ML20236K946
| ML20236K946 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 11/04/1987 |
| From: | Boger B Office of Nuclear Reactor Regulation |
| To: | Thadani A Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20236K951 | List: |
| References | |
| NUDOCS 8711100033 | |
| Download: ML20236K946 (2) | |
Text
j, 1
d Movember 4, 1987 I
MEMORANDUM FOR:
Ashok C. Thadani, Assistant Director for Systems Division of Engineering and Systems Technology l
FROM:
Bruce A. Boger, Assistant Director j
for Region I Reactors Division of Reactor Projects I/II l
SUBJECT:
P0TENTIAL CAUSE FOR TURBINE TRIP W/0 BYPASS SCRAMS j
l General Electric has been offering a turbine upgrade program to utilities l
called " partial arc emission". We don't know how many plants have modified the turbine control logic or how many are planning to implement the modification.
We do know that four plants in Regions I and II implemented the modification; i
all four experienced severe vibration in the EHC system.
In three of the plants, the vibration severed the EHC oil supply piping, causing a turbine q
trip with loss of bypass valve capability and a reactor scram.
As a result of i
inspections of the EHC system at Limerick, Dick Clark has summarized what we i
know on the problem (enclosures 1 and 2).
The utilities in Region I and II who modified their turbines did so under 10
)
CFR 50.59. We understand that some licensees have informally discussed this i
turbine modification with your staff.
We recommend that NRR not endorse this I
modification.
Although turbine trin w/o bypass is an analysed transient in l
BWR reloads, it has not been contidered to be a likely event and coping with j
the transient is not emphasized in operator training programs.
/s/
1 Bruce A. Boger, Assistant Director for Region I Reactors Division of Reactor Projects I/II I
Enclosures:
As stated cc:
Steven A. Varga, DRP Charles E. Rossi, DOEA Lawrence Shao, DEST John W. Craig, SPLB M. Wayne Hodges, SRXB DISTRIBUTION 4 Docket: File !
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g,.....,e November 4, 1987 MEMORANDUM FOR:
Ashok C. Thadani, Assistant Director i
for Systems Division of Engineering and Systems Technology' FROM:
-Bruce A. Boger, Assistant Director for Region ILReactors.
Division of Reactor Projects I/II
SUBJECT:
POTENTIAL CAUSE-FOR TURBINE TRIP W/0 BYPASS SCRAMS General Electric has been offering :a turbine upgrade program to utilities called " partial arc emission". We don't know how many plants have modified the turbine control _ logic or how many are planning to implement the modification.
We do know that four plants in Regions I and II implemented the modification; I
all four experienced severe vibration in the EHC system.
In three of the plants, the vibration severed the EHC oil supply piping,. causing'a turbine l
trip with ic:s of oypass. valve capability _and a reactor scram. As. a result. of
'j inspections of the EHC system at Limerick, Dick Clark has sumarized what we~
know on the problem (enclosures 1 and 2).
The utilities in Region I and II who modified their turbine., did so under '10' CFR 50.59. We understand that some licensees.have informally discussed this j
turbine modification with your staff.
We recomend that NRR not endorse this i
modification. Although turbine trip w/o bypass is an analysed transient in j
BWR reloads, it has not been considered to be a likely event and _ coping with
'1 the transient is' not emphasized in operator training programs.
)
Bruce A. Bog
, Assistant' Director.
1 for Region I Reactors Division of Reactor Projects I/II
Enclosures:
As stated cc:
Steven A. Varga, DRP Charles E. Rossi, DOEA Lawrence Shao, DEST John W. Craig, SPLB M. Wayne Hodges, SRXB
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