Information Notice 1992-35, Higher than Predicted Erosion/Corrosion in Unisolable Reactor Coolant Pressure Boundary Piping Inside Containment at a Boiling Water Reactor: Difference between revisions

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| issue date = 05/06/1992
| issue date = 05/06/1992
| title = Higher than Predicted Erosion/Corrosion in Unisolable Reactor Coolant Pressure Boundary Piping Inside Containment at a Boiling Water Reactor
| title = Higher than Predicted Erosion/Corrosion in Unisolable Reactor Coolant Pressure Boundary Piping Inside Containment at a Boiling Water Reactor
| author name = Rossi C E
| author name = Rossi C
| author affiliation = NRC/NRR
| author affiliation = NRC/NRR
| addressee name =  
| addressee name =  
Line 13: Line 13:
| document type = NRC Information Notice
| document type = NRC Information Notice
| page count = 5
| page count = 5
| revision = 0
}}
}}
{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555May 6, 1992NRC INFORMATION NOTICE 92-35: HIGHER THAN PREDICTED EROSION/CORROSION INUNISOLABLE REACTOR COOLANT PRESSURE BOUNDARYPIPING INSIDE CONTAINMENT AT A BOILINGWATER REACTOR
{{#Wiki_filter:UNITED STATES
 
NUCLEAR REGULATORY COMMISSION
 
OFFICE OF NUCLEAR REACTOR REGULATION
 
WASHINGTON, D.C. 20555 May 6, 1992 NRC INFORMATION NOTICE 92-35:   HIGHER THAN PREDICTED EROSION/CORROSION IN
 
UNISOLABLE REACTOR COOLANT PRESSURE BOUNDARY
 
PIPING INSIDE CONTAINMENT AT A BOILING
 
WATER REACTOR


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


==Purpose==
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information noticeto alert addressees to erosion/corrosion rates that could be higher thanpredicted in certain unisolable reactor coolant pressure boundary piping insidethe containment drywell at boiling water reactors. It is expected that recip-ients will review the information for applicability to their facilities andconsider actions, as appropriate, to avoid similar problems. However, sugges-tions contained in this information notice are not NRC requirements; therefore,no specific action or written response is required.
notice
 
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information     than
 
to alert addressees to erosion/corrosion rates that could     be higher
 
piping inside
 
predicted in certain unisolable reactor coolant pressure boundary that recip- the containment drywell at boiling water reactors.     It is expected
 
and
 
ients will review the information for applicability to their facilities sugges- consider actions, as appropriate, to avoid similar   problems.     However, therefore, tions contained in this information notice are not NRC requirements;
no specific action or written response is   required.


