N.W.
Washington, DC 20037 Records Center Institute of Nuclear Power Operations 700 Galleria Parkway Atlanta, GA 30339
Special Report 2002-01 UTLRNC- 4623 March 15, 2002 Page 1 Description of Event At 1130, 3/4/02, maintenance activities were being performed on the Unit Vent system.
When Unit Vent air flow was reduced to below 46,900 standard cubic feet per minute (scfim), Unit Vent radiation monitor GT-RT-21B failed due to a loss of isokinetic sampling flow. Compensatory sampling measures of the Unit Vent were instituted and investigation of the GT-RT-21B failure was commenced. An error in the software programming for GT-RT-21B was discovered and corrected. This error had been present from 1/16/02 until corrected on 3/5/02 making GT-RT-21B Inoperable for this time period. Subsequent testing restored GT-RT-21B to Operable status.
Root Cause The root cause of the event was inadequate guidance from the equipment vendor Sorrento Electronics, to modify the installed software data base used in GT-RT-21B.
GT-RT-21B has two air flow rates that can be employed depending on radiation level sensed at the radiation detector, low air flow used in low to medium radiation level channels, and high flow used for medium to high range radiation level channels with the low range channel normally in service. When not in service, the medium and high range channels have a different color status indicated on plant monitors than the operating channel. Modification Package 99-1028 was created to alter the status color of out of service channels to match the operating channel since the radiation monitor was operational with any of the three channels in service. Equipment vendor Sorrento Electronics supplied hardware and software upgrades to accomplish the desired Modification. Imbedded within the software package upgrade was an omission to modify a correction factor and when this Modification was installed, the net result was that with air flow rates lower than 46,900 scfin, GT-RT-21B would isolate air flow to the detection chamber and this rendered the unit Inoperable.
Corrective Actions Investigations initiated when GT-RT-21B failed, exposed the fault in the Modification software package. Proper correction factor values were obtained and applied to the software program. Channel operability was re-established utilizing plant approved surveillance procedures.
Special Report 2002-01 ULNRC- 4623 March 15, 2002 Page 2 Basis for Reportabilitv This event is being reported as a Special Report per FSAR Technical Specification 16.3.3.4 (c) because GT-RT-21B was Inoperable from 0902, 1/16/02 until 1833, 3/5/02, for a total of 48 days, 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />, 31 minutes which is greater than the 7 days allowed by the FSAR Technical Specification 16.3.3.4 (c).
If you have any questions or require additional information, contact Mark Reidmeyer, Supervisor, Regional Regulatory Affairs, at (573) 676-4306.
Sincerely, Warren A. Witt Manager, Callaway Plant WAW/ewh