Information Notice 1991-87, Hydrogen-Embrittlement of Raychem Cryofit Couplines

Hydrogen-Embrittlement of Raychem Cryofit Couplines

ML031190196
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
Issue date:	12/27/1991
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-91-087, NUDOCS 9112200262
Download: ML031190196 (10)

UNITED STATES -

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 December 27, 1991 NRC INFORMATION NOTICE 91-87: HYDROGEN EMBRITTLEMENT OF RAYCHEM CRYOFIT

COUPLINGS

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 regarding the possible hydrogen embrittlement of

Raychem Cryofit couplings that could result in failure. 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

In July 1991 at the Seabrook Station, the licensee measured an unidentified

leakage rate exceeding the 1.0 gpm technical specification limit from the

Reactor Coolant System while the plant was operating in Mode 1 at 100 percent

power. The source of the leak was determined to be in the vicinity of the

pressurizer and, following plant shutdown, was located specifically in the gas

space sampling line coming from the pressurizer. The leak was caused by a 360-

degree circumferential fracture at the midpoint of a Raychem Cryofit

coupling. During subsequent line inspection, a second Cryofit coupling located

in the same line fractured in a similar manner after an accidental physical

impact. Both couplings are located downstream of the root isolation valve.

Discussion

Raychem Cryofit couplings are hollow cylindrical devices made of a special

alloy (50 percent titanium and 50 percent nickel) called Tinel that expands as

temperature is decreased and contracts as temperature increases (because of a

phase change). When the coupling is properly installed, a rapid joining of

two pipe ends can effectively be performed. The licensee performed a

metallurgical examination of the failed couplings and of other couplings in the

Seabrook Station, correlated the metallurgical findings with the various

exposure environments, and determined that the cause of the coupling failure

was hydrogen embrittlement of the Tinel. The licensee also determined that.

the combination of high hydrogen content in the exposure medium and high

temperature was the critical determining.factor. No other combination of -

(9 22116Z#

KJ

IN 91-87 December 27, 1991 exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

To address the above findings, the licensee removed and replaced

approximately 400 of the 3000 or more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

if they should fail (closely connected to the Reactor Coolant System

or located on containment penetrations).

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.

irles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical contact: Walter P. Haass, NRR

(301) 504-3219 Attachment: List of Recently Issued NRC Information Notices

Attachment

IN 91-87 December 27, 1991 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

91-86 New Reporting Requirements 12/27/91 All licensees authorized

for Contamination Events at to use byproduct materials

Medical Facilities for human use.

(10 CFR 30.50)

91-85 Potential Failures of 12/26/91 All holders of OLs or CPs

Thermostatic Control Valves for nuclear power reactors.

for Diesel Generator Jacket

Cooling Water

91-84 Problems with Criticality 12/26/91 All Nuclear Regulatory

Alarm Components/Systems Commission (NRC) fuel

cycle licensees, interim

spent fuel storage licens- ees, and critical mass

licensees.

91-83 Solenoid-Operated Valve 12/20/91 All holders of OLs or CPs

Failures Resulted in for nuclear power reactors.

Turbine Overspeed

91-18, High-Energy Piping Failures 12/18/91 All holders of OLs or CPs

Supp. 1 Caused by Wall Thinning for nuclear power reactors.

91-82 Problems with Diaphragms 12/18/91 All holders of OLs or CPs

in Safety-Related Tanks for nuclear power reactors.

91-81 Switchyard Problems that 12/16/91 All holders of OLs or CPs

Contribute to Loss of for nuclear power reactors.

Offsite Power

91-80 Failure of Anchor 12/11/91 All holders of OLs or CPs

Head Threads on Post- for nuclear power reactors.