==Description of Circumstances==
==Description of Circumstances==
The Pennsylvania Power and Light Company (the licensee) recently performederosion/corrosion inspections at the Susquehanna Steam Electric Station, Unit1, and may have identified an unexpectedly high rate of erosion/corrosion incertain main feedwater (FW) piping inside containment (Attachment 1). Erosionof this portion of FW piping is of particular concern since this portioncannot be isolated from the reactor vessel, and erosion/corrosion inspectionstrategies may not direct attention to that part of the FW system.When the licensee began operating the unit commercially in June 1982, thenominal wall thickness for the pipe was about 0.688 inch. During the currentrefueling outage, wall thinning was found in one of the 20 inch by 12 inchreducing tee risers approximately 10 inches downstream from the tee in the 12inch pipe section, immediately above a circumferential pipe weld. During theprevious refueling outage (18 months ago) the licensee had measured the pipewall as 0.619 inch thick at that location. During the current refuelingoutage, the licensee measured a thickness of 0.521 inch at the same location.The licensee measured a thickness of 0.482 inch within about 2 inches of thatlocation. The licensee calculated a minimum allowable wall thickness of 0.440inch for that portion of FW pipe. Previous experience and models had indicatedan erosion wear rate of no more than 0.085 inch each cycle. However, the most9205010009 r& / A EC /i'-'- 9 /JA J20'o IN 92-35May 6, 1992 recent measurement indicates a higher wear rate that may be greater than 0.100inch each cycle.The licensee evaluated the data for the FW system and determined that continuedoperation could not be justified for another fuel cycle. Therefore, thelicensee repaired, rather than replaced, the FW pipe in accordance with SectionXI of the American Society of Mechanical Engineers (ASME) Boiler and PressureVessel Code.DiscussionThe licensee determined that although it had expected to find erosion/corrosionat this location, the magnitude of wall thinning exceeded expectations. Thelicensee is continuing its investigation to determine the root cause of theunexpected erosion/corrosion rate.Related Generic CommunicationsFollowing a pipe rupture at the Surry Power Station in 1986, the NRC issuedBulletin 87-01, "Thinning of Pipe Walls in Nuclear Power Plants," July 9, 1987.In this bulletin, the staff requested licensees and applicants to inform theNRC about their programs for monitoring the wall thickness of carbon steelpiping in both safety-related and nonsafety-related high energy fluidsystems.In 1989, following an audit of the erosion/corrosion programs at 10 plants,the NRC issued Generic Letter (GL) 89-08, "Erosion/Corrosion-Induced Pipe WallThinning," May 2, 1989. In this generic letter, the staff requested licenseesand applicants to implement long term erosion/corrosion monitoring programs.The staff made this request to obtain assurances that the addressees had imple-mented procedures or administrative controls to maintain the structural integrityof all carbon steel systems carrying high energy fluids.The NRC also issued several information notices on the subject of erosion/corrosio IN 92-35May 6, 1992 This information notice requiresyou have any questions about theof the technical contacts listedReactor Regulation (NRR) projectno specific action or written response. Ifinformation in this notice, please contact onebelow or the appropriate Office of Nuclearmanager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contacts:K. I. Parczewski, NRR(301) 504-2705S. Barber, Region I(717) 542-2134David(301)Gamberoni, NRR504-1171John White, Region I(215) 337-5114
performed
 
The Pennsylvania Power and Light Company (the licensee) recently Station,          Unit
 
erosion/corrosion inspections at   the Susquehanna Steam   Electric
 
unexpectedly high rate of erosion/corrosion       in
 
1, and may have identified an                                            1). Erosion
 
certain main feedwater (FW) piping inside containment (Attachment portion
 
of this portion of FW piping is of particular concern since   this
 
cannot be isolated from the reactor vessel, and erosion/corrosion inspection
 
strategies may not direct attention to that part of the FW system.
 
the
 
When the licensee began operating the unit commercially in June 1982, current
 
nominal wall thickness for the pipe was about 0.688 inch. During         the
 
refueling outage, wall thinning was found in one of the 20 inch by 12 inch 12 reducing tee risers approximately 10 inches downstream from the tee During  in the
 
pipe  weld.              the
 
inch pipe section, immediately above a circumferential
 
had  measured    the  pipe
 
previous refueling outage (18 months ago) the licensee
 
wall as 0.619 inch thick at that location. During the current refueling
 
outage, the licensee measured a thickness of 0.521 inch at the same location. of that
 
The licensee measured a thickness of 0.482 inch within about 2 inches of 0.440
  location. The licensee calculated a minimum allowable wall       thickness
 
indicated
 
inch for that portion of FW pipe. Previous experience and models had the most
 
an erosion wear rate of no more than 0.085 inch each cycle.       However,
  9205010009              Ar& EC                  9                        /           /JA J20'o
 
/i'-'-
 
IN 92-35 May 6, 1992 recent measurement indicates a higher wear rate that may be greater than 0.100
inch each cycle.
 
The licensee evaluated the data for the FW system and determined that continued
 
operation could not be justified for another fuel cycle. Therefore, the
 
licensee repaired, rather than replaced, the FW pipe in accordance with Section
 
XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure
 
Vessel Code.
 
Discussion
 
The licensee determined that although it had expected to find erosion/corrosion
 
at this location, the magnitude of wall thinning exceeded expectations. The
 
licensee is continuing its investigation to determine the root cause of the
 
unexpected erosion/corrosion rate.
 
