Information Notice 1996-64, Modifications to Containment Blowout Panels Without Appropriate Design Controls
KJ~UNITED STATES NUCLEAR REGULATORY
COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555-0001 December 10, 1996 NRC INFORMATION
NOTICE 96-64: MODIFICATIONS
TO CONTAINMENT
BLOWOUT PANELS WITHOUT APPROPRIATE
DESIGN CONTROLS
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
for operating
outside of the design basis as a result of modifying structures
without appropriate
design controls.
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
North Anna, Units 1 & 2 On February 13, 1996, it was identified
that six blowout panels for both units' incore instrument
tunnels had been modified by installing
hasps and locks without appropriate
design controls.
Additionally, several steam generator
and reactor coolant loop containment
cubicle door panels had been modified by tack welding their sheet metal covers to the door frames and adding stiffener
plates around the door handles. These modifications
were not reviewed prior to installation
to assure their compliance
with design bases assumptions
contained
in the Updated Final Safety Analysis Report (UFSAR), and existed for an extended time period during past operating
cycles.Cooper On November 21, 1995, it was recognized
that the accident analysis for High Energy Line Break outside Primary Containment
contained
a key assumption
that had been rendered invalid. For a postulated
High Energy Line Break inside the Reactor Building Main Steam Tunnel (Steam Tunnel), the Steam Tunnel blowout panels had been credited with rupturing
to allow a vent path to the Turbine Building, thereby preventing
compartment
overpressurization.
In an effort to reduce Secondary
Containment
leakage, maintenance
was performed
on the DfP blowout panels in 1985 to cover them with fiberglass.
As a result, the blowout panels would rupture at a higher pressure than credited in the High Energy Line Break analysis.
This was 9612060222n
POR tE 0 it r-te
IN 96-64 December 10, 1996 apparently
attributable
to an inadequate
investigation
of the blowout panels' design basis functions
prior to the initiation
of the maintenance.
Quad Cities On May 10, 1996, a tornado caused structural
damage to the metal siding that forms the secondary
containment
barrier for the refueling
floors on both Units. Subsequent
documented
inspections
revealed approximately
270 (out of 1496) damaged explosion
bolts.It was observed that not all of the damaged bolts were a result of this tornado. On August 23, 1996, it was concluded, through calculations, that not all of the design requirements
for the siding would have been met and this would have placed secondary containment
In an inoperable
condition.
The previously
damaged explosion
bolts were damaged by either a pressure load or by ineffective
work practices.
Nine Mile Point, Unit 1 On October 25, 1993, i was determined
that the relief (blowout)
panels in the Nine Mile Point Unit I turbine and reactor buildings
would not blow out at the design pressure of 2.15 kph (45 lbfft 2) because the bolt fasteners
for the panels were larger than designed and had a higher ultimate strength than designed.
The initial engineering
evaluation
of this condition erroneously
determined
that the turbine and reactor building panels would blow out at 2.87 kph (60 VIWf 2) and 2.54 kph (53 VbWt 2), respectively, to relieve internal building pressure prior to structural
failure of the buildings, and the panels were declared operable.
On March 27, 1995, i was determined
that there was an error in the design assumptions
for load distribution.
Revised calculations
confirmed
that the relief panels would not blow out until the internal building pressure exceeded the minimum documented
building structural
design of 3.83 kph (80 VIW 2). The cause of this event was inadequate
quality control measures during initial construction
which resulted in oversize bolts being installed
in the relief panels.Discussion
The purpose of blowout panels is to prevent overpressure
or overtemperature
conditions
in a compartment
or other enclosure
that could be structurally
damaged due to a high energy line break inside the compartment, or that contains equipment
that would be damaged by the overpressure
or overtemperature
condition.
This function may or may not be a "safety-related" function depending
on whether the high energy line break could result in loss of (1)the capability
to reach and maintain safe shutdown, or (2) the capability
to mitigate an accident in which a high energy line break is postulated
to occur as a passive or consequential
additional
failure. In addition to the overpressure "active" function, blowout panels may also have a passive function such as tornado missile protection.
Blowout panels are designed to open at specific design differential
pressures.
