Information Notice 1994-06, Potential Failure of Long-Term Emergency Nitrogen Supply for the Automatic Depressurization System Valves

Potential Failure of Long-Term Emergency Nitrogen Supply for the Automatic Depressurization System Valves

ML031070043
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:	01/28/1994
From:	Grimes B Office of Nuclear Reactor Regulation
To:
References
IN-94-006, NUDOCS 9401240035
Download: ML031070043 (9)

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4. UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 January 28, 1994 o- I-

NRC INFORMATION NOTICE NO. 94-06: OTENTIAL FAILURE OF LONG-TERM EMERGENCY

NITROGEN SUPPLY FOR THE AUTOMATIC

K11 DEPRESSURIZATION SYSTEM VALVES

Addressees

All holders of operating licenses or construction permits for boiling water

reactors.

PurDose

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

notice to alert addressees of the potential failure of the long-term nitrogen

supply for the automatic depressurization system valves following a loss-of- coolant accident (LOCA). It is expected that recipients will review this

information notice 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 January 1993, during a review of the components that form the pressure

boundary of the of the safety-related portion of the nitrogen supply system at

the Fitzpatrick Nuclear Power Plant, the licensee found that certain parts of

the drywell cooler air-operated dampers and their associated solenoid valves

were made of Buna-N, an elastomer material that is not suitable for high- temperature conditions. These air dampers and solenoid valves are supplied by

the same nitrogen header that provides the 100-day nitrogen supply for the

automatic depressurization system (ADS) valves. Consequently, the failure of

the Buna-N parts as a result of high temperatures that would exist following a

LOCA could lead to depressurization of the nitrogen system and consequent

inability to provide the 100-day supply of nitrogen to the ADS valves. The

short-term operability of the ADS valves following a LOCA would be maintained

because the ADS valves also are supplied by nitrogen accumulators and supply

lines that are separated from the main nitrogen header by check valves.

The licensee found that there was a sufficient number of components with

Buna-N materials supplied by the nitrogen header, and that their combined

failure at high temperature could lead to a total leakage rate greater than

the available nitrogen header makeup rate. These components consisted of

12 drywell cooler air-operated damper actuators, the 12 associated actuator

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._AIN 94-06 January 28, 1994 pressure regulators, and 5 solenoid valves on separate components. These

solenoid valves were located on two core spray testable check valves, two

reactor vessel head vent valves, and on the actuator pneumatic control line

for the drywell cooler air actuated dampers.

Discussion

The problem was caused by the inadequate design of modifications that were

made in 1985 to upgrade the ADS pneumatic supply. The original nitrogen

supply system at Fitzpatrick was designed to provide the pneumatic supply to

both safety-related and non-safety-related instruments and controls, including

the ADS valves inside the drywell. The accumulators were included In the

original design to ensure a safety grade pneumatic supply to the safety- related features. However, these accumulators only have a capacity sufficient

to open the ADS valves five times at design pressure following a LOCA. In

1985 the licensee added an NRC-required modification to the nitrogen supply

system, which provides a 100-day post-LOCA pneumatic supply to the ADS valves

(Item II.K.3.28 of NUREG-0737, 'Clarification of TMI Action Plan

Requirements'). However, the licensee did not upgrade all of the non-safety- related components connected to the nitrogen header or provide isolation of

portions of the system that could fall.

Following the discovery of the unsuitable materials, the licensee performed an

evaluation to justify continued plant operation until a planned shutdown on

February 26, 1993. Since then the licensee has taken the following corrective

actions to limit the potential nitrogen leak rate to an acceptable value:

• Provided a modification to fix the drywell cooler inlet dampers in the

open position, isolate the nitrogen supply to these dampers, and replace

the drywell cooler outlet damper solenoid valves with qualified valves.

• Isolated the nitrogen supply to the core spray testable check valves.

• Replaced the solenoid valves on the reactor head vent isolation valves

with environmentally qualified isolation valves.

• Modified the annunciator response procedures to require isolation of the

air-operated damper actuators and the opening of a backup nitrogen

header supply valve if a low header pressure alarm is received.

IJN 94-06 January 28, 1994 Evaluations and calculations show that, with the actions taken that are

required by the annunciator procedures cited above, leakage through all 12 air-operated dampers and the solenoid valves on the associated pneumatic

supply lines would be within the nitrogen header makeup capacity.

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, D ctor

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: David H. Shum, NRR

(301) 504-2860

Attachment:

List of Recently Issued NRC Information Notices

Att--hment

IN _,06 January 28, 1994 Page I of I

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

93-85, Problems with X-Relays 01/20/94 All holders of OLs or CPs

Rev. 1 in DB- and DHP-Type for nuclear power reactors.

