ML17208A158: Difference between revisions
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==Subject:== | ==Subject:== | ||
[External_Sender] Discussion of I&C Related Issues regarding TSTF-505 | [External_Sender] Discussion of I&C Related Issues regarding TSTF-505 Michelle, | ||
Industry Suggested Resolution: An | The industry would like to discuss three issues related to instrumentation and control (I&C) systems modified by TSTF-505. These issues were raised by the NRC the May 4, 2017 document. | ||
Issue 1: Many of the Conditions in the NRC's t able are for conditions similar to "One or more channels-inoperable" or "two or more channels-inoperable." While the safety function may be performed with some number of channels inoperable, it may not be possible to perform the functi on for all circumstances in which the phrase "or more" would be applicable. | |||
Industry Suggested Resolution: An alternat ive to the presentat ion in TSTF-505 would be to limit the TS Condition to when the minimum number of channels needed to perform the function are operable (assuming no additional failures). The Required Actions and Completion Times would be th e same and would provide the option to calculate a RICT. Either a new condition would be created that applies when less than the minimum number of channels are operabl e or, depending on the construction of the TS, LCO 3.0.3 would apply. The licensee would need to justify that the function can still be performed in the revised Action. | |||
Issue 2: The NRC table included the following for NUREG-1431, Westinghouse plants: | |||
NUREG-1431 LCO Condition LCO and Condition Text/Description Comments/ Notes 3.3.1.F LCO: The RTS instrumentation for each Function in Table 3.3.1-1 shall be OPERABLE. | |||
Condition: One Power Range Neutron Flux - High channel inoperable. | |||
Treat as LOF Industry Question: Please explain why one Power Range Neutron Flux - High channel inoperable is treated as a lo ss of the ability to perform the safety function. | |||
Issue 3: The NRC table included the following for NUREG-1431, Westinghouse plants: | |||
NUREG-1431 LCO | |||
Condition LCO and Condition Text/Description Comments/ Notes NUREG-1431 LCO Condition LCO and Condition Text/Description Comments/ Notes 3.3.1.DD LCO: The RTS instrumentation for each Function in Table 3.3.1-1 shall be OPERABLE. | |||
Condition: One RTB train inoperable. | |||
Treat as LOF. | |||
Industry Question: As the Reactor Trip Breaker trains are independent and redundant, plese explain why one inoperable RTB trai n would prevent the performance of the safety function. | |||
We look forward to discussing these issues with the NRC staff. | We look forward to discussing these issues with the NRC staff. | ||
Brian | Brian | ||
Brian D. Mann Vice President of | Brian D. Mann Vice President of Indus try Programs and Services EXCEL Services Corporation Mobile (804) 339-7034 Main (301) 984-4400 E-mail: brian.mann@excelservices.com Web: www.excelservices.com Web: www.nukapedia.com}} | ||
Revision as of 17:19, 29 June 2018
| ML17208A158 | |
| Person / Time | |
|---|---|
| Site: | Technical Specifications Task Force |
| Issue date: | 07/24/2017 |
| From: | Mann B D Excel Services Corp |
| To: | Michelle Honcharik NRC/NRR/DSS/STSB |
| Honcharik M C | |
| References | |
| TSTF-505 | |
| Download: ML17208A158 (2) | |
Text
From: Brian Mann <Brian.Mann@excelservices.com> Sent: Monday, July 24, 2017 2:38 PM To: Honcharik, Michelle Cc: ANDERSON, Victoria; Tjader, Theodore; kjse@pge.com; Myung.Kang@duke-energy.com
Subject:
[External_Sender] Discussion of I&C Related Issues regarding TSTF-505 Michelle,
The industry would like to discuss three issues related to instrumentation and control (I&C) systems modified by TSTF-505. These issues were raised by the NRC the May 4, 2017 document.
Issue 1: Many of the Conditions in the NRC's t able are for conditions similar to "One or more channels-inoperable" or "two or more channels-inoperable." While the safety function may be performed with some number of channels inoperable, it may not be possible to perform the functi on for all circumstances in which the phrase "or more" would be applicable.
Industry Suggested Resolution: An alternat ive to the presentat ion in TSTF-505 would be to limit the TS Condition to when the minimum number of channels needed to perform the function are operable (assuming no additional failures). The Required Actions and Completion Times would be th e same and would provide the option to calculate a RICT. Either a new condition would be created that applies when less than the minimum number of channels are operabl e or, depending on the construction of the TS, LCO 3.0.3 would apply. The licensee would need to justify that the function can still be performed in the revised Action.
Issue 2: The NRC table included the following for NUREG-1431, Westinghouse plants:
NUREG-1431 LCO Condition LCO and Condition Text/Description Comments/ Notes 3.3.1.F LCO: The RTS instrumentation for each Function in Table 3.3.1-1 shall be OPERABLE.
Condition: One Power Range Neutron Flux - High channel inoperable.
Treat as LOF Industry Question: Please explain why one Power Range Neutron Flux - High channel inoperable is treated as a lo ss of the ability to perform the safety function.
Issue 3: The NRC table included the following for NUREG-1431, Westinghouse plants:
NUREG-1431 LCO
Condition LCO and Condition Text/Description Comments/ Notes NUREG-1431 LCO Condition LCO and Condition Text/Description Comments/ Notes 3.3.1.DD LCO: The RTS instrumentation for each Function in Table 3.3.1-1 shall be OPERABLE.
Condition: One RTB train inoperable.
Treat as LOF.
Industry Question: As the Reactor Trip Breaker trains are independent and redundant, plese explain why one inoperable RTB trai n would prevent the performance of the safety function.
We look forward to discussing these issues with the NRC staff.
Brian
Brian D. Mann Vice President of Indus try Programs and Services EXCEL Services Corporation Mobile (804) 339-7034 Main (301) 984-4400 E-mail: brian.mann@excelservices.com Web: www.excelservices.com Web: www.nukapedia.com