Information Notice 1992-85, Potential Failures of Emergency Core Cooling Systems Caused by Foreign Material Blackage: Difference between revisions

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{{#Wiki_filter:;- UNITED STATES NUCLEAR REGULATORY
{{#Wiki_filter:;-  


COMMISSION
===UNITED STATES===
NUCLEAR REGULATORY COMMISSION


===OFFICE OF NUCLEAR REACTOR REGULATION===
===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C. 20555 December 23, 1992 NRC INFORMATION
WASHINGTON, D.C.


NOTICE 92-85: POTENTIAL
20555


FAILURES OF EMERGENCY
===December 23, 1992===
NRC INFORMATION NOTICE 92-85:


CORE COOLING SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE
===POTENTIAL FAILURES OF EMERGENCY CORE COOLING===
SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE


==Addressees==
==Addressees==
All holders of operating
All holders of operating licenses or construction permits for nuclear power


licenses or construction
reactors.


permits for nuclear power reactors.
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
 
notice to alert addressees to the potential failure of emergency core cooling
 
systems (ECCS) caused by foreign material blockage.
 
===It is expected that===
recipients will review the information for applicability to their facilities
 
and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements;
therefore, no specific action or written response is required.


==Purpose==
==Description of Circumstances==
The U.S. Nuclear Regulatory


Commission (NRC) is issuing this information
===H. B. Robinson Unit 2===
On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot


notice to alert addressees
shutdown, plant personnel were performing an operations surveillance test of


to the potential
the B safety injection (SI) pump. This test found that the recirculation flow


failure of emergency
was 20 percent lower than it had been when it was last measured on July 12,
1992.


core cooling systems (ECCS) caused by foreign material blockage.
Prompted by the resident inspector, the Carolina Power and Light


It is expected that recipients
Company (the licensee) retested this pump on August 24, 1992, and found no


will review the information
recirculation flow.


for applicability
===The licensee also tested the A SI pump and found the===
recirculation flow was 10 percent lower than when it was last measured.


to their facilities
The


and consider actions, as appropriate, to avoid similar problems.
licensee declared both pumps inoperable and took the unit to cold shutdown.


However, suggestions
On August 25, 1992, the licensee opened the B SI pump recirculation line and


contained
removed a single piece of white plastic, about the size of a nickel, from the


in this information
inline orifice.


notice are not NRC requirements;
Previously, on July 8, 1992, the licensee had declared the B SI pump
therefore, no specific action or written response is required.Description


of Circumstances
inoperable after a quarterly inservice inspection surveillance test found that


H. B. Robinson Unit 2 On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot shutdown, plant personnel
it was producing a recirculation flow of 11.4 Liters [3 gallons] per minute, rather than the required 132.5 Liters [35 gallons] per minute.


were performing
On July 9,
1992, the licensee shut down the plant to determine the cause of the low flow.


an operations
The licensee removed the recirculation line for the B SI pump and found that


surveillance
debris was obstructing the inline orifice.


test of the B safety injection (SI) pump. This test found that the recirculation
9212170209 Pyt


flow was 20 percent lower than it had been when it was last measured on July 12, 1992. Prompted by the resident inspector, the Carolina Power and Light Company (the licensee)
I (  
retested this pump on August 24, 1992, and found no recirculation
/'a


flow. The licensee also tested the A SI pump and found the recirculation
q9A Ac


flow was 10 percent lower than when it was last measured.
s


The licensee declared both pumps inoperable
e


and took the unit to cold shutdown.On August 25, 1992, the licensee opened the B SI pump recirculation
0C20 28


line and removed a single piece of white plastic, about the size of a nickel, from the inline orifice.Previously, on July 8, 1992, the licensee had declared the B SI pump inoperable
IN 92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying that


after a quarterly
recirculation flows for both SI pumps were acceptable, the licensee returned


inservice
the unit to service.


inspection
The licensee also tested all other ECCS pumps that could


surveillance
have had contact with foreign material.


test found that it was producing
===The licensee believed, prior to plant===
startup, that all debris had been removed.


a recirculation
===Point Beach Unit 2===
On September 28, 1992, the Wisconsin Electric Power Company (the licensee)
performed an ASME Section XI quarterly test of containment spray pumps and


flow of 11.4 Liters [3 gallons] per minute, rather than the required 132.5 Liters [35 gallons] per minute. On July 9, 1992, the licensee shut down the plant to determine
valves. During the test, the licensee noted that the discharge pressure for


the cause of the low flow.The licensee removed the recirculation
the A train containment spray pump was zero and that the pump was making an


line for the B SI pump and found that debris was obstructing
abnormal noise.


the inline orifice.9212170209 Pyt I ( /'a q9A Ac s e 0C20 28 IN 92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying
The test was stopped and the pump was declared inoperable.


that recirculation
Upon disassembly of the pump, a foam rubber plug was found blocking the


flows for both SI pumps were acceptable, the licensee returned the unit to service. The licensee also tested all other ECCS pumps that could have had contact with foreign material.
impeller suction.


The licensee believed, prior to plant startup, that all debris had been removed.Point Beach Unit 2 On September
The licensee removed the plug and retested the pump.


28, 1992, the Wisconsin
The


Electric Power Company (the licensee)performed
test was successfully completed and the pump was declared operable.


an ASME Section XI quarterly
Discussion


test of containment
The licensee at H. B. Robinson determined that the foreign material found in


spray pumps and valves. During the test, the licensee noted that the discharge
the SI system was a plastic material that had been used during a modification


pressure for the A train containment
of the Residual Heat Removal (RHR) system performed in March through


spray pump was zero and that the pump was making an abnormal noise. The test was stopped and the pump was declared inoperable.
June 1992.


Upon disassembly
The plastic material is manufactured by DuPont and the trade name


of the pump, a foam rubber plug was found blocking the impeller suction. The licensee removed the plug and retested the pump. The test was successfully
is Delrin-AF.


completed
At the time of the RHR modification, the plastic material had


and the pump was declared operable.Discussion
been cut into-four 23=centimeter [9-inch]-diameter,-circular pieces for use-as


The licensee at H. B. Robinson determined
weld purge dams. However, after completing the modification, the licensee did


that the foreign material found in the SI system was a plastic material that had been used during a modification
not account for two of the four pieces.


of the Residual Heat Removal (RHR) system performed
Delrin-AF decomposes at RCS system


in March through June 1992. The plastic material is manufactured
conditions because of reaction with the water and thermal degradation. The


by DuPont and the trade name is Delrin-AF.
licensee suspected that the purge dam pieces broke,. entered the RHR piping


At the time of the RHR modification, the plastic material had been cut into-four
after breaking, and migrated into the refueling water storage tank (RWST) and


23=centimeter
SI header during initial cavity draindown.


[9-inch]-diameter,-circular
The licensee sent divers with cameras into the RWST to inspect for the


pieces for use-as weld purge dams. However, after completing
plastic.


the modification, the licensee did not account for two of the four pieces. Delrin-AF
The divers found three fragments of Delrin-AF plastic and also other


decomposes
pieces of miscellaneous debris.


at RCS system conditions
===The location and size of the recovered===
Delrin-AF material agrees with the material migration theory since all of the


because of reaction with the water and thermal degradation.
pieces were larger than those recovered from the B SI pump in July and August.


The licensee suspected
The licensee inspected orifices for the SI pump minimum flow recirculation


that the purge dam pieces broke,. entered the RHR piping after breaking, and migrated into the refueling
lines and also visually inspected piping, tanks, and components to find and


water storage tank (RWST) and SI header during initial cavity draindown.
remove any foreign material.


