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:;-                                   UNITED STATES


COMMISSION
NUCLEAR REGULATORY COMMISSION


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


NOTICE 92-85: POTENTIAL
WASHINGTON, D.C. 20555 December 23, 1992 NRC INFORMATION NOTICE 92-85:   POTENTIAL FAILURES OF EMERGENCY CORE COOLING


FAILURES OF EMERGENCY
SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE
 
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


permits for nuclear power reactors.
reactors.


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


Commission (NRC) is issuing this information
notice to alert addressees to the potential failure of emergency core cooling


notice to alert addressees
systems (ECCS) caused by foreign material blockage. It is expected that


to the potential
recipients will review the information for applicability to their facilities


failure of emergency
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.


core cooling systems (ECCS) caused by foreign material blockage.
==Description of Circumstances==


It is expected that recipients
===H. B. Robinson Unit 2===
  On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot


will review the information
shutdown, plant personnel were performing an operations surveillance test of


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


to their facilities
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


and consider actions, as appropriate, to avoid similar problems.
Company (the licensee) retested this pump on August 24, 1992, and found no


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


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


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


notice are not NRC requirements;
On August 25, 1992, the licensee opened the B SI pump recirculation line and
therefore, no specific action or written response is required.Description


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


H. B. Robinson Unit 2 On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot shutdown, plant personnel
inline orifice.


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


an operations
inoperable after a quarterly inservice inspection surveillance test found that


surveillance
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.


test of the B safety injection (SI) pump. This test found that the recirculation
The licensee removed the recirculation line for the B SI pump and found that


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)
debris was obstructing the inline orifice.
retested this pump on August 24, 1992, and found no recirculation


flow. The licensee also tested the A SI pump and found the recirculation
9212170209    Pyt                                          I  (        /'a


flow was 10 percent lower than when it was last measured.
q9A Ac      s


The licensee declared both pumps inoperable
e                0C20  28


and took the unit to cold shutdown.On August 25, 1992, the licensee opened the B SI pump recirculation
IN 92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying that


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 flows for both SI pumps were acceptable, the licensee returned


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


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


inspection
startup, that all debris had been removed.


surveillance
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


test found that it was producing
valves. During the test, the licensee noted that the discharge pressure for


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


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


the cause of the low flow.The licensee removed the recirculation
Upon disassembly of the pump, a foam rubber plug was found blocking the


line for the B SI pump and found that debris was obstructing
impeller suction. The licensee removed the plug and retested the pump. The


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
test was successfully completed and the pump was declared operable.


that recirculation
Discussion


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


The licensee believed, prior to plant startup, that all debris had been removed.Point Beach Unit 2 On September
the SI system was a plastic material that had been used during a modification


28, 1992, the Wisconsin
of the Residual Heat Removal (RHR) system performed in March through


Electric Power Company (the licensee)performed
June 1992. The plastic material is manufactured by DuPont and the trade name


an ASME Section XI quarterly
is Delrin-AF. At the time of the RHR modification, the plastic material had


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


spray pumps and valves. During the test, the licensee noted that the discharge
weld purge dams. However, after completing the modification, the licensee did


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


spray pump was zero and that the pump was making an abnormal noise. The test was stopped and the pump was declared inoperable.
conditions because of reaction with the water and thermal degradation. The


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


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


completed
SI header during initial cavity draindown.


and the pump was declared operable.Discussion
The licensee sent divers with cameras into the RWST to inspect for the


The licensee at H. B. Robinson determined
plastic. The divers found three fragments of Delrin-AF plastic and also other


that the foreign material found in the SI system was a plastic material that had been used during a modification
pieces of miscellaneous debris. The location and size of the recovered


of the Residual Heat Removal (RHR) system performed
Delrin-AF material agrees with the material migration theory since all of the


in March through June 1992. The plastic material is manufactured
pieces were larger than those recovered from the B SI pump in July and August.


by DuPont and the trade name is Delrin-AF.
The licensee inspected orifices for the SI pump minimum flow recirculation


At the time of the RHR modification, the plastic material had been cut into-four
lines and also visually inspected piping, tanks, and components to find and


23=centimeter
remove any foreign material. Also, the licensee evaluated the potential


[9-inch]-diameter,-circular
effect on other ECCS equipment and concluded that the ECCS equipment would


pieces for use-as weld purge dams. However, after completing
continue to be operable and reliable.


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


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


at RCS system conditions
the plug was most likely left in the piping after modifications were made to


because of reaction with the water and thermal degradation.
install full flow test lines in the RHR, containment spray and safety


The licensee suspected
injection systems, during the 1991 refueling outage. The NRC reviewed the


that the purge dam pieces broke,. entered the RHR piping after breaking, and migrated into the refueling
event and determined that one train of the safety injection system piping was


water storage tank (RWST) and SI header during initial cavity draindown.
rendered inoperable in the recirculation mode because of the presence of the


The licensee sent divers with cameras into the RWST to inspect for the plastic. The divers found three fragments
plug. This condition had continued for about a year and was caused by


of Delrin-AF
inadequate foreign material exclusion controls during the system modifications


plastic and also other pieces of miscellaneous
made in the previous outage.


debris. The location and size of the recovered Delrin-AF
The presence of small debris may not be detected by operational or post


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


theory since all of the pieces were larger than those recovered
debris could collect and cause blockage after extended operation. These


from the B SI pump in July and August.The licensee inspected
examples illustrate the consequences of failure to ensure accountability of


orifices for the SI pump minimum flow recirculation
all materials that are used when safety systems are opened and to perform


lines and also visually inspected
cleanliness checks of all affected areas prior to system closure.