Tensioning System During

Surveillance Inspection

91-79 Deficiencies in the 12/06/91 All holders of OLs or CPs

Procedures for Instal- for nuclear power reactors.

ling Thermo-Lag Fire

Barrier Materials

OL = Operating License

CP = Construction Permit

UNITED STATES K-)s FIRST CLASS MAIL

NUCLEAR REGULATORY COMMISSION POSTAGE b FEES PAID

WASHINGTON, D.C. 20555 USNRC

PERMIT No G-7 OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, $300

IN 91-87 December 27, 1991 exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

To address the above findings, the licensee removed and replaced

approximately 400 of the 3000 or more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

if they should fail (closely connected to the Reactor Coolant System

or located on containment penetrations).

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. Original Signod b

Charles E.Ro~sg

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical contact: Walter P. Haass, NRR

(301) 504-3219 Attachment: List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCE

OFC :VIB/DRIS :VIB/DRIS :BC:VIB/DRIS :D:DRIS :OGCB/NRR :DOEA/NRR

____- _ __ __ __ _ ___-__ __ _ __ __ __ ___------:--------------

--------------:---,,-- - - --- --- -- c--

NAME :WHaass :GCwalina :LNorrholm :BGrimes :CBerlinger  : m y

DATE :11/7/91* :11/7/91* :11/19/91*  : 12/16/91* :12/17/91* :12J~>l

OFC :Tech Editor :RI

NAME :JMain :JDurr  :  :

DATE :11/01/91* :11/18/91*

OFFICIAL RECORD COPY

Document Name: IN 91-87

INl XX-XX

December XX, 1991 exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

To address the above findings, the licensee removed and replaced

approximately 400 of the 3000 or more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

if they should faile (closely connected to the Reactor Coolant System

or located on containment penetrations).

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

Walter P. Haass, NRR

301-492-3219 Attachment: List of Recently Issued NRC Information Notices

DISTRIBUTION

CBerlinger VIB R/F DRIS R/F BKGrimes

WHaass ERossi LNorrholm GCwalina

• SEE PREVIOUS CONCURRENCE 6C X

OFC :VIB/DRIS :VIB/DRIS :BC:VIB/DRIS :D:DRIS :OGCB/NRR :DOEA/NRR

NAME :WHaass :GCwalina :LNorrholm :BGrimes :CBerlinger :CRossi

DATE :11/7/91* :11/7/91* :11/19/91* 12/16/91 :UrL/17/91 OFC :Tech Editor :RI

NAME : :JDurr  :  :

DATE :11/01/91* :11/18/91*  :  :

OFFICIAL RECORD COPY

Document Name: RAYCHMIN

IN XX-XX

December XX, 1991 exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

To address the above findings, the licensee removed and replaced

approximately 400 of the 3000 or more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

if they should faile (closely connected to the Reactor Coolant System

or located on containment penetrations).

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

Walter P. Haass, NRR

301-492-3219 Attachment: List of Recently Issued NRC Information Notices

DISTRIBUTION

CBerlinger VIB R/F DRIS R/F BKGrimes

WHaass ERossi LNorrholm GCwalina

• SEE PREVIOUS CONCURRENCE

OC :IDIS :IDIS :BC:ID:D' :0:DOEA/NRR

NAME :WHaass :GCwalina :LNorrholm /IcG#lp:CBerlinger :CRossi

DATE :11/7/91* :11/7/91* :11/19/91*  : 1t-//4/91  : / /91 OFC :Tech Editor :RI

NAME : :JDurr

DATE :11/01/91* :11/18/91*  :

OFFICIAL RECORD COPY

Document Name: RAYCHMIN

IN XX-XX

--- November XX, 1991 exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

As a result of the above findin gthe licensee removed and replaced

.approximately 400 of the 3000 more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

related to potential failure (closely connected to the Reactor Coolant System

or located on containment penetrations).

