Information Notice 1995-20, Failures in Rosemount Pressure Transmitters Due to Hydrogen Permeation Into Sensor Cell

Failures in Rosemount Pressure Transmitters Due to Hydrogen Permeation Into Sensor Cell

ML031290416
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:	03/22/1995
From:	Grimes B Office of Nuclear Reactor Regulation
To:
References
IN-95-020, NUDOCS 9503200279
Download: ML031290416 (12)

--J

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 March 22, 1995 NRC INFORMATION NOTICE 95-20: FAILURES IN ROSEMOUNT PRESSURE TRANSMITTERS

DUE TO HYDROGEN PERMEATION INTO THE SENSOR CELL

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 a potential failure mode in Rosemount Nuclear

Instruments, Incorporated, Model 1152, 1153 and 1154 pressure transmitters due

to hydrogen gas permeation through the isolating diaphragm exposed to process

fluid. It is expected that recipients will review the information for

applicability to their facilities. However, suggestions contained in this

information notice are not NRC requirements; therefore, no specific action or

written response is required.

Description of Circumstances

On November 22, 1994, St. Lucie Unit 1 was in a cold shutdown condition and in

the process of filling and venting the reactor coolant system (RCS). With RCS

pressure at 0.45 MPa [50 psig] and RCS temperature at approximately 38 eC [100

OF], a safety injection actuation was initiated when two of the four

pressurizer pressure channels generated high pressure signals. When the

output from the two transmitters exceeded 11.91 MPa [1712 psig], the manual

safety injection block, which had been established during cooldown, cleared.

With the safety injection block cleared, and the two properly functioning

pressurizer pressure transmitters indicating 0.45 MPa [50 psig], the safety

injection actuation logic was satisfied and a safety injection was initiated.

It was determined that the two pressurizer pressure channels indicated high

pressure because of an erroneous high output from the pressure transmitters.

These transmitters are Rosemount Model 1153 gauge pressure transmitters that

had been sent back to Rosemount for refurbishment because they were

susceptible to sensor cell oil leakage as discussed in NRC Information Notice 89-42, "Failure of Rosemount Models 1153 and 1154 Transmitters," NRC Bulletin

90-01 "Loss of Fill Oil in Transmitters Manufactured by Rosemount," and NRC

Bulletin 90-01, Supplement 1. The failed transmitters had been in service at

St. Lucie since April 1993 (about one cycle) with no apparent symptoms.

0o q3-230

9503200279

>Pa 12-1 4

IN 95-20

March 22, 1995 A review of recorded pressurizer pressure channel signals indicated that the

failures involved a gradual increase in transmitter output over an approximate

5 minute period, culminating in an output plateau near the upper end of the

transmitter range. The two failures occurred approximately 10 minutes apart.

Transmitter outputs remained high following the event. Loop calibrations were

subsequently performed, and both transmitters showed extremely slow response.

The transmitters were subsequently replaced and preserved for analysis. A

third pressure transmitter on the pressurizer that had been refurbished in the

same manner and time frame did not fail.

Discussions between licensee and Rosemount personnel indicated that the

failure mode encountered at St. Lucie was not typical of oil loss as discussed

in the NRC generic communications cited above. A preliminary inspection of

the transmitter sensing modules confirmed that no oil loss had occurred.

However, the high pressure side isolating diaphragm of the sensor cell of each

failed transmitter was bulged. Rosemount stated that the failure modes were

indicative of gas entrapment in the sensor cell. A detailed discussion of the

failure is given in a Part 21 notification by Rosemount dated March 21, 1995, (Accession No. 9503220185).

Discussion

The failed transmitters were sent to the Southwest Research Institute

laboratory for analysis of gases trapped in the sensor cells. The laboratory

extracted the gas from one transmitter sensor cell and determined that it was

hydrogen. No corrosion, galvanic action, water leakage or oil breakdown was

observable. Gamma back scatter examination was performed to determine the

composition of the isolating diaphragm material. This examination indicated

that the material of the diaphragms was Monel metal instead of the Type-316 stainless steel specified for safety-related Model 1152, 1153 and 1154 transmitters in this application. Monel metal is a corrosion-resistant alloy

of primarily nickel and copper which may be used in transmitters of this type

for some plant applications. Monel is known to be permeable to monatomic

hydrogen.

