ML20097D419
| ML20097D419 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/07/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20097D410 | List: |
| References | |
| NUDOCS 9602120353 | |
| Download: ML20097D419 (3) | |
Text
@A EE2 k UNITED STATES p
NUCLEAR REGULATORY COMMISSION E
WASHINGTON, D.C. 30506 0001 4
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/SAFETYEVALUATIONBYTHEOFFICEOFNUCLEARR RELATED TO AMENDMENT NO. 218 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 208 TO FACILITY OPERATING LICENSE NO. DPR-79 l
TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-327 kND 50-328
1.0 INTRODUCTION
By application dated December 8,1995, the Tennessee Valley Authority (the licensee) proposed an amendment to the Technical Specifications (TS) for Sequoyah Nuclear Plant (SQN) Units 1 and 2.
The requested changes would decrease the frequency specified in surveillance requirements (SRs) 4.6.2.1.1.d and 4.6.2.1.2.b for conducting air or smoke tests of the containment spray system headers and Residual Heat Removal System headers, respectively, from every 5 years to every 10 years. The tests are conducted to verify that each spray nozzle is unobstructed.
Guidance for the proposed changes was provided in Generic Letter 93-05, "Line-Item Technical Specifications Improvements to Reduce Surveillance Requirements for Testing During Power Operation."
2.0 EVALUATION The Containment Spray (CS) System contains two redundant spray headers containing 312 nozzles per header.
It is designed to prevent containment pressure from exceeding its maximum design pressure during a large break loss of coolant accident by spraying borated water through the spray headers l
located at the top of the cor 'ainment building. The cooler spray water condenses the steam in the containment atmosphere.
If additional cooling is needed, two separate spray headers, containing 147 nozzles per header, supplied by the Residual Heat Removal (RHR) System, can be aligned manually to spray the containment atmosphere.
To ensure that these nozzles are not obstructed, the licensee injects hot air into each header at 5-year intervals and uses an infrared camera to detect flow from each nozzle. Test personnel manipulate the camera from the top of the polar crane, approximately 100 feet from the reactor cavity floor (which is a potential personnel safety hazard).
In December 1992, the NRC issued NUREG-1366, " Improvements to Technical Specifications Surveillance Requirements."
It indicated that operating history was reviewed to determine the success of the surveillance tests ENCLOSURE 3 9602120353 960207 DR ADOCK 05000327 i
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performed at various pressurized water reactors. Of the many tests reviewed, only three indicated nozzle flow problems. These problems were construction related and not due to header degradation. The conclusion drawn from the evaluation was that the corrosion of stainless steel piping is negligible during the extended surveillance interval and recomended that the interval be extended to 10 years.
In addition, GL 93-05 also recomends that the surveillance interval be extended to 10 years, and points out that seven nozzles were found to be clogged at a nuclear power plant. The cause of this problem was the coating material that was applied to the carbon steel CS system piping. Since the CS and RHR piping at SQN are stainless steel, these problems are not a concern at SQN.
Following initial startup, the licensee performed flow tests of the CS and RHR nozzles three times on Unit I and twice on Unit 2.
No plugging or flow degradation problems were detected. These tests demonstrated that obstructions did not exist in any of the spray nozzles.
Based on this analysis, the licensee's proposal to change the CS and RHR spray system nozzle testing frequency from 5 years to 10 years will continue to provide adequate assurance that the nozzles will be operable to mitigate the consequences of a design basis accident at SQN.
Therefore, the staff finds the proposed change acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendment.
The State official had no coments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (61 FR 182). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment;
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: David E. LaBarge Dated: February 7, 1996
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Mr. Oliver D. Kingsley, Jr.
SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:
Mr. O. J. Zeringue, Sr. Vice President TVA Representative Nuclear Operations Tennessee Valley Authority Tennessee Valley Authority 11921 Rockville Pike 3B Lookout Place Suite 402 1101 Market Street Rockville, MD 20852 Chattanooga, TN 37402-2801 Regional Administrator Dr. Mark 0. Medford, Vice President U.S. Nuclear Regulatory Commission Engineering & Technical Services Region II Tennessee Valley Authority 101 Marietta Street, NW., Suite 2900 3B Lookout Place Atlanta, GA 30323 1101 Market Street Chattanooga, TN 37402-2801 Mr. William E. Holland Senior Resident Inspector Mr. D. E. Nunn, Vice President Sequoyah Nuclear Plant New Plant Completion U.S. Nuclear Regulatory Commission Tennessee Valley Authority 2600 Igou Ferry Road i
3B Lookout Place Soddy Daisy, TN 37379 1101 Market Street Chattanooga, TN 37402-2801 Mr. Michael H. Mobley, Director 1
Division of Radiological Health Mr. R. J. Adney, Site Vice President 3rd Floor, L and C Annex Sequoyah Nuclear Plant 401 Church Street Tennessee Valley Authority Nashville, TN 37243-1532 P.O. Box 2000 Soddy Daisy, TN 37379 County Judge Hamilton County Courthouse General Counsel Chattanooga, TN 37402-2801 Tennessee Valley Authority ET llH 400 West Summit Hill Drive Knoxville, TN 37902 Mr. P. P. Carier, Manager Corporate Licensing Tennessee Valley Authority 4G Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Ralph H. Shell Site Licensing Manager Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37379