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

Walter P. Haass, NRR

301-492-3219 Attachment: List of Recently Issued NRC Information Notices

DISTRIBUTION

CBerlinger VIB R/F DRIS R/F BKGrimes

WHaass ERossi LNorrholm GCwalina

• SEE PREVIOUS CONCURRENCE

OFC :VIB/DRIS :VIB/DRIS :BC:VIB/DRIS :D I :CB/NRR :DOEA/NRR

NAME :WHaass :GCwalina :LNorrholm / es :CBerlinger :CRossi

DATE :11/7/91* :11/7/91* :11/19/91*  :(z//G/91 C  : / /91 OFC :Tech Editor :RI

NAME  : :JDurr

DATE :11/01/91* :11/18/91*  :

OFFICIAL RECORD COPY

Document Name: RAYCHMIN

IN XX-XX

November XX, 1991 Discussion

Raychem Cryofit couplings are hollow cylindrical devices made of a special

alloy (50 percent titanium and 50 percent nickel) called Tinel that expands as

temperature is decreased and contracts as temperature increases (because of a

phase change). When the coupling is properly installed, a rapid joining of

two pipe ends can effectively be performed. The licensee performed a

metallurgical examination of the failed couplings and of other couplings in

the Seabrook Station, correlated the metallurgical findings with the various

exposure environments, and determined that the cause of the coupling failure

was hydrogen embrittlement of the Tinel. The licensee also determined that

the combination of high hydrogen content in the exposure medium and high

temperature was the critical determining factor. No other combination of

exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

As a result of the above findings, the licensee removed and replaced

approximately 400 of the 3000 or more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

related to their potential failure (closely connected to the Reactor Coolant

System or located on containment penetrations).

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

Walter P. Haass, NRR

301-492-3219 Attachment: List of Recently Issued NRC Information Notices

OFC :VIB:DRIS :VIB:DRIS :BC: B:DRIS :D:DRIS :OGCB/NRR :DOEA/NRR

________________ ______________ ___ _____

_____________

---

______________ ___ __ __ __

NAME :WHaass :GCwalina :L :BKGrimestid :CBerlinger :CRossi

DATE  :\k / /91

/1  : / /9191  : / /91 OFC :Tech. Editor :RI

---

 :---------------:-Af-k i7~-------------- -------------- -------------- -------------

NAME  : Jfain / :JD

DATE :11/01/91 0'Il/l/91  : / /91 / /91 OFFICIAL RECORD COPY Document Name: RAYCHTMIN

DISTRIBUTION: VIB Reading DRIS Reading BKGrimes

CBerlinger Rossi LNorrholm GCwalina

VlHaass

K * K J

Discussion

Raychem Cryofit couplings are hollow cylindrical devices made of a special

alloy (50 percent titanium and 50 percent nickel) called Tinel that expands as

temperature is decreased and contracts as temperature increases (because of a

phase change). When the coupling is properly installed, a rapid joining of

two pipe ends can effectively be performed. The licensee performed a

metallurgical examination of the failed couplings and-of other couplings in

the Seabrook Station, correlated the metallurgical findings with the various

exposure environments, and determined that the cause of the coupling failure

was hydrogen embrittlement of the Tinel. The licensee also determined that

the combination of high hydrogen content in the exposure medium and high

temperature was the critical determining factor. No other combination of

exposure environments resulted in degradation of the Tinel. The vendor had

been unaware of this application limitation for the Cryofit coupling since

testing in these environments had not been performed.

As a result of the above findings, the licensee removed and replaced

approximately 400 of the 3000 or more Cryofit couplings in the Seabrook

Station with socket-welded joints or compression fittings. Many of the

replacements were conservatively selected because of the safety implications

related to their potential failure (closely connected to the Reactor Coolant

System or located on containment penetrations).

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

Walter P. Haass, NRR

301-492-3219 Attachment:

List of Recently Issued NRC Information Notices

OFC :VIB:D~'i :VIB:DRIS :BC:VIB:DRIS :D:DRIS :OGCB/NRR :DOEA/NRR

NAME :WH sE I :GC :LNorrholm :BKGrimes :CBerlinger :CRossi

DATE :I1/ 7 /91  :/ /91  : / /91 /91  : / /91 /91 OFC :Tech. Editor :RI

NAME : :JDurr  :  :

DATE :11/01/91  : / /91  : / /91 / /91 OFFICIAL RECORD COPY

Document Name: RAYCHMIIN