Licensees discovered
that as-found configurations
either would not allow the panels to open until after exceeding
the design pressure, or in the Quad Cities example, did not meet all of secondary containment
design bases described
in the UFSAR. Modifications
made to satisfy apparently
valid concerns did not adequately
evaluate the effects on the panels' design bases or
IN 96-64 December 10, 1996 adequately
consider the design assumptions
used for analyzing
containment
structures
and supports.
The modifications
were not recognized
as having the potential
to place the structures
outside of their design bases.Previous Similar Generic Communication
NRC Information
Notice 96-17, "Reactor Operations
Inconsistent
with the Updated Final Safety Analysis Report," dated March 18, 1996, (Accession
No. 9603150213).
This information
notice requires no written response.
If you have any questions
about the information
in this notice, please contact the technical
contacts listed below or the appropriate
Office of Nuclear Reactor Regulation
Project Manager.References
1. NRC Inspection
Report 50-338/96-01
& 501339/96-01, dated March 21, 1996, (Accession
Number 9604090115)
2. Cooper Nuclear Station Licensee Event Report 50-298/95-018-01, dated May 31, 1996, (Accession
Number 9606110378)
3. Quad Cities Nuclear Power Station Licensee Event Report 50-254 &50-265/96-016, dated September
20, 1996, (Accession
Number 9609300009)
4. Nine Mile Point Nuclear Station Unit 1 Licensee Event Report 50-220195-005-01, dated June 26, 1996, (Accession
Number 9607010370)
r Thomas T. Martin, Director Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical
contacts:
Donald R. Taylor, RHI (540) 984-5421 E-mail: drt@nrc.gov
Neal K. Hunemuller, NRR (301) 415-1152 E-mail: nkh@nrc.gov
Attachment:
List of Recently Issued Information
Notices
K>Attachment
IN 96-64 December 10, 1996 LIST OF RECENTLY ISSUED NRC INFORMATION
NOTICES Information
Date of Notice No. Subject Issuance Issued to 96-63 96-62 96-61 Potential
Safety Issue Regarding
the Shipment of Fissile Material Potential
Failure of the Instantaneous
Trip Function of General Electric RMS-9 Programmers
Failure of a Main Steam Safety Valve to Reseat Caused by an Improperly
Installed
Release Nut Potential
Common-Mode
Post-Accident Failure of Residual Heat Removal Heat Exchangers
Potential
Degradation
of Post Loss-of-Coolant
Recirculation
Capability
as a Result of Debris RCP Seal Replacement
with Pump on Backseat 12/05/96 11/20/96 11/20/96 11/14/96 10/30/96 10/30/96 All U.S. Nuclear Regulatory
Commission
licensees
authorized
to possess special nuclear material in unsealed quantities
greater than a critical mass All holders of OLs and CPs for nuclear power plants 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 pressurized-water
reactors 96-60 96-59 96-58 OL = Operating
License CP = Construction
Permit
IN 96-64* -K' December 10, 1996 adequately
consider the design assumptions
used for analyzing
containment
structures
and supports.
The modifications
were not recognized
as having the potential
to place the structures
outside of their design bases.Previous Similar Generic Communication
NRC Information
Notice 96-17, "Reactor Operations
Inconsistent
with the Updated Final Safety Analysis Report," dated March 18, 1996, (Accession
No. 9603150213).
This information
notice requires no written response.
If you have any questions
about the information
in this notice, please contact the technical
contacts listed below or the appropriate
Office of Nuclear Reactor Regulation
Project Manager.References
1. NRC Inspection
Report 50-338/96-01
& 50/339/96-01, dated March 21, 1996, (Accession
Number 9604090115)
2. Cooper Nuclear Station Licensee Event Report 50-298/95-018-01, dated May 31, 1996, (Accession
Number 9606110378)
3. Quad Cities Nuclear Power Station Licensee Event Report 50-254 &50-265/96-016, dated September
20, 1996, (Accession
Number 9609300009)
4. Nine Mile Point Nuclear Station Unit 1 Licensee Event Report 50-220/95-005-01, dated June 26, 1996, (Accession
Number 9607010370)
original signed by D.B. Matthews hLhomas T. Martin, Director Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical
contacts:
Donald R. Taylor, RII (540) 984-5421 E-mail: drt@nrc.gov
Neal K. Hunemuller, NRR (301) 415-1152 E-mail: nkhenrc.gov
Attachment:
List of Recently Issued Information
Notices Tech Editor has reviewed and concurred
on DOCUMENT NAME: 96-64.IN
- See previous concurrence
To receive a copy of this document, Indicate In the box: "C" a Copy without enclosures "EN' E Copy wqtpcdures "N" -No copy OFFICE PECB C:SCSB C:PECB D:DRP9 O/1 I NAME INHunemuller
CBerlinger
AChaffee*
TMartW f I DATE 12/ /96 11/18/96 11/22/96 12/ /96 OFFICIAL RECORD COPY
K-, IN 96-xx November xx, 1996 adequately
consider the design assumptions
used for analyzing
containment
struct sand containment
structures
and supports.
