ML20246N045
| ML20246N045 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/30/1989 |
| From: | Cintula T NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rosenthal J NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20246N050 | List: |
| References | |
| AEOD-E906, NUDOCS 8909080024 | |
| Download: ML20246N045 (2) | |
Text
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AUG 30 1NB MEMORANDUM FOR:. Jack E. Rosenthal, Chief AEOD/E906
. Reactor Operations Analysis Branch Division of Safety Programs Office for Analysis end Evaluation of Operational Data THRU:
George F. Lanik, Chief Reactor Systems Section GE & CE Reactor.0peraticns Analysis Branch Division'cf Safety Frograms Office for Analysis and Evaluation of Operational Data FROM:
Theodore C. Cintula Reactor Systems Section GE & CE Reactor Operations Analysis Branch Division of Safety Programs Office for Analysis.and Evaluation of Operational Data
SUBJECT:
FAILURE 0F STEAM GENERATOR ISOLATION CHECK YALVE Enclosed for your information is a copy of my AEOD Engineering Evaluation Report on the failure of the steam generator isolation check valve of both units at Calvert Clifis.
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.The report suggests that a failed steam generator isolation check valve could lead to a mere severe steam line break accident than analyzed in the FSAR.
The failure of the steem generator isolation check vahe may permit both stcem generators to ccwcrir.cte in a postulated Steam ifne break scencrio. Thus, it is possible both steam generators may blow den simultaneously through a commer.
break in the sten ;1ue. With both steam generators blowing down, steam generator differential pressure may not be sufficient. to isolate AFW flow to the 3
ruptured stees generator. The continuation or feed during a blowdewn of two
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steam generators may result. in a more rapni end prolonged cooldown and a i
kn eater insertion of positive core reactivit.y than assumed i:: the FSAR with an (Mgie cctive f ailure (the most reactive control element assembly in its fully withdrawn pen % ion after the reactor triph i
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t Jack E< Rosenthal 2-The. report concludes that regulatory' practice has not ' identified that' the steam generator isolation' check valves has two' safety functions. The. report suggests-
- periodic testing for both safety fu ctions of-this valve _would be appropriate, si em F
Theodbre C. Cintula Recctor Systems Section GE & CE Reactor Operations Analysis Branch Division of Safety. Programs -
Office for. Analysis and Evaluation of Operational Data
Enclosures:
As stated d
9 Distribution:
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