ML022700334
| ML022700334 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/27/2002 |
| From: | NRC/OCM |
| To: | |
| References | |
| BL-01-001, FOIA/PA-2002-0229 | |
| Download: ML022700334 (6) | |
Text
STATUS OF NRC STAFF, REVIEW OF FENOC'S BULLETIN 2001-01 RESPONSE FOR DAVIS-BESSE
- Brief for the Commissioners' TAs
- November 30, 2001
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r AGENDA FOR DISCUSSION
"* Purpose To discuss the results of the staff's ongoing assessment of FENOC's responses to Bulletin 2001-01 for Davis-Besse To discuss the change in the staff's decision regarding issuance of an Order
"* Success Commissioners' TAs understand the basis for the staff's decisions regarding responses to Bulletin 2001-01 for Davis-Besse
"* Introduction and discussion of changes - Larry Burkhart (5 minutes)
"* Discussion of status of staff's review - Jack Strosnider and Rich Barrett (15 minutes)
CHANGE IN LICENSEE'S PLANS/COMMITMENTS
- The Licensee proposed changing its commitments to include Commencing its refueling outage on February 16, 2002, vice March 31,92002, Perform a qualified visual inspection of 100% of the VHP nozzles and undertaking NDE of those nozzles that have indications of cracking, Characterizing any cracks that are identified in VHP nozzles, S*Operating at a lower RCS hot leg temperature to reduce the head temperature effects on crack initiation and growth, Maximizing the availability of the plant's redundant critical safety systems until shutdown, and Providing increased human factors reliability through additional training, personnel, etc.
RISK ASSESSMENTS*
IE Freq. (/ry) j/
CCDP (/ry)
Delta CDF (/ry)
LERF (/ry)
Delta CDF (12/31/01 )(/ry)
Delta CDF (3/31/02)(/ry)
Delta CDF (2/1-6/02)(/ry)
Base Scenario 4.OE-02 2.7E-03
)t X
\\1 E-04 1E -06 1,4E-5*
0 5
4E-05 Alternate Scenario**
2.OE-02 2.OE-03
!4E-05o 4E-07,
/
3E-06 8 E-O
- Risk numbers are approximate due to the varius*,u rcerainties associated with this issue.
"**Includes some. credit for pat insfdectiorls, compens tory ctions to reduce CCDP, and shortened Aýt shortene raio of operation
RISK-INFORMED DECISIONMAKING GUIDELINES RG 1.174 Intended for licensing basis changes (permanent changes)
ACDF less than 1 E-06/ry: very small changes are allowed with tracking of cumulative inpacts on CDF ACDF between 1 E-06/ry and 1 E-05/ry: small changes are allowed with tracking of cumulative impacts on CDF ACDF>1 E-05/ry are not normally allowed
- RG 1.182 Intended for managing risk associated with maintenance activities (short-duration)
ICDP<1IE-06 and ILERP 1 E-07: normal work controls apply ICDP between 1 E-06 and 1 E-05 or ILERP between 1 E-07 and 1 E-06 Assess non-quantifiable factors Establish risk management actions ICDP>1 E-05 or ILERP>1 E-06 Configuration should not normally be entered voluntarily
RG 1.174 SAFETY PRINCIPLES
"* Current Regulations are met It is likely that, if inspections were performed today, the current regulations would not be met (TS requirements and GDC)
"* Defense-in-depth philosophy is maintained It is likely that one of 3 barriers is degraded However, Davis-Besse has a large, dry containment (licensee states that conditional containment failure probability is1.5E-03)
- Sufficient safety margins are maintained o It is likely that safety margins are reduced
- Only a small increase in CDF results ACDF (assuming operation until 2/16/02 and crediti is approximately 8E-06/ry pi.
- The basis of risk measurement is monitored using performance measurement strategies o Will not occur until inspection is performed Ic
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