ML061790233
| ML061790233 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 03/08/2006 |
| From: | Dingler M Wolf Creek |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML061790233 (9) | |
Text
RIC 2006 Session W3D GSI 191 Industry Actions for GSI 191 Maurice (Mo) Dingler Technical Staff Engineer Wolf Creek Nuclear Operating Company 3/8/06
2 Key Message z
GSI 191 is a priority issue for the industry z
Licensees are implementing hardware changes at the earliest possible outage z
The many facets of GSI 191 resolution are stretching the capabilities of the industry to resolve all facets by end of 2007 Chemical effects issue is evolving as tests are being completed by the industry Downstream effects of debris on fuel is not a well understood phenomena Manufacturing, scheduling,strainer testing
3 Industry Produced Documents major ones z
NEI 02-01 Condition Assessment Guidelines Debris Source Inside PWR Containments z
NEI 04-07 Pressurized Water Reactor Sump Performance Evaluation Methodology z
WCAP 16362 -NP PRA Modeling for Sump Blockage z
WCAP 16406-P Evaluation of Downstream Sump Debris Efforts in Support of GSI 191 z
WCAP 16204 Evaluation of Potential WRG&EPG Changes to address NRC Bulletin 2003-01 Recommendations z
Letter 2005-429 Transmittal of two WOG Documents - Template to Support WOG chemistry Efforts Follow on Testing and Framework to Interim Safety Assessment for GSI 191 z
WCAP 16530 Evaluation of Post-Accident Chemical Effects in Containment Sump Fluids to Support GSI 191 z
EPRI 101805 Design Basis Accident Testing of PWR Unqualified Original Equipment Manufacturer Coatings
4 After Initial Evaluations z
Plants reviewing evaluations for refinements to the initial evaluation z
Downstream Wear/ Blockage Pumps/Valves/Fuel concerns z Possible solutions
- Change out valves and pump wear surfaces
- Change the debris source term z Change insulation z Install debris interceptor z Have vendor test to determine screen specific bypass factor z Determine hardness factors of the certain debris z Combination of all
5 After Initial Evaluations z Chemical Effects
- Data provided to hardware vendors to determine head loss with a plant specific debris mix and screen
- Head loss concerns z Possible solutions
- Install screens with margin to handle
- Change the Buffer agent to less reactive agent
- Combination of all
6 After Initial Evaluations z NOTE
- Each potential solution is plant depended and can impact other aspects of the evaluation
7 Future issues z This is a change in the License basis for the plant
- Methods has to be in place to maintain as-built to the evaluation or evaluate any changes z Understand the evaluation z Know your margins
- Coatings nonqualified
- Latent debris
- Changes to flow balances when the throttle value openings are change.
- Changes in coating types - use generic or specific
- Changes in insulations
8 Future Issues Cont.
- Examples of new programs that will be needed to be put in place z Latent Debris
- Periodic surveys that monitor changes-NRC SE Requirement
- Enhancements to current containment cleanliness programs z Coatings-
- Periodic assessment be identified, described, and implemented during routine outages-NRC SE Requirements z Enhancement to Equipment /Rad Protection labeling programs
- need to understand changes to amounts
9 Summary z The evaluations will be completed.
z Sump screens can and will be replaced z Downstream effects will be addressed z Chemical effects will be addressed z Plants will need to understand the evaluations so they can address future issues as they occur.