ML19257B795
| ML19257B795 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/10/1980 |
| From: | Domeck C TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML19257B792 | List: |
| References | |
| 575, NUDOCS 8001180354 | |
| Download: ML19257B795 (2) | |
Text
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s u >< o License No. NPF-3 Serial No. 575 Page One of Two January 10, 1980 SAFETY EVALUATION FOR DELAY IN TESTING OF REACTOR VESSEL INTERNALS VENT VALVES The internals vent valves are provided to relieve the pressure generated by steaming in the core following a LOCA so that the core remains sufficiently covered.
Inspection and manual actuation of the internals vent valves fulfill the following purposes:
1.
Ensure valve operability
- 2.
Ensure that valves are not stuck during normal operation.
3.
Demonstrate that the valves are fully open at the forces equivalent to the differential pressure assumed in the safety analyses.
The inspection program for these valves also ensures that of these components will be maintained at the structural integrity of the plant.
To the extent applicable, an acceptable level throughout the life Section XI of the ASME Boiler and Pressure Vessel Code.this program is in compliance with Davis-Besse Unit of these valves be descastrated at1 Technical Specification 4.4.10.1.b requires that opera least once per 18 months during shutdown.
Technical Specification 4.0.2.a provides a maximum allowable extension of 4.5 months (25% of 18 months) for the 18 month period.
The valves were last tested on May 12, 1978 during the BPRA/ ORA removal outage.
In order to meet the Technical Specification surveillance interval, the valve operability should, theref ore, be demonst rated by March 2 7, 1980.
This License Amen dmen t Request provides for a relaxation in that schedule by approximately two mon ths.
The testing is now proposed to be completed by May 30, 1980.
The present scheduled date for the first refueling outage at Davis-Besse Unit 1 is March 15, 1980.
The projected refueling schedule does not ment of Technical Specification surveillance requirement guarantee the fulfill-27, 1980.
for the internals vent valves by March It should be noted that Davis-Besse Unit I has undergone several prolonged outages (including the March 30 to July 11, 1979 This saving in core operating time is enough to accountoutage) af ter the testing done in May 1 for the delay in testing since the intent of Section XI of ASME Boiler and Pressure Vessel Code is to provide a mechanism for the direction of an inspection based on operating power facility.
time of the Paragraph IWA-2400(a) of the 1974 Section XI with addenda through Summer 1975 states:
"...These inspection intervals represent calendar years af ter the reactor facility has been placed into commercial service.
The interval may be extended by as much as one year to permit inspections to be con-current with plant outages."
1770 327 800118025f5E#f'
Docket !;o. 50-346 License !;o. NPF-3 Page Two of Two Serial f;o. 575 January 10, 1980 In addition to the above, B6'a' has informed Toledo Edison (letter DB-79-22 3 dated ;;ovember 20, 1979) that an extension in the required technical specifi-cation for exercising the valves by several months is justified.
This is based on successful demonstration of valve exercise at A!;O-1, SMUD, Crystal River-III and Oconee-1.
Pursuant to the above, if the scheduled date for completion of valve testing is extended to May 30, 1980:
- 1) The probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the FSAR is not inc re as ed.
- 2) A possibility for an accident or malfunctien of a different type than any evaluated previously in the FSAR it not created.
- 3) The margin of safety as defined in the basis af any Technical Specification is not reduced.
Consequently, this is not an unreviewed safety question.
d-
/- l0 ~ $0 1770 328