Monatomic hydrogen may be generated by a galvanic cell reaction between Monel

and stainless steel, and this may enhance the permeation of hydrogen from the

system through the diaphragm. Rosemount has postulated that over a period of

months at power, monatomic hydrogen permeated or diffused through the Monel

isolating diaphragms where it went into solution in the sensor cell fill oil.

As some of the hydrogen recombined into diatomic hydrogen (chemical symbol

"H2" - the usual form of hydrogen gas), it became trapped because the

isolating diaphragm, being relatively impermeable to H2, retained it.

Rosemount postulated that during constant pressure operation, a sensor with H2 under the isolator diaphragm may not exhibit symptoms or erroneous output as

the H2 may be completely dissolved in the silicone oil.

IN 95-20

March 22, 1995 This was apparently the case with the two confirmed failures on November 22,

1994, described above at St. Lucie Unit 1. The transmitters reportedly

operated normally during the 16 month period prior to the plant outage. The

monatomic hydrogen permeating the isolator during this time had no apparent

affect on the transmitter operation. However, the precipitating sequence of

events leading to the apparent sudden noticeable failure (as opposed to

gradual, but detectable, degradation) involved (1) plant depressurization

which allowed the entrapped H to come out of solution and form a partial

pressure within the sensor ceil oil volume which may have caused some

deformation of the relatively flexible isolating diaphragms, followed by (2) a

partial re-pressurization. The repressurization may have caused the fill oil, which is the capacitor dielectric within the sensor, to be replaced partially

with hydrogen gas. This would lead to an increase in the output signal. In

addition, repressurization may have caused a deflection of the center

diaphragm within the sensor, also contributing to the increase in output.

Based on the St. Lucie Unit 1 experience, conditions most likely to result in

adverse transmitter failure consequences would be those involving a primary

system depressurization followed by a partial or full repressurization. Such

sequences would include steam line relief valve openings or breaks, loss-of- coolant accidents, and steam generator overfeeding events. In these cases, the transmitter should function normally during the initial depressurization.

For pressurized water reactors it is likely that a safety injection actuation

signal would be generated if primary system pressure went below the low

pressure actuation setpoint. During any subsequent repressurization, multiple

transmitter failures could lead to erroneously high pressure signals which

could disable interlocks, disable any automatic reinitiation of safety

injection if required, and could lead to opening of power-operated relief

valves. In addition, under these conditions the operator could be presented

with conflicting information on the reactor coolant system pressure, including, for a loss of coolant accident, some information indicating the

primary system was subcooled and other information indicating a saturated

primary system.

For boiling water reactors, failed transmitters could result in opening of the

primary system relief valves and result in system blowdown. Failure of the

pressure transmitters could also block automatic injection. While pump start

signals would not be affected (low level in the reactor pressure vessel or

high pressure in the drywell) low pressure injection could be precluded by

closed injection valves. This is because low pressure emergency core cooling

system logic typically includes a permissive which requires indication of low

reactor pressure prior to opening the injection valves. In such a case, operators would need to bypass the permissive and open the injection valves

from the control room. A similar scenario was discussed in IN 93-89.

Rosemount has made a preliminary determination that about 270 Model 1152, 1153 and 1154 safety-related transmitters constitute the suspect group. Rosemount

has identified most of these by serial number and is in the process of

informing affected utilities (see Attachment 1). The suspect lot is believed

at this time to be limited to those units manufactured (or refurbished)

4 95-20

'I4arch 22, 1995 by Rosemount after September 1989 and is also limited to the higher pressure

transmitters of pressure range codes 6, 7, 8, 9, and 0. The failures at St.

Lucie occurred in range code 9 transmitters. Differential pressure

transmitters, as well as both absolute and gauge-type pressure transmitters

could be affected.

Measures such as alerting and briefing operators, conducting special training

sessions and running event scenarios on simulators may help in responding to a

pressure transmitter failure.

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 Project Support

Office of Nuclear Reactor Regulation

Technical contacts: S.V. Athavale, NRR Mark S. Miller, RII

(301)415-2974 (407) 464-7822 Stephen Alexander, NRR Jerry L. Mauck, NRR

(301) 415-2995 (301) 415-3248 Attachments:

1. List of Rosemount Transmitters with Monel

instead of Type 316 stainless steel diaphragms.

