ML100750355
| ML100750355 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/08/2009 |
| From: | Morrison R NRC/RGN-II/DRP/RPB4 |
| To: | Marvin Sykes NRC/RGN-II/DRP/RPB3 |
| References | |
| FOIA/PA-2010-0010 | |
| Download: ML100750355 (2) | |
Text
- f Sykes, Marvin From:
Sent:
To:
Subject:
Attachments:
Morrison, Catherine Thursday, October 08, 2009 2:00 PM Sykes, Marvin CR RB Summary Points.doc CR RB Summary Points.doc 1.
TALKING POINTS On October 2, during cutting of containment in preparation for steam generator replacements, Progress Energy discovered a separation in the nominally 42 inch thick concrete wall surrounding the reactor containment liner.
The reactor was shutdown at the time of discovery.
" The separation is approximately 1/2 inch wide and located within the concrete in the plane near the horizontal tendons.
No problems have been noted with the liner.
The licensee is investigating the extent of the cracks and has initiated assessment of the implications.
Region II inspectors are onsite performing independent assessments of the overall condition of the containment structure. The inspection results will be documented in an NRC inspection report.
The reactor building is designed serve as one of three barriers protecting the public and environment from radiation exposure.
The building has a carbon steel liner with a nominal liner thickness of 3/8 inch for the cylinder wall and dome, and 1/4 inch for the base. The steel liner is the primary barrier to a release.
The 3.5 feet thick reinforced concrete wall and post-tensioning system with tendons in a horizontal and vertical lattice structure that ensures the proper response to any internal or external loads such that integrity of the liner is maintained.
There are 144 vertical tendons and 282 hoop tendons.
Each hoop tendon extends 120 degrees around the cylinder.
Following construction, the building was subjected to a one-time structural integrity test of 63.3 psig (115% of the FSAR original design pressure of 55 psig).
In 1976, Crystal River repaired a concrete delamination issue affecting the dome. A containment structural integrity test was successfully performed after the repair.
A containment pressure test that simulates accident pressure conditions was last performed in 2005 and was successful.