ML21307A105: Difference between revisions

From kanterella
Jump to navigation Jump to search
(StriderTol Bot insert)
 
(StriderTol Bot change)
Line 15: Line 15:


=Text=
=Text=
{{#Wiki_filter:PRA Counterpart Meeting Antonios M. Zoulis, Branch Chief Laura Kozak, Senior Reactor Analyst PRA Oversight Branch, DRA, NRR November 2021
{{#Wiki_filter:}}
 
Open Phase Condition (OPC)
The NRC has a concern that licensees are not evaluating the OPC, and the Open Phase Isolation System (OPIS) for inclusion into their PRA models of record. This has been observed during the Open Phase TI inspections.
While the level of risk from OPC doesnt rise to the level of backfit, it can affect Risk Informed Decisionmaking activities. It also does not reflect the as-built as operated plant.
OPC can particularly affect plant risk during RICT or (a)(4) assessments when plant configurations change. For instance, by removing an offsite power transformer from service for a workweek configuration leaving the plant and its safety buses aligned to a single source of offsite power for the duration of the maintenance window.
 
Requirements Supporting Review 1-5.3 of the ANS PRA Standard discusses monitoring of PRA inputs and collecting new information for the PRA Configuration Control Program.
The OPC is industry-wide operational experience that affects the PRA. It resulted in plant modifications, procedure changes, and in some cases, operator actions.
This may change the results of the PRA and can affect RIDM in the future.
 
Requirement        NFPA-805        SFCP                      RICT              50.69            a(4)
* As-built, as-
* License
* License
* License
* 10 CFR
* NUMARC operated          condition        condition                  Condition          50.69(e)(1)        93-01, Rev plant
* Standard
* ASME/ANS
* ASME/ANS
* ASME/ANS          4F, Section Section          Ra-Sa-2009                  Standard          Ra-Sa-2009        11.3.3 2.4.3.3                                      Ra-Sa-2009 (a)(4)
NFPA-Reflect As-              RICT 805              built As-Operated plant SFCP                    50.69 4
 
Questions?
5
 
Back Up Slide Requirements Supporting Review Could affect PRA:
Monitor PRA inputs and                - Design Input Changes - Operation collect new information
                                                                      - Maintenance Maintains and                    - Industry-wide Upgrades the PRA                  operational history consistent with the as-ASME/ANS Ra-Sa-                    built, as operated 2009 Section 1-5                          plant                      - Changes to inputs or Key Elements                                        new information shall PRA Configuration                  Ensures cumulative Control (CC)                                                        be evaluated impact of pending                  - Relevant changes to a changes is considered                specific application (i.e.,
RICT, SFCP, 50.69) shall Maintains CC of                  meet pertinent SRs for computer codes                    the application.
Documentation 7}}

Revision as of 17:51, 16 January 2022

Thurs - NRC Presentation for Counterpart Meeting
ML21307A105
Person / Time
Issue date: 11/30/2021
From: Laura Kozak, Antonios Zoulis
NRC/NRR/DRA/APOB, Division Reactor Projects III
To:
References
Download: ML21307A105 (7)
v • d • e


Text

Retrieved from "https://kanterella.com/w/index.php?title=ML21307A105&oldid=3389589"