2. List of Recently Issued NRC Information Notices

A#A Ata

Attachment 1 IN 95-20

March 22, 1995 Page 1 of I

ORGANIZATIONS IN THE U.S. TO WHOM ROSEMOUNT REPORTED SENDING

TRANSMITTERS OR SENSOR MODULES WITH MONEL ISOLATORS

Customer

Arizona Public Service

Baltimore Gas & Electric

Bechtel

Boston Edison

Carolina Power & Light

Commonwealth Edison

Consumers Power

Duke Power

Duquesne Light Company

Ellis & Watts

Florida Power Corp.

Florida Power & Light

Georgia Power

GPU

Gulf States Utilities

Houston Lighting & Power

Illinois Power

Maine Yankee Atomic Power Company

New Hampshire Yankee, Inc.

New York Power Authority

Niagara Mohawk Power Corp.

Northern States Power

Omaha Public Power District

Pacific Gas & Electric

Pennsylvania Power & Light

Philadelphia Electric Company

Portland GE

Public Service Electric & Gas

South Carolina Electric & Gas

Southern Cal. Edison

Systems Energy

Toledo Edison

TU Electric

TVA

Vermont Yankee

Virginia Power

Washington Public Power Supply System

Westinghouse

Wolf Creek NOC

Yankee Atomic

Attachment 2 IN 95-20

March 22, 1995 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

95-19 Failure of Reactor Trip 03/22/95 All holders of OLs or CPs

Breaker to Open Because for nuclear power reactors.

of Cutoff Switch Material

Lodged in the Trip Latch

Mechanism

95-18 Potential Pressure-Locking 03/15/95 All holders of OLs or CPs

of Safety-Related Power- for nuclear power reactors.

Operated Gate Valves

95-17 Reactor Vessel Top Guide 03/10/95 All holders oi OLs or CPs

and Core Plate Cracking

95-16 Vibration Caused by 03/09/95 All holders of OLs or CPs

Increased Recirculation for boiling water reactors.

Flow in a Boiling Water

Reactor

95-15 Inadequate Logic Testing 03/07/95 All holders of OLs or CPs

of Safety-Related Circuits for nuclear power reactors.

95-14 Susceptibility of Con- 02/28/95 All holders of OLs or CPs

tainment Sump Recircula- for nuclear power reactors.

tion Gate Valves to

Pressure Locking

95-13 Potential for Data 02/24/95 All holders of OLs or CPs

Collection Equipment to for nuclear power reactors.

Affect Protection System

Performance

95-12 Potentially Nonconforming 02/21/95 All holders of OLs or CPs

Fasteners Supplied by for nuclear power reactors.

A&G Engineering II, Inc.

Failure of Condensate 02/24/95 All holders of OLs or CPs

Piping Because of Erosion/ for nuclear power reactors.

Corrosion at a Flow- Straightening Device

OL = Operating License

CP = Construction Permit

IN 95-20

March 22, 1995 by Rosemount after September 1989 and is also limited to the higher pressure

transmitters of pressure range codes 6, 7, 8, 9, and 0. The failures at St.

Lucie occurred in range code 9 transmitters. Differential pressure

transmitters, as well as both absolute and gauge-type pressure transmitters

could be affected.

Measures such as alerting and briefing operators, conducting special training

sessions and running event scenarios on simulators may help in responding to a

pressure transmitter failure.

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 Project Support

Office of Nuclear Reactor Regulation

Technical contacts: S.V. Athavale, NRR Mark S. Miller, RII

(301)415-2974 (407) 464-7822 Stephen Alexander, NRR Jerry L. Mauck, NRR

(301) 415-2995 (301) 415-3248 Attachments:

1. List of Rosemount Transmitters with Monel

instead of Type 316 stainless steel diaphragms.

2. List of Recently Issued NRC Information Notices

DOCUMENT NAME: 95-20.IN

• See previous concurrence.

C/HCIB:NRR

JMauck*

03/22/95 To receive a copy of this document, Indicate In the box: wC" = Copy without attachment/enclosure 'E" = Copy with attachmentienciosure GNU No copy

[OFFICE HICB/DRCH:NRR ITSIB/DOTS:NRR TSIB/DOTS:NRR I SRXB/DOTS:NRR I HICB/DRCH I

NAME SVAthavale* SAlexander* RMGallo* RCJones* JSWermiel*

DATE 03/22/95 103/22/95 03/22/95 03/22/95 To receive a copy of this document, Indicate Inthe box: 0 a Copy without attachmentlenclosura E = Copy with attachment/enclo N" o

