ML16154A750
| ML16154A750 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/29/1994 |
| From: | Boger B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Lainas G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML16154A749 | List: |
| References | |
| NUDOCS 9501170050 | |
| Download: ML16154A750 (1) | |
Text
AUG 2 9 1994 MEMORANDUM FOR:
Gus C. Lainas. Assistant Director for Region 11 Reactors Division of Reactor Projects gul office of Nuclear Reactor Regulation FROM:
Bruce A. Boger, Acting Director Division of Reactor Projects
SUBJECT:
REVISION 1 TO TASK INTERFACE AGREEMENT (TIA 94-013)
TECHNICAL ASSISTANCE REQUEST, SAFETY IMPLICATIONS RELATED TO A POTENTIAL STEAM LINE BREAK BLOWING DOWN BOTH STEAM GENERATORS AT OCONEE This revision to TIA 94-013 is prompted by the August 10, 1994 steam generator bloWdown event on Oconee Unit 3. As discussed during Operating Reactors Events Briefing 94-29, the rapid blowdown/depressurization of steam generator
~3B was attributed to the random repositioning of the associated turbine bypass valves when Integrated Control System power was momentarily lost and then II) n d through W restored to the valves/ controllers.
Although subsequently corrce hog controller modificationo this event revealed another potential steam line related failure that could have blown down both steam generators.
More importantlyb since recovery from such an occurrence would involve either steam generator "trickle feeding" or primary "feed and bleed", this event also demonstrated the inherent problems associated with trickle feeding a hot dry steam generator.
Similar to the postulated steam line related failure addressed in TIA.94-0b3, dated March 31,
- 1994, the potential steam line related failure discussed above is directly related to the fact that Oconee relies on the turbine stop valves for isolation because there are no main steam isolation valves. Accordingly since the Oconee design does not incorporate any automatic features for steam break isolation upstream of the turbine stop valves, it is requested that you expand the scope of TIA 94-013 to include potential steam line related failures associated with other branch lines and components upstream of the turbine stop valves.
if you have any questions regarding this matter, please contact Robert Carroll at (404) 331-5543 or Lee Keller at (803) 882-6927.
Original signed by 9501170050 950106 Jons P. Jaudon kfor) 9501170 05000269 Bruce A. Boger, Acting Director PGDR ADOCK Division of Reactor Projects cc:
A. Gibson, RH R. Crlenjak, RI1 W. Rogers. RII cc cont'd:
(See page 2)