ML15112A403
| ML15112A403 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/22/1999 |
| From: | Labarge D NRC (Affiliation Not Assigned) |
| To: | Mccollum W DUKE POWER CO. |
| References | |
| IEB-88-008, IEB-88-8, TAC-MA1059, TAC-MA1060, TAC-MA1061, NUDOCS 9902240448 | |
| Download: ML15112A403 (6) | |
Text
February 22, 1999 Mr. W. R. McCollum, Jr.
Vice President, Oconee Site Duke Energy Corporation P.O. Box 1439 Seneca, SC 29679
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 - SUPPLEMENTAL RESPONSE TO NRC BULLETIN 88-08 (TAC NOS. MA1059, MA1060, AND MA1061)
Dear Mr. McCollum:
By letter dated February 26, 1998, Duke Energy Corporation submitted an update to its response to NRC Bulletin 88-08 as a followup action stemming from the investigation of a leak in the high pressure injection normal makeup line on Oconee Nuclear Station, Unit 2, that caused the unit to be shut down on April 21, 1997.
In order to complete its review of your submittal, the staff has determined that additional information will be needed. It is requested that your response be provided by July 16, 1999, as discussed with Mr. Ed Burchfield of your staff.
Sincerely, ORIGINAL SIGNED BY:
David.E. LaBarge, Senior Project Manager Project Directorate 11-2 Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287
Enclosure:
Request for Additional Information cc w/encl: See next page Distribution:
PD 11-2,Rdg.
OGC Clockeit-Fil3 JZwolinski e-mail RCN - SE only PUBLIC HBerkow COgle, RII MHartzman ACRS JFair DLaBarge To receive a copy of this document, indicate in the box: "C" = Copy without attachment/enclosure "E"=Cop with ttachmentlenclosure "N" = No copy OFFICE PM:
L A:PDll-nN D:P NAME DL90a:cn LBerry K U HBer DATE 2-I//99 199
')/3199
/ /99
/ /99
/97 DOCUMENT NAME:
G:\\OCONEE\\01059RAl.WPD OFFICIAL RECORD COPY K
9902240448 99022 PDR ADOCK 05000269 Q
~~PDR 9
)~j\\
tpjk REGt UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 22, 1999 Mr. W. R. McCollum, Jr.
Vice President, Oconee Site Duke Energy Corporation P. 0. Box 1439 Seneca, SC 29679
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 - SUPPLEMENTAL RESPONSE TO NRC BULLETIN 88-08 (TAC NOS. MA1059, MA1060, AND MA1061)
Dear Mr. McCollum:
By letter dated February 26, 1998, Duke Energy Corporation submitted an update to its response to NRC Bulletin 88-08 as a followup action stemming from the investigation of a leak in the high pressure injection normal makeup line on Oconee Nuclear Station, Unit 2, that caused the unit to be shut down on April 21, 1997.
In order to complete its review of your submittal, the staff has determined that additional information will be needed. It is requested that your response be provided by July 16, 1999, as discussed with Mr. Ed Burchfield of your staff.
Sincerely, David E. LaBarge, Senior Project Manager Project Directorate 11-2 Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287
Enclosure:
Request for Additional Information cc w/encl: See next page
Oconee Nuclear Station cc:
Ms. Lisa F. Vaughn Mr. J. E. Burchfield Legal Department (PBO5E)
Compliance Manager Duke Energy Corporation Duke Energy Corporation 422 South Church Street Oconee Nuclear Site Charlotte, North Carolina 28201-1006 P. 0. Box 1439 Seneca, South Carolina 29679 Anne Cottington, Esquire Winston and Strawn Ms. Karen E. Long 1400 L Street, NW.
Assistant Attorney General Washington, DC 20005 North Carolina Department of Justice Mr. Rick N. Edwards P. O. Box 629 Framatome Technologies Raleigh, North Carolina 27602 Suite 525 1700 Rockville Pike L. A. Keller Rockville, Maryland 20852-1631 Manager - Nuclear Regulatory Licensing Manager, LIS Duke Energy Corporation NUS Corporation 526 South Church Street 2650 McCormick Drive, 3rd Floor Charlotte, North Carolina 28201-1006 Clearwater, Florida 34619-1035 Mr. Richard M. Fry, Director Senior Resident Inspector Division of Radiation Protection U. S. Nuclear Regulatory North Carolina Department of Commission Environment, Health, and 7812B Rochester Highway Natural Resources Seneca, South Carolina 29672 3825 Barrett Drive Raleigh, North Carolina 27609-7721 Virgil R. Autry, Director Division of Radioactive Waste Management Mr. Steven P. Shaver Bureau of Land and Waste Management Senior Sales Engineer Department of Health and Environmental Westinghouse Electric Company Control 5929 Carnegie Blvd.