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


to find and remove any foreign material.
Containment Emergency Sumps and Incorrect Screen Configurations," which


Also, the licensee evaluated
addressed problems that could result from debris in containment emergency


the potential effect on other ECCS equipment
sumps.


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


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


would continue to be operable and reliable.a
the technical contact listed below or the appropriate Office of Nuclear


IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
Reactor Regulation (NRR) project manager.


that the plug was most likely left in the piping after modifications
rnan K. Grimes, Director


were made to install full flow test lines in the RHR, containment
Division of Operating Reactor Support


spray and safety injection
Office of Nuclear Reactor Regulation


systems, during the 1991 refueling
Technical contact:  Eric Benner, NRR


outage. The NRC reviewed the event and determined
(301) 504-1171 Attachment:  List of Recently Issued NRC Information Notices


that one train of the safety injection
z


system piping was rendered inoperable
C


in the recirculation
D    --
                                                                                Attachment


mode because of the presence of the plug. This condition
IN 92-85 z-4                                                                              December 23, 1992 V                                                                              Page I of 1
0
a


had continued
z


for about a year and was caused by inadequate
-_          _
                11                                      LIST OF RECENTLY ISSUED


foreign material exclusion
0
                                                        NRCINFORMATION NOTICES


controls during the system modifications
>n


made in the previous outage.The presence of small debris may not be detected by operational
V


or post modification
0-4U    Information                                  Vate of


testing since blockages
-v                  Notice No.            Subject                Issuance    Issued to


may not appear immediately.
cmm


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
z 0 Cfl


These examples illustrate
U1      92-84          Release of Patients


the consequences
Treated with Temporary


of failure to ensure accountability
Implants


of all materials
12/17/92    All Nuclear Regulatory


that are used when safety systems are opened and to perform cleanliness
Comnission Medical


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


On November 21, 1989, the NRC issued Information
(
      Ca/            88-23,         Potential for Gas              12/18/92    All holders of OLs or CPs


Notice (IN) 89-77, "Debris In Containment
Supp. 4        Binding of High-Pres-                      for nuclear power reactors


Emergency
sure Safety Injection


Sumps and Incorrect
Pumps during A Design


Screen Configurations," which addressed
z                    Basis Accident


problems that could result from debris in containment
92-83          Thrust Limits for              12/17/92    All holders of OLs or CPs


emergency sumps.This information
Limitorque Actuators                        for nuclear power reactors


notice requires no specific action or written response.
and Potential Over- stressing of Motor- Operated Valves


If you have any questions
92-82          Results of Thermo-Lag          12/15/92    All holders of OLs or CPs


about the information
330-1 Combustibility                      for nuclear power reactors


in this notice, please contact the technical
Testing


contact listed below or the appropriate
92-81          Potential Deficiency          12/11/92    All holders of OLs or CPs


Office of Nuclear Reactor Regulation (NRR) project manager.rnan K. Grimes, Director Division of Operating
of Electrical Cables                        for nuclear power reactors.


===Reactor Support Office of Nuclear Reactor Regulation===
with Bonded Hypalon
Technical


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


Notices
92-80          Results of Thermo-Lag          12/07/92    All holders of OLs or CPs


z-4 V a 0 z 0 V-v z C D -->n-_ _z 11 0-4U cmm U1 0 Cfl Ca/z Attachment
330-1 Combustibility                      for nuclear power reactors.


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


===NOTICES Information===
92-79          Non-Power Reactor              12/01/92    All holders of OLs or CPs(
Notice No. Subject 92-84 Release of Patients Treated with Temporary Implants 88-23, Potential
                                    Emergency Event Response                  for test and research


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


Actuators and Potential
92-78          Piston to Cylinder            11/30/92    All holders of OLs or CPs


Over-stressing
Liner Tin Smearing on                      for nuclear power reactors.


of Motor-Operated Valves 92-82 Results of Thermo-Lag
Cooper-Bessemer KSV


330-1 Combustibility
Diesel Engines


Testing 92-81 Potential
DL - Operating License


Deficiency
CP- Construction Permit


of Electrical
'U


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


330-1 Combustibility
December xx, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that


Testing 92-79 Non-Power
the plug was most likely left in the piping after modifications were made to


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


Event Response 92-78 Piston to Cylinder Liner Tin Smearing on Cooper-Bessemer
spray and safety injection systems, during the 1991 refueling outage. The NRC


KSV Diesel Engines Vate of Issuance Issued to 12/17/92 All Nuclear Regulatory
reviewed the event and determined that one train of the safety injection


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


Medical (Licensees.
presence of the plug. The NRC issued a Notice of Violation and Proposed


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


License CP -Construction
was classified at Severity Level III, continued for about a year and was


Permit
caused by inadequate foreign material exclusion controls during the system


'U IN 92-XX December xx, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
modifications made in the previous outage.


that the plug was most likely left in the piping after modifications
The presence of small debris may not be detected by operational or post


were made to install full flow test lines-in the residual heat removal (RHR), containment
modification testing since blockages may not appear immediately. However, small debris may migrate into areas with smaller cross sections where the


spray and safety injection
debris could collect and cause blockage after extended operation. Whenever


systems, during the 1991 refueling
safety systems are opened, it is important to ensure accountability of any


outage. The NRC reviewed the event and determined
materials that are used and to perform cleanliness checks of all affected


that one train of the safety injection system piping was rendered inoperable
areas prior to system closure.