The licensee sent divers with cameras into the RWST to inspect for the plastic. The divers found three fragments
===Also, the licensee evaluated the potential===
effect on other ECCS equipment and concluded that the ECCS equipment would


of Delrin-AF
continue to be operable and reliable.


plastic and also other pieces of miscellaneous
a


debris. The location and size of the recovered Delrin-AF
IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that


material agrees with the material migration
the plug was most likely left in the piping after modifications were made to


theory since all of the pieces were larger than those recovered
install full flow test lines in the RHR, containment spray and safety


from the B SI pump in July and August.The licensee inspected
injection systems, during the 1991 refueling outage.


orifices for the SI pump minimum flow recirculation
===The NRC reviewed the===
event and determined that one train of the safety injection system piping was


lines and also visually inspected
rendered inoperable in the recirculation mode because of the presence of the


piping, tanks, and components
plug.


to find and remove any foreign material.
This condition had continued for about a year and was caused by


Also, the licensee evaluated
inadequate foreign material exclusion controls during the system modifications


the potential effect on other ECCS equipment
made in the previous outage.


and concluded
The presence of small debris may not be detected by operational or post


that the ECCS equipment
modification testing since blockages may not appear immediately.


would continue to be operable and reliable.a
However, small debris may migrate into areas with smaller cross sections where the


IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
debris could collect and cause blockage after extended operation.


that the plug was most likely left in the piping after modifications
These


were made to install full flow test lines in the RHR, containment
examples illustrate the consequences of failure to ensure accountability of


spray and safety injection
all materials that are used when safety systems are opened and to perform


systems, during the 1991 refueling
cleanliness checks of all affected areas prior to system closure.


outage. The NRC reviewed the event and determined
===Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In


that one train of the safety injection
Containment Emergency Sumps and Incorrect Screen Configurations," which


system piping was rendered inoperable
addressed problems that could result from debris in containment emergency


in the recirculation
sumps.


mode because of the presence of the plug. This condition
This information notice requires no specific action or written response.


had continued
If


for about a year and was caused by inadequate
you have any questions about the information in this notice, please contact


foreign material exclusion
the technical contact listed below or the appropriate Office of Nuclear


controls during the system modifications
Reactor Regulation (NRR) project manager.


made in the previous outage.The presence of small debris may not be detected by operational
rnan K. Grimes, Director


or post modification
===Division of Operating Reactor Support===
Office of Nuclear Reactor Regulation


testing since blockages
Technical contact:


may not appear immediately.
===Eric Benner, NRR===
(301) 504-1171 Attachment:


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
===List of Recently Issued NRC Information Notices===


These examples illustrate
z-4 V


the consequences
a


of failure to ensure accountability
0z


of all materials
0
V


that are used when safety systems are opened and to perform cleanliness
-v


checks of all affected areas prior to system closure.Related Generic Communication
z


On November 21, 1989, the NRC issued Information
C


Notice (IN) 89-77, "Debris In Containment
D


Emergency
--
>n


Sumps and Incorrect
-_
_
z


Screen Configurations," which addressed
11
0-4U


problems that could result from debris in containment
cmm


emergency sumps.This information
U1 0 Cfl


notice requires no specific action or written response.
Ca/
z


If you have any questions
Attachment


about the information
IN 92-85 December 23,
1992 Page I of 1


in this notice, please contact the technical
===LIST OF RECENTLY ISSUED===
NRC INFORMATION NOTICES


contact listed below or the appropriate
Information


Office of Nuclear Reactor Regulation (NRR) project manager.rnan K. Grimes, Director Division of Operating
Notice No.


===Reactor Support Office of Nuclear Reactor Regulation===
Subject
Technical


contact: Eric Benner, NRR (301) 504-1171 Attachment:
92-84
List of Recently Issued NRC Information


Notices
===Release of Patients===
Treated with Temporary


z-4 V a 0 z 0 V-v z C D -->n-_ _z 11 0-4U cmm U1 0 Cfl Ca/z Attachment
Implants


IN 92-85 December 23, 1992 Page I of 1 LIST OF RECENTLY ISSUED NRC INFORMATION
88-23,  


===NOTICES Information===
===Potential for Gas===
Notice No. Subject 92-84 Release of Patients Treated with Temporary Implants 88-23, Potential
Supp. 4 Binding of High-Pres- sure Safety Injection


for Gas Supp. 4 Binding of High-Pres- sure Safety Injection Pumps during A Design Basis Accident 92-83 Thrust Limits for Limitorque
===Pumps during A Design===
Basis Accident


Actuators and Potential
92-83


Over-stressing
===Thrust Limits for===
Limitorque Actuators


of Motor-Operated Valves 92-82 Results of Thermo-Lag
and Potential Over- stressing of Motor-
 
===Operated Valves===
92-82 Results of Thermo-Lag


330-1 Combustibility
330-1 Combustibility


Testing 92-81 Potential
Testing
 
92-81  
 
===Potential Deficiency===
of Electrical Cables


Deficiency
with Bonded Hypalon


of Electrical
Jackets


Cables with Bonded Hypalon Jackets 92-80 Results of Thermo-Lag
92-80  
Results of Thermo-Lag


330-1 Combustibility
330-1 Combustibility


Testing 92-79 Non-Power
Testing
 
92-79 Non-Power Reactor
 
===Emergency Event Response===
92-78
 
===Piston to Cylinder===
Liner Tin Smearing on
 
Cooper-Bessemer KSV
 
===Diesel Engines===
Vate of


Reactor Emergency
Issuance


Event Response 92-78 Piston to Cylinder Liner Tin Smearing on Cooper-Bessemer
Issued to


KSV Diesel Engines Vate of Issuance Issued to 12/17/92 All Nuclear Regulatory
12/17/92  


Comnission
===All Nuclear Regulatory===
Comnission Medical


Medical (Licensees.
(
Licensees.


12/18/92 All holders of OLs or CPs for nuclear power reactors 12/17/92 All holders of OLs or CPs for nuclear power reactors 12/15/92 All holders of OLs or CPs for nuclear power reactors 12/11/92 All holders of OLs or CPs for nuclear power reactors.12/07/92 All holders of OLs or CPs for nuclear power reactors.12/01/92 All holders of OLs or CPs(for test and research reactors.11/30/92 All holders of OLs or CPs for nuclear power reactors.DL -Operating
12/18/92  


License CP -Construction
===All holders of OLs or CPs===
for nuclear power reactors


Permit
12/17/92


'U IN 92-XX December xx, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
===All holders of OLs or CPs===
for nuclear power reactors


that the plug was most likely left in the piping after modifications
12/15/92


were made to install full flow test lines-in the residual heat removal (RHR), containment
===All holders of OLs or CPs===
for nuclear power reactors


spray and safety injection
12/11/92


systems, during the 1991 refueling
===All holders of OLs or CPs===
for nuclear power reactors.


outage. The NRC reviewed the event and determined
12/07/92


that one train of the safety injection system piping was rendered inoperable
===All holders of OLs or CPs===
for nuclear power reactors.


in the recirculation
12/01/92 All holders of OLs or CPs(
for test and research


mode because of the presence of the plug. The NRC issued a Notice of Violation
reactors.


and Proposed Imposition
11/30/92


of Civil Penalty in the amount of $75,000. This violation, which was classified
===All holders of OLs or CPs===
for nuclear power reactors.


at Severity Level III, continued
DL - Operating License


for about a year and was caused by inadequate
CP - Construction Permit


foreign material exclusion
'U


controls during the system modifications
IN 92-XX


made in the previous outage.The presence of small debris may not be detected by operational
December xx, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that


or post modification
the plug was most likely left in the piping after modifications were made to


testing since blockages
install full flow test lines-in the residual heat removal (RHR), containment


may not appear immediately.
spray and safety injection systems, during the 1991 refueling outage. The NRC


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
reviewed the event and determined that one train of the safety injection


Whenever safety systems are opened, it is important
system piping was rendered inoperable in the recirculation mode because of the


to ensure accountability
presence of the plug.


of any materials
===The NRC issued a Notice of Violation and Proposed===
Imposition of Civil Penalty in the amount of $75,000.


that are used and to perform cleanliness
===This violation, which===
was classified at Severity Level III, continued for about a year and was


checks of all affected areas prior to system closure.Related Generic Communication
caused by inadequate foreign material exclusion controls during the system


On November 21, 1989, the NRC issued Information
modifications made in the previous outage.


Notice (IN) 89-77, "Debris In Containment
The presence of small debris may not be detected by operational or post


Emergency
modification testing since blockages may not appear immediately.


Sumps and Incorrect
However, small debris may migrate into areas with smaller cross sections where the


Screen Configurations," which addressed
debris could collect and cause blockage after extended operation.


problems that could result from debris in containment
Whenever


emergency sumps.This information
safety systems are opened, it is important to ensure accountability of any


notice requires no specific action or written response.
materials that are used and to perform cleanliness checks of all affected


If you have any questions
areas prior to system closure.


about the information
===Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In


in this notice, please contact the technical
Containment Emergency Sumps and Incorrect Screen Configurations," which


contact listed below or the appropriate
addressed problems that could result from debris in containment emergency


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
sumps.


===Reactor Support Office of Nuclear Reactor Regulation===
This information notice requires no specific action or written response.
Technical


contact: Eric Benner, NRR (301) 504-1171 Attachment:
If
List of Recently Issued NRC Information


Notices*SEE PREVIOUS CONCURRENCE
you have any questions about the information in this notice, please contact


OEAB:DORS
the technical contact listed below or the appropriate Office of Nuclear
 
Reactor Regulation (NRR) project manager.
 