The modifications
were not recognized
a aving the potential
to place the structures
outside of their design bases.Previous Similar Generic Communication
NRC Information
Notice 96-17, "Reactor Operations
Inconsistenth
the Updated Final Safety Analysis Report," dated March 18, 1996, (Accession
N .9603150213).
This information
notice requires no written response.
If u have any questions
about the information
in this notice, please contact the technical
ontacts listed below or the appropriate
Office of Nuclear Reactor Regulation
Project Managr.References
1. NRC Inspection
Report 50-338/96-01
0/339/96-01, dated March 21, 1996, (Accession
Number 9604090115)
2. Cooper Nuclear Station License vent Report 50-298/95-018-01, dated May 31, 1996, (Accession
Num er 9606110378)
3. Quad Cities Nuclear Power tation Licensee Event Report 50-254 &50-265/96-016, dated Se ember 20, 1996, (Accession
Number 9609300009)
4. Nine Mile Point Nule Station Unit 1 Licensee Event Report 50-220/95-005-01, dated June 26, 1996, (A sion Number 9607010370)
Thomas T. Martin, Director Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technica contacts:
Donald R. Taylor, RII (540) 984-5421 E-mail: drt@nrc.gov
Neal K. Hunemuller, NRR (301) 415-1152 E-mail: nkh@nrc.gov
Attachment:
List of Recently Issued Information
Notices DOC ENT NAME: G:INKHXBLWTPNLS.IN
See previous concurren To rle a copy of this document, Indicate In the box: "C"
- Copy without enclosures "E" -copy w igsures "N" No copy OYFICE PECB C:SCSB I C:PECB D:DR r NAME NHunemuller
CBerlinger
- AChaffee*
TMartfn 1n!DATE 11/ /96 11/18/96 11/22/96 / /96D OFFICIAL RECORD COPY-
v>K>~IN 96-xx November xx, 1996 Pane% 3 nf R meet all of the secondary
containment
design bases described
In the UFSA Modifications
made to satisfy apparently
valid concerns did not adequa evaluate the effects on the panels' design bases or adequately
consider the de gn assumptions
used for analyzing
containment
structures
and suppo .The modifications
were not recognized
as having the potential
to pia the structures
outside of their design bases.Previous Similar Generic Communications
/NRC Information
Notice 96-17, "Reactor Operations
consistent
with the Updated Final Safety Analysis Report," dated March 18, 1996, cession No. 9603150213).
This information
notice requires no written r ponse. If you have any questions
about the information
in this notice, please con t the technical
contacts listed below or the appropriate
Office of Nuclear Reactor R ulation Project Manager.References
1. NRC Inspection
Report i38196-01
& 601339196-01, dated March 21, 1996, (Accession
Number 96 090115)2. Cooper Nuclear Staon Licensee Event Report 60-298195-018-01, dated May 31, 1996, (Ac sslon Number 9606110378)
3. Quad Cities N lear Power Station Licensee Event Report 50-254 &60-265196-01 dated September20, 1996, (Accession
Number9609300009)
4. Nine Mile Iont Nuclear Station Unit I Licensee Event Report 50-220195-005-01, dated Jue 26, 1996, (Accession
Number 9607010370)
contacts: Thomas T. Martin, Director Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Donald R. Taylor, RH (540) 984-5421 E-mall: drt@nrc.gov
Neal K. Hunemuller, NRR (301) 415-1152 E-mall: nkh@nrc.gov
Attachment:
List of Recently Issued Information
Notices TACt q4 2 6°DOCUMENT NAME: G:INKHRBLWTPNLS.IN
- See previous concurrence
To receive a copy of this document, Indicate In the box: "C" = Copy without enclosures
wE" -Copy with enclosures "N" n No copy OFFICE PECB J .C:SCSB I C:PECB D:DRPM l NAME NHunemullert
CBerlinger
- AChaffee Ok& ITMartin DATE 11/L/96 11/18/96 11/L/96 ' 11/ /96 OFFICIAL RECORD COPY
v IN 96-xx November xx, 1996 for analyzing
containment
structures
and supports:
The modifications
were not recognized
as having the potential
to place the structures
outside of their design bases.Previous Similar Generic Communications
NRC Information
Notice 96-17, "Reactor Operations
Inconsistent
with Updated Final Safety Analysis Report," dated March 18, 1996, (Acc 9603150213).
