ML17289A929: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
| Line 18: | Line 18: | ||
=Text= | =Text= | ||
{{#Wiki_filter:}} | {{#Wiki_filter:From: Brian Mann <Brian.Mann@excelservices.com> Sent: Monday, October 16, 2017 9:26 AM To: Honcharik, Michelle Cc: Whitman, Jennifer; Cusumano, Victor | ||
==Subject:== | |||
[External_Sender] TSTF-542 Issue that affects BWR/5 and BWR/6 plants Attachments: Variation Discussion.docx Michelle, We have found an issue with the TSTF-542 traveler that affects BWR/5 and BWR/6 plants. When High Pressure Core Spray (HPCS) is being credited as the operable ECCS subsystem to meet TS 3.5.2, "Reactor Pressure Vessel Water Inventory Control," Table 3.3.5.2-1 (RPV WIC Instrumentation) requires the HPCS Level 8 function (3.a) and the HPCS manual initiation function (3.e) to be operable. However, the Level 8 function closes the HPCS injection valve and prevents injecting water into the vessel until the water level drops below the setpoint, which is below the main team lines within the vessel. If a licensee were to have an unexpected draining event so severe that they want to use HPCS to respond, it's unlikely they would wait until the water level dropped that low before injecting. Instead, they could manually start the HPCS pump and defeat the Level 8 interlock to open the injection valve, rendering the Level 8 function inoperable. It doesn't make sense to us to require the Level 8 function if in most cases the licensee would make it inoperable to perform the function. | |||
We have drafted the attached variation discussion which removes the HPCS Level 8 function and HPCS manual initiation function from Table 3.3.5.2-1. The justification for crediting manually starting the HPCS pump and opening the valve is similar to the variations written by plants that do not have an ECCS manual initiation function in their design. | |||
We'd like to have a call with the NRC this week to discuss the variation. We believe it would be beneficial to the industry and the NRC to agree on a standard description. | |||
Brian | |||
Brian D. Mann Vice President of Industry 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 20:54, 12 June 2018
| ML17289A929 | |
| Person / Time | |
|---|---|
| Site: | Technical Specifications Task Force |
| Issue date: | 10/16/2017 |
| From: | Mann B D Excel Services Corp |
| To: | Honcharik M C Office of Nuclear Reactor Regulation |
| Honcharik M C | |
| Shared Package | |
| ml17289A902 | List: |
| References | |
| Download: ML17289A929 (1) | |
Text
From: Brian Mann <Brian.Mann@excelservices.com> Sent: Monday, October 16, 2017 9:26 AM To: Honcharik, Michelle Cc: Whitman, Jennifer; Cusumano, Victor
Subject:
[External_Sender] TSTF-542 Issue that affects BWR/5 and BWR/6 plants Attachments: Variation Discussion.docx Michelle, We have found an issue with the TSTF-542 traveler that affects BWR/5 and BWR/6 plants. When High Pressure Core Spray (HPCS) is being credited as the operable ECCS subsystem to meet TS 3.5.2, "Reactor Pressure Vessel Water Inventory Control," Table 3.3.5.2-1 (RPV WIC Instrumentation) requires the HPCS Level 8 function (3.a) and the HPCS manual initiation function (3.e) to be operable. However, the Level 8 function closes the HPCS injection valve and prevents injecting water into the vessel until the water level drops below the setpoint, which is below the main team lines within the vessel. If a licensee were to have an unexpected draining event so severe that they want to use HPCS to respond, it's unlikely they would wait until the water level dropped that low before injecting. Instead, they could manually start the HPCS pump and defeat the Level 8 interlock to open the injection valve, rendering the Level 8 function inoperable. It doesn't make sense to us to require the Level 8 function if in most cases the licensee would make it inoperable to perform the function.
We have drafted the attached variation discussion which removes the HPCS Level 8 function and HPCS manual initiation function from Table 3.3.5.2-1. The justification for crediting manually starting the HPCS pump and opening the valve is similar to the variations written by plants that do not have an ECCS manual initiation function in their design.
We'd like to have a call with the NRC this week to discuss the variation. We believe it would be beneficial to the industry and the NRC to agree on a standard description.
Brian
Brian D. Mann Vice President of Industry 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