ML18039A653
| ML18039A653 | |
| Person / Time | |
|---|---|
| Issue date: | 01/25/2018 |
| From: | Js Hyslop NRC/NRR/DRA/APLB |
| To: | Anderson V Nuclear Energy Institute |
| Wu A | |
| Shared Package | |
| ML18039A549 | List: |
| References | |
| FAQ 14-0007 | |
| Download: ML18039A653 (1) | |
Text
From: Hyslop, JS Sent: Thursday, January 25, 2018 1:42 PM To: ANDERSON, Victoria <vka@nei.org>
Cc: Melly, Nicholas <Nicholas.Melly@nrc.gov>; Robinson, Jay <Jay.Robinson@nrc.gov>
Subject:
- Victoria, The following paragraph replaces the 2nd paragraph in Section 3.1 of the FAQ.
Fire ignition frequencies for general transient fires and for transient fires from welding and cutting are dependent on the weighting factors for maintenance, occupancy, storage, and hot work. Floor area is introduced into the factor (TISRF, see equations 7 and 8 below) to avoid diluting the transient frequency of individual ignition sources for larger TISR areas, and to avoid overemphasizing this frequency of individual ignition sources for smaller TISR areas. This FAQ recognizes that the approach for locating ignition sources, grouping transient fire scenarios, and as a result assigning transient fire frequency to ignition sources in a TISR may vary depending on room configuration and transient ignition source ZOI to efficiently evaluate fire risk.
Also, we had an action to review the paragraph that specified a floor on no less than 1% of the frequency of the PAU. We have decided to remove that paragraph, and substitute nothing in its place. So there is no longer a floor being proposed by the staff.
These two actions meet the commitment we made to industry in the last FAQ meeting.
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