ML20079N908
| ML20079N908 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/25/1983 |
| From: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, L-83-94, NUDOCS 8303040464 | |
| Download: ML20079N908 (9) | |
Text
,
P. O. BOX 14000, JUNO BEACH. FL 33408 e
FLORIDA POWER & LIGHT COMPANY L
February 25$983
.'t c
{,5}
-wi M
vp Ga ~
$~4 O y-;n 7
El Mr. James P. O'Reilly Regional Administrator, RegionII
[
8(3 U. S. Nuclear Regulatory Commission h
101 Marietta Street, Suite 3100 Atlan 3, Georgia 30303
Dear Mr. O'Reilly:
RE:
St. Lucie Unit 2 Docket No. 50-389, 50.55 (e),82-014 VALVES WILL NOT RESPOND TO COMMAND SIGNALS On June 30, 1982, Florida Power and Light Company notified Recion II Office of Inspection and Enforcement, in accordance with the recuire-ments of 10CFR50.55(e) of a potential deficiency regarding the failure of reactor shutdown cooling by-pass valves to respond to command sigrals.
Attached please find our final resolution of this issue.
Very truly yours,
')
/
Robert E. Uhrig Vice President Advanced Systems & Technology 4
C~fh$5011.
?r,g r
2' T M A 7 8303040464 830225 PDR ADOCK 05000389 O
~
PEOPLE.. SERVING PEOPt. E
T I
SUMMARY
During a planned test of the Shutdown Cooling System (SDCS) heat exchanger bypass valves, deficiencies were discovered including the valve controller
. design and the routing of power cables along with control cables. These deficiencies resulted in erratic behavior when valve control was in the manual mode. This behavior would not have gone undetected prior to plant startup and would not have precluded bringing the plant to cold shutdown conditions.
Therefore, safe operation of the plant would not have been affected. As such, this issue is not reportable with respect to 10CFR50.55(e).
II DESCRIPTION The SDCS heat exchanger bypass valves (FCV-3301 and FCV-3300) are used to control flow through the heat exchanger (i.e., adjust the Reactor Coolant System (RCS) cooldown rate). During a planned test, the valves responded erratically when in the manual mode of operation (correct operation was obtained in the automatic mode).
Design problems with the valve controllers (Modutronic Control Units, Model 10B) were identified by the supplier of the controllers, Limitorque Corporation.
In addition, it was determined that the routing of the power cables along with the control cables could have contributed to the erratic behavior.
-III CORRECTIVE ACTION
.The Model 10B controllers are presently being replaced with Model 10A controllers.
Auxiliary interposing relays were installed to minimize any possible interference
. effects from routing the power cables along with the control cables. Retesting
.of valve behavior with the Model 10A controllers and the interposing relays will be completed during the startup test program.
IV SAFETY IMPLICATION Safe operation of the plant would not be affected by the presence of the Model 20B valve controllers because deficiencies would not have reasonably gone un-detected prior to plant startup. The anomalous behavior was detected during l
a test of the SDCS heat exchanger bypass valves. The behavior also would have been detected during the hot operational tests (pre-core).
Therefore, plant startup would not have been permitted with the above deficiencies.
Even with the deficient valve controller and cable routing, plant cooldown would not have been precluded.
If the erratic behavior occurred during a plant shutdown, the cooldown could be continued cautiously with concomitant effects on the RCS cooldown rate.
If the valves failed such that they could not be opened, the RCS cooldown rate would be larger than desired.
However, the SDCS header o
valves could then be operated from the control room and the cooldown rate could be adjusted.
Also, the SDCS heat exchanger bypass valve could be accessed and adjusted manually.
If the valves failed such that they could not be closed, the cooldown rate would be smaller than desired. However, there would always be some. flow through the heat exchanger and the RCS could be cooled.
In this case,
).
,also, the valves could be accessed and adjusted manually. Therefore, the RCS g
could always be brought to cold shutdown conditions and safe operation of the
,p1 ant would not be affected.
o S.
i V
CONCLUSION This issue is not reportable with respect to 10CFR50.55(e).