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


mode because of the presence of the plug. The NRC issued a Notice of Violation
Containment Emergency Sumps and Incorrect Screen Configurations," which


and Proposed Imposition
addressed problems that could result from debris in containment emergency


of Civil Penalty in the amount of $75,000. This violation, which was classified
sumps.


at Severity Level III, continued
This information notice requires no specific action or written response. 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
Brian K. Grimes, Director


or post modification
Division of Operating Reactor Support


testing since blockages
Office of Nuclear Reactor Regulation


may not appear immediately.
Technical contact:  Eric Benner, NRR


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
(301) 504-1171 Attachment: List of Recently Issued NRC Information Notices


Whenever safety systems are opened, it is important
*SEE PREVIOUS CONCURRENCE


to ensure accountability
OEAB:DORS      ASC/OEAB:DORS    ADM:RPB      PM:PD2-1:DRPE


of any materials
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


that are used and to perform cleanliness
RJones*        AChaffee*    JBirmingham , Lieberman* GMarcus            BGrimes


checks of all affected areas prior to system closure.Related Generic Communication
10/08/92      11/09/92      12////92 ~/'  2/09/92      12/1i/927      12/  /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG


On November 21, 1989, the NRC issued Information
'  J


Notice (IN) 89-77, "Debris In Containment
4 I                                K)
                                                              IN 92-XX


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


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


Screen Configurations," which addressed
install full flow test lines in the residual heat removal (RHR), containment


problems that could result from debris in containment
spray and safety injection systems, during the 1991 refueling outage. The NRC


emergency sumps.This information
reviewed the event and determined that one train of the safety injection


notice requires no specific action or written response.
system piping was rendered inoperable in the recirculation mode because of the


If you have any questions
presence of the plug. The NRC is issuing a Notice of Violation and Proposed


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


in this notice, please contact the technical
has been classified at Severity Level III, continued for about a year and was


contact listed below or the appropriate
caused by inadequate foreign material exclusion controls during the system


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
modifications made in the previous outage.


===Reactor Support Office of Nuclear Reactor Regulation===
The presence of small debris may not be detected by operational or post
Technical


contact: Eric Benner, NRR (301) 504-1171 Attachment:
modification testing since blockages may not appear immediately. However, small debris may migrate into areas with smaller cross sections where the
List of Recently Issued NRC Information


Notices*SEE PREVIOUS CONCURRENCE
debris could collect and cause blockage after extended operation. Whenever


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


ASC/OEAB:DORS
materials that are used and to perform cleanliness checks of all affected


ADM:RPB PM:PD2-1:DRPE
areas prior to system closure.


DGarcia* AGautam* JMain* BMozafari*
===Related Generic Communication===
10/07/92 10/14/92 09/28/92 10/13/92 C/SRXB:DSSA
On November 21, 1989, the NRC issued Information Notice (IN)89-77, "Debris In


C/OEAB:DORS
Containment Emergency Sumps and Incorrect Screen Configurations," which


OGCB:DORS
addressed problems that could result from debris in containment emergency


OE C/OGCB:DORS
sumps.


D/DORS RJones* AChaffee*
This information notice requires no specific action or written response. If
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
you have any questions about the information in this notice, please contact


that the plug was most likely left in the piping after modifications
the technical contact listed below or the appropriate Office of Nuclear


were made to install full flow test lines in the residual heat removal (RHR), containment
Reactor Regulation (NRR) project manager.


spray and safety injection
Brian K. Grimes, Director


systems, during the 1991 refueling
Division of Operating Reactor Support


outage. The NRC reviewed the event and determined
Office of Nuclear Reactor Regulation


that one train of the safety injection system piping was rendered inoperable
Technical contact:  Eric Benner, NRR


in the recirculation
(301) 504-1171 Attachment: List of Recently Issued NRC Information Notices


mode because of the presence of the plug. The NRC is issuing a Notice of Violation
*SEE PREVIOUS CONCURRENCE


and Proposed Imposition
OEAB:DORS      ASC/OEAB:DORS    ADM:RPB        PM:PD2-1:DRPE


of Civil Penalty in the amount of $75,000. This violation, which has been classified
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    D/DORS


at Severity Level III, continued
RJones*        AChaffee*    JBirmingham    JLieberman GMarcus            BGrimes


for about a year and was caused by inadequate
10/08/92      11/09/92    12/ /92        12/f /92    12/ /92          12/ /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG


foreign material exclusion
I I


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


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


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


may not appear immediately.
The licensee inspected orifices for the SI pump minimum flow recirculation