Related Generic Communications
 
Following a pipe rupture at the Surry Power Station in 1986, the NRC issued
 
Bulletin 87-01, "Thinning of Pipe Walls in Nuclear Power Plants," July 9, 1987.
 
In this bulletin, the staff requested licensees and applicants to inform the
 
NRC about their programs for monitoring the wall thickness of carbon steel
 
piping in both safety-related and nonsafety-related high energy fluid
 
systems.
 
In 1989, following an audit of the erosion/corrosion programs at 10 plants, the NRC issued Generic Letter (GL) 89-08, "Erosion/Corrosion-Induced Pipe Wall
 
Thinning," May 2, 1989. In this generic letter, the staff requested licensees
 
and applicants to implement long term erosion/corrosion monitoring programs.
 
The staff made this request to obtain assurances that the addressees had imple- mented procedures or administrative controls to maintain the structural integrity
 
of all carbon steel systems carrying high energy fluids.
 
The NRC also issued several information notices on the subject of erosion/
corrosion.
 
IN 92-35 May 6, 1992 This information notice requires  no specific action or written response. If
 
you have any questions about the  information in this notice, please contact one
 
of the technical contacts 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: K. I. Parczewski, NRR       S. Barber, Region I
 
(301) 504-2705              (717) 542-2134 David Gamberoni, NRR        John White, Region I
 
(301) 504-1171              (215) 337-5114 Attachments:
1. Feedwater System Erosion/Corrosion Location
 
2. List of Recently Issued NRC Information Notices
 
II*
                      REACTOR                              REACTOR
 
REACTOR
 
VESSEL                VESSEL                              VESSEL
 
24' X 12- FLOW
 
l                      -
                                  20 X 12'
                                  REDUCING
 
REDUCING
 
TEE
 
o-            I A -
                                                                                    r--,
                      1, I                    I--O      l  lI                  7
                                      20-      24 X 20-                24-
        12- 20- X 12'
            REDUCER                            REDUCER
 
"BP
 
FEEDWATER
 
LINE
 
EROSION/
                          CORROSI ON
 
ZONE
 
1    I    FLOW
 
20" X 12"
                                            REDUCING
 
TEE
 
FLOW                                            (D      'OOb
 
co        rr
 
'0      r-%.
 
FEEDWATER SYSTEM EROSION/CORROSION LOCATION                                            "-I"
 
Attachment 2 IN 92-35 May 6, 1992 LIST OF RECENTLY ISSUED
 
NRC INFORMATION NOTICES
 
Information                                      Date of
 
Notice No.            Subject                    Issuance  Issued to
 
92-34          New Exposure Limits for          05/06/92  All licensees whose opera- Airborne Uranium and                      tions can cause airborne
 
Thorium                                    concentrations of uranium
 
and thorium.
 
92-33          Increased Instrument            04/30/92  All holders of OLs or CPs
 
Response Time When                          for nuclear power reactors.
 
Pressure Dampening
 
Devices are Installed
 
92-32          Problems Identified with        04/29/92  All holders of OLs or CPs
 
Emergency Ventilation                      for nuclear power reactors.
 
Systems for Near-Site
 
(Within 10 Miles) Emer- gency Operations Facili- ties and Technical Support
 
Centers
 
92-31          Electrical Connection            04/27/92  All holders of OLs or CPs
 
Problem in Johnson                          for nuclear power reactors.
 
Yokogawa Corporation
 
YS-80 Programmable Indi- cating Controllers
 
92-30          Falsification of Plant          04/23/92  All holders of OLs or CPs
 
Records                                    for nuclear power reactors
 
and all licensed operators
 
and senior operators.
 
92-21,          Spent Fuel Pool Re-              04/22/92  All holders of OLs or CPs
 
Supp. 1        activity Calculations                      for nuclear power reactors.
 
92-29          Potential Breaker Mis-          04/17/92  All holders of OLs or CPs
 
coordination Caused by                    for nuclear power reactors.
 
