ML20198P917
| ML20198P917 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/13/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20198P911 | List: |
| References | |
| NUDOCS 9801220292 | |
| Download: ML20198P917 (1) | |
Text
-.
- ((
t UNITED STATES
,j NUCLEAR REGULATORY COMMISSION wAswiwoTow, p.c. smewooi l
%, * * * * * /j SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 230 TO FACIL_ITY OPERATING LICENSE NO. DPR-77 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT. UNIT 1 DOCKET NO. 50-327
1.0 INTRODUCTION
in a submittal dated November 21,1997, the Tennessee Valley Authority (WA), the licensee for Sequoyah Nuclear Plant (SON), Unit 1, proposed to change Section 4.4.3.2.1 of the SON Unit 1 Technical Specifications (TS) for the remainder of Cycle 9 to perform stroke testing of the power-operated relief valves (PORVs) in Mode 5 rather than in Mode 4. This change would be in effect for approximately 8 months (from January 1998 to September 1998), when SON Unit 1 commences the next scheduled refueling outage. Any entry into Mode 4 for other reasons during Unit 1 Cycle 9 of operation would require performance of this surveillance testing.
2.0 EVALUATION TS Surveillance Requirement (SR) 4.4.3.2.1.b requires each PORV to be demonstrated operable at least once per 18 months by operating the valve through one complete cycle of full travel during Mode 4, This change was submitted because the last operability verification (stroke test) was incorrectly performed with the plant in Mode 5 ('eactor coolant system temperature less than 200'F) rather than in Mode 4 (temperature between 200*F and 350'F) as required by TS 4.4.3.2.1.b. This error was not discovered until early November 1997. As stated in the licensee's application, the cause of the error was the result of less than adequate change management during implementation of the TS. This SR was placed in the same procedure as a simihr stroke test required by the ASME Code Pump and Valve Inservice Testing Program. However, the ASME test is required to be performed in Mode 5 (less than 200'F) for personnel safety considerations.
During the SQN Unit i refueling outage in March-May 1997, the PORVs were full-stroke tested with the reactor coolant system less than 200'F but with a bubble in the pressurizer for pressure control. The PORVs relieve pressure from, and e, connected to, the top of the pressurizer. The pressurizer water / steam mixture was at saturated conditions at about 420'F and 309 psia for the test. These conditions are very similar to pressurizer conditions that have been performed in the past with the reactor coolant system within the Mode 4 temperature range. Historically this test is performed at the low end of the Mode 4 temperature range. The key parameters for this test is pressurizer pressure and temperature, not reactor coolant temperature. Therefore, the tests performed on May 2,1997 on Unit 1 PORVs (in Mode 5) were technically equivalent to tests that would have been performed with the unit in Mode 4.
Therefore, this request no significant safety implications.
9901220292 990113 PD8 ADOCK 05000327 P
2 The Unit 1 PORVs were tested on March 2,1996, with the plant in Mode 4 (i.e., in full compliance with the TS requirements). Those tests remain valid until January 18,1998. If TS relief is not granted and implemented by that date, TS 3.4.3.2.a requires operation with the PORV block valves closed until a valid TS test is performed. The licensee's request states that operation with the PORV block valves closed is inappropriate since the safety benefit of the PORVs would be circumvented. Shutting down the unit solely for the purpose of perfacning this testing has a finite risk, would put an unnecessary thermal cycle on the plant, and would have no recognizable safety value.
3.0 CONCLUSION
Based on the above evaluation, the NRC staff finds the licensee's proposed temporary change to TS SR 4.4.3.2.1.b to be acceptable.
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes 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 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 (62 FR 63565 dated December 1,1997). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 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 endagered 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 deinse and security or to the health and safety of the public.
Principal Contributor: Ronald W. Hernan Dated: Jarmary 13, 1996
.