Circuit Breakers Manu- factured by Westinghouse

94-05 Potential Failure of 01/19/94 All holders of OLs or CPs

Steam Generator Tubes for pressurized water

with Kinetically Welded reactors (PWRs).

Sleeves

94-04 Digital Integrated 01/14/94 All NRC licensees except

Circuit Sockets with licensed operators.

Intermittent Contact

94-03 Deficiencies Identified 01/11/94 All holders of OLs or CPs

during Service Water System for nuclear power reactors.

Operational Performance

Inspections

94-02 Inoperability of General 01/07/94 All holders of OLs or CPs

Electric Magne-Blast for nuclear power reactors.

Breaker Because of Mis- alignment of Close-Latch

Spring

94-01 Turbine Blade Failures 01/07/94 Al 1 holders of OLs or CPs

Caused by Torsional for nuclear power reactors.

Excitation from Electrical

System Disturbance

93-101 Jet Pump Hold-Down Beam 12/17/93 All holders of OLs or CPs

Failure for boiling-water reactors.93-100 Reporting Requirements 12/22/93 All U.S. Nuclear Regulatory

for Bankruptcy Commission licensees.

91-29, Potential Deficiencies 12/22/93 All holders of OLs or CPs

Supp. 2 Found During Electrical for nuclear power reactors.

Distribution System

Functional Inspections

OL - Operating License

CP - Construction Permit

\s IN 94-06 January 28, 1994 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.

Orginal 1gnidb

Brian K.Grimel

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: David H. Shum, NRR

(301) 504-2860

Attachment:

List of Recently Issued NRC Information Notices

• qFF PRFVTIlOU rCONrCRRFNCF

OFFICE: *OGCB:DORS *Tech Ed *SPLB:DSSA *C:SPLB:DSSA *D:DSSA:NRR

NAME: DCKirkpatrick DGable DHShum CEMcCracken ACThadani

DATE: 10/01/93 Oj  %' b /04/93 10/12/93 1 11/23/93 j 12/30/93 C:OGCB:DORS

GHMarcus* Ii

01/04/94 01/1- 94 Document Name: 94-06.IN

IN 94-XX

January xx, 1994 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.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

David H. Shum, NRR

(301) 504-2860

Attachment:

List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCE

OFFICE: *OGCB:DORS *Tech Ed *SPLB:DSSA *C:SPLB:DSSA l *D:DSSA:NRR 1 NAME: DCKirkpatrick DGable DHShum CEMcCracken 7 ACThadani

DATE: l 10/01/9 q/, 10/04/93 , 10/12/93 , 11/23/93 l 12/30/93

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C:OGCB:DORS D:DORS:NRR

GHMarcus OM BKGrimes -

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Document Name: IN93ADSN.DCK

IN 94-XX

January xx, 1994 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.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

David H. Shum, NRR

(301) 504-2860

Attachment:

List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCE

OFFICE: *OGCB:DORS *Tech Ed *SPLB:DSSA I *C:SPLB:DSSA D:DSSA 9 I

NAME: DCKirkpatrick DGable DHSh )6 J CEMcCracken ACThadani

DATE: 10/01/93 10/04/93 l 10/12/93 J 11/23/93 1 12 $/93 C:OGCB:DORS D:DORS:NRR

GHMarcus BKGrimes

/ //

Document Name: IN93ADSN.DCK

l IN 93-XX

October xx, 1993 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.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

David H. Shum, NRR

(301) 504-2860

Attachment:

List of Recently Issued NRC Information Notices

• SFF PRFVTAOS CONCURRENCE

OFFICE: OGCB:DORS *Tech Ed SPLB:DSSA C:SPM.gA D:DSSA:NRR

NAME: DCKirkpatri DGable DHShum ACEM ac en ACThadanil

DATE: -_10//_/9

_ _ _ _ __ __ _ _ _ _ _ _ _ _10/04/93

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C:OGCB:DORS D:DORS:NRR

GHMarcus BKGrimes

'10/ /93 10/ /93 Document Name: IN93ADSN.DCK

I

IN 93-XX

October xx, 1993 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.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

David H. Shum, NRR

(301) 504-2860

Attachment: List of Recently Issued NRC Information Notices

OFFICE: *OGCB:DORS *Tech Ed *C:OGCB:DORS D:DORS:NRR

NAME: DCKirkpatrick D GHMarcus BKGrimes

lNDATE: ae/ /93 S10/M/93

10I/ /93 10/ /93 10/ /93 Document Name: IN93ADSN.DCK