Instantaneous Trip
 
Circuitry
 
OL = Operating License


===Attachments:===
CP = Construction Permit}}
1. Feedwater System2. List of RecentlyErosion/Corrosion LocationIssued NRC Information Notices II*REACTORVESSELl12- 20- X 12'REDUCERREACTORVESSEL20 X 12'-REDUCING1, I I--OREACTORVESSEL24' X 12-REDUCINGTEEo- IFLOWIl l7r--, A -20-24 X 20-REDUCER24-"BPFEEDWATERLINEEROSION/CORROSI ONZONE1I FLOW20" X 12"REDUCINGTEEFLOWFEEDWATER SYSTEM EROSION/CORROSION LOCATION(D 'OObco rr'0 r-%."-I" Attachment 2IN 92-35May 6, 1992 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to92-3492-3392-32New Exposure Limits forAirborne Uranium andThoriumIncreased InstrumentResponse Time WhenPressure DampeningDevices are InstalledProblems Identified withEmergency VentilationSystems for Near-Site(Within 10 Miles) Emer-gency Operations Facili-ties and Technical SupportCentersElectrical ConnectionProblem in JohnsonYokogawa CorporationYS-80 Programmable Indi-cating ControllersFalsification of PlantRecordsSpent Fuel Pool Re-activity CalculationsPotential Breaker Mis-coordination Caused byInstantaneous TripCircuitry05/06/9204/30/9204/29/9204/27/9204/23/9204/22/9204/17/92All licensees whose opera-tions can cause airborneconcentrations of uraniumand thorium.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.92-3192-3092-21,Supp. 192-29Allforandandholders of OLs or CPsnuclear power reactorsall licensed operatorssenior operators.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.OL = Operating LicenseCP = Construction Permit}}


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

Latest revision as of 03:22, 24 November 2019

Higher than Predicted Erosion/Corrosion in Unisolable Reactor Coolant Pressure Boundary Piping Inside Containment at a Boiling Water Reactor
ML031200365
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, 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, Three Mile Island, 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, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, 05000370  Entergy icon.png
Issue date: 05/06/1992
From: Rossi C
Office of Nuclear Reactor Regulation
To:
References
IN-92-035, NUDOCS 9205010009
Download: ML031200365 (5)
v • d • e


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 May 6, 1992 NRC INFORMATION NOTICE 92-35: HIGHER THAN PREDICTED EROSION/CORROSION IN

UNISOLABLE REACTOR COOLANT PRESSURE BOUNDARY

PIPING INSIDE CONTAINMENT AT A BOILING

WATER REACTOR

Addressees

power

All holders of operating licenses or construction permits for nuclear

reactors.

Purpose

notice

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

to alert addressees to erosion/corrosion rates that could be higher

piping inside

predicted in certain unisolable reactor coolant pressure boundary that recip- the containment drywell at boiling water reactors. It is expected

and

ients will review the information for applicability to their facilities sugges- consider actions, as appropriate, to avoid similar problems. However, therefore, tions contained in this information notice are not NRC requirements;

no specific action or written response is required.

Description of Circumstances

performed

The Pennsylvania Power and Light Company (the licensee) recently Station, Unit

erosion/corrosion inspections at the Susquehanna Steam Electric

unexpectedly high rate of erosion/corrosion in

1, and may have identified an 1). Erosion

certain main feedwater (FW) piping inside containment (Attachment portion

of this portion of FW piping is of particular concern since this

cannot be isolated from the reactor vessel, and erosion/corrosion inspection

strategies may not direct attention to that part of the FW system.

the

When the licensee began operating the unit commercially in June 1982, current

nominal wall thickness for the pipe was about 0.688 inch. During the

refueling outage, wall thinning was found in one of the 20 inch by 12 inch 12 reducing tee risers approximately 10 inches downstream from the tee During in the

pipe weld. the

inch pipe section, immediately above a circumferential

had measured the pipe

previous refueling outage (18 months ago) the licensee

wall as 0.619 inch thick at that location. During the current refueling

outage, the licensee measured a thickness of 0.521 inch at the same location. of that

The licensee measured a thickness of 0.482 inch within about 2 inches of 0.440

location. The licensee calculated a minimum allowable wall thickness

indicated

inch for that portion of FW pipe. Previous experience and models had the most

an erosion wear rate of no more than 0.085 inch each cycle. However,

9205010009 Ar& EC 9 / /JA J20'o

/i'-'-

IN 92-35 May 6, 1992 recent measurement indicates a higher wear rate that may be greater than 0.100

inch each cycle.