OFFICE OECB/DOPS: OECB/DOPS:NRR C/OECB/DOPS L /gRCNr

INAME _DCKirkpatrick* EFGoodwin* AEChaffee* BABoger* D tzF

DATE 03/22/95 03/22/95 03/22/95 03/22/95 03/zz495

IN 95-20

'1.- March XX, 1995 limited to those units manufactured (or refurbished) by Rosemount after

September 1989 and is also limited to the higher pressure transmitters of

pressure range codes 6, 7, 8, 9, and 0. The failures at St. Lucie occurred in

code 9 transmitters. Differential pressure transmitters, as well as both

absolute and gauge-type pressure transmitters could be affected.

Measures such as alerting and briefing operators, conducting special training

sessions and running event scenarios on simulators may help in identifying the

existence of the above described pressure transmitter failure mode.

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.

Attachments:

1. List of Rosemount Transmitters with Monel

instead of SS 316 stainless steel diaphragms.

2. List of Recently Issued NRC Information Notices

DOCUMENT NAME: 95-20.IN

To receive a c of this document, Indicate in the box: "C" = Copy without attachment/encLosure "E' = Copy with Z W

attachment/eno IM- No copy

are

OFFICE H B/DRCH:NR T TSIB/DOTS:NRR lSRXB/DOTS;IRRM H tl W V

INAME SAthavale SAlexander - RMGallo

3 RCJones 1 JDATE 03/1z2/95 o03/ 9 03/.!,I95 _ A 3/ 5 4 3

95 03tu

TO receive a copy of this document, indicate'in the box: 'C"= Copy without

attachment/enclosure "E" = Copy with attachment/enclosure "N"= No copy

OFFICE OECB/DOPS:NRR I OECB/DOPS:NRR C/OECP D/DRCH:NRR I D/DOPS:NRR

NAME DCKirkpatricL j47F 2F Goodwin / 21 AECh ee BABoger BKGrimes

DATE 03/-t=095 '03/ 2 95 03/ 595 03/ /95 Chic.- ~-l

i ' v-,

IN 95-20

March 22, 1995 This information notice requires no specific action or written response. If

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

technical contact listed below, or the appropriate project manager in the

Office of Nuclear Reactor Regulation (NRR).

Brian K. Grimes, Director

Division of Project Support

Office of Nuclear Reactor Regulation

Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

• See previous concurrence DOCUMENT NAME: G:\ASHAR\TLGINFON.HGA

To receive a copy of this document, indicate in the box C=Copy wlo attachment/enclosure E=Copy with attachment/enclosure

K1- ranxt

OFFICE ECGB:DE E ECGB:DE I E ECGB:DE E NRR:DSSA DE:DD lN DE:D

NAME HAshar RRothman GBagchi CMcCracken GLainas BSheron

DATE 02/27/95* 03/03/95* 03/07/95* 03/13/95* 03/15/95* / 95 TECH ED OECB/DOPS l OECB/DOPS OECB/DOPS C:OECB/DOPS D:DOPS/NRR

TJCarter RLDennig RJKiessel AEChaffee BKGrimes

1/u /95 /95 / 95 /9 /95 / /95 OFFICIAL RECORD COPY

0

-

From: Robert C Jones (RCJ)

To: WN4:DCK1 Date: Wednesday, March 22, 1995 7:23 am

Subject: ROSEMONT PRESSURE TRANSMITTER FAILURE IN

The revised IN is acceptable to SRXB. You can use this E-Mail as a record of

my concurrence.

9503270224 m50

PDR ICE 24 NTiZrCE9,5-0 213 pDR

From: Bruce A Boger (BAB2)

To: WN4:DCK1 Date: Wednesday, March 22, 1995 7:23 am

Subject: ROSEMONT PRESSURE TRANSMITTER FAILURE IN

You have my concurrence on the IN.

9503270226 950322 PDR I&E

NOTrCE9S5-020 PDR

i

From: Robert M. Gallo (RMG)

To: WN4:DCK1 Date: Wednesday, March 22, 1995 8:18 am

Subject: ROSEMONT PRESSURE TRANSMITTER FAILURE IN

GALLO CONCURS, NOTING THE COMMENT FROM STEVE ALEXANDER ABOUT 95-21 VICE 95-20

ON PAGE 2 OF THE IN.

9503270228 950322 -- -

PIDR 1SE

NI3TICE95S020 PDR