ML20216D472
| ML20216D472 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/11/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20216D468 | List: |
| References | |
| NUDOCS 9803170074 | |
| Download: ML20216D472 (3) | |
Text
.
p us S-UNITED STATES s
j NUCLEAR REGULATORY COMMISSION
\\,...../g WASHINGTON, D.C. 30eeH001 SAFEJY EVALU AT!ON BY THF_,GFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 94 AND 81 TO FACILITY OPERATING LICENSE NOS. NPF-76 AND NPF-80 STP NUCLEAR OPERATING COMPANY DOCKET NOS. 50-498 AND 50-499
)
SOUTH TEXAS PROJECT. UNITS 1 AND 2
1.0 INTRODUCTION
By application dated December 17,1997, STP Nuclear Operating Company, et.al., (the licensee) requested changes to the Technical Specifications (TSs) (Appendix A to Facility Operating License Nos. NPF-76 and NPF-80) for the South Texas Project, Units 1 and 2 (STP). The proposed changes would revise TS 4.6.2.1.d to extend the surveillance interval of the containment spray system nozzle air flow test to ten years from five ysars.
2.0 BACKGROUND
The proposed amendment is consistent with NUREG-1366, " Improvements to Technical Specifications Surveillance Requirements," Item 8.1, " Containment Spray System," dated December 1992; Generic Letter (GL) 93-05, "Line-Item Technical Specifications improvements to Reduce Surveillance Requirements for Testing During Power Operation," item 8.1, "Containmerit Spray System," dated September 27,1993; and NUREG-1431, Revision 1, " Standard Technical Specifications, Westinghouse Plants," Specification 3.6, " Containment Systems," dated April 7, 1995.
3.0 DISCUSSION i
TS 4.6 't.1.d requires performance of an air or smoke flow test through the spray nozzles to verify that the nozzles are unobstructed. This surveillance requirement is a qualitative check to ensure that each spray nozzle is unobstructed and provides assurance that spray coverage of the containment during an accident is not degraded. The containment spray system is designed to p ovide post-accident cooling and depressurization of the containment atmosphere and a mechanism for removal of iodine from the containment atmosphere. In conjunction with the recirculation fluid pH control system, the containment spray system ensures a containment sump pH of 7.0 during the recirculation phase of a postulated loss-of-coolant accident.
4.0 EVALUATION The STP containment spray system header and nozzles are passive devices that are not normally exposed to fluids or debris. The syclem piping and nozzles are fabricated of stainless steel which is highly resistant to corrosion, especially in a low-stress application such as at STP.
9003170074 900311 f
I PDR ADOCK 05000498 g
P..
PDR 4
- +
. l k
11 is unlikely that nozzles with satisfactory air flow at a five year interval will become obstructed if the interval is extended to ten years because the environment is not conducive to corrosion and l
the system will not normally be open or exposed to debris which could foul the nozzles.
l In NUREG-1366, industry operating experience history was evaluated to determine the cause of problems discovered when performing this surveillance. In all cases, the problems discovered were related to construction, and not the result of normal operation. In GL 93-05, the staff noted that a containment spray system air flow test for San Onofre, Unit 1, indicated that several i
nozzles were blocked. The resulting investigacion found that seven nozzles were clogged with sodium silicate, a coating material that was applied to the carbon steel containment spray system piping at San Onofre in 1977. However, as s ted above, the STP containment spray system u
piping and nozzles are stainless steel and as...ot coated.
The containment spray system nozzles for STP have been tested satisfactority twice since construction. This shows that the construction problems identified in NUREG-1366 do not exist at STP. Also, the tests show that over a period cf normal operation, the spray nozzles did not j
become obstructed.
l 5.0
SUMMARY
Extending the surveillance interval of the containment spray system nozzle air flow test to ten years from five years is acceptable based on the spray header / nozzles being fabricated from stainless steel, the spray header / nozzles being located in an environment that is not conducive to corrosion, and STP cod industry operating experience.
6.0 STATE CONSULTATION
l l
In accordance with the Commission's regulations, the Texas State official was notified of the proposed issuance of the amendments. The State official had no comments.
7.0 g_NVIRONMENTAL CONSIDERATION The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC 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 individaal or cumulative occupational radiation exposure. The Commission has previrasly issued a proposed finding that the amendments involve no s!gnificant hazards conaderation, and there has been no public comment on such finding (63 FR 4325). 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 s
envdonmental impact statement of environmental assessment need be prepared in connection with the issuance of the amendments.
8.0 CONCLUSION
i 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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
PrincipalContributor, T. Alexion Date: March 11, 1998 l
4