ML19322D362
| ML19322D362 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/02/1979 |
| From: | Lanning W NRC - NRC THREE MILE ISLAND TASK FORCE |
| To: | Parler W NRC - NRC THREE MILE ISLAND TASK FORCE |
| Shared Package | |
| ML19322D361 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8002110695 | |
| Download: ML19322D362 (1) | |
Text
I w
f
- V. k cg'o Uf;ITED STATES g
,g NUCLEAR REGULATORY COMMISSION y y
'.2, W ASHINGT ON, D. C. 20555 g
4
%*****/
JUL 2 1979 MEMORANDUM FOR: William Parler, Task Leader, Group 1 FROM:
Wayne D. Lanning, Group 1
SUBJECT:
ADDITIONAL PRECURSOR EVENT
Reference:
Cordle, H. et. al., Technical Report on Beznau Unit One Incident of Kugust 20, 1974: TG-1 TRIP / REACTOR TRIP /SANTY INJECTION ACTUATION, Westinghouse Report Sa/251, September 2,1974 (Froprietary Information)
The Reference describes an incident at a foreign reactor which is similar
~
to the event at TMI-2 and could have provided some insight into the behavior of the pressurizer level indication resulting from a failed-open relief valve.
A turbine trip on the Beznau reactor followed by failure of the steam dump system to operate resulted in a reactor trip and the opening of the pressurizer l
relief valves (2).
One of these valves subsequently failed to close and the resulting blowdown of the pressurizer resulted in the rupture of the pressurizer relief tank bursting disk.
Steam was formed in the RCS hot legs and the pressurizer level was high off scale for 3 to 5 minutes.
The operator isolated the open relief valve, and the transient was mitigated in approximately 10 minutes after turbine trip.
e ennine if this -event was reported by Westinghouse to the NRC I su a
to its customers.
If not, we should determine what Regulatory requirements
[
are applicable (if any) and make an appmpriate recommendation in our report.
n f"oup1
~
e.'
x r w/o enc 1.
(fj)@
D (U)y 0m G aup 1 menbers fDUD
.. \\
ush,,,q 7[2.
g u- - 2 7~
)
E"~~
,p +pp u n) i urhm ik w"was w v
j" u
a 0 w3 h.qd ? " * d' w d m f Q)J/ pg&
. gl r, o,, /,u_}.
hy 51
$((ik f jf G,ncbatY -
00 1
0 LLu gnu $a'd,ff%f
'b