SVPLTR 16-0017, Submittal of Post Accident Monitoring Report Instrumentation

Submittal of Post Accident Monitoring Report Instrumentation

ML16104A030
Person / Time
Site:	Dresden
Issue date:	04/08/2016
From:	Karaba P Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SVPLTR 16-0017
Download: ML16104A030 (3)

Text

Dresden Generating Station

,

7

) !liV Exelon Generation 6500 North Dresden Road Morris. IL 60450 www,exeloncorp,com SVPLTR # 16-0017 April 8, 2016 ,

U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 3 Renewed Facility Operating License No. DPR-25 NRC Docket No. 50-249

Subject:

Post Accident Monitoring Report The attached report is submitted in accordance with Dresden Nuclear Power Station, Unit 3 Technical Specifications 3.3.3.1, "Post Accident Monitoring (PAM} Instrumentation," and 5.6.6, "Post Accident Monitoring Instrumentation Report." The report is required due to the ,

inoperability of one Main Steam Line Isolation Valve position indication for a period in excess of the 30 day restoration time. Accordingly, this report is due on April 13, 2016.

There are no regulatory commitments contained in this submittal. Should you have any questions concerning this letter, please contact Mr. Bruce Franzen at (815) 416-2800.

Respectfully,

~~-

Peter J Karaba Site Vice President Dresden Nuclear Power Station

Enclosure:

Dresden Unit 3 Post Accident Monitoring Report cc: Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - Dresden Nuclear Power Station

Dresden Unit 3 Post Accident Monitoring Report This Report is being submitted for Dresden Nuclear Power Station (DNPS), Unit 3 in accordance with Technical Specification (TS) 5.6.6, "Post Accident Monitoring Instrumentation Report." Additionally, TS 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," requires two channels of Penetration Flow Path Primary Containment Isolation Valve (PCIV) position indication to be Operable during plant operation in Modes 1 and 2. On February 29, 2016, the position indication for one main steam isolation valve (MSIV) was declared inoperable and TS 3.3.3.1, Condition A was entered. TS 3.3.3.1, Condition A requires channel restoration to Operable status in 30 days. If TS 3.3.3.1 Condition A is not satisfied in 30 days, then TS 3.3.3.1, Condition 8 is entered. Exelon Generation Company, LLC has determined that the position indication circuit cannot be restored within 30 days; therefore, TS 3.3.3.1, Condition 8 requires initiation of action in accordance with TS 5.6.6. This Administrative TS requires the submittal of a written report outlining the preplanned alternate method of monitoring, the cause

. of the inoperability, and the plans and schedule for restoring the instrument to Operable status within the following 14 days.

Description of Issue On February 29, 2016, while at full power, it was noted that the open indicating light for MSIV 3-0203-18 in the Main Control Room (MGR) was not lit. Alternate verification through the use of steam line flow and computer points monitoring valve position was utilized to verify that the valve was open; however, without the positive open indication in the MGR, the valve position was declared inoperable.

Further troubleshooting has determined that the source of the position indication issue is located insicfe DNPS, Unit 3 Drywell and cannot be accessed to affect repairs until the unit is shutdown.

Cause of the lnoperabilitv and Action Taken A circuit fault has rendered the MSIV 3-0203-18 valve position indication circuit unreliable. This fault is preventing positive verification of the valve position which is required by PAM PCIV position indications in accordance with TS 3.3.3.1. Troubleshooting under Work Order 01902902-01 has determined that the fault for the MSIV 3-0203-18 position indication circuit is located within the DNPS, Unit 3 Drywell.

Pre-planned Alternate Method of Monitoring With reliable closed valve indications, the two MSIV closed lights alone would provide the MGR with confirmation of isolation of an individual main steam line as required by TS 3.3.3.1.

The alternate method for monitoring isolation of the 38 main steam line as a penetration flow path is fulfilled by three indications.

Due to the unreliable closed indication for the 3-0203-1 8, indication of valve position may be determined from other system parameters including main steam line flow through the following indicators:

Fl 3-0640-23A 3A MN STM LINE FLOW Fl 3-0640-238 38 MN STM LINE FLOW Fl 3-0640-23C 3C MN STM LINE FLOW

Fl 3-0640-230 30 MN STM LINE FLOW In addition, the second MSIV in series, 3-0203-28, is fully operable, capable of isolating the line upon an isolation signal. Position indication for the 3-0203-28 MSIV.is available in the MCR, as required by TS 3.3.3.1, and can be used to show the 38 main steam line is isolated.

Combining the main steam line flow for the 38 main steam line, the closed indication of the outboard MSIV 3-0203-28, and the MSIV 3-0203-18 shown "not open" by computer point C176 provides the alternate method to assess isolation of the 38 Main Steam Line.