===Brian K. Grimes, Director===
Division of Operating Reactor Support


ASC/OEAB:DORS
===Office of Nuclear Reactor Regulation===
Technical contact: Eric Benner, NRR


ADM:RPB PM:PD2-1:DRPE
(301) 504-1171 Attachment:  


DGarcia* AGautam* JMain* BMozafari*
===List of Recently Issued NRC Information Notices===
10/07/92 10/14/92 09/28/92 10/13/92 C/SRXB:DSSA
*SEE PREVIOUS CONCURRENCE


C/OEAB:DORS
OEAB:DORS


OGCB:DORS
ASC/OEAB:DORS


OE C/OGCB:DORS
ADM:RPB


D/DORS RJones* AChaffee*
PM:PD2-1:DRPE
JBirmingham , Lieberman*
GMarcus BGrimes 10/08/92 11/09/92 12////92 ~/ ' 2/09/92 12/1 i/927 12/ /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG


4 I' J K)IN 92-XX December xx, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
DGarcia*
AGautam*
JMain*
BMozafari*
10/07/92  
10/14/92
09/28/92
10/13/92 C/SRXB:DSSA


that the plug was most likely left in the piping after modifications
C/OEAB:DORS OGCB:DORS


were made to install full flow test lines in the residual heat removal (RHR), containment
OE


spray and safety injection
C/OGCB:DORS


systems, during the 1991 refueling
D/DORS


outage. The NRC reviewed the event and determined
RJones*
AChaffee*
JBirmingham , Lieberman* GMarcus


that one train of the safety injection system piping was rendered inoperable
BGrimes


in the recirculation
10/08/92
11/09/92
12////92 ~/ '
2/09/92
12/1 i/927
12/ /92 DOCUMENT NAME:
G:\\DMG\\INDEBRIS.DMG


mode because of the presence of the plug. The NRC is issuing a Notice of Violation
4 I


and Proposed Imposition
'
J


of Civil Penalty in the amount of $75,000. This violation, which has been classified
K)
IN 92-XX


at Severity Level III, continued
===December xx, 1992===
The licensee for Point Beach Unit 2 reviewed plant records and determined that


for about a year and was caused by inadequate
the plug was most likely left in the piping after modifications were made to


foreign material exclusion
install full flow test lines in the residual heat removal (RHR), containment


controls during the system modifications
spray and safety injection systems, during the 1991 refueling outage. The NRC


made in the previous outage.The presence of small debris may not be detected by operational
reviewed the event and determined that one train of the safety injection


or post modification
system piping was rendered inoperable in the recirculation mode because of the


testing since blockages
presence of the plug. The NRC is issuing a Notice of Violation and Proposed


may not appear immediately.
Imposition of Civil Penalty in the amount of $75,000. This violation, which


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
has been classified at Severity Level III, continued for about a year and was


Whenever safety systems are opened, it is important
caused by inadequate foreign material exclusion controls during the system


to ensure accountability
modifications made in the previous outage.


of any materials
The presence of small debris may not be detected by operational or post


that are used and to perform cleanliness
modification testing since blockages may not appear immediately. However, small debris may migrate into areas with smaller cross sections where the


checks of all affected areas prior to system closure.Related Generic Communication
debris could collect and cause blockage after extended operation. Whenever


On November 21, 1989, the NRC issued Information
safety systems are opened, it is important to ensure accountability of any


Notice (IN) 89-77, "Debris In Containment
materials that are used and to perform cleanliness checks of all affected


Emergency
areas prior to system closure.


Sumps and Incorrect
===Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In


Screen Configurations," which addressed
Containment Emergency Sumps and Incorrect Screen Configurations," which


problems that could result from debris in containment
addressed problems that could result from debris in containment emergency


emergency sumps.This information
sumps.


notice requires no specific action or written response.
This information notice requires no specific action or written response.


If you have any questions
If


about the information
you have any questions about the information in this notice, please contact


in this notice, please contact the technical
the technical contact listed below or the appropriate Office of Nuclear


contact listed below or the appropriate
Reactor Regulation (NRR) project manager.


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
===Brian K. Grimes, Director===
Division of Operating Reactor Support


===Reactor Support Office of Nuclear Reactor Regulation===
===Office of Nuclear Reactor Regulation===
Technical
Technical contact: Eric Benner, NRR


contact: Eric Benner, NRR (301) 504-1171 Attachment:  
(301) 504-1171 Attachment:  
List of Recently Issued NRC Information


Notices*SEE PREVIOUS CONCURRENCE
===List of Recently Issued NRC Information Notices===
*SEE PREVIOUS CONCURRENCE


OEAB:DORS
OEAB:DORS
Line 523: Line 613:
ASC/OEAB:DORS
ASC/OEAB:DORS


ADM:RPB PM:PD2-1:DRPE
ADM:RPB
 
PM:PD2-1:DRPE


DGarcia* AGautam* JMain* BMozafari*
DGarcia*  
10/07/92 10/14/92 09/28/92 10/13/92 C/SRXB:DSSA
AGautam*  
JMain*  
BMozafari*
10/07/92  
10/14/92  
09/28/92  
10/13/92 C/SRXB:DSSA


C/OEAB:DORS
C/OEAB:DORS OGCB:DORS


OGCB:DORS
OE AzK


OE AzK C/OGCB:DORS
C/OGCB:DORS


RJones* AChaffee*  
RJones*  
AChaffee*  
JBirmingham
JBirmingham


JLieberman
===JLieberman GMarcus===
10/08/92
11/09/92
12/ /92
12/f /92
12/ /92 DOCUMENT NAME: G:\\DMG\\INDEBRIS.DMG


GMarcus 10/08/92 11/09/92 12/ /92 12/f /92 12/ /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG
D/DORS


D/DORS BGrimes 12/ /92 I I IN 92-XX December xx, 1992 pieces of miscellaneous
BGrimes


debris. The location and size of the recovered Delrin-AF
12/
/92


material agrees with the material migration
I I


theory since all of the pieces were larger than those recovered
IN 92-XX


from the B SI pump in July and August.The licensee inspected
===December xx, 1992===
pieces of miscellaneous debris. The location and size of the recovered


orifices for the SI pump minimum flow recirculation
Delrin-AF material agrees with the material migration theory since all of the


lines, and visually inspected
pieces were larger than those recovered from the B SI pump in July and August.


piping, tanks, and components
The licensee inspected orifices for the SI pump minimum flow recirculation


to find and remove any foreign material.
lines, and visually inspected piping, tanks, and components to find and remove


Also, the licensee evaluated
any foreign material.


the potential
===Also, the licensee evaluated the potential effect on===
other ECCS equipment and concluded that the ECCS equipment would continue to


effect on other ECCS equipment
be operable and reliable.


and concluded
7-1- t-
The staff notes thatl$resence of small debris may not be detected by


that the ECCS equipment
operational or post-modification testing since blockages may not appear


would continue to be operable and reliable.7-1- t-The staff notes thatl$resence
immediately.


of small debris may not be detected by operational
However, small debris may migrate into areas with smaller cross


or post-modification
sections where the debris can collect and cause blockage after extended


testing since blockages
operation. Whenever safety systems are opened, it is important to ensure


may not appear immediately.
accountability of any materials that are used and to perform'cleanliness


However, small debris may migrate into areas with smaller cross sections where the debris can collect and cause blockage after extended operation.
checks of all affected areas prior to system closure.


Whenever safety systems are opened, it is important
===Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In


to ensure accountability
Containment Emergency Sumps and Incorrect Screen Configurations," which


of any materials
addressed problems that could result from debris in containment emergency


that are used and to perform'cleanliness
sumps.


checks of all affected areas prior to system closure.Related Generic Communication
This information notice requires no specific action or written response.


On November 21, 1989, the NRC issued Information
If


Notice (IN) 89-77, "Debris In Containment
you have any questions about the information in this notice, please contact


Emergency
the technical contact listed below or the appropriate Office of Nuclear


Sumps and Incorrect
Reactor Regulation (NRR) project manager.


Screen Configurations," which addressed
===Brian K. Grimes, Director===
Division of Operating Reactor Support


problems that could result from debris in containment
===Office of Nuclear Reactor Regulation===
Technical cor


emergency sumps.This information
Attachment:
*SEE PREVIOUS


notice requires no specific action or written response.
OEAB:DORS


If you have any questions
DGarcia*
10/07/92 C/SRXB:DSSA


about the information
RJones*
10/08/92


in this notice, please contact the technical
===DOCUMENT NAME===
itact:


contact listed below or the appropriate
===Eric Benner, NRR===
(301) 504-1171


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
===List of Recently Issued NRC Information Notices===
CONCURRENCE


===Reactor Support Office of Nuclear Reactor Regulation===
ASC/OEAB:DORS
Technical


cor Attachment:
ADM:RPB
*SEE PREVIOUS OEAB:DORS DGarcia*10/07/92 C/SRXB:DSSA


RJones*10/08/92 DOCUMENT NAME itact: Eric Benner, NRR (301) 504-1171 List of Recently Issued NRC Information
PM:PD2-1:DRPE


===Notices CONCURRENCE===
AGautam*
ASC/OEAB:DORS
JMain*
BMozafari*
10/14/92
09/28/92
10/13/92 C/OEAB:DORS OGCB:DORS
 