However, small debris may migrate into areas with smaller cross sections where the debris could collect and cause blockage after extended operation.
lines, and visually inspected piping, tanks, and components to find and remove


Whenever safety systems are opened, it is important
any foreign material. Also, the licensee evaluated the potential effect on


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


of any materials
be operable and reliable.


that are used and to perform cleanliness
7-1- t- The staff notes thatl$resence of small debris may not be detected by


checks of all affected areas prior to system closure.Related Generic Communication
operational or post-modification testing since blockages may not appear


On November 21, 1989, the NRC issued Information
immediately. However, small debris may migrate into areas with smaller cross


Notice (IN) 89-77, "Debris In Containment
sections where the debris can collect and cause blockage after extended


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


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


Screen Configurations," which addressed
checks of all affected areas prior to system closure.


problems that could result from debris in containment
===Related Generic Communication===
On November 21, 1989, the NRC issued Information Notice (IN)89-77, "Debris In


emergency sumps.This information
Containment Emergency Sumps and Incorrect Screen Configurations," which


notice requires no specific action or written response.
addressed problems that could result from debris in containment emergency


If you have any questions
sumps.


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


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


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


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


===Reactor Support Office of Nuclear Reactor Regulation===
Brian K. Grimes, Director
Technical


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


Notices*SEE PREVIOUS CONCURRENCE
Office of Nuclear Reactor Regulation


OEAB:DORS
Technical coritact:   Eric Benner, NRR


ASC/OEAB:DORS
(301) 504-1171 Attachment: List of Recently Issued NRC Information Notices


ADM:RPB PM:PD2-1:DRPE
*SEE PREVIOUS CONCURRENCE


DGarcia* AGautam* JMain* BMozafari*
OEAB:DORS        ASC/OEAB:DORS      ADM:RPB      PM:PD2-1:DRPE
10/07/92 10/14/92 09/28/92 10/13/92 C/SRXB:DSSA


C/OEAB:DORS
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/OGC B:DORS  D/DORS


OGCB:DORS
RJones*          AChaffee*      JBirmingham* JLieberman* GMarc us*        BGrimes


OE AzK C/OGCB:DORS
10/08/92        11/09/92        12/11/92      12/09/92      12/11 /92      12/ /92 DOCUMENT NAME E: G:\DMG\INDEBRIS.DMG


RJones* AChaffee*
*SEE PREVIOUS CONCURRENCE
JBirmingham


JLieberman
OEAB:DORS      ASC/OEAB:DORS        ADM:RPB    PM:PD2-1:DRPE


GMarcus 10/08/92 11/09/92 12/ /92 12/f /92 12/ /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG
DGarcia*      AGautam*            JMain*      BMozafari*
10/07/92       10/14/92             09/28/92   10/13/92 C/SRXB:DSSA    C/OEAB:DORS          C/OGCB:DORS D/DORS


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


debris. The location and size of the recovered Delrin-AF
10/08/92      11/09/92              / /92      / /92 DOCUMENT NAME:  G:\DMG\INDEBRIS.DMG


material agrees with the material migration
IN 92-XX


theory since all of the pieces were larger than those recovered
November xx, 1992 Related Generic Communication


from the B SI pump in July and August.The licensee inspected
On November 21, 1989, the NRC issued Information Notice (IN)89-77, 'Debris In


orifices for the SI pump minimum flow recirculation
Containment Emergency Sumps and Incorrect Screen Configurations," in which it


lines, and visually inspected
discussed problems that could result from debris found in containment


piping, tanks, and components
emergency sumps.


to find and remove any foreign material.
This information notice requires no specific action or written response. If


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


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


effect on other ECCS equipment
Reactor Regulation (NRR) project manager.


and concluded
Brian K. Grimes, Director


that the ECCS equipment
Division of Operating Reactor Support


would continue to be operable and reliable.7-1- t-The staff notes thatl$resence
Office of Nuclear Reactor Regulation


of small debris may not be detected by operational
Technical contacts:    D. Garcia, NRR


or post-modification
(301) 504-1170
Attachment:
List of Recently Issued NRC Information Notices


testing since blockages
*SEE PREVIOUS CONCURRENCE


may not appear immediately.
OEAB:DORS      ASC/OEAB:DORS          ADM:RPB        PM:PD2-1:DRPE


However, small debris may migrate into areas with smaller cross sections where the debris can collect and cause blockage after extended operation.
DGarcia*      AGautam*                JMain*          BMozafari*
10/07/92        10/14/92              09/28/92        10/13/92 C/SRXB:DSSA    C/OE f DORS            C/OGCB:DORS    D/DORS


Whenever safety systems are opened, it is important
RJones*        AChaffee                GMarcus        BGrimes


to ensure accountability
10/08/92        Il /.ci/92                / /92 I        / /92 DOCUMENT NAME:  G:\DMG\INDEBRIS.DMC


of any materials
IN 92-XX


that are used and to perform'cleanliness
October xx, 1992 Related Generic Communication


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


On November 21, 1989, the NRC issued Information
Containment Emergency Sumps and Incorrect Screen Configurations," in which it


Notice (IN) 89-77, "Debris In Containment
discussed problems that could result from debris found in containment


Emergency
emergency sumps.