Plan and Schedule for Restoring the Instrumentation Channels The PAM instrumentation is planned to be restored during an outage of sufficient duration, either a forced outage or the upcoming 2016 ONPS, Unit 3 Refueling Outage 03R24.

Dresden Generating Station

,

7

) !liV Exelon Generation 6500 North Dresden Road Morris. IL 60450 www,exeloncorp,com SVPLTR # 16-0017 April 8, 2016 ,

U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 3 Renewed Facility Operating License No. DPR-25 NRC Docket No. 50-249

Subject:

Post Accident Monitoring Report The attached report is submitted in accordance with Dresden Nuclear Power Station, Unit 3 Technical Specifications 3.3.3.1, "Post Accident Monitoring (PAM} Instrumentation," and 5.6.6, "Post Accident Monitoring Instrumentation Report." The report is required due to the ,

inoperability of one Main Steam Line Isolation Valve position indication for a period in excess of the 30 day restoration time. Accordingly, this report is due on April 13, 2016.

There are no regulatory commitments contained in this submittal. Should you have any questions concerning this letter, please contact Mr. Bruce Franzen at (815) 416-2800.

Respectfully,

~~-

Peter J Karaba Site Vice President Dresden Nuclear Power Station

Enclosure:

Dresden Unit 3 Post Accident Monitoring Report cc: Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - Dresden Nuclear Power Station

Dresden Unit 3 Post Accident Monitoring Report This Report is being submitted for Dresden Nuclear Power Station (DNPS), Unit 3 in accordance with Technical Specification (TS) 5.6.6, "Post Accident Monitoring Instrumentation Report." Additionally, TS 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," requires two channels of Penetration Flow Path Primary Containment Isolation Valve (PCIV) position indication to be Operable during plant operation in Modes 1 and 2. On February 29, 2016, the position indication for one main steam isolation valve (MSIV) was declared inoperable and TS 3.3.3.1, Condition A was entered. TS 3.3.3.1, Condition A requires channel restoration to Operable status in 30 days. If TS 3.3.3.1 Condition A is not satisfied in 30 days, then TS 3.3.3.1, Condition 8 is entered. Exelon Generation Company, LLC has determined that the position indication circuit cannot be restored within 30 days; therefore, TS 3.3.3.1, Condition 8 requires initiation of action in accordance with TS 5.6.6. This Administrative TS requires the submittal of a written report outlining the preplanned alternate method of monitoring, the cause

. of the inoperability, and the plans and schedule for restoring the instrument to Operable status within the following 14 days.

Description of Issue On February 29, 2016, while at full power, it was noted that the open indicating light for MSIV 3-0203-18 in the Main Control Room (MGR) was not lit. Alternate verification through the use of steam line flow and computer points monitoring valve position was utilized to verify that the valve was open; however, without the positive open indication in the MGR, the valve position was declared inoperable.

Further troubleshooting has determined that the source of the position indication issue is located insicfe DNPS, Unit 3 Drywell and cannot be accessed to affect repairs until the unit is shutdown.

Cause of the lnoperabilitv and Action Taken A circuit fault has rendered the MSIV 3-0203-18 valve position indication circuit unreliable. This fault is preventing positive verification of the valve position which is required by PAM PCIV position indications in accordance with TS 3.3.3.1. Troubleshooting under Work Order 01902902-01 has determined that the fault for the MSIV 3-0203-18 position indication circuit is located within the DNPS, Unit 3 Drywell.

Pre-planned Alternate Method of Monitoring With reliable closed valve indications, the two MSIV closed lights alone would provide the MGR with confirmation of isolation of an individual main steam line as required by TS 3.3.3.1.

The alternate method for monitoring isolation of the 38 main steam line as a penetration flow path is fulfilled by three indications.

Due to the unreliable closed indication for the 3-0203-1 8, indication of valve position may be determined from other system parameters including main steam line flow through the following indicators:

Fl 3-0640-23A 3A MN STM LINE FLOW Fl 3-0640-238 38 MN STM LINE FLOW Fl 3-0640-23C 3C MN STM LINE FLOW

Fl 3-0640-230 30 MN STM LINE FLOW In addition, the second MSIV in series, 3-0203-28, is fully operable, capable of isolating the line upon an isolation signal. Position indication for the 3-0203-28 MSIV.is available in the MCR, as required by TS 3.3.3.1, and can be used to show the 38 main steam line is isolated.

Combining the main steam line flow for the 38 main steam line, the closed indication of the outboard MSIV 3-0203-28, and the MSIV 3-0203-18 shown "not open" by computer point C176 provides the alternate method to assess isolation of the 38 Main Steam Line.

Plan and Schedule for Restoring the Instrumentation Channels The PAM instrumentation is planned to be restored during an outage of sufficient duration, either a forced outage or the upcoming 2016 ONPS, Unit 3 Refueling Outage 03R24.