OE
 
C/OGC
 
AChaffee*
JBirmingham* JLieberman* GMarc
 
11/09/92
12/11/92
12/09/92
12/11 E:
G:\\DMG\\INDEBRIS.DMG


ADM:RPB PM:PD2-1:DRPE
B:DORS


AGautam* JMain* BMozafari*
us*
10/14/92 09/28/92 10/13/92 C/OEAB:DORS
/92 D/DORS


OGCB:DORS
BGrimes


OE C/OGC AChaffee*
12/ /92
JBirmingham*
JLieberman*
GMarc 11/09/92 12/11/92 12/09/92 12/11 E: G:\DMG\INDEBRIS.DMG


B:DORS us*/92 D/DORS BGrimes 12/ /92
*SEE PREVIOUS CONCURRENCE
*SEE PREVIOUS CONCURRENCE


OEAB:DORS DGarcia*10/07/92 ASC/OEAB:DORS
OEAB:DORS
 
DGarcia*
10/07/92 ASC/OEAB:DORS


AGautam*10/14/92 ADM:RPB JMain*09/28/92 PM:PD2-1:DRPE
AGautam*
10/14/92 ADM:RPB
 
JMain*
09/28/92 PM:PD2-1:DRPE


BMozafari*
BMozafari*
10/13/92 C/SRXB:DSSA
10/13/92 C/SRXB:DSSA


RJones*10/08/92 DOCUMENT NAME: C/OEAB:DORS
RJones*
10/08/92 DOCUMENT NAME:
C/OEAB:DORS


C/OGCB:DORS
C/OGCB:DORS


AChaffee*  
AChaffee*  
GMarcus 11/09/92 / /92 G:\DMG\INDEBRIS.DMG
GMarcus
 
11/09/92  
/ /92 G:\\DMG\\INDEBRIS.DMG
 
D/DORS


D/DORS BGrimes/ /92 IN 92-XX November xx, 1992 Related Generic Communication
BGrimes


On November 21, 1989, the NRC issued Information
/
/92


Notice (IN) 89-77, 'Debris In Containment
IN 92-XX


Emergency
===November xx, 1992 Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, 'Debris In


Sumps and Incorrect
Containment Emergency Sumps and Incorrect Screen Configurations," in which it


Screen Configurations," in which it discussed
discussed problems that could result from debris found in containment


problems that could result from debris found in containment
emergency sumps.


emergency
This information notice requires no specific action or written response.


sumps.This information
If


notice requires no specific action or written response.
you have any questions about the information in this notice, please contact


If you have any questions
the technical contact listed below or the appropriate Office of Nuclear


about the information
Reactor Regulation (NRR) project manager.


in this notice, please contact the technical
===Brian K. Grimes, Director===
Division of Operating Reactor Support


contact listed below or the appropriate
===Office of Nuclear Reactor Regulation===
Technical contacts:


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
===D. Garcia, NRR===
(301) 504-1170
Attachment:


===Reactor Support Office of Nuclear Reactor Regulation===
===List of Recently Issued NRC Information Notices===
Technical
*SEE PREVIOUS CONCURRENCE


contacts: D. Garcia, NRR (301) 504-1170 Attachment:
OEAB:DORS
List of Recently Issued NRC Information


Notices*SEE PREVIOUS CONCURRENCE
DGarcia*
10/07/92 ASC/OEAB:DORS


OEAB:DORS DGarcia*10/07/92 ASC/OEAB:DORS
AGautam*
10/14/92 ADM:RPB


AGautam*10/14/92 ADM:RPB JMain*09/28/92 PM:PD2-1:DRPE
JMain*
09/28/92 PM:PD2-1:DRPE


BMozafari*
BMozafari*
10/13/92 C/SRXB:DSSA
10/13/92 C/SRXB:DSSA


RJones*10/08/92 C/OE f DORS AChaffee Il /.ci/92 C/OGCB:DORS
RJones*
10/08/92 C/OE f DORS
 
AChaffee
 
Il /.ci/92 C/OGCB:DORS
 
GMarcus


GMarcus/ /92 I D/DORS BGrimes/ /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMC
/  
/92 I


IN 92-XX October xx, 1992 Related Generic Communication
D/DORS


On November 21, 1989, the NRC issued Information
BGrimes


Notice (IN) 89-77, "Debris In Containment
/
/92 DOCUMENT NAME: G:\\DMG\\INDEBRIS.DMC


Emergency
IN 92-XX


Sumps and Incorrect
===October xx, 1992 Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In


Screen Configurations," in which it discussed
Containment Emergency Sumps and Incorrect Screen Configurations," in which it


problems that could result from debris found in containment
discussed problems that could result from debris found in containment


emergency
emergency sumps.


sumps.This information
This information notice requires no specific action or written response.


notice requires no specific action or written response.
If


If you have any questions
you have any questions about the information in this notice, please contact


about the information
the technical contact listed below or the appropriate Office of Nuclear


in this notice, please contact the technical
Reactor Regulation (NRR) project manager.


contact listed below or the appropriate
===Brian K. Grimes, Director===
Division of Operating Reactor Support


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
===Office of Nuclear Reactor Regulation===
Technical contacts:


===Reactor Support Office of Nuclear Reactor Regulation===
===D. Garcia, NRR===
Technical
(301) 504-1170
Attachment:


contacts: D. Garcia, NRR (301) 504-1170 Attachment:
===List of Recently Issued NRC Information Notices===
List of Recently Issued NRC Information
*SEE PREVIOUS CONCURRENCE


Notices*SEE PREVIOUS CONCURRENCE
OEAB:DORS


OEAB:DORS DGarcia*10/07/92 ASC/OEAB:DgRS
DGarcia*
10/07/92 ASC/OEAB:DgRS


/cLAGautamOC
/cLAGautamOC


/6 //~/ 92 ADM:RPB JMain*09/28/92 PM:PD2-1:DRPE
/6 //~/  
92 ADM:RPB
 
JMain*
09/28/92 PM:PD2-1:DRPE


BMozafari*
BMozafari*
10/13/92 C/SRXB:DSSA
10/13/92 C/SRXB:DSSA


RJones*10/08/92 C/OEAB:DORS
RJones*
10/08/92 C/OEAB:DORS


AChaffee/ /92 C/OGCB:DORS
AChaffee


GMarcus/ /92 D/DORS BGrimes/ /92 DOCUMENT NAME: G:\DEBRIS.DMG
/  
/92 C/OGCB:DORS


IN 92-XX October xx, 1992 Related Generic Communication
GMarcus


On November 21, 1989, the NRC issued Information
/
/92 D/DORS


Notice (IN) 89-77, 'Debris In Containment
BGrimes


Emergency
/
/92 DOCUMENT NAME: G:\\DEBRIS.DMG


Sumps and Incorrect
IN 92-XX


Screen Configurations,'  
===October xx, 1992 Related Generic Communication===
in which it discussed
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, 'Debris In


problems that could result from debris found in containment
Containment Emergency Sumps and Incorrect Screen Configurations,' in which it


emergency
discussed problems that could result from debris found in containment


sumps.This information
emergency sumps.


notice requires no specific action or written response.
This information notice requires no specific action or written response. If


If you have any questions
you have any questions about the information in this notice, please contact


about the information
the technical contact listed below or the appropriate Office of Nuclear


in this notice, please contact the technical
Reactor Regulation (NRR)
project manager.


contact listed below or the appropriate
===Brian K. Grimes, Director===
Division of Operating Reactor Support


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
===Office of Nuclear Reactor Regulation===
Technical contacts:


===Reactor Support Office of Nuclear Reactor Regulation===
===Denise M. Garcia, NRR===
Technical
(301) 504-1170
Attachment:


contacts: Denise M. Garcia, NRR (301) 504-1170 Attachment:
===List of Recently Issued NRC Information Notices===
List of Recently Issued NRC Information
*SEE PREVIOUS


Notices*SEE PREVIOUS 0 : RS ,92 C/ SA RJon'es/0 /1(/92 CONCURRENCE
0  
:  
RS
 
,92 C/  
SA
 
RJon'es
 
/0 /1(/92 CONCURRENCE


ASC/OEAB:DORS
ASC/OEAB:DORS


AGautam/ /92 C/OEAB:DORS
AGautam


AChaffee/ /92 ADM:RPB JMain*09/28/92 C/OGCB:DORS
/  
/92 C/OEAB:DORS


GMarcus/ /92 PM:PD2-1 :DRP fl,_fv, BMozafari/0//13/92 D/DORS BGrimes/ /92 DOCUMENT NAME: G:\DEBRIS.DMG
AChaffee


This information
/
/92 ADM:RPB


notice requires no specific action or written response.
JMain*
09/28/92 C/OGCB:DORS


If you have any questions
GMarcus


about the information
/
/92 PM:PD2-1 :DRP


in this notice, please contact the technical
fl,_fv, BMozafari


contact listed below or the appropriate
/0//13/92 D/DORS


Office of Nuclear Reactor Regulation (NRR) project manager.Charles E. Rossi, Director Division of Operational
BGrimes


===Events Assessment===
/
Office of Nuclear Reactor Regulation
/92 DOCUMENT NAME: G:\\DEBRIS.DMG
 