This report is final and completes requirements for reporting to the NRC.
l l
L t
i 1
1 1
(___
g".
P. O. BOX 14000, JUNO BE ACH, FL 33408 a
bN FI ORIDA POWER & LIGHT COMPANY February 2g1983>
~,.
'.i m.
m cxs 2:D ro "C
CD D_;d Mr. James P. O'Reilly 32
#N k-U Regional Administrator, RegionII CC U. S. Nuclear Regulatory Commission
-i 101 Marietta Street, Suite 3100
.c-v'; ;
88
'N Atlanta, Georgia 30303
Dear Mr. O'Reilly:
RE:
St. Lucie Unit 2 Docket No. 50-389, 50.55 (e),82-014 VALVES WILL NOT RESPOND TO COMMAND SIGNALS On June 30, 1982, Florida Power and Light Company notified Region II Office of Inspection and Enforcement, in accordance with the require-ments of 10CFR50.55(e) of a potential deficiency regarding the failure of reactor shutdown cooling by-pass valves to respond to command signals.
Attached please find our final resolution of this issue.
Very truly yours, O
t p.
Robert E. Uhrig I
Vice President Advanced Systems & Technology
'[Of
%o n Y
v-qo m _zy
~
PEOPLE.. SERVING PEOPLE i
l
T r
b-I
SUMMARY
'During a planned test of the Shutdown Cooling System (SDCS) heat exchanger bypass valves, deficiencies were discovered including the valve controller design and.the routing of power cables along with control cables.
These deficiencies resulted in erratic behavior when valve control was in the manual mode.- This behavior would 'not have gone undetected prior to plant startup and would not have precluded bringing the plant to cold shutdown conditions.
i Therefore,. safe operation of the plant would not have been affected. As such, this issue is not reportable with respect to 10CFR50.55(e).
II DESCRIPTION The SDCS heat exchanger bypass valves (FCV-3301 and FCV-3306) are used to control flow through the heat exchanger (i.e., adjust the Reactor Coolant System (RCS) cooldown rate).. During a planned test, the valves responded erratically when in the manual mode of operation (correct operation was obtained in the automatic mode). Design problems with the valve controllers (Modutronic Control Units, Model 10B) were identified by the supplier of the controllers,
{
Limitorque Corporation.
In addition, it was determined that the routing of the power cables along with the control cables could have contributed to the erratic behavior.
III CORRECTIVE ACTION The Model 10B controllers are presently being replaced with Model 10A controllers.
Auxiliary interposing relays were installed to minimize any possible interference effects from routing the power cables along with the control cables. Retesting of valve behavior with the Model 10A controllers and the interposing relays will be completed during the startup test program.
IV SAFETY IMPLICATION Safe operation of the plant would not be affected by the presence of the Model 10B valve controllers because deficiencies would not have reasonably gone un-detected prior to plant startup. The anomalous behavior was detected during a test of the SDCS heat exchanger bypass valves.
The behavior also would have been detected during the hot operational tests (pre-core).
Therefore, plant startup would not have been permitted with the above deficiencies.
Even with the deficient valve controller and cable routing, plant cooldown would not have been precluded.
If the erratic behavior occurred during a plant shutdown, the cooldown could be continued cautiously with concomitant effects on the BCS cooldown rate.
If the valves failed such that they could not be opened, the RCS cooldown rate would be larger than desired.
However, the. SDCS header valves could then be operated from the control room and the cooldown rate could be adjusted. Also, the SDCS heat exchanger bypass valve could be accessed and adjusted manually.
If the valves failed such that they could not be closed, the cooldown rate would be smaller than desired.
However, there would always be some flow through the heat exchanger and the RCS could be cooled.
In this case, also, the valves could be accessed and adjusted manually.
Therefore, the RCS could always be brought to cold shutdown conditions and safe operation of the plant would not be affected.
o(
V CONCLUSION This issue is not reportable with respect to 10CFR50.55(e).