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


Screen Configurations," which addressed
you have any questions about the information in this notice, please contact


problems that could result from debris in containment
the technical contact listed below or the appropriate Office of Nuclear


emergency sumps.This information
Reactor Regulation (NRR) project manager.


notice requires no specific action or written response.
Brian K. Grimes, Director


If you have any questions
Division of Operating Reactor Support


about the information
Office of Nuclear Reactor Regulation
 
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
Technical


cor Attachment:
(301) 504-1170
*SEE PREVIOUS OEAB:DORS DGarcia*10/07/92 C/SRXB:DSSA
Attachment:


RJones*10/08/92 DOCUMENT NAME itact: Eric Benner, NRR (301) 504-1171 List of Recently Issued NRC Information
===List of Recently Issued NRC Information Notices===
 
===Notices CONCURRENCE===
ASC/OEAB:DORS
 
ADM:RPB PM:PD2-1:DRPE
 
AGautam* 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
 
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       ASC/OEAB:DgRS        ADM:RPB        PM:PD2-1:DRPE


AGautam*10/14/92 ADM:RPB JMain*09/28/92 PM:PD2-1:DRPE
DGarcia*   /cLAGautamOC            JMain*          BMozafari*
10/07/92       /6 //~/92            09/28/92       10/13/92 C/SRXB:DSSA    C/OEAB:DORS          C/OGCB:DORS    D/DORS


BMozafari*
RJones*         AChaffee            GMarcus        BGrimes
10/13/92 C/SRXB:DSSA


RJones*10/08/92 DOCUMENT NAME: C/OEAB:DORS
10/08/92          / /92                / /92          / /92 DOCUMENT NAME:   G:\DEBRIS.DMG


C/OGCB:DORS
IN 92-XX


AChaffee*
October xx, 1992 Related Generic Communication
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


On November 21, 1989, the NRC issued Information
Containment Emergency Sumps and Incorrect Screen Configurations,' in which it


Notice (IN) 89-77, 'Debris In Containment
discussed problems that could result from debris found in containment


Emergency
emergency sumps.


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


Screen Configurations," in which it discussed
you have any questions about the information in this notice, please contact


problems that could result from debris found in containment
the technical contact listed below or the appropriate Office of Nuclear


emergency
Reactor Regulation (NRR) project manager.


sumps.This information
Brian K. Grimes, Director


notice requires no specific action or written response.
Division of Operating Reactor Support


If you have any questions
Office of Nuclear Reactor Regulation


about the information
Technical contacts:  Denise M. Garcia, NRR


in this notice, please contact the technical
(301) 504-1170
Attachment:


contact listed below or the appropriate
===List of Recently Issued NRC Information Notices===
 
*SEE PREVIOUS CONCURRENCE
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 AChaffee Il /.ci/92 C/OGCB:DORS
 
GMarcus/ /92 I D/DORS BGrimes/ /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.
0    :  RS    ASC/OEAB:DORS        ADM:RPB        PM:PD2-1 :DRP  fl,_fv, AGautam              JMain*          BMozafari


If you have any questions
,92          / /92              09/28/92      /0//13/92 C/        SA  C/OEAB:DORS          C/OGCB:DORS    D/DORS


about the information
RJon'es        AChaffee            GMarcus        BGrimes


in this notice, please contact the technical
/0/1(/92        / /92                / /92            / /92 DOCUMENT NAME:  G:\DEBRIS.DMG


contact listed below or the appropriate
This information notice requires no specific action or written response. If


Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating
you have any questions about the information in this notice, please contact


===Reactor Support Office of Nuclear Reactor Regulation===
the technical contact listed below or the appropriate Office of Nuclear
Technical


contacts: D. Garcia, NRR (301) 504-1170 Attachment:
Reactor Regulation (NRR) project manager.
List of Recently Issued NRC Information


Notices*SEE PREVIOUS CONCURRENCE
Charles E. Rossi, Director


OEAB:DORS DGarcia*10/07/92 ASC/OEAB:DgRS
Division of Operational Events Assessment


/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 : RS ,92 C/ SA RJon'es/0 /1(/92 CONCURRENCE
ASC/OEAB:DORS
AGautam/ /92 C/OEAB:DORS
AChaffee/ /92 ADM:RPB JMain*09/28/92 C/OGCB:DORS
GMarcus/ /92 PM:PD2-1 :DRP fl,_fv, BMozafari/0//13/92 D/DORS BGrimes/ /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 Reactor Regulation (NRR) project manager.Charles E. Rossi, Director Division of Operational
===Events Assessment===
Office of Nuclear Reactor Regulation
Office of Nuclear Reactor Regulation


Technical
Technical contacts:  Denise M. Garcia, NRR


contacts: Denise M. Garcia, NRR (301) 504-1171 Attachment:
(301) 504-1171 Attachment:
List of Recently Issued NRC Information


Notices OEAB:DOEA DGarcia/ /92 SC/OEAB:DOEA
===List of Recently Issued NRC Information Notices===
OEAB:DOEA     SC/OEAB:DOEA         ADM:RPB        PM:PD2-1:DRPE