This information notice requires no specific action or written response. If
 
you have any questions about the information in this notice, please contact
 
the technical contact listed below or the appropriate Office of Nuclear


Technical
Reactor Regulation (NRR) project manager.


contacts: Denise M. Garcia, NRR (301) 504-1171 Attachment:
===Charles E. Rossi, Director===
List of Recently Issued NRC Information
Division of Operational Events Assessment


Notices OEAB:DOEA DGarcia/ /92 SC/OEAB:DOEA
===Office of Nuclear Reactor Regulation===
Technical contacts:


AGautam/ /92 ADM:RPB JMain Q h 9/ 2J /f2 PM:PD2-1:DRPE
===Denise M. Garcia, NRR===
(301) 504-1171 Attachment:


BMozafari/ /92 C/SRXB:DST
===List of Recently Issued NRC Information Notices===
OEAB:DOEA


RJones/ /92 C/OEAB:DOEA
DGarcia


AChaffee/ /92 C/OGCB:DOEA
/  
/92 SC/OEAB:DOEA


GMarcus/ /92 D/DOEA CRossi/ /92 DOCUMENT NAME: G:\DEBRIS.DMG
AGautam


K-)UNITED STATES NUCLEAR REGULATORY
/
/92 ADM:RPB


COMMISSION
JMain Q h


===OFFICE OF NUCLEAR REACTOR REGULATION===
9/ 2J /f2 PM:PD2-1:DRPE
WASHINGTON, D.C. 20555 December 23, 1992 NRC INFORMATION


NOTICE 92-85: POTENTIAL
BMozafari


FAILURES OF EMERGENCY
/
/92 C/SRXB:DST


CORE COOLING SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE
RJones


==Addressees==
/
All holders of operating
/92 C/OEAB:DOEA


licenses or construction
AChaffee


permits for nuclear power reactors.
/
/92 C/OGCB:DOEA


==Purpose==
GMarcus
The U.S. Nuclear Regulatory


Commission (NRC) is issuing this information
/
/92 D/DOEA


notice to alert addressees
CRossi


to the potential
/
/92 DOCUMENT NAME: G:\\DEBRIS.DMG


failure of emergency
K-)


core cooling systems (ECCS) caused by foreign material blockage.
===UNITED STATES===
NUCLEAR REGULATORY COMMISSION


It is expected that recipients
===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C.


will review the information
20555


for applicability
===December 23, 1992===
NRC INFORMATION NOTICE 92-85: POTENTIAL FAILURES OF EMERGENCY CORE COOLING


to their facilities
===SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE===


and consider actions, as appropriate, to avoid similar problems.
==Addressees==
All holders of operating licenses or construction permits for nuclear power


However, suggestions
reactors.


contained
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information


in this information
notice to alert addressees to the potential failure of emergency core cooling


notice are not NRC requirements;
systems (ECCS) caused by foreign material blockage. It is expected that
therefore, no specific action or written response is required.Description


of Circumstances
recipients will review the information for applicability to their facilities


H. B. Robinson Unit 2 On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot shutdown, plant personnel
and consider actions, as appropriate, to avoid similar problems.


were performing
However, suggestions contained in this information notice are not NRC requirements;
therefore, no specific action or written response is required.


an operations
==Description of Circumstances==


surveillance
===H. B. Robinson Unit 2===
On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot


test of the B safety injection (SI) pump. This test found that the recirculation
shutdown, plant personnel were performing an operations surveillance test of


flow was 20 percent lower than it had been when it was last measured on July 12, 1992. Prompted by the resident inspector, the Carolina Power and Light Company (the licensee)  
the B safety injection (SI) pump.
retested this pump on August 24, 1992, and found no recirculation


flow. The licensee also tested the A SI pump and found the recirculation
===This test found that the recirculation flow===
was 20 percent lower than it had been when it was last measured on July 12,
1992.


flow was 10 percent lower than when it was last measured.
Prompted by the resident inspector, the Carolina Power and Light


The licensee declared both pumps inoperable
Company (the licensee) retested this pump on August 24, 1992, and found no


and took the unit to cold shutdown.On August 25, 1992, the licensee opened the B SI pump recirculation
recirculation flow. The licensee also tested the A SI pump and found the


line and removed a single piece of white plastic, about the size of a nickel, from the inline orifice.Previously, on July 8, 1992, the licensee had declared the B SI pump inoperable
recirculation flow was 10 percent lower than when it was last measured.


after a quarterly
The


inservice
licensee declared both pumps inoperable and took the unit to cold shutdown.


inspection
On August 25, 1992, the licensee opened the B SI pump recirculation line and


surveillance
removed a single piece of white plastic, about the size of a nickel, from the


test found that it was producing
inline orifice.


a recirculation
Previously, on July 8, 1992, the licensee had declared the B SI pump


flow of 11.4 Liters [3 gallons] per minute, rather than the required 132.5 Liters [35 gallons] per minute. On July 9, 1992, the licensee shut down the plant to determine
inoperable after a quarterly inservice inspection surveillance test found that


the cause of the low flow.The licensee removed the recirculation
it was producing a recirculation flow of 11.4 Liters [3 gallons] per minute, rather than the required 132.5 Liters [35 gallons] per minute.


line for the B SI pump and found that debris was obstructing
On July 9,
1992, the licensee shut down the plant to determine the cause of the low flow.


the inline orifice.9212 0209
The licensee removed the recirculation line for the B SI pump and found that
<-2 <off92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying


that recirculation
debris was obstructing the inline orifice.


flows for both SI pumps were acceptable, the licensee returned the unit to service. The licensee also tested all other ECCS pumps that could have had contact with foreign material.
9212
0209


The licensee believed, prior to plant startup, that all debris had been removed.Point Beach Unit 2 On September
<-2
<off92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying that


28, 1992, the Wisconsin
recirculation flows for both SI pumps were acceptable, the licensee returned


Electric Power Company (the licensee)performed
the unit to service. The licensee also tested all other ECCS pumps that could


an ASME Section XI quarterly
have had contact with foreign material. The licensee believed, prior to plant


test of containment
startup, that all debris had been removed.


spray pumps and valves. During the test, the licensee noted that the discharge
===Point Beach Unit 2===
On September 28, 1992, the Wisconsin Electric Power Company (the licensee)
performed an ASME Section XI quarterly test of containment spray pumps and


pressure for the A train containment
valves. During the test, the licensee noted that the discharge pressure for


spray pump was zero and that the pump was making an abnormal noise. The test was stopped and the pump was declared inoperable.
the A train containment spray pump was zero and that the pump was making an


Upon disassembly
abnormal noise. The test was stopped and the pump was declared inoperable.


of the pump, a foam rubber plug was found blocking the impeller suction. The licensee removed the plug and retested the pump. The test was successfully
Upon disassembly of the pump, a foam rubber plug was found blocking the


completed
impeller suction. The licensee removed the plug and retested the pump. The


and the pump was declared operable.Discussion
test was successfully completed and the pump was declared operable.


The licensee at H. B. Robinson determined
Discussion


that the foreign material found in the SI system was a plastic material that had been used during a modification
The licensee at H. B. Robinson determined that the foreign material found in


of the Residual Heat Removal (RHR) system performed
the SI system was a plastic material that had been used during a modification


in March through June 1992. The plastic material is manufactured
of the Residual Heat Removal (RHR) system performed in March through


by DuPont and the trade name is Delrin-AF.
June 1992. The plastic material is manufactured by DuPont and the trade name


At the time of the RHR modification, the plastic material had been cut into four 23-centimeter
is Delrin-AF. At the time of the RHR modification, the plastic material had


(9-inch] diameter, circular pieces for use as weld purge dams. However, after completing
been cut into four 23-centimeter (9-inch] diameter, circular pieces for use as


the modification, the licensee did not account for two of the four pieces. Delrin-AF
weld purge dams.


decomposes
However, after completing the modification, the licensee did


at RCS system conditions
not account for two of the four pieces. Delrin-AF decomposes at RCS system


because of reaction with the water and thermal degradation.
conditions because of reaction with the water and thermal degradation. The


The licensee suspected
licensee suspected that the purge dam pieces broke, entered the RHR piping


that the purge dam pieces broke, entered the RHR piping after breaking, and migrated into the refueling
after breaking, and migrated into the refueling water storage tank (RWST) and


water storage tank (RWST) and SI header during initial cavity draindown.
SI header during initial cavity draindown.