The licensee evaluated the data for the FW system and determined that continued

operation could not be justified for another fuel cycle. Therefore, the

licensee repaired, rather than replaced, the FW pipe in accordance with Section

XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure

Vessel Code.

Discussion

The licensee determined that although it had expected to find erosion/corrosion

at this location, the magnitude of wall thinning exceeded expectations. The

licensee is continuing its investigation to determine the root cause of the

unexpected erosion/corrosion rate.

Related Generic Communications

Following a pipe rupture at the Surry Power Station in 1986, the NRC issued

Bulletin 87-01, "Thinning of Pipe Walls in Nuclear Power Plants," July 9, 1987.

In this bulletin, the staff requested licensees and applicants to inform the

NRC about their programs for monitoring the wall thickness of carbon steel

piping in both safety-related and nonsafety-related high energy fluid

systems.

In 1989, following an audit of the erosion/corrosion programs at 10 plants, the NRC issued Generic Letter (GL) 89-08, "Erosion/Corrosion-Induced Pipe Wall

Thinning," May 2, 1989. In this generic letter, the staff requested licensees

and applicants to implement long term erosion/corrosion monitoring programs.

The staff made this request to obtain assurances that the addressees had imple- mented procedures or administrative controls to maintain the structural integrity

of all carbon steel systems carrying high energy fluids.

The NRC also issued several information notices on the subject of erosion/

corrosion.

IN 92-35 May 6, 1992 This information notice requires no specific action or written response. If

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

of the technical contacts 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: K. I. Parczewski, NRR S. Barber, Region I

(301) 504-2705 (717) 542-2134 David Gamberoni, NRR John White, Region I

(301) 504-1171 (215) 337-5114 Attachments:

1. Feedwater System Erosion/Corrosion Location

2. List of Recently Issued NRC Information Notices

II*

REACTOR REACTOR

REACTOR

VESSEL VESSEL VESSEL

24' X 12- FLOW

l -

20 X 12'

REDUCING

REDUCING

TEE

o- I A -

r--,

1, I I--O l lI 7

20- 24 X 20- 24-

12- 20- X 12'

REDUCER REDUCER

"BP

FEEDWATER

LINE

EROSION/

CORROSI ON

ZONE

1 I FLOW

20" X 12"

REDUCING

TEE

FLOW (D 'OOb

co rr

'0 r-%.

FEEDWATER SYSTEM EROSION/CORROSION LOCATION "-I"

Attachment 2 IN 92-35 May 6, 1992 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

92-34 New Exposure Limits for 05/06/92 All licensees whose opera- Airborne Uranium and tions can cause airborne

Thorium concentrations of uranium

and thorium.

92-33 Increased Instrument 04/30/92 All holders of OLs or CPs

Response Time When for nuclear power reactors.

Pressure Dampening

Devices are Installed

92-32 Problems Identified with 04/29/92 All holders of OLs or CPs

Emergency Ventilation for nuclear power reactors.

Systems for Near-Site

(Within 10 Miles) Emer- gency Operations Facili- ties and Technical Support

Centers

92-31 Electrical Connection 04/27/92 All holders of OLs or CPs

Problem in Johnson for nuclear power reactors.

Yokogawa Corporation

YS-80 Programmable Indi- cating Controllers

92-30 Falsification of Plant 04/23/92 All holders of OLs or CPs

Records for nuclear power reactors

and all licensed operators

and senior operators.

92-21, Spent Fuel Pool Re- 04/22/92 All holders of OLs or CPs

Supp. 1 activity Calculations for nuclear power reactors.

92-29 Potential Breaker Mis- 04/17/92 All holders of OLs or CPs

coordination Caused by for nuclear power reactors.

Instantaneous Trip

Circuitry

OL = Operating License

CP = Construction Permit


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