ML12213A384
| ML12213A384 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/02/2011 |
| From: | Hernandez P NRC/OE |
| To: | Marilyn Evans Division of Operating Reactor Licensing |
| References | |
| FOIA/PA-2012-0121 | |
| Download: ML12213A384 (2) | |
Text
J Graves, Herman From:
Hernandez, Pete Sent:
Friday, December 02, 201.1 3:47 PM To:
Evans, Michele Cc:
Howe, Allen; Lund, Louise; Auluck, Rajender; CuadradoDeJesus, Samuel; Gonzalez, Hipolito; Haskell, Russell; Hernandez, Pete; Hills, David; Hoang, Dan; Lehman, Bryce; Lupold, Timothy; Mahoney, Michael; Miller, Barry; Morey, Dennis; Murphy, Martin; Nolan, Ryan; Rezai, Ali; Rihm, Roger; Sanchez Santiago, Elba; Sheikh, Abdul; Snyder, Amy; Thorp, John; Wiebe, Joel; Zimmerman, Jacob; Graves, Herman
Subject:
RE: Davis Besse POP Good afternoon Michele, Here are the key messages regarding the Davis Besse Shield Building and I've attached the updated POP with the decision made by the tech staff.
Key Messaqes:
Tech staff unanimously concurred on the decision that the licensee provided reasonable assurance for the Shield Building will perform its safety function. There are no further questions from the NRC to be answered before startup can commence.
" A CAL was issued addressing completed and planned actions for the licensee to provide continued long-term confidence of the SB safety functions.
Region 3 is implementing their Communication plan to notify internal and external stakeholders.
The licensee expects to enter Mode 4 today December 2, 2011 at 1800 and continue progressing with Dant startup.
2011-2-12 POP -
Davis-Besse Co...
1 DAVIS-BESSE NUCLEAR POWER STATION CONTAINMENT SHIELD BUILDING ISSUE 121212011 PURPOSE:
To inform NRR senior management of situation at Davis-Besse with the Containment Shield Building cracks identified, and licensee response.
EXPECTED NRR management to understand the status of Davis-Besse's Containment OUTCOMES: Shield Building (SB).
PROCESS:
Note: Region 3 has the lead for this issue and they are implementing their communication strategy to inform stakeholders, including interested Congressman, press and general public, of the decisions and rationale.
This document is for NRR Internal information only.
Backaround While creating an access hole for Reactor Pressure Vessel head replacement, three issues were identified:
(#1) Extensive cracking in the shoulder region, (#2) Cracking in the structural region outside the flute shoulder region near the main steam piping penetrations, (#3) Cracking indications via Impact Response (IR) mapping in the cylindrical portion of the building near the top of the building at the interface between the domed roof and the cylindrical wall. All three issues were evaluated.
The licensee conducted IR mapping, and core bores to determine the operability of the SB. Questions from NRC staff regarding the assumptions and calculations were resolved through more in-depth calculations and discussion between the NRC and licensee. After clarification of NRC questions, final calculations were provided to NRC technical staff on Thursday, December 1, 2012.
Decision NRC Technical staff on site at Davis Besse and at headquarters reviewed the final calculations on Thursday and Friday, December 1 and December 2, 2011.
The conclusion was made that the licensee had provided reasonable assurance that with the current condition, the SB will perform its safety function. All technical staff from the region and headquarters concurred with this conclusion. There are no further questions from the NRC to be answered before startup can commence.
The Technical review team will take the recommendation to senior management in the region, and the senior management will communicate the decision to the licensee.
The licensee expects to enter Mode 4 today, December 2, 2011 at 1800 and continue progressing with plant startup.
A Confirmatory Action Letter will be issued today with completed and planned actions for the licensee to provide continued long-term confidence of the SB ability to meet the safety functions.
A public meeting will be held on December 15, 2011.
NRC Question:
The licensee still has unresolved questions to answer regarding the design basis of the plant.
Basically, when the SB was built the requirements and codes it was built under were for an uncracked building. Because the building is now cracked, the question of whether the SB still meets the requirements as stated in the FSAR and licensing basis needs to be evaluated.