AGautam/ /92 ADM:RPB JMain Q h 9/ 2J /f2 PM:PD2-1:DRPE
DGarcia        AGautam               JMain Q h     BMozafari


BMozafari/ /92 C/SRXB:DST
/ /92          / /92                9/ 2J /f2      / /92 C/SRXB:DST     C/OEAB:DOEA          C/OGCB:DOEA  D/DOEA


RJones/ /92 C/OEAB:DOEA
RJones         AChaffee              GMarcus      CRossi


AChaffee/ /92 C/OGCB:DOEA
/ /92         / /92                / /92          / /92 DOCUMENT NAME:  G:\DEBRIS.DMG


GMarcus/ /92 D/DOEA CRossi/ /92 DOCUMENT NAME: G:\DEBRIS.DMG
K-)
                                  UNITED STATES


K-)UNITED STATES NUCLEAR REGULATORY
NUCLEAR REGULATORY COMMISSION


COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION


===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C. 20555 December 23, 1992 NRC INFORMATION NOTICE 92-85:    POTENTIAL FAILURES OF EMERGENCY CORE COOLING
WASHINGTON, D.C. 20555 December 23, 1992 NRC INFORMATION


NOTICE 92-85: POTENTIAL
SYSTEMS CAUSED BY FOREIGN MATERIAL BLOCKAGE
 
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


permits for nuclear power reactors.
reactors.


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


Commission (NRC) is issuing this information
notice to alert addressees to the potential failure of emergency core cooling


notice to alert addressees
systems (ECCS) caused by foreign material blockage. It is expected that


to the potential
recipients will review the information for applicability to their facilities


failure of emergency
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.


core cooling systems (ECCS) caused by foreign material blockage.
==Description of Circumstances==


It is expected that recipients
===H. B. Robinson Unit 2===
On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot


will review the information
shutdown, plant personnel were performing an operations surveillance test of


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


to their facilities
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


and consider actions, as appropriate, to avoid similar problems.
Company (the licensee) retested this pump on August 24, 1992, and found no


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


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


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


notice are not NRC requirements;
On August 25, 1992, the licensee opened the B SI pump recirculation line and
therefore, no specific action or written response is required.Description


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


H. B. Robinson Unit 2 On August 23, 1992, while the H. B. Robinson Nuclear Plant was in mode 4, hot shutdown, plant personnel
inline orifice.


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


an operations
inoperable after a quarterly inservice inspection surveillance test found that


surveillance
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.


test of the B safety injection (SI) pump. This test found that the recirculation
The licensee removed the recirculation line for the B SI pump and found that


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)
debris was obstructing the inline orifice.
retested this pump on August 24, 1992, and found no recirculation


flow. The licensee also tested the A SI pump and found the recirculation
9212  0209


flow was 10 percent lower than when it was last measured.
<-2                    <off92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying that


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


and took the unit to cold shutdown.On August 25, 1992, the licensee opened the B SI pump recirculation
the unit to service. The licensee also tested all other ECCS pumps that could


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


after a quarterly
startup, that all debris had been removed.


inservice
===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


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


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


test found that it was producing
abnormal noise. The test was stopped and the pump was declared inoperable.


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


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


the cause of the low flow.The licensee removed the recirculation
test was successfully completed and the pump was declared operable.


line for the B SI pump and found that debris was obstructing
Discussion


the inline orifice.9212 0209
The licensee at H. B. Robinson determined that the foreign material found in
<-2 <off92-85 December 23, 1992 On July 12, 1992, after flushing the B SI pump and verifying


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


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


The licensee believed, prior to plant startup, that all debris had been removed.Point Beach Unit 2 On September
June 1992. The plastic material is manufactured by DuPont and the trade name


28, 1992, the Wisconsin
is Delrin-AF. At the time of the RHR modification, the plastic material had


Electric Power Company (the licensee)performed
been cut into four 23-centimeter (9-inch] diameter, circular pieces for use as


an ASME Section XI quarterly
weld purge dams. However, after completing the modification, the licensee did


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


spray pumps and valves. During the test, the licensee noted that the discharge
conditions because of reaction with the water and thermal degradation. The


pressure for the A train containment
licensee suspected that the purge dam pieces broke, entered the RHR piping


spray pump was zero and that the pump was making an abnormal noise. The test was stopped and the pump was declared inoperable.
after breaking, and migrated into the refueling water storage tank (RWST) and


Upon disassembly
SI header during initial cavity draindown.


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


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


and the pump was declared operable.Discussion
pieces of miscellaneous debris. The location and size of the recovered


The licensee at H. B. Robinson determined
Delrin-AF material agrees with the material migration theory since all of the


that the foreign material found in the SI system was a plastic material that had been used during a modification
pieces were larger than those recovered from the B SI pump in July and August.


of the Residual Heat Removal (RHR) system performed
The licensee inspected orifices for the SI pump minimum flow recirculation


in March through June 1992. The plastic material is manufactured
lines and also visually inspected piping, tanks, and components to find and


by DuPont and the trade name is Delrin-AF.
remove any foreign material. Also, the licensee evaluated the potential


At the time of the RHR modification, the plastic material had been cut into four 23-centimeter
effect on other ECCS equipment and concluded that the ECCS equipment would