The licensee sent divers with cameras into the RWST to inspect for the plastic. The divers found three fragments
The licensee sent divers with cameras into the RWST to inspect for the


of Delrin-AF
plastic. The divers found three fragments of Delrin-AF plastic and also other


plastic and also other pieces of miscellaneous
pieces of miscellaneous debris. The location and size of the recovered


debris. The location and size of the recovered Delrin-AF
Delrin-AF material agrees with the material migration theory since all of the


material agrees with the material migration
pieces were larger than those recovered from the B SI pump in July and August.


theory since all of the pieces were larger than those recovered
The licensee inspected orifices for the SI pump minimum flow recirculation


from the B SI pump in July and August.The licensee inspected
lines and also visually inspected piping, tanks, and components to find and


orifices for the SI pump minimum flow recirculation
remove any foreign material. Also, the licensee evaluated the potential


lines and also visually inspected
effect on other ECCS equipment and concluded that the ECCS equipment would


piping, tanks, and components
continue to be operable and reliable.


to find and remove any foreign material.
IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that


Also, the licensee evaluated
the plug was most likely left in the piping after modifications were made to


the potential effect on other ECCS equipment
install full flow test lines in the RHR, containment spray and safety


and concluded
injection systems, during the 1991 refueling outage.


that the ECCS equipment
===The NRC reviewed the===
event and determined that one train of the safety injection system piping was


would continue to be operable and reliable.
rendered inoperable in the recirculation mode because of the presence of the


IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
plug. This condition had continued for about a year and was caused by


that the plug was most likely left in the piping after modifications
inadequate foreign material exclusion controls during the system modifications


were made to install full flow test lines in the RHR, containment
made in the previous outage.


spray and safety injection
The presence of small debris may not be detected by operational or post


systems, during the 1991 refueling
modification testing since blockages may not appear immediately.


outage. The NRC reviewed the event and determined
However, small debris may migrate into areas with smaller cross sections where the


that one train of the safety injection
debris could collect and cause blockage after extended operation. These


system piping was rendered inoperable
examples illustrate the consequences of failure to ensure accountability of


in the recirculation
all materials that are used when safety systems are opened and to perform


mode because of the presence of the plug. This condition
cleanliness checks of all affected areas prior to system closure.


had continued
===Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In


for about a year and was caused by inadequate
Containment Emergency Sumps and Incorrect Screen Configurations," which


foreign material exclusion
addressed problems that could result from debris in containment emergency


controls during the system modifications
sumps.


made in the previous outage.The presence of small debris may not be detected by operational
This information notice requires no specific action or written response. If


or post modification
you have any questions about the information in this notice, please contact


testing since blockages
the technical contact listed below or the appropriate Office of Nuclear


may not appear immediately.
Reactor Regulation (NRR) project manager.


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
rnan K. Grimes, Director


These examples illustrate
===Division of Operating Reactor Support===
Office of Nuclear Reactor Regulation


the consequences
Technical contact:


of failure to ensure accountability
===Eric Benner, NRR===
(301) 504-1171 Attachment:


of all materials
===List of Recently Issued NRC Information Notices===


that are used when safety systems are opened and to perform cleanliness
l


checks of all affected areas prior to system closure.Related Generic Communication
I


On November 21, 1989, the NRC issued Information
1 K"
K-,
I


Notice (IN) 89-77, "Debris In Containment
Attachment


Emergency
IN 92-85


Sumps and Incorrect
===December 23, 1992 LIST OF RECENTLY ISSUED===
NRC INFORMATION NOTICES


Screen Configurations," which addressed
Information


problems that could result from debris in containment
Date of


emergency sumps.This information
Notice No.


notice requires no specific action or written response.
Subject


If you have any questions
Issuance


about the information
Issued to


in this notice, please contact the technical
92-84
88-23, Supp. 4
92-83
92-82
92-81
92-80


contact listed below or the appropriate
===Release of Patients===
Treated with Temporary


Office of Nuclear Reactor Regulation (NRR) project manager.rnan K. Grimes, Director Division of Operating
Implants


===Reactor Support Office of Nuclear Reactor Regulation===
===Potential for Gas===
Technical
Binding of High-Pres- sure Safety Injection


contact: Eric Benner, NRR (301) 504-1171 Attachment:
===Pumps during A Design===
List of Recently Issued NRC Information
Basis Accident


Notices
===Thrust Limits for===
Limitorque Actuators


l I 1 K" K-, I Attachment
and Potential Over- stressing of Motor-


IN 92-85 December 23, 1992 LIST OF RECENTLY ISSUED NRC INFORMATION
===Operated Valves===
Results of Thermo-Lag


NOTICES Information
330-1 Combustibility


Date of Notice No. Subject Issuance Issued to 92-84 88-23, Supp. 4 92-83 92-82 92-81 92-80 Release of Patients Treated with Temporary Implants Potential
Testing


for Gas Binding of High-Pres- sure Safety Injection Pumps during A Design Basis Accident Thrust Limits for Limitorque
===Potential Deficiency===
of Electrical Cables


Actuators and Potential
with Bonded Hypalon


Over-stressing
Jackets


of Motor-Operated Valves Results of Thermo-Lag
Results of Thermo-Lag


330-1 Combustibility
330-1 Combustibility


Testing Potential
Testing


Deficiency
Non-Power Reactor


of Electrical
===Emergency Event Response===
Piston to Cylinder


Cables with Bonded Hypalon Jackets Results of Thermo-Lag
===Liner Tin Smearing on===
Cooper-Bessemer KSV


330-1 Combustibility
===Diesel Engines===
12/17/92
12/18/92
12/17/92
12/15/92
12/11/92
12/07/92
12/01/92
11/30/92
 
===All Nuclear Regulatory===
Commission Medical
 
Licensees.
 
===All holders of OLs or CPs===
for nuclear power reactors.


Testing Non-Power
===All holders of OLs or CPs===
for nuclear power reactors.


Reactor Emergency
===All holders of OLs or CPs===
for nuclear power reactors.


Event Response Piston to Cylinder Liner Tin Smearing on Cooper-Bessemer
===All holders of OLs or CPs===
for nuclear power reactors.


KSV Diesel Engines 12/17/92 12/18/92 12/17/92 12/15/92 12/11/92 12/07/92 12/01/92 11/30/92 All Nuclear Regulatory
===All holders of OLs or CPs===
for nuclear power reactors.


Commission
===All holders of OLs or CPs===
for test and research


Medical Licensees.
reactors.


All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for test and research reactors.All holders of OLs or CPs for nuclear power reactors.92-79 92-78 OL = Operating
===All holders of OLs or CPs===
for nuclear power reactors.


License CP = Construction
92-79
92-78 OL = Operating License


Permit}}
CP = Construction Permit}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Latest revision as of 10:17, 16 January 2025

Potential Failures of Emergency Core Cooling Systems Caused by Foreign Material Blackage
ML031190717
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000419, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Crane  Entergy icon.png
Issue date: 12/23/1992
From: Grimes B
Office of Nuclear Reactor Regulation
To:
References
IN-92-085, NUDOCS 9212170209
Download: ML031190717 (16)
v • d • e


-

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C.

20555

December 23, 1992

NRC INFORMATION NOTICE 92-85:

POTENTIAL FAILURES OF EMERGENCY CORE COOLING

SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information

notice to alert addressees to the potential failure of emergency core cooling

systems (ECCS) caused by foreign material blockage.

It is expected that

recipients will review the information for applicability to their facilities

and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

H. B. Robinson Unit 2

On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot

shutdown, plant personnel were performing an operations surveillance test of

the B safety injection (SI) pump. This test found that the recirculation flow

was 20 percent lower than it had been when it was last measured on July 12,

1992.

Prompted by the resident inspector, the Carolina Power and Light

Company (the licensee) retested this pump on August 24, 1992, and found no

recirculation flow.

The licensee also tested the A SI pump and found the

recirculation flow was 10 percent lower than when it was last measured.

The

licensee declared both pumps inoperable and took the unit to cold shutdown.

On August 25, 1992, the licensee opened the B SI pump recirculation line and

removed a single piece of white plastic, about the size of a nickel, from the

inline orifice.

Previously, on July 8, 1992, the licensee had declared the B SI pump

inoperable after a quarterly inservice inspection surveillance test found that

it was producing a recirculation flow of 11.4 Liters [3 gallons] per minute, rather than the required 132.5 Liters [35 gallons] per minute.

On July 9,

1992, the licensee shut down the plant to determine the cause of the low flow.

The licensee removed the recirculation line for the B SI pump and found that

debris was obstructing the inline orifice.

9212170209 Pyt

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0C20 28

IN 92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying that

recirculation flows for both SI pumps were acceptable, the licensee returned

the unit to service.

The licensee also tested all other ECCS pumps that could

have had contact with foreign material.

The licensee believed, prior to plant

startup, that all debris had been removed.

Point Beach Unit 2

On September 28, 1992, the Wisconsin Electric Power Company (the licensee)

performed an ASME Section XI quarterly test of containment spray pumps and

valves. During the test, the licensee noted that the discharge pressure for

the A train containment spray pump was zero and that the pump was making an

abnormal noise.

The test was stopped and the pump was declared inoperable.

Upon disassembly of the pump, a foam rubber plug was found blocking the

impeller suction.

The licensee removed the plug and retested the pump.

