Information Notice 1996-64, Modifications to Containment Blowout Panels Without Appropriate Design Controls

Modifications to Containment Blowout Panels Without Appropriate Design Controls

ML031050506
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, 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
Issue date:	12/10/1996
From:	Martin T Office of Nuclear Reactor Regulation
To:
References
IN-96-064, NUDOCS 9612060222
Download: ML031050506 (9)

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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 lbfft2) 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)

Ž 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 Potential Safety Issue 12/05/96 All U.S. Nuclear

Regarding the Shipment Regulatory Commission

of Fissile Material licensees authorized

to possess special

nuclear material in

unsealed quantities

greater than a critical

mass

96-62 Potential Failure of the 11/20/96 All holders of OLs

Instantaneous Trip Function and CPs for nuclear

of General Electric RMS-9 power plants

Programmers

96-61 Failure of a Main Steam Safety 11/20/96 All holders of OLs or

Valve to Reseat Caused by an CPs for nuclear power

Improperly Installed Release reactors

Nut

96-60 Potential Common-Mode Post- 11/14/96 All holders of OLs or

Accident Failure of Residual CPs for nuclear power

Heat Removal Heat Exchangers reactors

96-59 Potential Degradation of 10/30/96 All holders of OLs or

Post Loss-of-Coolant CPs for nuclear power

Recirculation Capability reactors

as a Result of Debris

96-58 RCP Seal Replacement with 10/30/96 All holders of OLs or

Pump on Backseat CPs for pressurized-water

reactors

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

E Copy wqtpcdures "N" - No copy

To receive a copy of this document, Indicate In the box: "C" a Copy without enclosures "EN'

OFFICE PECB C:SCSB C:PECB D:DRP9 O/1I

NAME INHunemuller CBerlinger AChaffee* TMartW fI

DATE 12/ /96 11/18/96 11/22/96 12/ /96 OFFICIAL RECORD COPY

IN 96-xx

K-, 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-

IN 96-xx

v> K>~ 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 & 601339196-01, dated March 21, 1996, i38196-01 (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)

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

contacts: 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 ion No.

9603150213).

This information notice requires no written response. If y have any

questions about the information in this notice, please cotact the 1technical

contacts listed below or the appropriate Office of Nuci r Reactor IRegulation

Project Manager.

References

1. NRC Inspection Report 50-338/96-01 & 50/ -01, dated March 21, 1996, (Accession Number 9604090115)

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 N No copy

Isdocument, Indicate In the box: "C"- Copy without encosures "E"- Copy with enclosures "N"

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 CPECBl D:DRPM l

NAME NHunemullerm/' CBerlinger IAChaffee MTartin

DATE 11//5/96 111/ 96 &I11/ /96 11/ /96 OFFICIAXL RECORD COPY