(9-inch] diameter, circular pieces for use as weld purge dams. However, after completing
continue to be operable and reliable.


the modification, the licensee did not account for two of the four pieces. Delrin-AF
IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined that


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


at RCS system conditions
install full flow test lines in the RHR, containment spray and safety


because of reaction with the water and thermal degradation.
injection systems, during the 1991 refueling outage. The NRC reviewed the


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


that the purge dam pieces broke, entered the RHR piping after breaking, and migrated into the refueling
rendered inoperable in the recirculation mode because of the presence of the


water storage tank (RWST) and SI header during initial cavity draindown.
plug. This condition had continued for about a year and was caused by


The licensee sent divers with cameras into the RWST to inspect for the plastic. The divers found three fragments
inadequate foreign material exclusion controls during the system modifications


of Delrin-AF
made in the previous outage.


plastic and also other pieces of miscellaneous
The presence of small debris may not be detected by operational or post


debris. The location and size of the recovered Delrin-AF
modification testing since blockages may not appear immediately. However, small debris may migrate into areas with smaller cross sections where the


material agrees with the material migration
debris could collect and cause blockage after extended operation. These


theory since all of the pieces were larger than those recovered
examples illustrate the consequences of failure to ensure accountability of


from the B SI pump in July and August.The licensee inspected
all materials that are used when safety systems are opened and to perform


orifices for the SI pump minimum flow recirculation
cleanliness checks of all affected areas prior to system closure.


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


piping, tanks, and components
Containment Emergency Sumps and Incorrect Screen Configurations," which


to find and remove any foreign material.
addressed problems that could result from debris in containment emergency


Also, the licensee evaluated
sumps.


the potential effect on other ECCS equipment
This information notice requires no specific action or written response. If


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


that the ECCS equipment
the technical contact listed below or the appropriate Office of Nuclear


would continue to be operable and reliable.
Reactor Regulation (NRR) project manager.


IN 92-85 December 23, 1992 The licensee for Point Beach Unit 2 reviewed plant records and determined
rnan K. Grimes, Director


that the plug was most likely left in the piping after modifications
Division of Operating Reactor Support


were made to install full flow test lines in the RHR, containment
Office of Nuclear Reactor Regulation
 
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
Technical contact:  Eric Benner, NRR


Notice (IN) 89-77, "Debris In Containment
(301) 504-1171 Attachment:  List of Recently Issued NRC Information Notices


Emergency
l


Sumps and Incorrect
I    1 K"
I


Screen Configurations," which addressed
K-,
                                                            Attachment


problems that could result from debris in containment
IN 92-85 December 23, 1992 LIST OF RECENTLY ISSUED


emergency sumps.This information
NRC INFORMATION NOTICES


notice requires no specific action or written response.
Information                                    Date of


If you have any questions
Notice No.            Subject                Issuance  Issued to


about the information
92-84          Release of Patients            12/17/92  All Nuclear Regulatory


in this notice, please contact the technical
Treated with Temporary                    Commission Medical


contact listed below or the appropriate
Implants                                  Licensees.


Office of Nuclear Reactor Regulation (NRR) project manager.rnan K. Grimes, Director Division of Operating
88-23,         Potential for Gas              12/18/92  All holders of OLs or CPs


===Reactor Support Office of Nuclear Reactor Regulation===
Supp. 4        Binding of High-Pres-                      for nuclear power reactors.
Technical


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


Notices
Pumps during A Design


l I 1 K" K-, I Attachment
Basis Accident


IN 92-85 December 23, 1992 LIST OF RECENTLY ISSUED NRC INFORMATION
92-83          Thrust Limits for              12/17/92  All holders of OLs or CPs


NOTICES Information
Limitorque Actuators                      for nuclear power reactors.


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
and Potential Over- stressing of Motor- Operated Valves


for Gas Binding of High-Pres- sure Safety Injection Pumps during A Design Basis Accident Thrust Limits for Limitorque
92-82          Results of Thermo-Lag          12/15/92  All holders of OLs or CPs


Actuators and Potential
330-1 Combustibility                      for nuclear power reactors.


Over-stressing
Testing


of Motor-Operated Valves Results of Thermo-Lag
92-81          Potential Deficiency            12/11/92  All holders of OLs or CPs


330-1 Combustibility
of Electrical Cables                      for nuclear power reactors.


Testing Potential
with Bonded Hypalon


Deficiency
Jackets


of Electrical
92-80          Results of Thermo-Lag          12/07/92  All holders of OLs or CPs


Cables with Bonded Hypalon Jackets Results of Thermo-Lag
330-1 Combustibility                      for nuclear power reactors.


330-1 Combustibility
Testing


Testing Non-Power
92-79          Non-Power Reactor              12/01/92  All holders of OLs or CPs


Reactor Emergency
Emergency Event Response                  for test and research


Event Response Piston to Cylinder Liner Tin Smearing on Cooper-Bessemer
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
92-78          Piston to Cylinder              11/30/92   All holders of OLs or CPs


Commission
Liner Tin Smearing on                      for nuclear power reactors.


