ML20086B467
| ML20086B467 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 06/19/1974 |
| From: | Brey H, Swart F PUBLIC SERVICE CO. OF COLORADO |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-50-267-74-4B, NUDOCS 8311170248 | |
| Download: ML20086B467 (6) | |
Text
Wi 0
O
[b public Servlee Comgany *F Cdesde P. O. Box 361, Platteville, Colorado 80651 vs v.,
/,
g June 19, 1974 1
/
Mr. Angelo Giambusso Deputy Director for Reactor Projects Directorate of Licensing U. S. Atomic Energy Commission Washington, D. C.
20545 REF: Facility Operating License No. DPR-34 Docket No. 50-267
Dear Mr. Giambusso:
Enclosed please find 3 copies of Abnormal Occurrence Report 50-267/74/10 and Supplemental Report 50-267/74/4B, submitted per the requirements of the Technical Specifications.
Y f~i /, / e. 4 4 v 8 '1 W4 Very truly yours,
(_(.. )
~
E' Frederic E. Swart Superintendent Fort St. Vrain Nuclear Generating Station FES:il UDIT kk j' Al 'n ' q '. '!
8311170248 740619 PDR ADOCK 05000267 y
4 S
PDR 4
Ct O:bpua a
i O.
O DATE:
.Tiene 3 1974 ABNORMAL OCCURRENCE FORT ST. VRAIN NUCLEA;'. GENERATING STATf0N PUBLIC SERVICE COMPANY OF COLORADO P. O. BOX 361 PLATTEVILLE, COLORADO 80651 s
REPORT NO. 50-267/74/10 Prelininary l
l Final
[jgj IDENTIFICATION OF OCCURREt:CE:
The following occurrence is considered an Abnormal Occurrence under definition 2.1C of the Technical Specifications.
I On May 23, 1974, excessive helium makeup to the PCRV was observed.
The static seal on.B helium circulator was found to be the primary point of leakage.
CONDITIONS PRIOR TO OCCURRENCE:
Steady State Power Routine Shutdown Routine Load Change Hot Shutdown Cold Shutdown X
Other (specify)
Refueling Shutdown Prior to low power Routine Startup physics test A-11.
r 1
i O.
O Page 2 The major plant parameters at the time of the event were an follows:
Power
- PTR, N/A MWth
- ELECT, N/A igle Secondary Coolant Pressure M/A psig 0
Temperature N/A F
Flow N/A
- /hr.
Primary Coolant Pressure 78 psig Temperature 100 0F Core Inlet 100 0F Core Outlet Flot N/A
- /hr.
DESCRIPTION OF OCCURRENCE:
On May 23, a significant loss of plant helium inventory became apparent.
This occurred at a time when the PCRV was being pressurized and helium deliveries were being made to the plant. A systematic check of all potential helium leakage points was initiated including:
a) Verification of system 11 (PCRV) valve line up and soap test of all valves.
b) Checking of PCRV relief system c)
Isolating of purification system clean up trains I
d) Leak check of brake and seal system e) Construction soap check of all valves and fittings I
on helium handling and purification system.
Some small valve packing leaks were located and repaired during these checks, but no significant helium leakage point was identified.
On May 22, a number of systems had been shut down including "n" helium circulator.
This circulator was taken out of service and partially isolated so that construction personnel could repair the inlet piping flange to the steam turbine. This isolation included setting of the brake and the static shaft 9
(~}
C)'
v Page 3 seal. Upon completion of this repair the auxiliaries were established on the circulator including buf fer helium and hearing water and the static seal and brakes were released.
Shortly thereafter the pressure loss rate on the PCRV was observed to stop.
"B" healium circulator was again shutdown and the brake and static seal on the shaft set.
The pressure loss rate was observed to be.
the same as before operation.
Subsequent testing of the seal has included the following:
a) Repeated actuation of the seal and subsequent checks of helium loss, b) Running of the circulator to try to dislodge any " material" which might be between the shaft and seal face.
c). Applying the seal with varying actuating pressures, both above and below the normal gas actuation dif f erential pressure.
d) Reducing buffer helium flow allowing small quantities of' bearing water to flow up the circulator shaft in an attempt to flush out any foreign material.
e) A high helium flow (35 acfm) was admitted to the "B" circulator buf f er system via the high pressure helium storage bottles to try to blow out any foreign material.
This high buffer helium flow apparently flushed out any material on the seal face. The following tests were performed to verify proper operability of the seal.
a) Bearing water was shut off, the seal was applied, and bearing water placed back on a total of ten cycles without a seal failure.
b)
"B" helium circulator was run at 4,000 rpm for two hours.
It was shut down and the seal actuated five times without a failure.
c) Item "A" was repeated again with no seal failure.
APPARENT CAUSE OF OCCURRENCE:
The cause of this seal problem appeared to be particulate matter in the seal mechanism. A drawing of the seal is attached.
ANALYSIS OF OCCURRENCE:
There appeared to be particle matter in the seal mechanism.
l
o.
O w
Page 4 CORRECTIVE ACTION:
No act,on other than testing of the seal as outlined in the " Description i
of Occurrence" is being taken.
FAILURE DATA /SIMILAR REPORTED OCCURRENCES:
None.
PROGRA!DfATIC It! PACT:
A delay of approxir.ately two daye in the "A" Series Startup Testing Program was encountered due to this seal malfunction.
Prepared by:
Approved:
W (n~etn 2.
li. Larry Bryy rederic E. Swart Assistant Superintend ent Superintendent Fort St. Vrain Nuclear Fort St. Vrain Nuclear Generating Station Generating Station c r v
~
o O
~
Lt j
!?
i I
s i fNi l(:
iM,j Tft
~
[ ]!,-
Q[i i
!il:
i nr.
i I'
\\
l ly'!!li.I!
- g*
,gW?
- n~.-1".
e s
X;
'~
rij
.6N
.J,.
l
< i.
c e
3 E
.iv b '
.C
,>e%
e yAg
- =
s
=
e I
t
$L, g~.-
g 3-;
o e
>?e
^
l A
(.
El3 l
l g
/
i
.m J;
e
~
'l%
i 'jy,r 5kkp'i f
h%
3 _-
7 s
. /
\\
Mii_
if
~I W
g c
e e
t J
l l'
i' d',
!{
c o f
/ -
.1 u
_p
,, y e
.,//
Q J
y 3u:
x 1
i
. l l
w-I
.