This information
notice requires no written response.
If y have questions
about the information
in this notice, please cotact the 1 contacts listed below or the appropriate
Office of Nuci r Reactor I Project Manager.ion No.any technical Regulation
References
1. NRC Inspection
Report 50-338/96-01
& 50/(Accession
Number 9604090115)
-01, dated March 21, 1996, 2. Cooper Nuclear Station Licensee Eve Report 50-298/95-018-01, dated May 31. 1996, (Accession
Number 96 110378)3. Quad Cities Nuclear Power Stati Licensee Event Report 50-254 &50-265/96-016, dated September
20, 1996, (Accession
Number 9609300009)
4. Nine Mile Point Nuclear St ion Unit 1 Licensee Event Report 50-220/95-
005-01, dated June 26, 19 , (Accession
Number 9607010370)
Thomas T. Martin, Director Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical
contacts:
onald R. Taylor. RII (540) 984-5421 E-mail drt@nrc.gov
Neal K. Hunemuller, NRR (301) 415-1152 E-mail nkh@nrc.gov
Attachment.
ist of Recently Issued Information
Notices DOCUMENT NAME: :\NKH\BLWTPNLS.IN
- See previous concurrence
To ecelve a copy of Is document, Indicate In the box: "C" -Copy without encosures "E" -Copy with enclosures "N" N No copy OFFICE 1PEV l. 1C:SCSB C:PECB D:DRPM NAME N nemuller %M CBerlinger
- AChaffee TMartin DATE 1/f?/96 11/18/96 11/ /96 11/ /96/Ukt lIAL KtLUKU L Y A .'4 L
IN 96-xx* .November
xx. 1996 This information
notice requires no written response.
If you have any questions
about the information
in this notice, please contact the technical contacts listed below or the appropriate
Office of Nuclear Reactor Regulation
Project Manager.References
1. NRC Inspection
Report 50-338/96-01
& 50/339/96-01.
dated March 21. 1996.(Accession
Number 9604090115)
2. Cooper Nuclear Station Licensee Event Report 50-298/95-018-01.
dated May 31. 1996, (Accession
Number 9606110378)
3. Quad Cities Nuclear Power Station Licensee Event Report 50-254 &50-265/96-016, dated September
20. 1996. (Accession
Number 9609300009)
4. Nine Mile Point Nuclear Station Unit 1 Licensee Event Report 50-220/95-
005-01, dated June 26. 1996. (Accession
Number 9607010370)
Thomas T. Martin. Director Division of Reactor Program Management
Office of Nuclear Reactor Regulation
Technical
contacts:
Donald R. Taylor, RII (540) 984-5421 E-mail drt@nrc.gov
Neal K. Hunemuller, NRR (301) 415-1152 E-mail nkh@nrc.gov
Attachment:List
of Recently Issued Information
Notices DOCUMENT NAME: G:\NKH\BLWTPNLS.IN
To receive a copy of this document, Indicate In tlh- ") " Copy without enclosures "En -Copy with enclosures "NW -No copy (OFFICE PECB l C:SCS6 A CPECB l D:DRPM l NAME NHunemullerm/
' CBerlinger
IAChaffee
MTartin DATE 11//5/96 111/ 96 &I11/ /96 11/ /96 OFFICIAXL
RECORD COPY