ML14196A038
| ML14196A038 | |
| Person / Time | |
|---|---|
| Site: | Boiling Water Reactor Owners Group |
| Issue date: | 09/08/2014 |
| From: | Anthony Mendiola Licensing Processes Branch (DPR) |
| To: | Leslie Hill BWR Owners Group |
| Golla J | |
| References | |
| Download: ML14196A038 (4) | |
Text
September 8, 2014 Ms. Lesa P. Hill, Chairman Boiling Water Reactor Owners Group Southern Nuclear c/o GE Hitachi BWROG 3901 Castle Hayne Road M/C F-12 Wilmington, NC 28402
SUBJECT:
FEEDBACK ON BOILING WATER REACTOR OWNERS GROUP REPORT BWROG-ECCS-TA13-004, BWROG ECCS STRAINER BYPASS TEST REPORT
Dear Ms. Hill:
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the Boiling Water Reactor (BWR) Owners Group (BWROG) report BWROG-ECCS-TA13-004, BWROG ECCS Strainer Bypass Test Report (Agencywide Documents Access and Management System Accession No. ML14085A215) and offers the following feedback:
- 1) The testing appeared to be well designed and controlled.
- 2) Was the preparation of the Rockwool adequate? The preparation was adjusted to be less destructive because the Rockwool was observed to break into very small pieces.
The Rockwool will be subjected to the same conditions as other potential debris sources.
During the blowdown phase it may undergo significant fragmentation.
- 3) There was some confusion about whether the PCI strainer with 3/32 inch holes was used. The description states that the 1/8 inch holes were used. Table 4-10 states that Test S1 used a PCI strainer with 3/32 inch holes. Please clarify what strainer and hole sizes were used in test S1.
- 4) It appears that the flow rate listed in Table 4-11 is incorrect. It is likely that the table has an error in the heading and that the flow was 279 gpm. At 718 gpm the approach velocity would be about 0.05 ft/sec. The listed approach velocity is 0.02 ft/sec. Based on other information it appears that the flow was 279 gpm. Please confirm the flow rate.
- 5) Was it validated that flow was not bypassing the in-service filters during testing?
- 6) Was the potential for the effect of the blowdown and chugging phases of the LOCA considered for the testing? These phases can disturb a debris bed and make bypass of debris more likely.
- 7) The summary section is confusing. The first bullet states that the full range of bypass quantities was 3.75 to 8.77 grams/sq ft. Later bullets list a minimum and maximum of 2.67 and 11.06 grams/sq ft. These are likely for different conditions, but the distinction was not clear.
- 8) On the second bullet it is not clear that the fiber diameters tested would have a significant effect on bypass. The Rockwool likely bypassed a greater amount because it
L. Hill was more easily fragmented into shorter fibers. The Temp Mat is generally stiffer and clumps together more than Nukon. This could have affected the results to a greater degree than the difference in fiber diameter.
- 9) Were any conclusions drawn about the fiber size distribution that bypassed the strainer?
If you have any questions regarding the above staff feedback, please contact Joseph Golla at 301-415-1002 or via e-mail at Joe.Golla@nrc.gov.
Sincerely,
/RA/
Anthony J. Mendiola, Chief Licensing Processes Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Project No. 691 cc: See next page
ML14196A038 NRR-106 OFFICE PLPB/PM PLPB/LA ESGB/BC DSS/SSIB/BC PLPB/BC NAME JGolla DBaxley GKulesa VCusumano AMendiola DATE 08/04/2014 07/29/2014 08/28/2014 09/04/2014 09/08/2014 Boiling Water Reactor Owners Group Project No. 691 cc:
BWROG Chairman Lesa P. Hill Southern Nuclear c/o GE Hitachi BWROG 3901 Castle Hayne Road M/C F-12 Wilmington, NC 28402 lphill@southernco.com BWROG Project Manager Michael Iannantuono GE-Hitachi Nuclear Energy PO Box 780 M/C A-70 3901 Castle Hayne Road Wilmington, NC 28402 Michael.iannantuono@ge.com BWROG Program Manager Kenneth McCall GE-Hitachi Nuclear Energy PO Box 780 M/C A-70 3901 Castle Hayne Road Wilmington, NC 28402 Kenneth.mccall@ge.com BWROG ECCS Suction Strainers Committee Chairman Steve Scammon slscammon@energy-northwest.com