ML14183A785
| ML14183A785 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 03/12/1997 |
| From: | Mozafari B NRC (Affiliation Not Assigned) |
| To: | Hinnant C CAROLINA POWER & LIGHT CO. |
| References | |
| TAC-M69478, NUDOCS 9703140128 | |
| Download: ML14183A785 (4) | |
Text
March 12, 1997 Mr. C. S. Hinnant, Vice President Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2 3581 West Entrance Road Hartsville, South Carolina 29550
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION ON SEISMIC QUALIFICATION OF MECHANICAL AND ELECTRICAL EQUIPMENT AT THE H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 (TAC NO. M69478)
Dear Mr. Hinnant:
By letter dated June 30, 1995, Carolina Power & Light Company submitted a summary report for the H. B. Robinson Steam Electric Plant, Unit No. 2, related to Generic Letter (GL) 87-02, "Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, USI A-46."
During our review, we identified the need for additional information as indicated in the enclosure.
To support the NRC staff's review schedule, your written response to this request for additional information is expected within 30 days of the receipt of this letter. Should you have any questions, do not hesitate to contact me at (301) 415-2020 e-mail me at blm@nrc.gov.
Sincerely, Original signed by:
Brenda Mozafari, Project Manager o
MProject Directorate II-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-261 Distribution Docket=7Fi le ACRS
Enclosure:
RAI PUBLIC OGC PDII-1 RF RWessman cc w/enclosure:
See next page SVarga ALee FILENAME -
G:\\ROBINSON\\ROB69478.RA 2 OFFICE LA:PDII-1 PM:PDII-1 (A)D:PDII-1 NAME EDunnington BMozafari FMReinh DATE 03///97 0 -/f. 97 03/12/97 COPY Yes No Yes/,No Yes/No OFFICIAL RECORD COPY 9703140128 970312 PDR ADOCK 05000261 P
Mr. C. S. Hinnant H. B. Robinson Steam Electric Carolina-Power & Light Company Plant, Unit No. 2 cc:
Mr. William D. Johnson Mr. Dayne H. Brown, Director Vice President and Senior Counsel Department of Environmental, Carolina Power & Light Company Health and Natural Resources Post Office Box 1551 Division of Radiation Protection Raleigh, North Carolina 27602 Post Office Box 27687 Raleigh, North Carolina 27611-7687 Ms. Karen E. Long Assistant Attorney General Mr. Robert P. Gruber State of North Carolina Executive Director Post Office Box 629 Public Staff -
NCUC Raleigh, North Carolina 27602 Post Office Box 29520 Raleigh, North Carolina 27626-0520 U.S. Nuclear Regulatory Commission Resident Inspector's Office Mr. Max Batavia, Chief H. B. Robinson Steam Electric Plant South Carolina Department of Health 2112 Old Camden Road Bureau of Radiological Health Hartsville, South Carolina 29550 and Environmental Control 2600 Bull Street Regional Administrator, Region II Columbia, South Carolina 29201 U.S. Nuclear Regulatory Commission 101 Marietta St., N.W., Ste. 2900 Mr. J. Cowan Atlanta, Georgia 30323 Vice President Nuclear Services and Environmental Mr. Dale E. Young Support Department Plant General Manager Carolina Power & Light Company Carolina Power & Light Company Post Office Box 1551 -
Mail OHS7 H. B. Robinson Steam Electric Plant Raleigh, North Carolina 27602 Unit No. 2 3581 West Entrance Road Hartsville, South Carolina 29550 Mr. Milton Shymlock U. S. Nuclear Regulatory Commission Public Service Commission 101 Marietta Street, N.W. Suite 2900 State of South Carolina Atlanta, Ga. 3023-0199 Post Office Drawer 11649 Columbia, South Carolina 29211 Mr. H. K. Chernoff Supervisor, Licensing/Regulatory Programs Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2 3581 West Entrance Road Hartsville, South Carolina 29550
REQUEST FOR ADDITIONAL INFORMATION REGARDING VERIFICATION OF SEISMIC ADEQUACY OF MECHANICAL AND ELECTRICAL EQUIPMENT IN OPERATING REACTORS FOR THE H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2
- 1.