This report is final and completes requirements for reporting to the NRC.
I l
l i
l l
l I
1
P. O. BOX 14000, JUNO BEACH, FL 33408
+
FLORIDA POWER & LIGHT COMPANY February 25, 1983 L-83-94 eg 7, C w
.a
~ Cro mm
$2 c:za MT N
~-' Q Kg Mr. James P. O'Reilly co Regional Administrator, RegionII
.. pi U. S. Nuclear Regulatory Commission
[f[
101 Marietta Street, Suite 3100 C[Q Atlanta, Georgia 30303 CC a
Dear Mr. O'Reilly:
RE:
St. Lucie Unit 2 Docket No. 50-389, 50.55 (e),82-014 VALVES WILL NOT RESPOND TO COMMAND SIGNALS On June 30, 1982, Florida Power and Light Company notified Region II Office of Inspection and Enforcement, in accordance with the require-ments of 10CFR50.55(e) of a potential deficiency regarding the failure of reactor shutdown cooling by-pass valves to respond to comunand signals.
Attached please find our final resolution of this issue.
Very truly yours, X
Robert E. Uhrig Vice President Advanced Systens & Technology 1
7f.\\
1
-)
af Ray g
PEOPLE.. SERVING PEOPLE
.J
g y_
s I
SUMMARY
During a planned test of 'the Shutdown Cooling System (SDCS) heat exchanger bypass valves, deficiencies were discovered including the valve controller
' design and the routing of power cables along with control cables. Ihese deficiencies resulted in erratic behavior when valve control was in the manual
-mode.
This behavior would not have gone undetected prior to plant startup and would not have precluded bringing the plant to cold shutdown conditions.
Therefore, safe operation of the plant would not have been affected. As such, this issue is not reportable with respect to 10CFR50.55(e).
II DESCRIPTION The SDCS heat exchanger bypass valves (FCV-3301 and FCV-3306) are used to control flow through the heat exchanger (i.e., adjust the Reactor Coolant System (RCS) cooldown rate). During a planned test, the valves responded erratically when in the manual mode of operation (correct operation was obtained in the automatic mode). Design problems with the valve controllers (Modutronic Control Units, Model 108) were identified by the supplier of the controllers,
)
Limitorque Corporation.
In addition, it was determined that the routing of the pcwer cables along with the control cables could have contributed to the erratic behavior, l
III CORRECTIVE ACTION The Model 10B controllers are presently being replaced with Model 10A controllers.
Auxiliary interposing relays were installed to minimize any possible interference effects from routing the power cables along with the control cables. Retesting of valve behavior with the Model 10A controllers and the interposing relays will be completed during the startup te'st program.
IV SAPETY IMPLICATION Safe operation of the plant would not be affected by the presence of the Model 20E valve controllers because deficiencies would not have reasonably gone un-detected prior to plant startup.
The anomalous behavior was detected during a test of the SDCS heat exchanger bypass valves. The behavior also would have been detected during the hot operational tests (pre-core).
Therefore, plant startup would not have been permitted with the above deficiencies.
Even with the deficient valve controller and cable routing, plant cooldown would not have been precluded.
If the erratic behavior occurred during a plant shutdown, the cooldown could be continued cautiously with concomitant effects on the RCS cooldown rate.
If the valves failed such that they could not be opened, the RCS cooldown rate would be larger than desired.
However, the SDCS header valves could then be operated from the control room and the cooldown rate could be adjusted. Also, the SDCS heat exchanger bypass valve could be accessed and adjusted manually.
If the valves failed such that they could not be closed, the cooldewn rate would be smaller than desired. However, there would always be some flow through the heat exchanger and the RCS could be cooled.
In this case, also, the valves could be accessed and adjusted manually.
Therefore, the RCS could always be brought to cold shutdown conditions and safe operation of the plant would not be affected.
l y
u i
V CONCLUSION This issue is not reportable with respect to 10CFR50.55(e).
l This report is final and completes requirements for reporting to the NRC.
)
1
,