ML091490328
| ML091490328 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 05/06/2009 |
| From: | NRC Region 1 |
| To: | |
| References | |
| FOIA/PA-2009-0070 | |
| Download: ML091490328 (1) | |
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"~DFR~XM Oyster Creek Inspection Planning Notes Proof Books "Proof Books" will be available, but do not contain a copy of the associated AMP. AMP Books are stored separately, on the same floor.
Repeatability of UT Locations Tamburro: OC intended to have the same NDE technicians perform the D/W UT measurements, but will instead get new techs. The techs that were used in 2006 are not available (retirement or other work). Different NDE techs will be taking the UT data, both exterior (sandbed) and inside the D/W. The same supervisors, as in, 2006 1R21, will be used.
Mr. Hawkins, NDE Level-Ill will supervise the exterior UT activities. He was inside the sandbed in 2006, but is not necessarily expected to enter the sandbeds in 1 R22. This increases the likelihood of location errors, especially inside the sandbed.
UT Data Availability PRIOR to Level-Ill Approval Tamburro acknowledges that NRC will observe all phases of the drywell thickness checks, including UT data taking in the field, data translation (from UT data logger to NDE paper data sheets), and independent verification of recorded data verses recorded data locations (i.e., with data sheets in-hand, go back to field and check that the recorded locations are consistent with the recorded data). However, Tamburro says that the NDE Data Sheets will not be made available to NRC until after the Level-Ill reviews &.approves them. This may become a time-management problem, because Tim O'Hara is not available after Oct 30 (Thursday).
Sandbed Access Only O'Hara and Richmond will enter the sandbed. Modes will not (reasonably) fit. Need to get external NDE critical observations (those that need a trained/experienced ISI inspector) done prior to Friday (Thursday is O'Hara's last full day with the team).
Evaluation of UT Data PRIOR to Startup Tamburro will perform 4 separate engineering evaluations of UT data. Two evaluations (external sandbed and [?? UTs at upper drywell evelations]) will be performed with a simple spreadsheet, to compare each reading against an acceptance criteria, based on the 2006 UT readings at those locations. Two evaluations (19 locations inside drywell at sandbed elevation, and in 2 trenches) will use Mathcad to perform a statistical analysis of the data arrays, similar to calculation C-1302-187-E310-041 & C-1302-187-5320-024. The Mathcad analysis of each array will determine the data skewness and kurtosis, to determine whether the scattering of data over each grid (array) is normally distributed. Tamburro initially stated that the evaluation will not have any limits or acceptance criteria on the values of skewness and kurtosis.
Need to have someone (Modes ??) determine whether any acceptance criteria needs to be applied to the calculated values of skewness and kurtosis.
Drywell Trench Inspections for Water Tamburro stated that the drywell unidentified leakage rate had been as high as 3 gpm, but dropped to 0.xx gpm when the "C" Recirc Pump was isolated. The "C' RRP is near one of the trenches. If the RRP seal was leaking and spraying water, then water accumulation in the trench may result. During initial drywell entry, water in at least one trench may be found.