Medical Licensees.
Cooper-Bessemer KSV


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
Diesel Engines


License CP = Construction
OL = Operating License


Permit}}
CP = Construction Permit}}


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

Revision as of 02:24, 24 November 2019

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 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 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

z

C

D --

Attachment

IN 92-85 z-4 December 23, 1992 V Page I of 1

0

a

z

-_ _

11 LIST OF RECENTLY ISSUED

0

NRCINFORMATION NOTICES

>n

V

0-4U Information Vate of

-v Notice No. Subject Issuance Issued to

cmm

z 0 Cfl

U1 92-84 Release of Patients

Treated with Temporary

Implants

12/17/92 All Nuclear Regulatory

Comnission Medical

Licensees.

(

Ca/ 88-23, Potential for Gas 12/18/92 All holders of OLs or CPs

Supp. 4 Binding of High-Pres- for nuclear power reactors

sure Safety Injection

Pumps during A Design

z Basis Accident

92-83 Thrust Limits for 12/17/92 All holders of OLs or CPs

Limitorque Actuators for nuclear power reactors

and Potential Over- stressing of Motor- Operated Valves

92-82 Results of Thermo-Lag 12/15/92 All holders of OLs or CPs

330-1 Combustibility for nuclear power reactors

Testing

92-81 Potential Deficiency 12/11/92 All holders of OLs or CPs

of Electrical Cables for nuclear power reactors.

with Bonded Hypalon

Jackets

92-80 Results of Thermo-Lag 12/07/92 All holders of OLs or CPs

330-1 Combustibility for nuclear power reactors.

Testing

92-79 Non-Power Reactor 12/01/92 All holders of OLs or CPs(

Emergency Event Response for test and research

reactors.

92-78 Piston to Cylinder 11/30/92 All holders of OLs or CPs

Liner Tin Smearing on for nuclear power reactors.

Cooper-Bessemer KSV

Diesel Engines

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 11/09/92 12////92 ~/' 2/09/92 12/1i/927 12/ /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG

' J

4 I K)

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 D/DORS

RJones* AChaffee* JBirmingham JLieberman GMarcus BGrimes

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

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 coritact: 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/OGC B:DORS D/DORS

RJones* AChaffee* JBirmingham* JLieberman* GMarc us* BGrimes

10/08/92 11/09/92 12/11/92 12/09/92 12/11 /92 12/ /92 DOCUMENT NAME E: G:\DMG\INDEBRIS.DMG

  • 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 C/OGCB:DORS D/DORS

RJones* AChaffee* GMarcus BGrimes

10/08/92 11/09/92 / /92 / /92 DOCUMENT NAME: G:\DMG\INDEBRIS.DMG

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 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/OE f DORS C/OGCB:DORS D/DORS

RJones* AChaffee GMarcus BGrimes

10/08/92 Il /.ci/92 / /92 I / /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 ASC/OEAB:DgRS ADM:RPB PM:PD2-1:DRPE

DGarcia* /cLAGautamOC JMain* BMozafari*

10/07/92 /6 //~/92 09/28/92 10/13/92 C/SRXB:DSSA C/OEAB:DORS C/OGCB:DORS D/DORS

RJones* AChaffee GMarcus BGrimes

10/08/92 / /92 / /92 / /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 CONCURRENCE

0  : RS ASC/OEAB:DORS ADM:RPB PM:PD2-1 :DRP fl,_fv, AGautam JMain* BMozafari

,92 / /92 09/28/92 /0//13/92 C/ SA C/OEAB:DORS C/OGCB:DORS D/DORS

RJon'es AChaffee GMarcus BGrimes

/0/1(/92 / /92 / /92 / /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

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 SC/OEAB:DOEA ADM:RPB PM:PD2-1:DRPE

DGarcia AGautam JMain Q h BMozafari

/ /92 / /92 9/ 2J /f2 / /92 C/SRXB:DST C/OEAB:DOEA C/OGCB:DOEA D/DOEA

RJones AChaffee GMarcus CRossi

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

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"

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K-,

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 Release of Patients 12/17/92 All Nuclear Regulatory

Treated with Temporary Commission Medical

Implants Licensees.

88-23, Potential for Gas 12/18/92 All holders of OLs or CPs

Supp. 4 Binding of High-Pres- for nuclear power reactors.

sure Safety Injection

Pumps during A Design

Basis Accident

92-83 Thrust Limits for 12/17/92 All holders of OLs or CPs

Limitorque Actuators for nuclear power reactors.

and Potential Over- stressing of Motor- Operated Valves

92-82 Results of Thermo-Lag 12/15/92 All holders of OLs or CPs

330-1 Combustibility for nuclear power reactors.

Testing

92-81 Potential Deficiency 12/11/92 All holders of OLs or CPs

of Electrical Cables for nuclear power reactors.

with Bonded Hypalon

Jackets

92-80 Results of Thermo-Lag 12/07/92 All holders of OLs or CPs

330-1 Combustibility for nuclear power reactors.

Testing

92-79 Non-Power Reactor 12/01/92 All holders of OLs or CPs

Emergency Event Response for test and research

reactors.

92-78 Piston to Cylinder 11/30/92 All holders of OLs or CPs

Liner Tin Smearing on for nuclear power reactors.

Cooper-Bessemer KSV

Diesel Engines

OL = Operating License

CP = Construction Permit


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