Describe the extent to which the seismic margin methodology, described in the report EPRI NP-6041, was used in the A-46 program at the H. B.
Robinson Steam Electric Plant (HBR), including outlier resolutions.
Since this methodology is known to yield analytical results that are not as conservative as what might be obtained by following the GIP-2 guidelines, it is generally not acceptable for the A-46 program.
Therefore, for each deviation from the GIP-2 guidelines, in situations where the margin methodology is utilized, identify the nature and the extent of the deviation, and provide the justification for its acceptance.
- 2.
In Table 5-4 of the submittal, under "Bounded Elevation," the spectra for the reactor/auxiliary building are bounded at elevation 258 feet, and for the containment building, the spectra are bounded at elevation 325 feet. Clarify whether the spectra at other elevations in both buildings are, indeed, not bounded. For the turbine building, provide a clarification for the seemingly inconsistent note, "SQUG generally not bounded by FSAR" (also refer to the last paragraph of page A-2 of the Third Party Audit Report (Appendix E to the submittal)).
In summary, explain in detail the significance of the spectra not being bounded, as Table 5-4 seems to imply, and provide the justification or resolution for the concern. Revise Table 5-4 for clarification and completeness.
- 3.
Referring to the in-structure response spectra provided in your 120-day response to the NRC's request in Supplement No. 1 to Generic Letter (GL) 87-02, dated May 22, 1992, the following information is requested:
- a. Identify structure(s) that have in-structure response spectra (5 percent critical damping) for elevations within 40 feet above the effective grade that are higher in amplitude than 1.5 times the SQUG Bounding Spectrum.
- b. With respect to the comparison of equipment seismic capacity and seismic demand, indicate which method in Table 4-1 of GIP-2 was used to evaluate the seismic adequacy for equipment installed on the corresponding floors in the structure(s) identified in Item (a) above. If you have elected to use method A in Table 4-1 of the GIP-2, provide a technical justification for not using the in-structure response spectra provided in your 120-day response.
ENCLOSURE
-2 It appears that some licensees, in responding to A-46 concerns, are making an incorrect comparison between each plant's safe shutdown earthquake (SSE) ground motion response spectrum and the SQUG Bounding Spectrum. The SSE ground motion response spectrum for most nuclear power plants is defined at the plant foundation level.
The SQUG Bounding Spectrum is defined at the free field ground surface.
For plants founded on deep soil or rock, there may not be a significant difference between the ground motion amplitudes at the foundation level and those at the ground surface. However, for sites where a structure is founded on shallow soil, the amplification of the ground motion from the foundation level to the ground surface may be significant.
- c. For the structure(s) identified in Item (a) above, provide the in-structure response spectra designated according to the height above the effective grade. If the in-structure response spectra identified in the 120-day response to Supplement No. 1 to GL 87-02 were not used, provide the response spectra that were actually used to verify the seismic adequacy of equipment within the structures identified in Item (a) above. Also, provide a comparison of these spectra to 1.5 times the Bounding Spectrum.
- 4.
Provide an assessment of the impact on plant safety in consideration of the proposed schedule for resolving all the identified outliers or open items by the completion of Refueling Outage 18, scheduled to occur during the spring of 1998.
- 5.
You indicated in Chapter 6 of the submittal that the anchorages in the 31 tanks and heat exchangers in the safe shutdown path are adequate.
Confirm that the tanks and heat exchangers were evaluated and found structurally adequate in accordance with the rules and procedures given in Section 7 of the GIP.
- 6.
You stated on page 27 of the submittal that the tightness check of expansion anchors was performed on a representative number of mechanical and electrical components. State whether the representative number meets the sample size criteria for expansion anchor tightness check as listed on Table C.2-4 of the GIP. If not, provide justification.
- 7.
Describe self-drilling snap-off anchors and their acceptance criteria.