ML072780214
| ML072780214 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/20/2007 |
| From: | Duke Energy Corp |
| To: | Office of Nuclear Reactor Regulation |
| Oudinot D | |
| Shared Package | |
| ML072830337 | List:
|
| References | |
| Download: ML072780214 (13) | |
Text
1 Duke Power Change Evaluation Example for NRC Review July 20, 2007
2 Change Evaluation Examples Change Definition Start with Fire Area Transition (Table B-3)
Sample evaluations (open items) for BH3 and WP3 Preliminary Risk Screening - bypassed step Risk Evaluation Integrated treatment using in-process FPRA
3 Change Evaluation Backup Documentation File Index
Fire Area Drawings (overview of fire area layout)
BH03 - BH03 Fire Area Drawing.pdf
WP3 - WP3 Fire Area Drawing.pdf
Fire Protection Features (tabulation of fire protection features for fire areas)
BH03 - BH03 Fire Protection Features.pdf
WP3 - WP3 Fire Protection Features.pdf
Fire Ignition Sources Summary Report (listing of fire ignition sources and bins for fire areas)
BH03 - BH03 Fire Ignition Sources Summary Report.pdf
WP3 - WP3 Fire Ignition Sources Summary Report.pdf
Fire Ignition Frequency Summary (fire ignition frequency summary for fire areas)
BH03 - BH03 Ignition Frequency Summary.pdf
WP3 - WP3 Ignition Frequency Summary.pdf
Fire Scenario Ignition Frequency (development of the scenario frequencies for the fire areas)
BH03 - BH03 Transient Scenario Frequency.pdf
WP3 - WP3 Transient Scenario Frequency.pdf
BH03 Switchgear - BH03 SWGR Scenario Frequency.pdf
WP3 Electrical Panel - WP3 Electrical Panel Scenario Frequency.pdf
Fire Scenario Summary (summary of the fire scenarios developed for the fire areas)
BH03 - BH03 Scenario Summary.pdf
WP3 - WP3 Scenario Summary.pdf
B-3 Table Open Items (list of items for change evaluation for fire areas)
BH03 - BH03 B_3 Table.pdf
WP3 - WP3 B_3 Table.pdf
4 FP Feature Evaluation Identify impacted components and/or circuits and scenarios Calculate change in risk:
Case 1 (non-compliant): Sum associated scenarios for in-situ configuration Case 2 (compliant): Sum associated scenarios reflecting deterministically compliant configuration Calculate the delta between the CDF for Case 1 and the CDF for Case 2
5 Example with Cable Damage
6 Example with No Cable Damage
7 For Manual Actions Identify impacted components and/or circuits and scenarios If function recovered is in FPRA model Case 1 (non-compliant): Sum associated scenarios with function failed Case 2 (compliant): Sum associated scenarios with function not failed Model change may be required to calculate change due to loss of power If function recovered is not in FPRA model Function is not risk significant (confirm basis for exclusion from model)
8 Change Evaluation Examples Based on sample open items Unit 3 Blockhouse (BH3)
All actions allowed or approved (dedicated shutdown via SSF)
No change evaluation needed (FAQ 06-0011, 12)
Risk characterization only West Pen Room (WP3 / AB098)
Shutdown from Control Room Sample treatment for unapproved actions
9 BH3 Unit 3 Blockhouse Note: Actions in BH3 allowed; no change evaluation required.
1.68E-07 N/A MFB 2 Fire 1.68E-07 N/A MFB 1 Fire Case 2 compliant Case 1 non-compliant Scenario
10 WP3 Open Item Disposition
WP3-01 & 02-OP: Manual action required for cold shutdown only
WP3-03-OP: See detailed evaluation in following pages
WP3-04-OP: Evaluation required, similar to WP3-03-OP
WP3-05 & 06-OP: Manual action required for cold shutdown only
WP3-07 & 08-OP: Evaluation required, similar to WP3-03-OP
WP3-09-OP: Manual action required for cold shutdown only
WP3-10-OP: See detailed evaluation in following pages
WP3-11, 12 & 13 -OP: Manual action required for cold shutdown only
WP3-14-OP: See detailed evaluation in following pages
Confirmation required that cold shutdown actions are not needed to support fire PRA
Evaluation required for WP3-04, 07 & 08-OP, similar to approach used for WP3-03, 10 & 14-OP
Characterization of Risk for fire area/zone 98 (WP3): Total CDF for all scenarios (B, C and D) is 5.82E-08, low risk contribution
Final Dispositions to be incorporated into the B-3 Table
11 AB098 Example No. 1 Note: Instrument Air (Backup Air) credited by exclusion throughout Unit 3 Aux Bldg. Case 1 CDF based on failing either Backup Air or 3FDWVA0315.
2.1E-09 CDF = 3.11E-08 CDF = 3.32E-08 Impacted Scenario:
D only - Hotwork 3FDWVA0315 excluded 3FDWVA0315 failed WP3-03-OP Risk Case 2 compliant /
baseline Case 1 non-compliant /
current Open Item
12 AB098 Example No. 2 Note: No single fire scenario affects both PORV and block valve circuits.
CDF = 5.2E-08 CDF = 5.2E-08 (see Note)
Impacted Scenario:
B, C, & D (sum)
PORV and block valve circuits separated PORV and block valve circuits in same fire area WP3-10-OP Risk Case 2 compliant /
baseline Case 1 non-compliant /
current Open Item
13 AB098 Example No. 3 Note: EFW availability in this scenario minimizes importance of SSF ASW.
CDF = 6.32E-10 CDF = 6.32E-10 Impacted Scenario:
C only - General Transient 3CCWVA0269 excluded 3CCWVA0269 failed WP3-14-OP Risk Case 2 Change Case 1 Current Open Item