2600 Bull Street Suite 500 Columbia, South Carolina 29201-1708 Charlotte, North Carolina 28209 County Supervisor of Oconee County Walhalla, South Carolina 29621
REQUEST FOR ADDITIONAL INFORMATION OCONEE NUCLEAR STATION UNITS 1, 2, AND 3 DUKE ENERGY CORPORATION SUPPLEMENT 1 TO OCONEE RESPONSE TO NRC BULLETIN 88-08 Page 4
[Page numbers correspond to those in the Duke Energy Corporation (Duke) submittal of February 26, 1998]
- 1.
Provide Duke calculation OSC-3681 (Reference 2 of the submittal), showing that the temperature data collected from the Unit 1 High Pressure Injection/Emergency Injection (HPI/EI) lines and the representative thermal load on the piping, determined from these data, reflected the thermal cycling conditions, which formed the basis for Bulletin 88-08.
- 2.
Provide a summary of the HPI piping reanalyses OSC-1304-06, OSC-1323-06, and OSC-1342-06 (Reference 3 of the submittal), showing that the thermal loading from OSC-3681 was considered as an additional load set in confirming the integrity of the HPl/El lines for 40-year plant life using the methodology of ASME Section III, Paragraph NB-3653.
Page 5
- 3.
Justify the applicability to Units 2 and 3 of the conclusion, based on Unit 1 thermal monitoring data (in Reference 5 of the submittal), that "the cause of the stratification is backflow through a leaking check valve while the unit is in start-up mode with one Reactor Coolant Pump off in that loop."
Page 6
- 4.
Provide the results of the Duke review that was completed on May 1, 1998, of the Structural Integrity Associates (SIA) analyses, received on February 24, 1998.
- 5.
- a.
Justify the applicability to Units 2 and 3 of the SIA analyses and conclusions, based on the 1990 Unit 1 thermocouple data.
- b.
Indicate when the "fatigue usage due to the self cycling of the stratification will be added to the fatigue usage resulting from the other design transients."
- c.
Indicate whether this "self cycling of the stratification" will be considered as an additional load set for calculating the overall fatigue usage of the pipe-to-safe end welds in the High Pressure Injection /Normal Make Up (HPI/NMU) lines in the three units.
- 6.
Indicate how the load set due to the "self cycling" of the stratification load set in the fatigue analysis will reflect the thermal flow conditions that existed in the 2A HPI/NMU nozzle/safe end/pipe welds and base metal at the time the leaking crack in the weld was discovered.
Enclosure
-2 Page 8
- 7.
The acceptance limits for the currently recorded thermocouple data are based on a limited cycle Class 1 fatigue analysis of the Unit 1 HPI/NMU nozzles provided by SIA in late May of 1997.
- a.
State the definition of "a limited cycle Class 1 fatigue analysis."
- b.
Provide the SIA calculations Duke-1 6Q-302 and Duke-1 6Q-303 (References 8 and 9 of the submittal).
- c.
State the acceptance limits for the currently recorded thermocouple data.
- d.
Justify the applicability of these acceptance limits to the HPI/NMU piping in Units 2 and 3, in view of the April 21, 1997, through-wall cracking event in the Unit 2 HPI/NMU safe-end weld.
- 8.
The cumulative usage factor of 0.028 per fuel cycle was based on the 1990 Unit 1 HPI/NMU thermocouple data for all postulated transients that could occur during a fuel cycle. State whether these postulated transients included thermal stratification cycling.
Page 9
- 9.
Duke concludes, in Section 5.0, that the solution to the back flow/stratification problem is rooted in solving the HPI flow perturbations noted during plant heat ups and cool downs.
This implies that back flow and leakage through a potential gap between the thermal sleeve and the nozzle safe end occurs only during plant heatup and cooldown. Justify the validity of this assumption. State why other mechanisms, such as turbulent penetration, which occur during normal operation, should not be included in the solution.
- 10.
Provide a detailed summary of the objectives of the Framatome computational fluid dynamics calculations. Indicate if these calculations will form the basis for determining the root cause of the thermal cycling that led to the through-wall cracking of the 2A1 HPI/NMU nozzle safe end-to-pipe weld. Also, indicate if these calculations will provide an insight into the thermohydraulic phenomena that caused the thermal cycling in the safe end weld and an estimate of the time interval for crack initiation in the weld and the surrounding base metal.
Page 10
- 11.
Section 5.0, Conclusions, states that a completed limited cycle thermal fatigue analysis indicates that there is insignificant fatigue usage due to back flow/thermal stratification.
Justify this conclusion in light of the through-wall cracking event in the 2A1 HPI/NMU nozzle safe end-to-pipe weld that occurred after, at most, 23 years of plant operation.
- 12.
Provide justification why temperature monitoring of the HPI/NMU and HPI/El lines should not continue beyond the stated outages for Units 1, 2, and 3.
-3
- 13.
The stress analysis to Class 1 rules for design transients, including the effects of back flow/thermal stratification, was scheduled for completion by May 1, 1998. State whether this analysis was completed. If it was, provide a detailed description and the results of this analysis. If it was not, provide the new schedule for completion.