ML20236A207
| ML20236A207 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/06/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236A205 | List: |
| References | |
| NUDOCS 8903160486 | |
| Download: ML20236A207 (3) | |
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UNITED STATES 1
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NUCLEAR REGULATORY COMMISSION
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g WASHINGTON, D. C. 20655 l
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l ENCLOSURE l
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 103 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 92 TO FACILITY OPERATING LICENSE NO. DPR-79 i
TENNESSEE VALLEY AUTHORITY l
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
By letter dated April 16, 1987, the Tennessee Valley Authority (TVA or the licensee) proposed changes to Sequoyah Nuclear Plant (SQN), Units 1 and 2 Technical Specifications (TS). The changes would delete Surveillance Requirement (SR) 4.6.1.8.d.4 (Units 1 and 2) for the Emergency Gas Treatment?
System (EGTS) and revise SRs 4.7.8.d.4 and 4.9.12.d.3 and associated BasesThe&
l (Units 1 and 2) for the Auxiliary Building Gas Treatment System (ABGTS).
se changes are based on calculations which indicate that the minimum heater capacity required is significantly less than the manufacturer's ratings currently listed in the TS. The licensee stated that the original heater power i
requirements reflect manufacturer's ratings based on a conservative analysis.
I A typographical error in SR 4.7.8.d.4 (Unit 1) is also corrected.
Subsequently, in their November 21, 1988 letter, the licensee withdrew the Technical Specification change request for both units on the ABGTS.
Therefore, j
our evaluation concerns only the EGTS and the typographical errors.
By letter dated June 17, 1987, the licensee provided a copy of Nonconformance Report SQN NEB 8408.
This report was referenced in the licensee's 1
justification of the proposed changes for the EGTS.
By letter dated
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November 21, 1988, the licensee withdrew its proposed changes on the ABGTS.
The information in these letters did not change the substance of the Federal l
Register Notice (52 FR 47793) published on December 16, 1987 on the proposed l
amendments for the ABG1'S and the typographical error and did not affect the staff's initial determination of no significant hazards consideration on these 1
proposed amendments in that notice.
2.0 EVALUATION 2.1 TS Change This change deletes Surveillance Requirement (SR) 4.6.1.8.d.4 which states:
that " Verifying that the heaters dissipate 16 1.6 kW when tested in accordance with ANSI N510-1975."
The EGTS was constructed with heaters in the ductwork upstream of the air cleanup units.
These heaters wereminstalled to maintain the relative humidity (RH) of the airstream passiqg through*the cleanup units to less than or equal to 70 percent. q q,3/ p g g g $
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. i The requested change was bas on TVA calculation, EN DES Calculation TI-ECS-98, " Maximum Annulus-
'tive Humidity Resulting from a Loss of Coolant Accident (LOCA) or HL., Energy Line Break (HELB) Inside Containment."
The maximum RH as calculated in the cited analysis in the annulus after a LOCA or HELB inside containment would be approximately 60. percent. This value is lower than the upper-bound RH of 70 percent that the duct heaters were installed to maintain.
Therefore, the licensee determined that the duct heaters in EGTS are not required for safety.
The licensee's analysis is based on conservative assumptions.
Initial steam i
pressure and temperature in the containment (23.0 psia and 327*F respectively) are assumed to remain constant as the accident progresses even though they would gradually decrease. A constant containment leak rate of 1.5 cubic feet per minute into the annulus is assumed. This is conservative since this leak rate is expected to decrease to half of the initial value after the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (
Reference:
TVA-EN-DESCalculationTI-ECS-98).
Based on the above, the staff concludes that the EGTS duct heaters are not required for safety and the licensee's proposed change is acceptable.
7 2.2 TS Change - SR 4.7,0.d.4 This change corrects a typographical error in SR 4.7.8.d.4 for Unit 1, from "dispite" to " dissipate."
The staff agrees. with the licensee that the word in SR 4.7.8.d.4 for Unit I should be " dissipate" instead of "dispite" in referring to the requirement that heaters will " dissipate 32 1 3.2 kW."
Therefore, the staff concludes that this proposed change is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance requirements.
The staff has determined that the amendments involve 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 l
issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public coment on such finding.
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 1,0 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no i
environmental impact statement nor enviror. mental assessment need be prepared in l
connection with the issuance of these amendments.
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4.0 CONCLUSION
The Commission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Register (52 FR 47'/93) on December 16, 1987 and consulted with the State of Tennessee.
No public comments were received and the State of Tennessee did not have any comments.
The staff has concluded, based on the considerations discussed above, that:
will not be endangered by operation in the proposed manner, and (2) public (1) there is reasonable assurance that the health and safety of the such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendments will not be inimical to the common defense and security nor to the health and safety of the public.
Principal Contributor:
S. B. Kim Dated: March 6, 1989 1
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