The

test was successfully completed and the pump was declared operable.

Discussion

The licensee at H. B. Robinson determined that the foreign material found in

the SI system was a plastic material that had been used during a modification

of the Residual Heat Removal (RHR) system performed in March through

June 1992.

The plastic material is manufactured by DuPont and the trade name

is Delrin-AF.

At the time of the RHR modification, the plastic material had

been cut into-four 23=centimeter [9-inch]-diameter,-circular pieces for use-as

weld purge dams. However, after completing the modification, the licensee did

not account for two of the four pieces.

Delrin-AF decomposes at RCS system

conditions because of reaction with the water and thermal degradation. The

licensee suspected that the purge dam pieces broke,. entered the RHR piping

after breaking, and migrated into the refueling water storage tank (RWST) and

SI header during initial cavity draindown.

The licensee sent divers with cameras into the RWST to inspect for the

plastic.

The divers found three fragments of Delrin-AF plastic and also other

pieces of miscellaneous debris.

The location and size of the recovered

Delrin-AF material agrees with the material migration theory since all of the

pieces were larger than those recovered from the B SI pump in July and August.

The licensee inspected orifices for the SI pump minimum flow recirculation

lines and also visually inspected piping, tanks, and components to find and

remove any foreign material.

Also, the licensee evaluated the potential

effect on other ECCS equipment and concluded that the ECCS equipment would

continue to be operable and reliable.

a

IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that

the plug was most likely left in the piping after modifications were made to

install full flow test lines in the RHR, containment spray and safety

injection systems, during the 1991 refueling outage.

The NRC reviewed the

event and determined that one train of the safety injection system piping was

rendered inoperable in the recirculation mode because of the presence of the

plug.

This condition had continued for about a year and was caused by

inadequate foreign material exclusion controls during the system modifications

made in the previous outage.

The presence of small debris may not be detected by operational or post

modification testing since blockages may not appear immediately.

However, small debris may migrate into areas with smaller cross sections where the

debris could collect and cause blockage after extended operation.

These

examples illustrate the consequences of failure to ensure accountability of

all materials that are used when safety systems are opened and to perform

cleanliness checks of all affected areas prior to system closure.

Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," which

addressed problems that could result from debris in containment emergency

sumps.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

rnan K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:

Eric Benner, NRR

(301) 504-1171 Attachment:

List of Recently Issued NRC Information Notices

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Attachment

IN 92-85 December 23,

1992 Page I of 1

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information

Notice No.

Subject

92-84

Release of Patients

Treated with Temporary

Implants

88-23,

Potential for Gas

Supp. 4 Binding of High-Pres- sure Safety Injection

Pumps during A Design

Basis Accident

92-83

Thrust Limits for

Limitorque Actuators

and Potential Over- stressing of Motor-

Operated Valves

92-82 Results of Thermo-Lag

330-1 Combustibility

Testing

92-81

Potential Deficiency

of Electrical Cables

with Bonded Hypalon

Jackets

92-80

Results of Thermo-Lag

330-1 Combustibility

Testing

92-79 Non-Power Reactor

Emergency Event Response

92-78

Piston to Cylinder

Liner Tin Smearing on

Cooper-Bessemer KSV

Diesel Engines

Vate of

Issuance

Issued to

12/17/92

All Nuclear Regulatory

Comnission Medical

(

Licensees.

12/18/92

All holders of OLs or CPs

for nuclear power reactors

12/17/92

All holders of OLs or CPs

for nuclear power reactors

12/15/92

All holders of OLs or CPs

for nuclear power reactors

12/11/92

All holders of OLs or CPs

for nuclear power reactors.

12/07/92

All holders of OLs or CPs

for nuclear power reactors.

12/01/92 All holders of OLs or CPs(

for test and research

reactors.

11/30/92

All holders of OLs or CPs

for nuclear power reactors.

DL - Operating License

CP - Construction Permit

'U

IN 92-XX

December xx, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that

the plug was most likely left in the piping after modifications were made to

install full flow test lines-in the residual heat removal (RHR), containment

spray and safety injection systems, during the 1991 refueling outage. The NRC

reviewed the event and determined that one train of the safety injection

system piping was rendered inoperable in the recirculation mode because of the

presence of the plug.

The NRC issued a Notice of Violation and Proposed

Imposition of Civil Penalty in the amount of $75,000.

This violation, which

was classified at Severity Level III, continued for about a year and was

caused by inadequate foreign material exclusion controls during the system

modifications made in the previous outage.

The presence of small debris may not be detected by operational or post

modification testing since blockages may not appear immediately.

However, small debris may migrate into areas with smaller cross sections where the

debris could collect and cause blockage after extended operation.

Whenever

safety systems are opened, it is important to ensure accountability of any

materials that are used and to perform cleanliness checks of all affected

areas prior to system closure.

Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," which

addressed problems that could result from debris in containment emergency

sumps.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: Eric Benner, NRR

(301) 504-1171 Attachment:

List of Recently Issued NRC Information Notices

  • SEE PREVIOUS CONCURRENCE

OEAB:DORS

ASC/OEAB:DORS

ADM:RPB

PM:PD2-1:DRPE

DGarcia*

AGautam*

JMain*

BMozafari*

10/07/92

10/14/92

09/28/92

10/13/92 C/SRXB:DSSA

C/OEAB:DORS OGCB:DORS

OE

C/OGCB:DORS

D/DORS

RJones*

AChaffee*

JBirmingham , Lieberman* GMarcus

BGrimes

10/08/92

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IN 92-XX

December xx, 1992

The licensee for Point Beach Unit 2 reviewed plant records and determined that

the plug was most likely left in the piping after modifications were made to

install full flow test lines in the residual heat removal (RHR), containment

spray and safety injection systems, during the 1991 refueling outage. The NRC

reviewed the event and determined that one train of the safety injection

system piping was rendered inoperable in the recirculation mode because of the

presence of the plug. The NRC is issuing a Notice of Violation and Proposed

Imposition of Civil Penalty in the amount of $75,000. This violation, which

has been classified at Severity Level III, continued for about a year and was

caused by inadequate foreign material exclusion controls during the system

modifications made in the previous outage.

The presence of small debris may not be detected by operational or post

modification testing since blockages may not appear immediately. However, small debris may migrate into areas with smaller cross sections where the

debris could collect and cause blockage after extended operation. Whenever

safety systems are opened, it is important to ensure accountability of any

materials that are used and to perform cleanliness checks of all affected

areas prior to system closure.

Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," which

addressed problems that could result from debris in containment emergency

sumps.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: Eric Benner, NRR

(301) 504-1171 Attachment:

List of Recently Issued NRC Information Notices

  • SEE PREVIOUS CONCURRENCE

OEAB:DORS

ASC/OEAB:DORS

ADM:RPB

PM:PD2-1:DRPE

DGarcia*

AGautam*

JMain*

BMozafari*

10/07/92

10/14/92

09/28/92

10/13/92 C/SRXB:DSSA

C/OEAB:DORS OGCB:DORS

OE AzK

C/OGCB:DORS

RJones*

AChaffee*

JBirmingham

JLieberman GMarcus

10/08/92

11/09/92

12/ /92

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12/ /92 DOCUMENT NAME: G:\\DMG\\INDEBRIS.DMG

D/DORS

BGrimes

12/

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I I

IN 92-XX

December xx, 1992

pieces of miscellaneous debris. The location and size of the recovered

Delrin-AF material agrees with the material migration theory since all of the

pieces were larger than those recovered from the B SI pump in July and August.

The licensee inspected orifices for the SI pump minimum flow recirculation

lines, and visually inspected piping, tanks, and components to find and remove

any foreign material.

Also, the licensee evaluated the potential effect on

other ECCS equipment and concluded that the ECCS equipment would continue to

be operable and reliable.

7-1- t-

The staff notes thatl$resence of small debris may not be detected by

operational or post-modification testing since blockages may not appear

immediately.

However, small debris may migrate into areas with smaller cross

sections where the debris can collect and cause blockage after extended

operation. Whenever safety systems are opened, it is important to ensure

accountability of any materials that are used and to perform'cleanliness

checks of all affected areas prior to system closure.

Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," which

addressed problems that could result from debris in containment emergency

sumps.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical cor

Attachment:

  • SEE PREVIOUS

OEAB:DORS

DGarcia*

10/07/92 C/SRXB:DSSA

RJones*

10/08/92

DOCUMENT NAME

itact:

Eric Benner, NRR

(301) 504-1171

List of Recently Issued NRC Information Notices

CONCURRENCE

ASC/OEAB:DORS

ADM:RPB

PM:PD2-1:DRPE

AGautam*

JMain*

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10/14/92

09/28/92

10/13/92 C/OEAB:DORS OGCB:DORS

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11/09/92

12/11/92

12/09/92

12/11 E:

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BGrimes

12/ /92

  • SEE PREVIOUS CONCURRENCE

OEAB:DORS

DGarcia*

10/07/92 ASC/OEAB:DORS

AGautam*

10/14/92 ADM:RPB

JMain*

09/28/92 PM:PD2-1:DRPE

BMozafari*

10/13/92 C/SRXB:DSSA

RJones*

10/08/92 DOCUMENT NAME:

C/OEAB:DORS

C/OGCB:DORS

AChaffee*

GMarcus

11/09/92

/ /92 G:\\DMG\\INDEBRIS.DMG

D/DORS

BGrimes

/

/92

IN 92-XX

November xx, 1992 Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, 'Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," in which it

discussed problems that could result from debris found in containment

emergency sumps.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts:

D. Garcia, NRR

(301) 504-1170

Attachment:

List of Recently Issued NRC Information Notices

  • SEE PREVIOUS CONCURRENCE

OEAB:DORS

DGarcia*

10/07/92 ASC/OEAB:DORS

AGautam*

10/14/92 ADM:RPB

JMain*

09/28/92 PM:PD2-1:DRPE

BMozafari*

10/13/92 C/SRXB:DSSA

RJones*

10/08/92 C/OE f DORS

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GMarcus

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D/DORS

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/92 DOCUMENT NAME: G:\\DMG\\INDEBRIS.DMC

IN 92-XX

October xx, 1992 Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," in which it

discussed problems that could result from debris found in containment

emergency sumps.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts:

D. Garcia, NRR

(301) 504-1170

Attachment:

List of Recently Issued NRC Information Notices

  • SEE PREVIOUS CONCURRENCE

OEAB:DORS

DGarcia*

10/07/92 ASC/OEAB:DgRS

/cLAGautamOC

/6 //~/

92 ADM:RPB

JMain*

09/28/92 PM:PD2-1:DRPE

BMozafari*

10/13/92 C/SRXB:DSSA

RJones*

10/08/92 C/OEAB:DORS

AChaffee

/

/92 C/OGCB:DORS

GMarcus

/

/92 D/DORS

BGrimes

/

/92 DOCUMENT NAME: G:\\DEBRIS.DMG

IN 92-XX

October xx, 1992 Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, 'Debris In

Containment Emergency Sumps and Incorrect Screen Configurations,' in which it

discussed problems that could result from debris found in containment

emergency sumps.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR)

project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts:

Denise M. Garcia, NRR

(301) 504-1170

Attachment:

List of Recently Issued NRC Information Notices

  • SEE PREVIOUS

0

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ASC/OEAB:DORS

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09/28/92 C/OGCB:DORS

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This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical contacts:

Denise M. Garcia, NRR

(301) 504-1171 Attachment:

List of Recently Issued NRC Information Notices

OEAB:DOEA

DGarcia

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AGautam

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K-)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C.

20555

December 23, 1992

NRC INFORMATION NOTICE 92-85: POTENTIAL FAILURES OF EMERGENCY CORE COOLING

SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information

notice to alert addressees to the potential failure of emergency core cooling

systems (ECCS) caused by foreign material blockage. It is expected that

recipients will review the information for applicability to their facilities

and consider actions, as appropriate, to avoid similar problems.

However, suggestions contained in this information notice are not NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

H. B. Robinson Unit 2

On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot

shutdown, plant personnel were performing an operations surveillance test of

the B safety injection (SI) pump.

This test found that the recirculation flow

was 20 percent lower than it had been when it was last measured on July 12,

1992.

Prompted by the resident inspector, the Carolina Power and Light

Company (the licensee) retested this pump on August 24, 1992, and found no

recirculation flow. The licensee also tested the A SI pump and found the

recirculation flow was 10 percent lower than when it was last measured.

The

licensee declared both pumps inoperable and took the unit to cold shutdown.

On August 25, 1992, the licensee opened the B SI pump recirculation line and

removed a single piece of white plastic, about the size of a nickel, from the

inline orifice.

Previously, on July 8, 1992, the licensee had declared the B SI pump

inoperable after a quarterly inservice inspection surveillance test found that

it was producing a recirculation flow of 11.4 Liters [3 gallons] per minute, rather than the required 132.5 Liters [35 gallons] per minute.

On July 9,

1992, the licensee shut down the plant to determine the cause of the low flow.

The licensee removed the recirculation line for the B SI pump and found that

debris was obstructing the inline orifice.

9212

0209

<-2

<off92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying that

recirculation flows for both SI pumps were acceptable, the licensee returned

the unit to service. The licensee also tested all other ECCS pumps that could

have had contact with foreign material. The licensee believed, prior to plant

startup, that all debris had been removed.

Point Beach Unit 2

On September 28, 1992, the Wisconsin Electric Power Company (the licensee)

performed an ASME Section XI quarterly test of containment spray pumps and

valves. During the test, the licensee noted that the discharge pressure for

the A train containment spray pump was zero and that the pump was making an

abnormal noise. The test was stopped and the pump was declared inoperable.

Upon disassembly of the pump, a foam rubber plug was found blocking the

impeller suction. The licensee removed the plug and retested the pump. The

test was successfully completed and the pump was declared operable.

Discussion

The licensee at H. B. Robinson determined that the foreign material found in

the SI system was a plastic material that had been used during a modification

of the Residual Heat Removal (RHR) system performed in March through

June 1992. The plastic material is manufactured by DuPont and the trade name

is Delrin-AF. At the time of the RHR modification, the plastic material had

been cut into four 23-centimeter (9-inch] diameter, circular pieces for use as

weld purge dams.

However, after completing the modification, the licensee did

not account for two of the four pieces. Delrin-AF decomposes at RCS system

conditions because of reaction with the water and thermal degradation. The

licensee suspected that the purge dam pieces broke, entered the RHR piping

after breaking, and migrated into the refueling water storage tank (RWST) and

SI header during initial cavity draindown.

The licensee sent divers with cameras into the RWST to inspect for the

plastic. The divers found three fragments of Delrin-AF plastic and also other

pieces of miscellaneous debris. The location and size of the recovered

Delrin-AF material agrees with the material migration theory since all of the

pieces were larger than those recovered from the B SI pump in July and August.

The licensee inspected orifices for the SI pump minimum flow recirculation

lines and also visually inspected piping, tanks, and components to find and

remove any foreign material. Also, the licensee evaluated the potential

effect on other ECCS equipment and concluded that the ECCS equipment would

continue to be operable and reliable.

IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that

the plug was most likely left in the piping after modifications were made to

install full flow test lines in the RHR, containment spray and safety

injection systems, during the 1991 refueling outage.

The NRC reviewed the

event and determined that one train of the safety injection system piping was

rendered inoperable in the recirculation mode because of the presence of the

plug. This condition had continued for about a year and was caused by

inadequate foreign material exclusion controls during the system modifications

made in the previous outage.

The presence of small debris may not be detected by operational or post

modification testing since blockages may not appear immediately.

However, small debris may migrate into areas with smaller cross sections where the

debris could collect and cause blockage after extended operation. These

examples illustrate the consequences of failure to ensure accountability of

all materials that are used when safety systems are opened and to perform

cleanliness checks of all affected areas prior to system closure.

Related Generic Communication

On November 21, 1989, the NRC issued Information Notice (IN) 89-77, "Debris In

Containment Emergency Sumps and Incorrect Screen Configurations," which

addressed problems that could result from debris in containment emergency

sumps.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

rnan K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:

Eric Benner, NRR

(301) 504-1171 Attachment:

List of Recently Issued NRC Information Notices

l

I

1 K"

K-,

I

Attachment

IN 92-85

December 23, 1992 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information

Date of

Notice No.

Subject

Issuance

Issued to

92-84

88-23, Supp. 4

92-83

92-82

92-81

92-80

Release of Patients

Treated with Temporary

Implants

Potential for Gas

Binding of High-Pres- sure Safety Injection

Pumps during A Design

Basis Accident

Thrust Limits for

Limitorque Actuators

and Potential Over- stressing of Motor-

Operated Valves

Results of Thermo-Lag

330-1 Combustibility

Testing

Potential Deficiency

of Electrical Cables

with Bonded Hypalon

Jackets

Results of Thermo-Lag

330-1 Combustibility

Testing

Non-Power Reactor

Emergency Event Response

Piston to Cylinder

Liner Tin Smearing on

Cooper-Bessemer KSV

Diesel Engines

12/17/92

12/18/92

12/17/92

12/15/92

12/11/92

12/07/92

12/01/92

11/30/92

All Nuclear Regulatory

Commission Medical

Licensees.

All holders of OLs or CPs

for nuclear power reactors.

All holders of OLs or CPs

for nuclear power reactors.

All holders of OLs or CPs

for nuclear power reactors.

All holders of OLs or CPs

for nuclear power reactors.

All holders of OLs or CPs

for nuclear power reactors.

All holders of OLs or CPs

for test and research

reactors.

All holders of OLs or CPs

for nuclear power reactors.

92-79

92-78 OL = Operating License

CP = Construction Permit


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